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...

Composite dark matter from a model with composite Higgs boson

DEFF Research Database (Denmark)

Yu. Khlopov, Maxim; Kouvaris, Christoforos

2008-01-01

In a previous paper \\cite{Khlopov:2007ic}, we showed how the minimal walking technicolor model (WTC) can provide a composite dark matter candidate, by forming bound states between a -2 electrically charged techniparticle and a $^4He^{++}$. We studied the properties of these \\emph......{techni-O-helium} $tOHe$ "atoms", which behave as warmer dark matter rather than cold. In this paper we extend our work on several different aspects. We study the possibility of a mixed scenario where both $tOHe$ and bound states between +2 and -2 electrically charged techniparticles coexist in the dark matter density....... We argue that these newly proposed bound states solely made of techniparticles, although they behave as Weakly Interacting Massive Particles (WIMPs), due to their large elastic cross section with nuclei, can only account for a small percentage of the dark matter density. Therefore we conclude...

Gravity-mediated (or Composite) Dark Matter Confronts Astrophysical Data

CERN Document Server

Lee, Hyun Min; Sanz, Veronica

2014-01-01

We consider the astrophysical bounds on a new form of dark matter, the so called Gravity-mediated Dark Matter. In this scenario, dark matter communicates with us through a mediator sector composed of gravitational resonances, namely a new scalar (radion) and a massive spin-two resonance (massive graviton). We consider specific models motivated by natural electroweak symmetry breaking or weak-scale dark matter in the context of models in warped extra-dimensions and their composite duals. The main Dark Matter annihilation mechanism is due to the interactions of KK gravitons to gauge bosons that propagate in bulk. We impose the bounds on monochromatic or continuum photons from Fermi-LAT and HESS. We also explore scenarios in which the Fermi gamma-ray line could be a manifestation of Gravity-mediated Dark Matter.

Dark and composite rogue waves in the coupled Hirota equations

International Nuclear Information System (INIS)

Chen, Shihua

2014-01-01

The intriguing dark and composite rogue wave dynamics in a coupled Hirota system are unveiled, based on the exact explicit rational solutions obtained under the assumption of equal background height. It is found that a dark rogue wave state would occur as a result of the strong coupling between two field components with large wavenumber difference, and there would appear plenty of composite structures that are attributed to the specific wavenumber difference and the free choice of three independent structural parameters. The coexistence of different fundamental rogue waves in such a coupled system is also demonstrated. - Highlights: • Exact rational rogue wave solutions under different parameter conditions are presented for the coupled Hirota equations. • The basic rogue wave features and hence the intriguing dark structures are unveiled. • We attributed the diversity of composite rogue wave dynamics to the free choice of three independent structural parameters. • The remarkable coexisting rogue wave behaviors in such a coupled system are demonstrated

A Model of Composite \\textit{B}\\,--\\,\\textit{L} Asymmetric Dark Matter

OpenAIRE

Ibe, Masahiro; Kamada, Ayuki; Kobayashi, Shin; Nakano, Wakutaka

2018-01-01

As the $B-L$ gauge symmetry is the most plausible addition among the various extensions of the Standard Model, it is attractive to identify symmetry which stabilizes dark matter with the $B-L$ gauge symmetry. Besides, dark matter which is stabilized by $B-L$ naturally leads to asymmetric dark matter. In this paper, we construct a model of composite asymmetric dark matter in a bottom-up approach. By assuming that the entropy of the dark sector is released to the Standard Model sector through a...

The Profile of Inelastic Collisions from Elastic Scattering Data

Directory of Open Access Journals (Sweden)

I. M. Dremin

2015-01-01

Full Text Available Using the unitarity relation in combination with experimental data about the elastic scattering in the diffraction cone, it is shown how the shape and the darkness of the inelastic interaction region of colliding protons change with increase of their energies. In particular, the collisions become fully absorptive at small impact parameters at LHC energies that results in some special features of inelastic processes. Possible evolution of this shape with the dark core at the LHC to the fully transparent one at higher energies is discussed that implies that the terminology of the black disk would be replaced by the black toroid. The approach to asymptotics is disputed. The ratio of the real to imaginary parts of the nonforward elastic scattering amplitude is briefly discussed. All the conclusions are only obtained in the framework of the indubitable unitarity condition using experimental data about the elastic scattering of protons in the diffraction cone without any reference to quantum chromodynamics (QCD or phenomenological approaches.

Composition-Dependent Energy Splitting between Bright and Dark Excitons in Lead Halide Perovskite Nanocrystals.

Science.gov (United States)

Chen, Lan; Li, Bin; Zhang, Chunfeng; Huang, Xinyu; Wang, Xiaoyong; Xiao, Min

2018-03-14

Perovskite semiconductor nanocrystals with different compositions have shown promise for applications in light-emitting devices. Dark excitonic states may suppress light emission from such nanocrystals by providing an additional nonradiative recombination channel. Here, we study the composition dependence of dark exciton dynamics in nanocrystals of lead halides by time-resolved photoluminescence spectroscopy at cryogenic temperatures. The presence of a spin-related dark state is revealed by magneto-optical spectroscopy. The energy splitting between bright and dark states is found to be highly sensitive to both halide elements and organic cations, which is explained by considering the effects of size confinement and charge screening, respectively, on the exchange interaction. These findings suggest the possibility of manipulating dark exciton dynamics in perovskite semiconductor nanocrystals by composition engineering, which will be instrumental in the design of highly efficient light-emitting devices.

Inelastic damage using continuum damage mechanics in composite plate reinforced by unidirectional fibers

Directory of Open Access Journals (Sweden)

Žmindák Milan

2018-01-01

Full Text Available It is well that a finite element method is very popular simulation method to predict the physical behavior of systems and structures. In the last years an increase of interest in a new type of numerical methods known as meshless methods was observed. The paper deals with application of radial basis functions on modelling of inelastic damage using continuum damage mechanics of layered plate composite structures reinforced with long unidirectional fibers. For numerical simulations of elastic-plastic damage of layered composite plates own computational programs were implemented in MATLAB programming language. We will use the Newton-Raphson method to solve nonlinear systems of equations. Evaluation damage during plasticity has been solved using return mapping algorithm. The results of elastic-plastic damage analysis of composite plate with unsymmetrical laminate stacking sequence are presented.

Unified scenario for composite right-handed neutrinos and dark matter

Science.gov (United States)

Davoudiasl, Hooman; Giardino, Pier Paolo; Neil, Ethan T.; Rinaldi, Enrico

2017-12-01

We entertain the possibility that neutrino masses and dark matter (DM) originate from a common composite dark sector. A minimal effective theory can be constructed based on a dark S U (3 )D interaction with three flavors of massless dark quarks; electroweak symmetry breaking gives masses to the dark quarks. By assigning a Z2 charge to one flavor, a stable "dark kaon" can provide a good thermal relic DM candidate. We find that "dark neutrons" may be identified as right handed Dirac neutrinos. Some level of "neutron-anti-neutron" oscillation in the dark sector can then result in non-zero Majorana masses for light standard model neutrinos. A simple ultraviolet completion is presented, involving additional heavy S U (3 )D-charged particles with electroweak and lepton Yukawa couplings. At our benchmark point, there are "dark pions" that are much lighter than the Higgs and we expect spectacular collider signals arising from the UV framework. This includes the decay of the Higgs boson to τ τ ℓℓ', where ℓ(ℓ') can be any lepton, with displaced vertices. We discuss the observational signatures of this UV framework in dark matter searches and primordial gravitational wave experiments; the latter signature is potentially correlated with the H →τ τ ℓℓ' decay.

Chasing a consistent picture for dark matter direct detection searches

NARCIS (Netherlands)

Arina, C.

2012-01-01

In this paper we assess the present status of dark matter direct searches by means of Bayesian statistics. We consider three particle physics models for spin-independent dark matter interaction with nuclei: elastic, inelastic and isospin violating scattering. We briefly present the state of the art

Exothermic dark matter

International Nuclear Information System (INIS)

Graham, Peter W.; Saraswat, Prashant; Harnik, Roni; Rajendran, Surjeet

2010-01-01

We propose a novel mechanism for dark matter to explain the observed annual modulation signal at DAMA/LIBRA which avoids existing constraints from every other dark matter direct detection experiment including CRESST, CDMS, and XENON10. The dark matter consists of at least two light states with mass ∼few GeV and splittings ∼5 keV. It is natural for the heavier states to be cosmologically long-lived and to make up an O(1) fraction of the dark matter. Direct detection rates are dominated by the exothermic reactions in which an excited dark matter state downscatters off of a nucleus, becoming a lower energy state. In contrast to (endothermic) inelastic dark matter, the most sensitive experiments for exothermic dark matter are those with light nuclei and low threshold energies. Interestingly, this model can also naturally account for the observed low-energy events at CoGeNT. The only significant constraint on the model arises from the DAMA/LIBRA unmodulated spectrum but it can be tested in the near future by a low-threshold analysis of CDMS-Si and possibly other experiments including CRESST, COUPP, and XENON100.

Composite Goldstone Dark Matter: Experimental Predictions from the Lattice

DEFF Research Database (Denmark)

Hietanen, Ari; Lewis, Randy; Pica, Claudio

2014-01-01

We study, via first principles lattice simulations, the nonperturbative dynamics of SU(2) gauge theory with two fundamental Dirac flavors. The model can be used simultaneously as a template for composite Goldstone boson dark matter and for breaking the electroweak symmetry dynamically. We compute...... the form factor, allowing us to estimate the associated electromagnetic charge radius. Surprisingly we observe that the form factor obeys vector meson dominance even for the two color theory. We finally compare the model predictions with dark matter direct detection experiments. Our results...

Baryon destruction by asymmetric dark matter

International Nuclear Information System (INIS)

Davoudiasl, Hooman; Morrissey, David E.; Tulin, Sean; Sigurdson, Kris

2011-01-01

We investigate new and unusual signals that arise in theories where dark matter is asymmetric and carries a net antibaryon number, as may occur when the dark matter abundance is linked to the baryon abundance. Antibaryonic dark matter can cause induced nucleon decay by annihilating visible baryons through inelastic scattering. These processes lead to an effective nucleon lifetime of 10 29 -10 32 yrs in terrestrial nucleon decay experiments, if baryon number transfer between visible and dark sectors arises through new physics at the weak scale. The possibility of induced nucleon decay motivates a novel approach for direct detection of cosmic dark matter in nucleon decay experiments. Monojet searches (and related signatures) at hadron colliders also provide a complementary probe of weak-scale dark-matter-induced baryon number violation. Finally, we discuss the effects of baryon-destroying dark matter on stellar systems and show that it can be consistent with existing observations.

Probing Sub-GeV Dark Matter with Conventional Detectors

DEFF Research Database (Denmark)

Kouvaris, Chris; Pradler, Josef

2017-01-01

The direct detection of dark matter particles with mass below the GeV scale is hampered by soft nuclear recoil energies and finite detector thresholds. For a given maximum relative velocity, the kinematics of elastic dark matter nucleus scattering sets a principal limit on detectability. Here, we...... propose to bypass the kinematic limitations by considering the inelastic channel of photon emission from bremsstrahlung in the nuclear recoil. Our proposed method allows us to set the first limits on dark matter below 500 MeV in the plane of dark matter mass and cross section with nucleons. In situations...... where a dark-matter-electron coupling is suppressed, bremsstrahlung may constitute the only path to probe low-mass dark matter awaiting new detector technologies with lowered recoil energy thresholds....

Bound-state formation for thermal relic dark matter and unitarity

International Nuclear Information System (INIS)

Harling, Benedict von; Petraki, Kalliopi

2014-01-01

We show that the relic abundance of thermal dark matter annihilating via a long-range interaction, is significantly affected by the formation and decay of dark matter bound states in the early universe, if the dark matter mass is above a few TeV . We determine the coupling required to obtain the observed dark matter density, taking into account both the direct 2-to-2 annihilations and the formation of bound states, and provide an analytical fit. We argue that the unitarity limit on the inelastic cross-section is realized only if dark matter annihilates via a long-range interaction, and we determine the upper bound on the mass of thermal-relic dark matter to be about 197 (139) TeV for (non)-self-conjugate dark matter

Probing Sub-GeV Dark Matter with Conventional Detectors.

Science.gov (United States)

Kouvaris, Chris; Pradler, Josef

2017-01-20

The direct detection of dark matter particles with mass below the GeV scale is hampered by soft nuclear recoil energies and finite detector thresholds. For a given maximum relative velocity, the kinematics of elastic dark matter nucleus scattering sets a principal limit on detectability. Here, we propose to bypass the kinematic limitations by considering the inelastic channel of photon emission from bremsstrahlung in the nuclear recoil. Our proposed method allows us to set the first limits on dark matter below 500 MeV in the plane of dark matter mass and cross section with nucleons. In situations where a dark-matter-electron coupling is suppressed, bremsstrahlung may constitute the only path to probe low-mass dark matter awaiting new detector technologies with lowered recoil energy thresholds.

Asymmetric thermal-relic dark matter. Sommerfeld-enhanced freeze-out, annihilation signals and unitarity bounds

International Nuclear Information System (INIS)

Baldes, Iason; Petraki, Kalliopi

2017-03-01

Dark matter that possesses a particle-antiparticle asymmetry and has thermalised in the early universe, requires a larger annihilation cross-section compared to symmetric dark matter, in order to deplete the dark antiparticles and account for the observed dark matter density. The annihilation cross-section determines the residual symmetric component of dark matter, which may give rise to annihilation signals during CMB and inside haloes today. We consider dark matter with long-range interactions, in particular dark matter coupled to a light vector or scalar force mediator. We compute the couplings required to attain a final antiparticle-to-particle ratio after the thermal freeze-out of the annihilation processes in the early universe, and then estimate the late-time annihilation signals. We show that, due to the Sommerfeld enhancement, highly asymmetric dark matter with long-range interactions can have a significant annihilation rate, potentially larger than symmetric dark matter of the same mass with contact interactions. We discuss caveats in this estimation, relating to the formation of stable bound states. Finally, we consider the non-relativistic partial-wave unitarity bound on the inelastic cross-section, we discuss why it can be realised only by long-range interactions, and showcase the importance of higher partial waves in this regime of large inelasticity. We derive upper bounds on the mass of symmetric and asymmetric thermal-relic dark matter for s-wave and p-wave annihilation, and exhibit how these bounds strengthen as the dark asymmetry increases.

Asymmetric thermal-relic dark matter: Sommerfeld-enhanced freeze-out, annihilation signals and unitarity bounds

Energy Technology Data Exchange (ETDEWEB)

Baldes, Iason [DESY, Notkestraße 85, Hamburg, D-22607 Germany (Germany); Petraki, Kalliopi, E-mail: iason.baldes@desy.de, E-mail: kpetraki@lpthe.jussieu.fr [Laboratoire de Physique Théorique et Hautes Energies (LPTHE), UMR 7589 CNRS and UPMC, 4 Place Jussieu, Paris, F-75252 France (France)

2017-09-01

Dark matter that possesses a particle-antiparticle asymmetry and has thermalised in the early universe, requires a larger annihilation cross-section compared to symmetric dark matter, in order to deplete the dark antiparticles and account for the observed dark matter density. The annihilation cross-section determines the residual symmetric component of dark matter, which may give rise to annihilation signals during CMB and inside haloes today. We consider dark matter with long-range interactions, in particular dark matter coupled to a light vector or scalar force mediator. We compute the couplings required to attain a final antiparticle-to-particle ratio after the thermal freeze-out of the annihilation processes in the early universe, and then estimate the late-time annihilation signals. We show that, due to the Sommerfeld enhancement, highly asymmetric dark matter with long-range interactions can have a significant annihilation rate, potentially larger than symmetric dark matter of the same mass with contact interactions. We discuss caveats in this estimation, relating to the formation of stable bound states. Finally, we consider the non-relativistic partial-wave unitarity bound on the inelastic cross-section, we discuss why it can be realised only by long-range interactions, and showcase the importance of higher partial waves in this regime of large inelasticity. We derive upper bounds on the mass of symmetric and asymmetric thermal-relic dark matter for s -wave and p -wave annihilation, and exhibit how these bounds strengthen as the dark asymmetry increases.

Asymmetric thermal-relic dark matter. Sommerfeld-enhanced freeze-out, annihilation signals and unitarity bounds

Energy Technology Data Exchange (ETDEWEB)

Baldes, Iason [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Petraki, Kalliopi [Nationaal Instuut voor Kernfysica en Hoge-Energiefysica (NIKHEF), Amsterdam (Netherlands); UMR 7589 CNRS et UPMC, Paris (France). Laboratoire de Physique Theorique et Hautes Energies (LPTHE)

2017-03-15

Dark matter that possesses a particle-antiparticle asymmetry and has thermalised in the early universe, requires a larger annihilation cross-section compared to symmetric dark matter, in order to deplete the dark antiparticles and account for the observed dark matter density. The annihilation cross-section determines the residual symmetric component of dark matter, which may give rise to annihilation signals during CMB and inside haloes today. We consider dark matter with long-range interactions, in particular dark matter coupled to a light vector or scalar force mediator. We compute the couplings required to attain a final antiparticle-to-particle ratio after the thermal freeze-out of the annihilation processes in the early universe, and then estimate the late-time annihilation signals. We show that, due to the Sommerfeld enhancement, highly asymmetric dark matter with long-range interactions can have a significant annihilation rate, potentially larger than symmetric dark matter of the same mass with contact interactions. We discuss caveats in this estimation, relating to the formation of stable bound states. Finally, we consider the non-relativistic partial-wave unitarity bound on the inelastic cross-section, we discuss why it can be realised only by long-range interactions, and showcase the importance of higher partial waves in this regime of large inelasticity. We derive upper bounds on the mass of symmetric and asymmetric thermal-relic dark matter for s-wave and p-wave annihilation, and exhibit how these bounds strengthen as the dark asymmetry increases.

Asymmetric thermal-relic dark matter: Sommerfeld-enhanced freeze-out, annihilation signals and unitarity bounds

International Nuclear Information System (INIS)

Baldes, Iason; Petraki, Kalliopi

2017-01-01

Dark matter that possesses a particle-antiparticle asymmetry and has thermalised in the early universe, requires a larger annihilation cross-section compared to symmetric dark matter, in order to deplete the dark antiparticles and account for the observed dark matter density. The annihilation cross-section determines the residual symmetric component of dark matter, which may give rise to annihilation signals during CMB and inside haloes today. We consider dark matter with long-range interactions, in particular dark matter coupled to a light vector or scalar force mediator. We compute the couplings required to attain a final antiparticle-to-particle ratio after the thermal freeze-out of the annihilation processes in the early universe, and then estimate the late-time annihilation signals. We show that, due to the Sommerfeld enhancement, highly asymmetric dark matter with long-range interactions can have a significant annihilation rate, potentially larger than symmetric dark matter of the same mass with contact interactions. We discuss caveats in this estimation, relating to the formation of stable bound states. Finally, we consider the non-relativistic partial-wave unitarity bound on the inelastic cross-section, we discuss why it can be realised only by long-range interactions, and showcase the importance of higher partial waves in this regime of large inelasticity. We derive upper bounds on the mass of symmetric and asymmetric thermal-relic dark matter for s -wave and p -wave annihilation, and exhibit how these bounds strengthen as the dark asymmetry increases.

From direct detection to relic abundance: the case of proton-philic spin-dependent inelastic Dark Matter

Energy Technology Data Exchange (ETDEWEB)

Scopel, Stefano; Yu, Hyeonhye, E-mail: scopel@sogang.ac.kr, E-mail: skyh2yu@gmail.com [Department of Physics, Sogang University, Seoul (Korea, Republic of)

2017-04-01

We discuss strategies to make inferences on the thermal relic abundance of a Weakly Interacting Massive Particle (WIMP) when the same effective dimension-six operator that explains an experimental excess in direct detection is assumed to drive decoupling at freeze-out, and apply them to the explicit scenario of WIMP inelastic up-scattering with spin-dependent couplings to protons (proton-philic Spin-dependent Inelastic Dark Matter, pSIDM), a phenomenological set-up containing two Dark Matter (DM) particles χ{sub 1} and χ{sub 2} with masses m {sub χ}= m {sub χ{sub 1}} and m {sub χ{sub 2}}= m {sub χ}+δ that we have shown in a previous paper to explain the DAMA effect in compliance with the constraints from other detectors. We also update experimental constraints on pSIDM, extend the analysis to the most general spin-dependent momentum-dependent interactions allowed by non-relativistic Effective Field Theory (EFT), and consider for the WIMP velocity distribution in our Galaxy f ( v ) both a halo-independent approach and a standard Maxwellian. Under these conditions we find that the DAMA effect can be explained in terms of the particle χ{sub 1} in compliance with all the other constraints for all the analyzed EFT couplings and also for a Maxwellian f ( v ). As far as the relic abundance is concerned, we show that the problem of calculating it by using direct detection data to fix the model parameters is affected by a strong sensitivity on f ( v ) and by the degeneracy between the WIMP local density ρ{sub χ} and the WIMP-nucleon scattering cross section, since ρ{sub χ} must be rescaled with respect to the observed DM density in the neighborhood of the Sun when the calculated relic density Ω is smaller than the observed one Ω{sub 0}. As a consequence, a DM direct detection experiment is not directly sensitive to the physical cut-off scale of the EFT, but on some dimensional combination that does not depend on the actual value of Ω. However, such degeneracy

Dark Kinetic Heating of Neutron Stars and an Infrared Window on WIMPs, SIMPs, and Pure Higgsinos.

Science.gov (United States)

Baryakhtar, Masha; Bramante, Joseph; Li, Shirley Weishi; Linden, Tim; Raj, Nirmal

2017-09-29

We identify a largely model-independent signature of dark matter (DM) interactions with nucleons and electrons. DM in the local galactic halo, gravitationally accelerated to over half the speed of light, scatters against and deposits kinetic energy into neutron stars, heating them to infrared blackbody temperatures. The resulting radiation could potentially be detected by the James Webb Space Telescope, the Thirty Meter Telescope, or the European Extremely Large Telescope. This mechanism also produces optical emission from neutron stars in the galactic bulge, and x-ray emission near the galactic center because dark matter is denser in these regions. For GeV-PeV mass dark matter, dark kinetic heating would initially unmask any spin-independent or spin-dependent dark matter-nucleon cross sections exceeding 2×10^{-45}  cm^{2}, with improved sensitivity after more telescope exposure. For lighter-than-GeV dark matter, cross-section sensitivity scales inversely with dark matter mass because of Pauli blocking; for heavier-than-PeV dark matter, it scales linearly with mass as a result of needing multiple scatters for capture. Future observations of dark sector-warmed neutron stars could determine whether dark matter annihilates in or only kinetically heats neutron stars. Because inelastic interstate transitions of up to a few GeV would occur in relativistic scattering against nucleons, elusive inelastic dark matter like pure Higgsinos can also be discovered.

Revisiting big-bang nucleosynthesis constraints on dark-matter annihilation

Energy Technology Data Exchange (ETDEWEB)

Kawasaki, Masahiro [Institute for Cosmic Ray Research, The University of Tokyo, Kashiwa 277-8582 (Japan); Kavli IPMU (WPI), UTIAS, The University of Tokyo, Kashiwa 277-8583 (Japan); Kohri, Kazunori [Theory Center, IPNS, KEK, Tsukuba 305-0801 (Japan); Sokendai, Tsukuba 305-0801 (Japan); Moroi, Takeo [Kavli IPMU (WPI), UTIAS, The University of Tokyo, Kashiwa 277-8583 (Japan); Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Takaesu, Yoshitaro, E-mail: takaesu@hep-th.phys.s.u-tokyo.ac.jp [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan)

2015-12-17

We study the effects of dark-matter annihilation during the epoch of big-bang nucleosynthesis on the primordial abundances of light elements. We improve the calculation of the light-element abundances by taking into account the effects of anti-nucleons emitted by the annihilation of dark matter and the interconversion reactions of neutron and proton at inelastic scatterings of energetic nucleons. Comparing the theoretical prediction of the primordial light-element abundances with the latest observational constraints, we derive upper bounds on the dark-matter pair-annihilation cross section. Implication to some of particle-physics models are also discussed.

Revisiting big-bang nucleosynthesis constraints on dark-matter annihilation

Directory of Open Access Journals (Sweden)

Masahiro Kawasaki

2015-12-01

Full Text Available We study the effects of dark-matter annihilation during the epoch of big-bang nucleosynthesis on the primordial abundances of light elements. We improve the calculation of the light-element abundances by taking into account the effects of anti-nucleons emitted by the annihilation of dark matter and the interconversion reactions of neutron and proton at inelastic scatterings of energetic nucleons. Comparing the theoretical prediction of the primordial light-element abundances with the latest observational constraints, we derive upper bounds on the dark-matter pair-annihilation cross section. Implication to some of particle-physics models are also discussed.

Inverted dipole feature in directional detection of exothermic dark matter

International Nuclear Information System (INIS)

Bozorgnia, Nassim; Gelmini, Graciela B.; Gondolo, Paolo

2017-01-01

Directional dark matter detection attempts to measure the direction of motion of nuclei recoiling after having interacted with dark matter particles in the halo of our Galaxy. Due to Earth's motion with respect to the Galaxy, the dark matter flux is concentrated around a preferential direction. An anisotropy in the recoil direction rate is expected as an unmistakable signature of dark matter. The average nuclear recoil direction is expected to coincide with the average direction of dark matter particles arriving to Earth. Here we point out that for a particular type of dark matter, inelastic exothermic dark matter, the mean recoil direction as well as a secondary feature, a ring of maximum recoil rate around the mean recoil direction, could instead be opposite to the average dark matter arrival direction. Thus, the detection of an average nuclear recoil direction opposite to the usually expected direction would constitute a spectacular experimental confirmation of this type of dark matter.

The search for dark matter in xenon: Innovative calibration strategies and novel search channels

Science.gov (United States)

Reichard, Shayne Edward

The direct detection dark matter experiment XENON1T became operational in early 2016, heralding the era of tonne-scale dark matter detectors. Direct detection experiments typically search for elastic scatters of dark matter particles off target nuclei. XENON1T's larger xenon target provides the advantage of stronger dark matter signals and lower background rates compared to its predecessors, XENON10 and XENON100; but, at the same time, calibration of the detector's response to backgrounds with traditional external sources becomes exceedingly more difficult. A 220Rn source is deployed on the XENON100 dark matter detector in order to address the challenges in calibration of tonne-scale liquid noble element detectors. I show that the subsequent 212Pb beta emission can be used for low-energy electronic recoil calibration in searches for dark matter. The isotope spreads throughout the entire active region of the detector, and its activity naturally decays below background level within a week after the source is closed. I find no increase in the activity of the troublesome 222Rn background after calibration. Alpha emitters are also distributed throughout the detector and facilitate calibration of its response to 222Rn. Using the delayed coincidence of 220Rn/216Po, I map for the first time the convective motion of particles in the XENON100 detector. Additionally, I make a competitive measurement of the half-life of 212Po, t1/2=293.9+/-(1.0)stat+/-(0.6)ns. In contrast to the elastic scattering of dark matter particles off nuclei, I explore inelastic scattering where the nucleus is excited to a low-lying state of 10-100 keV, with a subsequent prompt de-excitation. I use the inelastic structure factors for the odd-mass xenon isotopes based on state-of-the-art large-scale shell-model calculations with chiral effective field theory WIMP-nucleon currents, finding that the inelastic channel is comparable to or can dominate the elastic channel for momentum transfers around 150 Me

Unified Origin for Baryonic Visible Matter and Antibaryonic Dark Matter

International Nuclear Information System (INIS)

Davoudiasl, Hooman; Morrissey, David E.; Tulin, Sean; Sigurdson, Kris

2010-01-01

We present a novel mechanism for generating both the baryon and dark matter densities of the Universe. A new Dirac fermion X carrying a conserved baryon number charge couples to the standard model quarks as well as a GeV-scale hidden sector. CP-violating decays of X, produced nonthermally in low-temperature reheating, sequester antibaryon number in the hidden sector, thereby leaving a baryon excess in the visible sector. The antibaryonic hidden states are stable dark matter. A spectacular signature of this mechanism is the baryon-destroying inelastic scattering of dark matter that can annihilate baryons at appreciable rates relevant for nucleon decay searches.

Unified origin for baryonic visible matter and antibaryonic dark matter.

Science.gov (United States)

Davoudiasl, Hooman; Morrissey, David E; Sigurdson, Kris; Tulin, Sean

2010-11-19

We present a novel mechanism for generating both the baryon and dark matter densities of the Universe. A new Dirac fermion X carrying a conserved baryon number charge couples to the standard model quarks as well as a GeV-scale hidden sector. CP-violating decays of X, produced nonthermally in low-temperature reheating, sequester antibaryon number in the hidden sector, thereby leaving a baryon excess in the visible sector. The antibaryonic hidden states are stable dark matter. A spectacular signature of this mechanism is the baryon-destroying inelastic scattering of dark matter that can annihilate baryons at appreciable rates relevant for nucleon decay searches.

Probes for dark matter physics

Science.gov (United States)

Khlopov, Maxim Yu.

The existence of cosmological dark matter is in the bedrock of the modern cosmology. The dark matter is assumed to be nonbaryonic and consists of new stable particles. Weakly Interacting Massive Particle (WIMP) miracle appeals to search for neutral stable weakly interacting particles in underground experiments by their nuclear recoil and at colliders by missing energy and momentum, which they carry out. However, the lack of WIMP effects in their direct underground searches and at colliders can appeal to other forms of dark matter candidates. These candidates may be weakly interacting slim particles, superweakly interacting particles, or composite dark matter, in which new particles are bound. Their existence should lead to cosmological effects that can find probes in the astrophysical data. However, if composite dark matter contains stable electrically charged leptons and quarks bound by ordinary Coulomb interaction in elusive dark atoms, these charged constituents of dark atoms can be the subject of direct experimental test at the colliders. The models, predicting stable particles with charge ‑ 2 without stable particles with charges + 1 and ‑ 1 can avoid severe constraints on anomalous isotopes of light elements and provide solution for the puzzles of dark matter searches. In such models, the excessive ‑ 2 charged particles are bound with primordial helium in O-helium atoms, maintaining specific nuclear-interacting form of the dark matter. The successful development of composite dark matter scenarios appeals for experimental search for doubly charged constituents of dark atoms, making experimental search for exotic stable double charged particles experimentum crucis for dark atoms of composite dark matter.

Exposing Dark Sector with Future Z-Factories arXiv

CERN Document Server

Liu, Jia; Wang, Xiao-Ping; Xue, Wei

We investigate the prospects of searching dark sector models via exotic Z-boson decay at future $e^+ e^-$ colliders with Giga Z and Tera Z options. Four general categories of dark sector models: Higgs portal dark matter, vector portal dark matter, inelastic dark matter and axion-like particles, are considered. Focusing on channels motivated by the dark sector models, we carry out a model independent study of the sensitivities of Z-factories in probing exotic decays. The limits on branching ratios of the exotic Z decay are typically $\\mathcal{O} (10^{-6} - 10^{-8.5}) $ for the Giga Z and $\\mathcal{O} (10^{-7.5} - 10^{-11})$ for the Tera Z, and they are compared with the projection for the high luminosity LHC. We demonstrate that future Z-factories can provide its unique and leading sensitivity, and highlight the complementarity with other experiments, including the indirect and direct dark matter search limits, and the existing collider limits. Future Z factories will play a leading role to uncover the hidden ...

Charged composite scalar dark matter

Science.gov (United States)

Balkin, Reuven; Ruhdorfer, Maximilian; Salvioni, Ennio; Weiler, Andreas

2017-11-01

We consider a composite model where both the Higgs and a complex scalar χ, which is the dark matter (DM) candidate, arise as light pseudo Nambu-Goldstone bosons (pNGBs) from a strongly coupled sector with TeV scale confinement. The global symmetry structure is SO(7)/SO(6), and the DM is charged under an exact U(1)DM ⊂ SO(6) that ensures its stability. Depending on whether the χ shift symmetry is respected or broken by the coupling of the top quark to the strong sector, the DM can be much lighter than the Higgs or have a weak-scale mass. Here we focus primarily on the latter possibility. We introduce the lowest-lying composite resonances and impose calculability of the scalar potential via generalized Weinberg sum rules. Compared to previous analyses of pNGB DM, the computation of the relic density is improved by fully accounting for the effects of the fermionic top partners. This plays a crucial role in relaxing the tension with the current DM direct detection constraints. The spectrum of resonances contains exotic top partners charged under the U(1)DM, whose LHC phenomenology is analyzed. We identify a region of parameters with f = 1.4 TeV and 200 GeV ≲ m χ ≲ 400 GeV that satisfies all existing bounds. This DM candidate will be tested by XENON1T in the near future.

Higgsino dark matter in high-scale supersymmetry

International Nuclear Information System (INIS)

Nagata, Natsumi

2014-11-01

We study a supersymmetric (SUSY) Standard Model in which a Higgsino is light enough to be dark matter, while the other SUSY particles are much heavier than the weak scale. We carefully treat the effects of heavy SUSY particles to the Higgsino nature, especially taking into account the renormalization effects due to the large hierarchy between the Higgsino and the SUSY breaking scales. Inelastic scattering of the Higgsino dark matter with a nucleus is studied, and the constraints on the scattering by the direct detection experiments are discussed. This gives an upper limit on the new physics scale. Bounds on the dark matter-nucleon elastic scattering, the electric dipole moments, and direct production of Higgsinos, on the other hand, give a lower limit. We show the current status on the limits and discuss the future prospects.

Consequences of inelastic discrete-level neutron-collision mechanics for inelastic continuum scattering

Energy Technology Data Exchange (ETDEWEB)

Hoogenboom, J.E. (Technische Hogeschool Delft (Netherlands))

1983-01-01

From the collision mechanics of inelastic discrete-level scattering several properties are derived for the secondary-neutron energy distribution (SNED) for inelastic continuum scattering, when conceived as scattering with continuously-distributed inelastic levels. Using assumptions about the level density and neutron cross section the SNED can be calculated and some examples are shown. A formula is derived to calculate from a given inelastic continuum SNED a function, which is proportional to the level density and the neutron cross section. From this relation further conditions follow for the SNED. Representations for the inelastic continuum SNED currently in use do not, in general, satisfy most of the derived conditions.

Consequences of inelastic discrete-level neutron-collision mechanics for inelastic continuum scattering

International Nuclear Information System (INIS)

Hoogenboom, J.E.

1983-01-01

From the collision mechanics of inelastic discrete-level scattering several properties are derived for the secondary-neutron energy distribution (SNED) for inelastic continuum scattering, when conceived as scattering with continuously-distributed inelastic levels. Using assumptions about the level density and neutron cross section the SNED can be calculated and some examples are shown. A formula is derived to calculate from a given inelastic continuum SNED a function, which is proportional to the level density and the neutron cross section. From this relation further conditions follow for the SNED. Representations for the inelastic continuum SNED currently in use do not, in general, satisfy most of the derived conditions. (author)

High Energy Electron Signals from Dark Matter Annihilation in the Sun

Energy Technology Data Exchange (ETDEWEB)

Schuster, Philip; /SLAC; Toro, Natalia; /Stanford U., ITP; Weiner, Neal; Yavin, Itay; /New York U., CCPP

2012-04-09

In this paper we discuss two mechanisms by which high energy electrons resulting from dark matter annihilations in or near the Sun can arrive at the Earth. Specifically, electrons can escape the sun if DM annihilates into long-lived states, or if dark matter scatters inelastically, which would leave a halo of dark matter outside of the sun. Such a localized source of electrons may affect the spectra observed by experiments with narrower fields of view oriented towards the sun, such as ATIC, differently from those with larger fields of view such as Fermi. We suggest a simple test of these possibilities with existing Fermi data that is more sensitive than limits from final state radiation. If observed, such a signal will constitute an unequivocal signature of dark matter.

Can the flyby anomaly be attributed to earth-bound dark matter?

International Nuclear Information System (INIS)

Adler, Stephen L.

2009-01-01

We make preliminary estimates to assess whether the recently reported flyby anomaly can be attributed to dark matter interactions. We consider both elastic and exothermic inelastic scattering from dark matter constituents; for isotropic dark matter velocity distributions, the former decrease, while the latter increase, the final flyby velocity. The fact that the observed flyby velocity anomaly shows examples with both positive and negative signs, requires the dominance of different dark matter scattering processes along different flyby trajectories. The magnitude of the observed anomalies requires dark matter densities many orders of magnitude greater than the galactic halo density. Such a large density could result from an accumulation cascade, in which the solar system-bound dark matter density is much higher than the galactic halo density, and the earth-bound density is much higher than the solar system-bound density. We discuss a number of strong constraints on the hypothesis of a dark matter explanation for the flyby anomaly. These require dark matter to be non-self-annihilating, with the dark matter scattering cross section on nucleons much larger, and the dark matter mass much lighter, than usually assumed.

Comparison of Measured Dark Current Distributions with Calculated Damage Energy Distributions in HgCdTe

Science.gov (United States)

Marshall, C. J.; Marshall, P. W.; Howe, C. L.; Reed, R. A.; Weller, R. A.; Mendenhall, M.; Waczynski, A.; Ladbury, R.; Jordan, T. M.

2007-01-01

This paper presents a combined Monte Carlo and analytic approach to the calculation of the pixel-to-pixel distribution of proton-induced damage in a HgCdTe sensor array and compares the results to measured dark current distributions after damage by 63 MeV protons. The moments of the Coulombic, nuclear elastic and nuclear inelastic damage distributions were extracted from Monte Carlo simulations and combined to form a damage distribution using the analytic techniques first described in [1]. The calculations show that the high energy recoils from the nuclear inelastic reactions (calculated using the Monte Carlo code MCNPX [2]) produce a pronounced skewing of the damage energy distribution. While the nuclear elastic component (also calculated using the MCNPX) contributes only a small fraction of the total nonionizing damage energy, its inclusion in the shape of the damage across the array is significant. The Coulombic contribution was calculated using MRED [3-5], a Geant4 [4,6] application. The comparison with the dark current distribution strongly suggests that mechanisms which are not linearly correlated with nonionizing damage produced according to collision kinematics are responsible for the observed dark current increases. This has important implications for the process of predicting the on-orbit dark current response of the HgCdTe sensor array.

Geneva University: Dark matter Search with the CDMS experiment

CERN Multimedia

Université de Genève

2011-01-01

Geneva University Physics Department 24, quai Ernest-Ansermet CH-1211 Geneva 4 Tel: (022) 379 62 73 Fax: (022) 379 69 92   Wednesday 21 September 2011 PARTICLE PHYSICS SEMINAR at 17.00 hrs – Stückelberg Auditorium “ Dark matter Search with the CDMS experiment ” Par Dr. Sebastian Arrenberg, Université de Zürich The Cryogenic Dark Matter Search experiment (CDMS) employs a total of 30 germanium and silicon detectors at the Soudan Underground Laboratory to detect weakly interacting massive particles (WIMPs) via their scattering from the target nuclei. Previous CDMS results, released in December 2009, set the world leading limit on the spin-independent WIMP-nucleon cross section above WIMP masses of ~50 GeV/c2 assuming elastic scattering.  In a subsequent analysis we investigated the inelastic dark matter scenario which was proposed to reconcile the disagreement between the results of DAMA/LIBRA and other existing dark matter searc...

Quantum Entangled Dark Solitons Formed by Ultracold Atoms in Optical Lattices

International Nuclear Information System (INIS)

Mishmash, R. V.; Carr, L. D.

2009-01-01

Inspired by experiments on Bose-Einstein condensates in optical lattices, we study the quantum evolution of dark soliton initial conditions in the context of the Bose-Hubbard Hamiltonian. An extensive set of quantum measures is utilized in our analysis, including von Neumann and generalized quantum entropies, quantum depletion, and the pair correlation function. We find that quantum effects cause the soliton to fill in. Moreover, soliton-soliton collisions become inelastic, in strong contrast to the predictions of mean-field theory. These features show that the lifetime and collision properties of dark solitons in optical lattices provide clear signals of quantum effects.

Deep inelastic scattering in the formalism with the wave functions of composite systems at rest

International Nuclear Information System (INIS)

Khvedelidze, A.M.; Kvinikhidze, A.N.; Sisakyan, A.N.

1987-01-01

A deep inelastic process of lepton-hadron scattering is studied in the bound-state rest frame. A new version of expansion of structure functions over an interaction constant is proposed, each term in it having spectral properties. It is shown that the impulse approximation is insufficient for a correct description of the elastic limit in the composite particle rest frame in contrast with the system of infinite momentum P Z → ∞. The leading asymptotics of the structure functions as x Bj → 1 can be obtained by allowing for the interaction of consituents in a final state. Using as an example a bound state ot two and three particles it is shown that the results of calculations of the relevant diagrams in the QCD model are in agreement with those obtained in th formalism P Z → ∞

Interatomic inelastic current

DEFF Research Database (Denmark)

Hansen, Tim; Solomon, Gemma C.; Hansen, Thorsten

2017-01-01

In order to identify the location of an inelastic event and to distinguish between situations that are before or after this event, we derive equations for the interatomic inelastic transmission as a perturbation series in the electron-phonon interaction. This series contains both even and odd...... to second order and the 1st order correction represents the lowest order term of this new family of terms. We apply this to three model systems and are able to distinguish between situations before and after the inelastic event as steps in the 2nd order transmission. We also see that when the transmission...

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.

Mixed dark matter from technicolor

DEFF Research Database (Denmark)

Belyaev, Alexander; T. Frandsen, Mads; Sannino, Francesco

2011-01-01

We study natural composite cold dark matter candidates which are pseudo Nambu-Goldstone bosons (pNGB) in models of dynamical electroweak symmetry breaking. Some of these can have a significant thermal relic abundance, while others must be mainly asymmetric dark matter. By considering the thermal...... abundance alone we find a lower bound of MW on the pNGB mass when the (composite) Higgs is heavier than 115 GeV. Being pNGBs, the dark matter candidates are in general light enough to be produced at the LHC....

Cosmological implications of a dark matter self-interaction energy density

International Nuclear Information System (INIS)

Stiele, Rainer; Boeckel, Tillmann; Schaffner-Bielich, Juergen

2010-01-01

We investigate cosmological constraints on an energy density contribution of elastic dark matter self-interactions characterized by the mass of the exchange particle m SI and coupling constant α SI . Because of the expansion behavior in a Robertson-Walker metric we investigate self-interacting dark matter that is warm in the case of thermal relics. The scaling behavior of dark matter self-interaction energy density (ρ SI ∝a -6 ) shows that it can be the dominant contribution (only) in the very early universe. Thus its impact on primordial nucleosynthesis is used to restrict the interaction strength m SI /√(α SI ), which we find to be at least as strong as the strong interaction. Furthermore we explore dark matter decoupling in a self-interaction dominated universe, which is done for the self-interacting warm dark matter as well as for collisionless cold dark matter in a two component scenario. We find that strong dark matter self-interactions do not contradict superweak inelastic interactions between self-interacting dark matter and baryonic matter (σ A SIDM weak ) and that the natural scale of collisionless cold dark matter decoupling exceeds the weak scale (σ A CDM >σ weak ) and depends linearly on the particle mass. Finally structure formation analysis reveals a linear growing solution during self-interaction domination (δ∝a); however, only noncosmological scales are enhanced.

Deep inelastic lepton-nucleus scattering from the light-cone quantum field theory

International Nuclear Information System (INIS)

Boqiang Ma; Ji Sun

1990-01-01

We show that for deep inelastic lepton-nucleus scattering, the conditions which validate the impulse approximation are hardly satisfied when using ordinary instant form dynamics in the rest frame of the nucleus, whereas they are well satisfied when using instant form dynamics in the infinite-momentum frame, or using light-front form dynamics in an ordinary frame. Therefore a reliable theoretical treatment of deep inelastic lepton-nucleus scattering should be performed in the time-ordered perturbation theory in the infinite-momentum frame, or its equivalent, the light-cone perturbation theory in an ordinary frame. To this end, we extend the light-cone quantum field theory to the baryon-meson field to establish a relativistic composite model of nuclei. We then apply the impulse approximation to deep inelastic lepton-nucleus scattering in this model.(author)

The DarkStars code: a publicly available dark stellar evolution package

CERN Document Server

Scott, Pat; Fairbairn, Malcolm

2009-01-01

We announce the public release of the 'dark' stellar evolution code DarkStars. The code simultaneously solves the equations of WIMP capture and annihilation in a star with those of stellar evolution assuming approximate hydrostatic equilibrium. DarkStars includes the most extensive WIMP microphysics of any dark evolution code to date. The code employs detailed treatments of the capture process from a range of WIMP velocity distributions, as well as composite WIMP distribution and conductive energy transport schemes based on the WIMP mean-free path in the star. We give a brief description of the input physics and practical usage of the code, as well as examples of its application to dark stars at the Galactic centre.

Impact parameter analysis of proton-proton elastic and inelastic interactions at 360 GeV/c

International Nuclear Information System (INIS)

Banerjee, S.; Ragavan, R.; Bailly, J

1987-01-01

Data obtained with the European Hybrid Spectrometer on the proton-proton elastic scattering at 360 GeV/c are presented. The differential cross sections of elastic and inelastic pp-interactions are studied as a function of the impact parameter. The results are compared to those obtained at other energies. They are interpreted in the framework of a simple geometrical Monte-Carlo model of inelastic collisions considering protons as composite particles having a definite effective radius with valence quarks inside. The shape of the inelastic overlap function is well reproduced for both pp- and π + p-interactions. The effective radii of the proton and pion as well as of the valence quarks are estimated for inelastic interactions. The model calculations indicate an increase of the effective radii both of protons and valence quarks and an increase of the proton opacity with increasing energy

Nearly Supersymmetric Dark Atoms

Energy Technology Data Exchange (ETDEWEB)

Behbahani, Siavosh R.; Jankowiak, Martin; /SLAC /Stanford U., ITP; Rube, Tomas; /Stanford U., ITP; Wacker, Jay G.; /SLAC /Stanford U., ITP

2011-08-12

Theories of dark matter that support bound states are an intriguing possibility for the identity of the missing mass of the Universe. This article proposes a class of models of supersymmetric composite dark matter where the interactions with the Standard Model communicate supersymmetry breaking to the dark sector. In these models supersymmetry breaking can be treated as a perturbation on the spectrum of bound states. Using a general formalism, the spectrum with leading supersymmetry effects is computed without specifying the details of the binding dynamics. The interactions of the composite states with the Standard Model are computed and several benchmark models are described. General features of non-relativistic supersymmetric bound states are emphasized.

Impeded Dark Matter

Energy Technology Data Exchange (ETDEWEB)

Kopp, Joachim; Liu, Jia [PRISMA Cluster of Excellence & Mainz Institute for Theoretical Physics,Johannes Gutenberg University,Staudingerweg 7, 55099 Mainz (Germany); Slatyer, Tracy R. [Center for Theoretical Physics, Massachusetts Institute of Technology,Cambridge, MA 02139 (United States); Wang, Xiao-Ping [PRISMA Cluster of Excellence & Mainz Institute for Theoretical Physics,Johannes Gutenberg University,Staudingerweg 7, 55099 Mainz (Germany); Xue, Wei [Center for Theoretical Physics, Massachusetts Institute of Technology,Cambridge, MA 02139 (United States)

2016-12-12

We consider dark matter models in which the mass splitting between the dark matter particles and their annihilation products is tiny. Compared to the previously proposed Forbidden Dark Matter scenario, the mass splittings we consider are much smaller, and are allowed to be either positive or negative. To emphasize this modification, we dub our scenario “Impeded Dark Matter”. We demonstrate that Impeded Dark Matter can be easily realized without requiring tuning of model parameters. For negative mass splitting, we demonstrate that the annihilation cross-section for Impeded Dark Matter depends linearly on the dark matter velocity or may even be kinematically forbidden, making this scenario almost insensitive to constraints from the cosmic microwave background and from observations of dwarf galaxies. Accordingly, it may be possible for Impeded Dark Matter to yield observable signals in clusters or the Galactic center, with no corresponding signal in dwarfs. For positive mass splitting, we show that the annihilation cross-section is suppressed by the small mass splitting, which helps light dark matter to survive increasingly stringent constraints from indirect searches. As specific realizations for Impeded Dark Matter, we introduce a model of vector dark matter from a hidden SU(2) sector, and a composite dark matter scenario based on a QCD-like dark sector.

Impeded Dark Matter

International Nuclear Information System (INIS)

Kopp, Joachim; Liu, Jia; Slatyer, Tracy R.; Wang, Xiao-Ping; Xue, Wei

2016-01-01

We consider dark matter models in which the mass splitting between the dark matter particles and their annihilation products is tiny. Compared to the previously proposed Forbidden Dark Matter scenario, the mass splittings we consider are much smaller, and are allowed to be either positive or negative. To emphasize this modification, we dub our scenario “Impeded Dark Matter”. We demonstrate that Impeded Dark Matter can be easily realized without requiring tuning of model parameters. For negative mass splitting, we demonstrate that the annihilation cross-section for Impeded Dark Matter depends linearly on the dark matter velocity or may even be kinematically forbidden, making this scenario almost insensitive to constraints from the cosmic microwave background and from observations of dwarf galaxies. Accordingly, it may be possible for Impeded Dark Matter to yield observable signals in clusters or the Galactic center, with no corresponding signal in dwarfs. For positive mass splitting, we show that the annihilation cross-section is suppressed by the small mass splitting, which helps light dark matter to survive increasingly stringent constraints from indirect searches. As specific realizations for Impeded Dark Matter, we introduce a model of vector dark matter from a hidden SU(2) sector, and a composite dark matter scenario based on a QCD-like dark sector.

New ideas on the detection of cold dark matter and magnetic monopoles

International Nuclear Information System (INIS)

Gonzalez-Mestres, L.; Perret-Gallix, D.

1988-05-01

Superheated superconducting granules (SSG) provide several interesting targets for cold dark matter detection, not only through coherent scattering off nuclei, but also for Majorana fermions through spin-spin interactions. The concept of 'localized micro-avalanche' should introduce crucial improvements in SSG devices and, eventually, make feasible a cold dark matter detector based on nucleus recoil. Recent results on the metastability of very large granules also suggest that a SSG large area monopole detector may be feasible, if the theoretically conjectured detection principle (destruction of the superheated state by two injected flux quanta) is checked experimentally. We also consider the use of special crystal scintillators to detect Majorana fermions through inelastic scattering

Contribution of the NN inelasticity into photodisintegration of the deuteron

International Nuclear Information System (INIS)

Sadovnikova, V.A.

1996-01-01

The technique of dispersion integration over the mass of composite particle is used to describe the reaction of the deuteron photodisintegration. The influence of the final state interaction on the total cross section, calculated with and without inelasticity is investigated. Numerical results depend on the choice of the vertex for the isobar photoproduction [ru

Interpreting dark matter direct detection independently of the local velocity and density distribution

International Nuclear Information System (INIS)

Fox, Patrick J.; Kribs, Graham D.; Tait, Tim M. P.

2011-01-01

We demonstrate precisely what particle physics information can be extracted from a single direct detection observation of dark matter while making absolutely no assumptions about the local velocity distribution and local density of dark matter. Our central conclusions follow from a very simple observation: the velocity distribution of dark matter is positive definite, f(v)≥0. We demonstrate the utility of this result in several ways. First, we show a falling deconvoluted recoil spectrum (deconvoluted of the nuclear form factor), such as from ordinary elastic scattering, can be 'mocked up' by any mass of dark matter above a kinematic minimum. As an example, we show that dark matter much heavier than previously considered can explain the CoGeNT excess. Specifically, m χ Ge can be in just as good agreement as light dark matter, while m χ >m Ge depends on understanding the sensitivity of xenon to dark matter at very low recoil energies, E R < or approx. 6 keVnr. Second, we show that any rise in the deconvoluted recoil spectrum represents distinct particle physics information that cannot be faked by an arbitrary f(v). As examples of resulting nontrivial particle physics, we show that inelastic dark matter and dark matter with a form factor can both yield such a rise.

Gravitational Waves from a Dark Phase Transition.

Science.gov (United States)

Schwaller, Pedro

2015-10-30

In this work, we show that a large class of models with a composite dark sector undergo a strong first order phase transition in the early Universe, which could lead to a detectable gravitational wave signal. We summarize the basic conditions for a strong first order phase transition for SU(N) dark sectors with n_{f} flavors, calculate the gravitational wave spectrum and show that, depending on the dark confinement scale, it can be detected at eLISA or in pulsar timing array experiments. The gravitational wave signal provides a unique test of the gravitational interactions of a dark sector, and we discuss the complementarity with conventional searches for new dark sectors. The discussion includes the twin Higgs and strongly interacting massive particle models as well as symmetric and asymmetric composite dark matter scenarios.

