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Letters in High Energy Physics
Number of Followers: 0  Open Access journalISSN (Print) 2632-2714 Published by Andromeda  [1 journal]
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- A Radio-Frequency Search for WIMPs in RXC J0225.1-2928
Authors: Michael Sarkis; Geoff Beck, Natasha Lavis
Abstract: Recent studies focusing on the use of radio data in indirect dark matter detection have led to a set of highly
competitive limits on the WIMP annihilation cross-section, especially in light of high-resolution data from
instruments like ASKAP and MeerKAT. In this work, we present an analysis of radio observations of the
RXC J0225.1-2928 galaxy cluster, taken from the recent MeerKAT Galaxy Cluster Legacy Survey public
data release. We adopt a robust morphological analysis of this source that allows us to derive a set of
upper limits on the annihilation cross-section, and in our most constraining scenario, these results are
comparable to the most stringent limits yet found in the literature.
PubDate: Mon, 20 Mar 2023 03:44:03 +000
- Constraining Sterile Neutrinos Using Decay Width Measurements of SM Bosons
Authors: Lopamudra Sahoo
Abstract: The mixing of right-handed neutrinos with the SM neutrinos contributes to the interactions of these neutrinos
with the SM particles. Consequently, they will contribute to the decay widths of the SM W, Z, and
Higgs bosons provided that they are kinematically allowed to be produced from these SM gauge bosons.
Here, we show that the measured decay widths of Higgs, Z andW bosons can be used to probe sterile neutrinos,
if they are kinematically allowed to be produced from these heavy Standard Model (SM) particle
decays via the active-sterile neutrino mixing. We analyze the sensitivity of these measured SM quantities
to constrain the active-sterile neutrino mixing as a function of the sterile neutrino mass. We make a comparative
study of these constraints with other existing constraints from electroweak precision data, beam
dump experiments, and peak searches, as well as from big bang nucleosynthesis.
PubDate: Mon, 20 Mar 2023 03:42:22 +000
- Sub-GeV Dark Matter and X-Rays
Authors: Marco Cirelli
Abstract: We present bounds on dark matter (DM) in the MeV to GeV mass range, obtained by using X-ray measurements
from the INTEGRAL telescope. A crucial element, which allows us to derive bounds competitive or
stronger than existing ones from other techniques, resides in the inclusion of the contribution from inverse
Compton scattering on galactic radiation fields and on the CMB. This contribution is based on [1], to which
we refer for additional details.
PubDate: Fri, 03 Mar 2023 17:37:44 +000
- Muon g-2 in Light of LHC and DM Experiments
Authors: Cem Salih; Mario E Gomez, Qaisar Shafi, Amit Tiwari
Abstract: We revisit and compare the muon g-2 implications of two classes of SUSY GUTs models in which the non-universal boundary conditions are
imposed at M_GUT. Even though the solutions to the muon g-2 discrepancy can be accommodated in both classes, the probe for such solutions
at the current LHC and DM experiments can be challenging when the models are setup in a flavor universal way. On the other hand, when the
flavor non-universal models are considered, the implications for muon g-2 can be extended to a wider parameter space, and they can be
probed through the several experiments such as at LHC through the electroweakino productions, or decay modes of the heavy Higgs bosons.
They can yield interesting phenomenology to be tested in the DM experiments as well.
PubDate: Fri, 03 Mar 2023 17:36:14 +000
- Neutrino Oscillation Caused by Spacetime Geometry
Authors: Indrajit Ghose; Riya Barick, Amitabha Lahiri
Abstract: The effects of gravitational interaction are generally neglected in particle physics. A first-order formulation
of gravity is presented to include gravity in the Quantum Mechanical Lagrangian of fermions. It is seen that
fermions minimally coupled to gravity give rise to a torsionless effective theory with a quartic interaction.
After passing through a thermal background, the most generic form of contortion contributes to neutrino
effective mass. This effective mass can change the current oscillation parameters.
