Dielectron and heavy-quark production in inelastic and high-multiplicity proton–proton collisions at s=13TeV

ALICE Collaboration

doi:10.1016/j.physletb.2018.11.009

Dielectron and heavy-quark production in inelastic and high-multiplicity proton–proton collisions at s=13TeV

ALICE Collaboration

Physics Education

Variable Energy Cyclotron Centre India
University of California at Berkeley
Czech Academy of Sciences
Lund University
Panjab University
CERN
Polytechnic University of Turin
Indian Institute of Technology Bombay
Korea Institute of Science and Technology Information
Yale University
Alikhanov Institute for Theoretical and Experimental Physics
GSI Helmholtz Centre for Heavy Ion Research
Universidade Estadual de Campinas
Russian Research Centre Kurchatov Institute
National Institute for Nuclear Physics
Universidad Nacional Autónoma de México
COMSATS University Islamabad
Enrico Fermi Center
University of Bologna
NASU - Bogolyubov Institute for Theoretical Physics
University of Bergen
Goethe University Frankfurt
St. Petersburg State University
Central China Normal University
Horia Hulubei National Institute of Physics and Nuclear Engineering
University of Birmingham
University of Münster
Heidelberg University
Creighton University
Ruder Boskovic Institute
University of Houston
Lawrence Berkeley National Laboratory
Nantes Université
Technical University of Munich
Technische Universität München
University of Oslo
Aligarh Muslim University

Research output: Contribution to journal › Journal article › peer-review

35 Scopus citations

Abstract

The measurement of dielectron production is presented as a function of invariant mass and transverse momentum (p_T) at midrapidity (|y_e|<0.8) in proton–proton (pp) collisions at a centre-of-mass energy of s=13 TeV. The contributions from light-hadron decays are calculated from their measured cross sections in pp collisions at s=7 TeV or 13 TeV. The remaining continuum stems from correlated semileptonic decays of heavy-flavour hadrons. Fitting the data with templates from two different MC event generators, PYTHIA and POWHEG, the charm and beauty cross sections at midrapidity are extracted for the first time at this collision energy: dσ_cc¯/dy|_y=0=974±138(stat.)±140(syst.)±214(BR)μb and dσ_bb¯/dy|_y=0=79±14(stat.)±11(syst.)±5(BR)μb using PYTHIA simulations and dσ_cc¯/dy|_y=0=1417±184(stat.)±204(syst.)±312(BR)μb and dσ_bb¯/dy|_y=0=48±14(stat.)±7(syst.)±3(BR)μb for POWHEG. These values, whose uncertainties are fully correlated between the two generators, are consistent with extrapolations from lower energies. The different results obtained with POWHEG and PYTHIA imply different kinematic correlations of the heavy-quark pairs in these two generators. Furthermore, comparisons of dielectron spectra in inelastic events and in events collected with a trigger on high charged-particle multiplicities are presented in various p_T intervals. The differences are consistent with the already measured scaling of light-hadron and open-charm production at high charged-particle multiplicity as a function of p_T. Upper limits for the contribution of virtual direct photons are extracted at 90% confidence level and found to be in agreement with pQCD calculations.

Original language	English
Pages (from-to)	505-518
Number of pages	14
Journal	Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume	788
DOIs	https://doi.org/10.1016/j.physletb.2018.11.009
State	Published - 2019.01.10

Quacquarelli Symonds(QS) Subject Topics

Physics & Astronomy

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10.1016/j.physletb.2018.11.009

