Guo-Li Wang

Spectrum for heavy quarkonia and mixture of the relevant wave functions within the framework of Bethe-Salpeter equation

Considering the fact that some excited states of the heavy quarkonia (charmonium and bottomonium) are still missing in experimental observations and potential applications of the relevant wave functions of the bound states, we re-analyze the spectrum and the relevant wave functions of the heavy quarkonia within the framework of Bethe-Salpeter (B.S.) equation with a proper QCD-inspired kernel. Such a kernel for the heavy quarkonia, relating to potential of the non-relativistic quark model, is instantaneous, so we call the corresponding B.S. equation as BS-In equation throughout the paper. Particularly, a new way to solve the B.S. equation, which is different from the traditional ones, is proposed here, and with it not only the known spectrum for the heavy quarkonia is re-generated, but also an important issue is brought in, i.e., the obtained solutions of the equation ‘automatically’ include the ‘fine’, ‘hyperfine’ splittings and the wave function mixture, such as S-D wave mixing in JPC = 1−− states, P-F wave mixing in JPC = 2++ states for charmonium, bottomonium etc. It is pointed out that the best place to test the wave mixture probably is at Z-factory (e+e− collider running at Z-boson pole with extremely high luminosity).

Is Z b (10610) a molecular state

A bstractWhether molecular states indeed exist in nature has been disputed for a long time. Several new resonances have been observed in the recent experiments and they seem to be of exotic structures and some of them have been proposed to be molecular states. The very recent observation of Zb(10610)[(10608.4 ± 2.0) MeV] and Zb(10650)[(10653.2 ± 1.5) MeV] encourages the interpretation of multi-quark states. In the Beter-Salpeter (BS) approach, we study the possibility if two heavy mesons can form a molecular state by exchanging light mesons. Our results indicate that two heavy mesons can form an isospin singlet (I = 0) bound state but cannot form an isospin triplet (I = 1) when the contribution of σ- exchange is reasonably small, i.e. as the coupling of σ with mesons gσ takes the value given in previous literatures. Thus we conclude that the newly observed Zb(10610) should not be a molecular state, but a tetraquark state instead, at most, the fraction of the molecular state in the physical resonance Zb(10610) is tiny.

Lepton-number violating four-body decays of heavy mesons

A bstractNeutrinoless hadron Lepton Number Violating (LNV) decays can be induced by virtual Majorana neutrino, which in turn indubitably show the Majorana nature of neutrinos. Many three-body LNV processes and Lepton Flavour Violating (LFV) processes have been studied extensively in theory and by experiment. As a supplement, we here study 75 four-body LNV (LFV) processes from heavy pseudoscalar B and D decays. Most of these processes have not been studied in theory and searched for in experiment, while they may have sizable decay rates. Since the four-body decay modes have the same vertexes and mixing parameters with three-body cases, so their branching fractions are comparable with the corresponding three-body decays. We calculate their decay widths and branching fractions with current bounds on heavy Majorana neutrino mixing parameters, and estimate some channels’ reconstruction events using the current experimental data from Belle.

Two-body strong decay of Z(3930) as the χc2(2P) state

A bstractThe new particle Z(3930) found by the Belle and BaBar Collaborations through the

Semi-leptonic production of DsJ(3040) and DJ(3000) in Bs and B decays

\gamma \gamma \to D\overline{D}

D-wave charmonia \eta _{c2}(1^1\!D_2), \psi _2(1^3\!D_2), and \psi _3(1^3\!D_3) in B_c decays

process is identified to be the χc2(2P) state. Since the mass of this particle is above the

Annihilation rate of 2−+ charmonium and bottomonium

D{{\overline{D}}^{{\left( * \right)}}}

Testing the nature of neutrinos from four-body τ decays

threshold, the OZI-allowed two-body strong decays are the main decay modes. In this paper, these strong decay modes are studied with two methods. One is the instantaneous Bethe-Salpeter method within Mandelstam formalism. The other is the combination of the 3P0 model and the former formalism. The total decay widths are 26.3 MeV and 27.3 MeV for the methods with or without the 3P0 vertex, respectively. The ratio of

The rare semi-leptonic B c decays involving orbitally excited final mesons

{\varGamma_{{D\overline{D}}}}

Four-body decays of B meson with lepton number violation

over