46025843
Heavy quark symmetry, chiral symmetry, and parity doublets of heavy mesons in the Bethe-Salpeter approach.
It is shown that there must exist degenerate parity doublets of heavy mesons with arbitrary spin if QCD possesses both heavy quark and chiral symmetries. The chiral symmetric pahase and chiral broken phase can be dynamically turned in the Bethe-Salpeter approach. In the chiral broken phase the mass splittings of the parity doublets can be calculated and they are proportional to the constituent mass [ital m] of the light quark to order [ital m]/[Lambda][sub [chi]].
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.
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.
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.
122507937
Superconformal models from super W-constrained SKP hierarchies via the super Kontsevich-Miwa transformation
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.
73519332
RHIC Performance for FY10 200 GeV Au+Au Heavy Ion Run
Since the last successful RHIC Au+Au run in 2007 (Run-7), the RHIC experiments have made numerous detector improvements and upgrades. In order to benefit from the enhanced detector capabilities and to increase the yield of rare events in the acquired heavy ion data a significant increase in luminosity is essential. In Run-7 RHIC achieved an average store luminosity of = 12 × 10 cm−2 s−1 by operating with 103 bunches (out of 111 possible), and by squeezing to β∗ = 0.85 m. This year, Run-10, we achieved = 20 × 10 cm−2 s−1, which put us an order of magnitude above the RHIC design luminosity. To reach these luminosity levels we decreased β∗ to 0.75 m, operated with 111 bunches per ring, and reduced longitudinal and transverse emittances by means of bunched-beam stochastic cooling. In addition we introduced a lattice to suppress intra-beam scattering (IBS) in both RHIC rings, upgraded the RF control system, and separated transition crossing times in the two rings. We present an overview of the changes and the results of Run-10 performance.
5758218
Adiabatic regularization of the quantum stress-energy tensor in curved spacetimes: Stochastic quantization method.
It is found that the adiabatic regularized quantum stress-energy tensor for matter in any background spacetime can be obtained in the framework of stochastic quantization. As an illustration, we investigate the modes of a massive scalar field with arbitrary curvature coupling to the inhomogeneous conformally flat spacetime. The difficulty of the mode-mixing behavior arising from the spacetime inhomogeneity is overcome and a simple algorithm is presented to evaluate the adiabatic regularized quantum stress-energy tensor. The expressions so obtained are useful in formulating the semiclassical theory of gravity and in the numerical study of the back-reaction effects of quantized fields in inhomogeneous spacetimes, such as the problems of homogenization in the early universe and the evaporation of a quantum black hole. It can be seen that our prescriptions may be extended to investigate more realistic models with fermions and gauge fields. This will be studied in future papers.
7506859
Light quark dependence of the Isgur-Wise function from QCD sum rules.
We study the light quark dependence of the Isgur-Wise function for ${\mathit{B}}_{\mathit{a}}$\ensuremath{\rightarrow}${\mathit{D}}_{\mathit{a}}$ and ${\mathit{B}}_{\mathit{a}}$\ensuremath{\rightarrow}${\mathit{D}}_{\mathit{a}}^{\mathrm{*}}$ in the framework of QCD sum rules. At zero recoil all the Isgur-Wise functions are equal, as required by heavy quark symmetry, and at nonzero recoil the Isgur-Wise function for ${\mathit{B}}_{\mathit{s}}$ decay falls faster than that for ${\mathit{B}}_{\mathit{u},}$d decay, which is just contrary to the recent prediction of the heavy meson chiral perturbation theory. As a by-product we also estimate SU(3)-breaking effects in the mass and the decay constant.
13115734
Boson-fermion transmutation and the statistics of anyons.
It is shown that, by allowing a transmutation between a boson and a fermion, the system with both bosons and fermions will have the statistical distribution function of an anyon.
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.