field-dark matter models: Topics by WorldWideScience.org

Sample records for field-dark matter models

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.
Dark matter model with non-Abelian gauge symmetry

International Nuclear Information System (INIS)

Zhang Hao; Li Chongsheng; Cao Qinghong; Li Zhao

2010-01-01

We propose a dark-matter model in which the dark sector is gauged under a new SU(2) group. The dark sector consists of SU(2) dark gauge fields, two triplet dark Higgs fields, and two dark fermion doublets (dark-matter candidates in this model). The dark sector interacts with the standard model sector through kinetic and mass mixing operators. The model explains both PAMELA and Fermi LAT data very well and also satisfies constraints from both the dark-matter relic density and standard model precision observables. The phenomenology of the model at the LHC is also explored.
Classical color fields as a dark matter candidate

OpenAIRE

Dzhunushaliev, Vladimir

2006-01-01

The model of Dark Matter is proposed in which the Dark Matter is a classical color field. The color fields are invisible as they may interact with colored elementary particles like 't Hooft - Polyakov monopole only. The comparison with the Universal Rotation Curve is carried out.
Can dark matter be a scalar field?

Energy Technology Data Exchange (ETDEWEB)

Jesus, J.F.; Malatrasi, J.L.G. [Universidade Estadual Paulista ' Júlio de Mesquita Filho' , Campus Experimental de Itapeva—R. Geraldo Alckmin, 519, Itapeva, SP (Brazil); Pereira, S.H. [Universidade Estadual Paulista ' Júlio de Mesquita Filho' , Departamento de Física e Química, Campus de Guaratinguetá, Av. Dr. Ariberto Pereira da Cunha, 333, 12516-410—Guaratinguetá, SP (Brazil); Andrade-Oliveira, F., E-mail: jfjesus@itapeva.unesp.br, E-mail: shpereira@gmail.com, E-mail: malatrasi440@gmail.com, E-mail: felipe.oliveira@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Burnaby Road, PO1 3FX, Portsmouth (United Kingdom)

2016-08-01

In this paper we study a real scalar field as a possible candidate to explain the dark matter in the universe. In the context of a free scalar field with quadratic potential, we have used Union 2.1 SN Ia observational data jointly with a Planck prior over the dark matter density parameter to set a lower limit on the dark matter mass as m ≥0.12 H {sub 0}{sup -1} eV ( c = h-bar =1). For the recent value of the Hubble constant indicated by the Hubble Space Telescope, namely H {sub 0}=73±1.8 km s{sup -1}Mpc{sup -1}, this leads to m ≥1.56×10{sup -33} eV at 99.7% c.l. Such value is much smaller than m ∼ 10{sup -22} eV previously estimated for some models. Nevertheless, it is still in agreement with them once we have not found evidences for a upper limit on the scalar field dark matter mass from SN Ia analysis. In practice, it confirms free real scalar field as a viable candidate for dark matter in agreement with previous studies in the context of density perturbations, which include scalar field self interaction.
Is Sextans dwarf galaxy in a scalar field dark matter halo?

International Nuclear Information System (INIS)

Lora, V.; Magaña, Juan

2014-01-01

The Bose-Einstein condensate/scalar field dark matter model, considers that the dark matter is composed by spinless-ultra-light particles which can be described by a scalar field. This model is an alternative model to the Λ-cold dark matter paradigm, and therefore should be studied at galactic and cosmological scales. Dwarf spheroidal galaxies have been very useful when studying any dark matter theory, because the dark matter dominates their dynamics. In this paper we study the Sextans dwarf spheroidal galaxy, embedded in a scalar field dark matter halo. We explore how the dissolution time-scale of the stellar substructures in Sextans, constrain the mass, and the self-interacting parameter of the scalar field dark matter boson. We find that for masses in the range (0.12< m φ <8) ×10 -22 eV, scalar field dark halos without self-interaction would have cores large enough to explain the longevity of the stellar substructures in Sextans, and small enough mass to be compatible with dynamical limits. If the self-interacting parameter is distinct to zero, then the mass of the boson could be as high as m φ ≈2×10 -21 eV, but it would correspond to an unrealistic low mass for the Sextans dark matter halo . Therefore, the Sextans dwarf galaxy could be embedded in a scalar field/BEC dark matter halo with a preferred self-interacting parameter equal to zero
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
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
Interacting diffusive unified dark energy and dark matter from scalar fields

Energy Technology Data Exchange (ETDEWEB)

Benisty, David; Guendelman, E.I. [Ben Gurion University of the Negev, Department of Physics, Beersheba (Israel)

2017-06-15

Here we generalize ideas of unified dark matter-dark energy in the context of two measure theories and of dynamical space time theories. In two measure theories one uses metric independent volume elements and this allows one to construct unified dark matter-dark energy, where the cosmological constant appears as an integration constant associated with the equation of motion of the measure fields. The dynamical space-time theories generalize the two measure theories by introducing a vector field whose equation of motion guarantees the conservation of a certain Energy Momentum tensor, which may be related, but in general is not the same as the gravitational Energy Momentum tensor. We propose two formulations of this idea: (I) by demanding that this vector field be the gradient of a scalar, (II) by considering the dynamical space field appearing in another part of the action. Then the dynamical space time theory becomes a theory of Diffusive Unified dark energy and dark matter. These generalizations produce non-conserved energy momentum tensors instead of conserved energy momentum tensors which leads at the end to a formulation of interacting DE-DM dust models in the form of a diffusive type interacting Unified dark energy and dark matter scenario. We solved analytically the theories for perturbative solution and asymptotic solution, and we show that the ΛCDM is a fixed point of these theories at large times. Also a preliminary argument as regards the good behavior of the theory at the quantum level is proposed for both theories. (orig.)
Geometrization of the electromagnetic field and dark matter

International Nuclear Information System (INIS)

Pestov, I.B.

2005-01-01

A general concept of potential field is introduced. The potential field that one puts in correspondence with dark matter, has fundamental geometrical interpretation (parallel transport) and has intrinsically inherent local symmetry. The equations of dark matter field are derived that are invariant with respect to the local transformations. It is shown how to reduce these equations to the Maxwell equations. Thus, the dark matter field may be considered as generalized electromagnetic field and a simple solution of the old problem is given to connect electromagnetic field with geometrical properties of the physical manifold itself. It is shown that gauge fixing renders generalized electromagnetic field effectively massive while the Maxwell electromagnetic field remains massless. To learn more about interactions between matter and dark matter on the microscopical level (and to recognize the fundamental role of internal symmetry) the general covariant Dirac equation is derived in the Minkowski space-time which describes the interactions of spinor field with dark matter field
A minimal model for two-component dark matter

International Nuclear Information System (INIS)

Esch, Sonja; Klasen, Michael; Yaguna, Carlos E.

2014-01-01

We propose and study a new minimal model for two-component dark matter. The model contains only three additional fields, one fermion and two scalars, all singlets under the Standard Model gauge group. Two of these fields, one fermion and one scalar, are odd under a Z_2 symmetry that renders them simultaneously stable. Thus, both particles contribute to the observed dark matter density. This model resembles the union of the singlet scalar and the singlet fermionic models but it contains some new features of its own. We analyze in some detail its dark matter phenomenology. Regarding the relic density, the main novelty is the possible annihilation of one dark matter particle into the other, which can affect the predicted relic density in a significant way. Regarding dark matter detection, we identify a new contribution that can lead either to an enhancement or to a suppression of the spin-independent cross section for the scalar dark matter particle. Finally, we define a set of five benchmarks models compatible with all present bounds and examine their direct detection prospects at planned experiments. A generic feature of this model is that both particles give rise to observable signals in 1-ton direct detection experiments. In fact, such experiments will be able to probe even a subdominant dark matter component at the percent level.
Scalar field dark matter in hybrid approach

NARCIS (Netherlands)

Friedrich, Pavel; Prokopec, Tomislav

2017-01-01

We develop a hybrid formalism suitable for modeling scalar field dark matter, in which the phase-space distribution associated to the real scalar field is modeled by statistical equal-time two-point functions and gravity is treated by two stochastic gravitational fields in the longitudinal gauge (in
Fermion field as inflaton, dark energy and dark matter

International Nuclear Information System (INIS)

Grams, Guilherme; Souza, Rudinei C de; Kremer, Gilberto M

2014-01-01

The search for constituents that can explain the periods of accelerating expansion of the Universe is a fundamental topic in cosmology. In this context, we investigate how fermionic fields minimally and non-minimally coupled with the gravitational field may be responsible for accelerated regimes during the evolution of the Universe. The forms of the potential and coupling of the model are determined through the technique of the Noether symmetry for two cases. The first case comprises a Universe filled only with the fermion field. Cosmological solutions are straightforwardly obtained for this case and an exponential inflation mediated by the fermion field is possible with a non-minimal coupling. The second case takes account of the contributions of radiation and baryonic matter in the presence of the fermion field. In this case the fermion field plays the role of dark energy and dark matter, and when a non-minimal coupling is allowed, it mediates a power-law inflation. (paper)
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
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.
Geometrization of the Electromagnetic Field and Dark Matter

CERN Document Server

Pestov, I B

2005-01-01

A general concept of potential field is introduced. The potential field that one puts in correspondence with dark matter, has fundamental geometrical interpretation (parallel transport) and has intrinsically inherent local symmetry. The equations of dark matter field are derived that are invariant with respect to the local transformations. It is shown how to reduce these equations to the Maxwell equations. Thus, the dark matter field may be considered as generalized lectromagnetic field and a simple solution of the old problem is given to connect electromagnetic field with geometrical properties of the physical manifold itself. It is shown that gauge fixing renders generalized electromagnetic field effectively massive while the Maxwell electromagnetic field remains massless. To learn more about interactions between matter and dark matter on the microscopical level (and to recognize the fundamental role of internal symmetry) the general covariant Dirac equation is derived in the Minkowski space--time which des...
Constraining scalar fields with stellar kinematics and collisional dark matter

International Nuclear Information System (INIS)

Amaro-Seoane, Pau; Barranco, Juan; Bernal, Argelia; Rezzolla, Luciano

2010-01-01

The existence and detection of scalar fields could provide solutions to long-standing puzzles about the nature of dark matter, the dark compact objects at the centre of most galaxies, and other phenomena. Yet, self-interacting scalar fields are very poorly constrained by astronomical observations, leading to great uncertainties in estimates of the mass m φ and the self-interacting coupling constant λ of these fields. To counter this, we have systematically employed available astronomical observations to develop new constraints, considerably restricting this parameter space. In particular, by exploiting precise observations of stellar dynamics at the centre of our Galaxy and assuming that these dynamics can be explained by a single boson star, we determine an upper limit for the boson star compactness and impose significant limits on the values of the properties of possible scalar fields. Requiring the scalar field particle to follow a collisional dark matter model further narrows these constraints. Most importantly, we find that if a scalar dark matter particle does exist, then it cannot account for both the dark-matter halos and the existence of dark compact objects in galactic nuclei
Unified Dark Matter scalar field models with fast transition

Energy Technology Data Exchange (ETDEWEB)

Bertacca, Daniele [Dipartimento di Fisica Galileo Galilei, Università di Padova, via F. Marzolo 8, I-35131 Padova (Italy); Bruni, Marco [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth, PO1 3FX (United Kingdom); Piattella, Oliver F. [Department of Physics, Universidade Federal do Espírito Santo, avenida Ferrari 514, 29075-910, Vitória, ES (Brazil); Pietrobon, Davide, E-mail: daniele.bertacca@pd.infn.it, E-mail: marco.bruni@port.ac.uk, E-mail: oliver.piattella@gmail.com, E-mail: davide.pietrobon@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, 91109 Pasadena CA U.S.A. (United States)

2011-02-01

We investigate the general properties of Unified Dark Matter (UDM) scalar field models with Lagrangians with a non-canonical kinetic term, looking specifically for models that can produce a fast transition between an early Einstein-de Sitter CDM-like era and a later Dark Energy like phase, similarly to the barotropic fluid UDM models in JCAP01(2010)014. However, while the background evolution can be very similar in the two cases, the perturbations are naturally adiabatic in fluid models, while in the scalar field case they are necessarily non-adiabatic. The new approach to building UDM Lagrangians proposed here allows to escape the common problem of the fine-tuning of the parameters which plague many UDM models. We analyse the properties of perturbations in our model, focusing on the the evolution of the effective speed of sound and that of the Jeans length. With this insight, we can set theoretical constraints on the parameters of the model, predicting sufficient conditions for the model to be viable. An interesting feature of our models is that what can be interpreted as w{sub DE} can be < −1 without violating the null energy conditions.
A Simple Singlet Fermionic Dark-Matter Model Revisited

International Nuclear Information System (INIS)

Qin Hong-Yi; Wang Wen-Yu; Xiong Zhao-Hua

2011-01-01

We evaluate the spin-independent elastic dark matter-nucleon scattering cross section in the framework of the simple singlet fermionic dark matter extension of the standard model and constrain the model parameter space with the following considerations: (i) new dark matter measurement, in which, apart from WMAP and CDMS, the results from the XENON experiment are also used in constraining the model; (ii) new fitted value of the quark fractions in nucleons, in which the updated value of f T s from the recent lattice simulation is much smaller than the previous one and may reduce the scattering rate significantly; (iii) new dark matter annihilation channels, in which the scenario where top quark and Higgs pairs produced by dark matter annihilation was not included in the previous works. We find that unlike in the minimal supersymmetric standard model, the cross section is just reduced by a factor of about 1/4 and dark matter lighter than 100 GeV is not favored by the WMAP, CDMS and XENON experiments. (the physics of elementary particles and fields)
Comprehensive asymmetric dark matter model

Science.gov (United States)

Lonsdale, Stephen J.; Volkas, Raymond R.

2018-05-01

Asymmetric dark matter (ADM) is motivated by the similar cosmological mass densities measured for ordinary and dark matter. We present a comprehensive theory for ADM that addresses the mass density similarity, going beyond the usual ADM explanations of similar number densities. It features an explicit matter-antimatter asymmetry generation mechanism, has one fully worked out thermal history and suggestions for other possibilities, and meets all phenomenological, cosmological and astrophysical constraints. Importantly, it incorporates a deep reason for why the dark matter mass scale is related to the proton mass, a key consideration in ADM models. Our starting point is the idea of mirror matter, which offers an explanation for dark matter by duplicating the standard model with a dark sector related by a Z2 parity symmetry. However, the dark sector need not manifest as a symmetric copy of the standard model in the present day. By utilizing the mechanism of "asymmetric symmetry breaking" with two Higgs doublets in each sector, we develop a model of ADM where the mirror symmetry is spontaneously broken, leading to an electroweak scale in the dark sector that is significantly larger than that of the visible sector. The weak sensitivity of the ordinary and dark QCD confinement scales to their respective electroweak scales leads to the necessary connection between the dark matter and proton masses. The dark matter is composed of either dark neutrons or a mixture of dark neutrons and metastable dark hydrogen atoms. Lepton asymmetries are generated by the C P -violating decays of heavy Majorana neutrinos in both sectors. These are then converted by sphaleron processes to produce the observed ratio of visible to dark matter in the universe. The dynamics responsible for the kinetic decoupling of the two sectors emerges as an important issue that we only partially solve.

Scalar field dark matter and the Higgs field

Directory of Open Access Journals (Sweden)

O. Bertolami

2016-08-01

Full Text Available We discuss the possibility that dark matter corresponds to an oscillating scalar field coupled to the Higgs boson. We argue that the initial field amplitude should generically be of the order of the Hubble parameter during inflation, as a result of its quasi-de Sitter fluctuations. This implies that such a field may account for the present dark matter abundance for masses in the range 10−6–10−4eV, if the tensor-to-scalar ratio is within the range of planned CMB experiments. We show that such mass values can naturally be obtained through either Planck-suppressed non-renormalizable interactions with the Higgs boson or, alternatively, through renormalizable interactions within the Randall–Sundrum scenario, where the dark matter scalar resides in the bulk of the warped extra-dimension and the Higgs is confined to the infrared brane.
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
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...
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.
Dark matter cosmic string in the gravitational field of a black hole

Science.gov (United States)

Nakonieczny, Łukasz; Nakonieczna, Anna; Rogatko, Marek

2018-03-01

We examined analytically and proposed a numerical model of an Abelian Higgs dark matter vortex in the spacetime of a stationary axisymmetric Kerr black hole. In analytical calculations the dark matter sector was modeled by an addition of a U(1)-gauge field coupled to the visible sector. The backreaction analysis revealed that the impact of the dark vortex presence is far more complicated than causing only a deficit angle. The vortex causes an ergosphere shift and the event horizon velocity is also influenced by its presence. These phenomena are more significant than in the case of a visible vortex sector. The area of the event horizon of a black hole is diminished and this decline is larger in comparison to the Kerr black hole with an Abelian Higgs vortex case. After analyzing the gravitational properties for the general setup, we focused on the subset of models that are motivated by particle physics. We retained the Abelian Higgs model as a description of the dark matter sector (this sector contained a heavy dark photon and an additional complex scalar) and added a real scalar representing the real component of the Higgs doublet in the unitary gauge, as well as an additional U(1)-gauge field representing an ordinary electromagnetic field. Moreover, we considered two coupling channels between the visible and dark sectors, which were the kinetic mixing between the gauge fields and a quartic coupling between the scalar fields. After solving the equations of motion for the matter fields numerically we analyzed properties of the cosmic string in the dark matter sector and its influence on the visible sector fields that are directly coupled to it. We found out that the presence of the cosmic string induced spatial variation in the vacuum expectation value of the Higgs field and a nonzero electromagnetic field around the black hole.
Scalar dark matter in the B−L model

International Nuclear Information System (INIS)

Rodejohann, Werner; Yaguna, Carlos E.

2015-01-01

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

International Nuclear Information System (INIS)

Abada, Abdessamad; Ghaffor, Djamal; Nasri, Salah

2011-01-01

We extend the standard model by adding two gauge-singlet Z 2 -symmetric scalar fields that interact with visible matter only through the Higgs particle. One is a stable dark matter WIMP, and the other one undergoes a spontaneous breaking of the symmetry that opens new channels for the dark matter annihilation, hence lowering the mass of the WIMP. We study the effects of the observed dark matter relic abundance on the WIMP annihilation cross section and find that in most regions of the parameters' space, light dark matter is viable. We also compare the elastic-scattering cross section of our dark matter candidate off a nucleus with existing (CDMSII and XENON100) and projected (SuperCDMS and XENON1T) experimental exclusion bounds. We find that most of the allowed mass range for light dark matter will be probed by the projected sensitivity of the XENON1T experiment.
Gravitational lensing due to dark matter modelled by a vector field

International Nuclear Information System (INIS)

Kiselev, V V; Yudin, D I

2006-01-01

The specified constant 4-vector field reproducing the spherically symmetric stationary metric of a cold dark matter halo in the region of flat rotation curves results in a constant angle of light deflection at small impact distances. The effective deflecting mass is a factor π/2 greater than the dark matter mass. The perturbation of deflection picture due to the halo edge is evaluated
Dark Matter Benchmark Models for Early LHC Run-2 Searches: Report of the ATLAS/CMS Dark Matter Forum

CERN Document Server

Abercrombie, Daniel; Akilli, Ece; Alcaraz Maestre, Juan; Allen, Brandon; Alvarez Gonzalez, Barbara; Andrea, Jeremy; Arbey, Alexandre; Azuelos, Georges; Azzi, Patrizia; Backovic, Mihailo; Bai, Yang; Banerjee, Swagato; Beacham, James; Belyaev, Alexander; Boveia, Antonio; Brennan, Amelia Jean; Buchmueller, Oliver; Buckley, Matthew R.; Busoni, Giorgio; Buttignol, Michael; Cacciapaglia, Giacomo; Caputo, Regina; Carpenter, Linda; Filipe Castro, Nuno; Gomez Ceballos, Guillelmo; Cheng, Yangyang; Chou, John Paul; Cortes Gonzalez, Arely; Cowden, Chris; D'Eramo, Francesco; De Cosa, Annapaola; De Gruttola, Michele; De Roeck, Albert; De Simone, Andrea; Deandrea, Aldo; Demiragli, Zeynep; DiFranzo, Anthony; Doglioni, Caterina; du Pree, Tristan; Erbacher, Robin; Erdmann, Johannes; Fischer, Cora; Flaecher, Henning; Fox, Patrick J.; Fuks, Benjamin; Genest, Marie-Helene; Gomber, Bhawna; Goudelis, Andreas; Gramling, Johanna; Gunion, John; Hahn, Kristian; Haisch, Ulrich; Harnik, Roni; Harris, Philip C.; Hoepfner, Kerstin; Hoh, Siew Yan; Hsu, Dylan George; Hsu, Shih-Chieh; Iiyama, Yutaro; Ippolito, Valerio; Jacques, Thomas; Ju, Xiangyang; Kahlhoefer, Felix; Kalogeropoulos, Alexis; Kaplan, Laser Seymour; Kashif, Lashkar; Khoze, Valentin V.; Khurana, Raman; Kotov, Khristian; Kovalskyi, Dmytro; Kulkarni, Suchita; Kunori, Shuichi; Kutzner, Viktor; Lee, Hyun Min; Lee, Sung-Won; Liew, Seng Pei; Lin, Tongyan; Lowette, Steven; Madar, Romain; Malik, Sarah; Maltoni, Fabio; Martinez Perez, Mario; Mattelaer, Olivier; Mawatari, Kentarou; McCabe, Christopher; Megy, Theo; Morgante, Enrico; Mrenna, Stephen; Narayanan, Siddharth M.; Nelson, Andy; Novaes, Sergio F.; Padeken, Klaas Ole; Pani, Priscilla; Papucci, Michele; Paulini, Manfred; Paus, Christoph; Pazzini, Jacopo; Penning, Bjorn; Peskin, Michael E.; Pinna, Deborah; Procura, Massimiliano; Qazi, Shamona F.; Racco, Davide; Re, Emanuele; Riotto, Antonio; Rizzo, Thomas G.; Roehrig, Rainer; Salek, David; Sanchez Pineda, Arturo; Sarkar, Subir; Schmidt, Alexander; Schramm, Steven Randolph; Shepherd, William; Singh, Gurpreet; Soffi, Livia; Srimanobhas, Norraphat; Sung, Kevin; Tait, Tim M.P.; Theveneaux-Pelzer, Timothee; Thomas, Marc; Tosi, Mia; Trocino, Daniele; Undleeb, Sonaina; Vichi, Alessandro; Wang, Fuquan; Wang, Lian-Tao; Wang, Ren-Jie; Whallon, Nikola; Worm, Steven; Wu, Mengqing; Wu, Sau Lan; Yang, Hongtao; Yang, Yong; Yu, Shin-Shan; Zaldivar, Bryan; Zanetti, Marco; Zhang, Zhiqing; Zucchetta, Alberto

2015-01-01

This document is the final report of the ATLAS-CMS Dark Matter Forum, a forum organized by the ATLAS and CMS collaborations with the participation of experts on theories of Dark Matter, to select a minimal basis set of dark matter simplified models that should support the design of the early LHC Run-2 searches. A prioritized, compact set of benchmark models is proposed, accompanied by studies of the parameter space of these models and a repository of generator implementations. This report also addresses how to apply the Effective Field Theory formalism for collider searches and present the results of such interpretations.
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.
Baryon-to-dark matter ratio from random angular fields

International Nuclear Information System (INIS)

McDonald, John

2013-01-01

We consider the baryon-to-dark matter ratio in models where the dark matter and baryon densities depend on angular fields θ d and θ b according to ρ d ∝θ d α and ρ b ∝θ b β , with all values of θ d and θ b being equally probable in a given randomly-selected domain. Under the assumption that anthropic selection depends primarily on the baryon density in galaxies at spherical collapse, we show that the probability density function for the baryon-to-dark matter ratio r = Ω B /Ω DM is purely statistical in nature and is independent of anthropic selection. We compute the probability density function for r as a function of α and β and show that the observed value of the baryon-to-dark matter ratio, r ≈ 1/5, is natural in this framework
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
A Unified Model of Phantom Energy and Dark Matter

Science.gov (United States)

Chaves, Max; Singleton, Douglas

2008-01-01

To explain the acceleration of the cosmological expansion researchers have considered an unusual form of mass-energy generically called dark energy. Dark energy has a ratio of pressure over mass density which obeys w = p/ρ theories based on graded Lie algebras naturally have such a negative kinetic energy and thus give a model for phantom energy in a less ad hoc manner. We find that the model also contains ordinary scalar fields and anti-commuting (Grassmann) vector fields which act as a form of two component dark matter. Thus from a gauge theory based o! n a graded algebra we naturally obtained both phantom energy and dark matter.
Perturbations of ultralight vector field dark matter

Energy Technology Data Exchange (ETDEWEB)

Cembranos, J.A.R.; Maroto, A.L.; Jareño, S.J. Núñez [Departamento de Física Teórica I, Universidad Complutense de Madrid, E-28040 Madrid (Spain)

2017-02-13

We study the dynamics of cosmological perturbations in models of dark matter based on ultralight coherent vector fields. Very much as for scalar field dark matter, we find two different regimes in the evolution: for modes with k{sup 2}≪Hma, we have a particle-like behaviour indistinguishable from cold dark matter, whereas for modes with k{sup 2}≫Hma, we get a wave-like behaviour in which the sound speed is non-vanishing and of order c{sub s}{sup 2}≃k{sup 2}/m{sup 2}a{sup 2}. This implies that, also in these models, structure formation could be suppressed on small scales. However, unlike the scalar case, the fact that the background evolution contains a non-vanishing homogeneous vector field implies that, in general, the evolution of the three kinds of perturbations (scalar, vector and tensor) can no longer be decoupled at the linear level. More specifically, in the particle regime, the three types of perturbations are actually decoupled, whereas in the wave regime, the three vector field perturbations generate one scalar-tensor and two vector-tensor perturbations in the metric. Also in the wave regime, we find that a non-vanishing anisotropic stress is present in the perturbed energy-momentum tensor giving rise to a gravitational slip of order (Φ−Ψ)/Φ∼c{sub s}{sup 2}. Moreover in this regime the amplitude of the tensor to scalar ratio of the scalar-tensor modes is also h/Φ∼c{sub s}{sup 2}. This implies that small-scale density perturbations are necessarily associated to the presence of gravity waves in this model. We compare their spectrum with the sensitivity of present and future gravity waves detectors.
Effective field theory of dark matter from membrane inflationary paradigm

Science.gov (United States)

Choudhury, Sayantan; Dasgupta, Arnab

2016-09-01

In this article, we have studied the cosmological and particle physics constraints on dark matter relic abundance from effective field theory of inflation from tensor-to-scalar ratio (r), in case of Randall-Sundrum single membrane (RSII) paradigm. Using semi-analytical approach we establish a direct connection between the dark matter relic abundance (ΩDMh2) and primordial gravity waves (r), which establishes a precise connection between inflation and generation of dark matter within the framework of effective field theory in RSII membrane. Further assuming the UV completeness of the effective field theory perfectly holds good in the prescribed framework, we have explicitly shown that the membrane tension, σ ≤ O(10-9) Mp4 , bulk mass scale M5 ≤ O(0.04 - 0.05) Mp, and cosmological constant Λ˜5 ≥ - O(10-15) Mp5 , in RSII membrane plays the most significant role to establish the connection between dark matter and inflation, using which we have studied the features of various mediator mass scale suppressed effective field theory "relevant operators" induced from the localized s, t and u channel interactions in RSII membrane. Taking a completely model independent approach, we have studied an exhaustive list of tree-level Feynman diagrams for dark matter annihilation within the prescribed setup and to check the consistency of the obtained results, further we apply the constraints as obtained from recently observed Planck 2015 data and Planck + BICEP2 + Keck Array joint data sets. Using all of these derived results we have shown that to satisfy the bound on, ΩDMh2 = 0.1199 ± 0.0027, as from Planck 2015 data, it is possible to put further stringent constraint on r within, 0.01 ≤ r ≤ 0.12, for thermally averaged annihilation cross-section of dark matter, 〈 σv 〉 ≈ O(10-28 - 10-27) cm3 / s, which are very useful to constrain various membrane inflationary models.
Dipolar dark matter with massive bigravity

International Nuclear Information System (INIS)

Blanchet, Luc; Heisenberg, Lavinia

2015-01-01

Massive gravity theories have been developed as viable IR modifications of gravity motivated by dark energy and the problem of the cosmological constant. On the other hand, modified gravity and modified dark matter theories were developed with the aim of solving the problems of standard cold dark matter at galactic scales. Here we propose to adapt the framework of ghost-free massive bigravity theories to reformulate the problem of dark matter at galactic scales. We investigate a promising alternative to dark matter called dipolar dark matter (DDM) in which two different species of dark matter are separately coupled to the two metrics of bigravity and are linked together by an internal vector field. We show that this model successfully reproduces the phenomenology of dark matter at galactic scales (i.e. MOND) as a result of a mechanism of gravitational polarisation. The model is safe in the gravitational sector, but because of the particular couplings of the matter fields and vector field to the metrics, a ghost in the decoupling limit is present in the dark matter sector. However, it might be possible to push the mass of the ghost beyond the strong coupling scale by an appropriate choice of the parameters of the model. Crucial questions to address in future work are the exact mass of the ghost, and the cosmological implications of the model
Massive graviton dark matter with environment dependent mass: A natural explanation of the dark matter-baryon ratio

Science.gov (United States)

Aoki, Katsuki; Mukohyama, Shinji

2017-11-01

We propose a scenario that can naturally explain the observed dark matter-baryon ratio in the context of bimetric theory with a chameleon field. We introduce two additional gravitational degrees of freedom, the massive graviton and the chameleon field, corresponding to dark matter and dark energy, respectively. The chameleon field is assumed to be nonminimally coupled to dark matter, i.e., the massive graviton, through the graviton mass terms. We find that the dark matter-baryon ratio is dynamically adjusted to the observed value due to the energy transfer by the chameleon field. As a result, the model can explain the observed dark matter-baryon ratio independently from the initial abundance of them.
Resonant SIMP dark matter

Directory of Open Access Journals (Sweden)

Soo-Min Choi

2016-07-01

Full Text Available We consider a resonant SIMP dark matter in models with two singlet complex scalar fields charged under a local dark U(1D. After the U(1D is broken down to a Z5 discrete subgroup, the lighter scalar field becomes a SIMP dark matter which has the enhanced 3→2 annihilation cross section near the resonance of the heavier scalar field. Bounds on the SIMP self-scattering cross section and the relic density can be fulfilled at the same time for perturbative couplings of SIMP. A small gauge kinetic mixing between the SM hypercharge and dark gauge bosons can be used to make SIMP dark matter in kinetic equilibrium with the SM during freeze-out.
Impact of semi-annihilations on dark matter phenomenology - an example of ZN symmetric scalar dark matter

International Nuclear Information System (INIS)

Belanger, G.; Kannike, K.; Pukhov, A.; Raidal, M.

2012-01-01

We study the impact of semi-annihilations χχ ↔ χX; where χ is dark matter and X is any standard model particle, on dark matter phenomenology. We formulate scalar dark matter models with minimal field content that predict non-trivial dark matter phenomenology for different discrete Abelian symmetries Z N , N > 2, and contain semi-annihilation processes. We implement such an example model in micrOMEGAs and show that semi-annihilations modify the phenomenology of this type of models. (authors)
Dark Matter in Quantum Gravity

OpenAIRE

Calmet, Xavier; Latosh, Boris

2018-01-01

We show that quantum gravity, whatever its ultra-violet completion might be, could account for dark matter. Indeed, besides the massless gravitational field recently observed in the form of gravitational waves, the spectrum of quantum gravity contains two massive fields respectively of spin 2 and spin 0. If these fields are long-lived, they could easily account for dark matter. In that case, dark matter would be very light and only gravitationally coupled to the standard model particles.

A Unified Model of Phantom Energy and Dark Matter

Directory of Open Access Journals (Sweden)

Douglas Singleton

2008-01-01

Full Text Available To explain the acceleration of the cosmological expansion researchers have considered an unusual form of mass-energy generically called dark energy. Dark energy has a ratio of pressure over mass density which obeys $w=p/ ho <-1/3$. This form of mass-energy leads to accelerated expansion. An extreme form of dark energy, called phantom energy, has been proposed which has $w=p/ ho <-1$. This possibility is favored by the observational data. The simplest model for phantom energy involves the introduction of a scalar field with a negative kinetic energy term. Here we show that theories based on graded Lie algebras naturally have such a negative kinetic energy and thus give a model for phantom energy in a less ad hoc manner. We find that the model also contains ordinary scalar fields and anti-commuting (Grassmann vector fields which act as a form of two component dark matter. Thus from a gauge theory based on a graded algebra we naturally obtained both phantom energy and dark matter.
Dark matter deprivation in the field elliptical galaxy NGC 7507

Science.gov (United States)

Lane, Richard R.; Salinas, Ricardo; Richtler, Tom

2015-02-01

Context. Previous studies have shown that the kinematics of the field elliptical galaxy NGC 7507 do not necessarily require dark matter. This is troubling because, in the context of ΛCDM cosmologies, all galaxies should have a large dark matter component. Aims: Our aims are to determine the rotation and velocity dispersion profile out to larger radii than do previous studies, and, therefore, more accurately estimate of the dark matter content of the galaxy. Methods: We use penalised pixel-fitting software to extract velocities and velocity dispersions from GMOS slit mask spectra. Using Jeans and MONDian modelling, we then produce models with the goal of fitting the velocity dispersion data. Results: NGC 7507 has a two-component stellar halo, with the outer halo counter rotating with respect to the inner halo, with a kinematic boundary at a radius of ~110'' (~12.4 kpc). The velocity dispersion profile exhibits an increase at ~70'' (~7.9 kpc), reminiscent of several other elliptical galaxies. Our best fit models are those under mild anisotropy, which include ~100 times less dark matter than predicted by ΛCDM, although mildly anisotropic models that are completely dark matter free fit the measured dynamics almost equally well. Our MONDian models, both isotropic and anisotropic, systematically fail to reproduce the measured velocity dispersions at almost all radii. Conclusions: The counter-rotating outer halo implies a merger remnant, as does the increase in velocity dispersion at ~70''. From simulations it seems plausible that the merger that caused the increase in velocity dispersion was a spiral-spiral merger. Our Jeans models are completely consistent with a no dark matter scenario, however, some dark matter can be accommodated, although at much lower concentrations than predicted by ΛCDM simulations. This indicates that NGC 7507 may be a dark matter free elliptical galaxy. Regardless of whether NGC 7507 is completely dark matter free or very dark matter poor
Dark matter and electroweak phase transition in the mixed scalar dark matter model

Science.gov (United States)

Liu, Xuewen; Bian, Ligong

2018-03-01

We study the electroweak phase transition in the framework of the scalar singlet-doublet mixed dark matter model, in which the particle dark matter candidate is the lightest neutral Higgs that comprises the C P -even component of the inert doublet and a singlet scalar. The dark matter can be dominated by the inert doublet or singlet scalar depending on the mixing. We present several benchmark models to investigate the two situations after imposing several theoretical and experimental constraints. An additional singlet scalar and the inert doublet drive the electroweak phase transition to be strongly first order. A strong first-order electroweak phase transition and a viable dark matter candidate can be accomplished in two benchmark models simultaneously, for which a proper mass splitting among the neutral and charged Higgs masses is needed.
Model-independent approach for dark matter phenomenology

Indian Academy of Sciences (India)

We have studied the phenomenology of dark matter at the ILC and cosmic positron experiments based on model-independent approach. We have found a strong correlation between dark matter signatures at the ILC and those in the indirect detection experiments of dark matter. Once the dark matter is discovered in the ...
Model-independent approach for dark matter phenomenology ...

Indian Academy of Sciences (India)

Abstract. We have studied the phenomenology of dark matter at the ILC and cosmic positron experiments based on model-independent approach. We have found a strong correlation between dark matter signatures at the ILC and those in the indirect detec- tion experiments of dark matter. Once the dark matter is discovered ...
Challenges for the kinetic unified dark matter model

International Nuclear Information System (INIS)

Giannakis, Dimitrios; Hu, Wayne

2005-01-01

Given that the dark matter and dark energy in the Universe affect cosmological observables only gravitationally, their phenomenology may be described by a single stress-energy tensor. True unification however requires a theory that reproduces the successful phenomenology of ΛCDM and that requirement places specific constraints on the stress structure of the matter. We show that a recently proposed unification through an offset quadratic kinetic term for a scalar field is exactly equivalent to a fluid with a closed-form barotropic equation of state plus cosmological constant. The finite pressure at high densities introduces a cutoff in the linear power spectrum, which may alleviate the dark matter substructure problem; we provide a convenient fitting function for such studies. Given that sufficient power must remain to reionize the Universe, the equation of state today is nonrelativistic with p∝ρ 2 and a Jeans scale in the parsec regime for all relevant densities. Structure may then be evolved into the nonlinear regime with standard hydrodynamic techniques. In fact, the model is equivalent to the well-studied collisional dark matter with negligible mean free path. If recent observations of the triaxiality of dark matter halos and ram pressure stripping in galaxy clusters are confirmed, this model will be ruled out
Dark matter effective field theory scattering in direct detection experiments

Energy Technology Data Exchange (ETDEWEB)

Schneck, K.; Cabrera, B.; Cerdeño, D. G.; Mandic, V.; Rogers, H. E.; Agnese, R.; Anderson, A. J.; Asai, M.; Balakishiyeva, D.; Barker, D.; Basu Thakur, R.; Bauer, D. A.; Billard, J.; Borgland, A.; Brandt, D.; Brink, P. L.; Bunker, R.; Caldwell, D. O.; Calkins, R.; Chagani, H.; Chen, Y.; Cooley, J.; Cornell, B.; Crewdson, C. H.; Cushman, P.; Daal, M.; Di Stefano, P. C. F.; Doughty, T.; Esteban, L.; Fallows, S.; Figueroa-Feliciano, E.; Godfrey, G. L.; Golwala, S. R.; Hall, J.; Harris, H. R.; Hofer, T.; Holmgren, D.; Hsu, L.; Huber, M. E.; Jardin, D. M.; Jastram, A.; Kamaev, O.; Kara, B.; Kelsey, M. H.; Kennedy, A.; Leder, A.; Loer, B.; Lopez Asamar, E.; Lukens, P.; Mahapatra, R.; McCarthy, K. A.; Mirabolfathi, N.; Moffatt, R. A.; Morales Mendoza, J. D.; Oser, S. M.; Page, K.; Page, W. A.; Partridge, R.; Pepin, M.; Phipps, A.; Prasad, K.; Pyle, M.; Qiu, H.; Rau, W.; Redl, P.; Reisetter, A.; Ricci, Y.; Roberts, A.; Saab, T.; Sadoulet, B.; Sander, J.; Schnee, R. W.; Scorza, S.; Serfass, B.; Shank, B.; Speller, D.; Toback, D.; Upadhyayula, S.; Villano, A. N.; Welliver, B.; Wilson, J. S.; Wright, D. H.; Yang, X.; Yellin, S.; Yen, J. J.; Young, B. A.; Zhang, J.

2015-05-18

We examine the consequences of the effective field theory (EFT) of dark matter–nucleon scattering for current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. We demonstrate that spectral differences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. We also discuss the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.
Are black holes a serious threat to scalar field dark matter models?

International Nuclear Information System (INIS)

Barranco, Juan; Degollado, Juan Carlos; Bernal, Argelia; Diez-Tejedor, Alberto; Megevand, Miguel; Alcubierre, Miguel; Nunez, Dario; Sarbach, Olivier

2011-01-01

Classical scalar fields have been proposed as possible candidates for the dark matter component of the universe. Given the fact that supermassive black holes seem to exist at the center of most galaxies, in order to be a viable candidate for the dark matter halo a scalar field configuration should be stable in the presence of a central black hole, or at least be able to survive for cosmological time scales. In the present work we consider a scalar field as a test field on a Schwarzschild background, and study under which conditions one can obtain long-lived configurations. We present a detailed study of the Klein-Gordon equation in the Schwarzschild space-time, both from an analytical and numerical point of view, and show that indeed there exist quasistationary solutions that can remain surrounding a black hole for large time scales.
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
Kinematics of radion field: a possible source of dark matter

Energy Technology Data Exchange (ETDEWEB)

Chakraborty, Sumanta [IUCAA, Pune (India); SenGupta, Soumitra [Indian Association for the Cultivation of Science, Department of Theoretical Physics, Kolkata (India)

2016-12-15

The discrepancy between observed virial and baryonic mass in galaxy clusters have lead to the missing mass problem. To resolve this, a new, non-baryonic matter field, known as dark matter, has been invoked. However, till date no possible constituents of the dark matter components are known. This has led to various models, by modifying gravity at large distances to explain the missing mass problem. The modification to gravity appears very naturally when effective field theory on a lower-dimensional manifold, embedded in a higher-dimensional spacetime is considered. It has been shown that in a scenario with two lower-dimensional manifolds separated by a finite distance is capable to address the missing mass problem, which in turn determines the kinematics of the brane separation. Consequences for galactic rotation curves are also described. (orig.)
Generalizing a unified model of dark matter, dark energy, and inflation with a noncanonical kinetic term

International Nuclear Information System (INIS)

De-Santiago, Josue; Cervantes-Cota, Jorge L.

2011-01-01

We study a unification model for dark energy, dark matter, and inflation with a single scalar field with noncanonical kinetic term. In this model, the kinetic term of the Lagrangian accounts for the dark matter and dark energy, and at early epochs, a quadratic potential accounts for slow roll inflation. The present work is an extension to the work by Bose and Majumdar [Phys. Rev. D 79, 103517 (2009).] with a more general kinetic term that was proposed by Chimento in Phys. Rev. D 69, 123517 (2004). We demonstrate that the model is viable at the background and linear perturbation levels.
Standard model Higgs boson-inflaton and dark matter

International Nuclear Information System (INIS)

Clark, T. E.; Liu Boyang; Love, S. T.; Veldhuis, T. ter

2009-01-01

The standard model Higgs boson can serve as the inflaton field of slow roll inflationary models provided it exhibits a large nonminimal coupling with the gravitational scalar curvature. The Higgs boson self interactions and its couplings with a standard model singlet scalar serving as the source of dark matter are then subject to cosmological constraints. These bounds, which can be more stringent than those arising from vacuum stability and perturbative triviality alone, still allow values for the Higgs boson mass which should be accessible at the LHC. As the Higgs boson coupling to the dark matter strengthens, lower values of the Higgs boson mass consistent with the cosmological data are allowed.
Connections between the seesaw model and dark matter searches

International Nuclear Information System (INIS)

Adulpravitchai, Adisorn; Gu Peihong; Lindner, Manfred

2010-01-01

In some dark matter models, the coupling of the dark matter particle to the standard model Higgs determines the dark matter relic density while it is also consistent with dark matter direct-detection experiments. On the other hand, the seesaw model for generating the neutrino masses probably arises from a spontaneous symmetry breaking of global lepton number. The dark matter particle thus can significantly annihilate into massless Majorons when the lepton number-breaking scale and hence the seesaw scale are near the electroweak scale. This leads to an interesting interplay between neutrino physics and dark matter physics, and the annihilation mode has an interesting implication on dark matter searches.
Dark energy and dark matter from hidden symmetry of gravity model with a non-Riemannian volume form

Energy Technology Data Exchange (ETDEWEB)

Guendelman, Eduardo [Ben-Gurion University of the Negev, Department of Physics, Beersheba (Israel); Nissimov, Emil; Pacheva, Svetlana [Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energy, Sofia (Bulgaria)

2015-10-15

We show that dark energy and dark matter can be described simultaneously by ordinary Einstein gravity interacting with a single scalar field provided the scalar field Lagrangian couples in a symmetric fashion to two different spacetime volume forms (covariant integration measure densities) on the spacetime manifold - one standard Riemannian given by √(-g) (square root of the determinant of the pertinent Riemannian metric) and another non-Riemannian volume form independent of the Riemannian metric, defined in terms of an auxiliary antisymmetric tensor gauge field of maximal rank. Integration of the equations of motion of the latter auxiliary gauge field produce an a priori arbitrary integration constant that plays the role of a dynamically generated cosmological constant or dark energy. Moreover, the above modified scalar field action turns out to possess a hidden Noether symmetry whose associated conserved current describes a pressureless ''dust'' fluid which we can identify with the dark matter completely decoupled from the dark energy. The form of both the dark energy and dark matter that results from the above class of models is insensitive to the specific form of the scalar field Lagrangian. By adding an appropriate perturbation, which breaks the above hidden symmetry and along with this couples dark matter and dark energy, we also suggest a way to obtain growing dark energy in the present universe's epoch without evolution pathologies. (orig.)
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.
Evading direct dark matter detection in Higgs portal models

Energy Technology Data Exchange (ETDEWEB)

Arcadi, Giorgio [Max Planck Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Gross, Christian, E-mail: christian.gross@helsinki.fi [Department of Physics and Helsinki Institute of Physics, Gustaf Hällströmin katu 2, FI-00014 Helsinki (Finland); Lebedev, Oleg [Department of Physics and Helsinki Institute of Physics, Gustaf Hällströmin katu 2, FI-00014 Helsinki (Finland); Pokorski, Stefan [Institute of Theoretical Physics, University of Warsaw, Pasteura 5, PL-02-093 Warsaw (Poland); Toma, Takashi [Physik-Department T30d, Technische Universität München, James-Franck-Straße, D-85748 Garching (Germany)

2017-06-10

Many models of Higgs portal Dark Matter (DM) find themselves under pressure from increasingly tight direct detection constraints. In the framework of gauge field DM, we study how such bounds can be relaxed while retaining the thermal WIMP paradigm. When the hidden sector gauge symmetry is broken via the Higgs mechanism, the hidden sector generally contains unstable states which are lighter than dark matter. These states provide DM with an efficient annihilation channel. As a result, the DM relic abundance and the direct detection limits are controlled by different parameters, and the two can easily be reconciled. This simple setup realizes the idea of “secluded” dark matter naturally.
Scalar field dark matter with spontaneous symmetry breaking and the 3.5 keV line

Science.gov (United States)

Cosme, Catarina; Rosa, João G.; Bertolami, O.

2018-06-01

We show that the present dark matter abundance can be accounted for by an oscillating scalar field that acquires both mass and a non-zero expectation value from interactions with the Higgs field. The dark matter scalar field can be sufficiently heavy during inflation, due to a non-minimal coupling to gravity, so as to avoid the generation of large isocurvature modes in the CMB anisotropies spectrum. The field begins oscillating after reheating, behaving as radiation until the electroweak phase transition and afterwards as non-relativistic matter. The scalar field becomes unstable, although sufficiently long-lived to account for dark matter, due to mass mixing with the Higgs boson, decaying mainly into photon pairs for masses below the MeV scale. In particular, for a mass of ∼7 keV, which is effectively the only free parameter, the model predicts a dark matter lifetime compatible with the recent galactic and extragalactic observations of a 3.5 keV X-ray line.
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...
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 Matter Detection Using Helium Evaporation and Field Ionization.

Science.gov (United States)

Maris, Humphrey J; Seidel, George M; Stein, Derek

2017-11-03

We describe a method for dark matter detection based on the evaporation of helium atoms from a cold surface and their subsequent detection using field ionization. When a dark matter particle scatters off a nucleus of the target material, elementary excitations (phonons or rotons) are produced. Excitations which have an energy greater than the binding energy of helium to the surface can result in the evaporation of helium atoms. We propose to detect these atoms by ionizing them in a strong electric field. Because the binding energy of helium to surfaces can be below 1 meV, this detection scheme opens up new possibilities for the detection of dark matter particles in a mass range down to 1 MeV/c^{2}.

Dark Matter Detection Using Helium Evaporation and Field Ionization

Science.gov (United States)

Maris, Humphrey J.; Seidel, George M.; Stein, Derek

2017-11-01

We describe a method for dark matter detection based on the evaporation of helium atoms from a cold surface and their subsequent detection using field ionization. When a dark matter particle scatters off a nucleus of the target material, elementary excitations (phonons or rotons) are produced. Excitations which have an energy greater than the binding energy of helium to the surface can result in the evaporation of helium atoms. We propose to detect these atoms by ionizing them in a strong electric field. Because the binding energy of helium to surfaces can be below 1 meV, this detection scheme opens up new possibilities for the detection of dark matter particles in a mass range down to 1 MeV /c2 .
Is neutralino dark matter compatible with flipped SU(5) models

Energy Technology Data Exchange (ETDEWEB)

McDonald, J.

1989-07-13

We consider the possibility that the lightest supersymmetric particle in flipped SUSY SU(5)xU(1) models is cosmologically stable and corresponds to a neutralino. Previous studies of dark matter in flipped SUSY SU(5) models have suggested that the decay of the oscillations of the SU(5) breaking scalar field would result in too many neutralinos, if they are stable. We show that it is possible for an acceptable density of neutralinos to occur in the case where the neutralino corresponds to a light photino, if the temperature at the end of the oscillation dominated period is dark matter in flipped SU(5) models. Direct detection of dark matter in forthcoming experiments will therefore not eliminate this class of models. (orig.).
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.
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.)
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
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.
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
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.
Dark matter and global symmetries

Directory of Open Access Journals (Sweden)

Yann Mambrini

2016-09-01

Full Text Available General considerations in general relativity and quantum mechanics are known to potentially rule out continuous global symmetries in the context of any consistent theory of quantum gravity. Assuming the validity of such considerations, we derive stringent bounds from gamma-ray, X-ray, cosmic-ray, neutrino, and CMB data on models that invoke global symmetries to stabilize the dark matter particle. We compute up-to-date, robust model-independent limits on the dark matter lifetime for a variety of Planck-scale suppressed dimension-five effective operators. We then specialize our analysis and apply our bounds to specific models including the Two-Higgs-Doublet, Left–Right, Singlet Fermionic, Zee–Babu, 3-3-1 and Radiative See-Saw models. Assuming that (i global symmetries are broken at the Planck scale, that (ii the non-renormalizable operators mediating dark matter decay have O(1 couplings, that (iii the dark matter is a singlet field, and that (iv the dark matter density distribution is well described by a NFW profile, we are able to rule out fermionic, vector, and scalar dark matter candidates across a broad mass range (keV–TeV, including the WIMP regime.
Relic abundance of mass-varying cold dark matter particles

International Nuclear Information System (INIS)

Rosenfeld, Rogerio

2005-01-01

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

Energy Technology Data Exchange (ETDEWEB)

Aguirre, Anthony; Diez-Tejedor, Alberto, E-mail: aguirre@scipp.ucsc.edu, E-mail: alberto.diez@fisica.ugto.mx [Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA, 95064 (United States)

2016-04-01

We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component would develop a Bose-Einstein condensate in the early universe that, for appropriate model parameters, could survive the ensuing cosmological evolution until now. The condensation of a dark matter component in equilibrium with the thermal plasma is a relativistic process, hence the amount of matter dictated by the charge asymmetry is complemented by a hot relic density frozen out at the time of decoupling. Contrary to the case of ordinary WIMPs, dark matter particles in a condensate must be lighter than a few tens of eV so that the density from thermal relics is not too large. Big-Bang nucleosynthesis constrains the temperature of decoupling to the scale of the QCD phase transition or above. This requires large dark matter-to-photon ratios and very weak interactions with standard model particles.
Dark matter haloes: a multistream view

Science.gov (United States)

Ramachandra, Nesar S.; Shandarin, Sergei F.

