scholarly journals Understanding caustic crossings in giant arcs: Characteristic scales, event rates, and constraints on compact dark matter

2018 ◽  
Vol 97 (2) ◽  
Author(s):  
Masamune Oguri ◽  
Jose M. Diego ◽  
Nick Kaiser ◽  
Patrick L. Kelly ◽  
Tom Broadhurst
Keyword(s):  
Dark Matter ◽  
Event Rates ◽  
Characteristic Scales

scholarly journals Realistic Calculations for Cold Dark Matter Detection Rates

2020 ◽  
Vol 13 ◽  
pp. 283
Author(s):  
T. S. Kosmas ◽  
M. Kortelainen ◽  
J. Suhonen ◽  
J. Toivanen
Keyword(s):  
Dark Matter ◽  
Nuclear Structure ◽  
Large Scale ◽  
Cold Dark Matter ◽  
Scattering Problem ◽  
Realistic Model ◽  
Supersymmetric Particle ◽  
Detection Rates ◽  
Model Spaces ◽  
Event Rates

The scattering of the cold dark matter (CDM) candidate LSP (Lightest Supersymmetric Particle) off nuclei is investigated. We focus on the nuclear-structure aspects of the LSP-nucleus scattering problem and computed the associated event rates as well as the annual modulation signals for the 23Na, 71Ga, 73Ge and 127I CDM detectors by using the nuclear shell model in realistic model spaces and exploiting microscopic effective two-body interactions. Large-scale computations had to be performed in order to achieve convergence of the results. The relevance of the spin-dependent and coherent channels for the event rates is discussed, from both the nuclear structure and the SUSY-model viewpoints.

scholarly journals Deformed shell model study of event rates for WIMP-73Ge scattering

2017 ◽  
Vol 32 (38) ◽  
pp. 1750210 ◽  
Author(s):  
R. Sahu ◽  
V. K. B. Kota
Keyword(s):  
Dark Matter ◽  
Inelastic Scattering ◽  
Shell Model ◽  
Energy Levels ◽  
Supersymmetric Model ◽  
Dark Matter Candidate ◽  
Detection Rates ◽  
Hartree Fock ◽  
Model Study ◽  
Event Rates

The event detection rates for the Weakly Interacting Massive Particles (WIMP) (a dark matter candidate) are calculated with [Formula: see text]Ge as the detector. The calculations are performed within the deformed shell model (DSM) based on Hartree–Fock states. First, the energy levels and magnetic moment for the ground state and two low-lying positive parity states for this nucleus are calculated and compared with experiment. The agreement is quite satisfactory. Then the nuclear wave functions are used to investigate the elastic and inelastic scattering of WIMP from [Formula: see text]Ge; inelastic scattering, especially for the [Formula: see text] transition, is studied for the first time. The nuclear structure factors which are independent of supersymmetric model are also calculated as a function of WIMP mass. The event rates are calculated for a given set of nucleonic current parameters. The calculation shows that [Formula: see text]Ge is a good detector for detecting dark matter.

WIMP event rates in directional experiments: The diurnal variation signature

Open Physics ◽  
2011 ◽  
Vol 9 (3) ◽  
Author(s):  
John Vergados ◽  
Charalampos Moustakidis
Keyword(s):  
Dark Matter ◽  
Diurnal Variation ◽  
Cold Dark Matter ◽  
Vacuum Energy ◽  
Direct Detection ◽  
Weakly Interacting Massive Particles ◽  
The Earth ◽  
Event Rates ◽  
Matter Detection ◽  
Direct Dark Matter

AbstractThe recent WMAP data have confirmed that exotic dark matter together with the vacuum energy (cosmological constant) dominate in the flat Universe. Modern particle theories provide viable cold dark matter candidates with masses in the GeV-TeV region. All such candidates will be called WIMPs (Weakly Interacting Massive Particles). The nature of dark matter can only be unraveled by its direct detection in the laboratory. In this work we present some theoretical elements relevant to the direct dark matter detection experiments, paying particular attention to directional experiments, i.e. experiments in which not only the energy but the direction of the recoiling nucleus is observed. Since the direction of observation is fixed with respect to the Earth, while the Earth is rotating around its axis, in a directional experiment the angle between the direction of observation and the Sun’s direction of motion will change during the day. So, since the event rates sensitively depend on this angle, the observed signal in such experiments will exhibit very interesting and characteristic periodic diurnal variation.

scholarly journals Direct detection of mirror matter in Twin Higgs models

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Zackaria Chacko ◽  
David Curtin ◽  
Michael Geller ◽  
Yuhsin Tsai
Keyword(s):  
Dark Matter ◽  
Cooling Rate ◽  
Direct Detection ◽  
The Earth ◽  
Electron Recoil ◽  
The Galaxy ◽  
The Masses ◽  
Event Rates ◽  
Modest Effect ◽  
Mirror Matter

