相关论文: Chiral Symmetry and Hyperfine Quark-Antiquark Spli…
Meson spin splittings are examined within an effective Coulomb gauge QCD Hamiltonian incorporating chiral symmetry and a transverse hyperfine interaction necessary for heavy quarks. For light and heavy quarkonium systems the…
We show that there is a large discrepancy between the expected light flavor dependence of the heavy pseudoscalar--vector mass splittings and the measured values. We demonstrate that the one--loop calculation is unreliable. Moreover,…
We compute the hyperfine splitting in a heavy quarkonium composed of different flavors in next-to-leading logarithmic approximation using the nonrelativistic renormalization group. We predict the mass difference of the vector and…
Recently we have proposed a new level-classification scheme of hadrons with a manifestly covariant framework. In this scheme the requirement of chiral symmetry on the light quark leads to a prediction of existence of new type of scalars…
The $SU(3)$ and hyperfine mass splittings of mesons containing a single heavy quark are computed to one-loop order in chiral perturbation theory with heavy quark spin symmetry. Electromagnetic contributions of order $\alpha_em$ are…
Chiral symmetry breaking parameters are calculated in quenched SU(2) gauge theory and with Abelian gauge fields projected in maximal Abelian gauge and in field strength gauge. Maximal Abelian gauge projected fields lead to chiral condensate…
We base our chiral symmetry approach on the quark-level linear sigma model Lagrangian. Then we review the Nambu--Goldstone theorem with vanishing pi, K, eta_8 masses. Next we dynamically generate the pi, K, eta_8 masses away from the chiral…
Masses of pseudoscalar and vector mesons, which are ground states of light or/and heavy quarks and antiquarks, have been calculated in the framework of an extended model of quasi-independent quarks with absolute uncertainties about 30 MeV.…
Chiral symmetry and heavy quark symmetry constrain the interactions of mesons containing a single heavy quark with low-momentum pions. Chiral corrections to the Isgur-Wise function for $\bar B_s \rightarrow D_s^{(*)}$ versus $\bar B…
A method for computing electromagnetic properties of hadrons in lattice QCD is described. The electromagnetic field is introduced dynamically, using a noncompact formulation. Employing enhanced electric charges, the dependence of the…
We investigate the properties of new scalar X_B, X_D and axial-vector X_B*, X_D* mesons, which are recently predicted, in the covariant meson-classification scheme, to exist as the partners of ground-state pseudoscalar B, D and vector B*,…
The hyperfine splittings $\Delta_D=(m_{D^*_s}-m_{D_s})-(m_{D^{*+}}-m_{D^+})$ and $\Delta_B=(m_{B^*_s}-m_{B_s})-(m_{B^{*0}}-m_{B^0})$ are analyzed in the framework of an effective lagrangian possessing chiral, heavy flavour and spin…
We sum up the next-to-leading logarithmic corrections to the heavy-quarkonium hyperfine splitting using the nonrelativistic renormalization group. On the basis of this result, we predict the mass of the $\eta_b$ meson to be $M(\eta_b)=9419…
Effects associated with hyperfine mass splitting between pseudo\-scalar and vector mesons may induce surprisingly large $1/{m}_{Q}^{2}$ corrections in the heavy quark expansion. We demonstrate this in a relativistic quark model by…
Starting with a hidden local symmetry Lagrangian at the vector manifestation (VM) fixed point that incorporates heavy-quark symmetry and matching the bare theory to QCD, we calculate the splitting of chiral doublers of heavy-light mesons…
The chiral symmetry of QCD requires energy-dependent pionic strong interactions at low energies. This constraint, however, is not fulfilled by the usual Breit--Wigner parameterization of pionic resonances, leading to masses larger than the…
We point out that the spectrum of pseudoscalar and scalar mesons exhibits a cuasi-degenerate chiral nonet in the energy region around 1.4 GeV whose scalar component has a slightly inverted spectrum. Based on the empirical linear rising of…
We extend our previous formulation of low-energy QCD in terms of an effective lagrangian containing operators of dimensionality $d\le 6$ constructed with pseudoscalars and quark fields, describing physics below the scale of chiral symmetry…
We compute flavor non-singlet meson screening masses in the chiral limit of QCD with $N_f=3$ quarks. The calculation is carried out at 12 temperatures from $T\approx 1$ GeV up to the electroweak scale. For each temperature we simulated…
This paper considers the implications of the heavy quark and chiral symmetries for the semi-leptonic decay $B \rightarrow D^* X \ell \bar \nu_\ell$. The general kinematic analysis for decays of the form {\sl pseudoscalar meson $\rightarrow$…