@article{f34522b7c5ba4d74b21160c063dd14cd,
title = "Observation of Medium-Induced Modifications of Jet Fragmentation in Pb-Pb Collisions at sNN =5.02 TeV Using Isolated Photon-Tagged Jets",
abstract = "Measurements of fragmentation functions for jets associated with an isolated photon are presented for the first time in pp 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 pp 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.",
author = "{(CMS Collaboration)} and Sirunyan, {A. M.} and A. Tumasyan and W. Adam and F. Ambrogi and E. Asilar and T. Bergauer and J. Brandstetter and E. Brondolin and M. Dragicevic and J. Er{\"o} and {Escalante Del Valle}, A. and M. Flechl and M. Friedl and R. Fr{\"u}hwirth and Ghete, {V. M.} and J. Grossmann and J. Hrubec and M. Jeitler and A. K{\"o}nig and N. Krammer and I. Kr{\"a}tschmer and D. Liko and T. Madlener and I. Mikulec and E. Pree and N. Rad and H. Rohringer and J. Schieck and R. Sch{\"o}fbeck and M. Spanring and D. Spitzbart and A. Taurok and W. Waltenberger and J. Wittmann and Wulz, {C. E.} and M. Zarucki and V. Chekhovsky and V. Mossolov and {Suarez Gonzalez}, J. and {De Wolf}, {E. A.} and {Di Croce}, D. and X. Janssen and J. Lauwers and {Van De Klundert}, M. and {Van Haevermaet}, H. and {Van Mechelen}, P. and {Van Remortel}, N. and {Abu Zeid}, S. and F. Blekman and Lee, {J. S.H.}",
note = "Publisher Copyright: {\textcopyright} 2018 CERN, for the CMS Collaboration. Published by the American Physical Society under the terms of the »https://creativecommons.org/licenses/by/4.0/» Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP.",
year = "2018",
month = dec,
day = "14",
doi = "10.1103/PhysRevLett.121.242301",
language = "English",
volume = "121",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "24",
}