WorldWideScience

Sample records for matter dm particle

  1. PPPC 4 DM secondary: a Poor Particle Physicist Cookbook for secondary radiation from Dark Matter

    Energy Technology Data Exchange (ETDEWEB)

    Buch, Jatan [Institut de Physique Théorique, Université Paris Saclay, CNRS, CEA,F-91191 Gif-sur-Yvette (France); Department of Physics, Indian Institute of Technology,Kharagpur, West Bengal - 721302 (India); Cirelli, Marco; Giesen, Gaëlle; Taoso, Marco [Institut de Physique Théorique, Université Paris Saclay, CNRS, CEA,F-91191 Gif-sur-Yvette (France)

    2015-09-11

    We enlarge the set of recipes and ingredients at disposal of any poor particle physicist eager to cook up signatures from weak-scale Dark Matter models by computing two secondary emissions due to DM particles annihilating or decaying in the galactic halo, namely the radio signals from synchrotron emission and the gamma rays from bremsstrahlung. We consider several magnetic field configurations and propagation scenarios for electrons and positrons. We also provide an improved energy loss function for electrons and positrons in the Galaxy, including synchrotron losses in the different configurations, bremsstrahlung losses, ionization losses and Inverse Compton losses with an updated InterStellar Radiation Field.

  2. PPPC 4 DM secondary: a Poor Particle Physicist Cookbook for secondary radiation from Dark Matter

    Energy Technology Data Exchange (ETDEWEB)

    Buch, Jatan; Cirelli, Marco; Giesen, Gaëlle; Taoso, Marco, E-mail: jbuch.iitkgp@gmail.com, E-mail: marco.cirelli@cea.fr, E-mail: gaelle.giesen@cea.fr, E-mail: marco.taoso@cea.fr [Institut de Physique Théorique, Université Paris Saclay, CNRS, CEA, F-91191 Gif-sur-Yvette (France)

    2015-09-01

    We enlarge the set of recipes and ingredients at disposal of any poor particle physicist eager to cook up signatures from weak-scale Dark Matter models by computing two secondary emissions due to DM particles annihilating or decaying in the galactic halo, namely the radio signals from synchrotron emission and the gamma rays from bremsstrahlung. We consider several magnetic field configurations and propagation scenarios for electrons and positrons. We also provide an improved energy loss function for electrons and positrons in the Galaxy, including synchrotron losses in the different configurations, bremsstrahlung losses, ionization losses and Inverse Compton losses with an updated InterStellar Radiation Field.

  3. PPPC 4 DM secondary: a Poor Particle Physicist Cookbook for secondary radiation from Dark Matter

    International Nuclear Information System (INIS)

    Buch, Jatan; Cirelli, Marco; Giesen, Gaëlle; Taoso, Marco

    2015-01-01

    We enlarge the set of recipes and ingredients at disposal of any poor particle physicist eager to cook up signatures from weak-scale Dark Matter models by computing two secondary emissions due to DM particles annihilating or decaying in the galactic halo, namely the radio signals from synchrotron emission and the gamma rays from bremsstrahlung. We consider several magnetic field configurations and propagation scenarios for electrons and positrons. We also provide an improved energy loss function for electrons and positrons in the Galaxy, including synchrotron losses in the different configurations, bremsstrahlung losses, ionization losses and Inverse Compton losses with an updated InterStellar Radiation Field

  4. PPPC 4 DM ID: a poor particle physicist cookbook for dark matter indirect detection

    Energy Technology Data Exchange (ETDEWEB)

    Cirelli, Marco; Panci, Paolo; Strumia, Alessandro [CERN Theory Division, CH-1211 Geneve (Switzerland); Corcella, Gennaro [Museo Storico della Fisica, Centro Studi e Ricerche E. Fermi, P. del Viminale 1, I-00185 Rome (Italy); Hektor, Andi; Kadastik, Mario; Raidal, Martti [National Institute of Chemical Physics and Biophysics, Ravala 10, 10143 Tallinn (Estonia); Hütsi, Gert [Tartu Observatory, Tõravere 61602 (Estonia); Sala, Filippo, E-mail: marco.cirelli@cea.fr [Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa (Italy)

    2011-03-01

    We provide ingredients and recipes for computing signals of TeV-scale Dark Matter annihilations and decays in the Galaxy and beyond. For each DM channel, we present the energy spectra at production, computed by high-statistics simulations. We estimate the Monte Carlo uncertainty by comparing the results yielded by the Pythia and Herwig event generators. We then provide the propagation functions for charged particles in the Galaxy, for several DM distribution profiles and sets of propagation parameters. Propagation of e{sup ±} is performed with an improved semi-analytic method that takes into account position-dependent energy losses in the Milky Way. Using such propagation functions, we compute the energy spectra of e{sup ±}, p-bar and d-bar at the location of the Earth. We then present the gamma ray fluxes, both from prompt emission and from Inverse Compton scattering in the galactic halo. Finally, we provide the spectra of extragalactic gamma rays. All results are available in numerical form and ready to be consumed.

  5. PPPC 4 DM ID: a poor particle physicist cookbook for dark matter indirect detection

    International Nuclear Information System (INIS)

    Cirelli, Marco; Panci, Paolo; Strumia, Alessandro; Corcella, Gennaro; Hektor, Andi; Kadastik, Mario; Raidal, Martti; Hütsi, Gert; Sala, Filippo

    2011-01-01

    We provide ingredients and recipes for computing signals of TeV-scale Dark Matter annihilations and decays in the Galaxy and beyond. For each DM channel, we present the energy spectra at production, computed by high-statistics simulations. We estimate the Monte Carlo uncertainty by comparing the results yielded by the Pythia and Herwig event generators. We then provide the propagation functions for charged particles in the Galaxy, for several DM distribution profiles and sets of propagation parameters. Propagation of e ± is performed with an improved semi-analytic method that takes into account position-dependent energy losses in the Milky Way. Using such propagation functions, we compute the energy spectra of e ± , p-bar and d-bar at the location of the Earth. We then present the gamma ray fluxes, both from prompt emission and from Inverse Compton scattering in the galactic halo. Finally, we provide the spectra of extragalactic gamma rays. All results are available in numerical form and ready to be consumed

  6. Asymmetric WIMP Dark Matter in the presence of DM/anti-DM oscillations

    International Nuclear Information System (INIS)

    Zaharijas, G.

    2014-01-01

    The general class of 'Asymmetric Dark Matter (DM)' scenarios assumes the existence of a primordial particle/anti-particle asymmetry in the dark matter sector related to the asymmetry in the baryonic one, as a way to achieve the observed similarity between the baryonic and dark matter energy densities today. Focusing on this framework we study the effect of oscillations between dark matter and its anti-particle on the re-equilibration of the initial asymmetry. We calculate the evolution of the dark matter relic abundance and show how oscillations re-open the parameter space of asymmetric dark matter models, in particular in the direction of allowing large (WIMP-scale) DM masses. We found in particular that a typical WIMP with a mass at the EW scale (about 1 TeV) having a primordial asymmetry of the same order as the baryon asymmetry, naturally gets the correct relic abundance if the δm mass term is in the ∼ meV range. This turns out to be a natural value for fermionic DM arising from the higher dimensional operator H 2 DM 2 /Λ where H is the Higgs field and Λ ∼ M Pl . Finally, we constrain the parameter space in this framework by applying up-to-date bounds from indirect detection signals on annihilating DM

  7. Consequences of DM/antiDM Oscillations for Asymmetric WIMP Dark Matter

    CERN Document Server

    Cirelli, Marco; Servant, Geraldine; Zaharijas, Gabrijela

    2012-01-01

    Assuming the existence of a primordial asymmetry in the dark sector, a scenario usually dubbed Asymmetric Dark Matter (aDM), we study the effect of oscillations between dark matter and its antiparticle on the re-equilibration of the initial asymmetry before freeze-out, which enable efficient annihilations to recouple. We calculate the evolution of the DM relic abundance and show how oscillations re-open the parameter space of aDM models, in particular in the direction of allowing large (WIMP-scale) DM masses. A typical wimp with a mass at the EW scale (\\sim 100 GeV - 1 TeV) presenting a primordial asymmetry of the same order as the baryon asymmetry naturally gets the correct relic abundance if the DM-number-violating Delta(DM) = 2 mass term is in the \\sim meV range. The re-establishment of annihilations implies that constraints from the accumulation of aDM in astrophysical bodies are evaded. On the other hand, the ordinary bounds from BBN, CMB and indirect detection signals on annihilating DM have to be consi...

  8. Extended micro objects as dark matter particles

    Science.gov (United States)

    Belotsky, K.; Rubin, S.; Svadkovsky, I.

    2017-05-01

    Models of various forms of composite dark matter (DM) predicted by particle theory and the DM constituents formed by gravity that are not reduced to new elementary particle candidates are discussed. Main attention is paid to a gravitational origin of the DM. The influence of extended mass spectrum of primordial black holes on observational limits is considered. It is shown that non-uniformly deformed extra space can be considered as point-like masses which possess only gravitational interaction with each other and with the ordinary particles. The recently discussed six-dimensional stable wormholes could contribute to the DM. The contribution of dark atoms is also considered.

  9. Condensed elementary particle matter

    International Nuclear Information System (INIS)

    Kajantie, K.

    1996-01-01

    Quark matter is a special case of condensed elementary particle matter, matter governed by the laws of particle physics. The talk discusses how far one can get in the study of particle matter by reducing the problem to computations based on the action. As an example the computation of the phase diagram of electroweak matter is presented. It is quite possible that ultimately an antireductionist attitude will prevail: experiments will reveal unpredicted phenomena not obviously reducible to the study of the action. (orig.)

  10. Particle dark matter - A theorist's perspective

    Indian Academy of Sciences (India)

    ture of the dark matter (DM) in the Universe, from the point of view of particle ... they must be electrically and (preferably) color neutral. .... in the general MssM and in two unification-based models: the constrained MssM ..... multi-TeV range.

  11. Particle dark matter: A multimessenger endeavour

    Science.gov (United States)

    Regis, M.

    2017-01-01

    The search for dark matter (DM) as a new, yet undiscovered, particle is explored through a complex host of different signals, from collider to direct and indirect searches. A special focus is dedicated to the latter ones, covering the full electromagnetic spectrum (from radio to gamma-rays), charged cosmic-rays and neutrinos. The expected DM signals are by definition faint, but the possibility to exploit a wide-field investigation offers promising prospects. In this brief review, I summarize the state-of-the-art in the search for particle DM signals, exploring some new ideas that are emerging in the effort of the scientific community to understand the elusive nature of DM.

  12. runDM: Running couplings of Dark Matter to the Standard Model

    Science.gov (United States)

    D'Eramo, Francesco; Kavanagh, Bradley J.; Panci, Paolo

    2018-02-01

    runDM calculates the running of the couplings of Dark Matter (DM) to the Standard Model (SM) in simplified models with vector mediators. By specifying the mass of the mediator and the couplings of the mediator to SM fields at high energy, the code can calculate the couplings at low energy, taking into account the mixing of all dimension-6 operators. runDM can also extract the operator coefficients relevant for direct detection, namely low energy couplings to up, down and strange quarks and to protons and neutrons.

  13. Matter: the fundamental particles

    CERN Multimedia

    Landua, Rolf

    2007-01-01

    "The largest particle physics centre in the world is located in Europe. It straddles the Franco-Swiss border, near Geneva. At CERN - the European Organisation for Nuclear Research , which is focused on the science of nuclear matter rather than on the exploitation of atomic energy - there are over 6 500 scientists." (1 page)

  14. Particle Dark Matter: An Overview

    International Nuclear Information System (INIS)

    Roszkowski, Leszek

    2009-01-01

    Dark matter in the Universe is likely to be made up of some new, hypothetical particle which would be a part of an extension of the Standard Model of particle physics. In this overview, I will first briefly review well motivated particle candidates for dark matter. Next I will focus my attention on the neutralino of supersymmetry which is the by far most popular dark matter candidate. I will discuss some recent progress and comment on prospects for dark matter detection.

  15. Ultralight particle dark matter

    International Nuclear Information System (INIS)

    Ringwald, A.

    2013-10-01

    We review the physics case for very weakly coupled ultralight particles beyond the Standard Model, in particular for axions and axion-like particles (ALPs): (i) the axionic solution of the strong CP problem and its embedding in well motivated extensions of the Standard Model; (ii) the possibility that the cold dark matter in the Universe is comprised of axions and ALPs; (iii) the ALP explanation of the anomalous transparency of the Universe for TeV photons; and (iv) the axion or ALP explanation of the anomalous energy loss of white dwarfs. Moreover, we present an overview of ongoing and near-future laboratory experiments searching for axions and ALPs: haloscopes, helioscopes, and light-shining-through-a-wall experiments.

  16. Ultralight particle dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Ringwald, A.

    2013-10-15

    We review the physics case for very weakly coupled ultralight particles beyond the Standard Model, in particular for axions and axion-like particles (ALPs): (i) the axionic solution of the strong CP problem and its embedding in well motivated extensions of the Standard Model; (ii) the possibility that the cold dark matter in the Universe is comprised of axions and ALPs; (iii) the ALP explanation of the anomalous transparency of the Universe for TeV photons; and (iv) the axion or ALP explanation of the anomalous energy loss of white dwarfs. Moreover, we present an overview of ongoing and near-future laboratory experiments searching for axions and ALPs: haloscopes, helioscopes, and light-shining-through-a-wall experiments.

  17. Dark matter and particle physics

    International Nuclear Information System (INIS)

    Peskin, Michael E.

    2007-01-01

    Astrophysicists now know that 80% of the matter in the universe is 'dark matter', composed of neutral and weakly interacting elementary particles that are not part of the Standard Model of particle physics. I will summarize the evidence for dark matter. I will explain why I expect dark matter particles to be produced at the CERN LHC. We will then need to characterize the new weakly interacting particles and demonstrate that they the same particles that are found in the cosmos. I will describe how this might be done. (author)

  18. Particle dark matter signal in DAMA/LIBRA

    International Nuclear Information System (INIS)

    Bernabei, R.; Belli, P.; Di Marco, A.; Montecchia, F.; Cappella, F.; D'Angelo, A.; Incicchitti, A.; Prosperi, D.; Cerulli, R.; Dai, C.J.; He, H.L.; Ma, X.H.; Sheng, X.D.; Wang, R.G.; Ye, Z.P.

    2012-01-01

    The DAMA/LIBRA experiment, running at LNGS, has a sensitive mass of about 250 kg highly radiopure NaI(Tl) and it is mainly devoted to the investigation of Dark Matter (DM) particles in the Galactic halo by exploiting the model independent DM annual modulation signature. The present DAMA/LIBRA experiment and the former DAMA/NaI one have released so far results corresponding to a total exposure of 1.17 ton×yr over 13 annual cycles. They provide a model independent evidence of the presence of DM particles in the galactic halo at 8.9σ C.L.

  19. Quark matter or new particles?

    Science.gov (United States)

    Michel, F. Curtis

    1988-01-01

    It has been argued that compression of nuclear matter to somewhat higher densities may lead to the formation of stable quark matter. A plausible alternative, which leads to radically new astrophysical scenarios, is that the stability of quark matter simply represents the stability of new particles compounded of quarks. A specific example is the SU(3)-symmetric version of the alpha particle, composed of spin-zero pairs of each of the baryon octet (an 'octet' particle).

  20. A lower bound on the mass of dark matter particles

    International Nuclear Information System (INIS)

    Boyarsky, Alexey; Ruchayskiy, Oleg; Iakubovskyi, Dmytro

    2009-01-01

    We discuss the bounds on the mass of Dark Matter (DM) particles, coming from the analysis of DM phase-space distribution in dwarf spheroidal galaxies (dSphs). After reviewing the existing approaches, we choose two methods to derive such a bound. The first one depends on the information about the current phase space distribution of DM particles only, while the second one uses both the initial and final distributions. We discuss the recent data on dSphs as well as astronomical uncertainties in relevant parameters. As an application, we present lower bounds on the mass of DM particles, coming from various dSphs, using both methods. The model-independent bound holds for any type of fermionic DM. Stronger, model-dependent bounds are quoted for several DM models (thermal relics, non-resonantly and resonantly produced sterile neutrinos, etc.). The latter bounds rely on the assumption that baryonic feedback cannot significantly increase the maximum of a distribution function of DM particles. For the scenario in which all the DM is made of sterile neutrinos produced via non-resonant mixing with the active neutrinos (NRP) this gives m NRP > 1.7 keV. Combining these results in their most conservative form with the X-ray bounds of DM decay lines, we conclude that the NRP scenario remains allowed in a very narrow parameter window only. This conclusion is independent of the results of the Lyman-α analysis. The DM model in which sterile neutrinos are resonantly produced in the presence of lepton asymmetry remains viable. Within the minimal neutrino extension of the Standard Model (the νMSM), both mass and the mixing angle of the DM sterile neutrino are bounded from above and below, which suggests the possibility for its experimental search

  1. Dark matter and particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Masiero, A [SISSA-ISAS, Trieste (Italy) and INFN, Sezione di Trieste (Italy); Pascoli, S [SISSA-ISAS, Trieste (Italy) and INFN, Sezione di Trieste (Italy)

    2001-11-15

    Dark matter constitutes a key-problem at the interface between Particle Physics, Astrophysics and Cosmology. Indeed, the observational facts which have been accumulated in the last years on dark matter point to the existence of an amount of non-baryonic dark matter. Since the Standard Model of Particle Physics does not possess any candidate for such non-baryonic dark matter, this problem constitutes a major indication for new Physics beyond the Standard Model. We analyze the most important candidates for non-baryonic dark matter in the context of extensions of the Standard Model (in particular supersymmetric models). The recent hints for the presence of a large amount of unclustered 'vacuum' energy (cosmological constant?) is discussed from the Astrophysical and Particle Physics perspective. (author)

  2. Muon Flux Limits for Majorana Dark Matter Particles

    DEFF Research Database (Denmark)

    Belotsky, Konstantin; Khlopov, Maxim; Kouvaris, Christoforos

    2009-01-01

    We analyze the effects of capture of dark matter (DM) particles, with successive annihilations, predicted in the minimal walking technicolor model (MWT) by the Sun and the Earth. We show that the Super-Kamiokande (SK) upper limit on excessive muon flux disfavors the mass interval between 100-200 Ge...

  3. The Particle Theory of Matter

    Science.gov (United States)

    Widick, Paul R.

    1969-01-01

    Described are activities that are designed to help elementary children understand the possibility of the particle theory of matter. Children work with beads, marbles, B-B shot and sand; by mixing these materials and others they are led to see that it is highly possible for the existence of particles which are not visible. (BR)

  4. Particle Dark Matter Searches Outside the Local Group

    Science.gov (United States)

    Regis, Marco; Xia, Jun-Qing; Cuoco, Alessandro; Branchini, Enzo; Fornengo, Nicolao; Viel, Matteo

    2015-06-01

    If dark matter (DM) is composed by particles which are nongravitationally coupled to ordinary matter, their annihilations or decays in cosmic structures can result in detectable radiation. We show that the most powerful technique to detect a particle DM signal outside the Local Group is to study the angular cross-correlation of nongravitational signals with low-redshift gravitational probes. This method allows us to enhance the signal to noise from the regions of the Universe where the DM-induced emission is preferentially generated. We demonstrate the power of this approach by focusing on GeV-TeV DM and on the recent cross-correlation analysis between the 2MASS galaxy catalogue and the Fermi-LAT γ -ray maps. We show that this technique is more sensitive than other extragalactic γ -ray probes, such as the energy spectrum and angular autocorrelation of the extragalactic background, and emission from clusters of galaxies. Intriguingly, we find that the measured cross-correlation can be well fitted by a DM component, with a thermal annihilation cross section and mass between 10 and 100 GeV, depending on the small-scale DM properties and γ -ray production mechanism. This solicits further data collection and dedicated analyses.

  5. Phenomenological and Astro-particle analysis of light dark matter particles

    International Nuclear Information System (INIS)

    Albornoz Vasquez, D.

    2011-09-01

    The nature of Dark Matter (DM) is still unveiled. Experimental efforts aiming to detect the Dark Matter have shown a great progress in the last decade. This work is devoted to the phenomenological and astro-particle studies of Dark Matter candidates of supersymmetric nature - the neutralino - and beyond - scalar particles. The former, in the (1-100) GeV mass range, is currently being tested by the Large Hadron Collider, direct detection and indirect detection experiments; this work shows that the interplay between experimental techniques is a decisive tool to thoroughly search for theoretical predictions. The latter is a non-standard candidate as light as 1 MeV which could be copiously produced at the Large Hadron Collider and, at the same time, it could explain other phenomena such as neutrino masses and/or the 511 keV line from the galactic center of the Milky Way. We start by describing the DM problem in Part I, where we give a review for evidence of the existence of DM, we set the cosmological framework in which we work and describe the history of DM from the Early Universe (EU), to the formation of structure and up to the current distribution of the DM in haloes. Then, in Part II, we go through the important Cosmological, Astro-particle and Particle Physics constraints to particle DM candidates and subsequently introduce models providing relatively light DM candidates, models of standard supersymmetric nature such as the Minimal Supersymmetric Standard Model (MSSM) and the Next-to-MSSM (NMSSM) with neutralino DM, and beyond N=1 SUSY in a light scalar DM scenario inspired in N=2 SUSY. Finally, in Part III we present the findings of the investigations carried out: we describe a numerical tool developed to scan the multidimensional supersymmetric parameter space, then we present an application of this tool to the search of light neutralino configurations in the MSSM and NMSSM as well as an application to the search for neutralino DM in directional detectors, and

  6. Searches for hadronically decaying Dark Matter mediator particles at ATLAS

    CERN Document Server

    Nindhito, Herjuno Rah

    2016-01-01

    Searches for hadronic resonances of the Dark Matter (DM) particles in the sub-TeV mass re- gion remain as a viable target at ATLAS. However, due to the bandwidth limitation, the events that available for performing an analysis were statistically limited. Reducing the event size by recording a fraction of the full event information overcomes this limitation. An analysis that is performed on those events is called Trigger-Level Analysis(TLA). This poster highlights the TLA strategy used to search for low-mass dijet resonances. No significant excesses are found in a region between 450 and 950 GeV. As an addition, limits are set on a simplified leptophobic Z’ model of DM mediator with axial coupling to quarks and DM particles as well as on Gaussian resonances.

  7. Matter and Interactions: a particle physics perspective

    OpenAIRE

    Organtini, Giovanni

    2011-01-01

    In classical mechanics matter and fields are completely separated. Matter interacts with fields. For particle physicists this is not the case. Both matter and fields are represented by particles. Fundamental interactions are mediated by particles exchanged between matter particles. In this paper we explain why particle physicists believe in such a picture, introducing the technique of Feynman diagrams starting from very basic and popular analogies with classical mechanics, making the physics ...

  8. Particle Dark Matter: Status and Searches

    OpenAIRE

    Sandick, Pearl

    2010-01-01

    A brief overview is given of the phenomenology of particle dark matter and the properties of some of the most widely studied dark matter candidates. Recent developments in direct and indirect dark matter searches are discussed.

  9. Particle Dark Matter (1/4)

    CERN Multimedia

    CERN. Geneva

    2011-01-01

    I review the phenomenology of particle dark matter, including the process of thermal freeze-out in the early universe, and the direct and indirect detection of WIMPs. I also describe some of the most popular particle candidates for dark matter and summarize the current status of the quest to discover dark matter's particle identity.

  10. On thermal gravitational contribution to particle production and dark matter

    Directory of Open Access Journals (Sweden)

    Yong Tang

    2017-11-01

    Full Text Available We investigate the particle production from thermal gravitational annihilation in the very early universe, which is an important contribution for particles that might not be in thermal equilibrium or/and might only have gravitational interaction, such as dark matter (DM. For particles with spin 0,1/2 and 1 we calculate the relevant cross sections through gravitational annihilation and give the analytic formulas with full mass-dependent terms. We find that DM with mass between TeV and 1016 GeV could have the relic abundance that fits the observation, with small dependence on its spin. We also discuss the effects of gravitational annihilation from inflatons. Interestingly, contributions from inflatons could be dominant and have the same power dependence on Hubble parameter of inflation as that from vacuum fluctuation. Also, fermion production from inflaton, in comparison to boson, is suppressed by its mass due to helicity selection.

  11. PPPC 4 DMν: a Poor Particle Physicist Cookbook for Neutrinos from Dark Matter annihilations in the Sun

    International Nuclear Information System (INIS)

    Baratella, Pietro; Cirelli, Marco; Hektor, Andi; Pata, Joosep; Piibeleht, Morten; Strumia, Alessandro

    2014-01-01

    We provide ingredients and recipes for computing neutrino signals of TeV-scale Dark Matter (DM) annihilations in the Sun. For each annihilation channel and DM mass we present the energy spectra of neutrinos at production, including: state-of-the-art energy losses of primary particles in solar matter, secondary neutrinos, electroweak radiation. We then present the spectra after propagation to the Earth, including (vacuum and matter) flavor oscillations and interactions in solar matter. We also provide a numerical computation of the capture rate of DM particles in the Sun. These results are available in numerical form http://www.marcocirelli.net/PPPC4DMID.html

  12. PPPC 4 DMν: a Poor Particle Physicist Cookbook for Neutrinos from Dark Matter annihilations in the Sun

    Energy Technology Data Exchange (ETDEWEB)

    Baratella, Pietro [Scuola Normale Superiore and INFN, Piazza dei Cavalieri 7, Pisa, 56126 (Italy); Cirelli, Marco [Institut de Physique Théorique, CNRS URA 2306 and CEA-Saclay, Gif-sur-Yvette, 91191 (France); Hektor, Andi; Pata, Joosep; Piibeleht, Morten; Strumia, Alessandro, E-mail: pietro.baratella@sissa.it, E-mail: marco.cirelli@cea.fr, E-mail: andi.hektor@cern.ch, E-mail: joosep.pata@cern.ch, E-mail: morten.piibeleht@cern.ch, E-mail: alessandro.strumia@cern.ch [National Institute of Chemical Physics and Biophysics, Ravala 10, Tallinn (Estonia)

    2014-03-01

    We provide ingredients and recipes for computing neutrino signals of TeV-scale Dark Matter (DM) annihilations in the Sun. For each annihilation channel and DM mass we present the energy spectra of neutrinos at production, including: state-of-the-art energy losses of primary particles in solar matter, secondary neutrinos, electroweak radiation. We then present the spectra after propagation to the Earth, including (vacuum and matter) flavor oscillations and interactions in solar matter. We also provide a numerical computation of the capture rate of DM particles in the Sun. These results are available in numerical form.

  13. PPPC 4 DMν: a Poor Particle Physicist Cookbook for Neutrinos from Dark Matter annihilations in the Sun

    Energy Technology Data Exchange (ETDEWEB)

    Baratella, Pietro [Scuola Normale Superiore and INFN, Piazza dei Cavalieri 7, Pisa, 56126 (Italy); Cirelli, Marco [Institut de Physique Théorique, CNRS URA 2306 & CEA-Saclay, Gif-sur-Yvette, 91191 (France); Hektor, Andi [National Institute of Chemical Physics and Biophysics, Ravala 10, Tallinn (Estonia); Helsinki Institute of Physics, P.O. Box 64, Helsinki, FI-00014 (Finland); Pata, Joosep; Piibeleht, Morten [National Institute of Chemical Physics and Biophysics, Ravala 10, Tallinn (Estonia); Strumia, Alessandro [National Institute of Chemical Physics and Biophysics, Ravala 10, Tallinn (Estonia); Dipartimento di Fisica dell’Università di Pisa and INFN, Largo Buonarroti 2, Pisa (Italy)

    2014-03-27

    We provide ingredients and recipes for computing neutrino signals of TeV-scale Dark Matter (DM) annihilations in the Sun. For each annihilation channel and DM mass we present the energy spectra of neutrinos at production, including: state-of-the-art energy losses of primary particles in solar matter, secondary neutrinos, electroweak radiation. We then present the spectra after propagation to the Earth, including (vacuum and matter) flavor oscillations and interactions in solar matter. We also provide a numerical computation of the capture rate of DM particles in the Sun. These results are available in numerical form http://www.marcocirelli.net/PPPC4DMID.html.

  14. Particle dark matter searches in the anisotropic sky

    Science.gov (United States)

    Fornengo, Nicolao; Regis, Marco

    2014-02-01

    Anisotropies in the electromagnetic emission produced by dark matter annihilation or decay in the extragalactic sky are a recent tool in the quest for a particle dark matter evidence. We review the formalism to compute the two-point angular power spectrum in the halo-model approach and discuss the features and the relative size of the various auto- and cross-correlation signals that can be envisaged for anisotropy studies. From the side of particle dark matter signals, we consider the full multi-wavelength spectrum, from the radio emission to X-ray and gamma-ray productions. We discuss the angular power spectra of the auto-correlation of each of these signals and of the cross-correlation between any pair of them. We then extend the search to comprise specific gravitational tracers of dark matter distribution in the Universe: weak-lensing cosmic shear, large-scale-structure matter distribution and CMB-lensing. We have shown that cross-correlating a multi-wavelength dark matter signal (which is a direct manifestation of its particle physics nature) with a gravitational tracer (which is a manifestation of the presence of large amounts of unseen matter in the Universe) may offer a promising tool to demonstrate that what we call DM is indeed formed by elementary particles.

  15. Particle dark matter searches in the anisotropic sky

    Directory of Open Access Journals (Sweden)

    Nicolao eFornengo

    2014-02-01

    Full Text Available Anisotropies in the electromagnetic emission produced by dark matter annihilation or decay in the extragalactic sky are a recent tool in the quest for a particle dark matter evidence. We review the formalism to compute the two-point angular power spectrum in the halo-model approach and discuss the features and the relative size of the various auto- and cross-correlation signals that can be envisaged for anisotropy studies. From the side of particle dark matter signals, we consider the full multi-wavelength spectrum, from the radio emission to X-ray and gamma-ray productions. We discuss the angular power spectra of the auto-correlation of each of these signals and of the cross-correlation between any pair of them. We then extend the search to comprise specific gravitational tracers of dark matter distribution in the Universe: weak-lensing cosmic shear, large-scale-structure matter distribution and CMB-lensing. We have shown that cross-correlating a multi-wavelength dark matter signal (which is a direct manifestation of its particle physics nature with a gravitational tracer (which is a manifestation of the presence of large amounts of unseen matter in the Universe may offer a promising tool to demonstrate that what we call DM is indeed formed by elementary particles.

  16. An introduction to particle dark matter

    CERN Document Server

    Profumo, Stefano

    2017-01-01

    What is the dark matter that fills the Universe and binds together galaxies? How was it produced? What are its interactions and particle properties?The paradigm of dark matter is one of the key developments at the interface of cosmology and elementary particle physics. It is also one of the foundations of the standard cosmological model. This book presents the state of the art in building and testing particle models for dark matter. Each chapter gives an analysis of questions, research directions, and methods within the field. More than 200 problems are included to challenge and stimulate the reader's knowledge and provide guidance in the practical implementation of the numerous 'tools of the trade' presented. Appendices summarize the basics of cosmology and particle physics needed for any quantitative understanding of particle models for dark matter.This interdisciplinary textbook is essential reading for anyone interested in the microscopic nature of dark matter as it manifests itself in particle physics ex...

  17. Unbound particles in dark matter halos

    Energy Technology Data Exchange (ETDEWEB)

    Behroozi, Peter S.; Loeb, Abraham; Wechsler, Risa H.

    2013-06-13

    We investigate unbound dark matter particles in halos by tracing particle trajectories in a simulation run to the far future (a = 100). We find that the traditional sum of kinetic and potential energies is a very poor predictor of which dark matter particles will eventually become unbound from halos. We also study the mass fraction of unbound particles, which increases strongly towards the edges of halos, and decreases significantly at higher redshifts. We discuss implications for dark matter detection experiments, precision calibrations of the halo mass function, the use of baryon fractions to constrain dark energy, and searches for intergalactic supernovae.

  18. Dark matter reflection of particle symmetry

    Science.gov (United States)

    Khlopov, Maxim Yu.

    2017-05-01

    In the context of the relationship between physics of cosmological dark matter and symmetry of elementary particles, a wide list of dark matter candidates is possible. New symmetries provide stability of different new particles and their combination can lead to a multicomponent dark matter. The pattern of symmetry breaking involves phase transitions in the very early Universe, extending the list of candidates by topological defects and even primordial nonlinear structures.

  19. Constraints on Dark Matter Interactions with Standard Model Particles from Cosmic Microwave Background Spectral Distortions.

    Science.gov (United States)

    Ali-Haïmoud, Yacine; Chluba, Jens; Kamionkowski, Marc

    2015-08-14

    We propose a new method to constrain elastic scattering between dark matter (DM) and standard model particles in the early Universe. Direct or indirect thermal coupling of nonrelativistic DM with photons leads to a heat sink for the latter. This results in spectral distortions of the cosmic microwave background (CMB), the amplitude of which can be as large as a few times the DM-to-photon-number ratio. We compute CMB spectral distortions due to DM-proton, DM-electron, and DM-photon scattering for generic energy-dependent cross sections and DM mass m_{χ}≳1 keV. Using Far-Infrared Absolute Spectrophotometer measurements, we set constraints on the cross sections for m_{χ}≲0.1 MeV. In particular, for energy-independent scattering we obtain σ_{DM-proton}≲10^{-24} cm^{2} (keV/m_{χ})^{1/2}, σ_{DM-electron}≲10^{-27} cm^{2} (keV/m_{χ})^{1/2}, and σ_{DM-photon}≲10^{-39} cm^{2} (m_{χ}/keV). An experiment with the characteristics of the Primordial Inflation Explorer would extend the regime of sensitivity up to masses m_{χ}~1 GeV.

  20. Light and heavy dark matter particles

    International Nuclear Information System (INIS)

    Boehm, C.; Fayet, P.; Silk, J.

    2004-01-01

    It has recently been pointed out that the 511 keV emission line detected by integral/SPI from the bulge of our galaxy could be explained by annihilations of light dark matter particles into e + e - . If such a signature is confirmed, then one might expect a conflict with the interpretation of very high energy gamma rays if they also turn out to be due to dark matter annihilations. Here, we propose a way to accommodate the existence of both signals being produced by dark matter annihilations through the existence of two stable (neutral) dark matter particles, as is possible in theories inspired from N=2 supersymmetry

  1. Sensitivity for detection of decay of dark matter particle using ICAL at ...

    Indian Academy of Sciences (India)

    India-based neutrino observatory; iron calorimeter; kolar event; dark matter particle; lifetime. PACS No. ... certain DM energy density in a limited volume of the ICAL cavern. The ICAL ..... of light. This time difference will generally be a positive quantity. ... (a) The lower limit in the lifetime of DMP vs. its mass for μ+μ− decay.

  2. Materials, matter and particles a brief history

    CERN Document Server

    Woolfson, Michael M

    2010-01-01

    This book traces the history of ideas about the nature of matter and also the way that mankind has used material resources that the world offers. Starting with the ideas of ancient civilizations that air, earth, fire and water were the basic ingredients of all matter, it traces the development of the science of chemistry beginning within the ranks of the alchemists. First, the idea of elements grew and then the atomic nature of matter was verified. Physicists had entered the scene, showing the nature of atoms in terms of fundamental particles and then introducing the concept of wave-particle d

  3. Search for dark-matter particles

    International Nuclear Information System (INIS)

    Cowsik, R.

    1991-01-01

    Experiments performed over the last two years have been very successful in drastically reducing the number of viable elementary particles that could possibly constitute the dark matter that dominates the large-scale gravitational dynamics of astronomical systems. The candidates that survive are the light neutrinos, the axion, and a supersymmetric particle with carefully chosen parameters called the neutralino. Baryonic dark matter, which might contribute not insignificantly over small scales, is perhaps present in the form of brown dwarfs, and a search for these is under way. In this article, the astrophysical studies which bear on the density and the phase-space structure of the dark-matter particles are reviewed and the implications of the various direct and indirect searches for these particles are discussed and, finally, alternative suggestions for the candidates and directions for further searches are pointed out. (author). 35 refs., 29 figs

  4. Coupled DM Heating in SCDEW Cosmologies

    Directory of Open Access Journals (Sweden)

    Silvio Bonometto

    2017-08-01

    Full Text Available Strongly-Coupled Dark Energy plus Warm dark matter (SCDEW cosmologies admit the stationary presence of ∼1% of coupled-DM and DE, since inflationary reheating. Coupled-DM fluctuations therefore grow up to non-linearity even in the early radiative expansion. Such early non-linear stages are modelized here through the evolution of a top-hat density enhancement, reaching an early virial balance when the coupled-DM density contrast is just 25–26, and the DM density enhancement is ∼10 % of the total density. During the time needed to settle in virial equilibrium, the virial balance conditions, however, continue to modify, so that “virialized” lumps undergo a complete evaporation. Here, we outline that DM particles processed by overdensities preserve a fraction of their virial momentum. Although fully non-relativistic, the resulting velocities (moderately affect the fluctuation dynamics over greater scales, entering the horizon later on.

  5. Searches for Dark Matter in events with long-lived particles at the LHC

    CERN Document Server

    Schioppa, Marco; The ATLAS collaboration

    2017-01-01

    The ATLAS, CMS and LHCb collaborations searched for Dark Matter (DM) in events with long-lived particles. Many theories of physics beyond the Standard Model predict the existence of stable, neutral, weakly-interacting and massive particles that are putative Dark Matter candidates. The observation of such matter at a collider could only establish that it is neutral, weakly-interactive, massive and stable on the distance-scales of tens of meters. The searches are performed using the LHC Run-I and Run-II datasets recorded with the ATLAS, CMS and LHCb detectors in proton-proton collisions at a center-of-mass energy of 7, 8 and 13 TeV. Signatures include both long-lived particles produced in association with DM and long-lived DM particles (e.g. dark photons decay in lepton-jets). This presentation covers only some of the many researches carried out with the LHC experiments in recent years. No deviation from SM background expectation was found up to now and exclusion limits on DM production cross section were set.

  6. The capture of dark matter particles through the evolution of low-mass stars

    International Nuclear Information System (INIS)

    Lopes, Ilidio; Casanellas, Jordi; Eugenio, Daniel

    2011-01-01

    We studied the rate at which stars capture dark matter (DM) particles, considering different assumptions regarding the DM characteristics and, in particular, investigating how the stellar physics influences the capture rate. Two scenarios were considered: first, we assumed the maximal values for the spin-dependent and spin-independent DM particle-nucleon scattering cross sections allowed by the limits from direct detection experiments. Second, we considered that both scattering cross sections are of the same order, with the aim of studying the dependencies of the capture rate on stellar elements other than hydrogen. We found that the characteristics of the capture rate are very different in the two scenarios. Furthermore, we quantified the uncertainties on the computed capture rate (C χ ) and on the ratio between the luminosities from DM annihilations and thermonuclear reactions (L χ /L nuc ) derived from an imprecise knowledge of the stellar structure and DM parameters. For instance, while an uncertainty of 10% on the typical DM velocity leads to similar errors on the computed C χ and L χ /L nuc , the same uncertainty on the stellar mass becomes more relevant and duplicates the errors. Our results may be used to evaluate the reliability of the computed capture rate for the hypothetical use of stars other than the Sun as DM probes.

  7. Dark matter CMB constraints and likelihoods for poor particle physicists

    Energy Technology Data Exchange (ETDEWEB)

    Cline, James M.; Scott, Pat, E-mail: jcline@physics.mcgill.ca, E-mail: patscott@physics.mcgill.ca [Department of Physics, McGill University, 3600 rue University, Montréal, QC, H3A 2T8 (Canada)

    2013-03-01

    The cosmic microwave background provides constraints on the annihilation and decay of light dark matter at redshifts between 100 and 1000, the strength of which depends upon the fraction of energy ending up in the form of electrons and photons. The resulting constraints are usually presented for a limited selection of annihilation and decay channels. Here we provide constraints on the annihilation cross section and decay rate, at discrete values of the dark matter mass m{sub χ}, for all the annihilation and decay channels whose secondary spectra have been computed using PYTHIA in arXiv:1012.4515 (''PPPC 4 DM ID: a poor particle physicist cookbook for dark matter indirect detection''), namely e, μ, τ, V → e, V → μ, V → τ, u, d s, c, b, t, γ, g, W, Z and h. By interpolating in mass, these can be used to find the CMB constraints and likelihood functions from WMAP7 and Planck for a wide range of dark matter models, including those with annihilation or decay into a linear combination of different channels.

  8. Dark matter CMB constraints and likelihoods for poor particle physicists

    International Nuclear Information System (INIS)

    Cline, James M.; Scott, Pat

    2013-01-01

    The cosmic microwave background provides constraints on the annihilation and decay of light dark matter at redshifts between 100 and 1000, the strength of which depends upon the fraction of energy ending up in the form of electrons and photons. The resulting constraints are usually presented for a limited selection of annihilation and decay channels. Here we provide constraints on the annihilation cross section and decay rate, at discrete values of the dark matter mass m χ , for all the annihilation and decay channels whose secondary spectra have been computed using PYTHIA in arXiv:1012.4515 (''PPPC 4 DM ID: a poor particle physicist cookbook for dark matter indirect detection''), namely e, μ, τ, V → e, V → μ, V → τ, u, d s, c, b, t, γ, g, W, Z and h. By interpolating in mass, these can be used to find the CMB constraints and likelihood functions from WMAP7 and Planck for a wide range of dark matter models, including those with annihilation or decay into a linear combination of different channels

  9. Atomic interactions of charged particles with matter

    International Nuclear Information System (INIS)

    Bichsel, H.

    1993-01-01

    Ideas about the interactions of charged particles with matter are discussed. First, some experimental information is presented. Concepts related to collision cross sections and the Bethe model for them are given. The stopping power is derived and applied to the discussion of depth dose functions ('Bragg curves'). Some details of the energy loss in microscopic volumes are discussed

  10. CASTing light on dark matter particles

    CERN Multimedia

    2005-01-01

    CERN's CAST collaboration recently released first results from its search for solar axions, a candidate dark matter particle. Though they haven't found any axions yet, they have done much to narrow the hunt. The CAST experiment. Physicists think the universe is permeated with dark matter, particles that don't emit or absorb radiation and so are invisible to traditional telescopes. So far no one has found direct signs of dark matter. A different breed of telescope, however, may be able to see such particles. CERN's Axion Solar Telescope (CAST), currently the world's only working axion helioscope, is a superconducting test magnet from the Large Hadron Collider (LHC) that has been refurbished and outfitted with X-ray detectors, plus a focusing mirror system for X-rays that was recovered from the German space program. CAST stares into the sun in search of particles called axions, one of the leading candidates for dark matter. On 9 November, the CAST collaboration released the results of their first experimen...

  11. Planckian Interacting Massive Particles as Dark Matter

    DEFF Research Database (Denmark)

    Garny, Mathias; Sandora, McCullen; Sloth, Martin S.

    2016-01-01

    . In this case the WIMP miracle is a mirage, and instead minimality as dictated by Occam's razor would indicate that dark matter is related to the Planck scale, where quantum gravity is anyway expected to manifest itself. Assuming within this framework that dark matter is a Planckian Interacting Massive Particle......, we show that the most natural mass larger than $0.01\\,\\textrm{M}_p$ is already ruled out by the absence of tensor modes in the CMB. This also indicates that we expect tensor modes in the CMB to be observed soon for this type of minimal dark matter model. Finally, we touch upon the KK graviton mode...... as a possible realization of this scenario within UV complete models, as well as further potential signatures and peculiar properties of this type of dark matter candidate. This paradigm therefore leads to a subtle connection between quantum gravity, the physics of primordial inflation, and the nature of dark...

  12. Planckian Interacting Massive Particles as Dark Matter.

    Science.gov (United States)

    Garny, Mathias; Sandora, McCullen; Sloth, Martin S

    2016-03-11

    The standard model could be self-consistent up to the Planck scale according to the present measurements of the Higgs boson mass and top quark Yukawa coupling. It is therefore possible that new physics is only coupled to the standard model through Planck suppressed higher dimensional operators. In this case the weakly interacting massive particle miracle is a mirage, and instead minimality as dictated by Occam's razor would indicate that dark matter is related to the Planck scale, where quantum gravity is anyway expected to manifest itself. Assuming within this framework that dark matter is a Planckian interacting massive particle, we show that the most natural mass larger than 0.01M_{p} is already ruled out by the absence of tensor modes in the cosmic microwave background (CMB). This also indicates that we expect tensor modes in the CMB to be observed soon for this type of minimal dark matter model. Finally, we touch upon the Kaluza-Klein graviton mode as a possible realization of this scenario within UV complete models, as well as further potential signatures and peculiar properties of this type of dark matter candidate. This paradigm therefore leads to a subtle connection between quantum gravity, the physics of primordial inflation, and the nature of dark matter.

  13. Colloquium: Toward living matter with colloidal particles

    Science.gov (United States)

    Zeravcic, Zorana; Manoharan, Vinothan N.; Brenner, Michael P.

    2017-07-01

    A fundamental unsolved problem is to understand the differences between inanimate matter and living matter. Although this question might be framed as philosophical, there are many fundamental and practical reasons to pursue the development of synthetic materials with the properties of living ones. There are three fundamental properties of living materials that we seek to reproduce: The ability to spontaneously assemble complex structures, the ability to self-replicate, and the ability to perform complex and coordinated reactions that enable transformations impossible to realize if a single structure acted alone. The conditions that are required for a synthetic material to have these properties are currently unknown. This Colloquium examines whether these phenomena could emerge by programming interactions between colloidal particles, an approach that bootstraps off of recent advances in DNA nanotechnology and in the mathematics of sphere packings. The argument is made that the essential properties of living matter could emerge from colloidal interactions that are specific—so that each particle can be programmed to bind or not bind to any other particle—and also time dependent—so that the binding strength between two particles could increase or decrease in time at a controlled rate. There is a small regime of interaction parameters that gives rise to colloidal particles with lifelike properties, including self-assembly, self-replication, and metabolism. The parameter range for these phenomena can be identified using a combinatorial search over the set of known sphere packings.

  14. Particle Dark Matter and DAMA/LIBRA

    International Nuclear Information System (INIS)

    Bernabei, R.; Nozzoli, F.; Belli, P.; Cappella, F.; D'Angelo, A.; Prosperi, D.; Cerulli, R.; Dai, C. J.; He, H. L.; Ma, X. H.; Sheng, X. D.; Wang, R. G.; Incicchitti, A.; Montecchia, F.; Ye, Z. P.

    2010-01-01

    The DAMA/LIBRA set-up (about 250 kg highly radiopure NaI(Tl) sensitive mass) is running at the Gran Sasso National Laboratory of the I.N.F.N.. The first DAMA/LIBRA results confirm the evidence for the presence of a Dark Matter particle component in the galactic halo, as pointed out by the former DAMA/NaI set-up; cumulatively the data support such evidence at 8.2 σ C.L. and satisfy all the many peculiarities of the Dark Matter annual modulation signature. The main aspects and prospects of this model independent experimental approach will be outlined.

  15. First search for a dark matter annual modulation signal with NaI(Tl) in the Southern Hemisphere by DM-Ice17

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa de Souza, E.; Cherwinka, J.; Cole, A.; Ezeribe, A. C.; Grant, D.; Halzen, F.; Heeger, K. M.; Hsu, L.; Hubbard, A. J. F.; Jo, J. H.; Karle, A.; Kauer, M.; Kudryavtsev, V. A.; Lim, K. E.; Macdonald, C.; Maruyama, R. H.; Mouton, F.; Paling, S. M.; Pettus, W.; Pierpoint, Z. P.; Reilly, B. N.; Robinson, M.; Rogers, F. R.; Sandstrom, P.; Scarff, A.; Spooner, N. J. C.; Telfer, S.; Yang, L.

    2017-02-28

    The first search for a dark matter annual modulation signal with NaI(Tl) target material in the Southern Hemisphere conducted with the DM-Ice17 experiment is presented. DM-Ice17 consists of 17 kg of NaI(Tl) scintillating crystal under 2200 m.w.e. overburden of Antarctic glacial ice. The analysis presented here utilizes a 60.8 kg yr exposure. While unable to exclude the signal reported by DAMA/LIBRA, the DM-Ice17 data are consistent with no modulation in the energy range of 4-20 keV, providing the strongest limits on WIMP candidates from a direct detection experiment located in the Southern Hemisphere. Additionally, the successful deployment and stable operation of 17 kg of NaI(Tl) crystal over 3.5 years establishes the South Pole ice as a viable location for future underground, low-background experiments.

  16. Strange particle production from quark matter droplets

    International Nuclear Information System (INIS)

    Werner, K.; Hladik, M.

    1995-01-01

    We recently introduced new methods to study ultrarelativistic nuclear scattering by providing a link between the string model approach and a thermal description. The string model is used to provide information about fluctuations in energy density. Regions of high energy density are considered to be quark matter droplets and treated macroscopically. At SPS energies, we find mainly medium size droplets---with energies up to few tens of Gev. A key issue is the microcanonical treatment of individual quark matter droplets. Each droplet hadronizes instantaneously according to the available n-body phase space. Due to the huge number of possible hadron configurations, special Monte Carlo techniques have been developed to calculate this disintegration. We present results concerning the production of strange particles from such a hadronization as compared to string decay. copyright 1995 American Institute of Physics

  17. Extraordinary Matter: Visualizing Space Plasmas and Particles

    Science.gov (United States)

    Barbier, S. B.; Bartolone, L.; Christian, E.; Thieman, J.; Eastman, T.; Lewis, E.

    2011-09-01

    Atoms and sub-atomic particles play a crucial role in the dynamics of our universe, but these particles and the space plasmas comprised of them are often overlooked in popular scientific and educational resources. Although the concepts are pertinent to a wide range of topics, even the most basic particle and plasma physics principles are generally unfamiliar to non-scientists. Educators and public communicators need assistance in explaining these concepts that cannot be easily demonstrated in the everyday world. Active visuals are a highly effective aid to understanding, but resources of this type are currently few in number and difficult to find, and most do not provide suitable context for audience comprehension. To address this need, our team is developing an online multimedia reference library of animations, visualizations, interactivities, and videos resources - Extraordinary Matter: Visualizing Space Plasmas and Particles. The site targets grades 9-14 and the equivalent in informal education and public outreach. Each ready-to-use product will be accompanied by a supporting explanation at a reading level matching the educational level of the concept. It will also have information on relevant science, technology, engineering, and mathematics (STEM) educational standards, activities, lesson plans, related products, links, and suggested uses. These products are intended to stand alone, making them adaptable to the widest range of uses, including scientist presentations, museum displays, educational websites and CDs, teacher professional development, and classroom use. This project is funded by a NASA Education and Public Outreach in Earth and Space Science (EPOESS) grant.

  18. Planckian Interacting Massive Particles as Dark Matter

    CERN Document Server

    Garny, Mathias; Sloth, Martin S.

    2016-03-10

    The Standard Model could be self-consistent up to the Planck scale according to the present measurements of the Higgs mass and top quark Yukawa coupling. It is therefore possible that new physics is only coupled to the Standard Model through Planck suppressed higher dimensional operators. In this case the WIMP miracle is a mirage, and instead minimality as dictated by Occam's razor would indicate that dark matter is related to the Planck scale, where quantum gravity is anyway expected to manifest itself. Assuming within this framework that dark matter is a Planckian Interacting Massive Particle, we show that the most natural mass larger than $0.01\\,\\textrm{M}_p$ is already ruled out by the absence of tensor modes in the CMB. This also indicates that we expect tensor modes in the CMB to be observed soon for this type of minimal dark matter model. Finally, we touch upon the KK graviton mode as a possible realization of this scenario within UV complete models, as well as further potential signatures and peculiar...

  19. Strange particles from dense hadronic matter

    International Nuclear Information System (INIS)

    Rafelski, J.; Letessier, J.; Tounsi, A.

    1996-01-01

    After a brief survey of the remarkable accomplishments of the current heavy ion collision experiments up to 200A GeV, we address in depth the role of strange particle production in the search for new phases of matter in these collisions. In particular, we show that the observed enhancement pattern of otherwise rarely produced multistrange antibaryons can be consistently explained assuming color deconfinement in a localized, rapidly disintegrating hadronic source. We develop the theoretical description of this source, and in particular study QCD based processes of strangeness production in the deconfined, thermal quark-gluon plasma phase, allowing for approach to chemical equilibrium and dynamical evolution. We also address thermal charm production. Using a rapid hadronization model we obtain final state particle yields, providing detailed theoretical predictions about strange particle spectra and yields as functions of heavy ion energy. Our presentation is comprehensive and self contained: we introduce the procedures used in data interpretation in considerable detail, discuss the particular importance of selected experimental results, and show how they impact the theoretical developments. (author)

  20. Particle dark matter from physics beyond the standard model

    International Nuclear Information System (INIS)

    Matchev, Konstantin

    2004-01-01

    In this talk I contrast three different particle dark matter candidates, all motivated by new physics beyond the Standard Model: supersymmetric dark matter, Kaluza-Klein dark matter, and scalar dark matter. I then discuss the prospects for their discovery and identification in both direct detection as well as collider experiments

  1. EDITORIAL: Focus on Dark Matter and Particle Physics

    Science.gov (United States)

    Aprile, Elena; Profumo, Stefano

    2009-10-01

    The quest for the nature of dark matter has reached a historical point in time, with several different and complementary experiments on the verge of conclusively exploring large portions of the parameter space of the most theoretically compelling particle dark matter models. This focus issue on dark matter and particle physics brings together a broad selection of invited articles from the leading experimental and theoretical groups in the field. The leitmotif of the collection is the need for a multi-faceted search strategy that includes complementary experimental and theoretical techniques with the common goal of a sound understanding of the fundamental particle physical nature of dark matter. These include theoretical modelling, high-energy colliders and direct and indirect searches. We are confident that the works collected here present the state of the art of this rapidly changing field and will be of interest to both experts in the topic of dark matter as well as to those new to this exciting field. Focus on Dark Matter and Particle Physics Contents DARK MATTER AND ASTROPHYSICS Scintillator-based detectors for dark matter searches I S K Kim, H J Kim and Y D Kim Cosmology: small-scale issues Joel R Primack Big Bang nucleosynthesis and particle dark matter Karsten Jedamzik and Maxim Pospelov Particle models and the small-scale structure of dark matter Torsten Bringmann DARK MATTER AND COLLIDERS Dark matter in the MSSM R C Cotta, J S Gainer, J L Hewett and T G Rizzo The role of an e+e- linear collider in the study of cosmic dark matter M Battaglia Collider, direct and indirect detection of supersymmetric dark matter Howard Baer, Eun-Kyung Park and Xerxes Tata INDIRECT PARTICLE DARK MATTER SEARCHES:EXPERIMENTS PAMELA and indirect dark matter searches M Boezio et al An indirect search for dark matter using antideuterons: the GAPS experiment C J Hailey Perspectives for indirect dark matter search with AMS-2 using cosmic-ray electrons and positrons B Beischer, P von

  2. Detection of dark matter particles with low temperature phonon sensors

    International Nuclear Information System (INIS)

    Sadoulet, B.

    1988-03-01

    Taking as an example the development effort in Berkeley, the author discusses for nonspecialists (Astronomers and Particle Physicists) the promises of phonon sensing at low temperature for the detection of dark matter particles and the difficulties faced. 31 refs

  3. Visualizing Space Plasmas and Particles: Extraordinary Matter

    Science.gov (United States)

    Barbier, B.; Bartolone, L. M.; Christian, E. R.; Eastman, T. E.; Lewis, E.; Thieman, J. R.

    2010-12-01

    A recent survey of museum visitors documented some startling misconceptions at a very basic level. Even in this "science attentive" group, one quarter of the respondents believed that an atom would explode if it lost an electron, one sixth said it would become a new atom or element, and one fifth said they had no idea what would happen. Only one fourth of the respondents indicated they were familiar with plasma as a state of matter. Current resources on these topics are few in number and/or are difficult to locate, and they rarely provide suitable context at a level understandable to high school students and educators or to the interested public. In response to this and other evidence of common misunderstandings of simple particle and plasma science, our team of space scientists and education specialists has embarked upon the development of "Extraordinary Matter: Visualizing Space Plasmas and Particles", an online NASA multimedia library. It is designed to assist formal and informal educators and scientists with explaining concepts that cannot be easily demonstrated in the everyday world. The newly released site, with a target audience equivalent to grades 9-14, includes both existing products, reviewed by our team for quality, and new products we have developed. Addition of products to our site is in large part determined by the results of our front-end evaluation to determine the specific needs, gaps, and priorities of potential audiences. Each ready-to-use product is accompanied by a supporting explanation at a reading level matching the educational level of the concept, along with educational standards addressed, and links to other associated resources. Some will include related educational activities. Products are intended to stand alone, making them adaptable to the widest range of uses, either individually or as a custom-selected group. Uses may include, for example, scientist presentations, museum displays, teacher professional development, and classroom

  4. Fundamental Particle Structure in the Cosmological Dark Matter

    Science.gov (United States)

    Khlopov, Maxim

    2013-11-01

    The nonbaryonic dark matter of the universe is assumed to consist of new stable forms of matter. Their stability reflects symmetry of micro-world and mechanisms of its symmetry breaking. Particle candidates for cosmological dark matter are lightest particles that bear new conserved quantum numbers. Dark matter particles may represent ideal gas of noninteracting particles. Self-interacting dark matter weakly or superweakly coupled to ordinary matter is also possible, reflecting nontrivial pattern of particle symmetry in the hidden sector of particle theory. In the early universe the structure of particle symmetry breaking gives rise to cosmological phase transitions, from which macroscopic cosmological defects or primordial nonlinear structures can be originated. Primordial black holes (PBHs) can be not only a candidate for dark matter, but also represent a universal probe for superhigh energy physics in the early universe. Evaporating PBHs turn to be a source of even superweakly interacting particles, while clouds of massive PBHs can serve as nonlinear seeds for galaxy formation. The observed broken symmetry of the three known families may provide a simultaneous solution for the problems of the mass of neutrino and strong CP-violation in the unique framework of models of horizontal unification. Dark matter candidates can also appear in the new families of quarks and leptons and the existence of new stable charged leptons and quarks is possible, hidden in elusive "dark atoms." Such possibility, strongly restricted by the constraints on anomalous isotopes of light elements, is not excluded in scenarios that predict stable double charged particles. The excessive -2 charged particles are bound in these scenarios with primordial helium in O-helium "atoms," maintaining specific nuclear-interacting form of the dark matter, which may provide an interesting solution for the puzzles of the direct dark matter searches. In the context of cosmoparticle physics, studying

  5. Dilaton could affect abundance of dark matter particles

    CERN Multimedia

    2007-01-01

    "The amount of dark matter left over from the early universe may be less than previously believed. new research shows that the "relic abundance" of stable dark matter particles such as the neutralino may be reduced as compared to standard cosmology theories due to the effects of the "dilaton", a particle with zero spin in the gravitational sector of strings." (1 page)

  6. Coherent radiation of photon by fast particles in exited matter

    International Nuclear Information System (INIS)

    Ryazanov, M.I.

    1981-01-01

    The review on the theory of coherent photon radiation by fast charged particle interaction with excited by external electromagnetic field atoms of matter is presented. The motive particle excites in the matter longitudinal electric oscillations (plasmons, longitudinal optical phonons, longitudinal excitons). Energy and momentum conservation laws in the course of quantum radiation in the matter by a charged particle are considered taking into account the energy-matter exchange. It follows from the conservation laws that for the processes investigated the quantum angle of escape is stiffly connected with its frequency. The cohe-- rent luminescence processes are considered as generalized Vavilov- Cherenkov radiation [ru

  7. Relic abundance of mass-varying cold dark matter particles

    International Nuclear Information System (INIS)

    Rosenfeld, Rogerio

    2005-01-01

    In models of coupled dark energy and dark matter the mass of the dark matter particle depends on the cosmological evolution of the dark energy field. In this Letter we exemplify in a simple model the effects of this mass variation on the relic abundance of cold dark matter

  8. Constraining properties of dark matter particles using astrophysical data

    NARCIS (Netherlands)

    Iakubovskyi, Dmytro

    2013-01-01

    A microscopic origin of dark matter phenomenon is the most plausible hypothesis to explain the mystery of dark matter. The dark matter particle hypothesis necessarily implies an extension of the Standard Model. In this thesis, we undertook a systematic model-independent program of studying the

  9. Astrophysical dark matter: candidates from particle physics and detection possibilities

    International Nuclear Information System (INIS)

    Freese, K.

    1989-01-01

    In this talk, I will discuss the arguments that 50% to 90% of the matter in galaxies, including our own, is made of an unknown type of dark matter. I will review the reason why cosmologists believe Ω = 1 and illustrate the contrast with the limits on the amount of baryonic matter from element abundances in Big Bang Nucleosynthesis. Other arguments for nonbaryonic dark matter will also be discussed. Candidates for the dark matter from particle physics will be presented. I will focus on cold dark matter candidates known as WIMPs, weakly interacting massive (O(GeV)) particles. I will try to illustrate why these particles are interesting for astrophysics and outline ideas for cornering them. Detection possibilities for these particles include indirect detection, which takes advantage of the annihilation products of these particles in the galactic halo, the sun, or the earth. Direct detection via newly proposed cryogenic detectors must be sensitive to <∼ keV energy deposits. Annual modulation of the dark matter signal can be used as a signature for these halo particles. I hope to motivate the interest in these particles and discuss ideas for finding them

  10. The ArDM experiment

    CERN Document Server

    Haranczyk, M; Badertscher, A; Boccone, V; Bourgeois, N; Bueno, A; Carmona-Benitez, M C; Chorowski, M; Creus, W; Curioni, A; Daw, E; Degunda, U; Dell'Antone, A; Droge, M; Epprecht, L; Haller, C; Horikawa, S; Kaufmann, L; Kisiel, J; Knecht, L; Laffranchi, M; Lagoda, J; Lazzaro, C; Lightfoot, P; Lozano, J; Lussi, D; Maire, G; Mania, S; Marchionni, A; Mavrokoridis, K; Melgarejo, A; Mijakowski, P; Natterer, G; Navas-Concha, S; Otiougova, P; Piotrowska, A; Polinski, J; de Prado, M; Przewlocki, P; Ravat, S; Regenfus, C; Resnati, F; Robinson, M; Rochet, J; Romero, L; Rondio, E; Rubbia, A; Scotto-Lavina, L; Spooner, N; Viant, T; Trawinski, A; Ulbricht, J; Zalewska, A

    2010-01-01

    The aim of the ArDM project is the development and operation of a one ton double-phase liquid argon detector for direct Dark Matter searches. The detector measures both the scintillation light and the ionization charge from ionizing radiation using two independent readout systems. This paper briefly describes the detector concept and presents preliminary results from the ArDM R&D program, including a 3 l prototype developed to test the charge readout system.

  11. Recent heavy particle decay in a matter dominated universe

    Science.gov (United States)

    Olive, K. A.; Seckel, D.; Vishniac, E.

    1984-09-01

    The cold matter scenario for galaxy formation solves the dark matter problem very nicely on small scales corresponding to galaxies and clusters of galaxies. It is, however, difficult to reconcile with a Universe with an Einstein-deSitter value of (UC OMEGA) = 1. Cold matter and (UC OMEGA) = 1 can be made compatible while retaining the feature that the Universe is matter dominated today. This is done by means of heavy (cold) particles whose decay subsequently leads to the unbinding of a large fraction of lighter clustered matter.

  12. Recent heavy particle decay in a matter dominated universe

    International Nuclear Information System (INIS)

    Olive, K.A.; Seckel, D.; Vishniac, E.

    1984-09-01

    The cold matter scenario for galaxy formation solves the dark matter problem very nicely on small scales corresponding to galaxies and clusters of galaxies. It is, however, difficult to reconcile with a Universe with an Einstein-deSitter value of Ω = 1. We will show here that cold matter and Ω = 1 can be made compatible while retaining the feature that the Universe is matter dominated today. This is done by means of heavy (cold) particles whose decay subsequently leads to the unbinding of a large fraction of lighter clustered matter. 33 references

  13. Recent heavy particle decay in a matter dominated universe

    Energy Technology Data Exchange (ETDEWEB)

    Olive, K.A.; Seckel, D.; Vishniac, E.

    1984-09-01

    The cold matter scenario for galaxy formation solves the dark matter problem very nicely on small scales corresponding to galaxies and clusters of galaxies. It is, however, difficult to reconcile with a Universe with an Einstein-deSitter value of ..cap omega.. = 1. We will show here that cold matter and ..cap omega.. = 1 can be made compatible while retaining the feature that the Universe is matter dominated today. This is done by means of heavy (cold) particles whose decay subsequently leads to the unbinding of a large fraction of lighter clustered matter. 33 references.

  14. Dark matter from gravitational particle production at reheating

    Energy Technology Data Exchange (ETDEWEB)

    Markkanen, Tommi [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom); Nurmi, Sami, E-mail: tommi.markkanen@kcl.ac.uk, E-mail: sami.t.nurmi@jyu.fi [Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 University of Jyväskylä (Finland)

    2017-02-01

    We show that curvature induced particle production at reheating generates adiabatic dark matter if there are non-minimally coupled spectator scalars weakly coupled to visible matter. The observed dark matter abundance implies an upper bound on spectator masses m and non-minimal coupling values ξ. For example, assuming quadratic inflation, instant reheating and a single spectator scalar with only gravitational couplings, the observed dark matter abundance is obtained for m ∼ 0.1 GeV and ξ ∼ 1. Larger mass and coupling values of the spectator are excluded as they would lead to overproduction of dark matter.

  15. Dark matter from gravitational particle production at reheating

    International Nuclear Information System (INIS)

    Markkanen, Tommi; Nurmi, Sami

    2017-01-01

    We show that curvature induced particle production at reheating generates adiabatic dark matter if there are non-minimally coupled spectator scalars weakly coupled to visible matter. The observed dark matter abundance implies an upper bound on spectator masses m and non-minimal coupling values ξ. For example, assuming quadratic inflation, instant reheating and a single spectator scalar with only gravitational couplings, the observed dark matter abundance is obtained for m ∼ 0.1 GeV and ξ ∼ 1. Larger mass and coupling values of the spectator are excluded as they would lead to overproduction of dark matter.

  16. Fine Particle Matter (PM2.5) Design Value

    Data.gov (United States)

    U.S. Environmental Protection Agency — Fine particulate matter or PM2.5 (total mass of particles below 2.5 micron is diameter) is known to cause adverse health effects in humans.See the following websites...

  17. α particles and the ''pasta'' phase in nuclear matter

    International Nuclear Information System (INIS)

    Avancini, S. S.; Barros, C. C. Jr.; Menezes, D. P.; Providencia, C.

    2010-01-01

    The effects of the α particles in nuclear matter at low densities are investigated within three different parametrizations of relativistic models at finite temperature. Both homogeneous and inhomogeneous matter (pasta phase) are described for neutral nuclear matter with fixed proton fractions and stellar matter subject to β equilibrium and trapped neutrinos. In homogeneous matter, α particles are present only at densities below 0.02 fm -3 and their presence decreases with increase of the temperature and, for a fixed temperature, the α particle fraction decreases for smaller proton fractions. A repulsive interaction is important to mimic the dissolution of the clusters in homogeneous matter. The effect of the α particles on the pasta structure is very small except close to the critical temperatures and/or proton fractions, when it may still predict a pasta phase while no pasta phase would occur in the absence of light clusters. It is shown that for densities above 0.01 fm 3 the α-particle fraction in the pasta phase is much larger than that in homogeneous matter.

  18. Suppression of coffee ring: (Particle) size matters

    Science.gov (United States)

    Bansal, Lalit; Seth, Pranjal; Murugappan, Bhubesh; Basu, Saptarshi

    2018-05-01

    Coffee ring patterns in drying sessile droplets are undesirable in various practical applications. Here, we experimentally demonstrate that on hydrophobic substrates, the coffee ring can be suppressed just by increasing the particle diameter. Particles with larger size flocculate within the evaporation timescale, leading to a significant gravimetric settling (for Pe > 1) triggering a uniform deposit. Interestingly, the transition to a uniform deposit is found to be independent of the internal flow field and substrate properties. Flocculation of particles also alters the particle packing at the nanoscale resulting in order to disorder transitions. In this letter, we exhibit a physical exposition on how particle size affects morphodynamics of the droplet drying at macro-nano length scales.

  19. Particles matter: Transformation of suspended particles in constructed wetlands

    NARCIS (Netherlands)

    Mulling, B.T.M.

    2013-01-01

    This thesis shows that constructed wetlands transform suspended particles in (treated) municipal wastewater through selective precipitation in ponds, biological filtering by plankton communities and physical and biological retention in reed beds. These processes effectively remove faecal indicator

  20. From basic processes to sensors: particle-matter interactions

    International Nuclear Information System (INIS)

    Laforge, Bertrand; Bourgeois, Christian

    2005-11-01

    This academic course aims at presenting and explaining techniques of detection of radiations displaying an energy higher that some tens of keV, such as those met in nuclear physics or in particle physics. In a first part, the author first analyses the operation of a biological sensor (the eye), and then presents some generalities about matter: Rutherford experiment, the atom, molecules and solids. The second part deals with interactions between radiations and matter. The author there addresses interactions of heavy charged particles (ionization with high or low energy transfer), interactions of electrons (ionization, Bremsstrahlung), multiple scattering and straggling, the Cherenkov effect, transition radiation, the interaction of γ radiations in matter (Compton effect, photoelectric effect), the interaction of neutrons in matter. Appendices address γ spectrometry, the radiation of a charged particle moving in a dielectric medium, and issues related to statistical fluctuations (distribution functions, fluctuation propagation, energy resolution, noises)

  1. Identification of Dark Matter particles with LHC and direct detection data

    CERN Document Server

    Bertone, Gianfranco; Fornasa, Mattia; de Austri, Roberto Ruiz; Trotta, Roberto

    2010-01-01

    Dark matter (DM) is currently searched for with a variety of detection strategies. Accelerator searches are particularly promising, but even if Weakly Interacting Massive Particles (WIMPs) are found at the Large Hadron Collider (LHC), it will be difficult to prove that they constitute the bulk of the DM in the Universe. We show that a significantly better reconstruction of the DM properties can be obtained with a combined analysis of LHC and direct detection (DD) data, by making a simple Ansatz on the WIMP local density, i.e. by assuming that the local density scales with the cosmological relic abundance. We demonstrate this method in an explicit example in the context of a 24-parameter supersymmetric model, with a neutralino LSP in the stau co-annihilation region. Our results show that future ton-scale DD experiments will allow to break degeneracies in the SUSY parameter space and achieve a significantly better reconstruction of the neutralino composition and its relic density than with LHC data alone.

  2. Elementary particles, dark matter candidate and new extended standard model

    Science.gov (United States)

    Hwang, Jaekwang

    2017-01-01

    Elementary particle decays and reactions are discussed in terms of the three-dimensional quantized space model beyond the standard model. Three generations of the leptons and quarks correspond to the lepton charges. Three heavy leptons and three heavy quarks are introduced. And the bastons (new particles) are proposed as the possible candidate of the dark matters. Dark matter force, weak force and strong force are explained consistently. Possible rest masses of the new particles are, tentatively, proposed for the experimental searches. For more details, see the conference paper at https://www.researchgate.net/publication/308723916.

  3. Particle Dark Matter constraints: the effect of Galactic uncertainties

    Energy Technology Data Exchange (ETDEWEB)

    Benito, Maria; Bernal, Nicolás; Iocco, Fabio [ICTP South American Institute for Fundamental Research Instituto de Física Teórica - Universidade Estadual Paulista (UNESP) Rua Dr. Bento Teobaldo Ferraz 271, 01140-070 São Paulo, SP Brazil (Brazil); Bozorgnia, Nassim; Calore, Francesca, E-mail: mariabenitocst@gmail.com, E-mail: nicolas.bernal@uan.edu.co, E-mail: n.bozorgnia@uva.nl, E-mail: calore@lapth.cnrs.fr, E-mail: fabio.iocco.astro@gmail.com [GRAPPA Institute, Institute for Theoretical Physics Amsterdam and Delta Institute for Theoretical Physics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands)

    2017-02-01

    Collider, space, and Earth based experiments are now able to probe several extensions of the Standard Model of particle physics which provide viable dark matter candidates. Direct and indirect dark matter searches rely on inputs of astrophysical nature, such as the local dark matter density or the shape of the dark matter density profile in the target in object. The determination of these quantities is highly affected by astrophysical uncertainties. The latter, especially those for our own Galaxy, are ill-known, and often not fully accounted for when analyzing the phenomenology of particle physics models. In this paper we present a systematic, quantitative estimate of how astrophysical uncertainties on Galactic quantities (such as the local galactocentric distance, circular velocity, or the morphology of the stellar disk and bulge) propagate to the determination of the phenomenology of particle physics models, thus eventually affecting the determination of new physics parameters. We present results in the context of two specific extensions of the Standard Model (the Singlet Scalar and the Inert Doublet) that we adopt as case studies for their simplicity in illustrating the magnitude and impact of such uncertainties on the parameter space of the particle physics model itself. Our findings point toward very relevant effects of current Galactic uncertainties on the determination of particle physics parameters, and urge a systematic estimate of such uncertainties in more complex scenarios, in order to achieve constraints on the determination of new physics that realistically include all known uncertainties.

