The difference in production rate between W and W− at hadron colliders is very sensitive to the the difference between upand down-quark distributions in the proton. This sensitivity allows for a variety of useful measurements. We consider the difference ds(x,Q ) − us(x,Q2) in the sea distributions and the difference ∆u(x,Q2)−∆d(x,Q2) in the polarized parton distribution functions. In both cases...

We use effective field theory techniques to examine the quantum corrections to the gravitational metrics of charged particles, with and without spin. In momentum space the masslessness of the photon implies the presence of nonanalytic pieces ∼ √ −q2, q2 log−q2, etc. in the form factors of the energy-momentum tensor. We show how the former reproduces the classical non-linear terms of the Reissne...

Let q be a prime power and g ∈ {6, 8, 12}. In this paper we obtain (q, g)-graphs on 2qg/2−3(q2 − 1) vertices for g = 6, 8, 12 as subgraphs of known (q + 1, g)-cages. We also obtain (q − r, 6)-graphs on 2(q2 − rq − 1) vertices, and (q − r, 8)-graphs on 2(q3−rq2−q+r) vertices where r is a positive integer such that q ≥ r+3. Furthermore, we find (q − 1, 12)-graphs of order 2q2(q3 − q2 − q + 1). So...

In this paper we investigate partial spreads of H(2n− 1, q2) through the related notion of partial spread sets of hermitian matrices, and the more general notion of constant rank-distance sets. We prove a tight upper bound on the maximum size of a linear constant rank-distance set of hermitian matrices over finite fields, and as a consequence prove the maximality of extensions of symplectic sem...

The q2 dependence of the π-η mixing amplitude is examined with the use of QCD sum rules. The linear slope of the mixing function θ(q2) is found to be much smaller than that for ρ-ω mixing. Thus the mixing amplitude is approximately the same in the space-like region as in the time-like one, and one may neglect the q2 dependence of the mixing. A comparison between a hadron-meson, an effective chi...

The cross section for inclusive inelastic electron scattering from the helium isotopes has been measured at momentum transfers squared of 0.8zQ2<5.0 (GeV/c)2 for 3He and 0.8LQ212.4 (GeV/c)2 for 4He. The data were taken at 8O and cover the range 0.6<x<l, where x = Q2/2MHeV, which includes the elastic peak, nuclear breakup threshold, the high momentum tail of the quasi elastic scattering, and pio...

Low-Q2 photons do not resolve partons in the proton, which gives problems when applying the deep inelastic scattering formalism, such as an unphysical, negative gluon density extracted from data. Considering instead hadronic fluctuations of the photon, we show that the generalised vector meson dominance model (GVDM) gives a good description of the measured cross section at low Q2, i.e. reproduc...