TY - JOUR
T1 - Evidence for Top Quark Production in Nucleus-Nucleus Collisions
AU - Sirunyan, A. M.
AU - Tumasyan, A.
AU - Adam, W.
AU - Ambrogi, F.
AU - Bergauer, T.
AU - Dragicevic, M.
AU - Erö, J.
AU - Escalante Del Valle, A.
AU - Frühwirth, R.
AU - Jeitler, M.
AU - Krammer, N.
AU - Lechner, L.
AU - Liko, D.
AU - Madlener, T.
AU - Mikulec, I.
AU - Rad, N.
AU - Schieck, J.
AU - Schöfbeck, R.
AU - Spanring, M.
AU - Templ, S.
AU - Waltenberger, W.
AU - Wulz, C. E.
AU - Zarucki, M.
AU - Chekhovsky, V.
AU - Litomin, A.
AU - Makarenko, V.
AU - Suarez Gonzalez, J.
AU - Darwish, M. R.
AU - De Wolf, E. A.
AU - Di Croce, D.
AU - Janssen, X.
AU - Kello, T.
AU - Lelek, A.
AU - Pieters, M.
AU - Rejeb Sfar, H.
AU - Van Haevermaet, H.
AU - Van Mechelen, P.
AU - Van Putte, S.
AU - Van Remortel, N.
AU - Blekman, F.
AU - Bols, E. S.
AU - Chhibra, S. S.
AU - D’Hondt, J.
AU - De Clercq, J.
AU - Lontkovskyi, D.
AU - Lowette, S.
AU - Marchesini, I.
AU - Moortgat, S.
AU - Python, Q.
AU - Sanchez Rosas, L. J.
N1 - Publisher Copyright:
© 2020 CERN.
PY - 2020/11/24
Y1 - 2020/11/24
N2 - Ultrarelativistic heavy ion collisions recreate in the laboratory the thermodynamical conditions prevailing in the early universe up to 10-6 sec, thereby allowing the study of the quark-gluon plasma (QGP), a state of quantum chromodynamics (QCD) matter with deconfined partons. The top quark, the heaviest elementary particle known, is accessible in nucleus-nucleus collisions at the CERN LHC, and constitutes a novel probe of the QGP. Here, we report the first evidence for the production of top quarks in nucleus-nucleus collisions, using lead-lead collision data at a nucleon-nucleon center-of-mass energy of 5.02 TeV recorded by the CMS experiment. Two methods are used to measure the cross section for top quark pair production (σtt) via the selection of charged leptons (electrons or muons) and bottom quarks. One method relies on the leptonic information alone, and the second one exploits, in addition, the presence of bottom quarks. The measured cross sections, σtt=2.54-0.74+0.84 and 2.03-0.64+0.71 μb, respectively, are compatible with expectations from scaled proton-proton data and QCD predictions.
AB - Ultrarelativistic heavy ion collisions recreate in the laboratory the thermodynamical conditions prevailing in the early universe up to 10-6 sec, thereby allowing the study of the quark-gluon plasma (QGP), a state of quantum chromodynamics (QCD) matter with deconfined partons. The top quark, the heaviest elementary particle known, is accessible in nucleus-nucleus collisions at the CERN LHC, and constitutes a novel probe of the QGP. Here, we report the first evidence for the production of top quarks in nucleus-nucleus collisions, using lead-lead collision data at a nucleon-nucleon center-of-mass energy of 5.02 TeV recorded by the CMS experiment. Two methods are used to measure the cross section for top quark pair production (σtt) via the selection of charged leptons (electrons or muons) and bottom quarks. One method relies on the leptonic information alone, and the second one exploits, in addition, the presence of bottom quarks. The measured cross sections, σtt=2.54-0.74+0.84 and 2.03-0.64+0.71 μb, respectively, are compatible with expectations from scaled proton-proton data and QCD predictions.
UR - https://www.scopus.com/pages/publications/85097318502
U2 - 10.1103/PhysRevLett.125.222001
DO - 10.1103/PhysRevLett.125.222001
M3 - Article
C2 - 33315428
AN - SCOPUS:85097318502
SN - 0031-9007
VL - 125
JO - Physical Review Letters
JF - Physical Review Letters
IS - 22
M1 - 222001
ER -