Study of a Solution with COTS for the LHCb Calorimeter Upgrade

AbstractWe present a solution made out of Components Out of Shelf (COTS) for the analog processing of the signal of the LHCb calorimeters in the framework of the foreseen upgrade of the detector. The present proposal is based on the current functional solution, yet, to meet the stringent noise requirements, a number of modifications are proposed. Preliminary results on the prototype boards show promising results

Model-Independent Observation of Exotic Contributions to B degrees -> J/psi K+pi(-) Decays

An angular analysis of B degrees -> J/psi K+pi(-) decays is performed, using proton-proton collision data corresponding to an integrated luminosity of 3 fb(-1) collected with the LHCb detector. The m(K+pi(-) ) spectrum is divided into fine bins. In each m(K+pi(-)) bin, the hypothesis that the three-dimensional angular distribution can be described by structures induced only by K* resonances is examined, making minimal assumptions about the K+pi(-) system. The data reject the K*-only hypothesis with a large significance, implying the observation of exotic contributions in a model-independent fashion. Inspection of the m(J/psi pi(-)) vs m(K+pi(-)) plane suggests structures near m(J/psi pi(-)) = 4200 and 4600 MeV

Measurement of the mass difference and relative production rate of the ωb- and Ξb- baryons

The mass difference between the ωb- and Ξb- baryons is measured using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb-1, and is found to be m(ωb-)-m(Ξb-)=248.54±0.51(stat)±0.38(syst) MeV/c2. The mass of the ωb- baryon is measured to be m(ωb-)=6045.9±0.5(stat)±0.6(syst) MeV/c2. This is the most precise determination of the ωb- mass to date. In addition, the production rate of ωb- baryons relative to that of Ξb- baryons is measured for the first time in pp collisions, using an LHCb dataset collected at a center-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 6 fb-1. Reconstructing beauty baryons in the kinematic region 2<η<6 and pT<20 GeV/c with their decays to a J/ψ meson and a hyperon, the ratio fωb-fΞb-×B(ωb-→J/ψω-)B(Ξb-→J/ψΞ-)=0.120±0.008(stat)±0.008(syst), is obtained, where fωb- and fΞb- are the fragmentation fractions of b quarks into ωb- and Ξb- baryons, respectively, and B represents the branching fractions of their respective decays