A measurement of the ratio of branching fractions 𝑅(𝐽/𝜓) =ℬ(𝐵+𝑐 →𝐽/𝜓𝜏+𝜈𝜏)/ℬ(𝐵+𝑐 →𝐽/𝜓𝜇+𝜈𝜇) in the 𝐽/𝜓 →𝜇+𝜇−, 𝜏+→𝜇+𝜈𝜇¯𝜈𝜏 decay channel is presented. This measurement uses a sample of proton-proton collision data collected at a center-of-mass energy of 13 TeV by the CMS experiment in 2018, corresponding to an integrated luminosity of 59.7 fb−1. The measured ratio, 𝑅(𝐽/𝜓) = 0.17+0.18−0.17(stat)+0.21−0.22(syst)+0.19−0.18(theo) = 0.17 ±0.33, agrees with the value of 0.2582 ±0.0038 predicted by the standard model, which assumes lepton flavor universality. By testing lepton flavor universality, this measurement is a probe of new physics using 𝐵+𝑐 mesons, which are currently only produced at the LHC.
Test of lepton flavor universality in semileptonic Bc+ meson decays in proton-proton collisions at sqrt(s) = 13 TeV
Cavallo, N.;Fabozzi, F.;
2025-01-01
Abstract
A measurement of the ratio of branching fractions 𝑅(𝐽/𝜓) =ℬ(𝐵+𝑐 →𝐽/𝜓𝜏+𝜈𝜏)/ℬ(𝐵+𝑐 →𝐽/𝜓𝜇+𝜈𝜇) in the 𝐽/𝜓 →𝜇+𝜇−, 𝜏+→𝜇+𝜈𝜇¯𝜈𝜏 decay channel is presented. This measurement uses a sample of proton-proton collision data collected at a center-of-mass energy of 13 TeV by the CMS experiment in 2018, corresponding to an integrated luminosity of 59.7 fb−1. The measured ratio, 𝑅(𝐽/𝜓) = 0.17+0.18−0.17(stat)+0.21−0.22(syst)+0.19−0.18(theo) = 0.17 ±0.33, agrees with the value of 0.2582 ±0.0038 predicted by the standard model, which assumes lepton flavor universality. By testing lepton flavor universality, this measurement is a probe of new physics using 𝐵+𝑐 mesons, which are currently only produced at the LHC.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.