2017-09-01

Mysterious dark matter constitutes about 85 per cent of all masses in the Universe. Clustering of dark matter plays a dominant role in the formation of all observed structures on scales from a fraction to a few hundreds of Mega-parsecs. Galaxies play a role of lights illuminating these structures so they can be observed. The observations in the last several decades have unveiled opulent geometry of these structures currently known as the cosmic web. Haloes are the highest concentrations of dark matter and host luminous galaxies. Currently the most accurate modelling of dark matter haloes is achieved in cosmological N-body simulations. Identifying the haloes from the distribution of particles in N-body simulations is one of the problems attracting both considerable interest and efforts. We propose a novel framework for detecting potential dark matter haloes using the field unique for dark matter-multistream field. The multistream field emerges at the non-linear stage of the growth of perturbations because the dark matter is collisionless. Counting the number of velocity streams in gravitational collapses supplements our knowledge of spatial clustering. We assume that the virialized haloes have convex boundaries. Closed and convex regions of the multistream field are hence isolated by imposing a positivity condition on all three eigenvalues of the Hessian estimated on the smoothed multistream field. In a single-scale analysis of high multistream field resolution and low softening length, the halo substructures with local multistream maxima are isolated as individual halo sites.
S-Channel Dark Matter Simplified Models and Unitarity

CERN Document Server

Englert, Christoph; Spannowsky, Michael

The ultraviolet structure of $s$-channel mediator dark matter simplified models at hadron colliders is considered. In terms of commonly studied $s$-channel mediator simplified models it is argued that at arbitrarily high energies the perturbative description of dark matter production in high energy scattering at hadron colliders will break down in a number of cases. This is analogous to the well documented breakdown of an EFT description of dark matter collider production. With this in mind, to diagnose whether or not the use of simplified models at the LHC is valid, perturbative unitarity of the scattering amplitude in the processes relevant to LHC dark matter searches is studied. The results are as one would expect: at the LHC and future proton colliders the simplified model descriptions of dark matter production are in general valid. As a result of the general discussion, a simple new class of previously unconsidered `Fermiophobic Scalar' simplified models is proposed, in which a scalar mediator couples to...
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.
EDITORIAL: Focus on Dark Matter and Particle Physics

Science.gov (United States)

Aprile, Elena; Profumo, Stefano

2009-10-01

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

NARCIS (Netherlands)

Cline, J.M.; Scott, P.; Kainulainen, K.; Weniger, C.

2013-01-01

One of the simplest models of dark matter is where a scalar singlet field S comprises some or all of the dark matter and interacts with the standard model through an vertical bar H vertical bar S-2(2) coupling to the Higgs boson. We update the present limits on the model from LHC searches for
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.
Consequences of dark matter-dark energy interaction on cosmological parameters derived from type Ia supernova data

International Nuclear Information System (INIS)

Amendola, Luca; Campos, Gabriela Camargo; Rosenfeld, Rogerio

2007-01-01

Models where the dark matter component of the Universe interacts with the dark energy field have been proposed as a solution to the cosmic coincidence problem, since in the attractor regime both dark energy and dark matter scale in the same way. In these models the mass of the cold dark matter particles is a function of the dark energy field responsible for the present acceleration of the Universe, and different scenarios can be parametrized by how the mass of the cold dark matter particles evolves with time. In this article we study the impact of a constant coupling δ between dark energy and dark matter on the determination of a redshift dependent dark energy equation of state w DE (z) and on the dark matter density today from SNIa data. We derive an analytical expression for the luminosity distance in this case. In particular, we show that the presence of such a coupling increases the tension between the cosmic microwave background data from the analysis of the shift parameter in models with constant w DE and SNIa data for realistic values of the present dark matter density fraction. Thus, an independent measurement of the present dark matter density can place constraints on models with interacting dark energy
Static Universe model existing due to the matter-dark energy coupling

International Nuclear Information System (INIS)

Cabo Bizet, A.; Cabo Montes de Oca, A.

2007-08-01

The work investigates a static, isotropic and almost homogeneous Universe containing a real scalar field modeling the Dark-Energy (quintaessence) interacting with pressureless matter. It is argued that the interaction between matter and the Dark Energy, is essential for the very existence of the considered solution. Assuming the possibility that Dark-Energy can be furnished by the Dilaton (a scalar field reflecting the condensation of string states with zero angular momentum) we fix the value of scalar field at the origin to the Planck scale. It became possible to fix the ratio of the amount of Dark Energy to matter energy, in the currently estimated value (0.7)/0.3 and also the observed magnitude of the Hubble constant. The small value of the mass for the scalar field chosen for fixing the above ratio and Hubble effect strength, results to be of the order of 10 -29 cm -1 , a small value which seems to be compatible with the zero mass of the Dilaton in the lowest approximations. (author)

Simplified Dark Matter Models

OpenAIRE

Morgante, Enrico

2018-01-01

I review the construction of Simplified Models for Dark Matter searches. After discussing the philosophy and some simple examples, I turn the attention to the aspect of the theoretical consistency and to the implications of the necessary extensions of these models.
Indirect detection constraints on s- and t-channel simplified models of dark matter

Science.gov (United States)

Carpenter, Linda M.; Colburn, Russell; Goodman, Jessica; Linden, Tim

2016-09-01

Recent Fermi-LAT observations of dwarf spheroidal galaxies in the Milky Way have placed strong limits on the gamma-ray flux from dark matter annihilation. In order to produce the strongest limit on the dark matter annihilation cross section, the observations of each dwarf galaxy have typically been "stacked" in a joint-likelihood analysis, utilizing optical observations to constrain the dark matter density profile in each dwarf. These limits have typically been computed only for singular annihilation final states, such as b b ¯ or τ+τ- . In this paper, we generalize this approach by producing an independent joint-likelihood analysis to set constraints on models where the dark matter particle annihilates to multiple final-state fermions. We interpret these results in the context of the most popular simplified models, including those with s- and t-channel dark matter annihilation through scalar and vector mediators. We present our results as constraints on the minimum dark matter mass and the mediator sector parameters. Additionally, we compare our simplified model results to those of effective field theory contact interactions in the high-mass limit.
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
Bouncing Cosmologies with Dark Matter and Dark Energy

Directory of Open Access Journals (Sweden)

Yi-Fu Cai

2016-12-01

Full Text Available We review matter bounce scenarios where the matter content is dark matter and dark energy. These cosmologies predict a nearly scale-invariant power spectrum with a slightly red tilt for scalar perturbations and a small tensor-to-scalar ratio. Importantly, these models predict a positive running of the scalar index, contrary to the predictions of the simplest inflationary and ekpyrotic models, and hence, could potentially be falsified by future observations. We also review how bouncing cosmological space-times can arise in theories where either the Einstein equations are modified or where matter fields that violate the null energy condition are included.
Particle dark matter from physics beyond the standard model

International Nuclear Information System (INIS)

Matchev, Konstantin

2004-01-01

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

International Nuclear Information System (INIS)

Feng, Jonathan L.; Kaplinghat, Manoj; Tu, Huitzu; Yu, Hai-Bo

2009-01-01

Can dark matter be stabilized by charge conservation, just as the electron is in the standard model? We examine the possibility that dark matter is hidden, that is, neutral under all standard model gauge interactions, but charged under an exact (\\rm U)(1) gauge symmetry of the hidden sector. Such candidates are predicted in WIMPless models, supersymmetric models in which hidden dark matter has the desired thermal relic density for a wide range of masses. Hidden charged dark matter has many novel properties not shared by neutral dark matter: (1) bound state formation and Sommerfeld-enhanced annihilation after chemical freeze out may reduce its relic density, (2) similar effects greatly enhance dark matter annihilation in protohalos at redshifts of z ∼ 30, (3) Compton scattering off hidden photons delays kinetic decoupling, suppressing small scale structure, and (4) Rutherford scattering makes such dark matter self-interacting and collisional, potentially impacting properties of the Bullet Cluster and the observed morphology of galactic halos. We analyze all of these effects in a WIMPless model in which the hidden sector is a simplified version of the minimal supersymmetric standard model and the dark matter is a hidden sector stau. We find that charged hidden dark matter is viable and consistent with the correct relic density for reasonable model parameters and dark matter masses in the range 1 GeV ∼ X ∼< 10 TeV. At the same time, in the preferred range of parameters, this model predicts cores in the dark matter halos of small galaxies and other halo properties that may be within the reach of future observations. These models therefore provide a viable and well-motivated framework for collisional dark matter with Sommerfeld enhancement, with novel implications for astrophysics and dark matter searches
Galactic signatures of decaying dark matter

International Nuclear Information System (INIS)

Zhang, Le; Sigl, Guenter

2009-05-01

If dark matter decays into electrons and positrons, it can affect Galactic radio emissions and the local cosmic ray fluxes. We propose a new, more general analysis of constraints on dark matter. The constraints can be obtained for any decaying dark matter model by convolving the specific dark matter decay spectrum with a response function. We derive this response function from full-sky radio surveys at 408 MHz, 1.42 GHz and 23 GHz, as well as from the positron flux recently reported by PAMELA. We discuss the influence of astrophysical uncertainties on the response function, such as from propagation and from the profiles of the dark matter and the Galactic magnetic field. As an application, we find that some widely used dark matter decay scenarios can be ruled out under modest assumptions. (orig.)
Galactic signatures of decaying dark matter

Energy Technology Data Exchange (ETDEWEB)

Zhang, Le; Sigl, Guenter [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Redondo, Javier [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2009-05-15

If dark matter decays into electrons and positrons, it can affect Galactic radio emissions and the local cosmic ray fluxes. We propose a new, more general analysis of constraints on dark matter. The constraints can be obtained for any decaying dark matter model by convolving the specific dark matter decay spectrum with a response function. We derive this response function from full-sky radio surveys at 408 MHz, 1.42 GHz and 23 GHz, as well as from the positron flux recently reported by PAMELA. We discuss the influence of astrophysical uncertainties on the response function, such as from propagation and from the profiles of the dark matter and the Galactic magnetic field. As an application, we find that some widely used dark matter decay scenarios can be ruled out under modest assumptions. (orig.)
Asymmetric dark matter and CP violating scatterings in a UV complete model

Energy Technology Data Exchange (ETDEWEB)

Baldes, Iason; Bell, Nicole F.; Millar, Alexander J.; Volkas, Raymond R. [ARC Centre of Excellence for Particle Physics at the Terascale,School of Physics, The University of Melbourne, Victoria, 3010 (Australia)

2015-10-21

We explore possible asymmetric dark matter models using CP violating scatterings to generate an asymmetry. In particular, we introduce a new model, based on DM fields coupling to the SM Higgs and lepton doublets, a neutrino portal, and explore its UV completions. We study the CP violation and asymmetry formation of this model, to demonstrate that it is capable of producing the correct abundance of dark matter and the observed matter-antimatter asymmetry. Crucial to achieving this is the introduction of interactions which violate CP with a T{sup 2} dependence.
Asymmetric dark matter and CP violating scatterings in a UV complete model

Energy Technology Data Exchange (ETDEWEB)

Baldes, Iason; Bell, Nicole F.; Millar, Alexander J.; Volkas, Raymond R., E-mail: i.baldes@student.unimelb.edu.au, E-mail: n.bell@unimelb.edu.au, E-mail: amillar@student.unimelb.edu.au, E-mail: raymondv@unimelb.edu.au [ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, The University of Melbourne, Victoria, 3010 Australia (Australia)

2015-10-01

We explore possible asymmetric dark matter models using CP violating scatterings to generate an asymmetry. In particular, we introduce a new model, based on DM fields coupling to the SM Higgs and lepton doublets, a neutrino portal, and explore its UV completions. We study the CP violation and asymmetry formation of this model, to demonstrate that it is capable of producing the correct abundance of dark matter and the observed matter-antimatter asymmetry. Crucial to achieving this is the introduction of interactions which violate CP with a T{sup 2} dependence.
An introduction to particle dark matter

CERN Document Server

Profumo, Stefano

2017-01-01

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

International Nuclear Information System (INIS)

Henriques, Alfredo B.; Potting, Robertus; Sa, Paulo M.

2009-01-01

We investigate a cosmological model, based on the Salam-Sezgin six-dimensional supergravity theory and on previous work by Anchordoqui, Goldberg, Nawata, and Nunez. Assuming a period of warm inflation, we show that it is possible to extend the evolution of the model back in time, to include the inflationary period, thus unifying inflation, dark matter, and dark energy within a single framework. Like the previous authors, we were not able to obtain the full dark matter content of the universe from the Salam-Sezgin scalar fields. However, even if only partially successful, this work shows that present-day theories, based on superstrings and supergravity, may eventually lead to a comprehensive modeling of the evolution of the universe. We find that the gravitational-wave spectrum of the model has a nonconstant negative slope in the frequency range (10 -15 -10 6 ) rad/s, and that, unlike standard (cold) inflation models, it shows no structure in the MHz/GHz range of frequencies.
Role of baryons in unified dark matter models

International Nuclear Information System (INIS)

Beca, L.M.G.; Avelino, P.P.; Carvalho, J.P. de M.; Martins, C.J.A.P.

2003-01-01

We discuss the importance of including baryons in analyses of unified dark matter scenarios, focusing on toy models involving a generalized Chaplygin gas. We determine observational constraints on this unified dark matter scenario coming from large-scale structure, type Ia supernovae and CMB data showing how this component can bring about a different behavior from the classical cold dark matter model with a cosmological constant and thus motivate further studies of this type of models. We also speculate on interesting new features which are likely to be important on nonlinear scales in this context
Heavy spin-2 Dark Matter

Energy Technology Data Exchange (ETDEWEB)

Babichev, Eugeny [Laboratoire de Physique Théorique, CNRS, Univ. Paris-Sud, Université Paris-Saclay,91405 Orsay (France); UPMC-CNRS, UMR7095, Institut d’Astrophysique de Paris, GReCO,98bis boulevard Arago, F-75014 Paris (France); Marzola, Luca; Raidal, Martti [National Institute of Chemical Physics and Biophysics,Rävala 10, 10143 Tallinn (Estonia); Laboratory of Theoretical Physics, Institute of Physics, University of Tartu,Ravila 14c, 50411 Tartu (Estonia); Schmidt-May, Angnis [Institut für Theoretische Physik, Eidgenössische Technische Hochschule Zürich,Wolfgang-Pauli-Strasse 27, 8093 Zürich (Switzerland); Urban, Federico; Veermäe, Hardi [National Institute of Chemical Physics and Biophysics,Rävala 10, 10143 Tallinn (Estonia); Strauss, Mikael von [UPMC-CNRS, UMR7095, Institut d’Astrophysique de Paris, GReCO,98bis boulevard Arago, F-75014 Paris (France)

2016-09-12

We provide further details on a recent proposal addressing the nature of the dark sectors in cosmology and demonstrate that all current observations related to Dark Matter can be explained by the presence of a heavy spin-2 particle. Massive spin-2 fields and their gravitational interactions are uniquely described by ghost-free bimetric theory, which is a minimal and natural extension of General Relativity. In this setup, the largeness of the physical Planck mass is naturally related to extremely weak couplings of the heavy spin-2 field to baryonic matter and therefore explains the absence of signals in experiments dedicated to Dark Matter searches. It also ensures the phenomenological viability of our model as we confirm by comparing it with cosmological and local tests of gravity. At the same time, the spin-2 field possesses standard gravitational interactions and it decays universally into all Standard Model fields but not into massless gravitons. Matching the measured DM abundance together with the requirement of stability constrains the spin-2 mass to be in the 1 to 100 TeV range.
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
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.
Growth of perturbations in dark matter coupled with quintessence

International Nuclear Information System (INIS)

Koivisto, Tomi

2005-01-01

We consider the evolution of linear perturbations in models with a nonminimal coupling between dark matter and scalar field dark energy. Growth of matter inhomogeneities in two examples of such models proposed in the literature are investigated in detail. Both of these models are based on a low-energy limit of effective string theory action, and have been previously shown to naturally lead to late acceleration of the Universe. However, we find that these models can be ruled out by taking properly into account the impact of the scalar field coupling on the formation of structure in the dark matter density. In particular, when the transition to acceleration in these models begins, the interaction with dark energy enhances the small scale clustering in dark matter much too strongly. We discuss also the role of an effective small scale sound speed squared and the issue of adiabatic initial conditions in models with a coupled dark sector
Two radiative inverse seesaw models, dark matter, and baryogenesis

International Nuclear Information System (INIS)

Baldes, Iason; Bell, Nicole F.; Petraki, Kalliopi; Volkas, Raymond R.

2013-01-01

The inverse seesaw mechanism allows the neutrino masses to be generated by new physics at an experimentally accessible scale, even with O(1) Yukawa couplings. In the inverse seesaw scenario, the smallness of neutrino masses is linked to the smallness of a lepton number violating parameter. This parameter may arise radiatively. In this paper, we study the cosmological implications of two contrasting radiative inverse seesaw models, one due to Ma and the other to Law and McDonald. The former features spontaneous, the latter explicit lepton number violation. First, we examine the effect of the lepton-number violating interactions introduced in these models on the baryon asymmetry of the universe. We investigate under what conditions a pre-existing baryon asymmetry does not get washed out. While both models allow a baryon asymmetry to survive only once the temperature has dropped below the mass of their heaviest fields, the Ma model can create the baryon asymmetry through resonant leptogenesis. Then we investigate the viability of the dark matter candidates arising within these models, and explore the prospects for direct detection. We find that the Law/McDonald model allows a simple dark matter scenario similar to the Higgs portal, while in the Ma model the simplest cold dark matter scenario would tend to overclose the universe
Effect of CP violation in the singlet-doublet dark matter model

Directory of Open Access Journals (Sweden)

Tomohiro Abe

2017-08-01

Full Text Available We revisit the singlet-doublet dark matter model with a special emphasis on the effect of CP violation on the dark matter phenomenology. The CP violation in the dark sector induces a pseudoscalar interaction of a fermionic dark matter candidate with the SM Higgs boson. The pseudoscalar interaction helps the dark matter candidate evade the strong constraints from the dark matter direct detection experiments. We show that the model can explain the measured value of the dark matter density even if dark matter direct detection experiments do not observe any signal. We also show that the electron electric dipole moment is an important complement to the direct detection for testing this model. Its value is smaller than the current upper bound but within the reach of future experiments.

Flooded Dark Matter and S level rise

International Nuclear Information System (INIS)

Randall, Lisa; Scholtz, Jakub; Unwin, James

2016-01-01

Most dark matter models set the dark matter relic density by some interaction with Standard Model particles. Such models generally assume the existence of Standard Model particles early on, with the dark matter relic density a later consequence of those interactions. Perhaps a more compelling assumption is that dark matter is not part of the Standard Model sector and a population of dark matter too is generated at the end of inflation. This democratic assumption about initial conditions does not necessarily provide a natural value for the dark matter relic density, and furthermore superficially leads to too much entropy in the dark sector relative to ordinary matter. We address the latter issue by the late decay of heavy particles produced at early times, thereby associating the dark matter relic density with the lifetime of a long-lived state. This paper investigates what it would take for this scenario to be compatible with observations in what we call Flooded Dark Matter (FDM) models and discusses several interesting consequences. One is that dark matter can be very light and furthermore, light dark matter is in some sense the most natural scenario in FDM as it is compatible with larger couplings of the decaying particle. A related consequence is that the decay of the field with the smallest coupling and hence the longest lifetime dominates the entropy and possibly the matter content of the Universe, a principle we refer to as “Maximum Baroqueness”. We also demonstrate that the dark sector should be colder than the ordinary sector, relaxing the most stringent free-streaming constraints on light dark matter candidates. We will discuss the potential implications for the core-cusp problem in a follow-up paper. The FDM framework will furthermore have interesting baryogenesis implications. One possibility is that dark matter is like the baryon asymmetry and both are simultaneously diluted by a late entropy dump. Alternatively, FDM is compatible with an elegant
Flooded Dark Matter and S level rise

Energy Technology Data Exchange (ETDEWEB)

Randall, Lisa; Scholtz, Jakub [Department of Physics, Harvard University,Cambridge, MA 02138 (United States); Unwin, James [Department of Physics, University of Illinois at Chicago,Chicago, IL 60607 (United States)

2016-03-03

Most dark matter models set the dark matter relic density by some interaction with Standard Model particles. Such models generally assume the existence of Standard Model particles early on, with the dark matter relic density a later consequence of those interactions. Perhaps a more compelling assumption is that dark matter is not part of the Standard Model sector and a population of dark matter too is generated at the end of inflation. This democratic assumption about initial conditions does not necessarily provide a natural value for the dark matter relic density, and furthermore superficially leads to too much entropy in the dark sector relative to ordinary matter. We address the latter issue by the late decay of heavy particles produced at early times, thereby associating the dark matter relic density with the lifetime of a long-lived state. This paper investigates what it would take for this scenario to be compatible with observations in what we call Flooded Dark Matter (FDM) models and discusses several interesting consequences. One is that dark matter can be very light and furthermore, light dark matter is in some sense the most natural scenario in FDM as it is compatible with larger couplings of the decaying particle. A related consequence is that the decay of the field with the smallest coupling and hence the longest lifetime dominates the entropy and possibly the matter content of the Universe, a principle we refer to as “Maximum Baroqueness”. We also demonstrate that the dark sector should be colder than the ordinary sector, relaxing the most stringent free-streaming constraints on light dark matter candidates. We will discuss the potential implications for the core-cusp problem in a follow-up paper. The FDM framework will furthermore have interesting baryogenesis implications. One possibility is that dark matter is like the baryon asymmetry and both are simultaneously diluted by a late entropy dump. Alternatively, FDM is compatible with an elegant
Natural SUSY dark matter model

International Nuclear Information System (INIS)

Mohanty, Subhendra; Rao, Soumya; Roy, D.P.

2013-01-01

The most natural region of cosmologically compatible dark matter relic density in terms of low fine-tuning in a minimal supersymmetric standard model with nonuniversal gaugino masses is the so called bulk annihilation region. We study this region in a simple and predictive SUSY- GUT model of nonuniversal gaugino masses, where the latter transform as a combination of singlet plus a nonsinglet representation of the GUTgroup SU(5). The model prediction for the direct dark matter detection rates is well below the present CDMS and XENON100 limits, but within the reach of a future 1Ton XENON experiment. The most interesting and robust model prediction is an indirect detection signal of hard positron events, which resembles closely the shape of the observed positron spectrum from the PAMELA experiment. (author)
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.
Seeded hot dark matter models with inflation

Science.gov (United States)

Gratsias, John; Scherrer, Robert J.; Steigman, Gary; Villumsen, Jens V.

1993-01-01

We examine massive neutrino (hot dark matter) models for large-scale structure in which the density perturbations are produced by randomly distributed relic seeds and by inflation. Power spectra, streaming velocities, and the Sachs-Wolfe quadrupole fluctuation are derived for this model. We find that the pure seeded hot dark matter model without inflation produces Sachs-Wolfe fluctuations far smaller than those seen by COBE. With the addition of inflationary perturbations, fluctuations consistent with COBE can be produced. The COBE results set the normalization of the inflationary component, which determines the large-scale (about 50/h Mpc) streaming velocities. The normalization of the seed power spectrum is a free parameter, which can be adjusted to obtain the desired fluctuations on small scales. The power spectra produced are very similar to those seen in mixed hot and cold dark matter models.
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.
Excluding the light dark matter window of a 331 model using LHC and direct dark matter detection data

Energy Technology Data Exchange (ETDEWEB)

Cogollo, D. [Departamento de Física, Universidade Federal de Campina Grande, Caixa Postal 10071, 58109-970, Campina Grande, PB (Brazil); Gonzalez-Morales, Alma X.; Queiroz, Farinaldo S. [Department of Physics and Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, CA 95064 (United States); Teles, P. Rebello, E-mail: diegocogollo@df.ufcg.edu.br, E-mail: alxogonz@ucsc.edu, E-mail: fdasilva@ucsc.edu, E-mail: patricia.rebello.teles@cern.ch [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)

2014-11-01

We sift the impact of the recent Higgs precise measurements, and recent dark matter direct detection results, on the dark sector of an electroweak extension of the Standard Model that has a complex scalar as dark matter. We find that in this model the Higgs decays with a large branching ratio into dark matter particles, and charged scalars when these are kinematically available, for any coupling strength differently from the so called Higgs portal. Moreover, we compute the abundance and spin-independent WIMP-nucleon scattering cross section, which are driven by the Higgs and Z{sup '} boson processes. We decisively exclude the 1–500 GeV dark matter window and find the most stringent lower bound in the literature on the scale of symmetry breaking of the model namely 10 TeV, after applying the LUX-2013 limit. Interestingly, the projected XENON1T constraint will be able to rule out the entire 1 GeV–1000 GeV dark matter mass range. Lastly, for completeness, we compute the charged scalar production cross section at the LHC and comment on the possibility of detection at current and future LHC runnings.
Excluding the light dark matter window of a 331 model using LHC and direct dark matter detection data

International Nuclear Information System (INIS)

Cogollo, D.; Gonzalez-Morales, Alma X.; Queiroz, Farinaldo S.; Teles, P. Rebello

2014-01-01

We sift the impact of the recent Higgs precise measurements, and recent dark matter direct detection results, on the dark sector of an electroweak extension of the Standard Model that has a complex scalar as dark matter. We find that in this model the Higgs decays with a large branching ratio into dark matter particles, and charged scalars when these are kinematically available, for any coupling strength differently from the so called Higgs portal. Moreover, we compute the abundance and spin-independent WIMP-nucleon scattering cross section, which are driven by the Higgs and Z ' boson processes. We decisively exclude the 1–500 GeV dark matter window and find the most stringent lower bound in the literature on the scale of symmetry breaking of the model namely 10 TeV, after applying the LUX-2013 limit. Interestingly, the projected XENON1T constraint will be able to rule out the entire 1 GeV–1000 GeV dark matter mass range. Lastly, for completeness, we compute the charged scalar production cross section at the LHC and comment on the possibility of detection at current and future LHC runnings
Collider and dark matter searches in the inert doublet model from Peccei-Quinn symmetry

Energy Technology Data Exchange (ETDEWEB)

Alves, Alexandre [Departamento de Ciências Exatas e da Terra, Universidade Federal de São Paulo,Diadema-SP, 09972-270 (Brazil); Camargo, Daniel A.; Dias, Alex G. [Universidade Federal do ABC, Centro de Ciências Naturais e Humanas,09210-580, Santo André-SP (Brazil); Longas, Robinson [Instituto de Física, Universidad de Antioquia,Calle 70 No. 52-21, Medellín (Colombia); Nishi, Celso C. [Universidade Federal do ABC, Centro de Matemática, Computação e Cognição Naturais,09210-580, Santo André-SP (Brazil); Queiroz, Farinaldo S. [Max-Planck-Institut fur Kernphysik,Saupfercheckweg 1, 69117 Heidelberg (Germany)

2016-10-04

Weakly Interacting Massive Particles (WIMPs) and axions are arguably the most compelling dark matter candidates in the literature. Could they coexist as dark matter particles? More importantly, can they be incorporated in a well motivated framework in agreement with experimental data? In this work, we show that this two component dark matter can be realized in the Inert Doublet Model in an elegant and natural manner by virtue of the spontaneous breaking of a Peccei-Quinn U(1){sub PQ} symmetry into a residual ℤ{sub 2} symmetry. The WIMP stability is guaranteed by the ℤ{sub 2} symmetry and a new dark matter component, the axion, arises. There are two interesting outcomes: (i) vector-like quarks needed to implement the Peccei-Quinn symmetry in the model may act as a portal between the dark sector and the SM fields with a supersymmetry-type phenomenology at colliders; (ii) two-component Inert Doublet Model re-opens the phenomenologically interesting 100–500 GeV mass region. We show that the model can successfully realize a two component dark matter framework and at the same time avoid low and high energy physics constraints such as monojet and dijet plus missing energy, as well as indirect and direct dark matter detection bounds.
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.
Simplified models for dark matter face their consistent completions

Energy Technology Data Exchange (ETDEWEB)

Gonçalves, Dorival; Machado, Pedro A. N.; No, Jose Miguel

2017-03-01

Simplified dark matter models have been recently advocated as a powerful tool to exploit the complementarity between dark matter direct detection, indirect detection and LHC experimental probes. Focusing on pseudoscalar mediators between the dark and visible sectors, we show that the simplified dark matter model phenomenology departs significantly from that of consistent ${SU(2)_{\\mathrm{L}} \\times U(1)_{\\mathrm{Y}}}$ gauge invariant completions. We discuss the key physics simplified models fail to capture, and its impact on LHC searches. Notably, we show that resonant mono-Z searches provide competitive sensitivities to standard mono-jet analyses at $13$ TeV LHC.
Status of the scalar singlet dark matter model

Science.gov (United States)

Athron, Peter; Balázs, Csaba; Bringmann, Torsten; Buckley, Andy; Chrząszcz, Marcin; Conrad, Jan; Cornell, Jonathan M.; Dal, Lars A.; Edsjö, Joakim; Farmer, Ben; Jackson, Paul; Kahlhoefer, Felix; Krislock, Abram; Kvellestad, Anders; McKay, James; Mahmoudi, Farvah; Martinez, Gregory D.; Putze, Antje; Raklev, Are; Rogan, Christopher; Saavedra, Aldo; Savage, Christopher; Scott, Pat; Serra, Nicola; Weniger, Christoph; White, Martin

2017-08-01

One of the simplest viable models for dark matter is an additional neutral scalar, stabilised by a Z_2 symmetry. Using the GAMBIT package and combining results from four independent samplers, we present Bayesian and frequentist global fits of this model. We vary the singlet mass and coupling along with 13 nuisance parameters, including nuclear uncertainties relevant for direct detection, the local dark matter density, and selected quark masses and couplings. We include the dark matter relic density measured by Planck, direct searches with LUX, PandaX, SuperCDMS and XENON100, limits on invisible Higgs decays from the Large Hadron Collider, searches for high-energy neutrinos from dark matter annihilation in the Sun with IceCube, and searches for gamma rays from annihilation in dwarf galaxies with the Fermi-LAT. Viable solutions remain at couplings of order unity, for singlet masses between the Higgs mass and about 300 GeV, and at masses above ˜ 1 TeV. Only in the latter case can the scalar singlet constitute all of dark matter. Frequentist analysis shows that the low-mass resonance region, where the singlet is about half the mass of the Higgs, can also account for all of dark matter, and remains viable. However, Bayesian considerations show this region to be rather fine-tuned.
Holographic vortices in the presence of dark matter sector

International Nuclear Information System (INIS)

Rogatko, Marek; Wysokinski, Karol I.

2015-01-01

The dark matter seem to be an inevitable ingredient of the total matter configuration in the Universe and the knowledge how the dark matter affects the properties of superconductors is of vital importance for the experiments aimed at its direct detection. The homogeneous magnetic field acting perpendicularly to the surface of (2+1) dimensional s-wave holographic superconductor in the theory with dark matter sector has been modeled by the additional U(1)-gauge field representing dark matter and coupled to the Maxwell one. As expected the free energy for the vortex configuration turns out to be negative. Importantly its value is lower in the presence of dark matter sector. This feature can explain why in the Early Universe first the web of dark matter appeared and next on these gratings the ordinary matter forming cluster of galaxies has formed.
Holographic vortices in the presence of dark matter sector

Energy Technology Data Exchange (ETDEWEB)

Rogatko, Marek; Wysokinski, Karol I. [Institute of Physics, Maria Curie-Skłodowska University, 20-031 Lublin, pl. Marii Curie-Skłodowskiej 1 (Poland)

2015-12-09

The dark matter seem to be an inevitable ingredient of the total matter configuration in the Universe and the knowledge how the dark matter affects the properties of superconductors is of vital importance for the experiments aimed at its direct detection. The homogeneous magnetic field acting perpendicularly to the surface of (2+1) dimensional s-wave holographic superconductor in the theory with dark matter sector has been modeled by the additional U(1)-gauge field representing dark matter and coupled to the Maxwell one. As expected the free energy for the vortex configuration turns out to be negative. Importantly its value is lower in the presence of dark matter sector. This feature can explain why in the Early Universe first the web of dark matter appeared and next on these gratings the ordinary matter forming cluster of galaxies has formed.
Holographic vortices in the presence of dark matter sector

Science.gov (United States)

Rogatko, Marek; Wysokinski, Karol I.

2015-12-01

The dark matter seem to be an inevitable ingredient of the total matter configuration in the Universe and the knowledge how the dark matter affects the properties of superconductors is of vital importance for the experiments aimed at its direct detection. The homogeneous magnetic field acting perpendicularly to the surface of (2+1) dimensional s-wave holographic superconductor in the theory with dark matter sector has been modeled by the additional U(1)-gauge field representing dark matter and coupled to the Maxwell one. As expected the free energy for the vortex configuration turns out to be negative. Importantly its value is lower in the presence of dark matter sector. This feature can explain why in the Early Universe first the web of dark matter appeared and next on these gratings the ordinary matter forming cluster of galaxies has formed.
Macro Dark Matter

CERN Document Server

Jacobs, David M; Lynn, Bryan W.

2015-01-01

Dark matter is a vital component of the current best model of our universe, $\\Lambda$CDM. There are leading candidates for what the dark matter could be (e.g. weakly-interacting massive particles, or axions), but no compelling observational or experimental evidence exists to support these particular candidates, nor any beyond-the-Standard-Model physics that might produce such candidates. This suggests that other dark matter candidates, including ones that might arise in the Standard Model, should receive increased attention. Here we consider a general class of dark matter candidates with characteristic masses and interaction cross-sections characterized in units of grams and cm$^2$, respectively -- we therefore dub these macroscopic objects as Macros. Such dark matter candidates could potentially be assembled out of Standard Model particles (quarks and leptons) in the early universe. A combination of earth-based, astrophysical, and cosmological observations constrain a portion of the Macro parameter space; ho...
Dark matter dynamics in Abell 3827: new data consistent with standard cold dark matter

Science.gov (United States)

Massey, Richard; Harvey, David; Liesenborgs, Jori; Richard, Johan; Stach, Stuart; Swinbank, Mark; Taylor, Peter; Williams, Liliya; Clowe, Douglas; Courbin, Frédéric; Edge, Alastair; Israel, Holger; Jauzac, Mathilde; Joseph, Rémy; Jullo, Eric; Kitching, Thomas D.; Leonard, Adrienne; Merten, Julian; Nagai, Daisuke; Nightingale, James; Robertson, Andrew; Romualdez, Luis Javier; Saha, Prasenjit; Smit, Renske; Tam, Sut-Ieng; Tittley, Eric

2018-06-01

We present integral field spectroscopy of galaxy cluster Abell 3827, using Atacama Large Millimetre Array (ALMA) and Very Large Telescope/Multi-Unit Spectroscopic Explorer. It reveals an unusual configuration of strong gravitational lensing in the cluster core, with at least seven lensed images of a single background spiral galaxy. Lens modelling based on Hubble Space Telescope imaging had suggested that the dark matter associated with one of the cluster's central galaxies may be offset. The new spectroscopic data enable better subtraction of foreground light, and better identification of multiple background images. The inferred distribution of dark matter is consistent with being centred on the galaxies, as expected by Λ cold dark matter. Each galaxy's dark matter also appears to be symmetric. Whilst, we do not find an offset between mass and light (suggestive of self-interacting dark matter) as previously reported, the numerical simulations that have been performed to calibrate Abell 3827 indicate that offsets and asymmetry are still worth looking for in collisions with particular geometries. Meanwhile, ALMA proves exceptionally useful for strong lens image identifications.
Dark Matter Profiles in Dwarf Galaxies: A Statistical Sample Using High-Resolution Hα Velocity Fields from PCWI

Science.gov (United States)

Relatores, Nicole C.; Newman, Andrew B.; Simon, Joshua D.; Ellis, Richard; Truong, Phuongmai N.; Blitz, Leo

2018-01-01

We present high quality Hα velocity fields for a sample of nearby dwarf galaxies (log M/M⊙ = 8.4-9.8) obtained as part of the Dark Matter in Dwarf Galaxies survey. The purpose of the survey is to investigate the cusp-core discrepancy by quantifying the variation of the inner slope of the dark matter distributions of 26 dwarf galaxies, which were selected as likely to have regular kinematics. The data were obtained with the Palomar Cosmic Web Imager, located on the Hale 5m telescope. We extract rotation curves from the velocity fields and use optical and infrared photometry to model the stellar mass distribution. We model the total mass distribution as the sum of a generalized Navarro-Frenk-White dark matter halo along with the stellar and gaseous components. We present the distribution of inner dark matter density profile slopes derived from this analysis. For a subset of galaxies, we compare our results to an independent analysis based on CO observations. In future work, we will compare the scatter in inner density slopes, as well as their correlations with galaxy properties, to theoretical predictions for dark matter core creation via supernovae feedback.
Collision of Bose Condensate Dark Matter structures

International Nuclear Information System (INIS)

Guzman, F. S.

2008-01-01

The status of the scalar field or Bose condensate dark matter model is presented. Results about the solitonic behavior in collision of structures is presented as a possible explanation to the recent-possibly-solitonic behavior in the bullet cluster merger. Some estimates about the possibility to simulate the bullet cluster under the Bose Condensate dark matter model are indicated.
Dark matter scenarios with multiple spin-2 fields

Science.gov (United States)

González Albornoz, N. L.; Schmidt-May, Angnis; von Strauss, Mikael

2018-01-01

We study ghost-free multimetric theories for (N+1) tensor fields with a coupling to matter and maximal global symmetry group SN×(Z2)N. Their mass spectra contain a massless mode, the graviton, and N massive spin-2 modes. One of the massive modes is distinct by being the heaviest, the remaining (N‑1) massive modes are simply identical copies of each other. All relevant physics can therefore be understood from the case N=2. Focussing on this case, we compute the full perturbative action up to cubic order and derive several features that hold to all orders in perturbation theory. The lighter massive mode does not couple to matter and neither of the massive modes decay into massless gravitons. We propose the lighter massive particle as a candidate for dark matter and investigate its phenomenology in the parameter region where the matter coupling is dominated by the massless graviton. The relic density of massive spin-2 can originate from a freeze-in mechanism or from gravitational particle production, giving rise to two different dark matter scenarios. The allowed parameter regions are very different from those in scenarios with only one massive spin-2 field and more accessible to experiments.

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
Dark matter from unification

DEFF Research Database (Denmark)

Kainulainen, Kimmo; Tuominen, Kimmo; Virkajärvi, Jussi Tuomas

2013-01-01

We consider a minimal extension of the Standard Model (SM), which leads to unification of the SM coupling constants, breaks electroweak symmetry dynamically by a new strongly coupled sector and leads to novel dark matter candidates. In this model, the coupling constant unification requires...... eigenstates of this sector and determine the resulting relic density. The results are constrained by available data from colliders and direct and indirect dark matter experiments. We find the model viable and outline briefly future research directions....... the existence of electroweak triplet and doublet fermions singlet under QCD and new strong dynamics underlying the Higgs sector. Among these new matter fields and a new right handed neutrino, we consider the mass and mixing patterns of the neutral states. We argue for a symmetry stabilizing the lightest mass...
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...
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.
Impact of semi-annihilations on dark matter phenomenology. An example of ZN symmetric scalar dark matter

International Nuclear Information System (INIS)

Bélanger, Geneviève; Kannike, Kristjan; Pukhov, Alexander; Raidal, Martti

2012-01-01

We study the impact of semi-annihilations x i x j ↔x k X and dark matter conversion x i x j ↔x k x l , where x i is any dark matter and X is any standard model particle, on dark matter phenomenology. We formulate minimal scalar dark matter models with an extra doublet and a complex singlet that predict non-trivial dark matter phenomenology with semi-annihilation processes for different discrete Abelian symmetries Z N , N > 2. We implement two such example models with Z 3 and Z 4 symmetry in micrOMEGAs and work out their phenomenology. We show that both semi-annihilations and dark matter conversion significantly modify the dark matter relic abundance in this type of models. In the Z 4 model, there are two stable neutral particles and therefore multi-component dark matter. We also study the possibility of dark matter direct detection in XENON100 in those models
Bounds on dark matter interactions with electroweak gauge bosons

Energy Technology Data Exchange (ETDEWEB)

Cotta, R. C.; Hewett, J. L.; Le, M. -P.; Rizzo, T. G.

2013-12-01

We investigate scenarios in which dark matter interacts with the Standard Model primarily through electroweak gauge bosons. We employ an effective field theory framework wherein the Standard Model and the dark matter particle are the only light states in order to derive model-independent bounds. Bounds on such interactions are derived from dark matter production by weak boson fusion at the LHC, indirect detection searches for the products of dark matter annihilation and from the measured invisible width of the Z⁰ . We find that limits on the UV scale, Λ , reach weak scale values for most operators and values of the dark matter mass, thus probing the most natural scenarios in the weakly interacting massive particle dark matter paradigm. Our bounds suggest that light dark matter ( m_χ ≲ m_Z / 2 or m _χ ≲ 100 – 200 GeV , depending on the operator) cannot interact only with the electroweak gauge bosons of the Standard Model, but rather requires additional operator contributions or dark sector structure to avoid overclosing the Universe.
Supersymmetric U(1)' model with multiple dark matters

International Nuclear Information System (INIS)

Hur, Taeil; Lee, Hye-Sung; Nasri, Salah

2008-01-01

We consider a scenario where a supersymmetric model has multiple dark matter particles. Adding a U(1) ' gauge symmetry is a well-motivated extension of the minimal supersymmetric standard model (MSSM). It can cure the problems of the MSSM such as the μ problem or the proton decay problem with high-dimensional lepton number and baryon number violating operators which R parity allows. An extra parity (U parity) may arise as a residual discrete symmetry after U(1) ' gauge symmetry is spontaneously broken. The lightest U-parity particle (LUP) is stable under the new parity becoming a new dark matter candidate. Up to three massive particles can be stable in the presence of the R parity and the U parity. We numerically illustrate that multiple stable particles in our model can satisfy both constraints from the relic density and the direct detection, thus providing a specific scenario where a supersymmetric model has well-motivated multiple dark matters consistent with experimental constraints. The scenario provides new possibilities in the present and upcoming dark matter searches in the direct detection and collider experiments
Dark Matter searches at ATLAS

CERN Document Server

Cortes-Gonzalez, Arely; The ATLAS collaboration

2016-01-01

If Dark Matter interacts weakly with the Standard Model it can be produced at the LHC. It can be identified via initial state radiation (ISR) of the incoming partons, leaving a signature in the detector of the ISR particle (jet, photon, Z or W) recoiling off of the invisible Dark Matter particles, resulting in a large momentum imbalance. Many signatures of large missing transverse momentum recoiling against jets, photons, heavy-flavor quarks, weak gauge bosons or Higgs bosons provide an interesting channel for Dark Matter searches. These LHC searches complement those from (in)direct detection experiments. Results of these searches with the ATLAS experiment, in both effective field theory and simplified models with pair WIMP production are discussed. Both 8TeV and 13TeV pp collision data has been used in these results.
Self-Destructing Dark Matter

Energy Technology Data Exchange (ETDEWEB)

Grossman, Yuval [Cornell U., LEPP; Harnik, Roni [Fermilab; Telem, Ofri [Cornell U., LEPP; Zhang, Yue [Northwestern U.

2017-12-01

We present Self-Destructing Dark Matter (SDDM), a new class of dark matter models which are detectable in large neutrino detectors. In this class of models, a component of dark matter can transition from a long-lived state to a short-lived one by scattering off of a nucleus or an electron in the Earth. The short-lived state then decays to Standard Model particles, generating a dark matter signal with a visible energy of order the dark matter mass rather than just its recoil. This leads to striking signals in large detectors with high energy thresholds. We present a few examples of models which exhibit self destruction, all inspired by bound state dynamics in the Standard Model. The models under consideration exhibit a rich phenomenology, possibly featuring events with one, two, or even three lepton pairs, each with a fixed invariant mass and a fixed energy, as well as non-trivial directional distributions. This motivates dedicated searches for dark matter in large underground detectors such as Super-K, Borexino, SNO+, and DUNE.
Status of the scalar singlet dark matter model

Energy Technology Data Exchange (ETDEWEB)

Athron, Peter; Balazs, Csaba [Monash University, School of Physics and Astronomy, Melbourne, VIC (Australia); Australian Research Council Centre of Excellence for Particle Physics at the Tera-scale (Australia); Bringmann, Torsten; Dal, Lars A.; Krislock, Abram; Raklev, Are [University of Oslo, Department of Physics, Oslo (Norway); Buckley, Andy [University of Glasgow, SUPA, School of Physics and Astronomy, Glasgow (United Kingdom); Chrzaszcz, Marcin [Universitaet Zuerich, Physik-Institut, Zurich (Switzerland); Polish Academy of Sciences, H. Niewodniczanski Institute of Nuclear Physics, Krakow (Poland); Conrad, Jan; Edsjoe, Joakim; Farmer, Ben [AlbaNova University Centre, Oskar Klein Centre for Cosmoparticle Physics, Stockholm (Sweden); Stockholm University, Department of Physics, Stockholm (Sweden); Cornell, Jonathan M. [McGill University, Department of Physics, Montreal, QC (Canada); Jackson, Paul; White, Martin [Australian Research Council Centre of Excellence for Particle Physics at the Tera-scale (Australia); University of Adelaide, Department of Physics, Adelaide, SA (Australia); Kahlhoefer, Felix [DESY, Hamburg (Germany); Kvellestad, Anders; Savage, Christopher [NORDITA, Stockholm (Sweden); McKay, James; Scott, Pat [Imperial College London, Department of Physics, Blackett Laboratory, London (United Kingdom); Mahmoudi, Farvah [Univ. Lyon, Univ. Lyon 1, ENS de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, Saint-Genis-Laval (France); CERN, Theoretical Physics Department, Geneva (Switzerland); Martinez, Gregory D. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Putze, Antje [LAPTh, Universite de Savoie, CNRS, Annecy-le-Vieux (France); Rogan, Christopher [Harvard University, Department of Physics, Cambridge, MA (United States); Saavedra, Aldo [Australian Research Council Centre of Excellence for Particle Physics at the Tera-scale (Australia); The University of Sydney, Centre for Translational Data Science, Faculty of Engineering and Information Technologies, School of Physics, Sydney, NSW (Australia); Serra, Nicola [Universitaet Zuerich, Physik-Institut, Zurich (Switzerland); Weniger, Christoph [University of Amsterdam, GRAPPA, Institute of Physics, Amsterdam (Netherlands); Collaboration: The GAMBIT Collaboration

2017-08-15

One of the simplest viable models for dark matter is an additional neutral scalar, stabilised by a Z{sub 2} symmetry. Using the GAMBIT package and combining results from four independent samplers, we present Bayesian and frequentist global fits of this model. We vary the singlet mass and coupling along with 13 nuisance parameters, including nuclear uncertainties relevant for direct detection, the local dark matter density, and selected quark masses and couplings. We include the dark matter relic density measured by Planck, direct searches with LUX, PandaX, SuperCDMS and XENON100, limits on invisible Higgs decays from the Large Hadron Collider, searches for high-energy neutrinos from dark matter annihilation in the Sun with IceCube, and searches for gamma rays from annihilation in dwarf galaxies with the Fermi-LAT. Viable solutions remain at couplings of order unity, for singlet masses between the Higgs mass and about 300 GeV, and at masses above ∝ 1 TeV. Only in the latter case can the scalar singlet constitute all of dark matter. Frequentist analysis shows that the low-mass resonance region, where the singlet is about half the mass of the Higgs, can also account for all of dark matter, and remains viable. However, Bayesian considerations show this region to be rather fine-tuned. (orig.)
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.
Z2 SIMP dark matter

International Nuclear Information System (INIS)

Bernal, Nicolás; Chu, Xiaoyong

2016-01-01

Dark matter with strong self-interactions provides a compelling solution to several small-scale structure puzzles. Under the assumption that the coupling between dark matter and the Standard Model particles is suppressed, such strongly interacting massive particles (SIMPs) allow for a successful thermal freeze-out through N-to-N' processes, where N dark matter particles annihilate to N' of them. In the most common scenarios, where dark matter stability is guaranteed by a Z 2 symmetry, the seemingly leading annihilating channel, i.e. 3-to-2 process, is forbidden, so the 4-to-2 one dominate the production of the dark matter relic density. Moreover, cosmological observations require that the dark matter sector is colder than the thermal bath of Standard Model particles, a condition that can be dynamically generated via a small portal between dark matter and Standard Model particles, à la freeze-in. This scenario is exemplified in the context of the Singlet Scalar dark matter model
Warm and cold fermionic dark matter via freeze-in

International Nuclear Information System (INIS)

Klasen, Michael; Yaguna, Carlos E.