Leptoquarks and compositeness scales from a contact interaction analysis of deep inelastic e±p scattering at HERA

International Nuclear Information System (INIS)

Aid, S.; Andrieu, B.

1995-04-01

A contact interaction analysis is presented to search for new phenomena beyond the Standard Model in deep inelastic e ± p →e ± hadrons scattering. The data are collected with the H1 detector at HERA and correspond to integrated luminosities of 0.909 pb -1 and 2.947 pb -1 for electron and positron beams, respectively. The differential cross sections dσ/dQ 2 are measured in the Q 2 range between 160 GeV 2 and 20,000 GeV 2 . The absence of any significant deviation from the Standard Model prediction is used to constrain the couplings and masses of new leptoquarks and to set limits on electron-quark compositeness scales and on the radius of light quarks. (orig.)

Inelastic electron holography: First results with surface plasmons

Energy Technology Data Exchange (ETDEWEB)

Falk, Roeder; Hannes, Lichte [Triebenberg Labor, Institute for Structure Physics, TU Dresden, 01062 Dresden (Germany)

2011-07-01

Inelastic interaction and wave optics seem to be incompatible in that inelastic processes destroy coherence, which is the fundamental requirement for holography. In special experiments it is shown that energy transfer larger than some undoubtedly destroys coherence of the inelastic electron with the elastic remainder. Consequently, the usual inelastic processes, such as phonon-, plasmon- or inner shell-excitations with energy transfer of several out to several, certainly produce incoherence with the elastic ones. However, it turned out that within the inelastic wave, *newborn* by the inelastic process, there is a sufficiently wide area of coherence for generating *inelastic holograms*. This is exploited to create holograms with electrons scattered at surface-plasmons, which opens up quantum mechanical investigation of these inelastic processes.

Solution of a simple inelastic scattering problem

International Nuclear Information System (INIS)

Knudson, S.K.

1975-01-01

Simple examples of elastic scattering, typically from square wells, serve as important pedagogical tools in discussion of the concepts and processes involved in elastic scattering events. An analytic solution of a model inelastic scattering system is presented here to serve in this role for inelastic events. The model and its solution are simple enough to be of pedagogical utility, but also retain enough of the important physical features to include most of the special characteristics of inelastic systems. The specific model chosen is the collision of an atom with a harmonic oscillator, interacting via a repulsive square well potential. Pedagogically important features of inelastic scattering, including its multistate character, convergence behavior, and dependence on an ''inelastic potential'' are emphasized as the solution is determined. Results are presented for various energies and strengths of inelastic scattering, which show that the model is capable of providing an elementary representation of vibrationally inelastic scattering

X-ray lines from dark matter: the good, the bad, and the unlikely

Energy Technology Data Exchange (ETDEWEB)

Frandsen, Mads T.; Sannino, Francesco; Shoemaker, Ian M.; Svendsen, Ole, E-mail: frandsen@cp3-origins.net, E-mail: sannino@cp3-origins.net, E-mail: shoemaker@cp3-origins.net, E-mail: svendsen@cp3-origins.net [CP" 3-Origins and Danish Institute for Advanced Study DIAS, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark)

2014-05-01

We consider three classes of dark matter (DM) models to account for the recently observed 3.5 keV line: metastable excited state DM, annihilating DM, and decaying DM. We study two examples of metastable excited state DM. The first, millicharged composite DM, has both inelasticity and photon emission built in, but with a very constrained parameter space. In the second example, up-scattering and decay come from separate sectors and is thus less constrained. The decay of the excited state can potentially be detectable at direct detection experiments. However we find that CMB constraints are at the border of excluding this as an interpretation of the DAMA signal. The annihilating DM interpretation of the X-ray line is found to be in mild tension with CMB constraints. Lastly, a generalized version of decaying DM can account for the data with a lifetime exceeding the age of the Universe for masses ∼<10{sup 6} GeV.

Gravitational Waves From a Dark (Twin) Phase Transition

CERN Document Server

Schwaller, Pedro

2015-01-01

In this work, we show that a large class of models with a composite dark sector undergo a strong first order phase transition in the early universe, which could lead to a detectable gravitational wave signal. We summarise the basic conditions for a strong first order phase transition for SU(N) dark sectors with n_f flavours, calculate the gravitational wave spectrum and show that, depending on the dark confinement scale, it can be detected at eLISA or in pulsar timing array experiments. The gravitational wave signal provides a unique test of the gravitational interactions of a dark sector, and we discuss the complementarity with conventional searches for new dark sectors. The discussion includes Twin Higgs and SIMP models as well as symmetric and asymmetric composite dark matter scenarios.

Global interpretation of direct Dark Matter searches after CDMS-II results

International Nuclear Information System (INIS)

Kopp, Joachim; Schwetz, Thomas; Zupan, Jure

2010-01-01

We perform a global fit to data from Dark Matter (DM) direct detection experiments, including the recent CDMS-II results. We discuss possible interpretations of the DAMA annual modulation signal in terms of spin-independent and spin-dependent DM-nucleus interactions, both for elastic and inelastic scattering. We find that for the spin-dependent inelastic scattering off protons a good fit to all data is obtained. We present a simple toy model realizing such a scenario. In all the remaining cases the DAMA allowed regions are disfavored by other experiments or suffer from severe fine tuning of DM parameters with respect to the galactic escape velocity. Finally, we also entertain the possibility that the two events observed in CDMS-II are an actual signal of elastic DM scattering, and we compare the resulting CDMS-II allowed regions to the exclusion limits from other experiments

Deep inelastic electron and muon scattering

International Nuclear Information System (INIS)

Taylor, R.E.

1975-07-01

From the review of deep inelastic electron and muon scattering it is concluded that the puzzle of deep inelastic scattering versus annihilation was replaced with the challenge of the new particles, that the evidence for the simplest quark-algebra models of deep inelastic processes is weaker than a year ago. Definite evidence of scale breaking was found but the specific form of that scale breaking is difficult to extract from the data. 59 references

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

Elastic and inelastic psi production by muons

International Nuclear Information System (INIS)

Loken, S.C.

1981-06-01

Results are presented on the elastic and inelastic production of psi (3.1). The elastic data are qualitative agreement with the predictions of photon-gluon fusion but have a steeper dependence on Q 2 than the model predicts. A QCD calculation accounts well for the shape of the inelastic data in inelasticity, Q 2 and E/sub γ/, but fails to account for the absolute cross section. At 209 GeV, the cross-section for elastic psi production is 0.36 +- 0.07 nb; for inelastic, 0.28 +- 0.06nb

Bright-Dark Mixed N-Soliton Solutions of the Multi-Component Mel'nikov System

Science.gov (United States)

Han, Zhong; Chen, Yong; Chen, Junchao

2017-10-01

By virtue of the Kadomtsev-Petviashvili (KP) hierarchy reduction technique, we construct the general bright-dark mixed N-soliton solution to the multi-component Mel'nikov system. This multi-component system comprised of multiple (say M) short-wave components and one long-wave component with all possible combinations of nonlinearities including all-positive, all-negative and mixed types. Firstly, the two-bright-one-dark (2-b-1-d) and one-bright-two-dark (1-b-2-d) mixed N-soliton solutions in short-wave components of the three-component Mel'nikov system are derived in detail. Then we extend our analysis to the M-component Mel'nikov system to obtain its general mixed N-soliton solution. The formula obtained unifies the all-bright, all-dark and bright-dark mixed N-soliton solutions. For the collision of two solitons, an asymptotic analysis shows that for an M-component Mel'nikov system with M ≥ 3, inelastic collision takes place, resulting in energy exchange among the short-wave components supporting bright solitons only if the bright solitons appear in at least two short-wave components. In contrast, the dark solitons in the short-wave components and the bright solitons in the long-wave component always undergo elastic collision which is only accompanied by a position shift.

Polarization phenomena in inelastic scattering

International Nuclear Information System (INIS)

Verhaar, B.J.

1974-01-01

An attempt is made to clarify the principles of inelastic scattering using the distorted wave Born approximation, concentrating on inelastic proton scattering. The principle aspects and merits of the microscopic description and the necessity of including the N-N spin orbit force are discussed. (7 figures) (U.S.)

Searches for vector-like quarks at future colliders and implications for composite Higgs models with dark matter

Science.gov (United States)

Chala, Mikael; Gröber, Ramona; Spannowsky, Michael

2018-03-01

Many composite Higgs models predict the existence of vector-like quarks with masses outside the reach of the LHC, e.g. m Q ≳ 2 TeV, in particular if these models contain a dark matter candidate. In such models the mass of the new resonances is bounded from above to satisfy the constraint from the observed relic density. We therefore develop new strategies to search for vector-like quarks at a future 100 TeV collider and evaluate what masses and interactions can be probed. We find that masses as large as ˜ 6.4 (˜9) TeV can be tested if the fermionic resonances decay into Standard Model (dark matter) particles. We also discuss the complementarity of dark matter searches, showing that most of the parameter space can be closed. On balance, this study motivates further the consideration of a higher-energy hadron collider for a next generation of facilities.

Elastic and inelastic surface effects on ion penetration and the resulting sputtering and backscattering

International Nuclear Information System (INIS)

Hassanein, A.M.; Smith, D.L.

1985-01-01

The computer code ITMC (Ion Transport in Materials and Compounds) has been developed to study in detail the transport of charged particles in solid materials and surface related phenomena such as sputtered atoms and backscattered ions. The code is based on Monte Carlo methods to follow the path and the damage produced by the charged particles in three dimension as they slow down in target materials. Single-element targets as well as alloys with possible different surface and bulk compositions or with layered structures of different materials can be used. Various models developed to calculate the inelastic energy losses with target electrons can be used in the code. Most known interatomic potentials can also be used to calculate the elastic energy losses. The major advantages of the code are its ability and flexibility to use and compare various models of elastic and inelastic energy losses in any target with different compounds and different surface and bulk composition

Electron Inelastic-Mean-Free-Path Database

Science.gov (United States)

SRD 71 NIST Electron Inelastic-Mean-Free-Path Database (PC database, no charge)   This database provides values of electron inelastic mean free paths (IMFPs) for use in quantitative surface analyses by AES and XPS.

Comparison of elastic and inelastic analyses

International Nuclear Information System (INIS)

Ammerman, D.J.; Heinstein, M.W.; Wellman, G.W.

1992-01-01

The use of inelastic analysis methods instead of the traditional elastic analysis methods in the design of radioactive material (RAM) transport packagings leads to a better understanding of the response of the package to mechanical loadings. Thus, better assessment of the containment, thermal protection, and shielding integrity of the package after a structure accident event can be made. A more accurate prediction of the package response can lead to enhanced safety and also allow for a more efficient use of materials, possibly leading to a package with higher capacity or lower weight. This paper discusses the advantages and disadvantages of using inelastic analysis in the design of RAM shipping packages. The use of inelastic analysis presents several problems to the package designer. When using inelastic analysis the entire nonlinear response of the material must be known, including the effects of temperature changes and strain rate. Another problem is that there currently is not an acceptance criteria for this type of analysis that is approved by regulatory agencies. Inelastic analysis acceptance criteria based on failure stress, failure strain , or plastic energy density could be developed. For both elastic and inelastic analyses it is also important to include other sources of stress in the analyses, such as fabrication stresses, thermal stresses, stresses from bolt preloading, and contact stresses at material interfaces. Offsetting these added difficulties is the improved knowledge of the package behavior. This allows for incorporation of a more uniform margin of safety, which can result in weight savings and a higher level of confidence in the post-accident configuration of the package. In this paper, comparisons between elastic and inelastic analyses are made for a simple ring structure and for a package to transport a large quantity of RAM by rail (rail cask) with lead gamma shielding to illustrate the differences in the two analysis techniques

Use of inelastic analysis in cask design

International Nuclear Information System (INIS)

Ammerman, Douglas J.; Breivik, Nicole L.

2000-01-01

In this paper, the advantages and disadvantages of inelastic analysis are discussed. Example calculations and designs showing the implications and significance of factors affecting inelastic analysis are given. From the results described in this paper it can be seen that inelastic analysis provides an improved method for the design of casks. It can also be seen that additional code and standards work is needed to give designers guidance in the use of inelastic analysis. Development of these codes and standards is an area where there is a definite need for additional work. The authors hope that this paper will help to define the areas where that need is most acute

Description of deep inelastic processes in terms of the wave functions of the composite systems in the rest frame

International Nuclear Information System (INIS)

Kvinikhidze, A.N.; Sisakyan, A.N.; Khvedelidze, A.M.

1988-01-01

Inelastic lepton-hadron scattering is studied in the rest frame of the composite particle. A new variant of expansion of the structure functions in the coupling constant is proposed, each term of which possesses the property of spectrality. It is shown that in the rest frame of the bound state, in contrast to the frame in which P/sub z/→∞, the impulse approximation is not adequate for a correct description of the elastic limit x/sub Bj/ →1. To obtain the leading asymptotic form of the structure functions for x/sub Bj/ →1 it is necessary to take into account the interaction of the constituents in the final state. The corresponding diagrams are indicated, and a calculation of these in QCD gives results in agreement with results obtained previously in the framework of field theory on the 0-plane

Deep inelastic processes and the parton model

International Nuclear Information System (INIS)

Altarelli, G.

The lecture was intended as an elementary introduction to the physics of deep inelastic phenomena from the point of view of theory. General formulae and facts concerning inclusive deep inelastic processes in the form: l+N→l'+hadrons (electroproduction, neutrino scattering) are first recalled. The deep inelastic annihilation e + e - →hadrons is then envisaged. The light cone approach, the parton model and their relation are mainly emphasized

Theory of deep inelastic lepton-hadron scattering

International Nuclear Information System (INIS)

Geyer, B.; Robaschik, D.; Wieczorek, E.

1979-01-01

The description of deep inelastic lepton-nucleon scattering in the lowest order of the electromagnetic and weak coupling constants leads to a study of virtual Compton amplitudes and their absorptive parts. Some aspects of quantum chromodynamics are discussed. Deep inelastic scattering enables a central quantity of quantum field theory, namely the light cone behaviour of the current commutator. The moments of structure functions are used for the description of deep inelastic scattering. (author)

Problems to be solved about inelastic behaviour of materials and inelastic analysis of structures at elevated temperature

International Nuclear Information System (INIS)

Ledermann, P.; Escatha, Y. d'.

1981-01-01

At elevated temperature, ASME CODE CASE N 47 demands, in its design and analysis part to demonstrate that none of eight damages, related to the monotonic and cyclic inelastic behaviour of the material and structure, will happen during the whole life of the reactor. However this demonstration, for strain limits and creep fatigue failure, using a purely elastic analysis as in the ASME CODE Section III, is usually impossible. Inelastic analysis is then necessary. We review some of the research work (theorical and experimental) which is being done to qualify methods for an inelastic analysis of structures at elevated temperature [fr

Dark group: dark energy and dark matter

International Nuclear Information System (INIS)

Macorra, A. de la

2004-01-01

We study the possibility that a dark group, a gauge group with particles interacting with the standard model particles only via gravity, is responsible for containing the dark energy and dark matter required by present day observations. We show that it is indeed possible and we determine the constrains for the dark group. The non-perturbative effects generated by a strong gauge coupling constant can de determined and a inverse power law scalar potential IPL for the dark meson fields is generated parameterizing the dark energy. On the other hand it is the massive particles, e.g., dark baryons, of the dark gauge group that give the corresponding dark matter. The mass of the dark particles is of the order of the condensation scale Λ c and the temperature is smaller then the photon's temperature. The dark matter is of the warm matter type. The only parameters of the model are the number of particles of the dark group. The allowed values of the different parameters are severely restricted. The dark group energy density at Λ c must be Ω DGc ≤0.17 and the evolution and acceptable values of dark matter and dark energy leads to a constrain of Λ c and the IPL parameter n giving Λ c =O(1-10 3 ) eV and 0.28≤n≤1.04

Inelastic scattering and deformation parameters

International Nuclear Information System (INIS)

Ford, J.L.C. Jr.

1978-01-01

In recent years there has been extensive study of nuclear shape parameters by electron scattering, μ meson atomic transitions, Coulomb excitation and direct nuclear inelastic scattering. Inelastic scattering of strongly absorbed particles, e.g., alpha-particles and heavy ions, at energies below and above the Coulomb barrier probe the charge and mass distributions within the nucleus. This paper summarizes measurements in this field performed at Oak Ridge National Laboratory

Peaked signals from dark matter velocity structures in direct detection experiments

Science.gov (United States)

Lang, Rafael F.; Weiner, Neal

2010-06-01

In direct dark matter detection experiments, conventional elastic scattering of WIMPs results in exponentially falling recoil spectra. In contrast, theories of WIMPs with excited states can lead to nuclear recoil spectra that peak at finite recoil energies ER. The peaks of such signals are typically fairly broad, with ΔER/Epeak ~ 1. We show that in the presence of dark matter structures with low velocity dispersion, such as streams or clumps, peaks from up-scattering can become extremely narrow with FWHM of a few keV only. This differs dramatically from the conventionally expected WIMP spectrum and would, once detected, open the possibility to measure the dark matter velocity structure with high accuracy. As an intriguing example, we confront the observed cluster of 3 events near 42 keV from the CRESST commissioning run with this scenario. Inelastic dark matter particles with a wide range of parameters are capable of producing such a narrow peak. We calculate the possible signals at other experiments, and find that such particles could also give rise to the signal at DAMA, although not from the same stream. Over some range of parameters, a signal would be visible at xenon experiments. We show that such dark matter peaks are a very clear signal and can be easily disentangled from potential backgrounds, both terrestrial or due to WIMP down-scattering, by an enhanced annual modulation in both the amplitude of the signal and its spectral shape.

Peaked signals from dark matter velocity structures in direct detection experiments

International Nuclear Information System (INIS)

Lang, Rafael F.; Weiner, Neal

2010-01-01

In direct dark matter detection experiments, conventional elastic scattering of WIMPs results in exponentially falling recoil spectra. In contrast, theories of WIMPs with excited states can lead to nuclear recoil spectra that peak at finite recoil energies E R . The peaks of such signals are typically fairly broad, with ΔE R /E peak ∼ 1. We show that in the presence of dark matter structures with low velocity dispersion, such as streams or clumps, peaks from up-scattering can become extremely narrow with FWHM of a few keV only. This differs dramatically from the conventionally expected WIMP spectrum and would, once detected, open the possibility to measure the dark matter velocity structure with high accuracy. As an intriguing example, we confront the observed cluster of 3 events near 42 keV from the CRESST commissioning run with this scenario. Inelastic dark matter particles with a wide range of parameters are capable of producing such a narrow peak. We calculate the possible signals at other experiments, and find that such particles could also give rise to the signal at DAMA, although not from the same stream. Over some range of parameters, a signal would be visible at xenon experiments. We show that such dark matter peaks are a very clear signal and can be easily disentangled from potential backgrounds, both terrestrial or due to WIMP down-scattering, by an enhanced annual modulation in both the amplitude of the signal and its spectral shape

Finite element analysis of inelastic structural behavior

International Nuclear Information System (INIS)

Argyris, J.H.; Szimmat, J.; Willam, K.J.

1977-01-01

The paper describes recent achievements in the finite element analysis of inelastic material behavior. The main purpose is to examine the interaction of three disciplines; (i) the finite element formulation of large deformation problems in the light of a systematic linearization, (ii) the constitutive modelling of inelastic processes in the rate-dependent and rate-independent response regime and (iii) the numerical solution of nonlinear rate problems via incremental iteration techniques. In the first part, alternative finite element models are developed for the idealization of large deformation problems. A systematic approach is presented to linearize the field equations locally by an incremental procedure. The finite element formulation is then examined for the description of inelastic material processes. In the second part, nonlinear and inelastic material phenomena are classified and illustrated with representative examples of concrete and metal components. In particular, rate-dependent and rate-independent material behavior is examined and representative constitutive models are assessed for their mathematical characterization. Hypoelastic, elastoplastic and endochronic models are compared for the description rate-independent material phenomena. In the third part, the numerial solution of inelastic structural behavior is discussed. In this context, several incremental techniques are developed and compared for tracing the evolution of the inelastic process. The numerical procedures are examined with regard to stability and accuracy to assess the overall efficiency. The 'optimal' incremental technique is then contrasted with the computer storage requirements to retain the data for the 'memory-characteristics' of the constitutive model

Damage-induced nonassociated inelastic flow in rock salt

International Nuclear Information System (INIS)

Chan, K.S.; Bodner, S.R.; Brodsky, N.S.; Fossum, A.F.; Munson, D.E.

1993-01-01

The multi-mechanism deformation coupled fracture model recently developed by CHAN, et al. (1992), for describing time-dependent, pressure-sensitive inelastic flow and damage evolution in crystalline solids was evaluated against triaxial creep experiments on rock salt. Guided by experimental observations, the kinetic equation and the flow law for damage-induced inelastic flow in the model were modified to account for the development of damage and inelastic dilatation in the transient creep regime. The revised model was then utilized to obtain the creep response and damage evolution in rock salt as a function of confining pressure and stress difference. Comparison between model calculation and experiment revealed that damage-induced inelastic flow is nonassociated, dilatational, and contributes significantly to the macroscopic strain rate observed in rock salt deformed at low confining pressures. The inelastic strain rate and volumetric strain due to damage decrease with increasing confining pressures, and all are suppressed at sufficiently high confining pressures

Neutron multiplicity in deep inelastic collisions: 400 MeV Cu + Au system

International Nuclear Information System (INIS)

Tamain, B.; Chechik, R.; Ruchs, H.; Hanappe, F.; Morjean, M.; Ngo, C.; Peter, J.; Dakowski, M.; Lucas, B.; Mazur, C.; Ribrag, M.; Signarbieux, C.

1979-01-01

The authors have detected in nine different positions of space the neutrons associated with the collision of 63 Cu on 197 Au at 400 MeV bombarding energy. The deep inelastic products were detected at two different angles: close to the gazing angle and 30 0 forwards of it. Their measses were measured using a time-of-flight technique. The neutrons were detected in coincidence with the fragments - the efficiency of the neutron detectors was measured relatively to a 252 Cf source during beam time. The neutron threshold was set at 300 keV. Within an accuracy of 10% all the emitted neutrons are evaporated by the fully accelerated deep inelastic fragments. It is shown that the excitation energy is shared between the fragments in proportion to their masses and that the relaxation time for internal equilibration of the composite system is very short (approximately 10 -22 s). (Auth.)

The dark universe dark matter and dark energy

CERN Multimedia

CERN. Geneva

2008-01-01

According to the standard cosmological model, 95% of the present mass density of the universe is dark: roughly 70% of the total in the form of dark energy and 25% in the form of dark matter. In a series of four lectures, I will begin by presenting a brief review of cosmology, and then I will review the observational evidence for dark matter and dark energy. I will discuss some of the proposals for dark matter and dark energy, and connect them to high-energy physics. I will also present an overview of an observational program to quantify the properties of dark energy.

Photon diffractive dissociation in deep inelastic scattering

International Nuclear Information System (INIS)

Ryskin, M.G.

1990-01-01

The new ep-collider HERA gives us the possibility to study the diffractive dissociation of virtual photon in deep inelastic ep-collision. The process of photon dissociation in deep inelastic scattering is the most direct way to measure the value of triple-pomeron vertex G 3P . It was shown that the value of the correct bare vertex G 3P may more than 4 times exceeds its effective value measuring in the triple-reggeon region and reaches the value of about 40-50% of the elastic pp-pomeron vertex. On the contrary in deep inelastic processes the perpendicular momenta q t of the secondary particles are large enough. Thus in deep inelastic reactions one can measure the absolute value of G 3P vertex in the most direct way and compare its value and q t dependence with the leading log QCD predictions

Detecting Stealth Dark Matter Directly through Electromagnetic Polarizability.

Science.gov (United States)

Appelquist, T; Berkowitz, E; Brower, R C; Buchoff, M I; Fleming, G T; Jin, X-Y; Kiskis, J; Kribs, G D; Neil, E T; Osborn, J C; Rebbi, C; Rinaldi, E; Schaich, D; Schroeder, C; Syritsyn, S; Vranas, P; Weinberg, E; Witzel, O

2015-10-23

We calculate the spin-independent scattering cross section for direct detection that results from the electromagnetic polarizability of a composite scalar "stealth baryon" dark matter candidate, arising from a dark SU(4) confining gauge theory-"stealth dark matter." In the nonrelativistic limit, electromagnetic polarizability proceeds through a dimension-7 interaction leading to a very small scattering cross section for dark matter with weak-scale masses. This represents a lower bound on the scattering cross section for composite dark matter theories with electromagnetically charged constituents. We carry out lattice calculations of the polarizability for the lightest "baryon" states in SU(3) and SU(4) gauge theories using the background field method on quenched configurations. We find the polarizabilities of SU(3) and SU(4) to be comparable (within about 50%) normalized to the stealth baryon mass, which is suggestive for extensions to larger SU(N) groups. The resulting scattering cross sections with a xenon target are shown to be potentially detectable in the dark matter mass range of about 200-700 GeV, where the lower bound is from the existing LUX constraint while the upper bound is the coherent neutrino background. Significant uncertainties in the cross section remain due to the more complicated interaction of the polarizablity operator with nuclear structure; however, the steep dependence on the dark matter mass, 1/m(B)(6), suggests the observable dark matter mass range is not appreciably modified. We briefly highlight collider searches for the mesons in the theory as well as the indirect astrophysical effects that may also provide excellent probes of stealth dark matter.

Compton profiles by inelastic ion-electron scattering

International Nuclear Information System (INIS)

Boeckl, H.; Bell, F.

1983-01-01

It is shown that Compton profiles (CP) can be measured by inelastic ion-electron scattering. Within the impulse approximation the binary-encounter peak (BEP) reflects the CP of the target atom whereas the electron-loss peak (ELP) is given by projectile CP's. Evaluation of experimental data reveals that inelastic ion-electron scattering might be a promising method to supply inelastic electron or photon scattering for the determination of target CP's. The measurement of projectile CP's is unique to ion scattering since one gains knowledge about wave-function effects because of the high excitation degree of fast heavy-ion projectiles

Implications of stress range for inelastic analysis

International Nuclear Information System (INIS)

Karabin, M.E.; Dhalla, A.K.

1981-01-01

The elastic stress range over a complete load cycle is routinely used to formulate simplified rules regarding the inelastic behavior of structures operating at elevated temperature. For example, a 300 series stainless steel structure operating at elevated temperature, in all probability, would satisfy the ASME Boiler and Pressure Vessel Code criteria if the linearized elastic stress range is less than three times the material yield strength. However, at higher elastic stress ranges it is difficult to judge, a priori, that a structural component would comply with inelastic Code criteria after a detailed inelastic analysis. The purpose of this paper is to illustrate that it is not the elastic stress range but the stress intensities at specific times during a thermal transient which provide a better insight into the inelastic response of the structure. The specific example of the CRBRP flued head design demonstrates that the temperature differential between various parts of the structure can be changed by modifying the insulation pattern and heat flow path in the structure, without significantly altering the elastic stress range over a complete load cycle. However, the modified design did reduce the stress intensity during steady state elevated temperature operation. This modified design satisfied the inelastic Code criteria whereas the initial design failed to comply with the strain accumulation criterion

The local dark matter phase-space density and impact on WIMP direct detection

International Nuclear Information System (INIS)

Catena, Riccardo; Ullio, Piero

2012-01-01

We present a new determination of the local dark matter phase-space density. This result is obtained implementing, in the limit of isotropic velocity distribution and spherical symmetry, Eddington's inversion formula, which links univocally the dark matter distribution function to the density profile, and applying, within a Bayesian framework, a Markov Chain Monte Carlo algorithm to sample mass models for the Milky Way against a broad and variegated sample of dynamical constraints. We consider three possible choices for the dark matter density profile, namely the Einasto, NFW and Burkert profiles, finding that the velocity dispersion, which characterizes the width in the distribution, tends to be larger for the Burkert case, while the escape velocity depends very weakly on the profile, with the mean value we obtain being in very good agreement with estimates from stellar kinematics. The derived dark matter phase-space densities differ significantly — most dramatically in the high velocity tails — from the model usually taken as a reference in dark matter detection studies, a Maxwell-Boltzmann distribution with velocity dispersion fixed in terms of the local circular velocity and with a sharp truncation at a given value of the escape velocity. We discuss the impact of astrophysical uncertainties on dark matter scattering rates and direct detection exclusion limits, considering a few sample cases and showing that the most sensitive ones are those for light dark matter particles and for particles scattering inelastically. As a general trend, regardless of the assumed profile, when adopting a self-consistent phase-space density, we find that rates are larger, and hence exclusion limits stronger, than with the standard Maxwell-Boltzmann approximation. Tools for applying our result on the local dark matter phase-space density to other dark matter candidates or experimental setups are provided

Direct detection of neutralino dark matter in the NMSSM

International Nuclear Information System (INIS)

Cerdeno, David G

2006-01-01

The direct detection of neutralino dark matter is analysed in the Next-to-Minimal Supersymmetric Standard Model (NMSSM). Sizable values for the neutralino detection cross section, within the reach of dark matter detectors, are attainable, due to the exchange of very light Higgses, which have a significant singlet composition. The lightest neutralino exhibits a large singlino-Higgsino composition, and a mass in the range 50 ∼ χ -0 1 ∼< 100 GeV

Acceleration of the universe dark energy or modified

International Nuclear Information System (INIS)

Cardenas, Rolando; Leyva, Yoelsy

2007-01-01

We present a composite model of dark energy, motivated in string and quantum field theory considerations. Then we speak on gravity theories in which the gravity Lagrangian is modified, resulting in a modification of General Relativity. We outline a methodology allowing a mapping between these two theories, i. e., both dark energy models and modified gravity can give the same cosmological dynamics. We apply aforementioned methodology to obtain the mapping composite dark energy-modified gravity for a particular case. Cosmic expansion history takes into account very large scales, the homogeneous Universe, and can not discriminate between above two theories. However, cosmic growth history takes into consideration intermediate cluster and galactic scales, the inhomogeneous Universe, and there might be the clue to discriminate whether the current acceleration of the Universe is because it is filled with a new fluid having repulsive gravity (dark energy) or it is just that gravity gets weaker and long scales (modified gravity). (Author)

Isotriplet Dark Matter on the Lattice

DEFF Research Database (Denmark)

Hietanen, Ari; Pica, Claudio; Sannino, Francesco

: a] It provides a natural complex weak isotriplet of Goldstone bosons of which the neutral component can be identified with a light composite dark matter state; b] It is expected to break the global symmetry spontaneously; c] It is free from fermionic composite states made by a techniglue...

Inelastic scattering of fast electrons by crystals

International Nuclear Information System (INIS)

Allen, L.J.; Josefsson, T.W.

1995-01-01

Generalized fundamental equations for electron diffraction in crystals, which include the effect of inelastic scattering described by a nonlocal interaction, are derived. An expression is obtained for the cross section for any specific type of inelastic scattering (e.g. inner-shell ionization, Rutherford backscattering). This result takes into account all other (background) inelastic scattering in the crystal leading to absorption from the dynamical Bragg-reflected beams, in practice mainly due to thermal diffuse scattering. There is a contribution to the cross section from all absorbed electrons, which form a diffuse background, as well as from the dynamical electrons. The approximations involved, assuming that the interactions leading to inelastic scattering can be described by a local potential are discussed, together with the corresponding expression for the cross section. It is demonstrated by means of an example for K-shell electron energy loss spectroscopy that nonlocal effects can be significant. 47 refs., 4 figs

Quantitative determination of elastic and inelastic attenuation coefficients by off-axis electron holography

International Nuclear Information System (INIS)

Kern, F.; Wolf, D.; Pschera, P.; Lubk, A.

2016-01-01

Off-axis electron holography is a well-established transmission electron microscopy technique, typically employed to investigate electric and magnetic fields in and around nanoscale materials, which modify the phase of the reconstructed electron wave function. Here, we elaborate on a detailed analysis of the two characteristic intensity terms that are completing the electron hologram, the conventional image intensity and the interference fringe intensity. We show how both are related to elastic and inelastic scattering absorption at the sample and how they may be separated to analyze the chemical composition of the sample. Since scattering absorption is aperture dependent, a quantitative determination of the corresponding attenuation coefficients (reciprocal mean free path lengths) requires the use of holographic image modi with well-defined objective aperture stops in the back-focal plane of the objective lens. The proposed method extends quantitative electron holography to a correlated three-in-one characterization of electric and magnetic fields, Z-contrast and dielectric losses in materials. - Highlights: • Quantitative determination of attenuation coefficients by electron holography. • Separation of elastic and inelastic attenuation coefficients (mean free path length). • Quantitative determination of the objective aperture semi-angle influence. • Compilation of elastic and inelastic attenuation from different materials.

Quantitative determination of elastic and inelastic attenuation coefficients by off-axis electron holography

Energy Technology Data Exchange (ETDEWEB)

Kern, F.; Wolf, D.; Pschera, P.; Lubk, A.

2016-12-15

Off-axis electron holography is a well-established transmission electron microscopy technique, typically employed to investigate electric and magnetic fields in and around nanoscale materials, which modify the phase of the reconstructed electron wave function. Here, we elaborate on a detailed analysis of the two characteristic intensity terms that are completing the electron hologram, the conventional image intensity and the interference fringe intensity. We show how both are related to elastic and inelastic scattering absorption at the sample and how they may be separated to analyze the chemical composition of the sample. Since scattering absorption is aperture dependent, a quantitative determination of the corresponding attenuation coefficients (reciprocal mean free path lengths) requires the use of holographic image modi with well-defined objective aperture stops in the back-focal plane of the objective lens. The proposed method extends quantitative electron holography to a correlated three-in-one characterization of electric and magnetic fields, Z-contrast and dielectric losses in materials. - Highlights: • Quantitative determination of attenuation coefficients by electron holography. • Separation of elastic and inelastic attenuation coefficients (mean free path length). • Quantitative determination of the objective aperture semi-angle influence. • Compilation of elastic and inelastic attenuation from different materials.

Can tonne-scale direct detection experiments discover nuclear dark matter?

Energy Technology Data Exchange (ETDEWEB)

Butcher, Alistair; Kirk, Russell; Monroe, Jocelyn; West, Stephen M., E-mail: Alistair.Butcher.2010@live.rhul.ac.uk, E-mail: Russell.Kirk.2008@live.rhul.ac.uk, E-mail: Jocelyn.Monroe@rhul.ac.uk, E-mail: Stephen.West@rhul.ac.uk [Department of Physics, Royal Holloway University of London, Egham, Surrey, TW20 0EX (United Kingdom)

2017-10-01

Models of nuclear dark matter propose that the dark sector contains large composite states consisting of dark nucleons in analogy to Standard Model nuclei. We examine the direct detection phenomenology of a particular class of nuclear dark matter model at the current generation of tonne-scale liquid noble experiments, in particular DEAP-3600 and XENON1T. In our chosen nuclear dark matter scenario distinctive features arise in the recoil energy spectra due to the non-point-like nature of the composite dark matter state. We calculate the number of events required to distinguish these spectra from those of a standard point-like WIMP state with a decaying exponential recoil spectrum. In the most favourable regions of nuclear dark matter parameter space, we find that a few tens of events are needed to distinguish nuclear dark matter from WIMPs at the 3 σ level in a single experiment. Given the total exposure time of DEAP-3600 and XENON1T we find that at best a 2 σ distinction is possible by these experiments individually, while 3 σ sensitivity is reached for a range of parameters by the combination of the two experiments. We show that future upgrades of these experiments have potential to distinguish a large range of nuclear dark matter models from that of a WIMP at greater than 3 σ .

Can tonne-scale direct detection experiments discover nuclear dark matter?

International Nuclear Information System (INIS)

Butcher, Alistair; Kirk, Russell; Monroe, Jocelyn; West, Stephen M.

2017-01-01

Models of nuclear dark matter propose that the dark sector contains large composite states consisting of dark nucleons in analogy to Standard Model nuclei. We examine the direct detection phenomenology of a particular class of nuclear dark matter model at the current generation of tonne-scale liquid noble experiments, in particular DEAP-3600 and XENON1T. In our chosen nuclear dark matter scenario distinctive features arise in the recoil energy spectra due to the non-point-like nature of the composite dark matter state. We calculate the number of events required to distinguish these spectra from those of a standard point-like WIMP state with a decaying exponential recoil spectrum. In the most favourable regions of nuclear dark matter parameter space, we find that a few tens of events are needed to distinguish nuclear dark matter from WIMPs at the 3 σ level in a single experiment. Given the total exposure time of DEAP-3600 and XENON1T we find that at best a 2 σ distinction is possible by these experiments individually, while 3 σ sensitivity is reached for a range of parameters by the combination of the two experiments. We show that future upgrades of these experiments have potential to distinguish a large range of nuclear dark matter models from that of a WIMP at greater than 3 σ .

Unstable gravitino dark matter prospects for indirect and direct detection

International Nuclear Information System (INIS)

Grefe, Michael

2011-11-01

We confront the signals expected from unstable gravitino dark matter with observations of indirect dark matter detection experiments in all possible cosmic-ray channels. For this purpose we calculate in detail the gravitino decay widths in theories with bilinear violation of R parity, particularly focusing on decay channels with three particles in the final state. Based on these calculations we predict the fluxes of gamma rays, charged cosmic rays and neutrinos expected from decays of gravitino dark matter. Although the predicted spectra could in principal explain the anomalies observed in the cosmic ray positron and electron fluxes as measured by PAMELA and Fermi LAT, we find that this possibility is ruled out by strong constraints from gamma-ray and antiproton observations. Therefore, we employ current data of indirect detection experiments to place strong constraints on the gravitino lifetime and the strength of R-parity violation. In addition, we discuss the prospects of forthcoming searches for a gravitino signal in the spectrum of cosmic-ray antideuterons, finding that they are in particular sensitive to rather low gravitino masses. Finally, we discuss in detail the prospects for detecting a neutrino signal from gravitino dark matter decays, finding that the sensitivity of neutrino telescopes like IceCube is competitive to observations in other cosmic ray channels, especially for rather heavy gravitinos. Moreover, we discuss the prospects for a direct detection of gravitino dark matter via R-parity violating inelastic scatterings off nucleons. We find that, although the scattering cross section is considerably enhanced compared to the case of elastic gravitino scattering, the expected signal is many orders of magnitude too small in order to hope for a detection in underground detectors. (orig.)

Unstable gravitino dark matter prospects for indirect and direct detection

Energy Technology Data Exchange (ETDEWEB)

Grefe, Michael

2011-11-15

We confront the signals expected from unstable gravitino dark matter with observations of indirect dark matter detection experiments in all possible cosmic-ray channels. For this purpose we calculate in detail the gravitino decay widths in theories with bilinear violation of R parity, particularly focusing on decay channels with three particles in the final state. Based on these calculations we predict the fluxes of gamma rays, charged cosmic rays and neutrinos expected from decays of gravitino dark matter. Although the predicted spectra could in principal explain the anomalies observed in the cosmic ray positron and electron fluxes as measured by PAMELA and Fermi LAT, we find that this possibility is ruled out by strong constraints from gamma-ray and antiproton observations. Therefore, we employ current data of indirect detection experiments to place strong constraints on the gravitino lifetime and the strength of R-parity violation. In addition, we discuss the prospects of forthcoming searches for a gravitino signal in the spectrum of cosmic-ray antideuterons, finding that they are in particular sensitive to rather low gravitino masses. Finally, we discuss in detail the prospects for detecting a neutrino signal from gravitino dark matter decays, finding that the sensitivity of neutrino telescopes like IceCube is competitive to observations in other cosmic ray channels, especially for rather heavy gravitinos. Moreover, we discuss the prospects for a direct detection of gravitino dark matter via R-parity violating inelastic scatterings off nucleons. We find that, although the scattering cross section is considerably enhanced compared to the case of elastic gravitino scattering, the expected signal is many orders of magnitude too small in order to hope for a detection in underground detectors. (orig.)

Deep inelastic scattering

International Nuclear Information System (INIS)

Aubert, J.J.

1982-01-01

Deep inelastic lepton-nucleon interaction experiments are renewed. Singlet and non-singlet structure functions are measured and the consistency of the different results is checked. A detailed analysis of the scaling violation is performed in terms of the quantum chromodynamics predictions [fr

Neutrino-Flavoured Sneutrino Dark Matter

CERN Document Server

March-Russell, John; McCullough, Matthew

2010-01-01

A simple theory of supersymmetric dark matter (DM) naturally linked to neutrino flavour physics is studied. The DM sector comprises a spectrum of mixed lhd-rhd sneutrino states where both the sneutrino flavour structure and mass splittings are determined by the associated neutrino masses and mixings. Prospects for indirect detection from solar capture are good due to a large sneutrino-nucleon cross-section afforded by the inelastic splitting (solar capture limits exclude an explanation of DAMA/LIBRA). We find parameter regions where all heavier states will have decayed, leaving only one flavour mixture of sneutrino as the candidate DM. Such regions have a unique `smoking gun' signature--sneutrino annihilation in the Sun produces a pair of neutrino mass eigenstates free from vacuum oscillations, with the potential for detection at neutrino telescopes through the observation of a hard spectrum of nu_mu and nu_tau (for a normal neutrino hierarchy). Next generation direct detection experiments can explore much of...

Dark energy and dark matter

International Nuclear Information System (INIS)

Comelli, D.; Pietroni, M.; Riotto, A.

2003-01-01

It is a puzzle why the densities of dark matter and dark energy are nearly equal today when they scale so differently during the expansion of the universe. This conundrum may be solved if there is a coupling between the two dark sectors. In this Letter we assume that dark matter is made of cold relics with masses depending exponentially on the scalar field associated to dark energy. Since the dynamics of the system is dominated by an attractor solution, the dark matter particle mass is forced to change with time as to ensure that the ratio between the energy densities of dark matter and dark energy become a constant at late times and one readily realizes that the present-day dark matter abundance is not very sensitive to its value when dark matter particles decouple from the thermal bath. We show that the dependence of the present abundance of cold dark matter on the parameters of the model differs drastically from the familiar results where no connection between dark energy and dark matter is present. In particular, we analyze the case in which the cold dark matter particle is the lightest supersymmetric particle

Big Bang synthesis of nuclear dark matter

International Nuclear Information System (INIS)

Hardy, Edward; Lasenby, Robert; March-Russell, John; West, Stephen M.

2015-01-01

We investigate the physics of dark matter models featuring composite bound states carrying a large conserved dark “nucleon” number. The properties of sufficiently large dark nuclei may obey simple scaling laws, and we find that this scaling can determine the number distribution of nuclei resulting from Big Bang Dark Nucleosynthesis. For plausible models of asymmetric dark matter, dark nuclei of large nucleon number, e.g. ≳10 8 , may be synthesised, with the number distribution taking one of two characteristic forms. If small-nucleon-number fusions are sufficiently fast, the distribution of dark nuclei takes on a logarithmically-peaked, universal form, independent of many details of the initial conditions and small-number interactions. In the case of a substantial bottleneck to nucleosynthesis for small dark nuclei, we find the surprising result that even larger nuclei, with size ≫10 8 , are often finally synthesised, again with a simple number distribution. We briefly discuss the constraints arising from the novel dark sector energetics, and the extended set of (often parametrically light) dark sector states that can occur in complete models of nuclear dark matter. The physics of the coherent enhancement of direct detection signals, the nature of the accompanying dark-sector form factors, and the possible modifications to astrophysical processes are discussed in detail in a companion paper.

Deep inelastic scattering near the Coulomb barrier

International Nuclear Information System (INIS)

Gehring, J.; Back, B.; Chan, K.

1995-01-01

Deep inelastic scattering was recently observed in heavy ion reactions at incident energies near and below the Coulomb barrier. Traditional models of this process are based on frictional forces and are designed to predict the features of deep inelastic processes at energies above the barrier. They cannot be applied at energies below the barrier where the nuclear overlap is small and friction is negligible. The presence of deep inelastic scattering at these energies requires a different explanation. The first observation of deep inelastic scattering near the barrier was in the systems 124,112 Sn + 58,64 Ni by Wolfs et al. We previously extended these measurements to the system 136 Xe + 64 Ni and currently measured the system 124 Xe + 58 Ni. We obtained better statistics, better mass and energy resolution, and more complete angular coverage in the Xe + Ni measurements. The cross sections and angular distributions are similar in all of the Sn + Ni and Xe + Ni systems. The data are currently being analyzed and compared with new theoretical calculations. They will be part of the thesis of J. Gehring

The Sommerfeld enhancement for dark matter with an excited state

International Nuclear Information System (INIS)

Slatyer, Tracy R.

2010-01-01

We present an analysis of the Sommerfeld enhancement to dark matter annihilation in the presence of an excited state, where the interaction inducing the enhancement is purely off-diagonal, such as in models of exciting or inelastic dark matter. We derive a simple and accurate semi-analytic approximation for the s-wave enhancement, which is valid provided the mass splitting between the ground and excited states is not too large, and discuss the cutoff of the enhancement for large mass splittings. We reproduce previously derived results in the appropriate limits, and demonstrate excellent agreement with numerical calculations of the enhancement. We show that the presence of an excited state leads to generically larger values of the Sommerfeld enhancement, larger resonances, and shifting of the resonances to lower mediator masses. Furthermore, in the presence of a mass splitting the enhancement is no longer a monotonic function of velocity: the enhancement where the kinetic energy is close to that required to excite the higher state can be up to twice as large as the enhancement at zero velocity

The dark components of the Universe are slowly clarified

Energy Technology Data Exchange (ETDEWEB)

Burdyuzha, V. V., E-mail: burdyuzh@asc.rssi.ru [Russian Academy of Sciences, Astro-Space Center, Lebedev Physical Institute (Russian Federation)

2017-02-15

The dark sector of the Universe is beginning to be clarified step by step. If the dark energy is vacuum energy, then 123 orders of this energy are reduced by ordinary physical processes. For many years, these unexplained orders were called a crisis of physics. There was indeed a “crisis” before the introduction of the holographic principle and entropic force in physics. The vacuum energy was spent on the generation of new quantum states during the entire life of the Universe, but in the initial period of its evolution the vacuum energy (78 orders) were reduced more effectively by the vacuum condensates produced by phase transitions, because the Universe lost the high symmetry during its expansion. Important problems of physical cosmology can be solved if the quarks, leptons, and gauge bosons are composite particles. The dark matter, partially or all consisting of familon-type pseudo-Goldstone bosons with a mass of 10{sup —5}–10{sup –3} eV, can be explained in the composite model. Three generations of elementary particles are absolutely necessary in this model. In addition, this model realizes three relativistic phase transitions in a medium of familons at different redshifts, forming a large-scale structure of dark matter that was “repeated” by baryons. We predict the detection of dark energy dynamics, the detection of familons as dark matter particles, and the development of spectroscopy for the dark medium due to the probable presence of dark atoms in it. Other viewpoints on the dark components of the Universe are also discussed briefly.

The dark components of the Universe are slowly clarified

International Nuclear Information System (INIS)

Burdyuzha, V. V.

2017-01-01

The dark sector of the Universe is beginning to be clarified step by step. If the dark energy is vacuum energy, then 123 orders of this energy are reduced by ordinary physical processes. For many years, these unexplained orders were called a crisis of physics. There was indeed a “crisis” before the introduction of the holographic principle and entropic force in physics. The vacuum energy was spent on the generation of new quantum states during the entire life of the Universe, but in the initial period of its evolution the vacuum energy (78 orders) were reduced more effectively by the vacuum condensates produced by phase transitions, because the Universe lost the high symmetry during its expansion. Important problems of physical cosmology can be solved if the quarks, leptons, and gauge bosons are composite particles. The dark matter, partially or all consisting of familon-type pseudo-Goldstone bosons with a mass of 10"—"5–10"–"3 eV, can be explained in the composite model. Three generations of elementary particles are absolutely necessary in this model. In addition, this model realizes three relativistic phase transitions in a medium of familons at different redshifts, forming a large-scale structure of dark matter that was “repeated” by baryons. We predict the detection of dark energy dynamics, the detection of familons as dark matter particles, and the development of spectroscopy for the dark medium due to the probable presence of dark atoms in it. Other viewpoints on the dark components of the Universe are also discussed briefly.

The dark components of the Universe are slowly clarified

Science.gov (United States)

Burdyuzha, V. V.

2017-02-01

The dark sector of the Universe is beginning to be clarified step by step. If the dark energy is vacuum energy, then 123 orders of this energy are reduced by ordinary physical processes. For many years, these unexplained orders were called a crisis of physics. There was indeed a "crisis" before the introduction of the holographic principle and entropic force in physics. The vacuum energy was spent on the generation of new quantum states during the entire life of the Universe, but in the initial period of its evolution the vacuum energy (78 orders) were reduced more effectively by the vacuum condensates produced by phase transitions, because the Universe lost the high symmetry during its expansion. Important problems of physical cosmology can be solved if the quarks, leptons, and gauge bosons are composite particles. The dark matter, partially or all consisting of familon-type pseudo-Goldstone bosons with a mass of 10—5-10-3 eV, can be explained in the composite model. Three generations of elementary particles are absolutely necessary in this model. In addition, this model realizes three relativistic phase transitions in a medium of familons at different redshifts, forming a large-scale structure of dark matter that was "repeated" by baryons. We predict the detection of dark energy dynamics, the detection of familons as dark matter particles, and the development of spectroscopy for the dark medium due to the probable presence of dark atoms in it. Other viewpoints on the dark components of the Universe are also discussed briefly.

Di-photon resonance and Dark Matter as heavy pions

CERN Document Server

Redi, Michele; Tesi, Andrea; Vigiani, Elena

2016-05-13

We analyse confining gauge theories where the 750 GeV di-photon resonance is a composite techni-pion that undergoes anomalous decays into SM vectors. These scenarios naturally contain accidentally stable techni-pions Dark Matter candidates. The di-photon resonance can acquire a larger width by decaying into Dark Matter through the CP-violating $\\theta$-term of the new gauge theory reproducing the cosmological Dark Matter density as thermal relic.

Significance of matrix diagonalization in modelling inelastic electron scattering

Energy Technology Data Exchange (ETDEWEB)

Lee, Z. [University of Ulm, Ulm 89081 (Germany); Hambach, R. [University of Ulm, Ulm 89081 (Germany); University of Jena, Jena 07743 (Germany); Kaiser, U.; Rose, H. [University of Ulm, Ulm 89081 (Germany)

2017-04-15

Electron scattering is always applied as one of the routines to investigate nanostructures. Nowadays the development of hardware offers more and more prospect for this technique. For example imaging nanostructures with inelastic scattered electrons may allow to produce component-sensitive images with atomic resolution. Modelling inelastic electron scattering is therefore essential for interpreting these images. The main obstacle to study inelastic scattering problem is its complexity. During inelastic scattering, incident electrons entangle with objects, and the description of this process involves a multidimensional array. Since the simulation usually involves fourdimensional Fourier transforms, the computation is highly inefficient. In this work we have offered one solution to handle the multidimensional problem. By transforming a high dimensional array into twodimensional array, we are able to perform matrix diagonalization and approximate the original multidimensional array with its twodimensional eigenvectors. Our procedure reduces the complicated multidimensional problem to a twodimensional problem. In addition, it minimizes the number of twodimensional problems. This method is very useful for studying multiple inelastic scattering. - Highlights: • 4D problems are involved in modelling inelastic electron scattering. • By means of matrix diagonalization, the 4D problems can be simplified as 2D problems. • The number of 2D problems is minimized by using this approach.

Inelastic light scattering in crystals

Science.gov (United States)

Sushchinskii, M. M.

The papers presented in this volume are concerned with a variety of problems in optics and solid state physics, such as Raman scattering of light in crystals and disperse media, Rayleigh and inelastic scattering during phase transitions, characteristics of ferroelectrics in relation to the general soft mode concept, and inelastic spectral opalescence. A group-theory approach is used to classify the vibrational spectra of the crystal lattice and to analyze the properties of idealized crystal models. Particular attention is given to surface vibrational states and to the study of the surface layers of crystals and films by light scattering methods.

Inelastic neutron scattering and lattice dynamics of minerals

Indian Academy of Sciences (India)

We review current research on minerals using inelastic neutron scattering and lattice dynamics calculations. Inelastic neutron scattering studies in combination with first principles and atomistic calculations provide a detailed understanding of the phonon dispersion relations, density of states and their manifestations in ...

Inelastic neutron scattering and lattice dynamics of minerals

Indian Academy of Sciences (India)

Abstract. We review current research on minerals using inelastic neutron scattering and lattice dynamics calculations. Inelastic neutron scattering studies in combination with first principles and atomistic calculations provide a detailed understanding of the phonon dispersion relations, density of states and their ...

