Observation of the decay Bs0→D¯0

Abstract

The first observation of the B 0 s →D 0 K þ K − decay is reported, together with the most precise branching fraction measurement of the mode B 0 →D 0 K þ K −. The results are obtained from an analysis of pp collision data corresponding to an integrated luminosity of 3.0 fb −1. The data were collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV. The branching fraction of the B 0 →D 0 K þ K − decay is measured relative to that of the decay B 0 →D 0 π þ π − to be BðB 0 →D 0 K þ K − Þ BðB 0 →D 0 π þ π − Þ ¼ ð6.9 AE 0.4 AE 0.3Þ%, where the first uncertainty is statistical and the second is systematic. The measured branching fraction of the B 0 s →D 0 K þ K − decay mode relative to that of the corresponding B 0 decay is BðB 0 s →D 0 K þ K − Þ BðB 0 →D 0 K þ K − Þ ¼ ð93.0 AE 8.9 AE 6.9Þ%. Using the known branching fraction of B 0 →D 0 π þ π − , the values of BðB 0 →D 0 K þ K − Þ ¼ ð6.1AE0.4AE0.3AE0.3Þ×10 −5 and BðB 0 s →D 0 K þ K − Þ ¼ ð5.7AE0.5AE0.4AE0.5Þ×10 −5 are obtained, where the third uncertainties arise from the branching fraction of the decay modes B 0 →D 0 π þ π − and B 0 →D 0 K þ K − , respectively.

Rare two-body decays of the top quark into a bottom meson plus an up or charm quark

“…The top mass is one of the key parameters of the Standard Model (SM), chiefly affecting theoretical predictions of Higgs boson properties and searches for new physics beyond the SM (BSM), as well as playing a leading role in the stability of the electroweak vacuum at asymptotic energies [2]. Having at hand different methods to determine m t , 1 Hereafter, unless explicitly stated otherwise, the t → W + b → B 0 (s) + X decays quoted by default are meant to represent also the equivalent t → W − b → B 0 (s) + X charge-conjugate decays. and thereby precisely derive its value, is essential for testing the overall SM consistency, reducing parametric uncertainties in the extraction of other various key SM parameters, and constraining BSM models through precision electroweak fits.…”

Study of CKM angle $γ$ sensitivity using flavor untagged $B^0_s\rightarrow \tilde{D}^{(*)0}ϕ$ decays

“…24 Another expected improvement could come from a time-dependent CP Dalitz plane analysis of the decay B 0 s → D( * )0 CP K + K − as anticipated in Ref. [35]. With the ultimate HL-LHC LHCb dataset, it should be possible to perform such an analysis, thus including the B 0 s → D( * )0 φ decay, to extract the CKM angle γ, as proposed a few years ago in [36].…”

Evidence for the decays B0 → $$ \overline{D} $$(*)0ϕ and updated measurements of the branching fractions of the $$ {B}_s^0 $$ → $$ \overline{D} $$(*)0ϕ decays

“…Meanwhile, the measurement of γ with B 0 s mesons is presently based only on the decay modes B 0 s → D ∓ s K ± [17] and B 0 s → D ∓ s K ± π + π − [18], which leads to a combined constraint γ = (79 +21 −24 ) • [16]. Additional methods employing other B 0 s decay modes are therefore of interest to improve the precision of the constraint provided by B 0 s modes and to verify compatibility with the B + modes, which dominate the precision of γ. The decays B 0 s → D ( * )0 ϕ were previously observed by the LHCb collaboration in 2013 [19], and in 2018 [14], with data samples corresponding to integrated luminosities of 1 fb −1 and 3 fb −1 , respectively.…”