English
Related papers

Related papers: Some Comments on an MeV Cold Dark Matter Scenario

200 papers

MeV dark matter (DM) particles annihilating or decaying to electron-positron pairs cannot, in principle, be observed via local cosmic-ray (CR) measurements because of the shielding solar magnetic field. In this letter, we take advantage of…

High Energy Astrophysical Phenomena · Physics 2017-07-19 Mathieu Boudaud , Julien Lavalle , Pierre Salati

If sub-GeV Dark matter(DM) annihilates to the charged particles such as $e^+ e^-$, $\mu^+ \mu^-$, or $\pi^+ \pi^-$, it generates an additional source of electrons and positrons in the cosmic ray (CR) population within our Milky Way. During…

High Energy Astrophysical Phenomena · Physics 2025-12-10 Guansen Wang , Bing-Yu Su , Lei Zu , Lei Feng

MeV particles have been advocated as Dark Matter (DM) candidates in different contexts. This hypothesis can be tested indirectly by searching for the Standard Model (SM) products of DM self-annihilations. As the signal from DM…

Astrophysics · Physics 2008-11-26 Sergio Palomares-Ruiz , Silvia Pascoli

The precise measurements of energy spectra of cosmic ray positrons and/or electrons by recent experiments show clear excesses above 10 GeV. Moreover, a potential sharp spectral feature was suggested by the Dark Matter Particle Explorer…

High Energy Physics - Phenomenology · Physics 2020-04-29 Lei Feng , Zhaofeng Kang , Qiang Yuan , Peng-Fei Yin , Yi-Zhong Fan

A new concept of generation of the cosmological baryon excess along with the cold dark matter (CDM) in the Universe is proposed and corresponding scenarios are outlined. Possible realizations of the idea in the framework of supersymmetric…

High Energy Physics - Phenomenology · Physics 2014-11-17 Vadim A. Kuzmin

The apparent gamma-ray excess in the Galactic center region and inner Galaxy has attracted considerable interest, notably because both its spectrum and radial distribution are consistent with an interpretation in terms of annihilating dark…

High Energy Astrophysical Phenomena · Physics 2014-12-03 Torsten Bringmann , Martin Vollmann , Christoph Weniger

Recent experimental observations, most notably those reported by the ATOMKI and Positron Annihilation into Dark Matter Experiment (PADME) collaborations, have hinted anomalies that may indicate the presence of a new resonance with a mass…

High Energy Physics - Phenomenology · Physics 2026-03-03 Marco Graziani

We reconsider the proposal of excited dark matter (DM) as an explanation for excess 511 keV gamma rays from positrons in the galactic center. We quantitatively compute the cross section for DM annihilation to nearby excited states, mediated…

High Energy Physics - Phenomenology · Physics 2014-11-20 Fang Chen , James M. Cline , Anthony Fradette , Andrew R. Frey , Charles Rabideau

Structure formation with cold dark matter (CDM) predicts halos with a central density cusp, which are observationally disfavored. If CDM particles have an annihilation cross section sigma*v ~ 10**(-29) (m/GeV) cm**2, then annihilations will…

Astrophysics · Physics 2010-04-06 M. Kaplinghat , L. Knox , M. S. Turner

We present the energy spectra of the fluxes of positrons, anti-protons and photons generated by Dark Matter annihilations in our galaxy, as univocally predicted by the model of Minimal Dark Matter. Due to multi-TeV masses and to the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Marco Cirelli , Roberto Franceschini , Alessandro Strumia

We revisit the possibility of light scalar dark matter, in the MeV to GeV mass bracket and coupled to electrons through fermion or vector mediators, in light of significant experimental and observational advances that probe new physics…

High Energy Physics - Phenomenology · Physics 2021-04-14 Céline Bœhm , Xiaoyong Chu , Jui-Lin Kuo , Josef Pradler

It has previously been proposed that annihilating dark matter particles with MeV-scale masses could be responsible for the flux of 511 keV photons observed from the region of the Galactic Bulge. The conventional wisdom, however, is that it…

High Energy Physics - Phenomenology · Physics 2009-07-14 Dan Hooper , Kathryn M. Zurek

Cold dark matter (CDM) models predict small-scale structure in excess of observations of the cores and abundance of dwarf galaxies. These problems might be solved, and the virtues of CDM models retained, even without postulating {\it ad…

Astrophysics · Physics 2009-10-31 Wayne Hu , Rennan Barkana , Andrei Gruzinov

AMS-02 provided the unprecedented statistics in the measurement of the positron fraction from cosmic rays. That may offer a unique opportunity to distinguish the positron spectrum coming from various dark matter (DM) annihilation channels,…

High Energy Physics - Phenomenology · Physics 2016-02-17 Yu-Heng Chen , Kingman Cheung , Po-Yan Tseng

It has been suggested ``that DM particles are strongly interacting composite macroscopically large objects ... made of well known light quarks (or ... antiquarks)." In doing so it is argued that these compact composite objects (CCOs) are…

Astrophysics · Physics 2008-11-26 Daniel T. Cumberbatch , Glenn D. Starkman , Joseph Silk

We calculate the CMB temperature distortion due to the energetic electrons and positrons produced by dark matter annihilation (Sunyaev-Zel'dovich effect), in dwarf spheroidal galaxies (dSphs). In the calculation we have included two…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Feng Huang , Xuelei Chen , Qiang Yuan , Xiaojun Bi

We consider electrically neutral complex vector particles $V$ below the GeV mass scale that, from a low energy perspective, couple to the photon via higher dimensional form factor interactions. We derive ensuing astrophysical constraints by…

High Energy Physics - Phenomenology · Physics 2023-08-02 Xiaoyong Chu , Junji Hisano , Alejandro Ibarra , Jui-Lin Kuo , Josef Pradler

Thermal freeze-out offers an attractive explanation of the dark matter density free from fine-tuning of initial conditions. For dark matter with a mass below tens of MeV, photons, electrons, and neutrinos are the only available direct…

High Energy Physics - Phenomenology · Physics 2024-05-10 Xiaoyong Chu , Josef Pradler

Dark Matter (DM) annihilation in our Galaxy may produce a linearly polarized synchrotron signal. We use, for the first time, synchrotron polarization to constrain the DM annihilation cross section by comparing theoretical predictions with…

High Energy Astrophysical Phenomena · Physics 2022-09-13 Silvia Manconi , Alessandro Cuoco , Julien Lesgourgues

PAMELA and ATIC recently reported excesses in e+ e- cosmic rays. Since the interpretation in terms of DM annihilations was found to be not easily compatible with constraints from photon observations, we consider the DM decay hypothesis and…

High Energy Physics - Phenomenology · Physics 2009-05-26 Enrico Nardi , Francesco Sannino , Alessandro Strumia
‹ Prev 1 2 3 10 Next ›