Weak lensing: Dark Matter, Dark Energy and Dark Gravity

International Nuclear Information System (INIS)

Heavens, Alan

2009-01-01

In this non-specialist review I look at how weak lensing can provide information on the dark sector of the Universe. The review concentrates on what can be learned about Dark Matter, Dark Energy and Dark Gravity, and why. On Dark Matter, results on the confrontation of theoretical profiles with observation are reviewed, and measurements of neutrino masses discussed. On Dark Energy, the interest is whether this could be Einstein's cosmological constant, and prospects for high-precision studies of the equation of state are considered. On Dark Gravity, we consider the exciting prospects for future weak lensing surveys to distinguish General Relativity from extra-dimensional or other gravity theories.

Deep inelastic scattering

International Nuclear Information System (INIS)

Zakharov, V.I.

1977-01-01

The present status of the quark-parton-gluon picture of deep inelastic scattering is reviewed. The general framework is mostly theoretical and covers investigations since 1970. Predictions of the parton model and of the asymptotically free field theories are compared with experimental data available. The valence quark approximation is concluded to be valid in most cases, but fails to account for the data on the total momentum transfer. On the basis of gluon corrections introduced to the parton model certain predictions concerning both the deep inelastic structure functions and form factors are made. The contributions of gluon exchanges and gluon bremsstrahlung are highlighted. Asymptotic freedom is concluded to be very attractive and provide qualitative explanation to some experimental observations (scaling violations, breaking of the Drell-Yan-West type relations). Lepton-nuclear scattering is pointed out to be helpful in probing the nature of nuclear forces and studying the space-time picture of the parton model

Gravitational coupling to two-particle bound states and momentum conservation in deep inelastic scattering

International Nuclear Information System (INIS)

Batiz, Zoltan; Gross, Franz

2000-01-01

The momentum conservation sum rule for deep inelastic scattering (DIS) from composite particles is investigated using the general theory of relativity. For two (1+1)-dimensional examples, it is shown that covariant theories automatically satisy the DIS momentum conservation sum rule provided the bound state is covariantly normalized. Therefore, in these cases the two DIS sum rules for baryon conservation and momentum conservation are equivalent. (c) 2000 The American Physical Society

New statistical model of inelastic fast neutron scattering

International Nuclear Information System (INIS)

Stancicj, V.

1975-07-01

A new statistical model for treating the fast neutron inelastic scattering has been proposed by using the general expressions of the double differential cross section in impuls approximation. The use of the Fermi-Dirac distribution of nucleons makes it possible to derive an analytical expression of the fast neutron inelastic scattering kernel including the angular momenta coupling. The obtained values of the inelastic fast neutron cross section calculated from the derived expression of the scattering kernel are in a good agreement with the experiments. A main advantage of the derived expressions is in their simplicity for the practical calculations

Deep inelastic scattering near the Coulomb barrier

Energy Technology Data Exchange (ETDEWEB)

Gehring, J.; Back, B.; Chan, K. [and others

1995-08-01

Deep inelastic scattering was recently observed in heavy ion reactions at incident energies near and below the Coulomb barrier. Traditional models of this process are based on frictional forces and are designed to predict the features of deep inelastic processes at energies above the barrier. They cannot be applied at energies below the barrier where the nuclear overlap is small and friction is negligible. The presence of deep inelastic scattering at these energies requires a different explanation. The first observation of deep inelastic scattering near the barrier was in the systems {sup 124,112}Sn + {sup 58,64}Ni by Wolfs et al. We previously extended these measurements to the system {sup 136}Xe + {sup 64}Ni and currently measured the system {sup 124}Xe + {sup 58}Ni. We obtained better statistics, better mass and energy resolution, and more complete angular coverage in the Xe + Ni measurements. The cross sections and angular distributions are similar in all of the Sn + Ni and Xe + Ni systems. The data are currently being analyzed and compared with new theoretical calculations. They will be part of the thesis of J. Gehring.

Inelastic instruments at the ISIS facility

International Nuclear Information System (INIS)

Taylor, A.D.

1988-01-01

This summarises the status of the inelastic spectrometers at the ISIS facility and gives some highlights from their scientific programme. The inelastic spectrometers HET, TFXA and IRIS are now being used routinely by UK and International research groups and have produced notable scientific results. Work has progressed steadily on eVS. The PRISMA spectrometer, the product of a collaboration between CNR, Italy and RAL, was installed this summer. Earlier this year an agreement was reached in principle between the Rutherford Appleton Laboratory and the University of Wurzburg (West Germany) to build a second spectrometer (ROTAX) for the study of coherent inelastic excitations. A more sophisticated technical concept than that of PRISMA, based on a nonuniformly rotating analyser, it will allow a greater flexibility in the choice of dynamic scans. Substantial progress has also been made on the design of MARI, the sister spectrometer to HET, which is being built as part of the UK-Japan collaboration on pulsed neutron scattering. (author)

Asymmetric capture of Dirac dark matter by the Sun

International Nuclear Information System (INIS)

Blennow, Mattias; Clementz, Stefan

2015-01-01

Current problems with the solar model may be alleviated if a significant amount of dark matter from the galactic halo is captured in the Sun. We discuss the capture process in the case where the dark matter is a Dirac fermion and the background halo consists of equal amounts of dark matter and anti-dark matter. By considering the case where dark matter and anti-dark matter have different cross sections on solar nuclei as well as the case where the capture process is considered to be a Poisson process, we find that a significant asymmetry between the captured dark particles and anti-particles is possible even for an annihilation cross section in the range expected for thermal relic dark matter. Since the captured number of particles are competitive with asymmetric dark matter models in a large range of parameter space, one may expect solar physics to be altered by the capture of Dirac dark matter. It is thus possible that solutions to the solar composition problem may be searched for in these type of models

Asymmetric capture of Dirac dark matter by the Sun

Energy Technology Data Exchange (ETDEWEB)

Blennow, Mattias; Clementz, Stefan [Department of Theoretical Physics, School of Engineering Sciences, KTH Royal Institute of Technology, Albanova University Center,106 91, Stockholm (Sweden)

2015-08-18

Current problems with the solar model may be alleviated if a significant amount of dark matter from the galactic halo is captured in the Sun. We discuss the capture process in the case where the dark matter is a Dirac fermion and the background halo consists of equal amounts of dark matter and anti-dark matter. By considering the case where dark matter and anti-dark matter have different cross sections on solar nuclei as well as the case where the capture process is considered to be a Poisson process, we find that a significant asymmetry between the captured dark particles and anti-particles is possible even for an annihilation cross section in the range expected for thermal relic dark matter. Since the captured number of particles are competitive with asymmetric dark matter models in a large range of parameter space, one may expect solar physics to be altered by the capture of Dirac dark matter. It is thus possible that solutions to the solar composition problem may be searched for in these type of models.

Asymmetric capture of Dirac dark matter by the Sun

Energy Technology Data Exchange (ETDEWEB)

Blennow, Mattias; Clementz, Stefan, E-mail: emb@kth.se, E-mail: scl@kth.se [Department of Theoretical Physics, School of Engineering Sciences, KTH Royal Institute of Technology, Albanova University Center, 106 91, Stockholm (Sweden)

2015-08-01

Current problems with the solar model may be alleviated if a significant amount of dark matter from the galactic halo is captured in the Sun. We discuss the capture process in the case where the dark matter is a Dirac fermion and the background halo consists of equal amounts of dark matter and anti-dark matter. By considering the case where dark matter and anti-dark matter have different cross sections on solar nuclei as well as the case where the capture process is considered to be a Poisson process, we find that a significant asymmetry between the captured dark particles and anti-particles is possible even for an annihilation cross section in the range expected for thermal relic dark matter. Since the captured number of particles are competitive with asymmetric dark matter models in a large range of parameter space, one may expect solar physics to be altered by the capture of Dirac dark matter. It is thus possible that solutions to the solar composition problem may be searched for in these type of models.

Evaluation of new pharmaceuticals using in vivo neutron inelastic scattering and neutron activation analysis

International Nuclear Information System (INIS)

Kehayias, J.J.

2000-01-01

Nutritional status of patients can be evaluated by monitoring changes in body composition, including depletion of protein and muscle, adipose tissue distribution and changes in hydration status, bone or cell mass. Fast neutron activation (for N and P) and neutron inelastic scattering (for C and O) are used to assess in vivo elements characteristic of specific body compartments. The fast neutrons are produced with a sealed deuterium-tritium (D-T) neutron generator. This method provides the most direct assessment of body composition. Non-bone phosphorus for muscle is measured by the 31 P(n,α) 28 Al reaction, and nitrogen for protein via the (n,2n) fast neutron reaction. Inelastic neutron scattering is used for the measurement of total body carbon and oxygen. Carbon is used to derive body fat, after subtracting carbon contributions due to protein, bone and glycogen. Carbon-to-oxygen (C/O) ratio is used to measure distribution of fat and lean tissue in the body and to monitor small changes of lean mass and its quality. In addition to evaluating the efficacy of new treatments, the system is used to study the mechanisms of lean tissue depletion with aging and to investigate methods for preserving function and quality of life in the elderly. (author)

Photoproduction of Inelastic and Elastic $J/\\psi$ Vector Mesons

Energy Technology Data Exchange (ETDEWEB)

Stundzia, Audrius Bronius [Toronto U.

1992-06-01

Results and analysis on the inelastic and elastic photoproduction of $J /\\psi$ vector mesons by Fermilab experiment E691 are presented. The inelastic, deep inelastic, coherent elastic and incoherent elastic cross sections were measured at ($E_{\\gamma}$) = 145 GeV. The $d\\sigma / dzdp^2_{\\tau}$} distribution and the photon energy dependence of the cross sections for these production processes were also measured. The deep inelastic $J /\\psi$ was analyzed in the colour-singlet photon-gluon-fusion model. It was found that the $d\\sigma / dzdp^2_{\\tau}$ distribution and the the rise of the cross section with $E\\gamma$ are both well described by a relatively soft gluon distribution [xG( x) $\\alpha$ ($1 - x )^{ng}$, where $n_g$ = 6.5 ± 1.1 (stat.)$^{+1.0}_{-0.6}$(syst.)].

Gamma-rays from deep inelastic collisions

International Nuclear Information System (INIS)

Stephens, F.S.

1979-01-01

The γ-rays associated with deep inelastic collisions can give information about the magnitude and orientation of the angular momentum transferred in these events. In this review, special emphasis is placed on understanding the origin and nature of these γ-rays in order to avoid some of the ambiguities that can arise. The experimental information coming from these γ-ray studies is reviewed, and compared briefly with that obtained by other methods and also with the expectations from current models for deep inelastic collisions. 15 figures

Resonant inelastic scattering by use of geometrical optics.

Science.gov (United States)

Schulte, Jörg; Schweiger, Gustav

2003-02-01

We investigate the inelastic scattering on spherical particles that contain one concentric inclusion in the case of input and output resonances, using a geometrical optics method. The excitation of resonances is included in geometrical optics by use of the concept of tunneled rays. To get a quantitative description of optical tunneling on spherical surfaces, we derive appropriate Fresnel-type reflection and transmission coefficients for the tunneled rays. We calculate the inelastic scattering cross section in the case of input and output resonances and investigate the influence of the distribution of the active material in the particle as well as the influence of the inclusion on inelastic scattering.

Dark matter and dark radiation

International Nuclear Information System (INIS)

Ackerman, Lotty; Buckley, Matthew R.; Carroll, Sean M.; Kamionkowski, Marc

2009-01-01

We explore the feasibility and astrophysical consequences of a new long-range U(1) gauge field ('dark electromagnetism') that couples only to dark matter, not to the standard model. The dark matter consists of an equal number of positive and negative charges under the new force, but annihilations are suppressed if the dark-matter mass is sufficiently high and the dark fine-structure constant α-circumflex is sufficiently small. The correct relic abundance can be obtained if the dark matter also couples to the conventional weak interactions, and we verify that this is consistent with particle-physics constraints. The primary limit on α-circumflex comes from the demand that the dark matter be effectively collisionless in galactic dynamics, which implies α-circumflex -3 for TeV-scale dark matter. These values are easily compatible with constraints from structure formation and primordial nucleosynthesis. We raise the prospect of interesting new plasma effects in dark-matter dynamics, which remain to be explored.

Proceedings, 8th International Workshop on the Dark Side of the Universe (DSU 2012)

CERN Document Server

2012-01-01

Recent observations suggest that about 95% of the Universe's energy lies in a dark sector. This sector is comprised of dark matter, a form of non-luminous matter, and dark energy whose origin and composition is unknown. Dark matter seems to make up 23% of the Universe and it possibly consists of new exotic particles that interact very weakly with ordinary matter. Dark energy, about 73% of the Universe, is responsible for a mysterious force that is speeding up its expansion. The origin and microscopic composition of dark matter and dark energy are outstanding fundamental problems in physics, and may possibly find a resolution in new theories pointing beyond the standard models of particle physics and cosmology. This prompts a strong connection between particle physics, astrophysics and cosmology. The aim of the meeting is to bring together experts from all around the world to discuss the latest advances in the theoretical, phenomenological and experimental aspects of the field.

Deep inelastic lepton scattering

International Nuclear Information System (INIS)

Nachtmann, O.

1977-01-01

Deep inelastic electron (muon) nucleon and neutrino nucleon scattering as well as electron positron annihilation into hadrons are reviewed from a theoretical point of view. The emphasis is placed on comparisons of quantum chromodynamics with the data. (orig.) [de

Inelastic Structural Control Based on MBC and FAM

Directory of Open Access Journals (Sweden)

Li Gang

2011-01-01

Full Text Available A complex structure has the characters of many degrees of freedom and intricate shape, especially inelastic behavior under strong external loadings. It is hard to apply the structural control technology to it. In this paper, a new method that combines the Market-Based Control (MBC strategy and Force Analogy Method (FAM is presented to analyze the inelastic behavior of structure with magnetorheological dampers. The MBC is used to reduce the structural vibration response, and FAM is proposed to perform the inelastic analysis. A numerical example is used to compare the control effect of the new method and LQR algorithm, which show the accuracy and efficiency of the proposed computational method.

Deep-inelastic electron-proton diffraction

International Nuclear Information System (INIS)

Dainton, J.B.

1995-11-01

Recent measurements by the H1 collaboration at HERA of the cross section for deep-inelastic electron-proton scattering in which the proton interacts with minimal energy transfer and limited 4-momentum transfer squared are presented in the form of the contribution F 2 D(3) to the proton structure function F 2 . By parametrising the cross section phenomenologically in terms of a leading effective Regge pole exchange and comparing the result with a similar parametrisation of hadronic pp physics, the proton interaction is demonstrated to be dominantly of a diffractive nature. The quantitative interpretation of the parametrisation in terms of the properties of an effective leading Regge pole exchange, the pomeron (IP), shows that there is no evidence for a 'harder' BFKL-motivated IP in such deep-inelastic proton diffraction. The total contribution of proton diffraction to deep-inelastic electron-proton scattering is measured to be ∝10% and to be rather insensitive to Bjorken-x and Q 2 . A first measurement of the partonic structure of diffractive exchange is presented. It is shown to be readily interpreted in terms of the exchange of gluons, and to suggest that the bulk of diffractive momentum transfer is carried by a leading gluon. (orig.)

The renormalization of several composite operator insertions, Wilson expansions of composite operators, and the applications to short-distance behaviour

International Nuclear Information System (INIS)

Collecott, P.S.

1978-01-01

The renormalization of composite operator insertions is examined within a normal product framework, and various identities between composite operator insertions are proved. In particular a proof of the Wilson expansion of composite operators in the presence of other composite operators is given. The analysis necessitates a re-examination of several physical processes, and it is shown in particular why the results for deep inelastic scattering still hold. (Auth.)

Average multiplications in deep inelastic processes and their interpretation

International Nuclear Information System (INIS)

Kiselev, A.V.; Petrov, V.A.

1983-01-01

Inclusive production of hadrons in deep inelastic proceseseus is considered. It is shown that at high energies the jet evolution in deep inelastic processes is mainly of nonperturbative character. With the increase of a final hadron state energy the leading contribution to an average multiplicity comes from a parton subprocess due to production of massive quark and gluon jets and their further fragmentation as diquark contribution becomes less and less essential. The ratio of the total average multiplicity in deep inelastic processes to the average multiplicity in e + e - -annihilation at high energies tends to unity

Quantum Field Theory of Interacting Dark Matter/Dark Energy: Dark Monodromies

CERN Document Server

D'Amico, Guido; Kaloper, Nemanja

2016-11-28

We discuss how to formulate a quantum field theory of dark energy interacting with dark matter. We show that the proposals based on the assumption that dark matter is made up of heavy particles with masses which are very sensitive to the value of dark energy are strongly constrained. Quintessence-generated long range forces and radiative stability of the quintessence potential require that such dark matter and dark energy are completely decoupled. However, if dark energy and a fraction of dark matter are very light axions, they can have significant mixings which are radiatively stable and perfectly consistent with quantum field theory. Such models can naturally occur in multi-axion realizations of monodromies. The mixings yield interesting signatures which are observable and are within current cosmological limits but could be constrained further by future observations.

Deep inelastic inclusive weak and electromagnetic interactions

International Nuclear Information System (INIS)

Adler, S.L.

1976-01-01

The theory of deep inelastic inclusive interactions is reviewed, emphasizing applications to electromagnetic and weak charged current processes. The following reactions are considered: e + N → e + X, ν + N → μ - + X, anti ν + N → μ + + X where X denotes a summation over all final state hadrons and the ν's are muon neutrinos. After a discussion of scaling, the quark-parton model is invoked to explain the principle experimental features of deep inelastic inclusive reactions

Inelastic scattering of quasifree electrons on O7+ projectiles

International Nuclear Information System (INIS)

Toth, G.; Grabbe, S.; Richard, P.; Bhalla, C.P.

1996-01-01

Absolute doubly differential cross sections (DDCS close-quote s) for the resonant inelastic scattering of quasifree target electrons on H-like projectiles have been measured. Electron spectra for 20.25-MeV O 7+ projectiles on an H 2 target were measured. The spectra contain a resonant contribution from the 3l3l ' doubly excited states of O 6+ , which decay predominantly to the 2l states of the O 7+ via autoionization, and a nonresonant contribution from the direct excitation of the projectiles to the O 7+ (2l) state by the quasifree target electrons. Close-coupling R-matrix calculations for the inelastic scattering of free electrons on O 7+ ions were performed. The relation between the electron-ion inelastic scattering calculation and the electron DDCS close-quote s for the ion-atom collision was established by using the inelastic scattering model (ISM). We found excellent agreement between the theoretical and measured resonant peak positions and relative peak heights. The calculated absolute double differential cross sections for the resonance processes are also in good agreement with the measured data. The implication is that collisions of highly charged ions on hydrogen can be used to obtain high-resolution, angle- resolved differential inelastic electron-scattering cross section. copyright 1996 The American Physical Society

Nuclear structure in deep-inelastic reactions

International Nuclear Information System (INIS)

Rehm, K.E.

1986-01-01

The paper concentrates on recent deep inelastic experiments conducted at Argonne National Laboratory and the nuclear structure effects evident in reactions between super heavy nuclei. Experiments indicate that these reactions evolve gradually from simple transfer processes which have been studied extensively for lighter nuclei such as 16 O, suggesting a theoretical approach connecting the one-step DWBA theory to the multistep statistical models of nuclear reactions. This transition between quasi-elastic and deep inelastic reactions is achieved by a simple random walk model. Some typical examples of nuclear structure effects are shown. 24 refs., 9 figs

Polarization transfer in inelastic scattering

International Nuclear Information System (INIS)

Moss, J.M.

1980-01-01

Polarization transfer experiments are now feasible for inelastic scattering experiments on complex nuclei. Experiments thus far have dealt with the spin-flip probability; this observable is sensitive to the action of spin-spin and tensor forces in inelastic scattering. Spin-flip probabilities at E approx. 40 MeV in isoscalar transitions in 12 C(12.71 MeV) and 15 O(8.89 MeV) show considerable deviation from DWBA-shell model predictions; this deviation indicates evidence for more complex reaction mechanisms. Experiments at intermediate energies will soon be possible and will yield data of much higher precision than is possible at lower (E < 100 MeV) energies. These experiments hold exciting promise in such areas as nuclear critical opalescence. 7 figures, 1 table

Constraints on Leptophilic Dark Matter from the AMS-02 Experiment

International Nuclear Information System (INIS)

Cavasonza, Leila Ali; Gast, Henning; Schael, Stefan; Krämer, Michael; Pellen, Mathieu

2017-01-01

The annihilation of dark matter particles in the Galactic halo of the Milky Way may lead to cosmic ray signatures that can be probed by the AMS-02 experiment, which has measured the composition and fluxes of charged cosmic rays with unprecedented precision. Given the absence of characteristic spectral features in the electron and positron fluxes measured by AMS-02, we derive upper limits on the dark matter annihilation cross section for leptophilic dark matter models. Our limits are based on a new background model that describes all recent measurements of the energy spectra of cosmic-ray positrons and electrons. For thermal dark matter relics, we can exclude dark matter masses below about 100 GeV. We include the radiation of electroweak gauge bosons in the dark matter annihilation process and compute the antiproton signal that can be expected within leptophilic dark matter models.

Constraints on Leptophilic Dark Matter from the AMS-02 Experiment

Energy Technology Data Exchange (ETDEWEB)

Cavasonza, Leila Ali; Gast, Henning; Schael, Stefan [I. Physikalisches Institut, RWTH Aachen University, D-52074 Aachen (Germany); Krämer, Michael [Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, D-52074 Aachen (Germany); Pellen, Mathieu, E-mail: cavasonza@physik.rwth-aachen.de [Institut für Theoretische Physik und Astrophysik, Universität Würzburg, D-97074 Würzburg (Germany)

2017-04-10

The annihilation of dark matter particles in the Galactic halo of the Milky Way may lead to cosmic ray signatures that can be probed by the AMS-02 experiment, which has measured the composition and fluxes of charged cosmic rays with unprecedented precision. Given the absence of characteristic spectral features in the electron and positron fluxes measured by AMS-02, we derive upper limits on the dark matter annihilation cross section for leptophilic dark matter models. Our limits are based on a new background model that describes all recent measurements of the energy spectra of cosmic-ray positrons and electrons. For thermal dark matter relics, we can exclude dark matter masses below about 100 GeV. We include the radiation of electroweak gauge bosons in the dark matter annihilation process and compute the antiproton signal that can be expected within leptophilic dark matter models.

Inelastic magnon scattering

Directory of Open Access Journals (Sweden)

Robert de Mello Koch

2017-05-01

Full Text Available We study the worldsheet S-matrix of a string attached to a D-brane in AdS5×S5. The D-brane is either a giant graviton or a dual giant graviton. In the gauge theory, the operators we consider belong to the su(2|3 sector of the theory. Magnon excitations of open strings can exhibit both elastic (when magnons in the bulk of the string scatter and inelastic (when magnons at the endpoint of an open string participate scattering. Both of these S-matrices are determined (up to an overall phase by the su(2|22 global symmetry of the theory. In this note we study the S-matrix for inelastic scattering. We show that it exhibits poles corresponding to boundstates of bulk and boundary magnons. A crossing equation is derived for the overall phase. It reproduces the crossing equation for maximal giant gravitons, in the appropriate limit. Finally, scattering in the su(2 sector is computed to two loops. This two loop result, which determines the overall phase to two loops, will be useful when a unique solution to the crossing equation is to be selected.

Inelastic structural design approach using their relaxation locus

International Nuclear Information System (INIS)

Kasahara, Naoto

2000-08-01

Elevated temperature structural design codes pay attention to strain concentration at structural discontinuities due to creep and plasticity, since it causes to enlarge creep-fatigue damage of materials. One of the difficulties to predict strain concentration is its dependency on loading, constitutive equations, and relaxation time. This study investigated fundamental mechanism of strain concentration and its main factors. The results revealed that strain concentration was caused from strain redistribution between elastic and inelastic region, which can be quantified by the characteristics of structural compliance. Characteristic of compliance is controlled by elastic region in structures and is insensitive to constitutive equations. It means that inelastic analysis is easily applied to get compliance characteristics. By utilizing this fact, simplified inelastic analysis method was proposed based on characteristics of compliance change for prediction of strain concentration. (author)

Asymmetric dark matter and the hadronic spectra of hidden QCD

Science.gov (United States)

Lonsdale, Stephen J.; Schroor, Martine; Volkas, Raymond R.

2017-09-01

The idea that dark matter may be a composite state of a hidden non-Abelian gauge sector has received great attention in recent years. Frameworks such as asymmetric dark matter motivate the idea that dark matter may have similar mass to the proton, while mirror matter and G ×G grand unified theories provide rationales for additional gauge sectors which may have minimal interactions with standard model particles. In this work we explore the hadronic spectra that these dark QCD models can allow. The effects of the number of light colored particles and the value of the confinement scale on the lightest stable state, the dark matter candidate, are examined in the hyperspherical constituent quark model for baryonic and mesonic states.

Determination of the rate of energy partition in deeply inelastic collisions

International Nuclear Information System (INIS)

Lazzarini, A.; Vandenbosch, R.

1984-01-01

We discuss how excitation energy is partitioned in a deeply inelastic collision. Using the nucleon exchange mechanism for the deep inelastic scattering process, it is possible to draw on existing information about the evolution of the charge and mass distributions with energy loss and combine this with recent information on the partition of excitation energy in deeply inelastic collisions to obtain rates of heating for the two reaction partners

Dark matter direct detection signals inferred from a cosmological N-body simulation with baryons

International Nuclear Information System (INIS)

Ling, F.-S.; Nezri, E.; Athanassoula, E.; Teyssier, R.

2010-01-01

We extract at redshift z = 0 a Milky Way sized object including gas, stars and dark matter (DM) from a recent, high-resolution cosmological N-body simulation with baryons. Its resolution is sufficient to witness the formation of a rotating disk and bulge at the center of the halo potential, therefore providing a realistic description of the birth and the evolution of galactic structures in the ΛCDM cosmology paradigm. The phase-space structure of the central galaxy reveals that, throughout a thick region, the dark halo is co-rotating on average with the stellar disk. At the Earth's location, the rotating component, sometimes called dark disk in the literature, is characterized by a minimum lag velocity v lag ≅ 75 km/s, in which case it contributes to around 25% of the total DM local density, whose value is ρ DM ≅ 0.37GeV/cm 3 . The velocity distributions also show strong deviations from pure Gaussian and Maxwellian distributions, with a sharper drop of the high velocity tail. We give a detailed study of the impact of these features on the predictions for DM signals in direct detection experiments. In particular, the question of whether the modulation signal observed by DAMA is or is not excluded by limits set by other experiments (CDMS, XENON and CRESST...) is re-analyzed and compared to the case of a standard Maxwellian halo. We consider spin-independent interactions for both the elastic and the inelastic scattering scenarios. For the first time, we calculate the allowed regions for DAMA and the exclusion limits of other null experiments directly from the velocity distributions found in the simulation. We then compare these results with the predictions of various analytical distributions. We find that the compatibility between DAMA and the other experiments is improved. In the elastic scenario, the DAMA modulation signal is slightly enhanced in the so-called channeling region, as a result of several effects that include a departure from a Maxwellian

Inelastic analysis acceptance criteria for radioactive material transportation containers

International Nuclear Information System (INIS)

Ammerman, D.J.; Ludwigsen, J.S.

1993-01-01

The design criteria currently used in the design of radioactive material (RAM) transportation containers are taken from the ASME Boiler and Pressure Vessel Code (ASME, 1992). These load-based criteria are ideally suited for pressure vessels where the loading is quasistatic and all stresses are in equilibrium with externally applied loads. For impact events, the use of load-based criteria is less supportable. Impact events tend to be energy controlled, and thus, energy-based acceptance criteria would appear to be more appropriate. Determination of an ideal design criteria depends on what behavior is desired. Currently there is not a design criteria for inelastic analysis for RAM nation packages that is accepted by the regulatory agencies. This lack of acceptance criteria is one of the major factors in limiting the use of inelastic analysis. In this paper inelastic analysis acceptance criteria based on stress and strain-energy density will be compared for two stainless steel test units subjected to impacts onto an unyielding target. Two different material models are considered for the inelastic analysis, a bilinear fit of the stress-strain curve and a power law hardening model that very closely follows the stress-strain curve. It is the purpose of this paper to stimulate discussion and research into the area of strain-energy density based inelastic analysis acceptance criteria

Inelastic analysis methods for piping systems

International Nuclear Information System (INIS)

Boyle, J.T.; Spence, J.

1980-01-01

The analysis of pipework systems which operate in an environment where local inelastic strains are evident is one of the most demanding problems facing the stress analyst in the nuclear field. The spatial complexity of even the most modest system makes a detailed analysis using finite element techniques beyond the scope of current computer technology. For this reason the emphasis has been on simplified methods. It is the aim of this paper to provide a reasonably complete, state-of-the-art review of inelastic pipework analysis methods and to attempt to highlight areas where reliable information is lacking and further work is needed. (orig.)

Inelastic neutron scattering from glass formers

International Nuclear Information System (INIS)

Buchenau, U.

1997-01-01

Neutron spectra below and above the glass transition temperature show a pronounced difference between strong and fragile glass formers in Angell's fragility scheme. The strong anharmonic increase of the inelastic scattering with increasing temperature in fragile substances is absent in the strongest glass former SiO 2 . That difference is reflected in the temperature dependence of Brillouin sound velocities above the glass transition. Coherent inelastic neutron scattering data indicate a mixture of sound waves and local modes at the low frequency boson peak. A relation between the fragility and the temperature dependence of the transverse hypersound velocity at the glass temperature is derived. (author)

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

Time dependent micromechanics in continuous graphite fiber/epoxy composites with fiber breaks

Science.gov (United States)

Zhou, Chao Hui

Time dependent micromechanics in graphite fiber/epoxy composites around fiber breaks was investigated with micro Raman spectroscopy (MRS) and two shear-lag based composite models, a multi-fiber model (VBI) and a single fiber model (SFM), which aim at predicting the strain/stress evolutions in the composite from the matrix creep behavior and fiber strength statistics. This work is motivated by the need to understand the micromechanics and predict the creep-rupture of the composites. Creep of the unfilled epoxy was characterized under different stress levels and at temperatures up to 80°C, with two power law functions, which provided the modeling parameters used as input for the composite models. Both the VBI and the SFM models showed good agreement with the experimental data obtained with MRS, when inelasticity (interfacial debonding and/or matrix yielding) was not significant. The maximum shear stress near a fiber break relaxed at t-alpha/2 (or as (1+ talpha)-1/2) and the load recovery length increased at talpha/2(or (1+ talpha)1/2) following the model predictions. When the inelastic zone became non-negligible, the viscoelastic VBI model lost its competence, while the SFM with inelasticity showed good agreement with the MRS measurements. Instead of using the real fiber spacing, an effective fiber spacing was used in model predictions, taking into account of the radial decay of the interfacial shear stress from the fiber surface. The comparisons between MRS data and the SFM showed that inelastic zone would initiate when the shear strain at the fiber end exceeds a critical value gammac which was determined to be 5% for this composite system at room temperature and possibly a smaller value at elevated temperatures. The stress concentrations in neighboring intact fibers played important roles in the subsequent fiber failure and damage growth. The VBI model predicts a constant stress concentration factor, 1.33, for the 1st nearest intact fiber, which is in good

Asymmetric dark matter and the Sun

DEFF Research Database (Denmark)

Frandsen, Mads Toudal; Sarkar, Subir

2010-01-01

Cold dark matter particles with an intrinsic matter-antimatter asymmetry do not annihilate after gravitational capture by the Sun and can affect its interior structure. The rate of capture is exponentially enhanced when such particles have self-interactions of the right order to explain structure...... formation on galactic scales. A `dark baryon' of mass 5 GeV is a natural candidate and has the required relic abundance if its asymmetry is similar to that of ordinary baryons. We show that such particles can solve the `solar composition problem'. The predicted small decrease in the low energy neutrino...

Elastic and inelastic photon scattering on the atomic nuclei

International Nuclear Information System (INIS)

Piskarev, I.M.

1982-01-01

Works on investigation of elastic and inelastic scattering of photons on heavy and intermediate nuclei are briefly reviewed. Theoretical problems of nuclear and electron Tompson, Releev and Delbrueck scatterings as well as nuclear resonance scattering are briefly discussed. It is shown that differential cross section of coherent elastic scattering is expressed by means of partial amplitudes of shown processes. Experimental investigations on elastic scattering in the region of threshold energies of photonucleon reactions are described. Problems of theoretical description of elastic scattering in different variants of collective models are considered. Discussed are works, investigating channels of inelastic photon scattering with excitation of nuclear Raman effect. It is noted that to describe channels of inelastic photon scattering it is necessary to use models, that correctly regard the microscopic structure of giant resonance levels to obtain information on the nature of these levels. Investigations of processes of photon elastic and inelastic scattering connected with fundamental characteristics of atomic nucleus, permit to obtain valuable spectroscopic information on high-lying levels of nucleus. Detail investigation of photon scattering in a wide range of energies is necessary [ru

Dark chocolate’s compositional effects revealed by oscillatory rheology

NARCIS (Netherlands)

van der Vaart, K.; Depypere, F.; De Graef, V.; Schall, P.; Fall, A.; Bonn, D.; Dewettinck, K.

2013-01-01

In this study, two types of oscillatory shear rheology are applied on dark chocolate with varying volume fraction, particle size distribution, and soy lecithin concentration. The first, a conventional strain sweep, allows for the separation of the elastic and viscous properties during the yielding.

Decaying dark matter from dark instantons

International Nuclear Information System (INIS)

Carone, Christopher D.; Erlich, Joshua; Primulando, Reinard

2010-01-01

We construct an explicit, TeV-scale model of decaying dark matter in which the approximate stability of the dark matter candidate is a consequence of a global symmetry that is broken only by instanton-induced operators generated by a non-Abelian dark gauge group. The dominant dark matter decay channels are to standard model leptons. Annihilation of the dark matter to standard model states occurs primarily through the Higgs portal. We show that the mass and lifetime of the dark matter candidate in this model can be chosen to be consistent with the values favored by fits to data from the PAMELA and Fermi-LAT experiments.

QCD expectations for deep inelastic scattering at small x

International Nuclear Information System (INIS)

Kwiecinski, J.

1993-01-01

The basic QCD expectations concerning the deep inelastic scattering at low x where x is the Bjorken scaling variable are reviewed. This includes discussion of the Lipatov equation which sums the leading powers of Ln(1/x) and the shadowing effects. Phenomenological implications of the theoretical expectations for the deep inelastic lepton-hadron scattering in the small x region which will be accessible at the HERA ep collider are described. We give predictions for structure functions F 2 and F L based on the k T factorization theorem and discuss jet production in deep inelastic lepton scattering. The list of other topical problems relevant for the small x physics is given. (author). 46 refs, 7 figs

Inelastic two composite particle systems scattering at high energy

International Nuclear Information System (INIS)

Zhang Yushun.

1986-11-01

In this paper, by using the collective coordinate of Bohr and phenomenological deformed optical potentials, the scattering amplitudes of two composite particle systems can be obtained and the collective excitation for two composite particle systems in the scattering process is discussed. (author). 10 refs, 6 figs, 2 tabs

A dynamic elastic and inelastic scattering theory of high-energy electrons

International Nuclear Information System (INIS)

Wang Zhonglin

1990-01-01

A review is given on the applications of elastic multislice theory for simulating the images and diffractions of reflection electron microscopy. The limitation of this theory is illustrated according to some experimental observations. A generalized elastic and inelastic multislice theory is then introduced from quantum mechanics; its applications for approaching inelastic plasmon excitation and phonon excitation (or thermal diffuse scattering) are discussed. The energy-filtered inelastic high resolution images can be simulated based on this theory

Pion inelastic scattering and the pion-nucleus effective interaction

International Nuclear Information System (INIS)

Carr, J.A.

1983-01-01

This work examines pion inelastic scattering with the primary purpose of gaining a better understanding of the properties of the pion-nucleus interaction. The main conclusion of the work is that an effective interaction which incorporates the most obvious theoretical corrections to the impulse approximation does a good job of explaining pion elastic and inelastic scattering from zero to 200 MeV without significant adjustments to the strength parameters of the force. Watson's multiple scattering theory is used to develop a theoretical interaction starting from the free pion-nucleon interaction. Elastic scattering was used to calibrate the isoscalar central interaction. It was found that the impulse approximation did poorly at low energy, while the multiple scattering corrections gave good agreement with all of the data after a few minor adjustments in the force. The distorted wave approximation for the inelastic transition matrix elements are evaluated for both natural and unnatural parity excitations. The isoscalar natural parity transitions are used to test the reaction theory, and it is found that the effective interaction calibrated by elastic scattering produces good agreement with the inelastic data. Calculations are also shown for other inelastic and charge exchange reactions. It appears that the isovector central interaction is reasonable, but the importance of medium corrections cannot be determined. The unnatural parity transitions are also reasonably described by the theoretical estimate of the spin-orbit interaction, but not enough systematic data exists to reach a firm conclusion

A unified inelastic constitutive equation in terms of anisotropic yield function

International Nuclear Information System (INIS)

Inoue, T.; Imatani, S.

1989-01-01

In order to describe the material behavior under complicated loading conditions, inelastic constitutive equations accounting for the plasticity-creep interaction have been proposed by several researchers. However, these models are developed to predict the hardening and/or softening phenomena during the inelastic deformation processes, and two important features still remain to be considered; material anisotropy induced by the prior deformation history and inelastic flow or, in another word, directionality of the inelastic strain rate. This paper deals with a unified constitutive model capable of expressing both the deformation-induced anisotropy and the anisotropic flow. In the first part of the paper, an anisotropic yield function which can simulate both the Bauschinger effect and the cross effect is proposed. Then, the excess stress theory is applied to a viscoplastic constitutive relationship so as to describe the plasticity-creep interaction behavior. The experimental verification is carried out for SUS304 stainless steel at 650 degrees C in a biaxial stress state. Moreover, a generalized flow rule of the inelastic strain rate is also developed, by which the description of the ratcheting process can be improved

A quark-parton description of the deep inelastic scattering processes

International Nuclear Information System (INIS)

Bajpai, R.P.

1977-01-01

A consistent description of various deep inelastic processes in a quark-parton model is presented. The valence quark probability distribution and the form of core quark probability distribution is fixed from the deep inelastic electroproduction data. Langacker and Suzuki prescription is used to fix the p and n quark core distribution. The differential excitation of quark currents similar to the Harari model of e + e - annihilation process is invoked in deep inelastic electroproduction and neutrino reactions. An effective phenomenological form of the weak currents associated with new quarks and the associated nucleon structure is determined. (author)

A multislice theory of electron inelastic scattering in a solid

International Nuclear Information System (INIS)

Wang, Z.L.

1989-01-01

A multislice theory is proposed to solve Yoshioka's coupling equations for elastic and inelastic scattered high-energy electrons in a solid. This method is capable, in principle, of including the non-periodic crystal structures and the electron multiple scattering among all the excited states in the calculations. It is proved that the proposed theory for calculating the energy-filtered inelastic images, based on the physical optics approach, is equivalent to the quantum-mechanical theory under some approximations. The basic theory of simulating the energy-filtered inelastic image of core-shell losses and thermal diffuse scattering is outlined. (orig.)

Morphology and Composition of Localized Lunar Dark Mantle Deposits With LROC Data

Science.gov (United States)

Gustafson, O.; Bell, J. F.; Gaddis, L. R.; Hawke, B. R.; Robinson, M. S.; LROC Science Team

2010-12-01

Clementine color (ultraviolet, visible or UVVIS) and Lunar Reconnaissance Orbiter (LRO) Wide Angle (WAC) and Narrow Angle (NAC) camera data provide the means to investigate localized lunar dark-mantle deposits (DMDs) of potential pyroclastic origin. Our goals are to (1) examine the morphology and physical characteristics of these deposits with LROC WAC and NAC data; (2) extend methods used in earlier studies of lunar DMDs with Clementine spectral reflectance (CSR) data; (3) use LRO WAC multispectral data to complement and extend the CSR data for compositional analyses; and (4) apply these results to identify the likely mode of emplacement and study the diversity of compositions among these deposits. Pyroclastic deposits have been recognized all across the Moon, identified by their low albedo, smooth texture, and mantling relationship to underlying features. Gaddis et al. (2003) presented a compositional analysis of 75 potential lunar pyroclastic deposits (LPDs) based on CSR measurements. New LRO camera (LROC) data permit more extensive analyses of such deposits than previously possible. Our study began with six sites on the southeastern limb of the Moon that contain nine of the cataloged 75 potential pyroclastic deposits: Humboldt (4 deposits), Petavius, Barnard, Abel B, Abel C, and Titius. Our analysis found that some of the DMDs exhibit qualities characteristic of fluid emplacement, such as flat surfaces, sharp margins, embaying relationships, and flow textures. We conclude that the localized DMDs are a complex class of features, many of which may have formed by a combination of effusive and pyroclastic emplacement mechanisms. We have extended this analysis to include additional localized DMDs from the catalog of 75 potential pyroclastic deposits. We have examined high resolution (up to 0.5 m/p) NAC images as they become available to assess the mode of emplacement of the deposits, locate potential volcanic vents, and assess physical characteristics of the DMDs

Inelastic analysis of prestressed concrete secondary containments

International Nuclear Information System (INIS)

Murray, D.W.; Chitnuyanondh, L.; Wong, C.; Rijub-Agha, K.Y.

1978-07-01

An elastic-plastic constitutive model for the simulation of stress-strain response of concrete under any biaxial combination of compressive and/or tensile stresses is developed. An effective tensile stress-strain curve is obtained indirectly from experimental results of a test on a large scale prestressed concrete wall segment. These concrete properties are then utilized in predicting the response of a second test and the results compared with the experiment. Modificications to the BOSOR5 program, in order to incorporate the new constitutive relation into it, are described. Techniques of modelling structures in order to perform inelastic analysis of thin shell axisymmetric prestressed concrete secondary containments are investigated. The results of inelastic BOSOR5 analyses of two different models of the University of Alberta Test Structure are presented. The predicted deterioration of the structure and the limit states associated with its behaviour are determined and discussed. It is concluded that the technique is a practical one which can be used for the inelastic analysis of Gentilly-type containment structures. (author)

Comparison study of inelastic analysis codes for high temperature structure

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Bum; Lee, H. Y.; Park, C. K.; Geon, G. P.; Lee, J. H

2004-02-01

LMR high temperature structures subjected to operating and transient loadings may exhibit very complex deformation behaviors due to the use of ductile material such as 316SS and the systematic analysis technology of high temperature structure for reliable safety assessment is essential. In this project, comparative study with developed inelastic analysis program NONSTA and the existing analysis codes was performed applying various types of loading including non-proportional loading. The performance of NONSTA was confirmed and the effect of inelastic constants on the analysis result was analyzed. Also, the applicability of the inelastic analysis was enlarged as a result of applying both the developed program and the existing codes to the analyses of the enhanced creep behavior and the elastic follow-up behavior of high temperature structures and the necessary items for improvements were deduced. Further studies on the improvement of NONSTA program and the decision of the proper values of inelastic constants are necessary.

Magnon and phonon thermometry with inelastic light scattering

Science.gov (United States)

Olsson, Kevin S.; An, Kyongmo; Li, Xiaoqin

2018-04-01

Spin caloritronics investigates the interplay between the transport of spin and heat. In the spin Seebeck effect, a thermal gradient across a magnetic material generates a spin current. A temperature difference between the energy carriers of the spin and lattice subsystems, namely the magnons and phonons, is necessary for such thermal nonequilibrium generation of spin current. Inelastic light scattering is a powerful method that can resolve the individual temperatures of magnons and phonons. In this review, we discuss the thermometry capabilities of inelastic light scattering for measuring optical and acoustic phonons, as well as magnons. A scattering spectrum offers three temperature sensitive parameters: frequency shift, linewidth, and integrated intensity. We discuss the temperatures measured via each of these parameters for both phonon and magnons. Finally, we discuss inelastic light scattering experiments that have examined the magnon and phonon temperatures in thermal nonequilibrium which are particularly relevant to spin caloritronic phenomena.

Comparison of typical inelastic analysis predictions with benchmark problem experimental results

International Nuclear Information System (INIS)

Clinard, J.A.; Corum, J.M.; Sartory, W.K.

1975-01-01

The results of exemplary inelastic analyses are presented for a series of experimental benchmark problems. Consistent analytical procedures and constitutive relations were used in each of the analyses, and published material behavior data were used in all cases. Two finite-element inelastic computer programs were employed. These programs implement the analysis procedures and constitutive equations for Type 304 stainless steel that are currently used in many analyses of elevated-temperature nuclear reactor system components. The analysis procedures and constitutive relations are briefly discussed, and representative analytical results are presented and compared to the test data. The results that are presented demonstrate the feasibility of performing inelastic analyses, and they are indicative of the general level of agreement that the analyst might expect when using conventional inelastic analysis procedures. (U.S.)

Spin-polarized inelastic tunneling through insulating barriers.

Science.gov (United States)

Lu, Y; Tran, M; Jaffrès, H; Seneor, P; Deranlot, C; Petroff, F; George, J-M; Lépine, B; Ababou, S; Jézéquel, G

2009-05-01

Spin-conserving hopping transport through chains of localized states has been evidenced by taking benefit of the high degree of spin-polarization of CoFeB-MgO-CoFeB magnetic tunnel junctions. In particular, our data show that relatively thick MgO barriers doped with boron favor the activation of spin-conserving inelastic channels through a chain of three localized states and leading to reduced magnetoresistance effects. We propose an extension of the Glazman-Matveev theory to the case of ferromagnetic reservoirs to account for spin-polarized inelastic tunneling through nonmagnetic localized states embedded in an insulating barrier.

Theory of single-spin inelastic tunneling spectroscopy.

Science.gov (United States)

Fernández-Rossier, J

2009-06-26

I show that recent experiments of inelastic scanning tunneling spectroscopy of single and a few magnetic atoms are modeled with a phenomenological spin-assisted tunneling Hamiltonian so that the inelastic dI/dV line shape is related to the spin spectral weight of the magnetic atom. This accounts for the spin selection rules and dI/dV spectra observed experimentally for single Fe and Mn atoms deposited on Cu2N. In the case of chains of Mn atoms it is found necessary to include both first and second-neighbor exchange interactions as well as single-ion anisotropy.

Development of inelastic design method for liquid metal reactor plants

International Nuclear Information System (INIS)

Takahashi, Yukio; Take, Kohji; Kaguchi, Hitoshi; Fukuda, Yoshio; Uno, Tetsuro.

1991-01-01

Effective utilization of inelastic analysis in structural design assessment is expected to play an important role for avoiding too conservative design of liquid metal reactor plants. Studies have been conducted by the authors to develop a guideline for application of detailed inelastic analysis in design assessment. Both fundamental material characteristics tests and structural failure tests were conducted. Fundamental investigations were made on inelastic analysis method and creep-fatigue life prediction method based on the results of material characteristics tests. It was demonstrated through structural failure tests that the design method constructed based on these fundamental investigations can predict failure lives in structures subjected to cyclic thermal loadings with sufficient accuracy. (author)

Theory of time-resolved inelastic x-ray diffraction

DEFF Research Database (Denmark)

Lorenz, Ulf; Møller, Klaus Braagaard; Henriksen, Niels Engholm

2010-01-01

Starting from a general theory of time-resolved x-ray scattering, we derive a convenient expression for the diffraction signal based on a careful analysis of the relevant inelastic scattering processes. We demonstrate that the resulting inelastic limit applies to a wider variety of experimental...... conditions than similar, previously derived formulas, and it directly allows the application of selection rules when interpreting diffraction signals. Furthermore, we present a simple extension to systems simultaneously illuminated by x rays and a laser beam....

Deep inelastic scattering in spontaneously broken gauge models

International Nuclear Information System (INIS)

Goloskokov, S.V.; Mikhov, S.G.; Morozov, P.T.; Stamenov, D.B.

1975-01-01

Deep inelastic lepton hadron scattering in the simplest spontaneously broken symmetry (the Kibble model) is analyzed. A hypothesis that the invariant coupling constant of the quartic selfinteraction for large spacelike momenta tends to a finite asymptotic value without spoiling the asymptotic freedom for the invariant coupling constant of the Yang-Mills field is used. It is shown that Biorken scaling for the moments of the structure functions of the deep inelastic lepton hadron scattering is violated by powers of logarithms

Inelastic behaviour of collagen networks in cell–matrix interactions and mechanosensation

Science.gov (United States)

Mohammadi, Hamid; Arora, Pamma D.; Simmons, Craig A.; Janmey, Paul A.; McCulloch, Christopher A.

2015-01-01

The mechanical properties of extracellular matrix proteins strongly influence cell-induced tension in the matrix, which in turn influences cell function. Despite progress on the impact of elastic behaviour of matrix proteins on cell–matrix interactions, little is known about the influence of inelastic behaviour, especially at the large and slow deformations that characterize cell-induced matrix remodelling. We found that collagen matrices exhibit deformation rate-dependent behaviour, which leads to a transition from pronounced elastic behaviour at fast deformations to substantially inelastic behaviour at slow deformations (1 μm min−1, similar to cell-mediated deformation). With slow deformations, the inelastic behaviour of floating gels was sensitive to collagen concentration, whereas attached gels exhibited similar inelastic behaviour independent of collagen concentration. The presence of an underlying rigid support had a similar effect on cell–matrix interactions: cell-induced deformation and remodelling were similar on 1 or 3 mg ml−1 attached collagen gels while deformations were two- to fourfold smaller in floating gels of high compared with low collagen concentration. In cross-linked collagen matrices, which did not exhibit inelastic behaviour, cells did not respond to the presence of the underlying rigid foundation. These data indicate that at the slow rates of collagen compaction generated by fibroblasts, the inelastic responses of collagen gels, which are influenced by collagen concentration and the presence of an underlying rigid foundation, are important determinants of cell–matrix interactions and mechanosensation. PMID:25392399

On deep inelastic lepton-nuclear interactions

International Nuclear Information System (INIS)

Garsevanishvili, V.R.; Darbaidze, Ya.Z.; Menteshashvili, Z.R.; Ehsakiya, Sh.M.

1981-01-01

The problem of building relativistic theory of nuclear reactions by way of involving relativistic methods, developed in the elementary particle theory, becomes rather actual at the time being. The paper presents some results of investigations into deep inelastic lepton-nuclear processes lA → l'(A-1)x, with the spectator nucleus-fragment in the finite state. To describe the reactions lA → l'(A-1)x (where l=an electron, muan, neutrino, antineutrino), the use is made of the self-similarity principle and multiparticle quasipotential formalism in the ''light front'' variables. The expressions are obtained for the differential cross-sections of lepton-nuclear processes and for the structure functions of deep inelastic scattering of neutrinos (antineutrinos) and charged leptons by nuclei

Comparison of typical inelastic analysis predictions with benchmark problem experimental results

International Nuclear Information System (INIS)

Clinard, J.A.; Corum, J.M.; Sartory, W.K.

1975-01-01

The results of exemplary inelastic analyses for experimental benchmark problems on reactor components are presented. Consistent analytical procedures and constitutive relations were used in each of the analyses, and the material behavior data presented in the Appendix were used in all cases. Two finite-element inelastic computer programs were employed. These programs implement the analysis procedures and constitutive equations for type 304 stainless steel that are currently used in many analyses of elevated-temperature nuclear reactor system components. The analysis procedures and constitutive relations are briefly discussed, and representative analytical results are presented and compared to the test data. The results that are presented demonstrate the feasibility of performing inelastic analyses for the types of problems discussed, and they are indicative of the general level of agreement that the analyst might expect when using conventional inelastic analysis procedures. (U.S.)

Dark matter and dark energy: The critical questions

International Nuclear Information System (INIS)

Michael S. Turner

2002-01-01

Stars account for only about 0.5% of the content of the Universe; the bulk of the Universe is optically dark. The dark side of the Universe is comprised of: at least 0.1% light neutrinos; 3.5% ± 1% baryons; 29% ± 4% cold dark matter; and 66% ± 6% dark energy. Now that we have characterized the dark side of the Universe, the challenge is to understand it. The critical questions are: (1) What form do the dark baryons take? (2) What is (are) the constituent(s) of the cold dark matter? (3) What is the nature of the mysterious dark energy that is causing the Universe to speed up

The inelastic scattering of medium energy α particles

International Nuclear Information System (INIS)

Crut, M.