2013-01-01

The freeze-in mechanism of dark matter production provides a simple and intriguing alternative to the WIMP paradigm. In this paper, we analyze whether freeze-in can be used to account for the dark matter in the so-called singlet fermionic model. In it, the SM is extended with only two additional fields, a singlet scalar that mixes with the Higgs boson, and the dark matter particle, a fermion assumed to be odd under a Z 2 symmetry. After numerically studying the generation of dark matter, we analyze the dependence of the relic density with respect to all the free parameters of the model. These results are then used to obtain the regions of the parameter space that are compatible with the dark matter constraint. We demonstrate that the observed dark matter abundance can be explained via freeze-in over a wide range of masses extending down to the keV range. As a result, warm and cold dark matter can be obtained in this model. It is also possible to have dark matter masses well above the unitarity bound for WIMPs
Collapsed Dark Matter Structures

Science.gov (United States)

Buckley, Matthew R.; DiFranzo, Anthony

2018-02-01

The distributions of dark matter and baryons in the Universe are known to be very different: The dark matter resides in extended halos, while a significant fraction of the baryons have radiated away much of their initial energy and fallen deep into the potential wells. This difference in morphology leads to the widely held conclusion that dark matter cannot cool and collapse on any scale. We revisit this assumption and show that a simple model where dark matter is charged under a "dark electromagnetism" can allow dark matter to form gravitationally collapsed objects with characteristic mass scales much smaller than that of a Milky-Way-type galaxy. Though the majority of the dark matter in spiral galaxies would remain in the halo, such a model opens the possibility that galaxies and their associated dark matter play host to a significant number of collapsed substructures. The observational signatures of such structures are not well explored but potentially interesting.
Collapsed Dark Matter Structures.

Science.gov (United States)

Buckley, Matthew R; DiFranzo, Anthony

2018-02-02

The distributions of dark matter and baryons in the Universe are known to be very different: The dark matter resides in extended halos, while a significant fraction of the baryons have radiated away much of their initial energy and fallen deep into the potential wells. This difference in morphology leads to the widely held conclusion that dark matter cannot cool and collapse on any scale. We revisit this assumption and show that a simple model where dark matter is charged under a "dark electromagnetism" can allow dark matter to form gravitationally collapsed objects with characteristic mass scales much smaller than that of a Milky-Way-type galaxy. Though the majority of the dark matter in spiral galaxies would remain in the halo, such a model opens the possibility that galaxies and their associated dark matter play host to a significant number of collapsed substructures. The observational signatures of such structures are not well explored but potentially interesting.
Jet Definitions in Effective Field Theory and Decaying Dark Matter

Science.gov (United States)

Cheung, William Man Yin

2012-06-01

In this thesis jet production and cosmological constraints on decaying dark matter are studied. The powerful framework of effective field theory is applied in both cases to further our knowledge of particle physics. We first discuss how to apply the Soft Collinear Effective Theory (SCET) for calculating hadronic jet production rate. By applying SCET power counting, we develop a consistent approach to perform phase space integrations. This approach is then successfully applied to one-loop calculations with regard to a variety of jet algorithms. This allows us to study if the soft contribution can be factorized from the collinear ones. In particular we point out the connection between such factorization and the choice of ultraviolet regulator. We then further our study of the (exclusive) kT and C/A jet algorithms in SCET with the introduction of an additional regulator. Regularizing the virtualities and rapidities of graphs in SCET, we are able to write the next-to-leading-order dijet cross section as the product of separate hard, jet, and soft contributions. We show how to reproduce the Sudakov form factor to next-to-leading logarithmic accuracy previously calculated by the coherent branching formalism. Our resummed expression only depends on the renormalization group evolution of the hard function, rather than on that of the hard and jet functions as is usual in SCET. Finally we present a complete analysis of the cosmological constraints on decaying dark matter. For this, we have updated and extended previous analyses to include Lyman-alpha forest, large scale structure, and weak lensing observations. Astrophysical constraints are not considered in this thesis. The bounds on the lifetime of decaying dark matter are dominated by either the late-time integrated Sachs-Wolfe effect for the scenario with weak reionization, or CMB polarisation observations when there is significant reionization. For the respective scenarios, the lifetimes for decaying dark matter are
Higgs decays to dark matter: Beyond the minimal model

International Nuclear Information System (INIS)

Pospelov, Maxim; Ritz, Adam

2011-01-01

We examine the interplay between Higgs mediation of dark-matter annihilation and scattering on one hand and the invisible Higgs decay width on the other, in a generic class of models utilizing the Higgs portal. We find that, while the invisible width of the Higgs to dark matter is now constrained for a minimal singlet scalar dark matter particle by experiments such as XENON100, this conclusion is not robust within more generic examples of Higgs mediation. We present a survey of simple dark matter scenarios with m DM h /2 and Higgs portal mediation, where direct-detection signatures are suppressed, while the Higgs width is still dominated by decays to dark matter.
Lepton flavor violation and scalar dark matter in a radiative model of neutrino masses

Energy Technology Data Exchange (ETDEWEB)

Esch, Sonja; Klasen, Michael; Lamprea, David R. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Theoretische Physik, Muenster (Germany); Yaguna, Carlos E. [Universidad Pedagogica y Tecnologica de Colombia, Escuela de Fisica, Tunja (Colombia)

2018-02-15

We consider a simple extension of the Standard Model that can account for the dark matter and explain the existence of neutrino masses. The model includes a vector-like doublet of SU(2), a singlet fermion, and two scalar singlets, all of them odd under a new Z{sub 2} symmetry. Neutrino masses are generated radiatively by one-loop processes involving the new fields, while the dark matter candidate is the lightest neutral particle among them. We focus specifically on the case where the dark matter particle is one of the scalars and its relic density is determined by its Yukawa interactions. The phenomenology of this setup, including neutrino masses, dark matter and lepton flavor violation, is analyzed in some detail. We find that the dark matter mass must be below 600 GeV to satisfy the relic density constraint. Lepton flavor violating processes are shown to provide the most promising way to test this scenario. Future μ → 3e and μ-e conversion experiments, in particular, have the potential to probe the entire viable parameter space of this model. (orig.)
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...
Asymmetric dark matter and baryogenesis from pseudoscalar inflation

Energy Technology Data Exchange (ETDEWEB)

Cado, Yann; Sabancilar, Eray, E-mail: yann.cado@epfl.ch, E-mail: eray.sabancilar@epfl.ch [Laboratory of Particle Physics and Cosmology, Institute of Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne (Switzerland)

2017-04-01

We show that both the baryon asymmetry of the Universe and the dark matter abundance can be explained within a single framework that makes use of maximally helical hypermagnetic fields produced during pseudoscalar inflation and the chiral anomaly in the Standard Model. We consider a minimal asymmetric dark matter model free from anomalies and constraints. We find that the observed baryon and the dark matter abundances are achieved for a wide range of inflationary parameters, and the dark matter mass ranges between 7–15 GeV . The novelty of our mechanism stems from the fact that the same source of CP violation occurring during inflation explains both baryonic and dark matter in the Universe with two inflationary parameters, hence addressing all the initial condition problems in an economical way.

Supersymmetric model for dark matter and baryogenesis motivated by the recent CDMS result.

Science.gov (United States)

Allahverdi, Rouzbeh; Dutta, Bhaskar; Mohapatra, Rabindra N; Sinha, Kuver

2013-08-02

We discuss a supersymmetric model for cogenesis of dark and baryonic matter where the dark matter (DM) has mass in the 8-10 GeV range as indicated by several direct detection searches, including most recently the CDMS experiment with the desired cross section. The DM candidate is a real scalar field. Two key distinguishing features of the model are the following: (i) in contrast with the conventional weakly interacting massive particle dark matter scenarios where thermal freeze-out is responsible for the observed relic density, our model uses nonthermal production of dark matter after reheating of the Universe caused by moduli decay at temperatures below the QCD phase transition, a feature which alleviates the relic overabundance problem caused by small annihilation cross section of light DM particles and (ii) baryogenesis occurs also at similar low temperatures from the decay of TeV scale mediator particles arising from moduli decay. A possible test of this model is the existence of colored particles with TeV masses accessible at the LHC.
Cosmic inflation constrains scalar dark matter

Directory of Open Access Journals (Sweden)

Tommi Tenkanen

2015-12-01

Full Text Available In a theory containing scalar fields, a generic consequence is a formation of scalar condensates during cosmic inflation. The displacement of scalar fields out from their vacuum values sets specific initial conditions for post-inflationary dynamics and may lead to significant observational ramifications. In this work, we investigate how these initial conditions affect the generation of dark matter in the class of portal scenarios where the standard model fields feel new physics only through Higgs-mediated couplings. As a representative example, we will consider a $ Z_2 $ symmetric scalar singlet $ s $ coupled to Higgs via $ \\lambda \\Phi ^\\dagger \\Phi s^2 $. This simple extension has interesting consequences as the singlet constitutes a dark matter candidate originating from non-thermal production of singlet particles out from a singlet condensate, leading to a novel interplay between inflationary dynamics and dark matter properties.
Revisiting the direct detection of dark matter in simplified models

OpenAIRE

Li, Tong

2018-01-01

In this work we numerically re-examine the loop-induced WIMP-nucleon scattering cross section for the simplified dark matter models and the constraint set by the latest direct detection experiment. We consider a fermion, scalar or vector dark matter component from five simplified models with leptophobic spin-0 mediators coupled only to Standard Model quarks and dark matter particles. The tree-level WIMP-nucleon cross sections in these models are all momentum-suppressed. We calculate the non-s...
Dissipative dark matter halos: The steady state solution

Science.gov (United States)

Foot, R.

2018-02-01

Dissipative dark matter, where dark matter particle properties closely resemble familiar baryonic matter, is considered. Mirror dark matter, which arises from an isomorphic hidden sector, is a specific and theoretically constrained scenario. Other possibilities include models with more generic hidden sectors that contain massless dark photons [unbroken U (1 ) gauge interactions]. Such dark matter not only features dissipative cooling processes but also is assumed to have nontrivial heating sourced by ordinary supernovae (facilitated by the kinetic mixing interaction). The dynamics of dissipative dark matter halos around rotationally supported galaxies, influenced by heating as well as cooling processes, can be modeled by fluid equations. For a sufficiently isolated galaxy with a stable star formation rate, the dissipative dark matter halos are expected to evolve to a steady state configuration which is in hydrostatic equilibrium and where heating and cooling rates locally balance. Here, we take into account the major cooling and heating processes, and numerically solve for the steady state solution under the assumptions of spherical symmetry, negligible dark magnetic fields, and that supernova sourced energy is transported to the halo via dark radiation. For the parameters considered, and assumptions made, we were unable to find a physically realistic solution for the constrained case of mirror dark matter halos. Halo cooling generally exceeds heating at realistic halo mass densities. This problem can be rectified in more generic dissipative dark matter models, and we discuss a specific example in some detail.
Dark energy with a gradient coupling to the dark matter fluid: cosmological dynamics and structure formation

Science.gov (United States)

Dutta, Jibitesh; Khyllep, Wompherdeiki; Tamanini, Nicola

2018-01-01

We consider scalar field models of dark energy interacting with dark matter through a coupling proportional to the contraction of the four-derivative of the scalar field with the four-velocity of the dark matter fluid. The coupling is realized at the Lagrangian level employing the formalism of Scalar-Fluid theories, which use a consistent Lagrangian approach for relativistic fluid to describe dark matter. This framework produces fully covariant field equations, from which we can derive unequivocal cosmological equations at both background and linear perturbations levels. The background evolution is analyzed in detail applying dynamical systems techniques, which allow us to find the complete asymptotic behavior of the universe given any set of model parameters and initial conditions. Furthermore we study linear cosmological perturbations investigating the growth of cosmic structures within the quasi-static approximation. We find that these interacting dark energy models give rise to interesting phenomenological dynamics, including late-time transitions from dark matter to dark energy domination, matter and accelerated scaling solutions and dynamical crossing of the phantom barrier. Moreover we obtain possible deviations from standard ΛCDM behavior at the linear perturbations level, which have an impact on the dynamics of structure formation and might provide characteristic observational signatures.
Dark matter admixed strange quark stars in the Starobinsky model

Science.gov (United States)

Lopes, Ilídio; Panotopoulos, Grigoris

2018-01-01

We compute the mass-to-radius profiles for dark matter admixed strange quark stars in the Starobinsky model of modified gravity. For quark matter, we assume the MIT bag model, while self-interacting dark matter inside the star is modeled as a Bose-Einstein condensate with a polytropic equation of state. We numerically integrate the structure equations in the Einstein frame, adopting the two-fluid formalism, and we treat the curvature correction term nonperturbatively. The effects on the properties of the stars of the amount of dark matter as well as the higher curvature term are investigated. We find that strange quark stars (in agreement with current observational constraints) with the highest masses are equally affected by dark matter and modified gravity.
Dark Matter Decays from Nonminimal Coupling to Gravity.

Science.gov (United States)

Catà, Oscar; Ibarra, Alejandro; Ingenhütt, Sebastian

2016-07-08

We consider the standard model extended with a dark matter particle in curved spacetime, motivated by the fact that the only current evidence for dark matter is through its gravitational interactions, and we investigate the impact on the dark matter stability of terms in the Lagrangian linear in the dark matter field and proportional to the Ricci scalar. We show that this "gravity portal" induces decay even if the dark matter particle only has gravitational interactions, and that the decay branching ratios into standard model particles only depend on one free parameter: the dark matter mass. We study in detail the case of a singlet scalar as a dark matter candidate, which is assumed to be absolutely stable in flat spacetime due to a discrete Z_{2} symmetry, but which may decay in curved spacetimes due to a Z_{2}-breaking nonminimal coupling to gravity. We calculate the dark matter decay widths and we set conservative limits on the nonminimal coupling parameter from experiments. The limits are very stringent and suggest that there must exist an additional mechanism protecting the singlet scalar from decaying via this gravity portal.
Dark Matter Decay between Phase Transitions at the Weak Scale.

Science.gov (United States)

Baker, Michael J; Kopp, Joachim

2017-08-11

We propose a new alternative to the weakly interacting massive particle paradigm for dark matter. Rather than being determined by thermal freeze-out, the dark matter abundance in this scenario is set by dark matter decay, which is allowed for a limited amount of time just before the electroweak phase transition. More specifically, we consider fermionic singlet dark matter particles coupled weakly to a scalar mediator S_{3} and to auxiliary dark sector fields, charged under the standard model gauge groups. Dark matter freezes out while still relativistic, so its abundance is initially very large. As the Universe cools down, the scalar mediator develops a vacuum expectation value (VEV), which breaks the symmetry that stabilizes dark matter. This allows dark matter to mix with charged fermions and decay. During this epoch, the dark matter abundance is reduced to give the value observed today. Later, the SM Higgs field also develops a VEV, which feeds back into the S_{3} potential and restores the dark sector symmetry. In a concrete model we show that this "VEV flip-flop" scenario is phenomenologically successful in the most interesting regions of its parameter space. We also comment on detection prospects at the LHC and elsewhere.
Interacting warm dark matter

International Nuclear Information System (INIS)

Cruz, Norman; Palma, Guillermo; Zambrano, David; Avelino, Arturo

2013-01-01

We explore a cosmological model composed by a dark matter fluid interacting with a dark energy fluid. The interaction term has the non-linear λρ m α ρ e β form, where ρ m and ρ e are the energy densities of the dark matter and dark energy, respectively. The parameters α and β are in principle not constrained to take any particular values, and were estimated from observations. We perform an analytical study of the evolution equations, finding the fixed points and their stability properties in order to characterize suitable physical regions in the phase space of the dark matter and dark energy densities. The constants (λ,α,β) as well as w m and w e of the EoS of dark matter and dark energy respectively, were estimated using the cosmological observations of the type Ia supernovae and the Hubble expansion rate H(z) data sets. We find that the best estimated values for the free parameters of the model correspond to a warm dark matter interacting with a phantom dark energy component, with a well goodness-of-fit to data. However, using the Bayesian Information Criterion (BIC) we find that this model is overcame by a warm dark matter – phantom dark energy model without interaction, as well as by the ΛCDM model. We find also a large dispersion on the best estimated values of the (λ,α,β) parameters, so even if we are not able to set strong constraints on their values, given the goodness-of-fit to data of the model, we find that a large variety of theirs values are well compatible with the observational data used
Circumscribing late dark matter decays model-independently

International Nuclear Information System (INIS)

Yueksel, Hasan; Kistler, Matthew D.

2008-01-01

A number of theories, spanning a wide range of mass scales, predict dark matter candidates that have lifetimes much longer than the age of the Universe, yet may produce a significant flux of gamma rays in their decays today. We constrain such late-decaying dark matter scenarios model-independently by utilizing gamma-ray line emission limits from the Galactic Center region obtained with the SPI spectrometer on INTEGRAL, and the determination of the isotropic diffuse photon background by SPI, COMPTEL, and EGRET observations. We show that no more than ∼5% of the unexplained MeV background can be produced by late dark matter decays either in the Galactic halo or cosmological sources.
Dark matter and dark energy from the solution of the strong CP problem.

Science.gov (United States)

Mainini, Roberto; Bonometto, Silvio A

2004-09-17

The Peccei-Quinn (PQ) solution of the strong CP problem requires the existence of axions, which are viable candidates for dark matter. If the Nambu-Goldstone potential of the PQ model is replaced by a potential V(|Phi|) admitting a tracker solution, the scalar field |Phi| can account for dark energy, while the phase of Phi yields axion dark matter. If V is a supergravity (SUGRA) potential, the model essentially depends on a single parameter, the energy scale Lambda. Once we set Lambda approximately equal to 10(10) GeV at the quark-hadron transition, |Phi| naturally passes through values suitable to solve the strong CP problem, later growing to values providing fair amounts of dark matter and dark energy.
Dark Matter in SuperGUT Unification Models

International Nuclear Information System (INIS)

Olive, Keith A

2011-01-01

After a brief update on the prospects for dark matter in the constrained version of the MSSM (CMSSM) and its differences with models based on minimal supergravity (mSUGRA), I will consider the effects of unifying the supersymmetry-breaking parameters at a scale above M GUT . One of the consequences of superGUT unification, is the ability to take vanishing scalar masses at the unification scale with a neutralino LSP dark matter candidate. This allows one to resurrect no-scale supergravity as a viable phenomenological model.
Constraining decaying dark matter with FERMI-LAT gamma rays

International Nuclear Information System (INIS)

Maccione, L.

2011-01-01

High energy electron sand positrons from decaying dark matter can produce a significant flux of gamma rays by inverse Compton of low energy photons in the interstellar radiation field. This possibility is inevitably related with the dark matter interpretation of the observed PAMELA and FERMI excesses. We will describe a simple and universal method to constrain dark matter models which produce electrons and positrons in their decay by using the FERMI-LAT gamma-ray observations in the energy range between 0.5 GeV and 300 GeV, by exploiting universal response functions that, once convolved with a specific dark matter model, produce the desired constraint. The response functions contain all the astrophysical inputs. Here is discussed the uncertainties in the determination of the response functions and apply them to place constraints on some specific dark matter decay models that can well fit the positron and electron fluxes observed by PAMELA and FERMI LAT, also taking into account prompt radiation from the dark matter decay. With the available data decaying dark matter can not be excluded as source of the PAMELA positron excess.
Asymmetric dark matter from spontaneous cogenesis in the supersymmetric standard model

Energy Technology Data Exchange (ETDEWEB)

Kamada, Kohei [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Yamaguchi, Masahide [Tokyo Institute of Technology (Japan). Dept. of Physics

2012-01-15

The observational relation between the density of baryon and dark matter in the Universe, {omega}{sub DM}/{omega}{sub B}{approx_equal}5, is one of the most difficult problems to solve in modern cosmology. We discuss a scenario that explains this relation by combining the asymmetric dark matter scenario and the spontaneous baryogenesis associated with the flat direction in the supersymmetric standard model. A part of baryon asymmetry is transferred to charge asymmetry D that dark matter carries, if a symmetry violating interaction that works at high temperature breaks not only B-L but also D symmetries simultaneously. In this case, the present number density of baryon and dark matter can be same order if the symmetric part of dark matter annihilates sufficiently. Moreover, the baryon number density can be enhanced as compared to that of dark matter if another B-L violating interaction is still in thermal equilibrium after the spontaneous genesis of dark matter, which accommodates a TeV scale asymmetric dark matter model. (orig.)
Dark Matter in the Heavens and at Colliders: Models and Constraints

Energy Technology Data Exchange (ETDEWEB)

Primulando, Reinard [College of William and Mary, Williamsburg, VA (United States)

2012-08-01

In this dissertation, we investigate various aspects of dark matter detection and model building. Motivated by the cosmic ray positron excess observed by PAMELA, we construct models of decaying dark matter to explain the excess. Specifically we present 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. Alternatively, the decaying operator can arise as a Planck suppressed correction in a model with an Abelian discrete symmetry and vector-like states at an intermediate scale that are responsible for generating lepton Yukawa couplings. A flavor-nonconserving dark matter decay is also considered in the case of fermionic dark matter. Assuming a general Dirac structure for the four-fermion contact interactions of interest, the cosmic-ray electron and positron spectra were studied. We show that good fits to the current data can be obtained for both charged-leptonflavor- conserving and flavor-violating decay channels. Motivated by a possible excess of gamma rays in the galactic center, we constructed a supersymmetric leptophilic higgs model to explain the excess. Finally, we consider an improvement on dark matter collider searches using the Razor analysis, which was originally utilized for supersymmetry searches by the CMS collaboration.
Sterile neutrino dark matter

CERN Document Server

Merle, Alexander

2017-01-01

This book is a new look at one of the hottest topics in contemporary science, Dark Matter. It is the pioneering text dedicated to sterile neutrinos as candidate particles for Dark Matter, challenging some of the standard assumptions which may be true for some Dark Matter candidates but not for all. So, this can be seen either as an introduction to a specialized topic or an out-of-the-box introduction to the field of Dark Matter in general. No matter if you are a theoretical particle physicist, an observational astronomer, or a ground based experimentalist, no matter if you are a grad student or an active researcher, you can benefit from this text, for a simple reason: a non-standard candidate for Dark Matter can teach you a lot about what we truly know about our standard picture of how the Universe works.
Secretly asymmetric dark matter

Science.gov (United States)

Agrawal, Prateek; Kilic, Can; Swaminathan, Sivaramakrishnan; Trendafilova, Cynthia

2017-01-01

We study a mechanism where the dark matter number density today arises from asymmetries generated in the dark sector in the early Universe, even though the total dark matter number remains zero throughout the history of the Universe. The dark matter population today can be completely symmetric, with annihilation rates above those expected from thermal weakly interacting massive particles. We give a simple example of this mechanism using a benchmark model of flavored dark matter. We discuss the experimental signatures of this setup, which arise mainly from the sector that annihilates the symmetric component of dark matter.
Dark matter scenarios in a constrained model with Dirac gauginos

CERN Document Server

Goodsell, Mark D.; Müller, Tobias; Porod, Werner; Staub, Florian

2015-01-01

We perform the first analysis of Dark Matter scenarios in a constrained model with Dirac Gauginos. The model under investigation is the Constrained Minimal Dirac Gaugino Supersymmetric Standard model (CMDGSSM) where the Majorana mass terms of gauginos vanish. However, $R$-symmetry is broken in the Higgs sector by an explicit and/or effective $B_\\mu$-term. This causes a mass splitting between Dirac states in the fermion sector and the neutralinos, which provide the dark matter candidate, become pseudo-Dirac states. We discuss two scenarios: the universal case with all scalar masses unified at the GUT scale, and the case with non-universal Higgs soft-terms. We identify different regions in the parameter space which fullfil all constraints from the dark matter abundance, the limits from SUSY and direct dark matter searches and the Higgs mass. Most of these points can be tested with the next generation of direct dark matter detection experiments.
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
The continuous tower of scalar fields as a system of interacting dark matter–dark energy

International Nuclear Information System (INIS)

Santos, Paulo

2015-01-01

This paper aims to introduce a new parameterisation for the coupling Q in interacting dark matter and dark energy models by connecting said models with the Continuous Tower of Scalar Fields model. Based upon the existence of a dark matter and a dark energy sectors in the Continuous Tower of Scalar Fields, a simplification is considered for the evolution of a single scalar field from the tower, validated in this paper. This allows for the results obtained with the Continuous Tower of Scalar Fields model to match those of an interacting dark matter–dark energy system, considering that the energy transferred from one fluid to the other is given by the energy of the scalar fields that start oscillating at a given time, rather than considering that the energy transference depends on properties of the whole fluids that are interacting.

Modeling the distribution of dark matter and its connection to galaxies

OpenAIRE

Mao, Yao-Yuan

2016-01-01

Despite the mysterious nature of dark matter and dark energy, the Lambda-Cold Dark Matter (LCDM) model provides a reasonably accurate description of the evolution of the cosmos and the distribution of galaxies. Today, we are set to tackle more specific and quantitative questions about the galaxy formation physics, the nature of dark matter, and the connection between the dark and the visible components. The answers to these questions are however elusive, because dark matter is not directly ob...
A hydrodynamic approach to cosmology - Texture-seeded cold dark matter and hot dark matter cosmogonies

Science.gov (United States)

Cen, R. Y.; Ostriker, J. P.; Spergel, D. N.; Turok, N.

1991-01-01

Hydrodynamical simulations of galaxy formation in a texture-seeded cosmology are presented, with attention given to Omega = 1 galaxies dominated by both hot dark matter (HDM) and cold dark matter (CDM). The simulations include both gravitational and hydrodynamical physics with a detailed treatment of collisional and radiative thermal processes, and use a cooling criterion to estimate galaxy formation. Background radiation fields and Zel'dovich-Sunyaev fluctuations are explicitly computed. The derived galaxy mass function is well fitted by the observed Schechter luminosity function for a baryonic M/L of 3 and total M/L of 60 in galaxies. In both HDM and CDM texture scenarios, the 'galaxies' and 'clusters' are significantly more strongly correlated than the dark matter due to physical bias processes. The slope of the correlation function in both cases is consistent with observations. In contrast to Gaussian models, peaks in the dark matter density distributrion are less correlated than average.
Searches for Dark Matter in ATLAS

CERN Document Server

Alpigiani, Cristiano; The ATLAS collaboration

2017-01-01

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

International Nuclear Information System (INIS)

Hannestad, Steen; Scherrer, Robert J.

2000-01-01

It has been shown by many independent studies that the cold dark matter scenario produces singular galactic dark halos, in strong contrast with observations. Possible remedies are that either the dark matter is warm so that it has significant thermal motion or that the dark matter has strong self-interactions. We combine these ideas to calculate the linear mass power spectrum and the spectrum of cosmic microwave background (CMB) fluctuations for self-interacting warm dark matter. Our results indicate that such models have more power on small scales than is the case for the standard warm dark matter model, with a CMB fluctuation spectrum which is nearly indistinguishable from standard cold dark matter. This enhanced small-scale power may provide better agreement with the observations than does standard warm dark matter. (c) 2000 The American Physical Society
Low Mass Dark Matter: Some Perspectives

International Nuclear Information System (INIS)

Chen Shaolong

2012-01-01

The low mass (10 GeV scale) dark matter is indicted and favored by several recent dark matter direct detection experimental results, such as DAMA and CoGeNT. In this talk, we discuss some aspects of the low mass dark matter. We study the indirect detection of dark matter through neutrino flux from their annihilation in the center of the Sun, in a class of models where the dark matter-nucleon spin-independent interactions break the isospin symmetry. The indirect detection using neutrino telescopes can impose a relatively stronger constraint and brings tension to such explanation, if the dark matter self-annihilation is dominated by heavy quarks or τ-lepton final states. The asymmetric dark matter doesn't suffer the constraints from the indirect detection results. We propose a model of asymmetric dark matter where the matter and dark matter share the common origin, the asymmetries in both the matter and dark matter sectors are simultaneously generated through leptogenesis, and we explore how this model can be tested in direct search experiments.
Weakly interacting dark matter and baryogenesis

International Nuclear Information System (INIS)

Gu Peihong; Lindner, Manfred; Sarkar, Utpal; Zhang Xinmin

2011-01-01

In the present Universe visible and dark matter contribute comparable energy density although they have different properties. This phenomenon can be explained if the dark matter relic density, originating from a dark matter asymmetry, is fully determined by the baryon asymmetry. Thus the dark matter mass is not arbitrary; rather, it becomes predictive. We realize this scenario in baryon (lepton) number conserving models where two or more neutral singlet scalars decay into two or three baryonic (leptonic) dark matter scalars, and also decay into quarks (leptons) through other on-shell and/or off-shell exotic scalar bilinears. The produced baryon (lepton) asymmetries in the dark matter scalar and in the standard model quarks (leptons) are thus equal and opposite. The dark matter mass can be predicted in a range from a few GeV to a few TeV, depending on the baryon (lepton) numbers of the decaying scalars and the dark matter scalar. The dark matter scalar can interact with the visible matter through the exchange of the standard model Higgs boson, opening a window for the dark matter direct detection experiments. These models also provide testable predictions in the searches for the exotic scalar bilinears at LHC.
Flipped dark matter

Energy Technology Data Exchange (ETDEWEB)

Ellis, J.; Hagelin, J.S.; Kelley, S.; Nanopoulos, D.V.; Olive, K.A.

1988-08-04

We study candidates for dark matter in a minimal flipped SU(5) x U(1) supersymmetric GUT. Since the model has no R-parity, spin-1/2 supersymmetric partners of conventional particles mix with other neutral fermions including neutrinos, and can decay into them. The lighest particle which is predominantly a gaugino/higgsino mixture decays with a lifetime tau/sub chi/ approx. = 1-10/sup 9/ s. The model contains a scalar 'flaton' field whose coherent oscillations decay before cosmological nucleosynthesis, and whose pseudoscalar partner contributes negligibly to ..cap omega.. if it is light enough to survive to the present epoch. The fermionic 'flatino' partner of the flaton has a lifetime tau/sub PHI/ approx. = 10/sup 28/-10/sup 34/ yr and is a viable candiate for metastable dark matter with ..cap omega.. < or approx. 1.
Dark matter: the astrophysical case

International Nuclear Information System (INIS)

Silk, J.

2012-01-01

The identification of dark matter is one of the most urgent problems in cosmology. I describe the astrophysical case for dark matter, from both an observational and a theoretical perspective. This overview will therefore focus on the observational motivations rather than the particle physics aspects of dark matter constraints on specific dark matter candidates. First, however, I summarize the astronomical evidence for dark matter, then I highlight the weaknesses of the standard cold dark matter model (LCDM) to provide a robust explanation of some observations. The greatest weakness in the dark matter saga is that we have not yet identified the nature of dark matter itself
Charming dark matter

Science.gov (United States)

Jubb, Thomas; Kirk, Matthew; Lenz, Alexander

2017-12-01

We have considered a model of Dark Minimal Flavour Violation (DMFV), in which a triplet of dark matter particles couple to right-handed up-type quarks via a heavy colour-charged scalar mediator. By studying a large spectrum of possible constraints, and assessing the entire parameter space using a Markov Chain Monte Carlo (MCMC), we can place strong restrictions on the allowed parameter space for dark matter models of this type.
Field Flows of Dark Energy

Energy Technology Data Exchange (ETDEWEB)

Cahn, Robert N.; de Putter, Roland; Linder, Eric V.

2008-07-08

Scalar field dark energy evolving from a long radiation- or matter-dominated epoch has characteristic dynamics. While slow-roll approximations are invalid, a well defined field expansion captures the key aspects of the dark energy evolution during much of the matter-dominated epoch. Since this behavior is determined, it is not faithfully represented if priors for dynamical quantities are chosen at random. We demonstrate these features for both thawing and freezing fields, and for some modified gravity models, and unify several special cases in the literature.
Interacting viscous ghost tachyon, K-essence and dilaton scalar field models of dark energy

International Nuclear Information System (INIS)

Karami, K; Fahimi, K

2013-01-01

We study the correspondence between the interacting viscous ghost dark energy model with the tachyon, K-essence and dilaton scalar field models in the framework of Einstein gravity. We consider a spatially non-flat FRW universe filled with interacting viscous ghost dark energy and dark matter. We reconstruct both the dynamics and potential of these scalar field models according to the evolutionary behavior of the interacting viscous ghost dark energy model, which can describe the accelerated expansion of the universe. Our numerical results show that the interaction and viscosity have opposite effects on the evolutionary properties of the ghost scalar field models. (paper)
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.
Dark matter implications of the WMAP-Planck Haze

Energy Technology Data Exchange (ETDEWEB)

Egorov, Andrey E.; Pierpaoli, Elena [University of Southern California, 3620 McClintock Ave., SGM 408, Los Angeles, CA 90089 (United States); Gaskins, Jennifer M. [California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Pietrobon, Davide, E-mail: egorov@usc.edu, E-mail: jgaskins@uva.nl, E-mail: pierpaol@usc.edu, E-mail: daddeptr@gmail.com [University of California, Berkeley, Space Sciences Laboratory, 7 Gauss Rd, Berkeley CA 94720 (United States)

2016-03-01

Gamma rays and microwave observations of the Galactic Center and surrounding areas indicate the presence of anomalous emission, whose origin remains ambiguous. The possibility of dark matter annihilation explaining both signals through prompt emission at gamma rays and secondary emission at microwave frequencies from interactions of high-energy electrons produced in annihilation with the Galactic magnetic fields has attracted much interest in recent years. We investigate the dark matter interpretation of the Galactic Center gamma-ray excess by searching for the associated synchrotron emission in the WMAP and Planck microwave data. Considering various magnetic field and cosmic-ray propagation models, we predict the synchrotron emission due to dark matter annihilation in our Galaxy, and compare it with the WMAP and Planck data at 23–70 GHz. In addition to standard microwave foregrounds, we separately model the microwave counterpart to the Fermi Bubbles and the signal due to dark matter annihilation, and use component separation techniques to extract the signal associated with each template from the total emission. We confirm the presence of the Haze at the level of ≈7% of the total sky intensity at 23 GHz in our chosen region of interest, with a harder spectrum (I ∼ ν{sup −0.8}) than the synchrotron from regular cosmic-ray electrons. The data do not show a strong preference towards fitting the Haze by either the Bubbles or dark matter emission only. Inclusion of both components provides a better fit with a dark matter contribution to the Haze emission of ≈20% at 23 GHz, however, due to significant uncertainties in foreground modeling, we do not consider this a clear detection of a dark matter signal. We set robust upper limits on the annihilation cross section by ignoring foregrounds, and also report best-fit dark matter annihilation parameters obtained from a complete template analysis. We conclude that the WMAP and Planck data are consistent with a
Dark matter implications of the WMAP-Planck Haze

International Nuclear Information System (INIS)

Egorov, Andrey E.; Pierpaoli, Elena; Gaskins, Jennifer M.; Pietrobon, Davide

2016-01-01

Gamma rays and microwave observations of the Galactic Center and surrounding areas indicate the presence of anomalous emission, whose origin remains ambiguous. The possibility of dark matter annihilation explaining both signals through prompt emission at gamma rays and secondary emission at microwave frequencies from interactions of high-energy electrons produced in annihilation with the Galactic magnetic fields has attracted much interest in recent years. We investigate the dark matter interpretation of the Galactic Center gamma-ray excess by searching for the associated synchrotron emission in the WMAP and Planck microwave data. Considering various magnetic field and cosmic-ray propagation models, we predict the synchrotron emission due to dark matter annihilation in our Galaxy, and compare it with the WMAP and Planck data at 23–70 GHz. In addition to standard microwave foregrounds, we separately model the microwave counterpart to the Fermi Bubbles and the signal due to dark matter annihilation, and use component separation techniques to extract the signal associated with each template from the total emission. We confirm the presence of the Haze at the level of ≈7% of the total sky intensity at 23 GHz in our chosen region of interest, with a harder spectrum (I ∼ ν −0.8 ) than the synchrotron from regular cosmic-ray electrons. The data do not show a strong preference towards fitting the Haze by either the Bubbles or dark matter emission only. Inclusion of both components provides a better fit with a dark matter contribution to the Haze emission of ≈20% at 23 GHz, however, due to significant uncertainties in foreground modeling, we do not consider this a clear detection of a dark matter signal. We set robust upper limits on the annihilation cross section by ignoring foregrounds, and also report best-fit dark matter annihilation parameters obtained from a complete template analysis. We conclude that the WMAP and Planck data are consistent with a dark
Dark matter and particle physics

Energy Technology Data Exchange (ETDEWEB)

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

2001-11-15

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

CERN Document Server

Ellis, John; Marzola, Luca; Raidal, Martti

2018-06-12

We perform frequentist and Bayesian statistical analyses of Higgs- and Z-portal models of dark matter particles with spin 0, 1/2 and 1. Our analyses incorporate data from direct detection and indirect detection experiments, as well as LHC searches for monojet and monophoton events, and we also analyze the potential impacts of future direct detection experiments. We find acceptable regions of the parameter spaces for Higgs-portal models with real scalar, neutral vector, Majorana or Dirac fermion dark matter particles, and Z-portal models with Majorana or Dirac fermion dark matter particles. In many of these cases, there are interesting prospects for discovering dark matter particles in Higgs or Z decays, as well as dark matter particles weighing $\\gtrsim 100$ GeV. Negative results from planned direct detection experiments would still allow acceptable regions for Higgs- and Z-portal models with Majorana or Dirac fermion dark matter particles.
Dark matter in the universe

CERN Document Server

Seigar, Marc S

2015-01-01

The study of dark matter, in both astrophysics and particle physics, has emerged as one of the most active and exciting topics of research in recent years. This book reviews the history behind the discovery of missing mass (or unseen mass) in the universe, and ties this into the proposed extensions to the Standard Model of Particle Physics (such as Supersymmetry), which were being proposed within the same time frame. This book is written as an introduction to these problems at the forefront of astrophysics and particle physics, with the goal of conveying the physics of dark matter to beginning undergraduate majors in scientific fields. The book goes on to describe existing and upcoming experiments and techniques, which will be used to detect dark matter either directly or indirectly.
Neutralino dark matter in BMSSM effective theory

International Nuclear Information System (INIS)

Berg, Marcus; Edsjö, Joakim; Lundström, Erik; Sjörs, Stefan; Gondolo, Paolo

2009-01-01

We study thermal neutralino dark matter in an effective field theory extension of the MSSM, called ''Beyond the MSSM'' (BMSSM) in Dine, Seiberg and Thomas (2007). In this class of effective field theories, the field content of the MSSM is unchanged, but the little hierarchy problem is alleviated by allowing small corrections to the Higgs/higgsino part of the Lagrangian. We perform parameter scans and compute the dark matter relic density. The light higgsino LSP scenario is modified the most; we find new regions of parameter space compared to the standard MSSM. This involves interesting interplay between the WMAP dark matter bounds and the LEP chargino bound. We also find some changes for gaugino LSPs, partly due to annihilation through a Higgs resonance, and partly due to coannihilation with light top squarks in models that are ruled in by the new effective terms
Electroweakly-interacting Dirac dark matter

International Nuclear Information System (INIS)

Nagata, Natsumi

2014-11-01

We consider a class of fermionic dark matter candidates that are charged under both the SU(2) L and U(1) Y gauge interactions. Such a dark matter is stringently restricted by the dark matter direct detection experiments, since the Z-boson exchange processes induce too large dark matter-nucleus elastic scattering cross sections. Effects of ultraviolet (UV) physics, however, split it into two Majorana fermions to evade the constraint. These effects may be probed by means of the dark matter-nucleus scattering via the Higgs-boson exchange process, as well as the electric dipole moments induced by the dark matter and its SU(2) L partner fields. In this Letter, we evaluate them with effective operators that describe the UV-physics effects. It turns out that the constraints coming from the experiments for the quantities have already restricted the dark matters with hypercharge Y≥3/2. Future experiments have sensitivities to probe this class of dark matter candidates, and may disfavor the Y≥1 cases if no signal is observed. In this case, only the Y=0 and 1/2 cases may be the remaining possibilities for the SU(2) L charged fermionic dark matter candidates.
Dark Matter Effective Theory

DEFF Research Database (Denmark)

Del Nobile, Eugenio; Sannino, Francesco

2012-01-01

We organize the effective (self)interaction terms for complex scalar dark matter candidates which are either an isosinglet, isodoublet or an isotriplet with respect to the weak interactions. The classification has been performed ordering the operators in inverse powers of the dark matter cutoff...... scale. We assume Lorentz invariance, color and charge neutrality. We also introduce potentially interesting dark matter induced flavor-changing operators. Our general framework allows for model independent investigations of dark matter properties....

Comprehensive asymmetric dark matter model

OpenAIRE

Lonsdale, Stephen J.; Volkas, Raymond R.

2018-01-01

Asymmetric dark matter (ADM) is motivated by the similar cosmological mass densities measured for ordinary and dark matter. We present a comprehensive theory for ADM that addresses the mass density similarity, going beyond the usual ADM explanations of similar number densities. It features an explicit matter-antimatter asymmetry generation mechanism, has one fully worked out thermal history and suggestions for other possibilities, and meets all phenomenological, cosmological and astrophysical...
Healthy imperfect dark matter from effective theory of mimetic cosmological perturbations

International Nuclear Information System (INIS)

Hirano, Shin'ichi; Nishi, Sakine; Kobayashi, Tsutomu

2017-01-01

We study the stability of a recently proposed model of scalar-field matter called mimetic dark matter or imperfect dark matter. It has been known that mimetic matter with higher derivative terms suffers from gradient instabilities in scalar perturbations. To seek for an instability-free extension of imperfect dark matter, we develop an effective theory of cosmological perturbations subject to the constraint on the scalar field's kinetic term. This is done by using the unifying framework of general scalar-tensor theories based on the ADM formalism. We demonstrate that it is indeed possible to construct a model of imperfect dark matter which is free from ghost and gradient instabilities. As a side remark, we also show that mimetic F (R) theory is plagued with the Ostrogradsky instability.
Healthy imperfect dark matter from effective theory of mimetic cosmological perturbations

Energy Technology Data Exchange (ETDEWEB)

Hirano, Shin' ichi; Nishi, Sakine; Kobayashi, Tsutomu, E-mail: s.hirano@rikkyo.ac.jp, E-mail: sakine@rikkyo.ac.jp, E-mail: tsutomu@rikkyo.ac.jp [Department of Physics, Rikkyo University, Toshima, Tokyo 171-8501 (Japan)

2017-07-01

We study the stability of a recently proposed model of scalar-field matter called mimetic dark matter or imperfect dark matter. It has been known that mimetic matter with higher derivative terms suffers from gradient instabilities in scalar perturbations. To seek for an instability-free extension of imperfect dark matter, we develop an effective theory of cosmological perturbations subject to the constraint on the scalar field's kinetic term. This is done by using the unifying framework of general scalar-tensor theories based on the ADM formalism. We demonstrate that it is indeed possible to construct a model of imperfect dark matter which is free from ghost and gradient instabilities. As a side remark, we also show that mimetic F (R) theory is plagued with the Ostrogradsky instability.
Dark matter and its detection

International Nuclear Information System (INIS)

Bi Xiaojun; Qin Bo

2011-01-01

We first explain the concept of dark matter,then review the history of its discovery and the evidence of its existence. We describe our understanding of the nature of dark matter particles, the popular dark matter models,and why the weakly interacting massive particles (called WIMPs) are the most attractive candidates for dark matter. Then we introduce the three methods of dark matter detection: colliders, direct detection and indirect detection. Finally, we review the recent development of dark matter detection, including the new results from DAMA, CoGent, PAMELA, ATIC and Fermi. (authors)
Dark matter wants Linear Collider

International Nuclear Information System (INIS)

Matsumoto, S.; Asano, M.; Fujii, K.; Takubo, Y.; Honda, T.; Saito, T.; Yamamoto, H.; Humdi, R.S.; Ito, H.; Kanemura, S; Nabeshima, T.; Okada, N.; Suehara, T.

2011-01-01

One of the main purposes of physics at the International Linear Collider (ILC) is to study the property of dark matter such as its mass, spin, quantum numbers, and interactions with particles of the standard model. We discuss how the property can or cannot be investigated at the ILC using two typical cases of dark matter scenario: 1) most of new particles predicted in physics beyond the standard model are heavy and only dark matter is accessible at the ILC, and 2) not only dark matter but also other new particles are accessible at the ILC. We find that, as can be easily imagined, dark matter can be detected without any difficulties in the latter case. In the former case, it is still possible to detect dark matter when the mass of dark matter is less than a half mass of the Higgs boson.
Dark matter properties implied by gamma ray interstellar emission models

Energy Technology Data Exchange (ETDEWEB)

Balázs, Csaba; Li, Tong, E-mail: csaba.balazs@monash.edu, E-mail: tong.li@monash.edu [ARC Centre of Excellence for Particle Physics at the Tera-scale, School of Physics and Astronomy, Monash University, Melbourne, Victoria 3800 (Australia)

2017-02-01

We infer dark matter properties from gamma ray residuals extracted using eight different interstellar emission scenarios proposed by the Fermi-LAT Collaboration to explain the Galactic Center gamma ray excess. Adopting the most plausible simplified ansatz, we assume that the dark matter particle is a Majorana fermion interacting with standard fermions via a scalar mediator. To trivially respect flavor constraints, we only couple the mediator to third generation fermions. Using this theoretical hypothesis, and the Fermi residuals, we calculate Bayesian evidences, including Fermi-LAT exclusion limits from 15 dwarf spheroidal galaxies as well. Our evidence ratios single out one of the Fermi scenarios as most compatible with the simplified dark matter model. In this scenario the dark matter (mediator) mass is in the 25-200 (1-1000) GeV range and its annihilation is dominated by bottom quark final state. Our conclusion is that the properties of dark matter extracted from gamma ray data are highly sensitive to the modeling of the interstellar emission.
Make dark matter charged again

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, Cambridge, MA 02138 (United States)

2017-05-01

We revisit constraints on dark matter that is charged under a U(1) gauge group in the dark sector, decoupled from Standard Model forces. We find that the strongest constraints in the literature are subject to a number of mitigating factors. For instance, the naive dark matter thermalization timescale in halos is corrected by saturation effects that slow down isotropization for modest ellipticities. The weakened bounds uncover interesting parameter space, making models with weak-scale charged dark matter viable, even with electromagnetic strength interaction. This also leads to the intriguing possibility that dark matter self-interactions within small dwarf galaxies are extremely large, a relatively unexplored regime in current simulations. Such strong interactions suppress heat transfer over scales larger than the dark matter mean free path, inducing a dynamical cutoff length scale above which the system appears to have only feeble interactions. These effects must be taken into account to assess the viability of darkly-charged dark matter. Future analyses and measurements should probe a promising region of parameter space for this model.
AMS-02 fits dark matter

Science.gov (United States)

Balázs, Csaba; Li, Tong

2016-05-01

In this work we perform a comprehensive statistical analysis of the AMS-02 electron, positron fluxes and the antiproton-to-proton ratio in the context of a simplified dark matter model. We include known, standard astrophysical sources and a dark matter component in the cosmic ray injection spectra. To predict the AMS-02 observables we use propagation parameters extracted from observed fluxes of heavier nuclei and the low energy part of the AMS-02 data. We assume that the dark matter particle is a Majorana fermion coupling to third generation fermions via a spin-0 mediator, and annihilating to multiple channels at once. The simultaneous presence of various annihilation channels provides the dark matter model with additional flexibility, and this enables us to simultaneously fit all cosmic ray spectra using a simple particle physics model and coherent astrophysical assumptions. Our results indicate that AMS-02 observations are not only consistent with the dark matter hypothesis within the uncertainties, but adding a dark matter contribution improves the fit to the data. Assuming, however, that dark matter is solely responsible for this improvement of the fit, it is difficult to evade the latest CMB limits in this model.
AMS-02 fits dark matter

Energy Technology Data Exchange (ETDEWEB)

Balázs, Csaba; Li, Tong [ARC Centre of Excellence for Particle Physics at the Tera-scale,School of Physics and Astronomy, Monash University, Melbourne, Victoria 3800 (Australia)

2016-05-05

In this work we perform a comprehensive statistical analysis of the AMS-02 electron, positron fluxes and the antiproton-to-proton ratio in the context of a simplified dark matter model. We include known, standard astrophysical sources and a dark matter component in the cosmic ray injection spectra. To predict the AMS-02 observables we use propagation parameters extracted from observed fluxes of heavier nuclei and the low energy part of the AMS-02 data. We assume that the dark matter particle is a Majorana fermion coupling to third generation fermions via a spin-0 mediator, and annihilating to multiple channels at once. The simultaneous presence of various annihilation channels provides the dark matter model with additional flexibility, and this enables us to simultaneously fit all cosmic ray spectra using a simple particle physics model and coherent astrophysical assumptions. Our results indicate that AMS-02 observations are not only consistent with the dark matter hypothesis within the uncertainties, but adding a dark matter contribution improves the fit to the data. Assuming, however, that dark matter is solely responsible for this improvement of the fit, it is difficult to evade the latest CMB limits in this model.
ADMX Dark-Matter Axion Search

International Nuclear Information System (INIS)

Rosenberg, Leslie J.