  4. Particle Correlations in Saturated QCD Matter

    CERN Document Server

    Baier, R; Nardi, M; Wiedemann, Urs Achim; Baier, Rudolf; Kovner, Alex; Nardi, Marzia; Wiedemann, Urs Achim

    2005-01-01

    We study quantitatively angular correlations in the two-particle spectrum produced by an energetic probe scattering off a dense hadronic target with sizeable saturation momentum. To this end, two parton inclusive cross sections for arbitrary projectiles with small color charge density are derived in the eikonal formalism. Our results are the following: For large momenta of the observed particles, the perturbative limit with characteristic back-to-back correlation is recovered. As the trigger momenta get closer to the saturation scale Q_s, the angular distribution broadens. When the momenta are significantly smaller than Q_s, the azimuthal distribution is broad but still peaked back-to-back. However, in a narrow momentum range (0.5 - 1.5) Q_s, we observe that the azimuthal correlation splits into a double peak with maxima displaced away from 180 degree. We argue that it is the soft multiple scattering physics that is responsible for the appearance of this shift in the angle of maximal correlation. We also poin...

  5. Dark Matter "Collider" from Inelastic Boosted Dark Matter.

    Science.gov (United States)

    Kim, Doojin; Park, Jong-Chul; Shin, Seodong

    2017-10-20

    We propose a novel dark matter (DM) detection strategy for models with a nonminimal dark sector. The main ingredients in the underlying DM scenario are a boosted DM particle and a heavier dark sector state. The relativistic DM impinged on target material scatters off inelastically to the heavier state, which subsequently decays into DM along with lighter states including visible (standard model) particles. The expected signal event, therefore, accompanies a visible signature by the secondary cascade process associated with a recoiling of the target particle, differing from the typical neutrino signal not involving the secondary signature. We then discuss various kinematic features followed by DM detection prospects at large-volume neutrino detectors with a model framework where a dark gauge boson is the mediator between the standard model particles and DM.

  6. Neutrinos as a probe of dark-matter particles

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, W.-Y. Pauchy, E-mail: wyhwang@phys.ntu.edu.tw [National Taiwan University, Asia Pacific Organization for Cosmology and Particle Astrophysics, Institute of Astrophysics, Center for Theoretical Sciences (China)

    2013-03-15

    We try to envision that there might be a dark-matter world and neutrinos, especially the right-handed ones, might be coupled directly with dark-matter particles in the dark-matter world. The candidate model would be the extended Standard Model based on SU{sub c}(3) Multiplication-Sign SU{sub L}(2) Multiplication-Sign U(1) Multiplication-Sign SU{sub f}(3) Multiplication-Sign SU{sub R}(2), with the search of the detailed version through the aid of the two working rules, 'Dirac similarity principle' and 'minimum Higgs hypothesis'.

  7. Black holes are neither particle accelerators nor dark matter probes.

    Science.gov (United States)

    McWilliams, Sean T

    2013-01-04

    It has been suggested that maximally spinning black holes can serve as particle accelerators, reaching arbitrarily high center-of-mass energies. Despite several objections regarding the practical achievability of such high energies, and demonstrations past and present that such large energies could never reach a distant observer, interest in this problem has remained substantial. We show that, unfortunately, a maximally spinning black hole can never serve as a probe of high energy collisions, even in principle and despite the correctness of the original diverging energy calculation. Black holes can indeed facilitate dark matter annihilation, but the most energetic photons can carry little more than the rest energy of the dark matter particles to a distant observer, and those photons are actually generated relatively far from the black hole where relativistic effects are negligible. Therefore, any strong gravitational potential could probe dark matter equally well, and an appeal to black holes for facilitating such collisions is unnecessary.

  8. Identifying WIMP dark matter from particle and astroparticle data

    Science.gov (United States)

    Bertone, Gianfranco; Bozorgnia, Nassim; Kim, Jong Soo; Liem, Sebastian; McCabe, Christopher; Otten, Sydney; Ruiz de Austri, Roberto

    2018-03-01

    One of the most promising strategies to identify the nature of dark matter consists in the search for new particles at accelerators and with so-called direct detection experiments. Working within the framework of simplified models, and making use of machine learning tools to speed up statistical inference, we address the question of what we can learn about dark matter from a detection at the LHC and a forthcoming direct detection experiment. We show that with a combination of accelerator and direct detection data, it is possible to identify newly discovered particles as dark matter, by reconstructing their relic density assuming they are weakly interacting massive particles (WIMPs) thermally produced in the early Universe, and demonstrating that it is consistent with the measured dark matter abundance. An inconsistency between these two quantities would instead point either towards additional physics in the dark sector, or towards a non-standard cosmology, with a thermal history substantially different from that of the standard cosmological model.

  9. SOLAR NEUTRINO PHYSICS: SENSITIVITY TO LIGHT DARK MATTER PARTICLES

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Ilidio [Centro Multidisciplinar de Astrofisica, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Silk, Joseph, E-mail: ilidio.lopes@ist.utl.pt, E-mail: ilopes@uevora.pt, E-mail: silk@astro.ox.ac.uk [Institut d' Astrophysique de Paris, UMR 7095 CNRS, Universite Pierre et Marie Curie, 98 bis Boulevard Arago, Paris 75014 (France)

    2012-06-20

    Neutrinos are produced in several neutrino nuclear reactions of the proton-proton chain and carbon-nitrogen-oxygen cycle that take place at different radii of the Sun's core. Hence, measurements of solar neutrino fluxes provide a precise determination of the local temperature. The accumulation of non-annihilating light dark matter particles (with masses between 5 GeV and 16 GeV) in the Sun produces a change in the local solar structure, namely, a decrease in the central temperature of a few percent. This variation depends on the properties of the dark matter particles, such as the mass of the particle and its spin-independent scattering cross-section on baryon-nuclei, specifically, the scattering with helium, oxygen, and nitrogen among other heavy elements. This temperature effect can be measured in almost all solar neutrino fluxes. In particular, by comparing the neutrino fluxes generated by stellar models with current observations, namely {sup 8}B neutrino fluxes, we find that non-annihilating dark matter particles with a mass smaller than 10 GeV and a spin-independent scattering cross-section with heavy baryon-nuclei larger than 3 Multiplication-Sign 10{sup -37} cm{sup -2} produce a variation in the {sup 8}B neutrino fluxes that would be in conflict with current measurements.

  10. More evidence in favor of light dark matter particles?

    International Nuclear Information System (INIS)

    Boehm, Celine; Ascasibar, Yago

    2004-01-01

    In a previous work, it was found that the light dark matter scenario could be a possible explanation to the 511 keV emission line detected at the center of our galaxy. Here, we show that hints of this scenario may also have been discovered in particle physics experiments. This could explain the discrepancy between the measurement of the fine structure constant and the value referenced in the CODATA. Finally, our results indicate that some of the light dark matter features could be tested in accelerators. Their discovery might favor N=2 supersymmetry

  11. Local Group dSph radio survey with ATCA (III): constraints on particle dark matter

    International Nuclear Information System (INIS)

    Regis, Marco; Colafrancesco, Sergio; Profumo, Stefano; De Blok, W.J.G.; Massardi, Marcella; Richter, Laura

    2014-01-01

    We performed a deep search for radio synchrotron emissions induced by weakly interacting massive particles (WIMPs) annihilation or decay in six dwarf spheroidal (dSph) galaxies of the Local Group. Observations were conducted with the Australia Telescope Compact Array (ATCA) at 16 cm wavelength, with an rms sensitivity better than 0.05 mJy/beam in each field. In this work, we first discuss the uncertainties associated with the modeling of the expected signal, such as the shape of the dark matter (DM) profile and the dSph magnetic properties. We then investigate the possibility that point-sources detected in the proximity of the dSph optical center might be due to the emission from a DM cuspy profile. No evidence for an extended emission over a size of few arcmin (which is the DM halo size) has been detected. We present the associated bounds on the WIMP parameter space for different annihilation/decay final states and for different astrophysical assumptions. If the confinement of electrons and positrons in the dSph is such that the majority of their power is radiated within the dSph region, we obtain constraints on the WIMP annihilation rate which are well below the thermal value for masses up to few TeV. On the other hand, for conservative assumptions on the dSph magnetic properties, the bounds can be dramatically relaxed. We show however that, within the next 10 years and regardless of the astrophysical assumptions, it will be possible to progressively close in on the full parameter space of WIMPs by searching for radio signals in dSphs with SKA and its precursors

  12. Local Group dSph radio survey with ATCA (III): constraints on particle dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Regis, Marco [Dipartimento di Fisica, Università di Torino, via P. Giuria 1, I-10125 Torino (Italy); Colafrancesco, Sergio [School of Physics, University of the Witwatersrand, Johannesburg (South Africa); Profumo, Stefano [Department of Physics, University of California, 1156 High St., Santa Cruz, CA 95064 (United States); De Blok, W.J.G. [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo (Netherlands); Massardi, Marcella [INAF—Istituto di Radioastronomia, Via Gobetti 101, I-40129, Bologna (Italy); Richter, Laura, E-mail: regis@to.infn.it, E-mail: sergio.colafrancesco@wits.ac.za, E-mail: profumo@ucsc.edu, E-mail: blok@astron.nl, E-mail: massardi@ira.inaf.it, E-mail: laura@ska.ac.za [SKA South Africa, 3rd Floor, The Park, Park Road, Pinelands, 7405 (South Africa)

    2014-10-01

    We performed a deep search for radio synchrotron emissions induced by weakly interacting massive particles (WIMPs) annihilation or decay in six dwarf spheroidal (dSph) galaxies of the Local Group. Observations were conducted with the Australia Telescope Compact Array (ATCA) at 16 cm wavelength, with an rms sensitivity better than 0.05 mJy/beam in each field. In this work, we first discuss the uncertainties associated with the modeling of the expected signal, such as the shape of the dark matter (DM) profile and the dSph magnetic properties. We then investigate the possibility that point-sources detected in the proximity of the dSph optical center might be due to the emission from a DM cuspy profile. No evidence for an extended emission over a size of few arcmin (which is the DM halo size) has been detected. We present the associated bounds on the WIMP parameter space for different annihilation/decay final states and for different astrophysical assumptions. If the confinement of electrons and positrons in the dSph is such that the majority of their power is radiated within the dSph region, we obtain constraints on the WIMP annihilation rate which are well below the thermal value for masses up to few TeV. On the other hand, for conservative assumptions on the dSph magnetic properties, the bounds can be dramatically relaxed. We show however that, within the next 10 years and regardless of the astrophysical assumptions, it will be possible to progressively close in on the full parameter space of WIMPs by searching for radio signals in dSphs with SKA and its precursors.

  13. Constraints on particle dark matter from cosmic-ray antiprotons

    International Nuclear Information System (INIS)

    Fornengo, N.; Vittino, A.; Maccione, L.

    2014-01-01

    Cosmic-ray antiprotons represent an important channel for dark matter indirect-detection studies. Current measurements of the antiproton flux at the top of the atmosphere and theoretical determinations of the secondary antiproton production in the Galaxy are in good agreement, with no manifest deviation which could point to an exotic contribution in this channel. Therefore, antiprotons can be used as a powerful tool for constraining particle dark matter properties. By using the spectrum of PAMELA data from 50 MV to 180 GV in rigidity, we derive bounds on the dark matter annihilation cross section (or decay rate, for decaying dark matter) for the whole spectrum of dark matter annihilation (decay) channels and under different hypotheses of cosmic-rays transport in the Galaxy and in the heliosphere. For typical models of galactic propagation, the constraints are strong, setting a lower bound on the dark matter mass of a ''thermal'' relic at about 40–80 GeV for hadronic annihilation channels. These bounds are enhanced to about 150 GeV on the dark matter mass, when large cosmic-rays confinement volumes in the Galaxy are considered, and are reduced to 3–4 GeV for annihilation to light quarks (no bound for heavy-quark production) when the confinement volume is small. Bounds for dark matter lighter than few tens of GeV are due to the low energy part of the PAMELA spectrum, an energy region where solar modulation is relevant: to this aim, we have implemented a detailed solution of the transport equation in the heliosphere, which allowed us not only to extend bounds to light dark matter, but also to determine the uncertainty on the constraints arising from solar modulation modelling. Finally, we estimate the impact of soon-to-come AMS-02 data on the antiproton constraints

  14. Distinguishing Dark Matter Stabilization Symmetries at Hadron Colliders with Mass Variables

    CERN Document Server

    Kim, Heejoo

    2017-01-01

    Cosmological and astrophysical observations, yet all gravitational, suggest that there exists stable matter, so-called dark matter (DM), in our universe, which is exerting gravity but hardly detectable in relevant experiments. The stability of DM indicates that DM needs to be either massless or protected by a new symmetry (henceforth called DM stabilizing symmetry) preventing its decay. It turns out that cosmological consideration suggests that massless particles be unlikely to constitute a dominant portion of the DM, motivating DM candidates with a sizable mass. While a massive particle, in general, may decay into lighter particles, the charge conservation associated with the symmetry ensures the stability of DM. There is a tremendous amount of effort in the search for DM candidates and it also comprises collider experiments. DM is, by definition, hard to be detected at colliders such as the LHC. So, its existence may be inferred from (visible) Standard Model (SM) particles emitted from a decay chain of a...

  15. Higgs particles interacting via a scalar Dark Matter field

    Directory of Open Access Journals (Sweden)

    Bhattacharya Yajnavalkya

    2016-01-01

    Full Text Available We study a system of two Higgs particles, interacting via a scalar Dark Matter mediating field. The variational method in the Hamiltonian formalism of QFT is used to derive relativistic wave equations for the two-Higgs system, using a truncated Fock-space trial state. Approximate solutions of the two-body equations are used to examine the existence of Higgs bound states.

  16. Consequences of DM/antiDM oscillations for asymmetric WIMP darkmatter

    DEFF Research Database (Denmark)

    Cirelli, M.; Panci, P.; Servant, G.

    2012-01-01

    Assuming the existence of a primordial asymmetry in the dark sector, a scenario usually dubbed Asymmetric Dark Matter (aDM), we study the effect of oscillations between dark matter and its antiparticle on the re-equilibration of the initial asymmetry before freeze-out, which enable efficient...... a primordial asymmetry of the same order as the baryon asymmetry naturally gets the correct relic abundance if the DM-number-violating Delta(DM) = 2 mass term is in the similar to meV range. The re-establishment of annihilations implies that constraints from the accumulation of aDM in astrophysical bodies...

  17. Light weakly interacting particles. Constraints and connection to dark matter

    International Nuclear Information System (INIS)

    Andreas, Sarah

    2013-07-01

    The so far unknown particle nature of dark matter is a main motivation for extending the Standard Model of particle physics. A recently promoted approach to solving this puzzle is the concept of hidden sectors. Since the interactions of such sectors with the visible sector are very weak, so are the current experimental bounds. Hidden sectors might even contain sub-GeV scale particles that have so far escaped detection. In this thesis, we study the phenomenology of Weakly Interacting Slim Particles (WISPs) as well as their connection to dark matter in different Standard Model extensions. In the Next-to-Minimal Supersymmetric Standard Model (NMSSM), a light CPodd Higgs, arising from spontaneous breaking of approximate symmetries, represents an example of a WISP. Light gauge bosons of an extra U(1) symmetry in a hidden sector are other well motivated candidates for WISPs and called hidden photons. Such light hidden photons appear naturally in supersymmetry or string theory and might resolve the observed deviation in the muon anomalous magnetic moment from predictions. Moreover, scenarios in which hidden sector dark matter interacts via a light hidden photon with the visible sector exhibit appealing features in view of recent astrophysical anomalies. We study how the coupling of the CP-odd Higgs A 0 to fermions can be constrained by current measurements for the case where the A 0 is lighter than two muons. Analysing measurements of different rare and radiative meson decays, the muon anomalous magnetic moment as well as results from beam dump and reactor experiments, we severely constrain the CP-odd Higgs to be heavier than 210 MeV or to couple to fermions four orders of magnitude weaker than the Standard Model Higgs. These results apply more generally to the coupling of an axion-like particle to matter. Hidden photons can be constrained by experiments since they couple to charged Standard Model particles via kinetic mixing with the ordinary photon. We derive several

  18. Light weakly interacting particles. Constraints and connection to dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Andreas, Sarah

    2013-07-15

    The so far unknown particle nature of dark matter is a main motivation for extending the Standard Model of particle physics. A recently promoted approach to solving this puzzle is the concept of hidden sectors. Since the interactions of such sectors with the visible sector are very weak, so are the current experimental bounds. Hidden sectors might even contain sub-GeV scale particles that have so far escaped detection. In this thesis, we study the phenomenology of Weakly Interacting Slim Particles (WISPs) as well as their connection to dark matter in different Standard Model extensions. In the Next-to-Minimal Supersymmetric Standard Model (NMSSM), a light CPodd Higgs, arising from spontaneous breaking of approximate symmetries, represents an example of a WISP. Light gauge bosons of an extra U(1) symmetry in a hidden sector are other well motivated candidates for WISPs and called hidden photons. Such light hidden photons appear naturally in supersymmetry or string theory and might resolve the observed deviation in the muon anomalous magnetic moment from predictions. Moreover, scenarios in which hidden sector dark matter interacts via a light hidden photon with the visible sector exhibit appealing features in view of recent astrophysical anomalies. We study how the coupling of the CP-odd Higgs A{sup 0} to fermions can be constrained by current measurements for the case where the A{sup 0} is lighter than two muons. Analysing measurements of different rare and radiative meson decays, the muon anomalous magnetic moment as well as results from beam dump and reactor experiments, we severely constrain the CP-odd Higgs to be heavier than 210 MeV or to couple to fermions four orders of magnitude weaker than the Standard Model Higgs. These results apply more generally to the coupling of an axion-like particle to matter. Hidden photons can be constrained by experiments since they couple to charged Standard Model particles via kinetic mixing with the ordinary photon. We derive

  19. A fast iterative method for computing particle beams penetrating matter

    International Nuclear Information System (INIS)

    Boergers, C.

    1997-01-01

    Beams of microscopic particles penetrating matter are important in several fields. The application motivating our parameter choices in this paper is electron beam cancer therapy. Mathematically, a steady particle beam penetrating matter, or a configuration of several such beams, is modeled by a boundary value problem for a Boltzmann equation. Grid-based discretization of this problem leads to a system of algebraic equations. This system is typically very large because of the large number of independent variables in the Boltzmann equation (six if time independence is the only dimension-reducing assumption). If grid-based methods are to be practical at all, it is therefore necessary to develop fast solvers for the discretized problems. This is the subject of the present paper. For two-dimensional, mono-energetic, linear particle beam problems, we describe an iterative domain decomposition algorithm based on overlapping decompositions of the set of particle directions and computationally demonstrate its rapid, grid independent convergence. There appears to be no fundamental obstacle to generalizing the method to three-dimensional, energy dependent problems. 34 refs., 15 figs., 6 tabs

  20. Particle production in hot and dense nuclear matter

    International Nuclear Information System (INIS)

    Eklund, A.

    1992-08-01

    The charged particle production in heavy ion reactions at 200 A GeV has been studied for projectiles of 16 O and 32 S on targets of Al, Cu, Ag and Au. Up to 700 charged particles are measured in the pseudorapidity region -1.7 32 S+Au. The measured particle density is used to estimate the energy density attained in central collisions and gives a values of ≅2 GeV/fm 3 . This is close to the energy density predicted for the phase transition from hadronic matter to a quark-gluon plasma. To measure the large number of charged particle produced, finely granulated detector systems are employed. Streamer tube detectors with pad readout and large area, multi-step avalanche chambers with optical readout have been developed for the measurements. The widths of the pseudorapidity distributions of charged particles increase with decreasing centrality of the collision as well as with increasing mass of the target nucleus. This behaviour is assumed to be due to the target fragmentation. The Monte-Carlo model for nucleus-nucleus collisions, VENUS 3.11, which includes rescattering, is in reasonable agreement with the data. The yield of charged particles for central collisions of the heavy targets with 33 S is found to be proportional to the target mass, A, at target rapidity. At midrapidity it is approximately proportional to A 0.3 . At midrapidity the charged particle measurements are supplemented by measurements of the transverse energy. The dimensionless, normalized variances of the multiplicity and transverse energy distributions are, to a large extent, governed by the collision geometry. The change in the normalized variance when studying the charged particle distribution in a narrow angular region is explained as being of statistical nature. (au)

  1. The search for fractional charge elemental particles and very massive particles in bulk matter

    International Nuclear Information System (INIS)

    Perl, M.

    2000-01-01

    The authors describe their ongoing work on, and future plans for, searches in bulk matter for fractional charge elementary particles and very massive elementary particles. Their primary interest is in searching for such particles that may have been produced in the early universe and may be found in the more primeval matter available in the solar system: meteorites, material from the moon's surface, and certain types of ancient terrestrial rocks. In the future the authors are interested in examining material brought back by sample return probes from asteroids. The authors will describe their experimental methods that are based on new modifications of the Millikan liquid drop technique and modern technology: micromachining, CCD cameras, and desktop computers. Extensions of the experimental methods and technology allow searches for very massive charged particles in primeval matter; particles with masses greater than 1,013 GeV. In the first such searches carried out on earth there will be uncertainties in the mass search range. Therefore the authors will also discuss the advantages of eventually carrying out such searches directly on an asteroid

  2. The search for Dark Matter in our galaxy; Suche nach Dunkler Materie in unserer Galaxie

    Energy Technology Data Exchange (ETDEWEB)

    Eitel, K. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Kernphysik; Boer, W. de [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Experimentelle Kernphysik

    2007-07-01

    The matter content in galaxies like the Milky Way as well as in the entire Universe is dominated by Dark Matter (DM). The nature of this DM is one of the great enigmas of modern astroparticle physics. A promising candidate for this DM is a weakly interacting massive particle (WIMP). DM can then be detected directly via rare elastic collisions of WIMPs with atomic nuclei in a well shielded underground detector or via the decay products from the annihilation of two WIMPs. Energetic gamma rays in cosmic radiation might therefore indicate an indirect signal of DM particles in our galaxy. We present two experimental approaches to search for WIMP Dark Matter. (orig.)

  3. Particle dark matter constraints from the Draco dwarf galaxy

    International Nuclear Information System (INIS)

    Tyler, Craig

    2002-01-01

    It is widely thought that neutralinos, the lightest supersymmetric particles, could comprise most of the dark matter. If so, then dark halos will emit radio and gamma ray signals initiated by neutralino annihilation. A particularly promising place to look for these indicators is at the center of the local group dwarf spheroidal galaxy Draco, and recent measurements of the motion of its stars have revealed it to be an even better target for dark matter detection than previously thought. We compute limits on WIMP properties for various models of Draco's dark matter halo. We find that if the halo is nearly isothermal, as the new measurements indicate, then current gamma ray flux limits prohibit much of the neutralino parameter space. If Draco has a moderate magnetic field, then current radio limits can rule out more of it. These results are appreciably stronger than other current constraints, and so acquiring more detailed data on Draco's density profile may become one of the most promising avenues for identifying dark matter

  4. Fundamentals of charged particle transport in gases and condensed matter

    CERN Document Server

    Robson, Robert E; Hildebrandt, Malte

    2018-01-01

    This book offers a comprehensive and cohesive overview of transport processes associated with all kinds of charged particles, including electrons, ions, positrons, and muons, in both gases and condensed matter. The emphasis is on fundamental physics, linking experiment, theory and applications. In particular, the authors discuss: The kinetic theory of gases, from the traditional Boltzmann equation to modern generalizations A complementary approach: Maxwell’s equations of change and fluid modeling Calculation of ion-atom scattering cross sections Extension to soft condensed matter, amorphous materials Applications: drift tube experiments, including the Franck-Hertz experiment, modeling plasma processing devices, muon catalysed fusion, positron emission tomography, gaseous radiation detectors Straightforward, physically-based arguments are used wherever possible to complement mathematical rigor.

  5. An Experiment and Detection Scheme for Cavity-Based Light Cold Dark Matter Particle Searches

    Directory of Open Access Journals (Sweden)

    Masroor H. S. Bukhari

    2017-01-01

    Full Text Available A resonance detection scheme and some useful ideas for cavity-based searches of light cold dark matter particles (such as axions are presented, as an effort to aid in the on-going endeavors in this direction as well as for future experiments, especially in possibly developing a table-top experiment. The scheme is based on our idea of a resonant detector, incorporating an integrated tunnel diode (TD and GaAs HEMT/HFET (High-Electron Mobility Transistor/Heterogeneous FET transistor amplifier, weakly coupled to a cavity in a strong transverse magnetic field. The TD-amplifier combination is suggested as a sensitive and simple technique to facilitate resonance detection within the cavity while maintaining excellent noise performance, whereas our proposed Halbach magnet array could serve as a low-noise and permanent solution replacing the conventional electromagnets scheme. We present some preliminary test results which demonstrate resonance detection from simulated test signals in a small optimal axion mass range with superior signal-to-noise ratios (SNR. Our suggested design also contains an overview of a simpler on-resonance dc signal read-out scheme replacing the complicated heterodyne read-out. We believe that all these factors and our propositions could possibly improve or at least simplify the resonance detection and read-out in cavity-based DM particle detection searches (and other spectroscopy applications and reduce the complications (and associated costs, in addition to reducing the electromagnetic interference and background.

  6. Feebly Interacting Dark Matter Particle as the Inflaton

    OpenAIRE

    Tenkanen, Tommi

    2016-01-01

    We present a scenario where a $Z_2$-symmetric scalar field $\\phi$ first drives cosmic inflation, then reheats the Universe but remains out-of-equilibrium itself, and finally comprises the observed dark matter abundance, produced by particle decays \\`{a} la freeze-in mechanism. We work model-independently without specifying the interactions of the scalar field besides its self-interaction coupling, $\\lambda\\phi^4$, non-minimal coupling to gravity, $\\xi\\phi^2R$, and coupling to another scalar f...

  7. Hypothetical Dark Matter/Axion rockets: What can be said about Dark Matter in terms of space physics propulsion

    International Nuclear Information System (INIS)

    Beckwith, Andrew

    2009-01-01

    This paper discusses dark matter (DM) particle candidates from non-supersymmetry (SUSY) processes and explores how a DM candidate particle in the 100-400 GeV range could be created. Thrust from DM particles is also proposed for Photon rocket and Axion rockets. It would use a magnetic field to convert DM particles to near photonlike particles in a chamber to create thrust from the discharge of the near-photon-like particles. The presence of DM particles would suggest that thrust from the emerging near-photon-like particle would be greater than with conventional photon rockets. This amplifies and improves on an 'axion rocket ramjet' for interstellar travel. It is assumed that the same methodology used in an axion ramjet could be used with DM, with perhaps greater thrust/power conversion efficiencies.

  8. Energy loss of particles in dense matter - calorimetry

    International Nuclear Information System (INIS)

    Wigmans, R.

    1987-08-01

    In the last decade, a class of detectors gradually have become more and more important in experimental particle physics. They are called calorimeters, or total absorption detectors. Basically a calorimeter is a block of matter, in which the particle to be measured interacts, and deposits all its energy in the form of a shower of decreasingly lower-energy particles. The block is made such that certain (usually small and hopefully constant) fraction of the initial particle energy is transformed in a measurable signal (light, electrical charge). This lecture mainly deals with sampling calorimeters but in section 2 also fully sensitive devices are briefly treated. In this section calorimeters for detecting electromagnetic showers are discussed. The physics processes relevant to em shower development are examined, and the factors that limit the performance of em calorimeters. Section 3 is devoted to readout techniques for sampling calorimeters. In sections 4-7 hadron calorimeters are discussed. The physics processes relevant to hadron shower development, their consequences for the calorimeter signals and the possibility for optimizing the performance of hadron calorimeters are examined. In section 8 an outlook for future development is given. 31 refs.; 48 figs

  9. Searches for Particle Dark Matter with gamma-rays.

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    In this contribution I review the present status and discuss some prospects for indirect detection of dark matter with gamma-rays. Thanks to the Fermi Large Area Telescope, searches in gamma-rays have reached sensitivities that allow to probe the most interesting parameter space of the weakly interacting massive particles (WIMP) paradigm. This gain in sensitivity is naturally accompanied by a number of detection claims or indications, the most recent being the claim of a line feature at a dark matter particle mass of ∼ 130 GeV at the Galactic Centre, a claim which requires confirmation from the Fermi-LAT collaboration and other experiments, for example HESS II or the planned Gamma-400 satellite. Predictions for the next generation air Cherenkov telescope, Cherenkov Telescope Array (CTA), together with forecasts on future Fermi-LAT constraints arrive at the exciting possibility that the cosmological benchmark cross-section could be probed from masses of a few GeV to a few TeV. Consequently, non-detection wou...

  10. Neutralino-nucleon cross sections for detection of low-mass dark matter particles

    International Nuclear Information System (INIS)

    Titkova, I.V.; Bednyakov, V.A.

    2004-01-01

    The weakly interacting massive particle (WIMP) is one of the main candidates for the relic dark matter. In the effective low-energy minimal supersymmetric standard model (effMSSM), the neutralino-nucleon spin and scalar cross sections in the low-mass regime were calculated. The calculated cross sections are compared with almost all currently available experimental exclusion curves for spin-dependent WIMP-proton and WIMP-neutron cross sections. It is demonstrated that in general about two-orders-of-magnitude improvement of the current DM experimental sensitivities is needed to reach the effMSSM SUSY predictions. To avoid misleading discrepancies between data and SUSY calculations, it is preferable to use a mixed spin-scalar coupling approach. It is noticed that the DAMA evidence favours the light Higgs coupling approach. It is noticed that the DAMA evidence favours the light Higgs sector in the effMSSM, a high event rate in a 73 Ge detector and relatively high upgoing muon fluxes from relic neutralino annihilations on the Earth and the Sun

  11. CONSTRAINT ON LIGHT DIPOLE DARK MATTER FROM HELIOSEISMOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Ilídio [Centro Multidisciplinar de Astrofísica, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Kadota, Kenji [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Silk, Joseph, E-mail: ilidio.lopes@ist.utl.pt, E-mail: ilopes@uevora.pt, E-mail: kadota.kenji@f.nagoya-u.jp, E-mail: silk@astro.ox.ac.uk [Institut d' Astrophysique de Paris, UMR 7095 CNRS, Université Pierre et Marie Curie, 98 bis Boulevard Arago, F-75014 Paris (France)

    2014-01-10

    We investigate the effects of a magnetic dipole moment of asymmetric dark matter (DM) in the evolution of the Sun. The dipole interaction can lead to a sizable DM scattering cross section even for light DM, and asymmetric DM can lead to a large DM number density in the Sun. We find that solar model precision tests, using as diagnostic the sound speed profile obtained from helioseismology data, exclude dipolar DM particles with a mass larger than 4.3 GeV and magnetic dipole moment larger than 1.6 × 10{sup –17} e cm.

  12. On the interpretation of dark matter self-interactions in Abell 3827

    DEFF Research Database (Denmark)

    Kahlhoefer, Felix; Schmidt-Hoberg, Kai; Kummer, Janis

    2015-01-01

    Self-interactions of dark matter (DM) particles can potentially lead to an observable separation between the DM halo and the stars of a galaxy moving through a region of large DM density. Such a separation has recently been observed in a galaxy falling into the core of the galaxy cluster Abell 3827...

  13. Temperature dependence of single-particle properties in nuclear matter

    International Nuclear Information System (INIS)

    Zuo, W.; Lu, G.C.; Li, Z.H.; Lombardo, U.; Schulze, H.-J.

    2006-01-01

    The single-nucleon potential in hot nuclear matter is investigated in the framework of the Brueckner theory by adopting the realistic Argonne V 18 or Nijmegen 93 two-body nucleon-nucleon interaction supplemented by a microscopic three-body force. The rearrangement contribution to the single-particle potential induced by the ground state correlations is calculated in terms of the hole-line expansion of the mass operator and provides a significant repulsive contribution in the low-momentum region around and below the Fermi surface. Increasing temperature leads to a reduction of the effect, while increasing density makes it become stronger. The three-body force suppresses somewhat the ground state correlations due to its strong short-range repulsion, increasing with density. Inclusion of the three-body force contribution results in a quite different temperature dependence of the single-particle potential at high enough densities as compared to that adopting the pure two-body force. The effects of three-body force and ground state correlations on the nucleon effective mass are also discussed

  14. Wave-particle dualism in matter wave interferometry

    International Nuclear Information System (INIS)

    Rauch, H.

    1984-01-01

    Neutron interferometry is a unique tool for investigations in the field of particle-wave dualism because massive elementary particles behave like waves within the interferometer. The invention of perfect crystal neutron interferometers providing widely separated coherent beams stimulated a great variety of experiments with matter waves in the field of basic quantum mechanics. The phase of the spatial and spinor wave function become a measurable quantity and can be influenced individually. High degrees of coherence and high order interferences have been observed by this technique. The 4π-symmetry of a spinor wave function and the mutual modulation of nuclear and magnetic phase shifts have been measured in the past. Recent experiments dealt with polarized neutron beams, which are handled to realize the spin-superposition of two oppositionally polarized subbeams resulting in final polarization perpendicular to both initial beam polarizations. The different action on the coherent beams of static and dynamic flippers have been visualized. Monolithic multicrystal arrangements in Laue position can also be used to achieve an extremely high energy (10 -9 eV) or angular resolution (0.001 sec of arc). This feature is based on the Pendelloesung interference within the perfect crystal. A transverse coherence length up to 6.5 mm is deduced from single slit diffraction experiments. (Auth.)

  15. Detecting particle dark matter signatures by cross-correlating γ-ray anisotropies with weak lensing

    Science.gov (United States)

    Camera, S.; Fornasa, M.; Fornengo, N.; Regis, M.

    2016-05-01

    The underlying nature of dark matter still represents one of the fundamental questions in contemporary cosmology. Although observations well agree with its description in terms of a new fundamental particle, neither direct nor indirect signatures of its particle nature have been detected so far, despite a strong experimental effort. Similarly, particle accelerators have hitherto failed at producing dark matter particles in collider physics experiments. Here, we illustrate how the cross-correlation between anisotropies in the diffuse γ-ray background and weak gravitational lensing effects represents a novel promising way in the quest of detecting particle dark matter signatures.

  16. Complementarity of DM searches in a consistent simplified model: the case of Z′

    International Nuclear Information System (INIS)

    Jacques, Thomas; Katz, Andrey; Morgante, Enrico; Racco, Davide; Rameez, Mohamed; Riotto, Antonio

    2016-01-01

    We analyze the constraints from direct and indirect detection on fermionic Majorana Dark Matter (DM). Because the interaction with the Standard Model (SM) particles is spin-dependent, a priori the constraints that one gets from neutrino telescopes, the LHC, direct and indirect detection experiments are comparable. We study the complementarity of these searches in a particular example, in which a heavy Z ′ mediates the interactions between the SM and the DM. We find that for heavy dark matter indirect detection provides the strongest bounds on this scenario, while IceCube bounds are typically stronger than those from direct detection. The LHC constraints are dominant for smaller dark matter masses. These light masses are less motivated by thermal relic abundance considerations. We show that the dominant annihilation channels of the light DM in the Sun and the Galactic Center are either bb̄ or tt̄, while the heavy DM annihilation is completely dominated by Zh channel. The latter produces a hard neutrino spectrum which has not been previously analyzed. We study the neutrino spectrum yielded by DM and recast IceCube constraints to allow proper comparison with constraints from direct and indirect detection experiments and LHC exclusions.

  17. Classroom Materials for Teaching "The Particle Nature of Matter." Practical Paper No. 173.

    Science.gov (United States)

    Pella, Milton O.; And Others

    This document presents the lesson plans and tests used in the research study reported in Technical Report 173 (ED 070 658), together with descriptions of models and films developed for the teaching program. Thirty-one lessons are included, covering the topics of matter and energy; making interferences; particles; a model for matter; particles and…

  18. Dark-Matter Particles without Weak-Scale Masses or Weak Interactions

    International Nuclear Information System (INIS)

    Feng, Jonathan L.; Kumar, Jason

    2008-01-01

    We propose that dark matter is composed of particles that naturally have the correct thermal relic density, but have neither weak-scale masses nor weak interactions. These models emerge naturally from gauge-mediated supersymmetry breaking, where they elegantly solve the dark-matter problem. The framework accommodates single or multiple component dark matter, dark-matter masses from 10 MeV to 10 TeV, and interaction strengths from gravitational to strong. These candidates enhance many direct and indirect signals relative to weakly interacting massive particles and have qualitatively new implications for dark-matter searches and cosmological implications for colliders

  19. Gravitino dark matter from increased thermal relic particles

    International Nuclear Information System (INIS)

    Okada, Nobuchika; Seto, Osamu

    2008-01-01

    We investigate the so-called superWIMP scenario with the gravitino as the lightest supersymmetric particle (LSP) in the context of nonstandard cosmology, in particular, brane world cosmology. As a candidate of the next-to-LSP (NLSP), we examine the slepton and the sneutrino. Brane world cosmological effects dramatically enhance the relic density of the slepton or sneutrino NLSP, so that the NLSP with mass of order 100 GeV can provide the correct abundance of gravitino dark matter through its decay. We find that with an appropriate five-dimensional Planck mass, this scenario can be realized consistently with the constraints from big bang nucleosynthesis for both NLSP candidates of the slepton and the sneutrino. The big bang nucleosynthesis constraints for the slepton NLSP are more stringent than that for the sneutrino; as the result, the gravitino must be rather warm in the slepton NLSP case. The energy density of the gravitino produced by thermal scattering is highly suppressed and negligible due to the brane world cosmological effects

  20. Survey of beta-particle interaction experiments with asymmetric matter

    Science.gov (United States)

    Van Horn, J. David; Wu, Fei

    2018-05-01

    Asymmetry is a basic property found at multiple scales in the universe. Asymmetric molecular interactions are fundamental to the operation of biological systems in both signaling and structural roles. Other aspects of asymmetry are observed and useful in many areas of science and engineering, and have been studied since the discovery of chirality in tartrate salts. The observation of parity violation in beta decay provided some impetus for later experiments using asymmetric particles. Here we survey historical work and experiments related to electron (e-) or positron (e+) polarimetry and their interactions with asymmetric materials in gas, liquid and solid forms. Asymmetric interactions may be classified as: 1) stereorecognition, 2) stereoselection and 3) stereoinduction. These three facets of physical stereochemistry are unique but interrelated; and examples from chemistry and materials science illustrate these aspects. Experimental positron and electron interactions with asymmetric materials may be classified in like manner. Thus, a qualitative assessment of helical and polarized positron experiments with different forms of asymmetric matter from the past 40 years is presented, as well as recent experiments with left-hand and right-hand single crystal quartz and organic compounds. The purpose of this classification and review is to evaluate the field for potential new experiments and directions for positron (or electron) studies with asymmetric materials.

  1. Probing the stability of superheavy dark matter particles with high-energy neutrinos

    International Nuclear Information System (INIS)

    Esmaili, Arman; Peres, O.L.G.

    2012-01-01

    Full text: There is currently mounting evidence for the existence of dark matter in our Universe from various astrophysical and cosmological observations, but the two of the most fundamental properties of the dark matter particle, the mass and the lifetime, are only weakly constrained by the astronomical and cosmological evidence of dark matter. We derive lower limits on the lifetime of dark matter particles with masses in the range 10 TeV - 10 18 GeV from the non-observation of ultrahigh energy neutrinos in the AMANDA, IceCube, Auger and ANITA experiments. All these experiments probe different energy windows and perfectly complement each other. For dark matter particles which produce neutrinos in a two body or a three body decay, we find that the dark matter lifetime must be longer than ∼ 10 26 s for masses between 10 TeV and the Grand Unification scale. We will consider various scenarios where the decay of the dark matter particle produces high energy neutrinos. Neutrinos travel in the Universe without suffering an appreciable attenuation, even for EeV neutrinos, in contrast to photons which rapidly lose their energy via pair production. This remarkable property makes neutrinos a very suitable messenger to constrain the lifetime of superheavy dark matter particles. Finally, we also calculate, for concrete particle physics scenarios, the limits on the strength of the interactions that induce the dark matter decay. (author)

  2. Probing the nature of dark matter particles with stellar streams

    OpenAIRE

    Banik, Nilanjan; Bertone, Gianfranco; Bovy, Jo; Bozorgnia, Nassim

    2018-01-01

    A key prediction of the standard cosmological model -- which relies on the assumption that dark matter is cold, i.e. non-relativistic at the epoch of structure formation -- is the existence of a large number of dark matter substructures on sub-galactic scales. This assumption can be tested by studying the perturbations induced by dark matter substructures on cold stellar streams. Here, we study the prospects for discriminating cold from warm dark matter by generating mock data for upcoming as...

  3. Softness of Nuclear Matter and the Production of Strange Particles in Neutron Stars

    Institute of Scientific and Technical Information of China (English)

    陈伟; 文德华; 刘良钢

    2003-01-01

    In the various models, we study the influences of the softness of nuclear matter, the vacuum fluctuation ofnucleons and σ mesons on the production of strange particles in neutron stars. Wefind that the stiffer the nuclear matter is, the more easily the strange particles is produced in neutron stars. The vacuum fluctuation of nucleons has large effect on strange particle production while that of σ meson has little effect on it.

  4. Active matter in silico : phase behaviour of attractive, repulsive and anisotropic self-propelled particles

    NARCIS (Netherlands)

    Prymidis, V.

    2017-01-01

    In this thesis we study emergent statistical properties of many-particle systems of self-propelled particles using computer simulations. Ensembles of self-propelled particles belong to the class of physical systems labeled active matter, a term that refers to systems whose individual components are

  5. Complementarity of DM Searches in a Consistent Simplified Model: the Case of Z'

    CERN Document Server

    Jacques, Thomas; Morgante, Enrico; Racco, Davide; Rameez, Mohamed; Riotto, Antonio

    2016-01-01

    We analyze the constraints from direct and indirect detection on fermionic Majorana Dark Matter (DM). Because the interaction with the Standard Model (SM) particles is spin-dependent, a priori the constraints that one gets from neutrino telescopes, the LHC and direct detection experiments are comparable. We study the complementarity of these searches in a particular example, in which a heavy $Z'$ mediates the interactions between the SM and the DM. We find that in most cases IceCube provides the strongest bounds on this scenario, while the LHC constraints are only meaningful for smaller dark matter masses. These light masses are less motivated by thermal relic abundance considerations. We show that the dominant annihilation channels of the light DM in the Sun are either $b \\bar b$ or $t \\bar t$, while the heavy DM annihilation is completely dominated by $Zh$ channel. The latter produces a hard neutrino spectrum which has not been previously analyzed. We study the neutrino spectrum yielded by DM and recast Ice...

  6. Dark clouds in particle physics and cosmology: the issues of dark matter and dark energy

    International Nuclear Information System (INIS)

    Zhang Xinmin

    2011-01-01

    Unveiling the nature of dark matter and dark energy is one of the main tasks of particle physics and cosmology in the 21st century. We first present an overview of the history and current status of research in cosmology, at the same time emphasizing the new challenges in particle physics. Then we focus on the scientific issues of dark energy, dark matter and anti-matter, and review the recent progress made in these fields. Finally, we discuss the prospects for future research on the experimental probing of dark matter and dark energy in China. (authors)

  7. Signatures of Earth-scattering in the direct detection of Dark Matter

    DEFF Research Database (Denmark)

    Kavanagh, Bradley J.; Catena, Riccardo; Kouvaris, Chris

    2017-01-01

    Direct detection experiments search for the interactions of Dark Matter (DM) particles with nuclei in terrestrial detectors. But if these interactions are sufficiently strong, DM particles may scatter in the Earth, affecting their distribution in the lab. We present a new analytic calculation...

  8. Constraints on dark matter particles charged under a hidden gauge group from primordial black holes

    International Nuclear Information System (INIS)

    Dai, De-Chang; Stojkovic, Dejan; Freese, Katherine

    2009-01-01

    In order to accommodate increasingly tighter observational constraints on dark matter, several models have been proposed recently in which dark matter particles are charged under some hidden gauge group. Hidden gauge charges are invisible for the standard model particles, hence such scenarios are very difficult to constrain directly. However black holes are sensitive to all gauge charges, whether they belong to the standard model or not. Here, we examine the constraints on the possible values of the dark matter particle mass and hidden gauge charge from the evolution of primordial black holes. We find that the existence of the primordial black holes with reasonable mass is incompatible with dark matter particles whose charge to mass ratio is of the order of one. For dark matter particles whose charge to mass ratio is much less than one, we are able to exclude only heavy dark matter in the mass range of 10 11 GeV–10 16 GeV. Finally, for dark matter particles whose charge to mass ratio is much greater than one, there are no useful limits coming from primordial black holes

  9. Constraints on the dark matter particle mass from the number of Milky Way satellites

    International Nuclear Information System (INIS)

    Polisensky, Emil; Ricotti, Massimo

    2011-01-01

    We have conducted N-body simulations of the growth of Milky Way-sized halos in cold and warm dark matter cosmologies. The number of dark matter satellites in our simulated Milky Ways decreases with decreasing mass of the dark matter particle. Assuming that the number of dark matter satellites exceeds or equals the number of observed satellites of the Milky Way, we derive lower limits on the dark matter particle mass. We find with 95% confidence m s >13.3 keV for a sterile neutrino produced by the Dodelson and Widrow mechanism, m s >8.9 keV for the Shi and Fuller mechanism, m s >3.0 keV for the Higgs decay mechanism, and m WDM >2.3 keV for a thermal dark matter particle. The recent discovery of many new dark matter dominated satellites of the Milky Way in the Sloan Digital Sky Survey allows us to set lower limits comparable to constraints from the complementary methods of Lyman-α forest modeling and x-ray observations of the unresolved cosmic x-ray background and of dark matter halos from dwarf galaxy to cluster scales. Future surveys like LSST, DES, PanSTARRS, and SkyMapper have the potential to discover many more satellites and further improve constraints on the dark matter particle mass.

  10. Asymmetric Dark Matter and Dark Radiation

    CERN Document Server

    Blennow, Mattias; Mena, Olga; Redondo, Javier; Serra, Paolo

    2012-01-01

    Asymmetric Dark Matter (ADM) models invoke a particle-antiparticle asymmetry, similar to the one observed in the Baryon sector, to account for the Dark Matter (DM) abundance. Both asymmetries are usually generated by the same mechanism and generally related, thus predicting DM masses around 5 GeV in order to obtain the correct density. The main challenge for successful models is to ensure efficient annihilation of the thermally produced symmetric component of such a light DM candidate without violating constraints from collider or direct searches. A common way to overcome this involves a light mediator, into which DM can efficiently annihilate and which subsequently decays into Standard Model particles. Here we explore the scenario where the light mediator decays instead into lighter degrees of freedom in the dark sector that act as radiation in the early Universe. While this assumption makes indirect DM searches challenging, it leads to signals of extra radiation at BBN and CMB. Under certain conditions, pre...

  11. Recent heavy-particle decay in a matter-dominated universe

    Energy Technology Data Exchange (ETDEWEB)

    Olive, K.A.; Seckel, D.; Vishniac, E.

    1985-05-01

    The cold-matter scenario for galaxy formation solves the dark-matter problem very nicely on small scales corresponding to galaxies and clusters of galaxies. It is, however, difficult to reconcile with a universe with an Einstein-deSitter value of ..cap omega.. = 1. We will show here that cold matter and ..cap omega.. = 1 can be made compatible while retaining the feature that the universe is matter-dominated today. This is done by means of heavy (cold) particles whose decay subsequently leads to the unbinding of a large fraction of lighter clustered matter.

  12. Recent heavy-particle decay in a matter-dominated universe

    International Nuclear Information System (INIS)

    Olive, K.A.; Seckel, D.; Vishniac, E.

    1985-01-01

    The cold-matter scenario for galaxy formation solves the dark-matter problem very nicely on small scales corresponding to galaxies and clusters of galaxies. It is, however, difficult to reconcile with a universe with an Einstein-deSitter value of Ω = 1. We will show here that cold matter and Ω = 1 can be made compatible while retaining the feature that the universe is matter-dominated today. This is done by means of heavy (cold) particles whose decay subsequently leads to the unbinding of a large fraction of lighter clustered matter

  13. Recent heavy-particle decay in a matter-dominated universe

    Science.gov (United States)

    Olive, K. A.; Seckel, D.; Vishniac, E.

    1985-05-01

    The cold-matter scenario for galaxy formation solves the dark-matter problem very nicely on small scales corresponding to galaxies and clusters of galaxies. It is, however, difficult to reconcile with a universe with an Einstein-deSitter value of Ω = 1. It is shown here that cold matter and Ω = 1 can be made compatible while retaining the feature that the universe is matter-dominated today. This is done by means of heavy (cold) particles whose decay subsequently leads to the unbinding of a large fraction of lighter clustered matter.

  14. Results on light dark matter particles with a low-threshold CRESST-II detector

    Energy Technology Data Exchange (ETDEWEB)

    Angloher, G.; Iachellini, N.F.; Hauff, D.; Kiefer, M.; Petricca, F.; Proebst, F.; Seidel, W.; Stodolsky, L.; Strauss, R.; Tanzke, A.; Wuestrich, M. [Max-Planck-Institut fuer Physik, Munich (Germany); Bento, A. [Universidade de Coimbra, Departamento de Fisica, Coimbra (Portugal); Bucci, C.; Canonica, L.; Gorla, P.; Pagliarone, C.; Schaeffner, K. [INFN, Laboratori Nazionali del Gran Sasso, Assergi (Italy); Defay, X.; Feilitzsch, F. von; Lanfranchi, J.C.; Muenster, A.; Potzel, W.; Schoenert, S.; Trinh Thi, H.H.; Ulrich, A.; Wawoczny, S.; Willers, M.; Zoeller, A. [Technische Universitaet Muenchen, Physik-Department and Excellence Cluster Universe, Garching (Germany); Erb, A. [Technische Universitaet Muenchen, Physik-Department and Excellence Cluster Universe, Garching (Germany); Walther-Meissner-Institut fuer Tieftemperaturforschung, Garching (Germany); Guetlein, A.; Kluck, H.; Schieck, J.; Tuerkoglu, C. [Institut fuer Hochenergiephysik der Oesterreichischen Akademie der Wissenschaften, Wien (Austria); Atominstitut, Vienna University of Technology, Wien (Austria); Jochum, J.; Loebell, J.; Strandhagen, C.; Uffinger, M.; Usherov, I. [Eberhard-Karls-Universitaet Tuebingen, Tuebingen (Germany); Kraus, H. [University of Oxford, Department of Physics, Oxford (United Kingdom); Reindl, F. [Max-Planck-Institut fuer Physik, Munich (Germany)

    2016-01-15

    The CRESST-II experiment uses cryogenic detectors to search for nuclear recoil events induced by the elastic scattering of dark matter particles in CaWO{sub 4} crystals. Given the low energy threshold of our detectors in combination with light target nuclei, low mass dark matter particles can be probed with high sensitivity. In this letter we present the results from data of a single detector module corresponding to 52 kg live days. A blind analysis is carried out. With an energy threshold for nuclear recoils of 307 eV we substantially enhance the sensitivity for light dark matter. Thereby, we extend the reach of direct dark matter experiments to the sub- GeV/c{sup 2} region and demonstrate that the energy threshold is the key parameter in the search for low mass dark matter particles. (orig.)

  15. Phenomenology of quintessino dark matter: Production of next lightest supersymmetric particles

    International Nuclear Information System (INIS)

    Bi Xiaojun; Wang Jianxiong; Zhang Chao; Zhang Xinmin

    2004-01-01

    In the model of quintessino as the dark matter particle, the dark matter and dark energy are unified in one superfield, where the dynamics of the Quintessence drives the Universe acceleration and its superpartner, quintessino, makes up the dark matter of the Universe. This scenario predicts the existence of long-lived τ-tilde as the next lightest supersymmetric particle. In this paper we study the possibility of detecting τ-tilde produced by the high energy cosmic neutrinos interacting with the earth matter. By a detailed calculation we find that the event rate is one to several hundred per year at a detector with an effective area of 1 km 2 . The study in this paper can be also applied to models of gravitino or axino dark matter particles

  16. Superweakly interacting massive particle dark matter signals from the early Universe

    International Nuclear Information System (INIS)

    Feng, Jonathan L.; Rajaraman, Arvind; Takayama, Fumihiro

    2003-01-01

    Cold dark matter may be made of superweakly interacting massive particles, super-WIMP's, that naturally inherit the desired relic density from late decays of metastable WIMP's. Well-motivated examples are weak-scale gravitinos in supergravity and Kaluza-Klein gravitons from extra dimensions. These particles are impossible to detect in all dark matter experiments. We find, however, that super-WIMP dark matter may be discovered through cosmological signatures from the early Universe. In particular, super-WIMP dark matter has observable consequences for big bang nucleosynthesis and the cosmic microwave background (CMB), and may explain the observed underabundance of 7 Li without upsetting the concordance between deuterium and CMB baryometers. We discuss the implications for future probes of CMB blackbody distortions and collider searches for new particles. In the course of this study, we also present a model-independent analysis of entropy production from late-decaying particles in light of Wilkinson microwave anisotropy probe data

  17. Direct detection of dark matter bound to the Earth

    DEFF Research Database (Denmark)

    Catena, Riccardo; Kouvaris, Chris

    2017-01-01

    We study the properties and direct detection prospects of an as of yet neglected population of dark matter (DM) particles moving in orbits gravitationally bound to the Earth. This DM population is expected to form via scattering by nuclei in the Earth's interior. We compute fluxes and nuclear...

  18. Impact of dark matter decays and annihilations on structure formation

    NARCIS (Netherlands)

    Mapelli, M.; Ripamonti, E.

    2007-01-01

    Abstract: We derived the evolution of the energy deposition in the intergalactic medium (IGM) by different decaying (or annihilating) dark matter (DM) candidates. Heavy annihilating DM particles (with mass larger than a few GeV) have no influence on reionization and heating, even if we assume that

  19. Impact of dark matter on reionization and heating

    NARCIS (Netherlands)

    Mapelli, M.; Ripamonti, E.

    2007-01-01

    Abstract: We derived the evolution of the energy deposition in the intergalactic medium (IGM) by different decaying (or annihilating) dark matter (DM) candidates. Heavy annihilating DM particles (with mass larger than a few GeV) have no influence on reionization and heating, even if we assume that

  20. Imperfect Dark Matter

    Energy Technology Data Exchange (ETDEWEB)

    Mirzagholi, Leila; Vikman, Alexander, E-mail: l.mirzagholi@physik.uni-muenchen.de, E-mail: alexander.vikman@lmu.de [Arnold Sommerfeld Center for Theoretical Physics, Ludwig Maximilian University Munich, Theresienstr. 37, Munich, D-80333 Germany (Germany)

    2015-06-01

    We consider cosmology of the recently introduced mimetic matter with higher derivatives (HD). Without HD this system describes irrotational dust—Dark Matter (DM) as we see it on cosmologically large scales. DM particles correspond to the shift-charges—Noether charges of the shifts in the field space. Higher derivative corrections usually describe a deviation from the thermodynamical equilibrium in the relativistic hydrodynamics. Thus we show that mimetic matter with HD corresponds to an imperfect DM which: i) renormalises the Newton's constant in the Friedmann equations, ii) has zero pressure when there is no extra matter in the universe, iii) survives the inflationary expansion which puts the system on a dynamical attractor with a vanishing shift-charge, iv) perfectly tracks any external matter on this attractor, v) can become the main (and possibly the only) source of DM, provided the shift-symmetry in the HD terms is broken during some small time interval in the radiation domination époque. In the second part of the paper we present a hydrodynamical description of general anisotropic and inhomogeneous configurations of the system. This imperfect mimetic fluid has an energy flow in the field's rest frame. We find that in the Eckart and in the Landau-Lifshitz frames the mimetic fluid possesses nonvanishing vorticity appearing already at the first order in the HD. Thus, the structure formation and gravitational collapse should proceed in a rather different fashion from the simple irrotational DM models.

  1. Imperfect Dark Matter

    International Nuclear Information System (INIS)

    Mirzagholi, Leila; Vikman, Alexander

    2015-01-01

    We consider cosmology of the recently introduced mimetic matter with higher derivatives (HD). Without HD this system describes irrotational dust—Dark Matter (DM) as we see it on cosmologically large scales. DM particles correspond to the shift-charges—Noether charges of the shifts in the field space. Higher derivative corrections usually describe a deviation from the thermodynamical equilibrium in the relativistic hydrodynamics. Thus we show that mimetic matter with HD corresponds to an imperfect DM which: i) renormalises the Newton's constant in the Friedmann equations, ii) has zero pressure when there is no extra matter in the universe, iii) survives the inflationary expansion which puts the system on a dynamical attractor with a vanishing shift-charge, iv) perfectly tracks any external matter on this attractor, v) can become the main (and possibly the only) source of DM, provided the shift-symmetry in the HD terms is broken during some small time interval in the radiation domination époque. In the second part of the paper we present a hydrodynamical description of general anisotropic and inhomogeneous configurations of the system. This imperfect mimetic fluid has an energy flow in the field's rest frame. We find that in the Eckart and in the Landau-Lifshitz frames the mimetic fluid possesses nonvanishing vorticity appearing already at the first order in the HD. Thus, the structure formation and gravitational collapse should proceed in a rather different fashion from the simple irrotational DM models

  2. Imperfect Dark Matter

    Science.gov (United States)

    Mirzagholi, Leila; Vikman, Alexander

    2015-06-01

    We consider cosmology of the recently introduced mimetic matter with higher derivatives (HD). Without HD this system describes irrotational dust—Dark Matter (DM) as we see it on cosmologically large scales. DM particles correspond to the shift-charges—Noether charges of the shifts in the field space. Higher derivative corrections usually describe a deviation from the thermodynamical equilibrium in the relativistic hydrodynamics. Thus we show that mimetic matter with HD corresponds to an imperfect DM which: i) renormalises the Newton's constant in the Friedmann equations, ii) has zero pressure when there is no extra matter in the universe, iii) survives the inflationary expansion which puts the system on a dynamical attractor with a vanishing shift-charge, iv) perfectly tracks any external matter on this attractor, v) can become the main (and possibly the only) source of DM, provided the shift-symmetry in the HD terms is broken during some small time interval in the radiation domination époque. In the second part of the paper we present a hydrodynamical description of general anisotropic and inhomogeneous configurations of the system. This imperfect mimetic fluid has an energy flow in the field's rest frame. We find that in the Eckart and in the Landau-Lifshitz frames the mimetic fluid possesses nonvanishing vorticity appearing already at the first order in the HD. Thus, the structure formation and gravitational collapse should proceed in a rather different fashion from the simple irrotational DM models.

  3. Annihilation physics of exotic galactic dark matter particles

    Science.gov (United States)

    Stecker, F. W.

    1990-01-01

    Various theoretical arguments make exotic heavy neutral weakly interacting fermions, particularly those predicted by supersymmetry theory, attractive candidates for making up the large amount of unseen gravitating mass in galactic halos. Such particles can annihilate with each other, producing secondary particles of cosmic-ray energies, among which are antiprotons, positrons, neutrinos, and gamma-rays. Spectra and fluxes of these annihilation products can be calculated, partly by making use of positron electron collider data and quantum chromodynamic models of particle production derived therefrom. These spectra may provide detectable signatures of exotic particle remnants of the big bang.

  4. Constraining particle dark matter using local galaxy distribution

    International Nuclear Information System (INIS)

    Ando, Shin’ichiro; Ishiwata, Koji

    2016-01-01

    It has been long discussed that cosmic rays may contain signals of dark matter. In the last couple of years an anomaly of cosmic-ray positrons has drawn a lot of attentions, and recently an excess in cosmic-ray anti-proton has been reported by AMS-02 collaboration. Both excesses may indicate towards decaying or annihilating dark matter with a mass of around 1–10 TeV. In this article we study the gamma rays from dark matter and constraints from cross correlations with distribution of galaxies, particularly in a local volume. We find that gamma rays due to inverse-Compton process have large intensity, and hence they give stringent constraints on dark matter scenarios in the TeV scale mass regime. Taking the recent developments in modeling astrophysical gamma-ray sources as well as comprehensive possibilities of the final state products of dark matter decay or annihilation into account, we show that the parameter regions of decaying dark matter that are suggested to explain the excesses are excluded. We also discuss the constrains on annihilating scenarios.

  5. Constraining Dark Matter using Mono-X, Dijet, and Dilepton Final States with the ATLAS Detector

    CERN Document Server

    Tolley, Emma; The ATLAS collaboration

    2017-01-01

    Weakly-coupled TeV-scale particles may mediate interactions between dark matter (DM) and Standard Model (SM) particles. DM production at colliders may be evident in “mono-X” topologies, and mediator production in in dijet and dilepton events. The latest results obtained by the ATLAS experiment are presented and interpreted following the LHC DM WG guidelines, with particular focus on the complementarity between different collider searches as well as direct detection experiments.

  6. New ideas for axion like particle dark matter search

    CERN Multimedia

    Betz, Michael; Zioutas, Konstantin

    2012-01-01

    In the context of finding suitable large magnets for RF and microwave axion search, the Tore supra ring had been proposed. This Tokamak which could probably be made available for DM search has a huge volume and a strong magnetic field (30000 liter and 4.5 Tesla). It appears on a first glance, as an interesting candidate for this kind of experiment. One can find a suitable microwave mode which meets the condition that the RF electric field is parallel to the magnetostatic field. The eigenfrequency field pattern and Q factor for this mode and a few adjacent ones are calculated the some field patterns shown graphically. The use of the torus type cavity is not restricted to the Tore Supra. It can in principle be applied to any torus type structure also scaled up toward smaller dimensions and higher frequencies. In the second part of the slide presentation some alternatives and other cavity magnet concepts are shown and discussed.

  7. Paul Scherrer Institut Scientific Report 2001. Volume I: Particles and Matter

    International Nuclear Information System (INIS)

    Gobrecht, J.; Gaeggeler, H.; Herlach, D.; Junker, K.; Kubik, P.; Meisel, E.; Zehnder, A.

    2002-03-01

    This scientific report comprises the activities of the following laboratories of PSI: for particle physics, for astrophysics, for muon spin spectroscopy, for micro- and nano- technology, for radio- and environmental chemistry,and for beam physics in the field of particles and matter sciences

  8. 5th International Heidelberg Conference on Dark Matter in Astro- and Particle Physics

    CERN Document Server

    Arnowitt, Richard; DARK 2004; Dark Matter in Astro- and Particle Physics

    2006-01-01

    The search for dark matter in the universe has established itself as one of the most exciting and central fields of astrophysics, particle physics and cosmology. The lectures and talks in this book emphasize the experimental and theoretical status and future perspectives, stressing in particular the interplay between astro- and particle physics.

  9. Dark matter particle production in b→s transitions with missing energy

    International Nuclear Information System (INIS)

    Bird, Chris; Jackson, Paul; Kowalewski, Robert; Pospelov, Maxim

    2004-01-01

    Dedicated underground experiments searching for dark matter have little sensitivity to GeV and sub-GeV masses of dark matter particles. We show that the decay of B mesons to K(K * ) and missing energy in the final state can be an efficient probe of dark matter models in this mass range. We analyze the minimal scalar dark matter model to show that the width of the decay mode with two dark matter scalars B→KSS may exceed the decay width in the standard model channel, B→Kνν-bar, by up to 2 orders of magnitude. Existing data from B physics experiments almost entirely exclude dark matter scalars with masses less than 1 GeV. Expected data from B factories probe the range of dark matter masses up to 2 GeV

  10. Intergalactic medium heating by dark matter

    NARCIS (Netherlands)

    Ripamonti, E.; Mapelli, M.; Ferrara, A.

    2006-01-01

    Abstract: We derive the evolution of the energy deposition in the intergalactic medium (IGM) by dark matter (DM) decays/annihilations for both sterile neutrinos and light dark matter (LDM) particles. At z > 200 sterile neutrinos transfer a fraction f_abs~0.5 of their rest mass energy into the IGM;

  11. Penetration of charged particles through ordered isotropic matter

    International Nuclear Information System (INIS)

    Sigmund, P.

    1977-01-01

    A brief summary of some new results on fluctuation phenomena in particle penetration is presented. The results include collision statistics, positive and negative correlations and a framework for the treatment of cumulative effects in particle penetration. Incorporation of projectile and target states in the description and energy-loss straggling are discussed. Small-angle multiple scattering is considered and a comment made on ionic charge states. (B.R.H.)

  12. Particle creation in a universe filled with radiation and dust-like matter

    International Nuclear Information System (INIS)

    Villalba, V.M.

    1993-01-01

    In this article the particle creation process of scalar and spin 1/2 particles in a spatially open cosmological model associated with a universe filled with radiation and dustlike matter is analyzed. The Klein-Gordon and the Dirac equations are solved via separation of variables. After comparing the in and out vacua, we obtain that the number of created particles corresponds to Planckian and Fermi-Dirac distributions for the scalar and Dirac cases respectively. (author)

  13. Ultraminimal technicolor and its dark matter technicolor interacting massive particles

    DEFF Research Database (Denmark)

    Ryttov, Thomas Aaby; Sannino, Francesco

    2008-01-01

    We introduce an explicit model with technifermion matter transforming according to multiple representations of the underlying technicolor gauge group. The model features simultaneously the smallest possible value of the naive S parameter and the smallest possible number of technifermions. The chi...... be sufficiently light to be directly produced and studied at the Large Hadron Collider (LHC)....

  14. Prospects for searching axion-like particle dark matter with dipole, toroidal and wiggler magnets

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Oliver K. [Yale Univ., New Haven, CT (United States). Dept. of Physics; Betz, Michael; Caspers, Fritz [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Jaeckel, Joerg [Institute for Particle Physics Phenomenology, Durham (United Kingdom); Lindner, Axel; Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Semertzidis, Yannis [Brookhaven National Lab., Upton, NY (United States); Sikivie, Pierre [Florida Univ., Gainesville, FL (United States). Dept. of Physics; Zioutas, Konstantin [Patras Univ. (Greece)

    2011-10-15

    In this work we consider searches for dark matter made of axions or axion-like particles (ALPs) using resonant radio frequency cavities inserted into dipole magnets from particle accelerators, wiggler magnets developed for accelerator based advanced light sources, and toroidal magnets similar to those used in particle physics detectors. We investigate the expected sensitivity of such ALP dark matter detectors and discuss the engineering aspects of building and tuning them. Brief mention is also made of even stronger field magnets that are becoming available due to improvements in magnetic technology. It is concluded that new experiments utilizing already existing magnets could greatly enlarge the mass region in searches for axion-like dark matter particles. (orig.)

  15. Prospects for searching axion-like particle dark matter with dipole, toroidal and wiggler magnets

    International Nuclear Information System (INIS)

    Baker, Oliver K.; Jaeckel, Joerg; Lindner, Axel; Ringwald, Andreas; Semertzidis, Yannis; Sikivie, Pierre

    2011-10-01

    In this work we consider searches for dark matter made of axions or axion-like particles (ALPs) using resonant radio frequency cavities inserted into dipole magnets from particle accelerators, wiggler magnets developed for accelerator based advanced light sources, and toroidal magnets similar to those used in particle physics detectors. We investigate the expected sensitivity of such ALP dark matter detectors and discuss the engineering aspects of building and tuning them. Brief mention is also made of even stronger field magnets that are becoming available due to improvements in magnetic technology. It is concluded that new experiments utilizing already existing magnets could greatly enlarge the mass region in searches for axion-like dark matter particles. (orig.)

  16. Constraints on the Dark Matter Particle Mass from the Number of Milky Way Satellites

    Science.gov (United States)

    2010-04-12

    assuming dark matter only simulations (we do not include the effect of baryons in our simulations). We adopted values for cosmological parameters from the...ar X iv :1 00 4. 14 59 v1 [ as tr o- ph .C O ] 9 A pr 2 01 0 Constraints on the Dark Matter Particle Mass from the Number of Milky Way...simulations of the growth of Milky Way-sized halos in cold and warm dark matter cosmologies. The number of dark matter satellites in our simulated Milky

  17. Signatures of Earth-scattering in the direct detection of Dark Matter

    DEFF Research Database (Denmark)

    Kavanagh, Bradley J.; Catena, Riccardo; Kouvaris, Chris

    2017-01-01

    Direct detection experiments search for the interactions of Dark Matter (DM) particles with nuclei in terrestrial detectors. But if these interactions are sufficiently strong, DM particles may scatter in the Earth, affecting their distribution in the lab. We present a new analytic calculation...... of this 'Earth-scattering' effect in the regime where DM particles scatter at most once before reaching the detector. We perform the calculation self-consistently, taking into account not only those particles which are scattered away from the detector, but also those particles which are deflected towards...... the detector. Taking into account a realistic model of the Earth and allowing for a range of DM-nucleon interactions, we present the EarthShadow code, which we make publicly available, for calculating the DM velocity distribution after Earth-scattering. Focusing on low-mass DM, we find that Earth...

  18. Unblinding the dark matter blind spots

    International Nuclear Information System (INIS)

    Han, Tao; Kling, Felix

    2017-01-01

    The dark matter (DM) blind spots in the Minimal Supersymmetric Standard Model (MSSM) refer to the parameter regions where the couplings of the DM particles to the Z-boson or the Higgs boson are almost zero, leading to vanishingly small signals for the DM direct detections. In this paper, we carry out comprehensive analyses for the DM searches under the blind-spot scenarios in MSSM. Guided by the requirement of acceptable DM relic abundance, we explore the complementary coverage for the theory parameters at the LHC, the projection for the future underground DM direct searches, and the indirect searches from the relic DM annihilation into photons and neutrinos. We find that (i) the spin-independent (SI) blind spots may be rescued by the spin-dependent (SD) direct detection in the future underground experiments, and possibly by the indirect DM detections from IceCube and SuperK neutrino experiments; (ii) the detection of gamma rays from Fermi-LAT may not reach the desirable sensitivity for searching for the DM blind-spot regions; (iii) the SUSY searches at the LHC will substantially extend the discovery region for the blind-spot parameters. As a result, the dark matter blind spots thus may be unblinded with the collective efforts in future DM searches.

  19. Getting the astrophysics and particle physics of dark matter out of next-generation direct detection experiments

    International Nuclear Information System (INIS)

    Peter, Annika H. G.

    2010-01-01

    The next decade will bring massive new data sets from experiments of the direct detection of weakly interacting massive particle dark matter. Mapping the data sets to the particle-physics properties of dark matter is complicated not only by the considerable uncertainties in the dark-matter model, but by its poorly constrained local distribution function (the 'astrophysics' of dark matter). I propose a shift in how to think about direct-detection data analysis. I show that by treating the astrophysical and particle-physics uncertainties of dark matter on equal footing, and by incorporating a combination of data sets into the analysis, one may recover both the particle physics and astrophysics of dark matter. Not only does such an approach yield more accurate estimates of dark-matter properties, but it may illuminate how dark matter coevolves with galaxies.

  20. The release of mineral matter and associated phosphorus as a function of the particle size coal

    Energy Technology Data Exchange (ETDEWEB)

    Claassens, V. [Sasol Technology Research & Development, Sasolburg (South Africa). Syngas & Coal Technologies

    2009-05-15

    The presence of phosphorus in carbon reductants is a major concern in the metallurgical industry. The behaviour of the phosphorus and mineral matter content (reported as ash) as a function of particle size was investigated. The primary aim of this study was to determine the reduction in phosphorus and mineral matter that occurred as the particle size decreased. A secondary aim was to determine how the phosphorus was distributed in the feed coal and to where it reported during floc-flotation. Results showed that the ash content decreased more rapidly than the phosphorus content as the mean particle size was reduced. It remains unclear why P-rejection is only half as effective as mineral matter rejection. Detailed liberation analysis of P-containing minerals is required to possibly explain this phenomenon.

  1. A New Form of Matter — Unmatter, Composed of Particles and Anti-Particles

    Directory of Open Access Journals (Sweden)

    Smarandache F.

