skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


This content will become publicly available on February 6, 2026

Title: Inhomogeneous energy injection in the 21-cm power spectrum: Sensitivity to dark matter decay
The 21-cm signal provides a novel avenue to measure the thermal state of the Universe during cosmic dawn and reionization (redshifts z ∼ 5 – 30 ), and thus to probe energy injection from decaying or annihilating dark matter (DM). These DM processes are inherently inhomogeneous: both decay and annihilation are density-dependent, and furthermore, the fraction of injected energy that is deposited at each point depends on the gas ionization and density, leading to further anisotropies in absorption and propagation. In this work, we develop a new framework for modeling the impact of spatially inhomogeneous energy injection and deposition during cosmic dawn, accounting for ionization and baryon density dependence, as well as the attenuation of propagating photons. We showcase how this first completely inhomogeneous treatment affects the predicted 21-cm power spectrum in the presence of exotic sources of energy injection, and forecast the constraints that upcoming HERA measurements of the 21-cm power spectrum will set on DM decays to photons and to electron/positron pairs. These projected constraints considerably surpass those derived from CMB and Lyman- α measurements, and for decays to electron/positron pairs they exceed all existing constraints in the sub-GeV mass range, reaching lifetimes of ∼ 10 28     s . Our analysis demonstrates the unprecedented sensitivity of 21-cm cosmology to exotic sources of energy injection during the cosmic dark ages. Our code, 21cm, includes all these effects and is publicly available in an accompanying release. Published by the American Physical Society2025  more » « less
Award ID(s):
2019786 2307354 2408637
PAR ID:
10588323
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
American Physical Society
Date Published:
Journal Name:
Physical Review D
Volume:
111
Issue:
4
ISSN:
2470-0010
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; ; ; ; ; ; et al (, Physical Review Letters)
    We search for dark matter (DM) with a mass [ 3 , 12 ]     GeV / c 2 using an exposure of 3.51     tonne   year with the XENONnT experiment. We consider spin-independent DM-nucleon interactions mediated by a heavy or light mediator, spin-dependent DM-neutron interactions, momentum-dependent DM scattering, and mirror DM. Using a lowered energy threshold compared to the previous weakly interacting massive particle search, a blind analysis of [0.5, 5.0] keV nuclear recoil events reveals no significant signal excess over the background. XENONnT excludes spin-independent DM-nucleon cross sections > 2.5 × 10 − 45     cm 2 at 90% confidence level for 6     GeV / c 2 DM. In the considered mass range, the DM sensitivity approaches the “neutrino fog,” the limitation where neutrinos produce a signal that is indistinguishable from that of light DM-xenon nucleus scattering. Published by the American Physical Society2025 
    more » « less
  2. ; ; ; ; ; ; ; ; ; ; et al (, Physical Review D)
    We measure the branching fraction and C P -violating flavor-dependent rate asymmetry of B 0 → π 0 π 0 decays reconstructed using the Belle II detector in an electron-positron collision sample containing 387 × 10 6     ϒ ( 4 S ) mesons. Using an optimized event selection, we find 125 ± 20 signal decays in a fit to background-discriminating and flavor-sensitive distributions. The resulting branching fraction is ( 1.25 ± 0.23 ) × 10 − 6 and the C P -violating asymmetry is 0.03 ± 0.30 . Published by the American Physical Society2025 
    more » « less
  3. ; ; ; ; ; ; ; ; ; ; et al (, Physical Review Letters)
    A dedicated search for upward-going air showers at zenith angles exceeding 110° and energies E > 0.1     EeV has been performed using the Fluorescence Detector of the Pierre Auger Observatory. The search is motivated by two “anomalous” radio pulses observed by the ANITA flights I and III that appear inconsistent with the standard model of particle physics. Using simulations of both regular cosmic-ray showers and upward-going events, a selection procedure has been defined to separate potential upward-going candidate events and the corresponding exposure has been calculated in the energy range [0.1–33] EeV. One event has been found in the search period between January 1, 2004, and December 31, 2018, consistent with an expected background of 0.27 ± 0.12 events from misreconstructed cosmic-ray showers. This translates to an upper bound on the integral flux of ( 7.2 ± 0.2 ) × 10 − 21     cm − 2   sr − 1   y − 1 and ( 3.6 ± 0.2 ) × 10 − 20     cm − 2   sr − 1   y − 1 for an E − 1 and E − 2 spectrum, respectively. An upward-going flux of showers normalized to the ANITA observations is shown to predict over 34 events for an E − 3 spectrum and over 8.1 events for a conservative E − 5 spectrum, in strong disagreement with the interpretation of the anomalous events as upward-going showers. Published by the American Physical Society2025 
    more » « less
  4. ; ; ; ; ; ; ; ; ; ; et al (, Physical Review Letters)
    The Cryogenic Underground Observatory for Rare Events (CUORE) is a detector array comprised by 988 5     cm × 5     cm × 5     cm TeO 2 crystals held below 20 mK, primarily searching for neutrinoless double-beta decay in Te 130 . Unprecedented in size among cryogenic calorimetric experiments, CUORE provides a promising setting for the study of exotic throughgoing particles. Using the first tonne year of CUORE’s exposure, we perform a search for hypothesized (FCPs), which are well-motivated by various standard model extensions and would have suppressed interactions with matter. Across the searched range of charges e / 24 − e / 2 no excess of FCP candidate tracks is observed over background, setting leading limits on the underground FCP flux with charges e / 24 − e / 5 at 90% confidence level. Using the low background environment and segmented geometry of CUORE, we establish the sensitivity of tonne-scale subkelvin detectors to diverse signatures of new physics. Published by the American Physical Society2024 
    more » « less
  5. ; ; ; ; ; ; ; ; ; ; et al (, Physical Review D)
    We present GFlaT, a new algorithm that uses a graph-neural-network to determine the flavor of neutral B mesons produced in ϒ ( 4 S ) decays. It improves previous algorithms by using the information from all charged final-state particles and the relations between them. We evaluate its performance using B decays to flavor-specific hadronic final states reconstructed in a 362     fb − 1 sample of electron-positron collisions collected at the ϒ ( 4 S ) resonance with the Belle II detector at the SuperKEKB collider. We achieve an effective tagging efficiency of ( 37.40 ± 0.43 ± 0.36 % ) , where the first uncertainty is statistical and the second systematic, which is 18% better than the previous Belle II algorithm. Demonstrating the algorithm, we use B 0 → J / ψ K S 0 decays to measure the mixing-induced and direct C P violation parameters, S = ( 0.724 ± 0.035 ± 0.009 ) and C = ( − 0.035 ± 0.026 ± 0.029 ) . Published by the American Physical Society2024 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email