1960-01-01

The aim of this work is to find out what are the properties of the so-called 'anomalous states' in medium weight nuclei. These states preferentially excited in the inelastic scattering of medium energy charged particles have an excitation energy at about 4 MeV for nuclei with Z ≤ 29 and in the range 2-3 MeV for high Z nuclei. From a combination of angular distribution data in the elastic and inelastic scattering of 30 MeV α particles, and correlation data between inelastic α particles and deexcitation γ rays, we show that for even-even nuclei, we can attribute spin 3 and parity minus to these 'anomalous states'. This is quite in agreement with the interpretation of these levels suggested by Lane as due to collective octupole oscillations. We give a resume of the theories used in the analysis of the data and a description of the experimental set-up. (author) [fr

Dark Dark Wood

DEFF Research Database (Denmark)

2017-01-01

2017 student Bachelor film. Synopsis: Young princess Maria has had about enough of her royal life – it’s all lesson, responsibilities and duties on top of each other, every hour of every day. Overwhelmed Maria is swept away on an adventure into the monster-filled dark, dark woods. During 2017...

Lowest order in inelastic tunneling approximation : efficient scheme for simulation of inelastic electron tunneling data

NARCIS (Netherlands)

Rossen, E.T.R.; Flipse, C.F.J.; Cerda, J.I.

2013-01-01

We have developed an efficient and accurate formalism which allows the simulation at the ab initio level of inelastic electron tunneling spectroscopy data under a scanning tunneling microscope setup. It exploits fully the tunneling regime by carrying out the structural optimization and vibrational

Interaction between bosonic dark matter and stars

Science.gov (United States)

Brito, Richard; Cardoso, Vitor; Macedo, Caio F. B.; Okawa, Hirotada; Palenzuela, Carlos

2016-02-01

We provide a detailed analysis of how bosonic dark matter "condensates" interact with compact stars, extending significantly the results of a recent Letter [1]. We focus on bosonic fields with mass mB , such as axions, axion-like candidates and hidden photons. Self-gravitating bosonic fields generically form "breathing" configurations, where both the spacetime geometry and the field oscillate, and can interact and cluster at the center of stars. We construct stellar configurations formed by a perfect fluid and a bosonic condensate, and which may describe the late stages of dark matter accretion onto stars, in dark-matter-rich environments. These composite stars oscillate at a frequency which is a multiple of f =2.5 ×1014(mBc2/eV ) Hz . Using perturbative analysis and numerical relativity techniques, we show that these stars are generically stable, and we provide criteria for instability. Our results also indicate that the growth of the dark matter core is halted close to the Chandrasekhar limit. We thus dispel a myth concerning dark matter accretion by stars: dark matter accretion does not necessarily lead to the destruction of the star, nor to collapse to a black hole. Finally, we argue that stars with long-lived bosonic cores may also develop in other theories with effective mass couplings, such as (massless) scalar-tensor theories.

The γ-ray angular distribution in fast neutron inelastic scattering from iron

Science.gov (United States)

Beyer, Roland; Dietz, Mirco; Bemmerer, Daniel; Junghans, Arnd R.; Kögler, Toni; Massarczyk, Ralph; Müller, Stefan; Schmidt, Konrad; Schwengner, Ronald; Szücs, Tamás; Takács, Marcell P.; Wagner, Andreas

2018-04-01

The angular distribution of γ-rays emitted after inelastic scattering of fast neutrons from iron was determined at the n ELBE neutron time-of-flight facility. An iron sample of natural isotopic composition was irradiated by a continuous photo-neutron spectrum in the energy range from about 0.1 up to 10 MeV. The de-excitation γ-rays of the four lowest excited states of 56Fe and the first excited state of 54Fe were detected using a setup of five high-purity germanium (HPGe) detectors and five LaBr3 scintillation detectors positioned around the sample at 30°, 55°, 90°, 125° and 150° with respect to the incoming neutron beam. The resulting angular distributions were fitted by Legendre polynomials up to 4th order and the angular distribution coefficients a2 and a4 were extracted. The angular distribution coefficients of three transitions in 56Fe are reported here for the first time. The results are applied to a previous measurement of the inelastic scattering cross section determined using a single HPGe detector positioned at 125°. Using the updated γ-ray angular distribution, the previous cross section results are in good agreement with reference data.

Modified dark matter: Relating dark energy, dark matter and baryonic matter

Science.gov (United States)

Edmonds, Douglas; Farrah, Duncan; Minic, Djordje; Ng, Y. Jack; Takeuchi, Tatsu

Modified dark matter (MDM) is a phenomenological model of dark matter, inspired by gravitational thermodynamics. For an accelerating universe with positive cosmological constant (Λ), such phenomenological considerations lead to the emergence of a critical acceleration parameter related to Λ. Such a critical acceleration is an effective phenomenological manifestation of MDM, and it is found in correlations between dark matter and baryonic matter in galaxy rotation curves. The resulting MDM mass profiles, which are sensitive to Λ, are consistent with observational data at both the galactic and cluster scales. In particular, the same critical acceleration appears both in the galactic and cluster data fits based on MDM. Furthermore, using some robust qualitative arguments, MDM appears to work well on cosmological scales, even though quantitative studies are still lacking. Finally, we comment on certain nonlocal aspects of the quanta of modified dark matter, which may lead to novel nonparticle phenomenology and which may explain why, so far, dark matter detection experiments have failed to detect dark matter particles.

Deep inelastic singlet structure functions and scaling violation

Energy Technology Data Exchange (ETDEWEB)

Wen-zhu, Li; Bing-xun, Hu

1984-02-01

The flavour singlet structure functions of deep inelastic scattering processes can yield more decisive tests of QCD than the non-singlet. We give analytical expression for flavour singlet structure functions through analysing the lepton-nucleon deep inelastic scattering processes by means of QCD and using Jacobi polynomials. This expression contains 4 to 5 parameters and shows the changes of the singlet structure functions with x and Q/sup 2/ very well. In QCD leading order, the conclusion is in reasonable agreement with experimental data.

An inelastic neutron scattering study of hematite nanoparticles

DEFF Research Database (Denmark)

Hansen, Mikkel Fougt; Klausen, Stine Nyborg; Lefmann, K

2003-01-01

We have studied the magnetic dynamics in nanocrystalline hematite by inelastic neutron scattering at the high-resolution time-of-flight spectrometer IRIS at ISIS. Compared to previous inelastic neutron scattering experiments an improvement of the resolution function is achieved and more detailed...... moment at the antiferromagnetic Bragg reflection. We have studied different weightings of the particle size distribution. The data and their temperature dependence can with good agreement be interpreted on the basis of the Neel-Brown theory for superparamagnetic relaxation and a model for the collective...

Signatures of asymmetric and inelastic tunneling on the spin torque bias dependence

KAUST Repository

Manchon, Aurelien; Zhang, S.; Lee, K.-J.

2010-01-01

The influence of structural asymmetries (barrier height and exchange splitting), as well as inelastic scattering (magnons and phonons) on the bias dependence of the spin transfer torque in a magnetic tunnel junction is studied theoretically using the free-electron model. We show that they modify the “conventional” bias dependence of the spin transfer torque, together with the bias dependence of the conductance. In particular, both structural asymmetries and bulk (inelastic) scattering add antisymmetric terms to the perpendicular torque (∝V and ∝je|V|) while the interfacial inelastic scattering conserves the junction symmetry and only produces symmetric terms (∝|V|n, n∊N). The analysis of spin torque and conductance measurements displays a signature revealing the origin (asymmetry or inelastic scattering) of the discrepancy.

Signatures of asymmetric and inelastic tunneling on the spin torque bias dependence

KAUST Repository

Manchon, Aurelien

2010-11-15

The influence of structural asymmetries (barrier height and exchange splitting), as well as inelastic scattering (magnons and phonons) on the bias dependence of the spin transfer torque in a magnetic tunnel junction is studied theoretically using the free-electron model. We show that they modify the “conventional” bias dependence of the spin transfer torque, together with the bias dependence of the conductance. In particular, both structural asymmetries and bulk (inelastic) scattering add antisymmetric terms to the perpendicular torque (∝V and ∝je|V|) while the interfacial inelastic scattering conserves the junction symmetry and only produces symmetric terms (∝|V|n, n∊N). The analysis of spin torque and conductance measurements displays a signature revealing the origin (asymmetry or inelastic scattering) of the discrepancy.

Inelastic electron scattering influence on the strong coupling oxide superconductors

International Nuclear Information System (INIS)

Gabovich, A.M.; Voitenko, A.I.

1995-01-01

The superconducting order parameters Δ and energy gap Δ g are calculated taking into account the pair-breaking inelastic quasiparticle scattering by thermal Bose-excitations, e.g., phonons. The treatment is self-consistent because the scattering amplitude depends on Δ. The superconducting transition for any strength of the inelastic scattering is the phase transition of the first kind and the dependences Δ (T) and Δ g (T) tend to rectangular curve that agrees well with the experiment for high-Tc oxides. On the basis of the developed theory the nuclear spin-lattice relaxation rate R s in the superconducting state is calculated. The Hebel-Slichter peak in R s (T) is shown to disappear for strong enough inelastic scattering

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

Dark fluid: A complex scalar field to unify dark energy and dark matter

International Nuclear Information System (INIS)

Arbey, Alexandre

2006-01-01

In this article, we examine a model which proposes a common explanation for the presence of additional attractive gravitational effects - generally considered to be due to dark matter - in galaxies and in clusters, and for the presence of a repulsive effect at cosmological scales - generally taken as an indication of the presence of dark energy. We therefore consider the behavior of a so-called dark fluid based on a complex scalar field with a conserved U(1)-charge and associated to a specific potential, and show that it can at the same time account for dark matter in galaxies and in clusters, and agree with the cosmological observations and constraints on dark energy and dark matter

Phenomenology of deep-inelastic processes

International Nuclear Information System (INIS)

Moretto, L.G.

1983-03-01

The field of heavy-ion deep-inelastic reactions is reviewed with particular attention to the experimental picture. The most important degrees of freedom involved in the process are identified and illustrated with relevant experiments. Energy dissipation and mass transfer are discussed in terms of particles and/or phonons exchanged in the process. The equilibration of the fragment neutron-to-proton ratios is inspected for evidence of giant isovector resonances. The angular momentum effects are observed in the fragment angular distributions and the angular momentum transfer is inferred from the magnitude and alignment of the fragments spins. The possible sources of light particles accompanying the deep-inelastic reactions are discussed. The use of the sequentially emitted particles as angular momentum probes is illustrated. The significance and uses of a thermalized component emitted by the dinucleus is reviewed. The possible presence of Fermi jets in the prompt component is shown to be critical to the justification of the one-body theories

Role of deep inelastic processes in nuclear physics: experimental and theoretical aspects of deep inelastic reactions

International Nuclear Information System (INIS)

Moretto, L.G.

1979-03-01

The collective modes excited in deep-inelastic reactions and their natural hierarchy provided by their characteristic relaxation times is described. The relaxation of the mass asymmetry mode is discussed in terms of a diffusion process. Charge distributions and angular distributions as a function of Z calculated with this model are in good agreement with experimental data. This diffusion model also treats the transfer of energy and angular momentum in terms of particle transfer, and is successfully compared with experimental γ-ray multiplicities as a function of both Q-value and mass asymmetry. The angular momentum transfer is again considered in connection with the sequential fission of heavy, deep-inelastic fragments and the excitation of collective modes in the exit channel is considered. The role of the giant E1 mode in the equilibration of the neutron-to-proton ratio is discussed. 39 references

Dark Mass Creation During EWPT Via Dark Energy Interaction

OpenAIRE

Kisslinger, Leonard S.; Casper, Steven

2013-01-01

We add Dark Matter Dark Energy terms with a quintessence field interacting with a Dark Matter field to a MSSM EW Lagrangian previously used to calculate the magnetic field created during the EWPT. From the expectation value of the quintessence field we estimate the Dark Matter mass for parameters used in previous work on Dark Matter-Dark Energy interactions.

Inelastic analysis of solids and structures

CERN Document Server

Kojic, M; Bathe, K J; Koji?, Milo

2005-01-01

Inelastic Analysis of Solids and Structures presents in a unified manner the physical and theoretical background of inelastic material models and computational methods, and illustrates the behavior of the models in typical engineering conditions.It is based on experimental observations and principles of mechanics, thus describing computational algorithms for stress calculation and presenting solved examples.The theoretical background is given to an extent necessary to describe the commonly employed material models in metal isotropic and orthotropic plasticity, thermoplasticity and viscoplasticity, and the plasticity of geological materials.The computational algorithms are developed in a unified manner with some detailed derivations of the algorithmic relations.The solved examples are designed to give insight into the material behavior in various engineering conditions, and to demonstrate the application of the computational algorithms.

Review of inelastic proton-proton reactions

CERN Document Server

Morrison, Douglas Robert Ogston

1973-01-01

The most important new results on inelastic proton-proton scattering obtained with the new machines, I.S.R. and N.A.L., are: (1) The inelastic cross-section increases monotonically with energy from threshold to 1500 GeV/c. Above 6 GeV/c the energy variation has a s /sup +0.04/ behaviour. (2) Scaling is observed at I.S.R. energies in pion production. Confirmation is obtained of the hypothesis of limiting fragmentation. (3) The results are in general, consistent with the two-component model-one class of events being produced by diffraction dissociation and the other by a short-range-order process (e.g. the multiperipheral model). (4) There are indications that the protons have a granular structure; this from observation of secondaries of large transverse momenta. (33 refs).

Hubble diagram as a probe of minicharged particles

International Nuclear Information System (INIS)

Ahlers, Markus

2009-01-01

The luminosity-redshift relation of cosmological standard candles provides information about the relative energy composition of our Universe. In particular, the observation of type Ia supernovae up to a redshift of z∼2 indicates a universe which is dominated today by dark matter and dark energy. The propagation distance of light from these sources is of the order of the Hubble radius and serves as a very sensitive probe of feeble inelastic photon interactions with background matter, radiation, or magnetic fields. In this paper we discuss the limits on minicharged particle models arising from a dimming effect in supernova surveys. We briefly speculate about a strong dimming effect as an alternative to dark energy.

Users guide to the inelastic rotor spectrometer (IRS)

International Nuclear Information System (INIS)

Bunce, L.J.

1987-11-01

The paper is a users guide to the inelastic rotor spectrometer installed on the Harwell 136 Mev electron linear accelerator HELIOS. The spectrometer is designed to measure neutron inelastic scattering for energy transfers from 50 meV to 400 meV and covering a range of Q values from 1 to 15 A 0-1 . The guide contains a description of:- time-of-flight scales, run and sample changer control units, sample environment, detectors, rotor system, 600 Hz operation of rotor, a run, and data processing. (U.K.)

Large inelastic deformation analysis of steel pressure vessels at high temperature

International Nuclear Information System (INIS)

Ikonen, K.

2001-01-01

This publication describes the calculation methodology developed for a large inelastic deformation analysis of pressure vessels at high temperature. Continuum mechanical formulation related to a large deformation analysis is presented. Application of the constitutive equations is simplified when the evolution of stress and deformation state of an infinitesimal material element is considered in the directions of principal strains determined by the deformation during a finite time increment. A quantitative modelling of time dependent inelastic deformation is applied for reactor pressure vessel steels. Experimental data of uniaxial tensile, relaxation and creep tests performed at different laboratories for reactor pressure vessel steels are investigated and processed. An inelastic deformation rate model of strain hardening type is adopted. The model simulates well the axial tensile, relaxation and creep tests from room temperature to high temperature with only a few fitting parameters. The measurement data refined for the inelastic deformation rate model show useful information about inelastic deformation phenomena of reactor pressure vessel steels over a wide temperature range. The methodology and calculation process are validated by comparing the calculated results with measurements from experiments on small scale pressure vessels. A reasonably good agreement, when taking several uncertainties into account, is obtained between the measured and calculated results concerning deformation rate and failure location. (orig.)

Neutrino telescopes sensitivity to dark matter

International Nuclear Information System (INIS)

Albuquerque, I.F.M.; Lamoureux, J.; Smoot, G.F.

2002-01-01

The nature of the dark matter of the Universe is yet unknown and most likely is connected with new physics. The search for its composition is underway through direct and indirect detection. Fundamental physical aspects such as energy threshold, geometry and location are taken into account to investigate proposed neutrino telescopes of km3 volume sensitivities to dark matter. These sensitivities are just sufficient to test a few weakly interacting massive particle scenarios. Telescopes of km3 volume, such as IceCube, can definitely discover or exclude superheavy (M>1010 GeV) strong interacting massive particles (simpzillas). Smaller neutrino telescopes such as ANTARES, AMANDA-II and NESTOR can probe a large region of simpzilla parameter space

Dark matter as a weakly coupled dark baryon

Science.gov (United States)

Mitridate, Andrea; Redi, Michele; Smirnov, Juri; Strumia, Alessandro

2017-10-01

Dark Matter might be an accidentally stable baryon of a new confining gauge interaction. We extend previous studies exploring the possibility that the DM is made of dark quarks heavier than the dark confinement scale. The resulting phenomenology contains new unusual elements: a two-stage DM cosmology (freeze-out followed by dark condensation), a large DM annihilation cross section through recombination of dark quarks (allowing to fit the positron excess). Light dark glue-balls are relatively long lived and give extra cosmological effects; DM itself can remain radioactive.

Deeply inelastic scattering at small x in 20 min

International Nuclear Information System (INIS)

Levin, E.M.

1992-01-01

A status report is presented on new phenomena that are anticipated in deeply inelastic scattering in the low x→0 region. A summary of the theoretical situation in the region of small x is given, including the importance for the understanding of high energy interaction in QCD, and the low x behaviour of deep inelastic structure function. This new area of physics will be studied experimentally at HERA. (R.P.) 16 refs.; 6 figs

Distribution of gaseous and particulate organic composition during dark α-pinene ozonolysis

Directory of Open Access Journals (Sweden)

A. R. Rickard

2010-03-01

Full Text Available Secondary Organic Aerosol (SOA affects atmospheric composition, air quality and radiative transfer, however major difficulties are encountered in the development of reliable models for SOA formation. Constraints on processes involved in SOA formation can be obtained by interpreting the speciation and evolution of organics in the gaseous and condensed phase simultaneously. In this study we investigate SOA formation from dark α-pinene ozonolysis with particular emphasis upon the mass distribution of gaseous and particulate organic species. A detailed model for SOA formation is compared with the results from experiments performed in the EUropean PHOtoREactor (EUPHORE simulation chamber, including on-line gas-phase composition obtained from Chemical-Ionization-Reaction Time-Of-Flight Mass-Spectrometry measurements, and off-line analysis of SOA samples performed by Ion Trap Mass Spectrometry and Liquid Chromatography. The temporal profile of SOA mass concentration is relatively well reproduced by the model. Sensitivity analysis highlights the importance of the choice of vapour pressure estimation method, and the potential influence of condensed phase chemistry. Comparisons of the simulated gaseous- and condensed-phase mass distributions with those observed show a generally good agreement. The simulated speciation has been used to (i propose a chemical structure for the principal gaseous semi-volatile organic compounds and condensed monomer organic species, (ii provide evidence for the occurrence of recently suggested radical isomerisation channels not included in the basic model, and (iii explore the possible contribution of a range of accretion reactions occurring in the condensed phase. We find that oligomer formation through esterification reactions gives the best agreement between the observed and simulated mass spectra.

Dark energy and dark matter in galaxy halos

International Nuclear Information System (INIS)

Tetradis, N.

2006-01-01

We consider the possibility that the dark matter is coupled through its mass to a scalar field associated with the dark energy of the Universe. In order for such a field to play a role at the present cosmological distances, it must be effectively massless at galactic length scales. We discuss the effect of the field on the distribution of dark matter in galaxy halos. We show that the profile of the distribution outside the galaxy core remains largely unaffected and the approximately flat rotation curves persist. The dispersion of the dark matter velocity is enhanced by a potentially large factor relative to the case of zero coupling between dark energy and dark matter. The counting rates in terrestrial dark matter detectors are similarly enhanced. Existing bounds on the properties of dark matter candidates can be extended to the coupled case, by taking into account the enhancement factor

Quantitative composition determination at the atomic level using model-based high-angle annular dark field scanning transmission electron microscopy

International Nuclear Information System (INIS)

Martinez, G.T.; Rosenauer, A.; De Backer, A.; Verbeeck, J.; Van Aert, S.

2014-01-01

High angle annular dark field scanning transmission electron microscopy (HAADF STEM) images provide sample information which is sensitive to the chemical composition. The image intensities indeed scale with the mean atomic number Z. To some extent, chemically different atomic column types can therefore be visually distinguished. However, in order to quantify the atomic column composition with high accuracy and precision, model-based methods are necessary. Therefore, an empirical incoherent parametric imaging model can be used of which the unknown parameters are determined using statistical parameter estimation theory (Van Aert et al., 2009, [1]). In this paper, it will be shown how this method can be combined with frozen lattice multislice simulations in order to evolve from a relative toward an absolute quantification of the composition of single atomic columns with mixed atom types. Furthermore, the validity of the model assumptions are explored and discussed. - Highlights: • A model-based method is extended from a relative toward an absolute quantification of chemical composition of single atomic columns from HAADF HRSTEM images. • The methodology combines statistical parameter estimation theory with frozen lattice multislice simulations to quantify chemical composition atomic column by atomic column. • Validity and limitations of this model-based method are explored and discussed. • Quantification results obtained for a complex structure show agreement with EDX refinement

DarkSide search for dark matter

Energy Technology Data Exchange (ETDEWEB)

Alexander, T.; Alton, D.; Arisaka, K.; Back, H. O.; Beltrame, P.; Benziger, J.; Bonfini, G.; Brigatti, A.; Brodsky, J.; Bussino, S.; Cadonati, L.; Calaprice, F.; Candela, A.; Cao, H.; Cavalcante, P.; Chepurnov, A.; Chidzik, S.; Cocco, A. G.; Condon, C.; D' Angelo, D.; Davini, S.; Vincenzi, M. De; Haas, E. De; Derbin, A.; Pietro, G. Di; Dratchnev, I.; Durben, D.; Empl, A.; Etenko, A.; Fan, A.; Fiorillo, G.; Franco, D.; Fomenko, K.; Forster, G.; Gabriele, F.; Galbiati, C.; Gazzana, S.; Ghiano, C.; Goretti, A.; Grandi, L.; Gromov, M.; Guan, M.; Guo, C.; Guray, G.; Hungerford, E. V.; Ianni, Al; Ianni, An; Joliet, C.; Kayunov, A.; Keeter, K.; Kendziora, C.; Kidner, S.; Klemmer, R.; Kobychev, V.; Koh, G.; Komor, M.; Korablev, D.; Korga, G.; Li, P.; Loer, B.; Lombardi, P.; Love, C.; Ludhova, L.; Luitz, S.; Lukyanchenko, L.; Lund, A.; Lung, K.; Ma, Y.; Machulin, I.; Mari, S.; Maricic, J.; Martoff, C. J.; Meregaglia, A.; Meroni, E.; Meyers, P.; Mohayai, T.; Montanari, D.; Montuschi, M.; Monzani, M. E.; Mosteiro, P.; Mount, B.; Muratova, V.; Nelson, A.; Nemtzow, A.; Nurakhov, N.; Orsini, M.; Ortica, F.; Pallavicini, M.; Pantic, E.; Parmeggiano, S.; Parsells, R.; Pelliccia, N.; Perasso, L.; Perasso, S.; Perfetto, F.; Pinsky, L.; Pocar, A.; Pordes, S.; Randle, K.; Ranucci, G.; Razeto, A.; Romani, A.; Rossi, B.; Rossi, N.; Rountree, S. D.; Saggese, P.; Saldanha, R.; Salvo, C.; Sands, W.; Seigar, M.; Semenov, D.; Shields, E.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvarov, Y.; Tartaglia, R.; Tatarowicz, J.; Testera, G.; Thompson, J.; Tonazzo, A.; Unzhakov, E.; Vogelaar, R. B.; Wang, H.; Westerdale, S.; Wojcik, M.; Wright, A.; Xu, J.; Yang, C.; Zavatarelli, S.; Zehfus, M.; Zhong, W.; Zuzel, G.

2013-11-22

The DarkSide staged program utilizes a two-phase time projection chamber (TPC) with liquid argon as the target material for the scattering of dark matter particles. Efficient background reduction is achieved using low radioactivity underground argon as well as several experimental handles such as pulse shape, ratio of ionization over scintillation signal, 3D event reconstruction, and active neutron and muon vetos. The DarkSide-10 prototype detector has proven high scintillation light yield, which is a particularly important parameter as it sets the energy threshold for the pulse shape discrimination technique. The DarkSide-50 detector system, currently in commissioning phase at the Gran Sasso Underground Laboratory, will reach a sensitivity to dark matter spin-independent scattering cross section of 10^-45 cm² within 3 years of operation.

Leading particle in deep inelastic scattering

International Nuclear Information System (INIS)

Petrov, V.A.

1984-01-01

The leading particle effect in deep inelastic scattering is considered. The change of the characteris cs shape of the leading particle inclusive spectrum with Q 2 is estimated to be rather significant at very high Q 2

Measurement of proton-proton inelastic scattering cross-section at $\\sqrt{s}$= 7 TeV

CERN Document Server

Antchev, G; Atanassov, I.; Avati, V.; Baechler, J.; Berardi, V.; Berretti, M.; Bossini, E.; Bozzo, M.; Brogi, P.; Brücken, E.; Buzzo, A.; Cafagna, F.S.; Calicchio, M.; Catanesi, M.G.; Covault, C.; Csanad, M.; Csörgö, T.; Deile, M.; Doubek, M.; Eggert, K.; Eremin, V.; Ferretti, R.; Ferro, F.; Fiergolski, A.; Garcia, F.; Giani, S.; Greco, V.; Grzanka, L.; Heino, J.; Hilden, T.; Intonti, R.A.; Kaspar, J.; Kopal, J.; Kundrat, V.; Kurvinen, K.; Lami, S.; Latino, G.; Lauhakangas, R.; Leszko, T.; Lippmaa, E.; Lokajicek, M.; Lo Vetere, M.; Lucas Rodriguez, F.; Macri, M.; Mäki, T.; Mercadante, A.; Minafra, N.; Minutoli, S.; Nemes, F.; Niewiadomski, H.; Oliveri, E.; Oljemark, F.; Orava, R.; Oriunno, M.; Österberg, K.; Palazzi, P.; Prochazka, J.; Quinto, M.; Radermacher, E.; Radicioni, E.; Ravotti, F.; Robutti, E.; Ropelewski, L.; Ruggiero, G.; Saarikko, H.; Santroni, A.; Scribano, A.; Smajek, J.; Snoeys, W.; Sziklai, J.; Taylor, C.; Turini, N.; Vacek, V.; Vitek, M.; Welti, J.; Whitmore, J.; Wyszkowski, P.

2013-01-01

The TOTEM experiment at the LHC has measured the inelastic proton-proton cross-section at $\\sqrt{s}$ = 7 TeV in a β* = 90 m run with low inelastic pile-up. The measurement was based on events with at least one charged particle in the T2 telescope acceptance of 5.3 < |η| < 6.5 in pseudorapidity. Combined with data from the T1 telescope, covering 3.1 < |η| < 4.7, the cross-section for inelastic events with at least one |η| < 6.5 final state particle was determined to be 70.5 2.9 mb. Based on models for low mass diffraction, the total inelastic cross-section was deduced to be 73.7 3.4 mb. An upper limit of 6.31 mb at 95 % confidence level on the cross-section for events with diffractive masses below 3.4 GeV was obtained from the difference between the overall inelastic cross-section obtained by TOTEM using elastic scattering and the cross-section for inelastic events with at least one |η| < 6.5 final state particle.

Is Self-Interacting Dark Matter Undergoing Dark Fusion?

Energy Technology Data Exchange (ETDEWEB)

McDermott, Samuel D.

2017-11-02

We suggest that two-to-two dark matter fusion may be the relaxation process that resolves the small-scale structure problems of the cold collisionless dark matter paradigm. In order for the fusion cross section to scale correctly across many decades of astrophysical masses from dwarf galaxies to galaxy clusters, we require the fractional binding energy released to be greater than v^n ~ [10^{-(2-3)}]^n, where n=1,2 depends on local dark sector chemistry. The size of the dark-sector interaction cross sections must be sigma ~ 0.1-1 barn, moderately larger than for Standard Model deuteron fusion, indicating a dark nuclear scale Lambda ~ O(100 MeV). Dark fusion firmly predicts constant sigma v below the characteristic velocities of galaxy clusters. Observations of the inner structure of galaxy groups with velocity dispersion of several hundred kilometer per second, of which a handful have been identified, could differentiate dark fusion from a dark photon model.

Applications of one-dimensional models in simplified inelastic analyses

International Nuclear Information System (INIS)

Kamal, S.A.; Chern, J.M.; Pai, D.H.

1980-01-01

This paper presents an approximate inelastic analysis based on geometric simplification with emphasis on its applicability, modeling, and the method of defining the loading conditions. Two problems are investigated: a one-dimensional axisymmetric model of generalized plane strain thick-walled cylinder is applied to the primary sodium inlet nozzle of the Clinch River Breeder Reactor Intermediate Heat Exchanger (CRBRP-IHX), and a finite cylindrical shell is used to simulate the branch shell forging (Y) junction. The results are then compared with the available detailed inelastic analyses under cyclic loading conditions in terms of creep and fatigue damages and inelastic ratchetting strains per the ASME Code Case N-47 requirements. In both problems, the one-dimensional simulation is able to trace the detailed stress-strain response. The quantitative comparison is good for the nozzle, but less satisfactory for the Y junction. Refinements are suggested to further improve the simulation

Probing dark matter with active galactic nuclei jets

International Nuclear Information System (INIS)

Gorchtein, Mikhail; Profumo, Stefano; Ubaldi, Lorenzo

2010-01-01

We study the possibility of detecting a signature of particle dark matter in the spectrum of gamma-ray photons from active galactic nuclei (AGNs) resulting from the scattering of high-energy particles in the AGN jet off of dark matter particles. We consider particle dark matter models in the context of both supersymmetry and universal extra dimensions , and we present the complete lowest-order calculation for processes where a photon is emitted in dark matter-electron and/or dark matter-proton scattering, where electrons and protons belong to the AGN jet. We find that the process is dominated by a resonance whose energy is dictated by the particle spectrum in the dark matter sector (neutralino and selectron for the case of supersymmetry, Kaluza-Klein photon and electron for universal extra dimensions ). The resulting gamma-ray spectrum exhibits a very characteristic spectral feature, consisting of a sharp break to a hard power-law behavior. Although the normalization of the gamma-ray flux depends strongly on assumptions on both the AGN jet geometry, composition and particle spectrum as well as on the particle dark matter model and density distribution, we show that for realistic parameters choices, and for two prominent nearby AGNs (Centaurus A and M87), the detection of this effect is in principle possible. Finally, we compare our predictions and results with recent gamma-ray observations from the Fermi, H.E.S.S., and VERITAS telescopes.

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.

Final Technical Report for ``Paths to Discovery at the LHC : Dark Matter and Track Triggering"

Energy Technology Data Exchange (ETDEWEB)

Hahn, Kristian [Northwestern Univ., Evanston, IL (United States)

2016-10-24

Particle Dark Matter (DM) is perhaps the most compelling and experimentally well-motivated new physics scenario anticipated at the Large Hadron Collider (LHC). The DE-SC0014073 award allowed the PI to define and pursue a path to the discovery of Dark Matter in Run-2 of the LHC with the Compact Muon Solenoid (CMS) experiment. CMS can probe regions of Dark Matter phase-space that direct and indirect detection experiments are unable to constrain. The PI’s team initiated the exploration of these regions, searching specifically for the associated production of Dark Matter with top quarks. The effort focuses on the high-yield, hadronic decays of W bosons produced in top decay, which provides the highest sensitivity to DM produced via through low-mass spin-0 mediators. The group developed identification algorithms that achieve high efficiency and purity in the selection of hadronic top decays, and analysis techniques that provide powerful signal discrimination in Run-2. The ultimate reach of new physics searches with CMS will be established at the high-luminosity LHC (HL-LHC). To fully realize the sensitivity the HL-LHC promises, CMS must minimize the impact of soft, inelastic (“pileup”) interactions on the real-time “trigger” system the experiment uses for data refinement. Charged particle trajectory information (“tracking”) will be essential for pileup mitigation at the HL-LHC. The award allowed the PI’s team to develop firmware-based data delivery and track fitting algorithms for an unprecedented, real-time tracking trigger to sustain the experiment’s sensitivity to new physics in the next decade.

Coupling q-Deformed Dark Energy to Dark Matter

Directory of Open Access Journals (Sweden)

Emre Dil

2016-01-01

Full Text Available We propose a novel coupled dark energy model which is assumed to occur as a q-deformed scalar field and investigate whether it will provide an expanding universe phase. We consider the q-deformed dark energy as coupled to dark matter inhomogeneities. We perform the phase-space analysis of the model by numerical methods and find the late-time accelerated attractor solutions. The attractor solutions imply that the coupled q-deformed dark energy model is consistent with the conventional dark energy models satisfying an acceleration phase of universe. At the end, we compare the cosmological parameters of deformed and standard dark energy models and interpret the implications.

Dark matters

International Nuclear Information System (INIS)

Silk, Joseph

2010-01-01

One of the greatest mysteries in the cosmos is that it is mostly dark. That is, not only is the night sky dark, but also most of the matter and the energy in the universe is dark. For every atom visible in planets, stars and galaxies today there exists at least five or six times as much 'Dark Matter' in the universe. Astronomers and particle physicists today are seeking to unravel the nature of this mysterious but pervasive dark matter, which has profoundly influenced the formation of structure in the universe. Dark energy remains even more elusive, as we lack candidate fields that emerge from well established physics. I will describe various attempts to measure dark matter by direct and indirect means, and discuss the prospects for progress in unravelling dark energy.

The Creative Side of the Dark Triad

Science.gov (United States)

Kapoor, Hansika

2015-01-01

This study associates the subclinical dark triad (DT) of personality--narcissism, psychopathy, and Machiavellianism, and their composite--with negative creativity. An instrument developed by the author assessed the likelihood of engaging in creativity, where negative creativity was defined as an act that is original and useful to the individual.…

Dissipation and fluctuations within a timedependent microscopic description of deep inelastic collisions

International Nuclear Information System (INIS)

Hofmann, H.

1978-01-01

In this talk I want to give a brief description of the linear response approach to deep inelastic collisions. In this model the relative motion of the two fragments as well as all slow 'shape-degrees' of the composite system are treated within the same physical picture. Among these 'shape-degrees' the most important ones will be those which represent: mass asymmetry, collective vibrations, and, possibly, rotations. The goal of the approach is an equation of motion which accounts for dissipative effects as well as for statistical fluctuations of all these macroscopic degrees and their conjugate momenta. It will be a Fokker Planck equation for the probability distribution in the classical phase space. (orig.) [de

Strong overtones modes in inelastic electron tunneling spectroscopy with cross-conjugated molecules

DEFF Research Database (Denmark)

Jørgensen, Jacob Lykkebo; Gagliardi, Alessio; Pecchia, Alessandro

2013-01-01

. With this in mind, we investigate a spectroscopic method capable of providing insight into these junctions for cross-conjugated molecules: inelastic electron tunneling spectroscopy (IETS). IETS has the advantage that the molecule interface is probed directly by the tunneling current. Previously, it has been thought...... and leading to suppressed levels of elastic current. In most theoretical studies, only the elastic contributions to the current are taken into account. In this paper, we study the inelastic contributions to the current in cross-conjugated molecules and find that while the inelastic contribution to the current...

Sub-horizon evolution of cold dark matter perturbations through dark matter-dark energy equivalence epoch

International Nuclear Information System (INIS)

Piattella, O.F.; Martins, D.L.A.; Casarini, L.

2014-01-01

We consider a cosmological model of the late universe constituted by standard cold dark matter plus a dark energy component with constant equation of state w and constant effective speed of sound. By neglecting fluctuations in the dark energy component, we obtain an equation describing the evolution of sub-horizon cold dark matter perturbations through the epoch of dark matter-dark energy equality. We explore its analytic solutions and calculate an exact w-dependent correction for the dark matter growth function, logarithmic growth function and growth index parameter through the epoch considered. We test our analytic approximation with the numerical solution and find that the discrepancy is less than 1% for 0k = during the cosmic evolution up to a = 100

Transverse momentum in semi-inclusive deep inelastic scattering

International Nuclear Information System (INIS)

Ceccopieri, Federico Alberto; Trentadue, Luca

2006-01-01

Within the framework of perturbative quantum chromodynamics we derive the evolution equations for transverse momentum dependent distributions and apply them to the case of semi-inclusive deep inelastic scattering. The evolution equations encode the perturbative component of transverse momentum generated by collinear parton branchings. The current fragmentation is described via transverse momentum dependent parton densities and fragmentation functions. Target fragmentation instead is described via fracture functions. We present, to leading logarithmic accuracy, the corresponding semi-inclusive deep inelastic scattering cross-section, which applies to the entire phase space of the detected hadron. Some phenomenological implications and further developments are briefly outlined

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)

Unification of dark energy and dark matter

International Nuclear Information System (INIS)

Takahashi, Fuminobu; Yanagida, T.T.

2006-01-01

We propose a scenario in which dark energy and dark matter are described in a unified manner. The ultralight pseudo-Nambu-Goldstone (pNG) boson, A, naturally explains the observed magnitude of dark energy, while the bosonic supersymmetry partner of the pNG boson, B, can be a dominant component of dark matter. The decay of B into a pair of electron and positron may explain the 511 keV γ ray from the Galactic Center

Tales from the dark side: Privacy dark strategies and privacy dark patterns

DEFF Research Database (Denmark)

Bösch, Christoph; Erb, Benjamin; Kargl, Frank

2016-01-01

Privacy strategies and privacy patterns are fundamental concepts of the privacy-by-design engineering approach. While they support a privacy-aware development process for IT systems, the concepts used by malicious, privacy-threatening parties are generally less understood and known. We argue...... that understanding the “dark side”, namely how personal data is abused, is of equal importance. In this paper, we introduce the concept of privacy dark strategies and privacy dark patterns and present a framework that collects, documents, and analyzes such malicious concepts. In addition, we investigate from...... a psychological perspective why privacy dark strategies are effective. The resulting framework allows for a better understanding of these dark concepts, fosters awareness, and supports the development of countermeasures. We aim to contribute to an easier detection and successive removal of such approaches from...

Inelastic transport theory for nanoscale systems

DEFF Research Database (Denmark)

Frederiksen, Thomas

2007-01-01

This thesis describes theoretical and numerical investigations of inelastic scat- tering and energy dissipation in electron transport through nanoscale sys- tems. A computational scheme, based on a combination of density functional theory (DFT) and nonequilibrium Green’s functions (NEGF), has been...

Elastic and inelastic heavy ion scattering

International Nuclear Information System (INIS)

Toepffer, C.; University of the Witwatersrand, Johannesburg; Richter, A.

1977-02-01

In the field of elastic and inelastic heavy ion scattering, the following issues are dealt with: semiclassical descriptive approximations, optical potentials, barriers, critical radii and angular momenta, excitation functions and the application to superheavy ions and high energies. (WL) [de

Study of inelastic decay of amplitudes in 49V

International Nuclear Information System (INIS)

Chou, B.H.

1980-01-01

Inelastic decay amplitudes from d-wave resonances in 49 V were obtained for 80 resonances in the proton energy range 2.2 to 3.1 MeV. With the 3 MV Van de Graaff accelerator and high resolution system at the Triangle Universities Nuclear Laboratory, an overall resolution of 350 eV was obtained. The experiment consisted of measurements of the angular distributions of the inelastically scattered protons and the subsequent deexcitation gamma rays. Forty five resonances were assigned J/sup π/ = 5/2 + , while thirty five resonances were assigned 3/2 + . The magnitudes of three inelastic decay amplitudes and the relative signs between these three amplitudes were determined. Large amplitude correlations were observed; the data are in the striking disagreement with the extreme statistical model. The present results provide the first explicit test of the multivariate reduced width amplitude distribution of Krieger and Porter; the agreement is excellent. The physical origin of these channel correlations has not yet been explained

Nuclear structure of 41Ca from inelastic proton scattering

International Nuclear Information System (INIS)

Vold, P.B.; Cline, D.; Voigt, M.J.A. de

1977-01-01

Angular distributions have been measured for inelastic and elastic scattering of 19 MeV protons on 40 41 Ca. A total of 89 levels were identified below 6.4 MeV in 41 Ca with an energy resolution of 12 keV. Inelastic transition strengths have been extracted using DWBA theory with a vibrational model form factor. These transition strengths correlate well with inelastic α-scattering and electromagnetic values. The quadrupole strengths are interpreted in terms of the coexistence model and imply that the excited-core admixture in the ground states of both 40 Ca and 41 Ca are approximately 5%. The octupole strengths in 41 Ca exhibits features characteristic of the weak coupling of an fsub(7/2) neutron to the lowest 3 - state in 40 Ca. The l = 5 strength exhibits a similar weak-coupling behavior. In both cases the microscopic structure appreciably reduces the transition strength for the highest spin member of the weak-coupling multiplets. (Auth.)

Effects of heating on composition, degree of darkness, and stacking nanostructure of soil humic acids

Energy Technology Data Exchange (ETDEWEB)

Katsumi, Naoya, E-mail: n-katsu@ishikawa-pu.ac.jp; Yonebayashi, Koyo; Okazaki, Masanori

2016-01-15

Wildfires and prescribed burning can affect both the quality and the quantity of organic matter in soils. In this study, we investigated qualitative and quantitative changes of soil humic substances in two different soils (an Entisol from a paddy field and an Inceptisol from a cedar forest) under several controlled heating conditions. Soil samples were heated in a muffle furnace at 200, 250, or 300 °C for 1, 3, 5, or 12 h. The humic acid and fulvic acid contents of the soil samples prior to and after heating were determined. The degree of darkness, elemental composition, carbon and nitrogen stable isotope ratios, {sup 13}C nuclear magnetic resonance spectra, and X-ray diffraction patterns of humic acids extracted from the soils before and after heating were measured. The proportion of humic acids in total carbon decreased with increasing heating time at high temperature (300 °C), but increased with increasing heating time at ≤ 250 °C. The degree of darkness of the humic acids increased with increasing heating time and temperature. During darkening, the H/C atomic ratios, the proportion of aromatic C, and the carbon and nitrogen stable isotope ratios increased, whereas the proportions of alkyl C and O-alkyl C decreased. X-ray diffraction analysis verified that a stacking nanostructure developed by heating. Changes in the chemical structure of the humic acids from the heated soils depended on the type of soil. The major structural components of the humic acids from the heated Entisol were aromatic C and carboxylic C, whereas aliphatic C, aromatic C, and carboxylic C structural components were found in the humic acids from the heated Inceptisol. These results suggest that the heat-induced changes in the chemical structure of the humic acids depended on the source plant. - Highlights: • Darkness of humic acids increased with increasing heating time and temperature. • Aromatic carbon content increased during darkening. • Carbon and nitrogen stable isotope

Earthquake response of inelastic structures

International Nuclear Information System (INIS)

Parulekar, Y.M.; Vaity, K.N.; Reddy, .R.; Vaze, K.K.; Kushwaha, H.S.

2004-01-01

The most commonly used method in the seismic analysis of structures is the response spectrum method. For seismic re-evaluation of existing facilities elastic response spectrum method cannot be used directly as large deformation above yield may be observed under Safe Shutdown Earthquake (SSE). The plastic deformation, i.e. hysteretic characteristics of various elements of the structure cause dissipation of energy. Hence the values of damping given by the code, which does not account hysteretic energy dissipation cannot be directly used. In this paper, appropriate damping values are evaluated for 5-storey, 10-storey and 15-storey shear beam structures, which deform beyond their yield limit. Linear elastic analysis is performed for the same structures using these damping values and the storey forces are compared with those obtained using inelastic time history analysis. A damping model, which relates ductility of the structure and damping, is developed. Using his damping model, a practical structure is analysed and results are compared with inelastic time history analysis and the comparison is found to be good

Incentives for use of inelastic analysis in RAM transport container design

International Nuclear Information System (INIS)

Ammerman, D.J.; Heinstein, M.W.

1992-01-01

The use of inelastic analysis methods instead of the traditional elastic analysis methods in the design of radioactive material (RAM) transport packagings leads to a better understanding of the response ofthe package to mechanical loadings. Thus, better assessment of the containment, thermal protection, and shielding integrity of the package after a structural accident event can be made. A more accurate prediction of the package response can lead to enhanced safety and also allow for a more efficient use of materials, possibly leading to a package with higher capacity and/or lower weight. This paper discusses the incentives for using inelastic analysis in the design of RAM shipping packages. Inelastic analysis provides an improved knowledge of the package behavior. It must be demonstrated that the use of inelastic analysis provides a better design to overcome the difficulties associated with this type of analysis. In this paper, comparisons between elastic and inelastic analyses are made to illustrate the differences in the two analysis techniques for two different types of packages. One is a package to transport a large quantity of RAM by rail with lead gamma shielding,and the other is a package to transport RAM by truck with depleteduranium gamma shielding. Analyses of the center-of-gravity-over-corner impacts will be compared for each package. The comparisons indicate thata package designed to just meet the elastic design criteria will actually undergo some yielding in the locations of highest stress. This results in two consequences in the predicted behavior of the cask. First,the overprediction of the stiffness of these yielded regions by theelastic analysis technique results in an underestimation of the stresses in other portions of the structure. Secondly, in an inelastic analysis, the yielding of a portion of a structure causes the force in thatregion to rise less rapidly than forces in adjacent regions

Multiplicity distributions in inelastic reactions on nuclei

CERN Document Server

Caneschi, L; Schwimmer, A

1976-01-01

The multiplicity distribution of the number of knocked-out nucleons and the correlation of the former with the multiplicity of the produced mesons, in inelastic particle-nucleus scattering, are computed.

Metamaterial Model of Tachyonic Dark Energy

Directory of Open Access Journals (Sweden)

Igor I. Smolyaninov

2014-02-01

Full Text Available Dark energy with negative pressure and positive energy density is believed to be responsible for the accelerated expansion of the universe. Quite a few theoretical models of dark energy are based on tachyonic fields interacting with itself and normal (bradyonic matter. Here, we propose an experimental model of tachyonic dark energy based on hyperbolic metamaterials. Wave equation describing propagation of extraordinary light inside hyperbolic metamaterials exhibits 2 + 1 dimensional Lorentz symmetry. The role of time in the corresponding effective 3D Minkowski spacetime is played by the spatial coordinate aligned with the optical axis of the metamaterial. Nonlinear optical Kerr effect bends this spacetime resulting in effective gravitational force between extraordinary photons. We demonstrate that this model has a self-interacting tachyonic sector having negative effective pressure and positive effective energy density. Moreover, a composite multilayer SiC-Si hyperbolic metamaterial exhibits closely separated tachyonic and bradyonic sectors in the long wavelength infrared range. This system may be used as a laboratory model of inflation and late time acceleration of the universe.

Revival of the unified dark energy-dark matter model?

International Nuclear Information System (INIS)

Bento, M.C.; Bertolami, O.; Sen, A.A.

2004-01-01

We consider the generalized Chaplygin gas (GCG) proposal for unification of dark energy and dark matter and show that it admits an unique decomposition into dark energy and dark matter components once phantomlike dark energy is excluded. Within this framework, we study structure formation and show that difficulties associated to unphysical oscillations or blowup in the matter power spectrum can be circumvented. Furthermore, we show that the dominance of dark energy is related to the time when energy density fluctuations start deviating from the linear δ∼a behavior

Effective exchange potentials for electronically inelastic scattering

International Nuclear Information System (INIS)

Schwenke, D.W.; Staszewska, G.; Truhlar, D.G.

1983-01-01

We propose new methods for solving the electron scattering close coupling equations employing equivalent local exchange potentials in place of the continuum-multiconfiguration-Hartree--Fock-type exchange kernels. The local exchange potentials are Hermitian. They have the correct symmetry for any symmetries of excited electronic states included in the close coupling expansion, and they have the same limit at very high energy as previously employed exchange potentials. Comparison of numerical calculations employing the new exchange potentials with the results obtained with the standard nonlocal exchange kernels shows that the new exchange potentials are more accurate than the local exchange approximations previously available for electronically inelastic scattering. We anticipate that the new approximations will be most useful for intermediate-energy electronically inelastic electron--molecule scattering

Neutrino physics with dark matter experiments and the signature of new baryonic neutral currents

International Nuclear Information System (INIS)

Pospelov, Maxim

2011-01-01

New neutrino states ν b , sterile under the standard model interactions, can be coupled to baryons via the isoscalar vector currents that are much stronger than the standard model weak interactions. If some fraction of solar neutrinos oscillate into ν b on their way to Earth, the coherently enhanced elastic ν b -nucleus scattering can generate a strong signal in the dark matter detectors. For the interaction strength a few hundred times stronger than the weak force, the elastic ν b -nucleus scattering via new baryonic currents may account for the existing anomalies in the direct detection dark matter experiments at low recoil. We point out that for solar-neutrino energies, the baryon-current-induced inelastic scattering is suppressed, so that the possible enhancement of a new force is not in conflict with signals at dedicated neutrino detectors. We check this explicitly by calculating the ν b -induced deuteron breakup, and the excitation of a 4.4 MeV γ line in 12 C. A stronger-than-weak force coupled to the baryonic current implies the existence of a new Abelian gauge group U(1) B with a relatively light gauge boson.

Testing light dark matter coannihilation with fixed-target experiments

Energy Technology Data Exchange (ETDEWEB)

Izaguirre, Eder; Kahn, Yonatan; Krnjaic, Gordan; Moschella, Matthew

2017-09-01

In this paper, we introduce a novel program of fixed-target searches for thermal-origin Dark Matter (DM), which couples inelastically to the Standard Model. Since the DM only interacts by transitioning to a heavier state, freeze-out proceeds via coannihilation and the unstable heavier state is depleted at later times. For sufficiently large mass splittings, direct detection is kinematically forbidden and indirect detection is impossible, so this scenario can only be tested with accelerators. Here we propose new searches at proton and electron beam fixed-target experiments to probe sub-GeV coannihilation, exploiting the distinctive signals of up- and down-scattering as well as decay of the excited state inside the detector volume. We focus on a representative model in which DM is a pseudo-Dirac fermion coupled to a hidden gauge field (dark photon), which kinetically mixes with the visible photon. We define theoretical targets in this framework and determine the existing bounds by reanalyzing results from previous experiments. We find that LSND, E137, and BaBar data already place strong constraints on the parameter space consistent with a thermal freeze-out origin, and that future searches at Belle II and MiniBooNE, as well as recently-proposed fixed-target experiments such as LDMX and BDX, can cover nearly all remaining gaps. We also briefly comment on the discovery potential for proposed beam dump and neutrino experiments which operate at much higher beam energies.

Cold dark matter plus not-so-clumpy dark relics

International Nuclear Information System (INIS)

Diamanti, Roberta; Ando, Shin'ichiro; Weniger, Christoph; Gariazzo, Stefano; Mena, Olga

2017-01-01

Various particle physics models suggest that, besides the (nearly) cold dark matter that accounts for current observations, additional but sub-dominant dark relics might exist. These could be warm, hot, or even contribute as dark radiation. We present here a comprehensive study of two-component dark matter scenarios, where the first component is assumed to be cold, and the second is a non-cold thermal relic. Considering the cases where the non-cold dark matter species could be either a fermion or a boson, we derive consistent upper limits on the non-cold dark relic energy density for a very large range of velocity dispersions, covering the entire range from dark radiation to cold dark matter. To this end, we employ the latest Planck Cosmic Microwave Background data, the recent BOSS DR11 and other Baryon Acoustic Oscillation measurements, and also constraints on the number of Milky Way satellites, the latter of which provides a measure of the suppression of the matter power spectrum at the smallest scales due to the free-streaming of the non-cold dark matter component. We present the results on the fraction f ncdm of non-cold dark matter with respect to the total dark matter for different ranges of the non-cold dark matter masses. We find that the 2σ limits for non-cold dark matter particles with masses in the range 1–10 keV are f ncdm ≤0.29 (0.23) for fermions (bosons), and for masses in the 10–100 keV range they are f ncdm ≤0.43 (0.45), respectively.

