25 research outputs found
Continuity of generalized parton distributions for the pion virtual Compton scattering
We discuss a consistent treatment of the light-front gauge-boson and meson
wave functions in the analyses of the generalized parton distributions(GPDs)
and the scattering amplitudes in deeply virtual Compton scattering(DVCS) for
the pion. The continuity of the GPDs at the crossover, where the longitudinal
momentum fraction of the probed quark is same with the skewedness parameter,
and the finiteness of the DVCS amplitude are ensured if the same light-front
radial wave function as that of the meson bound state wave function is used for
the gauge boson bound state arising from the pair-creation(or nonvalence)
diagram. The frame-independence of our model calculation is also guaranteed by
the constraint from the sum rule between the GPDs and the form factors.Comment: 14 pages, 9 figures, we (1) changed the title, (2) added references,
(3) discussed the GPD value at the crossover in Sec. III, version to appear
in Phys. Rev.
Search for the exotic resonance in the NOMAD experiment
A search for exotic Theta baryon via Theta -> proton +Ks decay mode in the
NOMAD muon neutrino DIS data is reported. The special background generation
procedure was developed. The proton identification criteria are tuned to
maximize the sensitivity to the Theta signal as a function of xF which allows
to study the Theta production mechanism. We do not observe any evidence for the
Theta state in the NOMAD data. We provide an upper limit on Theta production
rate at 90% CL as 2.13 per 1000 of neutrino interactions.Comment: Accepted to European Physics Journal