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@article{70ba421095b74a65bf6cb306d2dc7e6b,

title = "Dielectron and heavy-quark production in inelastic and high-multiplicity proton–proton collisions at s=13TeV",

abstract = "The measurement of dielectron production is presented as a function of invariant mass and transverse momentum (pT) at midrapidity (|ye|<0.8) in proton–proton (pp) collisions at a centre-of-mass energy of s=13 TeV. The contributions from light-hadron decays are calculated from their measured cross sections in pp collisions at s=7 TeV or 13 TeV. The remaining continuum stems from correlated semileptonic decays of heavy-flavour hadrons. Fitting the data with templates from two different MC event generators, PYTHIA and POWHEG, the charm and beauty cross sections at midrapidity are extracted for the first time at this collision energy: dσcc¯/dy|y=0=974±138(stat.)±140(syst.)±214(BR)μb and dσbb¯/dy|y=0=79±14(stat.)±11(syst.)±5(BR)μb using PYTHIA simulations and dσcc¯/dy|y=0=1417±184(stat.)±204(syst.)±312(BR)μb and dσbb¯/dy|y=0=48±14(stat.)±7(syst.)±3(BR)μb for POWHEG. These values, whose uncertainties are fully correlated between the two generators, are consistent with extrapolations from lower energies. The different results obtained with POWHEG and PYTHIA imply different kinematic correlations of the heavy-quark pairs in these two generators. Furthermore, comparisons of dielectron spectra in inelastic events and in events collected with a trigger on high charged-particle multiplicities are presented in various pT intervals. The differences are consistent with the already measured scaling of light-hadron and open-charm production at high charged-particle multiplicity as a function of pT. Upper limits for the contribution of virtual direct photons are extracted at 90\% confidence level and found to be in agreement with pQCD calculations.",

author = "\{ALICE Collaboration\} and S. Acharya and F. Torales-Acosta and D. Adamov{\'a} and J. Adolfsson and Aggarwal, \{M. M.\} and \{Aglieri Rinella\}, G. and M. Agnello and N. Agrawal and Z. Ahammed and Ahn, \{S. U.\} and S. Aiola and A. Akindinov and M. Al-Turany and Alam, \{S. N.\} and Albuquerque, \{D. S.D.\} and D. Aleksandrov and B. Alessandro and \{Alfaro Molina\}, R. and Y. Ali and A. Alici and A. Alkin and J. Alme and T. Alt and L. Altenkamper and I. Altsybeev and Anaam, \{M. N.\} and C. Andrei and D. Andreou and Andrews, \{H. A.\} and A. Andronic and M. Angeletti and V. Anguelov and C. Anson and T. Anti{\v c}i{\'c} and F. Antinori and P. Antonioli and R. Anwar and N. Apadula and L. Aphecetche and H. Appelsh{\"a}user and S. Arcelli and R. Arnaldi and Arnold, \{O. W.\} and Arsene, \{I. C.\} and M. Arslandok and A. Augustinus and R. Averbeck and Azmi, \{M. D.\} and A. Badal{\`a} and Kim, \{E. J.\}",

note = "Publisher Copyright: {\textcopyright} 2018 The Author",

year = "2019",

month = jan,

day = "10",

doi = "10.1016/j.physletb.2018.11.009",

language = "English",

volume = "788",

pages = "505--518",

journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",

issn = "0370-2693",

}

TY - JOUR

T1 - Dielectron and heavy-quark production in inelastic and high-multiplicity proton–proton collisions at s=13TeV

AU - ALICE Collaboration

AU - Acharya, S.

AU - Torales-Acosta, F.

AU - Adamová, D.

AU - Adolfsson, J.

AU - Aggarwal, M. M.

AU - Aglieri Rinella, G.

AU - Agnello, M.

AU - Agrawal, N.

AU - Ahammed, Z.

AU - Ahn, S. U.

AU - Aiola, S.

AU - Akindinov, A.

AU - Al-Turany, M.

AU - Alam, S. N.

AU - Albuquerque, D. S.D.

AU - Aleksandrov, D.

AU - Alessandro, B.

AU - Alfaro Molina, R.

AU - Ali, Y.

AU - Alici, A.

AU - Alkin, A.

AU - Alme, J.

AU - Alt, T.

AU - Altenkamper, L.

AU - Altsybeev, I.

AU - Anaam, M. N.

AU - Andrei, C.

AU - Andreou, D.

AU - Andrews, H. A.

AU - Andronic, A.

AU - Angeletti, M.

AU - Anguelov, V.

AU - Anson, C.

AU - Antičić, T.

AU - Antinori, F.

AU - Antonioli, P.

AU - Anwar, R.