    2005-04-01

    Full Text Available Besides matter and antimatter there must exist unmatter (as a new form of matter in accordance with the neutrosophy theory that between an entity and its opposite there exist intermediate entities . Unmatter is neither matter nor antimatter, but something in between. An atom of unmatter is formed either by (1: electrons, protons, and antineutrons, or by (2: antielectrons, antiprotons, and neutrons. At CERN it will be possible to test the production of unmatter. The existence of unmatter in the universe has a similar chance to that of the antimatter, and its production also difficult for present technologies.

  2. Physical considerations relevant to HZE-particle transport in matter.

    Science.gov (United States)

    Schimmerling, W

    1988-06-01

    High-energy, highly charged (HZE) heavy nuclei may seem at first sight to be an exotic type of radiation, only remotely connected with nuclear power generation. On closer examination it becomes evident that heavy-ion accelerators are being seriously considered for driving inertial confinement fusion reactors, and high-energy heavy nuclei in the cosmic radiation are likely to place significant constraints on satellite power system deployment and space-based power generation. The use of beams of heavy nuclei in an increasing number of current applications, as well as their importance for the development of the state of the art of the future, makes it necessary to develop at the same time a good understanding of their transport through matter.

  3. Relationship between particle matter and meteorological data in Canada

    Science.gov (United States)

    Bahrami, Azad; Memarian Fard, Mahsa; Bahrami, Ala

    2017-04-01

    The fine particulate matter (PM2.5) has a strong influence on the hydrological cycle, cloud formation, visibility, global climate, and human health. The meteorological conditions have important effects on PM2.5 mass concentration. Canada's National Air Pollution Surveillance (NAPS) network measures air pollutants at urban, suburban and rural locations in Canada. In this study, the point monthly relationships between meteorological data provided by Environment of Canada and PM2.5 mass concentration from January 1st, 2010 to December 31st, 2015 of fifteen speciation stations in Canada were analyzed. The correlation analysis results between PM2.5 concentrations and precipitation as well as surface pressure demonstrated a negative correlation. It should be noted that the correlation between temperature and special humidity with PM2.5 in cold seasons and warm seasons were negative and positive respectively. Moreover, the weak correlation between wind speed and PM2.5 were obtained.

  4. Search for weakly interacting massive particles with the Cryogenic Dark Matter Search experiment

    Energy Technology Data Exchange (ETDEWEB)

    Saab, Tarek [Stanford U.

    2002-01-01

    From individual galaxies, to clusters of galaxies, to in between the cushions of your sofa, Dark Matter appears to be pervasive on every scale. With increasing accuracy, recent astrophysical measurements, from a variety of experiments, are arriving at the following cosmological model : a flat cosmology (Ωk = 0) with matter and energy densities contributing roughly 1/3 and 2/3 (Ωm = 0.35, ΩΛ = 0.65). Of the matter contribution, it appears that only ~ 10% (Ωb ~ 0.04) is attributable to baryons. Astrophysical measurements constrain the remaining matter to be non-realtivistic, interacting primarily gravitationally. Various theoretical models for such Dark Matter exist. A leading candidate for the non-baryonic matter are Weakly Interacting Massive Particles (dubbed WIMPS). These particles, and their relic density may be naturally explained within the framework of Super-Symmetry theories. SuperSymmetry also offers predictions as to the scattering rates of WIMPs with baryonic matter allowing for the design and tailoring of experiments that search specifically for the WIMPs. The Cryogenic Dark Matter Search experiment is searching for evidence of WIMP interactions in crystals of Ge and Si. Using cryogenic detector technology to measure both the phonon and ionization response to a particle recoil the CDMS detectors are able to discriminate between electron and nuclear recoils, thus reducing the large rates of electron recoil backgrounds to levels with which a Dark Matter search is not only feasible, but far-reaching. This thesis will describe in some detail the physical principles behind the CDMS detector technology, highlighting the final step in the evolution of the detector design and characterization techniques. In addition, data from a 100 day long exposure of the current run at the Stanford Underground Facility will be presented, with focus given to detector performance as well as to the implications on allowable WIMP mass - cross-section parameter space.

  5. Phantom dark energy with varying-mass dark matter particles: Acceleration and cosmic coincidence problem

    International Nuclear Information System (INIS)

    Leon, Genly; Saridakis, Emmanuel N.

    2010-01-01

    We investigate several varying-mass dark matter particle models in the framework of phantom cosmology. We examine whether there exist late-time cosmological solutions, corresponding to an accelerating universe and possessing dark energy and dark matter densities of the same order. Imposing exponential or power-law potentials and exponential or power-law mass dependence, we conclude that the coincidence problem cannot be solved or even alleviated. Thus, if dark energy is attributed to the phantom paradigm, varying-mass dark matter models cannot fulfill the basic requirement that led to their construction.

  6. DEPFET detectors for direct detection of MeV dark matter particles

    Energy Technology Data Exchange (ETDEWEB)

    Baehr, A.; Ninkovic, J.; Treis, J. [Max-Planck-Gesellschaft Halbleiterlabor, Munich (Germany); Kluck, H.; Schieck, J. [Institut fuer Hochenergiephysik, Oesterreichische Akademie der Wissenschaften, Vienna (Austria); Atominstitut, Technische Universitaet Wien, Vienna (Austria)

    2017-12-15

    The existence of dark matter is undisputed, while the nature of it is still unknown. Explaining dark matter with the existence of a new unobserved particle is among the most promising possible solutions. Recently dark matter candidates in the MeV mass region received more and more interest. In comparison to the mass region between a few GeV to several TeV, this region is experimentally largely unexplored. We discuss the application of a RNDR DEPFET semiconductor detector for direct searches for dark matter in the MeV mass region. We present the working principle of the RNDR DEPFET devices and review the performance obtained by previously performed prototype measurements. The future potential of the technology as dark matter detector is discussed and the sensitivity for MeV dark matter detection with RNDR DEPFET sensors is presented. Under the assumption of six background events in the region of interest and an exposure of 1 kg year a sensitivity of about anti σ{sub e} = 10{sup -41} cm{sup 2} for dark matter particles with a mass of 10 MeV can be reached. (orig.)

  7. A particle dark matter footprint on the first generation of stars

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Ilídio [Centro Multidisciplinar de Astrofísica, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Silk, Joseph, E-mail: ilidio.lopes@ist.utl.pt, E-mail: silk@astro.ox.ac.uk [Institut d' Astrophysique de Paris, F-75014 Paris (France)

    2014-05-01

    Dark matter particles with properties identical to those of dark matter candidates hinted at by several international collaborations dedicated to the experimental detection of dark matter (DAMA, COGENT, CRESST, and CDMS-II, although not, most notably, by LUX), which also have a dark matter asymmetry that is identical to the observed baryon asymmetry (Planck and Wilkinson Microwave Anisotropy Probe), may produce a significant impact on the evolution of the first generation of low-metallicity stars. The lifetimes of these stars in different phases of stellar evolution are significantly extended, namely, in the pre-main sequence, main sequence, and red giant phases. In particular, intermediate-mass stars in the red giant phase experience significant changes in their luminosity and chemical composition. The annihilations of dark matter particles affect the interior of the star in such a way that the 3α reaction becomes less efficient in the production of carbon and oxygen. This dark matter effect contradicts the excess of carbon and other metals observed today in stars of low mass and low metallicity. Hence, we can impose an upper limit on the dark matter halo density, and therefore on the redshift, at which the first generation of low-metallicity stars formed.

  8. Quasi-particle description of strongly interacting matter: Towards a foundation

    International Nuclear Information System (INIS)

    Bluhm, M.; Kaempfer, B.; Schulze, R.; Seipt, D.

    2007-01-01

    We confront our quasi-particle model for the equation of state of strongly interacting matter with recent first-principle QCD calculations. In particular, we test its applicability at finite baryon densities by comparing with Taylor expansion coefficients of the pressure for two quark flavours. We outline a chain of approximations starting from the Φ-functional approach to QCD which motivates the quasi-particle picture. (orig.)

  9. CCDM model from quantum particle creation: constraints on dark matter mass

    International Nuclear Information System (INIS)

    Jesus, J.F.; Pereira, S.H.

    2014-01-01

    In this work the results from the quantum process of matter creation have been used in order to constrain the mass of the dark matter particles in an accelerated Cold Dark Matter model (Creation Cold Dark Matter, CCDM). In order to take into account a back reaction effect due to the particle creation phenomenon, it has been assumed a small deviation ε for the scale factor in the matter dominated era of the form t 2/3+ε . Based on recent H(z) data, the best fit values for the mass of dark matter created particles and the ε parameter have been found as m = 1.6× 10 3 GeV, restricted to a 68.3% c.l. interval of 1.5 < m < 6.3× 10 7 ) GeV and ε = -0.250 +0.15 -0.096 at 68.3% c.l. For these best fit values the model correctly recovers a transition from decelerated to accelerated expansion and admits a positive creation rate near the present era. Contrary to recent works in CCDM models where the creation rate was phenomenologically derived, here we have used a quantum mechanical result for the creation rate of real massive scalar particles, given a self consistent justification for the physical process. This method also indicates a possible solution to the so called ''dark degeneracy'', where one can not distinguish if it is the quantum vacuum contribution or quantum particle creation which accelerates the Universe expansion

  10. Internally mixed soot, sulfates, and organic matter in aerosol particles from Mexico City

    Science.gov (United States)

    Adachi, K.; Buseck, P. R.

    2008-05-01

    Soot particles are major aerosol constituents that result from emissions of burning of fossil fuel and biomass. Because they both absorb sunlight and contribute to cloud formation, they are an influence on climate on local, regional, and global scales. It is therefore important to evaluate their optical and hygroscopic properties and those effects on the radiation budget. Those properties commonly change through reaction with other particles or gases, resulting in complex internal mixtures. Using transmission electron microscopy, we measured ~8000 particles (25 samples) with aerodynamic diameters from 0.05 to 0.3 μm that were collected in March 2006 from aircraft over Mexico City (MC) and adjacent areas. More than 50% of the particles consist of internally mixed soot, organic matter, and sulfate. Imaging combined with chemical analysis of individual particles show that many are coated, consist of aggregates, or both. Coatings on soot particles can amplify their light absorption, and coagulation with sulfates changes their hygroscopic properties, resulting in shorter lifetime. Our results suggest that a mixture of materials from multiple sources such as vehicles, power plants, and biomass burning occurs in individual particles, thereby increasing their complexity. Through changes in their optical and hygroscopic properties, internally mixed soot particles have a greater effect on the regional climate than uncoated soot particles. Moreover, soot occurs in more than 60% of all particles in the MC plumes, suggesting its important role in the formation of secondary aerosol particles.

  11. Eureka! Physics of Particles, Matter and the Universe

    International Nuclear Information System (INIS)

    O'Sullivan, Colm T

    1997-01-01

    To provide a simple account of the whole of physics within 200 pages (excluding a glossary and index) of a small-format book is an extraordinarily ambitious project, yet this is what Roger Blin-Stoyle has attempted in Eureka! and, on the whole, he has succeeded admirably. Furthermore, he has achieved this without resorting to much more than a dozen mathematical expressions, most of them in the treatment of special relativity. To say that the account is comprehensive would be something of an understatement; this reviewer failed to detect a single topic, pure or applied, which could be described as part of mainstream physics which did not get at least a mention in these pages. The book is well written and the explanations are clear, as one would expect from an author who is an eminent scientist and who has given a professional lifetime to physics education and the promotion of the discipline. The reader should be warned, however, not to expect anything very radical - there are no novel treatments, no unique insights. The strength of the book lies in its clarity and compactness. The material is presented in a matter-of-fact manner with no forced emphasis on the exotic, so often a feature of recent attempts to present physics to the lay reader. The modern trend towards early specialization in physics courses in schools and universities has many unhappy consequences, not least of which is the loss of awareness of the essential unity of the subject. In this little book Professor Blin-Stoyle makes a valiant and welcome attempt to address the balance. Anyone with an interest in getting to know what is involved in that area of human knowledge we call physics could do a lot worse than start here. (book review)

  12. Impacts of dark matter particle annihilation on recombination and the anisotropies of the cosmic microwave background

    International Nuclear Information System (INIS)

    Zhang Le; Chen Xuelei; Lei Yian; Si Zongguo

    2006-01-01

    The recombination history of the Universe provides a useful tool for constraining the annihilation of dark matter particles. Even a small fraction of dark matter particles annihilated during the cosmic dark age can provide sufficient energy to affect the ionization state of the baryonic gas. Although this effect is too small for neutralinos, lighter dark matter particle candidates, e.g. with mass of 1-100 MeV, which was proposed recently to explain the observed excess of positrons in the galactic center, may generate observable differences in the cosmic microwave background (CMB) temperature and polarization anisotropies. The annihilations at the era of recombination affects mainly the CMB anisotropy at small angular scales (large l), and is distinctively different from the effect of early reionization. We perform a multiparameter analysis of the CMB data, including both the Wilkinson Microwave Anisotropy Probe (WMAP) first year and three year data, and the ACBAR, Boomerang, CBI, and VSA data. Assuming that the observed excess of e + e - pairs in the galactic center region is produced by dark matter annihilation, and that a sizable fraction of the energy produced in the annihilation is deposited in the baryonic gas during recombination, we obtain a 95% dark matter mass limit of M<8 MeV with the current data set

  13. Exotic particles at the LHC. Production via the Higgs portal and WIMP dark matter searches

    Energy Technology Data Exchange (ETDEWEB)

    Hessler, Andre Georg

    2016-09-05

    This thesis addresses two different aspects of the search for Physics Beyond the Standard Model at the Large Hadron Collider (LHC). First, and motivated by the recent discovery of a new interaction mediated by the Higgs boson, we systematically analyze the impact of the Higgs interaction on the production of new particles at the LHC. Second, we investigate the collider signatures of long-lived particles decaying into leptons and invisible energy, and which are predicted to exist in a class of neutrino mass models with a weakly interacting dark matter particle.

  14. Predicting soil particle density from clay and soil organic matter contents

    DEFF Research Database (Denmark)

    Schjønning, Per; McBride, R.A.; Keller, T.

    2017-01-01

    Soil particle density (Dp) is an important soil property for calculating soil porosity expressions. However, many studies assume a constant value, typically 2.65Mgm−3 for arable, mineral soils. Fewmodels exist for the prediction of Dp from soil organic matter (SOM) content. We hypothesized...

  15. Single Particle Potential of a Σ Hyperon in Nuclear Matter. II Rearrangement Effects

    International Nuclear Information System (INIS)

    Dabrowski, J.

    2000-01-01

    The rearrangement contribution to the real part of the single particle potential of a Σ hyperon in nuclear matter, U Σ , is investigated. The isospin and spin dependent parts of U Σ are considered. Results obtained for four models of the Nijmegen baryon-baryon interaction are presented and discussed. (author)

  16. Time scales for spinodal decomposition in nuclear matter with pseudo-particle model

    Energy Technology Data Exchange (ETDEWEB)

    Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F.

    1993-12-31

    Dynamical instabilities arising from fluctuations in the spinodal zone for nuclear matter are studied using a large variety of zero range interactions in the frame of a pseudo-particle model. Scale times for spinodal decomposition are extracted and a possible link with decomposition in real heavy-ion collisions is discussed. (author) 12 refs.; 6 figs.; 1 tab.

  17. Time scales for spinodal decomposition in nuclear matter with pseudo-particle model

    International Nuclear Information System (INIS)

    Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F.

    1993-01-01

    Dynamical instabilities arising from fluctuations in the spinodal zone for nuclear matter are studied using a large variety of zero range interactions in the frame of a pseudo-particle model. Scale times for spinodal decomposition are extracted and a possible link with decomposition in real heavy-ion collisions is discussed. (author) 12 refs.; 6 figs.; 1 tab

  18. Teaching the Conceptual Scheme "The Particle Nature of Matter" in the Elementary School.

    Science.gov (United States)

    Pella, Milton O.; And Others

    Conclusions of an extensive project aimed to prepare lessons and associated materials related to teaching concepts included in the scheme "The Particle Nature of Matter" for grades two through six are presented. The hypothesis formulated for the project was that children in elementary schools can learn theoretical concepts related to the particle…

  19. Search for Higgs portal DM at the ILC

    Energy Technology Data Exchange (ETDEWEB)

    Ko, P. [School of Physics, KIAS,Seoul 02455 (Korea, Republic of); Quantum Universe Center, KIAS,Seoul 02455 (Korea, Republic of); Yokoya, Hiroshi [Quantum Universe Center, KIAS,Seoul 02455 (Korea, Republic of)

    2016-08-18

    Higgs portal dark matter (DM) models are simple interesting and viable DM models. There are three types of the models depending on the DM spin: scalar, fermion and vector DM models. In this paper, we consider renormalizable, unitary and gauge invariant Higgs portal DM models, and study how large parameter regions can be surveyed at the International Linear Collider (ILC) experiment at √s=500 GeV. For the Higgs portal singlet fermion and vector DM cases, the force mediator involves two scalar propagators, the SM-like Higgs boson and the dark Higgs boson. We show that their interference generates interesting and important patterns in the mono-Z plus missing E{sub T} signatures at the ILC, and the results are completely different from those obtained from the Higgs portal DM models within the effective field theories. In addition, we show that it would be possible to distinguish the spin of DM in the Higgs portal scenarios, if the shape of the recoil-mass distribution is observed. We emphasize that the interplay between these collider observations and those in the direct detection experiments has to be performed in the model with renomalizability and unitarity to combine the model analyses in different scales.

  20. What is modified gravity and how to differentiate it from particle dark matter?

    Energy Technology Data Exchange (ETDEWEB)

    Calmet, Xavier; Kuntz, Ibere [University of Sussex, Physics and Astronomy, Brighton (United Kingdom)

    2017-02-15

    An obvious criterion to classify theories of modified gravity is to identify their gravitational degrees of freedom and their coupling to the metric and the matter sector. Using this simple idea, we show that any theory which depends on the curvature invariants is equivalent to general relativity in the presence of new fields that are gravitationally coupled to the energy-momentum tensor. We show that they can be shifted into a new energy-momentum tensor. There is no a priori reason to identify these new fields as gravitational degrees of freedom or matter fields. This leads to an equivalence between dark matter particles gravitationally coupled to the standard model fields and modified gravity theories designed to account for the dark matter phenomenon. Due to this ambiguity, it is impossible to differentiate experimentally between these theories and any attempt of doing so should be classified as a mere interpretation of the same phenomenon. (orig.)

  1. Natural Dark Matter from an unnatural Higgs boson and new colored particles at the TeV scale

    International Nuclear Information System (INIS)

    Pierce, Aaron; Thaler, Jesse

    2007-01-01

    The thermal relic abundance of Dark Matter motivates the existence of new electroweak scale particles, independent of naturalness considerations. However, most unnatural Dark Matter models do not ensure the presence of new particles charged under SU(3) C , resulting in challenging LHC phenomenology. Here, we present a class of models with scalar electroweak doublet Dark Matter that require a host of colored particles at the TeV scale. In these models, the Higgs boson is apparently fine-tuned, but the Dark Matter doublet is kept light without any additional fine-tuning

  2. Fermionic dark matter in a simple t-channel model

    International Nuclear Information System (INIS)

    Goyal, Ashok; Kumar, Mukesh

    2016-01-01

    We consider a fermionic dark matter (DM) particle in renormalizable Standard Model (SM) gauge interactions in a simple t-channel model. The DM particle interactions with SM fermions is through the exchange of scalar and vector mediators which carry colour or lepton number. In the case of coloured mediators considered in this study, we find that if the DM is thermally produced and accounts for the observed relic density almost the entire parameter space is ruled out by the direct detection observations. The bounds from the monojet plus missing energy searches at the Large Hadron Collider are less stringent in this case. In contrast for the case of Majorana DM, we obtain strong bounds from the monojet searches which rule out DM particles of mass less than about a few hundred GeV for both the scalar and vector mediators.

  3. Interacting dark matter disguised as warm dark matter

    International Nuclear Information System (INIS)

    Boehm, Celine; Riazuelo, Alain; Hansen, Steen H.; Schaeffer, Richard

    2002-01-01

    We explore some of the consequences of dark-matter-photon interactions on structure formation, focusing on the evolution of cosmological perturbations and performing both an analytical and a numerical study. We compute the cosmic microwave background anisotropies and matter power spectrum in this class of models. We find, as the main result, that when dark matter and photons are coupled, dark matter perturbations can experience a new damping regime in addition to the usual collisional Silk damping effect. Such dark matter particles (having quite large photon interactions) behave like cold dark matter or warm dark matter as far as the cosmic microwave background anisotropies or matter power spectrum are concerned, respectively. These dark-matter-photon interactions leave specific imprints at sufficiently small scales on both of these two spectra, which may allow us to put new constraints on the acceptable photon-dark-matter interactions. Under the conservative assumption that the abundance of 10 12 M · galaxies is correctly given by the cold dark matter, and without any knowledge of the abundance of smaller objects, we obtain the limit on the ratio of the dark-matter-photon cross section to the dark matter mass σ γ-DM /m DM -6 σ Th /(100 GeV)≅6x10 -33 cm 2 GeV -1

  4. Second Graders' Emerging Particle Models of Matter in the Context of Learning through Model-Based Inquiry

    Science.gov (United States)

    Samarapungavan, Ala; Bryan, Lynn; Wills, Jamison

    2017-01-01

    In this paper, we present a study of second graders' learning about the nature of matter in the context of content-rich, model-based inquiry instruction. The goal of instruction was to help students learn to use simple particle models to explain states of matter and phase changes. We examined changes in students' ideas about matter, the coherence…

  5. Atmospheric fate of oil matter adsorbed on sea salt particles under UV light

    Science.gov (United States)

    Vaitilingom, M.; Avij, P.; Huang, H.; Valsaraj, K. T.

    2014-12-01

    The presence of liquid petroleum hydrocarbons at the sea water surface is an important source of marine pollution. An oil spill in sea-water will most likely occur due to an involuntary accident from tankers, offshore platforms, etc. However, a large amount of oil is also deliberately spilled in sea-water during the clean-out process of tank vessels (e.g. for the Mediterranean Sea, 490,000 tons/yr). Moreover, the pollution caused by an oil spill does not only affect the aquatic environment but also is of concern for the atmospheric environment. A portion of the oil matter present at the sea-water surface is transported into the atmosphere viaevaporation and adsorption at the surface of sea spray particles. Few studies are related to the presence of oil matter in airborne particles resulting from their adsorption on sea salt aerosols. We observed that the non-volatile oil matter was adsorbed at the surface of sea-salt crystals (av. size of 1.1 μm). Due to their small size, these particles can have a significant residence time in the atmosphere. The hydrocarbon matter adsorbed at the surface of these particles can also be transformed by catalyzers present in the atmosphere (i.e. UV, OH, O3, ...). In this work, we focused on the photo-oxidation rates of the C16 to C30alkanes present in these particles. We utilized a bubble column reactor, which produced an abundance of small sized bubbles. These bubbles generated droplets upon bursting at the air-salt water interface. These droplets were then further dried up and lifted to the top of the column where they were collected as particles. These particles were incubated in a controlled reactor in either dark conditions or under UV-visible light. The difference of alkane content analyzed by GC-MS between the particles exposed to UV or the particles not exposed to UV indicated that up to 20% in mass was lost after 20 min of light exposure. The degradation kinetics varied for each range of alkanes (C16-20, C21-25, C26

  6. Dark matter physics, flavor physics and LHC constraints in the dark matter model with a bottom partner

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Tomohiro [Institute for Advanced Research, Nagoya University,Nagoya 464-8602 (Japan); Kobayashi-Maskawa Institute for the Origin of Particles and the Universe,Nagoya University, Nagoya 464-8602 (Japan); Kawamura, Junichiro [Department of Physics, Waseda University,Tokyo 169-8555 (Japan); Okawa, Shohei [Department of Physics, Nagoya University,Nagoya 464-8602 (Japan); Omura, Yuji [Kobayashi-Maskawa Institute for the Origin of Particles and the Universe,Nagoya University, Nagoya 464-8602 (Japan)

    2017-03-10

    In the scenario that dark matter (DM) is a weakly interacting massive particle, there are many possibilities of the interactions with the Standard Model (SM) particles to achieve the relic density of DM. In this paper, we consider a simple DM model where the DM candidate is a complex scalar boson. The model contains a new complex gauge singlet scalar boson and a new fermion whose gauge charge is the same as the right-handed down-type quark. We dub the new fermion the bottom partner. These new particles have Yukawa interactions with the SM down-type quarks. The DM candidate interacts with the SM particles through the Yukawa interactions. The Yukawa interactions are not only relevant to the annihilation process of the DM but also contribute to the flavor physics, such as the ΔF=2 processes. In addition, the flavor alignment of the Yukawa couplings is related to the decay modes of the bottom partner, and thus we can find the explicit correlations among the physical observables in DM physics, flavor physics, and the signals at the LHC. We survey the ΔF=2 processes based on the numerical analyses of the thermal relic density, the direct detection of the DM, and the current LHC bounds. We investigate the perturbative bound on the Yukawa coupling as well. A Study of a fermionic DM model with extra scalar quarks is also given for comparison.

  7. Particle-beam driven inertial confinement fusion. A theoretical approach of the particle beam-matter interaction

    International Nuclear Information System (INIS)

    Duborgel, Bernard; Dufour, J.M.; Fedotoff, Michel; Gouard, Philippe.

    1981-11-01

    A major difficulty in the relativistic electron beam (REB) inertial confinement approach is the low REB-target coupling resulting from long electron range in the matter. The beam stagnation mechanism, induced in a thin target by macroscopic electric and magnetic fields, can appreciably enhance this coupling. The chapter 2 of the rapport contributes to the theoretical study of this effect. Models and numerical programs are described, which permit to establish the characteristics of this mechanism and evaluate the role of the various parameters. These models were used to interpret thin foils heating experiments performed on CHANTECLAIR generator at the Centre of Valduc. The orientation of particle research to the light ions beams (LIB) has to led to an intensive study of ions-matter interaction. DEPION model described in chapter 3 of the report provides an evaluation of energy deposition characteristics for any ion incident upon a target, taking into account their evolution during the plasma heating phase [fr

  8. DM Considerations for Deep Drilling

    OpenAIRE

    Dubois-Felsmann, Gregory

    2016-01-01

    An outline of the current situation regarding the DM plans for the Deep Drilling surveys and an invitation to the community to provide feedback on what they would like to see included in the data processing and visualization of these surveys.

  9. 12 billion DM for Germany

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The German atomic industry has achieved the break-through to the world market: Brazil orders eight nuclear electricity generating plants from Siemens-AEG daughter Kraftwerk-Union. US concerns attacked the twelve billion DM deal, the biggest export order in the history of German industry. Without avail - the contract is to be signed in Bonn this week. (orig./LH) [de

  10. Effects of particle size and dry matter content of a total mixed ration on intraruminal equilibration and net portal flux of volatile fatty acids in lactating dairy cows

    DEFF Research Database (Denmark)

    Storm, Adam Christian; Kristensen, Niels Bastian

    2010-01-01

    Effects of physical changes in consistency of ruminal contents on intraruminal equilibration and net portal fluxes of volatile fatty acids (VFA) in dairy cows were studied. Four Danish Holstein cows (121 ± 17 d in milk, 591 ± 24 kg of body weight, mean ± SD) surgically fitted with a ruminal cannula...... and permanent indwelling catheters in the major splanchnic blood vessels were used. The experimental design was a 4 × 4 Latin square with a 2 × 2 factorial design of treatments. Treatments differed in forage (grass hay) particle size (FPS; 3.0 and 30 mm) and feed dry matter (DM) content of the total mixed...... ration (44.3 and 53.8%). The feed DM did not affect chewing time, ruminal variables, or net portal flux of VFA. However, decreasing the FPS decreased the overall chewing and rumination times by 151 ± 55 and 135 ± 29 min/d, respectively. No effect of the reduced chewing time was observed on ruminal p...

  11. Possible interaction between baryons and dark-matter particles revealed by the first stars

    Science.gov (United States)

    Barkana, Rennan

    2018-03-01

    The cosmic radio-frequency spectrum is expected to show a strong absorption signal corresponding to the 21-centimetre-wavelength transition of atomic hydrogen around redshift 20, which arises from Lyman-α radiation from some of the earliest stars. By observing this 21-centimetre signal—either its sky-averaged spectrum or maps of its fluctuations, obtained using radio interferometers—we can obtain information about cosmic dawn, the era when the first astrophysical sources of light were formed. The recent detection of the global 21-centimetre spectrum reveals a stronger absorption than the maximum predicted by existing models, at a confidence level of 3.8 standard deviations. Here we report that this absorption can be explained by the combination of radiation from the first stars and excess cooling of the cosmic gas induced by its interaction with dark matter. Our analysis indicates that the spatial fluctuations of the 21-centimetre signal at cosmic dawn could be an order of magnitude larger than previously expected and that the dark-matter particle is no heavier than several proton masses, well below the commonly predicted mass of weakly interacting massive particles. Our analysis also confirms that dark matter is highly non-relativistic and at least moderately cold, and primordial velocities predicted by models of warm dark matter are potentially detectable. These results indicate that 21-centimetre cosmology can be used as a dark-matter probe.

  12. Possible interaction between baryons and dark-matter particles revealed by the first stars.

    Science.gov (United States)

    Barkana, Rennan

    2018-02-28

    The cosmic radio-frequency spectrum is expected to show a strong absorption signal corresponding to the 21-centimetre-wavelength transition of atomic hydrogen around redshift 20, which arises from Lyman-α radiation from some of the earliest stars. By observing this 21-centimetre signal-either its sky-averaged spectrum or maps of its fluctuations, obtained using radio interferometers-we can obtain information about cosmic dawn, the era when the first astrophysical sources of light were formed. The recent detection of the global 21-centimetre spectrum reveals a stronger absorption than the maximum predicted by existing models, at a confidence level of 3.8 standard deviations. Here we report that this absorption can be explained by the combination of radiation from the first stars and excess cooling of the cosmic gas induced by its interaction with dark matter. Our analysis indicates that the spatial fluctuations of the 21-centimetre signal at cosmic dawn could be an order of magnitude larger than previously expected and that the dark-matter particle is no heavier than several proton masses, well below the commonly predicted mass of weakly interacting massive particles. Our analysis also confirms that dark matter is highly non-relativistic and at least moderately cold, and primordial velocities predicted by models of warm dark matter are potentially detectable. These results indicate that 21-centimetre cosmology can be used as a dark-matter probe.

  13. Detecting Boosted Dark Matter from the Sun with Large Volume Neutrino Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Joshua; /SLAC; Cui, Yanou; /Perimeter Inst. Theor. Phys.; Zhao, Yue; /Stanford U., ITP /Stanford U., Phys. Dept.

    2015-04-02

    We study novel scenarios where thermal dark matter (DM) can be efficiently captured in the Sun and annihilate into boosted dark matter. In models with semi-annihilating DM, where DM has a non-minimal stabilization symmetry, or in models with a multi-component DM sector, annihilations of DM can give rise to stable dark sector particles with moderate Lorentz boosts. We investigate both of these possibilities, presenting concrete models as proofs of concept. Both scenarios can yield viable thermal relic DM with masses O(1)-O(100) GeV. Taking advantage of the energetic proton recoils that arise when the boosted DM scatters off matter, we propose a detection strategy which uses large volume terrestrial detectors, such as those designed to detect neutrinos or proton decays. In particular, we propose a search for proton tracks pointing towards the Sun. We focus on signals at Cherenkov-radiation-based detectors such as Super-Kamiokande (SK) and its upgrade Hyper-Kamiokande (HK). We find that with spin-dependent scattering as the dominant DM-nucleus interaction at low energies, boosted DM can leave detectable signals at SK or HK, with sensitivity comparable to DM direct detection experiments while being consistent with current constraints. Our study provides a new search path for DM sectors with non-minimal structure.

  14. Dynamics of Dissolved Organic Matter and Microbes in Seawater through Sub-Micron Particle Size Analyses

    Digital Repository Service at National Institute of Oceanography (India)

    Goes, J.I.; Balch, W.M.; Vaughn, J.M.; Gomes, H.R.

    -78. Hansell, D.A. and Carlson, C.A., (1998) Deep-ocean gradients in the concentration of dissolved organic carbon. Nature, 395, 263-266. J. E. (1977) Characterization of suspended matter in the Gulf of Mexico ? II. Particles size analysis of suspended matter.... and Morris, I. (1980) Extracellular release of carbon by marine phytoplankton: a physiological approach. Limnol. Oceanogr., 25, 262-279. Maurer, L. G. (1976) Organic polymers in seawater: changes with depth in the Gulf of Mexico. Deep-Sea Res., 23, 1059...

  15. Nuclear matter with a pseudo-particle model: static bulk and surface properties

    International Nuclear Information System (INIS)

    Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F.

    1993-01-01

    Direct calculations of cold and hot nuclear matter (bulk and surface properties) are carried out within the frame of a pseudo-particle model using a gaussian decomposition of the distribution function. Comparisons with Hartree-Fock calculations, for a large class of effective interactions, show that such a model is reliable to reproduce accurately the equation of state of nuclear matter for large ranges of densities and temperatures. The number of gaussians per nucleon and the gaussian widths are critical parameters in that semi-classical model. (orig.)

  16. Nuclear matter with pseudo-particle model: static bulk and surface properties

    Energy Technology Data Exchange (ETDEWEB)

    Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F.

    1993-12-31

    Direct calculations of cold and hot nuclear matter (bulk and surface properties) are carried out within the frame of a pseudo-particle model using a Gaussian decomposition of the distribution function. Comparisons with Hartree-Fock calculations, for a large class of effective interactions, show that such a model is reliable to reproduce accurately the equation of state of nuclear matter for large ranges of densities and temperatures. The number of Gaussian per nucleon and the Gaussian widths are critical parameters in that semi-classical model. (author) 13 refs.; 9 figs.; 2 tabs.

  17. Nuclear matter with pseudo-particle model: static bulk and surface properties

    International Nuclear Information System (INIS)

    Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F.

    1993-01-01

    Direct calculations of cold and hot nuclear matter (bulk and surface properties) are carried out within the frame of a pseudo-particle model using a Gaussian decomposition of the distribution function. Comparisons with Hartree-Fock calculations, for a large class of effective interactions, show that such a model is reliable to reproduce accurately the equation of state of nuclear matter for large ranges of densities and temperatures. The number of Gaussian per nucleon and the Gaussian widths are critical parameters in that semi-classical model. (author) 13 refs.; 9 figs.; 2 tabs

  18. Nuclear matter with a pseudo-particle model: static bulk and surface properties

    Energy Technology Data Exchange (ETDEWEB)

    Idier, D. (Lab. de Physique Nucleaire CNRS/IN2P3, Univ. de Nantes (France)); Benhassine, B. (Lab. de Physique Nucleaire CNRS/IN2P3, Univ. de Nantes (France)); Farine, M. (Lab. de Physique Nucleaire CNRS/IN2P3, Univ. de Nantes (France)); Remaud, B. (Lab. de Physique Nucleaire CNRS/IN2P3, Univ. de Nantes (France)); Sebille, F. (Lab. de Physique Nucleaire CNRS/IN2P3, Univ. de Nantes (France))

    1993-11-15

    Direct calculations of cold and hot nuclear matter (bulk and surface properties) are carried out within the frame of a pseudo-particle model using a gaussian decomposition of the distribution function. Comparisons with Hartree-Fock calculations, for a large class of effective interactions, show that such a model is reliable to reproduce accurately the equation of state of nuclear matter for large ranges of densities and temperatures. The number of gaussians per nucleon and the gaussian widths are critical parameters in that semi-classical model. (orig.)

  19. Ionization history of the universe as a test for superheavy dark matter particles

    International Nuclear Information System (INIS)

    Doroshkevich, A.G.; Naselsky, P.D.

    2002-01-01

    In this paper we discuss the possible distortions of the ionization history of the universe caused by an injection of nonthermal energy due to decays of hypothetical superheavy dark matter (SHDM) particles. These particles are usually considered as a possible source of ultrahigh energy cosmic rays in the framework of the top-down model. Estimates of the fraction of energy of decays converted to the UV range show that, for suitable parameters of the SHDM particles, significant distortions of the power spectra of the cosmic microwave background anisotropy appear. A comparison with the observed power spectrum allows us to restrict some properties of the SHDM particles. These decays can also increase by about 5-10 times the degree of ionization of hydrogen at redshifts z∼10-50, which essentially accelerates the formation of molecules of H 2 and the first stars during the 'dark ages'

  20. Dark Radiation or Warm Dark Matter from long lived particle decays in the light of Planck

    International Nuclear Information System (INIS)

    Di Bari, Pasquale; King, Stephen F.; Merle, Alexander

    2013-01-01

    Although Planck data supports the standard ΛCDM model, it still allows for the presence of Dark Radiation corresponding up to about half an extra standard neutrino species. We propose a scenario for obtaining a fractional “effective neutrino species” from a thermally produced particle which decays into a much lighter stable relic plus standard fermions. At lifetimes much longer than ∼1 s, both the relic particles and the non-thermal neutrino component contribute to Dark Radiation. By increasing the stable-to-unstable particle mass ratio, the relic particle no longer acts as Dark Radiation but instead becomes a candidate for Warm Dark Matter with mass O(1 keV–100 GeV). In both cases it is possible to address the lithium problem

  1. Direct and Indirect Dark Matter Detection in Gauge Theories

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Farinaldo [Federal Univ. of Paraba (Brazil)

    2013-01-01

    The Dark matter (DM) problem constitutes a key question at the interface among Particle Physics, Astrophysics and Cosmology. The observational data which have been accumulated in the last years point to an existence of non baryonic amount of DM. Since the Standard Model (SM) does not provide any candidate for such non-baryonic DM, the evidence of DM is a major indication for new physics beyond the SM. We will study in this work one of the most popular DM candidates, the so called WIMPs (Weakly Interacting Massive Particles) from a direct and indirect detection perspective. In order to approach the direct and indirect dection of DM in the context of Particle Physics in a more pedagogic way, we will begin our discussion talking about a minimal extension of the SM. Later we will work on the subject in a 3-3-1 model. Next, we will study the role of WIMPs in the Big Bang Nucleosynthesis. Lastly, we will look for indirect DM signals in the center of our galaxy using the NASA Satellite, called Fermi-LAT. Through a comprehensive analysis of the data events observed by Fermi-LAT and some background models, we will constrain the dark matter annihilation cross section for several annihilation channels and dark matter halo profiles.

  2. Salamfestschrift. A collection of talks from the conference on highlights of particle and condensed matter physics

    International Nuclear Information System (INIS)

    Ali, A.; Ellis, J.; Randjbar Daemi, S.; eds)

    1994-01-01

    The book contains papers, mainly on particle physics, presented at the meeting held between 8 and 12 March 1993 at the ICTP in Trieste to honor Professor Abdus Salam. The articles have been grouped in 6 chapters: Standard Model (6 papers), Beyond the Standard Model (4 papers), Astro-Particle Physics and Cosmology (3 papers), Strings and Quantum Gravity (5 papers), Mathematical Physics and Condensed Matter (2 papers), Salam's Collaborators and Students (13 papers). A separate abstract was prepared for each paper. Refs, figs and tabs

  3. A 3.55 keV hint for decaying axion-like particle dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Jaeckel, Joerg [Heidelberg Univ. (Germany). Inst. fuer Theoretische Physik; Redondo, Javier [Muenchen Univ. (Germany). Arnold Sommerfeld Center; Max-Planck-Institut fuer Physik, Muenchen (Germany); Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2014-02-15

    Recently, indications for an emission line at 3.55 keV have been found in the combined spectra of a large number of galaxy clusters and also in Andromeda. This line could not be identified with any known spectral line. It is tempting to speculate that it has its origin in the decay of a particle contributing all or part of the dark matter. In this note we want to point out that axion-like particles being all or part of the dark matter are an ideal candidate to produce such a feature. More importantly the parameter values necessary are quite feasible in extensions of the Standard Model based on string theory and could be linked up to a variety of other intriguing phenomena, which also potentially allow for new tests of this speculation.

  4. A 3.55 keV hint for decaying axion-like particle dark matter

    International Nuclear Information System (INIS)

    Jaeckel, Joerg; Ringwald, Andreas

    2014-02-01

    Recently, indications for an emission line at 3.55 keV have been found in the combined spectra of a large number of galaxy clusters and also in Andromeda. This line could not be identified with any known spectral line. It is tempting to speculate that it has its origin in the decay of a particle contributing all or part of the dark matter. In this note we want to point out that axion-like particles being all or part of the dark matter are an ideal candidate to produce such a feature. More importantly the parameter values necessary are quite feasible in extensions of the Standard Model based on string theory and could be linked up to a variety of other intriguing phenomena, which also potentially allow for new tests of this speculation.

  5. SIGNATURES OF DARK MATTER BURNING IN NUCLEAR STAR CLUSTERS

    International Nuclear Information System (INIS)

    Casanellas, Jordi; Lopes, IlIdio

    2011-01-01

    In order to characterize how dark matter (DM) annihilation inside stars changes the aspect of a stellar cluster, we computed the evolution until the ignition of the He burning of stars from 0.7 M sun to 3.5 M sun within halos of DM with different characteristics. We found that, when a cluster is surrounded by a dense DM halo, the positions of the cluster' stars in the H-R diagram have a brighter and hotter turnoff point than in the classical scenario without DM, therefore giving the cluster a younger appearance. The high DM densities required to produce these effects are expected only in very specific locations, such as near the center of our Galaxy. In particular, if DM is formed by the 8 GeV weakly interacting massive particles recently invoked to reconcile the results from direct detection experiments, then this signature is predicted for halos of DM with a density ρ χ = 3 x 10 5 GeV cm -3 . A DM density gradient inside the stellar cluster would result in a broader main sequence, turnoff, and red giant branch regions. Moreover, we found that for very high DM halo densities the bottom of the isochrones in the H-R diagram rises to higher luminosities, leading to a characteristic signature on the stellar cluster. We argue that this signature could be used to indirectly probe the presence of DM particles in the location of a cluster.

  6. Gamma-rays from decaying dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Bertone, G. [Paris-6 Univ., 75 (France). Inst. d' Astrophysique; Buchmueller, W.; Covi, L.; Ibarra, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2007-10-15

    We study the prospects for detecting gamma-rays from decaying Dark Matter (DM), focusing in particular on gravitino DM in R-parity breaking vacua. Given the substantially different angular distribution of the predicted gamma-ray signal with respect to the case of annihilating DM, and the relatively poor (of order 0.1 ) angular resolution of gamma-ray detectors, the best strategy for detection is in this case to look for an exotic contribution to the gamma-ray flux at high galactic latitudes, where the decaying DM contribution would resemble an astrophysical extragalactic component, similar to the one inferred by EGRET observations. Upcoming experiments such as GLAST and AMS-02 may identify this exotic contribution and discriminate it from astrophysical sources, or place significant constraints on the mass and lifetime of DM particles. (orig.)

  7. Minerals as Time-Integrating Luminescence Detectors for setting bounds on dark matter particle characteristics

    International Nuclear Information System (INIS)

    Polymeris, G.S.; Kitis, G.; Liolios, A.K.; Tsirliganis, N.C.; Zioutas, K.

    2006-01-01

    Terrestrial material, since its formation, is supposed to receive additional radiation dose from its exposure to fluxes of dark matter particles. The present work investigates the possibility for bound estimation of interaction parameters of dark matter particles with ordinary matter, by measuring the accumulated doses of certain geological materials. It is proposed that Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) could enable the differentiation between the individual dose components, attributing a possible excessive dose, beyond the anticipated from cosmic rays and environmental radioactivity, to interactions with dark matter particles. Dosimetric properties of natural calcium fluoride, such as low detectable dose limit and low energy threshold (well below 1keV), indicate it as a promising Thermoluminescent Dosimeter (TLD) for the proposed method. The limitations imposed by the 'background' of cosmic rays and environmental radioactivity are discussed, and initial limits for the interaction strengths with ordinary matter, and/or the mass of WIMPs and axions are derived. The use of sedimentary quartz, sited in a free-from background-radiation environment, would yield a value of 4x10 -8 GeV -1 as an upper limit for the axion-to-photon interaction constant g aγγ and a value of 3x10 -8 GeV as a lower limit for the neutralino mass. The best limits, g aγγ =1.1x10 -10 GeV -1 for solar axions and m=3000GeV for neutralinos, could be derived for natural calcium fluoride as a dosimeter

  8. Quasi-particles and effective mean field in strongly interacting matter

    International Nuclear Information System (INIS)

    Levai, P.; Ko, C.M.

    2010-01-01

    We introduce a quasi-particle model of strongly interacting quark-gluon matter and explore the possible connection to an effective field theoretical description consisting of a scalar σ field by introducing a dynamically generated mass, M(σ), and a self-consistently determined interaction term, B(σ). We display a possible connection between the two types of effective description, using the Friedberg-Lee model.

  9. Mechanism for thermal relic dark matter of strongly interacting massive particles.

    Science.gov (United States)

    Hochberg, Yonit; Kuflik, Eric; Volansky, Tomer; Wacker, Jay G

    2014-10-24

    We present a new paradigm for achieving thermal relic dark matter. The mechanism arises when a nearly secluded dark sector is thermalized with the standard model after reheating. The freeze-out process is a number-changing 3→2 annihilation of strongly interacting massive particles (SIMPs) in the dark sector, and points to sub-GeV dark matter. The couplings to the visible sector, necessary for maintaining thermal equilibrium with the standard model, imply measurable signals that will allow coverage of a significant part of the parameter space with future indirect- and direct-detection experiments and via direct production of dark matter at colliders. Moreover, 3→2 annihilations typically predict sizable 2→2 self-interactions which naturally address the "core versus cusp" and "too-big-to-fail" small-scale structure formation problems.

  10. Compatibility of a dark matter discovery at XENONnT or LZ with the WIMP thermal production mechanism

    Science.gov (United States)

    Catena, Riccardo; Conrad, Jan; Krauss, Martin B.

    2018-05-01

    The discovery of dark matter (DM) at XENONnT or LZ would place constraints on DM particle mass and coupling constants. It is interesting to ask when these constraints can be compatible with the DM thermal production mechanism. We address this question within the most general set of renormalizable models that preserve Lorentz and gauge symmetry, and that extend the standard model by one DM candidate of mass mDM and one particle of mass Mmed mediating DM-quark interactions. Our analysis divides into two parts. First, we postulate that XENONnT/LZ has detected μS˜O (100 ) signal events, and use this input to calculate the DM relic density, ΩDMh2. Then, we identify the regions in the Mmed-ΩDMh2 plane which are compatible with the observed signal and with current CMB data. We find that for most of the models considered here, O (100 ) signal events at XENONnT/LZ and the DM thermal production are only compatible for resonant DM annihilations, i.e. for Mmed≃2 mDM. In this case, XENONnT/LZ would be able to simultaneously measure mDM and Mmed. We also discuss the dependence of our results on mDM, μS and the DM spin, and provide analytic expressions for annihilation cross sections and mediator decay widths for all models considered in this study.

  11. Asymmetric Dark Matter and Dark Radiation

    International Nuclear Information System (INIS)

    Blennow, Mattias; Martinez, Enrique Fernandez; Mena, Olga; Redondo, Javier; Serra, Paolo

    2012-01-01

    Asymmetric Dark Matter (ADM) models invoke a particle-antiparticle asymmetry, similar to the one observed in the Baryon sector, to account for the Dark Matter (DM) abundance. Both asymmetries are usually generated by the same mechanism and generally related, thus predicting DM masses around 5 GeV in order to obtain the correct density. The main challenge for successful models is to ensure efficient annihilation of the thermally produced symmetric component of such a light DM candidate without violating constraints from collider or direct searches. A common way to overcome this involves a light mediator, into which DM can efficiently annihilate and which subsequently decays into Standard Model particles. Here we explore the scenario where the light mediator decays instead into lighter degrees of freedom in the dark sector that act as radiation in the early Universe. While this assumption makes indirect DM searches challenging, it leads to signals of extra radiation at BBN and CMB. Under certain conditions, precise measurements of the number of relativistic species, such as those expected from the Planck satellite, can provide information on the structure of the dark sector. We also discuss the constraints of the interactions between DM and Dark Radiation from their imprint in the matter power spectrum

  12. Particle Physics Foundations of Dark Matter, Dark Energy, and Inflation (2/3)

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Ninety-five percent of the present mass-energy density of the Universe is dark. Twenty-five percent is in the form of dark matter holding together galaxies and other large scale structures, and 70% is in the form of dark energy driving an accelerated expansion of the universe. Dark matter and dark energy cannot be explained within the standard model of particle physics. In the first lecture I will review the evidence for dark matter and the observations that point to an explanation in the form of cold dark matter. I will then describe the expected properties of a hypothetical Weakly-Interacting Massive Particle, or WIMP, and review experimental and observational approaches to test the hypothesis. Finally, I will discuss how the LHC might shed light on the problem. In the second lecture I will review the theoretical foundations and observational evidence that the dominant component of the present mass density of the Universe has a negative pressure, which leads to an accelerated expansion of the Universe...

  13. Particle Physics Foundations of Dark Matter, Dark Energy, and Inflation (3/3)

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Ninety-five percent of the present mass-energy density of the Universe is dark. Twenty-five percent is in the form of dark matter holding together galaxies and other large scale structures, and 70% is in the form of dark energy driving an accelerated expansion of the universe. Dark matter and dark energy cannot be explained within the standard model of particle physics. In the first lecture I will review the evidence for dark matter and the observations that point to an explanation in the form of cold dark matter. I will then describe the expected properties of a hypothetical Weakly-Interacting Massive Particle, or WIMP, and review experimental and observational approaches to test the hypothesis. Finally, I will discuss how the LHC might shed light on the problem. In the second lecture I will review the theoretical foundations and observational evidence that the dominant component of the present mass density of the Universe has a negative pressure, which leads to an accelerated expansion of the Universe...

  14. Particle Physics Foundations of Dark Matter, Dark Energy, and Inflation (1/3)

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Ninety-five percent of the present mass-energy density of the Universe is dark. Twenty-five percent is in the form of dark matter holding together galaxies and other large scale structures, and 70% is in the form of dark energy driving an accelerated expansion of the universe. Dark matter and dark energy cannot be explained within the standard model of particle physics. In the first lecture I will review the evidence for dark matter and the observations that point to an explanation in the form of cold dark matter. I will then describe the expected properties of a hypothetical Weakly-Interacting Massive Particle, or WIMP, and review experimental and observational approaches to test the hypothesis. Finally, I will discuss how the LHC might shed light on the problem. In the second lecture I will review the theoretical foundations and observational evidence that the dominant component of the present mass density of the Universe has a negative pressure, which leads to an accelerated expansion of the Universe...

  15. Chemical characterization of freshly emitted particulate matter from aircraft exhaust using single particle mass spectrometry

    Science.gov (United States)

    Abegglen, Manuel; Brem, B. T.; Ellenrieder, M.; Durdina, L.; Rindlisbacher, T.; Wang, J.; Lohmann, U.; Sierau, B.

    2016-06-01

    Non-volatile aircraft engine emissions are an important anthropogenic source of soot particles in the upper troposphere and in the vicinity of airports. They influence climate and contribute to global warming. In addition, they impact air quality and thus human health and the environment. The chemical composition of non-volatile particulate matter emission from aircraft engines was investigated using single particle time-of-flight mass spectrometry. The exhaust from three different aircraft engines was sampled and analyzed. The soot particulate matter was sampled directly behind the turbine in a test cell at Zurich Airport. Single particle analyses will focus on metallic compounds. The particles analyzed herein represent a subset of the emissions composed of the largest particles with a mobility diameter >100 nm due to instrumental restrictions. A vast majority of the analyzed particles was shown to contain elemental carbon, and depending on the engine and the applied thrust the elemental carbon to total carbon ratio ranged from 83% to 99%. The detected metallic compounds were all internally mixed with the soot particles. The most abundant metals in the exhaust were Cr, Fe, Mo, Na, Ca and Al; V, Ba, Co, Cu, Ni, Pb, Mg, Mn, Si, Ti and Zr were also detected. We further investigated potential sources of the ATOFMS-detected metallic compounds using Inductively Coupled Plasma Mass Spectrometry. The potential sources considered were kerosene, engine lubrication oil and abrasion from engine wearing components. An unambiguous source apportionment was not possible because most metallic compounds were detected in several of the analyzed sources.

  16. Dark matter (energy) may be indistinguishable from modified gravity (MOND)

    Science.gov (United States)

    Sivaram, C.

    For Newtonian dynamics to hold over galactic scales, large amounts of dark matter (DM) are required which would dominate cosmic structures. Accounting for the strong observational evidence that the universe is accelerating requires the presence of an unknown dark energy (DE) component constituting about 70% of the matter. Several ingenious ongoing experiments to detect the DM particles have so far led to negative results. Moreover, the comparable proportions of the DM and DE at the present epoch appear unnatural and not predicted by any theory. For these reasons, alternative ideas like MOND and modification of gravity or general relativity over cosmic scales have been proposed. It is shown in this paper that these alternate ideas may not be easily distinguishable from the usual DM or DE hypotheses. Specific examples are given to illustrate this point that the modified theories are special cases of a generalized DM paradigm.

  17. Light mediators in dark matter direct detections

    International Nuclear Information System (INIS)

    Li, Tai; Miao, Sen; Zhou, Yu-Feng

    2015-01-01

    In an extended effective operator framework, we investigate in detail the effects of light mediators on the event spectra of dark matter (DM)-nucleus scatterings. The presence of light mediators changes the interpretation of the current experimental data, especially the determination of DM particle mass. We show by analytic and numerical illustrations that in general for all the operators relevant to spin-independent scatterings, the DM particle mass allowed by a given set of experimental data increases significantly when the mediator particle becomes lighter. For instance, in the case of CDMS-II-Si experiment, the allowed DM particle mass can reach ∼50 (100) GeV at 68% (90%) confidence level, which is much larger than ∼10 GeV in the case with contact interactions. The increase of DM particle mass saturates when the mediator mass is below O(10) MeV. The upper limits from other experiments such as SuperCDMS, CDMSlite, CDEX, XENON10/100, LUX, PandaX etc. all tend to be weaker toward high DM mass regions. In a combined analysis, we show that the presence of light mediators can partially relax the tension in the current results of CDMS-II-Si, SuperCDMS and LUX

  18. Dark matter electron anisotropy. A universal upper limit

    International Nuclear Information System (INIS)

    Borriello, Enrico; Maccione, Luca; Cuoco, Alessandro

    2010-12-01

    Indirect searches of particle Dark Matter (DM) with high energy Cosmic Rays (CR) are affected by large uncertainties, coming both from the DM side, and from poor understanding of the astrophysical backgrounds. We show that, on the contrary, the DM intrinsic degree of anisotropy in the arrival directions of high energy CR electrons and positrons does not suffer from these unknowns. Furthermore, if contributions from possible local sources are neglected, the intrinsic DM anisotropy sets the maximum degree of total anisotropy. As a consequence, if some anisotropy larger than the DM upper bound is detected, its origin could not be ascribed to DM, and would constitute an unambiguous evidence for the presence of astrophysical local discrete sources of high energy electrons and positrons. The Fermi-LAT will be able to probe such scenarios in the next years. (orig.)

  19. Black hole genesis of dark matter

    Science.gov (United States)

    Lennon, Olivier; March-Russell, John; Petrossian-Byrne, Rudin; Tillim, Hannah

    2018-04-01

    We present a purely gravitational infra-red-calculable production mechanism for dark matter (DM) . The source of both the DM relic abundance and the hot Standard Model (SM) plasma is a primordial density of micro black holes (BHs), which evaporate via Hawking emission into both the dark and SM sectors. The mechanism has four qualitatively different regimes depending upon whether the BH evaporation is 'fast' or 'slow' relative to the initial Hubble rate, and whether the mass of the DM particle is 'light' or 'heavy' compared to the initial BH temperature. For each of these regimes we calculate the DM yield, Y, as a function of the initial state and DM mass and spin. In the 'slow' regime Y depends on only the initial BH mass over a wide range of initial conditions, including scenarios where the BHs are a small fraction of the initial energy density. The DM is produced with a highly non-thermal energy spectrum, leading in the 'light' DM mass regime (~260 eV and above depending on DM spin) to a strong constraint from free-streaming, but also possible observational signatures in structure formation in the spin 3/2 and 2 cases. The 'heavy' regime (~1.2 × 108 GeV to MPl depending on spin) is free of these constraints and provides new possibilities for DM detection. In all cases there is a dark radiation component predicted.

  20. Evidence of dark matter from biological observations

    International Nuclear Information System (INIS)

    Zioutas, K.

    1990-01-01

    In accordance with the generally accepted properties of dark matter (DM) candidates, the probability of their interaction with living matter must be equal to that for inorganic matter, and the expected effects might be unique and provide the etiology related to the appearance of several biological phenomena having sometimes fatal late effects. Although collisions with DM are rare, the charged secondaries (recoiling atoms) are expected to be high linear energy transfer particles favouring the highest relative biological effectiveness values for this, as yet invisible, part of the natural background radiation. A few cases are given, where a correlation between DM interaction and phenomena in living matter might already exist, or can show up in existing data: biorhythms with periodicities identical to known cosmic frequencies are explainable with gravitationally clustered DM around the sun, the moon, the earth, etc. The observed arrhythmia, when biological probes are moved (in airplanes, satellites, etc.) support this idea strongly. It is also proposed to implement some of the biological properties and processes (such as element composition and chemical reactions) in future DM detectors in order to improve their sensitivity. The interdisciplinary feedback is bidirectional: huge DM detectors could be used in attempt to understand enigmatic biological behaviour. (orig.)

  1. Paul Scherrer Institute Scientific Report 1998. Volume I: Particles and Matter

    Energy Technology Data Exchange (ETDEWEB)

    Baltensperger, U; Herlach, D; Kettle, P -R; Lorenzen, R [eds.

    1999-09-01

    The new department Particles and Matter, created 1 October 1998 aims to strengthen the two pillars of PSI, research at large facilities and research with interdisciplinary teams. Particle Physics and Astrophysics at PSI have an established tradition in the field of particle and Xray detectors and both co-operate with the Laboratory for Micro and Nano Technology. The research of the latter is focussed on Si/SiGe and Si/SiC nano structures, with the aim of both understanding their nano technology properties and eventually producing light from silicon, and on interdisciplinary molecular nano technology. The Laboratory for Radio and Environmental Chemistry concentrates on the chemical analysis of super heavy elements and their homologues produced with ion beams at the proton accelerator and at the spallation neutron source (SINQ), and on the investigation of agglomerates formed from nanoparticles (aerosols) in the atmosphere for environmental and climate research. (author) figs., tabs., refs.

  2. Paul Scherrer Institute Scientific Report 1998. Volume I: Particles and Matter

    International Nuclear Information System (INIS)

    Baltensperger, U.; Herlach, D.; Kettle, P.-R.; Lorenzen, R.

    1999-01-01

    The new department Particles and Matter, created 1 October 1998 aims to strengthen the two pillars of PSI, research at large facilities and research with interdisciplinary teams. Particle Physics and Astrophysics at PSI have an established tradition in the field of particle and Xray detectors and both co-operate with the Laboratory for Micro and Nano Technology. The research of the latter is focussed on Si/SiGe and Si/SiC nano structures, with the aim of both understanding their nano technology properties and eventually producing light from silicon, and on interdisciplinary molecular nano technology. The Laboratory for Radio and Environmental Chemistry concentrates on the chemical analysis of super heavy elements and their homologues produced with ion beams at the proton accelerator and at the spallation neutron source (SINQ), and on the investigation of agglomerates formed from nanoparticles (aerosols) in the atmosphere for environmental and climate research. (author)

  3. Calculation of the stopping power and the path of charged particles in matter. Application example

    International Nuclear Information System (INIS)

    Barre, Bertrand; Du Lieu, Pierre

    1969-05-01

    The path of a charged particle in matter is calculated by integrating the stopping power of the medium against this particle. Depending on the energy of the particle, stopping powers are calculated using Lindhard, Bethe, or semi-empirical smoothing solutions. After exposing recent theories in this field, the authors present a Fortran subroutine which performs these various operations, and covers all energy domains. This routine is available for operation on IBM 360; it uses a magnetic tape library that can take into account experimental results. The subprogram presentation, leaving the user the option of entering the data and using the results at his discretion, allows a particularly flexible use. At the end of this note, some considerations on possible further improvements in the program, and a bibliography of the articles that have dealt with the question from a theoretical or an experimental point of view are discussed [fr

  4. Light Readout for a 1 ton Liquid Argon Dark Matter Detector

    CERN Document Server

    Boccone, Vittorio; Baudis, Laura; Otyugova, Polina; Regenfus, Christian

    2010-01-01

    Evidence for dark matter (DM) has been reported using astronomical observations in systems such as the Bullet cluster. Weakly interactive massive particles (WIMPs), in particular the lightest neutralino, are the most popular DM candidates within the Minimal Supersymmetric Standard Model (MSSM). Many groups in the world are focussing their attention on the direct detection of DM in the laboratory. The detectors should have large target masses and excellent noise rejection capabilities because of the small cross section between DM and ordinary matter (σWIMP−nucleon < 4 · 10−8 pb). Noble liquids are today considered to be one of the best options for large-size DM experiments, as they have a relatively low ionization energy, good scintillation properties and long electron lifetime. Moreover noble liquid detectors are easily scalable to large masses. This thesis deals with the development of a large (1 ton) LAr WIMP detector (ArDM) which could measure simultaneously light and charge from the scintilla...

  5. Particle physics and cosmology beyond the Standard Model: inflation, dark matter and flavour

    International Nuclear Information System (INIS)

    Heurtier, L.

    2015-01-01

    This thesis has been focusing on beyond the Standard Model aspects of particle physics and their implication in cosmology. We have gone through this work along the timeline of the Universe History focusing on three major topics that are the inflationary period, the dark matter relic density production and detection, and finally the question of flavor changing constraints on low energy supersymmetric theories. In the first part of this thesis, after reviewing the theoretical and phenomenological aspects of both the Big Bang theory and the theory of Inflation we will study in detail how describing Inflation in a high energy supersymmetric theory. The second part of this thesis is dedicated to dark matter. We have studied phenomenological aspects of simple models, extending the present Standard Model with simple abelian symmetries, by assuming that the constituent of dark matter would be able to exchange information with the visible sector by the help of a mediator particle. We have studied in particular possible interactions of heavy or light dark matter with respectively the strong and the electroweak sectors of the Standard Model. Our models are strongly constrained of course by experiments. The third part of this work will be dedicated to a different aspect of beyond Standard Model theories, that is the treatment of the flavour changing processes of particle physics. The Minimal Supersymmetric Standard Model (MSSM), as one of these possible enlargement of the Standard Model, introduces new processes of flavour changing that are highly constrained by experiment. We present some works in which we consider the possibility of adding so called Dirac Gauginos to the MSSM to render flavour changing weaker in the theory, and propose different flavour patterns theories

  6. CP violating scalar Dark Matter

    Science.gov (United States)

    Cordero-Cid, A.; Hernández-Sánchez, J.; Keus, V.; King, S. F.; Moretti, S.; Rojas, D.; Sokołowska, D.

    2016-12-01

    We study an extension of the Standard Model (SM) in which two copies of the SM scalar SU(2) doublet which do not acquire a Vacuum Expectation Value (VEV), and hence are inert, are added to the scalar sector. We allow for CP-violation in the inert sector, where the lightest inert state is protected from decaying to SM particles through the conservation of a Z 2 symmetry. The lightest neutral particle from the inert sector, which has a mixed CP-charge due to CP-violation, is hence a Dark Matter (DM) candidate. We discuss the new regions of DM relic density opened up by CP-violation, and compare our results to the CP-conserving limit and the Inert Doublet Model (IDM). We constrain the parameter space of the CP-violating model using recent results from the Large Hadron Collider (LHC) and DM direct and indirect detection experiments.

  7. Cancellation Mechanism for Dark-Matter-Nucleon Interaction.

    Science.gov (United States)

    Gross, Christian; Lebedev, Oleg; Toma, Takashi

    2017-11-10

    We consider a simple Higgs portal dark-matter model, where the standard model is supplemented with a complex scalar whose imaginary part plays the role of weakly interacting massive particle dark matter (DM). We show that the direct DM detection cross section vanishes at the tree level and zero momentum transfer due to a cancellation by virtue of a softly broken symmetry. This cancellation is operative for any mediator masses. As a result, our electroweak-scale dark matter satisfies all of the phenomenological constraints quite naturally.

  8. Effects of salinity and organic matter on the partitioning of perfluoroalkyl acid (PFAs) to clay particles.

    Science.gov (United States)

    Jeon, Junho; Kannan, Kurunthachalam; Lim, Byung J; An, Kwang Guk; Kim, Sang Don

    2011-06-01

    The influence of salinity and organic matter on the distribution coefficient (K(d)) for perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in a brackish water-clay system was studied. The distribution coefficients (K(d)) for PFAs onto inorganic clay surfaces increased with salinity, providing evidence for electrostatic interaction for the sorption of PFAs, whereas the relationship between K(d) and organic carbon content (f(oc)) suggested that hydrophobic interaction is the primary driving force for the sorption of PFAs onto organic matter. The organic carbon normalized adsorption coefficient (K(oc)) of PFAs can be slightly overestimated due to the electrostatic interaction within uncoated inorganic surfaces. In addition, the dissolved organic matter released from coated clay particles seemed to solvate PFA molecules in solution, which contributed to a decrease in K(d). A positive relationship between K(d) and salinity was apparent, but an empirical relationship for the 'salting-out' effect was not evident. The K(d) values of PFAs are relatively small compared with those reported for persistent organic pollutants. Thus, sorption may not be a significant route of mass transfer of PFAs from water columns in estuarine environments. However, enhancement of sorption of PFAs to particulate matter at high salinity values could evoke potential risks to benthic organisms in estuarine areas.

  9. A Search for Weakly Interacting Particles with the Cryogenic Dark Matter Search Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bruch, Tobias [Univ. of Zurich (Switzerland)

    2010-01-01

    Dark matter particles cannot only be detected directly in laboratories, but also indirectly by their annihilation products. Previous predictions of the neutrino flux from WIMP annihilation in the Earth and the Sun have assumed that galactic dark matter is distributed according to the SHM. Although the dark disc has a local density comparable to the dark halo, its higher phase space density at low velocities greatly enhances capture rates in the Sun and Earth. For typical dark disc properties, the resulting muon flux from the Earth is increased by three orders of magnitude over the SHM, while for the Sun the increase is one order of magnitude. This significantly increases the prospects of neutrino telescopes to fix or constrain parameters in WIMP models. The flux from the Earth is extremely sensitive to the detailed properties of the dark disc, while the flux from the Sun is more robust.

  10. Novel dark matter phenomenology at colliders

    Science.gov (United States)

    Wardlow, Kyle Patrick

    While a suitable candidate particle for dark matter (DM) has yet to be discovered, it is possible one will be found by experiments currently investigating physics on the weak scale. If discovered on that energy scale, the dark matter will likely be producible in significant quantities at colliders like the LHC, allowing the properties of and underlying physical model characterizing the dark matter to be precisely determined. I assume that the dark matter will be produced as one of the decay products of a new massive resonance related to physics beyond the Standard Model, and using the energy distributions of the associated visible decay products, develop techniques for determining the symmetry protecting these potential dark matter candidates from decaying into lighter Standard Model (SM) particles and to simultaneously measure the masses of both the dark matter candidate and the particle from which it decays.

  11. Searches for Dark Matter with the ATLAS detector

    CERN Document Server

    Fischer, Cora; The ATLAS collaboration

    2017-01-01

    Dark matter searches carried out with the ATLAS experiment with Run 2 data are summarised and presented. Interpretations focus on simplified models where the dark matter particles are produced via the exchange of a heavy new mediator. The results of different analyses are combined as an exclusion in the plane m_DM vs M_med. Exclusion limits are also compared with direct dark matter search experiments.

  12. The generation of high-power charge particle micro beams and its interaction with condensed matter

    International Nuclear Information System (INIS)

    Vogel, N.; Skvortsov, V.A.

    1996-01-01

    As has been observed experimentally, the action of a picosecond laser beam on an Al-target in air gives rise to the generation and acceleration of high-power micro electron and ion beams. An original theoretical model for describing the generation and particle acceleration of such micro beams as a result of the micro channeling effect is presented. It was found that extreme states of matter, with compression in the Gbar pressure range, can be produced by such micro beams. (author). 3 figs., 12 refs

  13. Water uptake by fresh Indonesian peat burning particles is limited by water-soluble organic matter

    Directory of Open Access Journals (Sweden)

    J. Chen

    2017-09-01

    Full Text Available The relationship between hygroscopic properties and chemical characteristics of Indonesian biomass burning (BB particles, which are dominantly generated from peatland fires, was investigated using a humidified tandem differential mobility analyzer. In addition to peat, acacia (a popular species at plantation and fern (a pioneering species after disturbance by fire were used for experiments. Fresh Indonesian peat burning particles are almost non-hygroscopic (mean hygroscopicity parameter, κ < 0.06 due to predominant contribution of water-insoluble organics. The range of κ spans from 0.02 to 0.04 (dry diameter = 100 nm, hereinafter for Riau peat burning particles, while that for Central Kalimantan ranges from 0.05 to 0.06. Fern combustion particles are more hygroscopic (κ = 0. 08, whereas the acacia burning particles have a mediate κ value (0.04. These results suggest that κ is significantly dependent on biomass types. This variance in κ is partially determined by fractions of water-soluble organic carbon (WSOC, as demonstrated by a correlation analysis (R = 0.65. κ of water-soluble organic matter is also quantified, incorporating the 1-octanol–water partitioning method. κ values for the water extracts are high, especially for peat burning particles (A0 (a whole part of the water-soluble fraction: κ = 0.18, A1 (highly water-soluble fraction: κ = 0.30. This result stresses the importance of both the WSOC fraction and κ of the water-soluble fraction in determining the hygroscopicity of organic aerosol particles. Values of κ correlate positively (R = 0.89 with the fraction of m∕z 44 ion signal quantified using a mass spectrometric technique, demonstrating the importance of highly oxygenated organic compounds to the water uptake by Indonesian BB particles. These results provide an experimentally validated reference for hygroscopicity of organics-dominated particles, thus contributing to more accurate

  14. Principles of space-time-matter cosmology, particles and waves in five dimensions

    CERN Document Server

    Overduin, James

    2018-01-01

    This book is a summing up of the prospects for unification between relativity and particle physics based on the extension of Einstein's theory of General Relativity to five dimensions. This subject was first established by Paul Wesson in his previous best-seller, Space-Time-Matter, and discussed from a different perspective in Five-Dimensional Physics, both published by World Scientific in 1999 and 2006 respectively. This third book brings the field up to date and details many new developments and connections to particle theory and wave mechanics in particular. It was in largely finished form at the time of Paul Wesson's untimely death in 2015, and has been completed and expanded by his former student and longtime collaborator, James Overduin.

  15. Effective mass of a #betta#-particle in nuclear matter and OBE #betta#-n interactions

    International Nuclear Information System (INIS)

    Bando, Hiroharu; Nagata, Sinobu.

    1982-01-01

    The effective mass of a lambda particle (M sub( lambda )*) in nuclear matter is investigated within the framework of the lowest-order Brueckner theory by employing the Nijmegen OBE lambda -N interaction model D and F. The non-locality mass (M tilde sub( lamda )) and the energy mass (anti M sub( lambda )) are evaluated and discussed in the light of the characteristics of the two models. In comparison with the model D, the model F yields smaller anti M sub( lambda ) and larger anti M sub( lamb da ) reflecting the stronger Majorana exchange force and the stronger lambda N- sigma N coupling tensor force. Final results of M sub( lambda )*/M sub( lambda ) are 0.85 for D and 0.79 for F. In view of the effective lambda mass inferred from observed properties of the single particle potential for lambda , the model D interaction seems to be more adequate. (author)

  16. Confinement of quasi-particles in a condensed matter system: an inelastic neutron scattering study

    International Nuclear Information System (INIS)

    Bera, A.K.