Cold dark matter plus not-so-clumpy dark relics

Energy Technology Data Exchange (ETDEWEB)

Diamanti, Roberta; Ando, Shin' ichiro; Weniger, Christoph [GRAPPA, Institute of Physics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Gariazzo, Stefano; Mena, Olga, E-mail: r.diamanti@uva.nl, E-mail: s.ando@uva.nl, E-mail: gariazzo@to.infn.it, E-mail: omena@ific.uv.es, E-mail: c.weniger@uva.nl [Instituto de Física Corpuscular (IFIC), CSIC-Universitat de Valencia, Apartado de Correos 22085, E-46071, Valencia (Spain)

2017-06-01

Various particle physics models suggest that, besides the (nearly) cold dark matter that accounts for current observations, additional but sub-dominant dark relics might exist. These could be warm, hot, or even contribute as dark radiation. We present here a comprehensive study of two-component dark matter scenarios, where the first component is assumed to be cold, and the second is a non-cold thermal relic. Considering the cases where the non-cold dark matter species could be either a fermion or a boson, we derive consistent upper limits on the non-cold dark relic energy density for a very large range of velocity dispersions, covering the entire range from dark radiation to cold dark matter. To this end, we employ the latest Planck Cosmic Microwave Background data, the recent BOSS DR11 and other Baryon Acoustic Oscillation measurements, and also constraints on the number of Milky Way satellites, the latter of which provides a measure of the suppression of the matter power spectrum at the smallest scales due to the free-streaming of the non-cold dark matter component. We present the results on the fraction f {sub ncdm} of non-cold dark matter with respect to the total dark matter for different ranges of the non-cold dark matter masses. We find that the 2σ limits for non-cold dark matter particles with masses in the range 1–10 keV are f {sub ncdm}≤0.29 (0.23) for fermions (bosons), and for masses in the 10–100 keV range they are f {sub ncdm}≤0.43 (0.45), respectively.

Inelastic pion scattering from 3H and 3He

International Nuclear Information System (INIS)

Berman, B.L.; Anderson, G.C.; Briscoe, W.J.; Mokhtari, A.; Petrov, A.M.; Sadler, M.E.; Barlow, D.B.; Nefkens, B.M.K.; Pillai, C.

1995-01-01

Cross sections have been measured for the inelastic scattering of π + and π - mesons from 3 H and 3 He in the 10-MeV interval just above the breakup thresholds, for incident pion energies of 142, 180, and 220 MeV and scattering angles of 40 degree, 60 degree, 80 degree, 90 degree, and 110 degree. No significant departure from unity is observed for the ratios of charge-symmetric cross sections. Comparisons are made with elastic pion-scattering and inelastic electron-scattering data

Path integral theory and deep inelastic scattering of nuclei

International Nuclear Information System (INIS)

Neto, J.L.

1981-10-01

A formalism, based on Feynman's path integral, is developed and used in the theory of deep inelastic collisions of nuclei. Having shown how to express the propagator of the Wigner function of an isolated system as a (double) path integral in phase space, random processes are considered and the influence functional in interacting systems is discussed. A semi-classical description for the reduced Wigner and a generalized Langevin equation are given. Finally, the formalism is used in a random matrix model for deep inelastic collisions. (U.K.)

Response of subsystems on inelastic structures

International Nuclear Information System (INIS)

Lin, J.; Mahin, S.A.

1984-01-01

Preliminary analysis are performed to obtain insight into the seismic response of subsystems supported on simple structures that yield during severe earthquake ground motions. Current design recommendations for subsystems accounting for yielding of the supporting structures are assessed and found to be unconservative. An amplification factor is defined to quantify the effects of inelastic deformations of the supporting structure on subsystem response. Design guidelines are formulated for predicting the amplification factor based on statistical evaluation of the results generated for ten earthquake ground motions. Using these values, design floor response spectra can be obtained from conventional linear elastic floor response spectra accounting for yielding of the supporting structure without having to perform inelastic analysis. The effects of non-zero subsystem mass are examined. The recommended amplification factors are found to be applicable even when the mass of subsystem approaches that of the supporting structure

The dark side of cosmology: dark matter and dark energy.

Science.gov (United States)

Spergel, David N

2015-03-06

A simple model with only six parameters (the age of the universe, the density of atoms, the density of matter, the amplitude of the initial fluctuations, the scale dependence of this amplitude, and the epoch of first star formation) fits all of our cosmological data . Although simple, this standard model is strange. The model implies that most of the matter in our Galaxy is in the form of "dark matter," a new type of particle not yet detected in the laboratory, and most of the energy in the universe is in the form of "dark energy," energy associated with empty space. Both dark matter and dark energy require extensions to our current understanding of particle physics or point toward a breakdown of general relativity on cosmological scales. Copyright © 2015, American Association for the Advancement of Science.

Analysis of metal-matrix composite structures. I - Micromechanics constitutive theory. II - Laminate analyses

Science.gov (United States)

Arenburg, R. T.; Reddy, J. N.

1991-01-01

The micromechanical constitutive theory is used to examine the nonlinear behavior of continuous-fiber-reinforced metal-matrix composite structures. Effective lamina constitutive relations based on the Abouli micromechanics theory are presented. The inelastic matrix behavior is modeled by the unified viscoplasticity theory of Bodner and Partom. The laminate constitutive relations are incorporated into a first-order deformation plate theory. The resulting boundary value problem is solved by utilizing the finite element method. Attention is also given to computational aspects of the numerical solution, including the temporal integration of the inelastic strains and the spatial integration of bending moments. Numerical results the nonlinear response of metal matrix composites subjected to extensional and bending loads are presented.

Inelastic neutron scattering from synthetic and biological polymers

International Nuclear Information System (INIS)

White, J.W.

1976-01-01

Neutron elastic and inelastic scattering measurements have provided many unique insights into structure, and by reviewing progress on synthetics, important differences likely to arise in biological systems are identified and a direction for studies of the latter is suggested. By neutron inelastic scattering it is possible to measure the frequency of thermally excited interatomic and intermolecular vibrations in crystals. With perfect organic and inorganic crystals the technique is now classical and has given great insight into the crystal forces responsible for the observed structures as well as the phase transitions they undergo. The study of polymer crystals immediately presents two problems of disorder: (1) Macroscopic disorder arises because the sample is a mixture of amorphous and crystalline fractions, and it may be acute enough to inhibit growth of a single crystal large enough for neutron studies. (2) Microscopic disorder in the packing of polymer chains in the ''crystalline'' regions is indicated by broadening of Bragg peaks. Both types of disorder problem arise in biological systems. The methods by which they were partially overcome to allow neutron measurements with synthetic polymers are described but first a classical example of the determination of interatomic forces by inelastic neutron scattering is given

The dark cube: dark and light character profiles

Directory of Open Access Journals (Sweden)

Danilo Garcia

2016-02-01

Full Text Available Background. Research addressing distinctions and similarities between people’s malevolent character traits (i.e., the Dark Triad: Machiavellianism, narcissism, and psychopathy has detected inconsistent linear associations to temperament traits. Additionally, these dark traits seem to have a common core expressed as uncooperativeness. Hence, some researchers suggest that the dark traits are best represented as one global construct (i.e., the unification argument rather than as ternary construct (i.e., the uniqueness argument. We put forward the dark cube (cf. Cloninger’s character cube comprising eight dark profiles that can be used to compare individuals who differ in one dark character trait while holding the other two constant. Our aim was to investigate in which circumstances individuals who are high in each one of the dark character traits differ in Cloninger’s “light” character traits: self-directedness, cooperativeness, and self-transcendence. We also investigated if people’s dark character profiles were associated to their light character profiles. Method. A total of 997 participants recruited from Amazon’s Mechanical Turk (MTurk responded to the Short Dark Triad and the Short Character Inventory. Participants were allocated to eight different dark profiles and eight light profiles based on their scores in each of the traits and any possible combination of high and low scores. We used three-way interaction regression analyses and t-tests to investigate differences in light character traits between individuals with different dark profiles. As a second step, we compared the individuals’ dark profile with her/his character profile using an exact cell-wise analysis conducted in the ROPstat software (http://www.ropstat.com. Results. Individuals who expressed high levels of Machiavellianism and those who expressed high levels of psychopathy also expressed low self-directedness and low cooperativeness. Individuals with high

Inelastic plasmon and inter-band electron-scattering potentials for Si from dielectric matrix calculations

International Nuclear Information System (INIS)

Josefsson, T.W.; Smith, A.E.

1994-01-01

Inelastic scattering of electrons in a crystalline environment may be represented by a complex non-hermitian potential. Completed generalised expressions for this inelastic electron scattering potential matrix, including virtual inelastic scattering, are derived for outer-shell electron and plasmon excitations. The relationship between these expressions and the general anisotropic dielectric response matrix of the solid is discussed. These generalised expressions necessarily include the off-diagonal terms representing effects due to departure from translational invariance in the interaction. Results are presented for the diagonal back structure dependent inelastic and virtual inelastic scattering potentials for Si, from a calculation of the inverse dielectric matrix in the random phase approximation. Good agreement is found with experiment as a function of incident energies from 10 eV to 100 keV. Anisotropy effects and hence the interaction de localisation represented by the off-diagonal scattering potential terms, are found to be significant below 1 keV. 38 refs., 2 figs

Cold dark matter plus not-so-clumpy dark relics

NARCIS (Netherlands)

Diamanti, R.; Ando, S.; Gariazzo, S.; Mena, O.; Weniger, C.

Various particle physics models suggest that, besides the (nearly) cold dark matter that accounts for current observations, additional but sub-dominant dark relics might exist. These could be warm, hot, or even contribute as dark radiation. We present here a comprehensive study of two-component dark

Hadron-nucleon inelastic collision mean free path in nuclear matter

International Nuclear Information System (INIS)

Strugalski, Z.

1980-01-01

Characteristics of atomic nuclei, used as targets in high energy hadron-nucleus collision experiments, are defined on the basis of the data on the nuclei sizes and radial nucleon density distributions in nuclei. Average mean free path for inelastic hadron-nucleon collisions in nuclei is estimated using existing experimental data on the pion-xenon nucleus collisions and the connection of it with the cross-section for hadron-nucleon elementary inelastic collisions is discussed

Supplying Dark Energy from Scalar Field Dark Matter

OpenAIRE

Gogberashvili, Merab; Sakharov, Alexander S.

2017-01-01

We consider the hypothesis that dark matter and dark energy consists of ultra-light self-interacting scalar particles. It is found that the Klein-Gordon equation with only two free parameters (mass and self-coupling) on a Schwarzschild background, at the galactic length-scales has the solution which corresponds to Bose-Einstein condensate, behaving as dark matter, while the constant solution at supra-galactic scales can explain dark energy.

Dark stars

DEFF Research Database (Denmark)

Maselli, Andrea; Pnigouras, Pantelis; Nielsen, Niklas Grønlund

2017-01-01

to the formation of compact objects predominantly made of dark matter. Considering both fermionic and bosonic (scalar φ4) equations of state, we construct the equilibrium structure of rotating dark stars, focusing on their bulk properties and comparing them with baryonic neutron stars. We also show that these dark......Theoretical models of self-interacting dark matter represent a promising answer to a series of open problems within the so-called collisionless cold dark matter paradigm. In case of asymmetric dark matter, self-interactions might facilitate gravitational collapse and potentially lead...... objects admit the I-Love-Q universal relations, which link their moments of inertia, tidal deformabilities, and quadrupole moments. Finally, we prove that stars built with a dark matter equation of state are not compact enough to mimic black holes in general relativity, thus making them distinguishable...

Highlights of electron-proton deep inelastic scattering at HERA

International Nuclear Information System (INIS)

Feltesse, J.

1996-02-01

Salient results on deep inelastic scattering from the H1 and ZEUS collaborations are reviewed. These include preliminary measurements of the proton structure function F 2 extending to new regimes at both high Q 2 and low Q 2 and x, studies of the hadronic final states and discussion on QCD interpretations of low x data. New determination of α s from jet rates in deep inelastic scattering based on 1994 data are presented. A consistent picture of the gluon density in the proton at low x from a variety of processes is obtained. (author)

EQUILIBRIUM OF TRUSS AND BEAM STRUCTURES OF INELASTIC MATERIALS

DEFF Research Database (Denmark)

Hagsten, Lars German

2017-01-01

A physically based method for the determination of equilibrium for structures with inelastic response is described. The method is based on minimisation of the potential energy. For structures with inelastic response, some of the applied energy is converted to non-mechanical energy. This part...... and shrinkage, as well as plastic strains from previous load scenarios, will also change the potential energy. The method is also capable of taken these effects into account. Three examples are included in order to support the physical understanding, and to illustrate the procedure for the application...

Dark nebulae, dark lanes, and dust belts

CERN Document Server

Cooke, Antony

2012-01-01

As probably the only book of its type, this work is aimed at the observer who wants to spend time with something less conventional than the usual fare. Because we usually see objects in space by means of illumination of one kind or another, it has become routine to see them only in these terms. However, part of almost everything that we see is the defining dimension of dark shading, or even the complete obscuration of entire regions in space. Thus this book is focused on everything dark in space: those dark voids in the stellar fabric that mystified astronomers of old; the dark lanes reported in many star clusters; the magical dust belts or dusty regions that have given so many galaxies their identities; the great swirling 'folds' that we associate with bright nebulae; the small dark feature detectable even in some planetary nebulae; and more. Many observers pay scant attention to dark objects and details. Perhaps they are insufficiently aware of them or of the viewing potential they hold, but also it may be...

Measurement and simulation of the inelastic resolution function of a time-of-flight spectrometer

International Nuclear Information System (INIS)

Roth, S.V.; Zirkel, A.; Neuhaus, J.; Petry, W.; Bossy, J.; Peters, J.; Schober, H.

2002-01-01

The deconvolution of inelastic neutron scattering data requires the knowledge of the inelastic resolution function. The inelastic resolution function of the time-of-flight spectrometer IN5/ILL has been measured by exploiting the sharp resonances of the roton and maxon excitations in superfluid 4 He for the two respective (q,ω) values. The calculated inelastic resolution function for three different instrumental setups is compared to the experimentally determined resolution function. The agreement between simulation and experimental data is excellent, allowing us in principle to extrapolate the simulations and thus to determine the resolution function in the whole accessible dynamic range of IN5 or any other time-of-flight spectrometer. (orig.)

Measurement and simulation of the inelastic resolution function of a time-of-flight spectrometer

CERN Document Server

Roth, S V; Neuhaus, J; Petry, W; Bossy, J; Peters, J; Schober, H

2002-01-01

The deconvolution of inelastic neutron scattering data requires the knowledge of the inelastic resolution function. The inelastic resolution function of the time-of-flight spectrometer IN5/ILL has been measured by exploiting the sharp resonances of the roton and maxon excitations in superfluid sup 4 He for the two respective (q,omega) values. The calculated inelastic resolution function for three different instrumental setups is compared to the experimentally determined resolution function. The agreement between simulation and experimental data is excellent, allowing us in principle to extrapolate the simulations and thus to determine the resolution function in the whole accessible dynamic range of IN5 or any other time-of-flight spectrometer. (orig.)

Sourcing dark matter and dark energy from α-attractors

Energy Technology Data Exchange (ETDEWEB)

Mishra, Swagat S.; Sahni, Varun [Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune 411 007 (India); Shtanov, Yuri, E-mail: swagat@iucaa.in, E-mail: varun@iucaa.in, E-mail: shtanov@bitp.kiev.ua [Bogolyubov Institute for Theoretical Physics, Kiev 03680 (Ukraine)

2017-06-01

In [1], Kallosh and Linde drew attention to a new family of superconformal inflationary potentials, subsequently called α-attractors [2]. The α-attractor family can interpolate between a large class of inflationary models. It also has an important theoretical underpinning within the framework of supergravity. We demonstrate that the α-attractors have an even wider appeal since they may describe dark matter and perhaps even dark energy. The dark matter associated with the α-attractors, which we call α-dark matter (αDM), shares many of the attractive features of fuzzy dark matter, with V (φ) = ½ m {sup 2}φ{sup 2}, while having none of its drawbacks. Like fuzzy dark matter, αDM can have a large Jeans length which could resolve the cusp-core and substructure problems faced by standard cold dark matter. αDM also has an appealing tracker property which enables it to converge to the late-time dark matter asymptote, ( w ) ≅ 0, from a wide range of initial conditions. It thus avoids the enormous fine-tuning problems faced by the m {sup 2}φ{sup 2} potential in describing dark matter.

Sourcing dark matter and dark energy from α-attractors

International Nuclear Information System (INIS)

Mishra, Swagat S.; Sahni, Varun; Shtanov, Yuri

2017-01-01

In [1], Kallosh and Linde drew attention to a new family of superconformal inflationary potentials, subsequently called α-attractors [2]. The α-attractor family can interpolate between a large class of inflationary models. It also has an important theoretical underpinning within the framework of supergravity. We demonstrate that the α-attractors have an even wider appeal since they may describe dark matter and perhaps even dark energy. The dark matter associated with the α-attractors, which we call α-dark matter (αDM), shares many of the attractive features of fuzzy dark matter, with V (φ) = ½ m 2 φ 2 , while having none of its drawbacks. Like fuzzy dark matter, αDM can have a large Jeans length which could resolve the cusp-core and substructure problems faced by standard cold dark matter. αDM also has an appealing tracker property which enables it to converge to the late-time dark matter asymptote, ( w ) ≅ 0, from a wide range of initial conditions. It thus avoids the enormous fine-tuning problems faced by the m 2 φ 2 potential in describing dark matter.

Gravitational wave from dark sector with dark pion

Energy Technology Data Exchange (ETDEWEB)

Tsumura, Koji [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Yamada, Masatoshi [Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg (Germany); Yamaguchi, Yuya, E-mail: ko2@gauge.scphys.kyoto-u.ac.jp, E-mail: m.yamada@thphys.uni-heidelberg.de, E-mail: yy@particle.sci.hokudai.ac.jp [Department of Physics, Faculty of Science, Hokkaido University, Sapporo 060-0810 (Japan)

2017-07-01

In this work, we investigate the spectra of gravitational waves produced by chiral symmetry breaking in dark quantum chromodynamics (dQCD) sector. The dark pion (π) can be a dark matter candidate as weakly interacting massive particle (WIMP) or strongly interacting massive particle (SIMP). For a WIMP scenario, we introduce the dQCD sector coupled to the standard model (SM) sector with classical scale invariance and investigate the annihilation process of the dark pion via the 2π → 2 SM process. For a SIMP scenario, we investigate the 3π → 2π annihilation process of the dark pion as a SIMP using chiral perturbation theory. We find that in the WIMP scenario the gravitational wave background spectra can be observed by future space gravitational wave antennas. On the other hand, when the dark pion is the SIMP dark matter with the constraints for the chiral perturbative limit and pion-pion scattering cross section, the chiral phase transition becomes crossover and then the gravitational waves are not produced.

Description of deeply inelastic collisions in terms of a transport equation

International Nuclear Information System (INIS)

Weidenmueller, H.A.

1977-01-01

A transport equation for deeply inelastic collisions is derived from a random-matrix model for the form factors for inelastic scattering and transfer reactions. The parametrization of these form factors is discussed. Results in one dimension indicate the importance of quantum fluctuations, and limitations of other approaches to the same problem. Results of three dimensions are compared with the data

Experience with conventional inelastic analysis procedures in very high temperature applications

International Nuclear Information System (INIS)

Mallett, R.H.; Thompson, J.M.; Swindeman, R.W.

1991-01-01

Conventional incremental plasticity and creep analysis procedures for inelastic analysis are applied to hot flue gas cleanup system components. These flue gas systems operate at temperatures where plasticity and creep are very much intertwined while the two phenomena are treated separately in the conventional inelastic analysis procedure. Data for RA333 material are represented in forms appropriate for the conventional inelastic analysis procedures. Behavior is predicted for typical operating cycles. Creep-fatigue damage is estimated based upon usage fractions. Excessive creep damage is predicted; the major contributions occur during high stress short term intervals caused by rapid temperature changes. In this paper these results are presented for discussion of the results and their interpretation in terms of creep-fatigue damage for very high temperature applications

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.

Sterman-Weinberg formula in deep inelastic scattering

International Nuclear Information System (INIS)

Dzhaparidze, G.Sh.; Kartvelishvili, V.G.

1981-01-01

The jet cross-section in current fragmentation region in deep inelastic scattering is obtained. It is shown that this jet produced in ep reaction is narrower, then the one from e + e - -annihilation [ru

Dark Energy vs. Dark Matter: Towards a Unifying Scalar Field?

OpenAIRE

Arbey, A.

2008-01-01

The standard model of cosmology suggests the existence of two components, "dark matter" and "dark energy", which determine the fate of the Universe. Their nature is still under investigation, and no direct proof of their existences has emerged yet. There exist alternative models which reinterpret the cosmological observations, for example by replacing the dark energy/dark matter hypothesis by the existence of a unique dark component, the dark fluid, which is able to mimic the behaviour of bot...

Inelastic J/ψphotoproduction

International Nuclear Information System (INIS)

Kraemer, M.; Steegborn, J.; Zerwas, P.M.

1994-11-01

Inelastic photoproduction of J/ψ particles at high energies is one of the processes to determine the gluon distribution in the nucleon. We have calculated the QCD radiative corrections to the color-singlet model of this reaction. They are large at moderate photon energies, but decrease with increasing energies. The cross section and the J/ψ energy spectrum are compared with the available fixed-target photoproduction data and predictions are given for the HERA energy range. (orig.)

Conformal Gravity: Dark Matter and Dark Energy

Directory of Open Access Journals (Sweden)

Robert K. Nesbet

2013-01-01

Full Text Available This short review examines recent progress in understanding dark matter, dark energy, and galactic halos using theory that departs minimally from standard particle physics and cosmology. Strict conformal symmetry (local Weyl scaling covariance, postulated for all elementary massless fields, retains standard fermion and gauge boson theory but modifies Einstein–Hilbert general relativity and the Higgs scalar field model, with no new physical fields. Subgalactic phenomenology is retained. Without invoking dark matter, conformal gravity and a conformal Higgs model fit empirical data on galactic rotational velocities, galactic halos, and Hubble expansion including dark energy.

Inclusive measurements of pion double charge exchange and inelastic scattering on 3He

International Nuclear Information System (INIS)

Yuly, M.E.

1993-06-01

A measurement was made at the Los Alamos Meson Physics Facility (LAMPF) of the doubly differential cross sections for three inclusive pion reactions on 3 He: π - double charge exchange (DCX), and π + and π - inelastic scattering. The cross sections for DCX were measured at incident energies of 120, 180, 210, and 240 MeV, and at angles of 25, 50, 80, 105, and 130 degrees, while inelastic scattering cross sections were measured at 120, 180, and 240 MeV and scattering angles of 50, 80, 105, and 130 degrees. The final pion energy spectrum was measured from 10 MeV up to the kinematic limit. In the Δ resonance region, where the isospin T = 3/2 channel dominates, the inelastic π - scattering should be almost entirely from the lone neutron in 3 He. The π + inelastic scattering was expected to have significant contributions from both single and double scattering, because the T = 3/2 channel favors π + -p scattering from the two protons in 3 He. The 3 He DCX spectra are similar to those observed for DCX in 4 He. The forward angle double peaks can be understood as a consequence of sequential single charge exchange (SSCX). Calculations using the SSCX model are in rough agreement with the measured shape of the 3 He DCX spectra. The doubly differential cross sections measured for the inelastic scattering reactions exhibit a strong enhancement near the kinematics for free π - -p scattering. The ratios of π + to π - scattering cross sections may indicate multiple scattering, as well as the agreement of the low outgoing energy part of the π + inelastic scattering spectra with the corresponding properly scaled DCX spectra. A distorted-wave impulse-approximation (DWIA) calculation of the quasielastic cross sections has been performed and a comparison made with the measured inelastic cross sections

Inelastic electron scattering from a moving nucleon

Energy Technology Data Exchange (ETDEWEB)

Kuhn, S.E. [Old Dominion Univ., Norfolk, VA (United States); Griffioen, K. [College of William and Mary, Williamsburg, VA (United States)

1994-04-01

The authors propose to measure inelastically scattered electrons in coincidence with spectator protons emitted backwards relative to the virtual photon direction in the reaction d(e, e{prime}p{sub s})X. In a simple spectator model, the backward proton has equal and opposite momentum to the neutron before it is struck, allowing the authors to study the dependence on kinematics and off-shell behaviour of the electron-nucleon inelastic cross section. If the photon couples to a quark in a 6-quark bag, a different dependence of the cross section on the kinematic variables (x, Q{sup 2}, and p{sub s}) can be observed. This proposed experiment requires large acceptance and beam energies above 6 GeV. It is ideally suited for the CEBAF Large Acceptance Spectrometer (CLAS).

The phenomenology of deep-inelastic processes

International Nuclear Information System (INIS)

Moretto, L.G.

1983-01-01

The field of heavy-ion deep-inelastic reactions is reviewed with particular attention to the experimental picture. The most important degrees of freedom involved in the process are identified and illustrated with relevant experiments. Energy dissipation and mass transfer are discussed in terms of particles and/or phonons exchanged in the process. The equilibration of the fragment neutron-to-proton ratios is inspected for evidence of giant isovector resonances. The angular momentum effects are observed in the fragment angular distributions and the angular momentum transfer is inferred from the magnitude and alignment of the fragments spins. The possible sources of light particles accompanying the deep-inelastic reactions are discussed. The use of the sequentially emitted particles as angular momentum probes is illustrated. The significance and uses of a thermalized component emitted by the dinucleus is reviewed. The possible presence of Fermi jets in the prompt component is shown to be critical to the justification of the one-body theories. (orig.)

Superparamagnetic iron oxide nanoparticles incorporated into silica nanoparticles by inelastic collision via ultrasonic field: Role of colloidal stability

Energy Technology Data Exchange (ETDEWEB)

Sodipo, Bashiru Kayode; Azlan, Abdul Aziz [Nano-Optoelectronics Research and Technology (NOR) Lab, School of Physics, Universiti Sains Malaysia, 11800 Pulau Pinang, Malaysia Nano-Biotechnology Research (Malaysia); Innovation (NanoBRI), Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800, Pulau Pinang (Malaysia)

2015-04-24

Superparamagnetic iron oxide nanoparticles (SPION)/Silica composite nanoparticles were prepared by ultrasonically irradiating colloidal suspension of silica and SPION mixture. Both silica and SPION were synthesized independently via co-precipitation and sol-gel method, respectively. Their mixtures were sonicated at different pH between 3 and 5. Electrophoresis measurement and other physicochemical analyses of the products demonstrate that at lower pH SPION was found incorporated into the silica. However, at pH greater than 4, SPION was unstable and unable to withstand the turbulence flow and shock wave from the ultrasonic field. Results suggest that the formation of the SPION/silica composite nanoparticles is strongly related to the inelastic collision induced by ultrasonic irradiation. More so, the formation the composite nanoparticles via the ultrasonic field are dependent on the zeta potential and colloidal stability of the particles.

Study on inelastic analysis method for structural design (1). Estimation method of loading history effect

International Nuclear Information System (INIS)

Tanaka, Yoshihiko; Kasahara, Naoto

2003-05-01

The advanced loop-type reactor system, one of the promising concepts in the Feasibility study of the FBR Cycle, adopts many innovative ideas to meet the challenging requirements for safety and economy. As a results, it seems that the structures of the reactor system would be subjected to severer loads than the predecessors. One of the countermeasures to them is the design by inelastic analysis. In the past, many studies showed that structural design by inelastic analysis is much more reasonable than one by conservative elastic analysis. However, inelastic analysis has hardly been adopted in nuclear design so far. One of the reasons is that inelastic analysis has loading history effect, that is, the analysis result would differ depending on the order of loads. It seems to be difficult to find the general solution for the loading history effect. Consequently, inelastic analysis output from the four deferent thermal load histories which consists of the thermal load cycle including the severest cold shock ('C') and the one including the severest hot shock ('H') were compared with each other. From this comparison, it was revealed that the thermal load history with evenly distributed 'H's among 'C's tend to give the most conservative damage estimation derived from inelastic analysis output. Therefore, such thermal load history pattern is proposed for the structural design by inelastic analysis. (author)

The CN/C15N isotopic ratio towards dark clouds

Science.gov (United States)

Hily-Blant, P.; Pineau des Forêts, G.; Faure, A.; Le Gal, R.; Padovani, M.

2013-09-01

Understanding the origin of the composition of solar system cosmomaterials is a central question, not only in the cosmochemistry and astrochemistry fields, and requires various approaches to be combined. Measurements of isotopic ratios in cometary materials provide strong constraints on the content of the protosolar nebula. Their relation with the composition of the parental dark clouds is, however, still very elusive. In this paper, we bring new constraints based on the isotopic composition of nitrogen in dark clouds, with the aim of understanding the chemical processes that are responsible for the observed isotopic ratios. We have observed and detected the fundamental rotational transition of C15N towards two starless dark clouds, L1544 and L1498. We were able to derive the column density ratio of C15N over 13CN towards the same clouds and obtain the CN/C15N isotopic ratios, which were found to be 500 ± 75 for both L1544 and L1498. These values are therefore marginally consistent with the protosolar value of 441. Moreover, this ratio is larger than the isotopic ratio of nitrogen measured in HCN. In addition, we present model calculations of the chemical fractionation of nitrogen in dark clouds, which make it possible to understand how CN can be deprived of 15N and HCN can simultaneously be enriched in heavy nitrogen. The non-fractionation of N2H+, however, remains an open issue, and we propose some chemical way of alleviating the discrepancy between model predictions and the observed ratios. Appendices are available in electronic form at http://www.aanda.orgThe reduced spectra (in FITS format) are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/557/A65

Effective dark energy equation of state in interacting dark energy models

International Nuclear Information System (INIS)

Avelino, P.P.; Silva, H.M.R. da

2012-01-01

In models where dark matter and dark energy interact non-minimally, the total amount of matter in a fixed comoving volume may vary from the time of recombination to the present time due to energy transfer between the two components. This implies that, in interacting dark energy models, the fractional matter density estimated using the cosmic microwave background assuming no interaction between dark matter and dark energy will in general be shifted with respect to its true value. This may result in an incorrect determination of the equation of state of dark energy if the interaction between dark matter and dark energy is not properly accounted for, even if the evolution of the Hubble parameter as a function of redshift is known with arbitrary precision. In this Letter we find an exact expression, as well as a simple analytical approximation, for the evolution of the effective equation of state of dark energy, assuming that the energy transfer rate between dark matter and dark energy is described by a simple two-parameter model. We also provide analytical examples where non-phantom interacting dark energy models mimic the background evolution and primary cosmic microwave background anisotropies of phantom dark energy models.

Effective dark energy equation of state in interacting dark energy models

Energy Technology Data Exchange (ETDEWEB)

Avelino, P.P., E-mail: ppavelin@fc.up.pt [Centro de Astrofisica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Departamento de Fisica e Astronomia da Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Silva, H.M.R. da, E-mail: hilberto.silva@gmail.com [Departamento de Fisica e Astronomia da Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

2012-07-24

In models where dark matter and dark energy interact non-minimally, the total amount of matter in a fixed comoving volume may vary from the time of recombination to the present time due to energy transfer between the two components. This implies that, in interacting dark energy models, the fractional matter density estimated using the cosmic microwave background assuming no interaction between dark matter and dark energy will in general be shifted with respect to its true value. This may result in an incorrect determination of the equation of state of dark energy if the interaction between dark matter and dark energy is not properly accounted for, even if the evolution of the Hubble parameter as a function of redshift is known with arbitrary precision. In this Letter we find an exact expression, as well as a simple analytical approximation, for the evolution of the effective equation of state of dark energy, assuming that the energy transfer rate between dark matter and dark energy is described by a simple two-parameter model. We also provide analytical examples where non-phantom interacting dark energy models mimic the background evolution and primary cosmic microwave background anisotropies of phantom dark energy models.

Magnetic Dynamics of Fine Particles Studied by Inelastic Neutron Scattering

DEFF Research Database (Denmark)

Hansen, Mikkel Fougt; Bødker, Franz; Mørup, Steen

2000-01-01

We give an introduction to inelastic neutron scattering and the dynamic scattering function for magnetic nanoparticles. Differences between ferromagnetic and antiferromagnetic nanoparticles are discussed and we give a review of recent results on ferromagnetic Fe nanoparticles and canted antiferro......We give an introduction to inelastic neutron scattering and the dynamic scattering function for magnetic nanoparticles. Differences between ferromagnetic and antiferromagnetic nanoparticles are discussed and we give a review of recent results on ferromagnetic Fe nanoparticles and canted...

Turning off the lights: How dark is dark matter?

International Nuclear Information System (INIS)

McDermott, Samuel D.; Yu Haibo; Zurek, Kathryn M.

2011-01-01

We consider current observational constraints on the electromagnetic charge of dark matter. The velocity dependence of the scattering cross section through the photon gives rise to qualitatively different constraints than standard dark matter scattering through massive force carriers. In particular, recombination epoch observations of dark matter density perturbations require that ε, the ratio of the dark matter to electronic charge, is less than 10 -6 for m X =1 GeV, rising to ε -4 for m X =10 TeV. Though naively one would expect that dark matter carrying a charge well below this constraint could still give rise to large scattering in current direct detection experiments, we show that charged dark matter particles that could be detected with upcoming experiments are expected to be evacuated from the Galactic disk by the Galactic magnetic fields and supernova shock waves and hence will not give rise to a signal. Thus dark matter with a small charge is likely not a source of a signal in current or upcoming dark matter direct detection experiments.

Measurement of proton inelastic scattering cross sections on fluorine

Energy Technology Data Exchange (ETDEWEB)

Chiari, M., E-mail: chiari@fi.infn.it [Department of Physics and Astronomy, University of Florence and INFN Florence, Sesto Fiorentino (Italy); Caciolli, A. [Department of Physics and Astronomy, University of Padua and INFN Padua, Padova (Italy); Calzolai, G. [Department of Physics and Astronomy, University of Florence and INFN Florence, Sesto Fiorentino (Italy); Climent-Font, A. [CMAM, Universidad Autonoma de Madrid, Madrid (Spain); Lucarelli, F.; Nava, S. [Department of Physics and Astronomy, University of Florence and INFN Florence, Sesto Fiorentino (Italy)

2016-10-01

Differential cross-sections for proton inelastic scattering on fluorine, {sup 19}F(p,p’){sup 19}F, from the first five excited levels of {sup 19}F at 110, 197, 1346, 1459 and 1554 keV were measured for beam energies from 3 to 7 MeV at a scattering angle of 150° using a LiF thin target (50 μg/cm{sup 2}) evaporated on a self-supporting C thin film (30 μg/cm{sup 2}). Absolute differential cross-sections were calculated with a method not dependent on the absolute values of collected beam charge and detector solid angle. The validity of the measured inelastic scattering cross sections was then tested by successfully reproducing EBS spectra collected from a thick Teflon (CF{sub 2}) target. As a practical application of these measured inelastic scattering cross sections in elastic backscattering spectroscopy (EBS), the feasibility of quantitative light element (C, N and O) analysis in aerosol particulate matter samples collected on Teflon by EBS measurements and spectra simulation is demonstrated.

Inelastic spectra to predict period elongation of structures under earthquake loading

DEFF Research Database (Denmark)

Katsanos, Evangelos; Sextos, A.G.

2015-01-01

Period lengthening, exhibited by structures when subjected to strong ground motions, constitutes an implicit proxy of structural inelasticity and associated damage. However, the reliable prediction of the inelastic period is tedious and a multi-parametric task, which is related to both epistemic ...... for period lengthening as a function of Ry and Tel. These equations may be used in the framework of the earthquake record selection and scaling....

Compton Composites Late in the Early Universe

Directory of Open Access Journals (Sweden)

Frederick Mayer

2014-07-01

Full Text Available Beginning roughly two hundred years after the big-bang, a tresino phase transition generated Compton-scale composite particles and converted most of the ordinary plasma baryons into new forms of dark matter. Our model consists of ordinary electrons and protons that have been bound into mostly undetectable forms. This picture provides an explanation of the composition and history of ordinary to dark matter conversion starting with, and maintaining, a critical density Universe. The tresino phase transition started the conversion of ordinary matter plasma into tresino-proton pairs prior to the the recombination era. We derive the appropriate Saha–Boltzmann equilibrium to determine the plasma composition throughout the phase transition and later. The baryon population is shown to be quickly modified from ordinary matter plasma prior to the transition to a small amount of ordinary matter and a much larger amount of dark matter after the transition. We describe the tresino phase transition and the origin, quantity and evolution of the dark matter as it takes place from late in the early Universe until the present.

Correlation holography: imaging of atoms when sigma/sub inelastic//sup >>sigma/elastic

International Nuclear Information System (INIS)

Csonka, P.L.

1979-01-01

Atomic-scale resolution of details is possible with this method, even if protons interact with the atoms overwhelmingly inelastically, i.e. when sigma/sub inelastic/ >>sigma/sub elastic/. Observation of small objects is compatible with quantum mechanics even if the disturbance of the object caused by the observation process is arbitrarily small

Unified Description of Dark Energy and Dark Matter

OpenAIRE

Petry, Walter

2008-01-01

Dark energy in the universe is assumed to be vacuum energy. The energy-momentum of vacuum is described by a scale-dependent cosmological constant. The equations of motion imply for the density of matter (dust) the sum of the usual matter density (luminous matter) and an additional matter density (dark matter) similar to the dark energy. The scale-dependent cosmological constant is given up to an exponent which is approximated by the experimentally decided density parameters of dark matter and...

Dark energy and dark matter from primordial QGP

Energy Technology Data Exchange (ETDEWEB)

Vaidya, Vaishali, E-mail: vaidvavaishali24@gmail.com; Upadhyaya, G. K., E-mail: gopalujiain@yahoo.co.in [School of Studies in Physics, Vikram University Ujjain (India)

2015-07-31

Coloured relics servived after hadronization might have given birth to dark matter and dark energy. Theoretical ideas to solve mystery of cosmic acceleration, its origin and its status with reference to recent past are of much interest and are being proposed by many workers. In the present paper, we present a critical review of work done to understand the earliest appearance of dark matter and dark energy in the scenario of primordial quark gluon plasma (QGP) phase after Big Bang.

Incremental-hinge piping analysis methods for inelastic seismic response prediction

International Nuclear Information System (INIS)

Jaquay, K.R.; Castle, W.R.; Larson, J.E.

1989-01-01

This paper proposes nonlinear seismic response prediction methods for nuclear piping systems based on simplified plastic hinge analyses. The simplified plastic hinge analyses utilize an incremental series of flat response spectrum loadings and replace yielded components with hinge elements when a predefined hinge moment is reached. These hinge moment values, developed by Rodabaugh, result in inelastic energy dissipation of the same magnitude as observed in seismic tests of piping components. Two definitions of design level equivalent loads are employed: one conservatively based on the peaks of the design acceleration response spectra, the other based on inelastic frequencies determined by the method of Krylov and Bogolyuboff recently extended by Lazzeri to piping. Both definitions account for piping system inelastic energy dissipation using Newmark-Hall inelastic response spectrum reduction factors and the displacement ductility results of the incremental-hinge analysis. Two ratchet-fatigue damage models are used: one developed by Rodabaugh that conservatively correlates Markl static fatigue expressions to seismic tests to failure of piping components; the other developed by Severud that uses the ratchet expression of Bree for elbows and Edmunds and Beer for straights, and defines ratchet-fatigue interaction using Coffin's ductility based fatigue equation. Comparisons of predicted behavior versus experimental results are provided for a high-level seismic test of a segment of a representative nuclear plant piping system. (orig.)

Excitation of the shear horizontal mode in a monolayer by inelastic helium atom scattering

DEFF Research Database (Denmark)

Bruch, L. W.; Hansen, Flemming Yssing

2005-01-01

Inelastic scattering of a low-energy atomic helium beam (HAS) by a physisorbed monolayer is treated in the one-phonon approximation using a time-dependent wave,packet formulation. The calculations show that modes with shear horizontal polarization can be excited near high symmetry azimuths....... The diffraction and inelastic processes arise from a strong coupling of the incident atom to the target and the calculated results show large departures from expectations based on analogies to inelastic thermal neutron scattering....

Mean associative multiplicities in deep inelastic processes

International Nuclear Information System (INIS)

Dzhaparidze, G.Sh.; Kiselev, A.V.; Petrov, V.A.

1981-01-01

The associative hadron multiplicities in deep inelastic and Drell--Yan processes are studied. In particular the mean multiplicities in different hard processes in QCD are found to be determined by the mean multiplicity in parton jet [ru

Codecaying Dark Matter.

Science.gov (United States)

Dror, Jeff Asaf; Kuflik, Eric; Ng, Wee Hao

2016-11-18

We propose a new mechanism for thermal dark matter freeze-out, called codecaying dark matter. Multicomponent dark sectors with degenerate particles and out-of-equilibrium decays can codecay to obtain the observed relic density. The dark matter density is exponentially depleted through the decay of nearly degenerate particles rather than from Boltzmann suppression. The relic abundance is set by the dark matter annihilation cross section, which is predicted to be boosted, and the decay rate of the dark sector particles. The mechanism is viable in a broad range of dark matter parameter space, with a robust prediction of an enhanced indirect detection signal. Finally, we present a simple model that realizes codecaying dark matter.

Interactions between dark energy and dark matter

Energy Technology Data Exchange (ETDEWEB)

Baldi, Marco

2009-03-20

We have investigated interacting dark energy cosmologies both concerning their impact on the background evolution of the Universe and their effects on cosmological structure growth. For the former aspect, we have developed a cosmological model featuring a matter species consisting of particles with a mass that increases with time. In such model the appearance of a Growing Matter component, which is negligible in early cosmology, dramatically slows down the evolution of the dark energy scalar field at a redshift around six, and triggers the onset of the accelerated expansion of the Universe, therefore addressing the Coincidence Problem. We propose to identify this Growing Matter component with cosmic neutrinos, in which case the present dark energy density can be related to the measured average mass of neutrinos. For the latter aspect, we have implemented the new physical features of interacting dark energy models into the cosmological N-body code GADGET-2, and we present the results of a series of high-resolution simulations for a simple realization of dark energy interaction. As a consequence of the new physics, cold dark matter and baryon distributions evolve differently both in the linear and in the non-linear regime of structure formation. Already on large scales, a linear bias develops between these two components, which is further enhanced by the non-linear evolution. We also find, in contrast with previous work, that the density profiles of cold dark matter halos are less concentrated in coupled dark energy cosmologies compared with {lambda}{sub CDM}. Also, the baryon fraction in halos in the coupled models is significantly reduced below the universal baryon fraction. These features alleviate tensions between observations and the {lambda}{sub CDM} model on small scales. Our methodology is ideally suited to explore the predictions of coupled dark energy models in the fully non-linear regime, which can provide powerful constraints for the viable parameter

Interactions between dark energy and dark matter

International Nuclear Information System (INIS)

Baldi, Marco

2009-01-01

We have investigated interacting dark energy cosmologies both concerning their impact on the background evolution of the Universe and their effects on cosmological structure growth. For the former aspect, we have developed a cosmological model featuring a matter species consisting of particles with a mass that increases with time. In such model the appearance of a Growing Matter component, which is negligible in early cosmology, dramatically slows down the evolution of the dark energy scalar field at a redshift around six, and triggers the onset of the accelerated expansion of the Universe, therefore addressing the Coincidence Problem. We propose to identify this Growing Matter component with cosmic neutrinos, in which case the present dark energy density can be related to the measured average mass of neutrinos. For the latter aspect, we have implemented the new physical features of interacting dark energy models into the cosmological N-body code GADGET-2, and we present the results of a series of high-resolution simulations for a simple realization of dark energy interaction. As a consequence of the new physics, cold dark matter and baryon distributions evolve differently both in the linear and in the non-linear regime of structure formation. Already on large scales, a linear bias develops between these two components, which is further enhanced by the non-linear evolution. We also find, in contrast with previous work, that the density profiles of cold dark matter halos are less concentrated in coupled dark energy cosmologies compared with Λ CDM . Also, the baryon fraction in halos in the coupled models is significantly reduced below the universal baryon fraction. These features alleviate tensions between observations and the Λ CDM model on small scales. Our methodology is ideally suited to explore the predictions of coupled dark energy models in the fully non-linear regime, which can provide powerful constraints for the viable parameter space of such scenarios

Unified dark energy-dark matter model with inverse quintessence

Energy Technology Data Exchange (ETDEWEB)

Ansoldi, Stefano [ICRA — International Center for Relativistic Astrophysics, INFN — Istituto Nazionale di Fisica Nucleare, and Dipartimento di Matematica e Informatica, Università degli Studi di Udine, via delle Scienze 206, I-33100 Udine (UD) (Italy); Guendelman, Eduardo I., E-mail: ansoldi@fulbrightmail.org, E-mail: guendel@bgu.ac.il [Department of Physics, Ben-Gurion University of the Negeev, Beer-Sheva 84105 (Israel)

2013-05-01

We consider a model where both dark energy and dark matter originate from the coupling of a scalar field with a non-canonical kinetic term to, both, a metric measure and a non-metric measure. An interacting dark energy/dark matter scenario can be obtained by introducing an additional scalar that can produce non constant vacuum energy and associated variations in dark matter. The phenomenology is most interesting when the kinetic term of the additional scalar field is ghost-type, since in this case the dark energy vanishes in the early universe and then grows with time. This constitutes an ''inverse quintessence scenario'', where the universe starts from a zero vacuum energy density state, instead of approaching it in the future.

Unified dark energy-dark matter model with inverse quintessence

International Nuclear Information System (INIS)

Ansoldi, Stefano; Guendelman, Eduardo I.

2013-01-01

We consider a model where both dark energy and dark matter originate from the coupling of a scalar field with a non-canonical kinetic term to, both, a metric measure and a non-metric measure. An interacting dark energy/dark matter scenario can be obtained by introducing an additional scalar that can produce non constant vacuum energy and associated variations in dark matter. The phenomenology is most interesting when the kinetic term of the additional scalar field is ghost-type, since in this case the dark energy vanishes in the early universe and then grows with time. This constitutes an ''inverse quintessence scenario'', where the universe starts from a zero vacuum energy density state, instead of approaching it in the future

Theory of inelastic ion-atom scattering at low and intermediate energies

Science.gov (United States)

Schmid, G. B.; Garcia, J. D.

1977-01-01

Ab initio calculations are presented of inelastic energy loss and ionization phenomena associated with Ar(+)-Ar collisions at small distances of closest approach and for laboratory collision energies ranging from several keV to several hundred keV. Outer-shell excitations are handled statistically; inner-shell excitations are calculated from the viewpoint of quasidiabatic molecular orbital promotion. Auger electron yield, average state of ionization, and average inelastic energy loss are calculated per collision as a function of distance of closest approach of the collision partners for several laboratory collision energies. Average charge-state probabilities per collision partner are calculated as a function of the average inelastic energy loss per atom. It is shown that the structure in the data is due to the underlying structure in the inner-shell independent-electron quasimolecular promotion probabilities.

Sputtering and inelastic processes

International Nuclear Information System (INIS)

Baranov, I.A.; Tsepelevic, S.O.

1987-01-01

Experimental data and models of a new type of material sputtering with ions of relatively high energies due to inelastic (electron) processes are reviewed. This area of investigations began to develop intensively during the latest years. New experimental data of the authors on differential characteristics of ultradisperse gold and americium dioxide layers with fission fragments are given as well. Practical applications of the new sputtering type are considered as well as setup of possibl experiments at heavy multiply charged ion accelerators

Measuring the speed of dark: Detecting dark energy perturbations

International Nuclear Information System (INIS)

Putter, Roland de; Huterer, Dragan; Linder, Eric V.

2010-01-01

The nature of dark energy can be probed not only through its equation of state but also through its microphysics, characterized by the sound speed of perturbations to the dark energy density and pressure. As the sound speed drops below the speed of light, dark energy inhomogeneities increase, affecting both cosmic microwave background and matter power spectra. We show that current data can put no significant constraints on the value of the sound speed when dark energy is purely a recent phenomenon, but can begin to show more interesting results for early dark energy models. For example, the best fit model for current data has a slight preference for dynamics [w(a)≠-1], degrees of freedom distinct from quintessence (c s ≠1), and early presence of dark energy [Ω de (a<<1)≠0]. Future data may open a new window on dark energy by measuring its spatial as well as time variation.

On structural inelasticity of modal substitution in freight transport

DEFF Research Database (Denmark)

Rich, Jeppe; Kveiborg, Ole; Overgård, Christian Hansen

2011-01-01

alternative available. The paper investigates the magnitude of this ‘‘structural inelasticity” of modal substitution in freight transport due to a sparser layout of rail and ship-based freight networks compared to road. In the analysis we use a recent Scandinavian freight demand model covering more than 800...... zones. We find that the structural inelasticity is very significant – in particular for transportation over less than 500 km. Moreover, the inelasticity varies greatly with commodity groups and between OD pairs, and it depends strongly on the port and rail infrastructure. The results suggest that pure...

A new approach to irreversibility in deep inelastic collisions

International Nuclear Information System (INIS)

Nemes, M.C.

1982-01-01

We use concepts of statistical mechanics to discuss the irreversible character of the experimental data in deep inelastic collisions. A definition of irreversibility proposed by Ruch permits a unified overview on current theories which describe these reactions. An information theoretical analysis of the data leads to a Fokker-Planck equation for the collective variables (excitation energy, charge and mass). The concept of mixing distance can serve as a quantitative measure to characterize the 'approach to equilibrium'. We apply it to the brownian motion as an illustration and also to the phenomenological analysis of deep inelastic scattering data with interesting results. (orig.)

Value of αs from deep-inelastic-scattering data

International Nuclear Information System (INIS)

Alekhin, S.I.

2003-01-01

We report the value of α s obtained from QCD analysis of existing data on deep-inelastic scattering of charged leptons off proton and deuterium and estimate its theoretical uncertainties with particular attention paid to impact of the high-twist contribution to the deep-inelastic-scattering structure functions. Taking into account the major uncertainties the value αNNLO s (M Z )=0.1143±0.0014(exp.)±0.0013(theor.) is obtained. An extrapolation of the LO-NLO-NNLO results to the higher orders makes it possible to estimate αN 3 LO s (M Z )∼0.113. (author)

Theoretical interpretation of medium energy nucleon nucleus inelastic scattering

International Nuclear Information System (INIS)

Lagrange, Christian

1970-06-01

A theoretical study is made of the medium energy nucleon-nucleus inelastic scattering (direct interaction), by applying the distorted wave Born approximation such as can be deduced from the paired equation method. It is applied to the interpretation of the inelastic scattering of 12 MeV protons by 63 Cu; this leads us to make use of different sets of wave functions to describe the various states of the target nucleus. We analyze the nature of these states and the shape of the nucleon-nucleus interaction potential, and we compare the results with those obtained from other theoretical and experimental work. (author) [fr

Higher Order Heavy Quark Corrections to Deep-Inelastic Scattering

Science.gov (United States)

Blümlein, Johannes; DeFreitas, Abilio; Schneider, Carsten

2015-04-01

The 3-loop heavy flavor corrections to deep-inelastic scattering are essential for consistent next-to-next-to-leading order QCD analyses. We report on the present status of the calculation of these corrections at large virtualities Q2. We also describe a series of mathematical, computer-algebraic and combinatorial methods and special function spaces, needed to perform these calculations. Finally, we briefly discuss the status of measuring αs (MZ), the charm quark mass mc, and the parton distribution functions at next-to-next-to-leading order from the world precision data on deep-inelastic scattering.

Higher order heavy quark corrections to deep-inelastic scattering

International Nuclear Information System (INIS)

Bluemlein, J.; Freitas, A. de; Johannes Kepler Univ., Linz; Schneider, C.

2014-11-01

The 3-loop heavy flavor corrections to deep-inelastic scattering are essential for consistent next-to-next-to-leading order QCD analyses. We report on the present status of the calculation of these corrections at large virtualities Q 2 . We also describe a series of mathematical, computer-algebraic and combinatorial methods and special function spaces, needed to perform these calculations. Finally, we briefly discuss the status of measuring α s (M Z ), the charm quark mass m c , and the parton distribution functions at next-to-next-to-leading order from the world precision data on deep-inelastic scattering.

Is Self-Interacting Dark Matter Undergoing Dark Fusion?

OpenAIRE

McDermott, Samuel D.

2018-01-01

We suggest that two-to-two dark matter fusion may be the relaxation process that resolves the small-scale structure problems of the cold collisionless dark matter paradigm. In order for the fusion cross section to scale correctly across many decades of astrophysical masses from dwarf galaxies to galaxy clusters, we require the fractional binding energy released to be greater than vn∼(10−(2−3))n, where n=1, 2 depends on local dark sector chemistry. The size of the dark-sector interaction cross...