Abstract We explore the possibility of discovering the mirror baryons and electrons of the Mirror Twin Higgs model in direct detection experiments, in a scenario in which these particles constitute a subcomponent of the observed DM. We consider a framework in which the mirror fermions are sub-nano-charged, as a consequence of kinetic mixing between the photon and its mirror counterpart. We consider both nuclear recoil and electron recoil experiments. The event rates depend on the fraction of mirror DM that is ionized, and also on its distribution in the galaxy. Since mirror DM is dissipative, at the location of the Earth it may be in the form of a halo or may have collapsed into a disk, depending on the cooling rate. For a given mirror DM abundance we determine the expected event rates in direct detection experiments for the limiting cases of an ionized halo, an ionized disk, an atomic halo and an atomic disk. We find that by taking advantage of the complementarity of the different experiments, it may be possible to establish not just the multi-component nature of mirror dark matter, but also its distribution in the galaxy. In addition, a study of the recoil energies may be able to determine the masses and charges of the constituents of the mirror sector. By showing that the mass and charge of mirror helium are integer multiples of those of mirror hydrogen, these experiments have the potential to distinguish the mirror nature of the theory. We also carefully consider mirror plasma screening effects, showing that the capture of mirror dark matter particles in the Earth has at most a modest effect on direct detection signals.

Effects ofCPviolation on event rates in the direct detection of dark matter

1999 ◽  
Vol 60 (6) ◽  
Author(s):  
Utpal Chattopadhyay ◽  
Tarek Ibrahim ◽  
Pran Nath
Keyword(s):  
Dark Matter ◽  
Direct Detection ◽  
Event Rates

scholarly journals Some Issues Related to the Direct Detection of Dark Matter

2021 ◽  
Vol 12 ◽  
pp. 1
Author(s):  
J. D. Vergados
Keyword(s):  
Dark Matter ◽  
Direct Detection ◽  
Branching Ratios ◽  
The Novel ◽  
Modulation Effect ◽  
The Earth ◽  
Nuclear Levels ◽  
Event Rates ◽  
Theoretical Issues

In this paper we review the theoretical issues involved in the direct detectionof supersymmetric (SUSY) dark matter. After a brief discussion of the allowedSYSY parameter space we focus on the determination of the traditional neutralinodetection rates, in experiments which measure the energy of the recoiling nucleus,such as the coherent and spin induced rates and the dependence of the rate onthe motion of the Earth (modulation effect). Then we examine the novel featuresappearing in directional experiments, which detect the recoiling nucleus in a givendirection. Next we estimate the branching ratios for transitions to accessibleexcited nuclear levels. Finally we estimate the event rates leading to the atomionization and subsequent detection of the outgoing electrons.

New detectors for neutrinos and dark matter

1994 ◽  
Vol 346 (1678) ◽  
pp. 111-120 ◽  
Keyword(s):  
Dark Matter ◽  
New Technology ◽  
Scale Up ◽  
Coherent Scattering ◽  
Mass Range ◽  
Coherent Detection ◽  
Partial Coherence ◽  
Neutrino Scattering ◽  
Nuclear Recoils ◽  
Event Rates

Hypothetical particles in the GeV mass range and with typical Galactic velocity 10 -3 c would have MeV range momentum, similar to that of solar or supernova neutrinos. Thus elastic collisions with target nuclei would in each case give keV range nuclear recoils. There would also be a cross-section enhancement arising from full or partial coherence over the constituent nucleons. Detectors for these low energy nuclear recoils can be based on ionization, scintillation or low temperature phonon techniques. Radioactive background in the detector materials provides the main obstacle to detecting low event rates and significant effort is now being made to develop more advanced ideas which will distinguish the nuclear recoil events from background. Examples are simultaneous measurement of ionization and phonon energy in semiconductors, and photon timing or wavelength filtering in scintillators. Several groups are actively constructing underground dark matter detectors with targets in the 1-100 kg range. Solar and supernova neutrino detectors based on coherent scattering would have much lower target masses (by factors 20—100) than conventional detectors but would still require a substantial scale-up of these new techniques. Experiments with reactor neutrinos will provide a first step in verifying coherent neutrino scattering. Further scale-up to allow extra-galactic neutrino detection is feasible in principle and a possible challenge for the 21st century. Macroscopic coherent detection of the relic neutrino background may also become possible with foreseeable new technology.

Searching for dark matter-spin-dependent event rates

2014 ◽  
Vol 29 (19) ◽  
pp. 1443003 ◽  
Author(s):  
P. C. Divari ◽  
J. D. Vergados
Keyword(s):  
Dark Matter ◽  
Long Range ◽  
Cross Section ◽  
Target Nucleus ◽  
Spin Structure ◽  
Structure Functions ◽  
Effective Coupling ◽  
Spin Structure Functions ◽  
Event Rates ◽  
Reduction Factors

We study the spin-dependent WIMP scattering off nuclei for a variety of targets of experimental interest. In evaluating the spin structure functions, we have included the recently proposed leading long-range two-body currents in the most important isovector contribution. We show, however, that such effects are essentially independent of the target nucleus and, as a result, they can be treated as a mere renormalization of the effective nucleon cross-section or, equivalently, of the corresponding effective coupling, with reduction factors around 25%. Using these effects in the spin structure functions, we compute the relevant event rates due to the spin for various targets of experimental interest.

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