Search for displaced photons produced in exotic decays of the Higgs boson using 13 TeV $pp$ collisions with the ATLAS detector

Autor: ATLAS Collaboration
Jazyk: angličtina
Rok vydání: 2022
Předmět:
photon: trajectory
p p: scattering
radiative decay [neutral particle]
transverse momentum: missing-energy
trajectory [photon]
exotic [decay]
13000 GeV-cms
electromagnetic [calorimeter]
FOS: Physical sciences
branching ratio: upper limit [Higgs particle]
channel cross section: upper limit
photon: particle identification
High Energy Physics - Experiment
High Energy Physics - Experiment (hep-ex)
neutral particle: pair production
neutral particle: long-lived
scattering [p p]
long-lived [neutral particle]
photon: production
pair production [neutral particle]
upper limit [channel cross section]
background
production [photon]
particle identification [photon]
rare decay [Higgs particle]
Higgs particle: rare decay
ATLAS
time delay
calorimeter: electromagnetic
CERN LHC Coll
Higgs particle: branching ratio: upper limit
missing-energy [transverse momentum]
neutral particle: radiative decay
colliding beams [p p]
decay: exotic
p p: colliding beams
Particle Physics - Experiment
experimental results
DOI: 10.3204/PUBDB-2022-05077
Popis: A search is performed for delayed and nonpointing photons originating from the displaced decay of a neutral long-lived particle (LLP). The analysis uses the full Run 2 data set of proton-proton collisions delivered by the LHC at a center-of-mass energy of $\sqrt{s}=13$ TeV between 2015 and 2018 and recorded by the ATLAS detector, corresponding to an integrated luminosity of 139 fb$^{-1}$. The capabilities of the ATLAS electromagnetic calorimeter are exploited to precisely measure the arrival times and trajectories of photons. The results are interpreted in a scenario where the LLPs are pair-produced in exotic decays of the 125 GeV Higgs boson, and each LLP subsequently decays into a photon and a particle that escapes direct detection, giving rise to missing transverse momentum. No significant excess is observed above the expectation due to Standard Model background processes. The results are used to set upper limits on the branching ratio of the exotic decay of the Higgs boson. A model-independent limit is also set on the production of photons with large values of displacement and time delay.
29 pages in total, no author list, 11 figures, 2 tables, submitted to Phys. Rev. D. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2019-14
Databáze: OpenAIRE