    2016-01-01

    The confinement of quasi particles, a well-known phenomenon in particle physics, can also be realized in a condensed matter system. In particle physics, baryons and mesons are produced by the confinement of quarks, where quarks are bound together by a strong interaction (gauge field) that grows stronger with increasing distance and, therefore, the quarks never exist as individual particles. The condensed matter analogue, confinement of magnetic quasiparticles (spinons) can be illustrated in quasi-one-dimensional spin-1/2 chains. We demonstrate experimentally such spinon confinement in the weakly coupled spin-1/2 XXZ antiferromagnetic chain compound SrCo_2V_2O_8 by single crystal inelastic neutron scattering. The compound SrCo_2V_2O_8 belongs to the general family SrM_2V_2O_8 (M = Ni, Co and Mn), having four-fold screw chains of edge sharing MO_6 octahedra along the crystallographic c axis. In the pure 1D magnetic state of SrCo_2V_2O_8 (above the 3D magnetic ordering temperature T_N =5 K) two spinons (excitations of individual chains) are created by a spin flip, and those spinons propagate independently by subsequent spin flips without any cost of energy. However, below the T_N, two spinons are bound together by weak interchain interactions since the separation between them frustrates the interchain interactions. The interchain interactions play the role of an attractive potential (equivalent to the gauge field), proportional to the distance between spinons, and result in confinement of spinons into bound pairs. (author)

  17. Implication of POC/234Th ratios in oceanic particulate matter. An approach to particle aggregation

    International Nuclear Information System (INIS)

    Hirose, Katumi

    2003-01-01

    234 Th has been widely applied as a tracer of particulate organic carbon (POC) fluxes in the upper ocean. Fundamental to this approach is the determination of 234 Th fluxes from water column measurements of the 234 Th- 238 U disequilibria, and the conversion of 234 Th flux to POC export, using the measured POC/ 234 Th ratio on particles. As such, POC/ 234 Th ratios are one of the most critical factors in quantifying the carbon export flux in ocean interior when using this approach. However, the POC/ 234 Th ratios show significant temporal and spatial variations, but cannot be predicted at this time. therefore, it is important to elucidate factors controlling the variations of the POC/ 234 Th ratios. To achieve this purpose, we should understand the chemical interactions between POC and 234 Th. In the open ocean, POC/ 234 Th ratios have been determined together with other oceanographic parameters. We examined here the relationship between POC/ 234 Th and primary production. The POC/ 234 Th ratios were linearly related to logarithmic values of primary production. Taken into account the complexation between surface ligand on particulate organic matter (POM) and 234 Th, a complexation model suggests that the size of particles adsorbing 234 Th is related to primary production; in the equatorial Pacific, the size of particles adsorbing 234 Th apparently decreases with increasing primary production, whereas opposite phenomenon occurs in the North Atlantic. Since the POC/ 234 Th ratios were determined in filtered particulate matter, this finding suggests that aggregation of small particles would be dominant in the equatorial Pacific, which can be explained by a chemical aggregation model. (author)

  18. Constraining Non-thermal and Thermal properties of Dark Matter

    Directory of Open Access Journals (Sweden)

    Bhupal eDev

    2014-05-01

    Full Text Available We describe the evolution of Dark Matter (DM abundance from the very onset of its creation from inflaton decay under the assumption of an instantaneous reheating. Based on the initial conditions such as the inflaton mass and its decay branching ratio to the DM species, the reheating temperature, and the mass and interaction rate of the DM with the thermal bath, the DM particles can either thermalize (fully/partially with the primordial bath or remain non-thermal throughout their evolution history. In the thermal case, the final abundance is set by the standard freeze-out mechanism for large annihilation rates, irrespective of the initial conditions. For smaller annihilation rates, it can be set by the freeze-in mechanism which also does not depend on the initial abundance, provided it is small to begin with. For even smaller interaction rates, the DM decouples while being non-thermal, and the relic abundance will be essentially set by the initial conditions. We put model-independent constraints on the DM mass and annihilation rate from over-abundance by exactly solving the relevant Boltzmann equations, and identify the thermal freeze-out, freeze-in and non-thermal regions of the allowed parameter space. We highlight a generic fact that inflaton decay to DM inevitably leads to an overclosure of the Universe for a large range of DM parameter space, and thus poses a stringent constraint that must be taken into account while constructing models of DM. For the thermal DM region, we also show the complementary constraints from indirect DM search experiments, Big Bang Nucleosynthesis, Cosmic Microwave Background, Planck measurements, and theoretical limits due to the unitarity of S-matrix. For the non-thermal DM scenario, we show the allowed parameter space in terms of the inflaton and DM masses for a given reheating temperature, and compute the comoving free-streaming length to identify the hot, warm and cold DM regimes.

  19. Rencontres de Moriond QCD 2012: Searches for Dark Matter, SUSY and other exotic particles

    CERN Multimedia

    CERN Bulletin

    2012-01-01

    The fact that SUSY and other new physics signals do not seem to hide in “obvious” places is bringing a healthy excitement to Moriond. Yesterday’s presentations confirmed that, with the 2012 LHC data, experiments will concentrate on searches for exotic particles that might decay into yet unexplored modes. In the meantime, they are setting unprecedented boundaries to regions where new particles (not just SUSY) could exist. The limits of what particle accelerators can bring to enlighten the mystery of Dark Matter were also presented and discussed.   Each bar on the picture represents a decay channel that the ATLAS Collaboration (top) and the CMS Collaborations (bottom) have analysed.  The value indicated on the scale (or on the relevant bar) defines the maximum mass that the particle in that search cannot have. Not knowing what kind of new physics we should really expect, and given the fact that it does not seem to be hiding in any of the obvious places, e...

  20. Input related microbial carbon dynamic of soil organic matter in particle size fractions

    Science.gov (United States)

    Gude, A.; Kandeler, E.; Gleixner, G.

    2012-04-01

    This paper investigated the flow of carbon into different groups of soil microorganisms isolated from different particle size fractions. Two agricultural sites of contrasting organic matter input were compared. Both soils had been submitted to vegetation change from C3 (Rye/Wheat) to C4 (Maize) plants, 25 and 45 years ago. Soil carbon was separated into one fast-degrading particulate organic matter fraction (POM) and one slow-degrading organo-mineral fraction (OMF). The structure of the soil microbial community were investigated using phospholipid fatty acids (PLFA), and turnover of single PLFAs was calculated from the changes in their 13C content. Soil enzyme activities involved in the degradation of carbohydrates was determined using fluorogenic MUF (methyl-umbelliferryl phosphate) substrates. We found that fresh organic matter input drives soil organic matter dynamic. Higher annual input of fresh organic matter resulted in a higher amount of fungal biomass in the POM-fraction and shorter mean residence times. Fungal activity therefore seems essential for the decomposition and incorporation of organic matter input into the soil. As a consequence, limited litter input changed especially the fungal community favouring arbuscular mycorrhizal fungi. Altogether, supply and availability of fresh plant carbon changed the distribution of microbial biomass, the microbial community structure and enzyme activities and resulted in different priming of soil organic matter. Most interestingly we found that only at low input the OMF fraction had significantly higher calculated MRT for Gram-positive and Gram-negative bacteria suggesting high recycling of soil carbon or the use of other carbon sources. But on average all microbial groups had nearly similar carbon uptake rates in all fractions and both soils, which contrasted the turnover times of bulk carbon. Hereby the microbial carbon turnover was always faster than the soil organic carbon turnover and higher carbon input

  1. Search for top squarks and dark matter particles in opposite-charge dilepton final states at √{s }=13 TeV

    Science.gov (United States)

    Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragicevic, M.; Erö, J.; Flechl, M.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Grossmann, J.; Hrubec, J.; Jeitler, M.; König, A.; Krammer, N.; Krätschmer, I.; Liko, D.; Madlener, T.; Mikulec, I.; Pree, E.; Rad, N.; Rohringer, H.; Schieck, J.; Schöfbeck, R.; Spanring, M.; Spitzbart, D.; Waltenberger, W.; Wittmann, J.; Wulz, C.-E.; Zarucki, M.; Chekhovsky, V.; Mossolov, V.; Suarez Gonzalez, J.; De Wolf, E. A.; Di Croce, D.; Janssen, X.; Lauwers, J.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Abu Zeid, S.; Blekman, F.; D'Hondt, J.; De Bruyn, I.; De Clercq, J.; Deroover, K.; Flouris, G.; Lontkovskyi, D.; Lowette, S.; Marchesini, I.; Moortgat, S.; Moreels, L.; Python, Q.; Skovpen, K.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Parijs, I.; Beghin, D.; Brun, H.; Clerbaux, B.; De Lentdecker, G.; Delannoy, H.; Dorney, B.; Fasanella, G.; Favart, L.; Goldouzian, R.; Grebenyuk, A.; Lenzi, T.; Luetic, J.; Maerschalk, T.; Marinov, A.; Seva, T.; Starling, E.; Vander Velde, C.; Vanlaer, P.; Vannerom, D.; Yonamine, R.; Zenoni, F.; Zhang, F.; Cimmino, A.; Cornelis, T.; Dobur, D.; Fagot, A.; Gul, M.; Khvastunov, I.; Poyraz, D.; Roskas, C.; Salva, S.; Tytgat, M.; Verbeke, W.; Zaganidis, N.; Bakhshiansohi, H.; Bondu, O.; Brochet, S.; Bruno, G.; Caputo, C.; Caudron, A.; David, P.; De Visscher, S.; Delaere, C.; Delcourt, M.; Francois, B.; Giammanco, A.; Komm, M.; Krintiras, G.; Lemaitre, V.; Magitteri, A.; Mertens, A.; Musich, M.; Piotrzkowski, K.; Quertenmont, L.; Saggio, A.; Vidal Marono, M.; Wertz, S.; Zobec, J.; Aldá Júnior, W. L.; Alves, F. L.; Alves, G. A.; Brito, L.; Correa Martins Junior, M.; Hensel, C.; Moraes, A.; Pol, M. E.; Rebello Teles, P.; Belchior Batista Das Chagas, E.; Carvalho, W.; Chinellato, J.; Coelho, E.; Da Costa, E. M.; Da Silveira, G. G.; De Jesus Damiao, D.; Fonseca De Souza, S.; Huertas Guativa, L. M.; Malbouisson, H.; Melo De Almeida, M.; Mora Herrera, C.; Mundim, L.; Nogima, H.; Sanchez Rosas, L. J.; Santoro, A.; Sznajder, A.; Thiel, M.; Tonelli Manganote, E. J.; Torres Da Silva De Araujo, F.; Vilela Pereira, A.; Ahuja, S.; Bernardes, C. A.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Romero Abad, D.; Ruiz Vargas, J. C.; Aleksandrov, A.; Hadjiiska, R.; Iaydjiev, P.; Misheva, M.; Rodozov, M.; Shopova, M.; Sultanov, G.; Dimitrov, A.; Litov, L.; Pavlov, B.; Petkov, P.; Fang, W.; Gao, X.; Yuan, L.; Ahmad, M.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Chen, Y.; Jiang, C. H.; Leggat, D.; Liao, H.; Liu, Z.; Romeo, F.; Shaheen, S. M.; Spiezia, A.; Tao, J.; Wang, C.; Wang, Z.; Yazgan, E.; Zhang, H.; Zhang, S.; Zhao, J.; Ban, Y.; Chen, G.; Li, Q.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Xu, Z.; Avila, C.; Cabrera, A.; Chaparro Sierra, L. F.; Florez, C.; González Hernández, C. F.; Ruiz Alvarez, J. D.; Segura Delgado, M. A.; Courbon, B.; Godinovic, N.; Lelas, D.; Puljak, I.; Ribeiro Cipriano, P. M.; Sculac, T.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Ferencek, D.; Kadija, K.; Mesic, B.; Starodumov, A.; Susa, T.; Ather, M. W.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Rykaczewski, H.; Finger, M.; Finger, M.; Carrera Jarrin, E.; El-khateeb, E.; Elgammal, S.; Mohamed, A.; Dewanjee, R. K.; Kadastik, M.; Perrini, L.; Raidal, M.; Tiko, A.; Veelken, C.; Eerola, P.; Kirschenmann, H.; Pekkanen, J.; Voutilainen, M.; Havukainen, J.; Heikkilä, J. K.; Järvinen, T.; Karimäki, V.; Kinnunen, R.; Lampén, T.; Lassila-Perini, K.; Laurila, S.; Lehti, S.; Lindén, T.; Luukka, P.; Siikonen, H.; Tuominen, E.; Tuominiemi, J.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Faure, J. L.; Ferri, F.; Ganjour, S.; Ghosh, S.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Kucher, I.; Leloup, C.; Locci, E.; Machet, M.; Malcles, J.; Negro, G.; Rander, J.; Rosowsky, A.; Sahin, M. Ö.; Titov, M.; Abdulsalam, A.; Amendola, C.; Antropov, I.; Baffioni, S.; Beaudette, F.; Busson, P.; Cadamuro, L.; Charlot, C.; Granier de Cassagnac, R.; Jo, M.; Lisniak, S.; Lobanov, A.; Martin Blanco, J.; Nguyen, M.; Ochando, C.; Ortona, G.; Paganini, P.; Pigard, P.; Salerno, R.; Sauvan, J. B.; Sirois, Y.; Stahl Leiton, A. G.; Strebler, T.; Yilmaz, Y.; Zabi, A.; Zghiche, A.; Agram, J.-L.; Andrea, J.; Bloch, D.; Brom, J.-M.; Buttignol, M.; Chabert, E. C.; Chanon, N.; Collard, C.; Conte, E.; Coubez, X.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Jansová, M.; Le Bihan, A.-C.; Tonon, N.; Van Hove, P.; Gadrat, S.; Beauceron, S.; Bernet, C.; Boudoul, G.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fay, J.; Finco, L.; Gascon, S.; Gouzevitch, M.; Grenier, G.; Ille, B.; Lagarde, F.; Laktineh, I. B.; Lethuillier, M.; Mirabito, L.; Pequegnot, A. L.; Perries, S.; Popov, A.; Sordini, V.; Vander Donckt, M.; Viret, S.; Khvedelidze, A.; Tsamalaidze, Z.; Autermann, C.; Feld, L.; Kiesel, M. K.; Klein, K.; Lipinski, M.; Preuten, M.; Schomakers, C.; Schulz, J.; Zhukov, V.; Albert, A.; Dietz-Laursonn, E.; Duchardt, D.; Endres, M.; Erdmann, M.; Erdweg, S.; Esch, T.; Fischer, R.; Güth, A.; Hamer, M.; Hebbeker, T.; Heidemann, C.; Hoepfner, K.; Knutzen, S.; Merschmeyer, M.; Meyer, A.; Millet, P.; Mukherjee, S.; Pook, T.; Radziej, M.; Reithler, H.; Rieger, M.; Scheuch, F.; Teyssier, D.; Thüer, S.; Flügge, G.; Kargoll, B.; Kress, T.; Künsken, A.; Müller, T.; Nehrkorn, A.; Nowack, A.; Pistone, C.; Pooth, O.; Stahl, A.; Aldaya Martin, M.; Arndt, T.; Asawatangtrakuldee, C.; Beernaert, K.; Behnke, O.; Behrens, U.; Bermúdez Martínez, A.; Bin Anuar, A. A.; Borras, K.; Botta, V.; Campbell, A.; Connor, P.; Contreras-Campana, C.; Costanza, F.; Diez Pardos, C.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Eren, E.; Gallo, E.; Garay Garcia, J.; Geiser, A.; Grados Luyando, J. M.; Grohsjean, A.; Gunnellini, P.; Guthoff, M.; Harb, A.; Hauk, J.; Hempel, M.; Jung, H.; Kasemann, M.; Keaveney, J.; Kleinwort, C.; Korol, I.; Krücker, D.; Lange, W.; Lelek, A.; Lenz, T.; Leonard, J.; Lipka, K.; Lohmann, W.; Mankel, R.; Melzer-Pellmann, I.-A.; Meyer, A. B.; Mittag, G.; Mnich, J.; Mussgiller, A.; Ntomari, E.; Pitzl, D.; Raspereza, A.; Savitskyi, M.; Saxena, P.; Shevchenko, R.; Spannagel, S.; Stefaniuk, N.; Van Onsem, G. P.; Walsh, R.; Wen, Y.; Wichmann, K.; Wissing, C.; Zenaiev, O.; Aggleton, R.; Bein, S.; Blobel, V.; Centis Vignali, M.; Dreyer, T.; Garutti, E.; Gonzalez, D.; Haller, J.; Hinzmann, A.; Hoffmann, M.; Karavdina, A.; Klanner, R.; Kogler, R.; Kovalchuk, N.; Kurz, S.; Lapsien, T.; Marconi, D.; Meyer, M.; Niedziela, M.; Nowatschin, D.; Pantaleo, F.; Peiffer, T.; Perieanu, A.; Scharf, C.; Schleper, P.; Schmidt, A.; Schumann, S.; Schwandt, J.; Sonneveld, J.; Stadie, H.; Steinbrück, G.; Stober, F. M.; Stöver, M.; Tholen, H.; Troendle, D.; Usai, E.; Vanhoefer, A.; Vormwald, B.; Akbiyik, M.; Barth, C.; Baselga, M.; Baur, S.; Butz, E.; Caspart, R.; Chwalek, T.; Colombo, F.; De Boer, W.; Dierlamm, A.; Faltermann, N.; Freund, B.; Friese, R.; Giffels, M.; Harrendorf, M. A.; Hartmann, F.; Heindl, S. M.; Husemann, U.; Kassel, F.; Kudella, S.; Mildner, H.; Mozer, M. U.; Müller, Th.; Plagge, M.; Quast, G.; Rabbertz, K.; Schröder, M.; Shvetsov, I.; Sieber, G.; Simonis, H. J.; Ulrich, R.; Wayand, S.; Weber, M.; Weiler, T.; Williamson, S.; Wöhrmann, C.; Wolf, R.; Anagnostou, G.; Daskalakis, G.; Geralis, T.; Kyriakis, A.; Loukas, D.; Topsis-Giotis, I.; Karathanasis, G.; Kesisoglou, S.; Panagiotou, A.; Saoulidou, N.; Kousouris, K.; Evangelou, I.; Foudas, C.; Kokkas, P.; Mallios, S.; Manthos, N.; Papadopoulos, I.; Paradas, E.; Strologas, J.; Triantis, F. A.; Csanad, M.; Filipovic, N.; Pasztor, G.; Surányi, O.; Veres, G. I.; Bencze, G.; Hajdu, C.; Horvath, D.; Hunyadi, Á.; Sikler, F.; Veszpremi, V.; Beni, N.; Czellar, S.; Karancsi, J.; Makovec, A.; Molnar, J.; Szillasi, Z.; Bartók, M.; Raics, P.; Trocsanyi, Z. L.; Ujvari, B.; Choudhury, S.; Komaragiri, J. R.; Bahinipati, S.; Bhowmik, S.; Mal, P.; Mandal, K.; Nayak, A.; Sahoo, D. K.; Sahoo, N.; Swain, S. K.; Bansal, S.; Beri, S. B.; Bhatnagar, V.; Chawla, R.; Dhingra, N.; Kalsi, A. K.; Kaur, A.; Kaur, M.; Kaur, S.; Kumar, R.; Kumari, P.; Mehta, A.; Singh, J. B.; Walia, G.; Kumar, Ashok; Shah, Aashaq; Bhardwaj, A.; Chauhan, S.; Choudhary, B. C.; Garg, R. B.; Keshri, S.; Kumar, A.; Malhotra, S.; Naimuddin, M.; Ranjan, K.; Sharma, R.; Bhardwaj, R.; Bhattacharya, R.; Bhattacharya, S.; Bhawandeep, U.; Dey, S.; Dutt, S.; Dutta, S.; Ghosh, S.; Majumdar, N.; Modak, A.; Mondal, K.; Mukhopadhyay, S.; Nandan, S.; Purohit, A.; Roy, A.; Roy Chowdhury, S.; Sarkar, S.; Sharan, M.; Thakur, S.; Behera, P. K.; Chudasama, R.; Dutta, D.; Jha, V.; Kumar, V.; Mohanty, A. K.; Netrakanti, P. K.; Pant, L. M.; Shukla, P.; Topkar, A.; Aziz, T.; Dugad, S.; Mahakud, B.; Mitra, S.; Mohanty, G. B.; Sur, N.; Sutar, B.; Banerjee, S.; Bhattacharya, S.; Chatterjee, S.; Das, P.; Guchait, M.; Jain, Sa.; Kumar, S.; Maity, M.; Majumder, G.; Mazumdar, K.; Sarkar, T.; Wickramage, N.; Chauhan, S.; Dube, S.; Hegde, V.; Kapoor, A.; Kothekar, K.; Pandey, S.; Rane, A.; Sharma, S.; Chenarani, S.; Eskandari Tadavani, E.; Etesami, S. 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M.; Hasegawa, S.; Hirschauer, J.; Hu, Z.; Jayatilaka, B.; Jindariani, S.; Johnson, M.; Joshi, U.; Klima, B.; Kreis, B.; Lammel, S.; Lincoln, D.; Lipton, R.; Liu, M.; Liu, T.; Lopes De Sá, R.; Lykken, J.; Maeshima, K.; Magini, N.; Marraffino, J. M.; Mason, D.; McBride, P.; Merkel, P.; Mrenna, S.; Nahn, S.; O'Dell, V.; Pedro, K.; Prokofyev, O.; Rakness, G.; Ristori, L.; Schneider, B.; Sexton-Kennedy, E.; Soha, A.; Spalding, W. J.; Spiegel, L.; Stoynev, S.; Strait, J.; Strobbe, N.; Taylor, L.; Tkaczyk, S.; Tran, N. V.; Uplegger, L.; Vaandering, E. W.; Vernieri, C.; Verzocchi, M.; Vidal, R.; Wang, M.; Weber, H. A.; Whitbeck, A.; Acosta, D.; Avery, P.; Bortignon, P.; Bourilkov, D.; Brinkerhoff, A.; Carnes, A.; Carver, M.; Curry, D.; Field, R. D.; Furic, I. K.; Gleyzer, S. V.; Joshi, B. M.; Konigsberg, J.; Korytov, A.; Kotov, K.; Ma, P.; Matchev, K.; Mei, H.; Mitselmakher, G.; Rank, D.; Shi, K.; Sperka, D.; Terentyev, N.; Thomas, L.; Wang, J.; Wang, S.; Yelton, J.; Joshi, Y. R.; Linn, S.; Markowitz, P.; Rodriguez, J. L.; Ackert, A.; Adams, T.; Askew, A.; Hagopian, S.; Hagopian, V.; Johnson, K. F.; Kolberg, T.; Martinez, G.; Perry, T.; Prosper, H.; Saha, A.; Santra, A.; Sharma, V.; Yohay, R.; Baarmand, M. M.; Bhopatkar, V.; Colafranceschi, S.; Hohlmann, M.; Noonan, D.; Roy, T.; Yumiceva, F.; Adams, M. R.; Apanasevich, L.; Berry, D.; Betts, R. R.; Cavanaugh, R.; Chen, X.; Evdokimov, O.; Gerber, C. E.; Hangal, D. A.; Hofman, D. J.; Jung, K.; Kamin, J.; Sandoval Gonzalez, I. D.; Tonjes, M. B.; Trauger, H.; Varelas, N.; Wang, H.; Wu, Z.; Zhang, J.; Bilki, B.; Clarida, W.; Dilsiz, K.; Durgut, S.; Gandrajula, R. P.; Haytmyradov, M.; Khristenko, V.; Merlo, J.-P.; Mermerkaya, H.; Mestvirishvili, A.; Moeller, A.; Nachtman, J.; Ogul, H.; Onel, Y.; Ozok, F.; Penzo, A.; Snyder, C.; Tiras, E.; Wetzel, J.; Yi, K.; Blumenfeld, B.; Cocoros, A.; Eminizer, N.; Fehling, D.; Feng, L.; Gritsan, A. V.; Maksimovic, P.; Roskes, J.; Sarica, U.; Swartz, M.; Xiao, M.; You, C.; Al-bataineh, A.; Baringer, P.; Bean, A.; Boren, S.; Bowen, J.; Castle, J.; Khalil, S.; Kropivnitskaya, A.; Majumder, D.; Mcbrayer, W.; Murray, M.; Royon, C.; Sanders, S.; Schmitz, E.; Tapia Takaki, J. D.; Wang, Q.; Ivanov, A.; Kaadze, K.; Maravin, Y.; Mohammadi, A.; Saini, L. K.; Skhirtladze, N.; Toda, S.; Rebassoo, F.; Wright, D.; Anelli, C.; Baden, A.; Baron, O.; Belloni, A.; Eno, S. C.; Feng, Y.; Ferraioli, C.; Hadley, N. J.; Jabeen, S.; Jeng, G. Y.; Kellogg, R. G.; Kunkle, J.; Mignerey, A. C.; Ricci-Tam, F.; Shin, Y. H.; Skuja, A.; Tonwar, S. C.; Abercrombie, D.; Allen, B.; Azzolini, V.; Barbieri, R.; Baty, A.; Bi, R.; Brandt, S.; Busza, W.; Cali, I. A.; D'Alfonso, M.; Demiragli, Z.; Gomez Ceballos, G.; Goncharov, M.; Hsu, D.; Hu, M.; Iiyama, Y.; Innocenti, G. M.; Klute, M.; Kovalskyi, D.; Lai, Y. S.; Lee, Y.-J.; Levin, A.; Luckey, P. D.; Maier, B.; Marini, A. C.; Mcginn, C.; Mironov, C.; Narayanan, S.; Niu, X.; Paus, C.; Roland, C.; Roland, G.; Salfeld-Nebgen, J.; Stephans, G. S. F.; Tatar, K.; Velicanu, D.; Wang, J.; Wang, T. W.; Wyslouch, B.; Benvenuti, A. C.; Chatterjee, R. M.; Evans, A.; Hansen, P.; Hiltbrand, J.; Kalafut, S.; Kubota, Y.; Lesko, Z.; Mans, J.; Nourbakhsh, S.; Ruckstuhl, N.; Rusack, R.; Turkewitz, J.; Wadud, M. A.; Acosta, J. G.; Oliveros, S.; Avdeeva, E.; Bloom, K.; Claes, D. R.; Fangmeier, C.; Gonzalez Suarez, R.; Kamalieddin, R.; Kravchenko, I.; Monroy, J.; Siado, J. E.; Snow, G. R.; Stieger, B.; Dolen, J.; Godshalk, A.; Harrington, C.; Iashvili, I.; Nguyen, D.; Parker, A.; Rappoccio, S.; Roozbahani, B.; Alverson, G.; Barberis, E.; Hortiangtham, A.; Massironi, A.; Morse, D. M.; Orimoto, T.; Teixeira De Lima, R.; Trocino, D.; Wood, D.; Bhattacharya, S.; Charaf, O.; Hahn, K. A.; Mucia, N.; Odell, N.; Pollack, B.; Schmitt, M. H.; Sung, K.; Trovato, M.; Velasco, M.; Dev, N.; Hildreth, M.; Hurtado Anampa, K.; Jessop, C.; Karmgard, D. J.; Kellams, N.; Lannon, K.; Li, W.; Loukas, N.; Marinelli, N.; Meng, F.; Mueller, C.; Musienko, Y.; Planer, M.; Reinsvold, A.; Ruchti, R.; Siddireddy, P.; Smith, G.; Taroni, S.; Wayne, M.; Wightman, A.; Wolf, M.; Woodard, A.; Alimena, J.; Antonelli, L.; Bylsma, B.; Durkin, L. S.; Flowers, S.; Francis, B.; Hart, A.; Hill, C.; Ji, W.; Liu, B.; Luo, W.; Winer, B. L.; Wulsin, H. W.; Cooperstein, S.; Driga, O.; Elmer, P.; Hardenbrook, J.; Hebda, P.; Higginbotham, S.; Kalogeropoulos, A.; Lange, D.; Luo, J.; Marlow, D.; Mei, K.; Ojalvo, I.; Olsen, J.; Palmer, C.; Piroué, P.; Stickland, D.; Tully, C.; Malik, S.; Norberg, S.; Barker, A.; Barnes, V. E.; Das, S.; Folgueras, S.; Gutay, L.; Jha, M. K.; Jones, M.; Jung, A. W.; Khatiwada, A.; Miller, D. H.; Neumeister, N.; Peng, C. C.; Qiu, H.; Schulte, J. F.; Sun, J.; Wang, F.; Xie, W.; Cheng, T.; Parashar, N.; Stupak, J.; Adair, A.; Chen, Z.; Ecklund, K. M.; Freed, S.; Geurts, F. J. M.; Guilbaud, M.; Kilpatrick, M.; Li, W.; Michlin, B.; Northup, M.; Padley, B. P.; Roberts, J.; Rorie, J.; Shi, W.; Tu, Z.; Zabel, J.; Zhang, A.; Bodek, A.; de Barbaro, P.; Demina, R.; Duh, Y. t.; Ferbel, T.; Galanti, M.; Garcia-Bellido, A.; Han, J.; Hindrichs, O.; Khukhunaishvili, A.; Lo, K. H.; Tan, P.; Verzetti, M.; Ciesielski, R.; Goulianos, K.; Mesropian, C.; Agapitos, A.; Chou, J. P.; Gershtein, Y.; Gómez Espinosa, T. A.; Halkiadakis, E.; Heindl, M.; Hughes, E.; Kaplan, S.; Kunnawalkam Elayavalli, R.; Kyriacou, S.; Lath, A.; Montalvo, R.; Nash, K.; Osherson, M.; Saka, H.; Salur, S.; Schnetzer, S.; Sheffield, D.; Somalwar, S.; Stone, R.; Thomas, S.; Thomassen, P.; Walker, M.; Delannoy, A. G.; Foerster, M.; Heideman, J.; Riley, G.; Rose, K.; Spanier, S.; Thapa, K.; Bouhali, O.; Castaneda Hernandez, A.; Celik, A.; Dalchenko, M.; De Mattia, M.; Delgado, A.; Dildick, S.; Eusebi, R.; Gilmore, J.; Huang, T.; Kamon, T.; Mueller, R.; Pakhotin, Y.; Patel, R.; Perloff, A.; Perniè, L.; Rathjens, D.; Safonov, A.; Tatarinov, A.; Ulmer, K. A.; Akchurin, N.; Damgov, J.; De Guio, F.; Dudero, P. R.; Faulkner, J.; Gurpinar, E.; Kunori, S.; Lamichhane, K.; Lee, S. W.; Libeiro, T.; Mengke, T.; Muthumuni, S.; Peltola, T.; Undleeb, S.; Volobouev, I.; Wang, Z.; Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Padeken, K.; Sheldon, P.; Tuo, S.; Velkovska, J.; Xu, Q.; Arenton, M. W.; Barria, P.; Cox, B.; Hirosky, R.; Joyce, M.; Ledovskoy, A.; Li, H.; Neu, C.; Sinthuprasith, T.; Wang, Y.; Wolfe, E.; Xia, F.; Harr, R.; Karchin, P. E.; Poudyal, N.; Sturdy, J.; Thapa, P.; Zaleski, S.; Brodski, M.; Buchanan, J.; Caillol, C.; Dasu, S.; Dodd, L.; Duric, S.; Gomber, B.; Grothe, M.; Herndon, M.; Hervé, A.; Hussain, U.; Klabbers, P.; Lanaro, A.; Levine, A.; Long, K.; Loveless, R.; Ruggles, T.; Savin, A.; Smith, N.; Smith, W. H.; Taylor, D.; Woods, N.; CMS Collaboration

    2018-02-01

    A search for new physics is presented in final states with two oppositely charged leptons (electrons or muons), jets identified as originating from b quarks, and missing transverse momentum (pTmiss). The search uses proton-proton collision data at √{s }=13 TeV amounting to 35.9 fb-1 of integrated luminosity collected using the CMS detector in 2016. Hypothetical signal events are efficiently separated from the dominant t t ¯ background with requirements on pTmiss and transverse-mass variables. No significant deviation is observed from the expected background. Exclusion limits are set in the context of simplified supersymmetric models with pair-produced top squarks. For top squarks, decaying exclusively to a top quark and a neutralino, exclusion limits are placed at 95% confidence level on the mass of the lightest top squark up to 800 GeV and on the lightest neutralino up to 360 GeV. These results, combined with searches in the single-lepton and all-jet final states, raise the exclusion limits up to 1050 GeV for the lightest top squark and up to 500 GeV for the lightest neutralino. For top squarks undergoing a cascade decay through charginos and sleptons, the mass limits reach up to 1300 GeV for top squarks and up to 800 GeV for the lightest neutralino. The results are also interpreted in a simplified model with a dark matter (DM) particle coupled to the top quark through a scalar or pseudoscalar mediator. For light DM, mediator masses up to 100 (50) GeV are excluded for scalar (pseudoscalar) mediators. The result for the scalar mediator achieves some of the most stringent limits to date in this model.

  2. The single-particle potential of nuclear matter in the LOCV framework

    Energy Technology Data Exchange (ETDEWEB)

    Modarres, M., E-mail: mmodares@ut.ac.ir [Physics Department, University of Tehran, North-Kargar Ave., 1439955961 Tehran (Iran, Islamic Republic of); Rajabi, A. [Physics Department, Shahid Rajaei Teacher Training University, Lavizan, 16788 Tehran (Iran, Islamic Republic of)

    2011-10-01

    The density and momentum dependence of single-particle potential (SPP) and effective mass of symmetric nuclear matter are studied in the framework of lowest order constrained variational (LOCV) method. The Reid68, the Reid68-{Delta} and the Av{sub 18} interactions are considered as the input nucleon-nucleon potentials. It is shown that the SPP of nuclear matter, at fixed density, is an increasing function of nucleon momentum, and it has different behavior for the Reid type potentials with respect to Av{sub 18} interaction. We find good agreements between our LOCV SPP and those coming from others many-body techniques such as the (Dirac-)Brueckner-Hartree-Foch ((D)BHF), the fermion hypernetted chain (FHNC), mean field (MF), etc. On the other hand SPP dramatically depends on the density at low and high nucleon momentums. While the effective mass of nuclear matter increases as we increase the nucleon momentum, it decreases at the Fermi surface. Again, good agreements are observed between our calculated effective mass and those coming from the methods mentioned above.

  3. Prospects for indirect detection of frozen-in dark matter

    Science.gov (United States)

    Heikinheimo, Matti; Tenkanen, Tommi; Tuominen, Kimmo

    2018-03-01

    We study observational consequences arising from dark matter (DM) of nonthermal origin, produced by dark freeze-out from a hidden sector heat bath. We assume this heat bath was populated by feebly coupled mediator particles, produced via a Higgs portal interaction with the Standard Model (SM). The dark sector then attained internal equilibrium with a characteristic temperature different from the SM photon temperature. We find that even if the coupling between the DM and the SM sectors is very weak, the scenario allows for indirect observational signals. We show how the expected strength of these signals depends on the temperature of the hidden sector at DM freeze-out.

  4. Emergence of the mass discrepancy-acceleration relation from dark matter-baryon interactions

    Science.gov (United States)

    Famaey, Benoit; Khoury, Justin; Penco, Riccardo

    2018-03-01

    The observed tightness of the mass discrepancy-acceleration relation (MDAR) poses a fine-tuning challenge to current models of galaxy formation. We propose that this relation could arise from collisional interactions between baryons and dark matter (DM) particles, without the need for modification of gravity or ad hoc feedback processes. We assume that these interactions satisfy the following three conditions: (i) the relaxation time of DM particles is comparable to the dynamical time in disk galaxies; (ii) DM exchanges energy with baryons due to elastic collisions; (iii) the product between the baryon-DM cross section and the typical energy exchanged in a collision is inversely proportional to the DM number density. As a proof of principle, we present an example of a particle physics model that gives a DM-baryon cross section with the desired density and velocity dependence. For consistency with direct detection constraints, our DM particles must be either very light (m ll mb) or very heavy (mgg mb), corresponding respectively to heating and cooling of DM by baryons. In both cases, our mechanism applies and an equilibrium configuration can in principle be reached. In this exploratory paper, we focus on the heavy DM/cooling case because it is technically simpler, since the average energy exchanged turns out to be approximately constant throughout galaxies. Under these assumptions, we find that rotationally-supported disk galaxies could naturally settle to equilibrium configurations satisfying a MDAR at all radii without invoking finely tuned feedback processes. We also discuss issues related to the small scale clumpiness of baryons, as well as predictions for pressure-supported systems. We argue in particular that galaxy clusters do not follow the MDAR despite being DM-dominated because they have not reached their equilibrium configuration. Finally, we revisit existing phenomenological, astrophysical and cosmological constraints on baryon-DM interactions in light

  5. Cryogenic phonon-mediated particle detectors for dark matter searches and neutrino physics

    International Nuclear Information System (INIS)

    Lee, A.T.J.

    1993-01-01

    This work describes the development of cryogenic phonon-mediated particle detectors for dark matter searches and neutrino detection. The detectors described in this work employ transition-edge sensors, which consist of a meander pattern of thin-film superconductor on a silicon substrate. When phonons from a particle interaction in the crystal impinge on the sensor in sufficient density, sections of the line are driven normal and provide a measurable resistance. A large fraction of the thesis describes work to fully characterize the phonon flux from particle interactions. In one set of experiments, ∼25% of the phonon energy from 59.54 keV gamma-ray events was found to propagate open-quotes ballisticallyclose quotes (i.e., with little or no scattering) across a 300 μm thick crystal of silicon. Gamma-rays produce electron recoils in silicon whereas with dark matter and neutrino experiments nuclear recoils are also of interest. Two experiments were done to measure the ballistic component that arises from neutron events, which interact via nuclear recoil. Measurements indicate that the fraction of energy that is ballistic is ∼50% greater for nuclear recoils than for electron recoils. Two novel detectors were fabricated and tested in an attempt to improve the sensitivity of the detectors. In the first detector, relatively large Al pads were linked by 2 μm wide Ti lines in a meander pattern. Phonons impinging on the Al pads create quasiparticles which diffuse in the Al pad until they are trapped in the lower gap Tl links. The sensitivity of the detector was found to be increased by this open-quotes funnelingclose quotes action. A second detector was built that incorporates 0.25 μm wide lines defined by direct electron-beam exposure of the photoresist. If the superconducting line is sufficiently narrow, single phonons are capable of driving sections normal which should improve the sensitivity and linearity of the detector

  6. Searching for dark matter at colliders

    Energy Technology Data Exchange (ETDEWEB)

    Richard, Francois [IN2P3/CNRS et Universite Paris-Sud 11 Centre Scientifique d' Orsay, Laboratoire de l' Accelerateur Lineaire, Orsay (France); Arcadi, Giorgio; Mambrini, Yann [Universite Paris-Sud, Laboratoire de Physique Theorique, Orsay (France)

    2015-04-01

    Dark Matter (DM) detection prospects at future e{sup +}e{sup -} colliders are reviewed under the assumption that DM particles are fermions of the Majorana or Dirac type. Although the discussion is quite general, one will keep in mind the recently proposed candidate based on an excess of energetic photons observed in the center of our Galaxy with the Fermi-LAT satellite. In the first part we will assume that DM interactions are mediated by vector bosons, Z or Z'. In the case of Z-boson Direct Detection limits force only axial couplings with the DM. This solution can be naturally accommodated by Majorana DM but is disfavored by the GC excess. Viable scenarios can be instead found in the case of Z' mediator. These scenarios can be tested at e{sup +}e{sup -} colliders through ISR events, e{sup +}e{sup -} → XX + γ. A sensitive background reduction can be achieved by using highly polarized beams. In the second part scalar particles, in particular Higgs particles, have been considered as mediators. The case of the SM Higgs mediator is excluded by limits on the invisible branching ratio of the Higgs. On the contrary particularly interesting is the case in which the DM interactions are mediated by the pseudoscalar state A in two Higgs-doublet model scenarios. In this last case the main collider signature is e{sup +}e{sup -} → HA, H → hh, A → XX. (orig.)

  7. Searching for dark matter at colliders

    International Nuclear Information System (INIS)

    Richard, Francois; Arcadi, Giorgio; Mambrini, Yann

    2015-01-01

    Dark Matter (DM) detection prospects at future e + e - colliders are reviewed under the assumption that DM particles are fermions of the Majorana or Dirac type. Although the discussion is quite general, one will keep in mind the recently proposed candidate based on an excess of energetic photons observed in the center of our Galaxy with the Fermi-LAT satellite. In the first part we will assume that DM interactions are mediated by vector bosons, Z or Z'. In the case of Z-boson Direct Detection limits force only axial couplings with the DM. This solution can be naturally accommodated by Majorana DM but is disfavored by the GC excess. Viable scenarios can be instead found in the case of Z' mediator. These scenarios can be tested at e + e - colliders through ISR events, e + e - → XX + γ. A sensitive background reduction can be achieved by using highly polarized beams. In the second part scalar particles, in particular Higgs particles, have been considered as mediators. The case of the SM Higgs mediator is excluded by limits on the invisible branching ratio of the Higgs. On the contrary particularly interesting is the case in which the DM interactions are mediated by the pseudoscalar state A in two Higgs-doublet model scenarios. In this last case the main collider signature is e + e - → HA, H → hh, A → XX. (orig.)

  8. Nitrogen isotopic composition of macromolecular organic matter in interplanetary dust particles

    Science.gov (United States)

    Aléon, Jérôme; Robert, François; Chaussidon, Marc; Marty, Bernard

    2003-10-01

    Nitrogen concentrations and isotopic compositions were measured by ion microprobe scanning imaging in two interplanetary dust particles L2021 K1 and L2036 E22, in which imaging of D/H and C/H ratios has previously evidenced the presence of D-rich macromolecular organic components. High nitrogen concentrations of 10-20 wt% and δ 15N values up to +400‰ are observed in these D-rich macromolecular components. The previous study of D/H and C/H ratios has revealed three different D-rich macromolecular phases. The one previously ascribed to macromolecular organic matter akin the insoluble organic matter (IOM) from carbonaceous chondrites is enriched in nitrogen by one order of magnitude compared to the carbonaceous chondrite IOM, although its isotopic composition is still similar to what is known from Renazzo (δ 15N = +208‰). The correlation observed in macromolecular organic material between the D- and 15N-excesses suggests that the latter originate probably from chemical reactions typical of the cold interstellar medium. These interstellar materials preserved to some extent in IDPs are therefore macromolecular organic components with various aliphaticity and aromaticity. They are heavily N-heterosubstituted as shown by their high nitrogen concentrations >10 wt%. They have high D/H ratios >10 -3 and δ 15N values ≥ +400‰. In L2021 K1 a mixture is observed at the micron scale between interstellar and chondritic-like organic phases. This indicates that some IDPs contain organic materials processed at various heliocentric distances in a turbulent nebula. Comparison with observation in comets suggests that these molecules may be cometary macromolecules. A correlation is observed between the D/H ratios and δ 15N values of macromolecular organic matter from IDPs, meteorites, the Earth and of major nebular reservoirs. This suggests that most macromolecular organic matter in the inner solar system was probably issued from interstellar precursors and further processed

  9. Influence of particle characteristics and organic matter content on the bioavailability and bioaccumulation of pyrene by clams

    International Nuclear Information System (INIS)

    Verrengia Guerrero, N.R.; Taylor, M.G.; Wider, E.A.; Simkiss, K.

    2003-01-01

    An experimental model with artificial particles and humic acids describes bioavailability of sediment-bound pyrene to clams. - Hydrophobic chemicals are known to associate with sediment particles including those from both suspended particulate matter and bottom deposits. The complex and variable composition of natural particles makes it very difficult therefore, to predict the bioavailability of sediment-bound contaminants. To overcome these problems we have previously devised a test system using artificial particles, with or without humic acids, for use as an experimental model of natural sediments. In the present work we have applied this experimental technique to investigate the bioavailability and bioaccumulation of pyrene by the freshwater fingernail clam Sphaerium corneum. The uptake and accumulation of pyrene in clams exposed to the chemical in the presence of a sample of natural sediment was also investigated. According to the results obtained, particle surface properties and organic matter content are the key factors for assessing the bioavailability and bioaccumulation of pyrene by clams

  10. Cosmological implications of Dark Matter bound states

    Energy Technology Data Exchange (ETDEWEB)

    Mitridate, Andrea [Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126, Pisa (Italy); Redi, Michele; Smirnov, Juri [INFN, Sezione di Firenze, and Dipartimento di Fisica e Astronomia, Università di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino (Italy); Strumia, Alessandro, E-mail: andrea.mitridate@gmail.com, E-mail: michele.redi@fi.infn.it, E-mail: juri.smirnov@mpi-hd.mpg.de, E-mail: alessandro.strumia@cern.ch [Dipartimento di Fisica dell' Università di Pisa and INFN, Pisa (Italy)

    2017-05-01

    We present generic formulæ for computing how Sommerfeld corrections together with bound-state formation affects the thermal abundance of Dark Matter with non-abelian gauge interactions. We consider DM as a fermion 3plet (wino) or 5plet under SU(2) {sub L} . In the latter case bound states raise to 11.5 TeV the DM mass required to reproduce the cosmological DM abundance and give indirect detection signals such as (for this mass) a dominant γ-line around 70 GeV. Furthermore, we consider DM co-annihilating with a colored particle, such as a squark or a gluino, finding that bound state effects are especially relevant in the latter case.

  11. How to save the WIMP. Global analysis of a dark matter model with two s-channel mediators

    International Nuclear Information System (INIS)

    Duerr, Michael; Kahlhoefer, Felix; Schmidt-Hoberg, Kai; Schwetz, Thomas; Vogl, Stefan

    2016-06-01

    A reliable comparison of different dark matter (DM) searches requires models that satisfy certain consistency requirements like gauge invariance and perturbative unitarity. As a well-motivated example, we study two-mediator DM (2MDM). The model is based on a spontaneously broken U(1)"' gauge symmetry and contains a Majorana DM particle as well as two s-channel mediators, one vector (the Z"') and one scalar (the dark Higgs). We perform a global scan over the parameters of the model assuming that the DM relic density is obtained by thermal freeze-out in the early Universe and imposing a large set of constraints: direct and indirect DM searches, monojet, dijet and dilepton searches at colliders, Higgs observables, electroweak precision tests and perturbative unitarity. We conclude that thermal DM is only allowed either close to an s-channel resonance or if at least one mediator is lighter than the DM particle. In these cases a thermal DM abundance can be obtained although DM couplings to the Standard Model are tiny. Interestingly, we find that vector-mediated DM-nucleon scattering leads to relevant constraints despite the velocity-suppressed cross section, and that indirect detection can be important if DM annihilations into both mediators are kinematically allowed.

  12. Reduction and processing of astrophysical data by visualization and creation of merger trees from dark matter particle simulations

    International Nuclear Information System (INIS)

    Riser, T.

    2012-01-01

    State of the art dark matter particle simulations of galaxy clusters produce vast amounts of raw data that need to be interpreted and scientifically understood. In this thesis two cornerstones involved in this process are presented. First, a unique and robust algorithm is shown, which extracts a so called ''merger tree'' from dark matter particle data. It represents the development and history of every galaxy that lives within the gravitational potential of the dark matter halos formed by the simulated structure formation process, with a special focus on the merging of smaller halos into bigger ones through the course of time. Second, a modern approach is discussed that facilitates the massively parallel calculative power of state of the art graphics cards to greatly improve the image quality of real-time particle visualizations without the requirement of additional geometric data. (author)

  13. Paul Scherrer Institute Scientific Report 2000. Volume I: Particles and Matter

    Energy Technology Data Exchange (ETDEWEB)

    Gobrecht, J; Gaeggeler, H; Herlach, D; Junker, K; Kettle, P -R; Kubik, P; Zehnder, A [eds.

    2001-07-01

    Although originally planned for fundamental research in nuclear physics, the particle beams of pions, muons, protons and neutrons are now used in a large variety of disciplines in both natural science and medicine. The beams at PSI have the world's highest intensities and therefore allow certain experiments to be performed, which would not be possible elsewhere. One of the characteristic developments in the Department for Particles and Matter at PSI in 2000 has been a stronger collaboration within the institute. Excellent examples are the collaboration of scientists and technicians from Particle Physics, Micro- and Nanotechnology and SLS to produce pixel detectors for use at SLS, the development of advanced x-ray optics for SLS and other light sources by people from Nanotechnology, an increased collaboration between Radiochemistry and Ion Beam Physics. Also collaborations beyond the department are increasing in strength where we like to mention common users meetings of the Muon Spin Rotation ({mu}SR) and Neutron Scattering communities, the help of the detector group of Particle Physics for instruments at SINQ, and the collaboration between Molecular Nanotechnology and Electrochemistry from the General Energy Department. Links to the industry have also been strengthened. One of the highlights of this year is the demonstration of the first electrically stimulated light emission from SiGe-heterostructures with a largely recognized publication in Science and several spontaneous reactions from semiconductor industries. Also other techniques and devices could be transferred to industry as for instance superconducting tunnel junction detectors developed for astrophysics with application in photon Time-of-Flight Mass Spectrometry to mention one. Progress in 2000 in all these topical areas is described in this report. A list of scientific publications in 2000 is also provided.

  14. Paul Scherrer Institute Scientific Report 2000. Volume I: Particles and Matter

    International Nuclear Information System (INIS)

    Gobrecht, J.; Gaeggeler, H.; Herlach, D.; Junker, K.; Kettle, P.-R.; Kubik, P.; Zehnder, A.

    2001-01-01

    Although originally planned for fundamental research in nuclear physics, the particle beams of pions, muons, protons and neutrons are now used in a large variety of disciplines in both natural science and medicine. The beams at PSI have the world's highest intensities and therefore allow certain experiments to be performed, which would not be possible elsewhere. One of the characteristic developments in the Department for Particles and Matter at PSI in 2000 has been a stronger collaboration within the institute. Excellent examples are the collaboration of scientists and technicians from Particle Physics, Micro- and Nanotechnology and SLS to produce pixel detectors for use at SLS, the development of advanced x-ray optics for SLS and other light sources by people from Nanotechnology, an increased collaboration between Radiochemistry and Ion Beam Physics. Also collaborations beyond the department are increasing in strength where we like to mention common users meetings of the Muon Spin Rotation (μSR) and Neutron Scattering communities, the help of the detector group of Particle Physics for instruments at SINQ, and the collaboration between Molecular Nanotechnology and Electrochemistry from the General Energy Department. Links to the industry have also been strengthened. One of the highlights of this year is the demonstration of the first electrically stimulated light emission from SiGe-heterostructures with a largely recognized publication in Science and several spontaneous reactions from semiconductor industries. Also other techniques and devices could be transferred to industry as for instance superconducting tunnel junction detectors developed for astrophysics with application in photon Time-of-Flight Mass Spectrometry to mention one. Progress in 2000 in all these topical areas is described in this report. A list of scientific publications in 2000 is also provided

  15. Paul Scherrer Institute Scientific Report 2000. Volume I: Particles and Matter

    Energy Technology Data Exchange (ETDEWEB)

    Gobrecht, J.; Gaeggeler, H.; Herlach, D.; Junker, K.; Kettle, P.-R.; Kubik, P.; Zehnder, A. [eds.

    2001-07-01

    Although originally planned for fundamental research in nuclear physics, the particle beams of pions, muons, protons and neutrons are now used in a large variety of disciplines in both natural science and medicine. The beams at PSI have the world's highest intensities and therefore allow certain experiments to be performed, which would not be possible elsewhere. One of the characteristic developments in the Department for Particles and Matter at PSI in 2000 has been a stronger collaboration within the institute. Excellent examples are the collaboration of scientists and technicians from Particle Physics, Micro- and Nanotechnology and SLS to produce pixel detectors for use at SLS, the development of advanced x-ray optics for SLS and other light sources by people from Nanotechnology, an increased collaboration between Radiochemistry and Ion Beam Physics. Also collaborations beyond the department are increasing in strength where we like to mention common users meetings of the Muon Spin Rotation ({mu}SR) and Neutron Scattering communities, the help of the detector group of Particle Physics for instruments at SINQ, and the collaboration between Molecular Nanotechnology and Electrochemistry from the General Energy Department. Links to the industry have also been strengthened. One of the highlights of this year is the demonstration of the first electrically stimulated light emission from SiGe-heterostructures with a largely recognized publication in Science and several spontaneous reactions from semiconductor industries. Also other techniques and devices could be transferred to industry as for instance superconducting tunnel junction detectors developed for astrophysics with application in photon Time-of-Flight Mass Spectrometry to mention one. Progress in 2000 in all these topical areas is described in this report. A list of scientific publications in 2000 is also provided.

  16. Organic matter content and particle size modifications in mangrove sediments as responses to sea level rise.

    Science.gov (United States)

    Sanders, Christian J; Smoak, Joseph M; Waters, Mathew N; Sanders, Luciana M; Brandini, Nilva; Patchineelam, Sambasiva R

    2012-06-01

    Mangroves sediments contain large reservoirs of organic material (OM) as mangrove ecosystems produce large quantities and rapidly burial OM. Sediment accumulation rates of approximately 2.0 mm year(-1), based on (210)Pb(ex) dating, were estimated at the margin of two well-developed mangrove forest in southern Brazil. Regional data point to a relative sea level (RSL) rise of up to ∼4.0 mm year(-1). This RSL rise in turn, may directly influence the origin and quantity of organic matter (OM) deposited along mangrove sediments. Lithostratigraphic changes show that sand deposition is replacing the mud (<63 μm) fraction and OM content is decreasing in successively younger sediments. Sediment accumulation in coastal areas that are not keeping pace with sea level rise is potentially conducive to the observed shifts in particle size and OM content. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. A Limit on the Warm Dark Matter Particle Mass from the Redshifted 21 cm Absorption Line

    Science.gov (United States)

    Safarzadeh, Mohammadtaher; Scannapieco, Evan; Babul, Arif

    2018-06-01

    The recent Experiment to Detect the Global Epoch of Reionization Signature (EDGES) collaboration detection of an absorption signal at a central frequency of ν = 78 ± 1 MHz points to the presence of a significant Lyα background by a redshift of z = 18. The timing of this signal constrains the dark matter particle mass (m χ ) in the warm dark matter (WDM) cosmological model. WDM delays the formation of small-scale structures, and therefore a stringent lower limit can be placed on m χ based on the presence of a sufficiently strong Lyα background due to star formation at z = 18. Our results show that coupling the spin temperature to the gas through Lyα pumping requires a minimum mass of m χ > 3 keV if atomic cooling halos dominate the star formation rate at z = 18, and m χ > 2 keV if {{{H}}}2 cooling halos also form stars efficiently at this redshift. These limits match or exceed the most stringent limits cited to date in the literature, even in the face of the many uncertainties regarding star formation at high redshift.

  18. A Search for weakly interacting dark matter particles with low temperature detectors capable of simultaneously measuring ionization and heat

    Energy Technology Data Exchange (ETDEWEB)

    Sonnenschein, Andrew Harry [UC, Santa Barbara

    1999-01-01

    Lots of gravitating material that doesn't emit or absorb light seems to be required in all sensible accounts of the dynamics of large-scale structures in the universe. The nature and extent of this mysterious "dark matter" has been one of the central puzzles in cosmology over the last decade. This dissertation describes an experiment that tests one possibility, that the dark matter is in the form of undiscovered Weakly Interacting Massive Particles (WIMPs) produced as a thermal relic of the big bang. In this chapter, we will review the most important observations that suggest the dark matter must exist and discuss the forms it could take.

  19. Gravitational waves as a new probe of Bose–Einstein condensate Dark Matter

    Directory of Open Access Journals (Sweden)

    P.S. Bhupal Dev

    2017-10-01

    Full Text Available There exists a class of ultralight Dark Matter (DM models which could give rise to a Bose–Einstein condensate (BEC in the early universe and behave as a single coherent wave instead of individual particles in galaxies. We show that a generic BEC-DM halo intervening along the line of sight of a gravitational wave (GW signal could induce an observable change in the speed of GWs, with the effective refractive index depending only on the mass and self-interaction of the constituent DM particles and the GW frequency. Hence, we propose to use the deviation in the speed of GWs as a new probe of the BEC-DM parameter space. With a multi-messenger approach to GW astronomy and/or with extended sensitivity to lower GW frequencies, the entire BEC-DM parameter space can be effectively probed by our new method in the near future.

  20. Direct dark matter search with the CRESST-III experiment - status and perspectives

    Science.gov (United States)

    Willers, M.; Angloher, G.; Bento, A.; Bucci, C.; Canonica, L.; Defay, X.; Erb, A.; Feilitzsch, F. v.; Ferreiro Iachellini, N.; Gütlein, A.; Gorla, P.; Hauff, D.; Jochum, J.; Kiefer, M.; Kluck, H.; Kraus, H.; Lanfranchi, J.-C.; Loebell, J.; Mancuso, M.; Münster, A.; Pagliarone, C.; Petricca, F.; Potzel, W.; Pröbst, F.; Puig, R.; Reindl, F.; Schäffner, K.; Schieck, J.; Schönert, S.; Seidel, W.; Stahlberg, M.; Stodolsky, L.; Strandhagen, C.; Strauss, R.; Tanzke, A.; Trinh Thi, H. H.; Türkoǧlu, C.; Uffinger, M.; Ulrich, A.; Usherov, I.; Wawoczny, S.; Wüstrich, M.; Zöller, A.

    2017-09-01

    The CRESST-III experiment, located in the Gran Sasso underground laboratory (LNGS, Italy), aims at the direct detection of dark matter (DM) particles. Scintillating CaWO4 crystals operated as cryogenic detectors are used as target material for DM-nucleus scattering. The simultaneous measurement of the phonon signal from the CaWO4 crystal and of the emitted scintillation light in a separate cryogenic light detector is used to discriminate backgrounds from a possible dark matter signal. The experiment aims to significantly improve the sensitivity for low-mass (≲ 5-10 GeV/c2) DM particles by using optimized detector modules with a nuclear recoil-energy threshold ≲ 100 eV. The current status of the experiment as well as projections of the sensitivity for spin-independent DM-nucleon scattering will be presented.

  1. Dark matter "transporting" mechanism explaining positron excesses

    Science.gov (United States)

    Kim, Doojin; Park, Jong-Chul; Shin, Seodong

    2018-04-01

    We propose a novel mechanism to explain the positron excesses, which are observed by satellite-based telescopes including PAMELA and AMS-02, in dark matter (DM) scenarios. The novelty behind the proposal is that it makes direct use of DM around the Galactic Center where DM populates most densely, allowing us to avoid tensions from cosmological and astrophysical measurements. The key ingredients of this mechanism include DM annihilation into unstable states with a very long laboratory-frame life time and their "retarded" decay near the Earth to electron-positron pair(s) possibly with other (in)visible particles. We argue that this sort of explanation is not in conflict with relevant constraints from big bang nucleosynthesis and cosmic microwave background. Regarding the resultant positron spectrum, we provide a generalized source term in the associated diffusion equation, which can be readily applicable to any type of two-"stage" DM scenarios wherein production of Standard Model particles occurs at completely different places from those of DM annihilation. We then conduct a data analysis with the recent AMS-02 data to validate our proposal.

  2. How do stars affect ψDM halos?

    Science.gov (United States)

    Chan, James H. H.; Schive, Hsi-Yu; Woo, Tak-Pong; Chiueh, Tzihong

    2018-04-01

    Wave dark matterDM) predicts a compact soliton core and a granular halo in every galaxy. This work presents the first simulation study of an elliptical galaxy by including both stars and ψDM, focusing on the systematic changes of the central soliton and halo granules. With the addition of stars in the inner halo, we find the soliton core consistently becomes more prominent by absorbing mass from the host halo than that without stars, and the halo granules become "non-isothermal", "hotter" in the inner halo and "cooler" in the outer halo, as opposed to the isothermal halo in pure ψDM cosmological simulations. Moreover, the composite (star+ψDM) mass density is found to follow a r-2 isothermal profile near the half-light radius in most cases. Most striking is the velocity dispersion of halo stars that increases rapidly toward the galactic center by a factor of at least 2 inside the half-light radius caused by the deepened soliton gravitational potential, a result that compares favorably with observations of elliptical galaxies and bulges in spiral galaxies. However in some rare situations we find a phase segregation turning a compact distribution of stars into two distinct populations with high and very low velocity dispersions; while the high-velocity component mostly resides in the halo, the very low-velocity component is bound to the interior of the soliton core, resembling stars in faint dwarf spheroidal galaxies.

  3. Collider, direct and indirect detection of supersymmetric dark matter

    International Nuclear Information System (INIS)

    Baer, Howard; Park, Eun-Kyung; Tata, Xerxes

    2009-01-01

    We present an overview of supersymmetry (SUSY) searches, both at collider experiments and via searches for dark matter (DM). We focus on three DM possibilities in the SUSY context: the thermally produced neutralino, a mixture of axion and axino, and the gravitino, and compare and contrast signals that may be expected at colliders, in direct detection (DD) experiments searching of DM relics left over from the Big Bang, and indirect detection (ID) experiments designed to detect the products of DM annihilations within the solar interior or galactic halo. Detection of DM particles using multiple strategies provides complementary information that may shed light on the new physics associated with the DM sector. In contrast to the minimal supergravity (mSUGRA) model where the measured cold DM relic density restricts us to special regions mostly on the edge of the m 0 -m 1/2 plane, the entire parameter plane becomes allowed if the universality assumption is relaxed in models with just one additional parameter. Then, thermally produced neutralinos with a well-tempered mix of wino, bino and higgsino components, or with a mass adjusted so that their annihilation in the early Universe is Higgs-resonance-enhanced, can be the DM. Well-tempered neutralinos typically yield heightened rates for DD and ID experiments compared with generic predictions from mSUGRA. If instead DM consists of axinos (possibly together with axions) or gravitinos, then there exists the possibility of detection of quasi-stable next-to-lightest SUSY particles at colliding beam experiments, with especially striking consequences if the next-lightest-supersymmetric-particle (NLSP) is charged, but no DD or ID detection. The exception for mixed axion/axino DM is that DD of axions may be possible.

  4. Academic Training Lecture Regular Programme: Particle Physics Foundations of Dark Matter, Dark Energy, and Inflation (1/3)

    CERN Multimedia

    2012-01-01

    Particle Physics Foundations of Dark Matter, Dark Energy, and Inflation (1/3), by Dr. Edward (Rocky) Kolb (University of Chicago).   Wednesday, May 9, 2012 from 11:00 to 12:00 (Europe/Zurich) at CERN ( 500-1-001 - Main Auditorium ) Ninety-five percent of the present mass-energy density of the Universe is dark.  Twenty-five percent is in the form of dark matter holding together galaxies and other large scale structures, and 70% is in the form of dark energy driving an accelerated expansion of the universe.  Dark matter and dark energy cannot be explained within the standard model of particle physics.  In the first lecture I will review the evidence for dark matter and the observations that point to an explanation in the form of cold dark matter.  I will then describe the expected properties of a hypothetical Weakly-Interacting Massive Particle, or WIMP, and review experimental and observational approaches to test the hypothesis.  Finally, I will discus...

  5. Carbon isotope ratios of organic matter in Bering Sea settling particles. Extremely high remineralization of organic carbon derived from diatoms

    International Nuclear Information System (INIS)

    Yasuda, Saki; Akagi, Tasuku; Naraoka, Hiroshi; Kitajima, Fumio; Takahashi, Kozo

    2016-01-01

    The carbon isotope ratios of organic carbon in settling particles collected in the highly-diatom-productive Bering Sea were determined. Wet decomposition was employed to oxidize relatively fresh organic matter. The amount of unoxidised organic carbon in the residue following wet decomposition was negligible. The δ 13 C of organic carbon in the settling particles showed a clear relationship against SiO 2 /CaCO 3 ratio of settling particles: approximately -26‰ and -19‰ at lower and higher SiO 2 /CaCO 3 ratios, respectively. The δ 13 C values were largely interpreted in terms of mixing of two major plankton sources. Both δ 13 C and compositional data can be explained consistently only by assuming that more than 98% of diatomaceous organic matter decays and that organic matter derived from carbonate-shelled plankton may remain much less remineralized. A greater amount of diatom-derived organic matter is discovered to be trapped with the increase of SiO 2 /CaCO 3 ratio of the settling particles. The ratio of organic carbon to inorganic carbon, known as the rain ratio, therefore, tends to increase proportionally with the SiO 2 /CaCO 3 ratio under an extremely diatom-productive condition. (author)

  6. Strategic field No.5 'the origin of matter and the universe'. Toward interdisciplinary researches in particle, nuclear and astrophysics

    International Nuclear Information System (INIS)

    Aoki, Shinya

    2011-01-01

    Four main research subjects in the strategic field No. 5 'The origin of matter and the universe', planned to be investigated on 'Kei' super computer, are explained in detail, by focusing on interdisciplinary aspect of researches among particle, nuclear and astrophysics. (author)

  7. THE USE OF STATIC AND DYNAMIC MECHANICAL MODELS IN TEACHING ASPECTS OF THE THEORETICAL CONCEPT, THE PARTICLE NATURE OF MATTER.

    Science.gov (United States)

    PELLA, MILTON O.; ZIEGLER, ROBERT E.

    THE RELATIVE EFFECTIVENESS OF TWO TYPES OF MECHANICAL MODELS FOR TEACHING ELEMENTARY SCHOOL STUDENTS TO USE THE PARTICLE IDEA OF MATTER TO EXPLAIN CERTAIN PHYSICAL PHENOMENA WAS INVESTIGATED. SUBJECTS WERE RANDOMLY SELECTED FROM STUDENTS ENROLLED IN GRADES TWO THROUGH SIX IN A SCHOOL SYSTEM. A SERIES OF DEMONSTRATIONS AND RELATED QUESTIONS WERE…

  8. Using MT2 to distinguish dark matter stabilization symmetries

    International Nuclear Information System (INIS)

    Agashe, Kaustubh; Kim, Doojin; Zhu Lijun; Walker, Devin G. E.

    2011-01-01

    We examine the potential of using colliders to distinguish models with parity (Z 2 ) stabilized dark matter (DM) from models in which the DM is stabilized by other symmetries, taking the latter to be a Z 3 symmetry for illustration. The key observation is that a heavier mother particle charged under a Z 3 stabilization symmetry can decay into one or two DM particles along with standard model particles. This can be contrasted with the decay of a mother particle charged under a parity symmetry; typically, only one DM particle appears in the decay chain. The arXiv:1003.0899 studied the distributions of visible invariant mass from the decay of a single such mother particle in order to highlight the resulting distinctive signatures of Z 3 symmetry versus parity symmetry stabilized dark matter candidates. We now describe a complementary study which focuses on decay chains of the two mother particles which are necessarily present in these events. We also include in our analysis the missing energy/momentum in the event. For the Z 3 symmetry stabilized mothers, the resulting inclusive final state can have two, three or four DM particles. In contrast, models with Z 2 symmetry can have only two. We show that the shapes and edges of the distribution of M T2 -type variables, along with ratio of the visible momentum/energy on the two sides of the event, are powerful in distinguishing these different scenarios. Finally we conclude by outlining future work which focuses on reducing combinatoric ambiguities from reconstructing multijet events. Increasing the reconstruction efficiency can allow better reconstruction of events with two or three dark matter candidates in the final state.

  9. Systematic problems with using dark matter simulations to model stellar halos

    International Nuclear Information System (INIS)

    Bailin, Jeremy; Bell, Eric F.; Valluri, Monica; Stinson, Greg S.; Debattista, Victor P.; Couchman, H. M. P.; Wadsley, James

    2014-01-01

    The limits of available computing power have forced models for the structure of stellar halos to adopt one or both of the following simplifying assumptions: (1) stellar mass can be 'painted' onto dark matter (DM) particles in progenitor satellites; (2) pure DM simulations that do not form a luminous galaxy can be used. We estimate the magnitude of the systematic errors introduced by these assumptions using a controlled set of stellar halo models where we independently vary whether we look at star particles or painted DM particles, and whether we use a simulation in which a baryonic disk galaxy forms or a matching pure DM simulation that does not form a baryonic disk. We find that the 'painting' simplification reduces the halo concentration and internal structure, predominantly because painted DM particles have different kinematics from star particles even when both are buried deep in the potential well of the satellite. The simplification of using pure DM simulations reduces the concentration further, but increases the internal structure, and results in a more prolate stellar halo. These differences can be a factor of 1.5-7 in concentration (as measured by the half-mass radius) and 2-7 in internal density structure. Given this level of systematic uncertainty, one should be wary of overinterpreting differences between observations and the current generation of stellar halo models based on DM-only simulations when such differences are less than an order of magnitude.

  10. Evaluation of respirable particle matter in gold mine tailings on the Witwatersrand

    International Nuclear Information System (INIS)

    Ojelede, M.E.; Annegarn, H.J.

    2007-01-01

    Within the Witwatersrand gold mining area of South Africa, wind-blown dust is a significant contributor to atmospheric air pollution brought to the fore with the reworking of old mine tailings. Approximately 40,000 hectares are covered with tailings in the Witwatersrand. Wind-erosion during late austral winter and early spring causes surfaces of these tailings to be exposed, particularly during higher wind speeds and in the absence of rainfall. Local residents complain as the surrounding areas experience unpleasant dust episodes. As a result of urban PM 10 and PM 2.5 respirable particulate matter, increased respiratory ailments, morbidity and mortality, and concerns about the health impacts of wind-blown mine tailings in South Africa have been reported. Since 1981, significant monitoring of dustfall has taken place on the Witwatersrand, however, characterization of the respirable fraction of gold mine tailings material and dustfall is lacking. This paper presented the results of a study that established the content of respirable particulate matter in exposed mine tailings and wind-blown dust, and their likely contributions to ambient air. The initial results of the particulate size distribution of material samples from tailings and dust deposits collected in ambient dustfall-monitors were provided. Particle size distributions from different deposit types include slimes and sand deposits, surface and core material, and wind-winnowed secondary deposits. Fractions of PM 10 in source and deposited material were also discussed. It was concluded that there was a significant fraction of PM 10 material in the mine tailings, and that further work to quantify the population exposure risk is needed. 11 refs., 1 tab., 6 figs

  11. Searches for Dark Matter in ATLAS

    CERN Document Server

    Alpigiani, Cristiano; The ATLAS collaboration

    2017-01-01

    Although the existence of Dark Matter (DM) is well established by many astronomical measurements, its nature still remains one of the unsolved puzzles of particles physics. The unprecedented energy reached by the Large Hadron Collider (LHC) at CERN has allowed exploration of previously unaccessible kinematic regimes in the search for new phenomena. An overview of most recent searches for dark matter with the ATLAS detector at LHC is presented and the interpretation of the results in terms of effective field theory and simplified models is discussed. The exclusion limits set by the ATLAS searches are compared to the constraints from direct dark matter detection experiments.

  12. Inelastic dark matter, non-standard halos and the DAMA/LIBRA results

    International Nuclear Information System (INIS)

    March-Russell, John; McCabe, Christopher; McCullough, Matthew

    2009-01-01

    The DAMA collaboration have claimed to detect particle dark matter (DM) via an annual modulation in their observed recoil event rate. This appears to be in strong disagreement with the null results of other experiments if interpreted in terms of elastic DM scattering, while agreement for a small region of parameter space is possible for inelastic DM (iDM) due to the altered kinematics of the collision. To date most analyses assume a simple galactic halo DM velocity distribution, the Standard Halo Model, but direct experimental support for the SHM is severely lacking and theoretical studies indicate possible significant differences. We investigate the dependence of DAMA and the other direct detection experiments on the local DM velocity distribution, utilizing the results of the Via Lactea and Dark Disc numerical simulations. We also investigate effects of varying the solar circular velocity, the DM escape velocity, and the DAMA quenching factor within experimental limits. Our data set includes the latest ZEPLIN-III results, as well as full publicly available data sets. Due to the more sensitive dependence of the inelastic cross section on the velocity distribution, we find that with Via Lactea the DAMA results can be consistent with all other experiments over an enlarged region of iDM parameter space, with higher mass particles being preferred, while Dark Disc does not lead to an improvement. A definitive test of DAMA for iDM requires heavy element detectors.

  13. Active matter beyond mean-field: ring-kinetic theory for self-propelled particles.

    Science.gov (United States)

    Chou, Yen-Liang; Ihle, Thomas

    2015-02-01

    Recently, Hanke et al. [Phys. Rev. E 88, 052309 (2013)] showed that mean-field kinetic theory fails to describe collective motion in soft active colloids and that correlations must not be neglected. Correlation effects are also expected to be essential in systems of biofilaments driven by molecular motors and in swarms of midges. To obtain correlations in an active matter system from first principles, we derive a ring-kinetic theory for Vicsek-style models of self-propelled agents from the exact N-particle evolution equation in phase space. The theory goes beyond mean-field and does not rely on Boltzmann's approximation of molecular chaos. It can handle precollisional correlations and cluster formation, which are both important to understand the phase transition to collective motion. We propose a diagrammatic technique to perform a small-density expansion of the collision operator and derive the first two equations of the Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) hierarchy. An algorithm is presented that numerically solves the evolution equation for the two-particle correlations on a lattice. Agent-based simulations are performed and informative quantities such as orientational and density correlation functions are compared with those obtained by ring-kinetic theory. Excellent quantitative agreement between simulations and theory is found at not-too-small noises and mean free paths. This shows that there are parameter ranges in Vicsek-like models where the correlated closure of the BBGKY hierarchy gives correct and nontrivial results. We calculate the dependence of the orientational correlations on distance in the disordered phase and find that it seems to be consistent with a power law with an exponent around -1.8, followed by an exponential decay. General limitations of the kinetic theory and its numerical solution are discussed.

