Two-loop representations of low-energy pion form factors and pi-pi scattering phases in the presence of isospin breaking

Details Two-loop representations of low-energy pion form factors and pi-pi scattering phases in the presence of isospin breaking Two-loop representations of low-energy pion form factors and pi-pi scattering phases in the presence of isospin breaking

2012-02-27

arxiv.org/abs/1202.5886v1

Physics

High Energy Physics

High Energy Physics - Phenomenology

57 pages, 12 figures

Scientific paper

Dispersive representations of the pi-pi scattering amplitudes and pion form factors, valid at two-loop accuracy in the low-energy expansion, are constructed in the presence of isospin-breaking effects induced by the difference between the charged and neutral pion masses. Analytical expressions for the corresponding phases of the scalar and vector pion form factors are computed. It is shown that each of these phases consists of the sum of a "universal" part and a form-factor dependent contribution. The first one is entirely determined in terms of the pi-pi scattering amplitudes alone, and reduces to the phase satisfying Watson's theorem in the isospin limit. The second one can be sizeable, although it vanishes in the same limit. The dependence of these isospin corrections with respect to the parameters of the subthreshold expansion of the pi-pi amplitude is studied, and an equivalent representation in terms of the S-wave scattering lengths is also briefly presented and discussed. In addition, partially analytical expressions for the two-loop form factors and pi-pi scattering amplitudes in the presence of isospin breaking are provided.

Affiliated with

Also associated with

No associations

Rating

Two-loop representations of low-energy pion form factors and pi-pi scattering phases in the presence of isospin breaking does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Two-loop representations of low-energy pion form factors and pi-pi scattering phases in the presence of isospin breaking, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Two-loop representations of low-energy pion form factors and pi-pi scattering phases in the presence of isospin breaking will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-263279