2004-01-01

The axion, a hypothetical elementary particle, emerged from a compelling solution to the Strong-CP Problem in QCD. Subsequently, the axion was recognized to be a good Cold Dark Matter candidate. Although dark-matter axions have only feeble couplings to matter and radiation, these axions may be detected through resonant conversion of axions into microwave photons in a high-Q cavity threaded by a strong static magnetic field. This technique is at present the only means whereby dark-matter axions with plausible couplings may be detected at the required sensitivity. This talk describes recent results from the Axion Dark Matter Experiment (ADMX), now the world's most sensitive search for axions. There will also be a short overview of the ADMX upgrade, which promises sensitivity to even the more feebly coupled dark matter axions even should they make up only a minority fraction of the local dark matter halo
Composite dark matter from a model with composite Higgs boson

International Nuclear Information System (INIS)

Khlopov, Maxim Yu.; Kouvaris, Chris

2008-01-01

In a previous paper [Phys. Rev. D77, 065002 (2008)], we showed how the minimal walking technicolor model can provide a composite dark matter candidate, by forming bound states between a -2 electrically charged techniparticle and a 4 He ++ . We studied the properties of these 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 are solely made of techniparticles, although they behave as weakly interacting massive particles, due to their large elastic cross section with nuclei, can only account for a small percentage of the dark matter density. Therefore, we conclude that within the minimal walking technicolor model, composite dark matter should be mostly composed of tOHe. Moreover, in this paper, we put cosmological bounds in the masses of the techniparticles, if they compose the dark matter density. Finally, we propose within this setup, a possible explanation of the discrepancy between the DAMA/NaI and DAMA/LIBRA findings and the negative results of CDMS and other direct dark matter searches that imply nuclear recoil measurement, which should accompany ionization.
Simplified Models for Dark Matter Searches at the LHC

CERN Document Server

Abdallah, Jalal; Arbey, Alexandre; Ashkenazi, Adi; Belyaev, Alexander; Berger, Joshua; Boehm, Celine; Boveia, Antonio; Brennan, Amelia; Brooke, Jim; Buchmueller, Oliver; Buckley, Matthew; Busoni, Giorgio; Calibbi, Lorenzo; Chauhan, Sushil; Daci, Nadir; Davies, Gavin; De Bruyn, Isabelle; de Jong, Paul; De Roeck, Albert; de Vries, Kees; del Re, Daniele; De Simone, Andrea; Di Simone, Andrea; Doglioni, Caterina; Dolan, Matthew; Dreiner, Herbi K.; Ellis, John; Eno, Sarah; Etzion, Erez; Fairbairn, Malcolm; Feldstein, Brian; Flaecher, Henning; Feng, Eric; Fox, Patrick; Genest, Marie-Hélène; Gouskos, Loukas; Gramling, Johanna; Haisch, Ulrich; Harnik, Roni; Hibbs, Anthony; Hoh, Siewyan; Hopkins, Walter; Ippolito, Valerio; Jacques, Thomas; Kahlhoefer, Felix; Khoze, Valentin V.; Kirk, Russell; Korn, Andreas; Kotov, Khristian; Kunori, Shuichi; Landsberg, Greg; Liem, Sebastian; Lin, Tongyan; Lowette, Steven; Lucas, Robyn; Malgeri, Luca; Malik, Sarah; McCabe, Christopher; Mete, Alaettin Serhan; Morgante, Enrico; Mrenna, Stephen; Nakahama, Yu; Newbold, Dave; Nordstrom, Karl; Pani, Priscilla; Papucci, Michele; Pataraia, Sophio; Penning, Bjoern; Pinna, Deborah; Polesello, Giacomo; Racco, Davide; Re, Emanuele; Riotto, Antonio Walter; Rizzo, Thomas; Salek, David; Sarkar, Subir; Schramm, Steven; Skubic, Patrick; Slone, Oren; Smirnov, Juri; Soreq, Yotam; Sumner, Timothy; Tait, Tim M.P.; Thomas, Marc; Tomalin, Ian; Tunnell, Christopher; Vichi, Alessandro; Volansky, Tomer; Weiner, Neal; West, Stephen M.; Wielers, Monika; Worm, Steven; Yavin, Itay; Zaldivar, Bryan; Zhou, Ning; Zurek, Kathryn

2015-01-01

This document outlines a set of simplified models for dark matter and its interactions with Standard Model particles. It is intended to summarize the main characteristics that these simplified models have when applied to dark matter searches at the LHC, and to provide a number of useful expressions for reference. The list of models includes both s-channel and t-channel scenarios. For s-channel, spin-0 and spin-1 mediation is discussed, and also realizations where the Higgs particle provides a portal between the dark and visible sectors. The guiding principles underpinning the proposed simplified models are spelled out, and some suggestions for implementation are presented.
Simplified models for dark matter searches at the LHC

Energy Technology Data Exchange (ETDEWEB)

Abdallah, Jalal; Araujo, Henrique; Arbey, Alexandre; Ashkenazi, Adi; Belyaev, Alexander; Berger, Joshua; Boehm, Celine; Boveia, Antonio; Brennan, Amelia; Brooke, Jim; Buchmueller, Oliver; Buckley, Matthew; Busoni, Giorgio; Calibbi, Lorenzo; Chauhan, Sushil; Daci, Nadir; Davies, Gavin; De Bruyn, Isabelle; De Jong, Paul; De Roeck, Albert; de Vries, Kees; Del Re, Daniele; De Simone, Andrea; Di Simone, Andrea; Doglioni, Caterina; Dolan, Matthew; Dreiner, Herbi K.; Ellis, John; Eno, Sarah; Etzion, Erez; Fairbairn, Malcolm; Feldstein, Brian; Flaecher, Henning; Feng, Eric; Fox, Patrick; Genest, Marie-Hélène; Gouskos, Loukas; Gramling, Johanna; Haisch, Ulrich; Harnik, Roni; Hibbs, Anthony; Hoh, Siewyan; Hopkins, Walter; Ippolito, Valerio; Jacques, Thomas; Kahlhoefer, Felix; Khoze, Valentin V.; Kirk, Russell; Korn, Andreas; Kotov, Khristian; Kunori, Shuichi; Landsberg, Greg; Liem, Sebastian; Lin, Tongyan; Lowette, Steven; Lucas, Robyn; Malgeri, Luca; Malik, Sarah; McCabe, Christopher; Mete, Alaettin Serhan; Morgante, Enrico; Mrenna, Stephen; Nakahama, Yu; Newbold, Dave; Nordstrom, Karl; Pani, Priscilla; Papucci, Michele; Pataraia, Sophio; Penning, Bjoern; Pinna, Deborah; Polesello, Giacomo; Racco, Davide; Re, Emanuele; Riotto, Antonio Walter; Rizzo, Thomas; Salek, David; Sarkar, Subir; Schramm, Steven; Skubic, Patrick; Slone, Oren; Smirnov, Juri; Soreq, Yotam; Sumner, Timothy; Tait, Tim M. P.; Thomas, Marc; Tomalin, Ian; Tunnell, Christopher; Vichi, Alessandro; Volansky, Tomer; Weiner, Neal; West, Stephen M.; Wielers, Monika; Worm, Steven; Yavin, Itay; Zaldivar, Bryan; Zhou, Ning; Zurek, Kathryn

2015-09-01

This document a outlines a set of simplified models for dark matter and its interactions with Standard Model particles. It is intended to summarize the main characteristics that these simplified models have when applied to dark matter searches at the LHC, and to provide a number of useful expressions for reference. The list of models includes both s-channel and t-channel scenarios. For s-channel, spin-0 and spin-1 mediations are discussed, and also realizations where the Higgs particle provides a portal between the dark and visible sectors. The guiding principles underpinning the proposed simplified models are spelled out, and some suggestions for implementation are presented.
Solar Extreme UV radiation and quark nugget dark matter model

Energy Technology Data Exchange (ETDEWEB)

Zhitnitsky, Ariel, E-mail: arz@phas.ubc.ca [Department of Physics and Astronomy, University of British Columbia, Vancouver, B.C. V6T 1Z1 (Canada)

2017-10-01

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

Science.gov (United States)

Zhitnitsky, Ariel

2017-10-01

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

Directory of Open Access Journals (Sweden)

Ki-Young Choi

2017-08-01

Full Text Available Many extensions of Standard Model (SM include a dark sector which can interact with the SM sector via a light mediator. We explore the possibilities to probe such a dark sector by studying the distortion of the CMB spectrum from the blackbody shape due to the elastic scatterings between the dark matter and baryons through a hidden light mediator. We in particular focus on the model where the dark sector gauge boson kinetically mixes with the SM and present the future experimental prospect for a PIXIE-like experiment along with its comparison to the existing bounds from complementary terrestrial experiments.
Evolution of perturbations in distinct classes of canonical scalar field models of dark energy

International Nuclear Information System (INIS)

Jassal, H. K.

2010-01-01

Dark energy must cluster in order to be consistent with the equivalence principle. The background evolution can be effectively modeled by either a scalar field or by a barotropic fluid. The fluid model can be used to emulate perturbations in a scalar field model of dark energy, though this model breaks down at large scales. In this paper we study evolution of dark energy perturbations in canonical scalar field models: the classes of thawing and freezing models. The dark energy equation of state evolves differently in these classes. In freezing models, the equation of state deviates from that of a cosmological constant at early times. For thawing models, the dark energy equation of state remains near that of the cosmological constant at early times and begins to deviate from it only at late times. Since the dark energy equation of state evolves differently in these classes, the dark energy perturbations too evolve differently. In freezing models, since the equation of state deviates from that of a cosmological constant at early times, there is a significant difference in evolution of matter perturbations from those in the cosmological constant model. In comparison, matter perturbations in thawing models differ from the cosmological constant only at late times. This difference provides an additional handle to distinguish between these classes of models and this difference should manifest itself in the integrated Sachs-Wolfe effect.
A simplified model of top-flavoured dark matter

Energy Technology Data Exchange (ETDEWEB)

Kast, Simon; Blanke, Monika [Karlsruher Institut fuer Technologie, Karlsruhe (Germany)

2016-07-01

We present the phenomenology of a new physics simplified model of top-flavoured dark matter. The dark matter particle is the lightest Dirac fermion of a new flavour-triplet coupling to the SM up-triplet via a new scalar mediator. The coupling is left general, following Dark Minimal Flavour Violation introduced in arXiv:1405.6709, and therefore is a new source of flavour violation. We study the impact of constraints from both flavour experiments, relic abundance and direct detection constraints, as well as collider bounds.
Searches for Dark Matter at the ATLAS experiment

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00143063; The ATLAS collaboration

2015-01-01

Abstract. Searches for strongly produced dark matters in events with jets, photons, heavy-flavor quarks or massive gauge bosons recoiling against large missing transverse momentum in ATLAS are presented. These "MET+X" signatures provide powerful probes to dark matter production at the LHC, allowing us to interpret results in terms of effective field theory and/or simplified models with pair production of Weakly Interactions Particles. Recent ATLAS results on dark matter searches at LHC Run I and the connection to astroparticle physics are discussed.
Dark matter in the universe

International Nuclear Information System (INIS)

Opher, Reuven

2001-01-01

We treat here the problem of dark matter in galaxies. Recent articles seem to imply that we are entering into the precision era of cosmology, implying that all of the basic physics of cosmology is known. However, we show here that recent observations question the pillar of the standard model: the presence of nonbaryonic 'dark matter' in galaxies. Using Newton's law of gravitation, observations indicate that most of the matter in galaxies in invisible or dark. From the observed abundances of light elements, dark matter in galaxies must be primarily nonbaryonic. The standard model and its problems in explaining nonbaryonic dark matter will first be discussed. This will be followed by a discussion of a modification of Newton's law of gravitation to explain dark matter in galaxies. (author)

Conformally invariant Inert Higgs doublet model: an unified model for Inflation and Dark matter

International Nuclear Information System (INIS)

Das, Moumita; Mohanty, Subhendra

2012-01-01

Motivation of our present study is the searching for an unified model which can describe both the inflation as well as dark matter. From particle physics point of view, Higgs can be the most interesting candidate for the scalar field inflation. Conformal coupling of the inflaton with the gravity can generate the density perturbation and we use this idea in a realistic inert Higgs doublet model. We study the loop corrections of this conformally coupled system and in present era there is electroweak symmetry breaking to provide the mass of the particles. Study of the mass spectrum in present era reveals the scalar dark matter with mass 33.7 GeV and lightest Higgs at 125.6 GeV.
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
Dark matter and leptogenesis linked by classical scale invariance

Energy Technology Data Exchange (ETDEWEB)

Khoze, Valentin V.; Plascencia, Alexis D. [Institute for Particle Physics Phenomenology, Department of Physics, Durham University,South Road, Durham, DH1 3LE United Kingdom (United Kingdom)

2016-11-07

In this work we study a classically scale invariant extension of the Standard Model that can explain simultaneously dark matter and the baryon asymmetry in the universe. In our set-up we introduce a dark sector, namely a non-Abelian SU(2) hidden sector coupled to the SM via the Higgs portal, and a singlet sector responsible for generating Majorana masses for three right-handed sterile neutrinos. The gauge bosons of the dark sector are mass-degenerate and stable, and this makes them suitable as dark matter candidates. Our model also accounts for the matter-anti-matter asymmetry. The lepton flavour asymmetry is produced during CP-violating oscillations of the GeV-scale right-handed neutrinos, and converted to the baryon asymmetry by the electroweak sphalerons. All the characteristic scales in the model: the electro-weak, dark matter and the leptogenesis/neutrino mass scales, are generated radiatively, have a common origin and related to each other via scalar field couplings in perturbation theory.
How cold is cold dark matter?

International Nuclear Information System (INIS)

Armendariz-Picon, Cristian; Neelakanta, Jayanth T.

2014-01-01

If cold dark matter consists of particles, these must be non-interacting and non-relativistic by definition. In most cold dark matter models however, dark matter particles inherit a non-vanishing velocity dispersion from interactions in the early universe, a velocity that redshifts with cosmic expansion but certainly remains non-zero. In this article, we place model-independent constraints on the dark matter temperature to mass ratio, whose square root determines the dark matter velocity dispersion. We only assume that dark matter particles decoupled kinetically while non-relativistic, when galactic scales had not entered the horizon yet, and that their momentum distribution has been Maxwellian since that time. Under these assumptions, using cosmic microwave background and matter power spectrum observations, we place upper limits on the temperature to mass ratio of cold dark matter today (away from collapsed structures). These limits imply that the present cold dark matter velocity dispersion has to be smaller than 54 m/s. Cold dark matter has to be quite cold, indeed
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.
Ratcheting Up The Search for Dark Matter

Energy Technology Data Exchange (ETDEWEB)

McDermott, Samuel Dylan [Univ. of Michigan, Ann Arbor, MI (United States)

2014-01-01

The last several years have included remarkable advances in two of the primary areas of fundamental particle physics: the search for dark matter and the discovery of the Higgs boson. This dissertation will highlight some contributions made on the forefront of these exciting fields. Although the circumstantial evidence supporting the dark matter hypothesis is now almost undeniably significant, indisputable direct proof is still lacking. As the direct searches for dark matter continue, we can maximize our prospects of discovery by using theoretical techniques complementary to the observational searches to rule out additional, otherwise accessible parameter space. In this dissertation, I report bounds on a wide range of dark matter theories. The models considered here cover the spectrum from the canonical case of self-conjugate dark matter with weak-scale interactions, to electrically charged dark matter, to non-annihilating, non-fermionic dark matter. These bounds are obtained from considerations of astrophysical and cosmological data, including, respectively: diffuse gamma ray photon observations; structure formation considerations, along with an explication of the novel local dark matter structure due to galactic astrophysics; and the existence of old pulsars in dark-matter-rich environments. I also consider the prospects for a model of neutrino dark matter which has been motivated by a wide set of seemingly contradictory experimental results. In addition, I include a study that provides the tools to begin solving the speculative ``inverse'' problem of extracting dark matter properties solely from hypothetical nuclear energy spectra, which we may face if dark matter is discovered with multiple direct detection experiments. In contrast to the null searches for dark matter, we have the example of the recent discovery of the Higgs boson. The Higgs boson is the first fundamental scalar particle ever observed, and precision measurements of the production and
Closing in on minimal dark matter and radiative neutrino masses

Energy Technology Data Exchange (ETDEWEB)

Sierra, D. Aristizabal [IFPA, Dép. AGO, Université de Liège, Bât B5, Sart Tilman B-4000 Liège 1 (Belgium); Departamento de Física, Universidad Técnica Federico Santa María, Casilla 110-V, Avda. España 1680, Valparaiso (Chile); Simoes, C.; Wegman, D. [IFPA, Dép. AGO, Université de Liège, Bât B5, Sart Tilman B-4000 Liège 1 (Belgium)

2016-06-20

We study one-loop radiative neutrino mass models in which one of the beyond-the-standard model fields is either a hypercharge-zero fermion quintet (minimal dark matter) or a hypercharge-zero scalar septet. By systematically classifying all possible one-loop such models we identify various processes that render the neutral component of these representations (dark matter) cosmologically unstable. Thus, our findings show that these scenarios are in general not reconcilable with dark matter stability unless tiny couplings or additional ad hoc symmetries are assumed, in contrast to minimal dark matter models where stability is entirely due to the standard model gauge symmetry. For some variants based on higher-order loops we find that α{sub 2} reaches a Landau pole at rather low scales, a couple orders of magnitude from the characteristic scale of the model itself. Thus, we argue that some of these variations although consistent with dark matter stability and phenomenological constraints are hard to reconcile with perturbativity criteria.
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.
Constraining decaying dark matter with Fermi LAT gamma-rays

International Nuclear Information System (INIS)

Zhang, Le; Sigl, Günter; Weniger, Christoph; Maccione, Luca; Redondo, Javier

2010-01-01

High energy electrons and positrons from decaying dark matter can produce a significant flux of gamma rays by inverse Compton off low energy photons in the interstellar radiation field. This possibility is inevitably related with the dark matter interpretation of the observed PAMELA and FERMI excesses. The aim of this paper is providing a simple and universal method to constrain dark matter models which produce electrons and positrons in their decay by using the Fermi LAT gamma-ray observations in the energy range between 0.5 GeV and 300 GeV. We provide a set of universal response functions that, once convolved with a specific dark matter model produce the desired constraints. Our response functions contain all the astrophysical inputs such as the electron propagation in the galaxy, the dark matter profile, the gamma-ray fluxes of known origin, and the Fermi LAT data. We study the uncertainties in the determination of the response functions and apply them to place constraints on some specific dark matter decay models that can well fit the positron and electron fluxes observed by PAMELA and Fermi LAT. To this end we also take into account prompt radiation from the dark matter decay. We find that with the available data decaying dark matter cannot be excluded as source of the PAMELA positron excess
Electroweak baryogenesis, large Yukawas and dark matter

International Nuclear Information System (INIS)

Provenza, Alessio; Quiros, Mariano; Ullio, Piero

2005-01-01

It has recently been shown that the electroweak baryogenesis mechanism is feasible in Standard Model extensions containing extra fermions with large Yukawa couplings. We show here that the lightest of these fermionic fields can naturally be a good candidate for cold dark matter. We find regions in the parameter space where the thermal relic abundance of this particle is compatible with the dark matter density of the Universe as determined by the WMAP experiment. We study direct and indirect dark matter detection for this model and compare with current experimental limits and prospects for upcoming experiments. We find, contrary to the standard lore, that indirect detection searches are more promising than direct ones, and they already exclude part of the parameter space
Enlightening Students about Dark Matter

Science.gov (United States)

Hamilton, Kathleen; Barr, Alex; Eidelman, Dave

2018-01-01

Dark matter pervades the universe. While it is invisible to us, we can detect its influence on matter we can see. To illuminate this concept, we have created an interactive javascript program illustrating predictions made by six different models for dark matter distributions in galaxies. Students are able to match the predicted data with actual experimental results, drawn from several astronomy papers discussing dark matter’s impact on galactic rotation curves. Programming each new model requires integration of density equations with parameters determined by nonlinear curve-fitting using MATLAB scripts we developed. Using our javascript simulation, students can determine the most plausible dark matter models as well as the average percentage of dark matter lurking in galaxies, areas where the scientific community is still continuing to research. In that light, we strive to use the most up-to-date and accepted concepts: two of our dark matter models are the pseudo-isothermal halo and Navarro-Frenk-White, and we integrate out to each galaxy’s virial radius. Currently, our simulation includes NGC3198, NGC2403, and our own Milky Way.
Unified dark energy and dust dark matter dual to quadratic purely kinetic K-essence

International Nuclear Information System (INIS)

Guendelman, Eduardo; Nissimov, Emil; Pacheva, Svetlana

2016-01-01

We consider a modified gravity plus single scalar-field model, where the scalar Lagrangian couples symmetrically both to the standard Riemannian volume-form (spacetime integration measure density) given by the square root of the determinant of the Riemannian metric, as well as to another non-Riemannian volume-form in terms of an auxiliary maximal-rank antisymmetric tensor gauge field. As shown in a previous paper, the pertinent scalar-field dynamics provides an exact unified description of both dark energy via dynamical generation of a cosmological constant, and dark matter as a ''dust'' fluid with geodesic flow as a result of a hidden Noether symmetry. Here we extend the discussion by considering a non-trivial modification of the purely gravitational action in the form of f(R) = R -αR 2 generalized gravity. Upon deriving the corresponding ''Einstein-frame'' effective action of the latter modified gravity-scalar-field theory we find explicit duality (in the sense of weak versus strong coupling) between the original model of unified dynamical dark energy and dust fluid dark matter, on one hand, and a specific quadratic purely kinetic ''k-essence'' gravity-matter model with special dependence of its coupling constants on only two independent parameters, on the other hand. The canonical Hamiltonian treatment and Wheeler-DeWitt quantization of the dual purely kinetic ''k-essence'' gravity-matter model is also briefly discussed. (orig.)
A comprehensive approach to dark matter studies: exploration of simplified top-philic models

Energy Technology Data Exchange (ETDEWEB)

Arina, Chiara; Backović, Mihailo [Centre for Cosmology, Particle Physics and Phenomenology (CP3),Université catholique de Louvain, Chemin du Cyclotron 2, B-1348 Louvain-la-Neuve (Belgium); Conte, Eric [Groupe de Recherche de Physique des Hautes Énergies (GRPHE), Université de Haute-Alsace,IUT Colmar, F-68008 Colmar Cedex (France); Fuks, Benjamin [Sorbonne Universités, UPMC University Paris 06, UMR 7589, LPTHE, F-75005, Paris (France); CNRS, UMR 7589, LPTHE, F-75005, Paris (France); Guo, Jun [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics,Chinese Academy of Sciences, Beijing 100190 (China); Institut Pluridisciplinaire Hubert Curien/Département Recherches Subatomiques,Université de Strasbourg/CNRS-IN2P3, F-67037 Strasbourg (France); Heisig, Jan [Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University,Sommerfeldstr. 16, D-52056 Aachen (Germany); Hespel, Benoît [Centre for Cosmology, Particle Physics and Phenomenology (CP3),Université catholique de Louvain, Chemin du Cyclotron 2, B-1348 Louvain-la-Neuve (Belgium); Krämer, Michael [Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University,Sommerfeldstr. 16, D-52056 Aachen (Germany); Maltoni, Fabio; Martini, Antony [Centre for Cosmology, Particle Physics and Phenomenology (CP3),Université catholique de Louvain, Chemin du Cyclotron 2, B-1348 Louvain-la-Neuve (Belgium); Mawatari, Kentarou [Laboratoire de Physique Subatomique et de Cosmologie, Université Grenoble-Alpes,CNRS/IN2P3, 53 Avenue des Martyrs, F-38026 Grenoble (France); Theoretische Natuurkunde and IIHE/ELEM, Vrije Universiteit Brussel andInternational Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Pellen, Mathieu [Universität Würzburg, Institut für Theoretische Physik und Astrophysik,Emil-Hilb-Weg 22, 97074 Würzburg (Germany); Vryonidou, Eleni [Centre for Cosmology, Particle Physics and Phenomenology (CP3),Université catholique de Louvain, Chemin du Cyclotron 2, B-1348 Louvain-la-Neuve (Belgium)

2016-11-21

Studies of dark matter lie at the interface of collider physics, astrophysics and cosmology. Constraining models featuring dark matter candidates entails the capability to provide accurate predictions for large sets of observables and compare them to a wide spectrum of data. We present a framework which, starting from a model Lagrangian, allows one to consistently and systematically make predictions, as well as to confront those predictions with a multitude of experimental results. As an application, we consider a class of simplified dark matter models where a scalar mediator couples only to the top quark and a fermionic dark sector (i.e. the simplified top-philic dark matter model). We study in detail the complementarity of relic density, direct/indirect detection and collider searches in constraining the multi-dimensional model parameter space, and efficiently identify regions where individual approaches to dark matter detection provide the most stringent bounds. In the context of collider studies of dark matter, we point out the complementarity of LHC searches in probing different regions of the model parameter space with final states involving top quarks, photons, jets and/or missing energy. Our study of dark matter production at the LHC goes beyond the tree-level approximation and we show examples of how higher-order corrections to dark matter production processes can affect the interpretation of the experimental results.
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....
Dark matter in and around stars

International Nuclear Information System (INIS)

Sivertsson, Sofia

2009-01-01

There is by now compelling evidence that most of the matter in the universe is in the form of dark matter, a form of matter quite different from the matter we experience in every day life. The gravitational effects of this dark matter have been observed in many different ways but its true nature is still unknown. In most models dark matter particles can annihilate with each other into standard model particles. The direct or indirect observation of such annihilation products could give important clues for the dark matter puzzle. For signals from dark matter annihilations to be detectable, typically high dark matter densities are required. Massive objects, such as stars, can increase the local dark matter density both via scattering off nucleons and by pulling in dark matter gravitationally as the star forms. Dark matter annihilations outside the star would give rise to gamma rays and this is discussed in the first paper. Furthermore dark matter annihilations inside the star would deposit energy inside the star which, if abundant enough, could alter the stellar evolution. Aspects of this are investigated in the second paper. Finally, local dark matter over densities formed in the early universe could still be around today; prospects of detecting gamma rays from such clumps are discussed in the third paper
Imprint of primordial non-Gaussianity on dark matter halo profiles

Energy Technology Data Exchange (ETDEWEB)

Dizgah, Azadeh Moradinezhad; Dodelson, Scott; Riotto, Antonio

2013-09-01

We study the impact of primordial non-Gaussianity on the density profile of dark matter halos by using the semi-analytical model introduced recently by Dalal {\\it et al.} which relates the peaks of the initial linear density field to the final density profile of dark matter halos. Models with primordial non-Gaussianity typically produce an initial density field that differs from that produced in Gaussian models. We use the path-integral formulation of excursion set theory to calculate the non-Gaussian corrections to the peak profile and derive the statistics of the peaks of non-Gaussian density field. In the context of the semi-analytic model for halo profiles, currently allowed values for primordial non-Gaussianity would increase the shapes of the inner dark matter profiles, but only at the sub-percent level except in the very innermost regions.
Light dark matter through assisted annihilation

International Nuclear Information System (INIS)

Dey, Ujjal Kumar; Maity, Tarak Nath; Ray, Tirtha Sankar

2017-01-01

In this paper we investigate light dark matter scenarios where annihilation to Standard Model particles at tree-level is kinematically forbidden. In such cases annihilation can be aided by massive Standard Model-like species, called assisters , in the initial state that enhances the available phase space opening up novel tree-level processes. We investigate the feasibility of such non-standard assisted annihilation processes to reproduce the observed relic density of dark matter. We present a simple scalar dark matter-scalar assister model where this is realised. We find that if the dark matter and assister are relatively degenerate the required relic density can be achieved for a keV-MeV scale dark matter. We briefly discuss the cosmological constraints on such dark matter scenarios.
Model-independent constraints on dark matter annihilation in dwarf spheroidal galaxies

OpenAIRE

Boddy, Kimberly K.; Kumar, Jason; Marfatia, Danny; Sandick, Pearl

2018-01-01

We present a general, model-independent formalism for determining bounds on the production of photons in dwarf spheroidal galaxies via dark matter annihilation, applicable to any set of assumptions about dark matter particle physics or astrophysics. As an illustration, we analyze gamma-ray data from the Fermi Large Area Telescope to constrain a variety of nonstandard dark matter models, several of which have not previously been studied in the context of dwarf galaxy searches.
Mixed dark matter in left-right symmetric models

Energy Technology Data Exchange (ETDEWEB)

Berlin, Asher [Department of Physics, University of Chicago,Chicago, Illinois 60637 (United States); Fox, Patrick J. [Theoretical Physics Department, Fermilab,Batavia, Illinois 60510 (United States); Hooper, Dan [Center for Particle Astrophysics, Fermi National Accelerator Laboratory,Batavia, Illinois 60510 (United States); Department of Astronomy and Astrophysics, University of Chicago,Chicago, Illinois 60637 (United States); Mohlabeng, Gopolang [Center for Particle Astrophysics, Fermi National Accelerator Laboratory,Batavia, Illinois 60510 (United States); Department of Physics and Astronomy, University of Kansas,Lawrence, Kansas 66045 (United States)

2016-06-08

Motivated by the recently reported diboson and dijet excesses in Run 1 data at ATLAS and CMS, we explore models of mixed dark matter in left-right symmetric theories. In this study, we calculate the relic abundance and the elastic scattering cross section with nuclei for a number of dark matter candidates that appear within the fermionic multiplets of left-right symmetric models. In contrast to the case of pure multiplets, WIMP-nucleon scattering proceeds at tree-level, and hence the projected reach of future direct detection experiments such as LUX-ZEPLIN and XENON1T will cover large regions of parameter space for TeV-scale thermal dark matter. Decays of the heavy charged W{sup ′} boson to particles in the dark sector can potentially shift the right-handed gauge coupling to larger values when fixed to the rate of the Run 1 excesses, moving towards the theoretically attractive scenario, g{sub R}=g{sub L}. This region of parameter space may be probed by future collider searches for new Higgs bosons or electroweak fermions.
Gravitino in the early Universe. A model of extra-dimension and a model of dark matter

International Nuclear Information System (INIS)

Gherson, D.

2007-10-01

This work can be related to the Horava-Witten M-theory in which the Universe could appear 5 dimensional at a stage of its evolution but also to theories of Baryogenesis through Lepto-genesis which imply high reheating temperatures after Inflation. The studied cosmological model is within the framework of a 5 dimensional supergravity with the extra-dimension compactified on an orbifold circle, where the matter and gauge field are located on one of the two branes localised at the orbifold fixed points and where the supergravity fields can propagate in the whole spatial dimensions. In the model, the Dark matter is made of neutralino which is supposed to be the lightest supersymmetric particle. We have shown that there are curves of constraints between the size of the extra-dimension and the reheating temperature of the Universe after Inflation. The constraints come from the measurements of the amount of Dark matter in the Universe and from the model of the Big Bang Nucleosynthesis of light elements. (author)

Inflatable Dark Matter.

Science.gov (United States)

Davoudiasl, Hooman; Hooper, Dan; McDermott, Samuel D

2016-01-22

We describe a general scenario, dubbed "inflatable dark matter," in which the density of dark matter particles can be reduced through a short period of late-time inflation in the early Universe. The overproduction of dark matter that is predicted within many, otherwise, well-motivated models of new physics can be elegantly remedied within this context. Thermal relics that would, otherwise, be disfavored can easily be accommodated within this class of scenarios, including dark matter candidates that are very heavy or very light. Furthermore, the nonthermal abundance of grand unified theory or Planck scale axions can be brought to acceptable levels without invoking anthropic tuning of initial conditions. A period of late-time inflation could have occurred over a wide range of scales from ∼MeV to the weak scale or above, and could have been triggered by physics within a hidden sector, with small but not necessarily negligible couplings to the standard model.
Dissipative hidden sector dark matter

Science.gov (United States)

Foot, R.; Vagnozzi, S.

2015-01-01

A simple way of explaining dark matter without modifying known Standard Model physics is to require the existence of a hidden (dark) sector, which interacts with the visible one predominantly via gravity. We consider a hidden sector containing two stable particles charged under an unbroken U (1 )' gauge symmetry, hence featuring dissipative interactions. The massless gauge field associated with this symmetry, the dark photon, can interact via kinetic mixing with the ordinary photon. In fact, such an interaction of strength ε ˜10-9 appears to be necessary in order to explain galactic structure. We calculate the effect of this new physics on big bang nucleosynthesis and its contribution to the relativistic energy density at hydrogen recombination. We then examine the process of dark recombination, during which neutral dark states are formed, which is important for large-scale structure formation. Galactic structure is considered next, focusing on spiral and irregular galaxies. For these galaxies we modeled the dark matter halo (at the current epoch) as a dissipative plasma of dark matter particles, where the energy lost due to dissipation is compensated by the energy produced from ordinary supernovae (the core-collapse energy is transferred to the hidden sector via kinetic mixing induced processes in the supernova core). We find that such a dynamical halo model can reproduce several observed features of disk galaxies, including the cored density profile and the Tully-Fisher relation. We also discuss how elliptical and dwarf spheroidal galaxies could fit into this picture. Finally, these analyses are combined to set bounds on the parameter space of our model, which can serve as a guideline for future experimental searches.
Dark matter universe.

Science.gov (United States)

Bahcall, Neta A

2015-10-06

Most of the mass in the universe is in the form of dark matter--a new type of nonbaryonic particle not yet detected in the laboratory or in other detection experiments. The evidence for the existence of dark matter through its gravitational impact is clear in astronomical observations--from the early observations of the large motions of galaxies in clusters and the motions of stars and gas in galaxies, to observations of the large-scale structure in the universe, gravitational lensing, and the cosmic microwave background. The extensive data consistently show the dominance of dark matter and quantify its amount and distribution, assuming general relativity is valid. The data inform us that the dark matter is nonbaryonic, is "cold" (i.e., moves nonrelativistically in the early universe), and interacts only weakly with matter other than by gravity. The current Lambda cold dark matter cosmology--a simple (but strange) flat cold dark matter model dominated by a cosmological constant Lambda, with only six basic parameters (including the density of matter and of baryons, the initial mass fluctuations amplitude and its scale dependence, and the age of the universe and of the first stars)--fits remarkably well all the accumulated data. However, what is the dark matter? This is one of the most fundamental open questions in cosmology and particle physics. Its existence requires an extension of our current understanding of particle physics or otherwise point to a modification of gravity on cosmological scales. The exploration and ultimate detection of dark matter are led by experiments for direct and indirect detection of this yet mysterious particle.
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.
Gamma-ray excess and the minimal dark matter model

International Nuclear Information System (INIS)

Duerr, Michael; Fileviez Perez, Pavel; Smirnov, Juri

2015-10-01

We point out that the gamma-ray excesses in the galactic center and in the dwarf galaxy Reticulum II can both be well explained within the simplest dark matter model. We find that the corresponding region of parameter space will be tested by direct and indirect dark matter searches in the near future.
Dark matter: Theoretical perspectives

International Nuclear Information System (INIS)

Turner, M.S.

1993-01-01

I both review and make the case for the current theoretical prejudice: a flat Universe whose dominant constituent is nonbaryonic dark matter, emphasizing that this is still a prejudice and not yet fact. The theoretical motivation for nonbaryonic dark matter is discussed in the context of current elementary-particle theory, stressing that: (1) there are no dark matter candidates within the standard model of particle physics; (2) there are several compelling candidates within attractive extensions of the standard model of particle physics; and (3) the motivation for these compelling candidates comes first and foremost from particle physics. The dark-matter problem is now a pressing issue in both cosmology and particle physics, and the detection of particle dark matter would provide evidence for ''new physics.'' The compelling candidates are: a very light axion ( 10 -6 eV--10 -4 eV); a light neutrino (20 eV--90 eV); and a heavy neutralino (10 GeV--2 TeV). The production of these particles in the early Universe and the prospects for their detection are also discussed. I briefly mention more exotic possibilities for the dark matter, including a nonzero cosmological constant, superheavy magnetic monopoles, and decaying neutrinos
The Brans-Dicke gravity as a theory of dark matter

International Nuclear Information System (INIS)

Kim, Hongsu

2010-01-01

The pure Brans-Dicke (BD) gravity with or without the cosmological constant Λ has been taken as a model theory for dark matter. Indeed, there has been a consensus that unless one modifies either the standard theory of gravity, namely, general relativity, or the standard model for particle physics, or both, one can never achieve a satisfying understanding of the phenomena associated with dark matter and dark energy. Along this line, our dark matter model in this work can be thought of as an attempt to modify the gravity side alone in the simplest fashion to achieve the goal. Among others, it is demonstrated that our model theory can successfully predict the emergence of a dark matter halo-like configuration in terms of a self-gravitating spacetime solution to the BD field equations and reproduce the flattened rotation curve in this dark halo-like object in terms of the non-trivial energy density of the BD scalar field, which was absent in the context of general relativity, where Newton's constant is strictly a 'constant' having no dynamics. Our model theory, however, is not entirely without flaw, such as the prediction of relativistic jets in all types of galaxies, which actually is not the case.
Testing the Bose-Einstein Condensate dark matter model at galactic cluster scale

International Nuclear Information System (INIS)

Harko, Tiberiu; Liang, Pengxiang; Liang, Shi-Dong; Mocanu, Gabriela

2015-01-01

The possibility that dark matter may be in the form of a Bose-Einstein Condensate (BEC) has been extensively explored at galactic scale. In particular, good fits for the galactic rotations curves have been obtained, and upper limits for the dark matter particle mass and scattering length have been estimated. In the present paper we extend the investigation of the properties of the BEC dark matter to the galactic cluster scale, involving dark matter dominated astrophysical systems formed of thousands of galaxies each. By considering that one of the major components of a galactic cluster, the intra-cluster hot gas, is described by King's β-model, and that both intra-cluster gas and dark matter are in hydrostatic equilibrium, bound by the same total mass profile, we derive the mass and density profiles of the BEC dark matter. In our analysis we consider several theoretical models, corresponding to isothermal hot gas and zero temperature BEC dark matter, non-isothermal gas and zero temperature dark matter, and isothermal gas and finite temperature BEC, respectively. The properties of the finite temperature BEC dark matter cluster are investigated in detail numerically. We compare our theoretical results with the observational data of 106 galactic clusters. Using a least-squares fitting, as well as the observational results for the dark matter self-interaction cross section, we obtain some upper bounds for the mass and scattering length of the dark matter particle. Our results suggest that the mass of the dark matter particle is of the order of μ eV, while the scattering length has values in the range of 10 −7 fm
Possible constraints on SUSY-model parameters from direct dark matter search

International Nuclear Information System (INIS)

Bednyakov, V.A.; Kovalenko, S.G.

1993-01-01

We consider the SUSY-model neutralino as a dominant Dark Matter particle in the galactic halo and investigate some general issues of direct DM searches via elastic neutralino-nucleus scattering. On the basis of conventional assumptions about the nuclear and nucleon structure, without referring to a specific SUSY-model, we prove that it is impossible in principle to extract more than three constrains on fundamental SUSY-model parameters from the direct Dark Matter searches. Three types of Dark Matter detector probing different groups of parameters are recognized. 21 refs., 1 tab
Dark matter universe

Science.gov (United States)

Bahcall, Neta A.

2015-01-01

Most of the mass in the universe is in the form of dark matter—a new type of nonbaryonic particle not yet detected in the laboratory or in other detection experiments. The evidence for the existence of dark matter through its gravitational impact is clear in astronomical observations—from the early observations of the large motions of galaxies in clusters and the motions of stars and gas in galaxies, to observations of the large-scale structure in the universe, gravitational lensing, and the cosmic microwave background. The extensive data consistently show the dominance of dark matter and quantify its amount and distribution, assuming general relativity is valid. The data inform us that the dark matter is nonbaryonic, is “cold” (i.e., moves nonrelativistically in the early universe), and interacts only weakly with matter other than by gravity. The current Lambda cold dark matter cosmology—a simple (but strange) flat cold dark matter model dominated by a cosmological constant Lambda, with only six basic parameters (including the density of matter and of baryons, the initial mass fluctuations amplitude and its scale dependence, and the age of the universe and of the first stars)—fits remarkably well all the accumulated data. However, what is the dark matter? This is one of the most fundamental open questions in cosmology and particle physics. Its existence requires an extension of our current understanding of particle physics or otherwise point to a modification of gravity on cosmological scales. The exploration and ultimate detection of dark matter are led by experiments for direct and indirect detection of this yet mysterious particle. PMID:26417091
Superball dark matter

CERN Document Server

Kusenko, A

1999-01-01

Supersymmetric models predict a natural dark-matter candidate, stable baryonic Q-balls. They could be copiously produced in the early Universe as a by-product of the Affleck-Dine baryogenesis. I review the cosmological and astrophysical implications, methods of detection, and the present limits on this form of dark matter.
Dark Matter Benchmark Models for Early LHC Run-2 Searches. Report of the ATLAS/CMS Dark Matter Forum

Energy Technology Data Exchange (ETDEWEB)

Abercrombie, Daniel [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). et al.

2015-07-06

One of the guiding principles of this report is to channel the efforts of the ATLAS and CMS collaborations towards a minimal basis of dark matter models that should influence the design of the early Run-2 searches. At the same time, a thorough survey of realistic collider signals of Dark Matter is a crucial input to the overall design of the search program.
Collider detection of dark matter electromagnetic anapole moments

Science.gov (United States)

Alves, Alexandre; Santos, A. C. O.; Sinha, Kuver

2018-03-01

Dark matter that interacts with the Standard Model by exchanging photons through higher multipole interactions occurs in a wide range of both strongly and weakly coupled hidden sector models. We study the collider detection prospects of these candidates, with a focus on Majorana dark matter that couples through the anapole moment. The study is conducted at the effective field theory level with the mono-Z signature incorporating varying levels of systematic uncertainties at the high-luminosity LHC. The projected collider reach on the anapole moment is then compared to the reach coming from direct detection experiments like LZ. Finally, the analysis is applied to a weakly coupled completion with leptophilic dark matter.
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)
Single top quarks and dark matter

Science.gov (United States)

Pinna, Deborah; Zucchetta, Alberto; Buckley, Matthew R.; Canelli, Florencia

2017-08-01

Processes with dark matter interacting with the standard model fermions through new scalars or pseudoscalars with flavor-diagonal couplings proportional to fermion mass are well motivated theoretically, and provide a useful phenomenological model with which to interpret experimental results. Two modes of dark matter production from these models have been considered in the existing literature: pairs of dark matter produced through top quark loops with an associated monojet in the event, and pair production of dark matter with pairs of heavy flavored quarks (tops or bottoms). In this paper, we demonstrate that a third, previously overlooked channel yields a non-negligible contribution to LHC dark matter searches in these models. In spite of a generally lower production cross section at LHC when compared to the associated top-pair channel, non-flavor violating single top quark processes are kinematically favored and can significantly increase the sensitivity to these models. Including dark matter production in association with a single top quark through scalar or pseudoscalar mediators, the exclusion limit set by the LHC searches for dark matter can be improved by 30% up to a factor of two, depending on the mass assumed for the mediator particle.
Can An Amended Standard Model Account For Cold Dark Matter?

International Nuclear Information System (INIS)

Goldhaber, Maurice

2004-01-01

It is generally believed that one has to invoke theories beyond the Standard Model to account for cold dark matter particles. However, there may be undiscovered universal interactions that, if added to the Standard Model, would lead to new members of the three generations of elementary fermions that might be candidates for cold dark matter particles
Simplified dark matter models in the light of AMS-02 antiproton data

Energy Technology Data Exchange (ETDEWEB)

Li, Tong [ARC Centre of Excellence for Particle Physics at the Tera-scale,School of Physics and Astronomy, Monash University,Melbourne, Victoria 3800 (Australia)

2017-04-19

In this work we perform an analysis of the recent AMS-02 antiproton flux and the antiproton-to-proton ratio in the framework of simplified dark matter models. To predict the AMS-02 observables we adopt the propagation and injection parameters determined by the observed fluxes of nuclei. We assume that the dark matter particle is a Dirac fermionic dark matter, with leptophobic pseudoscalar or axialvector mediator that couples only to Standard Model quarks and dark matter particles. We find that the AMS-02 observations are consistent with the dark matter framework within the uncertainties. The antiproton data prefer a dark matter (mediator) mass in the 700 GeV–5 TeV region for the annihilation with pseudoscalar mediator and greater than 700 GeV (200 GeV–1 TeV) for the annihilation with axialvector mediator, respectively, at about 68% confidence level. The AMS-02 data require an effective dark matter annihilation cross section in the region of 1×10{sup −25}–1×10{sup −24} (1×10{sup −25}–4×10{sup −24}) cm{sup 3}/s for the simplified model with pseudoscalar (axialvector) mediator. The constraints from the LHC and Fermi-LAT are also discussed.
Simplified dark matter models in the light of AMS-02 antiproton data

International Nuclear Information System (INIS)

Li, Tong

2017-01-01

In this work we perform an analysis of the recent AMS-02 antiproton flux and the antiproton-to-proton ratio in the framework of simplified dark matter models. To predict the AMS-02 observables we adopt the propagation and injection parameters determined by the observed fluxes of nuclei. We assume that the dark matter particle is a Dirac fermionic dark matter, with leptophobic pseudoscalar or axialvector mediator that couples only to Standard Model quarks and dark matter particles. We find that the AMS-02 observations are consistent with the dark matter framework within the uncertainties. The antiproton data prefer a dark matter (mediator) mass in the 700 GeV–5 TeV region for the annihilation with pseudoscalar mediator and greater than 700 GeV (200 GeV–1 TeV) for the annihilation with axialvector mediator, respectively, at about 68% confidence level. The AMS-02 data require an effective dark matter annihilation cross section in the region of 1×10 −25 –1×10 −24 (1×10 −25 –4×10 −24 ) cm 3 /s for the simplified model with pseudoscalar (axialvector) mediator. The constraints from the LHC and Fermi-LAT are also discussed.
From superWIMPs to decaying dark matter. Models, bounds and indirect searches

International Nuclear Information System (INIS)

Weniger, Christoph

2010-06-01

Despite lots of observational and theoretical efforts, the particle nature of dark matter remains unknown. Beyond the paradigmatic WIMPs (Weakly Interacting Massive Particles), many theoretically well motivated models exist where dark matter interacts much more weakly than electroweak with Standard Model particles. In this case new phenomena occur, like the decay of dark matter or the interference with the standard cosmology of the early Universe. In this thesis we study some of these aspects of superweakly coupled dark matter in general, and in the special case of hidden U(1) X gauginos that kinetically mix with hypercharge. There, we will assume that the gauge group remains unbroken, similar to the Standard Model U(1) em . We study different kinds of cosmological bounds, including bounds from thermal overproduction, from primordial nucleosynthesis and from structure formation. Furthermore, we study the possible cosmic-ray signatures predicted by this scenario, with emphasis on the electron and positron channel in light of the recent observations by PAMELA and Fermi LAT. Moreover we study the cosmic-ray signatures of decaying dark matter independently of concrete particle-physics models. In particular we analyze in how far the rise in the positron fraction above 10 GeV, as observed by PAMELA, can be explained by dark matter decay. Lastly, we concentrate on related predictions for gamma-ray observations with the Fermi LAT, and propose to use the dipole-like anisotropy of the prompt gamma-ray dark matter signal to distinguish exotic dark matter contributions from the extragalactic gamma-ray background. (orig.)
From superWIMPs to decaying dark matter. Models, bounds and indirect searches

Energy Technology Data Exchange (ETDEWEB)

Weniger, Christoph

2010-06-15

Despite lots of observational and theoretical efforts, the particle nature of dark matter remains unknown. Beyond the paradigmatic WIMPs (Weakly Interacting Massive Particles), many theoretically well motivated models exist where dark matter interacts much more weakly than electroweak with Standard Model particles. In this case new phenomena occur, like the decay of dark matter or the interference with the standard cosmology of the early Universe. In this thesis we study some of these aspects of superweakly coupled dark matter in general, and in the special case of hidden U(1){sub X} gauginos that kinetically mix with hypercharge. There, we will assume that the gauge group remains unbroken, similar to the Standard Model U(1){sub em}. We study different kinds of cosmological bounds, including bounds from thermal overproduction, from primordial nucleosynthesis and from structure formation. Furthermore, we study the possible cosmic-ray signatures predicted by this scenario, with emphasis on the electron and positron channel in light of the recent observations by PAMELA and Fermi LAT. Moreover we study the cosmic-ray signatures of decaying dark matter independently of concrete particle-physics models. In particular we analyze in how far the rise in the positron fraction above 10 GeV, as observed by PAMELA, can be explained by dark matter decay. Lastly, we concentrate on related predictions for gamma-ray observations with the Fermi LAT, and propose to use the dipole-like anisotropy of the prompt gamma-ray dark matter signal to distinguish exotic dark matter contributions from the extragalactic gamma-ray background. (orig.)

Quantum field theory in curved spacetime and the dark matter problem

International Nuclear Information System (INIS)

Grib, A. A.; Pavlov, Yu. V.

2007-01-01

Quantum field theory in nonstationary curved Friedmann spacetime leads to the phenomenon of creation of massive particles. The hypothesis that in the end of inflation gravitation creates from vacuum superheavy particles decaying on quarks and leptons leading to the observed baryon charge is investigated. Taking the complex scalar field for these particles in analogy with K 0 -meson theory one obtains two components - the long living and short living ones, so that the long living component after breaking the Grand Unification symmetry has a long life time and is observed today as dark matter. The hypothesis that ultra high energy cosmic rays occur as manifestation of superheavy dark matter is considered and some experimental possibilities of the proposed scheme are analyzed
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
The Cosmology of Composite Inelastic Dark Matter

Energy Technology Data Exchange (ETDEWEB)

Spier Moreira Alves, Daniele; Behbahani, Siavosh R.; /SLAC /Stanford U., ITP; Schuster, Philip; Wacker, Jay G.; /SLAC

2011-08-19

Composite dark matter is a natural setting for implementing inelastic dark matter - the O(100 keV) mass splitting arises from spin-spin interactions of constituent fermions. In models where the constituents are charged under an axial U(1) gauge symmetry that also couples to the Standard Model quarks, dark matter scatters inelastically off Standard Model nuclei and can explain the DAMA/LIBRA annual modulation signal. This article describes the early Universe cosmology of a minimal implementation of a composite inelastic dark matter model where the dark matter is a meson composed of a light and a heavy quark. The synthesis of the constituent quarks into dark hadrons results in several qualitatively different configurations of the resulting dark matter composition depending on the relative mass scales in the system.
Revisiting simplified dark matter models in terms of AMS-02 and Fermi-LAT

Science.gov (United States)

Li, Tong

2018-01-01

We perform an analysis of the simplified dark matter models in the light of cosmic ray observables by AMS-02 and Fermi-LAT. We assume fermion, scalar or vector dark matter particle with a leptophobic spin-0 mediator that couples only to Standard Model quarks and dark matter via scalar and/or pseudo-scalar bilinear. The propagation and injection parameters of cosmic rays are determined by the observed fluxes of nuclei from AMS-02. We find that the AMS-02 observations are consistent with the dark matter framework within the uncertainties. The AMS-02 antiproton data prefer 30 (50) GeV - 5 TeV dark matter mass and require an effective annihilation cross section in the region of 4 × 10-27 (7 × 10-27) - 4 × 10-24 cm3/s for the simplified fermion (scalar and vector) dark matter models. The cross sections below 2 × 10-26 cm3/s can evade the constraint from Fermi-LAT dwarf galaxies for about 100 GeV dark matter mass.
Dark matter: Theoretical perspectives

Energy Technology Data Exchange (ETDEWEB)

Turner, M.S. (Chicago Univ., IL (United States). Enrico Fermi Inst. Fermi National Accelerator Lab., Batavia, IL (United States))

1993-01-01

I both review and make the case for the current theoretical prejudice: a flat Universe whose dominant constituent is nonbaryonic dark matter, emphasizing that this is still a prejudice and not yet fact. The theoretical motivation for nonbaryonic dark matter is discussed in the context of current elementary-particle theory, stressing that: (1) there are no dark matter candidates within the standard model of particle physics; (2) there are several compelling candidates within attractive extensions of the standard model of particle physics; and (3) the motivation for these compelling candidates comes first and foremost from particle physics. The dark-matter problem is now a pressing issue in both cosmology and particle physics, and the detection of particle dark matter would provide evidence for new physics.'' The compelling candidates are: a very light axion ( 10[sup [minus]6] eV--10[sup [minus]4] eV); a light neutrino (20 eV--90 eV); and a heavy neutralino (10 GeV--2 TeV). The production of these particles in the early Universe and the prospects for their detection are also discussed. I briefly mention more exotic possibilities for the dark matter, including a nonzero cosmological constant, superheavy magnetic monopoles, and decaying neutrinos.
Dark matter: Theoretical perspectives

Energy Technology Data Exchange (ETDEWEB)

Turner, M.S. [Chicago Univ., IL (United States). Enrico Fermi Inst.]|[Fermi National Accelerator Lab., Batavia, IL (United States)

1993-01-01

I both review and make the case for the current theoretical prejudice: a flat Universe whose dominant constituent is nonbaryonic dark matter, emphasizing that this is still a prejudice and not yet fact. The theoretical motivation for nonbaryonic dark matter is discussed in the context of current elementary-particle theory, stressing that: (1) there are no dark matter candidates within the standard model of particle physics; (2) there are several compelling candidates within attractive extensions of the standard model of particle physics; and (3) the motivation for these compelling candidates comes first and foremost from particle physics. The dark-matter problem is now a pressing issue in both cosmology and particle physics, and the detection of particle dark matter would provide evidence for ``new physics.`` The compelling candidates are: a very light axion ( 10{sup {minus}6} eV--10{sup {minus}4} eV); a light neutrino (20 eV--90 eV); and a heavy neutralino (10 GeV--2 TeV). The production of these particles in the early Universe and the prospects for their detection are also discussed. I briefly mention more exotic possibilities for the dark matter, including a nonzero cosmological constant, superheavy magnetic monopoles, and decaying neutrinos.
Unified TeV scale picture of baryogenesis and dark matter.

