14,819 research outputs found
QCD Factorization for the Pion Diffractive Dissociation Into Two Jets
We report a detailed study of the process of pion diffraction dissociation
into two jets with large transverse momenta. We find that the standard
collinear factorization does not hold in this reaction. The structure of
non-factorizable contributions is discussed and the results are compared with
the experimental data. Our conclusion is that the existing theoretical
uncertainties do not allow, for the time being, for a quantitative extraction
of the pion distribution amplitude. (Talk presented at the Workshop on
Exclusive Processes at High Momentum Transfer, Jefferson News, VA, May 15-18,
2002)Comment: 6 pages, latex, two figure
On zero-divisors in group rings of groups with torsion
Nontrivial pairs of zero-divisors in group rings are introduced and
discussed. A problem on the existence of nontrivial pairs of zero-divisors in
group rings of free Burnside groups of odd exponent is solved in the
affirmative. Nontrivial pairs of zero-divisors are also found in group rings of
free products of groups with torsion.Comment: 8 pages, to appear in Canadian Math. Bul
Exclusive diffractive electroproduction of dijets in collinear factorization
Exclusive electroproduction of hard dijets can be described within the
collinear factorization. This process has clear experimental signature and
provides one with an interesting alternative venue to test QCD description of
hard diffractive processes and extract information on generalized nucleon
parton distributions. In this work we present detailed leading-order QCD
calculations of the relevant cross sections, including longitudinal momentum
fraction distribution of the dijets and their azimuthal angle dependence.Comment: 11 pages, 14 Postscript figures, uses revtex4.st
- …