PubDate: Mon, 27 Feb 2023 11:19:33 +000
- Dark Matter Freeze-out and Freeze-in beyond Kinetic Equilibrium
Authors: Andrzej Hryczuk
Abstract: In the standard approach to the determination of the dark matter (DM) thermal relic abundance, both
from thermal freeze-out and freeze-in mechanisms, one takes into account only the zeroth moment of the
Boltzmann equation, i.e., the equation for the evolution of the particle number density. In case of freezeout,
this comes from the assumption of local thermal equilibrium, while for freeze-in, this comes from
neglecting DM annihilation processes. This proceedings report discusses how to go beyond this assumption,
reports on the introduction of DRAKE—a numerical precision tool that can trace not only the dark
matter relic density but also its velocity dispersion and full phase space distribution function—and finally
presents a new mechanism of decreasing the dark matter relic density through injecting even more DM
particles into the thermal bath.
PubDate: Mon, 27 Feb 2023 11:17:40 +000
- Capture of Dark Matter Particles by a Galaxy in the Case of a Bimodal
Distribution of Their Velocities
Authors: Serge Parnovsky; Ruth Durrer, Aleksei Parnowski
Abstract: We have analyzed the rate of capture of dark matter (DM) particles by the galaxy in the case of the existence
of two different types of DM or a bimodal velocity distribution function for DM. It is shown that, in
addition to the scenario considered in our previous work which is based on the assumption of a unimodal
distribution, more complex scenarios are possible in which the transition to the state of intense capture
and/or exit from it can occur in two stages. A detailed description is given of the change in the curve describing
the rate of capture of dark matter particles as a function of the rate of increase in the baryon mass
of the galaxy for various values of the rate of decrease of the DM density
PubDate: Mon, 27 Feb 2023 11:11:09 +000
- Rotation Curves of Galaxies via Reissner-Nordstrom Induced Gravity and an
Alternative Explanation of Dark Matter
Authors: J. Buitrago
Abstract: The dynamics of a neutral test particle in the spacetime geometry corresponding to a central massive
and charged object (Reissner-Nordstrom Metric) is examined. For a radial distance r = Q2/M (in natural
units), the gravitational force is null, independently of the value of G, and repulsive below this value. It
is shown that within typical atomic and molecular distances, there is a repulsive force albeit negligible in
comparison with the electromagnetic one ruling the atomic world. For an eventual extremal black hole
having a mass equal to the Planck Mass, a limit to an electric charge equal to 1 (MeV)0 is found. At the
galactic scale and for galaxies with a compact central nucleus with mass below or of the order of M⊙, the
repulsive force can reproduce the flat rotation curve of stellar orbits observed in many galaxies.
PubDate: Mon, 27 Feb 2023 11:08:53 +000
- Effective Field Theories for Dark Matter Pairs in the Early Universe
Authors: Gramos Qerimi
Abstract: In this conference paper, we consider effective field theories of non-relativistic dark matter particles interacting with a light force mediator in the early expanding universe. We present a general framework, where to account in a systematic way for the relevant processes that may affect the dynamics during thermal freeze-out. In the temperature regime where near-threshold effects, most notably the formation of bound states and Sommerfeld enhancement, have a large impact on the dark matter relic density, we scrutinize possible contributions from higher excited states and radiative corrections in the annihilations and decays of dark-matter pairs.
PubDate: Mon, 27 Feb 2023 11:07:03 +000
- An A4 Model for keV-Scale Sterile Neutrino Dark Matter
Authors: Mayengbam Kishan Singh
Abstract: We develop an A4 × Z4 × Z2 symmetry model of neutrino masses and mixings within the minimal extended
seesaw mechanism where three right-handed neutrinos νR1, νR2, and νR3 and a keV-scale singlet
sterile neutrino S are added to the Standard Model. This model breaks μ-τ symmetry of the neutrino mass
matrix and successfully explains leptonic mixing with nonzero θ13.We study the phenomenological results
of the keV-scale sterile neutrino as a dark matter candidate by calculating the relic abundance and its decay
rate to active neutrinos. Significant results are also observed for solar and atmospheric mixing angles
within the 3σ bounds, sum of the active neutrino masses (Σmi < 0.12 eV), and effective neutrino mass from
neutrinoless double beta decay, meff ∼ (0.001174–0.004367) eV for NH and meff ∼ (0.04766–0.05088) eV for
IH.
