9159427
Poincaré invariance of anomalous gauge theories.
We establish the Poincare invariance of anomalous gauge theories in two dimensions, for both the Abelian and non-Abelian cases, in the canonical Hamiltonian formalism. It is shown that, despite the noncovariant appearance of the constraints of these theories, Poincare generators can be constructed which obey the correct algebra and yield the correct transformations in the constrained space.
42763584
Algebraic consistency in anomalous gauge theories.
A consistency condition for anomalous gauge theories is used to show that the usual form of the chiral anomaly is inadmissible and that a different but equivalent form yields Faddeev's Schwinger term.
39619210
Entropy in dilatonic black hole background.
The entropy of a scalar field is calculated semiclassically in the background of a dilatonic black hole. The area and cutoff dependences are normal except in the extremal case, where the area is zero but the entropy nonzero.
35025289
Hadronic transition amplitudes under null-plane Bethe-Salpeter dynamics.
A two-tier form of the Bethe-Salpeter (BS) framework is employed for the evaluation of a few typical transition amplitudes involving strong and electromagnetic decays of qq-bar hadrons with Lgreater than or equal to0. The two-tier BS framework, whose rationale has been described in some recent publications, is characterized by (i) a three-dimensional reduction of the BS equation under the null-plane ansatz to make a first contact with mass spectral data and (ii) a reconstructed four-dimensional BS wave function to restore the virtual qq-bar effects (higher Fock states) for the evaluation of hadronic transition amplitudes through the lowest-order Feynman (quark-triangle) diagrams. The processes explicitly considered are the pion form factor F/sub ..pi../(k/sup 2/), (..omega..,a/sub 2/)..--> gamma pi.., (rho,f/sub 2/)->..pi pi.., (a/sub 1/,a/sub 2/)..-->..rho..pi.., and b/sub 1/..--> omega pi... These illustrate the different types of coupling structures that are generally encountered in such a composite-hadron model. The agreement with the data on almost all these amplitudes is excellent, using the same basic constants (..omega../sub 0/,C/sub 0/,m/sub u//sub d/) as employed recently for a successful description of the mass spectra of qq-bar and qqq hadrons, as well as of some pionic amplitudes.
30997914
Null-plane Bethe-Salpeter dynamics: Mass spectra, decay constants of pseudoscalar mesons, and the pion form factor.
A new relativistic definition of the reduced mass ({mu}{sub 12}) of a {ital q{bar q}} pair, so as to be in conformity with the standard Wightman-Garding definition of its relative four-momenta {ital q}{sub {mu}}, is introduced into the kernel of an ongoing Bethe-Salpeter (BS) program on a two-tier basis. The new definition of {mu}{sub 12} (involving the hadron mass {ital M}) is found to produce a natural Regge asymptotic behavior ({ital M}{sup 2}{approximately}{ital N}) in the hadron mass spectra, while retaining the property of an asymptotically linear ({approximately}{ital r}) confinement in the three-dimensional structure of the BS kernel. The relativistic structure of {mu}{sub 12} is responsible for a significant improvement in the fits to the ground-state masses of {ital q{bar q}} and {ital Q{bar q}} mesons as compared to its nonrelativistic definition {ital m}{sub 1}{ital m}{sub 2}/({ital m}{sub 1}+{ital m}{sub 2}). The leptonic decay constants {ital f}{sub {ital p}} and the charge radii thus calculated are also in excellent agreement with data ({pi},{ital k}) where available, while {ital f}{sub {ital p}} predictions for {ital Q{bar q}} mesons have good overlap with recent lattice predictions. Further, the scaling property ({approximately}{ital k}{sub {mu}}{sup {minus}2}) of the hadron's electromagnetic form factor at largemore » {ital k}{sup 2} is a consequence of the on-shell'' form of its null-plane wave function. All these results (which are indicated in the barest outline) are preceded by a perspective summary of the theoretical premises and practical working of the BS equation with a four-fermion interaction kernel as a necessary background on a two-tier basis.« less