37211097
Calculation of chiral-symmetry breaking and pion properties as a Goldstone boson.
A procedure for picking out the solution of the covariant Bethe-Salpeter equation corresponding to the Goldstone boson in a spontaneous-chiral-symmetry-breaking theory is described under very general assumptions. Physical quantities for chiral-symmetry breaking and the pion are calculated with this procedure taking into account gluon ladder exchange and a covariant chiral-symmetric generalization of the confinement potential. Satisfactory results are obtained with reasonable values of the parameters.
123741473
Hadronic Width of P-Wave Heavy Quarkonium States with Massive Gluons
The hadronic decay widths of P-wave quarkonium states are calculated in the broken QCD with massive gluons. The comparison with preliminary data is also discussed.
35673041
Decays of excited charmed Lambda -type and Sigma -type baryons in heavy hadron chiral perturbation theory.
Ground states and some excited p-wave states of heavy baryons are studied within the framework of heavy hadron chiral perturbation theory. The effective Lagrangian is written out to terms of the next-to-leading order in 1/${\mathit{m}}_{\mathit{Q}}$ or 1/${\mathrm{\ensuremath{\Lambda}}}_{\mathrm{\ensuremath{\chi}}}$. The coupling constants are estimated using the experimental data of \ensuremath{\Lambda} and \ensuremath{\Sigma} baryons in the static limit of the s quark. The single pion and double pion decay rates of these charmed baryons have been estimated. The numerical results show that both ${\mathrm{\ensuremath{\Lambda}}}_{\mathit{c}}$(1/${2}^{\mathrm{\ensuremath{-}}}$) and ${\mathrm{\ensuremath{\Lambda}}}_{\mathit{c}}$(3/${2}^{\mathrm{\ensuremath{-}}}$) are very narrow. We conclude that the two pion channel may offer the best hope for detecting the ${\mathrm{\ensuremath{\Sigma}}}_{\mathit{c}}$(3/${2}^{\mathrm{\ensuremath{-}}}$) and ${\mathrm{\ensuremath{\Sigma}}}_{\mathit{c}}$(1/${2}^{\mathrm{\ensuremath{-}}}$) p-wave doublet.
122507937
Superconformal models from super W-constrained SKP hierarchies via the super Kontsevich-Miwa transformation
42952650
Null vectors in super Virasoro representations of the superconformal algebra.
Using the fusion procedure, a complete and straightforward algorithm for finding null vectors in Verma modules of the {ital N}=1 superconformal algebra is given.
124195329
W-T IDENTITIES, NORMALIZATION OF THE BS WAVE-FUNCTION AND PROPERTIES OF THE PION
We discuss some problems concerned with the normalization of the BS wave function in connection with Ward-Takahashi identities in the Lorentz covariant Bethe-Salpeter formalism proposed in the previous work. Physical quantities of the pion as a Goldstone boson, including the π0 → 2γ amplitude are calculated in the QCD motivated models and results are in agreement with the experimental data.
46429286
Adiabatic regularization of the quantum stress-energy tensor in curved spacetimes: Path-integral quantization method.
A possible way to obtain the adiabatic regularized quantum stress-energy tensor in a background curved spacetime is developed within the method of path-integral quantization. As an illustration, we study the mode of a massive scalar field with arbitrary curvature coupling to the inhomogeneous conformally flat spacetime. The results so obtained are useful to investigate the back-reaction effects of a quantized field in the early Universe with an inhomogeneity.
11192776
Preservation of proton polarization by a partial Siberian snake.
A 9[degree] solenoidal spin rotator or 5% partial Siberian Snake was used to successfully accelerate polarized protons for the first time to 10.8 GeV kinetic energy in the Brookhaven Alternating Gradient Synchrotron with partial depolarization due to the intrinsic resonance crossing. It was found that a 5% partial snake can effectively overcome 18 imperfection resonances in this energy range. We also observed an interference between the spin flip induced by an intrinsic resonance and linear coupling due to the solenoid field of the partial snake.
16523443
Heavy to light baryon transition form factors.
Recently, Stech found form factor relations for heavy to light transitions based on two simple dynamical assumptions for a spectator particle. In this paper we generalize his approach to the case of baryons and find that for ${\mathrm{\ensuremath{\Lambda}}}_{\mathit{Q}}$\ensuremath{\rightarrow}\ensuremath{\Lambda} (Q=b or c) only one independent form factor remains in the limit ${\mathit{m}}_{\mathit{Q}}$\ensuremath{\rightarrow}\ensuremath{\infty}. Furthermore, combining with the model of Guo and Kroll we determine both of the two form factors for ${\mathrm{\ensuremath{\Lambda}}}_{\mathit{Q}}$\ensuremath{\rightarrow}\ensuremath{\Lambda} in the heavy quark limit. The results are applied to ${\mathrm{\ensuremath{\Lambda}}}_{\mathit{b}}$\ensuremath{\rightarrow}\ensuremath{\Lambda}+J/\ensuremath{\psi} which is not clarified both theoretically and experimentally. It is found that the branching ratio of ${\mathrm{\ensuremath{\Lambda}}}_{\mathit{b}}$\ensuremath{\rightarrow}\ensuremath{\Lambda}+J/\ensuremath{\psi} is of order ${10}^{\mathrm{\ensuremath{-}}5}$. \textcopyright{} 1996 The American Physical Society.
12724895
Reexamination of the perturbative pion form factor with Sudakov suppression.
The perturbative pion form factor with Sudakov suppression is reexamined. To guarantee the reliability of the perturbative calculations we suggest that the running coupling constant should be frozen at {alpha}{sub {ital s}}({ital t}={l_angle}{ital k}{sub {ital T}}{r_angle}) and {l_angle}{ital k}{sub {ital T}}{r_angle} is the average transverse momentum which can be determined by the pionic wave function. In addition we correct the previous calculations about the Sudakov suppression factor which plays an important role in the perturbative calculations for the pion form factor.
29696360
Nonperturbative effects on the Wilson coefficients and the Delta I=(1/2 rule in kaon decays.
We apply the vacuum-background-field method and the modified renormalization-group equation in the energy region {mu}{lt}1 GeV to correct the Wilson coefficients in the {Delta}{ital S}=1 effective weak Hamiltonian responsible for {ital K}{r arrow}2{pi} decays. We find that the change of {ital C}{sub {plus minus}} results in an enhancement to the {Delta}{ital I}={1/2} amplitude by a factor of 2 at the scale {mu}=0.6 GeV for {ital K}{r arrow}2{pi} decays.