  14. Cold light dark matter in extended seesaw models

    Science.gov (United States)

    Boulebnane, Sami; Heeck, Julian; Nguyen, Anne; Teresi, Daniele

    2018-04-01

    We present a thorough discussion of light dark matter produced via freeze-in in two-body decays A→ B DM . If A and B are quasi-degenerate, the dark matter particle has a cold spectrum even for keV masses. We show this explicitly by calculating the transfer function that encodes the impact on structure formation. As examples for this setup we study extended seesaw mechanisms with a spontaneously broken global U(1) symmetry, such as the inverse seesaw. The keV-scale pseudo-Goldstone dark matter particle is then naturally produced cold by the decays of the quasi-degenerate right-handed neutrinos.

  15. Multiwavelength analysis of dark matter annihilation and RX-DMFIT

    International Nuclear Information System (INIS)

    McDaniel, A.; Jeltema, T.; Profumo, S.; Storm, E.

    2017-01-01

    Dark matter (DM) particles are predicted by several well motivated models to yield Standard Model particles through self-annihilation that can potentially be detected by astrophysical observations. In particular, the production of charged particles from DM annihilation in astrophysical systems that contain magnetic fields yields radio emission through synchrotron radiation and X-ray emission through inverse Compton scattering of ambient photons. We introduce RX-DMFIT, a tool used for calculating the expected secondary emission from DM annihilation. RX-DMFIT includes a wide range of customizable astrophysical and particle parameters and incorporates important astrophysics including the diffusion of charged particles, relevant radiative energy losses, and magnetic field modelling. We demonstrate the use and versatility of RX-DMFIT by analyzing the potential radio and X-ray signals for a variety of DM particle models and astrophysical environments including galaxy clusters, dwarf spheroidal galaxies and normal galaxies. We then apply RX-DMFIT to a concrete example using Segue I radio data to place constraints for a range of assumed DM annihilation channels. For WIMP models with M χ ≤ 100 GeV and assuming weak diffusion, we find that the leptonic μ + μ − and τ + τ − final states provide the strongest constraints, placing limits on the DM particle cross-section well below the thermal relic cross-section, while even for the b b-bar channel we find limits close to the thermal relic cross-section. Our analysis shows that radio emission provides a highly competitive avenue for dark matter searches.

  16. Multiwavelength analysis of dark matter annihilation and RX-DMFIT

    Energy Technology Data Exchange (ETDEWEB)

    McDaniel, A.; Jeltema, T.; Profumo, S. [Department of Physics, University of California, 1156 High St. Santa Cruz, CA, 95064 (United States); Storm, E., E-mail: alexmcdaniel@ucsc.edu, E-mail: tesla@ucsc.edu, E-mail: profumo@ucsc.edu, E-mail: e.m.storm@uva.nl [GRAPPA, Institute of Physics, Universiteit van Amsterdam Science Park 904, 1098XH Amsterdam (Netherlands)

    2017-09-01

    Dark matter (DM) particles are predicted by several well motivated models to yield Standard Model particles through self-annihilation that can potentially be detected by astrophysical observations. In particular, the production of charged particles from DM annihilation in astrophysical systems that contain magnetic fields yields radio emission through synchrotron radiation and X-ray emission through inverse Compton scattering of ambient photons. We introduce RX-DMFIT, a tool used for calculating the expected secondary emission from DM annihilation. RX-DMFIT includes a wide range of customizable astrophysical and particle parameters and incorporates important astrophysics including the diffusion of charged particles, relevant radiative energy losses, and magnetic field modelling. We demonstrate the use and versatility of RX-DMFIT by analyzing the potential radio and X-ray signals for a variety of DM particle models and astrophysical environments including galaxy clusters, dwarf spheroidal galaxies and normal galaxies. We then apply RX-DMFIT to a concrete example using Segue I radio data to place constraints for a range of assumed DM annihilation channels. For WIMP models with M {sub χ} ≤ 100 GeV and assuming weak diffusion, we find that the leptonic μ{sup +}μ{sup −} and τ{sup +}τ{sup −} final states provide the strongest constraints, placing limits on the DM particle cross-section well below the thermal relic cross-section, while even for the b b-bar channel we find limits close to the thermal relic cross-section. Our analysis shows that radio emission provides a highly competitive avenue for dark matter searches.

  17. Can annihilating dark matter be lighter than a few GeVs?

    International Nuclear Information System (INIS)

    Boehm, C; Ensslin, T A; Silk, J

    2004-01-01

    We estimate the gamma-ray fluxes from the residual annihilations of dark matter (DM) particles having a mass m dm from [MeV, O(10) GeV] (a possible solution to the DM issue provided they have a new kind of interactions and no significant coupling to the Z) and compare them to observations. We find that particles lighter than O(100 MeV) can be viable DM candidates provided their dominant annihilation cross section is S-wave suppressed so as to satisfy the gamma-ray constraints. A similar conclusion is obtained for particles lighter than O(10) GeV from the study of radio fluxes, assuming a NFW profile and that they mainly annihilate into electrons

  18. Towards a generalized Landau theory of quasi-particles for hot dense matter

    International Nuclear Information System (INIS)

    Leermakers, R.

    1985-01-01

    In this thesis it is tried to construct a Landau quasi-particle theory for relativistic systems, using field-theoretical methods. It includes a perturbative calculation of the pressure of a quark-gluon plasma. It reports the existence of a hitherto unnoticed plasmon contribution of the order g 3 due to transverse quasi-gluons. A new and Lorentz covariant formulation of the Landau theory is being developed, for a general relativistic system. A detailed calculation is presented of the observables of a quantum electrodynamical (QED) plasma, in lowest orders of perturbation theory. A transverse plasmon effect is discovered, both analytically and numerically. In addition, the analysis shows quasi-electrons and positrons to be stable excitations at any temperature. This is proven in all orders of perturbation theory. Along with a Landau theory for quark-gluon matter, a linearized kinetic equation is derived for the singlet quark distribution function, with a collision term for soft encounters between quasi-quarks. (Auth.)

  19. Solar Extreme UV radiation and quark nugget dark matter model

    Science.gov (United States)

    Zhitnitsky, Ariel

    2017-10-01

    We advocate the idea that the surprising emission of extreme ultra violet (EUV) radiation and soft x-rays from the Sun are powered externally by incident dark matter (DM) particles. The energy and the spectral shape of this otherwise unexpected solar irradiation is estimated within the quark nugget dark matter model. This model was originally invented as a natural explanation of the observed ratio Ωdark ~ Ωvisible when the DM and visible matter densities assume the same order of magnitude values. This generic consequence of the model is a result of the common origin of both types of matter which are formed during the same QCD transition and both proportional to the same fundamental dimensional parameter ΛQCD. We also present arguments suggesting that the transient brightening-like "nanoflares" in the Sun may be related to the annihilation events which inevitably occur in the solar atmosphere within this dark matter scenario.

  20. Decaying dark matter and the PAMELA anomaly

    International Nuclear Information System (INIS)

    Ibarra, Alejandro; Tran, David

    2009-01-01

    Astrophysical and cosmological observations do not require the dark matter particles to be absolutely stable. If they are indeed unstable, their decay into positrons might occur at a sufficiently large rate to allow the indirect detection of dark matter through an anomalous contribution to the cosmic positron flux. In this paper we discuss the implications of the excess in the positron fraction recently reported by the PAMELA collaboration for the scenario of decaying dark matter. To this end, we have performed a model-independent analysis of possible signatures by studying various decay channels in the case of both a fermionic and a scalar dark matter particle. We find that the steep rise in the positron fraction measured by PAMELA at energies larger than 10 GeV can naturally be accommodated in several realizations of the decaying dark matter scenario. The data point toward a rather heavy dark matter particle, m DM ∼> 300 GeV, which preferentially decays directly into first or second generation charged leptons with a lifetime τ DM ∼ 10 26 s

  1. The Distribution and Annihilation of Dark Matter Around Black Holes

    Science.gov (United States)

    Schnittman, Jeremy D.

    2015-01-01

    We use a Monte Carlo code to calculate the geodesic orbits of test particles around Kerr black holes, generating a distribution function of both bound and unbound populations of dark matter (DM) particles. From this distribution function, we calculate annihilation rates and observable gamma-ray spectra for a few simple DM models. The features of these spectra are sensitive to the black hole spin, observer inclination, and detailed properties of the DM annihilation cross-section and density profile. Confirming earlier analytic work, we find that for rapidly spinning black holes, the collisional Penrose process can reach efficiencies exceeding 600%, leading to a high-energy tail in the annihilation spectrum. The high particle density and large proper volume of the region immediately surrounding the horizon ensures that the observed flux from these extreme events is non-negligible.

  2. Model-independent implications of the e±, p-bar cosmic ray spectra on properties of Dark Matter

    International Nuclear Information System (INIS)

    Cirelli, M.; Kadastik, M.; Raidal, M.; Strumia, A.

    2009-01-01

    Taking into account spins, we classify all two-body non-relativistic Dark Matter annihilation channels to the allowed polarization states of Standard Model particles, computing the energy spectra of the stable final-state particles relevant for indirect DM detection. We study the DM masses, annihilation channels and cross sections that can reproduce the PAMELA indications of an e + excess consistently with the PAMELA p-bar data and the ATIC/PPB-BETS e + +e - data. From the PAMELA data alone, two solutions emerge: (i) either the DM particles that annihilate into W,Z,h must be heavier than about 10 TeV or (ii) the DM must annihilate only into leptons. Thus in both cases a DM particle compatible with the PAMELA excess seems to have quite unexpected properties. The solution (ii) implies a peak in the e + +e - energy spectrum, which, indeed, seems to appear in the ATIC/PPB-BETS data around 700 GeV. If upcoming data from ATIC-4 and GLAST confirm this feature, this would point to a O(1) TeV DM annihilating only into leptons. Otherwise the solution (i) would be favored. We comment on the implications of these results for DM models, direct DM detection and colliders as well as on the possibility of an astrophysical origin of the excess

  3. RESPON DAN KOPING PASIEN DM POST AMPUTASI

    Directory of Open Access Journals (Sweden)

    Candra Kusuma Negara

    2017-09-01

    Full Text Available Penyakit DM merupakan masalah kesehatan yang sangat penting karena berkaitan dengan tingginya kejadian komplikasi dan mortalitas yang tinggi. Bagi kebanyakan orang penyakit DM adalah suatu penyakit yang sangat mengkhawatirkan dan masyarakat sadar akan besarnya potensi bahaya yang ditimbulkannya. Bagi individu yang menderita DM dengan pasca amputasi, kehidupan selanjutnya merupakan babak baru yang penuh tantangan dan perubahan serta akan melalui proses koping terhadap proses perubahan tersebut. Secara umum penelitian ini bertujuan untuk mengeksplorasi berbagai pengalaman pasien DM pasca amputasi tentang respon dan koping yang dialaminya. Penelitian ini menggunakan studi fenomenologi. Pengambilan data menggunakan indepth interview pada empat orang partisipan yang dirawat jalan di Poli kaki diabetic RSUD Ulin Banjarmasin yang dilengkapi dengan pedoman wawancara dan informed consent. Metode analisis yang terstruktur dari Creswell menjadi 6 langkah. Terdapat 2 Tema yang ditemukan dalam penelitian ini yaitu berbagai respon post amputasi dan Berbagai koping pasien DM post amputasi. Berbagai respon post amputasi terdiri dari tiga Sub-Tema yaitu: (1 Mengalami hambatan fisik, (2 Mengalami perubahan peran, (3 Mengalami proses berduka, dan Terdapat empat Sub-Tema yang menggambarkan berbagai koping pasien DM post amputasi yaitu: (1 Lebih banyak beribadah, (2 Menerima keadaan, (3 Motivasi yang kuat, (4 Mencari dukungan sosial.

  4. Is Large-Scale-Structure formation a new probe of the Dark Matter interactions with Standard Model particles?

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    In the last few decades, there have been extensive efforts made to discover dark matter particles through a significant experimental program based on direct and indirect detection techniques. However so far these searches remain unsuccessful, thus questioning our ability to elucidate one of the biggest challenges of modern Cosmology. In this talk I will review some of the key aspects of these techniques and present a new strategy to characterise the dark matter interactions with the visible sector without having to rely on critical assumptions.

  5. Effects of QCD bound states on dark matter relic abundance

    Energy Technology Data Exchange (ETDEWEB)

    Liew, Seng Pei [Department of Physics, The University of Tokyo,Bunkyo-ku, Tokyo 113-0033 (Japan); Luo, Feng [Kavli IPMU (WPI), UTIAS, The University of Tokyo,Kashiwa, Chiba 277-8583 (Japan)

    2017-02-17

    We study scenarios where there exists an exotic massive particle charged under QCD in the early Universe. We calculate the formation and dissociation rates of bound states formed by pairs of these particles, and apply the results in dark matter (DM) coannihilation scenarios, including also the Sommerfeld effect. We find that on top of the Sommerfeld enhancement, bound-state effects can further significantly increase the largest possible DM masses which can give the observed DM relic abundance, by ∼30–100% with respect to values obtained by considering the Sommerfeld effect only, for the color triplet or octet exotic particles we consider. In particular, it indicates that the Bino DM mass in the right-handed stop-Bino coannihilation scenario in the Minimal Supersymmetric extension of the Standard Model (MSSM) can reach ∼2.5 TeV, even though the potential between the stop and antistop prior to forming a bound state is repulsive. We also apply the bound-state effects in the calculations of relic abundance of long-lived or metastable massive colored particles, and discuss the implications on the BBN constraints and the abundance of a super-weakly interacting DM. The corrections for the bound-state effect when the exotic massive colored particles also carry electric charges, and the collider bounds are also discussed.

  6. The development and application of the AstroFit program for complementary dark matter studies

    International Nuclear Information System (INIS)

    Nguyen, Ngoc-Lan Nelly

    2013-02-01

    This doctoral thesis describes the development and application of the AstroFit program. Many studies have shown the existence of dark matter (DM), a mass component that constitutes over eighty percent of the entire matter in the Universe. From historical astrophysical evidence to latest reconstructions with sophisticated methods, the gravitational effect of DM can be shown, but its nature remains unknown. Many theoretical explanations aim at describing DM, for example as weakly interacting massive particles (WIMPs), within particular frameworks. The majority of these frameworks extend the existing standard model of particle physics (SM), so that new particles are added to the known set of elementary particles. One of these frameworks is the constrained supersymmetric standard model (CMSSM) that naturally introduces a DM candidate in form of the lightest supersymmetric particle(LSP). Searches for DM particles are undertaken in three different ways. First, directly with fixed-target experiments that measure WIMPs coming towards the Earth with nuclei of the target material. Second, indirectly by reconstructing DM signatures in particle spectra of known particles observed with ground-based telescopes, spaceborne satellites or balloon-borne experiments. And third, indirectly via direct production of DM at particle colliders such as the Large Hadron Collider (LHC) and energy reconstructions where missing transverse energy is presumably carried away by the DM particles. Global fit programs used in particle physics, such as Fittino, are designed to fit parameters of theories beyond the SM simultaneously that are in accordance with the experimental and observed data in order to probe models and constrain the parameter space. To explore complementarity in DM research, the AstroFit interface program has been developed to combine all available information from direct and indirect searches for DM as well as collider searches for new physics in such global fits. To demonstrate

  7. The development and application of the AstroFit program for complementary dark matter studies

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ngoc-Lan Nelly

    2013-02-15

    This doctoral thesis describes the development and application of the AstroFit program. Many studies have shown the existence of dark matter (DM), a mass component that constitutes over eighty percent of the entire matter in the Universe. From historical astrophysical evidence to latest reconstructions with sophisticated methods, the gravitational effect of DM can be shown, but its nature remains unknown. Many theoretical explanations aim at describing DM, for example as weakly interacting massive particles (WIMPs), within particular frameworks. The majority of these frameworks extend the existing standard model of particle physics (SM), so that new particles are added to the known set of elementary particles. One of these frameworks is the constrained supersymmetric standard model (CMSSM) that naturally introduces a DM candidate in form of the lightest supersymmetric particle(LSP). Searches for DM particles are undertaken in three different ways. First, directly with fixed-target experiments that measure WIMPs coming towards the Earth with nuclei of the target material. Second, indirectly by reconstructing DM signatures in particle spectra of known particles observed with ground-based telescopes, spaceborne satellites or balloon-borne experiments. And third, indirectly via direct production of DM at particle colliders such as the Large Hadron Collider (LHC) and energy reconstructions where missing transverse energy is presumably carried away by the DM particles. Global fit programs used in particle physics, such as Fittino, are designed to fit parameters of theories beyond the SM simultaneously that are in accordance with the experimental and observed data in order to probe models and constrain the parameter space. To explore complementarity in DM research, the AstroFit interface program has been developed to combine all available information from direct and indirect searches for DM as well as collider searches for new physics in such global fits. To demonstrate

  8. Self-interacting asymmetric dark matter coupled to a light massive dark photon

    International Nuclear Information System (INIS)

    Petraki, Kalliopi; Pearce, Lauren; Kusenko, Alexander

    2014-01-01

    Dark matter (DM) with sizeable self-interactions mediated by a light species offers a compelling explanation of the observed galactic substructure; furthermore, the direct coupling between DM and a light particle contributes to the DM annihilation in the early universe. If the DM abundance is due to a dark particle-antiparticle asymmetry, the DM annihilation cross-section can be arbitrarily large, and the coupling of DM to the light species can be significant. We consider the case of asymmetric DM interacting via a light (but not necessarily massless) Abelian gauge vector boson, a dark photon. In the massless dark photon limit, gauge invariance mandates that DM be multicomponent, consisting of positive and negative dark ions of different species which partially bind in neutral dark atoms. We argue that a similar conclusion holds for light dark photons; in particular, we establish that the multi-component and atomic character of DM persists in much of the parameter space where the dark photon is sufficiently light to mediate sizeable DM self-interactions. We discuss the cosmological sequence of events in this scenario, including the dark asymmetry generation, the freeze-out of annihilations, the dark recombination and the phase transition which gives mass to the dark photon. We estimate the effect of self-interactions in DM haloes, taking into account this cosmological history. We place constraints based on the observed ellipticity of large haloes, and identify the regimes where DM self-scattering can affect the dynamics of smaller haloes, bringing theory in better agreement with observations. Moreover, we estimate the cosmological abundance of dark photons in various regimes, and derive pertinent bounds

  9. Structural, chemical and isotopic examinations of interstellar organic matter extracted from meteorites and interstellar dust particles

    Science.gov (United States)

    Busemann, Henner; Alexander, Conel M. O'D.; Nittler, Larry R.; Stroud, Rhonda M.; Zega, Tom J.; Cody, George D.; Yabuta, Hikaru; Kilcoyne, A. L. David

    2008-10-01

    Meteorites and Interplanetary Dust Particles (IDPs) are supposed to originate from asteroids and comets, sampling the most primitive bodies in the Solar System. They contain abundant carbonaceous material. Some of this, mostly insoluble organic matter (IOM), likely originated in the protosolar molecular cloud, based on spectral properties and H and N isotope characteristics. Together with cometary material returned with the Stardust mission, these samples provide a benchmark for models aiming to understand organic chemistry in the interstellar medium, as well as for mechanisms that secured the survival of these fragile molecules during Solar System formation. The carrier molecules of the isotope anomalies are largely unknown, although amorphous carbonaceous spheres, so-called nanoglobules, have been identified as carriers. We are using Secondary Ion Mass Spectrometry to identify isotopically anomalous material in meteoritic IOM and IDPs at a ~100-200 nm scale. Organics of most likely interstellar origin are then extracted with the Focused-Ion-Beam technique and prepared for synchrotron X-ray and Transmission Electron Microscopy. These experiments yield information on the character of the H- and N-bearing interstellar molecules: While the association of H and N isotope anomalies with nanoglobules could be confirmed, we have also identified amorphous, micron-sized monolithic grains. D-enrichments in meteoritic IOM appear not to be systematically associated with any specific functional groups, whereas 15N-rich material can be related to imine and nitrile functionality. The large 15N- enrichments observed here (δ15N > 1000 ‰) cannot be reconciled with models using interstellar ammonia ice reactions, and hence, provide new constraints for understanding the chemistry in cold interstellar clouds.

  10. Constraints on the dark matter annihilation from Fermi-LAT observation of M31

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhengwei; Yuan, Qiang [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, 2 West Beijing Road, Nanjing, 210008 (China); Huang, Xiaoyuan [Physik-Department T30d, Technische Universität München, James-Franck-Straße, Garching, D-85748 Germany (Germany); Xu, Yupeng, E-mail: lizw@ihep.ac.cn, E-mail: huangxiaoyuan@gmail.com, E-mail: yuanq@pmo.ac.cn, E-mail: xuyp@ihep.ac.cn [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, 19B Yuquan Road, Beijing, 100049 (China)

    2016-12-01

    Gamma-ray is a good probe of dark matter (DM) particles in the Universe. We search for the DM annihilation signals in the direction of the Andromeda galaxy (M31) using 7.5 year Fermi-LAT pass 8 data. Similar to Pshirkov et al. (2016), we find that there is residual excess emission from the direction of M31 if only the galactic disk as traced by the far infrared emission is considered. Adding a point-like source will improve the fitting effectively, although additional slight improvements can be found if an extended component such as a uniform disk or two bubbles is added instead. Taking the far infrared disk plus a point source as the background model, we search for the DM annihilation signals in the data. We find that there is strong degeneracy between the emission from the galaxy and that from 10s GeV mass DM annihilation in the main halo with quark final state. However, the required DM annihilation cross section is about 10{sup −25}–10{sup −24} cm{sup 3}s{sup −1}, orders of magnitude larger than the constraints from observations of dwarf spheroidal galaxies, indicating a non-DM origin of the emission. If DM subhalos are taken into account, the degeneracy is broken. When considering the enhancement from DM subhalos, the constraints on DM model parameters are comparable to (or slightly weaker than) those from the population of dwarf spheroidal galaxies. We also discuss the inverse Compton scattering component from DM annihilation induced electrons/positrons. For the first time we include an energy dependent template of the inverse Compton emission (i.e., a template cube) in the data analysis to take into account the effect of diffusion of charged particles. We find a significant improvement of the constraints in the high mass range of DM particles after considering the inverse Compton emission.

  11. A Raman spectroscopic study of organic matter in interplanetary dust particles and meteorites using multiple wavelength laser excitation

    OpenAIRE

    Starkey, N. A.; Franchi, I. A.; Alexander, C. M. O'D.

    2013-01-01

    Raman spectroscopy was used to investigate insoluble organic matter (IOM) from a range of chondritic meteorites, and a suite of interplanetary dust particles (IDPs). Three monochromatic excitation wavelengths (473 nm, 514 nm, 632 nm) were applied sequentially to assess variations in meteorite and IDP Raman peak parameters (carbon D and G bands) as a function of excitation wavelength (i.e., dispersion). Greatest dispersion occurs in CVs > OCs > CMs > CRs with type 3 chondrites compared at diff...

  12. Particle-size fractionation and stable carbon isotope distribution applied to the study of soil organic matter dynamics

    International Nuclear Information System (INIS)

    Cerri, C.; Feller, C.; Balesdent, J.; Victoria, R.; Plenecassagne, A.

    1985-01-01

    The present Note concerns the dynamics of organic matter in soils under forest (C 3 -type vegetation) and 12 and 50 years old sugar-cane (C 4 -type vegetation) cultivation. The decomposition rate of ‘forest organic matter” and the accumulation rate of “sugar-cane organic matter” are estimated through 13 C measurements of total soil and different organic fractions (particle-size, fractionation) [fr

  13. Characterization of particulate matter emissions from on-road gasoline and diesel vehicles using a soot particle aerosol mass spectrometer

    OpenAIRE

    Dallmann, T. R.; Onasch, T. B.; Kirchstetter, T. W.; Worton, D. R.; Fortner, E. C.; Herndon, S. C.; Wood, E. C.; Franklin, J. P.; Worsnop, D. R.; Goldstein, A. H.; Harley, R. A.

    2014-01-01

    Particulate matter (PM) emissions were measured in July 2010 from on-road motor vehicles driving through a highway tunnel in the San Francisco Bay area. A soot particle aerosol mass spectrometer (SP-AMS) was used to measure the chemical composition of PM emitted by gasoline and diesel vehicles at high time resolution. Organic aerosol (OA) and black carbon (BC) concentrations were measured during various time periods that had different levels of diesel influence, as well as d...

  14. Apoastron shift constraints on dark matter distribution at the Galactic Center

    International Nuclear Information System (INIS)

    Zakharov, A. F.; Nucita, A. A.; De Paolis, F.; Ingrosso, G.

    2007-01-01

    The existence of dark matter (DM) at scales of a few parsecs down to ≅10 -5 pc around the centers of galaxies and, in particular, in the Galactic Center region has been considered in the literature. Under the assumption that such a DM clump, principally constituted by nonbaryonic matter (like weakly interacting massive particles) does exist at the center of our galaxy, the study of the γ-ray emission from the Galactic Center region allows us to constrain both the mass and the size of this DM sphere. Further constraints on the DM distribution parameters may be derived by observations of bright infrared stars around the Galactic Center. Hall and Gondolo [J. Hall and P. Gondolo, Phys. Rev. D 74, 063511 (2006)] used estimates of the enclosed mass obtained in various ways and tabulated by Ghez et al. [A. M. Ghez et al., Astron. Nachr. 324, 527 (2003); A. M. Ghez et al., Astrophys. J. 620, 744 (2005)]. Moreover, if a DM cusp does exist around the Galactic Center it could modify the trajectories of stars moving around it in a sensible way depending on the DM mass distribution. Here, we discuss the constraints that can be obtained with the orbit analysis of stars (as S2 and S16) moving inside the DM concentration with the present and next generations of large telescopes. In particular, consideration of the S2 star apoastron shift may allow improving limits on the DM mass and size

  15. On the effects of organic matter and sulphur-containing compounds on the CCN activation of combustion particles

    Directory of Open Access Journals (Sweden)

    A. Petzold

    2005-01-01

    Full Text Available The European PartEmis project (Measurement and prediction of emissions of aerosols and gaseous precursors from gas turbine engines was focussed on the characterisation and quantification of exhaust emissions from a gas turbine engine. The combustion aerosol characterisation included on-line measurements of mass and number concentration, size distribution, mixing state, thermal stability of internally mixed particles, hygroscopicity, cloud condensation nuclei (CCN activation potential, and off-line analysis of chemical composition. Based on this extensive data set, the role of sulphuric acid coating and of the organic fraction of the combustion particles for the CCN activation was investigated. Modelling of CCN activation was conducted using microphysical and chemical properties obtained from the measurements as input data. Coating the combustion particles with water-soluble sulphuric acid, increases the potential CCN activation, or lowers the activation diameter, respectively. The adaptation of a Köhler model to the experimental data yielded coatings from 0.1 to 3 vol-% of water-soluble matter, which corresponds to an increase in the fraction of CCN-activated combustion particles from ≤10−4 to ≌10−2 at a water vapour saturation ratio Sw=1.006. Additional particle coating by coagulation of combustion particles and aqueous sulphuric acid particles formed by nucleation further reduces the CCN activation diameter. In contrast, particles containing a large fraction of non-volatile organic compounds grow significantly less at high relative humidity than particles with a lower content of non-volatile OC. The resulting reduction in the potential CCN activation with an increasing fraction of non-volatile OC becomes visible as a trend in the experimental data. While a coating of water-soluble sulphuric acid increases the potential CCN activation, or lowers the activation diameter, respectively, the non-volatile organic compounds, mainly found at

  16. Life cycle impact assessment modeling for particulate matter: A new approach based on physico-chemical particle properties.

    Science.gov (United States)

    Notter, Dominic A

    2015-09-01

    Particulate matter (PM) causes severe damage to human health globally. Airborne PM is a mixture of solid and liquid droplets suspended in air. It consists of organic and inorganic components, and the particles of concern range in size from a few nanometers to approximately 10μm. The complexity of PM is considered to be the reason for the poor understanding of PM and may also be the reason why PM in environmental impact assessment is poorly defined. Currently, life cycle impact assessment is unable to differentiate highly toxic soot particles from relatively harmless sea salt. The aim of this article is to present a new impact assessment for PM where the impact of PM is modeled based on particle physico-chemical properties. With the new method, 2781 characterization factors that account for particle mass, particle number concentration, particle size, chemical composition and solubility were calculated. Because particle sizes vary over four orders of magnitudes, a sound assessment of PM requires that the exposure model includes deposition of particles in the lungs and that the fate model includes coagulation as a removal mechanism for ultrafine particles. The effects model combines effects from particle size, solubility and chemical composition. The first results from case studies suggest that PM that stems from emissions generally assumed to be highly toxic (e.g. biomass combustion and fossil fuel combustion) might lead to results that are similar compared with an assessment of PM using established methods. However, if harmless PM emissions are emitted, established methods enormously overestimate the damage. The new impact assessment allows a high resolution of the damage allocatable to different size fractions or chemical components. This feature supports a more efficient optimization of processes and products when combating air pollution. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Dark Matter

    Directory of Open Access Journals (Sweden)

    Einasto J.

    2011-06-01

    Full Text Available I give a review of the development of the concept of dark matter. The dark matter story passed through several stages from a minor observational puzzle to a major challenge for theory of elementary particles. Modern data suggest that dark matter is the dominant matter component in the Universe, and that it consists of some unknown non-baryonic particles. Dark matter is the dominant matter component in the Universe, thus properties of dark matter particles determine the structure of the cosmic web.

  18. Interference effects of two scalar boson propagators on the LHC search for the singlet fermion DM

    Energy Technology Data Exchange (ETDEWEB)

    Ko, P., E-mail: pko@kias.re.kr; Li, Jinmian, E-mail: jmli@kias.re.kr

    2017-02-10

    A gauge invariant UV-completion for singlet fermion DM interacting with the standard model (SM) particles involves a new singlet scalar. Therefore the model contains two scalar mediators, mixtures of the SM Higgs boson and a singlet scalar boson. Collider phenomenology of the interference effect between these two scalar propagators is studied in this work. This interference effect can be either constructive or destructive in the DM production cross section depending on both singlet scalar and DM masses, and it will soften the final state jets in the full mass region. Applying the CMS mono-jet search to our model, we find the interference effect plays a very important role in the DM search sensitivity, and the DM production cross section of our model is more than one order of magnitude below the LHC sensitivity at current stage.

  19. Cold deconfined matter EOS through an HTL quasi-particle model

    OpenAIRE

    Romatschke, Paul

    2002-01-01

    Using quasi-particle models, lattice data can be mapped to finite chemical potential. By comparing a simple and an HTL quasi-particle model, we derive the general trend that a full inclusion of the plasmon effect will give.

  20. SEARCH FOR DARK MATTER ANNIHILATION SIGNALS FROM THE FORNAX GALAXY CLUSTER WITH H.E.S.S

    Energy Technology Data Exchange (ETDEWEB)

    Abramowski, A. [Institut fuer Experimentalphysik, Universitaet Hamburg, Luruper Chaussee 149, D 22761 Hamburg (Germany); Acero, F. [Laboratoire de Physique Theorique et Astroparticules, Universite Montpellier 2, CNRS/IN2P3, CC 70, Place Eugene Bataillon, F-34095 Montpellier Cedex 5 (France); Aharonian, F.; Bernloehr, K.; Bochow, A. [Max-Planck-Institut fuer Kernphysik, P.O. Box 103980, D 69029 Heidelberg (Germany); Akhperjanian, A. G. [National Academy of Sciences of the Republic of Armenia, Yerevan (Armenia); Anton, G.; Balzer, A.; Brucker, J. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Str. 1, D 91058 Erlangen (Germany); Barnacka, A. [Nicolaus Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warsaw (Poland); Barres de Almeida, U. [Department of Physics, University of Durham, South Road, Durham DH1 3LE (United Kingdom); Becherini, Y. [Astroparticule et Cosmologie (APC), CNRS, Universite Paris 7 Denis Diderot, 10, rue Alice Domon et Leonie Duquet, F-75205 Paris Cedex 13 (France); Becker, J. [Institut fuer Theoretische Physik, Lehrstuhl IV: Weltraum und Astrophysik, Ruhr-Universitaet Bochum, D 44780 Bochum (Germany); Behera, B. [Landessternwarte, Universitaet Heidelberg, Koenigstuhl, D 69117 Heidelberg (Germany); Birsin, E. [Institut fuer Physik, Humboldt-Universitaet zu Berlin, Newtonstr. 15, D 12489 Berlin (Germany); Biteau, J.; Brun, F. [Laboratoire Leprince-Ringuet, Ecole Polytechnique, CNRS/IN2P3, F-91128 Palaiseau (France); Boisson, C. [LUTH, Observatoire de Paris, CNRS, Universite Paris Diderot, 5 Place Jules Janssen, 92190 Meudon (France); Bolmont, J. [LPNHE, Universite Pierre et Marie Curie Paris 6, Universite Denis Diderot Paris 7, CNRS/IN2P3, 4 Place Jussieu, F-75252, Paris Cedex 5 (France); Bordas, P., E-mail: bjoern.opitz@desy.de [Institut fuer Astronomie und Astrophysik, Universitaet Tuebingen, Sand 1, D 72076 Tuebingen (Germany); Collaboration: H.E.S.S. Collaboration; and others

    2012-05-10

    The Fornax galaxy cluster was observed with the High Energy Stereoscopic System for a total live time of 14.5 hr, searching for very high energy (VHE; E > 100GeV) {gamma}-rays from dark matter (DM) annihilation. No significant signal was found in searches for point-like and extended emissions. Using several models of the DM density distribution, upper limits on the DM velocity-weighted annihilation cross-section ({sigma}v) as a function of the DM particle mass are derived. Constraints are derived for different DM particle models, such as those arising from Kaluza-Klein and supersymmetric models. Various annihilation final states are considered. Possible enhancements of the DM annihilation {gamma}-ray flux, due to DM substructures of the DM host halo, or from the Sommerfeld effect, are studied. Additional {gamma}-ray contributions from internal bremsstrahlung and inverse Compton radiation are also discussed. For a DM particle mass of 1 TeV, the exclusion limits at 95% of confidence level reach values of ({sigma}v){sup 95%C.L.} {approx} 10{sup -23} cm{sup 3} s{sup -1}, depending on the DM particle model and halo properties. Additional contribution from DM substructures can improve the upper limits on ({sigma}v) by more than two orders of magnitude. At masses around 4.5 TeV, the enhancement by substructures and the Sommerfeld resonance effect results in a velocity-weighted annihilation cross-section upper limit at the level of ({sigma}v){sup 95%C.L.} {approx}10{sup -26} cm{sup 3} s{sup -1}.

  1. SEARCH FOR DARK MATTER ANNIHILATION SIGNALS FROM THE FORNAX GALAXY CLUSTER WITH H.E.S.S

    International Nuclear Information System (INIS)

    Abramowski, A.; Acero, F.; Aharonian, F.; Bernlöhr, K.; Bochow, A.; Akhperjanian, A. G.; Anton, G.; Balzer, A.; Brucker, J.; Barnacka, A.; Barres de Almeida, U.; Becherini, Y.; Becker, J.; Behera, B.; Birsin, E.; Biteau, J.; Brun, F.; Boisson, C.; Bolmont, J.; Bordas, P.

    2012-01-01

    The Fornax galaxy cluster was observed with the High Energy Stereoscopic System for a total live time of 14.5 hr, searching for very high energy (VHE; E > 100GeV) γ-rays from dark matter (DM) annihilation. No significant signal was found in searches for point-like and extended emissions. Using several models of the DM density distribution, upper limits on the DM velocity-weighted annihilation cross-section (σv) as a function of the DM particle mass are derived. Constraints are derived for different DM particle models, such as those arising from Kaluza-Klein and supersymmetric models. Various annihilation final states are considered. Possible enhancements of the DM annihilation γ-ray flux, due to DM substructures of the DM host halo, or from the Sommerfeld effect, are studied. Additional γ-ray contributions from internal bremsstrahlung and inverse Compton radiation are also discussed. For a DM particle mass of 1 TeV, the exclusion limits at 95% of confidence level reach values of (σv) 95%C.L. ∼ 10 –23 cm 3 s –1 , depending on the DM particle model and halo properties. Additional contribution from DM substructures can improve the upper limits on (σv) by more than two orders of magnitude. At masses around 4.5 TeV, the enhancement by substructures and the Sommerfeld resonance effect results in a velocity-weighted annihilation cross-section upper limit at the level of (σv) 95%C.L. ∼10 –26 cm 3 s –1 .

  2. Searching for dark matter signals in the left-right symmetric gauge model with CP symmetry

    International Nuclear Information System (INIS)

    Guo Wanlei; Wu Yueliang; Zhou Yufeng

    2010-01-01

    We investigate the singlet scalar dark matter (DM) candidate in a left-right symmetric gauge model with two Higgs bidoublets in which the stabilization of the DM particle is induced by the discrete symmetries P and CP. According to the observed DM abundance, we predict the DM direct and indirect detection cross sections for the DM mass range from 10 to 500 GeV. We show that the DM indirect detection cross section is not sensitive to the light Higgs mixing and Yukawa couplings except for the resonance regions. The predicted spin-independent DM-nucleon elastic scattering cross section is found to be significantly dependent on the above two factors. Our results show that the future DM direct search experiments can cover the most parts of the allowed parameter space. The PAMELA antiproton data can only exclude two very narrow regions in the two Higgs bidoublets model. It is very difficult to detect the DM direct or indirect signals in the resonance regions due to the Breit-Wigner resonance effect.

  3. WEAKLY INTERACTING MASSIVE PARTICLE DARK MATTER AND FIRST STARS: SUPPRESSION OF FRAGMENTATION IN PRIMORDIAL STAR FORMATION

    International Nuclear Information System (INIS)

    Smith, Rowan J.; Glover, Simon C. O.; Klessen, Ralf S.; Iocco, Fabio; Schleicher, Dominik R. G.; Hirano, Shingo; Yoshida, Naoki

    2012-01-01

    We present the first three-dimensional simulations to include the effects of dark matter annihilation feedback during the collapse of primordial minihalos. We begin our simulations from cosmological initial conditions and account for dark matter annihilation in our treatment of the chemical and thermal evolution of the gas. The dark matter is modeled using an analytical density profile that responds to changes in the peak gas density. We find that the gas can collapse to high densities despite the additional energy input from the dark matter. No objects supported purely by dark matter annihilation heating are formed in our simulations. However, we find that dark matter annihilation heating has a large effect on the evolution of the gas following the formation of the first protostar. Previous simulations without dark matter annihilation found that protostellar disks around Population III stars rapidly fragmented, forming multiple protostars that underwent mergers or ejections. When dark matter annihilation is included, however, these disks become stable to radii of 1000 AU or more. In the cases where fragmentation does occur, it is a wide binary that is formed.

  4. Late decaying 2-component dark matter scenario as an explanation of the AMS-02 positron excess

    Energy Technology Data Exchange (ETDEWEB)

    Buch, Jatan; Ralegankar, Pranjal; Rentala, Vikram, E-mail: jatan_buch@brown.edu, E-mail: pranjal6@illinois.edu, E-mail: rentala@phy.iitb.ac.in [Department of Physics, Indian Institute of Technology - Bombay, Powai, Mumbai 400076 (India)

    2017-10-01

    The long standing anomaly in the positron flux as measured by the PAMELA and AMS-02 experiments could potentially be explained by dark matter (DM) annihilations. This scenario typically requires a large 'boost factor' to be consistent with a thermal relic dark matter candidate produced via freeze-out. However, such an explanation is disfavored by constraints from CMB observations on energy deposition during the epoch of recombination. We discuss a scenario called late-decaying two-component dark matter (LD2DM), where the entire DM consists of two semi-degenerate species. Within this framework, the heavier species is produced as a thermal relic in the early universe and decays to the lighter species over cosmological timescales. Consequently, the lighter species becomes the DM which populates the universe today. We show that annihilation of the lighter DM species with an enhanced cross-section, produced via such a non-thermal mechanism, can explain the observed AMS-02 positron flux while avoiding CMB constraints. The observed DM relic density can be correctly reproduced as well with simple s -wave annihilation cross-sections. We demonstrate that the scenario is safe from CMB constraints on late-time energy depositions during the cosmic 'dark ages'. Interestingly, structure formation constraints force us to consider small mass splittings between the two dark matter species. We explore possible cosmological and particle physics signatures in a toy model that realizes this scenario.

  5. Late decaying 2-component dark matter scenario as an explanation of the AMS-02 positron excess

    International Nuclear Information System (INIS)

    Buch, Jatan; Ralegankar, Pranjal; Rentala, Vikram

    2017-01-01

    The long standing anomaly in the positron flux as measured by the PAMELA and AMS-02 experiments could potentially be explained by dark matter (DM) annihilations. This scenario typically requires a large 'boost factor' to be consistent with a thermal relic dark matter candidate produced via freeze-out. However, such an explanation is disfavored by constraints from CMB observations on energy deposition during the epoch of recombination. We discuss a scenario called late-decaying two-component dark matter (LD2DM), where the entire DM consists of two semi-degenerate species. Within this framework, the heavier species is produced as a thermal relic in the early universe and decays to the lighter species over cosmological timescales. Consequently, the lighter species becomes the DM which populates the universe today. We show that annihilation of the lighter DM species with an enhanced cross-section, produced via such a non-thermal mechanism, can explain the observed AMS-02 positron flux while avoiding CMB constraints. The observed DM relic density can be correctly reproduced as well with simple s -wave annihilation cross-sections. We demonstrate that the scenario is safe from CMB constraints on late-time energy depositions during the cosmic 'dark ages'. Interestingly, structure formation constraints force us to consider small mass splittings between the two dark matter species. We explore possible cosmological and particle physics signatures in a toy model that realizes this scenario.

  6. Decoherence as a way to measure extremely soft collisions with dark matter

    Science.gov (United States)

    Riedel, C. Jess; Yavin, Itay

    2017-07-01

    A new frontier in the search for dark matter (DM) is based on the idea of detecting the decoherence caused by DM scattering against a mesoscopic superposition of normal matter. Such superpositions are uniquely sensitive to very small momentum transfers from new particles and forces, especially DM with a mass below 100 MeV. Here we investigate what sorts of dark sectors are inaccessible with existing methods but would induce noticeable decoherence in the next generation of matter interferometers. We show that very soft but medium range (0.1 nm - 1 μ m ) elastic interactions between nuclei and DM are particularly suitable. We construct toy models for such interactions, discuss existing constraints, and delineate the expected sensitivity of forthcoming experiments. The first hints of DM in these devices would appear as small variations in the anomalous decoherence rate with a period of one sidereal day. This is a generic signature of interstellar sources of decoherence, clearly distinguishing it from terrestrial backgrounds. The OTIMA experiment under development in Vienna will begin to probe Earth-thermalizing DM once sidereal variations in the background decoherence rate are pushed below one part in a hundred for superposed 5-nm gold nanoparticles. The proposals by Bateman et al. and Geraci et al. could be similarly sensitive although they would require at least a month of data taking. DM that is absorbed or elastically reflected by the Earth, and so avoids a greenhouse density enhancement, would not be detectable by those three experiments. On the other hand, the aggressive proposals of the MAQRO collaboration and Pino et al. would immediately open up many orders of magnitude in DM mass, interaction range, and coupling strength, regardless of how DM behaves in bulk matter.

  7. Probing the nature of Dark Matter with the SKA

    Science.gov (United States)

    Colafrancesco, S.; Regis, M.; Marchegiani, P.; Beck, G.; Beck, R.; Zechlin, H.; Lobanov, A.; Horns, D.

    2015-04-01

    Dark Matter (DM) is a fundamental ingredient of our Universe and of structure formation, and yet its nature is elusive to astrophysical probes. Information on the nature and physical properties of the WIMP (neutralino) DM (the leading candidate for a cosmologically relevant DM) can be obtained by studying the astrophysical signals of their annihilation/decay. Among the various e.m. signals, secondary electrons produced by neutralino annihilation generate synchrotron emission in the magnetized atmosphere of galaxy clusters and galaxies which could be observed as a diffuse radio emission (halo or haze) centered on the DM halo. A deep search for DM radio emission with SKA in local dwarf galaxies, galaxy regions with low star formation and galaxy clusters (with offset DM-baryonic distribution, like e.g. the Bullet cluster) can be very effective in constraining the neutralino mass, composition and annihilation cross-section. For the case of a dwarf galaxy, like e.g. Draco, the constraints on the DM annihilation cross-section obtainable with SKA1-MID will be at least a factor $\\sim 10^3$ more stringent than the limits obtained by Fermi-LAT in the $\\gamma$-rays. These limits scale with the value of the B field, and the SKA will have the capability to determine simultaneously both the magnetic field in the DM-dominated structures and the DM particle properties. The optimal frequency band for detecting the DM-induced radio emission is around $\\sim 1$ GHz, with the SKA1-MID Band 1 and 4 important to probe the synchrotron spectral curvature at low-$\

  8. A search for low-mass dark matter with the cryogenic dark matter search and the development of highly multiplexed phonon-mediated particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Moore, David Craig [California Inst. of Technology (CalTech), Pasadena, CA (United States)

    2012-01-01

    A wide variety of astrophysical observations indicate that approximately 85% of the matter in the universe is nonbaryonic and nonluminous. Understanding the nature of this "dark matter" is one of the most important outstanding questions in cosmology. Weakly Interacting Massive Particles (WIMPs) are a leading candidate for dark matter since they would be thermally produced in the early universe in the correct abundance to account for the observed relic density of dark matter. If WIMPs account for the dark matter, then rare interactions from relic WIMPs should be observable in terrestrial detectors. Recently, unexplained excess events in the DAMA/LIBRA, CoGeNT, and CRESST-II experiments have been interpreted as evidence of scattering from WIMPs with masses ~10 GeV and spin-independent scattering cross sections of 10-41-10-40 cm2. The Cryogenic Dark Matter Search (CDMS II) attempts to identify WIMP interactions using an array of cryogenic germanium and silicon particle detectors located at the Soudan Underground Laboratory in northern Minnesota. In this dissertation, data taken by CDMS II are reanalyzed using a 2 keV recoil energy threshold to increase the sensitivity to WIMPs with masses ~10 GeV. These data disfavor an explanation for the DAMA/LIBRA, CoGeNT, and CRESST-II results in terms of spin-independent elastic scattering of WIMPs with masses ≲12 GeV, under standard assumptions. At the time of publication, they provided the strongest constraints on spin-independent elastic scattering from 5-9 GeV, ruling out previously unexplored parameter space. To detect WIMPs or exclude the remaining parameter space favored by the most popular models will ultimately require detectors with target masses ≳1 ton, requiring an increase in mass by more than two orders of magnitude over CDMS II. For cryogenic detectors such as CDMS, scaling to such large target masses will require individual detector elements to be fabricated more quickly and cheaply, while

  9. Atmospheric fate and transport of fine volcanic ash: Does particle shape matter?

    Science.gov (United States)

    White, C. M.; Allard, M. P.; Klewicki, J.; Proussevitch, A. A.; Mulukutla, G.; Genareau, K.; Sahagian, D. L.

    2013-12-01

    Volcanic ash presents hazards to infrastructure, agriculture, and human and animal health. In particular, given the economic importance of intercontinental aviation, understanding how long ash is suspended in the atmosphere, and how far it is transported has taken on greater importance. Airborne ash abrades the exteriors of aircraft, enters modern jet engines and melts while coating interior engine parts causing damage and potential failure. The time fine ash stays in the atmosphere depends on its terminal velocity. Existing models of ash terminal velocities are based on smooth, quasi-spherical particles characterized by Stokes velocity. Ash particles, however, violate the various assumptions upon which Stokes flow and associated models are based. Ash particles are non-spherical and can have complex surface and internal structure. This suggests that particle shape may be one reason that models fail to accurately predict removal rates of fine particles from volcanic ash clouds. The present research seeks to better parameterize predictive models for ash particle terminal velocities, diffusivity, and dispersion in the atmospheric boundary layer. The fundamental hypothesis being tested is that particle shape irreducibly impacts the fate and transport properties of fine volcanic ash. Pilot studies, incorporating modeling and experiments, are being conducted to test this hypothesis. Specifically, a statistical model has been developed that can account for actual volcanic ash size distributions, complex ash particle geometry, and geometry variability. Experimental results are used to systematically validate and improve the model. The experiments are being conducted at the Flow Physics Facility (FPF) at UNH. Terminal velocities and dispersion properties of fine ash are characterized using still air drop experiments in an unconstrained open space using a homogenized mix of source particles. Dispersion and sedimentation dynamics are quantified using particle image

  10. On the Sunyaev-Zel'dovich effect from dark matter annihilation or decay in galaxy clusters

    International Nuclear Information System (INIS)

    Lavalle, Julien; Boehm, Céline; Barthès, Julien

    2010-01-01

    We revisit the prospects for detecting the Sunyaev Zel'dovich (SZ) effect induced by dark matter (DM) annihilation or decay. We show that with standard (or even extreme) assumptions for DM properties, the optical depth associated with relativistic electrons injected from DM annihilation or decay is much smaller than that associated with thermal electrons, when averaged over the angular resolution of current and future experiments. For example, we find: τ DM ∼ 10 −9 −10 −5 (depending on the assumptions) for m χ = 1 GeV and a density profile ρ∝r −1 for a template cluster located at 50 Mpc and observed within an angular resolution of 10'', compared to τ th ∼ 10 −3 −10 −2 . This, together with a full spectral analysis, enables us to demonstrate that, for a template cluster with generic properties, the SZ effect due to DM annihilation or decay is far below the sensitivity of the Planck satellite. This is at variance with previous claims regarding heavier annihilating DM particles. Should DM be made of lighter particles, the current constraints from 511 keV observations on the annihilation cross section or decay rate still prevent a detectable SZ effect. Finally, we show that spatial diffusion sets a core of a few kpc in the electron distribution, even for very cuspy DM profiles, such that improving the angular resolution of the instrument, eg with ALMA, does not necessarily improve the detection potential. We provide useful analytical formulæ parameterized in terms of the DM mass, decay rate or annihilation cross section and DM halo features, that allow quick estimates of the SZ effect induced by any given candidate and any DM halo profile

  11. Gravitational wave as probe of superfluid dark matter

    Science.gov (United States)

    Cai, Rong-Gen; Liu, Tong-Bo; Wang, Shao-Jiang

    2018-02-01

    In recent years, superfluid dark matter (SfDM) has become a competitive model of emergent modified Newtonian dynamics (MOND) scenario: MOND phenomenons naturally emerge as a derived concept due to an extra force mediated between baryons by phonons as a result of axionlike particles condensed as superfluid at galactic scales; Beyond galactic scales, these axionlike particles behave as normal fluid without phonon-mediated MOND-like force between baryons, therefore SfDM also maintains the usual success of Λ CDM at cosmological scales. In this paper, we use gravitational waves (GWs) to probe the relevant parameter space of SfDM. GWs through Bose-Einstein condensate (BEC) could propagate with a speed slightly deviation from the speed-of-light due to the change in the effective refractive index, which depends on the SfDM parameters and GW-source properties. We find that Five hundred meter Aperture Spherical Telescope (FAST), Square Kilometre Array (SKA) and International Pulsar Timing Array (IPTA) are the most promising means as GW probe of relevant parameter space of SfDM. Future space-based GW detectors are also capable of probing SfDM if a multimessenger approach is adopted.

  12. Exploring the Cosmic Frontier, Task A - Direct Detection of Dark Matter, Task B - Experimental Particle Astrophysics

    International Nuclear Information System (INIS)

    Matthews, John A.J.; Gold, Michael S.

    2016-01-01

    This report summarizes the work of Task A and B for the period 2013-2016. For Task A the work is for direct detection of dark matter with the single-phase liquid argon experiment Mini-CLEAN. For Task B the work is for the search for new physics in the analysis of fluorescence events with the Auger experiment and for the search for the indirect detection of dark matter with the HAWC experiment.

  13. Exploring the Cosmic Frontier, Task A - Direct Detection of Dark Matter, Task B - Experimental Particle Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, John A.J. [Univ. of New Mexico, Albuquerque, NM (United States); Gold, Michael S. [Univ. of New Mexico, Albuquerque, NM (United States)

    2016-08-11

    This report summarizes the work of Task A and B for the period 2013-2016. For Task A the work is for direct detection of dark matter with the single-phase liquid argon experiment Mini-CLEAN. For Task B the work is for the search for new physics in the analysis of fluorescence events with the Auger experiment and for the search for the indirect detection of dark matter with the HAWC experiment.

  14. DaMaSCUS-CRUST: Dark Matter Simulation Code for Underground Scatterings - Crust Edition

    Science.gov (United States)

    Emken, Timon; Kouvaris, Chris

    2018-03-01

    DaMaSCUS-CRUST determines the critical cross-section for strongly interacting DM for various direct detection experiments systematically and precisely using Monte Carlo simulations of DM trajectories inside the Earth's crust, atmosphere, or any kind of shielding. Above a critical dark matter-nucleus scattering cross section, any terrestrial direct detection experiment loses sensitivity to dark matter, since the Earth crust, atmosphere, and potential shielding layers start to block off the dark matter particles. This critical cross section is commonly determined by describing the average energy loss of the dark matter particles analytically. However, this treatment overestimates the stopping power of the Earth crust; therefore, the obtained bounds should be considered as conservative. DaMaSCUS-CRUST is a modified version of DaMaSCUS (ascl:1706.003) that accounts for shielding effects and returns a precise exclusion band.

  15. Supersymmetric dark matter after LHC run 1

    International Nuclear Information System (INIS)

    Bagnaschi, E.A.; Buchmueller, O.; Cavanaugh, R.; Illinois Univ., Chicago, IL

    2015-08-01

    Different mechanisms operate in various regions of the MSSM parameter space to bring the relic density of the lightest neutralino, χ 0 1 , assumed here to be the LSP and thus the Dark Matter (DM) particle, into the range allowed by astrophysics and cosmology. These mechanisms include coannihilation with some nearly-degenerate next-to-lightest supersymmetric particle (NLSP) such as the lighter stau τ 1 , stop t 1 or chargino χ ± 1 , resonant annihilation via direct-channel heavy Higgs bosons H/A, the light Higgs boson h or the Z boson, and enhanced annihilation via a larger Higgsino component of the LSP in the focus-point region. These mechanisms typically select lower-dimensional subspaces in MSSM scenarios such as the CMSSM, NUHM1, NUHM2 and pMSSM10. We analyze how future LHC and direct DM searches can complement each other in the exploration of the different DM mechanisms within these scenarios. We find that the τ 1 coannihilation regions of the CMSSM, NUHM1, NUHM2 can largely be explored at the LHC via searches for missing E T events and long-lived charged particles, whereas their H/A funnel, focus-point and χ ± 1 coannihilation regions can largely be explored by the LZ and Darwin DM direct detection experiments. We find that the dominant DM mechanism in our pMSSM10 analysis is χ ± 1 coannihilation: parts of its parameter space can be explored by the LHC, and a larger portion by future direct DM searches.

  16. Collective ratchet effects and reversals for active matter particles on quasi-one-dimensional asymmetric substrates.

    Science.gov (United States)

    McDermott, Danielle; Olson Reichhardt, Cynthia J; Reichhardt, Charles

    2016-10-19

    Using computer simulations, we study a two-dimensional system of sterically interacting self-mobile run-and-tumble disk-shaped particles with an underlying periodic quasi-one-dimensional asymmetric substrate, and show that a rich variety of collective active ratchet behaviors arise as a function of particle density, activity, substrate period, and the maximum force exerted by the substrate. The net dc drift, or ratchet transport flux, is nonmonotonic since it increases with increased activity but is diminished by the onset of self-clustering of the active particles. Increasing the particle density decreases the ratchet transport flux for shallow substrates but increases the ratchet transport flux for deep substrates due to collective hopping events. At the highest particle densities, the ratchet motion is destroyed by a self-jamming effect. We show that it is possible to realize reversals of the direction of the net dc drift in the deep substrate limit when multiple rows of active particles can be confined in each substrate minimum, permitting emergent particle-like excitations to appear that experience an inverted effective substrate potential. We map out a phase diagram of the forward and reverse ratchet effects as a function of the particle density, activity, and substrate properties.

  17. Naturalness of MSSM dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera, María Eugenia [Instituto de Física, Universidade de São Paulo,São Paulo SP 05508-900 (Brazil); Casas, J. Alberto [Instituto de Física Teórica, IFT-UAM/CSIC, Universidad Autónoma de Madrid,Cantoblanco, 28049 Madrid (Spain); Delgado, Antonio [Department of Physics, University of Notre Dame,Notre Dame, IN 46556 (United States); Robles, Sandra [Instituto de Física Teórica, IFT-UAM/CSIC, Universidad Autónoma de Madrid,Cantoblanco, 28049 Madrid (Spain); Departamento de Física Teórica, Universidad Autónoma de Madrid,Cantoblanco, 28049 Madrid (Spain); Austri, Roberto Ruiz de [Instituto de Física Corpuscular,IFIC-UV/CSIC, Valencia (Spain)

    2016-08-08

    There exists a vast literature examining the electroweak (EW) fine-tuning problem in supersymmetric scenarios, but little concerned with the dark matter (DM) one, which should be combined with the former. In this paper, we study this problem in an, as much as possible, exhaustive and rigorous way. We have considered the MSSM framework, assuming that the LSP is the lightest neutralino, χ{sub 1}{sup 0}, and exploring the various possibilities for the mass and composition of χ{sub 1}{sup 0}, as well as different mechanisms for annihilation of the DM particles in the early Universe (well-tempered neutralinos, funnels and co-annihilation scenarios). We also present a discussion about the statistical meaning of the fine-tuning and how it should be computed for the DM abundance, and combined with the EW fine-tuning. The results are very robust and model-independent and favour some scenarios (like the h-funnel when M{sub χ{sub 1{sup 0}}} is not too close to m{sub h}/2) with respect to others (such as the pure wino case). These features should be taken into account when one explores “natural SUSY” scenarios and their possible signatures at the LHC and in DM detection experiments.

  18. The Argon Dark Matter Experiment

    CERN Document Server

    AUTHOR|(CDS)2071720

    2009-01-01

    The ArDM experiment, a 1 ton liquid argon TPC/Calorimeter, is designed for the detection of dark matter particles which can scatter off the spinless argon nucleus, producing nuclear recoils. These events will be discerned by their light to charge ratio, as well as the time structure of the scintillation light. The experiment is presently under construction and commissioning on surface at CERN. Cryogenic operation and light detection performance was recently confirmed in a test run of the full 1 ton liquid argon target under purely calorimetric operation and with a prototype light readout system. This note describes the experimental concept, the main detector components and presents some first results.

  19. On the interpretation of dark matter self-interactions in Abell 3827

    International Nuclear Information System (INIS)

    Kahlhoefer, Felix; Schmidt-Hoberg, Kai; Kummer, Janis; Sarkar, Subir

    2015-04-01

    Self-interactions of dark matter particles can potentially lead to an observable separation between the dark matter halo and the stars of a galaxy moving through a region of large dark matter density. Such a separation has recently been observed in a galaxy falling into the core of the galaxy cluster Abell 3827. We estimated the DM self-interaction cross section needed to reproduce the observed effects and find that the sensitivity of Abell 3827 has been significantly overestimated in a previous study. Our corrected estimate is σ/m DM ∝3 cm 2 g -1 when self-interactions result in an effective drag force and σ/m DM ∝ 1.5 cm 2 g -1 for the case of contact interactions, in some tension with previous upper bounds.

  20. The motion of color-charged particles as a means of testing the non-Abelian dark matter model

    OpenAIRE

    Dzhunushaliev, V.; Folomeev, V.; Protsenko, N.

    2018-01-01

    A possibility is discussed for experimental testing of the dark matter model supported by a classic non-Abelian SU(3) gauge (Yang-Mills) field. Our approach is based on the analysis of the motion of color-charged particles on the background of color electric and magnetic fields using the Wong equations. Estimating the magnitudes of the color fields near the edge of a galaxy, we employ them in obtaining the general analytic solutions to the Wong equations. Using the latter, we calculate the ma...

  1. The determination of the hadron mean free path for particle-producing collisions in intranuclear matter by measurement

    International Nuclear Information System (INIS)

    Strugalski, Z.; Mousa, M.

    1987-01-01

    It is shown how it is possible to determine the hadron mean free path in > for particle-producing collisions in intranuclear matter by measurement. The mean free path for the collisions of pions inside 54 131 Xe nuclei at 3.5 GeV/c momentum has been measured. The relation between in > in units nucleons/S and the hadron-nucleon inelastic cross section σ in in units S/nucleon is found: in >k1/σ in , where S∼10 fm 2 , k=3.0±0.15; physical meaning of S is given in this paper

  2. Dark matter relic abundance and light sterile neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yi-Lei [Center for High Energy Physics,Peking University, Beijing 100871 (China); Zhu, Shou-hua [Center for High Energy Physics,Peking University, Beijing 100871 (China); Institute of Theoretical Physics & State Key Laboratory of Nuclear Physics and Technology,Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter,Beijing 100871 (China)

    2017-01-09

    In this paper, we calculate the relic abundance of the dark matter particles when they can annihilate into sterile neutrinos with the mass ≲100 GeV in a simple model. Unlike the usual standard calculations, the sterile neutrino may fall out of the thermal equilibrium with the thermal bath before the dark matter freezes out. In such a case, if the Yukawa coupling y{sub N} between the Higgs and the sterile neutrino is small, this process gives rise to a larger Ω{sub DM}h{sup 2} so we need a larger coupling between the dark matter and the sterile neutrino for a correct relic abundance.

  3. Water uptake by fresh Indonesian peat burning particles is limited by water-soluble organic matter

    Science.gov (United States)

    Chen, Jing; Hapsari Budisulistiorini, Sri; Itoh, Masayuki; Lee, Wen-Chien; Miyakawa, Takuma; Komazaki, Yuichi; Qing Yang, Liu Dong; Kuwata, Mikinori

    2017-09-01

    The relationship between hygroscopic properties and chemical characteristics of Indonesian biomass burning (BB) particles, which are dominantly generated from peatland fires, was investigated using a humidified tandem differential mobility analyzer. In addition to peat, acacia (a popular species at plantation) and fern (a pioneering species after disturbance by fire) were used for experiments. Fresh Indonesian peat burning particles are almost non-hygroscopic (mean hygroscopicity parameter, κ octanol-water partitioning method. κ values for the water extracts are high, especially for peat burning particles (A0 (a whole part of the water-soluble fraction): κ = 0.18, A1 (highly water-soluble fraction): κ = 0.30). This result stresses the importance of both the WSOC fraction and κ of the water-soluble fraction in determining the hygroscopicity of organic aerosol particles. Values of κ correlate positively (R = 0.89) with the fraction of m/z 44 ion signal quantified using a mass spectrometric technique, demonstrating the importance of highly oxygenated organic compounds to the water uptake by Indonesian BB particles. These results provide an experimentally validated reference for hygroscopicity of organics-dominated particles, thus contributing to more accurate estimation of environmental and climatic impacts driven by Indonesian BB particles on both regional and global scales.

  4. Scalar dark matter in the B−L model

    International Nuclear Information System (INIS)

    Rodejohann, Werner; Yaguna, Carlos E.

    2015-01-01

    The U(1) B−L extension of the Standard Model requires the existence of right-handed neutrinos and naturally realizes the seesaw mechanism of neutrino mass generation. We study the possibility of explaining the dark matter in this model with an additional scalar field, ϕ DM , that is a singlet of the Standard Model but charged under U(1) B−L . An advantage of this scenario is that the stability of ϕ DM can be guaranteed by appropriately choosing its B−L charge, without the need of an extra ad hoc discrete symmetry. We investigate in detail the dark matter phenomenology of this model. We show that the observed dark matter density can be obtained via gauge or scalar interactions, and that semi-annihilations could play an important role in the latter case. The regions consistent with the dark matter density are determined in each instance and the prospects for detection in future experiments are analyzed. If dark matter annihilations are controlled by the B−L gauge interaction, the mass of the dark matter particle should lie below 5 TeV and its direct detection cross section can be easily probed by XENON1T; if instead they are controlled by scalar interactions, the dark matter mass can be much larger and the detection prospects are less certain. Finally, we show that this scenario can be readily extended to accommodate multiple dark matter particles

  5. Annual variability in light absorption by particles and colored dissolved organic matter in the Crimean coastal waters (the Black Sea)

    Science.gov (United States)

    Churilova, T.; Moiseeva, N.; Efimova, T.; Suslin, V.; Krivenko, O.; Zemlianskaia, E.

    2017-11-01

    Bio-optical studies were carried out in coastal waters around the Crimea peninsula in different seasons 2016. It was shown that variability of chlorophyll a concentration (Chl-a), light absorption by suspended particles (ap(λ)), phytoplankton pigments (aph(λ)), non-algal particles (aNAP(λ)) and by colored dissolved organic matter (aCDOM(λ)) in the Crimea coastal water was high ( order of magnitudes) in all seasons 2016. Relationships between ap(440), aph(440) and Chl-a were obtained and their seasonal differences were analyzed. Spectral distribution of aNAP(λ) and aCDOM(λ) were parameterized. Seasonality in aCDOM(λ) parameterization was revealed, but - in aNAP(λ) parameterization was not revealed. The budget of light absorption by aph(λ), aNAP(λ) i aCDOM(λ) at 440 nm was assessed and its seasonal dynamics was analyzed.

  6. Cardiopulmonary Toxicity Induced by Ambient Particulate Matter (BI City Concentrated Ambient Particle Study)

    Energy Technology Data Exchange (ETDEWEB)

    Annette Rohr; James Wagner Masako Morishita; Gerald Keeler; Jack Harkema

    2010-06-30

    Alterations in heart rate variability (HRV) have been reported in rodents exposed to concentrated ambient particles (CAPs) from different regions of the United States. The goal of this study was to compare alterations in cardiac function induced by CAPs in two distinct regional atmospheres. AirCARE 1, a mobile laboratory with an EPA/Harvard fine particle (particulate matter <2.5 {micro}m; PM{sub 2.5}) concentrator was located in urban Detroit, MI, where the PM mixture is heavily influenced by motor vehicles, and in Steubenville, OH, where PM is derived primarily from long-range transport and transformation of power plant emissions, as well as from local industrial operations. Each city was studied during both winter and summer months, for a total of four sampling periods. Spontaneously hypertensive rats instrumented for electrocardiogram (ECG) telemetry were exposed to CAPs 8 h/day for 13 consecutive days during each sampling period. Heart rate (HR), and indices of HRV (standard deviation of the average normal-to-normal intervals [SDNN]; square root of the mean squared difference of successive normal-to-normal intervals [rMSSD]), were calculated for 30-minute intervals during exposures. A large suite of PM components, including nitrate, sulfate, elemental and organic carbon, and trace elements, were monitored in CAPs and ambient air. In addition, a unique sampler, the Semi-Continuous Elements in Air Sampler (SEAS) was employed to obtain every-30-minute measurements of trace elements. Positive matrix factorization (PMF) methods were applied to estimate source contributions to PM{sub 2.5}. Mixed modeling techniques were employed to determine associations between pollutants/CAPs components and HR and HRV metrics. Mean CAPs concentrations in Detroit were 518 and 357 {micro}g/m{sup 3} (summer and winter, respectively) and 487 and 252 {micro}g/m{sup 3} in Steubenville. In Detroit, significant reductions in SDNN were observed in the summer in association with cement

  7. CONDENSED MATTER: STRUCTURE, THERMAL AND MECHANICAL PROPERTIES: Pair interaction of bilayer-coated nanoscopic particles

    Science.gov (United States)

    Zhang, Qi-Yi

    2009-02-01

    The pair interaction between bilayer membrane-coated nanosized particles has been explored by using the self-consistent field (SCF) theory. The bilayer membranes are composed of amphiphilic polymers. For different system parameters, the pair-interaction free energies are obtained. Particular emphasis is placed on the analysis of a sequence of structural transformations of bilayers on spherical particles, which occur during their approaching processes. For different head fractions of amphiphiles, the asymmetrical morphologies between bilayers on two particles and the inverted micellar intermediates have been found in the membrane fusion pathway. These results can benefit the fabrication of vesicles as encapsulation vectors for drug and gene delivery.

  8. DaMaSCUS: the impact of underground scatterings on direct detection of light dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Emken, Timon; Kouvaris, Chris, E-mail: emken@cp3.sdu.dk, E-mail: kouvaris@cp3.sdu.dk [CP3-Origins, University of Southern Denmark, Campusvej 55, DK-5230 Odense (Denmark)

    2017-10-01

    Conventional dark matter direct detection experiments set stringent constraints on dark matter by looking for elastic scattering events between dark matter particles and nuclei in underground detectors. However these constraints weaken significantly in the sub-GeV mass region, simply because light dark matter does not have enough energy to trigger detectors regardless of the dark matter-nucleon scattering cross section. Even if future experiments lower their energy thresholds, they will still be blind to parameter space where dark matter particles interact with nuclei strongly enough that they lose enough energy and become unable to cause a signal above the experimental threshold by the time they reach the underground detector. Therefore in case dark matter is in the sub-GeV region and strongly interacting, possible underground scatterings of dark matter with terrestrial nuclei must be taken into account because they affect significantly the recoil spectra and event rates, regardless of whether the experiment probes DM via DM-nucleus or DM-electron interaction. To quantify this effect we present the publicly available Dark Matter Simulation Code for Underground Scatterings (DaMaSCUS), a Monte Carlo simulator of DM trajectories through the Earth taking underground scatterings into account. Our simulation allows the precise calculation of the density and velocity distribution of dark matter at any detector of given depth and location on Earth. The simulation can also provide the accurate recoil spectrum in underground detectors as well as the phase and amplitude of the diurnal modulation caused by this shadowing effect of the Earth, ultimately relating the modulations expected in different detectors, which is important to decisively conclude if a diurnal modulation is due to dark matter or an irrelevant background.

  9. DaMaSCUS: the impact of underground scatterings on direct detection of light dark matter

    International Nuclear Information System (INIS)

    Emken, Timon; Kouvaris, Chris

    2017-01-01

    Conventional dark matter direct detection experiments set stringent constraints on dark matter by looking for elastic scattering events between dark matter particles and nuclei in underground detectors. However these constraints weaken significantly in the sub-GeV mass region, simply because light dark matter does not have enough energy to trigger detectors regardless of the dark matter-nucleon scattering cross section. Even if future experiments lower their energy thresholds, they will still be blind to parameter space where dark matter particles interact with nuclei strongly enough that they lose enough energy and become unable to cause a signal above the experimental threshold by the time they reach the underground detector. Therefore in case dark matter is in the sub-GeV region and strongly interacting, possible underground scatterings of dark matter with terrestrial nuclei must be taken into account because they affect significantly the recoil spectra and event rates, regardless of whether the experiment probes DM via DM-nucleus or DM-electron interaction. To quantify this effect we present the publicly available Dark Matter Simulation Code for Underground Scatterings (DaMaSCUS), a Monte Carlo simulator of DM trajectories through the Earth taking underground scatterings into account. Our simulation allows the precise calculation of the density and velocity distribution of dark matter at any detector of given depth and location on Earth. The simulation can also provide the accurate recoil spectrum in underground detectors as well as the phase and amplitude of the diurnal modulation caused by this shadowing effect of the Earth, ultimately relating the modulations expected in different detectors, which is important to decisively conclude if a diurnal modulation is due to dark matter or an irrelevant background.

  10. Dark matter and the solar neutrino problem: Can particle physics provide a single solution

    International Nuclear Information System (INIS)

    West, G.B.

    1989-01-01

    We show how a relatively simple extension of the standard model can give a ''natural'' explanation for both the solar neutrino and dark matter problems. What is required is a new stable neutral lepton with a mass in the 4--8 GeV range. One possibility is a fourth generation neutrino interacting with matter either electromagnetically or via higgs-exchange (in addition, of course, to Z degree-exchange). In the former case, a new charged lepton with mass ∼10GeV would be required in order to generate a sufficiently large magnetic moment. The present experimental situation makes this possibility rather doubtful. In the latter case, a light higgs with mass ∼1GeV is required; this is still not ruled out experimentally. In any case, direct (or indirect) detection of dark matter will, during the next year, seal the fate of this model. 29 refs

  11. Direct Detection Phenomenology in Models Where the Products of Dark Matter Annihilation Interact with Nuclei

    DEFF Research Database (Denmark)

    Cherry, John F.; Frandsen, Mads T.; Shoemaker, Ian M.

