Search results for "Dark matter"

Dark radiation and interacting scenarios

2013

An extra dark radiation component can be present in the universe in the form of sterile neutrinos, axions or other very light degrees of freedom which may interact with the dark matter sector. We derive here the cosmological constraints on the dark radiation abundance, on its effective velocity and on its viscosity parameter from current data in dark radiation-dark matter coupled models. The cosmological bounds on the number of extra dark radiation species do not change significantly when considering interacting schemes. We also find that the constraints on the dark radiation effective velocity are degraded by an order of magnitude while the errors on the viscosity parameter are a factor of…

Updated CMB and x- and gamma-ray constraints on Majoron dark matter

2013

The Majoron provides an attractive dark matter candidate, directly associated with the mechanism responsible for spontaneous neutrino mass generation within the standard model SU(3)(c) circle times SU(2)(L) circle times U(1)(Y) framework. Here we update the cosmological and astrophysical constraints on Majoron dark matter coming from the cosmic microwave background and a variety of x- and gamma-ray observations.

First microscopic evaluation of spin-dependent WIMP-nucleus scattering off 183W

2021

We perform the first consistent calculation of elastic-scattering and inelastic-scattering structure functions for spin-dependent WIMP-nucleus scattering for 183W in a microscopic nuclear-theory framework. The nuclear structure calculations are performed in the microscopic interacting boson-fermion model (IBFM-2). Our results show that while 183W is very insensitive to spin-dependent elastic scattering, the structure function for inelastic scattering is quite sizable at small momentum transfers. Moreover, to our knowledge 183W provides the first studied case where inelastic scattering can compete with elastic scattering as the primary detection signal. peerReviewed

Response of the XENON100 dark matter detector to nuclear recoils

2013

Results from the nuclear recoil calibration of the XENON100 dark matter detector installed underground at the Laboratori Nazionali del Gran Sasso (LNGS), Italy are presented. Data from measurements with an external 241AmBe neutron source are compared with a detailed Monte Carlo simulation which is used to extract the energy dependent charge-yield Qy and relative scintillation efficiency Leff. A very good level of absolute spectral matching is achieved in both observable signal channels - scintillation S1 and ionization S2 - along with agreement in the 2-dimensional particle discrimination space. The results confirm the validity of the derived signal acceptance in earlier reported dark matte…

Sensitivity of a tonne-scale NEXT detector for neutrinoless double-beta decay searches

2021

The NEXT collaboration: et al.

Tachyonic production of dark relics : a non-perturbative quantum study

2023

We study production of dark relics during reheating after the end of inflation in a system consisting of a non-minimally coupled spectator scalar field and the inflaton. We derive a set of renormalized quantum transport equations for the one-point function and the two-point function of the spectator field and solve them numerically. We find that our system can embody both tachyonic and parametric instabilities. The former is an expected result due to the non-minimal coupling, but the latter displays new features driven by a novel interplay of the two-point function with the Ricci scalar. We find that when the parametric instability driven by the two-point function takes place, it dominates …

The search for dark matter gauge bosons with the Mainz Microtron

2011

Abstract A pilot experiment in the search for light gauge bosons at the spectrometer setup of the A1 collaboration at MAMI is presented. Light gauge bosons arise naturally in a wide range of theoretical approaches beyond the standard model and are in accordance with several pieces of experimental evidence not yet understood in the standard model. A first test measurement at MAMI showed that existing limits on the coupling of such a light gauge boson can be improved by nearly an order of magnitude by fixed target experiments at existing electron accelerators.

Erratum: Study of the electromagnetic background in the XENON100 experiment [Phys. Rev. D 83, 082001 (2011)]

2012

Cosmological promising parameters of stau in the minimal supersymmetric standard model

2009

We find that we can account for the possible descrepancy of the primordial abundance of 7 Li between the observation and the prediction of the Big-Bang Nucleosynthesis in a scenario of the Big-Bang Nucleosynthesis with the Minimal Supersymmetric Standard Model. This scenario is consistent with a stau-neutralino coannihilation scenario to explain the relic abundance of dark matter. The solution to the discrepancy is given by taking the values of parameters; the mass of the neutralino as 300 GeV and the mass difference between the stau and the neutralino as (100 – 120) MeV.

Gamow–Teller beta decays of the odd-mass neighbors of the solar-neutrino detector 127I

2002

Abstract Calculations of the energy spectra and the log ft values of Gamow–Teller beta transitions of neutron-odd and proton-odd nuclei close to the solar-neutrino detector 127I are performed using the microscopic quasiparticle–phonon model. The information obtained from the beta transition strengths is valuable in solar-neutrino detection and dark matter search both in present and future large-scale experiments. Realistic interactions within a realistic single-particle valence space were used in the calculations. The overall correspondence in terms of the excitation spectra and the log ft values between theory and experiments can be regarded as quite good when considering the completely mi…