Bibcode
Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragicevic, M.; Erö, J.; Escalante Del Valle, A.; Flechl, M.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Grossmann, J.; Hrubec, J.; Jeitler, M.; König, A.; Krammer, N.; Krätschmer, I.; Liko, D.; Madlener, T.; Mikulec, I.; Pree, E.; Rad, N.; Rohringer, H.; Schieck, J.; Schöfbeck, R.; Spanring, M.; Spitzbart, D.; Taurok, A.; Waltenberger, W.; Wittmann, J.; Wulz, C.-E.; Zarucki, M.; Chekhovsky, V.; Mossolov, V.; Suarez Gonzalez, J.; De Wolf, E. A.; Di Croce, D.; Janssen, X.; Lauwers, J.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Abu Zeid, S.; Blekman, F.; D'Hondt, J.; De Bruyn, I.; De Clercq, J.; Deroover, K.; Flouris, G.; Lontkovskyi, D.; Lowette, S.; Marchesini, I.; Moortgat, S.; Moreels, L.; Python, Q.; Skovpen, K.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Parijs, I.; Beghin, D.; Bilin, B.; Brun, H.; Clerbaux, B.; De Lentdecker, G.; Delannoy, H.; Dorney, B.; Fasanella, G.; Favart, L.; Goldouzian, R.; Grebenyuk, A.; Kalsi, A. K.; Lenzi, T.; Luetic, J.; Maerschalk, T.; Marinov, A.; Seva, T.; Starling, E.; Vander Velde, C.; Vanlaer, P.; Vannerom, D.; Yonamine, R.; Zenoni, F.; Cornelis, T.; Dobur, D.; Fagot, A.; Gul, M.; Khvastunov, I.; Poyraz, D.; Roskas, C.; Salva, S.; Trocino, D.; Tytgat, M.; Verbeke, W.; Vit, M. et al.
Bibliographical reference
Physical Review Letters, Volume 121, Issue 24, id.242301
Advertised on:
12
2018
Journal
Citations
31
Refereed citations
28
Description
Measurements of fragmentation functions for jets associated with an
isolated photon are presented for the first time in p p and Pb-Pb
collisions. The analysis uses data collected with the CMS detector at
the CERN LHC at a nucleon-nucleon center-of-mass energy of 5.02 TeV.
Fragmentation functions are obtained for jets with
pTjet>30 GeV /c in events containing an
isolated photon with pTγ>60 GeV /c ,
using charged tracks with transverse momentum
pTtrk>1 GeV /c in a cone around the jet axis.
The association with an isolated photon constrains the initial
pT and azimuthal angle of the parton whose shower produced
the jet. For central Pb-Pb collisions, modifications of the jet
fragmentation functions are observed when compared to those measured in
p p collisions, while no significant differences are found in the 50%
most peripheral collisions. Jets in central Pb-Pb events show an excess
(depletion) of low (high) pT particles, with a transition
around 3 GeV /c . This measurement shows for the first time the
in-medium shower modifications of partons (quark dominated) with
well-defined initial kinematics. It constitutes a new well-controlled
reference for testing theoretical models of the parton passage through
the quark-gluon plasma.