Erratum: Compton scattering from the proton at fourth order NLO in the chiral expansion [Phys. Rev. C63, 064608 (2001)]

Abstract

We present calculations of differential cross sections for Compton scattering from the proton, using amplitudes calculated to fourth order in heavy baryon chiral perturbation theory. We compare with available data up to 200 MeV. We find that the agreement for angles below 90 o is acceptable over the whole energy range, but that at more backward angles the agreement decreases above about 100 MeV, and fails completely above the photoproduction threshold.12.39Fe 13.60Fz 11.30Rd

Effective theory of theΔ(1232)resonance in Compton scattering off the nucleon

“…In particular, significant progress has been made recently using dispersion relations [11,12] and effective Lagrangian models [13][14][15]. On the other hand, previous calculations using chiral perturbation theory (χPT) appear to work only at low photon energies-energies at or below the pion-production threshold [16,17]. This present study attempts to extend these χPT calculations above the pion threshold and into the Delta-resonance region.…”

“…[17,19] and in Appendix A. F (1) has the property that F (1) ∼ 1 for ω < ∼ m π . A crucial feature of Eq.…”

“…They are the only loop graphs with this counting index if we adopt Coulomb gauge and employ the heavy-baryon expansion. Explicit computation [17,19] reveals that the sum of these graphs indeed produces a Compton amplitude that behaves as:…”

“…3, we have used the O(q 3 ) HBχPT result of Refs. [17,19]. This is done in order to avoid difficulties with the treatment of the nucleon-mass-scale M N inside the loops.…”

Chiral perturbation theory for electroweak reactions on deuterium

“…(6) Going to next order in the chiral expansion single-nucleon counterterms which shift the polarizabilities enter the calculation. Using the γp amplitude computed by McGovern to O(e 2 P 2 ) [25] we fitted γp data over the kinematic range ω, |t| < 180 MeV [26]. Figure 3.…”