Inelastic electron and light scattering from the elementary electronic excitations in quantum wells: Zero magnetic field

Directory of Open Access Journals (Sweden)

Manvir S. Kushwaha

2012-09-01

Full Text Available The most fundamental approach to an understanding of electronic, optical, and transport phenomena which the condensed matter physics (of conventional as well as nonconventional systems offers is generally founded on two experiments: the inelastic electron scattering and the inelastic light scattering. This work embarks on providing a systematic framework for the theory of inelastic electron scattering and of inelastic light scattering from the electronic excitations in GaAs/Ga1−xAlxAs quantum wells. To this end, we start with the Kubo's correlation function to derive the generalized nonlocal, dynamic dielectric function, and the inverse dielectric function within the framework of Bohm-Pines’ random-phase approximation. This is followed by a thorough development of the theory of inelastic electron scattering and of inelastic light scattering. The methodological part is then subjected to the analytical diagnoses which allow us to sense the subtlety of the analytical results and the importance of their applications. The general analytical results, which know no bounds regarding, e.g., the subband occupancy, are then specified so as to make them applicable to practicality. After trying and testing the eigenfunctions, we compute the density of states, the Fermi energy, the full excitation spectrum made up of intrasubband and intersubband – single-particle and collective (plasmon – excitations, the loss functions for all the principal geometries envisioned for the inelastic electron scattering, and the Raman intensity, which provides a measure of the real transitions induced by the (laser probe, for the inelastic light scattering. It is found that the dominant contribution to both the loss peaks and the Raman peaks comes from the collective (plasmon excitations. As to the single-particle peaks, the analysis indicates a long-lasting lack of quantitative comparison between theory and experiments. It is inferred that the inelastic electron

Electron Dynamics by Inelastic X-Ray Scattering

CERN Document Server

Schülke, Winfried

2007-01-01

The book offers the first comprehensive review of experimental methods, theory, and successful applications of synchrotron radiation based inelastic X-ray scattering (IXS) spectroscopy, which enables the investigation of electron dynamics in condensed matter (correlated motion and excitation).

Parity violation in deep inelastic scattering

Energy Technology Data Exchange (ETDEWEB)

Souder, P. [Syracuse Univ., NY (United States)

1994-04-01

AA beam of polarized electrons at CEBAF with an energy of 8 GeV or more will be useful for performing precision measurements of parity violation in deep inelastic scattering. Possible applications include precision tests of the Standard Model, model-independent measurements of parton distribution functions, and studies of quark correlations.

Influence functionals in deep inelastic reactions

International Nuclear Information System (INIS)

Avishai, Y.

1978-01-01

It is suggested that the concept of influence functionals introduced by Feynman and Vernon could be applied to the study of deep inelastic reactions among heavy ions if the coupling between the relative motion and the internal degrees of freedom has a separable form as suggested by Hofmann and Siemens. (Auth.)

Neptune's New Dark Vortex: Aerosol Properties from Optical Data

Science.gov (United States)

Tollefson, J.; Luszcz-Cook, S.; Wong, M. H.; De Pater, I.

2016-12-01

Over the past year, amateur and professional astronomers alike have monitored the appearance of a new dark vortex on Neptune, dubbed SDS-2015 for "southern dark spot discovered in 2015" (Wong et al. 2016; CBET 4278). The discovery of SDS-2015 is fortuitous, being one of only five dark spots observed on Neptune since Voyager 2 imaged the Great Dark Spot (Smith et al. 1989, Science 246, 1422). A companion abstract (Wong et al., this meeting) will present Hubble Space Telescope images of SDS-2015, showcasing the discovery of the vortex in September 2015 and subsequent observations in May 2016. These observations span the optical regime. Longer wavelengths track bright companion clouds thought to form as air is diverted around SDS-2015. Shorter wavelengths reveal the dark spot itself. Combined, these data probe the vertical extent of the dark spot and Neptune's surrounding upper atmosphere. We present preliminary radiative transfer analyses of SDS-2015 using our multispectral data. Our model is the same as that in Luszcz-Cook et al. (2016, Icarus 276, 52) but extended to optical wavelengths. Prior to this work, little was known about the composition and vertical extent of Neptune's dark spots. Only data at optical wavelengths reveal these vortices, suggesting they consist of clearings in the background of fine, evenly-distributed haze particle. Alternatively, the spots may consist of low-albedo aerosols, causing their apparent darkness. Radiative transfer modeling is also one way to determine the vortex top altitude. Simulations of the Great Dark Spot by Stratman et al. (2001, Icarus 151, 275) found that the vortex top altitude is coupled to the brightness of companion clouds, where cloud opacity weakened as the top of the vortex reached higher into the tropopause region. The modeling presented here will compare these hypotheses and provide the first glimpses into the vertical structure of SDS-2015.

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.

Parity violation in deep inelastic electron scattering

International Nuclear Information System (INIS)

Taylor, R.E.

1979-11-01

Neutral currents in electron scattering and the Weinberg-Salam model are reviewed. This generally accepted model is consistent with experimental results from neutrino interactions; an appropriate deep inelastic electron scattering experiment would measure couplings that don't involve neutrinos to see if they are also correctly described by the theory. The SLAC-Yale experiment measures a difference in the e-d inelastic cross section for right- and left-handed electrons. The polarized source, beam monitors, scattering experiment, checks of helicity dependence, and results are described. It is concluded that the data obtained are in agreement with the Weinberg-Salam model, and that the best value of sin 2 theta/sub W/ for these data is in excellent agreement with the average values of that parameter deduced from neutrino experiments. Future experiments with polarized electrons are discussed. 12 figures, 2 tables

Deep inelastic processes. Phenomenology. Quark-parton model

International Nuclear Information System (INIS)

Ioffe, B.L.; Lipatov, L.N.; Khoze, V.A.

1983-01-01

Main theoretical approaches and experimental results related to deep inelastic processes are systematically outlined: electroproduction, neutrino scattering on nucleon, electron-positron pairs annihilation into hadron γγ collisions, production of lepton pairs in hadron collisions with a large effective mass or hadrons with large transverse momenta. Kinematics and phenomenology, space-time description of deep inelastic processes, sum rules, parton and quark-parton models are considered. The experiment is briefly discussed in the book. It is performed from the stand point of comparing it with the theory, experimental data are given as of June, 1982. Since the time of accomplishing the study on the manuscript a number of new experimental results not changing however the statements made in the book appeared. Principal consists in experiments with colliding proton-antiproton beams in CERN, which resulted in discovery of intermediate W-bozon

Full inelastic cross section, effective stopping and ranges of fast multiply charged ions

International Nuclear Information System (INIS)

Alimov, R.A.; Arslanbekov, T.U.; Matveev, B.I.; Rakhmatov, A.S.

1994-01-01

Inelastic processes taking place in collision of fast multiply charged ions with atoms are considered on the base of mechanism of sudden momentum transfer. The simple estimations are proposed of full inelastic cross sections, effective stopping and ion ranges in gaseous medium. (author). 10 refs

Modeling of Inelastic Collisions in a Multifluid Plasma: Excitation and Deexcitation

Science.gov (United States)

2016-05-31

DATES COVERED (From - To) 4. TITLE AND SUBTITLE Modeling of Inelastic Collisions in a Multifluid Plasma: Excitation and 5a. CONTRACT NUMBER...describe here a model for inelastic collisions for electronic excitation and deexcitation processes in a general, multifluid plasma. The model is derived... Excitation and Deexcitationa) Hai P. Le1, b) and Jean-Luc Cambier2, c) 1)Department of Mathematics, University of California, Los Angeles, California

Nonlocal astrophysics dark matter, dark energy and physical vacuum

CERN Document Server

Alexeev, Boris V

2017-01-01

Non-Local Astrophysics: Dark Matter, Dark Energy and Physical Vacuum highlights the most significant features of non-local theory, a highly effective tool for solving many physical problems in areas where classical local theory runs into difficulties. The book provides the fundamental science behind new non-local astrophysics, discussing non-local kinetic and generalized hydrodynamic equations, non-local parameters in several physical systems, dark matter, dark energy, black holes and gravitational waves. Devoted to the solution of astrophysical problems from the position of non-local physics Provides a solution for dark matter and dark energy Discusses cosmological aspects of the theory of non-local physics Includes a solution for the problem of the Hubble Universe expansion, and of the dependence of the orbital velocity from the center of gravity

Particle Production in Deep Inelastic Muon Scattering

Energy Technology Data Exchange (ETDEWEB)

Ryan, John James [MIT

1991-01-01

The E665 spectrometer at Fermila.b measured Deep-Inelastic Scattering of 490 GeV /c muons off several targets: Hydrogen, Deuterium, and Xenon. Events were selected from the Xenon and Deuterium targets, with a range of energy exchange, $\

A method to describe inelastic gamma field distribution in neutron gamma density logging.

Science.gov (United States)

Zhang, Feng; Zhang, Quanying; Liu, Juntao; Wang, Xinguang; Wu, He; Jia, Wenbao; Ti, Yongzhou; Qiu, Fei; Zhang, Xiaoyang

2017-11-01

Pulsed neutron gamma density logging (NGD) is of great significance for radioprotection and density measurement in LWD, however, the current methods have difficulty in quantitative calculation and single factor analysis for the inelastic gamma field distribution. In order to clarify the NGD mechanism, a new method is developed to describe the inelastic gamma field distribution. Based on the fast-neutron scattering and gamma attenuation, the inelastic gamma field distribution is characterized by the inelastic scattering cross section, fast-neutron scattering free path, formation density and other parameters. And the contribution of formation parameters on the field distribution is quantitatively analyzed. The results shows the contribution of density attenuation is opposite to that of inelastic scattering cross section and fast-neutron scattering free path. And as the detector-spacing increases, the density attenuation gradually plays a dominant role in the gamma field distribution, which means large detector-spacing is more favorable for the density measurement. Besides, the relationship of density sensitivity and detector spacing was studied according to this gamma field distribution, therefore, the spacing of near and far gamma ray detector is determined. The research provides theoretical guidance for the tool parameter design and density determination of pulsed neutron gamma density logging technique. Copyright © 2017 Elsevier Ltd. All rights reserved.

New interactions in the dark sector mediated by dark energy

International Nuclear Information System (INIS)

Brookfield, Anthony W.; Bruck, Carsten van de; Hall, Lisa M. H.

2008-01-01

Cosmological observations have revealed the existence of a dark matter sector, which is commonly assumed to be made up of one particle species only. However, this sector might be more complicated than we currently believe: there might be more than one dark matter species (for example, two components of cold dark matter or a mixture of hot and cold dark matter) and there may be new interactions between these particles. In this paper we study the possibility of multiple dark matter species and interactions mediated by a dark energy field. We study both the background and the perturbation evolution in these scenarios. We find that the background evolution of a system of multiple dark matter particles (with constant couplings) mimics a single fluid with a time-varying coupling parameter. However, this is no longer true on the perturbative level. We study the case of attractive and repulsive forces as well as a mixture of cold and hot dark matter particles

Dissipative phenomena in deep inelastic heavy ion collisions

International Nuclear Information System (INIS)

Gross, D.H.E.; Krappe, H.J.; Lindenberger, K.H.; Lipperheide, R.; Moehring, K.

1978-01-01

During this meeting the following theoretical concepts for deep-inelastic heavy ion reactions were discussed: the energy transfer and friction, direct or statistical mechanisms, dissipation and fluctuation. (WL) [de

Bound-state wave functions at rest in describing deep inelastic scattering

International Nuclear Information System (INIS)

Khvedelidze, A.M.; Kvinikhidze, A.N.

1991-01-01

The deep inelastic process of the lepton-hadron scattering is studied in the bound-state rest frame. A new version of expanding structure functions in interaction constant powers is proposed, each term in it having spectral properties. This expansion makes it possible to consider contributions of composites in the final state to the cross section. It is shown that, as compared with the system P z →∞, the impulse approximation is insufficient for describing correctly the elastic limit in the composite particle rest frame. The leading asymptotics of structure functions as χ Bj →1 can be obtained by taking into account the interaction of contituents in the final state. It is shown that in contrast to the 'light-cone' formalism the ratio F 2 en (χ)/F 2 ep (χ) as χ Bj →1 depends on the explicit form of the spatial part of the nucleon wave function and, in particular, assuming the relativistic character of internal motion, it may be lower than the well-known prediction (i.e. 3/7). This is due to the correct consideration of spin degrees of freedom of the wave function of the nucleon at rest. (orig.)

The Dark Cube: dark character profiles and OCEAN

Directory of Open Access Journals (Sweden)

Danilo Garcia

2017-09-01

Full Text Available Background The Big Five traits (i.e., openness, conscientiousness, extraversion, agreeableness, and neuroticism: OCEAN have been suggested to provide a meaningful taxonomy for studying the Dark Triad: Machiavellianism, narcissism, and psychopathy. Nevertheless, current research consists of mixed and inconsistent associations between the Dark Triad and OCEAN. Here we used the Dark Cube (Garcia & Rosenberg, 2016, a model of malevolent character theoretically based on Cloninger’s biopsychosocial model of personality and in the assumption of a ternary structure of malevolent character. We use the dark cube profiles to investigate differences in OCEAN between individuals who differ in one dark character trait while holding the other two constant (i.e., conditional relationships. Method Participants (N = 330 responded to the Short Dark Triad Inventory and the Big Five Inventory and were grouped according to the eight possible combinations using their dark trait scores (M, high Machiavellianism; m, low Machiavellianism; N, high narcissism; n, low narcissism; P, high psychopathy; p, low psychopathy: MNP “maleficent”, MNp “manipulative narcissistic”, MnP “anti-social”, Mnp “Machiavellian”, mNP “psychopathic narcissistic”, mNp “narcissistic”, mnP “psychopathic”, and mnp “benevolent”. Results High narcissism-high extraversion and high psychopathy-low agreeableness were consistently associated across comparisons. The rest of the comparisons showed a complex interaction. For example, high Machiavellianism-high neuroticism only when both narcissism and psychopathy were low (Mnp vs. mnp, high narcissism-high conscientiousness only when both Machiavellianism and psychopathy were also high (MNP vs. MnP, and high psychopathy-high neuroticism only when Machiavellianism was low and narcissism was high (mNP vs. mNp. Conclusions We suggest that the Dark Cube is a useful tool in the investigation of a consistent Dark Triad Theory

The Dark Cube: dark character profiles and OCEAN.

Science.gov (United States)

Garcia, Danilo; González Moraga, Fernando R

2017-01-01

The Big Five traits (i.e., openness, conscientiousness, extraversion, agreeableness, and neuroticism: OCEAN) have been suggested to provide a meaningful taxonomy for studying the Dark Triad: Machiavellianism, narcissism, and psychopathy. Nevertheless, current research consists of mixed and inconsistent associations between the Dark Triad and OCEAN. Here we used the Dark Cube (Garcia & Rosenberg, 2016), a model of malevolent character theoretically based on Cloninger's biopsychosocial model of personality and in the assumption of a ternary structure of malevolent character. We use the dark cube profiles to investigate differences in OCEAN between individuals who differ in one dark character trait while holding the other two constant (i.e., conditional relationships). Participants ( N  = 330) responded to the Short Dark Triad Inventory and the Big Five Inventory and were grouped according to the eight possible combinations using their dark trait scores (M, high Machiavellianism; m, low Machiavellianism; N, high narcissism; n, low narcissism; P, high psychopathy; p, low psychopathy): MNP "maleficent", MNp "manipulative narcissistic", MnP "anti-social", Mnp "Machiavellian", mNP "psychopathic narcissistic", mNp "narcissistic", mnP "psychopathic", and mnp "benevolent". High narcissism-high extraversion and high psychopathy-low agreeableness were consistently associated across comparisons. The rest of the comparisons showed a complex interaction. For example, high Machiavellianism-high neuroticism only when both narcissism and psychopathy were low (Mnp vs. mnp), high narcissism-high conscientiousness only when both Machiavellianism and psychopathy were also high (MNP vs. MnP), and high psychopathy-high neuroticism only when Machiavellianism was low and narcissism was high (mNP vs. mNp). We suggest that the Dark Cube is a useful tool in the investigation of a consistent Dark Triad Theory. This approach suggests that the only clear relationships were narcissism

Interacting agegraphic dark energy

International Nuclear Information System (INIS)

Wei, Hao; Cai, Rong-Gen

2009-01-01

A new dark energy model, named ''agegraphic dark energy'', has been proposed recently, based on the so-called Karolyhazy uncertainty relation, which arises from quantum mechanics together with general relativity. In this note, we extend the original agegraphic dark energy model by including the interaction between agegraphic dark energy and pressureless (dark) matter. In the interacting agegraphic dark energy model, there are many interesting features different from the original agegraphic dark energy model and holographic dark energy model. The similarity and difference between agegraphic dark energy and holographic dark energy are also discussed. (orig.)

The interaction between dark energy and dark matter

International Nuclear Information System (INIS)

He Jianhua; Wang Bin

2010-01-01

In this review we first present a general formalism to study the growth of dark matter perturbations in the presence of interactions between dark matter(DM) and dark energy(DE). We also study the signature of such interaction on the temperature anisotropies of the large scale cosmic microwave background (CMB). We find that the effect of such interaction has significant signature on both the growth of dark matter structure and the late Integrated Sachs Wolfe effect(ISW). We further discuss the potential possibility to detect the coupling by cross-correlating CMB maps with tracers of the large scale structure. We finally confront this interacting model with WMAP 5-year data as well as other data sets. We find that in the 1σ range, the constrained coupling between dark sectors can solve the coincidence problem.

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.)

The lineshape of inelastic neutron scattering in the relaxor ferroelectrics

International Nuclear Information System (INIS)

Ivanov, M.A.; Kozlovski, M.; Piesiewicz, T.; Stephanovich, V.A.; Weron, A.; Wymyslowski, A.

2005-01-01

The possibilities of theoretical and experimental investigations of relaxor ferroelectrics by inelastic neutron scattering method are considered. The simple model to description of the peculiarities of inelastic neutron scattering lineshapes in ferroelectric relaxors is suggested. The essence of this model is to consider the interaction of the phonon subsystem of relaxor ferroelectrics with the ensemble of defects and impurities. The modification of the Latin Hypercube Sampling (LHS) method is presented. The optimization of planning of experiment by the modified LHS method is considered [ru

Dark Matter in the Universe

CERN Multimedia

CERN. Geneva

2012-01-01

The question “What is the Universe made of?” is the longest outstanding problem in all of physics. Ordinary atoms only constitute 5% of the total, while the rest is of unknown composition. Already in 1933 Fritz Zwicky observed that the rapid motions of objects within clusters of galaxies were unexplained by the gravitation pull of luminous matter, and he postulated the existence of Dunkle Materie, or dark matter. A variety of dark matter candidates exist, including new fundamental particles already postulated in particle theories: axions and WIMPs (weakly interacting massive particles). Over the past 25 years, there has been a three pronged approach to WIMP detection: creating them at particle accelerators; searched for detection of astrophysical WIMPs scattering off of nuclei in underground detectors; and “indirect detection” of WIMP annihilation products (neutrinos, positrons, or photons). As yet the LHC has only placed bounds rather than finding discovery. For 13 years the DAMA experiment has proc...

Dark information of black hole radiation raised by dark energy

Science.gov (United States)

Ma, Yu-Han; Chen, Jin-Fu; Sun, Chang-Pu

2018-06-01

The "lost" information of black hole through the Hawking radiation was discovered being stored in the correlation among the non-thermally radiated particles (Parikh and Wilczek, 2000 [31], Zhang et al., 2009 [16]). This correlation information, which has not yet been proved locally observable in principle, is named by dark information. In this paper, we systematically study the influences of dark energy on black hole radiation, especially on the dark information. Calculating the radiation spectrum in the existence of dark energy by the approach of canonical typicality, which is reconfirmed by the quantum tunneling method, we find that the dark energy will effectively lower the Hawking temperature, and thus makes the black hole has longer life time. It is also discovered that the non-thermal effect of the black hole radiation is enhanced by dark energy so that the dark information of the radiation is increased. Our observation shows that, besides the mechanical effect (e.g., gravitational lensing effect), the dark energy rises the stored dark information, which could be probed by a non-local coincidence measurement similar to the coincidence counting of the Hanbury-Brown-Twiss experiment in quantum optics.

Boundary-integral equation formulation for time-dependent inelastic deformation in metals

Energy Technology Data Exchange (ETDEWEB)

Kumar, V; Mukherjee, S

1977-01-01

The mathematical structure of various constitutive relations proposed in recent years for representing time-dependent inelastic deformation behavior of metals at elevated temperatues has certain features which permit a simple formulation of the three-dimensional inelasticity problem in terms of real time rates. A direct formulation of the boundary-integral equation method in terms of rates is discussed for the analysis of time-dependent inelastic deformation of arbitrarily shaped three-dimensional metallic bodies subjected to arbitrary mechanical and thermal loading histories and obeying constitutive relations of the kind mentioned above. The formulation is based on the assumption of infinitesimal deformations. Several illustrative examples involving creep of thick-walled spheres, long thick-walled cylinders, and rotating discs are discussed. The implementation of the method appears to be far easier than analogous BIE formulations that have been suggested for elastoplastic problems.

Diffraction and absorption of inelastically scattered electrons for K-shell ionization

International Nuclear Information System (INIS)

Josefsson, T.W.; Allen, L.J.

1995-01-01

An expression for the nonlocal inelastic scattering cross section for fast electrons in a crystalline environment, which explicitly includes diffraction as well as absorption for the inelastically scattered electrons, is used to carry out realistic calculations of K-shell electron energy loss spectroscopy (EELS) and energy dispersive x-ray (EDX) analysis cross sections. The calculations demonstrate quantitatively why, in EDX spectroscopy, integration over the dynamical states of the inelastically scattered electron averages in such a way that an effective plane wave representation of the scattered electrons is a good approximation. This is only the case for large enough acceptance angles of the detector in an EELS experiment. For EELS with smaller detector apertures, explicit integration over the dynamical final states is necessary and inclusion of absorption for the scattered electrons is important, particularly for thicker crystals. 50 refs., 7 figs

Signatures of dark radiation in neutrino and dark matter detectors

Science.gov (United States)

Cui, Yanou; Pospelov, Maxim; Pradler, Josef

2018-05-01

We consider the generic possibility that the Universe's energy budget includes some form of relativistic or semi-relativistic dark radiation (DR) with nongravitational interactions with standard model (SM) particles. Such dark radiation may consist of SM singlets or a nonthermal, energetic component of neutrinos. If such DR is created at a relatively recent epoch, it can carry sufficient energy to leave a detectable imprint in experiments designed to search for very weakly interacting particles: dark matter and underground neutrino experiments. We analyze this possibility in some generality, assuming that the interactive dark radiation is sourced by late decays of an unstable particle, potentially a component of dark matter, and considering a variety of possible interactions between the dark radiation and SM particles. Concentrating on the sub-GeV energy region, we derive constraints on different forms of DR using the results of the most sensitive neutrino and dark matter direct detection experiments. In particular, for interacting dark radiation carrying a typical momentum of ˜30 MeV /c , both types of experiments provide competitive constraints. This study also demonstrates that non-standard sources of neutrino emission (e.g., via dark matter decay) are capable of creating a "neutrino floor" for dark matter direct detection that is closer to current bounds than is expected from standard neutrino sources.

Dark chocolate acceptability: influence of cocoa origin and processing conditions.

Science.gov (United States)

Torres-Moreno, Miriam; Tarrega, Amparo; Costell, Elvira; Blanch, Consol

2012-01-30

Chocolate properties can vary depending on cocoa origin, composition and manufacturing procedure, which affect consumer acceptability. The aim of this work was to study the effect of two cocoa origins (Ghana and Ecuador) and two processing conditions (roasting time and conching time) on dark chocolate acceptability. Overall acceptability and acceptability for different attributes (colour, flavour, odour and texture) were evaluated by 95 consumers. Differences in acceptability among dark chocolates were mainly related to differences in flavour acceptability. The use of a long roasting time lowered chocolate acceptability in Ghanaian samples while it had no effect on acceptability of Ecuadorian chocolates. This response was observed for most consumers (two subgroups with different frequency consumption of dark chocolate). However, for a third group of consumers identified as distinguishers, the most acceptable dark chocolate samples were those produced with specific combinations of roasting time and conching time for each of the cocoa geographical origin considered. To produce dark chocolates from a single origin it is important to know the target market preferences and to select the appropriate roasting and conching conditions. Copyright © 2011 Society of Chemical Industry.

Inelastic neutron scattering from clusters

International Nuclear Information System (INIS)

Gudel, H.U.

1985-01-01

Magnetic excitations in clusters of paramagnetic ions have non-vanishing cross-sections for inelastic neutron scattering (INS). Exchange splittings can be determined, the temperature dependence of exchange can be studied, intra- and intercluster effects can be separated and magnetic form factors determined. INS provides a more direct access to the molecular properties than bulk techniques. Its application is restricted to complexes with no or few (< 10%) hydrogen atoms

Dark energy and extended dark matter halos

Science.gov (United States)

Chernin, A. D.; Teerikorpi, P.; Valtonen, M. J.; Dolgachev, V. P.; Domozhilova, L. M.; Byrd, G. G.

2012-03-01

The cosmological mean matter (dark and baryonic) density measured in the units of the critical density is Ωm = 0.27. Independently, the local mean density is estimated to be Ωloc = 0.08-0.23 from recent data on galaxy groups at redshifts up to z = 0.01-0.03 (as published by Crook et al. 2007, ApJ, 655, 790 and Makarov & Karachentsev 2011, MNRAS, 412, 2498). If the lower values of Ωloc are reliable, as Makarov & Karachentsev and some other observers prefer, does this mean that the Local Universe of 100-300 Mpc across is an underdensity in the cosmic matter distribution? Or could it nevertheless be representative of the mean cosmic density or even be an overdensity due to the Local Supercluster therein. We focus on dark matter halos of groups of galaxies and check how much dark mass the invisible outer layers of the halos are able to host. The outer layers are usually devoid of bright galaxies and cannot be seen at large distances. The key factor which bounds the size of an isolated halo is the local antigravity produced by the omnipresent background of dark energy. A gravitationally bound halo does not extend beyond the zero-gravity surface where the gravity of matter and the antigravity of dark energy balance, thus defining a natural upper size of a system. We use our theory of local dynamical effects of dark energy to estimate the maximal sizes and masses of the extended dark halos. Using data from three recent catalogs of galaxy groups, we show that the calculated mass bounds conform with the assumption that a significant amount of dark matter is located in the invisible outer parts of the extended halos, sufficient to fill the gap between the observed and expected local matter density. Nearby groups of galaxies and the Virgo cluster have dark halos which seem to extend up to their zero-gravity surfaces. If the extended halo is a common feature of gravitationally bound systems on scales of galaxy groups and clusters, the Local Universe could be typical or even

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

Structure functions in electron-nucleon deep inelastic scattering

Energy Technology Data Exchange (ETDEWEB)

Saleem, M.; Fazal-E-Aleem (University of the Punjab, Lahore (Pakistan). Dept. of Physics)

1982-06-26

The phenomenological expressions for the structure functions in electron-nucleon deep inelastic scattering are proposed and are shown to satisfy the experimental data as well as a number of sum rules.

Deep inelastic lepton scattering from nucleons and nuclei

International Nuclear Information System (INIS)

Berger, E.L.

1986-02-01

A pedagogical review is presented of results obtained from inclusive deep inelastic scattering of leptons from nucleons and nuclei, with particular emphasis on open questions to be explored in future experiments

A Phenomenological Study on Inelastic Torsion Caused By Nonlinear Behavior Changes during Earthquake Excitations

Directory of Open Access Journals (Sweden)

Seyed Bahram Beheshti-Aval

2014-12-01

Full Text Available Torsion of many symmetric structures, which were designed based on the seismic codes, is due to their asymmetricity induced during inelastic behavior. Although the structure was designed symmetrically assuming elastic based criteria, different factors such as material inconsistency in structure, construction details discrepancy and construction errors may result in asymmetric behavior in inelastic deformation range. So far, these considerations have been rarely contemplated in previous published investigations and should be studied regarding the importance of irregularity in increase of seismic demand of structures in the inelastic range. In this paper, as the first step, the asymmetry and irregularity in plan due to non-similar inelastic characteristics with respect to axis passing through center of gravity as well as the effect and importance of each irregularity factors are studied by changing the excitation properties applying to one-storey one-bay steel structures. This simplified structure is chosen due to studying and illustrating the absolute effect of this kind of irregularity in which higher mode effect is eliminated. The results show that the behavior of a structure with inelastic asymmetry is completely different from the structure with elastic asymmetry. As for inelastic asymmetry structure, although the translational and rotational oscillations before yielding were uncouple, these DOFs after yielding become coupled until reaching the terminal rotation point (rotation reaches a constant value and then become uncoupled, i.e., again oscillated symmetrically. This behavior is different from the structures with elastic asymmetricity, in which the translational and rotational movements being coupled during all the excitation time. This effect has not been recognized in previews studies on inelastic behavior of initially elastic symmetry buildings. The study of these behaviors aids the designer to choose the appropriate rehabilitation

Inelastic neutron scattering method in hard coal quality monitoring

International Nuclear Information System (INIS)

Cywicka-Jakiel, T.; Loskiewicz, J.; Tracz, G.

1994-07-01

Nuclear methods in mining industry and power generation plants are nowadays very important especially because of the need for optimization of combustion processes and reduction of environmental pollution. On-line analysis of coal quality not only economic benefits but contribute to environmental protection too. Neutron methods especially inelastic scattering and PGNAA are very useful for analysis of coal quality where calorific valve, ash and moisture content are the most important. Using Pu-Be or Am-Be isotopic sources and measuring carbon 4.43 MeV γ-rays from neutron inelastic scattering: 12 C(n,n'γ) 12 C we can evaluate calorific valve in hard coals with precision better than in PGNAA method. This is mainly because of large cross-section for inelastic scattering and the strong correlation between carbon content and calorific value shown in the paper for different coal basins. The influence of moisture on 4.43 MeV carbon γ-rays in considered in the paper in theoretical and experimental aspects and appropriate formula is introduced. Also the possibilities of determine ash, moisture, Cl, Na and Si in coal are shown. (author). 11 refs, 15 figs

Inelastic neutron scattering method in hard coal quality monitoring

Energy Technology Data Exchange (ETDEWEB)

Cywicka-Jakiel, T.; Loskiewicz, J.; Tracz, G. [Institute of Nuclear Physics, Cracow (Poland)

1994-07-01

Nuclear methods in mining industry and power generation plants are nowadays very important especially because of the need for optimization of combustion processes and reduction of environmental pollution. On-line analysis of coal quality not only economic benefits but contribute to environmental protection too. Neutron methods especially inelastic scattering and PGNAA are very useful for analysis of coal quality where calorific valve, ash and moisture content are the most important. Using Pu-Be or Am-Be isotopic sources and measuring carbon 4.43 MeV {gamma}-rays from neutron inelastic scattering: {sup 12}C(n,n`{gamma}){sup 12}C we can evaluate calorific valve in hard coals with precision better than in PGNAA method. This is mainly because of large cross-section for inelastic scattering and the strong correlation between carbon content and calorific value shown in the paper for different coal basins. The influence of moisture on 4.43 MeV carbon {gamma}-rays in considered in the paper in theoretical and experimental aspects and appropriate formula is introduced. Also the possibilities of determine ash, moisture, Cl, Na and Si in coal are shown. (author). 11 refs, 15 figs.

Inelastic pion scattering by 13C at low energies

International Nuclear Information System (INIS)

Mitchell, J.H.

1987-03-01

Angular distributions for inelastically scattered pions were obtained for several states in 13 C at an incident energy of 65 MeV. The data include results from both π + and π - measurements. In addition, π - measurements were made at T/sub π/ = 50 MeV at one angle to give a two point fixed-q excitation function. The data are compared to theory and the data of others. As might be expected, medium corrections are shown to be considerably more important at low energies than at resonance. This is true for inelastic transitions of multipolarity 0,2 and 3. Parameters derived from an analysis of elastic pion scattering and SCX data also provide an adequate description of the inelastic transitions. The charge asymmetry in the cross sections for the 9/2 + state that was seen at resonance persists at these energies. This result is consistent with an impulse approximation treatment of the spin-flip amplitude. This is true even though the incoming energy of the pions is far below the range where the validity of an impulse treatment is expected. 65 refs., 45 figs

Developments in inelastic instrumentation at ISIS

International Nuclear Information System (INIS)

Taylor, A.D.; Bowden, Z.A.; Carlile, C.J.

1989-01-01

The authors summarize developments on the three scheduled inelastic spectrometers HET, TFXA and IRIS and illustrate their scientific program with some recent highlights. They give details of commissioning experiments on PRISMA and discuss the status of the eVS and polarization programs. The status of the MARI project is reviewed. 15 refs., 22 figs

Focusing polycapillary to reduce parasitic scattering for inelastic x-ray measurements at high pressure

International Nuclear Information System (INIS)

Chow, P.; Xiao, Y. M.; Rod, E.; Bai, L. G.; Shen, G. Y.; Sinogeikin, S.; Gao, N.; Ding, Y.; Mao, H.-K.

2015-01-01

The double-differential scattering cross-section for the inelastic scattering of x-ray photons from electrons is typically orders of magnitude smaller than that of elastic scattering. With samples 10-100 μm size in a diamond anvil cell at high pressure, the inelastic x-ray scattering signals from samples are obscured by scattering from the cell gasket and diamonds. One major experimental challenge is to measure a clean inelastic signal from the sample in a diamond anvil cell. Among the many strategies for doing this, we have used a focusing polycapillary as a post-sample optic, which allows essentially only scattered photons within its input field of view to be refocused and transmitted to the backscattering energy analyzer of the spectrometer. We describe the modified inelastic x-ray spectrometer and its alignment. With a focused incident beam which matches the sample size and the field of view of polycapillary, at relatively large scattering angles, the polycapillary effectively reduces parasitic scattering from the diamond anvil cell gasket and diamonds. Raw data collected from the helium exciton measured by x-ray inelastic scattering at high pressure using the polycapillary method are compared with those using conventional post-sample slit collimation

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

Unified quantum theory of elastic and inelastic atomic scattering from a physisorbed monolayer solid

DEFF Research Database (Denmark)

Bruch, L. W.; Hansen, Flemming Yssing; Dammann, Bernd

2017-01-01

A unified quantum theory of the elastic and inelastic scattering of low energy He atoms by a physisorbed monolayer solid in the one-phonon approximation is given. It uses a time-dependent wave packet with phonon creation and annihilation components and has a self-consistent feedback between...... the wave functions for elastic and inelastic scattered atoms. An attenuation of diffraction scattering by inelastic processes thus is inherent in the theory. The atomic motion and monolayer vibrations in the harmonic approximation are treated quantum mechanically and unitarity is preserved. The evaluation...... of specific one-phonon events includes contributions from diffuse inelastic scattering in other phonon modes. Effects of thermally excited phonons are included using a mean field approximation. The theory is applied to an incommensurate Xe/Pt(111) monolayer (incident energy Ei = 4-16 meV), a commensurate Xe...

Charm production and mass scales in deep inelastic processes

International Nuclear Information System (INIS)

Close, F.E.; Scott, D.M.; Sivers, D.

1976-07-01

Because of their large mass, the production of charmed particles offers the possibility of new insight into fundamental dynamics. An approach to deep inelastic processes is discussed in which Generalized Vector Meson Dominance is used to extend parton model results away from the strict Bjorken scaling limit into regions where mass scales play an important role. The processes e + e - annihilation, photoproduction, deep inelastic leptoproduction, photon-photon scattering and the production of lepton pairs in hadronic collisions are discussed. The GCMD approach provides a reasonably unified framework and makes specific predictions concerning the way in which these reactions reflect an underlying flavour symmetry, broken by large mass differences. (author)

Inelastic scattering of 275 keV neutrons by silver

International Nuclear Information System (INIS)

Litvinsky, L.L.; Zhigalov, Ya.A.; Krivenko, V.G.; Purtov, O.A.; Sabbagh, S.

1997-01-01

Neutron total, elastic and inelastic scattering cross-scattering of Ag at the E n = 275 KeV neutron energy were measured by using the filtered neutron beam of the WWR-M reactor in Kiev. The d-neutron strength function S n2 of Ag was determined from the analysis of all available data in the E n ≤ keV energy region on neutron inelastic scattering cross-sections with excitation of the first isomeric levels I π m = 7/2 + , E m ∼ 90 keV of 107,109 Ag: S n2 = (1.03 ± 0.19) · 10 -4 . (author). 10 refs, 3 figs

Inelastic photoproduction of ω and rho+-mesons

International Nuclear Information System (INIS)

Nelson, C.A. Jr.; May, E.N.; Abramson, J.; Andrews, D.E.; Harvey, J.; Lobkowicz, F.; Singer, M.N.; Thorndike, E.H.; Nordberg, M.E. Jr.

1978-01-01

We report measurements of inelastic photoproduction of ω and rho +- mesons from hydrogen and deuterium at incident photon energies in the range 7.5-10.5 GeV. For ωΔ and rho - Δ ++ production differential cross sections dsigma/dt' and spin density matrices are presented. For higher missing masses the cross sections dsigma/dM/sub X/ 2 and invariant structure functions F(x) are also given. The data are compared to a one-pion-exchange model. We conclude that pion exchange is dominant for inelastic ω photoproduction, but unimportant for rho +- during annealing, even though the resistively determined transport scattering time increased by a factor of 7.8 during annealing. Orbital depairing was found to follow a relation zeta = zeta 0 + αH 2 and to increase with annealing in a manner expected from the change in mean free path determined from measurements of H/sub cnu/

Hadronic inelastic cross sections from analyses of the elastic channel

International Nuclear Information System (INIS)

Beggio, P.C.; Martini, A.F.; Menon, M.J.

1997-01-01

We present a comparative analysis of the Inelastic Overlap Functions predicted by three models for elastic scattering: Chou and Yang, Henzi and Valin and Martini and Menon. The results are also compared with two model independent extractions (Amaldi-Schubert and Carvalho-Menon). We then calculate the predictions for the corresponding integrated inelastic cross-sections from the three models and compare the results with the experimental data on pp and pp scattering available above 10 GeV. Similarities and differences between all modes predictions are presented and discussed. (author)

Preparation of magnetic imprinted graphene oxide composite for catalytic degradation of Congo red under dark ambient conditions.

Science.gov (United States)

Yang, Xiaochao; You, Xiaoxiao; Zhang, Bin; Guo, Chuigen; Yu, Chaosheng

2017-10-01

Magnetic imprinted N-doped P25/Fe 3 O 4 -graphene oxide (MIGNT) was prepared with methyl orange as the dummy template and pyrrole as functional monomer for catalytic degradation of Congo red (CR). Hummers method and the hydrothermal method were used to synthesize Fe 3 O 4 -GO and N-doped P25, respectively. The results of adsorption and degradation experiments showed that the adsorption capacity and catalytic degradation ability of the imprinted composite for CR were obviously higher than those of a non-imprinted one. Moreover, the effect factors on degradation efficiency of CR, such as the initial concentration of CR, catalysis time, pH of the solution and temperature, were investigated. The MIGNT was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, a physical property measurement system and a thermal gravimetric analyzer. The degradation products of CR were detected with high performance liquid chromatography and a mass spectrometer. The MIGNT was a brand-new imprinted composite and had high degradation efficiency for CR under dark ambient conditions. The MIGNT could be recycled conveniently, due to its magnetic property, and could be used as an effective, environmentally friendly and low-cost catalytic degradation material for the treatment of water contaminated by CR.

Dark influences: imprints of dark satellites on dwarf galaxies

NARCIS (Netherlands)

Starkenburg, T. K.; Helmi, A.

Context. In the context of the current Λ cold dark matter cosmological model small dark matter halos are abundant and satellites of dwarf galaxies are expected to be predominantly dark. Since low mass galaxies have smaller baryon fractions, interactions with these satellites may leave particularly

Deep inelastic neutron scattering

International Nuclear Information System (INIS)

Mayers, J.

1989-03-01

The report is based on an invited talk given at a conference on ''Neutron Scattering at ISIS: Recent Highlights in Condensed Matter Research'', which was held in Rome, 1988, and is intended as an introduction to the techniques of Deep Inelastic Neutron Scattering. The subject is discussed under the following topic headings:- the impulse approximation I.A., scaling behaviour, kinematical consequences of energy and momentum conservation, examples of measurements, derivation of the I.A., the I.A. in a harmonic system, and validity of the I.A. in neutron scattering. (U.K.)

Gamma-rays from deep inelastic collisions

International Nuclear Information System (INIS)

Stephens, F.S.

1981-01-01

My objective in this talk is to consider the question: 'What can be learned about deep inelastic collisions (DIC) from studying the associated gamma-rays'. First, I discuss the origin and nature of the gamma-rays from DIC, then the kinds of information gamma-ray spectra contain, and finally come to the combination of these two subjects. (orig./HSI)

Development of an inelastic stress analysis code 'KINE-T' and its evaluations

International Nuclear Information System (INIS)

Kobatake, K.; Takahashi, S.; Suzuki, M.

1977-01-01

Referring to the ASME B and PVC Code Case 1592-7, the inelastic stress analysis is required for the designs of the class 1 components in elevated temperature if the results of the elastic stress analysis and/or simplified inelastic analysis do not satisfy the requirements. Authors programmed a two-dimensional axisymmetric inelastic analysis code 'KINE-T', and carried out its evaluations and an application. This FEM code is based on the incremental method and the following: elastic-plastic constitutive equation (yield condition of von Mises; flow rule of Prandtl-Reuss; Prager's hardening rule); creep constitutive equation (equation of state approach; flow rule of von Mises; strain hardening rule); the temperature dependency of the yield function is considered; solution procedure of the assembled stiffness matrix is the 'initial stress method'. After the completion of the programming, authors compared the output with not only theoretical results but also with those of the MARC code and the ANSYS code. In order to apply the code to the practical designing, authors settled a quasi-component two-dimensional axisymmetric model and a loading cycle (500 cycles). Then, an inelastic analysis and its integrity evaluation are carried out

Some applications of polarized inelastic neutron scattering

Indian Academy of Sciences (India)

A brief account of applications of polarized inelastic neutron scattering in condensed matter research is given. ... the itinerant antiferromagnet chromium we demonstrate that the dynamics of the longitudinal and transverse excitations are very different, resolving a long standing puzzle concerning the slope of their dispersion.

Search for parity-nonconservation effects in deep-inelastic μN interaction

International Nuclear Information System (INIS)

Bushnin, Yu.B.; Dunaitsev, A.F.; Dzelyadin, R.I.; Zallo, A.

1976-01-01

The difference in the cross sections for deep inelastic scattering of muons with average momenta 21 GeV/c with right and left helicity at large angles, i.e., with large momentum transfer, has been measured. No statistically-significant dependence of cross sections on the longitudinal polarization of muons has been found, i.e., no parity-nonconservation effects in deep inelastic μN interaction have been observed. The limitations have been obtained for the constant of vector-axial interaction

Progress on calculation of direct inelastic scattering cross section of neutron

Energy Technology Data Exchange (ETDEWEB)

Zhenpeng, Chen [Qinghua Univ., Beijing, BJ (China). Dept. of Physics

1996-06-01

For n+ {sup 238}U inelastic scattering cross, there exist discrepancies among the available evaluations in various libraries. This is partly duo to the difference of direct inelastic scattering cross section calculated with coupled channel optical model (CCOM). The research on the level frame used in CCOM calculation, the research on used parameters of spherical optical model in CCOM calculation and the research on the amplitude of octupole phonon {beta}{sub 3} were presented. (2 figs.).

Adiabatic instability in coupled dark energy/dark matter models

International Nuclear Information System (INIS)

Bean, Rachel; Flanagan, Eanna E.; Trodden, Mark

2008-01-01

We consider theories in which there exists a nontrivial coupling between the dark matter sector and the sector responsible for the acceleration of the Universe. Such theories can possess an adiabatic regime in which the quintessence field always sits at the minimum of its effective potential, which is set by the local dark matter density. We show that if the coupling strength is much larger than gravitational, then the adiabatic regime is always subject to an instability. The instability, which can also be thought of as a type of Jeans instability, is characterized by a negative sound speed squared of an effective coupled dark matter/dark energy fluid, and results in the exponential growth of small scale modes. We discuss the role of the instability in specific coupled cold dark matter and mass varying neutrino models of dark energy and clarify for these theories the regimes in which the instability can be evaded due to nonadiabaticity or weak coupling.

Diffractive, diffusive, and statistical aspects of deep inelastic heavy-ion collisions

International Nuclear Information System (INIS)

Lee, S.Y.; McGrath, R.L.; Dean, D.R.

1984-01-01

Deep inelastic collisions between ''light'' heavy ions are considered in a formalism containing diffractive, diffusive, and statistical aspects. A closed-form diffractive cross section is derived, with the deflection function being parametrized in a classically-motivated way. A statistical argument is used to demonstrate how the observed double differential cross section is built up from different diffractive contributions each with its own weight. The form of the weighting function is derived. The observed forward-peaked exponentially-decaying form of deep inelastic collision angular distributions is accounted for. The possibility of exciting a nonzero spin state is explicitly included, enabling the same formalism to be used to explain the spin polarization occurring in deep inelastic collisions. This quantity is much more sensitive than the angular distribution to the choice of deflection function parametrization. Reasonable fits to data are obtained with only one free parameter, apart from an overall normalization factor

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

Hadron-pair production on transversely polarized targets in semi-inclusive deep inelastic scattering

CERN Document Server

Braun, Christopher

Nucleons such as protons and neutrons are composite objects made of quarks, which are bound together by the strong force via the exchange of gluons. The probability of finding a quark of flavor q carrying the momentum fraction x of the fast moving parent nucleon is described by a parton distribution function (PDF) f q 1 ( x ) , the number density. The spin, an intrinsic angular momentum of elementary particles such as quarks but also of composite objects like nucleons, couples with magnetic fields, which allows one to align it. Taking into account this additional parameter, the spin, the scheme of PDFs in leading twist is expanded by the helicity distribution g q 1 ( x ) and the transversity distribution h q 1 ( x ) . The first distribution covers the case where the nucleon and the quark are longitudinally polarized, while a transverse polarization is taken into account by the latter. A tool for the investigation of the PDFs is inclusive deep inelastic scattering (DIS) of electro- magnetic probes off (un)pola...

Metastable dark energy

Directory of Open Access Journals (Sweden)

Ricardo G. Landim

2017-01-01

Full Text Available We build a model of metastable dark energy, in which the observed vacuum energy is the value of the scalar potential at the false vacuum. The scalar potential is given by a sum of even self-interactions up to order six. The deviation from the Minkowski vacuum is due to a term suppressed by the Planck scale. The decay time of the metastable vacuum can easily accommodate a mean life time compatible with the age of the universe. The metastable dark energy is also embedded into a model with SU(2R symmetry. The dark energy doublet and the dark matter doublet naturally interact with each other. A three-body decay of the dark energy particle into (cold and warm dark matter can be as long as large fraction of the age of the universe, if the mediator is massive enough, the lower bound being at intermediate energy level some orders below the grand unification scale. Such a decay shows a different form of interaction between dark matter and dark energy, and the model opens a new window to investigate the dark sector from the point-of-view of particle physics.

Sensitivity of the elastic scattering matrix elements to the range of the inelastic potentials

International Nuclear Information System (INIS)

Rawitscher, G.H.; Rasoanaivo, R.Y.

1983-01-01

The solution to a system of coupled equations is examined with regard to the effect of the long range part of the inelastic potentials upon the elastic phase shifts. It is found that those parts of the inelastic potentials which occur beyond the range of the elastic to inelastic transition potentials affect the elastic phase shifts in only a minor way. The proof is given theoretically by means of a Green's function formulation which includes the long range part of the inelastic potentials perturbatively. When applied to the calculation of the effect of breakup on the deuteron-nucleus elastic scattering, the argument confirms the finding that errors in the long range part of the potentials in the breakup channels do not sensitively affect the elastic deuteron scattering cross section. This result explains why the elastic scattering is not very sensitive to the choice of the discretization procedure of the breakup space

Partially acoustic dark matter, interacting dark radiation, and large scale structure

Energy Technology Data Exchange (ETDEWEB)

Chacko, Zackaria [Maryland Center for Fundamental Physics, Department of Physics, University of Maryland,Stadium Dr., College Park, MD 20742 (United States); Cui, Yanou [Maryland Center for Fundamental Physics, Department of Physics, University of Maryland,Stadium Dr., College Park, MD 20742 (United States); Department of Physics and Astronomy, University of California-Riverside,University Ave, Riverside, CA 92521 (United States); Perimeter Institute, 31 Caroline Street, North Waterloo, Ontario N2L 2Y5 (Canada); Hong, Sungwoo [Maryland Center for Fundamental Physics, Department of Physics, University of Maryland,Stadium Dr., College Park, MD 20742 (United States); Okui, Takemichi [Department of Physics, Florida State University,College Avenue, Tallahassee, FL 32306 (United States); Tsai, Yuhsinz [Maryland Center for Fundamental Physics, Department of Physics, University of Maryland,Stadium Dr., College Park, MD 20742 (United States)

2016-12-21

The standard paradigm of collisionless cold dark matter is in tension with measurements on large scales. In particular, the best fit values of the Hubble rate H{sub 0} and the matter density perturbation σ{sub 8} inferred from the cosmic microwave background seem inconsistent with the results from direct measurements. We show that both problems can be solved in a framework in which dark matter consists of two distinct components, a dominant component and a subdominant component. The primary component is cold and collisionless. The secondary component is also cold, but interacts strongly with dark radiation, which itself forms a tightly coupled fluid. The growth of density perturbations in the subdominant component is inhibited by dark acoustic oscillations due to its coupling to the dark radiation, solving the σ{sub 8} problem, while the presence of tightly coupled dark radiation ameliorates the H{sub 0} problem. The subdominant component of dark matter and dark radiation continue to remain in thermal equilibrium until late times, inhibiting the formation of a dark disk. We present an example of a simple model that naturally realizes this scenario in which both constituents of dark matter are thermal WIMPs. Our scenario can be tested by future stage-IV experiments designed to probe the CMB and large scale structure.

Partially acoustic dark matter, interacting dark radiation, and large scale structure

International Nuclear Information System (INIS)

Chacko, Zackaria; Cui, Yanou; Hong, Sungwoo; Okui, Takemichi; Tsai, Yuhsinz

2016-01-01

The standard paradigm of collisionless cold dark matter is in tension with measurements on large scales. In particular, the best fit values of the Hubble rate H 0 and the matter density perturbation σ 8 inferred from the cosmic microwave background seem inconsistent with the results from direct measurements. We show that both problems can be solved in a framework in which dark matter consists of two distinct components, a dominant component and a subdominant component. The primary component is cold and collisionless. The secondary component is also cold, but interacts strongly with dark radiation, which itself forms a tightly coupled fluid. The growth of density perturbations in the subdominant component is inhibited by dark acoustic oscillations due to its coupling to the dark radiation, solving the σ 8 problem, while the presence of tightly coupled dark radiation ameliorates the H 0 problem. The subdominant component of dark matter and dark radiation continue to remain in thermal equilibrium until late times, inhibiting the formation of a dark disk. We present an example of a simple model that naturally realizes this scenario in which both constituents of dark matter are thermal WIMPs. Our scenario can be tested by future stage-IV experiments designed to probe the CMB and large scale structure.

Inflation, Dark Matter, and Dark Energy in the String Landscape

OpenAIRE

Liddle, Andrew R; Ureña-López, L Arturo

2006-01-01

We consider the conditions needed to unify the description of dark matter, dark energy and inflation in the context of the string landscape. We find that incomplete decay of the inflaton field gives the possibility that a single field is responsible for all three phenomena. By contrast, unifying dark matter and dark energy into a single field, separate from the inflaton, appears rather difficult.