Science.gov (United States)

Babu, K S; Mohapatra, R N; Nasri, Salah

2007-04-20

We present a simple extension of the minimal supersymmetric standard model which provides a unified picture of cosmological baryon asymmetry and dark matter. Our model introduces a gauge singlet field N and a color triplet field X which couple to the right-handed quark fields. The out-of-equilibrium decay of the Majorana fermion N mediated by the exchange of the scalar field X generates adequate baryon asymmetry for MN approximately 100 GeV and MX approximately TeV. The scalar partner of N (denoted N1) is naturally the lightest SUSY particle as it has no gauge interactions and plays the role of dark matter. The model is experimentally testable in (i) neutron-antineutron oscillations with a transition time estimated to be around 10(10)sec, (ii) discovery of colored particles X at LHC with mass of order TeV, and (iii) direct dark matter detection with a predicted cross section in the observable range.
Dark matter from decaying topological defects

International Nuclear Information System (INIS)

Hindmarsh, Mark; Kirk, Russell; West, Stephen M.

2014-01-01

We study dark matter production by decaying topological defects, in particular cosmic strings. In topological defect or ''top-down'' (TD) scenarios, the dark matter injection rate varies as a power law with time with exponent p−4. We find a formula in closed form for the yield for all p < 3/2, which accurately reproduces the solution of the Boltzmann equation. We investigate two scenarios (p = 1, p = 7/6) motivated by cosmic strings which decay into TeV-scale states with a high branching fraction into dark matter particles. For dark matter models annihilating either by s-wave or p-wave, we find the regions of parameter space where the TD model can account for the dark matter relic density as measured by Planck. We find that topological defects can be the principal source of dark matter, even when the standard freeze-out calculation under-predicts the relic density and hence can lead to potentially large ''boost factor'' enhancements in the dark matter annihilation rate. We examine dark matter model-independent limits on this scenario arising from unitarity and discuss example model-dependent limits coming from indirect dark matter search experiments. In the four cases studied, the upper bound on Gμ for strings with an appreciable channel into TeV-scale states is significantly more stringent than the current Cosmic Microwave Background limits
SOLAR CONSTRAINTS ON ASYMMETRIC DARK MATTER

International Nuclear Information System (INIS)

Lopes, Ilídio; Silk, Joseph

2012-01-01

The dark matter content of the universe is likely to be a mixture of matter and antimatter, perhaps comparable to the measured asymmetric mixture of baryons and antibaryons. During the early stages of the universe, the dark matter particles are produced in a process similar to baryogenesis, and dark matter freezeout depends on the dark matter asymmetry and the annihilation cross section (s-wave and p-wave annihilation channels) of particles and antiparticles. In these η-parameterized asymmetric dark matter (ηADM) models, the dark matter particles have an annihilation cross section close to the weak interaction cross section, and a value of dark matter asymmetry η close to the baryon asymmetry η B . Furthermore, we assume that dark matter scattering of baryons, namely, the spin-independent scattering cross section, is of the same order as the range of values suggested by several theoretical particle physics models used to explain the current unexplained events reported in the DAMA/LIBRA, CoGeNT, and CRESST experiments. Here, we constrain ηADM by investigating the impact of such a type of dark matter on the evolution of the Sun, namely, the flux of solar neutrinos and helioseismology. We find that dark matter particles with a mass smaller than 15 GeV, a spin-independent scattering cross section on baryons of the order of a picobarn, and an η-asymmetry with a value in the interval 10 –12 -10 –10 , would induce a change in solar neutrino fluxes in disagreement with current neutrino flux measurements. This result is also confirmed by helioseismology data. A natural consequence of this model is suppressed annihilation, thereby reducing the tension between indirect and direct dark matter detection experiments, but the model also allows a greatly enhanced annihilation cross section. All the cosmological ηADM scenarios that we discuss have a relic dark matter density Ωh 2 and baryon asymmetry η B in agreement with the current WMAP measured values, Ω DM h 2 = 0
Clumpy cold dark matter

Science.gov (United States)

Silk, Joseph; Stebbins, Albert

1993-01-01

A study is conducted of cold dark matter (CDM) models in which clumpiness will inhere, using cosmic strings and textures suited to galaxy formation. CDM clumps of 10 million solar mass/cu pc density are generated at about z(eq) redshift, with a sizable fraction surviving. Observable implications encompass dark matter cores in globular clusters and in galactic nuclei. Results from terrestrial dark matter detection experiments may be affected by clumpiness in the Galactic halo.
Dark matter in a constrained E6 inspired SUSY model

International Nuclear Information System (INIS)

Athron, P.; Harries, D.; Nevzorov, R.; Williams, A.G.

2016-01-01

We investigate dark matter in a constrained E 6 inspired supersymmetric model with an exact custodial symmetry and compare with the CMSSM. The breakdown of E 6 leads to an additional U(1) N symmetry and a discrete matter parity. The custodial and matter symmetries imply there are two stable dark matter candidates, though one may be extremely light and contribute negligibly to the relic density. We demonstrate that a predominantly Higgsino, or mixed bino-Higgsino, neutralino can account for all of the relic abundance of dark matter, while fitting a 125 GeV SM-like Higgs and evading LHC limits on new states. However we show that the recent LUX 2016 limit on direct detection places severe constraints on the mixed bino-Higgsino scenarios that explain all of the dark matter. Nonetheless we still reveal interesting scenarios where the gluino, neutralino and chargino are light and discoverable at the LHC, but the full relic abundance is not accounted for. At the same time we also show that there is a huge volume of parameter space, with a predominantly Higgsino dark matter candidate that explains all the relic abundance, that will be discoverable with XENON1T. Finally we demonstrate that for the E 6 inspired model the exotic leptoquarks could still be light and within range of future LHC searches.
Flavored dark matter beyond Minimal Flavor Violation

International Nuclear Information System (INIS)

Agrawal, Prateek; Blanke, Monika; Gemmler, Katrin

2014-01-01

We study the interplay of flavor and dark matter phenomenology for models of flavored dark matter interacting with quarks. We allow an arbitrary flavor structure in the coupling of dark matter with quarks. This coupling is assumed to be the only new source of violation of the Standard Model flavor symmetry extended by a U(3) χ associated with the dark matter. We call this ansatz Dark Minimal Flavor Violation (DMFV) and highlight its various implications, including an unbroken discrete symmetry that can stabilize the dark matter. As an illustration we study a Dirac fermionic dark matter χ which transforms as triplet under U(3) χ , and is a singlet under the Standard Model. The dark matter couples to right-handed down-type quarks via a colored scalar mediator with a coupling. We identify a number of ''flavor-safe'' scenarios for the structure of which are beyond Minimal Flavor Violation. Also, for dark matter and collider phenomenology we focus on the well-motivated case of b-flavored dark matter. Furthermore, the combined flavor and dark matter constraints on the parameter space of turn out to be interesting intersections of the individual ones. LHC constraints on simplified models of squarks and sbottoms can be adapted to our case, and monojet searches can be relevant if the spectrum is compressed
Novel dark matter phenomenology at colliders

Science.gov (United States)

Wardlow, Kyle Patrick

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

Science.gov (United States)

Giedt, Joel; Thomas, Anthony W; Young, Ross D

2009-11-13

Recent lattice measurements have given accurate estimates of the quark condensates in the proton. We use these results to significantly improve the dark matter predictions in benchmark models within the constrained minimal supersymmetric standard model. The predicted spin-independent cross sections are at least an order of magnitude smaller than previously suggested and our results have significant consequences for dark matter searches.
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.
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.
Mirror matter as self-interacting dark matter

International Nuclear Information System (INIS)

Mohapatra, R.N.; Nussinov, S.; Teplitz, V.L.

2002-01-01

It has been argued that the observed core density profile of galaxies is inconsistent with having a dark matter particle that is collisionless and that alternative dark matter candidates which are self-interacting may explain observations better. One new class of self-interacting dark matter that has been proposed in the context of mirror universe models of particle physics is the mirror hydrogen atom, whose stability is guaranteed by the conservation of mirror baryon number. We show that the effective transport cross section for mirror hydrogen atoms has the right order of magnitude for solving the 'cuspy' halo problem. Furthermore, the suppression of dissipation effects for mirror atoms due to a higher mirror mass scale prevents the mirror halo matter from collapsing into a disk, strengthening the argument for mirror matter as galactic dark matter
Dark matter and the equivalence principle

Science.gov (United States)

Frieman, Joshua A.; Gradwohl, Ben-Ami

1993-01-01

A survey is presented of the current understanding of dark matter invoked by astrophysical theory and cosmology. Einstein's equivalence principle asserts that local measurements cannot distinguish a system at rest in a gravitational field from one that is in uniform acceleration in empty space. Recent test-methods for the equivalence principle are presently discussed as bases for testing of dark matter scenarios involving the long-range forces between either baryonic or nonbaryonic dark matter and ordinary matter.
Dark matter and galactic cosmic rays

International Nuclear Information System (INIS)

Taillet, R.

2010-12-01

Dark matter is one of the major problems encountered by modern cosmology and astrophysics, resisting the efforts of both theoreticians and experimentalists. The problem itself is easy to state: many indirect astrophysical measurements indicate that the mass contained in the Universe seems to be dominated by a new type of matter which has never been directly seen yet, this is why it is called dark matter. This hypothesis of dark matter being made of new particles is of great interest for particle physicists, whose theories provide many candidates: dark matter is one of the major topics of astro-particle physics. This work focuses on searching dark matter in the form of new particles, more precisely to indirect detection, i.e. the search of particles produced by dark matter annihilation rather than dark matter particles themselves. In this framework, I will present the studies I have been doing in the field of cosmic rays physics (particularly cosmic ray sources), in several collaborations. In particular, the study of the antimatter component of cosmic rays can give relevant information about dark matter. The last chapter is dedicated to my teaching activities

Inflationary imprints on dark matter

Energy Technology Data Exchange (ETDEWEB)

Nurmi, Sami; Tenkanen, Tommi; Tuominen, Kimmo, E-mail: sami.nurmi@helsinki.fi, E-mail: tommi.tenkanen@helsinki.fi, E-mail: kimmo.i.tuominen@helsinki.fi [University of Helsinki and Helsinki Institute of Physics, P.O. Box 64, FI-00014, University of Helsinki (Finland)

2015-11-01

We show that dark matter abundance and the inflationary scale H could be intimately related. Standard Model extensions with Higgs mediated couplings to new physics typically contain extra scalars displaced from vacuum during inflation. If their coupling to Standard Model is weak, they will not thermalize and may easily constitute too much dark matter reminiscent to the moduli problem. As an example we consider Standard Model extended by a Z{sub 2} symmetric singlet s coupled to the Standard Model Higgs Φ via λ Φ{sup †}Φ s{sup 2}. Dark matter relic density is generated non-thermally for λ ∼< 10{sup −7}. We show that the dark matter yield crucially depends on the inflationary scale. For H∼ 10{sup 10} GeV we find that the singlet self-coupling and mass should lie in the regime λ{sub s}∼> 10{sup −9} and m{sub s}∼< 50 GeV to avoid dark matter overproduction.
Dark Matter candidates in a baryogenesis inspired scenario

International Nuclear Information System (INIS)

Provenza, A; Quiros, M; Ullio, P

2006-01-01

It has recently been shown that the electroweak baryogenesis mechanism is feasible in Standard Model extensions containing extra fermions with large Yukawa couplings. We show that the lightest of these fermionic fields can naturally be a good candidate for cold dark matter. We find regions in the parameter space where the thermal relic abundance of this particle is compatible with the dark matter density of the Universe as determined by the WMAP experiment. We study direct and indirect dark matter detection for this model and compare with current experimental limits and prospects for upcoming experiments. We find, contrary to the standard lore, that indirect detection searches are more promising than direct ones, and they already exclude part of the parameter space
Simplified models of dark matter with a long-lived co-annihilation partner

Science.gov (United States)

Khoze, Valentin V.; Plascencia, Alexis D.; Sakurai, Kazuki

2017-06-01

We introduce a new set of simplified models to address the effects of 3-point interactions between the dark matter particle, its dark co-annihilation partner, and the Standard Model degree of freedom, which we take to be the tau lepton. The contributions from dark matter co-annihilation channels are highly relevant for a determination of the correct relic abundance. We investigate these effects as well as the discovery potential for dark matter co-annihilation partners at the LHC. A small mass splitting between the dark matter and its partner is preferred by the co-annihilation mechanism and suggests that the co-annihilation partners may be long-lived (stable or meta-stable) at collider scales. It is argued that such long-lived electrically charged particles can be looked for at the LHC in searches of anomalous charged tracks. This approach and the underlying models provide an alternative/complementarity to the mono-jet and multi-jet based dark matter searches widely used in the context of simplified models with s-channel mediators. We consider four types of simplified models with different particle spins and coupling structures. Some of these models are manifestly gauge invariant and renormalizable, others would ultimately require a UV completion. These can be realised in terms of supersymmetric models in the neutralino-stau co-annihilation regime, as well as models with extra dimensions or composite models.
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
Particle Dark Matter: An Overview

International Nuclear Information System (INIS)

Roszkowski, Leszek

2009-01-01

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

OpenAIRE

Ema, Yohei; Nakayama, Kazunori; Tang, Yong

2018-01-01

In the purely gravitational dark matter scenario, the dark matter particle does not have any interaction except for gravitational one. We study the gravitational particle production of dark matter particle in such a minimal setup and show that correct amount of dark matter can be produced depending on the inflation model and the dark matter mass. In particular, we carefully evaluate the particle production rate from the transition epoch to the inflaton oscillation epoch in a realistic inflati...
Connecting dark matter annihilation to the vertex functions of Standard Model fermions

Energy Technology Data Exchange (ETDEWEB)

Kumar, Jason; Light, Christopher, E-mail: jkumar@hawaii.edu, E-mail: lightc@hawaii.edu [Department of Physics and Astronomy, University of Hawaii, Honolulu, HI 96822, Hawaii (United States)

2017-07-01

We consider scenarios in which dark matter is a Majorana fermion which couples to Standard Model fermions through the exchange of charged mediating particles. The matrix elements for various dark matter annihilation processes are then related to one-loop corrections to the fermion-photon vertex, where dark matter and the charged mediators run in the loop. In particular, in the limit where Standard Model fermion helicity mixing is suppressed, the cross section for dark matter annihilation to various final states is related to corrections to the Standard Model fermion charge form factor. These corrections can be extracted in a gauge-invariant manner from collider cross sections. Although current measurements from colliders are not precise enough to provide useful constraints on dark matter annihilation, improved measurements at future experiments, such as the International Linear Collider, could improve these constraints by several orders of magnitude, allowing them to surpass the limits obtainable by direct observation.
Directly detecting isospin-violating dark matter

OpenAIRE

Kelso, Chris; Kumar, Jason; Marfatia, Danny; Sandick, Pearl

2018-01-01

We consider the prospects for multiple dark matter direct detection experiments to determine if the interactions of a dark matter candidate are isospin-violating. We focus on theoretically well-motivated examples of isospin-violating dark matter (IVDM), including models in which dark matter interactions with nuclei are mediated by a dark photon, a Z, or a squark. We determine that the best prospects for distinguishing IVDM from the isospin-invariant scenario arise in the cases of dark photon–...
Flavored dark matter beyond Minimal Flavor Violation

CERN Document Server

Agrawal, Prateek; Gemmler, Katrin

2014-10-13

We study the interplay of flavor and dark matter phenomenology for models of flavored dark matter interacting with quarks. We allow an arbitrary flavor structure in the coupling of dark matter with quarks. This coupling is assumed to be the only new source of violation of the Standard Model flavor symmetry extended by a $U(3)_\\chi$ associated with the dark matter. We call this ansatz Dark Minimal Flavor Violation (DMFV) and highlight its various implications, including an unbroken discrete symmetry that can stabilize the dark matter. As an illustration we study a Dirac fermionic dark matter $\\chi$ which transforms as triplet under $U(3)_\\chi$, and is a singlet under the Standard Model. The dark matter couples to right-handed down-type quarks via a colored scalar mediator $\\phi$ with a coupling $\\lambda$. We identify a number of "flavor-safe" scenarios for the structure of $\\lambda$ which are beyond Minimal Flavor Violation. For dark matter and collider phenomenology we focus on the well-motivated case of $b$-...
Dark Matter "Collider" from Inelastic Boosted Dark Matter.

Science.gov (United States)

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

2017-10-20

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

OpenAIRE

Berlin, Asher; Blinov, Nikita

2017-01-01

We consider a class of models in which thermal dark matter is lighter than an MeV. If dark matter thermalizes with the Standard Model below the temperature of neutrino-photon decoupling, equilibration and freeze-out cools and heats the Standard Model bath comparably, alleviating constraints from measurements of the effective number of neutrino species. We demonstrate this mechanism in a model consisting of fermionic dark matter coupled to a light scalar mediator. Thermal dark matter can be as...
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.)
Plasma dark matter direct detection

Energy Technology Data Exchange (ETDEWEB)

Clarke, J.D.; Foot, R., E-mail: j.clarke5@pgrad.unimelb.edu.au, E-mail: rfoot@unimelb.edu.au [ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, University of Melbourne, Victoria 3010 Australia (Australia)

2016-01-01

Dark matter in spiral galaxies like the Milky Way may take the form of a dark plasma. Hidden sector dark matter charged under an unbroken U(1)' gauge interaction provides a simple and well defined particle physics model realising this possibility. The assumed U(1)' neutrality of the Universe then implies (at least) two oppositely charged dark matter components with self-interactions mediated via a massless 'dark photon' (the U(1)' gauge boson). In addition to nuclear recoils such dark matter can give rise to keV electron recoils in direct detection experiments. In this context, the detailed physical properties of the dark matter plasma interacting with the Earth is required. This is a complex system, which is here modelled as a fluid governed by the magnetohydrodynamic equations. These equations are numerically solved for some illustrative examples, and implications for direct detection experiments discussed. In particular, the analysis presented here leaves open the intriguing possibility that the DAMA annual modulation signal is due primarily to electron recoils (or even a combination of electron recoils and nuclear recoils). The importance of diurnal modulation (in addition to annual modulation) as a means of probing this kind of dark matter is also emphasised.
Observational constraints on the unified dark matter and dark energy model based on the quark bag model

International Nuclear Information System (INIS)

Montiel, Ariadna; Salzano, Vincenzo; Lazkoz, Ruth

2014-01-01

In this work we investigate if a small fraction of quarks and gluons, which escaped hadronization and survived as a uniformly spread perfect fluid, can play the role of both dark matter and dark energy. This fluid, as developed in [1], is characterized by two main parameters: β, related to the amount of quarks and gluons which act as dark matter; and γ, acting as the cosmological constant. We explore the feasibility of this model at cosmological scales using data from type Ia Supernovae (SNeIa), Long Gamma-Ray Bursts (LGRB) and direct observational Hubble data. We find that: (i) in general, β cannot be constrained by SNeIa data nor by LGRB or H(z) data; (ii) γ can be constrained quite well by all three data sets, contributing with ≈78% to the energy–matter content; (iii) when a strong prior on (only) baryonic matter is assumed, the two parameters of the model are constrained successfully.
Observational constraints on the unified dark matter and dark energy model based on the quark bag model

Energy Technology Data Exchange (ETDEWEB)

Montiel, Ariadna, E-mail: amontiel@fis.cinvestav.mx [Departamento de Física, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, 07000 México DF (Mexico); Salzano, Vincenzo, E-mail: vincenzo.salzano@ehu.es [Departamento de Física Teórica e Historia de la Ciencia, Universidad del País Vasco (UPV/EHU), Apdo. 644, E-48080 Bilbao (Spain); Lazkoz, Ruth, E-mail: ruth.lazkoz@ehu.es [Departamento de Física Teórica e Historia de la Ciencia, Universidad del País Vasco (UPV/EHU), Apdo. 644, E-48080 Bilbao (Spain)

2014-06-02

In this work we investigate if a small fraction of quarks and gluons, which escaped hadronization and survived as a uniformly spread perfect fluid, can play the role of both dark matter and dark energy. This fluid, as developed in [1], is characterized by two main parameters: β, related to the amount of quarks and gluons which act as dark matter; and γ, acting as the cosmological constant. We explore the feasibility of this model at cosmological scales using data from type Ia Supernovae (SNeIa), Long Gamma-Ray Bursts (LGRB) and direct observational Hubble data. We find that: (i) in general, β cannot be constrained by SNeIa data nor by LGRB or H(z) data; (ii) γ can be constrained quite well by all three data sets, contributing with ≈78% to the energy–matter content; (iii) when a strong prior on (only) baryonic matter is assumed, the two parameters of the model are constrained successfully.
Searching dark matter at LHC

International Nuclear Information System (INIS)

Nojiri, Mihoko M.

2007-01-01

We now believe that the dark matter in our Universe must be an unknown elementary particle, which is charge neutral and weakly interacting. The standard model must be extended to include it. The dark matter was likely produced in the early universe from the high energy collisions of the particles. Now LHC experiment starting from 2008 will create such high energy collision to explore the nature of the dark matter. In this article we explain how dark matter and LHC physics will be connected in detail. (author)
Scalar dark matter in leptophilic two-Higgs-doublet model

Science.gov (United States)

Bandyopadhyay, Priyotosh; Chun, Eung Jin; Mandal, Rusa

2018-04-01

Two-Higgs-Doublet Model of Type-X in the large tan ⁡ β limit becomes leptophilic to allow a light pseudo-scalar A and thus provides an explanation of the muon g - 2 anomaly. Introducing a singlet scalar dark matter S in this context, one finds that two important dark matter properties, nucleonic scattering and self-annihilation, are featured separately by individual couplings of dark matter to the two Higgs doublets. While one of the two couplings is strongly constrained by direct detection experiments, the other remains free to be adjusted for the relic density mainly through the process SS → AA. This leads to the 4τ final states which can be probed by galactic gamma ray detections.
Interacting Dark Matter and q-Deformed Dark Energy Nonminimally Coupled to Gravity

Directory of Open Access Journals (Sweden)

Emre Dil

2016-01-01

Full Text Available In this paper, we propose a new approach to study the dark sector of the universe by considering the dark energy as an emerging q-deformed bosonic scalar field which is not only interacting with the dark matter, but also nonminimally coupled to gravity, in the framework of standard Einsteinian gravity. In order to analyze the dynamic of the system, we first give the quantum field theoretical description of the q-deformed scalar field dark energy and then construct the action and the dynamical structure of this interacting and nonminimally coupled dark sector. As a second issue, we perform the phase-space analysis of the model to check the reliability of our proposal by searching the stable attractor solutions implying the late-time accelerating expansion phase of the universe.
Axion dark matter and Planck favor non-minimal couplings to gravity

Energy Technology Data Exchange (ETDEWEB)

Folkerts, Sarah, E-mail: sarah.folkerts@lmu.de [Arnold Sommerfeld Center, Ludwig-Maximilians-University, Theresienstr. 37, 80333 München (Germany); Germani, Cristiano, E-mail: cristiano.germani@lmu.de [Arnold Sommerfeld Center, Ludwig-Maximilians-University, Theresienstr. 37, 80333 München (Germany); Redondo, Javier, E-mail: javier.redondo@lmu.de [Arnold Sommerfeld Center, Ludwig-Maximilians-University, Theresienstr. 37, 80333 München (Germany); Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, 80805 München (Germany)

2014-01-20

Constraints on inflationary scenarios and isocurvature perturbations have excluded the simplest and most generic models of dark matter based on QCD axions. Considering non-minimal kinetic couplings of scalar fields to gravity substantially changes this picture. The axion can account for the observed dark matter density avoiding the overproduction of isocurvature fluctuations. Finally, we show that assuming the same non-minimal kinetic coupling to the axion (dark matter) and to the standard model Higgs boson (inflaton) provides a minimal picture of early time cosmology.
Directly detecting isospin-violating dark matter

Science.gov (United States)

Kelso, Chris; Kumar, Jason; Marfatia, Danny; Sandick, Pearl

2018-03-01

We consider the prospects for multiple dark matter direct detection experiments to determine if the interactions of a dark matter candidate are isospin-violating. We focus on theoretically well-motivated examples of isospin-violating dark matter (IVDM), including models in which dark matter interactions with nuclei are mediated by a dark photon, a Z , or a squark. We determine that the best prospects for distinguishing IVDM from the isospin-invariant scenario arise in the cases of dark photon-or Z -mediated interactions, and that the ideal experimental scenario would consist of large exposure xenon- and neon-based detectors. If such models just evade current direct detection limits, then one could distinguish such models from the standard isospin-invariant case with two detectors with of order 100 ton-year exposure.

10th Symposium on Sources and Detection of Dark Matter and Dark Energy in the Universe

CERN Document Server

UCLA Dark Matter 2012

2012-01-01

These proceedings provide the latest results on dark matter and dark energy research. The UCLA Department of Physics and Astronomy hosted its tenth Dark Matter and Dark Energy conference in Marina del Rey and brought together all the leaders in the field. The symposium provided a scientific forum for the latest discussions in the field. Topics covered at the symposium: •Status of measurements of the equation of state of dark energy and new experiments •The search for missing energy events at the LHC and implications for dark matter search •Theoretical calculations on all forms of dark matter (SUSY, axions, sterile neutrinos, etc.) •Status of the indirect search for dark matter •Status of the direct search for dark matter in detectors around the world •The low-mass wimp search region •The next generation of very large dark matter detectors •New underground laboratories for dark matter search
SOLAR CONSTRAINTS ON ASYMMETRIC DARK MATTER

Energy Technology Data Exchange (ETDEWEB)

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

2012-10-01

The dark matter content of the universe is likely to be a mixture of matter and antimatter, perhaps comparable to the measured asymmetric mixture of baryons and antibaryons. During the early stages of the universe, the dark matter particles are produced in a process similar to baryogenesis, and dark matter freezeout depends on the dark matter asymmetry and the annihilation cross section (s-wave and p-wave annihilation channels) of particles and antiparticles. In these {eta}-parameterized asymmetric dark matter ({eta}ADM) models, the dark matter particles have an annihilation cross section close to the weak interaction cross section, and a value of dark matter asymmetry {eta} close to the baryon asymmetry {eta}{sub B}. Furthermore, we assume that dark matter scattering of baryons, namely, the spin-independent scattering cross section, is of the same order as the range of values suggested by several theoretical particle physics models used to explain the current unexplained events reported in the DAMA/LIBRA, CoGeNT, and CRESST experiments. Here, we constrain {eta}ADM by investigating the impact of such a type of dark matter on the evolution of the Sun, namely, the flux of solar neutrinos and helioseismology. We find that dark matter particles with a mass smaller than 15 GeV, a spin-independent scattering cross section on baryons of the order of a picobarn, and an {eta}-asymmetry with a value in the interval 10{sup -12}-10{sup -10}, would induce a change in solar neutrino fluxes in disagreement with current neutrino flux measurements. This result is also confirmed by helioseismology data. A natural consequence of this model is suppressed annihilation, thereby reducing the tension between indirect and direct dark matter detection experiments, but the model also allows a greatly enhanced annihilation cross section. All the cosmological {eta}ADM scenarios that we discuss have a relic dark matter density {Omega}h {sup 2} and baryon asymmetry {eta}{sub B} in agreement with
The search for dark matter

International Nuclear Information System (INIS)

Smith, Nigel; Spooner, Neil

2000-01-01

Experiments housed deep underground are searching for new particles that could simultaneously solve one of the biggest mysteries in astrophysics and reveal what lies beyond the Standard Model of particle physics. Physicists are very particular about balancing budgets. Energy, charge and momentum all have to be conserved and often money as well. Astronomers were therefore surprised and disturbed to learn in the 1930s that our own Milky Way galaxy behaved as if it contained more matter than could be seen with telescopes. This puzzling non-luminous matter became known as ''dark matter'' and we now know that over 90% of the matter in the entire universe is dark. In later decades the search for this dark matter shifted from the heavens to the Earth. In fact, the search for dark matter went underground. Today there are experiments searching for dark matter hundreds and thousands of metres below ground in mines, road tunnels and other subterranean locations. These experiments are becoming more sensitive every year and are beginning to test various new models and theories in particle physics and cosmology. (UK)
Dark matter assimilation into the baryon asymmetry

International Nuclear Information System (INIS)

D'Eramo, Francesco; Fei, Lin; Thaler, Jesse

2012-01-01

Pure singlets are typically disfavored as dark matter candidates, since they generically have a thermal relic abundance larger than the observed value. In this paper, we propose a new dark matter mechanism called a ssimilation , which takes advantage of the baryon asymmetry of the universe to generate the correct relic abundance of singlet dark matter. Through assimilation, dark matter itself is efficiently destroyed, but dark matter number is stored in new quasi-stable heavy states which carry the baryon asymmetry. The subsequent annihilation and late-time decay of these heavy states yields (symmetric) dark matter as well as (asymmetric) standard model baryons. We study in detail the case of pure bino dark matter by augmenting the minimal supersymmetric standard model with vector-like chiral multiplets. In the parameter range where this mechanism is effective, the LHC can discover long-lived charged particles which were responsible for assimilating dark matter
Implications of unitarity and gauge invariance for simplified dark matter models

International Nuclear Information System (INIS)

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

2016-01-01

We show that simplified models used to describe the interactions of dark matter with Standard Model particles do not in general respect gauge invariance and that perturbative unitarity may be violated in large regions of the parameter space. The modifications necessary to cure these inconsistencies may imply a much richer phenomenology and lead to stringent constraints on the model. We illustrate these observations by considering the simplified model of a fermionic dark matter particle and a vector mediator. Imposing gauge invariance then leads to strong constraints from dilepton resonance searches and electroweak precision tests. Furthermore, the new states required to restore perturbative unitarity can mix with Standard Model states and mediate interactions between the dark and the visible sector, leading to new experimental signatures such as invisible Higgs decays. The resulting constraints are typically stronger than the ‘classic’ constraints on DM simplified models such as monojet searches and make it difficult to avoid thermal overproduction of dark matter.
Implications of unitarity and gauge invariance for simplified dark matter models

International Nuclear Information System (INIS)

Kahlhoefer, Felix; Schmidt-Hoberg, Kai; Schwetz, Thomas; Vogl, Stefan; Stockholm Univ.

2015-10-01

We show that simplified models used to describe the interactions of dark matter with Standard Model particles do not in general respect gauge invariance and that perturbative unitarity may be violated in large regions of the parameter space. The modifications necessary to cure these inconsistencies may imply a much richer phenomenology and lead to stringent constraints on the model. We illustrate these observations by considering the simplified model of a fermionic dark matter particle and a vector mediator. Imposing gauge invariance then leads to strong constraints from dilepton resonance searches and electroweak precision tests. Furthermore, the new states required to restore perturbative unitarity can mix with Standard Model states and mediate interactions between the dark and the visible sector, leading to new experimental signatures such as invisible Higgs decays. The resulting constraints are typically stronger than the 'classic' constraints on DM simplified models such as monojet searches and make it difficult to avoid thermal overproduction of dark matter.
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.
LEP shines light on dark matter

International Nuclear Information System (INIS)

Fox, Patrick J.; Harnik, Roni; Kopp, Joachim; Tsai, Yuhsin

2011-01-01

Dark matter pair production at high energy colliders may leave observable signatures in the energy and momentum spectra of the objects recoiling against the dark matter. We use LEP data on monophoton events with large missing energy to constrain the coupling of dark matter to electrons. Within a large class of models, our limits are complementary to and competitive with limits on dark matter annihilation and on WIMP-nucleon scattering from indirect and direct searches. Our limits, however, do not suffer from systematic and astrophysical uncertainties associated with direct and indirect limits. For example, we are able to rule out light (< or approx. 10 GeV) thermal relic dark matter with universal couplings exclusively to charged leptons. In addition, for dark matter mass below about 80 GeV, LEP limits are stronger than Fermi constraints on annihilation into charged leptons in dwarf spheroidal galaxies. Within its kinematic reach, LEP also provides the strongest constraints on the spin-dependent direct detection cross section in models with universal couplings to both quarks and leptons. In such models the strongest limit is also set on spin-independent scattering for dark matter masses below ∼4 GeV. Throughout our discussion, we consider both low energy effective theories of dark matter, as well as several motivated renormalizable scenarios involving light mediators.
Asymmetric Dark Matter Models and the LHC Diphoton Excess

DEFF Research Database (Denmark)

Frandsen, Mads T.; Shoemaker, Ian M.

2016-01-01

The existence of dark matter (DM) and the origin of the baryon asymmetry are persistent indications that the SM is incomplete. More recently, the ATLAS and CMS experiments have observed an excess of diphoton events with invariant mass of about 750 GeV. One interpretation of this excess is decays...... have for models of asymmetric DM that attempt to account for the similarity of the dark and visible matter abundances....
Thermal Dark Matter Below a MeV.

Science.gov (United States)

Berlin, Asher; Blinov, Nikita

2018-01-12

We consider a class of models in which thermal dark matter is lighter than a MeV. If dark matter thermalizes with the standard model below the temperature of neutrino-photon decoupling, equilibration and freeze-out cool and heat the standard model bath comparably, alleviating constraints from measurements of the effective number of neutrino species. We demonstrate this mechanism in a model consisting of fermionic dark matter coupled to a light scalar mediator. Thermal dark matter can be as light as a few keV, while remaining compatible with existing cosmological and astrophysical observations. This framework motivates new experiments in the direct search for sub-MeV thermal dark matter and light force carriers.
Dark matter for excess of AMS-02 positrons and antiprotons

Directory of Open Access Journals (Sweden)

Chuan-Hung Chen

2015-07-01

Full Text Available We propose a dark matter explanation to simultaneously account for the excess of antiproton-to-proton and positron power spectra observed in the AMS-02 experiment while having the right dark matter relic abundance and satisfying the current direct search bounds. We extend the Higgs triplet model with a hidden gauge symmetry of SU(2X that is broken to Z3 by a quadruplet scalar field, rendering the associated gauge bosons stable weakly-interacting massive particle dark matter candidates. By coupling the complex Higgs triplet and the SU(2X quadruplet, the dark matter candidates can annihilate into triplet Higgs bosons each of which in turn decays into lepton or gauge boson final states. Such a mechanism gives rise to correct excess of positrons and antiprotons with an appropriate choice of the triplet vacuum expectation value. Besides, the model provides a link between neutrino mass and dark matter phenomenology.
The state equation of Yang-Mills field dark energy models

International Nuclear Information System (INIS)

Zhao Wen; Zhang Yang

2006-01-01

In this paper, we study the possibility of building Yang-Mills (YM) field dark energy models with equation of state (EoS) crossing -1, and find that it cannot be realized by the single YM field models, no matter what kind of Lagrangian or initial condition. But the states of -1 -1 to <-1, and it will go to the critical state of ω = -1 with the expansion of the universe, which character is the same as the single YM field models, and the big rip is naturally avoided
Constraining Secluded Dark Matter models with the public data from the 79-string IceCube search for dark matter in the Sun

Energy Technology Data Exchange (ETDEWEB)

Ardid, M.; Felis, I.; Martínez-Mora, J.A. [Institut d' Investigació per a la Gestió Integrada de les Zones Costaneres (IGIC), Universitat Politècnica de València, C/Paranimf 1, 46730 Gandia (Spain); Herrero, A., E-mail: mardid@fis.upv.es, E-mail: ivfeen@upv.es, E-mail: aherrero@mat.upv.es, E-mail: jmmora@fis.upv.es [Institut de Matemàtica Multidisciplinar, Universitat Politècnica de València, Camí de Vera s/n, 46022 València (Spain)

2017-04-01

The 79-string IceCube search for dark matter in the Sun public data is used to test Secluded Dark Matter models. No significant excess over background is observed and constraints on the parameters of the models are derived. Moreover, the search is also used to constrain the dark photon model in the region of the parameter space with dark photon masses between 0.22 and ∼ 1 GeV and a kinetic mixing parameter ε ∼ 10{sup −9}, which remains unconstrained. These are the first constraints of dark photons from neutrino telescopes. It is expected that neutrino telescopes will be efficient tools to test dark photons by means of different searches in the Sun, Earth and Galactic Center, which could complement constraints from direct detection, accelerators, astrophysics and indirect detection with other messengers, such as gamma rays or antiparticles.
Condensation of galactic cold dark matter

International Nuclear Information System (INIS)

Visinelli, Luca

2016-01-01

We consider the steady-state regime describing the density profile of a dark matter halo, if dark matter is treated as a Bose-Einstein condensate. We first solve the fluid equation for “canonical” cold dark matter, obtaining a class of density profiles which includes the Navarro-Frenk-White profile, and which diverge at the halo core. We then solve numerically the equation obtained when an additional “quantum pressure” term is included in the computation of the density profile. The solution to this latter case is finite at the halo core, possibly avoiding the “cuspy halo problem” present in some cold dark matter theories. Within the model proposed, we predict the mass of the cold dark matter particle to be of the order of M_χc"2≈10"−"2"4 eV, which is of the same order of magnitude as that predicted in ultra-light scalar cold dark matter models. Finally, we derive the differential equation describing perturbations in the density and the pressure of the dark matter fluid.
Pulsar timing signal from ultralight scalar dark matter

International Nuclear Information System (INIS)

Khmelnitsky, Andrei; Rubakov, Valery

2014-01-01

An ultralight free scalar field with mass around 10 −23 −10 −22 eV is a viable dark mater candidate, which can help to resolve some of the issues of the cold dark matter on sub-galactic scales. We consider the gravitational field of the galactic halo composed out of such dark matter. The scalar field has oscillating in time pressure, which induces oscillations of gravitational potential with amplitude of the order of 10 −15 and frequency in the nanohertz range. This frequency is in the range of pulsar timing array observations. We estimate the magnitude of the pulse arrival time residuals induced by the oscillating gravitational potential. We find that for a range of dark matter masses, the scalar field dark matter signal is comparable to the stochastic gravitational wave signal and can be detected by the planned SKA pulsar timing array experiment
MATTER IN THE BEAM: WEAK LENSING, SUBSTRUCTURES, AND THE TEMPERATURE OF DARK MATTER

Energy Technology Data Exchange (ETDEWEB)

Mahdi, Hareth S.; Elahi, Pascal J.; Lewis, Geraint F. [Sydney Institute for Astronomy, School of Physics, A28, The University of Sydney, NSW 2006 (Australia); Power, Chris, E-mail: hareth@physics.usyd.edu.au [International Centre for Radio Astronomy Research, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia)

2016-08-01

Warm dark matter (WDM) models offer an attractive alternative to the current cold dark matter (CDM) cosmological model. We present a novel method to differentiate between WDM and CDM cosmologies, namely, using weak lensing; this provides a unique probe as it is sensitive to all of the “matter in the beam,” not just dark matter haloes and the galaxies that reside in them, but also the diffuse material between haloes. We compare the weak lensing maps of CDM clusters to those in a WDM model corresponding to a thermally produced 0.5 keV dark matter particle. Our analysis clearly shows that the weak lensing magnification, convergence, and shear distributions can be used to distinguish between CDM and WDM models. WDM models increase the probability of weak magnifications, with the differences being significant to ≳5 σ , while leaving no significant imprint on the shear distribution. WDM clusters analyzed in this work are more homogeneous than CDM ones, and the fractional decrease in the amount of material in haloes is proportional to the average increase in the magnification. This difference arises from matter that would be bound in compact haloes in CDM being smoothly distributed over much larger volumes at lower densities in WDM. Moreover, the signature does not solely lie in the probability distribution function but in the full spatial distribution of the convergence field.
On wave dark matter in spiral and barred galaxies

International Nuclear Information System (INIS)

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

2015-01-01

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

Energy Technology Data Exchange (ETDEWEB)

Bettoni, Dario [Institut für Theoretische Physik, Ruprecht-Karls-Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg (Germany); Nusser, Adi [Physics Department and the Asher Space Science Institute—Technion, Haifa 32000 (Israel); Blas, Diego; Sibiryakov, Sergey, E-mail: d.bettoni@thphys.uni-heidelberg.de, E-mail: adi@physics.technion.ac.il, E-mail: diego.blas@cern.ch, E-mail: sergey.sibiryakov@cern.ch [Theoretical Physics Department, CERN, CH-1211 Geneva 23 (Switzerland)

2017-05-01

We develop the framework for testing Lorentz invariance in the dark matter sector using galactic dynamics. We consider a Lorentz violating (LV) vector field acting on the dark matter component of a satellite galaxy orbiting in a host halo. We introduce a numerical model for the dynamics of satellites in a galactic halo and for a galaxy in a rich cluster to explore observational consequences of such an LV field. The orbital motion of a satellite excites a time dependent LV force which greatly affects its internal dynamics. Our analysis points out key observational signatures which serve as probes of LV forces. These include modifications to the line of sight velocity dispersion, mass profiles and shapes of satellites. With future data and a more detailed modeling these signatures can be exploited to constrain a new region of the parameter space describing the LV in the dark matter sector.
Gravity-mediated (or Composite) Dark Matter

CERN Document Server

Lee, Hyun Min; Sanz, Veronica

2014-01-01

Dark matter could have an electroweak origin, yet communicate with the visible sector exclusively through gravitational interactions. In a set-up addressing the hierarchy problem, we propose a new dark matter scenario where gravitational mediators, arising from the compactification of extra-dimensions, are responsible for dark matter interactions and its relic abundance in the Universe. We write an explicit example of this mechanism in warped extra-dimensions and work out its constraints. We also develop a dual picture of the model, based on a four-dimensional scenario with partial compositeness. We show that Gravity-mediated Dark Matter is equivalent to a mechanism of generating viable dark matter scenarios in a strongly-coupled, near-conformal theory, such as in composite Higgs models.

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
Onset of the nonlinear regime in unified dark matter models

International Nuclear Information System (INIS)

Avelino, P.P.; Beca, L.M.G.; Carvalho, J.P.M. de; Martins, C.J.A.P.; Copeland, E.J.

2004-01-01

We discuss the onset of the nonlinear regime in the context of unified dark matter models involving a generalized Chaplygin gas. We show that the transition from dark-matter-like to dark-energy-like behavior will never be smooth. In some regions of space the transition will never take place while in others it may happen sooner or later than naively expected. As a result the linear theory used in previous studies may break down late in the matter dominated era even on large cosmological scales. We study the importance of this effect showing that its magnitude depends on the exact form of the equation of state in the low density regime. We expect that our results will be relevant for other unified dark matter scenarios, particularly those where the quartessence candidate is a perfect fluid
A hypothesis concerning the nature of dark matter

International Nuclear Information System (INIS)

Paduroiu, Sinziana; Rusu, Mircea

2004-01-01

In this paper we briefly review the main observational facts that lead to the hypothesis of the so called 'dark matter' as a considerable part of the matter in the Universe that is not visible. The expansion rate of the universe, the birth of the galaxies and their rotation curves are some of the phenomena that can be explained by the existence of dark matter. Generally, there are two models for dark matter: the hot dark matter (HDM) model and the cold dark matter one (CDM). In this paper we will refer mainly to the cold dark matter model. Two different opinions regarding the nature of dark matter and its contribution to the total mass of the matter in the Universe due to a cosmological constant will be discussed. In the first part some particles candidates for dark matter like neutralino and axions will be considered and their prediction made by supersymmetry theory. In the second part different alternative models will be presented that imply singularities of the gravitational theory; inflationary models; and in particular one model that introduces a new expression in the gravitational potential as an attempt to explain the phenomena that made us believe in the existence of this kind of matter. (authors)
The search for decaying Dark Matter

CERN Document Server

Herder, J W den; Ruchayskiy, O.; Abazajian, K.; Frenk, C.; Hansen, S.; Jonker, P.; Kouveliotou, C.; Lesgourgues, J.; Neronov, A.; Ohashi, T.; Paerels, F.; Paltani, S.; Piro, L.; Pohl, M.; Shaposhnikov, M.; Silk, J.; Valle, J.W.F.

2009-01-01

We propose an X-ray mission called Xenia to search for decaying superweakly interacting Dark Matter particles (super-WIMP) with a mass in the keV range. The mission and its observation plan are capable of providing a major break through in our understanding of the nature of Dark Matter (DM). It will confirm, or reject, predictions of a number of particle physics models by increasing the sensitivity of the search for decaying DM by about two orders of magnitude through a wide-field imaging X-ray spectrometer in combination with a dedicated observation program. The proposed mission will provide unique limits on the mixing angle and mass of neutral leptons, right handed partners of neutrinos, which are important Dark Matter candidates. The existence of these particles is strongly motivated by observed neutrino flavor oscillations and the problem of baryon asymmetry of the Universe. In super-WIMP models, the details of the formation of the cosmic web are different from those of LambdaCDM. The proposed mission wil...
ASTROPHYSICS. Exclusion of leptophilic dark matter models using XENON100 electronic recoil data.

Science.gov (United States)

2015-08-21

Laboratory experiments searching for galactic dark matter particles scattering off nuclei have so far not been able to establish a discovery. We use data from the XENON100 experiment to search for dark matter interacting with electrons. With no evidence for a signal above the low background of our experiment, we exclude a variety of representative dark matter models that would induce electronic recoils. For axial-vector couplings to electrons, we exclude cross sections above 6 × 10(-35) cm(2) for particle masses of m(χ) = 2 GeV/c(2). Independent of the dark matter halo, we exclude leptophilic models as an explanation for the long-standing DAMA/LIBRA signal, such as couplings to electrons through axial-vector interactions at a 4.4σ confidence level, mirror dark matter at 3.6σ, and luminous dark matter at 4.6σ. Copyright © 2015, American Association for the Advancement of Science.
Simplified dark matter models with a spin-2 mediator at the LHC

Energy Technology Data Exchange (ETDEWEB)

Kraml, Sabine [Universite Grenoble-Alpes, CNRS/IN2P3, Laboratoire de Physique Subatomique et de Cosmologie, Grenoble (France); Laa, Ursula [Universite Grenoble-Alpes, CNRS/IN2P3, Laboratoire de Physique Subatomique et de Cosmologie, Grenoble (France); LAPTh, Universite Savoie Mont Blanc, CNRS, B.P.110, Annecy Cedex (France); Mawatari, Kentarou [Universite Grenoble-Alpes, CNRS/IN2P3, Laboratoire de Physique Subatomique et de Cosmologie, Grenoble (France); Theoretische Natuurkunde and IIHE/ELEM, Vrije Universiteit Brussel, and International Solvay Institutes, Brussels (Belgium); Yamashita, Kimiko [Ochanomizu University, Department of Physics, Graduate School of Humanities and Sciences, and Program for Leading Graduate Schools, Tokyo (Japan)

2017-05-15

We consider simplified dark matter models where a dark matter candidate couples to the standard model (SM) particles via an s-channel spin-2 mediator, and study constraints on the model parameter space from the current LHC data. Our focus lies on the complementarity among different searches, in particular monojet and multijet plus missing-energy searches and resonance searches. For universal couplings of the mediator to SM particles, missing-energy searches can give stronger constraints than WW, ZZ, dijet, dihiggs, t anti t, b anti b resonance searches in the low-mass region and/or when the coupling of the mediator to dark matter is much larger than its couplings to SM particles. The strongest constraints, however, come from diphoton and dilepton resonance searches. Only if these modes are suppressed, missing-energy searches can be competitive in constraining dark matter models with a spin-2 mediator. (orig.)
Simplified dark matter models with a spin-2 mediator at the LHC

International Nuclear Information System (INIS)

Kraml, Sabine; Laa, Ursula; Mawatari, Kentarou; Yamashita, Kimiko

2017-01-01

We consider simplified dark matter models where a dark matter candidate couples to the standard model (SM) particles via an s-channel spin-2 mediator, and study constraints on the model parameter space from the current LHC data. Our focus lies on the complementarity among different searches, in particular monojet and multijet plus missing-energy searches and resonance searches. For universal couplings of the mediator to SM particles, missing-energy searches can give stronger constraints than WW, ZZ, dijet, dihiggs, t anti t, b anti b resonance searches in the low-mass region and/or when the coupling of the mediator to dark matter is much larger than its couplings to SM particles. The strongest constraints, however, come from diphoton and dilepton resonance searches. Only if these modes are suppressed, missing-energy searches can be competitive in constraining dark matter models with a spin-2 mediator. (orig.)
Dark Matter

International Nuclear Information System (INIS)

Audouze, J.; Tran Thanh Van, J.