AU - Apadula, N.

AU - Aphecetche, L.

AU - Appelshäuser, H.

AU - Arcelli, S.

AU - Arnaldi, R.

AU - Arnold, O. W.

AU - Arsene, I. C.

AU - Arslandok, M.

AU - Augustinus, A.

AU - Averbeck, R.

AU - Azmi, M. D.

AU - Badalà, A.

AU - Kim, E. J.

PY - 2019/1/10

Y1 - 2019/1/10

N2 - The measurement of dielectron production is presented as a function of invariant mass and transverse momentum (pT) at midrapidity (|ye|<0.8) in proton–proton (pp) collisions at a centre-of-mass energy of s=13 TeV. The contributions from light-hadron decays are calculated from their measured cross sections in pp collisions at s=7 TeV or 13 TeV. The remaining continuum stems from correlated semileptonic decays of heavy-flavour hadrons. Fitting the data with templates from two different MC event generators, PYTHIA and POWHEG, the charm and beauty cross sections at midrapidity are extracted for the first time at this collision energy: dσcc¯/dy|y=0=974±138(stat.)±140(syst.)±214(BR)μb and dσbb¯/dy|y=0=79±14(stat.)±11(syst.)±5(BR)μb using PYTHIA simulations and dσcc¯/dy|y=0=1417±184(stat.)±204(syst.)±312(BR)μb and dσbb¯/dy|y=0=48±14(stat.)±7(syst.)±3(BR)μb for POWHEG. These values, whose uncertainties are fully correlated between the two generators, are consistent with extrapolations from lower energies. The different results obtained with POWHEG and PYTHIA imply different kinematic correlations of the heavy-quark pairs in these two generators. Furthermore, comparisons of dielectron spectra in inelastic events and in events collected with a trigger on high charged-particle multiplicities are presented in various pT intervals. The differences are consistent with the already measured scaling of light-hadron and open-charm production at high charged-particle multiplicity as a function of pT. Upper limits for the contribution of virtual direct photons are extracted at 90% confidence level and found to be in agreement with pQCD calculations.

AB - The measurement of dielectron production is presented as a function of invariant mass and transverse momentum (pT) at midrapidity (|ye|<0.8) in proton–proton (pp) collisions at a centre-of-mass energy of s=13 TeV. The contributions from light-hadron decays are calculated from their measured cross sections in pp collisions at s=7 TeV or 13 TeV. The remaining continuum stems from correlated semileptonic decays of heavy-flavour hadrons. Fitting the data with templates from two different MC event generators, PYTHIA and POWHEG, the charm and beauty cross sections at midrapidity are extracted for the first time at this collision energy: dσcc¯/dy|y=0=974±138(stat.)±140(syst.)±214(BR)μb and dσbb¯/dy|y=0=79±14(stat.)±11(syst.)±5(BR)μb using PYTHIA simulations and dσcc¯/dy|y=0=1417±184(stat.)±204(syst.)±312(BR)μb and dσbb¯/dy|y=0=48±14(stat.)±7(syst.)±3(BR)μb for POWHEG. These values, whose uncertainties are fully correlated between the two generators, are consistent with extrapolations from lower energies. The different results obtained with POWHEG and PYTHIA imply different kinematic correlations of the heavy-quark pairs in these two generators. Furthermore, comparisons of dielectron spectra in inelastic events and in events collected with a trigger on high charged-particle multiplicities are presented in various pT intervals. The differences are consistent with the already measured scaling of light-hadron and open-charm production at high charged-particle multiplicity as a function of pT. Upper limits for the contribution of virtual direct photons are extracted at 90% confidence level and found to be in agreement with pQCD calculations.

UR - https://www.scopus.com/pages/publications/85057849439

U2 - 10.1016/j.physletb.2018.11.009

DO - 10.1016/j.physletb.2018.11.009

M3 - Journal article

AN - SCOPUS:85057849439

SN - 0370-2693

VL - 788

SP - 505

EP - 518

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

ER -

Dielectron and heavy-quark production in inelastic and high-multiplicity proton–proton collisions at s=13TeV

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