    2015-01-01

    We investigate the direct detection phenomenology of a class of dark matter (DM) models in which DM does not directly interact with nuclei, {but rather} the products of its annihilation do. When these annihilation products are very light compared to the DM mass, the scattering in direct detection...... to nuclei, the limit from annihilation to relativistic particles in the Sun can be stronger than that of conventional non-relativistic direct detection by more than three orders of magnitude for masses in a 2-7 GeV window.......We investigate the direct detection phenomenology of a class of dark matter (DM) models in which DM does not directly interact with nuclei, {but rather} the products of its annihilation do. When these annihilation products are very light compared to the DM mass, the scattering in direct detection...... experiments is controlled by relativistic kinematics. This results in a distinctive recoil spectrum, a non-standard and or even absent annual modulation, and the ability to probe DM masses as low as a $\\sim$10 MeV. We use current LUX data to show that experimental sensitivity to thermal relic annihilation...

  12. Self-interacting dark matter

    Science.gov (United States)

    Mavromatos, Nick E.; Argüelles, Carlos R.; Ruffini, Remo; Rueda, Jorge A.

    Self-interacting dark matter (SIDM) is a hypothetical form of dark matter (DM), characterized by relatively strong (compared to the weak interaction strength) self-interactions (SIs), which has been proposed to resolve a number of issues concerning tensions between simulations and observations at the galactic or smaller scales. We review here some recent developments discussed at the 14th Marcel Grossmann Meeting (MG14), paying particular attention to restrictions on the SIDM (total) cross-section from using novel observables in merging galactic structures, as well as the rôle of SIDM on the Milky Way halo and its central region. We report on some interesting particle-physics inspired SIDM models that were discussed at MG14, namely the glueball DM, and a right-handed neutrino DM (with mass of a few tens of keV, that may exist in minimal extensions of the standard model (SM)), interacting among themselves via vector bosons mediators in the dark sector. A detailed phenomenology of the latter model on galactic scales, as well as the potential role of the right handed neutrinos in alleviating some of the small-scale cosmology problems, namely the discrepancies between observations and numerical simulations within standard ΛCDM and ΛWDM cosmologies are reported.

  13. On the Existence of Low-Mass Dark Matter and its Direct Detection

    Science.gov (United States)

    Bateman, James; McHardy, Ian; Merle, Alexander; Morris, Tim R.; Ulbricht, Hendrik

    2015-01-01

    Dark Matter (DM) is an elusive form of matter which has been postulated to explain astronomical observations through its gravitational effects on stars and galaxies, gravitational lensing of light around these, and through its imprint on the Cosmic Microwave Background (CMB). This indirect evidence implies that DM accounts for as much as 84.5% of all matter in our Universe, yet it has so far evaded all attempts at direct detection, leaving such confirmation and the consequent discovery of its nature as one of the biggest challenges in modern physics. Here we present a novel form of low-mass DM χ that would have been missed by all experiments so far. While its large interaction strength might at first seem unlikely, neither constraints from particle physics nor cosmological/astronomical observations are sufficient to rule out this type of DM, and it motivates our proposal for direct detection by optomechanics technology which should soon be within reach, namely, through the precise position measurement of a levitated mesoscopic particle which will be perturbed by elastic collisions with χ particles. We show that a recently proposed nanoparticle matter-wave interferometer, originally conceived for tests of the quantum superposition principle, is sensitive to these collisions, too. PMID:25622565

  14. On the Existence of Low-Mass Dark Matter and its Direct Detection

    Science.gov (United States)

    Bateman, James; McHardy, Ian; Merle, Alexander; Morris, Tim R.; Ulbricht, Hendrik

    2015-01-01

    Dark Matter (DM) is an elusive form of matter which has been postulated to explain astronomical observations through its gravitational effects on stars and galaxies, gravitational lensing of light around these, and through its imprint on the Cosmic Microwave Background (CMB). This indirect evidence implies that DM accounts for as much as 84.5% of all matter in our Universe, yet it has so far evaded all attempts at direct detection, leaving such confirmation and the consequent discovery of its nature as one of the biggest challenges in modern physics. Here we present a novel form of low-mass DM χ that would have been missed by all experiments so far. While its large interaction strength might at first seem unlikely, neither constraints from particle physics nor cosmological/astronomical observations are sufficient to rule out this type of DM, and it motivates our proposal for direct detection by optomechanics technology which should soon be within reach, namely, through the precise position measurement of a levitated mesoscopic particle which will be perturbed by elastic collisions with χ particles. We show that a recently proposed nanoparticle matter-wave interferometer, originally conceived for tests of the quantum superposition principle, is sensitive to these collisions, too.

  15. Unitarity limits on the mass and radius of dark matter particles

    Science.gov (United States)

    Griest, Kim; Kamionkowski, Marc

    1989-01-01

    Using partial wave unitarity and the observed density of the Universe, it is show that a stable elementary particle which was once in thermal equilibrium cannot have a mass greater than 340 TeV. An extended object which was once in thermal equilibrium cannot have a radius less than 7.5 x 10(exp -7) fm. A lower limit to the relic abundance of such particles is also found.

  16. H.E.S.S. OBSERVATIONS OF THE GLOBULAR CLUSTERS NGC 6388 AND M15 AND SEARCH FOR A DARK MATTER SIGNAL

    International Nuclear Information System (INIS)

    Abramowski, A.; Acero, F.; Aharonian, F.; Bernloehr, K.; Bochow, A.; Akhperjanian, A. G.; Anton, G.; Balzer, A.; Brucker, J.; Barnacka, A.; Barres de Almeida, U.; Bazer-Bachi, A. R.; Borrel, V.; Becherini, Y.; Becker, J.; Behera, B.; Boisson, C.; Bolmont, J.; Bordas, P.

    2011-01-01

    Observations of the globular clusters (GCs) NGC 6388 and M15 were carried out by the High Energy Stereoscopic System array of Cherenkov telescopes for a live time of 27.2 and 15.2 hr, respectively. No gamma-ray signal is found at the nominal target position of NGC 6388 and M15. In the primordial formation scenario, GCs are formed in a dark matter (DM) halo and DM could still be present in the baryon-dominated environment of GCs. This opens the possibility of observing a DM self-annihilation signal. The DM content of the GCs NGC 6388 and M15 is modeled taking into account the astrophysical processes that can be expected to influence the DM distribution during the evolution of the GC: the adiabatic contraction of DM by baryons, the adiabatic growth of a black hole in the DM halo, and the kinetic heating of DM by stars. Ninety-five percent confidence level exclusion limits on the DM particle velocity-weighted annihilation cross section are derived for these DM halos. In the TeV range, the limits on the velocity-weighted annihilation cross section are derived at the 10 -25 cm 3 s -1 level and a few 10 -24 cm 3 s -1 for NGC 6388 and M15, respectively.

  17. Impact of natural organic matter on particle behavior and phototoxicity of titanium dioxide nanoparticles

    Science.gov (United States)

    Due to their inherent phototoxicity and inevitable environmental release, titanium dioxide nanoparticles (nano-TiO2) are increasingly studied in the field of aquatic toxicology. One of the particular interests is the interactions between nano-TiO2 and natural organic matter (NOM)...

  18. Heavy metal pollution in sediment from Sisimiut, Greenland. Adsorption to organic matter and fine particles

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Villumsen, Arne

    2006-01-01

    . The pollution could be linked to human activities in Sisimiut, a link that have not been investigated previously in Greenland. Except from the most polluted samples there was good correlation between heavy metal concentration and organic matter. Also some relation between fine fraction and heavy metal...

  19. iTIMP: isotriplet Technicolor Interacting Massive Particle as Dark Matter

    DEFF Research Database (Denmark)

    T. Frandsen, Mads; Sannino, Francesco

    2010-01-01

    We suggest that a weak isotriplet composite scalar possessing an unbroken U(1) global symmetry naturally arises in technicolor models leading to an interesting type of dark matter candidate: the iTIMP. We propose explicit models of the iTIMP, study earth based constraints and suggest possible...

  20. Making the most of the relic density for dark matter searches at the LHC 14 TeV Run

    International Nuclear Information System (INIS)

    Busoni, Giorgio; Simone, Andrea De; Jacques, Thomas; Morgante, Enrico; Riotto, Antonio

    2015-01-01

    As the LHC continues to search for new weakly interacting particles, it is important to remember that the search is strongly motivated by the existence of dark matter. In view of a possible positive signal, it is essential to ask whether the newly discovered weakly interacting particle can be be assigned the label 'dark matter'. Within a given set of simplified models and modest working assumptions, we reinterpret the relic abundance bound as a relic abundance range, and compare the parameter space yielding the correct relic abundance with projections of the Run II exclusion regions. Assuming that dark matter is within the reach of the LHC, we also make the comparison with the potential 5σ discovery regions. Reversing the logic, relic density calculations can be used to optimize dark matter searches by motivating choices of parameters where the LHC can probe most deeply into the dark matter parameter space. In the event that DM is seen outside of the region giving the correct relic abundance, we will learn that either thermal relic DM is ruled out in that model, or the DM-quark coupling is suppressed relative to the DM coupling strength to other SM particles

  1. Template Composite Dark Matter

    DEFF Research Database (Denmark)

    Drach, Vincent; Hietanen, Ari; Pica, Claudio

    2015-01-01

    We present a non perturbative study of SU(2) gauge theory with two fundamental Dirac flavours. We discuss how the model can be used as a template for composite Dark Matter (DM). We estimate one particular interaction of the DM candidate with the Standard Model : the interaction through photon...

  2. A NOVEL APPROACH IN THE WEAKLY INTERACTING MASSIVE PARTICLE QUEST: CROSS-CORRELATION OF GAMMA-RAY ANISOTROPIES AND COSMIC SHEAR

    International Nuclear Information System (INIS)

    Camera, Stefano; Fornasa, Mattia; Fornengo, Nicolao; Regis, Marco

    2013-01-01

    Both cosmic shear and cosmological gamma-ray emission stem from the presence of dark matter (DM) in the universe: DM structures are responsible for the bending of light in the weak-lensing regime and those same objects can emit gamma rays, either because they host astrophysical sources (active galactic nuclei or star-forming galaxies) or directly by DM annihilations (or decays, depending on the properties of the DM particle). Such gamma rays should therefore exhibit strong correlation with the cosmic shear signal. In this Letter, we compute the cross-correlation angular power spectrum of cosmic shear and gamma rays produced by the annihilation/decay of weakly interacting massive particle DM, as well as by astrophysical sources. We show that this observable provides novel information on the composition of the extragalactic gamma-ray background (EGB), since the amplitude and shape of the cross-correlation signal strongly depend on which class of sources is responsible for the gamma-ray emission. If the DM contribution to the EGB is significant (at least in a definite energy range), although compatible with current observational bounds, its strong correlation with the cosmic shear makes such signal potentially detectable by combining Fermi Large Area Telescope data with forthcoming galaxy surveys, like the Dark Energy Survey and Euclid. At the same time, the same signal would demonstrate that the weak-lensing observables are indeed due to particle DM matter and not to possible modifications of general relativity.

  3. A Novel Approach in the Weakly Interacting Massive Particle Quest: Cross-correlation of Gamma-Ray Anisotropies and Cosmic Shear

    Science.gov (United States)

    Camera, Stefano; Fornasa, Mattia; Fornengo, Nicolao; Regis, Marco

    2013-07-01

    Both cosmic shear and cosmological gamma-ray emission stem from the presence of dark matter (DM) in the universe: DM structures are responsible for the bending of light in the weak-lensing regime and those same objects can emit gamma rays, either because they host astrophysical sources (active galactic nuclei or star-forming galaxies) or directly by DM annihilations (or decays, depending on the properties of the DM particle). Such gamma rays should therefore exhibit strong correlation with the cosmic shear signal. In this Letter, we compute the cross-correlation angular power spectrum of cosmic shear and gamma rays produced by the annihilation/decay of weakly interacting massive particle DM, as well as by astrophysical sources. We show that this observable provides novel information on the composition of the extragalactic gamma-ray background (EGB), since the amplitude and shape of the cross-correlation signal strongly depend on which class of sources is responsible for the gamma-ray emission. If the DM contribution to the EGB is significant (at least in a definite energy range), although compatible with current observational bounds, its strong correlation with the cosmic shear makes such signal potentially detectable by combining Fermi Large Area Telescope data with forthcoming galaxy surveys, like the Dark Energy Survey and Euclid. At the same time, the same signal would demonstrate that the weak-lensing observables are indeed due to particle DM matter and not to possible modifications of general relativity.

  4. A NOVEL APPROACH IN THE WEAKLY INTERACTING MASSIVE PARTICLE QUEST: CROSS-CORRELATION OF GAMMA-RAY ANISOTROPIES AND COSMIC SHEAR

    Energy Technology Data Exchange (ETDEWEB)

    Camera, Stefano [CENTRA, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Lisboa (Portugal); Fornasa, Mattia [School of Physics and Astronomy, University of Nottingham, Nottingham (United Kingdom); Fornengo, Nicolao; Regis, Marco [Dipartimento di Fisica, Universita di Torino and INFN, Torino (Italy)

    2013-07-01

    Both cosmic shear and cosmological gamma-ray emission stem from the presence of dark matter (DM) in the universe: DM structures are responsible for the bending of light in the weak-lensing regime and those same objects can emit gamma rays, either because they host astrophysical sources (active galactic nuclei or star-forming galaxies) or directly by DM annihilations (or decays, depending on the properties of the DM particle). Such gamma rays should therefore exhibit strong correlation with the cosmic shear signal. In this Letter, we compute the cross-correlation angular power spectrum of cosmic shear and gamma rays produced by the annihilation/decay of weakly interacting massive particle DM, as well as by astrophysical sources. We show that this observable provides novel information on the composition of the extragalactic gamma-ray background (EGB), since the amplitude and shape of the cross-correlation signal strongly depend on which class of sources is responsible for the gamma-ray emission. If the DM contribution to the EGB is significant (at least in a definite energy range), although compatible with current observational bounds, its strong correlation with the cosmic shear makes such signal potentially detectable by combining Fermi Large Area Telescope data with forthcoming galaxy surveys, like the Dark Energy Survey and Euclid. At the same time, the same signal would demonstrate that the weak-lensing observables are indeed due to particle DM matter and not to possible modifications of general relativity.

  5. Dark Matter Search in a Beam-Dump eXperiment (BDX) at Jefferson Lab

    International Nuclear Information System (INIS)

    Battaglieri, M.

    2016-01-01

    MeV-GeV dark matter (DM) is theoretically well motivated but remarkably unexplored. This proposal presents the MeV-GeV DM discovery potential for a ∼ 1 m$^3$ segmented CsI(Tl) scintillator detector placed downstream of the Hall A beam-dump at Jefferson Lab, receiving up to 10 22 electrons-on-target (EOT) in 285 days. This experiment (Beam-Dump eXperiment or BDX) would be sensitive to elastic DM-electron and to inelastic DM scattering at the level of 10 counts per year, reaching the limit of the neutrino irreducible background. The distinct signature of a DM interaction will be an electromagnetic shower of few hundreds of MeV, together with a reduced activity in the surrounding active veto counters. A detailed description of the DM particle χ production in the dump and subsequent interaction in the detector has been performed by means of Monte Carlo simulations. Different approaches have been used to evaluate the expected backgrounds: the cosmogenic background has been extrapolated from the results obtained with a prototype detector running at INFN-LNS (Italy), while the beam-related background has been evaluated by GEANT4 Monte Carlo simulations. The proposed experiment will be sensitive to large regions of DM parameter space, exceeding the discovery potential of existing and planned experiments in the MeV-GeV DM mass range by up to two orders of magnitude.

  6. Dark Matter Search in a Beam-Dump eXperiment (BDX) at Jefferson Lab

    Energy Technology Data Exchange (ETDEWEB)

    Battaglieri, M. [Univ. of Genova (Italy). National Institute for Nuclear Physics. et al

    2016-07-05

    MeV-GeV dark matter (DM) is theoretically well motivated but remarkably unexplored. This proposal presents the MeV-GeV DM discovery potential for a $\\sim$1 m$^3$ segmented CsI(Tl) scintillator detector placed downstream of the Hall A beam-dump at Jefferson Lab, receiving up to 10$^{22}$ electrons-on-target (EOT) in 285 days. This experiment (Beam-Dump eXperiment or BDX) would be sensitive to elastic DM-electron and to inelastic DM scattering at the level of 10 counts per year, reaching the limit of the neutrino irreducible background. The distinct signature of a DM interaction will be an electromagnetic shower of few hundreds of MeV, together with a reduced activity in the surrounding active veto counters. A detailed description of the DM particle $\\chi$ production in the dump and subsequent interaction in the detector has been performed by means of Monte Carlo simulations. Different approaches have been used to evaluate the expected backgrounds: the cosmogenic background has been extrapolated from the results obtained with a prototype detector running at INFN-LNS (Italy), while the beam-related background has been evaluated by GEANT4 Monte Carlo simulations. The proposed experiment will be sensitive to large regions of DM parameter space, exceeding the discovery potential of existing and planned experiments in the MeV-GeV DM mass range by up to two orders of magnitude.

  7. Quantification of the carbonaceous matter origin in submicron marine aerosol particles by dual carbon isotope analysis

    Science.gov (United States)

    Ceburnis, D.; Garbaras, A.; Szidat, S.; Rinaldi, M.; Fahrni, S.; Perron, N.; Wacker, L.; Leinert, S.; Remeikis, V.; Facchini, M. C.; Prevot, A. S. H.; Jennings, S. G.; O'Dowd, C. D.

    2011-01-01

    Dual carbon isotope analysis has been performed for the first time demonstrating a potential in organic matter apportionment between three principal sources: marine, terrestrial (non-fossil) and fossil fuel due to unique isotopic signatures. The results presented here, utilising combinations of dual carbon isotope analysis, provides a conclusive evidence of a dominant biogenic organic fraction to organic aerosol over biologically active oceans. In particular, the NE Atlantic, which is also subjected to notable anthropogenic influences via pollution transport processes, was found to contain 80% organic aerosol matter of biogenic origin directly linked to plankton emissions. The remaining carbonaceous aerosol was of fossil-fuel origin. By contrast, for polluted air advecting out from Europe into the NE Atlantic, the source apportionment is 30% marine biogenic, 40% fossil fuel, and 30% continental non-fossil fuel. The dominant marine organic aerosol source in the atmosphere has significant implications for climate change feedback processes.

  8. Membrane flux dynamics in the submerged ultrafiltration hybrid treatment process during particle and natural organic matter removal

    Institute of Scientific and Technical Information of China (English)

    Wei Zhang; Xiaojian Zhang; Yonghong Li; Jun Wang; Chao Chen

    2011-01-01

    Particles and natural organic matter (NOM) are two major concerns in surface water,which greatly influence the membrane filtration process.The objective of this article is to investigate the effect of particles,NOM and their interaction on the submerged ultrafiltration (UF) membrane flux under conditions of solo UF and coagulation and PAC adsorption as the pretreatment of UF.Particles,NOM and their mixture were spiked in tap water to simulate raw water.Exponential relationship,(JP/JP0 =axexp{-k[t-(n- 1)T]}),was developed to quantify the normalized membrane flux dynamics during the filtration period and fitted the results well.In this equation,coefficient a was determined by the value of Jp/Jp0 at the beginning of a filtration cycle,reflecting the flux recovery after backwashing,that is,the irreversible fouling.The coefficient k reflected the trend of flux dynamics.Integrated total permeability (ΣJp) in one filtration period could be used as a quantified indicator for comparison of different hybrid membrane processes or under different scenarios.According to the results,there was an additive effect on membrane flux by NOM and particles during solo UF process.This additive fouling could be alleviated by coagulation pretreatment since particles helped the formation of flocs with coagulant,which further delayed the decrease of membrane flux and benefited flux recovery by backwashing.The addition of PAC also increased membrane flux by adsorbing NOM and improved flux recovery through backwashing.

  9. Variations in Spectral Absorption Properties of Phytoplankton, Non-algal Particles and Chromophoric Dissolved Organic Matter in Lake Qiandaohu

    Directory of Open Access Journals (Sweden)

    Liangliang Shi

    2017-05-01

    Full Text Available Light absorption by phytoplankton, non-algal particles (NAP and chromophoric dissolved organic matter (CDOM was investigated at 90 sites of a clear, deep artificial lake (Lake Qiandaohu to study natural variability of absorption coefficients. Our study shows that CDOM absorption is a major contributor to the total absorption signal in Lake Qiandaohu during all seasons, except autumn when it has an equivalent contribution as total particle absorption. The exponential slope of CDOM absorption varies within a narrow range around a mean value of 0.0164 nm−1 ( s d = 0.00176 nm−1. Our study finds some evidence for thIS autochthonous production of CDOM in winter and spring. Absorption by phytoplankton, and therefore its contribution to total absorption, is generally greatest in spring, suggesting that phytoplankton growth in Lake Qiandaohu occurs predominantly in the spring. Phytoplankton absorption in freshwater lakes generally has a direct relationship with chlorophyll-a concentration, similar to the one established for open ocean waters. The NAP absorption, whose relative contribution to total absorption is highest in summer, has a spectral shape that can be well fitted by an exponential function with an average slope of 0.0065 nm−1 ( s d = 0.00076 nm−1. There is significant spatial variability present in the summer of Lake Qiandaohu, especially in the northwestern and southwestern extremes where the optical properties of the water column are strongly affected by the presence of allochthonous matter. Variations in the properties of the particle absorption spectra with depths provides evidence that the water column was vertically inhomogeneous and can be monitored with an optical measurement program. Moreover, the optical inhomogeneity in winter is less obvious. Our study will support the parameterization of the Bio-optical model for Lake Qiandaohu from in situ or remotely sensing aquatic color signals.

  10. LATTICE SIMULATIONS OF THE THERMODYNAMICS OF STRONGLY INTERACTING ELEMENTARY PARTICLES AND THE EXPLORATION OF NEW PHASES OF MATTER IN RELATIVISTIC HEAVY ION COLLISIONS

    International Nuclear Information System (INIS)

    KARSCH, F.

    2006-01-01

    At high temperatures or densities matter formed by strongly interacting elementary particles (hadronic matter) is expected to undergo a transition to a new form of matter--the quark gluon plasma--in which elementary particles (quarks and gluons) are no longer confined inside hadrons but are free to propagate in a thermal medium much larger in extent than the typical size of a hadron. The transition to this new form of matter as well as properties of the plasma phase are studied in large scale numerical calculations based on the theory of strong interactions--Quantum Chromo Dynamics (QCD). Experimentally properties of hot and dense elementary particle matter are studied in relativistic heavy ion collisions such as those currently performed at the relativistic heavy ion collider (RHIC) at BNL. We review here recent results from studies of thermodynamic properties of strongly interacting elementary particle matter performed on Teraflops-Computer. We present results on the QCD equation of state and discuss the status of studies of the phase diagram at non-vanishing baryon number density

  11. On wave dark matter in spiral and barred galaxies

    International Nuclear Information System (INIS)

    Martinez-Medina, Luis A.; Matos, Tonatiuh; Bray, Hubert L.

    2015-01-01

    We recover spiral and barred spiral patterns in disk galaxy simulations with a Wave Dark Matter (WDM) background (also known as Scalar Field Dark Matter (SFDM), Ultra-Light Axion (ULA) dark matter, and Bose-Einstein Condensate (BEC) dark matter). Here we show how the interaction between a baryonic disk and its Dark Matter Halo triggers the formation of spiral structures when the halo is allowed to have a triaxial shape and angular momentum. This is a more realistic picture within the WDM model since a non-spherical rotating halo seems to be more natural. By performing hydrodynamic simulations, along with earlier test particles simulations, we demonstrate another important way in which wave dark matter is consistent with observations. The common existence of bars in these simulations is particularly noteworthy. This may have consequences when trying to obtain information about the dark matter distribution in a galaxy, the mere presence of spiral arms or a bar usually indicates that baryonic matter dominates the central region and therefore observations, like rotation curves, may not tell us what the DM distribution is at the halo center. But here we show that spiral arms and bars can develop in DM dominated galaxies with a central density core without supposing its origin on mechanisms intrinsic to the baryonic matter

  12. Nuclei and models, 2001-2003. DEA fields, particles and matter

    International Nuclear Information System (INIS)

    Sida, J.L.

    2003-01-01

    This document gathers a series of 6 lessons dedicated to students in the first year of their thesis (DEA) in fields and particles physics: 1) the extent of nuclear physics, 2) the nucleus as a cluster of interacting fermions, 3) models and deformation, 4) nuclei and rotation, 5) isospin and exotic nuclei, and 6) fission reactions from the saddle point to the scission point

  13. Neutron propagation in moving matter: the Fizeau experiment with massive particles

    International Nuclear Information System (INIS)

    Klein, A.G.; Opat, G.I.; Cimmino, A.

    1981-01-01

    Using a two-slit neutron interferometer, the authors have mesured the shift of the interference pattern induced by the motion of a quartz rod. The measured shift is found to be in agreement with the quantum mechanical prediction derived from a relativity argument. Some peculiarities of the case of massive particles as compared with the classic Fizeau photon case are discussed

  14. Paul Scherrer Institute Scientific Report 1999. Volume I: Particles and Matter

    International Nuclear Information System (INIS)

    Gobrecht, J.; Gaeggeler, H.; Herlach, D.; Junker, K.; Kettle, P.-R.; Kubik, P.; Zehnder, A.

    2000-01-01

    Although originally planned for fundamental research in nuclear physics, the particle beams of pions, muons, protons and neutrons are now used in a large variety of disciplines in both natural science and medicine. The beams at PSI have the world's highest intensities and therefore allow certain experiments to be performed, which would not be possible elsewhere. The highlight of research this year was the first-ever determination of the chemical properties of the superheavy element 107 Bohrium. This was undertaken, by an international team led by H. Gaeggeler of PSI's Laboratory for Radiochemistry. Bohrium was produced by bombarding a Berkelium target with Neon ions from the Injector I cyclotron and six atoms were detected after having passed through an online gas chromatography device. At the Laboratory for Particle Physics the focus has shifted from nuclear physics to elementary particle physics with about a fifty-fifty split between investigations of rare processes or particle decays using the high intensity muon, pion and recently also polarized neutron beams of PSI, and research at the highest energy frontier at CERN (Geneva) and DESY (Hamburg). Important space instrumentation has been contributed by the Laboratory for Astrophysics to the European Space Agency and NASA satellite programmes. The Laboratory for Micro and Nanotechnology continued to focus on research into molecular nanotechnology and SiGeC nanostructures, the latter with the aim of producing silicon based optoelectronics. Progress in 1999 in these topical areas is described in this report. A list of scientific publications in 1999 is also provided

  15. Paul Scherrer Institute Scientific Report 1999. Volume I: Particles and Matter

    Energy Technology Data Exchange (ETDEWEB)

    Gobrecht, J; Gaeggeler, H; Herlach, D; Junker, K; Kettle, P -R; Kubik, P; Zehnder, A [eds.

    2000-07-01

    lthough originally planned for fundamental research in nuclear physics, the particle beams of pions, muons, protons and neutrons are now used in a large variety of disciplines in both natural science and medicine. The beams at PSI have the world's highest intensities and therefore allow certain experiments to be performed, which would not be possible elsewhere. The highlight of research this year was the first-ever determination of the chemical properties of the superheavy element {sup 107} Bohrium. This was undertaken, by an international team led by H. Gaeggeler of PSI's Laboratory for Radiochemistry. Bohrium was produced by bombarding a Berkelium target with Neon ions from the Injector I cyclotron and six atoms were detected after having passed through an online gas chromatography device. At the Laboratory for Particle Physics the focus has shifted from nuclear physics to elementary particle physics with about a fifty-fifty split between investigations of rare processes or particle decays using the high intensity muon, pion and recently also polarized neutron beams of PSI, and research at the highest energy frontier at CERN (Geneva) and DESY (Hamburg). Important space instrumentation has been contributed by the Laboratory for Astrophysics to the European Space Agency and NASA satellite programmes. The Laboratory for Micro and Nanotechnology continued to focus on research into molecular nanotechnology and SiGeC nanostructures, the latter with the aim of producing silicon based optoelectronics. Progress in 1999 in these topical areas is described in this report. A list of scientific publications in 1999 is also provided.

  16. Properties of galactic dark matter: Constraints from astronomical observations

    International Nuclear Information System (INIS)

    Burch, B.; Cowsik, R.

    2013-01-01

    The distributions of normal matter and of dark matter in the Galaxy are coupled to each other as they both move in the common gravitational potential. In order to fully exploit this interplay and to derive the various properties of dark matter relevant to their direct and indirect detection, we have comprehensively reviewed the astronomical observations of the spatial and velocity distributions of the components of normal matter. We then postulate that the phase-space distribution of dark matter follows a lowered-isothermal form and self-consistently solve Poisson's equation to construct several models for the spatial and velocity distributions of dark matter. In this paper, we compute the total gravitational potential of the normal and dark matter components and investigate their consistency with current observations of the rotation curve of the Galaxy and of the spatial and velocity distributions of blue horizontal-branch and blue straggler stars. Even with this demand of consistency, a large number of models with a range of parameters characterizing the dark matter distribution remain. We find that the best choice of parameters, within the range of allowed values for the surface density of the disk 55 M ☉ pc –2 , are the following: the dark matter density at the Galactic center ρ DM, c ≈ 100-250 GeV cm –3 , the local dark matter density ρ DM (R 0 ) ≈ 0.56-0.72 GeV cm –3 , and the rms speed of dark matter particles 〈v DM 2 (R 0 )〉 1/2 ≈490−−550 km s –1 . We also discuss possible astronomical observations that may further limit the range of the allowed models. The predictions of the allowed models for direct and indirect detection will be discussed separately in a companion paper.

  17. Comparison between particulate matter and ultrafine particle emission by electronic and normal cigarettes in real-life conditions.

    Science.gov (United States)

    Ruprecht, Ario Alberto; De Marco, Cinzia; Pozzi, Paolo; Munarini, Elena; Mazza, Roberto; Angellotti, Giorgia; Turla, Francesca; Boffi, Roberto

    2014-01-01

    Electronic cigarettes may be safer than conventional cigarettes as they generate less indoor pollution in terms of particulate matter (PM); however, recent findings in experimental conditions demonstrated that secondhand exposure to PM may be expected from e-cigarette smoking. The aim of the present study was to investigate the emission of PM generated by e-cigarettes and normal cigarettes under real-life conditions. Real-time measurement and comparison of PM and ultrafine particles (UFP) generated by electronic cigarettes with and without nicotine and by normal cigarettes in a 50 m3 office of an Italian comprehensive cancer center was performed. PM mass as PM1, PM2.5, PM7, PM10, total suspended particles (TSP) in μg/m³ and UFP in number of particles per cubic centimeter from 10 to 1,000 nanometers were measured. Outdoor concentrations were measured contemporaneously to compensate for urban background changes. Regardless of their nicotine content, e-cigarettes generated lower PM levels than conventional cigarettes. Notably, nicotine-enriched e-cigarettes produced lower PM levels than their nicotine-free counterparts. E-cigarettes appear to generate less indoor pollution than normal cigarettes and may therefore be safer. Further studies are required to investigate the long-term health-related effects of secondhand e-cigarette exposure.

  18. "Non-cold" dark matter at small scales: a general approach

    Science.gov (United States)

    Murgia, R.; Merle, A.; Viel, M.; Totzauer, M.; Schneider, A.

    2017-11-01

    Structure formation at small cosmological scales provides an important frontier for dark matter (DM) research. Scenarios with small DM particle masses, large momenta or hidden interactions tend to suppress the gravitational clustering at small scales. The details of this suppression depend on the DM particle nature, allowing for a direct link between DM models and astrophysical observations. However, most of the astrophysical constraints obtained so far refer to a very specific shape of the power suppression, corresponding to thermal warm dark matter (WDM), i.e., candidates with a Fermi-Dirac or Bose-Einstein momentum distribution. In this work we introduce a new analytical fitting formula for the power spectrum, which is simple yet flexible enough to reproduce the clustering signal of large classes of non-thermal DM models, which are not at all adequately described by the oversimplified notion of WDM . We show that the formula is able to fully cover the parameter space of sterile neutrinos (whether resonantly produced or from particle decay), mixed cold and warm models, fuzzy dark matter, as well as other models suggested by effective theory of structure formation (ETHOS). Based on this fitting formula, we perform a large suite of N-body simulations and we extract important nonlinear statistics, such as the matter power spectrum and the halo mass function. Finally, we present first preliminary astrophysical constraints, based on linear theory, from both the number of Milky Way satellites and the Lyman-α forest. This paper is a first step towards a general and comprehensive modeling of small-scale departures from the standard cold DM model.

  19. A fresh look into the interacting dark matter scenario

    Science.gov (United States)

    Escudero, Miguel; Lopez-Honorez, Laura; Mena, Olga; Palomares-Ruiz, Sergio; Villanueva-Domingo, Pablo

    2018-06-01

    The elastic scattering between dark matter particles and radiation represents an attractive possibility to solve a number of discrepancies between observations and standard cold dark matter predictions, as the induced collisional damping would imply a suppression of small-scale structures. We consider this scenario and confront it with measurements of the ionization history of the Universe at several redshifts and with recent estimates of the counts of Milky Way satellite galaxies. We derive a conservative upper bound on the dark matter-photon elastic scattering cross section of σγ DM non-cold dark matter candidates, such as interacting and warm dark matter scenarios. Let us emphasize that bounds of similar magnitude to the ones obtained here could be also derived for models with dark matter-neutrino interactions and would be as constraining as the tightest limits on such scenarios.

  20. Relationship between rumen protozoal growth, intake of DM, TDN, N, DOM and VFA production rate in buffalo calves

    International Nuclear Information System (INIS)

    Verma, D.N.; Singh, U.B.

    1981-01-01

    Relationships between in vivo rumen protozoal growth and intakes of dry matter (DM), nitrogen, digestible organic matter (DOM), total digestible nutrients (TDN) and volatile fatty acid (VFA) production have been studied. Isotope dilution technique and 14 C-labelled rumen protozoa were used in the studies. (author)

  1. Size distribution of alkyl amines in continental particulate matter and their online detection in the gas and particle phase

    Directory of Open Access Journals (Sweden)

    T. C. VandenBoer

    2011-05-01

    Full Text Available An ion chromatographic method is described for the quantification of the simple alkyl amines: methylamine (MA, dimethylamine (DMA, trimethylamine (TMA, ethylamine (EA, diethylamine (DEA and triethylamine (TEA, in the ambient atmosphere. Limits of detection (3σ are in the tens of pmol range for all of these amines, and good resolution is achieved for all compounds except for TMA and DEA. The technique was applied to the analysis of time-integrated samples collected using a micro-orifice uniform deposition impactor (MOUDI with ten stages for size resolution of particles with aerodynamic diameters between 56 nm and 18 μm. In eight samples from urban and rural continental airmasses, the mass loading of amines consistently maximized on the stage corresponding to particles with aerodynamic diameters between 320 and 560 nm. The molar ratio of amines to ammonium (R3NH+/NH4+ in fine aerosol ranged between 0.005 and 0.2, and maximized for the smallest particle sizes. The size-dependence of the R3NH+/NH4+ ratio indicates differences in the relative importance of the processes leading to the incorporation of amines and ammonia into secondary particles. The technique was also used to make simultaneous hourly online measurements of amines in the gas phase and in fine particulate matter using an Ambient Ion Monitor Ion Chromatograph (AIM-IC. During a ten day campaign in downtown Toronto, DMA, TMA + DEA, and TEA were observed to range from below detection limit to 2.7 ppt in the gas phase. In the particle phase, MAH+ and TMAH+ + DEAH+ were observed to range from below detection limit up to 15 ng m−3. The presence of detectable levels of amines in the particle phase corresponded to periods with higher relative humidity and higher mass loadings of nitrate. While the hourly measurements made using the AIM-IC provide data that can

  2. Little composite dark matter

    Science.gov (United States)

    Balkin, Reuven; Perez, Gilad; Weiler, Andreas

    2018-02-01

    We examine the dark matter phenomenology of a composite electroweak singlet state. This singlet belongs to the Goldstone sector of a well-motivated extension of the Littlest Higgs with T-parity. A viable parameter space, consistent with the observed dark matter relic abundance as well as with the various collider, electroweak precision and dark matter direct detection experimental constraints is found for this scenario. T-parity implies a rich LHC phenomenology, which forms an interesting interplay between conventional natural SUSY type of signals involving third generation quarks and missing energy, from stop-like particle production and decay, and composite Higgs type of signals involving third generation quarks associated with Higgs and electroweak gauge boson, from vector-like top-partners production and decay. The composite features of the dark matter phenomenology allows the composite singlet to produce the correct relic abundance while interacting weakly with the Higgs via the usual Higgs portal coupling λ _{ {DM}}˜ O(1%), thus evading direct detection.

  3. Little composite dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Balkin, Reuven; Weiler, Andreas [Technische Universitaet Muenchen, First Physik-Department, Garching (Germany); Perez, Gilad [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel)

    2018-02-15

    We examine the dark matter phenomenology of a composite electroweak singlet state. This singlet belongs to the Goldstone sector of a well-motivated extension of the Littlest Higgs with T-parity. A viable parameter space, consistent with the observed dark matter relic abundance as well as with the various collider, electroweak precision and dark matter direct detection experimental constraints is found for this scenario. T-parity implies a rich LHC phenomenology, which forms an interesting interplay between conventional natural SUSY type of signals involving third generation quarks and missing energy, from stop-like particle production and decay, and composite Higgs type of signals involving third generation quarks associated with Higgs and electroweak gauge boson, from vector-like top-partners production and decay. The composite features of the dark matter phenomenology allows the composite singlet to produce the correct relic abundance while interacting weakly with the Higgs via the usual Higgs portal coupling λ{sub DM} ∝ O(1%), thus evading direct detection. (orig.)

  4. Dynamics of the diffusive DM-DE interaction – Dynamical system approach

    Energy Technology Data Exchange (ETDEWEB)

    Haba, Zbigniew [Institute of Theoretical Physics, University of Wroclaw, Plac Maxa Borna 9, 50-204 Wrocław (Poland); Stachowski, Aleksander; Szydłowski, Marek, E-mail: zhab@ift.uni.wroc.pl, E-mail: aleksander.stachowski@uj.edu.pl, E-mail: marek.szydlowski@uj.edu.pl [Astronomical Observatory, Jagiellonian University, Orla 171, 30-244 Krakow (Poland)

    2016-07-01

    We discuss dynamics of a model of an energy transfer between dark energy (DE) and dark matter (DM) . The energy transfer is determined by a non-conservation law resulting from a diffusion of dark matter in an environment of dark energy. The relativistic invariance defines the diffusion in a unique way. The system can contain baryonic matter and radiation which do not interact with the dark sector. We treat the Friedman equation and the conservation laws as a closed dynamical system. The dynamics of the model is examined using the dynamical systems methods for demonstration how solutions depend on initial conditions. We also fit the model parameters using astronomical observation: SNIa, H ( z ), BAO and Alcock-Paczynski test. We show that the model with diffuse DM-DE is consistent with the data.

  5. Paul Scherrer Institute Scientific Report 1999. Volume I: Particles and Matter

    Energy Technology Data Exchange (ETDEWEB)

    Gobrecht, J.; Gaeggeler, H.; Herlach, D.; Junker, K.; Kettle, P.-R.; Kubik, P.; Zehnder, A. [eds.

    2000-07-01

    lthough originally planned for fundamental research in nuclear physics, the particle beams of pions, muons, protons and neutrons are now used in a large variety of disciplines in both natural science and medicine. The beams at PSI have the world's highest intensities and therefore allow certain experiments to be performed, which would not be possible elsewhere. The highlight of research this year was the first-ever determination of the chemical properties of the superheavy element {sup 107} Bohrium. This was undertaken, by an international team led by H. Gaeggeler of PSI's Laboratory for Radiochemistry. Bohrium was produced by bombarding a Berkelium target with Neon ions from the Injector I cyclotron and six atoms were detected after having passed through an online gas chromatography device. At the Laboratory for Particle Physics the focus has shifted from nuclear physics to elementary particle physics with about a fifty-fifty split between investigations of rare processes or particle decays using the high intensity muon, pion and recently also polarized neutron beams of PSI, and research at the highest energy frontier at CERN (Geneva) and DESY (Hamburg). Important space instrumentation has been contributed by the Laboratory for Astrophysics to the European Space Agency and NASA satellite programmes. The Laboratory for Micro and Nanotechnology continued to focus on research into molecular nanotechnology and SiGeC nanostructures, the latter with the aim of producing silicon based optoelectronics. Progress in 1999 in these topical areas is described in this report. A list of scientific publications in 1999 is also provided.

  6. Torsion as a dark matter candidate from the Higgs portal

    Science.gov (United States)

    Belyaev, Alexander S.; Thomas, Marc C.; Shapiro, Ilya L.

    2017-05-01

    Torsion is a metric-independent component of gravitation, which may provide a more general geometry than the one taking place within general relativity. On the other hand, torsion could lead to interesting phenomenology in both particle physics and cosmology. In the present work it is shown that a torsion field interacting with the SM Higgs doublet and having a negligible coupling to standard model (SM) fermions is protected from decaying by a Z2 symmetry, and therefore becomes a promising dark matter (DM) candidate. This model provides a good motivation for Higgs portal vector DM scenario. We evaluate the DM relic density and explore direct DM detection and collider constraints on this model to understand its consistency with experimental data and establish the most up-to-date limits on its parameter space. We have found in the model when the Higgs boson is only partly responsible for the generation of torsion mass, there is a region of parameter space where torsion contributes 100% to the DM budget of the Universe. Furthermore, we present the first results on the potential of the LHC to probe the parameter space of minimal scenario with Higgs portal vector DM using mono-jet searches and have found that LHC at high luminosity will be sensitive to the substantial part of model parameter space which cannot be probed by other experiments.

  7. Anomaly-free dark matter models are not so simple

    Science.gov (United States)

    Ellis, John; Fairbairn, Malcolm; Tunney, Patrick

    2017-08-01

    We explore the anomaly-cancellation constraints on simplified dark matter (DM) models with an extra U(1)' gauge boson Z '. We show that, if the Standard Model (SM) fermions are supplemented by a single DM fermion χ that is a singlet of the SM gauge group, and the SM quarks have non-zero U(1)' charges, the SM leptons must also have non-zero U(1)' charges, in which case LHC searches impose strong constraints on the Z ' mass. Moreover, the DM fermion χ must have a vector-like U(1)' coupling. If one requires the DM particle to have a purely axial U(1)' coupling, which would be the case if χ were a Majorana fermion and would reduce the impact of direct DM searches, the simplest possibility is that it is accompanied by one other new singlet fermion, but in this case the U(1)' charges of the SM leptons still do not vanish. This is also true in a range of models with multiple new singlet fermions with identical charges. Searching for a leptophobic model, we then introduce extra fermions that transform non-trivially under the SM gauge group. We find several such models if the DM fermion is accompanied by two or more other new fermions with non-identical charges, which may have interesting experimental signatures. We present benchmark representatives of the various model classes we discuss.

  8. Signals of composite electroweak-neutral Dark Matter: LHC/direct detection interplay

    International Nuclear Information System (INIS)

    Barbieri, Riccardo; Rychkov, Slava; Torre, Riccardo

    2010-01-01

    In a strong-coupling picture of ElectroWeak Symmetry Breaking, a composite electroweak-neutral state in the TeV mass range, carrying a global (quasi-)conserved charge, makes a plausible Dark Matter (DM) candidate, with the ongoing direct DM searches being precisely sensitive to the expected signals. To exploit the crucial interplay between direct DM searches and the LHC, we consider a composite iso-singlet vector V, mixed with the hypercharge gauge field, as the essential mediator of the interaction between the DM particle and the nucleus. Based on a suitable effective chiral Lagrangian, we give the expected properties and production rates of V, showing its possible discovery at the maximal LHC energy with about 100 fb -1 of integrated luminosity.

  9. Electron anisotropy: A tool to discriminate dark matter in cosmic rays

    International Nuclear Information System (INIS)

    Borriello, Enrico; Maccione, Luca; Cuoco, Alessandro

    2012-01-01

    Indirect searches of particle Dark Matter (DM) with high energy Cosmic Rays (CR) are typically affected by large uncertainties. We show that, on the contrary, the DM intrinsic degree of anisotropy in the arrival directions of high energy CR electrons and positrons (CRE) is basically model independent and offers a straightforward criterion to discriminate among CRE from DM or from local discrete sources, like e.g. pulsars. In particular, in absence of the latter, DM sets the maximum degree of total anisotropy. As a consequence, if a larger anisotropy is detected, this would constitute an unambiguous evidence for the presence of astrophysical local discrete CRE sources. The Fermi-LAT will be able to probe such scenarios in the next years.

  10. The search for decaying Dark Matter

    CERN Document Server

    Herder, J W den; Ruchayskiy, O.; Abazajian, K.; Frenk, C.; Hansen, S.; Jonker, P.; Kouveliotou, C.; Lesgourgues, J.; Neronov, A.; Ohashi, T.; Paerels, F.; Paltani, S.; Piro, L.; Pohl, M.; Shaposhnikov, M.; Silk, J.; Valle, J.W.F.

    2009-01-01

    We propose an X-ray mission called Xenia to search for decaying superweakly interacting Dark Matter particles (super-WIMP) with a mass in the keV range. The mission and its observation plan are capable of providing a major break through in our understanding of the nature of Dark Matter (DM). It will confirm, or reject, predictions of a number of particle physics models by increasing the sensitivity of the search for decaying DM by about two orders of magnitude through a wide-field imaging X-ray spectrometer in combination with a dedicated observation program. The proposed mission will provide unique limits on the mixing angle and mass of neutral leptons, right handed partners of neutrinos, which are important Dark Matter candidates. The existence of these particles is strongly motivated by observed neutrino flavor oscillations and the problem of baryon asymmetry of the Universe. In super-WIMP models, the details of the formation of the cosmic web are different from those of LambdaCDM. The proposed mission wil...

  11. On the Possible Links Between Electroweak Symmetry Breaking and Dark Matter

    International Nuclear Information System (INIS)

    Hambye, Thomas; Tytgat, Michel H. G.

    2009-01-01

    The mechanism behind electroweak symmetry breaking (EWSB) and the nature of dark matter (DM) are currently very important issues in particle physics. Usually, in most models, these two issues are not or poorly connected. However, since a natural dark matter candidate is a weakly interacting massive particle or WIMP, with mass around the electroweak scale, it is clearly of interest to investigate the possibility that DM and EWSB are closely related. In the context of a very simple extension of the Standard Model, the Inert Doublet Model, we show that dark matter could play a crucial role in the breaking of the electroweak symmetry. In this model, dark matter is the lightest component of an inert scalar doublet which can induce dynamically electroweak symmetry breaking at one loop level. Moreover, in a large fraction of the parameter space of this model, the mass of the dark matter particle is essentially determined by the electroweak scale, so that the fact that the WIMP DM mass is around the electroweak scale is not a coincidence.

  12. Supersymmetric model for dark matter and baryogenesis motivated by the recent CDMS result.

    Science.gov (United States)

    Allahverdi, Rouzbeh; Dutta, Bhaskar; Mohapatra, Rabindra N; Sinha, Kuver

    2013-08-02

    We discuss a supersymmetric model for cogenesis of dark and baryonic matter where the dark matter (DM) has mass in the 8-10 GeV range as indicated by several direct detection searches, including most recently the CDMS experiment with the desired cross section. The DM candidate is a real scalar field. Two key distinguishing features of the model are the following: (i) in contrast with the conventional weakly interacting massive particle dark matter scenarios where thermal freeze-out is responsible for the observed relic density, our model uses nonthermal production of dark matter after reheating of the Universe caused by moduli decay at temperatures below the QCD phase transition, a feature which alleviates the relic overabundance problem caused by small annihilation cross section of light DM particles and (ii) baryogenesis occurs also at similar low temperatures from the decay of TeV scale mediator particles arising from moduli decay. A possible test of this model is the existence of colored particles with TeV masses accessible at the LHC.

  13. Super-cool Dark Matter arXiv

    CERN Document Server

    Hambye, Thomas; Teresi, Daniele

    In dimension-less theories of dynamical generation of the weak scale, the Universe can undergo a period of low-scale inflation during which all particles are massless and super-cool. This leads to a new mechanism of generation of the cosmological Dark Matter (DM) relic density: super-cooling can easily suppress the amount of DM to the desired level. This is achieved for TeV-scale DM, if super-cooling ends when quark condensates form at the QCD phase transition. Along this scenario, the baryon asymmetry can be generated either at the phase transition or through leptogenesis. We show that the above mechanism takes place in old and new dimension-less models.

  14. Behavior of secondary particles in particulate matter collected at eastern Kanagawa

    International Nuclear Information System (INIS)

    Nishida, Tomohiro; Kikawada, Yoshikazu; Oi, Takao; Honda, Teruyuki

    2008-01-01

    The suspended particulate matters collected in 100 periods from 2002/10/28 to 2004/10/29 were separated into the water soluble and insoluble components and their main components were analyzed. The characteristics of atmosphere in the east part of Kagawa prefecture and of the secondary particulates were presumed. Therefore, it was considered that in the samples other than Mn the origins of water soluble and insoluble components are different each other from their behavior. The water-soluble part may be mostly ammonium salt (secondary particulate) from the measurement of NH 4 + . Furthermore, it became clear that the evolution of secondary particulate varies largely with season. Then, the variation with season was presumed by the main component analysis using the statistical software, SPSS adding to the correlation coefficient. This method has proved to be effective. (M.H.)

  15. Cytokines, Type 2 DM and the Metabolic Syndrome | Ogbera ...

    African Journals Online (AJOL)

    comparable in the DM subjects with and without the Mets and also comparable in obese DM and non obese DM subjects. Of the Mets defining criteria, waist circumference (WC) and Triglyceride (TG) were found to be significantly associated with only two of the studied cytokines. The correlation coefficient and p values of ...

  16. Fermionic minimal dark matter in 5D gauge-Higgs unification

    Science.gov (United States)

    Maru, Nobuhito; Okada, Nobuchika; Okada, Satomi

    2017-12-01

    We propose a minimal dark matter (MDM) scenario in the context of a simple gauge-Higgs unification (GHU) model based on the gauge group S U (3 )×U (1 )' in five-dimensional Minkowski space with a compactification of the fifth dimension on the 1S/Z2 orbifold. A pair of vectorlike S U (3 ) multiplet fermions in a higher-dimensional representation is introduced in the bulk, and the DM particle is identified with the lightest mass eigenstate among the components in the multiplets. In the original model description, the DM particle communicates with the Standard Model (SM) particles only through the bulk gauge interaction, and hence our model is the GHU version of the MDM scenario. There are two typical realizations of the DM particle in four-dimensional effective theory: (i) the DM particle is mostly composed of the SM S U (2 )L multiplets, or (ii) the DM is mostly composed of the SM S U (2 )L singlets. Since the case (i) is very similar to the original MDM scenario, we focus on the case (ii), which is a realization of the Higgs-portal DM scenario in the context of the GHU model. We identify an allowed parameter region to be consistent with the current experimental constraints, which will be fully covered by the direct dark matter detection experiments in the near future. In the presence of the bulk multiplet fermions in higher-dimensional S U (3 ) representations, we reproduce the 125 GeV Higgs boson mass through the renormalization group evolution of Higgs quartic coupling with the compactification scale of 10-100 TeV.

  17. Constraints on decaying Dark Matter from XMM-Newton observations of M31

    CERN Document Server

    Boyarsky, Alexey; Ruchayskiy, Oleg; Savchenko, Vladimir

    2007-01-01

    We derive constraints on parameters of the radiatively decaying Dark Matter (DM) particles, using XMM-Newton EPIC spectra of the Andromeda galaxy (M31). Using the observations of the outer (5'-13') parts of M31 we improve the existing constraints. For the case of sterile neutrino DM, combining our constraints with the latest computation of abundances of sterile neutrino in the Dodelson-Widrow (DW) scenario, we obtain the lower mass limit m_s 5.6 kev), we argue that the scenario in which all the DM is produced via DW mechanism is ruled out. We discuss however other production mechanisms and note that the sterile neutrino remains a viable candidate of Dark Matter, either warm or cold.

  18. Chemical compositions and sources of organic matter in fine particles of soils and sands from the vicinity of Kuwait city.

    Science.gov (United States)

    Rushdi, Ahmed I; Al-Zarban, Sheikha; Simoneit, Bernd R T

    2006-09-01

    Fine particles in the atmosphere from soil and sand resuspension contain a variety of organic compounds from natural biogenic and anthropogenic matter. Soil and sand samples from various sites near Kuwait city were collected, sieved to retain the fine particles, and extracted with a mixture of dichloromethane and methanol. The extracts were derivatized and analyzed by gas chromatography-mass spectrometry in order to characterize the chemical compositions and sources of the organic components. The major inputs of organic compounds were from both natural biogenic and anthropogenic sources in these samples. Vegetation was the major natural source of organic compounds and included n-alkanols, n-alkanoic acids, n-alkanes, sterols and triterpenoids. Saccharides had high concentrations (31-43%) in the sand dune and seafront samples, indicating sources from decomposed vegation materials and/or the presence of viable microbiota such as bacteria and fungi. Vehicular emission products, leakage of lubricating oils, discarded plastics and emissions from cooking operations were the major anthropogenic inputs in the samples from the urban areas. This input was mainly UCM, n-alkanes, hopanes, plasticizers and cholesterol, respectively.

  19. Distinguishing nanomaterial particles from background airborne particulate matter for quantitative exposure assessment

    Science.gov (United States)

    Ono-Ogasawara, Mariko; Serita, Fumio; Takaya, Mitsutoshi

    2009-10-01

    As the production of engineered nanomaterials quantitatively expands, the chance that workers involved in the manufacturing process will be exposed to nanoparticles also increases. A risk management system is needed for workplaces in the nanomaterial industry based on the precautionary principle. One of the problems in the risk management system is difficulty of exposure assessment. In this article, examples of exposure assessment in nanomaterial industries are reviewed with a focus on distinguishing engineered nanomaterial particles from background nanoparticles in workplace atmosphere. An approach by JNIOSH (Japan National Institute of Occupational Safety and Health) to quantitatively measure exposure to carbonaceous nanomaterials is also introduced. In addition to real-time measurements and qualitative analysis by electron microscopy, quantitative chemical analysis is necessary for quantitatively assessing exposure to nanomaterials. Chemical analysis is suitable for quantitative exposure measurement especially at facilities with high levels of background NPs.

  20. Revisit of cosmic ray antiprotons from dark matter annihilation with updated constraints on the background model from AMS-02 and collider data

    Science.gov (United States)

    Cui, Ming-Yang; Pan, Xu; Yuan, Qiang; Fan, Yi-Zhong; Zong, Hong-Shi

    2018-06-01

    We study the cosmic ray antiprotons with updated constraints on the propagation, proton injection, and solar modulation parameters based on the newest AMS-02 data near the Earth and Voyager data in the local interstellar space, and on the cross section of antiproton production due to proton-proton collisions based on new collider data. We use a Bayesian approach to properly consider the uncertainties of the model predictions of both the background and the dark matter (DM) annihilation components of antiprotons. We find that including an extra component of antiprotons from the annihilation of DM particles into a pair of quarks can improve the fit to the AMS-02 antiproton data considerably. The favored mass of DM particles is about 60~100 GeV, and the annihilation cross section is just at the level of the thermal production of DM (langleσvrangle ~ O(10‑26) cm3 s‑1).

  1. Evaluation of solid particle number and black carbon for very low particulate matter emissions standards in light-duty vehicles.

    Science.gov (United States)

    Chang, M-C Oliver; Shields, J Erin

    2017-06-01

    To reliably measure at the low particulate matter (PM) levels needed to meet California's Low Emission Vehicle (LEV III) 3- and 1-mg/mile particulate matter (PM) standards, various approaches other than gravimetric measurement have been suggested for testing purposes. In this work, a feasibility study of solid particle number (SPN, d50 = 23 nm) and black carbon (BC) as alternatives to gravimetric PM mass was conducted, based on the relationship of these two metrics to gravimetric PM mass, as well as the variability of each of these metrics. More than 150 Federal Test Procedure (FTP-75) or Supplemental Federal Test Procedure (US06) tests were conducted on 46 light-duty vehicles, including port-fuel-injected and direct-injected gasoline vehicles, as well as several light-duty diesel vehicles equipped with diesel particle filters (LDD/DPF). For FTP tests, emission variability of gravimetric PM mass was found to be slightly less than that of either SPN or BC, whereas the opposite was observed for US06 tests. Emission variability of PM mass for LDD/DPF was higher than that of both SPN and BC, primarily because of higher PM mass measurement uncertainties (background and precision) near or below 0.1 mg/mile. While strong correlations were observed from both SPN and BC to PM mass, the slopes are dependent on engine technologies and driving cycles, and the proportionality between the metrics can vary over the course of the test. Replacement of the LEV III PM mass emission standard with one other measurement metric may imperil the effectiveness of emission reduction, as a correlation-based relationship may evolve over future technologies for meeting stringent greenhouse standards. Solid particle number and black carbon were suggested in place of PM mass for the California LEV III 1-mg/mile FTP standard. Their equivalence, proportionality, and emission variability in comparison to PM mass, based on a large light-duty vehicle fleet examined, are dependent on engine

  2. Sharing but not caring. Dark matter and the baryon asymmetry of the universe

    Energy Technology Data Exchange (ETDEWEB)

    Bernal, Nicolas [Universidad Estadual Paulista, Sao Paulo (Brazil). Inst. de Fisica Teorica; Austrian Academy of Sciences, Vienna (Austria). Inst. of High Energy Physics; Fong, Chee Sheng [Sao Paulo Univ. (Brazil). Inst. de Fisica; Fonseca, Nayara [Sao Paulo Univ. (Brazil). Inst. de Fisica; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2016-09-15

    We consider scenarios where Dark Matter (DM) particles carry baryon and/or lepton numbers, which can be defined if there exist operators connecting the dark to the visible sector. As a result, the DM fields become intimately linked to the Standard Model (SM) ones and can be maximally asymmetric just like the ordinary matter. In particular, we discuss minimal scenarios where the DM is a complex scalar or a Dirac fermion coupled to operators with nonzero baryon and/or lepton numbers, and that consist of only SM fields. We consider an initial asymmetry stored in either the SM or the DM sector; the main role of these operators is to properly share the asymmetry between the two sectors, in accordance with observations. After the chemical decoupling, the DM and SM sectors do not care about each other as there is only an ineffective communication between them. Once the DM mass is specified, the Wilson coefficients of these operators are fixed by the requirement of the correct transfer of the asymmetry. We study the phenomenology of this framework at colliders, direct detection and indirect detection experiments. In particular, the LHC phenomenology is very rich and can be tested in different channels such as the two same-sign leptons with two jets, monojet and monojet with a monolepton.

  3. Sharing but not caring: dark matter and the baryon asymmetry of the universe

    Energy Technology Data Exchange (ETDEWEB)

    Bernal, Nicolás [ICTP South American Institute for Fundamental Research, Instituto de Física Teórica, Universidade Estadual Paulista,R. Dr. Bento Teobaldo Ferraz 271, 01140-070 São Paulo (Brazil); Institute of High Energy Physics, Austrian Academy of Sciences,Nikolsdorfer Gasse 18, 1050 Vienna (Austria); Fong, Chee Sheng [Instituto de Física, Universidade de São Paulo,Rua do Matão 1371, 05508-090 São Paulo (Brazil); Fonseca, Nayara [Instituto de Física, Universidade de São Paulo,Rua do Matão 1371, 05508-090 São Paulo (Brazil); DESY,Notkestraße 85, 22607 Hamburg (Germany)

    2016-09-02

    We consider scenarios where Dark Matter (DM) particles carry baryon and/or lepton numbers, which can be defined if there exist operators connecting the dark to the visible sector. As a result, the DM fields become intimately linked to the Standard Model (SM) ones and can be maximally asymmetric just like the ordinary matter. In particular, we discuss minimal scenarios where the DM is a complex scalar or a Dirac fermion coupled to operators with nonzero baryon and/or lepton numbers, and that consist of only SM fields. We consider an initial asymmetry stored in either the SM or the DM sector; the main role of these operators is to properly share the asymmetry between the two sectors, in accordance with observations. After the chemical decoupling, the DM and SM sectors do not care about each other as there is only an ineffective communication between them. Once the DM mass is specified, the Wilson coefficients of these operators are fixed by the requirement of the correct transfer of the asymmetry. We study the phenomenology of this framework at colliders, direct detection and indirect detection experiments. In particular, the LHC phenomenology is very rich and can be tested in different channels such as the two same-sign leptons with two jets, monojet and monojet with a monolepton.

  4. Fermi-LAT kills dark matter interpretations of AMS-02 data. Or not?

    Energy Technology Data Exchange (ETDEWEB)

    Belotsky, Konstantin; Budaev, Ruslan; Kirillov, Alexander; Laletin, Maxim, E-mail: k-belotsky@yandex.ru, E-mail: buday48@mail.ru, E-mail: AAKirillov@mephi.ru, E-mail: maxim.laletin@ulg.ac.be [Department of Elementary Particle Physics, National Research Nuclear University MEPhI, 115409 Kashirskoe shosse 31, Moscow (Russian Federation)

    2017-01-01

    A number of papers attempt to explain the positron anomaly in cosmic rays, observed by PAMELA and AMS-02, in terms of dark matter (DM) decays or annihilations. However, the recent progress in cosmic gamma-ray studies challenges these attempts. Indeed, as we show, any rational DM model explaining the positron anomaly abundantly produces final state radiation and Inverse Compton gamma rays, which inevitably leads to a contradiction with Fermi-LAT isotropic diffuse gamma-ray background measurements. Furthermore, the Fermi-LAT observation of Milky Way dwarf satellites, supposed to be rich in DM, revealed no significant signal in gamma rays. We propose a generic approach in which the major contribution to cosmic rays comes from the dark matter disc and prove that the tension between the DM origin of the positron anomaly and the cosmic gamma-ray observations can be relieved. We consider both a simple model, in which DM decay/annihilate into charged leptons, and a model-independent minimal case of particle production, and we estimate the optimal thickness of DM disk. Possible mechanisms of formation and its properties are briefly discussed.

  5. Sharing but not caring. Dark matter and the baryon asymmetry of the universe

    International Nuclear Information System (INIS)

    Bernal, Nicolas

    2016-09-01

    We consider scenarios where Dark Matter (DM) particles carry baryon and/or lepton numbers, which can be defined if there exist operators connecting the dark to the visible sector. As a result, the DM fields become intimately linked to the Standard Model (SM) ones and can be maximally asymmetric just like the ordinary matter. In particular, we discuss minimal scenarios where the DM is a complex scalar or a Dirac fermion coupled to operators with nonzero baryon and/or lepton numbers, and that consist of only SM fields. We consider an initial asymmetry stored in either the SM or the DM sector; the main role of these operators is to properly share the asymmetry between the two sectors, in accordance with observations. After the chemical decoupling, the DM and SM sectors do not care about each other as there is only an ineffective communication between them. Once the DM mass is specified, the Wilson coefficients of these operators are fixed by the requirement of the correct transfer of the asymmetry. We study the phenomenology of this framework at colliders, direct detection and indirect detection experiments. In particular, the LHC phenomenology is very rich and can be tested in different channels such as the two same-sign leptons with two jets, monojet and monojet with a monolepton.

  6. The 21 cm signal and the interplay between dark matter annihilations and astrophysical processes

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Honorez, Laura [Theoretische Natuurkunde, Vrije Universiteit Brussel and The International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Mena, Olga; Moliné, Ángeles; Palomares-Ruiz, Sergio [Instituto de Física Corpuscular (IFIC), CSIC-Universitat de València, Apartado de Correos 22085, E-46071 Valencia (Spain); Vincent, Aaron C., E-mail: llopezho@vub.ac.be, E-mail: omena@ific.uv.es, E-mail: maria.moline@ist.utl.pt, E-mail: sergio.Palomares.Ruiz@ific.uv.es, E-mail: aaron.vincent@durham.ac.uk [Institute for Particle Physics Phenomenology (IPPP), Department of Physics, Durham University, Durham DH1 3LE (United Kingdom)

    2016-08-01

    Future dedicated radio interferometers, including HERA and SKA, are very promising tools that aim to study the epoch of reionization and beyond via measurements of the 21 cm signal from neutral hydrogen. Dark matter (DM) annihilations into charged particles change the thermal history of the Universe and, as a consequence, affect the 21 cm signal. Accurately predicting the effect of DM strongly relies on the modeling of annihilations inside halos. In this work, we use up-to-date computations of the energy deposition rates by the products from DM annihilations, a proper treatment of the contribution from DM annihilations in halos, as well as values of the annihilation cross section allowed by the most recent cosmological measurements from the Planck satellite. Given current uncertainties on the description of the astrophysical processes driving the epochs of reionization, X-ray heating and Lyman-α pumping, we find that disentangling DM signatures from purely astrophysical effects, related to early-time star formation processes or late-time galaxy X-ray emissions, will be a challenging task. We conclude that only annihilations of DM particles with masses of ∼100 MeV, could leave an unambiguous imprint on the 21 cm signal and, in particular, on the 21 cm power spectrum. This is in contrast to previous, more optimistic results in the literature, which have claimed that strong signatures might also be present even for much higher DM masses. Additional measurements of the 21 cm signal at different cosmic epochs will be crucial in order to break the strong parameter degeneracies between DM annihilations and astrophysical effects and undoubtedly single out a DM imprint for masses different from ∼100 MeV.

  7. Study of the boxlike dark matter signals from dwarf spheroidal galaxies with Fermi-LAT data

    Science.gov (United States)

    Li, Shang; Liang, Yun-Feng; Xia, Zi-Qing; Zu, Lei; Duan, Kai-Kai; Shen, Zhao-Qiang; Feng, Lei; Yuan, Qiang; Fan, Yi-Zhong

    2018-04-01

    The observation of a special spectral feature in the gamma-ray data would be one of the best ways to identify dark matter (DM). The box-shaped gamma-ray spectra could be generated by the decay of intermediate particles produced by DM annihilation or decay. It provides another kind of signal that can be relatively easily distinguished from astrophysical backgrounds besides the linelike signals. Dwarf spheroidal galaxies are expected to be dominated by DM and may be one of the most promising targets for indirect DM searches. In this paper, we study the box-shaped DM signals with Fermi-LAT observations of dwarf spheroidal galaxies. We analyze 106 months of Fermi-LAT data to derive the upper limits on the annihilation cross section or the decay timescale of DM. In addition, we compare the results for different sample selections and DM density distributions. We expect that more dwarf spheroidal galaxies will be found and the sensitivity of box-shaped gamma-ray signal searches will be significantly improved in the future.

  8. Photons from dark matter in a (non-universal) extra dimension model

    International Nuclear Information System (INIS)

    Regis, Marco

    2008-01-01

    We study the multi-wavelength signal induced by pairs annihilations at the galactic center (GC) of a recently proposed dark matter (DM) candidate. The weakly interacting massive particle (WIMP) candidate, named A - , is the first Kaluza-Klein mode of a five-dimensional Abelian gauge boson. Electroweak precision tests and the DM cosmological bound constrain its mass and pair annihilation rate in small ranges, leading to precise predictions of indirect signals from what concerns the particle physics side. The related multi-wavelength emission is expected to be faint, unless a significant enhancement of the DM density is present at the GC. We find that in this case, and depending on few additional assumptions, the next generation of gamma-ray and wide-field radio observations can test the model, possibly even with the detection of the induced monochromatic gamma-ray emission

  9. Dark Matter characterization at the LHC in the Effective Field Theory approach

    Energy Technology Data Exchange (ETDEWEB)

    Belyaev, Alexander; Panizzi, Luca [School of Physics and Astronomy, University of Southampton,Southampton SO17 1BJ (United Kingdom); Particle Physics Department, Rutherford Appleton Laboratory,Didcot, Oxon OX11 0QX (United Kingdom); Pukhov, Alexander [Skobeltsyn Institute of Nuclear Physics, Moscow State University,Moscow 119992 (Russian Federation); Thomas, Marc [School of Physics and Astronomy, University of Southampton,Southampton SO17 1BJ (United Kingdom); Particle Physics Department, Rutherford Appleton Laboratory,Didcot, Oxon OX11 0QX (United Kingdom)

    2017-04-19

    We have studied the complete set of dimension 5 and dimension 6 effective operators involving the interaction of scalar, fermion and vector Dark Matter (DM) with SM quarks and gluons, to explore the possibility to distinguish these operators and characterise the spin of DM at the LHC. We have found that three factors — the effective dimension of the operator, the structure of the SM part of the operator and the parton densities of the SM particles connected to the operator — uniquely define the shape of the (unobservable) invariant mass distribution of the DM pair and, consequently, the shape of the (observable) E{sub T}{sup miss} distribution related to it. Using χ{sup 2} analysis, we found that at the LHC, with a luminosity of 300 fb{sup −1}, certain classes of EFT operators can be distinguished from each other. Hence, since DM spin is partly correlated with the factors defining the shape of E{sub T}{sup miss}, the LHC can potentially shed a light also on DM spin. We have also observed a drastic difference in the efficiencies (up to two orders of magnitude) for large E{sub T}{sup miss} cuts scenarios with different DM spin, thus indicating that the DM discovery potential strongly depends on it. The study we perform here can be applied more generally than within the EFT paradigm, where the DM mediator is not produced on-the-mass-shell, such as the case of t-channel mediator or mediator with mass below 2M{sub DM}, where the invariant mass of the DM pair is not fixed.

  10. Dark Matter characterization at the LHC in the Effective Field Theory approach

    Science.gov (United States)

    Belyaev, Alexander; Panizzi, Luca; Pukhov, Alexander; Thomas, Marc

    2017-04-01

    We have studied the complete set of dimension 5 and dimension 6 effective operators involving the interaction of scalar, fermion and vector Dark Matter (DM) with SM quarks and gluons, to explore the possibility to distinguish these operators and characterise the spin of DM at the LHC. We have found that three factors — the effective dimension of the operator, the structure of the SM part of the operator and the parton densities of the SM particles connected to the operator — uniquely define the shape of the (unobservable) invariant mass distribution of the DM pair and, consequently, the shape of the (observable) E T miss distribution related to it. Using χ2 analysis, we found that at the LHC, with a luminosity of 300 fb-1, certain classes of EFT operators can be distinguished from each other. Hence, since DM spin is partly correlated with the factors defining the shape of E T miss , the LHC can potentially shed a light also on DM spin. We have also observed a drastic difference in the efficiencies (up to two orders of magnitude) for large E T miss cuts scenarios with different DM spin, thus indicating that the DM discovery potential strongly depends on it. The study we perform here can be applied more generally than within the EFT paradigm, where the DM mediator is not produced on-the-mass-shell, such as the case of t-channel mediator or mediator with mass below 2 M DM, where the invariant mass of the DM pair is not fixed.

  11. Galactic center gamma-ray excess from dark matter annihilation: is there a black hole spike?

    Science.gov (United States)

    Fields, Brian D; Shapiro, Stuart L; Shelton, Jessie

    2014-10-10

    If the supermassive black hole Sgr A* at the center of the Milky Way grew adiabatically from an initial seed embedded in a Navarro-Frenk-White dark matter (DM) halo, then the DM profile near the hole has steepened into a spike. We calculate the dramatic enhancement to the gamma-ray flux from the Galactic center (GC) from such a spike if the 1-3 GeV excess observed in Fermi data is due to DM annihilations. We find that for the parameter values favored in recent fits, the point-source-like flux from the spike is 35 times greater than the flux from the inner 1° of the halo, far exceeding all Fermi point source detections near the GC. We consider the dependence of the spike signal on astrophysical and particle parameters and conclude that if the GC excess is due to DM, then a canonical adiabatic spike is disfavored by the data. We discuss alternative Galactic histories that predict different spike signals, including (i) the nonadiabatic growth of the black hole, possibly associated with halo and/or black hole mergers, (ii) gravitational interaction of DM with baryons in the dense core, such as heating by stars, or (iii) DM self-interactions. We emphasize that the spike signal is sensitive to a different combination of particle parameters than the halo signal and that the inclusion of a spike component to any DM signal in future analyses would provide novel information about both the history of the GC and the particle physics of DM annihilations.

  12. The effects of cultivation on the organic matter of total soil and in the different soil particle size separates using radiocarbon dating

    International Nuclear Information System (INIS)

    Gazineu, M.H.P.

