23950285
Coherent-state path integrals and the bosonization of chiral fermions.
By using coherent-state path integrals I provide a derivation of a two-dimensional chiral boson action which is equivalent to a free Weyl fermion.
33893527
Edge waves in the quantum Hall effect and quantum dots.
We have studied numerically the spectrum of low-energy excitations for quantum dots containing up to 400 electrons near densities corresponding to the quantum-Hall-effect filling fraction \ensuremath{\nu}=1. The results show that, despite strong Coulomb interaction effects, the edge modes are well described as weakly interacting chiral boson edge waves.
49271770
Problems with Finite Density Simulations of Lattice QCD
We present a discussion of problems that have arisen in attempts to understand the behavior of lattice QCD at high densities. The effects observed in the lattice simulations do not seem to be consistent with what we expect from the usual ideas of chiral symmetry breaking. In particular, at zero quark mass, there does not seem to be a massive baryon at finite density.
124848823
Six lectures on lattice field theory
11439667
Schur functions, chiral bosons, and the quantum-Hall-effect edge states.
I demonstrate how the many-body wave function may be used to describe the bosonization of the edge excitations of a droplet of \ensuremath{\nu}=1 quantum-Hall liquid. In particular, I exhibit an isomorphism between the charge-neutral edge-state excitations of the droplet and the space of universal symmetric polynomials. There are two natural bases for this space; the first, the Schur functions, correspond to the fermion picture; the second, generated by the power sums, yields the Bose picture and the Kac-Moody algebra. I also show explicitly how the loop group LU(1) acts to create the coherent-state deformations of the droplet shape used in path-integral bosonization and in the quantization of chiral bosons.
121710395
Deconfinement and chiral symmetry restoration at finite temperatures in SU(2) and SU(3) gauge theories
At zero temperature SU(2) and SU(3) gauge theories confine quarks and spontaneously break chiral symmetry. At some non-zero temperatures T/sub c/(T/sub F/) these gauge theories lose confinement (chiral-symmetry breaking). We have studied the order of these phase transitions and the relation between T/sub c/ and T/sub F/ using simulation methods which neglect internal fermion loops. For SU(2) both transitions are second order and 1 less than or equal to T/sub F//T/sub c/ < 1.30. For SU(3) the transitions are first order and we find 1 less than or equal to T/sub F//T/sub c/ less than or equal to 1.05, with T/sub c/ approx. = 200 MeV.
32440270
Exclusive decays and masses of the B mesons.
32942434
Determination of the cross sections for the production of fragments from relativistic nucleus-nucleus interactions. I. Measurements.
Relativistic iron, lanthanum, holmium, and gold projectile nuclei with several different energies have been fragmented in targets of polyethylene, carbon, aluminum, copper, and lead. Our detectors cleanly resolve the individual charges of the heaviest of these fragments and provide some limited information on the masses. We have measured 1256 elemental partial cross sections for the production of fragments from interactions in these target materials. Values have been derived for another 417 cross sections in a hydrogen medium. These cross sections depend on the energy and mass of the projectile nuclei as well as on the nature of the target. Total charge-changing cross sections were also found, but only in a composite target, and have been shown to be weakly dependent on energy. The mean mass losses observed for fragments that have lost a few protons show that typically many neutrons are lost with each proton, producing fragment nuclei that must be highly proton rich, and consequently very unstable. The cross sections for charge pickup on heavy targets show a rapid increase with decreasing energy, particularly for the heaviest targets. The systematics of the dependencies of the partial cross sections will be discussed in a companion paper.
44832895
Charge, mass, and energy changes during fragmentation of relativistic nuclei.
We have examined the fragmentation of relativistic lanthanum and gold nuclei incident on targets of polyethylene, carbon, aluminum, and copper. Attention has been concentrated on those fragments whose atomic numbers were only changed by +1 to -3 from those of the incident nuclei. The cross section for the production of fragments with increased charge is about 10% that for fragments that have lost one charge, or about 1% of the total interaction cross section. We find that the velocity distributions of these fragments can be explained by assuming that they also lose significant numbers of neutrons when they pick up or lose charge, without a need to invoke any energy or momentum loss in the interaction, although we cannot exclude small losses. In particular, we cannot confirm the recent report of large energy losses during the charge pickup process. The relative numbers of neutrons lost can be represented by a simple Gaussian model, and, for those fragments with decreased charge, are much larger than the proton losses. These fragments consequently have large proton excesses and will be highly unstable.
9087449
Study of pi + pi - transitions from the Upsilon (3S) and a search for the hb.
We have investigated the transitions Y(3S)~m+vr Y(1S), Y(3S)~~+~ Y(2S) and the cascade process Y(3S)~Y(2S)+X,Y(2S)~m+w Y(1S), both in the exclusive decay mode, with the daughter Y state decaying into two leptons, and in the inclusive decay mode, with the daughter Y state decaying hadronically. Results are presented on the branching fractions and properties of the system. The m+ ~ invariant-mass spectra for the decays Y( 3S)~~+ m Y( 1S) and Y(3S)~m ~ Y(2S) are measured and compared with theoretical predictions. We also present the results of a search for the h&(1 'P, ) and Y(1 'D) states in inclusive Y(3S) decays, and for the ex
1906801
Improved upper limit on flavor-changing neutral-current decays of the b quark.
We report the results of a new search for flavor-changing neutral-current decays of the b quark and present a 90%-confidence-level upper limit for the branching fraction for B..-->..l/sup +/l/sup -/X of 1.2 x 10/sup -3/.