Dark Sky Protection and Education - Izera Dark Sky Park

Science.gov (United States)

Berlicki, Arkadiusz; Kolomanski, Sylwester; Mrozek, Tomasz; Zakowicz, Grzegorz

2015-08-01

Darkness of the night sky is a natural component of our environment and should be protected against negative effects of human activities. The night darkness is necessary for balanced life of plants, animals and people. Unfortunately, development of human civilization and technology has led to the substantial increase of the night-sky brightness and to situation where nights are no more dark in many areas of the World. This phenomenon is called "light pollution" and it can be rank among such problems as chemical pollution of air, water and soil. Besides the environment, the light pollution can also affect e.g. the scientific activities of astronomers - many observatories built in the past began to be located within the glow of city lights making the night observations difficult, or even impossible.In order to protect the natural darkness of nights many so-called "dark sky parks" were established, where the darkness is preserved, similar to typical nature reserves. The role of these parks is not only conservation but also education, supporting to make society aware of how serious the problem of the light pollution is.History of the dark sky areas in Europe began on November 4, 2009 in Jizerka - a small village situated in the Izera Mountains, when Izera Dark Sky Park (IDSP) was established - it was the first transboundary dark sky park in the World. The idea of establishing that dark sky park in the Izera Mountains originated from a need to give to the society in Poland and Czech Republic the knowledge about the light pollution. Izera Dark Sky Park is a part of the astro-tourism project "Astro Izery" that combines tourist attraction of Izera Valley and astronomical education under the wonderful starry Izera sky. Besides the IDSP, the project Astro Izery consists of the set of simple astronomical instruments (gnomon, sundial), natural educational trail "Solar System Model", and astronomical events for the public. In addition, twice a year we organize a 3-4 days

Results from the DarkSide-50 Dark Matter Experiment

Energy Technology Data Exchange (ETDEWEB)

Fan, Alden [Univ. of California, Los Angeles, CA (United States)

2016-01-01

While there is tremendous astrophysical and cosmological evidence for dark matter, its precise nature is one of the most significant open questions in modern physics. Weakly interacting massive particles (WIMPs) are a particularly compelling class of dark matter candidates with masses of the order 100 GeV and couplings to ordinary matter at the weak scale. Direct detection experiments are aiming to observe the low energy (<100 keV) scattering of dark matter off normal matter. With the liquid noble technology leading the way in WIMP sensitivity, no conclusive signals have been observed yet. The DarkSide experiment is looking for WIMP dark matter using a liquid argon target in a dual-phase time projection chamber located deep underground at Gran Sasso National Laboratory (LNGS) in Italy. Currently filled with argon obtained from underground sources, which is greatly reduced in radioactive ³⁹Ar, DarkSide-50 recently made the most sensitive measurement of the ³⁹Ar activity in underground argon and used it to set the strongest WIMP dark matter limit using liquid argon to date. This work describes the full chain of analysis used to produce the recent dark matter limit, from reconstruction of raw data to evaluation of the final exclusion curve. The DarkSide- 50 apparatus is described in detail, followed by discussion of the low level reconstruction algorithms. The algorithms are then used to arrive at three broad analysis results: The electroluminescence signals in DarkSide-50 are used to perform a precision measurement of ii longitudinal electron diffusion in liquid argon. A search is performed on the underground argon data to identify the delayed coincidence signature of ⁸⁵Kr decays to the ⁸⁵mRb state, a crucial ingredient in the measurement of the ³⁹Ar activity in the underground argon. Finally, a full description of the WIMP search is given, including development of cuts, efficiencies, energy scale, and exclusion

Deeply inelastic transfer reactions induced by heavy ions in rare earth targets. II. Interpretation of experimental data

International Nuclear Information System (INIS)

Rivet, M.F.; Bimbot, R.; Ngo, C.

1979-01-01

The experimental angular distributions and cross sections for a series of deeply inelastic transfer reactions induced by various projectiles in rare earth targets have been interpreted using a model which includes a dynamical coupling between relative motion and mass asymmetry and treats statistical fluctuations. As the transfer reactions considered correspond to an increase of the potential energy of the composite system their observation is mainly due to fluctuations. The calculation reproduces correctly the angular distributions, but the cross sections are underestimated. Several effects are discussed which may increase these cross sections and are neglected in the calculation

Unified description of H-atom-induced chemicurrents and inelastic scattering.

Science.gov (United States)

Kandratsenka, Alexander; Jiang, Hongyan; Dorenkamp, Yvonne; Janke, Svenja M; Kammler, Marvin; Wodtke, Alec M; Bünermann, Oliver

2018-01-23

The Born-Oppenheimer approximation (BOA) provides the foundation for virtually all computational studies of chemical binding and reactivity, and it is the justification for the widely used "balls and springs" picture of molecules. The BOA assumes that nuclei effectively stand still on the timescale of electronic motion, due to their large masses relative to electrons. This implies electrons never change their energy quantum state. When molecules react, atoms must move, meaning that electrons may become excited in violation of the BOA. Such electronic excitation is clearly seen for: ( i ) Schottky diodes where H adsorption at Ag surfaces produces electrical "chemicurrent;" ( ii ) Au-based metal-insulator-metal (MIM) devices, where chemicurrents arise from H-H surface recombination; and ( iii ) Inelastic energy transfer, where H collisions with Au surfaces show H-atom translation excites the metal's electrons. As part of this work, we report isotopically selective hydrogen/deuterium (H/D) translational inelasticity measurements in collisions with Ag and Au. Together, these experiments provide an opportunity to test new theories that simultaneously describe both nuclear and electronic motion, a standing challenge to the field. Here, we show results of a recently developed first-principles theory that quantitatively explains both inelastic scattering experiments that probe nuclear motion and chemicurrent experiments that probe electronic excitation. The theory explains the magnitude of chemicurrents on Ag Schottky diodes and resolves an apparent paradox--chemicurrents exhibit a much larger isotope effect than does H/D inelastic scattering. It also explains why, unlike Ag-based Schottky diodes, Au-based MIM devices are insensitive to H adsorption.

On a simplified inelastic analysis of structures

International Nuclear Information System (INIS)

Zarka, J.; Engel, J.J.; Inglebert, G.

1980-01-01

In this paper two main problems are considered: the derivation of cyclic constitutive relations during inelastic regime where hardening, softening and creep can occur, and the development of the eventual periodical state in the structure during cyclic thermodynamical loadings. We give a very simple and practical framework to solve these problems in one unique manner. Its essential feature consits in the introduction of a family of internal parameters which characterize local inelastic mechanisms and the family of transformed internal parameters which are linearly linked to the previous ones through a symmetrical non-negative matrix and are indeed the opposite of the associated residual stresses. Thanks to that, the treatment of the local plastic or viscoplastic yield conditions can be easily made from only the classical simple purely elastic (or viscoelastic) analysis. This property allows important results during cyclic loadings: conditions for elastic shakedown, plastic shakedown, ratcheting and bounds for the limiting state. Several examples are given in the text. (orig.)

Inelastic X-ray scattering activities in Europe

International Nuclear Information System (INIS)

Dorner, B.

1984-01-01

Inelastic X-ray scattering requires an energy determination before and after the scattering process together with a technique to vary at least one energy continuously in a controlled way. Sufficiently monochromatic beams can only be produced by Bragg reflection from single crystals. Stationary X-ray monochromators are standard equipment of conventional X-ray generators to select a particular characteristic line. Quite often they are curved to focus on the sample or the detector. Devices with variable Bragg angle have been and are used as analyzers in Compton scattering which is inelastic X-ray scattering with moderate resolution. With the rapidly increasing availability of synchrotron radiation (SR) monochromators and analyzers became more and more sophisticated improving momentum (Q) resolution and only somewhat the energy resolution ΔE which stays in the order of eV. Very high energy resolution can only be obtained with Bragg angles Theta near to 90 0 . This field is the topic of the present paper

Measurement of the inelastic proton-proton cross section at $\\sqrt{s}$ = 7 TeV

CERN Document Server

Chatrchyan, Serguei; Sirunyan, Albert M; Tumasyan, Armen; Adam, Wolfgang; Aguilo, Ernest; Bergauer, Thomas; Dragicevic, Marko; Erö, Janos; Fabjan, Christian; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hammer, Josef; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Kiesenhofer, Wolfgang; Knünz, Valentin; Krammer, Manfred; Krätschmer, Ilse; Liko, Dietrich; Mikulec, Ivan; Pernicka, Manfred; Rahbaran, Babak; Rohringer, Christine; Rohringer, Herbert; Schöfbeck, Robert; Strauss, Josef; Taurok, Anton; Waltenberger, Wolfgang; Walzel, Gerhard; Widl, Edmund; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Bansal, Monika; Bansal, Sunil; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Luyckx, Sten; Mucibello, Luca; Ochesanu, Silvia; Roland, Benoit; Rougny, Romain; Selvaggi, Michele; Staykova, Zlatka; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Blekman, Freya; Blyweert, Stijn; D'Hondt, Jorgen; Gonzalez Suarez, Rebeca; Kalogeropoulos, Alexis; Maes, Michael; Olbrechts, Annik; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Villella, Ilaria; Clerbaux, Barbara; De Lentdecker, Gilles; Dero, Vincent; Gay, Arnaud; Hreus, Tomas; Léonard, Alexandre; Marage, Pierre Edouard; Mohammadi, Abdollah; Reis, Thomas; Thomas, Laurent; Vander Marcken, Gil; Vander Velde, Catherine; Vanlaer, Pascal; Wang, Jian; Adler, Volker; Beernaert, Kelly; Cimmino, Anna; Costantini, Silvia; Garcia, Guillaume; Grunewald, Martin; Klein, Benjamin; Lellouch, Jérémie; Marinov, Andrey; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Ryckbosch, Dirk; Strobbe, Nadja; Thyssen, Filip; Tytgat, Michael; Verwilligen, Piet; Walsh, Sinead; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Bruno, Giacomo; Castello, Roberto; Ceard, Ludivine; Delaere, Christophe; Du Pree, Tristan; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Hollar, Jonathan; Lemaitre, Vincent; Liao, Junhui; Militaru, Otilia; Nuttens, Claude; Pagano, Davide; Pin, Arnaud; Piotrzkowski, Krzysztof; Schul, Nicolas; Vizan Garcia, Jesus Manuel; Beliy, Nikita; Caebergs, Thierry; Daubie, Evelyne; Hammad, Gregory Habib; Alves, Gilvan; Correa Martins Junior, Marcos; De Jesus Damiao, Dilson; Martins, Thiago; Pol, Maria Elena; Henrique Gomes E Souza, Moacyr; Aldá Júnior, Walter Luiz; Carvalho, Wagner; Custódio, Analu; Melo Da Costa, Eliza; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Matos Figueiredo, Diego; Mundim, Luiz; Nogima, Helio; Oguri, Vitor; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Soares Jorge, Luana; Sznajder, Andre; Souza Dos Anjos, Tiago; Bernardes, Cesar Augusto; De Almeida Dias, Flavia; Tomei, Thiago; De Moraes Gregores, Eduardo; Lagana, Caio; Da Cunha Marinho, Franciole; Mercadante, Pedro G; Novaes, Sergio F; Padula, Sandra; Genchev, Vladimir; Iaydjiev, Plamen; Piperov, Stefan; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Tcholakov, Vanio; Trayanov, Rumen; Vutova, Mariana; Dimitrov, Anton; Hadjiiska, Roumyana; Kozhuharov, Venelin; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Jiang, Chun-Hua; Liang, Dong; Liang, Song; Meng, Xiangwei; Tao, Junquan; Wang, Jian; Wang, Xianyou; Wang, Zheng; Xiao, Hong; Xu, Ming; Zang, Jingjing; Zhang, Zhen; Asawatangtrakuldee, Chayanit; Ban, Yong; Guo, Yifei; Li, Wenbo; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Teng, Haiyun; Wang, Dayong; Zhang, Linlin; Zou, Wei; Avila, Carlos; Gomez, Juan Pablo; Gomez Moreno, Bernardo; Osorio Oliveros, Andres Felipe; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Plestina, Roko; Polic, Dunja; Puljak, Ivica; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Duric, Senka; Kadija, Kreso; Luetic, Jelena; Morovic, Srecko; Attikis, Alexandros; Galanti, Mario; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Finger, Miroslav; Finger Jr, Michael; Assran, Yasser; Elgammal, Sherif; Ellithi Kamel, Ali; Mahmoud, Mohammed; Radi, Amr; Kadastik, Mario; Müntel, Mait; Raidal, Martti; Rebane, Liis; Tiko, Andres; Eerola, Paula; Fedi, Giacomo; Voutilainen, Mikko; Härkönen, Jaakko; Heikkinen, Mika Aatos; Karimäki, Veikko; Kinnunen, Ritva; Kortelainen, Matti J; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Peltola, Timo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Ungaro, Donatella; Wendland, Lauri; Banzuzi, Kukka; Karjalainen, Ahti; Korpela, Arja; Tuuva, Tuure; Besancon, Marc; Choudhury, Somnath; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Ferri, Federico; Ganjour, Serguei; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Malcles, Julie; Millischer, Laurent; Nayak, Aruna; Rander, John; Rosowsky, André; Shreyber, Irina; Titov, Maksym; Baffioni, Stephanie; Beaudette, Florian; Benhabib, Lamia; Bianchini, Lorenzo; Bluj, Michal; Broutin, Clementine; Busson, Philippe; Charlot, Claude; Daci, Nadir; Dahms, Torsten; Dobrzynski, Ludwik; Granier de Cassagnac, Raphael; Haguenauer, Maurice; Miné, Philippe; Mironov, Camelia; Naranjo, Ivo Nicolas; Nguyen, Matthew; Ochando, Christophe; Paganini, Pascal; Sabes, David; Salerno, Roberto; Sirois, Yves; Veelken, Christian; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Bloch, Daniel; Bodin, David; Brom, Jean-Marie; Cardaci, Marco; Chabert, Eric Christian; Collard, Caroline; Conte, Eric; Drouhin, Frédéric; Ferro, Cristina; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Juillot, Pierre; Le Bihan, Anne-Catherine; Van Hove, Pierre; Fassi, Farida; Mercier, Damien; Beauceron, Stephanie; Beaupere, Nicolas; Bondu, Olivier; Boudoul, Gaelle; Chasserat, Julien; Chierici, Roberto; Contardo, Didier; Depasse, Pierre; El Mamouni, Houmani; Fay, Jean; Gascon, Susan; Gouzevitch, Maxime; Ille, Bernard; Kurca, Tibor; Lethuillier, Morgan; Mirabito, Laurent; Perries, Stephane; Sordini, Viola; Tschudi, Yohann; Verdier, Patrice; Viret, Sébastien; Roinishvili, Vladimir; Anagnostou, Georgios; Autermann, Christian; Beranek, Sarah; Edelhoff, Matthias; Feld, Lutz; Heracleous, Natalie; Hindrichs, Otto; Jussen, Ruediger; Klein, Katja; Merz, Jennifer; Ostapchuk, Andrey; Perieanu, Adrian; Raupach, Frank; Sammet, Jan; Schael, Stefan; Sprenger, Daniel; Weber, Hendrik; Wittmer, Bruno; Zhukov, Valery; Ata, Metin; Caudron, Julien; Dietz-Laursonn, Erik; Duchardt, Deborah; Erdmann, Martin; Fischer, Robert; Güth, Andreas; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Klingebiel, Dennis; Kreuzer, Peter; Magass, Carsten; Merschmeyer, Markus; Meyer, Arnd; Olschewski, Mark; Papacz, Paul; Pieta, Holger; Reithler, Hans; Schmitz, Stefan Antonius; Sonnenschein, Lars; Steggemann, Jan; Teyssier, Daniel; Weber, Martin; Bontenackels, Michael; Cherepanov, Vladimir; Erdogan, Yusuf; Flügge, Günter; Geenen, Heiko; Geisler, Matthias; Haj Ahmad, Wael; Hoehle, Felix; Kargoll, Bastian; Kress, Thomas; Kuessel, Yvonne; Nowack, Andreas; Perchalla, Lars; Pooth, Oliver; Sauerland, Philip; Stahl, Achim; Aldaya Martin, Maria; Behr, Joerg; Behrenhoff, Wolf; Behrens, Ulf; Bergholz, Matthias; Bethani, Agni; Borras, Kerstin; Burgmeier, Armin; Cakir, Altan; Calligaris, Luigi; Campbell, Alan; Castro, Elena; Costanza, Francesco; Dammann, Dirk; Diez Pardos, Carmen; Eckerlin, Guenter; Eckstein, Doris; Flucke, Gero; Geiser, Achim; Glushkov, Ivan; Gunnellini, Paolo; Habib, Shiraz; Hauk, Johannes; Hellwig, Gregor; Jung, Hannes; Kasemann, Matthias; Katsas, Panagiotis; Kleinwort, Claus; Kluge, Hannelies; Knutsson, Albert; Krämer, Mira; Krücker, Dirk; Kuznetsova, Ekaterina; Lange, Wolfgang; Lohmann, Wolfgang; Lutz, Benjamin; Mankel, Rainer; Marfin, Ihar; Marienfeld, Markus; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mnich, Joachim; Mussgiller, Andreas; Naumann-Emme, Sebastian; Olzem, Jan; Perrey, Hanno; Petrukhin, Alexey; Pitzl, Daniel; Raspereza, Alexei; Ribeiro Cipriano, Pedro M; Riedl, Caroline; Ron, Elias; Rosin, Michele; Salfeld-Nebgen, Jakob; Schmidt, Ringo; Schoerner-Sadenius, Thomas; Sen, Niladri; Spiridonov, Alexander; Stein, Matthias; Walsh, Roberval; Wissing, Christoph; Blobel, Volker; Draeger, Jula; Enderle, Holger; Erfle, Joachim; Gebbert, Ulla; Görner, Martin; Hermanns, Thomas; Höing, Rebekka Sophie; Kaschube, Kolja; Kaussen, Gordon; Kirschenmann, Henning; Klanner, Robert; Lange, Jörn; Mura, Benedikt; Nowak, Friederike; Peiffer, Thomas; Pietsch, Niklas; Rathjens, Denis; Sander, Christian; Schettler, Hannes; Schleper, Peter; Schlieckau, Eike; Schmidt, Alexander; Schröder, Matthias; Schum, Torben; Seidel, Markus; Sola, Valentina; Stadie, Hartmut; Steinbrück, Georg; Thomsen, Jan; Vanelderen, Lukas; Barth, Christian; Berger, Joram; Böser, Christian; Chwalek, Thorsten; De Boer, Wim; Descroix, Alexis; Dierlamm, Alexander; Feindt, Michael; Guthoff, Moritz; Hackstein, Christoph; Hartmann, Frank; Hauth, Thomas; Heinrich, Michael; Held, Hauke; Hoffmann, Karl-Heinz; Honc, Simon; Katkov, Igor; Komaragiri, Jyothsna Rani; Lobelle Pardo, Patricia; Martschei, Daniel; Mueller, Steffen; Müller, Thomas; Niegel, Martin; Nürnberg, Andreas; Oberst, Oliver; Oehler, Andreas; Ott, Jochen; Quast, Gunter; Rabbertz, Klaus; Ratnikov, Fedor; Ratnikova, Natalia; Röcker, Steffen; Scheurer, Armin; Schilling, Frank-Peter; Schott, Gregory; Simonis, Hans-Jürgen; Stober, Fred-Markus Helmut; Troendle, Daniel; Ulrich, Ralf; Wagner-Kuhr, Jeannine; Wayand, Stefan; Weiler, Thomas; Zeise, Manuel; Daskalakis, Georgios; Geralis, Theodoros; Kesisoglou, Stilianos; Kyriakis, Aristotelis; Loukas, Demetrios; Manolakos, Ioannis; Markou, Athanasios; Markou, Christos; Mavrommatis, Charalampos; Ntomari, Eleni; Gouskos, Loukas; Mertzimekis, Theodoros; Panagiotou, Apostolos; Saoulidou, Niki; Evangelou, Ioannis; Foudas, Costas; Kokkas, Panagiotis; Manthos, Nikolaos; Papadopoulos, Ioannis; Patras, Vaios; Bencze, Gyorgy; Hajdu, Csaba; Hidas, Pàl; Horvath, Dezso; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Beni, Noemi; Czellar, Sandor; Molnar, Jozsef; Palinkas, Jozsef; Szillasi, Zoltan; Karancsi, János; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Beri, Suman Bala; Bhatnagar, Vipin; Dhingra, Nitish; Gupta, Ruchi; Kaur, Manjit; Mehta, Manuk Zubin; Nishu, Nishu; Saini, Lovedeep Kaur; Sharma, Archana; Singh, Jasbir; Kumar, Ashok; Kumar, Arun; Ahuja, Sudha; Bhardwaj, Ashutosh; Choudhary, Brajesh C; Malhotra, Shivali; Naimuddin, Md; Ranjan, Kirti; Sharma, Varun; Shivpuri, Ram Krishen; Banerjee, Sunanda; Bhattacharya, Satyaki; Dutta, Suchandra; Gomber, Bhawna; Jain, Sandhya; Jain, Shilpi; Khurana, Raman; Sarkar, Subir; Sharan, Manoj; Abdulsalam, Abdulla; Choudhury, Rajani Kant; Dutta, Dipanwita; Kailas, Swaminathan; Kumar, Vineet; Mehta, Pourus; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Aziz, Tariq; Ganguly, Sanmay; Guchait, Monoranjan; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Mohanty, Gagan Bihari; Parida, Bibhuti; Sudhakar, Katta; Wickramage, Nadeesha; Banerjee, Sudeshna; Dugad, Shashikant; Arfaei, Hessamaddin; Bakhshiansohi, Hamed; Etesami, Seyed Mohsen; Fahim, Ali; Hashemi, Majid; Hesari, Hoda; Jafari, Abideh; Khakzad, Mohsen; Mohammadi Najafabadi, Mojtaba; Paktinat Mehdiabadi, Saeid; Safarzadeh, Batool; Zeinali, Maryam; Abbrescia, Marcello; Barbone, Lucia; Calabria, Cesare; Chhibra, Simranjit Singh; Colaleo, Anna; Creanza, Donato; De Filippis, Nicola; De Palma, Mauro; Fiore, Luigi; Iaselli, Giuseppe; Lusito, Letizia; Maggi, Giorgio; Maggi, Marcello; Marangelli, Bartolomeo; My, Salvatore; Nuzzo, Salvatore; Pacifico, Nicola; Pompili, Alexis; Pugliese, Gabriella; Selvaggi, Giovanna; Silvestris, Lucia; Singh, Gurpreet; Venditti, Rosamaria; Zito, Giuseppe; Abbiendi, Giovanni; Benvenuti, Alberto; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Grandi, Claudio; Guiducci, Luigi; Marcellini, Stefano; Masetti, Gianni; Meneghelli, Marco; Montanari, Alessandro; Navarria, Francesco; Odorici, Fabrizio; Perrotta, Andrea; Primavera, Federica; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gian Piero; Travaglini, Riccardo; Albergo, Sebastiano; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Frosali, Simone; Gallo, Elisabetta; Gonzi, Sandro; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Tropiano, Antonio; Benussi, Luigi; Bianco, Stefano; Colafranceschi, Stefano; Fabbri, Franco; Piccolo, Davide; Fabbricatore, Pasquale; Musenich, Riccardo; Tosi, Silvano; Benaglia, Andrea; De Guio, Federico; Di Matteo, Leonardo; Fiorendi, Sara; Gennai, Simone; Ghezzi, Alessio; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Martelli, Arabella; Massironi, Andrea; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Sala, Silvano; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Carrillo Montoya, Camilo Andres; Cavallo, Nicola; De Cosa, Annapaola; Dogangun, Oktay; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lista, Luca; Meola, Sabino; Merola, Mario; Paolucci, Pierluigi; Azzi, Patrizia; Bacchetta, Nicola; Bisello, Dario; Branca, Antonio; Carlin, Roberto; Checchia, Paolo; Dorigo, Tommaso; Dosselli, Umberto; Gasparini, Fabrizio; Gasparini, Ugo; Gozzelino, Andrea; Kanishchev, Konstantin; Lacaprara, Stefano; Lazzizzera, Ignazio; Margoni, Martino; Meneguzzo, Anna Teresa; Pazzini, Jacopo; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Vanini, Sara; Zotto, Pierluigi; Zumerle, Gianni; Gabusi, Michele; Ratti, Sergio P; Riccardi, Cristina; Torre, Paola; Vitulo, Paolo; Biasini, Maurizio; Bilei, Gian Mario; Fanò, Livio; Lariccia, Paolo; Lucaroni, Andrea; Mantovani, Giancarlo; Menichelli, Mauro; Nappi, Aniello; Romeo, Francesco; Saha, Anirban; Santocchia, Attilio; Spiezia, Aniello; Taroni, Silvia; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Broccolo, Giuseppe; Castaldi, Rino; D'Agnolo, Raffaele Tito; Dell'Orso, Roberto; Fiori, Francesco; Foà, Lorenzo; Giassi, Alessandro; Kraan, Aafke; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Palla, Fabrizio; Rizzi, Andrea; Serban, Alin Titus; Spagnolo, Paolo; Squillacioti, Paola; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Barone, Luciano; Cavallari, Francesca; Del Re, Daniele; Diemoz, Marcella; Fanelli, Cristiano; Grassi, Marco; Longo, Egidio; Meridiani, Paolo; Micheli, Francesco; Nourbakhsh, Shervin; Organtini, Giovanni; Paramatti, Riccardo; Rahatlou, Shahram; Sigamani, Michael; Soffi, Livia; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Biino, Cristina; Cartiglia, Nicolo; Costa, Marco; Demaria, Natale; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Musich, Marco; Obertino, Maria Margherita; Pastrone, Nadia; Pelliccioni, Mario; Potenza, Alberto; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Solano, Ada; Staiano, Amedeo; Vilela Pereira, Antonio; Belforte, Stefano; Candelise, Vieri; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; Marone, Matteo; Montanino, Damiana; Penzo, Aldo; Schizzi, Andrea; Heo, Seong Gu; Kim, Tae Yeon; Nam, Soon-Kwon; Chang, Sunghyun; Kim, Dong Hee; Kim, Gui Nyun; Kong, Dae Jung; Park, Hyangkyu; Ro, Sang-Ryul; Son, Dong-Chul; Son, Taejin; Kim, Jae Yool; Kim, Zero Jaeho; Song, Sanghyeon; Choi, Suyong; Gyun, Dooyeon; Hong, Byung-Sik; Jo, Mihee; Kim, Hyunchul; Kim, Tae Jeong; Lee, Kyong Sei; Moon, Dong Ho; Park, Sung Keun; Choi, Minkyoo; Kim, Ji Hyun; Park, Chawon; Park, Inkyu; Park, Sangnam; Ryu, Geonmo; Cho, Yongjin; Choi, Young-Il; Choi, Young Kyu; Goh, Junghwan; Kim, Min Suk; Kwon, Eunhyang; Lee, Byounghoon; Lee, Jongseok; Lee, Sungeun; Seo, Hyunkwan; Yu, Intae; Bilinskas, Mykolas Jurgis; Grigelionis, Ignas; Janulis, Mindaugas; Juodagalvis, Andrius; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-de La Cruz, Ivan; Lopez-Fernandez, Ricardo; Magaña Villalba, Ricardo; Martínez-Ortega, Jorge; Sánchez Hernández, Alberto; Villasenor-Cendejas, Luis Manuel; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Salazar Ibarguen, Humberto Antonio; Casimiro Linares, Edgar; Morelos Pineda, Antonio; Reyes-Santos, Marco A; Krofcheck, David; Bell, Alan James; Butler, Philip H; Doesburg, Robert; Reucroft, Steve; Silverwood, Hamish; Ahmad, Muhammad; Ansari, Muhammad Hamid; Asghar, Muhammad Irfan; Hoorani, Hafeez R; Khalid, Shoaib; Khan, Wajid Ali; Khurshid, Taimoor; Qazi, Shamona; Shah, Mehar Ali; Shoaib, Muhammad; Bialkowska, Helena; Boimska, Bozena; Frueboes, Tomasz; Gokieli, Ryszard; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Wrochna, Grzegorz; Zalewski, Piotr; Brona, Grzegorz; Bunkowski, Karol; Cwiok, Mikolaj; Dominik, Wojciech; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Almeida, Nuno; Bargassa, Pedrame; David Tinoco Mendes, Andre; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Seixas, Joao; Varela, Joao; Vischia, Pietro; Belotelov, Ivan; Bunin, Pavel; Gavrilenko, Mikhail; Golutvin, Igor; Gorbunov, Ilya; Kamenev, Alexey; Karjavin, Vladimir; Kozlov, Guennady; Lanev, Alexander; Malakhov, Alexander; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Shmatov, Sergey; Smirnov, Vitaly; Volodko, Anton; Zarubin, Anatoli; Evstyukhin, Sergey; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Vorobyev, Andrey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Kirsanov, Mikhail; Krasnikov, Nikolai; Matveev, Viktor; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Erofeeva, Maria; Gavrilov, Vladimir; Kossov, Mikhail; Lychkovskaya, Natalia; Popov, Vladimir; Safronov, Grigory; Semenov, Sergey; Stolin, Viatcheslav; Vlasov, Evgueni; Zhokin, Alexander; Belyaev, Andrey; Boos, Edouard; Dubinin, Mikhail; Dudko, Lev; Khein, Lev; Klyukhin, Vyacheslav; Kodolova, Olga; Lokhtin, Igor; Markina, Anastasia; Obraztsov, Stepan; Perfilov, Maxim; Petrushanko, Sergey; Popov, Andrey; Proskuryakov, Alexander; Sarycheva, Ludmila; Savrin, Viktor; Snigirev, Alexander; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Mesyats, Gennady; Rusakov, Sergey V; Vinogradov, Alexey; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Grishin, Viatcheslav; Kachanov, Vassili; Konstantinov, Dmitri; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Djordjevic, Milos; Ekmedzic, Marko; Krpic, Dragomir; Milosevic, Jovan; Aguilar-Benitez, Manuel; Alcaraz Maestre, Juan; Arce, Pedro; Battilana, Carlo; Calvo, Enrique; Cerrada, Marcos; Chamizo Llatas, Maria; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Domínguez Vázquez, Daniel; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Ferrando, Antonio; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Merino, Gonzalo; Puerta Pelayo, Jesus; Quintario Olmeda, Adrián; Redondo, Ignacio; Romero, Luciano; Santaolalla, Javier; Senghi Soares, Mara; Willmott, Carlos; Albajar, Carmen; Codispoti, Giuseppe; de Trocóniz, Jorge F; Brun, Hugues; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Lloret Iglesias, Lara; Piedra Gomez, Jonatan; Brochero Cifuentes, Javier Andres; Cabrillo, Iban Jose; Calderon, Alicia; Chuang, Shan-Huei; Duarte Campderros, Jordi; Felcini, Marta; Fernandez, Marcos; Gomez, Gervasio; Gonzalez Sanchez, Javier; Graziano, Alberto; Jorda, Clara; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Munoz Sanchez, Francisca Javiela; Rodrigo, Teresa; Rodríguez-Marrero, Ana Yaiza; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Bachtis, Michail; Baillon, Paul; Ball, Austin; Barney, David; Benitez, Jose F; Bernet, Colin; Bianchi, Giovanni; Bloch, Philippe; Bocci, Andrea; Bonato, Alessio; Botta, Cristina; Breuker, Horst; Camporesi, Tiziano; Cerminara, Gianluca; Christiansen, Tim; Coarasa Perez, Jose Antonio; D'Enterria, David; Dabrowski, Anne; De Roeck, Albert; Di Guida, Salvatore; Dobson, Marc; Dupont-Sagorin, Niels; Elliott-Peisert, Anna; Frisch, Benjamin; Funk, Wolfgang; Georgiou, Georgios; Giffels, Manuel; Gigi, Dominique; Gill, Karl; Giordano, Domenico; Giunta, Marina; Glege, Frank; Gomez-Reino Garrido, Robert; Govoni, Pietro; Gowdy, Stephen; Guida, Roberto; Hansen, Magnus; Harris, Philip; Hartl, Christian; Harvey, John; Hegner, Benedikt; Hinzmann, Andreas; Innocente, Vincenzo; Janot, Patrick; Kaadze, Ketino; Karavakis, Edward; Kousouris, Konstantinos; Lecoq, Paul; Lee, Yen-Jie; Lenzi, Piergiulio; Lourenco, Carlos; Magini, Nicolo; Maki, Tuula; Malberti, Martina; Malgeri, Luca; Mannelli, Marcello; Masetti, Lorenzo; Meijers, Frans; Mersi, Stefano; Meschi, Emilio; Moser, Roland; Mozer, Matthias Ulrich; Mulders, Martijn; Musella, Pasquale; Nesvold, Erik; Orimoto, Toyoko; Orsini, Luciano; Palencia Cortezon, Enrique; Perez, Emmanuelle; Perrozzi, Luca; Petrilli, Achille; Pfeiffer, Andreas; Pierini, Maurizio; Pimiä, Martti; Piparo, Danilo; Polese, Giovanni; Quertenmont, Loic; Racz, Attila; Reece, William; Rodrigues Antunes, Joao; Rolandi, Gigi; Rovelli, Chiara; Rovere, Marco; Sakulin, Hannes; Santanastasio, Francesco; Schäfer, Christoph; Schwick, Christoph; Segoni, Ilaria; Sekmen, Sezen; Sharma, Archana; Siegrist, Patrice; Silva, Pedro; Simon, Michal; Sphicas, Paraskevas; Spiga, Daniele; Tsirou, Andromachi; Veres, Gabor Istvan; Vlimant, Jean-Roch; Wöhri, Hermine Katharina; Worm, Steven; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Gabathuler, Kurt; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; König, Stefan; Kotlinski, Danek; Langenegger, Urs; Meier, Frank; Renker, Dieter; Rohe, Tilman; Sibille, Jennifer; Bäni, Lukas; Bortignon, Pierluigi; Buchmann, Marco-Andrea; Casal, Bruno; Chanon, Nicolas; Deisher, Amanda; Dissertori, Günther; Dittmar, Michael; Donegà, Mauro; Dünser, Marc; Eugster, Jürg; Freudenreich, Klaus; Grab, Christoph; Hits, Dmitry; Lecomte, Pierre; Lustermann, Werner; Marini, Andrea Carlo; Martinez Ruiz del Arbol, Pablo; Mohr, Niklas; Moortgat, Filip; Nägeli, Christoph; Nef, Pascal; Nessi-Tedaldi, Francesca; Pandolfi, Francesco; Pape, Luc; Pauss, Felicitas; Peruzzi, Marco; Ronga, Frederic Jean; Rossini, Marco; Sala, Leonardo; Sanchez, Ann - Karin; Starodumov, Andrei; Stieger, Benjamin; Takahashi, Maiko; Tauscher, Ludwig; Thea, Alessandro; Theofilatos, Konstantinos; Treille, Daniel; Urscheler, Christina; Wallny, Rainer; Weber, Hannsjoerg Artur; Wehrli, Lukas; Amsler, Claude; Chiochia, Vincenzo; De Visscher, Simon; 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Sellers, Paul; Skhirtladze, Nikoloz; Snowball, Matthew; Yelton, John; Zakaria, Mohammed; Gaultney, Vanessa; Hewamanage, Samantha; Lebolo, Luis Miguel; Linn, Stephan; Markowitz, Pete; Martinez, German; Rodriguez, Jorge Luis; Adams, Todd; Askew, Andrew; Bochenek, Joseph; Chen, Jie; Diamond, Brendan; Gleyzer, Sergei V; Haas, Jeff; Hagopian, Sharon; Hagopian, Vasken; Jenkins, Merrill; Johnson, Kurtis F; Prosper, Harrison; Veeraraghavan, Venkatesh; Weinberg, Marc; Baarmand, Marc M; Dorney, Brian; Hohlmann, Marcus; Kalakhety, Himali; Vodopiyanov, Igor; Adams, Mark Raymond; Anghel, Ioana Maria; Apanasevich, Leonard; Bai, Yuting; Bazterra, Victor Eduardo; Betts, Russell Richard; Bucinskaite, Inga; Callner, Jeremy; Cavanaugh, Richard; Evdokimov, Olga; Gauthier, Lucie; Gerber, Cecilia Elena; Hofman, David Jonathan; Khalatyan, Samvel; Lacroix, Florent; Malek, Magdalena; O'Brien, Christine; Silkworth, Christopher; Strom, Derek; Turner, Paul; Varelas, Nikos; Akgun, Ugur; Albayrak, Elif Asli; Bilki, Burak; 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Kellogg, Richard G; Kirn, Malina; Kolberg, Ted; Lu, Ying; Marionneau, Matthieu; Mignerey, Alice; Pedro, Kevin; Peterman, Alison; Skuja, Andris; Temple, Jeffrey; Tonjes, Marguerite; Tonwar, Suresh C; Twedt, Elizabeth; Apyan, Aram; Bauer, Gerry; Bendavid, Joshua; Busza, Wit; Butz, Erik; Cali, Ivan Amos; Chan, Matthew; Dutta, Valentina; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Hahn, Kristan Allan; Kim, Yongsun; Klute, Markus; Krajczar, Krisztian; Li, Wei; Luckey, Paul David; Ma, Teng; Nahn, Steve; Paus, Christoph; Ralph, Duncan; Roland, Christof; Roland, Gunther; Rudolph, Matthew; Stephans, George; Stöckli, Fabian; Sumorok, Konstanty; Sung, Kevin; Velicanu, Dragos; Wenger, Edward Allen; Wolf, Roger; Wyslouch, Bolek; Yang, Mingming; Yilmaz, Yetkin; Yoon, Sungho; Zanetti, Marco; Cooper, Seth; Dahmes, Bryan; De Benedetti, Abraham; Franzoni, Giovanni; Gude, Alexander; Kao, Shih-Chuan; Klapoetke, Kevin; Kubota, Yuichi; Mans, Jeremy; Pastika, Nathaniel; Rusack, Roger; Sasseville, Michael; Singovsky, Alexander; Tambe, Norbert; Turkewitz, Jared; Cremaldi, Lucien Marcus; Kroeger, Rob; Perera, Lalith; Rahmat, Rahmat; Sanders, David A; Avdeeva, Ekaterina; Bloom, Kenneth; Bose, Suvadeep; Butt, Jamila; Claes, Daniel R; Dominguez, Aaron; Eads, Michael; Keller, Jason; Kravchenko, Ilya; Lazo-Flores, Jose; Malbouisson, Helena; Malik, Sudhir; Snow, Gregory R; Baur, Ulrich; Godshalk, Andrew; Iashvili, Ia; Jain, Supriya; Kharchilava, Avto; Kumar, Ashish; Shipkowski, Simon Peter; Smith, Kenneth; Alverson, George; Barberis, Emanuela; Baumgartel, Darin; Chasco, Matthew; Haley, Joseph; Nash, David; Trocino, Daniele; Wood, Darien; Zhang, Jinzhong; Anastassov, Anton; Kubik, Andrew; Mucia, Nicholas; Odell, Nathaniel; Ofierzynski, Radoslaw Adrian; Pollack, Brian; Pozdnyakov, Andrey; Schmitt, Michael Henry; Stoynev, Stoyan; Velasco, Mayda; Won, Steven; Antonelli, Louis; Berry, Douglas; Brinkerhoff, Andrew; Hildreth, Michael; Jessop, Colin; Karmgard, Daniel John; Kolb, Jeff; Lannon, Kevin; Luo, Wuming; Lynch, Sean; 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Hu, Zhen; Jones, Matthew; Koybasi, Ozhan; Kress, Matthew; Laasanen, Alvin T; Leonardo, Nuno; Maroussov, Vassili; Merkel, Petra; Miller, David Harry; Neumeister, Norbert; Shipsey, Ian; Silvers, David; Svyatkovskiy, Alexey; Vidal Marono, Miguel; Yoo, Hwi Dong; Zablocki, Jakub; Zheng, Yu; Guragain, Samir; Parashar, Neeti; Adair, Antony; Boulahouache, Chaouki; Ecklund, Karl Matthew; Geurts, Frank JM; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Zabel, James; Betchart, Burton; Bodek, Arie; Chung, Yeon Sei; Covarelli, Roberto; de Barbaro, Pawel; Demina, Regina; Eshaq, Yossof; Ferbel, Thomas; Garcia-Bellido, Aran; Goldenzweig, Pablo; Han, Jiyeon; Harel, Amnon; Miner, Daniel Carl; Vishnevskiy, Dmitry; Zielinski, Marek; Bhatti, Anwar; Ciesielski, Robert; Demortier, Luc; Goulianos, Konstantin; Lungu, Gheorghe; Malik, Sarah; Mesropian, Christina; Arora, Sanjay; Barker, Anthony; Chou, John Paul; Contreras-Campana, Christian; Contreras-Campana, Emmanuel; Duggan, Daniel; Ferencek, Dinko; Gershtein, Yuri; Gray, Richard; Halkiadakis, Eva; Hidas, Dean; Lath, Amitabh; Panwalkar, Shruti; Park, Michael; Patel, Rishi; Rekovic, Vladimir; Robles, Jorge; Rose, Keith; Salur, Sevil; Schnetzer, Steve; Seitz, Claudia; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Cerizza, Giordano; Hollingsworth, Matthew; Spanier, Stefan; Yang, Zong-Chang; York, Andrew; Eusebi, Ricardo; Flanagan, Will; Gilmore, Jason; Kamon, Teruki; Khotilovich, Vadim; Montalvo, Roy; Osipenkov, Ilya; Pakhotin, Yuriy; Perloff, Alexx; Roe, Jeffrey; Safonov, Alexei; Sakuma, Tai; Sengupta, Sinjini; Suarez, Indara; Tatarinov, Aysen; Toback, David; Akchurin, Nural; Damgov, Jordan; Dragoiu, Cosmin; Dudero, Phillip Russell; Jeong, Chiyoung; Kovitanggoon, Kittikul; Lee, Sung Won; Libeiro, Terence; Roh, Youn; Volobouev, Igor; Appelt, Eric; Delannoy, Andrés G; Florez, Carlos; Greene, Senta; Gurrola, Alfredo; Johns, Willard; Johnston, Cody; Kurt, Pelin; Maguire, Charles; Melo, Andrew; Sharma, Monika; Sheldon, Paul; Snook, Benjamin; Tuo, Shengquan; 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2013-07-16

A measurement is presented of the inelastic proton-proton cross section at a centre-of-mass energy of $\\sqrt{s}$ = 7 TeV. Using the CMS detector at the LHC, the inelastic cross section is measured through two independent methods based on information from (i) forward calorimetry (for pseudorapidity 3 200 MeV. The measurements cover a large fraction of the inelastic cross section for particle production over about 9 units of pseudorapidity and down to small transverse momenta. The results are compared with those of other experiments, and with models used to describe high-energy hadronic interactions.

arXiv Supplying Dark Energy from Scalar Field Dark Matter

CERN Document Server

Gogberashvili, Merab

We consider the hypothesis that dark matter and dark energy consists of ultra-light self-interacting scalar particles. It is found that the Klein-Gordon equation with only two free parameters (mass and self-coupling) on a Schwarzschild background, at the galactic length-scales has the solution which corresponds to Bose-Einstein condensate, behaving as dark matter, while the constant solution at supra-galactic scales can explain dark energy.

High energy resolution inelastic x-ray scattering at the SRI-CAT

International Nuclear Information System (INIS)

Macrander, A.T.

1996-08-01

This report is a combination of vugraphs and two papers. The vugraphs give information on the beamline at the APS for IXS and the science addressable by IXS. They also cover the 10 milli-eV resolution spectrometer and the 200 milli-eV resolution spectrometer. The first paper covers the performance of the focusing Ge(444) backscattering analyzers for the inelastic x-ray scattering. The second paper discusses inelastic x-ray scattering from TiC and Ti single crystals

Medium energy inelastic proton-nucleus scattering with spin dependent NN interaction

International Nuclear Information System (INIS)

Ahmad, I.; Auger, J.P.

1981-12-01

The previously proposed effective profile expansion method for the Glauber multiple scattering model calculation has been extended to the case of proton-nucleus inelastic scattering with spin dependent NN interaction. Using the method which turns out to be computationally simple and of relatively wider applicability, a study of sensitivity of proton-nucleus inelastic scattering calculation to the sometimes neglected momentum transfer dependence of the NN scattering amplitude has been made. We find that the calculated polarization is particularly sensitive in this respect. (author)

Conversion of Gravitons into Dark Photons in Cosmological Dark Magnetic Fields

OpenAIRE

Masaki, Emi; Soda, Jiro

2018-01-01

It is well known that gravitons can convert into photons, and vice versa, in the presence of cosmological magnetic fields. We study this conversion process in the context of atomic dark matter scenario. In this scenario, we can expect cosmological dark magnetic fields, which are free from the stringent constraint from the cosmic microwave observations. We find that gravitons can effectively convert into dark photons in the presence of cosmological dark magnetic fields. The graviton-dark photo...

Direct evidence for inelastic neutron 'acceleration' by 177Lum

International Nuclear Information System (INIS)

Roig, O.; Meot, V.; Rosse, B.; Belier, G.; Daugas, J.-M.; Morel, P.; Letourneau, A.; Menelle, A.

2011-01-01

The inelastic neutron acceleration cross section on the long-lived metastable state of 177 Lu has been measured using a direct method. High-energy neutrons have been detected using a specially designed setup placed on a cold neutron beam extracted from the ORPHEE reactor in Saclay. The 146±19 b inelastic neutron acceleration cross section in the ORPHEE cold neutron flux confirms the high cross section for this process on the 177 Lu m isomer. The deviation from the 258±58 b previously published obtained for a Maxwellian neutron flux at a 323 K temperature could be explained by the presence of a low energy resonance. Resonance parameters are deduced and discussed.

Multiple production of hadrons in deep inelastic processes

International Nuclear Information System (INIS)

Kiselev, A.V.; Petrov, V.A.

1985-01-01

Formulas are proposed for the description of the mean multiplicity of hadrons in deep inelastic processes. On the basis of the existing data, predictions are made for the behavior of the mean multiplicity at higher energies

Coherence effects in deep inelastic scattering

International Nuclear Information System (INIS)

Andersson, B.; Gustafson, G.; Loennblad, L.; Pettersson, U.

1988-09-01

We present a framework for deep inelastic scattering, with bound state properties in accordance with a QCD force field acting like a vortex line in a colour superconducting vacuum, which implies some simple coherence effects. Within this scheme one may describe the results of present energies very well, but one obtains an appreciable depletion of gluon radiation in the HERA energy regime. (authors)

Solution of neutron slowing down equation including multiple inelastic scattering

International Nuclear Information System (INIS)

El-Wakil, S.A.; Saad, A.E.

1977-01-01

The present work is devoted the presentation of an analytical method for the calculation of elastically and inelastically slowed down neutrons in an infinite non absorbing homogeneous medium. On the basis of the Central limit theory (CLT) and the integral transform technique the slowing down equation including inelastic scattering in terms of the Green function of elastic scattering is solved. The Green function is decomposed according to the number of collisions. A formula for the flux at any lethargy O (u) after any number of collisions is derived. An equation for the asymptotic flux is also obtained

Inelastic neutron scattering of H2 adsorbed in HKUST-1

International Nuclear Information System (INIS)

Liu, Y.; Brown, C.M.; Neumann, D.A.; Peterson, V.K.; Kepert, C.J.

2007-01-01

A series of inelastic neutron scattering (INS) investigations of hydrogen adsorbed in activated HKUST-1 (Cu 3 (1,3,5-benzenetricarboxylate) 2 ) result in INS spectra with rich features, even at very low loading ( 2 :Cu). The distinct inelastic features in the spectra show that there are three binding sites that are progressively populated when the H 2 loading is less than 2.0 H 2 :Cu, which is consistent with the result obtained from previous neutron powder diffraction experiments. The temperature dependence of the INS spectra reveals the relative binding enthalpies for H 2 at each site

Strongly interacting light dark matter

International Nuclear Information System (INIS)

Bruggisser, Sebastian; Riva, Francesco; Urbano, Alfredo

2016-07-01

In the presence of approximate global symmetries that forbid relevant interactions, strongly coupled light Dark Matter (DM) can appear weakly coupled at small-energy and generate a sizable relic abundance. Fundamental principles like unitarity restrict these symmetries to a small class, where the leading interactions are captured by effective operators up to dimension-8. Chiral symmetry, spontaneously broken global symmetries and non-linearly realized supersymmetry are examples of this. Their DM candidates (composite fermions, pseudo-Nambu-Goldstone Bosons and Goldstini) are interesting targets for LHC missing-energy searches.

Late forming dark matter in theories of neutrino dark energy

International Nuclear Information System (INIS)

Das, Subinoy; Weiner, Neal

2011-01-01

We study the possibility of late forming dark matter, where a scalar field, previously trapped in a metastable state by thermal or finite density effects, goes through a phase transition near the era matter-radiation equality and begins to oscillate about its true minimum. Such a theory is motivated generally if the dark energy is of a similar form, but has not yet made the transition to dark matter, and, in particular, arises automatically in recently considered theories of neutrino dark energy. If such a field comprises the present dark matter, the matter power spectrum typically shows a sharp break at small, presently nonlinear scales, below which power is highly suppressed and previously contained acoustic oscillations. If, instead, such a field forms a subdominant component of the total dark matter, such acoustic oscillations may imprint themselves in the linear regime.

Role of atom--atom inelastic collisions in two-temperature nonequilibrium plasmas

International Nuclear Information System (INIS)

Kunc, J.A.

1987-01-01

The contribution of inelastic atom--atom collisions to the production of electrons and excited atoms in two-temperature (with electron temperature T/sub e/, atomic temperature T/sub a/, and atomic density N/sub a/), steady-state, nonequilibrium atomic hydrogen plasma is investigated. The results are valid for plasmas having large amounts of atomic hydrogen as one of the plasma components, so that e--H and H--H inelastic collisions and interaction of these atoms with radiation dominate the production of electrons and excited hydrogen atoms. Densities of electrons and excited atoms are calculated in low-temperature plasma, with T/sub e/ and T/sub a/≤8000 K and 10 16 cm -3 ≤N/sub a/≤10 18 cm -3 , and with different degrees of the reabsorption of radiation. The results indicate that inelastic atom--atom collisions are important for production of electrons and excited atoms in partially ionized plasmas with medium and high atomic density and temperatures below 8000 K

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...

Linear scale bounds on dark matter--dark radiation interactions and connection with the small scale crisis of cold dark matter

DEFF Research Database (Denmark)

Hannestad, Steen; Archidiacono, Maria; Bohr, Sebastian

2017-01-01

One of the open questions in modern cosmology is the small scale crisis of the cold dark matter paradigm. Increasing attention has recently been devoted to self-interacting dark matter models as a possible answer. However, solving the so-called "missing satellites" problem requires in addition...... the presence of an extra relativistic particle (dubbed dark radiation) scattering with dark matter in the early universe. Here we investigate the impact of different theoretical models devising dark matter dark radiation interactions on large scale cosmological observables. We use cosmic microwave background...... data to put constraints on the dark radiation component and its coupling to dark matter. We find that the values of the coupling allowed by the data imply a cut-off scale of the halo mass function consistent with the one required to match the observations of satellites in the Milky Way....

Inelastic surface vibrations versus energy-dependent nucleus ...

Indian Academy of Sciences (India)

Limitations of the static Woods–Saxon potential and the applicability of the energy dependent Woods–Saxon potential (EDWSP) model within the framework of one-dimensional Wong formula to explore the sub-barrier fusion data are highlighted. The inelastic surface excitations of the fusing nuclei are found to be ...

Dark Matter Caustics

International Nuclear Information System (INIS)

Natarajan, Aravind

2010-01-01

The continuous infall of dark matter with low velocity dispersion in galactic halos leads to the formation of high density structures called caustics. Dark matter caustics are of two kinds : outer and inner. Outer caustics are thin spherical shells surrounding galaxies while inner caustics have a more complicated structure that depends on the dark matter angular momentum distribution. The presence of a dark matter caustic in the plane of the galaxy modifies the gas density in its neighborhood which may lead to observable effects. Caustics are also relevant to direct and indirect dark matter searches.

Unifying dark energy and dark matter with the modified Ricci model

International Nuclear Information System (INIS)

Zhang, Linsen; Wu, Puxun; Yu, Hongwei

2011-01-01

In this paper, two modified Ricci models are considered as the candidates of unified dark matter-dark energy. In model one, the energy density is given by ρ MR =3M pl (αH 2 + βH), whereas, in model two, by ρ MR =3M pl ((α)/(6)R + γH H -1 ). We find that they can explain both dark matter and dark energy successfully. A constant equation of state of dark energy is obtained in model one, which means that it gives the same background evolution as the wCDM model, while model two can give an evolutionary equation of state of dark energy with the phantom divide line crossing in the near past. (orig.)

Why we need to see the dark matter to understand the dark energy

OpenAIRE

Kunz, Martin

2007-01-01

The cosmological concordance model contains two separate constituents which interact only gravitationally with themselves and everything else, the dark matter and the dark energy. In the standard dark energy models, the dark matter makes up some 20% of the total energy budget today, while the dark energy is responsible for about 75%. Here we show that these numbers are only robust for specific dark energy models and that in general we cannot measure the abundance of the dark constituents sepa...