    1982-07-01

    The effects of cultivation on the organic matter and nutrients in the total soil and in five particle size separates were studied through chemical analyses and radiocarbon dating. Samples were taken from the A and B horizons of an uncultivated field and of fields cultivated during 5,60 and 90 years which had never received treatment with fertilizers. (M.A.) [pt

  13. The Relative Effectiveness of the Use of Static and Dynamic Mechanical Models in Teaching Elementary School Children the Theoretical Concept--The Particle Nature of Matter.

    Science.gov (United States)

    Ziegler, Robert Edward

    This study is concerned with determining the relative effectiveness of a static and dynamic theoretical model in teaching elementary school students to use the particle idea of matter when explaining certain physical phenomena. A clinical method of personal individual interview-testing, teaching, and retesting of a random sample population from…

  14. Higgs decays to dark matter: Beyond the minimal model

    International Nuclear Information System (INIS)

    Pospelov, Maxim; Ritz, Adam

    2011-01-01

    We examine the interplay between Higgs mediation of dark-matter annihilation and scattering on one hand and the invisible Higgs decay width on the other, in a generic class of models utilizing the Higgs portal. We find that, while the invisible width of the Higgs to dark matter is now constrained for a minimal singlet scalar dark matter particle by experiments such as XENON100, this conclusion is not robust within more generic examples of Higgs mediation. We present a survey of simple dark matter scenarios with m DM h /2 and Higgs portal mediation, where direct-detection signatures are suppressed, while the Higgs width is still dominated by decays to dark matter.

  15. Beyond effective field theory for dark matter searches at the LHC

    International Nuclear Information System (INIS)

    Buchmueller, O.; Dolan, Matthew J.; McCabe, Christopher

    2014-01-01

    We study the validity of effective field theory (EFT) interpretations of monojet searches for dark matter at the LHC for vector and axial-vector interactions. We show that the EFT approach is valid when the mediator has mass m med greater than 2.5 TeV. We find that the current limits on the contact interaction scale Λ in the EFT apply to theories that are perturbative for dark matter mass m DM <800 GeV. However, for all values of m DM in these theories, the mediator width is larger than the mass, so that a particle-like interpretation of the mediator is doubtful. Furthermore, consistency with the thermal relic density occurs only for 170≲m DM ≲510 GeV. For lighter mediator masses, the EFT limit either under-estimates the true limit (because the process is resonantly enhanced) or over-estimates it (because the missing energy distribution is too soft). We give some ‘rules of thumb’ that can be used to estimate the limit on Λ (to an accuracy of ∼50%) for any m DM and m med from knowledge of the EFT limit. We also compare the relative sensitivities of monojet and dark matter direct detection searches finding that both dominate in different regions of the m DM – m med plane. Comparing only the EFT limit with direct searches is misleading and can lead to incorrect conclusions about the relative sensitivity of the two search approaches

  16. Tomographic-spectral approach for dark matter detection in the cross-correlation between cosmic shear and diffuse γ-ray emission

    Energy Technology Data Exchange (ETDEWEB)

    Camera, S. [Jodrell Bank Centre for Astrophysics, The University of Manchester, Alan Turing Building, Oxford Road, Manchester M13 9PL (United Kingdom); Fornasa, M. [School of Physics and Astronomy, University of Nottingham, University Campus, Nottingham NG7 2RD (United Kingdom); Fornengo, N.; Regis, M., E-mail: stefano.camera@manchester.ac.uk, E-mail: fornasam@gmail.com, E-mail: fornengo@to.infn.it, E-mail: regis@to.infn.it [Dipartimento di Fisica, Università di Torino, Via P. Giuria 1, 10125 Torino (Italy)

    2015-06-01

    We recently proposed to cross-correlate the diffuse extragalactic γ-ray background with the gravitational lensing signal of cosmic shear. This represents a novel and promising strategy to search for annihilating or decaying particle dark matter (DM) candidates. In the present work, we demonstrate the potential of a tomographic-spectral approach: measuring the cross-correlation in separate bins of redshift and energy significantly improves the sensitivity to a DM signal. Indeed, the technique proposed here takes advantage of the different scaling of the astrophysical and DM components with redshift and, simultaneously of their different energy spectra and different angular extensions. The sensitivity to a particle DM signal is extremely promising even when the DM-induced emission is quite faint. We first quantify the prospects of detecting DM by cross-correlating the Fermi Large Area Telescope (LAT) diffuse γ-ray background with the cosmic shear expected from the Dark Energy Survey. Under the hypothesis of a significant subhalo boost, such a measurement can deliver a 5σ detection of DM, if the DM particle is lighter than 300 GeV and has a thermal annihilation rate. We then forecast the capability of the European Space Agency Euclid satellite (whose launch is planned for 2020), in combination with an hypothetical future γ-ray detector with slightly improved specifications compared to current telescopes. We predict that the cross-correlation of their data will allow a measurement of the DM mass with an uncertainty of a factor of 1.5–2, even for moderate subhalo boosts, for DM masses up to few hundreds of GeV and thermal annihilation rates.

  17. Tomographic-spectral approach for dark matter detection in the cross-correlation between cosmic shear and diffuse γ-ray emission

    Science.gov (United States)

    Camera, S.; Fornasa, M.; Fornengo, N.; Regis, M.

    2015-06-01

    We recently proposed to cross-correlate the diffuse extragalactic γ-ray background with the gravitational lensing signal of cosmic shear. This represents a novel and promising strategy to search for annihilating or decaying particle dark matter (DM) candidates. In the present work, we demonstrate the potential of a tomographic-spectral approach: measuring the cross-correlation in separate bins of redshift and energy significantly improves the sensitivity to a DM signal. Indeed, the technique proposed here takes advantage of the different scaling of the astrophysical and DM components with redshift and, simultaneously of their different energy spectra and different angular extensions. The sensitivity to a particle DM signal is extremely promising even when the DM-induced emission is quite faint. We first quantify the prospects of detecting DM by cross-correlating the Fermi Large Area Telescope (LAT) diffuse γ-ray background with the cosmic shear expected from the Dark Energy Survey. Under the hypothesis of a significant subhalo boost, such a measurement can deliver a 5σ detection of DM, if the DM particle is lighter than 300 GeV and has a thermal annihilation rate. We then forecast the capability of the European Space Agency Euclid satellite (whose launch is planned for 2020), in combination with an hypothetical future γ-ray detector with slightly improved specifications compared to current telescopes. We predict that the cross-correlation of their data will allow a measurement of the DM mass with an uncertainty of a factor of 1.5-2, even for moderate subhalo boosts, for DM masses up to few hundreds of GeV and thermal annihilation rates.

  18. Tomographic-spectral approach for dark matter detection in the cross-correlation between cosmic shear and diffuse γ-ray emission

    International Nuclear Information System (INIS)

    Camera, S.; Fornasa, M.; Fornengo, N.; Regis, M.

    2015-01-01

    We recently proposed to cross-correlate the diffuse extragalactic γ-ray background with the gravitational lensing signal of cosmic shear. This represents a novel and promising strategy to search for annihilating or decaying particle dark matter (DM) candidates. In the present work, we demonstrate the potential of a tomographic-spectral approach: measuring the cross-correlation in separate bins of redshift and energy significantly improves the sensitivity to a DM signal. Indeed, the technique proposed here takes advantage of the different scaling of the astrophysical and DM components with redshift and, simultaneously of their different energy spectra and different angular extensions. The sensitivity to a particle DM signal is extremely promising even when the DM-induced emission is quite faint. We first quantify the prospects of detecting DM by cross-correlating the Fermi Large Area Telescope (LAT) diffuse γ-ray background with the cosmic shear expected from the Dark Energy Survey. Under the hypothesis of a significant subhalo boost, such a measurement can deliver a 5σ detection of DM, if the DM particle is lighter than 300 GeV and has a thermal annihilation rate. We then forecast the capability of the European Space Agency Euclid satellite (whose launch is planned for 2020), in combination with an hypothetical future γ-ray detector with slightly improved specifications compared to current telescopes. We predict that the cross-correlation of their data will allow a measurement of the DM mass with an uncertainty of a factor of 1.5–2, even for moderate subhalo boosts, for DM masses up to few hundreds of GeV and thermal annihilation rates

  19. The Flavour Portal to Dark Matter

    CERN Document Server

    Calibbi, Lorenzo; Zaldivar, Bryan

    2015-01-01

    We present a class of models in which dark matter (DM) is a fermionic singlet under the Standard Model (SM) gauge group but is charged under a symmetry of flavour that acts as well on the SM fermions. Interactions between DM and SM particles are mediated by the scalar fields that spontaneously break the flavour symmetry, the so-called flavons. In the case of gauged flavour symmetries, the interactions are also mediated by the flavour gauge bosons. We first discuss the construction and the generic features of this class of models. Then a concrete example with an abelian flavour symmetry is considered. We compute the complementary constraints from the relic abundance, direct detection experiments and flavour observables, showing that wide portions of the parameter space are still viable. Other possibilities like non-abelian flavour symmetries can be analysed within the same framework.

  20. A Raman spectroscopic study of organic matter in interplanetary dust particles and meteorites using multiple wavelength laser excitation

    Science.gov (United States)

    Starkey, N. A.; Franchi, I. A.; Alexander, C. M. O'd.

    2013-10-01

    Raman spectroscopy was used to investigate insoluble organic matter (IOM) from a range of chondritic meteorites, and a suite of interplanetary dust particles (IDPs). Three monochromatic excitation wavelengths (473 nm, 514 nm, 632 nm) were applied sequentially to assess variations in meteorite and IDP Raman peak parameters (carbon D and G bands) as a function of excitation wavelength (i.e., dispersion). Greatest dispersion occurs in CVs > OCs > CMs > CRs with type 3 chondrites compared at different excitation wavelengths displaying conformable relationships, in contrast to type 2 chondrites. These findings indicate homogeneity in the structural nature of type 3 chondrite IOM, while organic matter (OM) in type 2 chondrites appears to be inherently more heterogeneous. If type 2 and type 3 chondrite IOM shares a common source, then thermal metamorphism may have a homogenizing effect on the originally more heterogeneous OM. IDP Raman G bands fall on an extension of the trend displayed by chondrite IOM, with all IDPs having Raman parameters indicative of very disordered carbon, with almost no overlap with IOM. The dispersion effect displayed by IDPs is most similar to CMs for the G band, but intermediate between CMs and CRs for the D band. The existence of some overlapping Raman features in the IDPs and IOM indicates that their OM may share a common origin, but the IDPs preserve more pristine OM that may have been further disordered by ion irradiation. H, C, and N isotopic data for the IDPs reveal that the disordered carbon in IDPs corresponds with higher δ15N and lower δ13C.

  1. Multisensor on-the-go mapping of readily dispersible clay, particle size and soil organic matter

    Science.gov (United States)

    Debaene, Guillaume; Niedźwiecki, Jacek; Papierowska, Ewa

    2016-04-01

    Particle size fractions affect strongly the physical and chemical properties of soil. Readily dispersible clay (RDC) is the part of the clay fraction in soils that is easily or potentially dispersible in water when small amounts of mechanical energy are applied to soil. The amount of RDC in the soil is of significant importance for agriculture and environment because clay dispersion is a cause of poor soil stability in water which in turn contributes to soil erodibility, mud flows, and cementation. To obtain a detailed map of soil texture, many samples are needed. Moreover, RDC determination is time consuming. The use of a mobile visible and near-infrared (VIS-NIR) platform is proposed here to map those soil properties and obtain the first detailed map of RDC at field level. Soil properties prediction was based on calibration model developed with 10 representative samples selected by a fuzzy logic algorithm. Calibration samples were analysed for soil texture (clay, silt and sand), RDC and soil organic carbon (SOC) using conventional wet chemistry analysis. Moreover, the Veris mobile sensor platform is also collecting electrical conductivity (EC) data (deep and shallow), and soil temperature. These auxiliary data were combined with VIS-NIR measurement (data fusion) to improve prediction results. EC maps were also produced to help understanding RDC data. The resulting maps were visually compared with an orthophotography of the field taken at the beginning of the plant growing season. Models were developed with partial least square regression (PLSR) and support vector machine regression (SVMR). There were no significant differences between calibration using PLSR or SVMR. Nevertheless, the best models were obtained with PLSR and standard normal variate (SNV) pretreatment and the fusion with deep EC data (e.g. for RDC and clay content: RMSECV = 0,35% and R2 = 0,71; RMSECV = 0,32% and R2 = 0,73 respectively). The best models were used to predict soil properties from the

  2. Possible constraints on SUSY-model parameters from direct dark matter search

    International Nuclear Information System (INIS)

    Bednyakov, V.A.; Kovalenko, S.G.

    1993-01-01

    We consider the SUSY-model neutralino as a dominant Dark Matter particle in the galactic halo and investigate some general issues of direct DM searches via elastic neutralino-nucleus scattering. On the basis of conventional assumptions about the nuclear and nucleon structure, without referring to a specific SUSY-model, we prove that it is impossible in principle to extract more than three constrains on fundamental SUSY-model parameters from the direct Dark Matter searches. Three types of Dark Matter detector probing different groups of parameters are recognized. 21 refs., 1 tab

  3. SOLAR CONSTRAINTS ON ASYMMETRIC DARK MATTER

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Ilidio [Centro Multidisciplinar de Astrofisica, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Silk, Joseph, E-mail: ilidio.lopes@ist.utl.pt, E-mail: silk@astro.ox.ac.uk [Institut d' Astrophysique de Paris, F-75014 Paris (France)

    2012-10-01

    The dark matter content of the universe is likely to be a mixture of matter and antimatter, perhaps comparable to the measured asymmetric mixture of baryons and antibaryons. During the early stages of the universe, the dark matter particles are produced in a process similar to baryogenesis, and dark matter freezeout depends on the dark matter asymmetry and the annihilation cross section (s-wave and p-wave annihilation channels) of particles and antiparticles. In these {eta}-parameterized asymmetric dark matter ({eta}ADM) models, the dark matter particles have an annihilation cross section close to the weak interaction cross section, and a value of dark matter asymmetry {eta} close to the baryon asymmetry {eta}{sub B}. Furthermore, we assume that dark matter scattering of baryons, namely, the spin-independent scattering cross section, is of the same order as the range of values suggested by several theoretical particle physics models used to explain the current unexplained events reported in the DAMA/LIBRA, CoGeNT, and CRESST experiments. Here, we constrain {eta}ADM by investigating the impact of such a type of dark matter on the evolution of the Sun, namely, the flux of solar neutrinos and helioseismology. We find that dark matter particles with a mass smaller than 15 GeV, a spin-independent scattering cross section on baryons of the order of a picobarn, and an {eta}-asymmetry with a value in the interval 10{sup -12}-10{sup -10}, would induce a change in solar neutrino fluxes in disagreement with current neutrino flux measurements. This result is also confirmed by helioseismology data. A natural consequence of this model is suppressed annihilation, thereby reducing the tension between indirect and direct dark matter detection experiments, but the model also allows a greatly enhanced annihilation cross section. All the cosmological {eta}ADM scenarios that we discuss have a relic dark matter density {Omega}h {sup 2} and baryon asymmetry {eta}{sub B} in agreement with

  4. SOLAR CONSTRAINTS ON ASYMMETRIC DARK MATTER

    International Nuclear Information System (INIS)

    Lopes, Ilídio; Silk, Joseph

    2012-01-01

    The dark matter content of the universe is likely to be a mixture of matter and antimatter, perhaps comparable to the measured asymmetric mixture of baryons and antibaryons. During the early stages of the universe, the dark matter particles are produced in a process similar to baryogenesis, and dark matter freezeout depends on the dark matter asymmetry and the annihilation cross section (s-wave and p-wave annihilation channels) of particles and antiparticles. In these η-parameterized asymmetric dark matter (ηADM) models, the dark matter particles have an annihilation cross section close to the weak interaction cross section, and a value of dark matter asymmetry η close to the baryon asymmetry η B . Furthermore, we assume that dark matter scattering of baryons, namely, the spin-independent scattering cross section, is of the same order as the range of values suggested by several theoretical particle physics models used to explain the current unexplained events reported in the DAMA/LIBRA, CoGeNT, and CRESST experiments. Here, we constrain ηADM by investigating the impact of such a type of dark matter on the evolution of the Sun, namely, the flux of solar neutrinos and helioseismology. We find that dark matter particles with a mass smaller than 15 GeV, a spin-independent scattering cross section on baryons of the order of a picobarn, and an η-asymmetry with a value in the interval 10 –12 -10 –10 , would induce a change in solar neutrino fluxes in disagreement with current neutrino flux measurements. This result is also confirmed by helioseismology data. A natural consequence of this model is suppressed annihilation, thereby reducing the tension between indirect and direct dark matter detection experiments, but the model also allows a greatly enhanced annihilation cross section. All the cosmological ηADM scenarios that we discuss have a relic dark matter density Ωh 2 and baryon asymmetry η B in agreement with the current WMAP measured values, Ω DM h 2 = 0

  5. Asymptotically Safe Dark Matter

    DEFF Research Database (Denmark)

    Sannino, Francesco; Shoemaker, Ian M.

    2015-01-01

    We introduce a new paradigm for dark matter (DM) interactions in which the interaction strength is asymptotically safe. In models of this type, the coupling strength is small at low energies but increases at higher energies, and asymptotically approaches a finite constant value. The resulting...... searches are the primary ways to constrain or discover asymptotically safe dark matter....

  6. Dark matter that can form dark stars

    International Nuclear Information System (INIS)

    Gondolo, Paolo; Huh, Ji-Haeng; Kim, Hyung Do; Scopel, Stefano

    2010-01-01

    The first stars to form in the Universe may be powered by the annihilation of weakly interacting dark matter particles. These so-called dark stars, if observed, may give us a clue about the nature of dark matter. Here we examine which models for particle dark matter satisfy the conditions for the formation of dark stars. We find that in general models with thermal dark matter lead to the formation of dark stars, with few notable exceptions: heavy neutralinos in the presence of coannihilations, annihilations that are resonant at dark matter freeze-out but not in dark stars, some models of neutrinophilic dark matter annihilating into neutrinos only and lighter than about 50 GeV. In particular, we find that a thermal DM candidate in standard Cosmology always forms a dark star as long as its mass is heavier than ≅ 50 GeV and the thermal average of its annihilation cross section is the same at the decoupling temperature and during the dark star formation, as for instance in the case of an annihilation cross section with a non-vanishing s-wave contribution

  7. Current trends in non-accelerator particle physics: 1, Neutrino mass and oscillation. 2, High energy neutrino astrophysics. 3, Detection of dark matter. 4, Search for strange quark matter. 5, Magnetic monopole searches

    International Nuclear Information System (INIS)

    He, Yudong

    1995-07-01

    This report is a compilation of papers reflecting current trends in non-accelerator particle physics, corresponding to talks that its author was invited to present at the Workshop on Tibet Cosmic Ray Experiment and Related Physics Topics held in Beijing, China, April 4--13, 1995. The papers are entitled 'Neutrino Mass and Oscillation', 'High Energy Neutrino Astrophysics', 'Detection of Dark Matter', 'Search for Strange Quark Matter', and 'Magnetic Monopole Searches'. The report is introduced by a survey of the field and a brief description of each of the author's papers

  8. Spatial distribution assessment of particulate matter in an urban street canyon using biomagnetic leaf monitoring of tree crown deposited particles

    International Nuclear Information System (INIS)

    Hofman, Jelle; Stokkaer, Ines; Snauwaert, Lies; Samson, Roeland

    2013-01-01

    Recently, biomagnetic monitoring of tree leaves has proven to be a good estimator for ambient particulate concentration. This paper investigates the usefulness of biomagnetic leaf monitoring of crown deposited particles to assess the spatial PM distribution inside individual tree crowns and an urban street canyon in Ghent (Belgium). Results demonstrate that biomagnetic monitoring can be used to assess spatial PM variations, even within single tree crowns. SIRM values decrease exponentially with height and azimuthal effects are obtained for wind exposed sides of the street canyon. Edge and canyon trees seem to be exposed differently. As far as we know, this study is the first to present biomagnetic monitoring results of different trees within a single street canyon. The results not only give valuable insights into the spatial distribution of particulate matter inside tree crowns and a street canyon, but also offer a great potential as validation tool for air quality modelling. Highlights: ► Spatial distribution of tree crown deposited PM was evaluated. ► SIRM values decrease exponentially with height. ► Azimuthal effects were observed at wind exposed sides of the street canyon. ► Edge and canyon trees seem to be exposed differently. ► Biomagnetic monitoring offers a great potential as validation of air quality models. -- Biomagnetic leaf monitoring provides useful insights into the spatial distribution of particulates inside individual tree crowns and an urban street canyon in Ghent (Belgium)

  9. Seasonal variation of absorption by particles and colored dissolved organic matter (CDOM) in Funka Bay, southwestern Hokkaido, Japan

    Science.gov (United States)

    Sasaki, Hiroaki; Miyamura, Tsuyoshi; Saitoh, Sei-ichi; Ishizaka, Joji

    2005-08-01

    Between November 2000 and October 2001, the seasonal variation in absorption by particles (phytoplankton and detritus) and colored dissolved organic matter (CDOM) was measured in Funka Bay (a subarctic coastal region of Japan). In autumn-winter, chlorophyll a concentration (Chl a) near the euphotic zone remained very low (summer and low during the spring bloom. This is because the package effect was greater during the spring bloom due to the presence of large diatoms, while small phytoplankton dominated during summer. Absorption at 440 nm by CDOM was higher than that of phytoplankton and detritus, except during the spring bloom, and the relative contribution of CDOM absorption to the total absorption coefficient was >50%. CDOM and detritus absorption did not increase with increasing Chl a, but it showed a time lag between the spring bloom. It is suggested that phytoplankton degradation started after the spring bloom; detritus absorption increased and, then, CDOM absorption increased. River runoff was not a significant influence in Funka Bay, therefore, CDOM production may be mainly related to microbial activity.

  10. LHC constraints on gauge boson couplings to dark matter

    CERN Document Server

    Crivellin, Andreas; Hibbs, Anthony

    2015-01-01

    Collider searches for energetic particles recoiling against missing transverse energy allow to place strong bounds on the interactions between dark matter (DM) and standard model particles. In this article we update and extend LHC constraints on effective dimension-7 operators involving DM and electroweak gauge bosons. A concise comparison of the sensitivity of the mono-photon, mono-W, mono-Z, mono-W/Z, invisible Higgs-boson decays in the vector boson fusion mode and the mono-jet channel is presented. Depending on the parameter choices, either the mono-photon or the mono-jet data provide the most stringent bounds at the moment. We furthermore explore the potential of improving the current 8 TeV limits at 14 TeV. Future strategies capable of disentangling the effects of the different effective operators involving electroweak gauge bosons are discussed as well.

  11. Dark Matter

    International Nuclear Information System (INIS)

    Bashir, A.; Cotti, U.; De Leon, C. L.; Raya, A; Villasenor, L.

    2008-01-01

    One of the biggest scientific mysteries of our time resides in the identification of the particles that constitute a large fraction of the mass of our Universe, generically known as dark matter. We review the observations and the experimental data that imply the existence of dark matter. We briefly discuss the properties of the two best dark-matter candidate particles and the experimental techniques presently used to try to discover them. Finally, we mention a proposed project that has recently emerged within the Mexican community to look for dark matter

  12. Laser Boost of a Small Interstellar Ram Jet to Obtain Operational Velocity. Implications for the DM Rocket/Ram Jet Model

    Science.gov (United States)

    Walcott Beckwith, Andrew

    2010-05-01

    In other conference research papers, Beckwith obtained a maximum DM mass/energy value of up to 5 TeV, as opposed to 400 GeV for DM, which may mean more convertible power for a dark matter ram jet. The consequences are from assuming that axions are CDM, and KK gravitons are for WDM, then ρWarm-Dark-Matter would dominate not only structure formation in early universe formation, but would also influence the viability of the DM ram jet applications for interstellar travel. The increase in convertible DM mass makes the ram jet a conceivable option. This paper in addition to describing the scientific issues leading to that 5 TeV mass for DM also what are necessary and sufficient laser boost systems which would permit a ram net to become operational.

  13. Dark matter direct detection with non-Maxwellian velocity structure

    International Nuclear Information System (INIS)

    Kuhlen, Michael; Weiner, Neal; Diemand, Jürg; Moore, Ben; Potter, Doug; Stadel, Joachim; Madau, Piero; Zemp, Marcel

    2010-01-01

    The velocity distribution function of dark matter particles is expected to show significant departures from a Maxwell-Boltzmann distribution. This can have profound effects on the predicted dark matter - nucleon scattering rates in direct detection experiments, especially for dark matter models in which the scattering is sensitive to the high velocity tail of the distribution, such as inelastic dark matter (iDM) or light (few GeV) dark matter (LDM), and for experiments that require high energy recoil events, such as many directionally sensitive experiments. Here we determine the velocity distribution functions from two of the highest resolution numerical simulations of Galactic dark matter structure (Via Lactea II and GHALO), and study the effects for these scenarios. For directional detection, we find that the observed departures from Maxwell-Boltzmann increase the contrast of the signal and change the typical direction of incoming DM particles. For iDM, the expected signals at direct detection experiments are changed dramatically: the annual modulation can be enhanced by more than a factor two, and the relative rates of DAMA compared to CDMS can change by an order of magnitude, while those compared to CRESST can change by a factor of two. The spectrum of the signal can also change dramatically, with many features arising due to substructure. For LDM the spectral effects are smaller, but changes do arise that improve the compatibility with existing experiments. We find that the phase of the modulation can depend upon energy, which would help discriminate against background should it be found

  14. Supersymmetric Dark Matter after LHC Run 1

    CERN Document Server

    Bagnaschi, E.A.; Cavanaugh, R.; Citron, M.; De Roeck, A.; Dolan, M.J.; Ellis, J.R.; Flächer, H.; Heinemeyer, S.; Isidori, G.; Malik, S.; Martínez Santos, D.; Olive, K.A.; Sakurai, K.; de Vries, K.J.; Weiglein, G.

    2015-10-23

    Different mechanisms operate in various regions of the MSSM parameter space to bring the relic density of the lightest neutralino, neutralino_1, assumed here to be the LSP and thus the Dark Matter (DM) particle, into the range allowed by astrophysics and cosmology. These mechanisms include coannihilation with some nearly-degenerate next-to-lightest supersymmetric particle (NLSP) such as the lighter stau (stau_1), stop (stop_1) or chargino (chargino_1), resonant annihilation via direct-channel heavy Higgs bosons H/A, the light Higgs boson h or the Z boson, and enhanced annihilation via a larger Higgsino component of the LSP in the focus-point region. These mechanisms typically select lower-dimensional subspaces in MSSM scenarios such as the CMSSM, NUHM1, NUHM2 and pMSSM10. We analyze how future LHC and direct DM searches can complement each other in the exploration of the different DM mechanisms within these scenarios. We find that the stau_1 coannihilation regions of the CMSSM, NUHM1, NUHM2 can largely be exp...

  15. Annihilation cross section of Kaluza Klien dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Rakesh, E-mail: rakesh-sharma-ujn@yahoo.co.in [Northern India Textile Research Association Technical Campus Ghaziabad U.P. 201002 (India); Upadhyaya, G. K., E-mail: gopalujjain@yahoo.co.in; Sharma, S. [School of Studies in Physics, Vikram University Ujjain, M.P. 456010 India (India)

    2015-07-31

    The question as to how this universe came into being and as to how it has evolved to its present stage, is an old question. The answer to this question unfolds many secrets regarding fundamental particles and forces between them. Theodor Kaluza proposed the concept that the universe is composed of more than four space-time dimensions. In his work, electromagnetism is united with gravity. Various extra dimension formulations have been proposed to solve a variety of problems. Recently, the idea of more than four space time dimensions is applied to the search for particle identity of dark matter (DM). Signature of dark matter can be revealed by analysis of very high energy electrons which are coming from outer space. We investigate recent advancement in the field of dark matter search with reference to very high energy electrons from outer space [1-8].

  16. Dark matter self-interactions and small scale structure

    Science.gov (United States)

    Tulin, Sean; Yu, Hai-Bo

    2018-02-01

    We review theories of dark matter (DM) beyond the collisionless paradigm, known as self-interacting dark matter (SIDM), and their observable implications for astrophysical structure in the Universe. Self-interactions are motivated, in part, due to the potential to explain long-standing (and more recent) small scale structure observations that are in tension with collisionless cold DM (CDM) predictions. Simple particle physics models for SIDM can provide a universal explanation for these observations across a wide range of mass scales spanning dwarf galaxies, low and high surface brightness spiral galaxies, and clusters of galaxies. At the same time, SIDM leaves intact the success of ΛCDM cosmology on large scales. This report covers the following topics: (1) small scale structure issues, including the core-cusp problem, the diversity problem for rotation curves, the missing satellites problem, and the too-big-to-fail problem, as well as recent progress in hydrodynamical simulations of galaxy formation; (2) N-body simulations for SIDM, including implications for density profiles, halo shapes, substructure, and the interplay between baryons and self-interactions; (3) semi-analytic Jeans-based methods that provide a complementary approach for connecting particle models with observations; (4) merging systems, such as cluster mergers (e.g., the Bullet Cluster) and minor infalls, along with recent simulation results for mergers; (5) particle physics models, including light mediator models and composite DM models; and (6) complementary probes for SIDM, including indirect and direct detection experiments, particle collider searches, and cosmological observations. We provide a summary and critical look for all current constraints on DM self-interactions and an outline for future directions.

  17. Pulse shape analysis for germanium detectors used in DM searches

    International Nuclear Information System (INIS)

    Sagdeev, I.R.; Drukier, A.K.; Welsh, D.J.; Klimenko, A.A.; Osetrov, S.B.; Smolnikov, A.A.

    1994-01-01

    Progress in Ge detector technology has resulted in ultralow backgrounds of less than 0.3 countskeV -1 kg -1 d -1 at energies between 6 and 9keV and from 12 to 20keV. Between 4 and 6keV it is less than 2 countskeV -1 kg -1 d -1 . Coupled with good energy resolution, 0.4keV FWHM at 10keV, this allows searches for DM particles with m≥qslant8GeV/c 2 .Electromagnetic interference (EMI) and acoustical pick-up are the main sources of background in the best Ge detectors. A PC-based on-line pulse shape analysis system is presented which permits rejection of large fraction of the EMI/acoustical background. The hardware uses a low cost, commercially available digital storage oscilloscope (DSO). The software consists of about 40000 lines of code in Pascal and assembly language. We tested this system using a low radioactive background Ge-system at the Baksan observatory. For low energy events (<100keV) this system permits improvement in the background by about 20-30%. ((orig.))

  18. Isotropic extragalactic flux from dark matter annihilations: lessons from interacting dark matter scenarios

    International Nuclear Information System (INIS)

    Moliné, Ángeles; Schewtschenko, Jascha A.; Boehm, Céline; Palomares-Ruiz, Sergio; Baugh, Carlton M.

    2016-01-01

    The extragalactic γ-ray and neutrino emission may have a contribution from dark matter (DM) annihilations. In the case of discrepancies between observations and standard predictions, one could infer the DM pair annihilation cross section into cosmic rays by studying the shape of the energy spectrum. So far all analyses of the extragalactic DM signal have assumed the standard cosmological model (ΛCDM) as the underlying theory. However, there are alternative DM scenarios where the number of low-mass objects is significantly suppressed. Therefore the characteristics of the γ-ray and neutrino emission in these models may differ from ΛCDM as a result. Here we show that the extragalactic isotropic signal in these alternative models has a similar energy dependence to that in ΛCDM, but the overall normalisation is reduced. The similarities between the energy spectra combined with the flux suppression could lead one to misinterpret possible evidence for models beyond ΛCDM as being due to CDM particles annihilating with a much weaker cross section than expected.

  19. Isotropic extragalactic flux from dark matter annihilations: lessons from interacting dark matter scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Moliné, Ángeles [CFTP, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Schewtschenko, Jascha A.; Boehm, Céline [Institute for Particle Physics Phenomenology (IPPP), Durham University, Durham DH1 3LE (United Kingdom); Palomares-Ruiz, Sergio [Instituto de Física Corpuscular (IFIC), CSIC-Universitat de València, Apartado de Correos 22085, E-46071 Valencia (Spain); Baugh, Carlton M., E-mail: maria.moline@ist.utl.pt, E-mail: jascha@schewtschenko.net, E-mail: Sergio.Palomares.Ruiz@ific.uv.es, E-mail: c.m.boehm@durham.ac.uk, E-mail: c.m.baugh@durham.ac.uk [Institute for Computational Cosmology (ICC), Durham University, Durham DH1 3LE (United Kingdom)

    2016-08-01

    The extragalactic γ-ray and neutrino emission may have a contribution from dark matter (DM) annihilations. In the case of discrepancies between observations and standard predictions, one could infer the DM pair annihilation cross section into cosmic rays by studying the shape of the energy spectrum. So far all analyses of the extragalactic DM signal have assumed the standard cosmological model (ΛCDM) as the underlying theory. However, there are alternative DM scenarios where the number of low-mass objects is significantly suppressed. Therefore the characteristics of the γ-ray and neutrino emission in these models may differ from ΛCDM as a result. Here we show that the extragalactic isotropic signal in these alternative models has a similar energy dependence to that in ΛCDM, but the overall normalisation is reduced. The similarities between the energy spectra combined with the flux suppression could lead one to misinterpret possible evidence for models beyond ΛCDM as being due to CDM particles annihilating with a much weaker cross section than expected.

  20. Discrete dark matter

    CERN Document Server

    Hirsch, M; Peinado, E; Valle, J W F

    2010-01-01

    We propose a new motivation for the stability of dark matter (DM). We suggest that the same non-abelian discrete flavor symmetry which accounts for the observed pattern of neutrino oscillations, spontaneously breaks to a Z2 subgroup which renders DM stable. The simplest scheme leads to a scalar doublet DM potentially detectable in nuclear recoil experiments, inverse neutrino mass hierarchy, hence a neutrinoless double beta decay rate accessible to upcoming searches, while reactor angle equal to zero gives no CP violation in neutrino oscillations.

  1. Light Inflaton -- hunting for it from CMB through the Dark Matter and down to the colliders

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    The models without additional energy scales (heavy particles) above the electroweak scale can provide relation between the low energy physics and cosmology. Probably the simplest example is the model with additional singlet scalar inflaton (with non-minimal coupling). It gets constraint simultaneously from the inflationary observations (tensor modes), dark matter production (for 7keV sterile neutrino DM), and searches in the reare decays. I will discuss the interplay of the cosmological and laboratory constraints in this model.

  2. Search for γ -Ray Line Signals from Dark Matter Annihilations in the Inner Galactic Halo from 10 Years of Observations with H.E.S.S.

    Science.gov (United States)

    Abdallah, H.; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Angüner, E. O.; Arakawa, M.; Arrieta, M.; Aubert, P.; Backes, M.; Balzer, A.; Barnard, M.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernlöhr, K.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bonnefoy, S.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Büchele, M.; Bulik, T.; Capasso, M.; Caroff, S.; Carosi, A.; Carr, J.; Casanova, S.; Cerruti, M.; Chakraborty, N.; Chaves, R. C. G.; Chen, A.; Chevalier, J.; Colafrancesco, S.; Condon, B.; Conrad, J.; Davids, I. D.; Decock, J.; Deil, C.; Devin, J.; deWilt, P.; Dirson, L.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Drury, L. O'C.; Dutson, K.; Dyks, J.; Edwards, T.; Egberts, K.; Eger, P.; Emery, G.; Ernenwein, J.-P.; Eschbach, S.; Farnier, C.; Fegan, S.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Funk, S.; Füßling, M.; Gabici, S.; Gallant, Y. A.; Garrigoux, T.; Gaté, F.; Giavitto, G.; Giebels, B.; Glawion, D.; Glicenstein, J. F.; Gottschall, D.; Grondin, M.-H.; Hahn, J.; Haupt, M.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holch, T. L.; Holler, M.; Horns, D.; Ivascenko, A.; Iwasaki, H.; Jacholkowska, A.; Jamrozy, M.; Janiak, M.; Jankowsky, D.; Jankowsky, F.; Jingo, M.; Jouvin, L.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katsuragawa, M.; Katz, U.; Kerszberg, D.; Khangulyan, D.; Khélifi, B.; King, J.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Komin, Nu.; Kosack, K.; Krakau, S.; Kraus, M.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lees, J.-P.; Lefaucheur, J.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Leser, E.; Liu, R.; Lohse, T.; Lorentz, M.; López-Coto, R.; Lypova, I.; Malyshev, D.; Marandon, V.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Mohrmann, L.; Morâ, K.; Moulin, E.; Murach, T.; Nakashima, S.; de Naurois, M.; Ndiyavala, H.; Niederwanger, F.; Niemiec, J.; Oakes, L.; O'Brien, P.; Odaka, H.; Ohm, S.; Ostrowski, M.; Oya, I.; Padovani, M.; Panter, M.; Parsons, R. D.; Pekeur, N. W.; Pelletier, G.; Perennes, C.; Petrucci, P.-O.; Peyaud, B.; Piel, Q.; Pita, S.; Poireau, V.; Poon, H.; Prokhorov, D.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Rauth, R.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rinchiuso, L.; Romoli, C.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Saito, S.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schandri, M.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwemmer, S.; Seglar-Arroyo, M.; Settimo, M.; Seyffert, A. S.; Shafi, N.; Shilon, I.; Shiningayamwe, K.; Simoni, R.; Sol, H.; Spanier, F.; Spir-Jacob, M.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Steppa, C.; Sushch, I.; Takahashi, T.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tibaldo, L.; Tiziani, D.; Tluczykont, M.; Trichard, C.; Tsirou, M.; Tsuji, N.; Tuffs, R.; Uchiyama, Y.; van der Walt, J.; van Eldik, C.; van Rensburg, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Völk, H. J.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zaborov, D.; Zacharias, M.; Zanin, R.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Ziegler, A.; Zorn, J.; Żywucka, N.; H. E. S. S. Collaboration

    2018-05-01

    Spectral lines are among the most powerful signatures for dark matter (DM) annihilation searches in very-high-energy γ rays. The central region of the Milky Way halo is one of the most promising targets given its large amount of DM and proximity to Earth. We report on a search for a monoenergetic spectral line from self-annihilations of DM particles in the energy range from 300 GeV to 70 TeV using a two-dimensional maximum likelihood method taking advantage of both the spectral and spatial features of the signal versus background. The analysis makes use of Galactic center observations accumulated over ten years (2004-2014) with the H.E.S.S. array of ground-based Cherenkov telescopes. No significant γ -ray excess above the background is found. We derive upper limits on the annihilation cross section ⟨σ v ⟩ for monoenergetic DM lines at the level of 4 ×10-28 cm3 s-1 at 1 TeV, assuming an Einasto DM profile for the Milky Way halo. For a DM mass of 1 TeV, they improve over the previous ones by a factor of 6. The present constraints are the strongest obtained so far for DM particles in the mass range 300 GeV-70 TeV. Ground-based γ -ray observations have reached sufficient sensitivity to explore relevant velocity-averaged cross sections for DM annihilation into two γ -ray photons at the level expected from the thermal relic density for TeV DM particles.

  3. Short-term bioavailability of carbon in soil organic matter fractions of different particle sizes and densities in grassland ecosystems.

    Science.gov (United States)

    Breulmann, Marc; Masyutenko, Nina Petrovna; Kogut, Boris Maratovich; Schroll, Reiner; Dörfler, Ulrike; Buscot, François; Schulz, Elke

    2014-11-01

    The quality, stability and availability of organic carbon (OC) in soil organic matter (SOM) can vary widely between differently managed ecosystems. Several approaches have been developed for isolating SOM fractions to examine their ecological roles, but links between the bioavailability of the OC of size-density fractions and soil microbial communities have not been previously explored. Thus, in the presented laboratory study we investigated the potential bioavailability of OC and the structure of associated microbial communities in different particle-size and density fractions of SOM. For this we used samples from four grassland ecosystems with contrasting management intensity regimes and two soil types: a Haplic Cambisol and a typical Chernozem. A combined size-density fractionation protocol was applied to separate clay-associated SOM fractions (CF1, <1 μm; CF2, 1-2 μm) from light SOM fractions (LF1, <1.8 g cm(-3); LF2, 1.8-2.0 g cm(-3)). These fractions were used as carbon sources in a respiration experiment to determine their potential bioavailability. Measured CO2-release was used as an index of substrate accessibility and linked to the soil microbial community structure, as determined by phospholipid fatty acids (PLFA) analysis. Several key factors controlling decomposition processes, and thus the potential bioavailability of OC, were identified: management intensity and the plant community composition of the grasslands (both of which affect the chemical composition and turnover of OC) and specific properties of individual SOM fractions. The PLFA patterns highlighted differences in the composition of microbial communities associated with the examined grasslands, and SOM fractions, providing the first broad insights into their active microbial communities. From observed interactions between abiotic and biotic factors affecting the decomposition of SOM fractions we demonstrate that increasing management intensity could enhance the potential bioavailability of

  4. Dark matter indirect detection with charged cosmic rays

    International Nuclear Information System (INIS)

    Giesen, Gaelle

    2015-01-01

    Overwhelming evidence for the existence of Dark Matter (DM), in the form of an unknown particle filling the galactic halos, originates from many observations in astrophysics and cosmology: its gravitational effects are apparent on galactic rotations, in galaxy clusters and in shaping the large scale structure of the Universe. On the other hand, a non-gravitational manifestation of its presence is yet to be unveiled. One of the most promising techniques is the one of indirect detection, aimed at identifying excesses in cosmic ray fluxes which could possibly be produced by DM annihilations or decays in the Milky Way halo. The current experimental efforts mainly focus in the GeV to TeV energy range, which is also where signals from WIMPs (Weakly Interacting Massive Particles) are expected. Focussing on charged cosmic rays, in particular antiprotons, electrons and positrons, as well as their secondary emissions, an analysis of current and foreseen cosmic ray measurements and improvements on astrophysical models are presented. Antiproton data from PAMELA imposes constraints on annihilating and decaying DM which are similar to (or even slightly stronger than) the most stringent bounds from gamma ray experiments, even when kinetic energies below 10 GeV are discarded. However, choosing different sets of astrophysical parameters, in the form of propagation models and halo profiles, allows the constraints to span over one or two orders of magnitude. In order to exploit fully the power of antiprotons to constrain or discover DM, effects which were previously perceived as sub-leading turn out to be relevant especially for the analysis of the newly released AMS-02 data. In fact, including energy losses, diffusive re-acceleration and solar modulation can somewhat modify the current bounds, even at large DM masses. A wrong interpretation of the data may arise if they are not taken into account. Finally, using the updated proton and helium fluxes just released by the AMS-02

  5. Phenomenology of Dark Matter from radio to gamma ray frequencies

    International Nuclear Information System (INIS)

    Vollmann, Martin

    2015-07-01

    Multiwavelength astronomical observations have been proven to be of crucial relevance in understanding the most fundamental questions in physics. One of the biggest mysteries of nature is the existence of a (still) unidentified type of matter that makes up most of the material universe. Although little is known about its nature, it is very likely that this exotic Dark Matter (DM) is made of so-called Weakly Interacting Massive Particles (WIMPs). In this thesis we investigate which strategies can best address the fundamental question: What is Dark Matter? Specifically, by following the ''WIMP'' paradigm as our guiding principle, we comprehensively discuss the phenomenology of prospective ''indirect'' detection scenarios of such WIMPs. Special consideration is given to extraterrestrial gamma rays and radio waves produced around the center of the Milky Way. In light of two recently highly debated claims of WIMP Dark Matter discovery, namely the 130 GeV gamma-ray line and the GeV gamma-ray excess, we invoke our methods to confront those hypotheses. In addition our study contains antiparticle cosmic-ray (antiproton and positron) data analyses. The phenomenology for indirect DM detection with these ''messengers'' is briefly discussed as well. By exploiting the high degree of symmetry of typical annihilating 2-WIMP initial states, we are able to employ a very powerful tool in theoretical particle physics: the generalized optical theorem. This theorem relates the amplitude of loop-suppressed processes, such as the 130 GeV line if interpreted as product of WIMP annihilations, with tree-level process which are constrained in the same way as with the GeV excess. Unprecedentedly reported analytical computations of partial-wave (and helicity) cross sections with general applicability are calculated and applied. The possibility that a non-trivial effect in the particle model for DM might enhance the strength of a gamma

  6. Directly Detecting MeV-Scale Dark Matter Via Solar Reflection.

    Science.gov (United States)

    An, Haipeng; Pospelov, Maxim; Pradler, Josef; Ritz, Adam

    2018-04-06

    If dark matter (DM) particles are lighter than a few   MeV/c^{2} and can scatter off electrons, their interaction within the solar interior results in a considerable hardening of the spectrum of galactic dark matter received on Earth. For a large range of the mass versus cross section parameter space, {m_{e},σ_{e}}, the "reflected" component of the DM flux is far more energetic than the end point of the ambient galactic DM energy distribution, making it detectable with existing DM detectors sensitive to an energy deposition of 10-10^{3}  eV. After numerically simulating the small reflected component of the DM flux, we calculate its subsequent signal due to scattering on detector electrons, deriving new constraints on σ_{e} in the MeV and sub-MeV range using existing data from the XENON10/100, LUX, PandaX-II, and XENON1T experiments, as well as making projections for future low threshold direct detection experiments.

  7. Directly Detecting MeV-Scale Dark Matter Via Solar Reflection

    Science.gov (United States)

    An, Haipeng; Pospelov, Maxim; Pradler, Josef; Ritz, Adam

    2018-04-01

    If dark matter (DM) particles are lighter than a few MeV /c2 and can scatter off electrons, their interaction within the solar interior results in a considerable hardening of the spectrum of galactic dark matter received on Earth. For a large range of the mass versus cross section parameter space, {me,σe}, the "reflected" component of the DM flux is far more energetic than the end point of the ambient galactic DM energy distribution, making it detectable with existing DM detectors sensitive to an energy deposition of 10 -103 eV . After numerically simulating the small reflected component of the DM flux, we calculate its subsequent signal due to scattering on detector electrons, deriving new constraints on σe in the MeV and sub-MeV range using existing data from the XENON10/100, LUX, PandaX-II, and XENON1T experiments, as well as making projections for future low threshold direct detection experiments.

  8. On dark matter interactions with the Standard Model through an anomalous Z'

    Science.gov (United States)

    Ismail, Ahmed; Katz, Andrey; Racco, Davide

    2017-10-01

    We study electroweak scale Dark Matter (DM) whose interactions with baryonic matter are mediated by a heavy anomalous Z'. We emphasize that when the DM is a Majorana particle, its low-velocity annihilations are dominated by loop suppressed annihilations into the gauge bosons, rather than by p-wave or chirally suppressed annihilations into the SM fermions. Because the Z ' is anomalous, these kinds of DM models can be realized only as effective field theories (EFTs) with a well-defined cutoff, where heavy spectator fermions restore gauge invariance at high energies. We formulate these EFTs, estimate their cutoff and properly take into account the effect of the Chern-Simons terms one obtains after the spectator fermions are integrated out. We find that, while for light DM collider and direct detection experiments usually provide the strongest bounds, the bounds at higher masses are heavily dominated by indirect detection experiments, due to strong annihilation into W + W -, ZZ, Zγ and possibly into gg and γγ. We emphasize that these annihilation channels are generically significant because of the structure of the EFT, and therefore these models are prone to strong indirect detection constraints. Even though we focus on selected Z' models for illustrative purposes, our setup is completely generic and can be used for analyzing the predictions of any anomalous Z'-mediated DM model with arbitrary charges.

  9. Dark matter interpretations of ATLAS searches for the electroweak production of supersymmetric particles in s = 8 $$ \\sqrt{s}=8 $$ TeV proton-proton collisions

    Energy Technology Data Exchange (ETDEWEB)

    Aaboud, M.; Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; Aben, R.; AbouZeid, O. S.; Abraham, N. L.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adachi, S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Affolder, A. A.; Agatonovic-Jovin, T.; Aguilar-Saavedra, J. A.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akerstedt, H.; Åkesson, T. P. A.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexopoulos, T.; Alhroob, M.; Ali, B.; Aliev, M.; Alimonti, G.; Alison, J.; Alkire, S. P.; Allbrooke, B. M. M.; Allen, B. W.; Allport, P. P.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Alshehri, A. A.; Alstaty, M.; Alvarez Gonzalez, B.; Álvarez Piqueras, D.; Alviggi, M. G.; Amadio, B. T.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amundsen, G.; Anastopoulos, C.; Ancu, L. 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V.; Choi, K.; Chomont, A. R.; Chouridou, S.; Chow, B. K. B.; Christodoulou, V.; Chromek-Burckhart, D.; Chudoba, J.; Chuinard, A. J.; Chwastowski, J. J.; Chytka, L.; Ciapetti, G.; Ciftci, A. K.; Cinca, D.; Cindro, V.; Cioara, I. A.; Ciocca, C.; Ciocio, A.; Cirotto, F.; Citron, Z. H.; Citterio, M.; Ciubancan, M.; Clark, A.; Clark, B. L.; Clark, M. R.; Clark, P. J.; Clarke, R. N.; Clement, C.; Coadou, Y.; Cobal, M.; Coccaro, A.; Cochran, J.; Colasurdo, L.; Cole, B.; Colijn, A. P.; Collot, J.; Colombo, T.; Compostella, G.; Conde Muiño, P.; Coniavitis, E.; Connell, S. H.; Connelly, I. A.; Consorti, V.; Constantinescu, S.; Conti, G.; Conventi, F.; Cooke, M.; Cooper, B. D.; Cooper-Sarkar, A. M.; Cormier, K. J. R.; Cornelissen, T.; Corradi, M.; Corriveau, F.; Cortes-Gonzalez, A.; Cortiana, G.; Costa, G.; Costa, M. J.; Costanzo, D.; Cottin, G.; Cowan, G.; Cox, B. E.; Cranmer, K.; Crawley, S. J.; Cree, G.; Crépé-Renaudin, S.; Crescioli, F.; Cribbs, W. A.; Crispin Ortuzar, M.; Cristinziani, M.; Croft, V.; Crosetti, G.; Cueto, A.; Cuhadar Donszelmann, T.; Cummings, J.; Curatolo, M.; Cúth, J.; Czirr, H.; Czodrowski, P.; D’amen, G.; D’Auria, S.; D’Onofrio, M.; Da Cunha Sargedas De Sousa, M. J.; Da Via, C.; Dabrowski, W.; Dado, T.; Dai, T.; Dale, O.; Dallaire, F.; Dallapiccola, C.; Dam, M.; Dandoy, J. R.; Dang, N. P.; Daniells, A. C.; Dann, N. S.; Danninger, M.; Dano Hoffmann, M.; Dao, V.; Darbo, G.; Darmora, S.; Dassoulas, J.; Dattagupta, A.; Davey, W.; David, C.; Davidek, T.; Davies, M.; Davison, P.; Dawe, E.; Dawson, I.; De, K.; de Asmundis, R.; De Benedetti, A.; De Castro, S.; De Cecco, S.; De Groot, N.; de Jong, P.; De la Torre, H.; De Lorenzi, F.; De Maria, A.; De Pedis, D.; De Salvo, A.; De Sanctis, U.; De Santo, A.; De Vivie De Regie, J. B.; Dearnaley, W. J.; Debbe, R.; Debenedetti, C.; Dedovich, D. V.; Dehghanian, N.; Deigaard, I.; Del Gaudio, M.; Del Peso, J.; Del Prete, T.; Delgove, D.; Deliot, F.; Delitzsch, C. M.; Dell’Acqua, A.; Dell’Asta, L.; Dell’Orso, M.; Della Pietra, M.; della Volpe, D.; Delmastro, M.; Delsart, P. A.; DeMarco, D. A.; Demers, S.; Demichev, M.; Demilly, A.; Denisov, S. P.; Denysiuk, D.; Derendarz, D.; Derkaoui, J. E.; Derue, F.; Dervan, P.; Desch, K.; Deterre, C.; Dette, K.; Deviveiros, P. O.; Dewhurst, A.; Dhaliwal, S.; Di Ciaccio, A.; Di Ciaccio, L.; Di Clemente, W. K.; Di Donato, C.; Di Girolamo, A.; Di Girolamo, B.; Di Micco, B.; Di Nardo, R.; Di Simone, A.; Di Sipio, R.; Di Valentino, D.; Diaconu, C.; Diamond, M.; Dias, F. A.; Diaz, M. A.; Diehl, E. B.; Dietrich, J.; Díez Cornell, S.; Dimitrievska, A.; Dingfelder, J.; Dita, P.; Dita, S.; Dittus, F.; Djama, F.; Djobava, T.; Djuvsland, J. I.; do Vale, M. A. B.; Dobos, D.; Dobre, M.; Doglioni, C.; Dolejsi, J.; Dolezal, Z.; Donadelli, M.; Donati, S.; Dondero, P.; Donini, J.; Dopke, J.; Doria, A.; Dova, M. T.; Doyle, A. T.; Drechsler, E.; Dris, M.; Du, Y.; Duarte-Campderros, J.; Duchovni, E.; Duckeck, G.; Ducu, O. 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F.; Rybar, M.; Rybkin, G.; Ryu, S.; Ryzhov, A.; Rzehorz, G. F.; Saavedra, A. F.; Sabato, G.; Sacerdoti, S.; Sadrozinski, H. F-W.; Sadykov, R.; Safai Tehrani, F.; Saha, P.; Sahinsoy, M.; Saimpert, M.; Saito, T.; Sakamoto, H.; Sakurai, Y.; Salamanna, G.; Salamon, A.; Salazar Loyola, J. E.; Salek, D.; Sales De Bruin, P. H.; Salihagic, D.; Salnikov, A.; Salt, J.; Salvatore, D.; Salvatore, F.; Salvucci, A.; Salzburger, A.; Sammel, D.; Sampsonidis, D.; Sanchez, A.; Sánchez, J.; Sanchez Martinez, V.; Sandaker, H.; Sandbach, R. L.; Sandhoff, M.; Sandoval, C.; Sankey, D. P. C.; Sannino, M.; Sansoni, A.; Santoni, C.; Santonico, R.; Santos, H.; Santoyo Castillo, I.; Sapp, K.; Sapronov, A.; Saraiva, J. G.; Sarrazin, B.; Sasaki, O.; Sato, K.; Sauvan, E.; Savage, G.; Savard, P.; Savic, N.; Sawyer, C.; Sawyer, L.; Saxon, J.; Sbarra, C.; Sbrizzi, A.; Scanlon, T.; Scannicchio, D. A.; Scarcella, M.; Scarfone, V.; Schaarschmidt, J.; Schacht, P.; Schachtner, B. M.; Schaefer, D.; Schaefer, L.; Schaefer, R.; Schaeffer, J.; Schaepe, S.; Schaetzel, S.; Schäfer, U.; Schaffer, A. C.; Schaile, D.; Schamberger, R. D.; Scharf, V.; Schegelsky, V. A.; Scheirich, D.; Schernau, M.; Schiavi, C.; Schier, S.; Schillo, C.; Schioppa, M.; Schlenker, S.; Schmidt-Sommerfeld, K. R.; Schmieden, K.; Schmitt, C.; Schmitt, S.; Schmitz, S.; Schneider, B.; Schnoor, U.; Schoeffel, L.; Schoening, A.; Schoenrock, B. D.; Schopf, E.; Schott, M.; Schouwenberg, J. F. P.; Schovancova, J.; Schramm, S.; Schreyer, M.; Schuh, N.; Schulte, A.; Schultens, M. J.; Schultz-Coulon, H. -C.; Schulz, H.; Schumacher, M.; Schumm, B. A.; Schune, Ph.; Schwartzman, A.; Schwarz, T. A.; Schweiger, H.; Schwemling, Ph.; Schwienhorst, R.; Schwindling, J.; Schwindt, T.; Sciolla, G.; Scuri, F.; Scutti, F.; Searcy, J.; Seema, P.; Seidel, S. C.; Seiden, A.; Seifert, F.; Seixas, J. M.; Sekhniaidze, G.; Sekhon, K.; Sekula, S. J.; Seliverstov, D. M.; Semprini-Cesari, N.; Serfon, C.; Serin, L.; Serkin, L.; Sessa, M.; Seuster, R.; Severini, H.; Sfiligoj, T.; Sforza, F.; Sfyrla, A.; Shabalina, E.; Shaikh, N. W.; Shan, L. Y.; Shang, R.; Shank, J. T.; Shapiro, M.; Shatalov, P. B.; Shaw, K.; Shaw, S. M.; Shcherbakova, A.; Shehu, C. Y.; Sherwood, P.; Shi, L.; Shimizu, S.; Shimmin, C. O.; Shimojima, M.; Shirabe, S.; Shiyakova, M.; Shmeleva, A.; Shoaleh Saadi, D.; Shochet, M. J.; Shojaii, S.; Shope, D. R.; Shrestha, S.; Shulga, E.; Shupe, M. A.; Sicho, P.; Sickles, A. M.; Sidebo, P. E.; Sidiropoulou, O.; Sidorov, D.; Sidoti, A.; Siegert, F.; Sijacki, Dj.; Silva, J.; Silverstein, S. B.; Simak, V.; Simic, Lj.; Simion, S.; Simioni, E.; Simmons, B.; Simon, D.; Simon, M.; Sinervo, P.; Sinev, N. B.; Sioli, M.; Siragusa, G.; Sivoklokov, S. Yu.; Sjölin, J.; Skinner, M. B.; Skottowe, H. P.; Skubic, P.; Slater, M.; Slavicek, T.; Slawinska, M.; Sliwa, K.; Slovak, R.; Smakhtin, V.; Smart, B. H.; Smestad, L.; Smiesko, J.; Smirnov, S. Yu.; Smirnov, Y.; Smirnova, L. N.; Smirnova, O.; Smith, M. N. K.; Smith, R. W.; Smizanska, M.; Smolek, K.; Snesarev, A. A.; Snyder, I. M.; Snyder, S.; Sobie, R.; Socher, F.; Soffer, A.; Soh, D. A.; Sokhrannyi, G.; Solans Sanchez, C. A.; Solar, M.; Soldatov, E. Yu.; Soldevila, U.; Solodkov, A. A.; Soloshenko, A.; Solovyanov, O. V.; Solovyev, V.; Sommer, P.; Son, H.; Song, H. Y.; Sood, A.; Sopczak, A.; Sopko, V.; Sorin, V.; Sosa, D.; Sotiropoulou, C. L.; Soualah, R.; Soukharev, A. M.; South, D.; Sowden, B. C.; Spagnolo, S.; Spalla, M.; Spangenberg, M.; Spanò, F.; Sperlich, D.; Spettel, F.; Spighi, R.; Spigo, G.; Spiller, L. A.; Spousta, M.; Denis, R. D. St.; Stabile, A.; Stamen, R.; Stamm, S.; Stanecka, E.; Stanek, R. W.; Stanescu, C.; Stanescu-Bellu, M.; Stanitzki, M. M.; Stapnes, S.; Starchenko, E. A.; Stark, G. H.; Stark, J.; Staroba, P.; Starovoitov, P.; Stärz, S.; Staszewski, R.; Steinberg, P.; Stelzer, B.; Stelzer, H. J.; Stelzer-Chilton, O.; Stenzel, H.; Stewart, G. A.; Stillings, J. A.; Stockton, M. C.; Stoebe, M.; Stoicea, G.; Stolte, P.; Stonjek, S.; Stradling, A. R.; Straessner, A.; Stramaglia, M. E.; Strandberg, J.; Strandberg, S.; Strandlie, A.; Strauss, M.; Strizenec, P.; Ströhmer, R.; Strom, D. M.; Stroynowski, R.; Strubig, A.; Stucci, S. A.; Stugu, B.; Styles, N. A.; Su, D.; Su, J.; Suchek, S.; Sugaya, Y.; Suk, M.; Sulin, V. V.; Sultansoy, S.; Sumida, T.; Sun, S.; Sun, X.; Sundermann, J. E.; Suruliz, K.; Susinno, G.; Sutton, M. R.; Suzuki, S.; Svatos, M.; Swiatlowski, M.; Sykora, I.; Sykora, T.; Ta, D.; Taccini, C.; Tackmann, K.; Taenzer, J.; Taffard, A.; Tafirout, R.; Taiblum, N.; Takai, H.; Takashima, R.; Takeshita, T.; Takubo, Y.; Talby, M.; Talyshev, A. A.; Tan, K. G.; Tanaka, J.; Tanaka, M.; Tanaka, R.; Tanaka, S.; Tanioka, R.; Tannenwald, B. B.; Tapia Araya, S.; Tapprogge, S.; Tarem, S.; Tartarelli, G. F.; Tas, P.; Tasevsky, M.; Tashiro, T.; Tassi, E.; Tavares Delgado, A.; Tayalati, Y.; Taylor, A. C.; Taylor, G. N.; Taylor, P. T. E.; Taylor, W.; Teischinger, F. A.; Teixeira-Dias, P.; Temming, K. K.; Temple, D.; Ten Kate, H.; Teng, P. K.; Teoh, J. J.; Tepel, F.; Terada, S.; Terashi, K.; Terron, J.; Terzo, S.; Testa, M.; Teuscher, R. J.; Theveneaux-Pelzer, T.; Thomas, J. P.; Thomas-Wilsker, J.; Thompson, P. D.; Thompson, A. S.; Thomsen, L. A.; Thomson, E.; Tibbetts, M. J.; Ticse Torres, R. E.; Tikhomirov, V. O.; Tikhonov, Yu. A.; Timoshenko, S.; Tipton, P.; Tisserant, S.; Todome, K.; Todorov, T.; Todorova-Nova, S.; Tojo, J.; Tokár, S.; Tokushuku, K.; Tolley, E.; Tomlinson, L.; Tomoto, M.; Tompkins, L.; Toms, K.; Tong, B.; Tornambe, P.; Torrence, E.; Torres, H.; Torró Pastor, E.; Toth, J.; Touchard, F.; Tovey, D. R.; Trefzger, T.; Tricoli, A.; Trigger, I. M.; Trincaz-Duvoid, S.; Tripiana, M. F.; Trischuk, W.; Trocmé, B.; Trofymov, A.; Troncon, C.; Trotta, R.; Trottier-McDonald, M.; Trovatelli, M.; Truong, L.; Trzebinski, M.; Trzupek, A.; Tseng, J. C-L.; Tsiareshka, P. V.; Tsipolitis, G.; Tsirintanis, N.; Tsiskaridze, S.; Tsiskaridze, V.; Tskhadadze, E. G.; Tsui, K. M.; Tsukerman, I. I.; Tsulaia, V.; Tsuno, S.; Tsybychev, D.; Tu, Y.; Tudorache, A.; Tudorache, V.; Tuna, A. N.; Tupputi, S. A.; Turchikhin, S.; Turecek, D.; Turgeman, D.; Turra, R.; Tuts, P. M.; Tyndel, M.; Ucchielli, G.; Ueda, I.; Ughetto, M.; Ukegawa, F.; Unal, G.; Undrus, A.; Unel, G.; Ungaro, F. C.; Unno, Y.; Unverdorben, C.; Urban, J.; Urquijo, P.; Urrejola, P.; Usai, G.; Usui, J.; Vacavant, L.; Vacek, V.; Vachon, B.; Valderanis, C.; Valdes Santurio, E.; Valencic, N.; Valentinetti, S.; Valero, A.; Valery, L.; Valkar, S.; Valls Ferrer, J. A.; Van Den Wollenberg, W.; Van Der Deijl, P. C.; van der Graaf, H.; van Eldik, N.; van Gemmeren, P.; Van Nieuwkoop, J.; van Vulpen, I.; van Woerden, M. C.; Vanadia, M.; Vandelli, W.; Vanguri, R.; Vaniachine, A.; Vankov, P.; Vardanyan, G.; Vari, R.; Varnes, E. W.; Varol, T.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vasquez, J. G.; Vasquez, G. A.; Vazeille, F.; Vazquez Schroeder, T.; Veatch, J.; Veeraraghavan, V.; Veloce, L. M.; Veloso, F.; Veneziano, S.; Ventura, A.; Venturi, M.; Venturi, N.; Venturini, A.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J. C.; Vest, A.; Vetterli, M. C.; Viazlo, O.; Vichou, I.; Vickey, T.; Vickey Boeriu, O. E.; Viehhauser, G. H. A.; Viel, S.; Vigani, L.; Villa, M.; Villaplana Perez, M.; Vilucchi, E.; Vincter, M. G.; Vinogradov, V. B.; Vittori, C.; Vivarelli, I.; Vlachos, S.; Vlasak, M.; Vogel, M.; Vokac, P.; Volpi, G.; Volpi, M.; von der Schmitt, H.; von Toerne, E.; Vorobel, V.; Vorobev, K.; Vos, M.; Voss, R.; Vossebeld, J. H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Vuillermet, R.; Vukotic, I.; Vykydal, Z.; Wagner, P.; Wagner, W.; Wahlberg, H.; Wahrmund, S.; Wakabayashi, J.; Walder, J.; Walker, R.; Walkowiak, W.; Wallangen, V.; Wang, C.; Wang, C.; Wang, F.; Wang, H.; Wang, H.; Wang, J.; Wang, J.; Wang, K.; Wang, R.; Wang, S. M.; Wang, T.; Wang, T.; Wang, W.; Wanotayaroj, C.; Warburton, A.; Ward, C. P.; Wardrope, D. R.; Washbrook, A.; Watkins, P. M.; Watson, A. T.; Watson, M. F.; Watts, G.; Watts, S.; Waugh, B. M.; Webb, S.; Weber, M. S.; Weber, S. W.; Weber, S. A.; Webster, J. S.; Weidberg, A. R.; Weinert, B.; Weingarten, J.; Weiser, C.; Weits, H.; Wells, P. S.; Wenaus, T.; Wengler, T.; Wenig, S.; Wermes, N.; Werner, M.; Werner, M. D.; Werner, P.; Wessels, M.; Wetter, J.; Whalen, K.; Whallon, N. L.; Wharton, A. M.; White, A.; White, M. J.; White, R.; Whiteson, D.; Wickens, F. J.; Wiedenmann, W.; Wielers, M.; Wiglesworth, C.; Wiik-Fuchs, L. A. M.; Wildauer, A.; Wilk, F.; Wilkens, H. G.; Williams, H. H.; Williams, S.; Willis, C.; Willocq, S.; Wilson, J. A.; Wingerter-Seez, I.; Winklmeier, F.; Winston, O. J.; Winter, B. T.; Wittgen, M.; Wittkowski, J.; Wolf, T. M. H.; Wolter, M. W.; Wolters, H.; Worm, S. D.; Wosiek, B. K.; Wotschack, J.; Woudstra, M. J.; Wozniak, K. W.; Wu, M.; Wu, M.; Wu, S. L.; Wu, X.; Wu, Y.; Wyatt, T. R.; Wynne, B. M.; Xella, S.; Xu, D.; Xu, L.; Yabsley, B.; Yacoob, S.; Yamaguchi, D.; Yamaguchi, Y.; Yamamoto, A.; Yamamoto, S.; Yamanaka, T.; Yamauchi, K.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, H.; Yang, Y.; Yang, Z.; Yao, W-M.; Yap, Y. C.; Yasu, Y.; Yatsenko, E.; Yau Wong, K. H.; Ye, J.; Ye, S.; Yeletskikh, I.; Yildirim, E.; Yorita, K.; Yoshida, R.; Yoshihara, K.; Young, C.; Young, C. J. S.; Youssef, S.; Yu, D. R.; Yu, J.; Yu, J. M.; Yu, J.; Yuan, L.; Yuen, S. P. Y.; Yusuff, I.; Zabinski, B.; Zaidan, R.; Zaitsev, A. M.; Zakharchuk, N.; Zalieckas, J.; Zaman, A.; Zambito, S.; Zanello, L.; Zanzi, D.; Zeitnitz, C.; Zeman, M.; Zemla, A.; Zeng, J. C.; Zeng, Q.; Zenin, O.; Ženiš, T.; Zerwas, D.; Zhang, D.; Zhang, F.; Zhang, G.; Zhang, H.; Zhang, J.; Zhang, L.; Zhang, M.; Zhang, R.; Zhang, R.; Zhang, X.; Zhang, Z.; Zhao, X.; Zhao, Y.; Zhao, Z.; Zhemchugov, A.; Zhong, J.; Zhou, B.; Zhou, C.; Zhou, L.; Zhou, L.; Zhou, M.; Zhou, N.; Zhu, C. G.; Zhu, H.; Zhu, J.; Zhu, Y.; Zhuang, X.; Zhukov, K.; Zibell, A.; Zieminska, D.; Zimine, N. I.; Zimmermann, C.; Zimmermann, S.; Zinonos, Z.; Zinser, M.; Ziolkowski, M.; Živković, L.; Zobernig, G.; Zoccoli, A.; zur Nedden, M.; Zwalinski, L.

    2016-09-01

    A selection of searches by the ATLAS experiment at the LHC for the electroweak production of SUSY particles are used to study their impact on the constraints on dark matter candidates. The searches use 20 fb-1 of proton-proton collision data at s√=8s=8 TeV. A likelihood-driven scan of a five-dimensional effective model focusing on the gaugino-higgsino and Higgs sector of the phenomenological minimal supersymmetric Standard Model is performed. This scan uses data from direct dark matter detection experiments, the relic dark matter density and precision flavour physics results. Further constraints from the ATLAS Higgs mass measurement and SUSY searches at LEP are also applied. A subset of models selected from this scan are used to assess the impact of the selected ATLAS searches in this five-dimensional parameter space. These ATLAS searches substantially impact those models for which the mass m(χ~01)m(χ~10) of the lightest neutralino is less than 65 GeV, excluding 86% of such models. The searches have limited impact on models with larger m(χ~01)m(χ~10) due to either heavy electroweakinos or compressed mass spectra where the mass splittings between the produced particles and the lightest supersymmetric particle is small.

  10. Konfirmasi spesifitas GAD65 terhadap anti-GAD65 pada tikus DM dan pasien DM tipe 1

    Directory of Open Access Journals (Sweden)

    Aulanni’a Aulanni’a

    2012-02-01

    Full Text Available The use of glutamic acid decarboxylase (GAD65 from bovine brain has been studied to obtain basic knowledge and diagnosis and prediction of Type 1 Diabetes Mellitus (DM patients. The importance of GAD65 in DM diagnosis based on its patogenesis. One of the autoimmune marker that can be used to detect beta-pancreas destruction in Diabetes Type I is the antibody to glutamic acid decarboxylase (GAD65. Most of the pre-diabetic patients indicate the reactive autoantibody to GAD65. For early detection of anti-GAD65 in the serum of the patient, human recombinat GAD65 has been succeed to be used. However this is not economical, therefore, it is necessary to find the alternative source of cheaper GAD65. The aim of this research is to develop an early detection kit of Type 1 DM based on antibody- GAD65, since the longest patient suffering from DM has higher probability to be complicated, especially for uncured patients. The anti- GAD65 antibodies induced by anti-GAD65 synthetized and labelled by alkaline phosphatase can be used as reagent detection early DM patients. The ten patients of DM as samples (positive of anti-GAD65 and five rats of DM were positive with western blott technique using reagents as result of this research. It can be concluded, GAD65 enzyme isolated from bovine brain induced anti-GAD65 production and have possibilities to be packaged in a diagnostic kit for patient pre DM.

  11. Weak annihilation cusp inside the dark matter spike about a black hole.

    Science.gov (United States)

    Shapiro, Stuart L; Shelton, Jessie

    2016-06-15

    We reinvestigate the effect of annihilations on the distribution of collisionless dark matter (DM) in a spherical density spike around a massive black hole. We first construct a very simple, pedagogic, analytic model for an isotropic phase space distribution function that accounts for annihilation and reproduces the "weak cusp" found by Vasiliev for DM deep within the spike and away from its boundaries. The DM density in the cusp varies as r -1/2 for s -wave annihilation, where r is the distance from the central black hole, and is not a flat "plateau" profile. We then extend this model by incorporating a loss cone that accounts for the capture of DM particles by the hole. The loss cone is implemented by a boundary condition that removes capture orbits, resulting in an anisotropic distribution function. Finally, we evolve an initial spike distribution function by integrating the Boltzmann equation to show how the weak cusp grows and its density decreases with time. We treat two cases, one for s -wave and the other for p -wave DM annihilation, adopting parameters characteristic of the Milky Way nuclear core and typical WIMP models for DM. The cusp density profile for p -wave annihilation is weaker, varying like ~ r -0.34 , but is still not a flat plateau.

