Spectroscopy,decay properties and Regge trajectories of the B and B_s mesons

A Gaussian wave function is used for detailed study of the mass spectra of the B and BS mesons using a Cornell potential incorporated with a O(1/m) correction in the potential energy term and expansion of the kinetic energy term up to O p~(10) for relativistic correction of the Hamiltonian.The predicted excited states for the B and B_s mesons are in very good agreement with results obtained by experiment.We assign B_2(5747) and B_(s2()5840) as the 1~3P~2 state,B1(5721) and Bs1(5830) as the 1P_1 state,B0(5732) as the 1~3P_0 state,B_(s1)(5850) as the 1~P 1 state and B(5970) as the 2~3S_1 state.We investigate the Regge trajectories in the(J,M~2) and(nr,M~2) planes with their corresponding parameters.The branching ratios for leptonic and radiative-leptonic decays are estimated for the B and BS mesons.Our results are in good agreement with experimental observations as well as outcomes of other theoretical models.     

Spectroscopy and decay properties of charmonium

The mass spectra of charmonium are investigated using a Coulomb plus linear(Cornell)potential.Gaussian wave functions in position space as well as in momentum space are employed to calculate the expectation values of potential and kinetic energy respectively.Various experimental states(X(4660)(5~3S_1),X(3872)(2~3P_1),X(3900)(2~1P_1),X(3915)(2~3P_0)and X(4274)(3~3P_1)etc.)are assigned as charmonium states.We also study the Regge trajectories,pseudoscalar and vector decay constants,electric and magnetic dipole transition rates,and annihilation decay widths for charmonium states.     

B → F + X decay and pseudoscalar decay constants of explicitly flavored heavy mesons

If the current theoretical pictures of explicitly flavored heavy mesons are quantitatively correct, we expect that the branching ratio of B → $\text{F}$ + X (anything) may be 6 percent even in a conservative estimate. Accurate measurement of this branching ratio will determine the value of the pseudoscalar decay constant f_F, of the wave function at origin of the s wave $\text{c}$ s bound state in the potential picture, and help to clarify dynamical properties of heavy meson binding.     

Spectrum and decay constants of heavy-light mesons

Heavy-light mesons masses and decay constants are calculated within the framework of the field correlator model. Good agreement is obtained with the experimental data.     

Lepton decay constants of light mesons

A theory of lepton decay constants based on the path-integral formalism is given for chiral and vector mesons. Decay constants of the pseudoscalar and vector mesons are calculated and compared to other existing results.     

Bs and Ds decay constants in three-flavor lattice QCD

Capitalizing on recent advances in lattice QCD, we present a calculation of the leptonic decay constants f(B(s)) and f(D(s)) that includes effects of one strange sea quark and two light sea quarks via an improved staggered action. By shedding the quenched approximation and the associated lattice scale uncertainty, lattice QCD greatly increases its predictive power. Nonrelativistic QCD is used to simulate heavy quarks with masses between 1.5m(c) and m(b). We arrive at the following results: f(B(s))=260+/-7+/-26+/-8+/-5 and f(D(s))=290+/-20+/-29+/-29+/-6 MeV. The first quoted error is the statistical uncertainty, and the rest estimate the sizes of higher order terms neglected in this calculation. All of these uncertainties are systematically improvable by including another order in the weak coupling expansion, the nonrelativistic expansion, or the Symanzik improvement program.     

Excited state mass spectra,decay properties and Regge trajectories of charm and charm-strange mesons

The framework of a phenomenological quark-antiquark potential(Coulomb plus linear confinement)model with a Gaussian wave function is used for detailed study of masses of the ground, orbitally and radially excited states of heavy-light Qq,(Q=c,q=u/d,s) mesons. We incorporate a O(1/m) correction to the potential energy term and relativistic corrections to the kinetic energy term of the Hamiltonian. The spin-hyperfine, spin-orbit and tensor interactions incorporating the effect of mixing are employed to obtain the pseudoscalar, vector, radially and orbitally excited state meson masses. The Regge trajectories in the(J,M~2) and(nr,M~2) planes for heavy-light mesons are investigated with their corresponding parameters. Leptonic and radiative leptonic decay widths and corresponding branching ratios are computed. The mixing parameters are also estimated. Our predictions are in good agreement with experimental results as well as lattice and other theoretical models.