Many measurements and searches for physics beyond the standard model at the LHC rely on the efficient identification of heavy-flavour jets, i.e. jets originating from bottom or charm quarks. In this paper, the discriminating variables and the algorithms used for heavy-flavour jet identification during the first years of operation of the CMS experiment in proton-proton collisions at a centre-of-mass energy of 13 TeV, are presented. Heavy-flavour jet identification algorithms have been improved compared to those used previously at centre-of-mass energies of 7 and 8 TeV. For jets with transverse momenta in the range expected in simulated t (t) over bar events, these new developments result in an efficiency of 68% for the correct identification of a b jet for a probability of 1% of misidentifying a light-flavour jet. The improvement in relative efficiency at this misidentification probability is about 15%, compared to previous CMS algorithms. In addition, for the first time algorithms have been developed to identify jets containing two b hadrons in Lorentz-boosted event topologies, as well as to tag c jets. The large data sample recorded in 2016 at a centre-of-mass energy of 13 TeV has also allowed the development of new methods to measure the efficiency and misidentification probability of heavy-flavour jet identification algorithms. The b jet identification efficiency is measured with a precision of a few per cent at moderate jet transverse momenta (between 30 and 300 GeV) and about 5% at the highest jet transverse momenta (between 500 and 1000 GeV).

Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV / Sirunyan, A.M., Tumasyan, A., Adam, W., Ambrogi, F., Asilar, E., Bergauer, T., Brandstetter, J., Brondolin, E., Dragicevic, M., Eroe, J., Del Valle, A.E., Flechl, M., Friedl, M., Fruehwirth, R., Ghete, V.M., Grossmann, J., Hrubec, J., Jeitler, M., Koenig, A., Krammer, N., et al.. - In: JOURNAL OF INSTRUMENTATION. - ISSN 1748-0221. - ELETTRONICO. - 13:(2018). [10.1088/1748-0221/13/05/P05011]

Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV

Creanza, D.;De Filippis, N.;Iaselli, G.;Maggi, G.;Pugliese, G.;
2018

Abstract

Many measurements and searches for physics beyond the standard model at the LHC rely on the efficient identification of heavy-flavour jets, i.e. jets originating from bottom or charm quarks. In this paper, the discriminating variables and the algorithms used for heavy-flavour jet identification during the first years of operation of the CMS experiment in proton-proton collisions at a centre-of-mass energy of 13 TeV, are presented. Heavy-flavour jet identification algorithms have been improved compared to those used previously at centre-of-mass energies of 7 and 8 TeV. For jets with transverse momenta in the range expected in simulated t (t) over bar events, these new developments result in an efficiency of 68% for the correct identification of a b jet for a probability of 1% of misidentifying a light-flavour jet. The improvement in relative efficiency at this misidentification probability is about 15%, compared to previous CMS algorithms. In addition, for the first time algorithms have been developed to identify jets containing two b hadrons in Lorentz-boosted event topologies, as well as to tag c jets. The large data sample recorded in 2016 at a centre-of-mass energy of 13 TeV has also allowed the development of new methods to measure the efficiency and misidentification probability of heavy-flavour jet identification algorithms. The b jet identification efficiency is measured with a precision of a few per cent at moderate jet transverse momenta (between 30 and 300 GeV) and about 5% at the highest jet transverse momenta (between 500 and 1000 GeV).
2018
Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV / Sirunyan, A.M., Tumasyan, A., Adam, W., Ambrogi, F., Asilar, E., Bergauer, T., Brandstetter, J., Brondolin, E., Dragicevic, M., Eroe, J., Del Valle, A.E., Flechl, M., Friedl, M., Fruehwirth, R., Ghete, V.M., Grossmann, J., Hrubec, J., Jeitler, M., Koenig, A., Krammer, N., et al.. - In: JOURNAL OF INSTRUMENTATION. - ISSN 1748-0221. - ELETTRONICO. - 13:(2018). [10.1088/1748-0221/13/05/P05011]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11589/138515
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