  12. Astrophysical limitations to the identification of dark matter: Indirect neutrino signals vis-a-vis direct detection recoil rates

    International Nuclear Information System (INIS)

    Serpico, Pasquale D.; Bertone, Gianfranco

    2010-01-01

    A convincing identification of dark matter (DM) particles can probably be achieved only through a combined analysis of different detections strategies, which provides an effective way of removing degeneracies in the parameter space of DM models. In practice, however, this program is made complicated by the fact that different strategies depend on different physical quantities, or on the same quantities but in a different way, making the treatment of systematic errors rather tricky. We discuss here the uncertainties on the recoil rate in direct-detection experiments and on the muon rate induced by neutrinos from dark matter annihilations in the Sun, and we show that, contrarily to the local DM density or overall cross section scale, irreducible astrophysical uncertainties affect the two rates in a different fashion, therefore limiting our ability to reconstruct the parameters of the dark matter particles. By varying within their respective errors astrophysical parameters such as the escape velocity and the velocity dispersion of dark matter particles, we show that the uncertainty on the relative strength of the neutrino and direct-detection signal is as large as a factor of 2 for typical values of the parameters, but can be even larger in some circumstances.

  13. The effective field theory of dark matter direct detection

    Energy Technology Data Exchange (ETDEWEB)

    Fitzpatrick, A. Liam; Haxton, Wick; Katz, Emanuel; Lubbers, Nicholas; Xu, Yiming

    2013-02-01

    We extend and explore the general non-relativistic effective theory of dark matter (DM) direct detection. We describe the basic non-relativistic building blocks of operators and discuss their symmetry properties, writing down all Galilean-invariant operators up to quadratic order in momentum transfer arising from exchange of particles of spin 1 or less. Any DM particle theory can be translated into the coefficients of an effective operator and any effective operator can be simply related to most general description of the nuclear response. We find several operators which lead to novel nuclear responses. These responses differ significantly from the standard minimal WIMP cases in their relative coupling strengths to various elements, changing how the results from different experiments should be compared against each other. Response functions are evaluated for common DM targets — F, Na, Ge, I, and Xe — using standard shell model techniques. We point out that each of the nuclear responses is familiar from past studies of semi-leptonic electroweak interactions, and thus potentially testable in weak interaction studies. We provide tables of the full set of required matrix elements at finite momentum transfer for a range of common elements, making a careful and fully model-independent analysis possible. Finally, we discuss embedding non-relativistic effective theory operators into UV models of dark matter.

  14. Quantifying particulate matter deposition in Niwot Ridge, Colorado: Collection of dry deposition using marble inserts and particle imaging using the FlowCAM

    Science.gov (United States)

    Goss, Natasha R.; Mladenov, Natalie; Seibold, Christine M.; Chowanski, Kurt; Seitz, Leslie; Wellemeyer, T. Barret; Williams, Mark W.

    2013-12-01

    Atmospheric wet and dry deposition are important sources of carbon for remote alpine lakes and soils. The carbon inputs from dry deposition in alpine National Atmospheric Deposition Program (NADP) collectors, including aeolian dust and biological material, are not well constrained due to difficulties in retaining particulate matter in the collectors. Here, we developed and tested a marble insert for dry deposition collection at the Niwot Ridge Long Term Ecological Research Station (NWT LTER) Soddie site (3345 m) between 24 May and 8 November 2011. We conducted laboratory tests of the insert's effect on particulate matter (PM) mass and non-purgeable organic carbon (DOC) and found that the insert did not significantly change either measurement. Thus, the insert may enable dry deposition collection of PM and DOC at NADP sites. We then developed a method for enumerating the collected wet and dry deposition with the Flow Cytometer and Microscope (FlowCAM), a dynamic-image particle analysis tool. The FlowCAM has the potential to establish morphology, which affects particle settling and retention, through particle diameter and aspect ratio. Particle images were used to track the abundance of pollen grains over time. Qualitative image examination revealed that most particles were biological in nature, such as intact algal cells and pollen. Dry deposition loading to the Soddie site as determined by FlowCAM measurements was highly variable, ranging from 100 to >230 g ha-1 d-1 in June-August 2011 and peaking in late June. No significant difference in diameter or aspect ratio was found between wet and dry deposition, suggesting fundamental similarities between those deposition types. Although FlowCAM statistics and identification of particle types proved insightful, our total-particle enumeration method had a high variance and underestimated the total number of particles when compared to imaging of relatively large volumes (60-125 mL) from a single sample. We recommend use of

  15. Dark matter detectors

    International Nuclear Information System (INIS)

    Forster, G.

    1995-01-01

    A fundamental question of astrophysics and cosmology is the nature of dark matter. Astrophysical observations show clearly the existence of some kind of dark matter, though they cannot yet reveal its nature. Dark matter can consist of baryonic particles, or of other (known or unknown) elementary particles. Baryonic dark matter probably exists in the form of dust, gas, or small stars. Other elementary particles constituting the dark matter can possibly be measured in terrestrial experiments. Possibilities for dark matter particles are neutrinos, axions and weakly interacting massive particles (WIMPs). While a direct detection of relic neutrinos seems at the moment impossible, there are experiments looking for baryonic dark matter in the form of Massive Compact Halo Objects, and for particle dark matter in the form of axions and WIMPS. (orig.)

  16. Fermilab | Science | Particle Physics

    Science.gov (United States)

    Photos and videos Latest news For the media Particle Physics Neutrinos Fermilab and the LHC Dark matter initiatives Research and development Key discoveries Benefits of particle physics Particle Accelerators society Particle Physics 101 Science of matter, energy, space and time How particle physics discovery

  17. TREX-DM: a low-background Micromegas-based TPC for low-mass WIMP detection

    Energy Technology Data Exchange (ETDEWEB)

    Iguaz, F.J.; Garza, J.G.; Castel, J.F.; Cebrian, S.; Dafni, T.; Garcia, J.A.; Irastorza, I.G.; Lagraba, A.; Luzon, G.; Peiro, A. [Universidad de Zaragoza, Grupo de Fisica Nuclear y Astroparticulas, Zaragoza (Spain); Aznar, F. [Universidad de Zaragoza, Grupo de Fisica Nuclear y Astroparticulas, Zaragoza (Spain); Universidad de Zaragoza, Centro Universitario de la Defensa, Zaragoza (Spain)

    2016-10-15

    If Dark Matter is made of Weakly Interacting Massive Particles (WIMPs) with masses below ∝20 GeV, the corresponding nuclear recoils in mainstream WIMP experiments are of energies too close, or below, the experimental threshold. Gas Time Projection Chambers (TPCs) can be operated with a variety of target elements, offer good tracking capabilities and, on account of the amplification in gas, very low thresholds are achievable. Recent advances in electronics and in novel radiopure TPC readouts, especially micro-mesh gas structure (Micromegas), are improving the scalability and low-background prospects of gaseous TPCs. Here we present TREX-DM, a prototype to test the concept of a Micromegas-based TPC to search for low-mass WIMPs. The detector is designed to host an active mass of ∝0.300 kg of Ar at 10 bar, or alternatively ∝0.160 kg of Ne at 10 bar, with an energy threshold below 0.4 keVee, and is fully built with radiopure materials. We will describe the detector in detail, the results from the commissioning phase on surface, as well as a preliminary background model. The anticipated sensitivity of this technique may go beyond current experimental limits for WIMPs of masses of 2-8 GeV. (orig.)

  18. Dark matter phenomenology of SM and enlarged Higgs sectors extended with vector-like leptons

    Energy Technology Data Exchange (ETDEWEB)

    Angelescu, Andrei [Universite Paris-Saclay, CNRS, Laboratoire de Physique Theorique, Orsay (France); Arcadi, Giorgio [Max Planck Institut fuer Kernphysik, Heidelberg (Germany)

    2017-07-15

    We will investigate the scenario in which the Standard Model (SM) Higgs sector and its two-doublet extension (called the Two Higgs Doublet Model or 2HDM) are the ''portal'' for the interactions between the Standard Model and a fermionic Dark Matter (DM) candidate. The latter is the lightest stable neutral particle of a family of vector-like leptons (VLLs). We will provide an extensive overview of this scenario combining the constraints coming purely from DM phenomenology with more general constraints like Electroweak Precision Test (EWPT) as well as with collider searches. In the case that the new fermionic sector interacts with the SM Higgs sector, constraints from DM phenomenology force the new states to lie above the TeV scale. This requirement is relaxed in the case of 2HDM. Nevertheless, strong constraints coming from EWPTs and the Renormalization Group Equations (RGEs) limit the impact of VLFs on collider phenomenology. (orig.)

  19. Dark matter phenomenology of SM and enlarged Higgs sectors extended with vector-like leptons.

    Science.gov (United States)

    Angelescu, Andrei; Arcadi, Giorgio

    2017-01-01

    We will investigate the scenario in which the Standard Model (SM) Higgs sector and its two-doublet extension (called the Two Higgs Doublet Model or 2HDM) are the "portal" for the interactions between the Standard Model and a fermionic Dark Matter (DM) candidate. The latter is the lightest stable neutral particle of a family of vector-like leptons (VLLs). We will provide an extensive overview of this scenario combining the constraints coming purely from DM phenomenology with more general constraints like Electroweak Precision Test (EWPT) as well as with collider searches. In the case that the new fermionic sector interacts with the SM Higgs sector, constraints from DM phenomenology force the new states to lie above the TeV scale. This requirement is relaxed in the case of 2HDM. Nevertheless, strong constraints coming from EWPTs and the Renormalization Group Equations (RGEs) limit the impact of VLFs on collider phenomenology.

  20. Structural composition of organic matter in particle-size fractions of soils along a climo-biosequence in the main range of Peninsular Malaysia

    Science.gov (United States)

    Jafarzadeh-Haghighi, Amir Hossein; Shamshuddin, Jusop; Hamdan, Jol; Zainuddin, Norhazlin

    2016-09-01

    Information on structural composition of organic matter (OM) in particle-size fractions of soils along a climo-biosequence is sparse. The objective of this study was to examine structural composition and morphological characteristics of OM in particle-size fractions of soils along a climo-biosequence in order to better understand the factors and processes affecting structural composition of soil organic matter. To explore changes in structural composition of OM in soils with different pedogenesis, the A-horizon was considered for further analyses including particle-size fractionation, solid-state 13C nuclear magnetic resonance (NMR) spectroscopy and scanning electron microscopy (SEM). Due to the increase in the thickness of organic layer with increasing elevation, the A-horizon was situated at greater depth in soils of higher elevation. The relationship between relative abundances of carbon (C) structures and particle-size fractions was examined using principal component analysis (PCA). It was found that alkyl C (20.1-73.4%) and O-alkyl C (16.8-67.7%) dominated particle-size fractions. The proportion of alkyl C increased with increasing elevation, while O-alkyl C showed an opposite trend. Results of PCA confirmed this finding and showed the relative enrichment of alkyl C in soils of higher elevation. Increase in the proportion of alkyl C in 250-2000 μm fraction is linked to selective preservation of aliphatic compounds derived from root litter. SEM results showed an increase in root contribution to the 250-2000 μm fraction with increasing elevation. For the changes in structural composition of OM in particle-size fractions of soils along the studied climo-biosequence are attributed to site-specific differences in pedogenesis as a function of climate and vegetation.

  1. A search for particle dark matter using cryogenic germanium and silicon detectors in the one- and two- tower runs of CDMS-II at Soudan

    International Nuclear Information System (INIS)

    Ogburn, Reuben Walter IV

    2008-01-01

    Images of the Bullet Cluster of galaxies in visible light, X-rays, and through gravitational lensing confirm that most of the matter in the universe is not composed of any known form of matter. The combined evidence from the dynamics of galaxies and clusters of galaxies, the cosmic microwave background, big bang nucleosynthesis, and other observations indicates that 80% of the universe's matter is dark, nearly collisionless, and cold. The identify of the dar, matter remains unknown, but weakly interacting massive particles (WIMPs) are a very good candidate. They are a natural part of many supersymmetric extensions to the standard model, and could be produced as a nonrelativistic, thermal relic in the early universe with about the right density to account for the missing mass. The dark matter of a galaxy should exist as a spherical or ellipsoidal cloud, called a 'halo' because it extends well past the edge of the visible galaxy. The Cryogenic Dark Matter Search (CDMS) seeks to directly detect interactions between WIMPs in the Milky Way's galactic dark matter halo using crystals of germanium and silicon. Our Z-sensitive ionization and phonon ('ZIP') detectors simultaneously measure both phonons and ionization produced by particle interactions. In order to find very rare, low-energy WIMP interactions, they must identify and reject background events caused by environmental radioactivity, radioactive contaminants on the detector,s and cosmic rays. In particular, sophisticated analysis of the timing of phonon signals is needed to eliminate signals caused by beta decays at the detector surfaces. This thesis presents the firs two dark matter data sets from the deep underground experimental site at the Soudan Underground Laboratory in Minnesota. These are known as 'Run 118', with six detectors (1 kg Ge, 65.2 live days before cuts) and 'Run 119', with twelve detectors (1.5 kg Ge, 74.5 live days before cuts). They have analyzed all data from the two runs together in a single

  2. Elemental and isotopic characterization of organic particles in carbonaceous chondrites by NanoSIMS imaging: assessment on the origin, accretion and preservation of organic matter in chondrites

    Science.gov (United States)

    Remusat, L.; Guan, Y.; Eiler, J. M.

    2009-12-01

    Chondrites accreted primitive components, including organic compounds sampled from the proto-solar nebula. However, the molecular and isotopic fingerprints of organic matter extracted from chondrites are also potentially influenced by complex evolution on the parent bodies. We have performed NanoSIMS in situ characterisation of organic matter in the matrices of carbonaceous chondrites Orgueil (CI), Murchison (CM), Tagish Lake (C2), Renazzo (CR) and Allende (CV) with a spatial resolution of ~200 nm; we could also constrains textural relationships between organic constituents and other phases. Those meteorites have undergone a diverse set of parent body processes. I.e., CI, C2 and CM meteorites have undergone aqueous alteration, and the CV’s are thermally metamorphosed. The CR’s are inferred to be the least altered class of chondrites. Despite these differences in parent body modification, the distributions of organic carbon in these meteorites is similar: in all cases it can be found as micron-size, randomly distributed organic particles that are surrounded by the clay minerals that dominate the matrix material, but are not specifically associated with sulfides, sulfates or oxides. In addition, there is a “diffuse” fraction of organic carbon intimately associated with the clay-rich matrix. We hypothesize that the C particles we identify are hosts of insoluble organic matter that co-accreted with other primitive constituents of these materials, whereas the diffuse C fraction is the soluble component (i.e., soluble in laboratory organic and aqueous solvents). Our analytical technique lacks the spatial resolution required to analyze the diffuse organic matter without contamination by associated clays. But we are able to analyze the compositions of the interiors of relatively large C-rich particles (>500 nm) without such contamination. Some fraction of the C-rich particles in all of the examined meteorites but Allende exhibit a very high enrichment in deuterium

  3. 1015 PTT Segment MEMS DM Development, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Microelectromechanical systems (MEMS) technology has the potential to create deformable mirrors (DM) with more than 10^4 actuators with size, weight, and power...

  4. Picometer-Resolution MEMS Segmented DM, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Microelectromechanical systems (MEMS) technology has the potential to create deformable mirrors (DM) with 10^4 actuators that have size, weight, and power...

  5. Picometer-Resolution MEMS Segmented DM, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Microelectromechanical systems (MEMS) technology has the potential to create deformable mirrors (DM) with 10^4 actuators that have size, weight, and power...

  6. Solar Extreme UV radiation and quark nugget dark matter model

    Energy Technology Data Exchange (ETDEWEB)

    Zhitnitsky, Ariel, E-mail: arz@phas.ubc.ca [Department of Physics and Astronomy, University of British Columbia, Vancouver, B.C. V6T 1Z1 (Canada)

    2017-10-01

    We advocate the idea that the surprising emission of extreme ultra violet (EUV) radiation and soft x-rays from the Sun are powered externally by incident dark matter (DM) particles. The energy and the spectral shape of this otherwise unexpected solar irradiation is estimated within the quark nugget dark matter model. This model was originally invented as a natural explanation of the observed ratio Ω{sub dark} ∼ Ω{sub visible} when the DM and visible matter densities assume the same order of magnitude values. This generic consequence of the model is a result of the common origin of both types of matter which are formed during the same QCD transition and both proportional to the same fundamental dimensional parameter Λ{sub QCD}. We also present arguments suggesting that the transient brightening-like 'nanoflares' in the Sun may be related to the annihilation events which inevitably occur in the solar atmosphere within this dark matter scenario.

  7. Correlation between dark matter and dark radiation in string compactifications

    International Nuclear Information System (INIS)

    Allahverdi, Rouzbeh; Cicoli, Michele; Dutta, Bhaskar; Sinha, Kuver

    2014-01-01

    Reheating in string compactifications is generically driven by the decay of the lightest modulus which produces Standard Model particles, dark matter and light hidden sector degrees of freedom that behave as dark radiation. This common origin allows us to find an interesting correlation between dark matter and dark radiation. By combining present upper bounds on the effective number of neutrino species N eff with lower bounds on the reheating temperature as a function of the dark matter mass m DM from Fermi data, we obtain strong constraints on the (N eff , m DM )-plane. Most of the allowed region in this plane corresponds to non-thermal scenarios with Higgsino-like dark matter. Thermal dark matter can be allowed only if N eff tends to its Standard Model value. We show that the above situation is realised in models with perturbative moduli stabilisation where the production of dark radiation is unavoidable since bulk closed string axions remain light and do not get eaten up by anomalous U(1)s

  8. DAMA RESULTS: DARK MATTER IN THE GALACTIC HALO

    Directory of Open Access Journals (Sweden)

    R. Bernabei

    2013-12-01

    Full Text Available Experimental efforts and theoretical developmens support that most of the Universe is Dark and a large fraction of it should be made of relic particles; many possibilities are open on their nature and interaction types. In particular, the DAMA/LIBRA experiment at Gran Sasso Laboratory (sensitive mass: ~250 kg is mainly devoted to the investigation of Dark Matter (DM particles in the Galactic halo by exploiting the model independent DM annual modulation signature with higly radiopure Na I(Tl targets. DAMA/LIBRA is the succesor of the first generation DAMA/NaI (sensitive mass: ~100 kg; cumulatively the two experiments have released so far the results obtained by analyzing an exposure of 1.17 t yr, collected over 13 annual cycles. The data show a model independent evidence of the presence of DM particles in the galactic halo at 8.9σ confidence level (C.L.. Some of the already achieved results are shortly reminded, the last upgrade occurred at fall 2010 is mentioned and future perspectives are sumarized.

  9. Particle Production in Hadron - Nuclear Matter in the Energy Range Between 50-GeV - 150-GeV

    CERN Document Server

    Braune, Kersten

    1980-01-01

    In an experiment at the CERN SPS the particle production in hadron-nucleus collisions in an energy range between 50 and 150 GeV was studied. The detector detects charged particles and separates them into two groups: fast particles, mainly produced pions, and slow particles, mainly recoil protons from the nucleus, whereby the boundary lies at a velocity v/c = 0.7. Multiplicity and angular respectively pseudo-rapidity distributions were measured. From the data analysis resulted that the slow particles are a measure for the number of collisions of the projectile in the nucleus. The properties of the fast particle were studied in dependence on . Thereby it was shown that at a description of the measured results using the variable the dependence on the projectile and on the mass number A of the target are extensively eliminated.

  10. Single-particle potential of the Λ hyperon in nuclear matter with chiral effective field theory NLO interactions including effects of Y N N three-baryon interactions

    Science.gov (United States)

    Kohno, M.

    2018-03-01

    Adopting hyperon-nucleon and hyperon-nucleon-nucleon interactions parametrized in chiral effective field theory, single-particle potentials of the Λ and Σ hyperons are evaluated in symmetric nuclear matter and in pure neutron matter within the framework of lowest-order Bruckner theory. The chiral NLO interaction bears strong Λ N -Σ N coupling. Although the Λ potential is repulsive if the coupling is switched off, the Λ N -Σ N correlation brings about the attraction consistent with empirical data. The Σ potential is repulsive, which is also consistent with empirical information. The interesting result is that the Λ potential becomes shallower beyond normal density. This provides the possibility of solving the hyperon puzzle without introducing ad hoc assumptions. The effects of the Λ N N -Λ N N and Λ N N -Σ N N three-baryon forces are considered. These three-baryon forces are first reduced to normal-ordered effective two-baryon interactions in nuclear matter and then incorporated in the G -matrix equation. The repulsion from the Λ N N -Λ N N interaction is of the order of 5 MeV at normal density and becomes larger with increasing density. The effects of the Λ N N -Σ N N coupling compensate the repulsion at normal density. The net effect of the three-baryon interactions on the Λ single-particle potential is repulsive at higher densities.

  11. Effects of a catalytic volatile particle remover (VPR) on the particulate matter emissions from a direct injection spark ignition engine.

    Science.gov (United States)

    Xu, Fan; Chen, Longfei; Stone, Richard

    2011-10-15

    Emissions of fine particles have been shown to have a large impact on the atmospheric environment and human health. Researchers have shown that gasoline engines, especially direct injection spark ignition (DISI) engines, tend to emit large amounts of small size particles compared to diesel engines fitted with diesel particulate filters (DPFs). As a result, the particle number emissions of DISI engines will be restricted by the forthcoming EU6 legislation. The particulate emission level of DISI engines means that they could face some challenges in meeting the EU6 requirement. This paper is an experimental study on the size-resolved particle number emissions from a spray guided DISI engine and the performance of a catalytic volatile particle remover (VPR), as the EU legislation seeks to exclude volatile particles. The performance of the catalytic VPR was evaluated by varying its temperature and the exhaust residence time. The effect of the catalytic VPR acting as an oxidation catalyst on particle emissions was also tested. The results show that the catalytic VPR led to a marked reduction in the number of particles, especially the smaller size (nucleation mode) particles. The catalytic VPR is essentially an oxidation catalyst, and when post three-way catalyst (TWC) exhaust was introduced to the catalytic VPR, the performance of the catalytic VPR was not affected much by the use of additional air, i.e., no significant oxidation of the PM was observed.

  12. Integrated dataset of impact of dissolved organic matter on particle behavior and phototoxicity of titanium dioxide nanoparticles

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset is generated to both qualitatively and quantitatively examine the interactions between nano-TiO2 and natural organic matter (NOM). This integrated...

  13. Dipolar dark matter

    International Nuclear Information System (INIS)

    Masso, Eduard; Mohanty, Subhendra; Rao, Soumya

    2009-01-01

    If dark matter (DM) has nonzero direct or transition, electric or magnetic dipole moment then it can scatter nucleons electromagnetically in direct detection experiments. Using the results from experiments like XENON, CDMS, DAMA, and COGENT, we put bounds on the electric and magnetic dipole moments of DM. If DM consists of Dirac fermions with direct dipole moments, then DM of mass less than 10 GeV is consistent with the DAMA signal and with null results of other experiments. If on the other hand DM consists of Majorana fermions then they can have only nonzero transition moments between different mass eigenstates. We find that Majorana fermions with masses 38 χ < or approx. 100-200 GeV and mass splitting of the order of (150-200) keV can explain the DAMA signal and the null observations from other experiments and in addition give the observed relic density of DM by dipole-mediated annihilation. The absence of the heavier DM state in the present Universe can be explained by dipole-mediated radiative decay. This parameter space for the mass and for dipole moments is allowed by limits from L3 but may have observable signals at LHC.

  14. Two-Step Single Particle Mass Spectrometry for On-Line Monitoring of Polycyclic Aromatic Hydrocarbons Bound to Ambient Fine Particulate Matter

    Science.gov (United States)

    Zimmermann, R.; Bente, M.; Sklorz, M.

    2007-12-01

    Polycyclic aromatic hydrocarbons (PAH) are formed as trace products in combustion processes and are emitted to the atmosphere. Larger PAH have low vapour pressure and are predominantly bound to the ambient fine particulate matter (PM). Upon inhalation, PAH show both, chronic human toxicity (i.e. many PAH are potent carcinogens) as well as acute human toxicity (i.e. inflammatory effects due to oxi-dative stress) and are discussed to be relevant for the observed health effect of ambient PM. Therefore a better understanding of the occurrence, dynamics and particle size dependence of particle bound-PAH is of great interest. On-line aerosol mass spectrometry in principle is the method of choice to investigate the size resolved changes in the chemical speciation of particles as well the status of internal vs. external mixing of chemical constituents. However the present available aerosol mass spectrometers (ATOFMS and AMS) do not allow detection of PAH from ambient air PM. In order to allow a single particle based monitoring of PAH from ambient PM a new single particle laser ionisation mass spectrometer was built and applied. The system is based on ATOFMS principle but uses a two- step photo-ionization. A tracked and sized particle firstly is laser desorbed (LD) by a IR-laser pulse (CO2-laser, λ=10.2 μm) and subsequently the released PAH are selectively ionized by an intense UV-laser pulse (ArF excimer, λ=248 nm) in a resonance enhanced multiphoton ionisation process (REMPI). The PAH-ions are detected in a time of flight mass spectrometer (TOFMS). A virtual impactor enrichment unit is used to increase the detection frequency of the ambient particles. With the current inlet system particles from about 400 nm to 10 μm are accessible. Single particle based temporal profiles of PAH containing particles ion (size distribution and PAH speciation) have been recorded in Oberschleissheim, Germany from ambient air. Furthermore profiles of relevant emission sources (e

  15. Long-range Self-interacting Dark Matter in the Sun

    International Nuclear Information System (INIS)

    Chen, Jing; Liang, Zheng-Liang; Wu, Yue-Liang; Zhou, Yu-Feng

    2015-01-01

    We investigate the implications of the long-rang self-interaction on both the self-capture and the annihilation of the self-interacting dark matter (SIDM) trapped in the Sun. Our discussion is based on a specific SIDM model in which DM particles self-interact via a light scalar mediator, or Yukawa potential, in the context of quantum mechanics. Within this framework, we calculate the self-capture rate across a broad region of parameter space. While the self-capture rate can be obtained separately in the Born regime with perturbative method, and in the classical limits with the Rutherford formula, our calculation covers the gap between in a non-perturbative fashion. Besides, the phenomenology of both the Sommerfeld-enhanced s- and p-wave annihilation of the solar SIDM is also involved in our discussion. Moreover, by combining the analysis of the Super-Kamiokande (SK) data and the observed DM relic density, we constrain the nuclear capture rate of the DM particles in the presence of the dark Yukawa potential. The consequence of the long-range dark force on probing the solar SIDM turns out to be significant if the force-carrier is much lighter than the DM particle, and a quantitative analysis is provided

  16. Search for dark matter particles in proton-proton collisions at $\\sqrt{s} =$ 8 TeV using the razor variables

    CERN Document Server

    Khachatryan, Vardan; Tumasyan, Armen; Adam, Wolfgang; Aşılar, Ece; Bergauer, Thomas; Brandstetter, Johannes; Brondolin, Erica; Dragicevic, Marko; Erö, Janos; Flechl, Martin; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hartl, Christian; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; König, Axel; Krammer, Manfred; Krätschmer, Ilse; Liko, Dietrich; Matsushita, Takashi; Mikulec, Ivan; Rabady, Dinyar; Rad, Navid; Rahbaran, Babak; Rohringer, Herbert; Schieck, Jochen; Schöfbeck, Robert; Strauss, Josef; Treberer-Treberspurg, Wolfgang; Waltenberger, Wolfgang; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Alderweireldt, Sara; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Knutsson, Albert; Lauwers, Jasper; Luyckx, Sten; Van De Klundert, Merijn; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Abu Zeid, Shimaa; Blekman, Freya; D'Hondt, Jorgen; Daci, Nadir; De Bruyn, Isabelle; Deroover, Kevin; Heracleous, Natalie; Keaveney, James; Lowette, Steven; Moortgat, Seth; Moreels, Lieselotte; Olbrechts, Annik; Python, Quentin; Strom, Derek; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Van Parijs, Isis; Barria, Patrizia; Brun, Hugues; Caillol, Cécile; Clerbaux, Barbara; De Lentdecker, Gilles; Fasanella, Giuseppe; Favart, Laurent; Goldouzian, Reza; Grebenyuk, Anastasia; Karapostoli, Georgia; Lenzi, Thomas; Léonard, Alexandre; Maerschalk, Thierry; Marinov, Andrey; Perniè, Luca; Randle-conde, Aidan; Seva, Tomislav; Vander Velde, Catherine; Vanlaer, Pascal; Yonamine, Ryo; Zenoni, Florian; Zhang, Fengwangdong; Beernaert, Kelly; Benucci, Leonardo; Cimmino, Anna; Crucy, Shannon; Dobur, Didar; Fagot, Alexis; Garcia, Guillaume; Gul, Muhammad; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Poyraz, Deniz; Ryckbosch, Dirk; Salva Diblen, Sinem; Sigamani, Michael; Tytgat, Michael; Van Driessche, Ward; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Beluffi, Camille; Bondu, Olivier; Brochet, Sébastien; Bruno, Giacomo; Caudron, Adrien; Ceard, Ludivine; De Visscher, Simon; Delaere, Christophe; Delcourt, Martin; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Jafari, Abideh; Jez, Pavel; Komm, Matthias; Lemaitre, Vincent; Mertens, Alexandre; Musich, Marco; Nuttens, Claude; Perrini, Lucia; Piotrzkowski, Krzysztof; Popov, Andrey; Quertenmont, Loic; Selvaggi, Michele; Vidal Marono, Miguel; Beliy, Nikita; Hammad, Gregory Habib; Aldá Júnior, Walter Luiz; Alves, Fábio Lúcio; Alves, Gilvan; Brito, Lucas; Correa Martins Junior, Marcos; Hamer, Matthias; Hensel, Carsten; Moraes, Arthur; Pol, Maria Elena; Rebello Teles, Patricia; Belchior Batista Das Chagas, Ewerton; Carvalho, Wagner; Chinellato, Jose; Custódio, Analu; Melo Da Costa, Eliza; De Jesus Damiao, Dilson; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Huertas Guativa, Lina Milena; Malbouisson, Helena; Matos Figueiredo, Diego; Mora Herrera, Clemencia; Mundim, Luiz; Nogima, Helio; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Sznajder, Andre; Tonelli Manganote, Edmilson José; Vilela Pereira, Antonio; Ahuja, Sudha; Bernardes, Cesar Augusto; De Souza Santos, Angelo; Dogra, Sunil; Tomei, Thiago; De Moraes Gregores, Eduardo; Mercadante, Pedro G; Moon, Chang-Seong; Novaes, Sergio F; Padula, Sandra; Romero Abad, David; Ruiz Vargas, José Cupertino; Aleksandrov, Aleksandar; Hadjiiska, Roumyana; Iaydjiev, Plamen; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Vutova, Mariana; Dimitrov, Anton; Glushkov, Ivan; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Fang, Wenxing; Ahmad, Muhammad; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Chen, Mingshui; Cheng, Tongguang; Du, Ran; Jiang, Chun-Hua; Leggat, Duncan; Plestina, Roko; Romeo, Francesco; Shaheen, Sarmad Masood; Spiezia, Aniello; Tao, Junquan; Wang, Chunjie; Wang, Zheng; Zhang, Huaqiao; Asawatangtrakuldee, Chayanit; Ban, Yong; Li, Qiang; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Xu, Zijun; Avila, Carlos; Cabrera, Andrés; Chaparro Sierra, Luisa Fernanda; Florez, Carlos; Gomez, Juan Pablo; Gomez Moreno, Bernardo; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Puljak, Ivica; Ribeiro Cipriano, Pedro M; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Kadija, Kreso; Luetic, Jelena; Micanovic, Sasa; Sudic, Lucija; Attikis, Alexandros; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Rykaczewski, Hans; Finger, Miroslav; Finger Jr, Michael; Awad, Adel; El-khateeb, Esraa; Elgammal, Sherif; Mohamed, Amr; Calpas, Betty; Kadastik, Mario; Murumaa, Marion; Raidal, Martti; Tiko, Andres; Veelken, Christian; Eerola, Paula; Pekkanen, Juska; Voutilainen, Mikko; Härkönen, Jaakko; Karimäki, Veikko; Kinnunen, Ritva; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Peltola, Timo; Tuominiemi, Jorma; Tuovinen, Esa; Wendland, Lauri; Talvitie, Joonas; Tuuva, Tuure; Besancon, Marc; Couderc, Fabrice; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Favaro, Carlotta; Ferri, Federico; Ganjour, Serguei; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Machet, Martina; Malcles, Julie; Rander, John; Rosowsky, André; Titov, Maksym; Zghiche, Amina; Abdulsalam, Abdulla; Antropov, Iurii; Baffioni, Stephanie; Beaudette, Florian; Busson, Philippe; Cadamuro, Luca; Chapon, Emilien; Charlot, Claude; Davignon, Olivier; Filipovic, Nicolas; Granier de Cassagnac, Raphael; Jo, Mihee; Lisniak, Stanislav; Mastrolorenzo, Luca; Miné, Philippe; Naranjo, Ivo Nicolas; Nguyen, Matthew; Ochando, Christophe; Ortona, Giacomo; Paganini, Pascal; Pigard, Philipp; Regnard, Simon; Salerno, Roberto; Sauvan, Jean-Baptiste; Sirois, Yves; Strebler, Thomas; Yilmaz, Yetkin; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Aubin, Alexandre; Bloch, Daniel; Brom, Jean-Marie; Buttignol, Michael; Chabert, Eric Christian; Chanon, Nicolas; Collard, Caroline; Conte, Eric; Coubez, Xavier; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Goetzmann, Christophe; Le Bihan, Anne-Catherine; Merlin, Jeremie Alexandre; Skovpen, Kirill; Van Hove, Pierre; Gadrat, Sébastien; Beauceron, Stephanie; Bernet, Colin; Boudoul, Gaelle; Bouvier, Elvire; Carrillo Montoya, Camilo Andres; Chierici, Roberto; Contardo, Didier; Courbon, Benoit; Depasse, Pierre; El Mamouni, Houmani; Fan, Jiawei; Fay, Jean; Gascon, Susan; Gouzevitch, Maxime; Ille, Bernard; Lagarde, Francois; Laktineh, Imad Baptiste; Lethuillier, Morgan; Mirabito, Laurent; Pequegnot, Anne-Laure; Perries, Stephane; Ruiz Alvarez, José David; Sabes, David; Sordini, Viola; Vander Donckt, Muriel; Verdier, Patrice; Viret, Sébastien; Toriashvili, Tengizi; Tsamalaidze, Zviad; Autermann, Christian; Beranek, Sarah; Feld, Lutz; Heister, Arno; Kiesel, Maximilian Knut; Klein, Katja; Lipinski, Martin; Ostapchuk, Andrey; Preuten, Marius; Raupach, Frank; Schael, Stefan; Schulte, Jan-Frederik; Verlage, Tobias; Weber, Hendrik; Zhukov, Valery; Ata, Metin; Brodski, Michael; Dietz-Laursonn, Erik; Duchardt, Deborah; Endres, Matthias; Erdmann, Martin; Erdweg, Sören; Esch, Thomas; Fischer, Robert; Güth, Andreas; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Knutzen, Simon; Merschmeyer, Markus; Meyer, Arnd; Millet, Philipp; Mukherjee, Swagata; Olschewski, Mark; Padeken, Klaas; Papacz, Paul; Pook, Tobias; Radziej, Markus; Reithler, Hans; Rieger, Marcel; Scheuch, Florian; Sonnenschein, Lars; Teyssier, Daniel; Thüer, Sebastian; Cherepanov, Vladimir; Erdogan, Yusuf; Flügge, Günter; Geenen, Heiko; Geisler, Matthias; Hoehle, Felix; Kargoll, Bastian; Kress, Thomas; Künsken, Andreas; Lingemann, Joschka; Nehrkorn, Alexander; Nowack, Andreas; Nugent, Ian Michael; Pistone, Claudia; Pooth, Oliver; Stahl, Achim; Aldaya Martin, Maria; Asin, Ivan; Bartosik, Nazar; Behnke, Olaf; Behrens, Ulf; Borras, Kerstin; Burgmeier, Armin; Campbell, Alan; Contreras-Campana, Christian; Costanza, Francesco; Diez Pardos, Carmen; Dolinska, Ganna; Dooling, Samantha; Dorland, Tyler; Eckerlin, Guenter; Eckstein, Doris; Eichhorn, Thomas; Flucke, Gero; Gallo, Elisabetta; Garay Garcia, Jasone; Geiser, Achim; Gizhko, Andrii; Gunnellini, Paolo; Hauk, Johannes; Hempel, Maria; Jung, Hannes; Kalogeropoulos, Alexis; Karacheban, Olena; Kasemann, Matthias; Katsas, Panagiotis; Kieseler, Jan; Kleinwort, Claus; Korol, Ievgen; Lange, Wolfgang; Leonard, Jessica; Lipka, Katerina; Lobanov, Artur; Lohmann, Wolfgang; Mankel, Rainer; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mittag, Gregor; Mnich, Joachim; Mussgiller, Andreas; Naumann-Emme, Sebastian; Nayak, Aruna; Ntomari, Eleni; Perrey, Hanno; Pitzl, Daniel; Placakyte, Ringaile; Raspereza, Alexei; Roland, Benoit; Sahin, Mehmet Özgür; Saxena, Pooja; Schoerner-Sadenius, Thomas; Seitz, Claudia; Spannagel, Simon; Stefaniuk, Nazar; Trippkewitz, Karim Damun; Walsh, Roberval; Wissing, Christoph; Blobel, Volker; Centis Vignali, Matteo; Draeger, Arne-Rasmus; Dreyer, Torben; Erfle, Joachim; Garutti, Erika; Goebel, Kristin; Gonzalez, Daniel; Görner, Martin; Haller, Johannes; Hoffmann, Malte; Höing, Rebekka Sophie; Junkes, Alexandra; Klanner, Robert; Kogler, Roman; Kovalchuk, Nataliia; Lapsien, Tobias; Lenz, Teresa; Marchesini, Ivan; Marconi, Daniele; Meyer, Mareike; Niedziela, Marek; Nowatschin, Dominik; Ott, Jochen; Pantaleo, Felice; Peiffer, Thomas; Perieanu, Adrian; Pietsch, Niklas; Poehlsen, Jennifer; Sander, Christian; Scharf, Christian; Schleper, Peter; Schlieckau, Eike; Schmidt, Alexander; Schumann, Svenja; Schwandt, Joern; Sola, Valentina; Stadie, Hartmut; Steinbrück, Georg; Stober, Fred-Markus Helmut; Tholen, Heiner; Troendle, Daniel; Usai, Emanuele; Vanelderen, Lukas; Vanhoefer, Annika; Vormwald, Benedikt; Barth, Christian; Baus, Colin; Berger, Joram; Böser, Christian; Butz, Erik; Chwalek, Thorsten; Colombo, Fabio; De Boer, Wim; Descroix, Alexis; Dierlamm, Alexander; Fink, Simon; Frensch, Felix; Friese, Raphael; Giffels, Manuel; Gilbert, Andrew; Haitz, Dominik; Hartmann, Frank; Heindl, Stefan Michael; Husemann, Ulrich; Katkov, Igor; Kornmayer, Andreas; Lobelle Pardo, Patricia; Maier, Benedikt; Mildner, Hannes; Mozer, Matthias Ulrich; Müller, Thomas; Müller, Thomas; Plagge, Michael; Quast, Gunter; Rabbertz, Klaus; Röcker, Steffen; Roscher, Frank; Schröder, Matthias; Sieber, Georg; Simonis, Hans-Jürgen; Ulrich, Ralf; Wagner-Kuhr, Jeannine; Wayand, Stefan; Weber, Marc; Weiler, Thomas; Williamson, Shawn; Wöhrmann, Clemens; Wolf, Roger; Anagnostou, Georgios; Daskalakis, Georgios; Geralis, Theodoros; Giakoumopoulou, Viktoria Athina; Kyriakis, Aristotelis; Loukas, Demetrios; Psallidas, Andreas; Topsis-Giotis, Iasonas; Agapitos, Antonis; Kesisoglou, Stilianos; Panagiotou, Apostolos; Saoulidou, Niki; Tziaferi, Eirini; Evangelou, Ioannis; Flouris, Giannis; Foudas, Costas; Kokkas, Panagiotis; Loukas, Nikitas; Manthos, Nikolaos; Papadopoulos, Ioannis; Paradas, Evangelos; Strologas, John; Bencze, Gyorgy; Hajdu, Csaba; Hazi, Andras; Hidas, Pàl; Horvath, Dezso; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Zsigmond, Anna Julia; Beni, Noemi; Czellar, Sandor; Karancsi, János; Molnar, Jozsef; Szillasi, Zoltan; Bartók, Márton; Makovec, Alajos; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Choudhury, Somnath; Mal, Prolay; Mandal, Koushik; Sahoo, Deepak Kumar; Sahoo, Niladribihari; Swain, Sanjay Kumar; Bansal, Sunil; Beri, Suman Bala; Bhatnagar, Vipin; Chawla, Ridhi; Gupta, Ruchi; Bhawandeep, Bhawandeep; Kalsi, Amandeep Kaur; Kaur, Anterpreet; Kaur, Manjit; Kumar, Ramandeep; Mehta, Ankita; Mittal, Monika; Singh, Jasbir; Walia, Genius; Kumar, Ashok; Bhardwaj, Ashutosh; Choudhary, Brajesh C; Garg, Rocky Bala; Malhotra, Shivali; Naimuddin, Md; Nishu, Nishu; Ranjan, Kirti; Sharma, Ramkrishna; Sharma, Varun; Bhattacharya, Rajarshi; Bhattacharya, Satyaki; Chatterjee, Kalyanmoy; Dey, Sourav; Dutta, Suchandra; Ghosh, Shamik; Majumdar, Nayana; Modak, Atanu; Mondal, Kuntal; Mukhopadhyay, Supratik; Nandan, Saswati; Purohit, Arnab; Roy, Ashim; Roy, Debarati; Roy Chowdhury, Suvankar; Sarkar, Subir; Sharan, Manoj; Chudasama, Ruchi; Dutta, Dipanwita; Jha, Vishwajeet; Kumar, Vineet; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Topkar, Anita; Aziz, Tariq; Banerjee, Sudeshna; Bhowmik, Sandeep; Chatterjee, Rajdeep Mohan; Dewanjee, Ram Krishna; Dugad, Shashikant; Ganguly, Sanmay; Ghosh, Saranya; Guchait, Monoranjan; Gurtu, Atul; Jain, Sandhya; Kole, Gouranga; Kumar, Sanjeev; Mahakud, Bibhuprasad; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Mitra, Soureek; Mohanty, Gagan Bihari; Parida, Bibhuti; Sarkar, Tanmay; Sur, Nairit; Sutar, Bajrang; Wickramage, Nadeesha; Chauhan, Shubhanshu; Dube, Sourabh; Kapoor, Anshul; Kothekar, Kunal; Rane, Aditee; Sharma, Seema; Bakhshiansohi, Hamed; Behnamian, Hadi; Etesami, Seyed Mohsen; Fahim, Ali; Khakzad, Mohsen; Mohammadi Najafabadi, Mojtaba; Naseri, Mohsen; Paktinat Mehdiabadi, Saeid; Rezaei Hosseinabadi, Ferdos; Safarzadeh, Batool; Zeinali, Maryam; Felcini, Marta; Grunewald, Martin; Abbrescia, Marcello; Calabria, Cesare; Caputo, Claudio; Colaleo, Anna; Creanza, Donato; Cristella, Leonardo; De Filippis, Nicola; De Palma, Mauro; Fiore, Luigi; Iaselli, Giuseppe; Maggi, Giorgio; Maggi, Marcello; Miniello, Giorgia; My, Salvatore; Nuzzo, Salvatore; Pompili, Alexis; Pugliese, Gabriella; Radogna, Raffaella; Ranieri, Antonio; Selvaggi, Giovanna; Silvestris, Lucia; Venditti, Rosamaria; Abbiendi, Giovanni; Battilana, Carlo; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Campanini, Renato; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Chhibra, Simranjit Singh; Codispoti, Giuseppe; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Grandi, Claudio; Guiducci, Luigi; Marcellini, Stefano; Masetti, Gianni; Montanari, Alessandro; Navarria, Francesco; Perrotta, Andrea; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gian Piero; Tosi, Nicolò; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Di Mattia, Alessandro; Giordano, Ferdinando; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Gori, Valentina; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Viliani, Lorenzo; Benussi, Luigi; Bianco, Stefano; Fabbri, Franco; Piccolo, Davide; Primavera, Federica; Calvelli, Valerio; Ferro, Fabrizio; Lo Vetere, Maurizio; Monge, Maria Roberta; Robutti, Enrico; Tosi, Silvano; Brianza, Luca; Dinardo, Mauro Emanuele; Fiorendi, Sara; Gennai, Simone; Gerosa, Raffaele; Ghezzi, Alessio; Govoni, Pietro; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Marzocchi, Badder; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Cavallo, Nicola; Di Guida, Salvatore; Esposito, Marco; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lanza, Giuseppe; Lista, Luca; Meola, Sabino; Merola, Mario; Paolucci, Pierluigi; Sciacca, Crisostomo; Thyssen, Filip; Azzi, Patrizia; Bacchetta, Nicola; Benato, Lisa; Bisello, Dario; Boletti, Alessio; Carlin, Roberto; Checchia, Paolo; Dall'Osso, Martino; Dorigo, Tommaso; Dosselli, Umberto; Gasparini, Fabrizio; Gasparini, Ugo; Gozzelino, Andrea; Lacaprara, Stefano; Margoni, Martino; Meneguzzo, Anna Teresa; Montecassiano, Fabio; Passaseo, Marina; Pazzini, Jacopo; Pegoraro, Matteo; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Zanetti, Marco; Zotto, Pierluigi; Zucchetta, Alberto; Zumerle, Gianni; Braghieri, Alessandro; Magnani, Alice; Montagna, Paolo; Ratti, Sergio P; Re, Valerio; Riccardi, Cristina; Salvini, Paola; Vai, Ilaria; Vitulo, Paolo; Alunni Solestizi, Luisa; Bilei, Gian Mario; Ciangottini, Diego; Fanò, Livio; Lariccia, Paolo; Mantovani, Giancarlo; Menichelli, Mauro; Saha, Anirban; Santocchia, Attilio; Androsov, Konstantin; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Castaldi, Rino; Ciocci, Maria Agnese; Dell'Orso, Roberto; Donato, Silvio; Fedi, Giacomo; Foà, Lorenzo; Giassi, Alessandro; Grippo, Maria Teresa; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Palla, Fabrizio; Rizzi, Andrea; Savoy-Navarro, Aurore; Spagnolo, Paolo; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Barone, Luciano; Cavallari, Francesca; D'imperio, Giulia; Del Re, Daniele; Diemoz, Marcella; Gelli, Simone; Jorda, Clara; Longo, Egidio; Margaroli, Fabrizio; Meridiani, Paolo; Organtini, Giovanni; Paramatti, Riccardo; Preiato, Federico; Rahatlou, Shahram; Rovelli, Chiara; Santanastasio, Francesco; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Bellan, Riccardo; Biino, Cristina; Cartiglia, Nicolo; Costa, Marco; Covarelli, Roberto; Degano, Alessandro; Demaria, Natale; Finco, Linda; Kiani, Bilal; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Monteil, Ennio; Obertino, Maria Margherita; Pacher, Luca; Pastrone, Nadia; Pelliccioni, Mario; Pinna Angioni, Gian Luca; Ravera, Fabio; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Solano, Ada; Staiano, Amedeo; Belforte, Stefano; Candelise, Vieri; Casarsa, Massimo; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; La Licata, Chiara; Schizzi, Andrea; Zanetti, Anna; Kropivnitskaya, Anna; Nam, Soon-Kwon; Kim, Dong Hee; Kim, Gui Nyun; Kim, Min Suk; Kong, Dae Jung; Lee, Sangeun; Lee, Seh Wook; Oh, Young Do; Sakharov, Alexandre; Son, Dong-Chul; Brochero Cifuentes, Javier Andres; Kim, Hyunsoo; Kim, Tae Jeong; Song, Sanghyeon; Cho, Sungwoong; Choi, Suyong; Go, Yeonju; Gyun, Dooyeon; Hong, Byung-Sik; Kim, Hyunchul; Kim, Yongsun; Lee, Byounghoon; Lee, Kisoo; Lee, Kyong Sei; Lee, Songkyo; Lim, Jaehoon; Park, Sung Keun; Roh, Youn; Yoo, Hwi Dong; Choi, Minkyoo; Kim, Hyunyong; Kim, Ji Hyun; Lee, Jason Sang Hun; Park, Inkyu; Ryu, Geonmo; Ryu, Min Sang; Choi, Young-Il; Goh, Junghwan; Kim, Donghyun; Kwon, Eunhyang; Lee, Jongseok; Yu, Intae; Dudenas, Vytautas; Juodagalvis, Andrius; Vaitkus, Juozas; Ahmed, Ijaz; Ibrahim, Zainol Abidin; Komaragiri, Jyothsna Rani; Md Ali, Mohd Adli Bin; Mohamad Idris, Faridah; Wan Abdullah, Wan Ahmad Tajuddin; Yusli, Mohd Nizam; Zolkapli, Zukhaimira; Casimiro Linares, Edgar; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-De La Cruz, Ivan; Hernandez-Almada, Alberto; Lopez-Fernandez, Ricardo; Mejia Guisao, Jhovanny; Sánchez Hernández, Alberto; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Pedraza, Isabel; Salazar Ibarguen, Humberto Antonio; Morelos Pineda, Antonio; Krofcheck, David; Butler, Philip H; Ahmad, Ashfaq; Ahmad, Muhammad; Hassan, Qamar; Hoorani, Hafeez R; Khan, Wajid Ali; Khurshid, Taimoor; Shoaib, Muhammad; Waqas, Muhammad; Bialkowska, Helena; Bluj, Michal; Boimska, Bożena; Frueboes, Tomasz; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Traczyk, Piotr; Zalewski, Piotr; Brona, Grzegorz; Bunkowski, Karol; Byszuk, Adrian; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Misiura, Maciej; Olszewski, Michal; Walczak, Marek; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Di Francesco, Agostino; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Hollar, Jonathan; Leonardo, Nuno; Lloret Iglesias, Lara; Nemallapudi, Mythra Varun; Nguyen, Federico; Rodrigues Antunes, Joao; Seixas, Joao; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Vischia, Pietro; Golutvin, Igor; Gorbounov, Nikolai; Gorbunov, Ilya; Karjavin, Vladimir; Kozlov, Guennady; Lanev, Alexander; Malakhov, Alexander; Matveev, Viktor; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Savina, Maria; Shmatov, Sergey; Shulha, Siarhei; Skatchkov, Nikolai; Smirnov, Vitaly; Tikhonenko, Elena; Zarubin, Anatoli; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Kuznetsova, Ekaterina; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Karneyeu, Anton; Kirsanov, Mikhail; Krasnikov, Nikolai; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Gavrilov, Vladimir; Lychkovskaya, Natalia; Popov, Vladimir; Pozdnyakov, Ivan; Safronov, Grigory; Spiridonov, Alexander; Vlasov, Evgueni; Zhokin, Alexander; Chistov, Ruslan; Danilov, Mikhail; Markin, Oleg; Rusinov, Vladimir; Tarkovskii, Evgenii; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Mesyats, Gennady; Rusakov, Sergey V; Baskakov, Alexey; Belyaev, Andrey; Boos, Edouard; Dubinin, Mikhail; Dudko, Lev; Ershov, Alexander; Gribushin, Andrey; Klyukhin, Vyacheslav; Kodolova, Olga; Lokhtin, Igor; Miagkov, Igor; Obraztsov, Stepan; Petrushanko, Sergey; Savrin, Viktor; Snigirev, Alexander; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Kachanov, Vassili; Kalinin, Alexey; Konstantinov, Dmitri; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Cirkovic, Predrag; Devetak, Damir; Milosevic, Jovan; Rekovic, Vladimir; Alcaraz Maestre, Juan; Calvo, Enrique; Cerrada, Marcos; Chamizo Llatas, Maria; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Escalante Del Valle, Alberto; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Navarro De Martino, Eduardo; Pérez-Calero Yzquierdo, Antonio María; Puerta Pelayo, Jesus; Quintario Olmeda, Adrián; Redondo, Ignacio; Romero, Luciano; Senghi Soares, Mara; de Trocóniz, Jorge F; Missiroli, Marino; Moran, Dermot; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Palencia Cortezon, Enrique; Vizan Garcia, Jesus Manuel; Cabrillo, Iban Jose; Calderon, Alicia; Castiñeiras De Saa, Juan Ramon; Curras, Esteban; De Castro Manzano, Pablo; Fernandez, Marcos; Garcia-Ferrero, Juan; Gomez, Gervasio; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Piedra Gomez, Jonatan; Rodrigo, Teresa; Rodríguez-Marrero, Ana Yaiza; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Trevisani, Nicolò; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Bachtis, Michail; Baillon, Paul; Ball, Austin; Barney, David; Benaglia, Andrea; Benhabib, Lamia; Berruti, Gaia Maria; Bloch, Philippe; Bocci, Andrea; Bonato, Alessio; Botta, Cristina; Breuker, Horst; Camporesi, Tiziano; Castello, Roberto; Cepeda, Maria; Cerminara, Gianluca; D'Alfonso, Mariarosaria; D'Enterria, David; Dabrowski, Anne; Daponte, Vincenzo; David Tinoco Mendes, Andre; De Gruttola, Michele; De Guio, Federico; De Roeck, Albert; Di Marco, Emanuele; Dobson, Marc; Dordevic, Milos; Dorney, Brian; Du Pree, Tristan; Duggan, Daniel; Dünser, Marc; Dupont, Niels; Elliott-Peisert, Anna; Franzoni, Giovanni; Fulcher, Jonathan; Funk, Wolfgang; Gigi, Dominique; Gill, Karl; Giordano, Domenico; Girone, Maria; Glege, Frank; Guida, Roberto; Gundacker, Stefan; Guthoff, Moritz; Hammer, Josef; Harris, Philip; Hegeman, Jeroen; Innocente, Vincenzo; Janot, Patrick; Kirschenmann, Henning; Knünz, Valentin; Kortelainen, Matti J; Kousouris, Konstantinos; Lecoq, Paul; Lourenco, Carlos; Lucchini, Marco Toliman; Magini, Nicolo; Malgeri, Luca; Mannelli, Marcello; Martelli, Arabella; Masetti, Lorenzo; Meijers, Frans; Mersi, Stefano; Meschi, Emilio; Moortgat, Filip; Morovic, Srecko; Mulders, Martijn; Neugebauer, Hannes; Orfanelli, Styliani; Orsini, Luciano; Pape, Luc; Perez, Emmanuelle; Peruzzi, Marco; Petrilli, Achille; Petrucciani, Giovanni; Pfeiffer, Andreas; Pierini, Maurizio; Piparo, Danilo; Racz, Attila; Reis, Thomas; Rolandi, Gigi; Rovere, Marco; Ruan, Manqi; Sakulin, Hannes; Schäfer, Christoph; Schwick, Christoph; Seidel, Markus; Sharma, Archana; Silva, Pedro; Simon, Michal; Sphicas, Paraskevas; Steggemann, Jan; Stoye, Markus; Takahashi, Yuta; Treille, Daniel; Triossi, Andrea; Tsirou, Andromachi; Veres, Gabor Istvan; Wardle, Nicholas; Wöhri, Hermine Katharina; Zagoździńska, Agnieszka; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; Kotlinski, Danek; Langenegger, Urs; Rohe, Tilman; Bachmair, Felix; Bäni, Lukas; Bianchini, Lorenzo; Casal, Bruno; Dissertori, Günther; Dittmar, Michael; Donegà, Mauro; Eller, Philipp; Grab, Christoph; Heidegger, Constantin; Hits, Dmitry; Hoss, Jan; Kasieczka, Gregor; Lecomte, Pierre; Lustermann, Werner; Mangano, Boris; Marionneau, Matthieu; Martinez Ruiz del Arbol, Pablo; Masciovecchio, Mario; Meinhard, Maren Tabea; Meister, Daniel; Micheli, Francesco; Musella, Pasquale; Nessi-Tedaldi, Francesca; Pandolfi, Francesco; Pata, Joosep; Pauss, Felicitas; Perrin, Gaël; Perrozzi, Luca; Quittnat, Milena; Rossini, Marco; Schönenberger, Myriam; Starodumov, Andrei; Takahashi, Maiko; Tavolaro, Vittorio Raoul; Theofilatos, Konstantinos; Wallny, Rainer; Aarrestad, Thea Klaeboe; Amsler, Claude; Caminada, Lea; Canelli, Maria Florencia; Chiochia, Vincenzo; De Cosa, Annapaola; Galloni, Camilla; Hinzmann, Andreas; Hreus, Tomas; Kilminster, Benjamin; Lange, Clemens; Ngadiuba, Jennifer; Pinna, Deborah; Rauco, Giorgia; Robmann, Peter; Salerno, Daniel; Yang, Yong; Chen, Kuan-Hsin; Doan, Thi Hien; Jain, Shilpi; Khurana, Raman; Konyushikhin, Maxim; Kuo, Chia-Ming; Lin, Willis; Lu, Yun-Ju; Pozdnyakov, Andrey; Yu, Shin-Shan; Kumar, Arun; Chang, Paoti; Chang, You-Hao; Chang, Yu-Wei; Chao, Yuan; Chen, Kai-Feng; Chen, Po-Hsun; Dietz, Charles; Fiori, Francesco; Grundler, Ulysses; Hou, George Wei-Shu; Hsiung, Yee; Liu, Yueh-Feng; Lu, Rong-Shyang; Miñano Moya, Mercedes; Petrakou, Eleni; Tsai, Jui-fa; Tzeng, Yeng-Ming; Asavapibhop, Burin; Kovitanggoon, Kittikul; Singh, Gurpreet; Srimanobhas, Norraphat; Suwonjandee, Narumon; Adiguzel, Aytul; Bakirci, Mustafa Numan; Cerci, Salim; Damarseckin, Serdal; Demiroglu, Zuhal Seyma; Dozen, Candan; Dumanoglu, Isa; Eskut, Eda; Girgis, Semiray; Gokbulut, Gul; Guler, Yalcin; Gurpinar, Emine; Hos, Ilknur; Kangal, Evrim Ersin; Onengut, Gulsen; Ozdemir, Kadri; Polatoz, Ayse; Sunar Cerci, Deniz; Zorbilmez, Caglar; Bilin, Bugra; Bilmis, Selcuk; Isildak, Bora; Karapinar, Guler; Yalvac, Metin; Zeyrek, Mehmet; Gülmez, Erhan; Kaya, Mithat; Kaya, Ozlem; Yetkin, Elif Asli; Yetkin, Taylan; Cakir, Altan; Cankocak, Kerem; Sen, Sercan; Vardarlı, Fuat Ilkehan; Grynyov, Boris; Levchuk, Leonid; Sorokin, Pavel; Aggleton, Robin; Ball, Fionn; Beck, Lana; Brooke, James John; Burns, Douglas; Clement, Emyr; Cussans, David; Flacher, Henning; Goldstein, Joel; Grimes, Mark; Heath, Greg P; Heath, Helen F; Jacob, Jeson; Kreczko, Lukasz; Lucas, Chris; Meng, Zhaoxia; Newbold, Dave M; Paramesvaran, Sudarshan; Poll, Anthony; Sakuma, Tai; Seif El Nasr-storey, Sarah; Senkin, Sergey; Smith, Dominic; Smith, Vincent J; Bell, Ken W; Belyaev, Alexander; Brew, Christopher; Brown, Robert M; Calligaris, Luigi; Cieri, Davide; Cockerill, David JA; Coughlan, John A; Harder, Kristian; Harper, Sam; Olaiya, Emmanuel; Petyt, David; Shepherd-Themistocleous, Claire; 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Bauerdick, Lothar AT; Beretvas, Andrew; Berryhill, Jeffrey; Bhat, Pushpalatha C; Bolla, Gino; Burkett, Kevin; Butler, Joel Nathan; Cheung, Harry; Chlebana, Frank; Cihangir, Selcuk; Elvira, Victor Daniel; Fisk, Ian; Freeman, Jim; Gottschalk, Erik; Gray, Lindsey; Green, Dan; Grünendahl, Stefan; Gutsche, Oliver; Hanlon, Jim; Hare, Daryl; Harris, Robert M; Hasegawa, Satoshi; Hirschauer, James; Hu, Zhen; Jayatilaka, Bodhitha; Jindariani, Sergo; Johnson, Marvin; Joshi, Umesh; Klima, Boaz; Kreis, Benjamin; Lammel, Stephan; Lewis, Jonathan; Linacre, Jacob; Lincoln, Don; Lipton, Ron; Liu, Tiehui; Lopes De Sá, Rafael; Lykken, Joseph; Maeshima, Kaori; Marraffino, John Michael; Maruyama, Sho; Mason, David; McBride, Patricia; Merkel, Petra; Mrenna, Stephen; Nahn, Steve; Newman-Holmes, Catherine; O'Dell, Vivian; Pedro, Kevin; Prokofyev, Oleg; Rakness, Gregory; Sexton-Kennedy, Elizabeth; Soha, Aron; Spalding, William J; Spiegel, Leonard; Stoynev, Stoyan; Strobbe, Nadja; Taylor, Lucas; Tkaczyk, Slawek; Tran, Nhan Viet; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vernieri, Caterina; Verzocchi, Marco; Vidal, Richard; Wang, Michael; Weber, Hannsjoerg Artur; Whitbeck, Andrew; Acosta, Darin; Avery, Paul; Bortignon, Pierluigi; Bourilkov, Dimitri; Brinkerhoff, Andrew; Carnes, Andrew; Carver, Matthew; Curry, David; Das, Souvik; Field, Richard D; Furic, Ivan-Kresimir; Konigsberg, Jacobo; Korytov, Andrey; Kotov, Khristian; Ma, Peisen; Matchev, Konstantin; Mei, Hualin; Milenovic, Predrag; Mitselmakher, Guenakh; Rank, Douglas; Rossin, Roberto; Shchutska, Lesya; Snowball, Matthew; Sperka, David; Terentyev, Nikolay; Thomas, Laurent; Wang, Jian; Wang, Sean-Jiun; Yelton, John; Linn, Stephan; Markowitz, Pete; Martinez, German; Rodriguez, Jorge Luis; Ackert, Andrew; Adams, Jordon Rowe; Adams, Todd; Askew, Andrew; Bein, Samuel; Bochenek, Joseph; Diamond, Brendan; Haas, Jeff; Hagopian, Sharon; Hagopian, Vasken; Johnson, Kurtis F; Khatiwada, Ajeeta; Prosper, Harrison; Weinberg, Marc; Baarmand, Marc M; Bhopatkar, Vallary; Colafranceschi, Stefano; Hohlmann, Marcus; Kalakhety, Himali; Noonan, Daniel; Roy, Titas; Yumiceva, Francisco; Adams, Mark Raymond; Apanasevich, Leonard; Berry, Douglas; Betts, Russell Richard; Bucinskaite, Inga; Cavanaugh, Richard; Evdokimov, Olga; Gauthier, Lucie; Gerber, Cecilia Elena; Hofman, David Jonathan; Kurt, Pelin; O'Brien, Christine; Sandoval Gonzalez, Irving Daniel; Turner, Paul; Varelas, Nikos; Wu, Zhenbin; Zakaria, Mohammed; Zhang, Jingyu; Bilki, Burak; Clarida, Warren; Dilsiz, Kamuran; Durgut, Süleyman; Gandrajula, Reddy Pratap; Haytmyradov, Maksat; Khristenko, Viktor; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Ogul, Hasan; Onel, Yasar; Ozok, Ferhat; Penzo, Aldo; Snyder, Christina; Tiras, Emrah; Wetzel, James; Yi, Kai; Anderson, Ian; Barnett, Bruce Arnold; Blumenfeld, Barry; Cocoros, Alice; Eminizer, Nicholas; Fehling, David; Feng, Lei; Gritsan, Andrei; Maksimovic, Petar; Osherson, Marc; Roskes, Jeffrey; Sarica, Ulascan; Swartz, Morris; Xiao, Meng; Xin, Yongjie; You, Can; Baringer, Philip; Bean, Alice; Bruner, Christopher; Kenny III, Raymond Patrick; Majumder, Devdatta; Malek, Magdalena; Mcbrayer, William; Murray, Michael; Sanders, Stephen; Stringer, Robert; Wang, Quan; Ivanov, Andrew; Kaadze, Ketino; Khalil, Sadia; Makouski, Mikhail; Maravin, Yurii; Mohammadi, Abdollah; Saini, Lovedeep Kaur; Skhirtladze, Nikoloz; Toda, Sachiko; Lange, David; Rebassoo, Finn; Wright, Douglas; Anelli, Christopher; Baden, Drew; Baron, Owen; Belloni, Alberto; Calvert, Brian; Eno, Sarah Catherine; Ferraioli, Charles; Gomez, Jaime; Hadley, Nicholas John; Jabeen, Shabnam; Kellogg, Richard G; Kolberg, Ted; Kunkle, Joshua; Lu, Ying; Mignerey, Alice; Shin, Young Ho; Skuja, Andris; Tonjes, Marguerite; Tonwar, Suresh C; Apyan, Aram; Barbieri, Richard; Baty, Austin; Bi, Ran; Bierwagen, Katharina; Brandt, Stephanie; Busza, Wit; Cali, Ivan Amos; Demiragli, Zeynep; Di Matteo, Leonardo; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Gulhan, Doga; Iiyama, Yutaro; Innocenti, Gian Michele; Klute, Markus; Kovalskyi, Dmytro; Krajczar, Krisztian; Lai, Yue Shi; Lee, Yen-Jie; Levin, Andrew; Luckey, Paul David; Marini, Andrea Carlo; Mcginn, Christopher; Mironov, Camelia; Narayanan, Siddharth; Niu, Xinmei; Paus, Christoph; Roland, Christof; Roland, Gunther; Salfeld-Nebgen, Jakob; Stephans, George; Sumorok, Konstanty; Tatar, Kaya; Varma, Mukund; Velicanu, Dragos; Veverka, Jan; Wang, Jing; Wang, Ta-Wei; Wyslouch, Bolek; Yang, Mingming; Zhukova, Victoria; Benvenuti, Alberto; Dahmes, Bryan; Evans, Andrew; Finkel, Alexey; Gude, Alexander; Hansen, Peter; Kalafut, Sean; Kao, Shih-Chuan; Klapoetke, Kevin; Kubota, Yuichi; Lesko, Zachary; Mans, Jeremy; Nourbakhsh, Shervin; Ruckstuhl, Nicole; Rusack, Roger; Tambe, Norbert; Turkewitz, Jared; Acosta, John Gabriel; Oliveros, Sandra; Avdeeva, Ekaterina; Bartek, Rachel; Bloom, Kenneth; Bose, Suvadeep; Claes, Daniel R; Dominguez, Aaron; Fangmeier, Caleb; Gonzalez Suarez, Rebeca; Kamalieddin, Rami; Knowlton, Dan; Kravchenko, Ilya; Meier, Frank; Monroy, Jose; Ratnikov, Fedor; Siado, Joaquin Emilo; Snow, Gregory R; Stieger, Benjamin; Alyari, Maral; Dolen, James; George, Jimin; Godshalk, Andrew; Harrington, Charles; Iashvili, Ia; Kaisen, Josh; Kharchilava, Avto; Kumar, Ashish; Rappoccio, Salvatore; Roozbahani, Bahareh; Alverson, George; Barberis, Emanuela; Baumgartel, Darin; Chasco, Matthew; Hortiangtham, Apichart; Massironi, Andrea; Morse, David Michael; Nash, David; Orimoto, Toyoko; Teixeira De Lima, Rafael; Trocino, Daniele; Wang, Ren-Jie; Wood, Darien; Zhang, Jinzhong; Bhattacharya, Saptaparna; Hahn, Kristan Allan; Kubik, Andrew; Low, Jia Fu; Mucia, Nicholas; Odell, Nathaniel; Pollack, Brian; Schmitt, Michael Henry; Sung, Kevin; Trovato, Marco; Velasco, Mayda; Dev, Nabarun; Hildreth, Michael; Jessop, Colin; Karmgard, Daniel John; Kellams, Nathan; Lannon, Kevin; Marinelli, Nancy; Meng, Fanbo; Mueller, Charles; Musienko, Yuri; Planer, Michael; Reinsvold, Allison; Ruchti, Randy; Rupprecht, Nathaniel; 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Adair, Antony; Akgun, Bora; Chen, Zhenyu; Ecklund, Karl Matthew; Geurts, Frank JM; Guilbaud, Maxime; Li, Wei; Michlin, Benjamin; Northup, Michael; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Rorie, Jamal; Tu, Zhoudunming; Zabel, James; Betchart, Burton; Bodek, Arie; de Barbaro, Pawel; Demina, Regina; Eshaq, Yossof; Ferbel, Thomas; Galanti, Mario; Garcia-Bellido, Aran; Han, Jiyeon; Hindrichs, Otto; Khukhunaishvili, Aleko; Lo, Kin Ho; Tan, Ping; Verzetti, Mauro; Chou, John Paul; Contreras-Campana, Emmanuel; Ferencek, Dinko; Gershtein, Yuri; Halkiadakis, Eva; Heindl, Maximilian; Hidas, Dean; Hughes, Elliot; Kaplan, Steven; Kunnawalkam Elayavalli, Raghav; Lath, Amitabh; Nash, Kevin; Saka, Halil; Salur, Sevil; Schnetzer, Steve; Sheffield, David; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Thomassen, Peter; Walker, Matthew; Foerster, Mark; Riley, Grant; Rose, Keith; Spanier, Stefan; Thapa, Krishna; Bouhali, Othmane; Castaneda Hernandez, Alfredo; Celik, Ali; Dalchenko, Mykhailo; De Mattia, Marco; Delgado, Andrea; Dildick, Sven; Eusebi, Ricardo; Gilmore, Jason; Huang, Tao; Kamon, Teruki; Krutelyov, Vyacheslav; Mueller, Ryan; Osipenkov, Ilya; Pakhotin, Yuriy; Patel, Rishi; Perloff, Alexx; Rathjens, Denis; Rose, Anthony; Safonov, Alexei; Tatarinov, Aysen; Ulmer, Keith; Akchurin, Nural; Cowden, Christopher; Damgov, Jordan; Dragoiu, Cosmin; Dudero, Phillip Russell; Faulkner, James; Kunori, Shuichi; Lamichhane, Kamal; Lee, Sung Won; Libeiro, Terence; Undleeb, Sonaina; Volobouev, Igor; Appelt, Eric; Delannoy, Andrés G; Greene, Senta; Gurrola, Alfredo; Janjam, Ravi; Johns, Willard; Maguire, Charles; Mao, Yaxian; Melo, Andrew; Ni, Hong; Sheldon, Paul; Tuo, Shengquan; Velkovska, Julia; Xu, Qiao; Arenton, Michael Wayne; Cox, Bradley; Francis, Brian; Goodell, Joseph; Hirosky, Robert; Ledovskoy, Alexander; Li, Hengne; Neu, Christopher; Sinthuprasith, Tutanon; Sun, Xin; Wang, Yanchu; Wolfe, Evan; Wood, John; Xia, Fan; Clarke, Christopher; Harr, Robert; Karchin, Paul Edmund; Kottachchi Kankanamge Don, Chamath; Lamichhane, Pramod; Sturdy, Jared; Belknap, Donald; Carlsmith, Duncan; Dasu, Sridhara; Dodd, Laura; Duric, Senka; Gomber, Bhawna; Grothe, Monika; Herndon, Matthew; Hervé, Alain; Klabbers, Pamela; Lanaro, Armando; Levine, Aaron; Long, Kenneth; Loveless, Richard; Mohapatra, Ajit; Ojalvo, Isabel; Perry, Thomas; Pierro, Giuseppe Antonio; Polese, Giovanni; Ruggles, Tyler; Sarangi, Tapas; Savin, Alexander; Sharma, Archana; Smith, Nicholas; Smith, Wesley H; Taylor, Devin; Verwilligen, Piet; Woods, Nathaniel

    2016-12-19

    A search for dark matter particles directly produced in proton-proton collisions recorded by the CMS experiment at the LHC is presented. The data correspond to an integrated luminosity of 18.8 inverse femtobarns, at a center-of-mass energy of 8 TeV. The event selection requires at least two jets and no isolated leptons. The razor variables are used to quantify the transverse momentum balance in the jet momenta. The study is performed separately for events with and without jets originating from b quarks. The observed yields are consistent with the expected backgrounds and, depending on the nature of the production mechanism, dark matter production at the LHC is excluded at 90% confidence level for a mediator mass scale Lambda below 1 TeV. The use of razor variables yields results that complement those previously published.

  17. Search for dark