1988-01-01

The book begins with the papers devoted to the experimental search of signatures of the dark matter which governs the evolution of the Universe as a whole. A series of contributions describe the presently considered experimental techniques (cryogenic detectors, supraconducting detectors...). A real dialogue concerning these techniques has been instaured between particle physicists and astrophysicists. After the progress report of the particle physicists, the book provides the reader with an updated situation concerning the research in cosmology. The second part of the book is devoted to the analysis of the backgrounds at different energies such as the possible role of the cooling flows in the constitution of massive galactic halos. Any search of dark matter implies necessarily the analysis of the spatial distributions of the large scale structures of the Universe. This report is followed by a series of statistical analyses of these distributions. These analyses concern mainly universes filled up with cold dark matter. The last paper of this third part concerns the search of clustering in the spatial distribution of QSOs. The presence of dark matter should affect the solar neighborhood and related to the existence of galactic haloes. The contributions are devoted to the search of such local dark matter. Primordial nucleosynthesis provides a very powerful tool to set up quite constraining limitations on the overall baryonic density. Even if on takes into account the inhomogeneities in density possibly induced by the Quark-Hadron transition, this baryonic density should be much lower than the overall density deduced from the dynamical models of Universe or the inflationary theories
Baryonic pinching of galactic dark matter halos

International Nuclear Information System (INIS)

Gustafsson, Michael; Fairbairn, Malcolm; Sommer-Larsen, Jesper

2006-01-01

High resolution cosmological N-body simulations of four galaxy-scale dark matter halos are compared to corresponding N-body/hydrodynamical simulations containing dark matter, stars and gas. The simulations without baryons share features with others described in the literature in that the dark matter density slope continuously decreases towards the center, with a density ρ DM ∝r -1.3±0.2 , at about 1% of the virial radius for our Milky Way sized galaxies. The central cusps in the simulations which also contain baryons steepen significantly, to ρ DM ∝r -1.9±0.2 , with an indication of the inner logarithmic slope converging. Models of adiabatic contraction of dark matter halos due to the central buildup of stellar/gaseous galaxies are examined. The simplest and most commonly used model, by Blumenthal et al., is shown to overestimate the central dark matter density considerably. A modified model proposed by Gnedin et al. is tested and it is shown that, while it is a considerable improvement, it is not perfect. Moreover, it is found that the contraction parameters in their model not only depend on the orbital structure of the dark-matter-only halos but also on the stellar feedback prescription which is most relevant for the baryonic distribution. Implications for dark matter annihilation at the galactic center are discussed and it is found that, although our simulations show a considerable reduced dark matter halo contraction as compared to the Blumenthal et al. model, the fluxes from dark matter annihilation are still expected to be enhanced by at least a factor of a hundred, as compared to dark-matter-only halos. Finally, it is shown that, while dark-matter-only halos are typically prolate, the dark matter halos containing baryons are mildly oblate with minor-to-major axis ratios of c/a=0.73±0.11, with their flattening aligned with the central baryonic disks
Dark matter at the Fermi scale

International Nuclear Information System (INIS)

Feng, Jonathan L

2006-01-01

Recent breakthroughs in cosmology reveal that a quarter of the Universe is composed of dark matter, but the microscopic identity of dark matter remains a deep mystery. I review recent progress in resolving this puzzle, focusing on two well-motivated classes of dark matter candidates: weakly interacting massive particles (WIMPs) and superWIMPs. These possibilities have similar motivations: they exist in the same well-motivated particle physics models, the observed dark matter relic density emerges naturally and dark matter particles have mass around 100 GeV, the energy scale identified as interesting over 70 years ago by Fermi. At the same time, they have widely varying implications for direct and indirect dark matter searches, particle colliders, Big Bang nucleosynthesis, the cosmic microwave background, and halo profiles and structure formation. If WIMPs or superWIMPs are a significant component of dark matter, we will soon be entering a golden era in which dark matter will be studied through diverse probes at the interface of particle physics, astroparticle physics and cosmology. I outline a programme of dark matter studies for each of these scenarios and discuss the prospects for identifying dark matter in the coming years. (topical review)
Scalar dark matter with type II seesaw

Directory of Open Access Journals (Sweden)

Arnab Dasgupta

2014-12-01

Full Text Available We study the possibility of generating tiny neutrino mass through a combination of type I and type II seesaw mechanism within the framework of an abelian extension of standard model. The model also provides a naturally stable dark matter candidate in terms of the lightest neutral component of a scalar doublet. We compute the relic abundance of such a dark matter candidate and also point out how the strength of type II seesaw term can affect the relic abundance of dark matter. Such a model which connects neutrino mass and dark matter abundance has the potential of being verified or ruled out in the ongoing neutrino, dark matter, as well as accelerator experiments.
Cosmological simulations of multicomponent cold dark matter.

Science.gov (United States)

Medvedev, Mikhail V

2014-08-15

The nature of dark matter is unknown. A number of dark matter candidates are quantum flavor-mixed particles but this property has never been accounted for in cosmology. Here we explore this possibility from the first principles via extensive N-body cosmological simulations and demonstrate that the two-component dark matter model agrees with observational data at all scales. Substantial reduction of substructure and flattening of density profiles in the centers of dark matter halos found in simulations can simultaneously resolve several outstanding puzzles of modern cosmology. The model shares the "why now?" fine-tuning caveat pertinent to all self-interacting models. Predictions for direct and indirect detection dark matter experiments are made.
SUSY dark matter: Beyond the standard paradigm

International Nuclear Information System (INIS)

Sandick, Pearl

2016-01-01

Within the framework of the Minimal Supersymmetric Standard Model (MSSM), we explore a decoupling of the parameters into separate sectors that determine consistency with collider data, the abundance of dark matter, and potential signatures at direct dark matter searches. We consider weak-scale bino-like neutralino dark matter, and find that annihilations via light slepton exchange present a viable mechanism for obtaining the appropriate dark matter abundance assuming a thermal history. Constraints and prospects for discovery of these models are discussed, including the possibility that direct dark matter searches may be sensitive to these models if light squarks exhibit left-right mixing. Differences between the scenarios presented here and the typical expectations for the MSSM are discussed.
Higgs particles interacting via a scalar Dark Matter field

Directory of Open Access Journals (Sweden)

Bhattacharya Yajnavalkya

2016-01-01

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

International Nuclear Information System (INIS)

Wilczek, F.

1995-01-01

The standard model of particle physics is marvelously successful. However, it is obviously not a complete or final theory. I shall argue here that the structure of the standard model gives some quite concrete, compelling hints regarding what lies beyond. Taking these hints seriously, one is led to predict the existence of new types of very weakly interacting matter, stable on cosmological time scales and produced with cosmologically interesting densities--that is, ''dark matter''. copyright 1995 American Institute of Physics
Scalar Dark Matter From Theory Space

Energy Technology Data Exchange (ETDEWEB)

Birkedal-Hansen, Andreas; Wacker, Jay G.

2003-12-26

The scalar dark matter candidate in a prototypical theory space little Higgs model is investigated. We review all details of the model pertinent to a relic density calculation. We perform a thermal relic density calculation including couplings to the gauge and Higgs sectors of the model. We find two regions of parameter space that give acceptable dark matter abundances. The first region has a dark matter candidate with a mass {Omicron}(100 GeV), the second region has a candidate with a mass greater than {Omicron}(500 GeV). The dark matter candidate in either region is an admixture of an SU(2) triplet and an SU(2) singlet, thereby constituting a possible WIMP (weakly interacting massive particle).
Scalar dark matter from theory space

International Nuclear Information System (INIS)

Birkedal-Hansen, Andreas; Wacker, Jay G.

2004-01-01

The scalar dark matter candidate in a prototypical theory space little Higgs model is investigated. We review all details of the model pertinent to a relic density calculation. We perform a thermal relic density calculation including couplings to the gauge and Higgs sectors of the model. We find two regions of parameter space that give acceptable dark matter abundances. The first region has a dark matter candidate with a mass O(100 GeV), the second region has a candidate with a mass greater than O(500 GeV). The dark matter candidate in either region is an admixture of an SU(2) triplet and an SU(2) singlet, thereby constituting a possible weakly interacting massive particle
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.
Superheavy dark matter through Higgs portal operators

Science.gov (United States)

Kolb, Edward W.; Long, Andrew J.

2017-11-01

The WIMPzilla hypothesis is that the dark matter is a super-weakly-interacting and superheavy particle. Conventionally, the WIMPzilla abundance is set by gravitational particle production during or at the end of inflation. In this study we allow the WIMPzilla to interact directly with Standard Model fields through the Higgs portal, and we calculate the thermal production (freeze-in) of WIMPzilla dark matter from the annihilation of Higgs boson pairs in the plasma. The two particle-physics model parameters are the WIMPzilla mass and the Higgs-WIMPzilla coupling. The two cosmological parameters are the reheating temperature and the expansion rate of the universe at the end of inflation. We delineate the regions of parameter space where either gravitational or thermal production is dominant, and within those regions we identify the parameters that predict the observed dark matter relic abundance. Allowing for thermal production opens up the parameter space, even for Planck-suppressed Higgs-WIMPzilla interactions.
Tools for model-independent bounds in direct dark matter searches

DEFF Research Database (Denmark)

Cirelli, M.; Del Nobile, E.; Panci, P.

2013-01-01

We discuss a framework (based on non-relativistic operators) and a self-contained set of numerical tools to derive the bounds from some current direct detection experiments on virtually any arbitrary model of Dark Matter elastically scattering on nuclei.......We discuss a framework (based on non-relativistic operators) and a self-contained set of numerical tools to derive the bounds from some current direct detection experiments on virtually any arbitrary model of Dark Matter elastically scattering on nuclei....

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...
TeV scale singlet dark matter

International Nuclear Information System (INIS)

Ponton, Eduardo; Randall, Lisa

2009-01-01

It is well known that stable weak scale particles are viable dark matter candidates since the annihilation cross section is naturally about the right magnitude to leave the correct thermal residual abundance. Many dark matter searches have focused on relatively light dark matter consistent with weak couplings to the Standard Model. However, in a strongly coupled theory, or even if the coupling is just a few times bigger than the Standard Model couplings, dark matter can have TeV-scale mass with the correct thermal relic abundance. Here we consider neutral TeV-mass scalar dark matter, its necessary interactions, and potential signals. We consider signals both with and without higher-dimension operators generated by strong coupling at the TeV scale, as might happen for example in an RS scenario. We find some potential for detection in high energy photons that depends on the dark matter distribution. Detection in positrons at lower energies, such as those PAMELA probes, would be difficult though a higher energy positron signal could in principle be detectable over background. However, a light dark matter particle with higher-dimensional interactions consistent with a TeV cutoff can in principle match PAMELA data.
Combined cosmological tests of a bivalent tachyonic dark energy scalar field model

International Nuclear Information System (INIS)

Keresztes, Zoltán; Gergely, László Á.

2014-01-01

A recently investigated tachyonic scalar field dark energy dominated universe exhibits a bivalent future: depending on initial parameters can run either into a de Sitter exponential expansion or into a traversable future soft singularity followed by a contraction phase. We also include in the model (i) a tiny amount of radiation, (ii) baryonic matter (Ω b h 2 = 0.022161, where the Hubble constant is fixed as h = 0.706) and (iii) cold dark matter (CDM). Out of a variety of six types of evolutions arising in a more subtle classification, we identify two in which in the past the scalar field effectively degenerates into a dust (its pressure drops to an insignificantly low negative value). These are the evolutions of type IIb converging to de Sitter and type III hitting the future soft singularity. We confront these background evolutions with various cosmological tests, including the supernova type Ia Union 2.1 data, baryon acoustic oscillation distance ratios, Hubble parameter-redshift relation and the cosmic microwave background (CMB) acoustic scale. We determine a subset of the evolutions of both types which at 1σ confidence level are consistent with all of these cosmological tests. At perturbative level we derive the CMB temperature power spectrum to find the best agreement with the Planck data for Ω CDM = 0.22. The fit is as good as for the ΛCDM model at high multipoles, but the power remains slightly overestimated at low multipoles, for both types of evolutions. The rest of the CDM is effectively generated by the tachyonic field, which in this sense acts as a combined dark energy and dark matter model
Dark matter: Theoretical perspectives

International Nuclear Information System (INIS)

Turner, M.S.

1993-01-01

The author both reviews and makes the case for the current theoretical prejudice: a flat Universe whose dominant constituent is nonbaryonic dark matter, emphasizing that this is still a prejudice and not yet fact. The theoretical motivation for nonbaryonic dark matter is discussed in the context of current elementary-particle theory, stressing that (i) there are no dark-matter candidates within the open-quotes standard modelclose quotes of particle physics, (ii) there are several compelling candidates within attractive extensions of the standard model of particle physics, and (iii) the motivation for these compelling candidates comes first and foremost from particle physics. The dark-matter problem is now a pressing issue in both cosmology and particle physics, and the detection of particle dark matter would provide evidence for open-quotes new physics.close quotes The compelling candidates are a very light axion (10 -6 --10 -4 eV), a light neutrino (20--90 eV), and a heavy neutralino (10 GeV--2 TeV). The production of these particles in the early Universe and the prospects for their detection are also discussed. The author briefly mentions more exotic possibilities for the dark matter, including a nonzero cosmological constant, superheavy magnetic monopoles, and decaying neutrinos. 119 refs
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.
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.
Is dark matter with long-range interactions a solution to all small-scale problems of Λ cold dark matter cosmology?

Science.gov (United States)

van den Aarssen, Laura G; Bringmann, Torsten; Pfrommer, Christoph

2012-12-07

The cold dark matter paradigm describes the large-scale structure of the Universe remarkably well. However, there exists some tension with the observed abundances and internal density structures of both field dwarf galaxies and galactic satellites. Here, we demonstrate that a simple class of dark matter models may offer a viable solution to all of these problems simultaneously. Their key phenomenological properties are velocity-dependent self-interactions mediated by a light vector messenger and thermal production with much later kinetic decoupling than in the standard case.
Dark energy from quantum matter

International Nuclear Information System (INIS)

Dappiaggi, Claudio; Hack, Thomas-Paul; Moeller, Jan; Pinamonti, Nicola

2010-07-01

We study the backreaction of free quantum fields on a flat Robertson-Walker spacetime. Apart from renormalization freedom, the vacuum energy receives contributions from both the trace anomaly and the thermal nature of the quantum state. The former represents a dynamical realisation of dark energy, while the latter mimics an effective dark matter component. The semiclassical dynamics yield two classes of asymptotically stable solutions. The first reproduces the CDM model in a suitable regime. The second lacks a classical counterpart, but is in excellent agreement with recent observations. (orig.)
Dark energy from quantum matter

Energy Technology Data Exchange (ETDEWEB)

Dappiaggi, Claudio; Hack, Thomas-Paul [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Moeller, Jan [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Gruppe Theorie; Pinamonti, Nicola [Rome-2 Univ. (Italy). Dipt. di Matematica

2010-07-15

We study the backreaction of free quantum fields on a flat Robertson-Walker spacetime. Apart from renormalization freedom, the vacuum energy receives contributions from both the trace anomaly and the thermal nature of the quantum state. The former represents a dynamical realisation of dark energy, while the latter mimics an effective dark matter component. The semiclassical dynamics yield two classes of asymptotically stable solutions. The first reproduces the CDM model in a suitable regime. The second lacks a classical counterpart, but is in excellent agreement with recent observations. (orig.)
A power-law coupled three-form dark energy model

Science.gov (United States)

Yao, Yan-Hong; Yan, Yang-Jie; Meng, Xin-He

2018-02-01

We consider a field theory model of coupled dark energy which treats dark energy as a three-form field and dark matter as a spinor field. By assuming the effective mass of dark matter as a power-law function of the three-form field and neglecting the potential term of dark energy, we obtain three solutions of the autonomous system of evolution equations, including a de Sitter attractor, a tracking solution and an approximate solution. To understand the strength of the coupling, we confront the model with the latest Type Ia Supernova, Baryon Acoustic Oscillations and Cosmic Microwave Background radiation observations, with the conclusion that the combination of these three databases marginalized over the present dark matter density parameter Ω _{m0} and the present three-form field κ X0 gives stringent constraints on the coupling constant, - 0.017< λ <0.047 (2σ confidence level), by which we present the model's applicable parameter range.
A power-law coupled three-form dark energy model

Energy Technology Data Exchange (ETDEWEB)

Yao, Yan-Hong; Yan, Yang-Jie; Meng, Xin-He [Nankai University, Department of Physics, Tianjin (China)

2018-02-15

We consider a field theory model of coupled dark energy which treats dark energy as a three-form field and dark matter as a spinor field. By assuming the effective mass of dark matter as a power-law function of the three-form field and neglecting the potential term of dark energy, we obtain three solutions of the autonomous system of evolution equations, including a de Sitter attractor, a tracking solution and an approximate solution. To understand the strength of the coupling, we confront the model with the latest Type Ia Supernova, Baryon Acoustic Oscillations and Cosmic Microwave Background radiation observations, with the conclusion that the combination of these three databases marginalized over the present dark matter density parameter Ω{sub m0} and the present three-form field κX{sub 0} gives stringent constraints on the coupling constant, -0.017 < λ < 0.047 (2σ confidence level), by which we present the model's applicable parameter range. (orig.)
Viable dark matter via radiative symmetry breaking in a scalar singlet Higgs portal extension of the standard model.

Science.gov (United States)

Steele, T G; Wang, Zhi-Wei; Contreras, D; Mann, R B

2014-05-02

We consider the generation of dark matter mass via radiative electroweak symmetry breaking in an extension of the conformal standard model containing a singlet scalar field with a Higgs portal interaction. Generating the mass from a sequential process of radiative electroweak symmetry breaking followed by a conventional Higgs mechanism can account for less than 35% of the cosmological dark matter abundance for dark matter mass M(s)>80 GeV. However, in a dynamical approach where both Higgs and scalar singlet masses are generated via radiative electroweak symmetry breaking, we obtain much higher levels of dark matter abundance. At one-loop level we find abundances of 10%-100% with 106 GeVdark matter mass. The dynamical approach also predicts a small scalar-singlet self-coupling, providing a natural explanation for the astrophysical observations that place upper bounds on dark matter self-interaction. The predictions in all three approaches are within the M(s)>80 GeV detection region of the next generation XENON experiment.
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.
The pursuit of dark matter at colliders—an overview

Science.gov (United States)

Penning, Björn

2018-06-01

Dark matter is one of the main puzzles in fundamental physics and the goal of a diverse, multi-pronged research programme. Underground and astrophysical searches look for dark matter particles in the cosmos, either by interacting directly or by searching for dark matter annihilation. Particle colliders, in contrast, might produce dark matter in the laboratory and are able to probe most basic dark-matter–matter interactions. They are sensitive to low dark matter masses, provide complementary information at higher masses and are subject to different systematic uncertainties. Collider searches are therefore an important part of an inter-disciplinary dark matter search strategy. This article highlights the experimental and phenomenological development in collider dark matter searches of recent years and their connection with the wider field.
Dark Matter Annihilation at the Galactic Center

Energy Technology Data Exchange (ETDEWEB)

Linden, Timothy Ryan [Univ. of California, Santa Cruz, CA (United States)

2013-06-01

Observations by the WMAP and PLANCK satellites have provided extraordinarily accurate observations on the densities of baryonic matter, dark matter, and dark energy in the universe. These observations indicate that our universe is composed of approximately ve times as much dark matter as baryonic matter. However, e orts to detect a particle responsible for the energy density of dark matter have been unsuccessful. Theoretical models have indicated that a leading candidate for the dark matter is the lightest supersymmetric particle, which may be stable due to a conserved R-parity. This dark matter particle would still be capable of interacting with baryons via weak-force interactions in the early universe, a process which was found to naturally explain the observed relic abundance of dark matter today. These residual annihilations can persist, albeit at a much lower rate, in the present universe, providing a detectable signal from dark matter annihilation events which occur throughout the universe. Simulations calculating the distribution of dark matter in our galaxy almost universally predict the galactic center of the Milky Way Galaxy (GC) to provide the brightest signal from dark matter annihilation due to its relative proximity and large simulated dark matter density. Recent advances in telescope technology have allowed for the rst multiwavelength analysis of the GC, with suitable e ective exposure, angular resolution, and energy resolution in order to detect dark matter particles with properties similar to those predicted by the WIMP miracle. In this work, I describe ongoing e orts which have successfully detected an excess in -ray emission from the region immediately surrounding the GC, which is di cult to describe in terms of standard di use emission predicted in the GC region. While the jury is still out on any dark matter interpretation of this excess, I describe several related observations which may indicate a dark matter origin. Finally, I discuss the
Dark sector impact on gravitational collapse of an electrically charged scalar field

Energy Technology Data Exchange (ETDEWEB)

Nakonieczna, Anna [Institute of Physics, Maria Curie-Skłodowska University,Plac Marii Curie-Skłodowskiej 1, 20-031 Lublin (Poland); Institute of Agrophysics, Polish Academy of Sciences,Doświadczalna 4, 20-290 Lublin (Poland); Rogatko, Marek [Institute of Physics, Maria Curie-Skłodowska University,Plac Marii Curie-Skłodowskiej 1, 20-031 Lublin (Poland); Nakonieczny, Łukasz [Institute of Theoretical Physics, Faculty of Physics, University of Warsaw,Pasteura 5, 02-093 Warszawa (Poland)

2015-11-04

Dark matter and dark energy are dominating components of the Universe. Their presence affects the course and results of processes, which are driven by the gravitational interaction. The objective of the paper was to examine the influence of the dark sector on the gravitational collapse of an electrically charged scalar field. A phantom scalar field was used as a model of dark energy in the system. Dark matter was modeled by a complex scalar field with a quartic potential, charged under a U(1)-gauge field. The dark components were coupled to the electrically charged scalar field via the exponential coupling and the gauge field-Maxwell field kinetic mixing, respectively. Complete non-linear simulations of the investigated process were performed. They were conducted from regular initial data to the end state, which was the matter dispersal or a singularity formation in a spacetime. During the collapse in the presence of dark energy dynamical wormholes and naked singularities were formed in emerging spacetimes. The wormhole throats were stabilized by the violation of the null energy condition, which occurred due to a significant increase of a value of the phantom scalar field function in its vicinity. The square of mass parameter of the dark matter scalar field potential controlled the formation of a Cauchy horizon or wormhole throats in the spacetime. The joint impact of dark energy and dark matter on the examined process indicated that the former decides what type of an object forms, while the latter controls the amount of time needed for the object to form. Additionally, the dark sector suppresses the natural tendency of an electrically charged scalar field to form a dynamical Reissner-Nordström spacetime during the gravitational collapse.
Asymptotically Safe Dark Matter

DEFF Research Database (Denmark)

Sannino, Francesco; Shoemaker, Ian M.

2015-01-01

We introduce a new paradigm for dark matter (DM) interactions in which the interaction strength is asymptotically safe. In models of this type, the coupling strength is small at low energies but increases at higher energies, and asymptotically approaches a finite constant value. The resulting...... searches are the primary ways to constrain or discover asymptotically safe dark matter....
Dark matter and particle physics

International Nuclear Information System (INIS)

Peskin, Michael E.

2007-01-01

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

International Nuclear Information System (INIS)

Desai, S.; Kahya, E. O.; Woodard, R. P.

2008-01-01

We discuss the implications for gravitational wave detectors of a class of modified gravity theories which dispense with the need for dark matter. These models, which are known as dark matter emulators, have the property that weak gravitational waves couple to the metric that would follow from general relativity without dark matter whereas ordinary particles couple to a combination of the metric and other fields which reproduces the result of general relativity with dark matter. We show that there is an appreciable difference in the Shapiro delays of gravitational waves and photons or neutrinos from the same source, with the gravitational waves always arriving first. We compute the expected time lags for GRB 070201, for SN 1987a and for Sco-X1. We estimate the probable error by taking account of the uncertainty in position, and by using three different dark matter profiles
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

Comparative testing of dark matter models with 15 HSB and 15 LSB galaxies

Science.gov (United States)

Kun, E.; Keresztes, Z.; Simkó, A.; Szűcs, G.; Gergely, L. Á.

2017-12-01

Context. We assemble a database of 15 high surface brightness (HSB) and 15 low surface brightness (LSB) galaxies, for which surface brightness density and spectroscopic rotation curve data are both available and representative for various morphologies. We use this dataset to test the Navarro-Frenk-White, the Einasto, and the pseudo-isothermal sphere dark matter models. Aims: We investigate the compatibility of the pure baryonic model and baryonic plus one of the three dark matter models with observations on the assembled galaxy database. When a dark matter component improves the fit with the spectroscopic rotational curve, we rank the models according to the goodness of fit to the datasets. Methods: We constructed the spatial luminosity density of the baryonic component based on the surface brightness profile of the galaxies. We estimated the mass-to-light (M/L) ratio of the stellar component through a previously proposed color-mass-to-light ratio relation (CMLR), which yields stellar masses independent of the photometric band. We assumed an axissymetric baryonic mass model with variable axis ratios together with one of the three dark matter models to provide the theoretical rotational velocity curves, and we compared them with the dataset. In a second attempt, we addressed the question whether the dark component could be replaced by a pure baryonic model with fitted M/L ratios, varied over ranges consistent with CMLR relations derived from the available stellar population models. We employed the Akaike information criterion to establish the performance of the best-fit models. Results: For 7 galaxies (2 HSB and 5 LSB), neither model fits the dataset within the 1σ confidence level. For the other 23 cases, one of the models with dark matter explains the rotation curve data best. According to the Akaike information criterion, the pseudo-isothermal sphere emerges as most favored in 14 cases, followed by the Navarro-Frenk-White (6 cases) and the Einasto (3 cases) dark
A model for the distribution of dark matter, galaxies, and the intergalactic medium in a cold dark matter-dominated universe

International Nuclear Information System (INIS)

Ryu, D.; Vishniac, E.T.; Chiang, W.H.

1989-01-01

Until now, most studies on the cold dark matter (CDM) universe have considered only the distribution of the dark matter and compared that with the observed distribution of galaxies. Even though the dark matter determines the overall dynamics of the large-scale structure, galaxies form out of the baryonic matter whose density and velocity distributions can be different from those of the dark matter, depending on the thermal history of the universe. In this paper, the authors study both the dark matter component and the baryonic component, that is, galaxies and the IGM, with several simplifying assumptions, by explicitly following the evolution. The dark matter, galaxies, and IGM are coupled through gravity; galaxies form out of the IGM by taking mass and momentum, whereas the IGM responds to the energy input from the galaxies
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
Search for Low-Mass Dark Matter wtih SuperCDMS Soudan and Study of Shorted Electric Field Configurations in CDMS Detectors

Energy Technology Data Exchange (ETDEWEB)

Schneck, Kristiana [Stanford Univ., CA (United States)

2015-01-01

The area of dark matter is one of the most interesting and exciting topics in physics today. Existing at the intersection of particle physics and astrophysics, the existence of a new dark matter particle can be used to explain many astrophysical and cosmological observations, as well as to reconcile outstanding issues in the standard model of particle physics. Experiments such as SuperCDMS are built to detect dark matter in the lab by looking for low-energy nuclear recoils produced by collisions between dark matter particles and atoms in terrestrial detectors. SuperCDMS Soudan is particularly well-suited to follow up on possible hints of low-mass dark matter seen by other recent experiments because of its low thresholds and excellent background discrimination. Analyzing SuperCDMS Soudan data to look for low-mass dark matter comes with particular challenges because of the low signal-to-noise very near threshold. However, with a detailed background model developed by scaling high-energy events down into the low-energy signal region, SuperCDMS Soudan produced worldleading limits on the existence of low-mass dark matter. In addition, a few SuperCDMS Soudan detectors experienced cold hardware problems that can affect the data collected. Of particular interest is one detector considered for the low-mass WIMP search that has one of its charge electrodes shorted to chassis ground. Three events were observed in this detector upon unblinding the SuperCDMS Soudan low-energy data, even though <1 event was expected based on pre-unblinding calulations. However, the data collected by the shorted detector may have been compromised since an electrode shorted to ground will modify the electric field in the detector. The SuperCDMS Detector Monte Carlo (DMC) provides an excellent way to model the effects of the modified electric field, so a new model of the expected backgrounds in the low-mass WIMP search is developed using the DMC to try to explain how the short may have affected the
Dark matter as a ghost free conformal extension of Einstein theory

International Nuclear Information System (INIS)

Barvinsky, A.O.

2014-01-01

We discuss ghost free models of the recently suggested mimetic dark matter theory. This theory is shown to be a conformal extension of Einstein general relativity. Dark matter originates from gauging out its local Weyl invariance as an extra degree of freedom which describes a potential flow of the pressureless perfect fluid. For a positive energy density of this fluid the theory is free of ghost instabilities, which gives strong preference to stable configurations with a positive scalar curvature and trace of the matter stress tensor. Instabilities caused by caustics of the geodesic flow, inherent in this model, serve as a motivation for an alternative conformal extension of Einstein theory, based on the generalized Proca vector field. A potential part of this field modifies the inflationary stage in cosmology, whereas its rotational part at the post inflationary epoch might simulate rotating flows of dark matter
CCDM model from quantum particle creation: constraints on dark matter mass

International Nuclear Information System (INIS)

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

2014-01-01

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

International Nuclear Information System (INIS)

Tytgat, M Hg

2008-01-01

The Inert Doublet Model (IDM) is a two doublet extension of the Higgs-Brout-Englert sector of the Standard Model with a Z2 symmetry in order to prevent FCNC. If the Z2 symmetry is not spontaneously broken, the lightest neutral extra scalar is a dark matter candidate. We briefly review the phenomenology of the model, emphasizing its relevance for the issue of Electroweak Symmetry Breaking (EWSB) and the prospects for detection of dark matter
Superheavy thermal dark matter and primordial asymmetries

International Nuclear Information System (INIS)

Bramante, Joseph; Unwin, James

2017-01-01

The early universe could feature multiple reheating events, leading to jumps in the visible sector entropy density that dilute both particle asymmetries and the number density of frozen-out states. In fact, late time entropy jumps are usually required in models of Affleck-Dine baryogenesis, which typically produces an initial particle-antiparticle asymmetry that is much too large. An important consequence of late time dilution, is that a smaller dark matter annihilation cross section is needed to obtain the observed dark matter relic density. For cosmologies with high scale baryogenesis, followed by radiation-dominated dark matter freeze-out, we show that the perturbative unitarity mass bound on thermal relic dark matter is relaxed to 10 10 GeV. We proceed to study superheavy asymmetric dark matter models, made possible by a sizable entropy injection after dark matter freeze-out, and identify how the Affleck-Dine mechanism would generate the baryon and dark asymmetries.
Superheavy thermal dark matter and primordial asymmetries

Energy Technology Data Exchange (ETDEWEB)

Bramante, Joseph [Perimeter Institute for Theoretical Physics,31 Caroline St N, Waterloo, ON N2L 2Y5 (Canada); Unwin, James [Department of Physics, University of Illinois at Chicago,845 W Taylor St, Chicago, IL 60607 (United States)

2017-02-23

The early universe could feature multiple reheating events, leading to jumps in the visible sector entropy density that dilute both particle asymmetries and the number density of frozen-out states. In fact, late time entropy jumps are usually required in models of Affleck-Dine baryogenesis, which typically produces an initial particle-antiparticle asymmetry that is much too large. An important consequence of late time dilution, is that a smaller dark matter annihilation cross section is needed to obtain the observed dark matter relic density. For cosmologies with high scale baryogenesis, followed by radiation-dominated dark matter freeze-out, we show that the perturbative unitarity mass bound on thermal relic dark matter is relaxed to 10{sup 10} GeV. We proceed to study superheavy asymmetric dark matter models, made possible by a sizable entropy injection after dark matter freeze-out, and identify how the Affleck-Dine mechanism would generate the baryon and dark asymmetries.
Evidence for dark matter interactions in cosmological precision data?

International Nuclear Information System (INIS)

Lesgourgues, Julien; Marques-Tavares, Gustavo; Schmaltz, Martin

2016-01-01

We study a two-parameter extension of the cosmological standard model ΛCDM in which cold dark matter interacts with a new form of dark radiation. The two parameters correspond to the energy density in the dark radiation fluid ΔN fluid and the interaction strength between dark matter and dark radiation. The interactions give rise to a very weak ''dark matter drag'' which damps the growth of matter density perturbations throughout radiation domination, allowing to reconcile the tension between predictions of large scale structure from the CMB and direct measurements of σ 8 . We perform a precision fit to Planck CMB data, BAO, large scale structure, and direct measurements of the expansion rate of the universe today. Our model lowers the χ-squared relative to ΛCDM by about 12, corresponding to a preference for non-zero dark matter drag by more than 3σ. Particle physics models which naturally produce a dark matter drag of the required form include the recently proposed non-Abelian dark matter model in which the dark radiation corresponds to massless dark gluons
Cosmological constraints on the gravitational interactions of matter and dark matter

International Nuclear Information System (INIS)

Bai, Yang; Salvado, Jordi; Stefanek, Ben A.

2015-01-01

Although there is overwhelming evidence of dark matter from its gravitational interaction, we still do not know its precise gravitational interaction strength or whether it obeys the equivalence principle. Using the latest available cosmological data and working within the framework of ΛCDM, we first update the measurement of the multiplicative factor of cosmology-relevant Newton’s constant over the standard laboratory-based value and find that it is consistent with one. In general relativity, dark matter equivalence principle breaking can be mimicked by a long-range dark matter force mediated by an ultra light scalar field. Using the Planck three year data, we find that the dark matter “fifth-force” strength is constrained to be weaker than 10 −4 of the gravitational force. We also introduce a phenomenological, post-Newtonian two-fluid description to explicitly break the equivalence principle by introducing a difference between dark matter inertial and gravitational masses. Depending on the decoupling time of the dark matter and ordinary matter fluids, the ratio of the dark matter gravitational mass to inertial mass is constrained to be unity at the 10 −6 level
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
Scalar field dark matter: behavior around black holes

Energy Technology Data Exchange (ETDEWEB)

Cruz-Osorio, Alejandro; Guzmán, F. Siddhartha; Lora-Clavijo, Fabio D., E-mail: alejandro@ifm.umich.mx, E-mail: guzman@ifm.umich.mx, E-mail: fadulora@ifm.umich.mx [Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio C-3, Cd. Universitaria, 58040 Morelia, Michoacán (Mexico)

2011-06-01

We present the numerical evolution of a massive test scalar fields around a Schwarzschild space-time. We proceed by using hyperboloidal slices that approach future null infinity, which is the boundary of scalar fields, and also demand the slices to penetrate the event horizon of the black hole. This approach allows the scalar field to be accreted by the black hole and to escape toward future null infinity. We track the evolution of the energy density of the scalar field, which determines the rate at which the scalar field is being diluted. We find polynomial decay of the energy density of the scalar field, and use it to estimate the rate of dilution of the field in time. Our findings imply that the energy density of the scalar field decreases even five orders of magnitude in time scales smaller than a year. This implies that if a supermassive black hole is the Schwarzschild solution, then scalar field dark matter would be diluted extremely fast.
Scalar field dark matter: behavior around black holes

International Nuclear Information System (INIS)

Cruz-Osorio, Alejandro; Guzmán, F. Siddhartha; Lora-Clavijo, Fabio D.

2011-01-01

We present the numerical evolution of a massive test scalar fields around a Schwarzschild space-time. We proceed by using hyperboloidal slices that approach future null infinity, which is the boundary of scalar fields, and also demand the slices to penetrate the event horizon of the black hole. This approach allows the scalar field to be accreted by the black hole and to escape toward future null infinity. We track the evolution of the energy density of the scalar field, which determines the rate at which the scalar field is being diluted. We find polynomial decay of the energy density of the scalar field, and use it to estimate the rate of dilution of the field in time. Our findings imply that the energy density of the scalar field decreases even five orders of magnitude in time scales smaller than a year. This implies that if a supermassive black hole is the Schwarzschild solution, then scalar field dark matter would be diluted extremely fast
Strongest model-independent bound on the lifetime of Dark Matter

CERN Document Server

Audren, Benjamin; Mangano, Gianpiero; Serpico, Pasquale Dario; Tram, Thomas

2014-01-01

Dark Matter is essential for structure formation in the late Universe so it must be stable on cosmological time scales. But how stable exactly? Only assuming decays into relativistic particles, we report an otherwise model independent bound on the lifetime of Dark Matter using current cosmological data. Since these decays affect only the low-$\\ell$ multipoles of the CMB, the Dark Matter lifetime is expected to correlate with the tensor-to-scalar ratio $r$ as well as curvature $\\Omega_k$. We consider two models, including $r$ and $r+\\Omega_k$ respectively, versus data from Planck, WMAP, WiggleZ and Baryon Acoustic Oscillations, with or without the BICEP2 data (if interpreted in terms of primordial gravitational waves). This results in a lower bound on the lifetime of CDM given by 160Gyr (without BICEP2) or 200Gyr (with BICEP2) at 95% confidence level.
Neutralino dark matter: Status and prospects

International Nuclear Information System (INIS)

Roszkowski, L.

1998-01-01

The lightest neutralino in minimal supersymmetry (SUSY) and other SUSY models is considered as a dark-matter candidate. The phenomenological and cosmological properties of the neutralino and some experimental constraints are discussed. A bino-like neutralino emerges as the most natural dark-matter candidate for a plausible range of parameters. Direct methods for dark-matter searches and relevant experiments are also reviewed
Tying dark matter to baryons with self-interactions.

Science.gov (United States)

Kaplinghat, Manoj; Keeley, Ryan E; Linden, Tim; Yu, Hai-Bo

2014-07-11

Self-interacting dark matter (SIDM) models have been proposed to solve the small-scale issues with the collisionless cold dark matter paradigm. We derive equilibrium solutions in these SIDM models for the dark matter halo density profile including the gravitational potential of both baryons and dark matter. Self-interactions drive dark matter to be isothermal and this ties the core sizes and shapes of dark matter halos to the spatial distribution of the stars, a radical departure from previous expectations and from cold dark matter predictions. Compared to predictions of SIDM-only simulations, the core sizes are smaller and the core densities are higher, with the largest effects in baryon-dominated galaxies. As an example, we find a core size around 0.3 kpc for dark matter in the Milky Way, more than an order of magnitude smaller than the core size from SIDM-only simulations, which has important implications for indirect searches of SIDM candidates.
Asymmetric Dark Matter and Dark Radiation

CERN Document Server

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

2012-01-01

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

International Nuclear Information System (INIS)

King, Steve F.; Roberts, Jonathan P.

2006-01-01

The prediction of neutralino dark matter is generally regarded as one of the successes of the Minimal Supersymmetric Standard Model (MSSM). However the successful regions of parameter space allowed by WMAP and collider constraints are quite restricted. We discuss fine-tuning with respect to both dark matter and Electroweak Symmetry Breaking (EWSB) and explore regions of MSSM parameter space with non-universal gaugino and third family scalar masses in which neutralino dark matter may be implemented naturally. In particular allowing non-universal gauginos opens up the bulk region that allows Bino annihilation via t-channel slepton exchange, leading to 'supernatural dark matter' corresponding to no fine-tuning at all with respect to dark matter. By contrast we find that the recently proposed 'well tempered neutralino' regions involve substantial fine-tuning of MSSM parameters in order to satisfy the dark matter constraints, although the fine tuning may be ameliorated if several annihilation channels act simultaneously. Although we have identified regions of 'supernatural dark matter' in which there is no fine tuning to achieve successful dark matter, the usual MSSM fine tuning to achieve EWSB always remains
Natural implementation of neutralino dark matter

Science.gov (United States)

King, Steve F.; Roberts, Jonathan P.

2006-09-01

The prediction of neutralino dark matter is generally regarded as one of the successes of the Minimal Supersymmetric Standard Model (MSSM). However the successful regions of parameter space allowed by WMAP and collider constraints are quite restricted. We discuss fine-tuning with respect to both dark matter and Electroweak Symmetry Breaking (EWSB) and explore regions of MSSM parameter space with non-universal gaugino and third family scalar masses in which neutralino dark matter may be implemented naturally. In particular allowing non-universal gauginos opens up the bulk region that allows Bino annihilation via t-channel slepton exchange, leading to ``supernatural dark matter'' corresponding to no fine-tuning at all with respect to dark matter. By contrast we find that the recently proposed ``well tempered neutralino'' regions involve substantial fine-tuning of MSSM parameters in order to satisfy the dark matter constraints, although the fine tuning may be ameliorated if several annihilation channels act simultaneously. Although we have identified regions of ``supernatural dark matter'' in which there is no fine tuning to achieve successful dark matter, the usual MSSM fine tuning to achieve EWSB always remains.
Dark-matter QCD-axion searches.

Science.gov (United States)

Rosenberg, Leslie J

2015-10-06

In the late 20th century, cosmology became a precision science. Now, at the beginning of the next century, the parameters describing how our universe evolved from the Big Bang are generally known to a few percent. One key parameter is the total mass density of the universe. Normal matter constitutes only a small fraction of the total mass density. Observations suggest this additional mass, the dark matter, is cold (that is, moving nonrelativistically in the early universe) and interacts feebly if at all with normal matter and radiation. There's no known such elementary particle, so the strong presumption is the dark matter consists of particle relics of a new kind left over from the Big Bang. One of the most important questions in science is the nature of this dark matter. One attractive particle dark-matter candidate is the axion. The axion is a hypothetical elementary particle arising in a simple and elegant extension to the standard model of particle physics that nulls otherwise observable CP-violating effects (where CP is the product of charge reversal C and parity inversion P) in quantum chromo dynamics (QCD). A light axion of mass 10(-(6-3)) eV (the invisible axion) would couple extraordinarily weakly to normal matter and radiation and would therefore be extremely difficult to detect in the laboratory. However, such an axion is a compelling dark-matter candidate and is therefore a target of a number of searches. Compared with other particle dark-matter candidates, the plausible range of axion dark-matter couplings and masses is narrowly constrained. This focused search range allows for definitive searches, where a nonobservation would seriously impugn the dark-matter QCD-axion hypothesis. Axion searches use a wide range of technologies, and the experiment sensitivities are now reaching likely dark-matter axion couplings and masses. This article is a selective overview of the current generation of sensitive axion searches. Not all techniques and experiments
Elementary particles, dark matter candidate and new extended standard model

Science.gov (United States)

Hwang, Jaekwang

2017-01-01

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

Science.gov (United States)

Bernal, T.; Fernández-Hernández, L. M.; Matos, T.; Rodríguez-Meza, M. A.

2018-04-01

Cold dark matter (CDM) has shown to be an excellent candidate for the dark matter (DM) of the Universe at large scales; however, it presents some challenges at the galactic level. The scalar field dark matter (SFDM), also called fuzzy, wave, Bose-Einstein condensate, or ultralight axion DM, is identical to CDM at cosmological scales but different at the galactic ones. SFDM forms core haloes, it has a natural cut-off in its matter power spectrum, and it predicts well-formed galaxies at high redshifts. In this work we reproduce the rotation curves of high-resolution low surface brightness (LSB) and SPARC galaxies with two SFDM profiles: (1) the soliton+NFW profile in the fuzzy DM (FDM) model, arising empirically from cosmological simulations of real, non-interacting scalar field (SF) at zero temperature, and (2) the multistate SFDM (mSFDM) profile, an exact solution to the Einstein-Klein-Gordon equations for a real, self-interacting SF, with finite temperature into the SF potential, introducing several quantum states as a realistic model for an SFDM halo. From the fits with the soliton+NFW profile, we obtained for the boson mass 0.212 motivated framework additional or alternative to the FDM profile.
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....
Secluded and putative flipped dark matter and Stueckelberg extensions of the standard model

Science.gov (United States)

Fortes, E. C. F. S.; Pleitez, V.; Stecker, F. W.

2018-02-01

We consider here three dark matter models with the gauge symmetry of the standard model plus an additional local U(1)D factor. One model is truly secluded and the other two models begin flipped, but end up secluded. All of these models include one dark fermion and one vector boson that gains mass via the Stueckelberg mechanism. We show that the would be flipped models provide an example dark matter composed of "almost least interacting particles" (ALIPs). Such particles are therefore compatible with the constraints obtained from both laboratory measurements and astrophysical observations.
Secluded and Putative Flipped Dark Matter and Stueckelberg Extensions of the Standard Model

Science.gov (United States)

Fortes, E. C. F. S.; Pleitez, V.; Stecker, F. W.

2018-01-01

We consider here three dark matter models with the gauge symmetry of the standard model plus an additional local U(1)D factor. One model is truly secluded and the other two models begin flipped, but end up secluded. All of these models include one dark fermion and one vector boson that gains mass via the Stueckelberg mechanism. We show that the would be flipped models provide an example dark matter composed of "almost least interacting particles" (ALIPs). Such particles are therefore compatible with the constraints obtained from both laboratory measurements and astrophysical observations.
Concentrated dark matter: Enhanced small-scale structure from codecaying dark matter

OpenAIRE

Dror, Jeff A.; Kuflik, Eric; Melcher, Brandon; Watson, Scott

2018-01-01

We study the cosmological consequences of codecaying dark matter—a recently proposed mechanism for depleting the density of dark matter through the decay of nearly degenerate particles. A generic prediction of this framework is an early dark matter dominated phase in the history of the Universe, that results in the enhanced growth of dark matter perturbations on small scales. We compute the duration of the early matter dominated phase and show that the perturbations are robust against washout...
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
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
Stable Higgs Bosons - new candidate for cold dark matter

International Nuclear Information System (INIS)

Hosotani, Yutaka

2010-01-01

The Higgs boson is in the backbone of the standard model of electroweak interactions. It must exist in some form for achieving unification of interactions. In the gauge-Higgs unification scenario the Higgs boson becomes a part of the extra-dimensional component of gauge fields. The Higgs boson becomes absolutely stable in a class of the gauge-Higgs unification models, serving as a promising candidate for cold dark matter in the universe. The observed relic abundance of cold dark matter is obtained with the Higgs mass around 70 GeV. The Higgs-nucleon scattering cross section is found to be close to the recent CDMS II XENON10 bounds in the direct detection of dark matter. In collider experiments stable Higgs bosons are produced in a pair, appearing as missing energies momenta so that the way of detecting Higgs bosons must be altered.
Building a better minimal supergravity: WIMP dark matter without flavor violation

International Nuclear Information System (INIS)

Craig, Nathaniel J.; Green, Daniel

2009-01-01

The appearance of a natural dark matter candidate, the neutralino, is among the principal successes of minimal supergravity (mSUGRA) and its descendents. In lieu of a suitable ultraviolet completion, however, theories of gravity-mediated supersymmetry breaking such as mSUGRA suffer from arbitrary degrees of flavor violation. Though theories of gauge-mediated supersymmetry breaking are free from such prohibitive flavor violation, they typically lack natural neutralino dark matter candidates. Yet this conventional dichotomy breaks down when the hidden sector is strongly coupled; in models of gauge-mediated supersymmetry breaking, the neutralino may be the lightest supersymmetric particle if the fields of the hidden sector possess large anomalous dimensions. In fact, general models of so-called 'sequestered' gauge mediation possess the full richness of neutralino dark matter found in mSUGRA without corresponding flavor problems. Here we explore generalized models of sequestered gauge mediation and the rich variety of neutralino dark matter they exhibit.
Terrestrial effects on dark matter-electron scattering experiments

DEFF Research Database (Denmark)

Emken, Timon; Kouvaris, Chris; Shoemaker, Ian M.

2017-01-01

A well-studied possibility is that dark matter may reside in a sector secluded from the Standard Model, except for the so-called photon portal: kinetic mixing between the ordinary and dark photons. Such interactions can be probed in dark matter direct detection experiments, and new experimental...... techniques involving detection of dark matter-electron scattering offer new sensitivity to sub-GeV dark matter. Typically however it is implicitly assumed that the dark matter is not altered as it traverses the Earth to arrive at the detector. In this paper we study in detail the effects of terrestrial...... stopping on dark photon models of dark matter, and find that they significantly reduce the sensitivity of XENON10 and DAMIC. In particular we find that XENON10 only excludes masses in the range (5-3000) MeV while DAMIC only probes (20-50) MeV. Their corresponding cross section sensitivity is reduced...
The mystery of dark matter

International Nuclear Information System (INIS)

Khalatbari, Azar

2015-01-01

As only 0.5 per cent (the shining part) of the Universe is seen by telescopes, and corresponds to a tenth of ordinary matter or 5 per cent of the cosmos, astrophysicists postulated that the remaining 95 per cent are made of dark matter and dark energy. But always more researchers put the existence of this dark matter and energy into question again. They notably think of giving up Newton's law of universal gravitation, and also the basic assumption of cosmology, i.e. the homogeneous character of the Universe. The article recalls the emergence of the notion of dark matter to explain the fact that stars stay within a galaxy, whereas with their observed speed and the application of the gravitational theory they should escape their galaxy. Then, the issue has been to find evidence of the existence of dark matter. Neutrinos were supposed to be a clue, but only for a while. The notion of dark energy was introduced more recently by researchers who, by the observation of supernovae, noticed that the Universe expansion was accelerated in time. Then, after having discussed the issues raised by the possible existence of dark energy, the article explains how and why a new non homogeneous cosmology emerged. It also evokes current and future researches in this field. In an interview, an astrophysicist outlines why we should dare to modify Newton's law
Dark-matter QCD-axion searches

International Nuclear Information System (INIS)

Rosenberg, Leslie J

2010-01-01

The axion is a hypothetical elementary particle appearing in a simple and elegant extension to the Standard Model of particle physics that cancels otherwise huge CP-violating effects in QCD; this extension has a broken U(1) axial symmetry, where the resulting Goldstone Boson is the axion. A light axion of mass 10 -(6-3) eV (the so-called i nvisible axion ) would couple extraordinarily weakly to normal matter and radiation and would therefore be extremely difficult to detect in the laboratory. However, such an axion would be a compelling dark-matter candidate and is therefore a target of a number of searches. Compared to other dark-matter candidates, the plausible range of axion dark-matter couplings and masses is narrowly constrained. This restricted search space allows for 'definitive' searches, where non-observation would seriously impugn the dark-matter QCD-axion hypothesis. Axion searches employ a wide range of technologies and techniques, from astrophysical observations to laboratory electromagnetic signal detection. For some experiments, sensitivities are have reached likely dark-matter axion couplings and masses. This is a brief and selective overview of axion searches. With only very limited space, I briefly describe just two of the many experiments that are searching for dark-matter axions.
Top-flavoured dark matter in Dark Minimal Flavour Violation

Energy Technology Data Exchange (ETDEWEB)

Blanke, Monika; Kast, Simon [Institut für Kernphysik, Karlsruhe Institute of Technology,Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Institut für Theoretische Teilchenphysik, Karlsruhe Institute of Technology,Engesserstraße 7, D-76128 Karlsruhe (Germany)

2017-05-31

We study a simplified model of top-flavoured dark matter in the framework of Dark Minimal Flavour Violation. In this setup the coupling of the dark matter flavour triplet to right-handed up-type quarks constitutes the only new source of flavour and CP violation. The parameter space of the model is restricted by LHC searches with missing energy final states, by neutral D meson mixing data, by the observed dark matter relic abundance, and by the absence of signal in direct detection experiments. We consider all of these constraints in turn, studying their implications for the allowed parameter space. Imposing the mass limits and coupling benchmarks from collider searches, we then conduct a combined analysis of all the other constraints, revealing their non-trivial interplay. Especially interesting is the combination of direct detection and relic abundance constraints, having a severe impact on the structure of the dark matter coupling matrix. We point out that future bounds from upcoming direct detection experiments, such as XENON1T, XENONnT, LUX-ZEPLIN, and DARWIN, will exclude a large part of the parameter space and push the DM mass to higher values.

