M. van Veghel

First observation of forward Z -> b(b)over-bar production in pp collisions at root s=8 TeV

Abstract The decay Z → b b ¯ 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 → b b ¯ 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 p T > 20 GeV and dijet invariant mass in the range 45 m j j 165 GeV. From a signal yield of 5462 ± 763 Z → b b ¯ 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 → b b ¯ production in the forward region of pp collisions.

Search for excited B-c(+) states

A bstractA search is performed in the invariant mass spectrum of the Bc+π+π− system for the excited Bc+ states Bc(21S0)+ and Bc(23S1)+ using a data sample of pp collisions collected by the LHCb experiment at the centre-of-mass energy of s=8

Measurement of the Ω 0 c Baryon Lifetime

\sqrt{s}=8

Studies of the resonance structure in D0→K∓π±π±π∓D0→K∓π±π±π∓decays

TeV, corresponding to an integrated luminosity of 2 fb−1. No evidence is seen for either state. Upper limits on the ratios of the production cross-sections of the Bc(21S0)+ and Bc(23S1)+ states times the branching fractions of Bc(21S0)+ → Bc+π+π− and Bc(23S1)+ → Bc*+π+π− over the production cross-section of the Bc+ state are given as a function of their masses. They are found to be between 0.02 and 0.14 at 95% confidence level for Bc(21S0)+ and Bc(23S1)+ in the mass ranges [6830, 6890] MeV/c2 and [6795, 6890] MeV/c2, respectively.

Erratum to: Measurement of the J/psi pair production cross-section in pp collisions at root s = 13 TeV (vol 6, 47, 2017)

A bstractA search for B+ → Ds+K+K− decays is performed using pp collision data corresponding to an integrated luminosity of 4.8 fb−1, collected at centre-of-mass energies of 7, 8 and 13 TeV with the LHCb experiment. A significant signal is observed for the first time and the branching fraction is determined to be ℬB+→Ds+K+K−=7.1±0.5±0.6±0.7×10−6,