New Heavy-Light Mesons Q

Physical Review D, 2000

We present lattice results for the spectrum of mesons containing one heavy quark and of baryons containing one or two heavy quarks. The calculation is done in the quenched approximation using the NRQCD formalism for the heavy quark. We analyze the dependence of the mass splittings on both the heavy and the light quark masses. Meson P -state fine structure and baryon hyperfine splittings are resolved for the first time. We fix the b quark mass using both M B and M Λ b , and our best estimate is m M S b (m M S b ) = 4.35(10)( −3 +2 )(20) GeV. The spectrum, obtained by interpolation to m b , is compared with the experimental data.

Nuclear Physics B-Proceedings Supplements, 2000

We present highlights of the spectrum of mesons and baryons calculated using NRQCD for heavy quarks and tadpole improved clover action for the light quarks.

International Journal of Modern Physics A, 2005

Recent progress in the theory of B-meson decays is reviewed with emphasis on the aspects related to the B-factory data.

The European Physical Journal C

Inspired by the lower statistical information in the bottom sector, in this paper, we calculate the masses and the strong decays of excited B and $$B_s$$ B s mesons in the framework of heavy quark effective theory (HQET). Using an effective chiral Lagrangian approach based on heavy quark spin-flavor and light quark chiral symmetry, we explore the flavor independent parameters $$\varDelta _F^{(c)} = \varDelta _F^{(b)}$$ Δ F ( c ) = Δ F ( b ) and $$\lambda _F^{(c)} = \lambda _F^{(b)}$$ λ F ( c ) = λ F ( b ) to calculate the masses of experimentally unknown bottom mesons. Our predictions are consistent with the available experimental results and other theoretical studies. Their strong decay to the ground state bottom mesons plus light pseudoscalar mesons is calculated in terms of the square of the couplings $$g_H$$ g H , $$g_S$$ g S , $$g_T$$ g T , $$g_X$$ g X , $$g_Y$$ g Y , and $$g_R$$ g R . The weighted average value of the couplings $$g_H$$ g H , $$g_S$$ g S and $$g_T$$ g T is obta...

Assuming Coulomb-like as well as confining scalar potential, we have solved Shrödinger equation perturbatively in 1/m Q with a heavy quark mass m Q . The lowest order equation is examined carefully. Mass levels are fitted with experimental data for D/B mesons at each level of perturbation. Meson wave functions obtained thereby can be used to calculate ordinary form factors as well as Isgur-Wise functions for semileptonic weak decays and other physical quantities. All the above calculations are expanded in 1/m Q order by order to determine parameters as well as to compare with results of Heavy Quark Effective Theory.

Physical Review D, 2009

We investigate the exclusive semileptonic Bc → (D, ηc, B, Bs)ℓν ℓ , η b → Bcℓν ℓ (ℓ = e, µ, τ) decays using the light-front quark model constrained by the variational principle for the QCD motivated effective Hamiltonian. The form factors f+(q 2) and f−(q 2) are obtained from the analytic continuation method in the q + = 0 frame. While the form factor f+(q 2) is free from the zero-mode, the form factor f−(q 2) is not free from the zero-mode in the q + = 0 frame. We quantify the zero-mode contributions to f−(q 2) for various semileptonic Bc decays. Using our effective method to relate the non-wave function vertex to the light-front valence wave function, we incorporate the zero-mode contribution as a convolution of zero-mode operator with the initial and final state wave functions. Our results are then compared to the available experimental data and the results from other theoretical approaches. Since the prediction on the magnetic dipole B * c → Bc + γ decay turns out to be very sensitive to the mass difference between B * c and Bc mesons, the decay width Γ(B * c → Bcγ) may help in determining the mass of B * c experimentally. Furthermore, we compare the results from the harmonic oscillator potential and the linear potential and identify the decay processes that are sensitive to the choice of confining potential. From the future experimental data on these sensitive processes, one may obtain more realistic information on the potential between quark and antiquark in the heavy meson system.

It is shown that a 25(20)% difference between the decay constants f Ds (f Bs ) and

Physical Review D, 1997

Operating just once with the naive Foldy-Wouthuysen-Tani transformation on the relativistic Fermi-Yang equation for Qq bound states described by the semi-relativistic Hamiltonian which includes Coulomb-like as well as confining scalar potentials, we have calculated heavy meson mass spectra of D and B together with higher spin states. Based on the formulation recently proposed, their masses and wave functions are expanded up to the second order in 1/m Q with a heavy quark mass m Q and the lowest order equation is examined carefully to obtain a complete set of eigenfunctions for the Schrödinger equation.

Physical Review D, 1999

We present a study of the heavy-light spectrum and of the Dand B-meson decay constants. The results were obtained in the quenched approximation, by using the nonperturbatively improved Clover lattice action at β = 6.2, with a sample of 100 configurations, on a 24 3 × 64 lattice. After a careful analysis of the systematic errors present in the extraction of the physical results, by assuming quite conservative discretization errors, we find

In this paper, Heavy Quark Effective Field Theory (HQET) is motivated and discussed. The lagrangian in this effective theory is derived to order 1/mQ and the 1-loop quantum corrections are added. Using this lagrangian, the mass of a meson is found in terms of 3 parameters, Λ ̄,λ1 and λ2. Mass splittings are then calculated between meson states when two of these parameters are the same. The decay rate of processes with the general form B ̄ → D⋆lν ̄ is derived both using the full theory and the HQET. It is shown that the form factors are given by one function, the Isgur-Wise function ξ(w).