The structure of nucleons is multidimensional and depends on the transverse momenta, spatial geometry, and polarization of the constituent partons. Such a structure can be studied using high-energy photons produced in ultraperipheral heavy-ion collisions. The first measurement of the azimuthal angular correlations of exclusively produced events with two jets in photon-lead interactions at large momentum transfer is presented, a process that is considered to be sensitive to the underlying nuclear gluon polarization. This study uses a data sample of ultraperipheral lead-lead collisions at s NN = 5.02 TeV , corresponding to an integrated luminosity of 0.38 nb - 1 , collected with the CMS experiment at the LHC. The measured second harmonic of the correlation between the sum and difference of the two jet transverse momentum vectors is found to be positive, and rising, as the dijet transverse momentum increases. A well-tuned model that has been successful at describing a wide range of proton scattering data from the HERA experiments fails to describe the observed correlations, suggesting the presence of gluon polarization effects.

Tumasyan, A., Adam, W., Bergauer, T., Dragicevic, M., Del Valle, A., Fruhwirth, R., et al. (2023). Azimuthal Correlations within Exclusive Dijets with Large Momentum Transfer in Photon-Lead Collisions. PHYSICAL REVIEW LETTERS, 131(5) [10.1103/PhysRevLett.131.051901].

Azimuthal Correlations within Exclusive Dijets with Large Momentum Transfer in Photon-Lead Collisions

Xiao J.;Benaglia A.;Beschi A.;Brivio F.;Cetorelli F.;Ciriolo V.;De Guio F.;Dinardo M. E.;Ghezzi A.;Govoni P.;Guzzi L.;Malberti M.;Massironi A.;Monti F.;Moroni L.;Paganoni M.;Ragazzi S.;Valsecchi D.;Zuolo D.;Pigazzini S.;Gerosa R.;
2023

Abstract

The structure of nucleons is multidimensional and depends on the transverse momenta, spatial geometry, and polarization of the constituent partons. Such a structure can be studied using high-energy photons produced in ultraperipheral heavy-ion collisions. The first measurement of the azimuthal angular correlations of exclusively produced events with two jets in photon-lead interactions at large momentum transfer is presented, a process that is considered to be sensitive to the underlying nuclear gluon polarization. This study uses a data sample of ultraperipheral lead-lead collisions at s NN = 5.02 TeV , corresponding to an integrated luminosity of 0.38 nb - 1 , collected with the CMS experiment at the LHC. The measured second harmonic of the correlation between the sum and difference of the two jet transverse momentum vectors is found to be positive, and rising, as the dijet transverse momentum increases. A well-tuned model that has been successful at describing a wide range of proton scattering data from the HERA experiments fails to describe the observed correlations, suggesting the presence of gluon polarization effects.
Articolo in rivista - Articolo scientifico
LHC, CMS, proton-lead collisions
English
2023
131
5
051901
open
Tumasyan, A., Adam, W., Bergauer, T., Dragicevic, M., Del Valle, A., Fruhwirth, R., et al. (2023). Azimuthal Correlations within Exclusive Dijets with Large Momentum Transfer in Photon-Lead Collisions. PHYSICAL REVIEW LETTERS, 131(5) [10.1103/PhysRevLett.131.051901].
File in questo prodotto:
File Dimensione Formato  
10281-453723_VoR.pdf

accesso aperto

Tipologia di allegato: Publisher’s Version (Version of Record, VoR)
Licenza: Creative Commons
Dimensione 33.2 MB
Formato Adobe PDF
33.2 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/453723
Citazioni
  • Scopus 3
  • ???jsp.display-item.citation.isi??? 2
Social impact