First observation of forward Z → <i>b</i>(<i>b</i>)over-bar production in <i>pp</i> collisions at √<i>s</i>=8 TeV

Aaij, R, Adeva, B, Adinolfi, M, Ajaltouni, Z, Akar, S, Albrecht, J, Alessio, F, Alexander, M, Albero, A Alfonso, Ali, S
et al (show 823 more authors) (2018) First observation of forward Z → <i>b</i>(<i>b</i>)over-bar production in <i>pp</i> collisions at √<i>s</i>=8 TeV. PHYSICS LETTERS B, 776. pp. 430-439.

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The decay Z→bb¯ is reconstructed in pp collision data, corresponding to 2 fb−1 of integrated luminosity, collected by the LHCb experiment at a centre-of-mass energy of s=8 TeV. The product of the Z production cross-section and the Z→bb¯ branching fraction is measured for candidates in the fiducial region defined by two particle-level b-quark jets with pseudorapidities in the range 2.2<η<4.2, with transverse momenta pT>20 GeV and dijet invariant mass in the range 45<mjj<165 GeV. From a signal yield of 5462±763 Z→bb¯ events, where the uncertainty is statistical, a production cross-section times branching fraction of 332±46±59 pb is obtained, where the first uncertainty is statistical and the second systematic. The measured significance of the signal yield is 6.0 standard deviations. This measurement represents the first observation of the Z→bb¯ production in the forward region of pp collisions.

Item Type: Article
Depositing User: Symplectic Admin
Date Deposited: 12 Jan 2018 12:22
Last Modified: 10 Oct 2023 17:23
DOI: 10.1016/j.physletb.2017.11.066
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