Branching ratios and CP asymmetries of $$B\rightarrow \chi _{c1}K(\pi ) $$ B → χ c 1 K ( π ) decays

Abstract

We investigate the exclusive nonleptonic decays B → χ c1 K (π ) in the conventional perturbative QCD (PQCD) formalism. The predictions of branching ratios and C P asymmetries are given in detail. We compare our results with available experimental data as well as predictions of other theoretical studies existing in the literature. It seems that the branching ratios of B → χ c1 K are more consistent with data than the earlier analyses. For the Cabibbo-suppressed B s decays, the branching ratios can reach the order of 10 −5 , which would be straight forward for experimental observations. The numerical results show that the direct C P asymmetries of the concerned decays are rather small. The mixinginduced C P asymmetry in the B 0 → χ c1 K S is very close to sin 2β, which suggests that this channel offer an alternative method for measuring the Cabbibo-Kobayashi-Maskawa (CKM) angle β. The obtained results in the present work could be tested by further experiments in the LHCb and forthcoming Belle II.

Revisiting nonfactorizable contributions to factorization-forbidden decays of $B$ mesons to charmonium

“…For the factorization-inhibited B decays in question, only the nonfactorization spectator diagrams contribute, which are displayed in Fig 1 . In the rest frame of the B meson, we define P i and k i with i = 1, 2, 3 to be the four-momenta of the mesons and quarks in the initial and final states, as indicated in Fig 1 . In the light-cone coordinates, they are parametrized as [54]…”

“…Using the same definition in Ref. [54], we study direct CP violation A dir CP and mixing-induced CP asymmetry S for the decays in question. The two CP -violating parameters can be expressed as…”

“…Motivated by the same idea, we have reason to believe that it is appropriate to analyze other factorization-inhibited decays, such as B → χ c2 K, in the PQCD approach. Moreover, we update the P -wave charmonium distribution amplitudes (DAs) according to our previous work [52], where the new universal nonperturbative objects are successful in describing the P -wave charmonium decays of B/B c meson [52][53][54].…”

Semileptonic decays of Bc meson to P -wave charmonium states

“…As a successive work of [15,41,42], in this paper, we do not attempt to resolve the R(J/ψ) anomaly beyond the SM, but provide more reliable calculations of those orbitally excited state modes within the SM. A future improvable measurement might reveal whether a similar anomaly also exists in R(X).…”