Dark matter and neutrino mass from the smallest non-Abelian chiral dark sector

Science.gov (United States)

Berryman, Jeffrey M.; de Gouvêa, André; Kelly, Kevin J.; Zhang, Yue

2017-10-01

All pieces of concrete evidence for phenomena outside the standard model (SM)—neutrino masses and dark matter—are consistent with the existence of new degrees of freedom that interact very weakly, if at all, with those in the SM. We propose that these new degrees of freedom organize themselves into a simple dark sector, a chiral S U (3 )×S U (2 ) gauge theory with the smallest nontrivial fermion content. Similar to the SM, the dark S U (2 ) is spontaneously broken while the dark S U (3 ) confines at low energies. At the renormalizable level, the dark sector contains massless fermions—dark leptons—and stable massive particles—dark protons. We find that dark protons with masses between 10 and 100 TeV satisfy all current cosmological and astrophysical observations concerning dark matter even if dark protons are a symmetric thermal relic. The dark leptons play the role of right-handed neutrinos and allow simple realizations of the seesaw mechanism or the possibility that neutrinos are Dirac fermions. In the latter case, neutrino masses are also parametrically different from charged-fermion masses and the lightest neutrino is predicted to be massless. Since the new "neutrino" and "dark-matter" degrees of freedom interact with one another, these two new-physics phenomena are intertwined. Dark leptons play a nontrivial role in early Universe cosmology while indirect searches for dark matter involve, decisively, dark-matter annihilations into dark leptons. These, in turn, may lead to observable signatures at high-energy neutrino and gamma-ray observatories, especially once one accounts for the potential Sommerfeld enhancement of the annihilation cross section, derived from the low-energy dark-sector effective theory, a possibility we explore quantitatively in some detail.

Inelastic scattering of neutrons

International Nuclear Information System (INIS)

Sal'nikov, O.A.

1984-06-01

The paper reviews the main problems concerning the mechanism of the inelastic scatterings of neutrons by nuclei, concentrating on the different models which calculate the angular distributions. In the region of overlapping levels, both the compound nucleus mechanism and the preequilibrium Griffin (exciton) model are discussed, and their contribution relative to that of a direct mechanism is considered. The parametrization of the level density and of the nuclear moment of inertia are also discussed. The excitation functions of discrete levels are also presented, and the importance of elucidating their five structure (for practical calculations, such as for shielding) is pointed out

Inelastic J/ψphotoproduction

International Nuclear Information System (INIS)

Kraemer, M.

1995-04-01

Inelastic photoproduction of J/ψ particles at high energies is one of the processes to determine the gluon distribution in the nucleon. The QCD radiative corrections to the color-singlet model of this reaction have recently been calculated. They are large at moderate photon energies, but decrease with increasing energies. I compare the cross section and the J/ψ energy spectrum with the available fixed-target photoproduction data. Predictions for the HERA energy range are given which demonstrate the sensitivity of the result to the parametrization of the gluon distribution in the small-x region. (orig.)

Asymmetric dark matter

International Nuclear Information System (INIS)

Kaplan, David E.; Luty, Markus A.; Zurek, Kathryn M.

2009-01-01

We consider a simple class of models in which the relic density of dark matter is determined by the baryon asymmetry of the Universe. In these models a B-L asymmetry generated at high temperatures is transferred to the dark matter, which is charged under B-L. The interactions that transfer the asymmetry decouple at temperatures above the dark matter mass, freezing in a dark matter asymmetry of order the baryon asymmetry. This explains the observed relation between the baryon and dark matter densities for the dark matter mass in the range 5-15 GeV. The symmetric component of the dark matter can annihilate efficiently to light pseudoscalar Higgs particles a or via t-channel exchange of new scalar doublets. The first possibility allows for h 0 →aa decays, while the second predicts a light charged Higgs-like scalar decaying to τν. Direct detection can arise from Higgs exchange in the first model or a nonzero magnetic moment in the second. In supersymmetric models, the would-be lightest supersymmetric partner can decay into pairs of dark matter particles plus standard model particles, possibly with displaced vertices.

Why we need to see the dark matter to understand the dark energy

International Nuclear Information System (INIS)

Kunz, M

2008-01-01

Abstract. The cosmological concordance model contains two separate constituents which interact only gravitationally with themselves and everything else, the dark matter and the dark energy. In the standard dark energy models, the dark matter makes up some 20% of the total energy budget today, while the dark energy is responsible for about 75%. Here we show that these numbers are only robust for specific dark energy models and that in general we cannot measure the abundance of the dark constituents separately without making strong assumptions

Inelastic surface vibrations versus energy-dependent nucleus ...

Indian Academy of Sciences (India)

Abstract. Limitations of the static Woods–Saxon potential and the applicability of the energy- dependent Woods–Saxon potential (EDWSP) model within the framework of one-dimensional. Wong formula to explore the sub-barrier fusion data are highlighted. The inelastic surface exci- tations of the fusing nuclei are found to ...

Inelastic collision of two solitons for generalized BBM equation with cubic nonlinearity

Directory of Open Access Journals (Sweden)

Jingdong Wei

2015-06-01

Full Text Available We study the inelastic collision of two solitary waves of different velocities for the generalized Benjamin-Bona-Mahony (BBM equation with cubic nonlinearity. It shows that one solitary wave is smaller than the other one in the H^1(R energy space. We explore the sharp estimates of the nonzero residue due to the collision, and prove the inelastic collision of two solitary waves and nonexistence of a pure 2-soliton solution.

Rapporteur talks at Singapore (deep inelastic scattering) and at Hadron 90 (conference summary)

International Nuclear Information System (INIS)

Close, F.E.

1990-11-01

This talk begins by reviewing the early years of deep inelastic scattering with particular reference to some theoretical work. Current highlights include an agreed uniform set of structure functions, polarised structure functions, possible violations of the Gottfried sum rule, deep inelastic scattering off nuclei and anticipated breakdown of naive perturbative quantum chromodynamics QCD as x → 0 at HERA. (author)

Theory of inelastic electron tunneling from a localized spin in the impulsive approximation.

Science.gov (United States)

Persson, Mats

2009-07-31

A simple expression for the conductance steps in inelastic electron tunneling from spin excitations in a single magnetic atom adsorbed on a nonmagnetic metal surface is derived. The inelastic coupling between the tunneling electron and the spin is via the exchange coupling and is treated in an impulsive approximation using the Tersoff-Hamann approximation for the tunneling between the tip and the sample.

Interacting Agegraphic Dark Energy

OpenAIRE

Wei, Hao; Cai, Rong-Gen

2007-01-01

A new dark energy model, named "agegraphic dark energy", has been proposed recently, based on the so-called K\\'{a}rolyh\\'{a}zy uncertainty relation, which arises from quantum mechanics together with general relativity. In this note, we extend the original agegraphic dark energy model by including the interaction between agegraphic dark energy and pressureless (dark) matter. In the interacting agegraphic dark energy model, there are many interesting features different from the original agegrap...

Inelastic collisions of medium energy atomic elements. Qualitative model of energy losses during collisions

International Nuclear Information System (INIS)

Pustovit, A.N.

2006-01-01

A new approach to the theoretical description of energy losses of atomic particle of medium energy during their interaction with the substance is proposed. The corner-stone of this approach is the supposition that all of the collision processes have inelastic nature during particle movement through the substance, while the calculation of the atomic particles braking is based on the law of their dispersion and the laws of energy and momentum conservation at the inelastic collisions. It is shown that inelastic atomic collision there are three dispersion zones for the only potential interaction with different laws, which characterize energy losses. The application conditions of this approach are determined [ru

Deep-inelastic scattering in 124,136Xe+58,64Ni at energies near the Coulomb barrier

International Nuclear Information System (INIS)

Gehring, J.; Back, B.B.; Chan, K.C.; Freer, M.; Henderson, D.; Jiang, C.L.; Rehm, K.E.; Schiffer, J.P.; Wolanski, M.; Wuosmaa, A.H.; Gehring, J.; Wolanski, M.

1997-01-01

Cross sections, angular distributions, and mass distributions have been measured for deep-inelastic scattering in 124 Xe+ 58 Ni and 136 Xe+ 64 Ni at laboratory energies in the vicinity of the Coulomb barrier. The mass distributions show distinct components due to deep-inelastic and fissionlike processes. The strength of deep-inelastic scattering is similar in the two systems measured and comparable to previous measurements in 58 Ni+ 112,124 Sn. copyright 1997 The American Physical Society

Detecting dark matter

International Nuclear Information System (INIS)

Dixon, Roger L.

2000-01-01

Dark matter is one of the most pressing problems in modern cosmology and particle physic research. This talk will motivate the existence of dark matter by reviewing the main experimental evidence for its existence, the rotation curves of galaxies and the motions of galaxies about one another. It will then go on to review the corroborating theoretical motivations before combining all the supporting evidence to explore some of the possibilities for dark matter along with its expected properties. This will lay the ground work for dark matter detection. A number of differing techniques are being developed and used to detect dark matter. These will be briefly discussed before the focus turns to cryogenic detection techniques. Finally, some preliminary results and expectations will be given for the Cryogenic Dark Matter Search (CDMS) experiment

Coupled dark matter-dark energy in light of near Universe observations

CERN Document Server

Honorez, Laura Lopez; Mena, Olga; Verde, Licia; Jimenez, Raul

2010-01-01

Cosmological analysis based on currently available observations are unable to rule out a sizeable coupling among the dark energy and dark matter fluids. We explore a variety of coupled dark matter-dark energy models, which satisfy cosmic microwave background constraints, in light of low redshift and near universe observations. We illustrate the phenomenology of different classes of dark coupling models, paying particular attention in distinguishing between effects that appear only on the expansion history and those that appear in the growth of structure. We find that while a broad class of dark coupling models are effectively models where general relativity (GR) is modified --and thus can be probed by a combination of tests for the expansion history and the growth of structure--, there is a class of dark coupling models where gravity is still GR, but the growth of perturbations is, in principle modified. While this effect is small in the specific models we have considered, one should bear in mind that an inco...

Dark matter and dark energy a challenge for modern cosmology

CERN Document Server

Gorini, Vittorio; Moschella, Ugo; Matarrese, Sabino

2011-01-01

This book brings together reviews from leading international authorities on the developments in the study of dark matter and dark energy, as seen from both their cosmological and particle physics side. Studying the physical and astrophysical properties of the dark components of our Universe is a crucial step towards the ultimate goal of unveiling their nature. The work developed from a doctoral school sponsored by the Italian Society of General Relativity and Gravitation. The book starts with a concise introduction to the standard cosmological model, as well as with a presentation of the theory of linear perturbations around a homogeneous and isotropic background. It covers the particle physics and cosmological aspects of dark matter and (dynamical) dark energy, including a discussion of how modified theories of gravity could provide a possible candidate for dark energy. A detailed presentation is also given of the possible ways of testing the theory in terms of cosmic microwave background, galaxy redshift su...

Leptogenesis, Dark Energy, Dark Matter and the neutrinos

International Nuclear Information System (INIS)

Sarkar, Utpal

2007-01-01

In this review we discuss how the models of neutrino masses can accommodate solutions to the problem of matter-antimatter asymmetry in the universe, dark energy or cosmological constant problem and dark matter candidates. The matter-antimatter asymmetry is explained by leptogenesis, originating from the lepton number violation associated with the neutrino masses. The dark energy problem is correlated with a mass varying neutrinos, which could originate from a pseudo-Nambu-Goldstone boson. In some radiative models of neutrino masses, there exists a Higgs doublet that does not acquire any vacuum expectation value. This field could be inert and the lightest inert particle could then be a dark matter candidate. We reviewed these scenarios in connection with models of neutrino masses with right-handed neutrinos and with triplet Higgs scalars

Near quantum limited amplification from inelastic Cooper-pair tunneling

Science.gov (United States)

Hofheinz, Max; Jebari, Salha; Blanchet, Florian; Grimm, Alexander; Hazra, Dibyendu; Albert, Romain; Portier, Fabien

Josephson parametric amplifiers approach quantum-limited noise performance but require strong external microwave pump tones which make them more difficult to use than DC powered amplifiers: The pump tone can affect the device under test and requires expensive room-temperature equipment. Inelastic Cooper pair tunneling processes through a small DC voltage-biased Josephson junction, where a tunneling Cooper pair dissipates its energy 2 eV in the form of two photons are reminiscent of parametric down conversion. We show that these processes can be used to provide amplification near the quantum limit without external microwave pump tone. We explain the measured gain and noise based on the P (E) theory of inelastic Cooper pair tunneling and general fluctuation-dissipation relations.

Studies in deep inelastic scattering and vector meson photoproduction

International Nuclear Information System (INIS)

Busenitz, J.K.

1985-01-01

The first part of this thesis is devoted to a space-time analysis of deep inelastic scattering from protons at rest. Techniques are developed for identifying important space-time regions. These are then applied to obtain a space-time picture of deep inelastic scattering in the leading logarithmic approximation of QCD, Physical mechanisms responsible for the space-time picture are discussed. In the second part of this thesis he reports on the observations of elastic omega photoproduction from hydrogen by Fermilab Experiment-401. The omega was detected via its decay into the π + π - π 0 channel. Measurements of the energy, momentum transfer, and angular dependence of the cross section have been made for photon energies between 60 and 225 GeV

Constraints on the coupling between dark energy and dark matter from CMB data

International Nuclear Information System (INIS)

Murgia, R.; Gariazzo, S.; Fornengo, N.

2016-01-01

We investigate a phenomenological non-gravitational coupling between dark energy and dark matter, where the interaction in the dark sector is parameterized as an energy transfer either from dark matter to dark energy or the opposite. The models are constrained by a whole host of updated cosmological data: cosmic microwave background temperature anisotropies and polarization, high-redshift supernovae, baryon acoustic oscillations, redshift space distortions and gravitational lensing. Both models are found to be compatible with all cosmological observables, but in the case where dark matter decays into dark energy, the tension with the independent determinations of H 0 and σ 8 , already present for standard cosmology, increases: this model in fact predicts lower H 0 and higher σ 8 , mostly as a consequence of the higher amount of dark matter at early times, leading to a stronger clustering during the evolution. Instead, when dark matter is fed by dark energy, the reconstructed values of H 0 and σ 8 nicely agree with their local determinations, with a full reconciliation between high- and low-redshift observations. A non-zero coupling between dark energy and dark matter, with an energy flow from the former to the latter, appears therefore to be in better agreement with cosmological data

Endochronic theory for inelasticity and failure analysis of concrete structures

Energy Technology Data Exchange (ETDEWEB)

Bazant, Z.P.; Bhat, P.D.; Shieh, C.L.

1976-12-01

A gradual accumulation of inelastic strain can be most conveniently described in terms of the so-called intrinsic time, whose increment depends on the time increment as well as the strain increments. This approach, which gives a particularly simple description of irreversibility of strain at unloading and cyclic loading, was previously developed for metals and is extended herein to concrete by introducing the hydrostatic pressure sensitivity of inelastic strain, the inelastic dilatancy produced by deviator strains, and the strain-softening tendency at high stress. Failure envelopes are obtained as a collection of the peaks of stress-strain diagrams. By comparison with experimental data from the literature, it is demonstrated that the proposed model predicts quite closely: stress-strain diagrams for concretes of different strength; uniaxial, biaxial and triaxial stress-strain diagrams and failure envelopes; failure envelopes for combined torsion and compression, lateral strains and volume expansion in uniaxial and biaxial tests; the behavior of spirally confined concrete; hysteresis loops or repeated high compression; cyclic creep up to 10/sup 6/ cycles; the strain rate effect; the decrease of long time strength; and the increase of short-time strength due to low stress creep.

Endochronic theory for inelasticity and failure analysis of concrete structures

International Nuclear Information System (INIS)

Bazant, Z.P.; Bhat, P.D.; Shieh, C.L.

1976-12-01

A gradual accumulation of inelastic strain can be most conveniently described in terms of the so-called intrinsic time, whose increment depends on the time increment as well as the strain increments. This approach, which gives a particularly simple description of irreversibility of strain at unloading and cyclic loading, was previously developed for metals and is extended herein to concrete by introducing the hydrostatic pressure sensitivity of inelastic strain, the inelastic dilatancy produced by deviator strains, and the strain-softening tendency at high stress. Failure envelopes are obtained as a collection of the peaks of stress-strain diagrams. By comparison with experimental data from the literature, it is demonstrated that the proposed model predicts quite closely: stress-strain diagrams for concretes of different strength; uniaxial, biaxial and triaxial stress-strain diagrams and failure envelopes; failure envelopes for combined torsion and compression, lateral strains and volume expansion in uniaxial and biaxial tests; the behavior of spirally confined concrete; hysteresis loops or repeated high compression; cyclic creep up to 10 6 cycles; the strain rate effect; the decrease of long time strength; and the increase of short-time strength due to low stress creep

Spin flip in inelastic scattering of protons on 28Si nuclei

International Nuclear Information System (INIS)

Wang Syn Chan; Komsan, M.N.Kh.; Osetinskij, G.M.; Golubev, S.L.; Kurepin, A.B.; Likhosherstov, V.N.

1975-01-01

We measured the energy and angular dependences of the spin-flip probability and of the differential cross section for inelastic scattering of protons in the resonance region of the reaction 28 Si(p,p') 23 Si* (2 + , 1.78 MeV) at E sub(p) = 3.095 and 3.34 MeV. The energy dependence of the spin-flip probability was found to have a resonance character. The angular distribution of the inelastic scattering and of the spin-flip probability is asymmetrical with respect to 90 deg in the c.m.s

Spin inelastic electron tunneling spectroscopy on local spin adsorbed on surface.

Science.gov (United States)

Fransson, J

2009-06-01

The recent experimental conductance measurements taken on magnetic impurities on metallic surfaces, using scanning tunneling microscopy technique and suggesting occurrence of inelastic scattering processes, are theoretically addressed. We argue that the observed conductance signatures are caused by transitions between the spin states that have opened due to, for example, exchange coupling between the local spins and the tunneling electrons, and are directly interpretable in terms of inelastic transitions energies. Feasible measurements using spin-polarized scanning tunneling microscopy that would enable new information about the excitation spectrum of the local spins are discussed.

Inelastic neutron scattering cross-section measurements on 7Li and 63,65Cu

Science.gov (United States)

Nyman, Markus; Belloni, Francesca; Ichinkhorloo, Dagvadorj; Pirovano, Elisa; Plompen, Arjan; Rouki, Chariklia

2017-09-01

The γ-ray production cross section for the 477.6-keV transition in 7Li following inelastic neutron scattering has been measured from the reaction threshold up to 18 MeV. This cross section is interesting as a possible standard for other inelastic scattering measurements. The experiment was conducted at the Geel Electron LINear Accelerator (GELINA) pulsed white neutron source with the Gamma Array for Inelastic Neutron Scattering (GAINS) spectrometer. Previous measurements of this cross section are reviewed and compared with our results. Recently, this cross section has also been calculated using the continuum discretized coupled-channels (CDCC) method. Experiments for studying neutrinoless double-β decay (2β0ν) or other very rare processes require greatly reducing the background radiation level (both intrinsic and external). Copper is a common shielding and structural material, used extensively in experiments such as COBRA, CUORE, EXO, GERDA, and MAJORANA. Understanding the background contribution arising from neutron interactions in Cu is important when searching for very weak experimental signals. Neutron inelastic scattering on natCu was investigated with GAINS. The results are compared with previous experimental data and evaluated nuclear data libraries.

Inelastic neutron scattering cross-section measurements on 7Li and 63,65Cu

Directory of Open Access Journals (Sweden)

Nyman Markus

2017-01-01

Full Text Available The γ-ray production cross section for the 477.6-keV transition in 7Li following inelastic neutron scattering has been measured from the reaction threshold up to 18 MeV. This cross section is interesting as a possible standard for other inelastic scattering measurements. The experiment was conducted at the Geel Electron LINear Accelerator (GELINA pulsed white neutron source with the Gamma Array for Inelastic Neutron Scattering (GAINS spectrometer. Previous measurements of this cross section are reviewed and compared with our results. Recently, this cross section has also been calculated using the continuum discretized coupled-channels (CDCC method. Experiments for studying neutrinoless double-β decay (2β0ν or other very rare processes require greatly reducing the background radiation level (both intrinsic and external. Copper is a common shielding and structural material, used extensively in experiments such as COBRA, CUORE, EXO, GERDA, and MAJORANA. Understanding the background contribution arising from neutron interactions in Cu is important when searching for very weak experimental signals. Neutron inelastic scattering on natCu was investigated with GAINS. The results are compared with previous experimental data and evaluated nuclear data libraries.

Shakedown analysis of composites

CERN Document Server

Weichert, D; Schwabe, F

1999-01-01

One of the advantages of composite materials compared to conventional materials stems from the different mechanical characteristics of each component of a composite. This may be used to design materials for specific technological $9 purposes, where in some sense controversial material properties are required. As example one may quote metal- matrix-composites (MMCs) exhibiting at the same time high hardness and fracture toughness. To predict failure of this type $9 of materials, it is important to understand the complex processes on the microstructural level leading to failure, including in particular inelastic effects, and to link them to the macroscopic material properties. In this paper, $9 failure of metal-matrix-composites under variables loads due to accumulated plastic deformations is investigated. For this, shakedown-analysis is carried out on the micro-level. Then, by use of the technique of homogenisation, the $9 results are linked to the overall material properties on the macro- level. The methodolo...

Mechanical Energy Changes in Perfectly Inelastic Collisions

Science.gov (United States)

Mungan, Carl E.

2013-01-01

Suppose a block of mass "m"[subscript 1] traveling at speed "v"[subscript 1] makes a one-dimensional perfectly inelastic collision with another block of mass "m"[subscript 2]. What else does one need to know to calculate the fraction of the mechanical energy that is dissipated in the collision? (Contains 1 figure.)

Quark seesaw mechanism, dark U (1 ) symmetry, and the baryon-dark matter coincidence

Science.gov (United States)

Gu, Pei-Hong; Mohapatra, Rabindra N.

2017-09-01

We attempt to understand the baryon-dark matter coincidence problem within the quark seesaw extension of the standard model where parity invariance is used to solve the strong C P problem. The S U (2 )L×S U (2 )R×U (1 )B -L gauge symmetry of this model is extended by a dark U (1 )X group plus inclusion of a heavy neutral vector-like fermion χL ,R charged under the dark group which plays the role of dark matter. All fermions are Dirac type in this model. Decay of heavy scalars charged under U (1 )X leads to simultaneous asymmetry generation of the dark matter and baryons after sphaleron effects are included. The U (1 )X group not only helps to stabilize the dark matter but also helps in the elimination of the symmetric part of the dark matter via χ -χ ¯ annihilation. For dark matter mass near the proton mass, it explains why the baryon and dark matter abundances are of similar magnitude (the baryon-dark matter coincidence problem). This model is testable in low threshold (sub-keV) direct dark matter search experiments.

Self-interacting dark matter constraints in a thick dark disk scenario

Science.gov (United States)

Vattis, Kyriakos; Koushiappas, Savvas M.

2018-05-01

A thick dark matter disk is predicted in cold dark matter simulations as the outcome of the interaction between accreted satellites and the stellar disk in Milky Way-sized halos. We study the effects of a self-interacting thick dark disk on the energetic neutrino flux from the Sun. We find that for particle masses between 100 GeV and 1 TeV and dark matter annihilation to τ+τ-, either the self-interaction may not be strong enough to solve the small-scale structure motivation or a dark disk cannot be present in the Milky Way.

A study of inelastic electron-phonon interactions on tunneling magnetoresistance of a nano-scale device

International Nuclear Information System (INIS)

Modarresi, M.; Roknabadi, M.R.; Shahtahmasbi, N.; Vahedi Fakhrabad, D.; Arabshahi, H.

2011-01-01

In this research, we have studied the effect of inelastic electron-phonon interactions on current-voltage characteristic and tunneling magnetoresistance of a polythiophene molecule that is sandwiched between two cobalt electrodes using modified Green's function method as proposed by Walczak. The molecule is described with a modified Su-Schrieffer-Heeger Hamiltonian. The ground state of the molecule is obtained by Hellman-Feynman theorem. Electrodes are described in the wide-band approximation and spin-flip is neglected during conduction. Our calculation results show that with increase in voltage the currents increase and tunneling magnetoresistance decreases. Change in tunneling magnetoresistance due to inelastic interactions is limited in a small bias voltage interval and can be neglected in the other bias voltages. -- Research Highlights: →We investigate the effect of inelastic interaction on transport properties. →Due to inelastic interactions tunneling magnetoresistance decreases. →Decrease in TMR is restricted in a small voltage interval.

Dark Matter Searches

International Nuclear Information System (INIS)

Moriyama, Shigetaka

2008-01-01

Recent cosmological as well as historical observations of rotational curves of galaxies strongly suggest the existence of dark matter. It is also widely believed that dark matter consists of unknown elementary particles. However, astrophysical observations based on gravitational effects alone do not provide sufficient information on the properties of dark matter. In this study, the status of dark matter searches is investigated by observing high-energy neutrinos from the sun and the earth and by observing nuclear recoils in laboratory targets. The successful detection of dark matter by these methods facilitates systematic studies of its properties. Finally, the XMASS experiment, which is due to start at the Kamioka Observatory, is introduced

Effect of gravity loading on inelastic seismic response of reinforced concrete structures

International Nuclear Information System (INIS)

Chowdhury, Rajib; Reddy, G. Rami; Roy, Raghupati; Dutta, Sekhar Chandra

2003-01-01

The effect of gravity loading is not considered in inelastic seismic response to avoid complexity and to reduce the number of influencing parameters. However, the possibility of considerable effect of this factor is indicated in many studies on inelastic seismic behaviour of structures. Hence, it is necessary to study the nature and extent of this effect on inelastic seismic behaviour of structures. The present paper attempts to fulfill this objective by studying the variation of energy dissipation due to presence of various level of axial load. The study is further extended to see the effect of axial force due to gravity loading on the ductility demand of hysteretic energy demand arising in structural elements of a simple one storey structures. The study shows that the presence of axial force may increase the energy dissipation capacity of structure leading to a reduction in ductility demand. (author)

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

Light dark Higgs boson in minimal sub-GeV dark matter scenarios

Science.gov (United States)

Darmé, Luc; Rao, Soumya; Roszkowski, Leszek

2018-03-01

Minimal scenarios with light (sub-GeV) dark matter whose relic density is obtained from thermal freeze-out must include new light mediators. In particular, a very well-motivated case is that of a new "dark" massive vector gauge boson mediator. The mass term for such mediator is most naturally obtained by a "dark Higgs mechanism" which leads to the presence of an often long-lived dark Higgs boson whose mass scale is the same as that of the mediator. We study the phenomenology and experimental constraints on two minimal, self-consistent dark sectors that include such a light dark Higgs boson. In one the dark matter is a pseudo-Dirac fermion, in the other a complex scalar. We find that the constraints from BBN and CMB are considerably relaxed in the framework of such minimal dark sectors. We present detection prospects for the dark Higgs boson in existing and projected proton beam-dump experiments. We show that future searches at experiments like Xenon1T or LDMX can probe all the relevant parameter space, complementing the various upcoming indirect constraints from astrophysical observations.

Dark catalysis

Energy Technology Data Exchange (ETDEWEB)

Agrawal, Prateek; Cyr-Racine, Francis-Yan; Randall, Lisa; Scholtz, Jakub, E-mail: prateekagrawal@fas.harvard.edu, E-mail: fcyrraci@physics.harvard.edu, E-mail: randall@physics.harvard.edu, E-mail: jscholtz@physics.harvard.edu [Department of Physics, Harvard University, 17 Oxford St., Cambridge, MA 02138 (United States)

2017-08-01

Recently it was shown that dark matter with mass of order the weak scale can be charged under a new long-range force, decoupled from the Standard Model, with only weak constraints from early Universe cosmology. Here we consider the implications of an additional charged particle C that is light enough to lead to significant dissipative dynamics on galactic times scales. We highlight several novel features of this model, which can be relevant even when the C particle constitutes only a small fraction of the number density (and energy density). We assume a small asymmetric abundance of the C particle whose charge is compensated by a heavy X particle so that the relic abundance of dark matter consists mostly of symmetric X and X-bar , with a small asymmetric component made up of X and C . As the universe cools, it undergoes asymmetric recombination binding the free C s into ( XC ) dark atoms efficiently. Even with a tiny asymmetric component, the presence of C particles catalyzes tight coupling between the heavy dark matter X and the dark photon plasma that can lead to a significant suppression of the matter power spectrum on small scales and lead to some of the strongest bounds on such dark matter theories. We find a viable parameter space where structure formation constraints are satisfied and significant dissipative dynamics can occur in galactic haloes but show a large region is excluded. Our model shows that subdominant components in the dark sector can dramatically affect structure formation.

Signature of the interaction between dark energy and dark matter in observations

International Nuclear Information System (INIS)

Abdalla, Elcio; Abramo, L. Raul; Souza, Jose C. C. de

2010-01-01

We investigate the effect of an interaction between dark energy and dark matter upon the dynamics of galaxy clusters. This effect is computed through the Layser-Irvine equation, which describes how an astrophysical system reaches virial equilibrium and was modified to include the dark interactions. Using observational data from almost 100 purportedly relaxed galaxy clusters we put constraints on the strength of the couplings in the dark sector. We compare our results with those from other observations and find that a positive (in the sense of energy flow from dark energy to dark matter) nonvanishing interaction is consistent with the data within several standard deviations.

Dancing in the dark: darkness as a signal in plants.

Science.gov (United States)

Seluzicki, Adam; Burko, Yogev; Chory, Joanne

2017-11-01

Daily cycles of light and dark provide an organizing principle and temporal constraints under which life on Earth evolved. While light is often the focus of plant studies, it is only half the story. Plants continuously adjust to their surroundings, taking both dawn and dusk as cues to organize their growth, development and metabolism to appropriate times of day. In this review, we examine the effects of darkness on plant physiology and growth. We describe the similarities and differences between seedlings grown in the dark versus those grown in light-dark cycles, and the evolution of etiolated growth. We discuss the integration of the circadian clock into other processes, looking carefully at the points of contact between clock genes and growth-promoting gene-regulatory networks in temporal gating of growth. We also examine daily starch accumulation and degradation, and the possible contribution of dark-specific metabolic controls in regulating energy and growth. Examining these studies together reveals a complex and continuous balancing act, with many signals, dark included, contributing information and guiding the plant through its life cycle. The extraordinary interconnection between light and dark is manifest during cycles of day and night and during seedling emergence above versus below the soil surface. © 2017 John Wiley & Sons Ltd.

A new theoretical model for inelastic tunneling in realistic systems : comparing STM simulations with experiments

NARCIS (Netherlands)

Rossen, E.T.R.

2012-01-01

This thesis has been dedicated to modeling the electron transport in tunnel junctions in order to efficiently describe and predict inelastic effects that occur when electrons pass a tunnel junction. These inelastic effects can be considered at several levels of sophistication, from very simple to

Cosmological anisotropy from non-comoving dark matter and dark energy

International Nuclear Information System (INIS)

Harko, Tiberiu; Lobo, Francisco S. N.

2013-01-01

We consider a cosmological model in which the two major fluid components of the Universe, dark energy and dark matter, flow with distinct four-velocities. This cosmological configuration is equivalent to a single anisotropic fluid, expanding with a four-velocity that is an appropriate combination of the two fluid four-velocities. The energy density of the single cosmological fluid is larger than the sum of the energy densities of the two perfect fluids, i.e., dark energy and dark matter, respectively, and contains a correction term due to the anisotropy generated by the differences in the four-velocities. Furthermore, the gravitational field equations of the two-fluid anisotropic cosmological model are obtained for a Bianchi type I geometry. By assuming that the non-comoving motion of the dark energy and dark matter induces small perturbations in the homogeneous and isotropic Friedmann-Lemaitre-Robertson-Walker type cosmological background, and that the anisotropy parameter is small, the equations of the cosmological perturbations due to the non-comoving nature of the two major components are obtained. The time evolution of the metric perturbations is explicitly obtained for the cases of the exponential and power law background cosmological expansion. The imprints of a non-comoving dark energy - dark matter on the Cosmic Microwave Background and on the luminosity distance are briefly discussed, and the temperature anisotropies and the quadrupole are explicitly obtained in terms of the metric perturbations of the flat background metric. Therefore, if there is a slight difference between the four-velocities of the dark energy and dark matter, the Universe would acquire some anisotropic characteristics, and its geometry will deviate from the standard FLRW one. In fact, the recent Planck results show that the presence of an intrinsic large scale anisotropy in the Universe cannot be excluded a priori, so that the model presented in this work can be considered as a

CHEMICAL APPLICATIONS OF INELASTIC X-RAY SCATTERING

Energy Technology Data Exchange (ETDEWEB)

HAYASHI,H.; UDAGAWA,Y.; GILLET,J.M.; CALIEBE,W.A.; KAO,C.C.

2001-08-01

Inelastic x-ray scattering (IXS), complementary to other more established inelastic scattering probes, such as light scattering, electron scattering, and neutron scattering, is becoming an important experimental technique in the study of elementary excitations in condensed matters. Over the past decade, IXS with total energy resolution of few meV has been achieved, and is being used routinely in the study of phonon dispersions in solids and liquids as well as dynamics in disordered and biological systems. In the study of electronic excitations, IXS with total energy resolution on the order of 100 meV to 1 eV is gaining wider applications also. For example, IXS has been used to study collective excitations of valence electrons, single electron excitations of valence electrons, as well as core electron excitations. In comparison with the alternative scattering techniques mentioned above, IXS has several advantages. First, IXS probes the full momentum transfer range of the dielectric response of the sample, whereas light scattering is limited to very small momentum transfers, and electron scattering suffers the effects of multiple scattering at large momentum transfers. Second, since IXS measures the bulk properties of the sample it is not surface sensitive, therefore it does not require special preparation of the sample. The greater flexibility in sample conditions and environments makes IXS an ideal probe in the study of liquids and samples under extreme temperature, pressure, and magnetic field. Third, the tunability of synchrotron radiation sources enables IXS to exploit element specificity and resonant enhancement of scattering cross sections. Fourth, IXS is unique in the study of dynamics of liquids and amorphous solids because it can probe the particular region of energy-momentum transfer phase space, which is inaccessible to inelastic neutron scattering. On the other hand, the main disadvantages of IXS are the small cross sections and the strong absorption of

Approximate analyses of inelastic effects in pipework

International Nuclear Information System (INIS)

Jobson, D.A.

1983-01-01

This presentation shows figures concerned with analyses of inelastic effects in pipework as follows: comparison of experimental and calculated simplified analyses results for free end rotation and for circumferential strain; interrupted stress relaxation; regenerated relaxation caused by reversed yield; buckling of straight pipe under combined bending and torsion; results of fatigues test of pipe bend

An orthogonality condition model treatment of elastic and inelastic (α, 12C) scattering

International Nuclear Information System (INIS)

Suzuki, Y.; Imanishi, B.

1981-02-01

Elastic and inelastic scattering of α-particles on the deformed nucleus 12 C are investigated in the range of incident α-particle energies of 9 to 11 MeV by using the coupled-channel method with orthogonality condition. A doubly folded potential generated by the shell model wave functions of the α-particle and the deformed nucleus 12 C is employed for the relative motion between the α-particle and 12 C. Good agreement between theory and experiment is obtained for the elastic and inelastic angular distributions and the resonance structures. It is found, from the Born series expansion of the T-matrix, that the orthogonality constraint stresses the effects of the channel-coupling between the elastic and inelastic processes, and it indicates that the DWBA does not work well in this system. (author)

Extra Dimensions are Dark: II Fermionic Dark Matter

OpenAIRE

Rizzo, Thomas G.

2018-01-01

Extra dimensions can be very useful tools when constructing new physics models. Previously, we began investigating toy models for the 5-D analog of the kinetic mixing/vector portal scenario where the interactions of bulk dark matter with the brane-localized fields of the Standard Model are mediated by a massive $U(1)_D$ dark photon also living in the bulk. In that setup, where the dark matter was taken to be a complex scalar, a number of nice features were obtained such as $U(1)_D$ breaking b...

Observational constraints on dark matter-dark energy scattering cross section

Energy Technology Data Exchange (ETDEWEB)

Kumar, Suresh [BITS Pilani, Department of Mathematics, Rajasthan (India); Nunes, Rafael C. [Universidade Federal de Juiz de Fora, Departamento de Fisica, Juiz de Fora, MG (Brazil)

2017-11-15

In this letter, we report precise and robust observational constraints on the dark matter-dark energy scattering cross section, using the latest data from cosmic microwave background (CMB) Planck temperature and polarization, baryon acoustic oscillations (BAO) measurements and weak gravitational lensing data from Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS). The scattering scenario consists of a pure momentum exchange between the dark components, and we find σ{sub d} < 10{sup -29} cm{sup 2} (m{sub dm}c{sup 2}/GeV) at 95% CL from the joint analysis (CMB + BAO + CFHTLenS), where m{sub dm} is a typical dark matter particle mass. We notice that the scattering among the dark components may influence the growth of large scale structure in the Universe, leaving the background cosmology unaltered. (orig.)

Inelastic Light Scattering Processes

Science.gov (United States)

Fouche, Daniel G.; Chang, Richard K.

1973-01-01

Five different inelastic light scattering processes will be denoted by, ordinary Raman scattering (ORS), resonance Raman scattering (RRS), off-resonance fluorescence (ORF), resonance fluorescence (RF), and broad fluorescence (BF). A distinction between fluorescence (including ORF and RF) and Raman scattering (including ORS and RRS) will be made in terms of the number of intermediate molecular states which contribute significantly to the scattered amplitude, and not in terms of excited state lifetimes or virtual versus real processes. The theory of these processes will be reviewed, including the effects of pressure, laser wavelength, and laser spectral distribution on the scattered intensity. The application of these processes to the remote sensing of atmospheric pollutants will be discussed briefly. It will be pointed out that the poor sensitivity of the ORS technique cannot be increased by going toward resonance without also compromising the advantages it has over the RF technique. Experimental results on inelastic light scattering from I(sub 2) vapor will be presented. As a single longitudinal mode 5145 A argon-ion laser line was tuned away from an I(sub 2) absorption line, the scattering was observed to change from RF to ORF. The basis, of the distinction is the different pressure dependence of the scattered intensity. Nearly three orders of magnitude enhancement of the scattered intensity was measured in going from ORF to RF. Forty-seven overtones were observed and their relative intensities measured. The ORF cross section of I(sub 2) compared to the ORS cross section of N2 was found to be 3 x 10(exp 6), with I(sub 2) at its room temperature vapor pressure.

Large-scale instability in interacting dark energy and dark matter fluids

International Nuclear Information System (INIS)

Väliviita, Jussi; Majerotto, Elisabetta; Maartens, Roy

2008-01-01

If dark energy interacts with dark matter, this gives a new approach to the coincidence problem. But interacting dark energy models can suffer from pathologies. We consider the case where the dark energy is modelled as a fluid with constant equation of state parameter w. Non-interacting constant-w models are well behaved in the background and in the perturbed universe. But the combination of constant w and a simple interaction with dark matter leads to an instability in the dark sector perturbations at early times: the curvature perturbation blows up on super-Hubble scales. Our results underline how important it is to carefully analyse the relativistic perturbations when considering models of coupled dark energy. The instability that we find has been missed in some previous work where the perturbations were not consistently treated. The unstable mode dominates even if adiabatic initial conditions are used. The instability also arises regardless of how weak the coupling is. This non-adiabatic instability is different from previously discovered adiabatic instabilities on small scales in the strong-coupling regime

Signals of dark matter in a supersymmetric two dark matter model

International Nuclear Information System (INIS)

Fukuoka, Hiroki; Suematsu, Daijiro; Toma, Takashi

2011-01-01

Supersymmetric radiative neutrino mass models have often two dark matter candidates. One is the usual lightest neutralino with odd R parity and the other is a new neutral particle whose stability is guaranteed by a discrete symmetry that forbids tree-level neutrino Yukawa couplings. If their relic abundance is comparable, dark matter phenomenology can be largely different from the minimal supersymmetric standard model (MSSM). We study this in a supersymmetric radiative neutrino mass model with the conserved R parity and a Z 2 symmetry weakly broken by the anomaly effect. The second dark matter with odd parity of this new Z 2 is metastable and decays to the neutralino dark matter. Charged particles and photons associated to this decay can cause the deviation from the expected background of the cosmic rays. Direct search of the neutralino dark matter is also expected to show different features from the MSSM since the relic abundance is not composed of the neutralino dark matter only. We discuss the nature of dark matter in this model by analyzing these signals quantitatively

Gate-controlled current and inelastic electron tunneling spectrum of benzene: a self-consistent study.

Science.gov (United States)

Liang, Y Y; Chen, H; Mizuseki, H; Kawazoe, Y

2011-04-14

We use density functional theory based nonequilibrium Green's function to self-consistently study the current through the 1,4-benzenedithiol (BDT). The elastic and inelastic tunneling properties through this Au-BDT-Au molecular junction are simulated, respectively. For the elastic tunneling case, it is found that the current through the tilted molecule can be modulated effectively by the external gate field, which is perpendicular to the phenyl ring. The gate voltage amplification comes from the modulation of the interaction between the electrodes and the molecules in the junctions. For the inelastic case, the electron tunneling scattered by the molecular vibrational modes is considered within the self-consistent Born approximation scheme, and the inelastic electron tunneling spectrum is calculated.

Microscopic study of elastic and inelastic ALPHA-nucleus scattering at medium energies

International Nuclear Information System (INIS)

Dao Tien Khoa; Hoang Si Than; Do Cong Cuong; Ngo Van Luyen; Nguyen Ngoc Quynh; Nguyen Tuan Anh

2007-01-01

Analyses of the inelastic α + 12 C scattering at medium energies have indicated that the strength of the Hoyle state (the isoscalar O 2 + excitation at 7.65 MeV in 12 C) seems to exhaust only 7 to 9% of the monopole energy weighted sum rule (EWSR), compared to about 15% of the EWSR extracted from inelastic electron scattering data. The full monopole transition strength predicted by realistic microscopic α-cluster models of the Hoyle state can be shown to exhaust up to 22% of the EWSR. To explore the missing monopole strength in the inelastic α + 12 C scattering, we have performed a fully microscopic folding model analysis of the inelastic α + 12 C scattering at E lab =104 to 240 MeV using the 3-α resonating group wave function of the Hoyle state obtained by Kamimura, and a complex density-dependent M3Y interaction newly parametrized based on the Brueckner Hartree Fock results for nuclear matter. Our folding model analysis has shown consistently that the missing monopole strength of the Hoyle state is not associated with the uncertainties in the analysis of the α + 12 C scattering, but is most likely due to the short lifetime and weakly bound structure of this state which significantly enhances absorption in the exit α + 12 C * (O 2 + ) channel. (author)

Analysis of inelastic neutron scattering results on model compounds ...

Indian Academy of Sciences (India)

Vibrational spectroscopy; nitrogenous bases; inelastic neutron scattering. PACS No. ... obtain good quality, high resolution results in this region. Here the .... knowledge of the character of each molecular transition as well as the calculated.

Inelastic scattering to collective states in double-magic nuclei

International Nuclear Information System (INIS)

Wambach, J.

1979-06-01

The paper discusses several aspects of inelastic scattering to collective states in the framework of the 'Shell Model RPA Approximation' with special emphasis on the analysis of giant resonance states. (orig./WL) [de

State-to-state inelastic and reactive molecular beam scattering from surfaces

International Nuclear Information System (INIS)

Lykke, K.R.; Kay, B.D.

1990-01-01

Resonantly enhanced multiphoton ionization (REMPI) laser spectroscopic and molecular beam-surface scattering techniques are coupled to study inelastic and reactive gas-surface scattering with state-to-state specificity. Rotational, vibrational, translational and angular distributions have been measured for the inelastic scattering of HCI and N 2 from Au(111). In both cases the scattering is direct-inelastic in nature and exhibits interesting dynamical features such as rotational rainbow scattering. In an effort to elucidate the dynamics of chemical reactions occurring on surfaces we have extended our quantum-resolved scattering studies to include the reactive scattering of a beam of gas phase H-atoms from a chlorinated metal surface M-CI. The nascent rotational and vibrational distributions of the HCI product are determined using REMPI. The thermochemistry for this reaction on Au indicates that the product formation proceeding through chemisorbed H-atoms is slightly endothermic while direct reaction of a has phase H-atom with M-CI is highly exothermic (ca. 50 kcal/mole). Details of the experimental techniques, results and implications regarding the scattering dynamics are discussed. 55 ref., 8 fig

Dark coupling

International Nuclear Information System (INIS)

Gavela, M.B.; Hernández, D.; Honorez, L. Lopez; Mena, O.; Rigolin, S.

2009-01-01

The two dark sectors of the universe—dark matter and dark energy—may interact with each other. Background and linear density perturbation evolution equations are developed for a generic coupling. We then establish the general conditions necessary to obtain models free from non-adiabatic instabilities. As an application, we consider a viable universe in which the interaction strength is proportional to the dark energy density. The scenario does not exhibit ''phantom crossing'' and is free from instabilities, including early ones. A sizeable interaction strength is compatible with combined WMAP, HST, SN, LSS and H(z) data. Neutrino mass and/or cosmic curvature are allowed to be larger than in non-interacting models. Our analysis sheds light as well on unstable scenarios previously proposed

Inelastic neutron scattering from superconducting rings

International Nuclear Information System (INIS)

Agafonov, A.I.

2010-01-01

For the first time the differential cross section for the inelastic magnetic neutron scattering by superconducting rings is derived taking account of the interaction of the neutron magnetic moment with the magnetic field generated by the superconducting current. Calculations of the scattering cross section are carried out for cold neutrons and thin film rings from type-II superconductors with the magnetic fields not exceeding the first critical field.

Inelastic scattering from amorphous solids

International Nuclear Information System (INIS)

Price, D.L.

1985-08-01

The potential of inelastic neutron scattering techniques for surveying various aspects of the dynamics of amorphous solids is briefly reviewed. The recent use of the Intense Pulsed Neutron Source to provide detailed information on the optical vibrations of glasses is discussed in more detail. The density of states represents an averaged quantity which gives information about the general characteristics of the structure and bonding. More extensive information can be obtained by studying the detailed wavevector dependence of the dynamic structure factor. 15 refs., 7 figs

Dark matter comes into sharper focus - on Earth and in the heavens

CERN Multimedia

1990-01-01

Observation of an elliptical galaxy that is acting as a gravitational lens, is helping astronomers in their understanding of dark matter. At the same time, experiments on earth have ruled out some of the hypothetical candidates for its composition (1

Dark Matter

International Nuclear Information System (INIS)

Holt, S. S.; Bennett, C. L.

1995-01-01

These proceedings represent papers presented at the Astrophysics conference in Maryland, organized by NASA Goddard Space Flight Center and the University of Maryland. The topics covered included low mass stars as dark matter, dark matter in galaxies and clusters, cosmic microwave background anisotropy, cold and hot dark matter, and the large scale distribution and motions of galaxies. There were eighty five papers presented. Out of these, 10 have been abstracted for the Energy Science and Technology database

Dark energy

International Nuclear Information System (INIS)

Wang, Yun

2010-01-01

Dark energy research aims to illuminate the mystery of the observed cosmic acceleration, one of the fundamental problems in physics and astronomy today. This book presents a systematic and detailed review of the current state of dark energy research, with the focus on the examination of the major observational techniques for probing dark energy. It can be used as a textbook to train students and others who wish to enter this extremely active field in cosmology.

Strategies for dark matter detection

International Nuclear Information System (INIS)

Silk, J.

1988-01-01

The present status of alternative forms of dark matter, both baryonic and nonbaryonic, is reviewed. Alternative arguments are presented for the predominance of either cold dark matter (CDM) or of baryonic dark matter (BDM). Strategies are described for dark matter detection, both for dark matter that consists of weakly interacting relic particles and for dark matter that consists of dark stellar remnants

Mapping the intramolecular contributions to the inelastic electron tunneling signal of a molecular junction

Czech Academy of Sciences Publication Activity Database

Foti, Giuseppe; Vázquez, Héctor

2016-01-01

Roč. 94, č. 4 (2016), 1-10, č. článku 045418. ISSN 1098-0121 R&D Projects: GA ČR GA15-19672S Institutional support: RVO:68378271 Keywords : single molecule transport * inelastic tunneling electron spectroscopy * DFT-NEGF * inelastic selection rules Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.736, year: 2014

Photocatalytic activity of Ti3+ self-doped dark TiO2 ultrafine nanorods, grey SiO2 nanotwin crystalline, and their composite under visible light

Science.gov (United States)

Zhang, Renhui; Yang, Yingchang; Leng, Senlin; Wang, Qing

2018-04-01

Efficient electron-holes separation is of crucial importance for the improvement of photocatalytic activity for photocatalytic reaction. In this work, dark TiO2 (D-TiO2) nanorods, grey SiO2 (G-SiO2) and D-TiO2/G-SiO2 composite with surface defects are synthesized. We report that the efficiency of photo-generated electrons and holes separation is well enhanced by introducing G-SiO2 into D-TiO2 lattice. Using first-principles method, we find that surface defects (O or Si vacancy) can be conducive to improving the optical absorption under visible-light region. Combination of the experimental results, for D-TiO2/G-SiO2 composite, the surface defects of TiO2 nanocrystallines can significantly improve the photocatalytic efficiency.

Inelastic Neutron Scattering Investigations of the Magnetic Excitations

DEFF Research Database (Denmark)

Feile, R; Kjems, Jørgen; Hauser, A.

1984-01-01

The magnetic excitations perpendicular to the antiferromagnetic chains in CsVX3 (X = Cl, Br, I) have been measured in the ordered state by inelastic neutron scattering. The dispersion relations and intensity distributions are those expected for ordinary spin waves in a triangular xy-model....

Hybrid Dark Matter

OpenAIRE

Chao, Wei

2018-01-01

Dark matter can be produced in the early universe via the freeze-in or freeze-out mechanisms. Both scenarios were investigated in references, but the production of dark matters via the combination of these two mechanisms are not addressed. In this paper we propose a hybrid dark matter model where dark matters have two components with one component produced thermally and the other one produced non-thermally. We present for the first time the analytical calculation for the relic abundance of th...

Elastic and inelastic electron and muon scattering

International Nuclear Information System (INIS)

Hand, L.N.

1977-01-01

The current status of experiments in the field of elastic and inelastic electron and muon scattering is discussed. The talk is divided into discussions of the single arm inclusive experiments at SLAC and Fermilab; the multiparticle inclusive experiments at SLAC, Fermilab und Cornell, and a description of selected results from exclusive channel measurements on electroproduced final states. (orig.) [de

Dijet production in diffractive deep inelastic scattering at HERA

International Nuclear Information System (INIS)

Chekanov, S.; Derrick, M.; Magill, S.

2007-08-01

The production of dijets in diffractive deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 61 pb -1 . The dijet cross section has been measured for virtualities of the exchanged virtual photon, 5 2 2 , and γ * p centre-of-mass energies, 100 T algorithm in the γ * p frame, were required to have a transverse energy E * T,jet >4 GeV and the jet with the highest transverse energy was required to have E * T,jet >5 GeV. All jets were required to be in the pseudorapidity range -3.5 * jet <0. The differential cross sections are compared to leading-order predictions and next-to-leading- order QCD calculations based on recent diffractive parton densities extracted from inclusive diffractive deep inelastic scattering data. (orig.)

Computer modeling of inelastic wave propagation in porous rock

International Nuclear Information System (INIS)

Cheney, J.A.; Schatz, J.F.; Snell, C.

1979-01-01

Computer modeling of wave propagation in porous rock has several important applications. Among them are prediction of fragmentation and permeability changes to be caused by chemical explosions used for in situ resource recovery, and the understanding of nuclear explosion effects such as seismic wave generation, containment, and site hardness. Of interest in all these applications are the distance from the source to which inelastic effects persist and the amount of porosity change within the inelastic region. In order to study phenomena related to these applications, the Cam Clay family of models developed at Cambridge University was used to develop a similar model that is applicable to wave propagation in porous rock. That model was incorporated into a finite-difference wave propagation computer code SOC. 10 figures, 1 table

Revealing inner shell dynamics with inelastic X-ray scattering

International Nuclear Information System (INIS)

Franck, C.

1990-01-01

One of the many opportunities provided by the Advanced Photon Source (APS) is to extend the study of intra-atomic dynamics. As a means of testing dynamic response, inelastic x-ray scattering is particularly promising since it allows us to independently vary the period of the exciting field in both space and time. As an example of this type of work, the author presents experiments performed at the Cornell High Energy Synchrotron Source (CHESS) laboratory, a prototype for the APS. This was inner shell inelastic scattering with a twist: in order to explore a new distance scale an x-ray fluorescence trigger was employed. Aside for the atomic insight gained, the experiment taught them the importance of the time structure of the synchrotron beam for coincidence experiments which are dominated by accidental events