Generalized parton distributions for weakly bound systems from light-front quantum mechanics

We present generalized parton distributions for weakly bound systems on the light cone in order to build intuition about the light-front formalism. Physics at the crossover is reviewed in terms of the light-cone Fock space representation. Furthermore, we link light-cone Fock components to the equal (light-cone) time projection of the covariant Bethe-Salpeter amplitude. Continuity of the distributions arises naturally in this weak binding model.Comment: 6 pages, 2 figures. Talk given at conference, "Exclusive Processes at High Momentum Transfer," held at Jefferson Laboratory, May 15-18, 200

Hadronic Parity Violation at Next-to-Leading Order

The flavor-conserving non-leptonic weak interaction can be studied experimentally through the observation of parity violation in nuclear and few-body systems. At hadronic scales, matrix elements of parity-violating four-quark operators ultimately give rise to the parity violating couplings between hadrons, and such matrix elements can be calculated non-perturbatively using lattice QCD. In this work, we investigate the running of isovector parity-violating operators from the weak scale down to hadronic scales using the renormalization group. We work at next-to-leading order in the QCD coupling, and include both neutral-current and charged-current interactions. At this order, results are renormalization scheme dependent, and we utilize 't Hooft-Veltman dimensional regularization. The evolution of Wilson coefficients at leading and next-to-leading order is compared. Next-to-leading order effects are shown to be non-negligible at hadronic scales.Comment: 16 pages, 2 figures, v2: statements pertaining to isovector parity violation corrected, refs added, results unchange

Double distributions: Loose ends

We point out that double distributions need not vanish at their boundary. Boundary terms do not change the ambiguity inherent in defining double distributions; instead, boundary conditions must be satisfied in order to switch between different decompositions. We analyze both the spin zero and spin one-half cases.Comment: 4 pages, 0 figures, RevTex 4, Brief Repor