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Search for light long-lived neutral particles from Higgs boson decays via vector-boson-fusion production from pp collisions at √s = 13 TeV with the ATLAS detector ATLAS Collaboration

Abstract

A search is reported for long-lived dark photons with masses between 0.1 GeV and 15 GeV, from exotic decays of Higgs bosons produced via vector-boson-fusion. Events that contain displaced collimated Standard Model fermions reconstructed in the calorimeter or muon spectrometer are probed. This search uses the full LHC Run 2 (2015– 2018) data sample collected in proton–proton collisions at √s = 13 TeV, corresponding to an integrated luminosity of 139 f b−1. Dominant backgrounds from Standard Model processes and non-collision sources are estimated using datadriven techniques. The observed event yields in the signal regions are consistent with the expected background. Upper limits on the Higgs boson to dark photon branching fraction are reported as a function of the dark photon mean proper decay length or of the dark photon mass and the coupling between the Standard Model and the potential dark sector. This search is combined with previous ATLAS searches obtained in the gluon–gluon fusion and WH production modes. A branching fraction above 10% is excluded at 95% CL for a 125 GeV Higgs boson decaying into two dark photons for dark photon mean proper decay lengths between 173 and 1296 mm and mass of 10 GeV.

Item Metadata

Title
Search for light long-lived neutral particles from Higgs boson decays via vector-boson-fusion production from pp collisions at √s = 13 TeV with the ATLAS detector
Creator
ATLAS Collaboration
Publisher
Springer Berlin Heidelberg
Date Issued
2024-07-22
Description
A search is reported for long-lived dark photons with masses between 0.1 GeV and 15 GeV, from exotic decays of Higgs bosons produced via vector-boson-fusion. Events that contain displaced collimated Standard Model fermions reconstructed in the calorimeter or muon spectrometer are probed. This search uses the full LHC Run 2 (2015– 2018) data sample collected in proton–proton collisions at √s = 13 TeV, corresponding to an integrated luminosity of 139 f b−1. Dominant backgrounds from Standard Model processes and non-collision sources are estimated using datadriven techniques. The observed event yields in the signal regions are consistent with the expected background. Upper limits on the Higgs boson to dark photon branching fraction are reported as a function of the dark photon mean proper decay length or of the dark photon mass and the coupling between the Standard Model and the potential dark sector. This search is combined with previous ATLAS searches obtained in the gluon–gluon fusion and WH production modes. A branching fraction above 10% is excluded at 95% CL for a 125 GeV Higgs boson decaying into two dark photons for dark photon mean proper decay lengths between 173 and 1296 mm and mass of 10 GeV.
Genre
Article
Type
Text
Language
eng
Date Available
2024-10-24
Provider
Vancouver : University of British Columbia Library
Rights
Attribution 4.0 International (CC BY 4.0)
DOI
10.14288/1.0447109
URI
http://hdl.handle.net/2429/89516
Affiliation
Science, Faculty of; TRIUMF; Non UBC; Physics and Astronomy, Department of
Citation
The European Physical Journal C. 2024 Jul 22;84(7):719
Publisher DOI
10.1140/epjc/s10052-024-12902-7
Peer Review Status
Reviewed
Scholarly Level
Faculty
Copyright Holder
The Author(s)
Rights URI
http://creativecommons.org/licenses/by/4.0/
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Attribution 4.0 International (CC BY 4.0)