TY - JOUR
T1 - Azimuthal Correlations within Exclusive Dijets with Large Momentum Transfer in Photon-Lead Collisions
AU - Tumasyan, A.
AU - Adam, W.
AU - Bergauer, T.
AU - Dragicevic, M.
AU - Del Valle, A. Escalante
AU - Frühwirth, R.
AU - Jeitler, M.
AU - Krammer, N.
AU - Lechner, L.
AU - Thakur, S.
AU - CMS Collaboration
N1 - Publisher Copyright:
© 2023 CERN, for the CMS Collaboration.
PY - 2023/8/4
Y1 - 2023/8/4
N2 - 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.
AB - 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.
UR - https://www.scopus.com/pages/publications/85168371955
U2 - 10.1103/PhysRevLett.131.051901
DO - 10.1103/PhysRevLett.131.051901
M3 - Article
C2 - 37595238
AN - SCOPUS:85168371955
SN - 0031-9007
VL - 131
JO - Physical Review Letters
JF - Physical Review Letters
IS - 5
M1 - 051901
ER -