Search results for "LHCB"
showing 6 items of 36 documents
First Observation of Top Quark Production in the Forward Region
2015
Top quark production in the forward region in proton-proton collisions is observed for the first time. The W + b final state with W → μν is reconstructed using muons with a transverse momentum, p[subscript T], larger than 25 GeV in the pseudorapidity range 2.0 20 GeV. The results are based on data corresponding to integrated luminosities of 1.0 and 2.0 fb[superscript -1] collected at center-of-mass energies of 7 and 8 TeV by LHCb. The inclusive top quark production cross sections in the fiducial region are σ(top)[7 TeV] = 239 ± 53(stat) ± 33(syst) ± 24(theory) fb, σ(top)[8 TeV] = 289 ± 43(stat) ± 40(syst) ± 29(theory) fb.These results, along with the observed differential yields and c…
Search for weakly decaying b -flavored pentaquarks
2018
Investigations of the existence of pentaquark states containing a single $b$ (anti)quark decaying weakly into four specific final states J/$\psi K^+\pi^- p$, J/$\psi K^- \pi^- p$, J/$\psi K^- \pi^+ p$, and $J/\psi \phi (1020) p$ are reported. The data sample corresponds to an integrated luminosity of 3.0/fb in 7 and 8 TeV pp collisions acquired with the LHCb detector. Signals are not observed and upper limits are set on the product of the production cross section times branching fraction with respect to that of the $\Lambda_b$.
Observation of the rare B(s)(0) + decay from the combined analysis of CMS and LHCb data.
2015
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported licence.-- et al.
Precision Measurement of the Mass and Lifetime of the Xi(-)(b) Baryon
2016
We report on measurements of the mass and lifetime of the Ξ[- over b] baryon using about 1800 Ξ[- over b] decays reconstructed in a proton-proton collision data set corresponding to an integrated luminosity of 3.0 fb[superscript -1] collected by the LHCb experiment. The decays are reconstructed in the Ξ[- over b] → Ξ[0 over c]π[superscript -], Ξ[0 over c] → pK[superscript -]K[superscript -]π[superscript +] channel and the mass and lifetime are measured using the Λ[0 over b] → Λ[+ over c]π[superscript -] mode as a reference. We measure M(Ξ[- over b] - M(Λ[0 over b]) = 178.36 ± 0.46 ± 0.16 MeV/c[superscript 2], (τ[subscript Ξ[- over b]/τ[subscript Λ[0 over b]) = 1.089 ± 0.026 ± 0.011, where…
Study of Bs->PhiGamma decays at LHCb
2021
This thesis describes two different analyses performed at LHCb using the B0s→φγ and B0→K∗0γ decay channels. First, the measurement of the ratio of branching fractions B(B0→K∗0γ)/B(B0s→φγ) is presented, giving the most precise value for B(B0s→φγ) to date. Secondly, the CP-violating observables S and C, as well as the mixing-induced A∆ parameter are measured through a time-dependent analysis of the B0s→φγ decay channel, this being the first time the S and C observables are probed in the Bs system. These studies are performed using data collected in 2011 and 2012 by the LHCb experiment at CERN, corresponding to an integrated luminosity of 3.0 fb−1 of pp collisions at a center-of-mass energy of…
Study of Long-Lived particles beyond the Standard Model at LHCb
2022
Long-lived particles are predicted in many extensions of the Standard Model but the experimental detection is very challenging because they decay out of the first trackers and usually scape to the trigger decisions. In this work we review several new physics models and summarize the experimental status concerning the related searches. We revise the capabilities of the high level trigger system of the LHCb experiment and evaluate the effect of the trigger to detect long-lived particles for two models: a previous work where Dark Higgs Model is assumed, and another one studied for first time in this work, the Composite Higgs involving light scalars signatures. A Montecarlo study about the deca…