Springer : Constraining light thermal inelastic dark matter with NA64

Mongillo, Martina; Hostert, Matheus; Massaro, Daniele; Oberhauser, Benjamin Banto; Pascoli, Silvia; Abdullahi, Asli; Crivelli, Paolo; Bueno, Laura Molina

doi:10.1140/epjc/s10052-023-11536-5

Article
Report number	arXiv:2302.05414 ; IRMP-CP3-23-09 ; FERMILAB-PUB-23-066-T ; CERN-TH-2023-018
Title	Constraining light thermal inelastic dark matter with NA64
Author(s)	Mongillo, Martina (Zurich, ETH) ; Abdullahi, Asli (Fermilab ; Durham U., IPPP) ; Oberhauser, Benjamin Banto (Zurich, ETH) ; Crivelli, Paolo (Zurich, ETH) ; Hostert, Matheus (Cambridge U., DAMTP ; Perimeter Inst. Theor. Phys. ; Minnesota U. ; Minnesota U., Theor. Phys. Inst.) ; Massaro, Daniele (Bologna U. ; INFN, Bologna ; Louvain U., CP3) ; Bueno, Laura Molina (Valencia U., IFIC) ; Pascoli, Silvia (Bologna U. ; INFN, Bologna ; CERN)
Publication	2023-05-10
Imprint	2023-02-10
Number of pages	14
In:	Eur. Phys. J. C 83 (2023) 391
DOI	10.1140/epjc/s10052-023-11536-5
Subject category	hep-ex ; Particle Physics - Experiment ; hep-ph ; Particle Physics - Phenomenology
Accelerator/Facility, Experiment	CERN SPS ; NA64
Abstract	A vector portal between the Standard Model and the dark sector is a predictive and compelling framework for thermal dark matter. Through co-annihilations, models of inelastic dark matter (iDM) and inelastic Dirac dark matter (i2DM) can reproduce the observed relic density in the MeV to GeV mass range without violating cosmological limits. In these scenarios, the vector mediator behaves like a semi-visible particle, evading traditional bounds on visible or invisible resonances, and uncovering new parameter space to explain the muon $(g-2)$ anomaly. By means of a more inclusive signal definition at the NA64 experiment, we place new constraints on iDM and i2DM using a missing energy technique. With a recast-based analysis, we contextualize the NA64 exclusion limits in parameter space and estimate the reach of the newly collected and expected future NA64 data. Our results motivate the development of an optimized search program for semi-visible particles, in which fixed-target experiments like NA64 provide a powerful probe in the sub-GeV mass range.
Copyright/License	preprint: (License: CC BY 4.0) publication: © 2023-2025 The Author(s) (License: CC-BY-4.0), sponsored by SCOAP³

$Production of $A'$ via a dark bremsstrahlung reaction ${e^-Z\rightarrow e^-ZA'}$ and subsequent semi-visible decay $A'\rightarrow\chi_2\chi_1$;$\chi_2 \rightarrow \chi_1 A'^* \rightarrow \chi_1 e^+ e^-$ .$ $Sketch of a semi-visible event in the NA64 setup. Note that only the detectors relevant for the discussion are depicted. The first drawing represents a prompt $\chi_2$ decay in the target, while in the second, $\chi_2$ has a longer lifetime and produces a leptonic pair in the HCAL.$ $Sketch of a semi-visible event in the NA64 setup. Note that only the detectors relevant for the discussion are depicted. The first drawing represents a prompt $\chi_2$ decay in the target, while in the second, $\chi_2$ has a longer lifetime and produces a leptonic pair in the HCAL.$ Show more plots

Corresponding record in: Inspire

Back to search

Record created 2023-05-25, last modified 2025-08-19

Fulltext:
FERMILAB-PUB-23-066-T -