Einstein's Gravity and Dark Energy/Matter

CERN Document Server

Sarfatti, J

2003-01-01

Should Einstein's general relativity be quantized in the usual way even though it is not renormalizable the way the spin 1/2 lepto-quark - spin 1 gauge force boson local field theories are? Condensed matter theorists using P.W. Anderson's "More is different" approach, consistent with Andrei Sakharov's idea of "metric elasticity" with gravity emergent out of quantum electrodynamic zero point vacuum fluctuations, is the approach I take in this paper. The QED vacuum in globally-flat Minkowski space-time is unstable due to exchange of virtual photons between virtual electrons and positron "holes" near the -mc2 Fermi surface well inside the 2mc2 energy gap. This results in a non-perturbative emergence of both Einstein's gravity and a unified dark energy/dark matter w = -1 exotic vacuum zero point fluctuation field controlled by the local macro-quantum vacuum coherent field. The latter is a Bose-Einstein condensate of virtual off-mass-shell bound electron-positron pairs. The dark matter exotic vacuum phase with pos...
Constraining Dark Matter with ATLAS

CERN Document Server

Czodrowski, Patrick; The ATLAS collaboration

2017-01-01

The presence of a non-baryonic dark matter component in the Universe is inferred from the observation of its gravitational interaction. If dark matter interacts weakly with the Standard Model it would be produced at the LHC, escaping the detector and leaving a large missing transverse momentum as their signature. The ATLAS detector has developed a broad and systematic search program for dark matter production in LHC collisions. The results of these searches on the first 13 TeV data, their interpretation, and the design and possible evolution of the search program will be presented.
Casting light on dark matter

International Nuclear Information System (INIS)

Ellis, John

2012-01-01

The prospects for detecting a candidate supersymmetric dark matter particle at the LHC are reviewed, and compared with the prospects for direct and indirect searches for astrophysical dark matter. The discussion is based on a frequentist analysis of the preferred regions of the Minimal supersymmetric extension of the Standard Model with universal soft supersymmetry breaking (the CMSSM). LHC searches may have good chances to observe supersymmetry in the near future - and so may direct searches for astrophysical dark matter particles, whereas indirect searches may require greater sensitivity, at least within the CMSSM.
Lepton jets from radiating dark matter

International Nuclear Information System (INIS)

Buschmann, Malte; Kopp, Joachim; Liu, Jia; Machado, Pedro A.N.

2015-01-01

The idea that dark matter forms part of a larger dark sector is very intriguing, given the high degree of complexity of the visible sector. In this paper, we discuss lepton jets as a promising signature of an extended dark sector. As a simple toy model, we consider an O(GeV) DM fermion coupled to a new U(1) ′ gauge boson (dark photon) with a mass of order GeV and kinetically mixed with the Standard Model photon. Dark matter production at the LHC in this model is typically accompanied by collinear radiation of dark photons whose decay products can form lepton jets. We analyze the dynamics of collinear dark photon emission both analytically and numerically. In particular, we derive the dark photon energy spectrum using recursive analytic expressions, using Monte Carlo simulations in Pythia, and using an inverse Mellin transform to obtain the spectrum from its moments. In the second part of the paper, we simulate the expected lepton jet signatures from radiating dark matter at the LHC, carefully taking into account the various dark photon decay modes and allowing for both prompt and displaced decays. Using these simulations, we recast two existing ATLAS lepton jet searches to significantly restrict the parameter space of extended dark sector models, and we compute the expected sensitivity of future LHC searches.
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
D-brane disformal coupling and thermal dark matter

Science.gov (United States)

Dutta, Bhaskar; Jimenez, Esteban; Zavala, Ivonne

2017-11-01

Conformal and disformal couplings between a scalar field and matter occur naturally in general scalar-tensor theories. In D-brane models of cosmology and particle physics, these couplings originate from the D-brane action describing the dynamics of its transverse (the scalar) and longitudinal (matter) fluctuations, which are thus coupled. During the post-inflationary regime and before the onset of big bang nucleosynthesis (BBN), these couplings can modify the expansion rate felt by matter, changing the predictions for the thermal relic abundance of dark matter particles and thus the annihilation rate required to satisfy the dark matter content today. We study the D-brane-like conformal and disformal couplings effect on the expansion rate of the Universe prior to BBN and its impact on the dark matter relic abundance and annihilation rate. For a purely disformal coupling, the expansion rate is always enhanced with respect to the standard one. This gives rise to larger cross sections when compared to the standard thermal prediction for a range of dark matter masses, which will be probed by future experiments. In a D-brane-like scenario, the scale at which the expansion rate enhancement occurs depends on the string coupling and the string scale.
Dragging force on galaxies due to streaming dark matter

Science.gov (United States)

Hara, Tetsuya; Miyoshi, Shigeru

1990-01-01

It has been reported that galaxies in large regions (approx. 10(exp 2) Mpc), including some clusters of galaxies, may be streaming coherently with velocities up to 600 km/sec or more with respect to the rest frame determined by the microwave background radiation. On the other hand, it is suggested that the dominant mass component of the universe is dark matter. Because we can only speculate the motion of dark matter from the galaxy motions, much attention should be paid to the correlation of velocities between the observed galaxies and cold dark matter. So the authors investigated whether such coherent large-scale streaming velocities are due to dark matter or only to baryonic objects which may be formed by piling up of gases due to some explosive events. It seems that, although each galaxy will not follow the motion of dark matter, clusters of galaxies may represent the velocity field of dark matter. The origin of the velocity field of dark matter would be due to the initial adiabatic perturbations and, in fact, the observed peculiar velocities of clusters are within the allowed region constrained from the isotropy of the microwave background radiation.
Natural Implementation of Neutralino Dark Matter

CERN Document Server

King, S F

2006-01-01

The prediction of neutralino dark matter is generally regarded as one of the successes of the Minimal Supersymmetric Standard Model (MSSM). However the successful regions of parameter space allowed by WMAP and collider constraints are quite restricted. We discuss fine-tuning with respect to both dark matter and Electroweak Symmetry Breaking (EWSB) and explore regions of MSSM parameter space with non-universal gaugino and third family scalar masses in which neutralino dark matter may be implemented naturally. In particular allowing non-universal gauginos opens up the bulk region that allows Bino annihilation via t-channel slepton exchange, leading to ``supernatural dark matter'' corresponding to no fine-tuning at all with respect to dark matter. By contrast we find that the recently proposed ``well tempered neutralino'' regions involve substantial fine-tuning of MSSM parameters in order to satisfy the dark matter constraints, although the fine tuning may be ameliorated if several annihilation channels act simu...
Gravity mediated Dark Matter models in the de Sitter space

OpenAIRE

Vancea, Ion V.

2018-01-01

In this paper, we generalize the simplified Dark Matter models with graviton mediator to the curved space-time, in particular to the de Sitter space. We obtain the generating functional of the Green's functions in the Euclidean de Sitter space for the covariant free gravitons. We determine the generating functional of the interacting theory between Dark Matter particles and the covariant gravitons. Also, we calculate explicitly the 2-point and 3-point interacting Green's functions for the sym...
Sterile neutrino, hidden dark matter and their cosmological signatures

International Nuclear Information System (INIS)

Das, Subinoy

2012-01-01

Though thermal dark matter has been the central idea behind the dark matter candidates, it is highly possible that dark matter of the universe is non-thermal in origin or it might be in thermal contact with some hidden or dark sector but not with standard model. Here we explore the cosmological bounds as well as the signatures on two types of non-thermal dark matter candidates. First we discuss a hidden dark matter with almost no interaction (or very feeble) with standard model particles so that it is not in thermal contact with visible sector but we assume it is thermalized with in a hidden sector due to some interaction. While encompassing the standard cold WIMP scenario, we do not require the freeze-out process to be non-relativistic. Rather, freeze-out may also occur when dark matter particles are semi-relativistic or relativistic. Especially we focus on the warm dark matter scenario in this set up and find the constraints on the warm dark matter mass, cross-section and hidden to visible sector temperature ratio which accounts for the observed dark-matter density, satisfies the Tremaine-Gunn bound on dark-matter phase space density and has a free-streaming length consistent with cosmological constraints on the matter power spectrum. Our method can also be applied to keV sterile neutrino dark matter which is not thermalized with standard model but is thermalized with in a dark sector. The second part of this proceeding focuses on an exotic dark matter candidate which arises from the existence of eV mass sterile neutrino through a late phase transition. Due to existence of a strong scalar force the light sterile states get trapped into stable degenerate micro nuggets. We find that its signature in matter power spectra is close to a warm dark matter candidate.
Thermalizing Sterile Neutrino Dark Matter.

Science.gov (United States)

Hansen, Rasmus S L; Vogl, Stefan

2017-12-22

Sterile neutrinos produced through oscillations are a well motivated dark matter candidate, but recent constraints from observations have ruled out most of the parameter space. We analyze the impact of new interactions on the evolution of keV sterile neutrino dark matter in the early Universe. Based on general considerations we find a mechanism which thermalizes the sterile neutrinos after an initial production by oscillations. The thermalization of sterile neutrinos is accompanied by dark entropy production which increases the yield of dark matter and leads to a lower characteristic momentum. This resolves the growing tensions with structure formation and x-ray observations and even revives simple nonresonant production as a viable way to produce sterile neutrino dark matter. We investigate the parameters required for the realization of the thermalization mechanism in a representative model and find that a simple estimate based on energy and entropy conservation describes the mechanism well.
Thermalizing Sterile Neutrino Dark Matter

Science.gov (United States)

Hansen, Rasmus S. L.; Vogl, Stefan

2017-12-01

Sterile neutrinos produced through oscillations are a well motivated dark matter candidate, but recent constraints from observations have ruled out most of the parameter space. We analyze the impact of new interactions on the evolution of keV sterile neutrino dark matter in the early Universe. Based on general considerations we find a mechanism which thermalizes the sterile neutrinos after an initial production by oscillations. The thermalization of sterile neutrinos is accompanied by dark entropy production which increases the yield of dark matter and leads to a lower characteristic momentum. This resolves the growing tensions with structure formation and x-ray observations and even revives simple nonresonant production as a viable way to produce sterile neutrino dark matter. We investigate the parameters required for the realization of the thermalization mechanism in a representative model and find that a simple estimate based on energy and entropy conservation describes the mechanism well.
Direct and indirect singlet scalar dark matter detection in the lepton-specific two-Higgs-doublet model

International Nuclear Information System (INIS)

Boucenna, M. S.; Profumo, S.

2011-01-01

A recent study of gamma-ray data from the Galactic center motivates the investigation of light (∼7-10 GeV) particle dark matter models featuring tau-lepton pairs as dominant annihilation final state. The lepton-specific two-Higgs-doublet model provides a natural framework where light, singlet scalar dark matter can pair-annihilate dominantly into tau leptons. We calculate the nucleon-dark matter cross section for singlet scalar dark matter within the lepton-specific two-Higgs-doublet model framework, and compare with recent results from direct detection experiments. We study how direct dark matter searches can be used to constrain the dark matter interpretation of gamma-ray observations, for different dominant annihilation final states. We show that models exist with the correct thermal relic abundance that could fit the claimed gamma-ray excess from the Galactic center region and have direct detection cross sections of the order of what is needed to interpret recent anomalous events reported by direct detection experiments.
Dark-matter decay as a complementary probe of multicomponent dark sectors.

Science.gov (United States)

Dienes, Keith R; Kumar, Jason; Thomas, Brooks; Yaylali, David

2015-02-06

In single-component theories of dark matter, the 2→2 amplitudes for dark-matter production, annihilation, and scattering can be related to each other through various crossing symmetries. The detection techniques based on these processes are thus complementary. However, multicomponent theories exhibit an additional direction for dark-matter complementarity: the possibility of dark-matter decay from heavier to lighter components. We discuss how this new detection channel may be correlated with the others, and demonstrate that the enhanced complementarity which emerges can be an important ingredient in probing and constraining the parameter spaces of such models.
Dark Matter

Indian Academy of Sciences (India)

What You See Ain't What. You Got, Resonance, Vol.4,. No.9,1999. Dark Matter. 2. Dark Matter in the Universe. Bikram Phookun and Biman Nath. In Part 11 of this article we learnt that there are compelling evidences from dynamics of spiral galaxies, like our own, that there must be non-luminous matter in them. In this.
Particle dark matter constraints from the Draco dwarf galaxy

International Nuclear Information System (INIS)

Tyler, Craig

2002-01-01

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

Energy Technology Data Exchange (ETDEWEB)

Arias, Paola [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Pontificia Univ. Catolica de Chile, Santiago (Chile). Facultad de Fisica; Cadamuro, Davide; Redondo, Javier [Max-Planck-Institut fuer Physik, Muenchen (Germany); Goodsell, Mark [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); European Organization for Nuclear Research (CERN), Geneva (Switzerland); Jaeckel, Joerg [Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology; Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2012-01-15

Very weakly interacting slim particles (WISPs), such as axion-like particles (ALPs) or hidden photons (HPs), may be non-thermally produced via the misalignment mechanism in the early universe and survive as a cold dark matter population until today. We find that, both for ALPs and HPs whose dominant interactions with the standard model arise from couplings to photons, a huge region in the parameter spaces spanned by photon coupling and ALP or HP mass can give rise to the observed cold dark matter. Remarkably, a large region of this parameter space coincides with that predicted in well motivated models of fundamental physics. A wide range of experimental searches - exploiting haloscopes (direct dark matter searches exploiting microwave cavities), helioscopes (searches for solar ALPs or HPs), or light-shining-through-a-wall techniques - can probe large parts of this parameter space in the foreseeable future. (orig.)
Evolution of Mass and Velocity Field in the Cosmic Web: Comparison between Baryonic and Dark Matter

Science.gov (United States)

Zhu, Weishan; Feng, Long-Long

2017-03-01

We investigate the evolution of the cosmic web since z = 5 in grid-based cosmological hydrodynamical simulations, focusing on the mass and velocity fields of both baryonic and cold dark matter. The tidal tensor of density is used as the main method for web identification, with λ th = 0.2-1.2. The evolution trends in baryonic and dark matter are similar, although moderate differences are observed. Sheets appear early, and their large-scale pattern may have been set up by z = 3. In terms of mass, filaments supersede sheets as the primary collapsing structures from z ˜ 2-3. Tenuous filaments assembled with each other to form prominent ones at z dark matter field, and is even moderately stronger between {\\boldsymbol{ω }} and {{\\boldsymbol{e}}}1, and ω and {{\\boldsymbol{e}}}3. Compared with dark matter, there is slightly less baryonic matter found residing in filaments and clusters, and its vorticity developed more significantly below 2-3 Mpc. These differences may be underestimated because of the limited resolution and lack of star formation in our simulation. The impact of the change of dominant structures in overdense regions at z ˜ 2-3 on galaxy formation and evolution is shortly discussed.
Dark matter influence on black objects thermodynamics

Science.gov (United States)

Rogatko, Marek; Wojnar, Aneta

2018-05-01

Physical process version of the first law of black hole thermodynamics in Einstein-Maxwell dark matter gravity was derived. The dark matter sector is mimicked by the additional U(1)-gauge field coupled to the ordinary Maxwell one. By considering any cross section of the black hole event horizon to the future of the bifurcation surface, the equilibrium state version of the first law of black hole mechanics was achieved. The considerations were generalized to the case of Einstein-Yang-Mills dark matter gravity theory. The main conclusion is that the influence of dark matter is crucial in the formation process of black objects. This fact may constitute the explanation of the recent observations of the enormous mass of the super luminous quasars formed in a relatively short time after Big Bang. We also pay attention to the compact binaries thermodynamics, when dark matter sector enters the game.
Di-photon excess illuminates dark matter

Energy Technology Data Exchange (ETDEWEB)

Backović, Mihailo [Center for Cosmology, Particle Physics and Phenomenology - CP3,Universite Catholique de Louvain, Louvain-la-neuve (Belgium); Mariotti, Alberto [Theoretische Natuurkunde and IIHE/ELEM, Vrije Universiteit Brussel,Pleinlaan 2, B-1050 Brussels (Belgium); International Solvay Institutes,Pleinlaan 2, B-1050 Brussels (Belgium); Redigolo, Diego [Laboratoire de Physique Théorique et Hautes Energies, CNRS UMR 7589,Universiteé Pierre et Marie Curie, 4 place Jussieu, F-75005, Paris (France)

2016-03-22

We propose a simplified model of dark matter with a scalar mediator to accommodate the di-photon excess recently observed by the ATLAS and CMS collaborations. Decays of the resonance into dark matter can easily account for a relatively large width of the scalar resonance, while the magnitude of the total width combined with the constraint on dark matter relic density leads to sharp predictions on the parameters of the Dark Sector. Under the assumption of a rather large width, the model predicts a signal consistent with ∼300 GeV dark matter particle and ∼750 GeV scalar mediator in channels with large missing energy. This prediction is not yet severely bounded by LHC Run I searches and will be accessible at the LHC Run II in the jet plus missing energy channel with more luminosity. Our analysis also considers astro-physical constraints, pointing out that future direct detection experiments will be sensitive to this scenario.

Di-photon excess illuminates dark matter

International Nuclear Information System (INIS)

Backović, Mihailo; Mariotti, Alberto; Redigolo, Diego

2016-01-01

We propose a simplified model of dark matter with a scalar mediator to accommodate the di-photon excess recently observed by the ATLAS and CMS collaborations. Decays of the resonance into dark matter can easily account for a relatively large width of the scalar resonance, while the magnitude of the total width combined with the constraint on dark matter relic density leads to sharp predictions on the parameters of the Dark Sector. Under the assumption of a rather large width, the model predicts a signal consistent with ∼300 GeV dark matter particle and ∼750 GeV scalar mediator in channels with large missing energy. This prediction is not yet severely bounded by LHC Run I searches and will be accessible at the LHC Run II in the jet plus missing energy channel with more luminosity. Our analysis also considers astro-physical constraints, pointing out that future direct detection experiments will be sensitive to this scenario.
Dark matter and cosmology

Energy Technology Data Exchange (ETDEWEB)

Schramm, D.N.

1992-03-01

The cosmological dark matter problem is reviewed. The Big Bang Nucleosynthesis constraints on the baryon density are compared with the densities implied by visible matter, dark halos, dynamics of clusters, gravitational lenses, large-scale velocity flows, and the {Omega} = 1 flatness/inflation argument. It is shown that (1) the majority of baryons are dark; and (2) non-baryonic dark matter is probably required on large scales. It is also noted that halo dark matter could be either baryonic or non-baryonic. Descrimination between ``cold`` and ``hot`` non-baryonic candidates is shown to depend on the assumed ``seeds`` that stimulate structure formation. Gaussian density fluctuations, such as those induced by quantum fluctuations, favor cold dark matter, whereas topological defects such as strings, textures or domain walls may work equally or better with hot dark matter. A possible connection between cold dark matter, globular cluster ages and the Hubble constant is mentioned. Recent large-scale structure measurements, coupled with microwave anisotropy limits, are shown to raise some questions for the previously favored density fluctuation picture. Accelerator and underground limits on dark matter candidates are also reviewed.
Dark matter and cosmology

Energy Technology Data Exchange (ETDEWEB)

Schramm, D.N.

1992-03-01

The cosmological dark matter problem is reviewed. The Big Bang Nucleosynthesis constraints on the baryon density are compared with the densities implied by visible matter, dark halos, dynamics of clusters, gravitational lenses, large-scale velocity flows, and the {Omega} = 1 flatness/inflation argument. It is shown that (1) the majority of baryons are dark; and (2) non-baryonic dark matter is probably required on large scales. It is also noted that halo dark matter could be either baryonic or non-baryonic. Descrimination between cold'' and hot'' non-baryonic candidates is shown to depend on the assumed seeds'' that stimulate structure formation. Gaussian density fluctuations, such as those induced by quantum fluctuations, favor cold dark matter, whereas topological defects such as strings, textures or domain walls may work equally or better with hot dark matter. A possible connection between cold dark matter, globular cluster ages and the Hubble constant is mentioned. Recent large-scale structure measurements, coupled with microwave anisotropy limits, are shown to raise some questions for the previously favored density fluctuation picture. Accelerator and underground limits on dark matter candidates are also reviewed.
Dark matter and cosmology

International Nuclear Information System (INIS)

Schramm, D.N.

1992-03-01

The cosmological dark matter problem is reviewed. The Big Bang Nucleosynthesis constraints on the baryon density are compared with the densities implied by visible matter, dark halos, dynamics of clusters, gravitational lenses, large-scale velocity flows, and the Ω = 1 flatness/inflation argument. It is shown that (1) the majority of baryons are dark; and (2) non-baryonic dark matter is probably required on large scales. It is also noted that halo dark matter could be either baryonic or non-baryonic. Descrimination between ''cold'' and ''hot'' non-baryonic candidates is shown to depend on the assumed ''seeds'' that stimulate structure formation. Gaussian density fluctuations, such as those induced by quantum fluctuations, favor cold dark matter, whereas topological defects such as strings, textures or domain walls may work equally or better with hot dark matter. A possible connection between cold dark matter, globular cluster ages and the Hubble constant is mentioned. Recent large-scale structure measurements, coupled with microwave anisotropy limits, are shown to raise some questions for the previously favored density fluctuation picture. Accelerator and underground limits on dark matter candidates are also reviewed
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...
Detecting superlight dark matter with Fermi-degenerate materials

Energy Technology Data Exchange (ETDEWEB)

Hochberg, Yonit [Theory Group, Lawrence Berkeley National Laboratory,Berkeley, CA 94709 (United States); Berkeley Center for Theoretical Physics, University of California, Berkeley, CA 94709 (United States); Pyle, Matt [Physics Department, University of California,Berkeley, CA 94709 (United States); Zhao, Yue [Michigan Center for Theoretical Physics, University of Michigan,Ann Arbor, MI 48109 (United States); Zurek, Kathryn M. [Theory Group, Lawrence Berkeley National Laboratory,Berkeley, CA 94709 (United States); Berkeley Center for Theoretical Physics, University of California,Berkeley, CA 94709 (United States)

2016-08-08

We examine in greater detail the recent proposal of using superconductors for detecting dark matter as light as the warm dark matter limit of O(keV). Detection of such light dark matter is possible if the entire kinetic energy of the dark matter is extracted in the scattering, and if the experiment is sensitive to O(meV) energy depositions. This is the case for Fermi-degenerate materials in which the Fermi velocity exceeds the dark matter velocity dispersion in the Milky Way of ∼10{sup −3}. We focus on a concrete experimental proposal using a superconducting target with a transition edge sensor in order to detect the small energy deposits from the dark matter scatterings. Considering a wide variety of constraints, from dark matter self-interactions to the cosmic microwave background, we show that models consistent with cosmological/astrophysical and terrestrial constraints are observable with such detectors. A wider range of viable models with dark matter mass below an MeV is available if dark matter or mediator properties (such as couplings or masses) differ at BBN epoch or in stellar interiors from those in superconductors. We also show that metal targets pay a strong in-medium suppression for kinetically mixed mediators; this suppression is alleviated with insulating targets.
Dark matter as a Bose-Einstein Condensate: the relativistic non-minimally coupled case

International Nuclear Information System (INIS)

Bettoni, Dario; Colombo, Mattia; Liberati, Stefano

2014-01-01

Bose-Einstein Condensates have been recently proposed as dark matter candidates. In order to characterize the phenomenology associated to such models, we extend previous investigations by studying the general case of a relativistic BEC on a curved background including a non-minimal coupling to curvature. In particular, we discuss the possibility of a two phase cosmological evolution: a cold dark matter-like phase at the large scales/early times and a condensed phase inside dark matter halos. During the first phase dark matter is described by a minimally coupled weakly self-interacting scalar field, while in the second one dark matter condensates and, we shall argue, develops as a consequence the non-minimal coupling. Finally, we discuss how such non-minimal coupling could provide a new mechanism to address cold dark matter paradigm issues at galactic scales
P-wave holographic superconductor/insulator phase transitions affected by dark matter sector

International Nuclear Information System (INIS)

Rogatko, Marek; Wysokinski, Karol I.

2016-01-01

The holographic approach to building the p-wave superconductors results in three different models: the Maxwell-vector, the SU(2) Yang-Mills and the helical. In the probe limit approximation, we analytically examine the properties of the first two models in the theory with dark matter sector. It turns out that the effect of dark matter on the Maxwell-vector p-wave model is the same as on the s-wave superconductor studied earlier. For the non-Abelian model we study the phase transitions between p-wave holographic insulator/superconductor and metal/superconductor. Studies of marginally stable modes in the theory under consideration allow us to determine features of p-wave holographic droplet in a constant magnetic field. The dependence of the superconducting transition temperature on the coupling constant α to the dark matter sector is affected by the dark matter density ρ_D. For ρ_D>ρ the transition temperature is a decreasing function of α. The critical chemical potential μ_c for the quantum phase transition between insulator and metal depends on the chemical potential of dark matter μ_D and for μ_D=0 is a decreasing function of α.
QCD Axion Dark Matter with a Small Decay Constant

Science.gov (United States)

Co, Raymond T.; Hall, Lawrence J.; Harigaya, Keisuke

2018-05-01

The QCD axion is a good dark matter candidate. The observed dark matter abundance can arise from misalignment or defect mechanisms, which generically require an axion decay constant fa˜O (1011) GeV (or higher). We introduce a new cosmological origin for axion dark matter, parametric resonance from oscillations of the Peccei-Quinn symmetry breaking field, that requires fa˜(108- 1011) GeV . The axions may be warm enough to give deviations from cold dark matter in large scale structure.
Baryonic dark matter

International Nuclear Information System (INIS)

Uson, Juan M.

2000-01-01

Many searches for baryonic dark matter have been conducted but, so far, all have been unsuccessful. Indeed, no more than 1% of the dark matter can be in the form of hydrogen burning stars. It has recently been suggested that most of the baryons in the universe are still in the form of ionized gas so that it is possible that there is no baryonic dark matter. Although it is likely that a significant fraction of the dark matter in the Milky Way is in a halo of non-baryonic matter, the data do not exclude the possibility that a considerable amount, perhaps most of it, could be in a tenuous halo of diffuse ionized gas
Inelastic dark matter

International Nuclear Information System (INIS)

Smith, David; Weiner, Neal

2001-01-01

Many observations suggest that much of the matter of the universe is nonbaryonic. Recently, the DAMA NaI dark matter direct detection experiment reported an annual modulation in their event rate consistent with a WIMP relic. However, the Cryogenic Dark Matter Search (CDMS) Ge experiment excludes most of the region preferred by DAMA. We demonstrate that if the dark matter can only scatter by making a transition to a slightly heavier state (Δm∼100 keV), the experiments are no longer in conflict. Moreover, differences in the energy spectrum of nuclear recoil events could distinguish such a scenario from the standard WIMP scenario. Finally, we discuss the sneutrino as a candidate for inelastic dark matter in supersymmetric theories
The Search of Axion Dark Matter

CERN Multimedia

CERN. Geneva

2006-01-01

The axion provides a solution to the strong CP problem and is a cold dark matter candidate. I will review the limits on the axion from particle physics, stellar evolution and cosmology. The various constraints suggest that the axion mass is in the micro-eV to milli-eV range. In this range, axions contribute significantly to the energy density of the universe in the form of cold dark matter. Dark matter axions can be searched for on Earth by stimulating their conversion to microwave photons in an electromagnetic cavity permeated by a strong magnetic field. Using this technique, limits on the local halo density have been placed by the Axion Dark Matter experiment at Lawrence Livermore National Laboratory. I will give a status report on ADMX and its upgrade presently under construction. I will also discuss the results from solar axion searches (Tokyo helioscope, CAST) and laser experiments (PVLAS).
Dark matter dynamics in Abell 3827 : new data consistent with standard cold dark matter.

OpenAIRE

Massey, R.; Harvey, D.; Liesenborgs, J.; Richard, J.; Stach, S.; Swinbank, M.; Taylor, P.; Williams, L.; Clowe, D.; Courbin, F.; Edge, A.; Israel, H.; Jauzac, M.; Joseph, R.; Jullo, E.

2018-01-01

We present integral field spectroscopy of galaxy cluster Abell 3827, using Atacama Large Millimetre Array (ALMA) and Very Large Telescope/Multi-Unit Spectroscopic Explorer. It reveals an unusual configuration of strong gravitational lensing in the cluster core, with at least seven lensed images of a single background spiral galaxy. Lens modelling based on Hubble Space Telescope imaging had suggested that the dark matter associated with one of the cluster's central galaxies may be offset. The ...
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.
runDM: Running couplings of Dark Matter to the Standard Model

Science.gov (United States)

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

2018-02-01

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

International Nuclear Information System (INIS)

Kremer, Gilberto M.; Sobreiro, Octavio A.S.

2012-01-01

We study a cosmological model for a spatially flat Universe whose constituents are a dark energy field and a matter field comprising baryons and dark matter. The constituents are assumed to interact with each other, and a non-equilibrium pressure is introduced to account for irreversible processes. We take the nonequilibrium pressure to be proportional to the Hubble parameter within the framework of a first-order thermodynamic theory. The dark energy and matter fields are coupled by their barotropic indexes, which depend on the ratio between their energy densities. We adjust the free parameters of the model to optimize the fits to the Hubble parameter data. We compare the viscous model with the non-viscous one, and show that the irreversible processes cause the dark-energy and matter-density parameters to become equal and the decelerated-accelerated transition to occur at earlier times. Furthermore, the density and deceleration parameters and the distance modulus have the correct behavior, consistent with a viable scenario of the present status of the Universe . (author)
Exceptional composite dark matter

Energy Technology Data Exchange (ETDEWEB)

Ballesteros, Guillermo [Universite Paris Saclay, CEA, CNRS, Institut de Physique Theorique, Gif-sur-Yvette (France); Carmona, Adrian [CERN, Theoretical Physics Department, Geneva (Switzerland); Chala, Mikael [Universitat de Valencia y IFIC, Universitat de Valencia-CSIC, Departament de Fisica Teorica, Burjassot, Valencia (Spain)

2017-07-15

We study the dark matter phenomenology of non-minimal composite Higgs models with SO(7) broken to the exceptional group G{sub 2}. In addition to the Higgs, three pseudo-Nambu-Goldstone bosons arise, one of which is electrically neutral. A parity symmetry is enough to ensure this resonance is stable. In fact, if the breaking of the Goldstone symmetry is driven by the fermion sector, this Z{sub 2} symmetry is automatically unbroken in the electroweak phase. In this case, the relic density, as well as the expected indirect, direct and collider signals are then uniquely determined by the value of the compositeness scale, f. Current experimental bounds allow one to account for a large fraction of the dark matter of the Universe if the dark matter particle is part of an electroweak triplet. The totality of the relic abundance can be accommodated if instead this particle is a composite singlet. In both cases, the scale f and the dark matter mass are of the order of a few TeV. (orig.)
Cold light dark matter in extended seesaw models

Science.gov (United States)

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

2018-04-01

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

Energy Technology Data Exchange (ETDEWEB)

Basu Thakur, Ritoban [Univ. of Illinois, Urbana-Champaign, IL (United States)

2014-01-01

Over 80 years ago we discovered the presence of Dark Matter in our universe. Endeavors in astronomy and cosmology are in consensus with ever improving precision that Dark Matter constitutes an essential 27% of our universe. The Standard Model of Particle Physics does not provide any answers to the Dark Matter problem. It is imperative that we understand Dark Matter and discover its fundamental nature. This is because, alongside other important factors, Dark Matter is responsible for formation of structure in our universe. The very construct in which we sit is defined by its abundance. The Milky Way galaxy, hence life, wouldn't have formed if small over densities of Dark Matter had not caused sufficient accretion of stellar material. Marvelous experiments have been designed based on basic notions to directly and in-directly study Dark Matter, and the Cryogenic Dark Matter Search (CDMS) experiment has been a pioneer and forerunner in the direct detection field. Generations of the CDMS experiment were designed with advanced scientific upgrades to detect Dark Matter particles of mass O(100) GeV/c². This mass-scale was set primarily by predictions from Super Symmetry. Around 2013 the canonical SUSY predictions were losing some ground and several observations (rather hints of signals) from various experiments indicated to the possibility of lighter Dark Matter of mass O(10) GeV/c². While the SuperCDMS experiment was probing the regular parameter space, the CDMSlite experiment was conceived to dedicatedly search for light Dark Matter using a novel technology. "CDMSlite" stands for CDMS - low ionization threshold experiment. Here we utilize a unique electron phonon coupling mechanism to measure ionization generated by scattering of light particles. Typically signals from such low energy recoils would be washed under instrumental noise. In CDMSlite via generation of Luke-Neganov phonons we can detect the small ionization energies, amplified in
Cosmological axion and a quark nugget dark matter model

Science.gov (United States)

Ge, Shuailiang; Liang, Xunyu; Zhitnitsky, Ariel

2018-02-01

We study a dark matter (DM) model offering a very natural explanation of two (naively unrelated) problems in cosmology: the observed relation ΩDM˜Ωvisible and the observed asymmetry between matter and antimatter in the Universe, known as the "baryogenesis" problem. In this framework, both types of matter (dark and visible) have the same QCD origin, form at the same QCD epoch, and are proportional to one and the same dimensional parameter of the system, ΛQCD, which explains how these two naively distinct problems could be intimately related, and could be solved simultaneously within the same framework. More specifically, the DM in this model is composed by two different ingredients: the (well-studied) DM axions and the (less-studied) quark nuggets made of matter or antimatter. We focus on the quantitative analysis of the relation between these two distinct components contributing to the dark sector of the theory determined by ΩDM≡[ΩDM(nuggets)+ΩDM(axion)] . We argue that the nuggets' DM component always traces the visible matter density, i.e., ΩDM(nuggets)˜Ωvisible , and this feature is not sensitive to the parameters of the system such as the axion mass ma or the misalignment angle θ0. It should be contrasted with conventional axion production mechanisms due to the misalignment when ΩDM(axion) is highly sensitive to the axion mass ma and the initial misalignment angle θ0. We also discuss the constraints on this model related to the inflationary scale HI, nonobservation of the isocurvature perturbations and the tensor modes. We also comment on some constraints related to various axion search experiments.

Toward a minimum branching fraction for dark matter annihilation into electromagnetic final states

International Nuclear Information System (INIS)

Dent, James B.; Scherrer, Robert J.; Weiler, Thomas J.

2008-01-01

Observational limits on the high-energy neutrino background have been used to place general constraints on dark matter that annihilates only into standard model particles. Dark matter particles that annihilate into neutrinos will also inevitably branch into electromagnetic final states through higher-order tree and loop diagrams that give rise to charged leptons, and these charged particles can transfer their energy into photons via synchrotron radiation or inverse Compton scattering. In the context of effective field theory, we calculate the loop-induced branching ratio to charged leptons and show that it is generally quite large, typically > or approx. 1%, when the scale of the dark matter mass exceeds the electroweak scale, M W . For a branching fraction >or approx. 3%, the synchrotron radiation bounds on dark matter annihilation are currently stronger than the corresponding neutrino bounds in the interesting mass range from 100 GeV to 1 TeV. For dark matter masses below M W , our work provides a plausible framework for the construction of a model for 'neutrinos-only' dark matter annihilations.
Signatures of top flavour-changing dark matter

International Nuclear Information System (INIS)

Hondt, Jorgen d'; Mariotti, Alberto; Moortgat, Seth; Tziveloglou, Pantelis

2015-12-01

We develop the phenomenology of scenarios in which a dark matter candidate interacts with a top quark through flavour-changing couplings, employing a simplified dark matter model with an s-channel vector-like mediator. We study in detail the top-charm flavour-changing interaction, by investigating the single top plus large missing energy signature at the LHC as well as constraints from the relic density and direct and indirect dark matter detection experiments. We present strategies to distinguish between the top-charm and top-up flavour-changing models by taking advantage of the lepton charge asymmetry as well as by using charm-tagging techniques on an extra jet. We also show the complementarity between the LHC and canonical dark matter experiments in exploring the viable parameter space of the models.
Signatures of top flavour-changing dark matter

Energy Technology Data Exchange (ETDEWEB)

Hondt, Jorgen d' ; Mariotti, Alberto; Moortgat, Seth; Tziveloglou, Pantelis [Vrieje Univ. Brussel (Belgium). Theoretische Natuurkunde and IIHE/ELEM; Mawatari, Kentarou [Vrieje Univ. Brussel (Belgium). Theoretische Natuurkunde and IIHE/ELEM; Grenoble-Alpes Univ., CNRS/IN2P3 (France). Lab. de Physique Subatomique et de Cosmologie; Onsem, Gerrit van [Vrieje Univ. Brussel (Belgium). Theoretische Natuurkunde and IIHE/ELEM; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2015-12-15

We develop the phenomenology of scenarios in which a dark matter candidate interacts with a top quark through flavour-changing couplings, employing a simplified dark matter model with an s-channel vector-like mediator. We study in detail the top-charm flavour-changing interaction, by investigating the single top plus large missing energy signature at the LHC as well as constraints from the relic density and direct and indirect dark matter detection experiments. We present strategies to distinguish between the top-charm and top-up flavour-changing models by taking advantage of the lepton charge asymmetry as well as by using charm-tagging techniques on an extra jet. We also show the complementarity between the LHC and canonical dark matter experiments in exploring the viable parameter space of the models.
First results from the LUX Dark Matter Experiment

CERN Multimedia

CERN. Geneva

2013-01-01

Discovery of the nature of dark matter is internationally recognized as one of the greatest contemporary challenges in science, fundamental to our understanding of the Universe. The most compelling candidates for dark matter are Weakly Interacting Massive Particles (WIMPs) that arise naturally in several models of physics beyond the Standard Model. The discovery of galactic WIMPs would therefore enlighten two of the outstanding problems of modern physics - the matter composition of the Universe and the extrapolation of the Standard Model of particle physics to GUT scales. Although no definitive signal has yet been discovered, the worldwide race towards direct detection has been dramatically accelerated by the remarkable progress and evolution of liquid xenon (LXe) time projection chambers (TPCs). They have shifted the scale of target mass by orders of magnitude whilst simultaneously reducing backgrounds to unprecedented low levels, becoming the leaders of the field and offering the most promising prospects fo...
Effective description of dark matter self-interactions in small dark matter haloes

International Nuclear Information System (INIS)

Kummer, Janis

2017-07-01

Self-interacting dark matter may have striking astrophysical signatures, such as observ- able offsets between galaxies and dark matter in merging galaxy clusters. Numerical N-body simulations used to predict such observables typically treat the galaxies as collisionless test particles, a questionable assumption given that each galaxy is embedded in its own dark matter halo. To enable a more accurate treatment we develop an effective description of small dark matter haloes taking into account the two major effects due to dark matter self-scatterings: deceleration and evaporation. We point out that self-scatterings can have a sizeable impact on the trajectories of galaxies, diminishing the separation between galaxies and dark matter in merging clusters. This effect depends sensitively on the underlying particle physics, in particular the angular dependence of the self-scattering cross section, and cannot be predicted from the momentum transfer cross section alone.
Update on hidden sectors with dark forces and dark matter

Energy Technology Data Exchange (ETDEWEB)

Andreas, Sarah

2012-11-15

Recently there has been much interest in hidden sectors, especially in the context of dark matter and ''dark forces'', since they are a common feature of beyond standard model scenarios like string theory and SUSY and additionally exhibit interesting phenomenological aspects. Various laboratory experiments place limits on the so-called hidden photon and continuously further probe and constrain the parameter space; an updated overview is presented here. Furthermore, for several hidden sector models with light dark matter we study the viability with respect to the relic abundance and direct detection experiments.
Constraining properties of dark matter particles using astrophysical data

NARCIS (Netherlands)

Iakubovskyi, Dmytro

2013-01-01

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

International Nuclear Information System (INIS)

Gaite, Jose

2015-01-01

The current cold dark matter cosmological model explains the large scale cosmic web structure but is challenged by the observation of a relatively smooth distribution of matter in galactic clusters. We consider various aspects of modeling the dark matter around galaxies as distributed in smooth halos and, especially, the smoothness of the dark matter halos seen in N-body cosmological simulations. We conclude that the problems of the cold dark matter cosmology on small scales are more serious than normally admitted
One dark matter mystery: halos in the cosmic web

Science.gov (United States)

Gaite, Jose

2015-01-01

The current cold dark matter cosmological model explains the large scale cosmic web structure but is challenged by the observation of a relatively smooth distribution of matter in galactic clusters. We consider various aspects of modeling the dark matter around galaxies as distributed in smooth halos and, especially, the smoothness of the dark matter halos seen in N-body cosmological simulations. We conclude that the problems of the cold dark matter cosmology on small scales are more serious than normally admitted.
The dark matter of galaxy voids

Science.gov (United States)

Sutter, P. M.; Lavaux, Guilhem; Wandelt, Benjamin D.; Weinberg, David H.; Warren, Michael S.

2014-03-01

How do observed voids relate to the underlying dark matter distribution? To examine the spatial distribution of dark matter contained within voids identified in galaxy surveys, we apply Halo Occupation Distribution models representing sparsely and densely sampled galaxy surveys to a high-resolution N-body simulation. We compare these galaxy voids to voids found in the halo distribution, low-resolution dark matter and high-resolution dark matter. We find that voids at all scales in densely sampled surveys - and medium- to large-scale voids in sparse surveys - trace the same underdensities as dark matter, but they are larger in radius by ˜20 per cent, they have somewhat shallower density profiles and they have centres offset by ˜ 0.4Rv rms. However, in void-to-void comparison we find that shape estimators are less robust to sampling, and the largest voids in sparsely sampled surveys suffer fragmentation at their edges. We find that voids in galaxy surveys always correspond to underdensities in the dark matter, though the centres may be offset. When this offset is taken into account, we recover almost identical radial density profiles between galaxies and dark matter. All mock catalogues used in this work are available at http://www.cosmicvoids.net.
Indirect search for dark matter with AMS

International Nuclear Information System (INIS)

Goy, Corinne

2006-01-01

This document summarises the potential of AMS in the indirect search for Dark Matter. Observations and cosmology indicate that the Universe may include a large amount of Dark Matter of unknown nature. A good candidate is the Ligthest Supersymmetric Particle in R-Parity conserving models. AMS offers a unique opportunity to study Dark Matter indirect signature in three spectra: gamma, antiprotons and positrons
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...
Dark matter in spiral galaxies

International Nuclear Information System (INIS)

Albada, T.S. van; Sancisi, R.

1986-01-01

Mass models of spiral galaxies based on the observed light distribution, assuming constant M/L for bulge and disc, are able to reproduce the observed rotation curves in the inner regions, but fail to do so increasingly towards and beyond the edge of the visible material. The discrepancy in the outer region can be accounted for by invoking dark matter; some galaxies require at least four times as much dark matter as luminous matter. There is no evidence for a dependence on galaxy luminosity or morphological type. Various arguments support the idea that a distribution of visible matter with constant M/L is responsible for the circular velocity in the inner region, i.e. inside approximately 2.5 disc scalelengths. Luminous matter and dark matter seem to 'conspire' to produce the flat observed rotation curves in the outer region. It seems unlikely that this coupling between disc and halo results from the large-scale gravitational interaction between the two components. Attempts to determine the shape of dark halos have not yet produced convincing results. (author)
2HDM portal for Singlet-Doublet Dark Matter

OpenAIRE

Arcadi, Giorgio

2018-01-01

We present an extensive analysis of a model in which the (Majorana) Dark Matter candidate is a mixture between a SU(2) singlet and two SU(2) doublets. This kind of setup takes the name of singlet-doublet model. We will investigate in detail an extension of this model in which the Dark Matter sector interactions with a 2-doublet Higgs sector enforcing the complementarity between Dark Matter phenomenology and searches of extra Higgs bosons.
DarkBit. A GAMBIT module for computing dark matter observables and likelihoods

Energy Technology Data Exchange (ETDEWEB)

Bringmann, Torsten; Dal, Lars A. [University of Oslo, Department of Physics, Oslo (Norway); Conrad, Jan; Edsjoe, Joakim; Farmer, Ben [AlbaNova University Centre, Oskar Klein Centre for Cosmoparticle Physics, Stockholm (Sweden); Stockholm University, Department of Physics, Stockholm (Sweden); Cornell, Jonathan M. [McGill University, Department of Physics, Montreal, QC (Canada); Kahlhoefer, Felix; Wild, Sebastian [DESY, Hamburg (Germany); Kvellestad, Anders; Savage, Christopher [NORDITA, Stockholm (Sweden); Putze, Antje [LAPTh, Universite de Savoie, CNRS, Annecy-le-Vieux (France); Scott, Pat [Blackett Laboratory, Imperial College London, Department of Physics, London (United Kingdom); Weniger, Christoph [University of Amsterdam, GRAPPA, Institute of Physics, Amsterdam (Netherlands); White, Martin [University of Adelaide, Department of Physics, Adelaide, SA (Australia); Australian Research Council Centre of Excellence for Particle Physics at the Tera-scale, Parkville (Australia); Collaboration: The GAMBIT Dark Matter Workgroup

2017-12-15

We introduce DarkBit, an advanced software code for computing dark matter constraints on various extensions to the Standard Model of particle physics, comprising both new native code and interfaces to external packages. This release includes a dedicated signal yield calculator for gamma-ray observations, which significantly extends current tools by implementing a cascade-decay Monte Carlo, as well as a dedicated likelihood calculator for current and future experiments (gamLike). This provides a general solution for studying complex particle physics models that predict dark matter annihilation to a multitude of final states. We also supply a direct detection package that models a large range of direct detection experiments (DDCalc), and that provides the corresponding likelihoods for arbitrary combinations of spin-independent and spin-dependent scattering processes. Finally, we provide custom relic density routines along with interfaces to DarkSUSY, micrOMEGAs, and the neutrino telescope likelihood package nulike. DarkBit is written in the framework of the Global And Modular Beyond the Standard Model Inference Tool (GAMBIT), providing seamless integration into a comprehensive statistical fitting framework that allows users to explore new models with both particle and astrophysics constraints, and a consistent treatment of systematic uncertainties. In this paper we describe its main functionality, provide a guide to getting started quickly, and show illustrative examples for results obtained with DarkBit (both as a stand-alone tool and as a GAMBIT module). This includes a quantitative comparison between two of the main dark matter codes (DarkSUSY and micrOMEGAs), and application of DarkBit's advanced direct and indirect detection routines to a simple effective dark matter model. (orig.)
Search for Dark Matter in Association with Top Quarks with the CMS Detector

CERN Document Server

Pinna, Deborah

2017-01-01

The evidence of the existence of dark matter is provided by astrophysical observationsat different scales. Nevertheless, information about its nature or non gravitationalinteractions is not yet available. Assuming interactions between dark matter and stan-dard model particles, dark matter can be produced in high energy collisions and theinteraction studied in detail.In this thesis, a search for dark matter produced in association with a top quark pairis performed using the data recorded by the CMS detector at two different center-of-mass energies of 8 and 13 TeV. The datasets correspond to integrated luminositiesof19.7fb−1and2.2fb−1, respectively. The analysis performed at8TeV considersonly the single-lepton decay of top quark pairs. It represented the first search of itskind in CMS and the results provide important insight on possible scalar interactionsbetween dark matter and standard model particles. The results are interpreted using adedicated effective field theory. Similar search is performed usin...
Phantom dark energy with varying-mass dark matter particles: Acceleration and cosmic coincidence problem

International Nuclear Information System (INIS)

Leon, Genly; Saridakis, Emmanuel N.

2010-01-01

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

QCD Axion Dark Matter with a Small Decay Constant.

Science.gov (United States)

Co, Raymond T; Hall, Lawrence J; Harigaya, Keisuke

2018-05-25

The QCD axion is a good dark matter candidate. The observed dark matter abundance can arise from misalignment or defect mechanisms, which generically require an axion decay constant f_{a}∼O(10^{11}) GeV (or higher). We introduce a new cosmological origin for axion dark matter, parametric resonance from oscillations of the Peccei-Quinn symmetry breaking field, that requires f_{a}∼(10^{8}-10^{11}) GeV. The axions may be warm enough to give deviations from cold dark matter in large scale structure.
Dark matter directional detection in non-relativistic effective theories

International Nuclear Information System (INIS)

Catena, Riccardo

2015-01-01

We extend the formalism of dark matter directional detection to arbitrary one-body dark matter-nucleon interactions. The new theoretical framework generalizes the one currently used, which is based on 2 types of dark matter-nucleon interaction only. It includes 14 dark matter-nucleon interaction operators, 8 isotope-dependent nuclear response functions, and the Radon transform of the first 2 moments of the dark matter velocity distribution. We calculate the recoil energy spectra at dark matter directional detectors made of CF 4 , CS 2 and 3 He for the 14 dark matter-nucleon interactions, using nuclear response functions recently obtained through numerical nuclear structure calculations. We highlight the new features of the proposed theoretical framework, and present our results for a spherical dark matter halo and for a stream of dark matter particles. This study lays the foundations for model independent analyses of dark matter directional detection experiments
Sterile neutrinos as dark matter

International Nuclear Information System (INIS)

Dodelson, S.; Widrow, L.M.

