Abstract
A measurement of the CP asymmetries Sf and {S}_{overline{f}} in B0 → D∓π± decays is reported. The decays are reconstructed in a dataset collected with the LHCb experiment in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV and corresponding to an integrated luminosity of 3.0 fb−1. The CP asymmetries are measured to be Sf = 0.058 ± 0.020(stat) ± 0.011(syst) and {S}_{overline{f}}=0.038pm 0.020left(mathrm{stat}right)pm 0.007left(mathrm{syst}right) . These results are in agreement with, and more precise than, previous determinations. They are used to constrain angles of the unitarity triangle, | sin (2β + γ) | and γ, to intervals that are consistent with the current world-average values.
Highlights
This paper presents a measurement of Sf and Sfwith B0 → D∓π± decays reconstructed in a dataset collected with the LHCb experiment in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV and corresponding to an integrated luminosity of 3.0 fb−1
The minimum distance of a track to a primary vertex (PV), the impact parameter (IP), is measured with a resolution of (15 + 29/pT) μm, where pT is the component of the momentum transverse to the beam, in GeV/c
As the quarks that accompany the b quark in B+ and B0 mesons differ, the SS calibration function is studied with B0 → J/ψ K∗0 decays from a sample that is disjoint to that used in the training of the boosted decision tree (BDT) classifiers
Summary
The LHCb detector [12, 13] is a single-arm forward spectrometer covering the pseudorapidity range 2–5, designed for the study of particles containing b or c quarks. The tracking system provides a measurement of the momentum, p, of charged particles with a relative uncertainty that varies from 0.5% at low momentum to 1.0% at 200 GeV/c. Different types of charged hadrons are distinguished using information from two ring-imaging Cherenkov detectors. Electrons and hadrons are identified by a calorimeter system consisting of scintillating-pad and preshower detectors, an electromagnetic calorimeter and a hadronic calorimeter. Decays of hadronic particles are described by EvtGen [19], in which final-state radiation is generated using Photos [20]. The interaction of the generated particles with the detector, and its response, are implemented using the Geant toolkit [21, 22] as described in ref. The interaction of the generated particles with the detector, and its response, are implemented using the Geant toolkit [21, 22] as described in ref. [23]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
