Some of semileptonic and nonleptonic decays of B c meson in a Bethe-Salpeter relativistic quark model

Abstract

The semileptonic decays B + c → P(V) + + +ν and the nonleptonic decays B + c → P(V) + L, where P(V) denotes a pseudoscalar (vector) charmonium or (bs)-meson, and L denotes a light meson, are studied in the framework of improved instantaneous BetheSalpeter (BS) equation and the Mandelstam formula. The numerical results (width and branching ratio of the decays) are presented in tables, and in order to compare conveniently, those obtained by other approaches are also put in the relevant tables. Based on the fact that the ratio−0.040 estimated here is in good agreement with the observation by LHCb, one may conclude that with respect to the decays the present framework works quite well. B c meson, Bethe-Salpeter quark model, decay PACS number(s): 13.20.He, 13.20Fc, 13.25.Ft, 13.25.Hw, 11.10.St Citation: Chang C H, Fu H F, Wang G L, et al. Some of semileptonic and nonleptonic decays of B c meson in a Bethe-Salpeter relativistic quark model. Sci China-Phys Mech Astron, doi: 10.1007/s11433-015-5671-x B c meson carries two heavy flavor quantum numbers explicitly, and it decays only via weak interactions, although the strong and electromagnetic interactions can affect the decays.As consequences, B c meson has a comparatively long lifetime and very rich weak decay channels with sizable branching ratios. Being an explicit double heavy flavor meson, its production cross section can be estimated by perturbative QCD quite reliably and one can conclude that only via strong interaction and at hadronic high energy collisions the meson can be produced so numerously that it can be observed experimentally [1][2][3]. Therefore, the meson is specially interesting in studying its production and decays both.The first successful observation of B c was achieved *Corresponding authors (CHANG ChaoHsi, through the semileptonic decay channel B c → J/ψ + + +ν by CDF collaboration in 1998 from Run-I at Tevatron. They obtained the mass of B c : m B c = 6.40 ± 0.39 ± 0.13 GeV and the lifetime: τ B c = 0.46 +0.18 −0.16 ± 0.03 ps [4]. Later on CDF collaboration further gave a more precise mass m B c = 6275.6 ± 2.9(stat) ± 5(syst) MeV/c 2 obtained through the exclusive non-leptonic decay B c → J/ψπ + [5], and upgraded their results [6]. In the meantime D0 collaboration at Tevatron also carried out the observations and confirmed CDF results [7]. Recently LHCb reported several new observations on B c decays [8]. Thus we may reasonably expect that at LHCb in the near future the B c data will be largely enhanced and new results are issued in time.In literatures, there are many works studying various B c decays [9-28] under different approaches. Among the approaches in the market, the one used in ref. [9] is that when

Relativistic effects in the semileptonic Bc decays to charmonium with the Bethe-Salpeter method

“…BS equation for a quark-antiquark bound state generally is written as [40] ( 0.000443 0.00185 0.00220 0.000562 16% Table 8. Comparisons of the branch ratios of B + c → (cc) + τ + + ν τ obtained by different ways, where q 0 means the leading order result; sum means the summed values of expanded items; BS means the result by BS method without expansion, and NR means the result by the non-relativistic wave function and the leading order expansion of the amplitude (in 10 −5 except the last column).…”

Relativistic corrections to the form factors of B into P-wave orbitally excited charmonium

“…The recent works on the B c two-body and quasi-two-body decays can be found in Refs. [36][37][38][39][40][41]. In this paper, we will calculate the relativistic corrections to the form factors of the B c meson decays into P -wave charmonia, i.e.…”

The strong decays of X(3940) and X(4160)

“…Using the improved BS method, we calculated the weak decay of B c to η c (1S) and η c (2S) [30], and the weak decay of B c to η c (3S) and η c (4S) [31]. Nobody has calculated B c to η c (4S), but the results of B c to η c (1S), η c (2S), η c (3S) were close to the other theoretical results.…”