A consistent model for \pi N transition distribution amplitudes and backward pion electroproduction

Dec, 2011
39 pages
Published in:
  • Phys.Rev.D 85 (2012) 054021
e-Print:
Report number:
  • CPHT-RR100.1111,
  • LPT-11-114

Citations per year

201220152018202120240123456
Abstract: (arXiv)
The extension of the concept of generalized parton distributions leads to the introduction of baryon to meson transition distribution amplitudes (TDAs), non-diagonal matrix elements of the nonlocal three quark operator between a nucleon and a meson state. We present a general framework for modelling nucleon to pion (πN\pi N) TDAs. Our main tool is the spectral representation for \pi N TDAs in terms of quadruple distributions. We propose a factorized Ansatz for quadruple distributions with input from the soft-pion theorem for \pi N TDAs. The spectral representation is complemented with a D-term like contribution from the nucleon exchange in the cross channel. We then study backward pion electroproduction in the QCD collinear factorization approach in which the non-perturbative part of the amplitude involves \pi N TDAs. Within our two component model for \pi N TDAs we update previous leading-twist estimates of the unpolarized cross section. Finally, we compute the transverse target single spin asymmetry as a function of skewness. We find it to be sizable in the valence region and sensitive to the phenomenological input of our \pi N TDA model.
Note:
  • 39 pages, 9 figures
  • 13.60.-r
  • 14.20.Dh
  • 13.60.Le
  • pi: electroproduction
  • pi nucleon: transition
  • factorization: collinear
  • spin: asymmetry
  • spectral representation
  • distribution amplitude
  • generalized parton distribution