Search Publications
γ
Carenza, Pierluca; Mastrototaro, Leonardo; Balaji, Shyam +1 more
The
X-ray polarimetric features of gamma-ray bursts across varied redshifts and hints for axionlike particles
Wang, Zhongxiang; Fang, Taotao; Huang, Feng +1 more
Polarimetric features during the prompt phase of gamma-ray bursts (GRBs) have been essential for elucidating the debated emission mechanisms and gaining insight into the inner structure of GRBs. However, the potential impact of photon-axionlike particle (ALP) mixing in extragalactic magnetic fields, leading to significant modifications to the init…
Multimessenger search for electrophilic feebly interacting particles from supernovae
Carenza, Pierluca; Balaji, Shyam; Luque, Pedro De la Torre
We study MeV-scale electrophilic feebly interacting particles (FIPs), that may be abundantly produced in supernova explosions, escape the star and decay into electrons and positrons. This exotic injection of leptons in the Milky Way leaves an imprint in both photon and cosmic ray fluxes. Specifically, positrons lose energy and annihilate almost at…
Robust constraints on feebly interacting particles using XMM-Newton
Carenza, Pierluca; Balaji, Shyam; Luque, Pedro De la Torre
During galactic supernova (SN) explosions, a large amount of feebly interacting particles (FIPs) may be produced. In this work we analyze electrophilic FIPs with masses in the MeV-range that escape from SN and decay into electron-positron pairs, causing an exotic leptonic injection. This contribution adds up to known components, leading to an unex…
Primordial black holes and scalar-induced gravitational waves from the polynomial attractor model
Wang, Yue; Gong, Yungui; Wang, Zhongkai +1 more
Primordial black holes (PBHs) generated in the early Universe are considered as one of the candidates for dark matter. To produce PBHs with sufficient abundance, the primordial scalar power spectrum needs to be enhanced to the order of 0.01. Considering the third-order polynomial potential with polynomial attractors, we show that PBHs with a mass …
Constraining the low-energy cosmic ray flux in the center molecular zone from MeV nuclear deexcitation line observations
Liu, Bing; Yang, Ruizhi
Low-energy cosmic rays (LECRs) dominate the ionization in dense regions of molecular clouds in which other ionizers such as UV or x-ray photons are effectively shielded. Thus, it was argued that the high ionization rate at the central molecular zone (CMZ) of our Galaxy is mainly caused by LECRs. However, the required LECR flux is orders of magnitu…
Precise measurement of pion-bump structure using future MeV gamma-ray detectors
Liu, Jiahao; Liu, Bing; Yang, Ruizhi
The pion-bump structure in the
Constraints on the parameters of keV-scale mass annihilating dark matter obtained with SRG/ART-XC observations
Burenin, R. A.; Krivonos, R. A.; Zakharov, E. I. +2 more
In this paper we present new constraints on the velocity-independent cross section of keV-scale mass annihilating dark matter particles obtained with SRG/ART-XC after 4 full-sky surveys. These constraints are derived from observations of the Milky Way Halo, 33 Local Group spheroidal dwarf (dSph) galaxies and separately for the dSph galaxy Ursa Maj…
Hunting for dark matter and new physics with GECCO
Moiseev, A. A.; Profumo, Stefano; Baring, Matthew G. +9 more
We outline the science opportunities in the areas of searches for dark matter and new physics offered by a proposed future MeV gamma-ray telescope, the Galactic Explorer with a Coded Aperture Mask Compton Telescope (GECCO). We point out that such an instrument would play a critical role in opening up a discovery window for particle dark matter wit…
Charging of free-falling test masses in orbit due to cosmic rays: Results from LISA Pathfinder
Mendes, L.; Russano, G.; Nofrarias, M. +72 more
A comprehensive summary of the measurements made to characterize test-mass charging due to the space environment during the LISA Pathfinder mission is presented. Measurements of the residual charge of the test mass after release by the grabbing and positioning mechanism show that the initial charge of the test masses was negative after all release…