PubDate: Mon, 27 Feb 2023 11:04:55 +000
- Potential for Definitive Discovery of a 70GeV Dark Matter WIMP with Only
Second-Order Gauge Couplings
Authors: Roland Allen
Abstract: As astronomical observations and their interpretation improve, the case for cold dark matter (CDM) becomes increasingly persuasive. A particularly appealing version of CDM is a weakly interacting massive particle (WIMP) with a mass near the electroweak scale, which can naturally have the observed relic abundance after annihilation in the early universe. But in order for a WIMP to be consistent with the currently stringent experimental constraints it must have relatively small cross-sections for indirect, direct, and collider detection. Using our calculations and estimates of these cross-sections, we discuss the potential for discovery of a recently proposed dark matter WIMP which has a mass of about 70 GeV/c$^2$ and only second-order couplings to W and Z bosons. There is evidence that indirect detection may already have been achieved, since analyses of the gamma rays detected by Fermi-LAT and the antiprotons observed by AMS-02 are consistent with 70 GeV dark matter having our calculated $\langle \sigma_{ann} v \rangle \approx 1.2 \times 10^{-26} $ cm$^3$/s. The estimated sensitivities for LZ and XENONnT indicate that these experiments may achieve direct detection within the next few years, since we estimate the relevant cross-section to be slightly above $10^{-48}$ cm$^2$. Other experiments such as PandaX, SuperCDMS, and especially DARWIN should be able to confirm on a longer time scale. The high-luminosity LHC might achieve collider detection within about 15 years, since we estimate a collider cross-section slightly below 1 femtobarn. Definitive confirmation should come from still more powerful planned collider experiments (such as a future circular collider) within 15-35 years.
PubDate: Thu, 02 Feb 2023 17:31:12 +000
- Majorana Neutrinos and Clockworked Yukawa Couplings Contribution to
Nonobservation of the Rare Leptonic Decay li → ljγ, Clockwork
Authors: Gayatri Ghosh
Abstract: The clockwork is an extra-dimensional setup for generating light particles with exponentially suppressed
or hierarchical couplings of light particles with N massive states having comparable masses near the
threshold scale of the mechanism in theories which contain no small parameters at the fundamental level.
We explore the prospect of charged lepton flavor violation (cLFV) in a clockwork framework which encompasses
Dirac mass terms as well as Majorana mass terms for the new clockwork fermions. We derive
the masses of the nonzero clockwork Majorana masses, and new particles in a clockwork framework and
for their Yukawa couplings to the lepton doublets, in the framework where the clockwork parameters are
universal. When the new clockwork Majorana masses are nonzero, neutrino masses are generated as a
result of the exchange of heavy messenger particles such as right-handed isosinglet neutrinos or isotriplet
scalar bosons known as the seesaw mechanism. In the case of nonzero clockwork Majorana masses, owing
to the sizable effective Yukawa couplings of the higher mass modes, neutrino masses can only be made
tiny by conjecturing a large Majorana mass in the teraelectron volt range for all the clockwork gears. This
is apparent from the constraints on the mass scale of the clockwork fermions due to the nonobservation of
the rare cLFV decay μ → eγ, τ → μγ, τ → eγ. A general description of the clockwork mechanism valid
for fermions, gauge bosons, and gravitons is discussed here. This mechanism can be implemented with a
discrete set of new fields or, in its continuum version, through an extra spatial dimension. In both cases,
the clockwork emerges as a useful tool for model-building applications. Notably, the continuum clockwork
offers a solution to the Higgs naturalness problem, which turns out to be the same as in linear dilaton duals
of Little String Theory.
PubDate: Wed, 01 Feb 2023 08:54:38 +000
- Search for Dark Matter Signatures with ANTARES and KM3NeT
Authors: Sara Rebecca Gozzini
Abstract: Extraterrestrial messengers can be used as trackers to probe the presence of dark matter particles in our
Galaxy. Sizable fluxes of high-energy neutrinos, measurable with neutrino telescopes, are expected from
pair annihilation and decay of dark matter in regions where it accumulates to a high density. This is the
case for massive celestial bodies such as the Sun and the very large dark matter reservoir at the Galactic
Center, which are inside the field of view of neutrino telescopes installed in the Mediterranean Sea.
ANTARES was operated for 16 years and was recently decommissioned, and KM3NeT is currently taking
its first data with its first detection lines. A search for signatures of Weakly Interacting Massive Particles
(WIMPs) has been performed in 14 years of all-flavor neutrino data, yielding competitive upper limits on
the strength of WIMP annihilation when targeting the Galactic Center. Limits on the WIMP-nucleon cross
section have been set considering the nonobservation of dark-matter-induced neutrinos from the direction
of the Sun. Other non-WIMP landscapes, such as the model predicting heavy dark matter candidates, have
been tested with dedicated searches in ANTARES data. The current results with the first installed KM3NeT
subdetectors are also discussed.
