119252520
Charmonium spectroscopy and decays
In this talk, I review the recent experimental developments on charmonium. These mainly include the precision measurements of spin-singlet states $\etac$, $\etac(2S)$, $h_c$, studies of the charmonium-like states X(3872) and the $Y$ states. Charmonium transitions and decays are also discussed.
118663699
Experimental overview of charmonium spectroscopy
In this talk, I review the recent experimental results on charmonium spectroscopy from BESIII, Belle, BaBar and CLEOc. Below the open-charm threshold, the masses and widths of spin-singlet states eta_c, eta_c(2S), h_c are measured with high precision. Above the threshold, chi_{c2}(2P) is identified in the process gamma gamma -> chi_{c2}(2P) -> gamma D bar{D}; Evidence of X(3823) is found in the M(chi_{c1} gamma) invariant-mass distribution for B -> gamma chi_{c1} K decays, the measured properties are consistent with the missing psi_2(1^{2}D_2) state.
119308558
Vacuum stability and Higgs diphoton decay rate in the Zee-Babu model
A bstractAlthough recent Higgs data from ATLAS and CMS are compatible with a Standard Model (SM) signal at 2σ level, both experiments see indications for an excess in the diphoton decay channel, which points to new physics beyond the SM. Given such a low Higgs mass mH ~ 125 GeV, another sign indicating the existence of new physics beyond the SM is the vacuum stability problem, i.e., the SM Higgs quartic coupling may run to negative values at a scale below the Planck scale. In this paper, we study the vacuum stability and enhanced Higgs diphoton decay rate in the Zee-Babu model, which was used to generate tiny Majorana neutrino masses at two-loop level. We find that it is rather difficult to find overlapping regions allowed by the vacuum stability and diphoton enhancement constraints. As a consequence, it is almost inevitable to introduce new ingredients into the model, in order to resolve these two issues simultaneously.
118385962
Possibility of $\Sigma_{c}(2800)$ and $\Lambda_{c}(2940)^{+}$ as $S$-wave $D^{(*)}N$ molecular states
In this talk, we give a brief review of our work studying the possibility of $\Sigma_{c}(2800)$ and $\Lambda_{c}(2940)^{+}$ as $S$-wave $D^{(*)}N$ molecular states from QCD sum rules.
119204098
Strong decays of the radial excited states B(2S) and D(2S)
Abstract The strong OZI allowed decays of the first radial excited states B ( 2 S ) and D ( 2 S ) are studied in the instantaneous Bethe–Salpeter method, and by using these OZI allowed channels we estimate the full decay widths: Γ B 0 ( 2 S ) = 24.4 MeV , Γ B + ( 2 S ) = 23.7 MeV , Γ D 0 ( 2 S ) = 11.3 MeV and Γ D + ( 2 S ) = 11.9 MeV . We also predict the masses of them: M B 0 ( 2 S ) = 5.777 GeV , M B + ( 2 S ) = 5.774 GeV , M D 0 ( 2 S ) = 2.390 GeV and M D + ( 2 S ) = 2.393 GeV .
119433952
Scaling behavior of the overlap quark propagator in the Landau gauge
The properties of the momentum space quark propagator in Landau gauge are examined for the overlap quark action in quenched lattice QCD. Numerical calculations are done on three lattices with different lattice spacings and similar physical volumes to explore the approach of the quark propagator toward the continuum limit. We have calculated the nonperturbative momentum-dependent wave-function renormalization function $Z({\ensuremath{\zeta}}^{2};p)$ and the nonperturbative mass function $M(p)$ for a variety of bare quark masses and perform an extrapolation to the chiral limit. We find the behavior of $Z({\ensuremath{\zeta}}^{2};p)$ and $M(p)$ are in reasonable agreement between the two finer lattices in the chiral limit, however the data suggest that an even finer lattice is desirable. The large momentum behavior is examined to determine the quark condensate.
118388877
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.