Virtual photons in baryon chiral perturbation theory
نویسندگان
چکیده
We construct the general Lagrangian for relativistic and heavy baryon chiral perturbation theory with virtual photons to fourth order. We work out the electromagnetic and strong isospin violating contributions to the nucleon self–energy, the nucleon mass and the scalar form factor of the nucleon. Electromagnetic effects for the shift to the Cheng–Dashen point can be as large as 2 MeV. We also discuss the corrections to Weinberg’s prediction for the scattering length difference a(π0p)− a(π0n) and show that they are small. Work supported in part by TMR, EC-Contract No. ERBFMRX-CT980169 (EURODAΦNE). email: [email protected] email: [email protected]
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تاریخ انتشار 1999