PubDate: Wed, 01 Feb 2023 08:52:59 +000
- Coherent Elastic Neutrino-Nucleus Scattering in the Standard Model and
Beyond
Authors: Valentina De Romeri
Abstract: I will present the physics potential of the coherent elastic neutrino-nucleus scattering (CEνNS) process. I
will first briefly review the status of current observations. Then, I will comment on their implications for
both precision tests of the Standard Model and for new physics in the neutrino sector. Finally, I will discuss
the relevance of these measurements for direct dark matter detection probes.
PubDate: Wed, 01 Feb 2023 08:51:42 +000
- VISHν: Flavour-Variant DFSZ Axion Model for Inflation, Neutrino Masses,
Dark Matter, and Baryogenesis
Authors: Raymond R. Volkas
Abstract: The standard flavour-blind DFSZ axion model for solving the strong-CP problem has in the past been
extended to account for nonzero neutrino masses and baryogenesis-via-leptogenesis through the Type-I
seesaw mechanism, in addition to having viable axion dark matter. Constructing a full and viable cosmological
history, however, requires dealing with the cosmological domain wall problem posed by standard
DFSZ. In this paper, I report on work with A. Sopov where this challenge is addressed through a flavourvariant
model called VISHν that removes the domain wall problem and incorporates successful Higgs-
Peccei-Quinn scalar inflation. As part of this, we ensure that the required new high-scale physics does not
add to the electroweak naturalness problem.
PubDate: Wed, 01 Feb 2023 08:49:56 +000
- Thermal Axions: Production Mechanisms and Cosmological Signals
Authors: Francesco D’Eramo
Abstract: Scattering and decay processes of thermal bath particles in the early universe can dump relativistic axions
in the primordial plasma. If produced with a significant abundance, their presence can leave observable
signatures in cosmological observables probing both the early and the late universe.We focus on the QCD
axion and present recent and significant improvements for the calculation of the axion production rate
across the different energy scales during the expansion of the universe. We apply these rates to predict
the abundance of produced axions and to derive the latest cosmological bounds on the axion mass and
couplings.
PubDate: Fri, 27 Jan 2023 00:00:00 +000
- Exploring Scenarios for Directional Dark Matter with NEWSdm
Authors: Giovanni Rosa
Abstract: Aiming at the direct detection of WIMPs as dark matter constituents, the NEWSdm Collaboration is performing
a wide experimental activity at the Gran Sasso Lab in Italy. Achievements in spatial resolution,
detection threshold, and directional tracking are reported. Measurements of low-energy neutron flux were
performed. Further study of background sources will allow scaling up of the detector mass. Applications
to boosted DM scenarios are envisaged.
PubDate: Fri, 27 Jan 2023 00:00:00 +000
- Mono-Z/W Signal from Nearly Degenerate Higgsinos at the LHC
Authors: Junichiro Kawamura
Abstract: In this paper, I point out that the hadronic mono-Z/W signal can give significant constraints on the higgsinos
at the LHC. The higgsinos at O(100 GeV) are well motivated to explain the size of the electroweak
(EW) scale in the minimal supersymmetric (SUSY) standard model. The higgsinos up to 110 (210) GeV can
be excluded by the 139 (300) fb−1 data, and the 3000 fb−1 data will discover (exclude) the higgsinos up to
280 (520) GeV, assuming that the higgsino states are effectively invisible in the detector. This strategy could
be applicable to other dark matter (DM) particles.
PubDate: Fri, 27 Jan 2023 00:00:00 +000
- Low-Threshold Scintillation Detector Development for Dark Matter and
Neutrino
Authors: Zhimin Wang
Abstract: It is still one of the main directions to search for dark matter with better sensitivity and to measure neutrinos
with good statistics and better precision. The technologies of scintillation detectors on the lowthreshold,
low background, and good directionality are valuable and can contribute to the study. In this
topic, I will try to introduce some progress on the development of the low threshold scintillation detector
for dark matter and neutrino in liquid argon (LAr) and liquid scintillator (LS) and make some review on
interesting topics.
PubDate: Sun, 08 Jan 2023 19:42:47 +000