1994-01-01

The simplest model that can accommodate a viable nonbaryonic dark matter candidate is the standard electroweak theory with the addition of right-handed (sterile) neutrinos. We consider a single generation of neutrinos with a Dirac mass μ and a Majorana mass M for the right-handed component. If M much-gt μ (standard hot dark matter corresponds to M=0), then sterile neutrinos are produced via oscillations in the early Universe with energy density independent of M. However, M is crucial in determining the large scale structure of the Universe; for M∼100 eV, sterile neutrinos make an excellent warm dark matter candidate
Dark matter dynamics in Abell 3827: new data consistent with standard cold dark matter

OpenAIRE

Massey , Richard; Harvey , David; Liesenborgs , Jori; Richard , Johan; Stach , Stuart; Swinbank , Mark; Taylor , Peter; Williams , Liliya; Clowe , Douglas; Courbin , Frédéric; Edge , Alastair; Israel , Holger; Jauzac , Mathilde; Joseph , Remy; Jullo , Eric

2018-01-01

10 pages, 5 figures. Comments welcome; International audience; We present integral field spectroscopy of galaxy cluster Abell 3827, using ALMA and VLT/MUSE. It reveals an unusual configuration of strong gravitational lensing in the cluster core, with at least seven lensed images of a single background spiral galaxy. Lens modelling based on HST imaging had suggested that the dark matter associated with one of the cluster's central galaxies may be offset. The new spectroscopic data enable bette...
Beyond WIMPs: the Quark (Anti Nugget Dark Matter

Directory of Open Access Journals (Sweden)

Zhitnitsky Ariel

2017-01-01

Full Text Available We review a testable dark matter (DM model outside of the standard WIMP paradigm. The model is unique in a sense that the observed ratio Ωdark ≃ Ωvisible for visible and dark matter densities finds its natural explanation as a result of their common QCD origin when both types of matter (DM and visible are formed during the QCD phase transition and both are proportional to single dimensional parameter of the system, Λqcd. We argue that the charge separation effect also inevitably occurs during the same QCD phase transition in the presence of the CP odd axion field a(x. It leads to preferential formation of one species of nuggets on the scales of the visible Universe where the axion field a(x is coherent. A natural outcome of this preferential evolution is that only one type of the visible baryons (not anti- baryons remain in the system after the nuggets complete their formation. Unlike conventional WIMP dark matter candidates, the nuggets and anti-nuggets are strongly interacting but macroscopically large objects. The rare events of annihilation of the anti-nuggets with visible matter lead to a number of observable effects. We argue that the relative intensities for a number of measured excesses of emission from the centre of galaxy (covering more than 11 orders of magnitude are determined by standard and well established physics. At the same time the absolute intensity of emission is determined by a single new fundamental parameter of the theory, the axion mass, 10−6eV ≲ ma ≲ 10−3eV. Finally, we comment on implications of these studies for the axion search experiments, including microwave cavity and the Orpheus experiments.
Tight connection between direct and indirect detection of dark matter through Higgs portal couplings to a hidden sector

International Nuclear Information System (INIS)

Arina, Chiara; Josse-Michaux, Francois-Xavier; Sahu, Narendra

2010-01-01

We present a hidden Abelian extension of the standard model including a complex scalar as a dark matter candidate and a light scalar acting as a long range force carrier between dark matter particles. The Sommerfeld enhanced annihilation cross section of the dark matter explains the observed cosmic ray excesses. The light scalar field also gives rise to potentially large cross sections of dark matter on the nucleon, therefore providing an interesting way to probe this model simultaneously at direct and indirect dark matter search experiments. We constrain the parameter space of the model by taking into account the CDMS-II exclusion limit as well as PAMELA and Fermi LAT data.
Exponential Potential versus Dark Matter

Science.gov (United States)

1993-10-15

scale of the solar system. Galaxy, Dark matter , Galaxy cluster, Gravitation, Quantum gravity...A two parameter exponential potential explains the anomalous kinematics of galaxies and galaxy clusters without need for the myriad ad hoc dark ... matter models currently in vogue. It also explains much about the scales and structures of galaxies and galaxy clusters while being quite negligible on the
Cancellation Mechanism for Dark-Matter-Nucleon Interaction.

Science.gov (United States)

Gross, Christian; Lebedev, Oleg; Toma, Takashi

2017-11-10

We consider a simple Higgs portal dark-matter model, where the standard model is supplemented with a complex scalar whose imaginary part plays the role of weakly interacting massive particle dark matter (DM). We show that the direct DM detection cross section vanishes at the tree level and zero momentum transfer due to a cancellation by virtue of a softly broken symmetry. This cancellation is operative for any mediator masses. As a result, our electroweak-scale dark matter satisfies all of the phenomenological constraints quite naturally.
The dark matter distribution of NGC 5921

Science.gov (United States)

Ali, Israa Abdulqasim Mohammed; Hashim, Norsiah; Abidin, Zamri Zainal

2018-04-01

We used the neutral atomic hydrogen data of the Very Large Array for the spiral galaxy NGC 5921 with z = 0.0045 at the distance of 22.4 Mpc, to investigate the nature of dark matter. The investigation was based on two theories, namely, dark matter and Modified Newtonian Dynamics (MOND). We presented the kinematic analysis of the rotation curve with two models of dark matter, namely, the Burkert and NFW profiles. The results revealed that the NFW halo model can reproduce the observed rotation curve, with χ 2_{red}≈ 1, while the Burkert model is unable to fit the observation data. Therefore, the dark matter density profile of NGC 5921 can be presented as a cuspy halo. We also tried to investigate the observed rotation curve of NGC 5921 with MOND, along with the possible assumption on baryonic matter and distance. We note that MOND is still incapable of mimicking the rotation curve with the observed data of the galaxy.
Chiral gravitational waves and baryon superfluid dark matter

Science.gov (United States)

Alexander, Stephon; McDonough, Evan; Spergel, David N.

2018-05-01

We develop a unified model of darkgenesis and baryogenesis involving strongly interacting dark quarks, utilizing the gravitational anomaly of chiral gauge theories. In these models, both the visible and dark baryon asymmetries are generated by the gravitational anomaly induced by the presence of chiral primordial gravitational waves. We provide a concrete model of an SU(2) gauge theory with two massless quarks. In this model, the dark quarks condense and form a dark baryon charge superfluid (DBS), in which the Higgs-mode acts as cold dark matter. We elucidate the essential features of this dark matter scenario and discuss its phenomenological prospects.
Recent Developments in Supersymmetric and Hidden Sector Dark Matter

International Nuclear Information System (INIS)

Feldman, Daniel; Liu Zuowei; Nath, Pran

2008-01-01

New results which correlate SUSY dark matter with LHC signals are presented, and a brief review of recent developments in supersymmetric and hidden sector dark matter is given. It is shown that the direct detection of dark matter is very sensitive to the hierarchical SUSY sparticle spectrum and the spectrum is very useful in distinguishing models. It is shown that the prospects of the discovery of neutralino dark matter are very bright on the 'Chargino Wall' due to a copious number of model points on the Wall, where the NLSP is the Chargino, and the spin independent neutralino-proton cross section is maintained at high values in the 10 -44 cm 2 range for neutralino masses up to ∼850 GeV. It is also shown that the direct detection of dark matter along with lepton plus jet signatures and missing energy provide dual, and often complementary, probes of supersymmetry. Finally, we discuss an out of the box possibility for dark matter, which includes dark matter from the hidden sector, which could either consist of extra weakly interacting dark matter (a Stino XWIMP), or milli-charged dark matter arising from the Stueckelberg extensions of the MSSM or the SM.
Lepton flavor violation induced by dark matter

Science.gov (United States)

Arcadi, Giorgio; Ferreira, C. P.; Goertz, Florian; Guzzo, M. M.; Queiroz, Farinaldo S.; Santos, A. C. O.

2018-04-01

Guided by gauge principles we discuss a predictive and falsifiable UV complete model where the Dirac fermion that accounts for the cold dark matter abundance in our Universe induces the lepton flavor violation (LFV) decays μ →e γ and μ →e e e as well as μ -e conversion. We explore the interplay between direct dark matter detection, relic density, collider probes and lepton flavor violation to conclusively show that one may have a viable dark matter candidate yielding flavor violation signatures that can be probed in the upcoming experiments. In fact, keeping the dark matter mass at the TeV scale, a sizable LFV signal is possible, while reproducing the correct dark matter relic density and meeting limits from direct-detection experiments.
Chromo-Rayleigh interactions of dark matter

International Nuclear Information System (INIS)

Bai, Yang; Osborne, James

2015-01-01

For a wide range of models, dark matter can interact with QCD gluons via chromo-Rayleigh interactions. We point out that the Large Hadron Collider (LHC), as a gluon machine, provides a superb probe of such interactions. In this paper, we introduce simplified models to UV-complete two effective dark matter chromo-Rayleigh interactions and identify the corresponding collider signatures, including four jets or a pair of di-jet resonances plus missing transverse energy. After performing collider studies for both the 8 TeV and 14 TeV LHC, we find that the LHC can be more sensitive to dark matter chromo-Rayleigh interactions than direct detection experiments and thus provides the best opportunity for future discovery of this class of models.
Basic model of fermion dark matter. Indirect detection of supersymmetric dark matter in γ astronomy with the CELESTE telescope

International Nuclear Information System (INIS)

Lavalle, J.

2004-10-01

The purpose of this thesis is to discuss both phenomenological and experimental aspects of Dark Matter, related to its indirect detection with gamma-ray astronomy. In the MSSM (Minimal Supersymmetric Standard Model) framework, neutralinos arise as natural candidates to non-baryonic and Cold Dark Matter, whose gravitational effects manifest in the Universe at different scales. As they are Majorana particles, they may in principle annihilate in high density regions, as the centres of galaxies, and produce gamma rays. Nevertheless, the expected fluxes are basically low compared to experimental sensitivities. After estimating gamma fluxes from M31 and Draco galaxies in the MSSM scheme, we first generalize the MSSM couplings by studying an effective Lagrangian. We show that the only constraint of imposing a relic abundance compatible with recent measurements obviously deplete significantly the gamma ray production, but also that predictions in this effective approach are more optimistic for indirect detection than the MSSM. In a second part, we present the indirect searches for Dark Matter performed with the CELESTE Cherenkov telescope towards the galaxy M31. We propose a statistical method to reconstruct spectra, mandatory to discriminate classical and exotic spectra. The M31 data analysis enables the extraction of an upper limit on the gamma ray flux, which is the first worldwide for a galaxy in the energy range 50-500 GeV, and whose astrophysical interest goes beyond indirect searches for Dark Matter. (author)
Reconstructing interacting entropy-corrected holographic scalar field models of dark energy in the non-flat universe

Energy Technology Data Exchange (ETDEWEB)

Karami, K; Khaledian, M S [Department of Physics, University of Kurdistan, Pasdaran Street, Sanandaj (Iran, Islamic Republic of); Jamil, Mubasher, E-mail: KKarami@uok.ac.ir, E-mail: MS.Khaledian@uok.ac.ir, E-mail: mjamil@camp.nust.edu.pk [Center for Advanced Mathematics and Physics (CAMP), National University of Sciences and Technology (NUST), Islamabad (Pakistan)

2011-02-15

Here we consider the entropy-corrected version of the holographic dark energy (DE) model in the non-flat universe. We obtain the equation of state parameter in the presence of interaction between DE and dark matter. Moreover, we reconstruct the potential and the dynamics of the quintessence, tachyon, K-essence and dilaton scalar field models according to the evolutionary behavior of the interacting entropy-corrected holographic DE model.
Black Hole Space-time In Dark Matter Halo

OpenAIRE

Xu, Zhaoyi; Hou, Xian; Gong, Xiaobo; Wang, Jiancheng

2018-01-01

For the first time, we obtain the analytical form of black hole space-time metric in dark matter halo for the stationary situation. Using the relation between the rotation velocity (in the equatorial plane) and the spherical symmetric space-time metric coefficient, we obtain the space-time metric for pure dark matter. By considering the dark matter halo in spherical symmetric space-time as part of the energy-momentum tensors in the Einstein field equation, we then obtain the spherical symmetr...
Mimicking dark matter through a non-minimal gravitational coupling with matter

International Nuclear Information System (INIS)

Bertolami, O.; Páramos, J.

2010-01-01

In this study one resorts to the phenomenology of models endowed with a non-minimal coupling between matter and geometry, in order to develop a mechanism through which dynamics similar to that due to the presence of dark matter is generated. As a first attempt, one tries to account for the flattening of the galaxy rotation curves as an effect of the non-(covariant) conservation of the energy-momentum tensor of visible matter. Afterwards, one assumes instead that this non-minimal coupling modifies the scalar curvature in a way that can be interpreted as a dark matter component (albeit with negative pressure). It is concluded that it is possible to mimic known dark matter density profiles through an appropriate power-law coupling f 2 = (R/R 0 ) n , with a negative index n — a fact that reflects the dominance of dark matter at large distances. The properties of the model are extensively discussed, and possible cosmological implications are addressed
Coupled dark matter-dark energy in light of near universe observations

International Nuclear Information System (INIS)

Honorez, Laura Lopez; Reid, Beth A.; Verde, Licia; Jimenez, Raul; Mena, Olga

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 inconsistency between reconstructed expansion history and growth may not uniquely indicate deviations from GR. Our low redshift constraints arise from cosmic velocities, redshift space distortions and dark matter abundance in galaxy voids. We find that current data constrain the dimensionless coupling to be |ξ| < 0.2, but prospects from forthcoming data are for a significant improvement. Future, precise measurements of the Hubble constant, combined with high-precision constraints on the growth of structure, could provide the key to rule out dark coupling models which survive other tests. We shall exploit as well weak equivalence principle violation arguments, which have the potential to highly disfavour a broad family of coupled models
Detecting dark matter with imploding pulsars in the galactic center.

Science.gov (United States)

Bramante, Joseph; Linden, Tim

2014-11-07

The paucity of old millisecond pulsars observed at the galactic center of the Milky Way could be the result of dark matter accumulating in and destroying neutron stars. In regions of high dark matter density, dark matter clumped in a pulsar can exceed the Schwarzschild limit and collapse into a natal black hole which destroys the pulsar. We examine what dark matter models are consistent with this hypothesis and find regions of parameter space where dark matter accumulation can significantly degrade the neutron star population within the galactic center while remaining consistent with observations of old millisecond pulsars in globular clusters and near the solar position. We identify what dark matter couplings and masses might cause a young pulsar at the galactic center to unexpectedly extinguish. Finally, we find that pulsar collapse age scales inversely with the dark matter density and linearly with the dark matter velocity dispersion. This implies that maximum pulsar age is spatially dependent on position within the dark matter halo of the Milky Way. In turn, this pulsar age spatial dependence will be dark matter model dependent.
Direct and indirect detection of dissipative dark matter

Energy Technology Data Exchange (ETDEWEB)

Fan, JiJi; Katz, Andrey; Shelton, Jessie, E-mail: jijifan1982@gmail.com, E-mail: katz.andrey@gmail.com, E-mail: jshelton137@gmail.com [Department of Physics, Harvard University, Cambridge, MA 02138 (United States)

2014-06-01

We study the constraints from direct detection and solar capture on dark matter scenarios with a subdominant dissipative component. This dissipative dark matter component in general has both a symmetric and asymmetric relic abundance. Dissipative dynamics allow this subdominant dark matter component to cool, resulting in its partial or total collapse into a smaller volume inside the halo (e.g., a dark disk) as well as a reduced thermal velocity dispersion compared to that of normal cold dark matter. We first show that these features considerably relax the limits from direct detection experiments on the couplings between standard model (SM) particles and dissipative dark matter. On the other hand, indirect detection of the annihilation of the symmetric dissipative dark matter component inside the Sun sets stringent and robust constraints on the properties of the dissipative dark matter. In particular, IceCube observations force dissipative dark matter particles with mass above 50 GeV to either have a small coupling to the SM or a low local density in the solar system, or to have a nearly asymmetric relic abundance. Possible helioseismology signals associated with purely asymmetric dissipative dark matter are discussed, with no present constraints.

Direct and indirect detection of dissipative dark matter

International Nuclear Information System (INIS)

Fan, JiJi; Katz, Andrey; Shelton, Jessie

2014-01-01

We study the constraints from direct detection and solar capture on dark matter scenarios with a subdominant dissipative component. This dissipative dark matter component in general has both a symmetric and asymmetric relic abundance. Dissipative dynamics allow this subdominant dark matter component to cool, resulting in its partial or total collapse into a smaller volume inside the halo (e.g., a dark disk) as well as a reduced thermal velocity dispersion compared to that of normal cold dark matter. We first show that these features considerably relax the limits from direct detection experiments on the couplings between standard model (SM) particles and dissipative dark matter. On the other hand, indirect detection of the annihilation of the symmetric dissipative dark matter component inside the Sun sets stringent and robust constraints on the properties of the dissipative dark matter. In particular, IceCube observations force dissipative dark matter particles with mass above 50 GeV to either have a small coupling to the SM or a low local density in the solar system, or to have a nearly asymmetric relic abundance. Possible helioseismology signals associated with purely asymmetric dissipative dark matter are discussed, with no present constraints
Dark matter, baryon asymmetry, and spontaneous B and L breaking

International Nuclear Information System (INIS)

Dulaney, Timothy R.; Wise, Mark B.; Perez, Pavel Fileviez

2011-01-01

We investigate the dark matter and the cosmological baryon asymmetry in a simple theory where baryon (B) and lepton (L) number are local gauge symmetries that are spontaneously broken. In this model, the cold dark matter candidate is the lightest new field with baryon number and its stability is an automatic consequence of the gauge symmetry. Dark matter annihilation is either through a leptophobic gauge boson whose mass must be below a TeV or through the Higgs boson. Since the mass of the leptophobic gauge boson has to be below the TeV scale, one finds that in the first scenario there is a lower bound on the elastic cross section of about 5x10 -46 cm 2 . Even though baryon number is gauged and not spontaneously broken until the weak scale, a cosmologically acceptable baryon excess is possible. There can be a tension between achieving both the measured baryon excess and the dark matter density.
Ordinary Dark Matter versus Mysterious Dark Matter in Galactic Rotation

Science.gov (United States)

Gallo, C. F.; Feng, James

2008-04-01

To theoretically describe the measured rotational velocity curves of spiral galaxies, there are two different approaches and conclusions. (1) ORDINARY DARK MATTER. We assume Newtonian gravity/dynamics and successfully find (via computer) mass distributions in bulge/disk configurations that duplicate the measured rotational velocities. There is ordinary dark matter within the galactic disk towards the cooler periphery which has lower emissivity/opacity. There are no mysteries in this scenario based on verified physics. (2) MYSTERIOUS DARK MATTER. Others INaccurately assume the galactic mass distributions follow the measured light distributions, and then the measured rotational velocity curves are NOT duplicated. To alleviate this discrepancy, speculations are invoked re ``Massive Peripheral Spherical Halos of Mysterious Dark Matter.'' But NO matter has been detected in this UNtenable Halo configuration. Many UNverified ``Mysteries'' are invoked as necessary and convenient. CONCLUSION. The first approach utilizing Newtonian gravity/dynamics and searching for the ordinary mass distributions within the galactic disk simulates reality and agrees with data.
Significant gamma-ray lines from dark matter annihilation

Energy Technology Data Exchange (ETDEWEB)

Duerr, Michael [DESY, Notkestrasse 85, 22607 Hamburg (Germany); Fileviez Perez, Pavel; Smirnov, Juri [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany)

2016-07-01

Gamma-ray lines from dark matter annihilation are commonly seen as a ''smoking gun'' for the particle nature of dark matter. However, in many dark matter models the continuum background from tree-level annihilations makes such a line invisible. I present two simple extensions of the Standard Model where the continuum contributions are suppressed and the gamma-ray lines are easily visible over the continuum background.
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.
Phenomenology of ELDER dark matter

Science.gov (United States)

Kuflik, Eric; Perelstein, Maxim; Lorier, Nicolas Rey-Le; Tsai, Yu-Dai

2017-08-01

We explore the phenomenology of Elastically Decoupling Relic (ELDER) dark matter. ELDER is a thermal relic whose present density is determined primarily by the cross-section of its elastic scattering off Standard Model (SM) particles. Assuming that this scattering is mediated by a kinetically mixed dark photon, we argue that the ELDER scenario makes robust predictions for electron-recoil direct-detection experiments, as well as for dark photon searches. These predictions are independent of the details of interactions within the dark sector. Together with the closely related Strongly-Interacting Massive Particle (SIMP) scenario, the ELDER predictions provide a physically motivated, well-defined target region, which will be almost entirely accessible to the next generation of searches for sub-GeV dark matter and dark photons. We provide useful analytic approximations for various quantities of interest in the ELDER scenario, and discuss two simple renormalizable toy models which incorporate the required strong number-changing interactions among the ELDERs, as well as explicitly implement the coupling to electrons via the dark photon portal.
Improved Limits for Higgs-Portal Dark Matter from LHC Searches.

Science.gov (United States)

Hoferichter, Martin; Klos, Philipp; Menéndez, Javier; Schwenk, Achim

2017-11-03

Searches for invisible Higgs decays at the Large Hadron Collider constrain dark matter Higgs-portal models, where dark matter interacts with the standard model fields via the Higgs boson. While these searches complement dark matter direct-detection experiments, a comparison of the two limits depends on the coupling of the Higgs boson to the nucleons forming the direct-detection nuclear target, typically parametrized in a single quantity f_{N}. We evaluate f_{N} using recent phenomenological and lattice-QCD calculations, and include for the first time the coupling of the Higgs boson to two nucleons via pion-exchange currents. We observe a partial cancellation for Higgs-portal models that makes the two-nucleon contribution anomalously small. Our results, summarized as f_{N}=0.308(18), show that the uncertainty of the Higgs-nucleon coupling has been vastly overestimated in the past. The improved limits highlight that state-of-the-art nuclear physics input is key to fully exploiting experimental searches.
Phenomenology of left-right symmetric dark matter

International Nuclear Information System (INIS)

Garcia-Cely, Camilo; Heeck, Julian

2016-01-01

We present a detailed study of dark matter phenomenology in low-scale left-right symmetric models. Stability of new fermion or scalar multiplets is ensured by an accidental matter parity that survives the spontaneous symmetry breaking of the gauge group by scalar triplets. The relic abundance of these particles is set by gauge interactions and gives rise to dark matter candidates with masses above the electroweak scale. Dark matter annihilations are thus modified by the Sommerfeld effect, not only in the early Universe, but also today, for instance, in the Center of the Galaxy. Majorana candidates—triplet, quintuplet, bi-doublet, and bi-triplet—bring only one new parameter to the model, their mass, and are hence highly testable at colliders and through astrophysical observations. Scalar candidates—doublet and 7-plet, the latter being only stable at the renormalizable level—have additional scalar-scalar interactions that give rise to rich phenomenology. The particles under discussion share many features with the well-known candidates wino, Higgsino, inert doublet scalar, sneutrino, and Minimal Dark Matter. In particular, they all predict a large gamma-ray flux from dark matter annihilations, which can be searched for with Cherenkov telescopes. We furthermore discuss models with unequal left-right gauge couplings, g R ≠ g L , taking the recent experimental hints for a charged gauge boson with 2 TeV mass as a benchmark point. In this case, the dark matter mass is determined by the observed relic density
Gamma-ray constraints on dark-matter annihilation to electroweak gauge and Higgs bosons

Energy Technology Data Exchange (ETDEWEB)

Fedderke, Michael A.; Kolb, Edward W.; Lin, Tongyan; Wang, Lian-Tao, E-mail: mfedderke@uchicago.edu, E-mail: Rocky.Kolb@uchicago.edu, E-mail: tongyan@kicp.uchicago.edu, E-mail: liantaow@uchicago.edu [Enrico Fermi Institute and Kavli Institute for Cosmological Physics, The University of Chicago, Chicago, Illinois, 60637-1433 (United States)

2014-01-01

Dark-matter annihilation into electroweak gauge and Higgs bosons results in γ-ray emission. We use observational upper limits on the fluxes of both line and continuum γ-rays from the Milky Way Galactic Center and from Milky Way dwarf companion galaxies to set exclusion limits on allowed dark-matter masses. (Generally, Galactic Center γ-ray line search limits from the Fermi-LAT and the H.E.S.S. experiments are most restrictive.) Our limits apply under the following assumptions: a) the dark matter species is a cold thermal relic with present mass density equal to the measured dark-matter density of the universe; b) dark-matter annihilation to standard-model particles is described in the non-relativistic limit by a single effective operator O∝J{sub DM}⋅J{sub SM}, where J{sub DM} is a standard-model singlet current consisting of dark-matter fields (Dirac fermions or complex scalars), and J{sub SM} is a standard-model singlet current consisting of electroweak gauge and Higgs bosons; and c) the dark-matter mass is in the range 5 GeV to 20 TeV. We consider, in turn, the 34 possible operators with mass dimension 8 or lower with non-zero s-wave annihilation channels satisfying the above assumptions. Our limits are presented in a large number of figures, one for each of the 34 possible operators; these limits can be grouped into 13 classes determined by the field content and structure of the operators. We also identify three classes of operators (coupling to the Higgs and SU(2){sub L} gauge bosons) that can supply a 130 GeV line with the desired strength to fit the putative line signal in the Fermi-LAT data, while saturating the relic density and satisfying all other indirect constraints we consider.
Accurate estimate of the relic density and the kinetic decoupling in nonthermal dark matter models

International Nuclear Information System (INIS)

Arcadi, Giorgio; Ullio, Piero

2011-01-01

Nonthermal dark matter generation is an appealing alternative to the standard paradigm of thermal WIMP dark matter. We reconsider nonthermal production mechanisms in a systematic way, and develop a numerical code for accurate computations of the dark matter relic density. We discuss, in particular, scenarios with long-lived massive states decaying into dark matter particles, appearing naturally in several beyond the standard model theories, such as supergravity and superstring frameworks. Since nonthermal production favors dark matter candidates with large pair annihilation rates, we analyze the possible connection with the anomalies detected in the lepton cosmic-ray flux by Pamela and Fermi. Concentrating on supersymmetric models, we consider the effect of these nonstandard cosmologies in selecting a preferred mass scale for the lightest supersymmetric particle as a dark matter candidate, and the consequent impact on the interpretation of new physics discovered or excluded at the LHC. Finally, we examine a rather predictive model, the G2-MSSM, investigating some of the standard assumptions usually implemented in the solution of the Boltzmann equation for the dark matter component, including coannihilations. We question the hypothesis that kinetic equilibrium holds along the whole phase of dark matter generation, and the validity of the factorization usually implemented to rewrite the system of a coupled Boltzmann equation for each coannihilating species as a single equation for the sum of all the number densities. As a byproduct we develop here a formalism to compute the kinetic decoupling temperature in case of coannihilating particles, which can also be applied to other particle physics frameworks, and also to standard thermal relics within a standard cosmology.
Diurnal modulation signal from dissipative hidden sector dark matter

Directory of Open Access Journals (Sweden)

R. Foot

2015-09-01

Full Text Available We consider a simple generic dissipative dark matter model: a hidden sector featuring two dark matter particles charged under an unbroken U(1′ interaction. Previous work has shown that such a model has the potential to explain dark matter phenomena on both large and small scales. In this framework, the dark matter halo in spiral galaxies features nontrivial dynamics, with the halo energy loss due to dissipative interactions balanced by a heat source. Ordinary supernovae can potentially supply this heat provided kinetic mixing interaction exists with strength ϵ∼10−9. This type of kinetically mixed dark matter can be probed in direct detection experiments. Importantly, this self-interacting dark matter can be captured within the Earth and shield a dark matter detector from the halo wind, giving rise to a diurnal modulation effect. We estimate the size of this effect for detectors located in the Southern hemisphere, and find that the modulation is large (≳10% for a wide range of parameters.
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 Boosted Dark Matter at direct detection experiments

OpenAIRE

Giudice, Gian F.; Kim, Doojin; Park, Jong-Chul; Shin, Seodong

2018-01-01

We explore a novel class of multi-particle dark sectors, called Inelastic Boosted Dark Matter (iBDM). These models are constructed by combining properties of particles that scatter off matter by making transitions to heavier states (Inelastic Dark Matter) with properties of particles that are produced with a large Lorentz boost in annihilation processes in the galactic halo (Boosted Dark Matter). This combination leads to new signals that can be observed at ordinary direct detection experimen...
Determining the dark matter mass with DeepCore

Energy Technology Data Exchange (ETDEWEB)

Das, Chitta R. [Centro de Física Teórica de Partículas, Instituto Superior Técnico (CFTP), Universidade Tćnica de Lisboa, Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal); Mena, Olga [Instituto de Física Corpuscular (IFIC), CSIC-Universitat de València, Apartado de Correos 22085, E-46071 Valencia (Spain); Palomares-Ruiz, Sergio, E-mail: sergio.palomares.ruiz@ist.utl.pt [Centro de Física Teórica de Partículas, Instituto Superior Técnico (CFTP), Universidade Tćnica de Lisboa, Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal); Instituto de Física Corpuscular (IFIC), CSIC-Universitat de València, Apartado de Correos 22085, E-46071 Valencia (Spain); Pascoli, Silvia [IPPP, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom)

2013-10-01

Cosmological and astrophysical observations provide increasing evidence of the existence of dark matter in our Universe. Dark matter particles with a mass above a few GeV can be captured by the Sun, accumulate in the core, annihilate, and produce high energy neutrinos either directly or by subsequent decays of Standard Model particles. We investigate the prospects for indirect dark matter detection in the IceCube/DeepCore neutrino telescope and its capabilities to determine the dark matter mass.
Search for dark matter in vector boson + MET final states with the CMS detector

Energy Technology Data Exchange (ETDEWEB)

Kutzner, Viktor; Acaroglu, Harun; Bispinck, Fabian; Brodski, Michael; Hebbeker, Thomas; Hoepfner, Kerstin; Materok, Marcel; Meyer, Arnd; Noll, Dennis; Padeken, Klaas [III. Physikalisches Institut A, RWTH Aachen (Germany)

2016-07-01

The origin of dark matter is one of the most important and challenging questions in high energy physics today. A search for dark matter is performed in the data collected by the CMS experiment in run I and run II. In this search, the dark matter particle recoils against a leptonically decaying W or Z boson, leading to the distinct signatures of either one or two isolated leptons and missing transverse energy. Both channels allow to study various specific features of dark matter production. Different aspects of the background determination and its systematic uncertainties are presented. Dark matter production can be described either by an effective field approach or by fully describing the mediator with a simplified model. Both options are discussed.
Self-interacting spin-2 dark matter

Science.gov (United States)

Chu, Xiaoyong; Garcia-Cely, Camilo

2017-11-01

Recent developments in bigravity allow one to construct consistent theories of interacting spin-2 particles that are free of ghosts. In this framework, we propose an elementary spin-2 dark matter candidate with a mass well below the TeV scale. We show that, in a certain regime where the interactions induced by the spin-2 fields do not lead to large departures from the predictions of general relativity, such a light dark matter particle typically self-interacts and undergoes self-annihilations via 3-to-2 processes. We discuss its production mechanisms and also identify the regions of the parameter space where self-interactions can alleviate the discrepancies at small scales between the predictions of the collisionless dark matter paradigm and cosmological N-body simulations.
Thermal relic dark matter beyond the unitarity limit

Energy Technology Data Exchange (ETDEWEB)

Harigaya, Keisuke [Berkeley Center for Theoretical Physics, Department of Physics, University of California,Berkeley, CA 94720 (United States); Theoretical Physics Group, Lawrence Berkeley National Laboratory,Berkeley, CA 94720 (United States); Ibe, Masahiro [Kavli IPMU (WPI), UTIAS, The University of Tokyo,Kashiwa, Chiba 277-8583 (Japan); ICRR, The University of Tokyo,Kashiwa, Chiba 277-8582 (Japan); Kaneta, Kunio [Center for Theoretical Physics of the Universe, Institute for Basic Science (IBS),Daejeon 34051 (Korea, Republic of); Nakano, Wakutaka; Suzuki, Motoo [Kavli IPMU (WPI), UTIAS, The University of Tokyo,Kashiwa, Chiba 277-8583 (Japan); ICRR, The University of Tokyo,Kashiwa, Chiba 277-8582 (Japan)

2016-08-25

We discuss a simple model of thermal relic dark matter whose mass can be much larger than the so-called unitarity limit on the mass of point-like particle dark matter. The model consists of new strong dynamics with one flavor of fermions in the fundamental representation which is much heavier than the dynamical scale of the new strong dynamics. Dark matter is identified with the lightest baryonic hadron of the new dynamics. The baryonic hadrons annihilate into the mesonic hadrons of the new strong dynamics when they have large radii. Resultantly, thermal relic dark matter with a mass in the PeV range is possible.
Multi-component fermionic dark matter and IceCube PeV scale neutrinos in left-right model with gauge unification

Science.gov (United States)

Borah, Debasish; Dasgupta, Arnab; Dey, Ujjal Kumar; Patra, Sudhanwa; Tomar, Gaurav

2017-09-01

We consider a simple extension of the minimal left-right symmetric model (LRSM) in order to explain the PeV neutrino events seen at the IceCube experiment from a heavy decaying dark matter. The dark matter sector is composed of two fermions: one at PeV scale and the other at TeV scale such that the heavier one can decay into the lighter one and two neutrinos. The gauge annihilation cross sections of PeV dark matter are not large enough to generate its relic abundance within the observed limit. We include a pair of real scalar triplets Ω L,R which can bring the thermally overproduced PeV dark matter abundance into the observed range through late time decay and consequent entropy release thereby providing a consistent way to obtain the correct relic abundance without violating the unitarity bound on dark matter mass. Another scalar field, a bitriplet under left-right gauge group is added to assist the heavier dark matter decay. The presence of an approximate global U(1) X symmetry can naturally explain the origin of tiny couplings required for long-lived nature of these decaying particles. We also show, how such an extended LRSM can be incorporated within a non-supersymmetric SO(10) model where the gauge coupling unification at a very high scale naturally accommodate a PeV scale intermediate symmetry, required to explain the PeV events at IceCube.
Detection of magnetized quark-nuggets, a candidate for dark matter.

Science.gov (United States)

VanDevender, J Pace; VanDevender, Aaron P; Sloan, T; Swaim, Criss; Wilson, Peter; Schmitt, Robert G; Zakirov, Rinat; Blum, Josh; Cross, James L; McGinley, Niall

2017-08-18

Quark nuggets are theoretical objects composed of approximately equal numbers of up, down, and strange quarks and are also called strangelets and nuclearites. They have been proposed as a candidate for dark matter, which constitutes ~85% of the universe's mass and which has been a mystery for decades. Previous efforts to detect quark nuggets assumed that the nuclear-density core interacts directly with the surrounding matter so the stopping power is minimal. Tatsumi found that quark nuggets could well exist as a ferromagnetic liquid with a ~10 12 -T magnetic field. We find that the magnetic field produces a magnetopause with surrounding plasma, as the earth's magnetic field produces a magnetopause with the solar wind, and substantially increases their energy deposition rate in matter. We use the magnetopause model to compute the energy deposition as a function of quark-nugget mass and to analyze testing the quark-nugget hypothesis for dark matter by observations in air, water, and land. We conclude the water option is most promising.

Vector dark matter annihilation with internal bremsstrahlung

Energy Technology Data Exchange (ETDEWEB)

Bambhaniya, Gulab, E-mail: gulab@prl.res.in [Physical Research Laboratory, Ahmedabad 380009 (India); Kumar, Jason, E-mail: jkumar@hawaii.edu [Department of Physics & Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Marfatia, Danny, E-mail: dmarf8@hawaii.edu [Department of Physics & Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Nayak, Alekha C., E-mail: acnayak@iitk.ac.in [Department of Physics, Indian Institute of Technology, Kanpur 208016 (India); Tomar, Gaurav, E-mail: tomar@prl.res.in [Physical Research Laboratory, Ahmedabad 380009 (India)

2017-03-10

We consider scenarios in which the annihilation of self-conjugate spin-1 dark matter to a Standard Model fermion–antifermion final state is chirality suppressed, but where this suppression can be lifted by the emission of an additional photon via internal bremsstrahlung. We find that this scenario can only arise if the initial dark matter state is polarized, which can occur in the context of self-interacting dark matter. In particular, this is possible if the dark matter pair forms a bound state that decays to its ground state before the constituents annihilate. We show that the shape of the resulting photon spectrum is the same as for self-conjugate spin-0 and spin-1/2 dark matter, but the normalization is less heavily suppressed in the limit of heavy mediators.
Planckian Interacting Massive Particles as Dark Matter.

Science.gov (United States)

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

2016-03-11

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

International Nuclear Information System (INIS)

Fornengo, N.; Regis, M.; Lineros, R.; Taoso, M.

2012-01-01

We present a detailed analysis of the radio synchrotron emission induced by WIMP dark matter annihilations and decays in extragalactic halos. We compute intensity, angular correlation, and source counts and discuss the impact on the expected signals of dark matter clustering, as well as of other astrophysical uncertainties as magnetic fields and spatial diffusion. Bounds on dark matter microscopic properties are then derived, and, depending on the specific set of assumptions, they are competitive with constraints from other indirect dark matter searches. At GHz frequencies, dark matter sources can become a significant fraction of the total number of sources with brightness below the microJansky level. We show that, at this level of fluxes (which are within the reach of the next-generation radio surveys), properties of the faint edge of differential source counts, as well as angular correlation data, can become an important probe for WIMPs
Cosmological radio emission induced by WIMP Dark Matter

Energy Technology Data Exchange (ETDEWEB)

Fornengo, N.; Regis, M. [Dipartimento di Fisica Teorica, Università di Torino, via P. Giuria 1, I-10125 Torino (Italy); Lineros, R.; Taoso, M., E-mail: fornengo@to.infn.it, E-mail: rlineros@ific.uv.es, E-mail: regis@to.infn.it, E-mail: mtaoso@phas.ubc.ca [IFIC, CSIC-Universidad de Valencia, Ed. Institutos, Apdo. Correos 22085, E-46071 Valencia (Spain)

2012-03-01

We present a detailed analysis of the radio synchrotron emission induced by WIMP dark matter annihilations and decays in extragalactic halos. We compute intensity, angular correlation, and source counts and discuss the impact on the expected signals of dark matter clustering, as well as of other astrophysical uncertainties as magnetic fields and spatial diffusion. Bounds on dark matter microscopic properties are then derived, and, depending on the specific set of assumptions, they are competitive with constraints from other indirect dark matter searches. At GHz frequencies, dark matter sources can become a significant fraction of the total number of sources with brightness below the microJansky level. We show that, at this level of fluxes (which are within the reach of the next-generation radio surveys), properties of the faint edge of differential source counts, as well as angular correlation data, can become an important probe for WIMPs.
Dark matter physics in neutrino specific two Higgs doublet model

Energy Technology Data Exchange (ETDEWEB)

Baek, Seungwon; Nomura, Takaaki [School of Physics, Korea Institute for Advanced Study,85 Hoegiro, Dongdaemun-gu, Seoul 02455 (Korea, Republic of)

2017-03-10

Although the seesaw mechanism is a natural explanation for the small neutrino masses, there are cases when the Majorana mass terms for the right-handed neutrinos are not allowed due to symmetry. In that case, if neutrino-specific Higgs doublet is introduced, neutrinos become Dirac particles and their small masses can be explained by its small VEV. We show that the same symmetry, which we assume a global U(1){sub X}, can also be used to explain the stability of dark matter. In our model, a new singlet scalar breaks the global symmetry spontaneously down to a discrete Z{sub 2} symmetry. The dark matter particle, lightest Z{sub 2}-odd fermion, is stabilized. We discuss the phenomenology of dark matter: relic density, direct detection, and indirect detection. We find that the relic density can be explained by a novel Goldstone boson channel or by resonance channel. In the most region of parameter space considered, the direct detections is suppressed well below the current experimental bound. Our model can be further tested in indirect detection experiments such as FermiLAT gamma ray searches or neutrinoless double beta decay experiments.
Dynamics of quintessence models of dark energy with exponential coupling to dark matter

International Nuclear Information System (INIS)

Gonzalez, Tame; Leon, Genly; Quiros, Israel

2006-01-01

We explore quintessence models of dark energy which exhibit non-minimal coupling between the dark matter and dark energy components of the cosmic fluid. The kind of coupling chosen is inspired by scalar-tensor theories of gravity. We impose a suitable dynamics of the expansion allowing us to derive exact Friedmann-Robertson-Walker solutions once the coupling function is given as input. Self-interaction potentials of single and double exponential types emerge as a result of our choice of the coupling function. The stability and existence of the solutions are discussed in some detail. Although, in general, models with appropriate interaction between the components of the cosmic mixture are useful for handling the coincidence problem, in the present study this problem cannot be avoided due to the choice of solution generating ansatz
Two component WIMP-FImP dark matter model with singlet fermion, scalar and pseudo scalar

Energy Technology Data Exchange (ETDEWEB)

Dutta Banik, Amit; Pandey, Madhurima; Majumdar, Debasish [Saha Institute of Nuclear Physics, HBNI, Astroparticle Physics and Cosmology Division, Kolkata (India); Biswas, Anirban [Harish Chandra Research Institute, Allahabad (India)

2017-10-15

We explore a two component dark matter model with a fermion and a scalar. In this scenario the Standard Model (SM) is extended by a fermion, a scalar and an additional pseudo scalar. The fermionic component is assumed to have a global U(1){sub DM} and interacts with the pseudo scalar via Yukawa interaction while a Z{sub 2} symmetry is imposed on the other component - the scalar. These ensure the stability of both dark matter components. Although the Lagrangian of the present model is CP conserving, the CP symmetry breaks spontaneously when the pseudo scalar acquires a vacuum expectation value (VEV). The scalar component of the dark matter in the present model also develops a VEV on spontaneous breaking of the Z{sub 2} symmetry. Thus the various interactions of the dark sector and the SM sector occur through the mixing of the SM like Higgs boson, the pseudo scalar Higgs like boson and the singlet scalar boson. We show that the observed gamma ray excess from the Galactic Centre as well as the 3.55 keV X-ray line from Perseus, Andromeda etc. can be simultaneously explained in the present two component dark matter model and the dark matter self interaction is found to be an order of magnitude smaller than the upper limit estimated from the observational results. (orig.)
The effective field theory of dark matter direct detection

Energy Technology Data Exchange (ETDEWEB)

Fitzpatrick, A. Liam; Haxton, Wick; Katz, Emanuel; Lubbers, Nicholas; Xu, Yiming

2013-02-01

We extend and explore the general non-relativistic effective theory of dark matter (DM) direct detection. We describe the basic non-relativistic building blocks of operators and discuss their symmetry properties, writing down all Galilean-invariant operators up to quadratic order in momentum transfer arising from exchange of particles of spin 1 or less. Any DM particle theory can be translated into the coefficients of an effective operator and any effective operator can be simply related to most general description of the nuclear response. We find several operators which lead to novel nuclear responses. These responses differ significantly from the standard minimal WIMP cases in their relative coupling strengths to various elements, changing how the results from different experiments should be compared against each other. Response functions are evaluated for common DM targets — F, Na, Ge, I, and Xe — using standard shell model techniques. We point out that each of the nuclear responses is familiar from past studies of semi-leptonic electroweak interactions, and thus potentially testable in weak interaction studies. We provide tables of the full set of required matrix elements at finite momentum transfer for a range of common elements, making a careful and fully model-independent analysis possible. Finally, we discuss embedding non-relativistic effective theory operators into UV models of dark matter.
Characteristic size and mass of galaxies in the Bose–Einstein condensate dark matter model

Directory of Open Access Journals (Sweden)

Jae-Weon Lee

2016-05-01

Full Text Available We study the characteristic length scale of galactic halos in the Bose–Einstein condensate (or scalar field dark matter model. Considering the evolution of the density perturbation we show that the average background matter density determines the quantum Jeans mass and hence the spatial size of galaxies at a given epoch. In this model the minimum size of galaxies increases while the minimum mass of the galaxies decreases as the universe expands. The observed values of the mass and the size of the dwarf galaxies are successfully reproduced with the dark matter particle mass m≃5×10−22 eV. The minimum size is about 6×10−3m/Hλc and the typical rotation velocity of the dwarf galaxies is O(H/m c, where H is the Hubble parameter and λc is the Compton wave length of the particle. We also suggest that ultra compact dwarf galaxies are the remnants of the dwarf galaxies formed in the early universe.
“Dark matter searches” with a focus on new techniques (Mono-X)

CERN Document Server

Pearce, JD; The ATLAS collaboration

2013-01-01

The quest to understand the nature of Dark Matter has never been so exciting. Vast improvements in direct detection sensitivity combined with tantalizing hints from astrophysical data have lead some to dub the 2010's as the "Dark Matter Decade". Today collider based experiments, such as ATLAS and CMS, offer a new vantage point in the search for non-gravitational dark matter interactions. If Dark Matter interacts weakly with the Standard Model it can be produced at the LHC and identified via the initial state radiation (ISR) of the incoming partons. The signature left in the detector is that of the ISR particle (jet, photon, Z or W) recoiling off of the invisible Dark Matter particles, which is manifest as a large momentum imbalance. Such collider based searches can be interpreted in terms of a higher dimensional effective field theory to place limits in the same parameter space as the direct detection and space-based experiments.
A 750 GeV portal: LHC phenomenology and dark matter candidates

Energy Technology Data Exchange (ETDEWEB)

D’Eramo, Francesco [Department of Physics, University of California Santa Cruz, 1156 High St., Santa Cruz, CA 95064 (United States); Santa Cruz Institute for Particle Physics, 1156 High St., Santa Cruz, CA 95064 (United States); Vries, Jordy de [Nikhef, Theory Group, Science Park 105, 1098 XG, Amsterdam (Netherlands); Panci, Paolo [Institut d’Astrophysique de Paris, UMR 7095 CNRS, Université Pierre et Marie Curie, 98 bis Boulevard Arago, Paris 75014 (France)

2016-05-16

We study the effective field theory obtained by extending the Standard Model field content with two singlets: a 750 GeV (pseudo-)scalar and a stable fermion. Accounting for collider productions initiated by both gluon and photon fusion, we investigate where the theory is consistent with both the LHC diphoton excess and bounds from Run 1. We analyze dark matter phenomenology in such regions, including relic density constraints as well as collider, direct, and indirect bounds. Scalar portal dark matter models are very close to limits from direct detection and mono-jet searches if gluon fusion dominates, and not constrained at all otherwise. Pseudo-scalar models are challenged by photon line limits and mono-jet searches in most of the parameter space.
Towards understanding thermal history of the Universe through direct and indirect detection of dark matter

Energy Technology Data Exchange (ETDEWEB)

Roszkowski, Leszek; Trojanowski, Sebastian [National Centre for Nuclear Research, Hoża 69, 00-681 Warsaw (Poland); Turzyński, Krzysztof, E-mail: leszek.roszkowski@ncbj.gov.pl, E-mail: sebastian.trojanowski@uci.edu, E-mail: Krzysztof-Jan.Turzynski@fuw.edu.pl [Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw (Poland)

2017-10-01

We examine the question to what extent prospective detection of dark matter by direct and indirect- detection experiments could shed light on what fraction of dark matter was generated thermally via the freeze-out process in the early Universe. By simulating putative signals that could be seen in the near future and using them to reconstruct WIMP dark matter properties, we show that, in a model- independent approach this could only be achieved in a thin sliver of the parameter space. However, with additional theoretical input the hypothesis about the thermal freeze-out as the dominant mechanism for generating dark matter can potentially be verified. We illustrate this with two examples: an effective field theory of dark matter with a vector messenger and a higgsino or wino dark matter within the MSSM.
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
Imperfect Dark Matter

Energy Technology Data Exchange (ETDEWEB)

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

2015-06-01

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

International Nuclear Information System (INIS)

Mirzagholi, Leila; Vikman, Alexander

2015-01-01

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

Science.gov (United States)

Mirzagholi, Leila; Vikman, Alexander

2015-06-01

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

International Nuclear Information System (INIS)

Cai, Yi; Spray, Andrew

2017-01-01

Semi-annihilation is a generic feature of dark matter theories stabilized by symmetries larger than a ℤ 2 . It contributes to thermal freeze out, but is irrelevant for direct and collider searches. This allows semi-annihilating dark matter to avoid those limits in a natural way. We use an effective operator approach to make the first model-independent study of the associated phenomenology. We enumerate all possible operators that contribute to 2→2 semi-annihilation up to dimension 6, plus leading terms at dimension 7. We find that when the only light states charged under the dark symmetry are dark matter, the model space is highly constrained. Only fifteen operators exist, and just two for single-component dark sectors. If there can be additional light, unstable “dark partner” states the possible phenomenology greatly increases, at the cost of additional model dependence in the dark partner decay modes. We also derive the irreducible constraints on models with single-component dark matter from cosmic ray searches and astrophysical observations. We find that for semi-annihilation to electrons and light quarks, the thermal relic cross sections can be excluded for dark matter masses up to 100 GeV. However, significant model space for semi-annihilating dark matter remains.
Early-matter-like dark energy and the cosmic microwave background

International Nuclear Information System (INIS)

Aurich, R.; Lustig, S.

2016-01-01

Early-matter-like dark energy is defined as a dark energy component whose equation of state approaches that of cold dark matter (CDM) at early times. Such a component is an ingredient of unified dark matter (UDM) models, which unify the cold dark matter and the cosmological constant of the ΛCDM concordance model into a single dark fluid. Power series expansions in conformal time of the perturbations of the various components for a model with early-matter-like dark energy are provided. They allow the calculation of the cosmic microwave background (CMB) anisotropy from the primordial initial values of the perturbations. For a phenomenological UDM model, which agrees with the observations of the local Universe, the CMB anisotropy is computed and compared with the CMB data. It is found that a match to the CMB observations is possible if the so-called effective velocity of sound c eff of the early-matter-like dark energy component is very close to zero. The modifications on the CMB temperature and polarization power spectra caused by varying the effective velocity of sound are studied
Properties of galactic dark matter: Constraints from astronomical observations

International Nuclear Information System (INIS)

Burch, B.; Cowsik, R.

2013-01-01

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

Science.gov (United States)

He, Jian-Hua; Hawken, Adam J; Li, Baojiu; Guzzo, Luigi

2015-08-14

We introduce the idea of an effective dark matter halo catalog in f(R) gravity, which is built using the effective density field. Using a suite of high resolution N-body simulations, we find that the dynamical properties of halos, such as the distribution of density, velocity dispersion, specific angular momentum and spin, in the effective catalog of f(R) gravity closely mimic those in the cold dark matter model with a cosmological constant (ΛCDM). Thus, when using effective halos, an f(R) model can be viewed as a ΛCDM model. This effective catalog therefore provides a convenient way for studying the baryonic physics, the galaxy halo occupation distribution and even semianalytical galaxy formation in f(R) cosmologies.

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