Observation of Forward Neutron Multiplicity Dependence of Dimuon Acoplanarity in Ultraperipheral Pb-Pb Collisions at root S-NN=5.02 TeV

Show full item record



Permalink

http://hdl.handle.net/10138/336424

Citation

The CMS Collaboration , Sirunyan , A M , Tumasyan , A , Eerola , P , Forthomme , L , Kirschenmann , H , Österberg , K , Voutilainen , M , Brücken , E , Garcia , F , Havukainen , J , Heikkilä , J , Karimäki , V , Kim , M , Kinnunen , R , Lampén , T , Lassila-Perini , K , Laurila , S , Lehti , S , Lindén , T , Luukka , P , Pekkanen , J , Siikonen , H , Tuominen , E , Tuominiemi , J , Viinikainen , J & Tuuva , T 2021 , ' Observation of Forward Neutron Multiplicity Dependence of Dimuon Acoplanarity in Ultraperipheral Pb-Pb Collisions at root S-NN=5.02 TeV ' , Physical Review Letters , vol. 127 , no. 12 , 122001 . https://doi.org/10.1103/PhysRevLett.127.122001

Title: Observation of Forward Neutron Multiplicity Dependence of Dimuon Acoplanarity in Ultraperipheral Pb-Pb Collisions at root S-NN=5.02 TeV
Author: The CMS collaboration; Sirunyan, A. M.; Tumasyan, A.; Eerola, P.; Forthomme, Laurent; Kirschenmann, H.; Österberg, K.; Voutilainen, M.; Brücken, Erik; Garcia, F.; Havukainen, J.; Heikkilä, Jaana; Karimäki, Veikko; Kim, Minsuk; Kinnunen, R.; Lampén, T.; Lassila-Perini, K.; Laurila, S.; Lehti, S.; Lindén, T.; Luukka, P.; Pekkanen, Juska; Siikonen, H.; Tuominen, E.; Tuominiemi, J.; Viinikainen, Jussi; Tuuva, T.
Contributor organization: Department of Physics
Helsinki Institute of Physics
Date: 2021-09-17
Language: eng
Number of pages: 19
Belongs to series: Physical Review Letters
ISSN: 0031-9007
DOI: https://doi.org/10.1103/PhysRevLett.127.122001
URI: http://hdl.handle.net/10138/336424
Abstract: The first measurement of the dependence of gamma gamma -> mu(+)mu(-) production on the multiplicity of neutrons emitted very close to the beam direction in ultraperipheral heavy ion collisions is reported. Data for lead-lead interactions at root S-NN = 5.02 TeV, with an integrated luminosity of approximately 1.5 nb(-1), are collected using the CMS detector at the LHC. The azimuthal correlations between the two muons in the invariant mass region 8 < m(mu mu) < 60 GeV are extracted for events including 0, 1, or at least 2 neutrons detected in the forward pseudorapidity range vertical bar eta vertical bar > 8.3. The back-to-back correlation structure from leading-order photon-photon scattering is found to be significantly broader for events with a larger number of emitted neutrons from each nucleus, corresponding to interactions with a smaller impact parameter. This observation provides a data-driven demonstration that the average transverse momentum of photons emitted from relativistic heavy ions has an impact parameter dependence. These results provide new constraints on models of photon-induced interactions in ultraperipheral collisions. They also provide a baseline to search for possible final-state effects on lepton pairs caused by traversing a quark-gluon plasma produced in hadronic heavy ion collisions.
Subject: 114 Physical sciences
PERIPHERAL COLLISIONS
PHYSICS
Peer reviewed: Yes
Rights: cc_by
Usage restriction: openAccess
Self-archived version: publishedVersion


Files in this item

Total number of downloads: Loading...

Files Size Format View
PhysRevLett.127.122001.pdf 493.9Kb PDF View/Open

This item appears in the following Collection(s)

Show full item record