Bose-stimulated scattering off a cold atom trap

The angle and temperature dependence of the photon scattering rate for Bose-stimulated atom recoil transitions between occupied states is compared to diffraction and incoherent Rayleigh scattering near the Bose-Einstein transition for an optically thin trap in the limit of large particle number, N. Each of these processes has a range of angles and temperatures for which it dominates over the others by a divergent factor as N->oo.Comment: 18 pages (REVTeX), no figure

Gluon corrections to Drell-Yan processes

Assuming that the Drell-Yan picture is approximately valid, I compute the O(g^2) gluon radiative corrections in QCD. The corrections are self-consistent, i.e. they satisfy several non-trivial constraints necessary for the validity of the whole picture. There are logarithmic scaling violations in the quark distribution functions, precisely equal to those found in electroproduction. Large transverse momenta (of order of the c.m. energy) are produced, balanced by radiation in the opposite direction. I compute the transverse momentum differential cross section for μ pairs as an exampl

Air modes of the Bacon internal resonator banjo

Sound measurements on a sequence of related, similar constructions with slightly different dimensions confirm a simple picture of the air modes of the internal resonator banjo’s body. For the purpose of this study, the air modes are decoupled from the soundboard (i.e., [drum] head) modes by replacing the head with 3/4 00 plywood. The resulting characteristic features survive the strong coupling of the air modes to the head and are in accord with the qualitative distinctions recognized by banjo players

Power Corrections and Higher Twists in QCD

People believe QCD to be the theory of strong interactions for a variety of reasons. Firstly, SU(3) of color is a subgroup of SU(5); second, it has instantons and a variety of other interesting topological properties; and, lastly, it agrees with high energy experiments. But on this last point, one must confess that there are a variety of obstacles that have thus far precluded any overwhelmingly convincing numerical confrontation with data. Theorists divide the sources of troubles into several classes. One of these is the power or higher twist corrections. I describe here a tentative approach of a systematic analysis of power corrections. The analysis is motivated by, and generalizes on, the operator product analysis of leptoproduction. In essence, I try to identify the appropriate set of process-independent, non-perturbative functions that characterize long-distance physics; these are to be convoluted with calculable short-distance amplitudes via an algorithm that generalizes the long distance-short distance factorization for the scaling limit

A QCD Outlook

My charge from the organizers of this QCD Symposium was to present a summary of what I regard to be the successes and the disappointments we have had with QCD. And furthermore, I was asked to discern the crucial issues and tests that lie ahead. So I have spent many hours gazing into my crystal ball. Consequently, rather than the typical conference summary, this discussion is far more metaphysics than physics

Testing Scaling and QCD with Muon Beams

Scaling in muon-nucleon scattering suggests that nucleons are made of pointlike, non-interacting, light quarks. This scaling will go away at higher energies if the quarks are characterized by some non-zero size, a. Specifically, scaling for Q^2 ≾(3a)^(-2) will disappear completely for Q^2≈a^(-2). Alternatively, scaling may persist, at least to the accuracy that it is currently observed. Then we may ask if the observed violations are indeed those predicted by quark-gluon gauce theory (QCD). However, there are other, more dramatic predictions of QCD which will be easier to test. The most striking of these is the prediction of large transverse momenta of order Q^2/log4Q^2 (transverse to the nominal jet axes)

Lederman's Shoulder, Weinberg's Nose, and Other Lessons from the Past

[No abstract