Dominant $2\pi \gamma$-exchange nucleon-nucleon interaction: Spin-spin and tensor potentials

Abstract

We calculate at two-loop order in chiral perturbation theory the electromagnetic corrections to the two-pion exchange nucleon-nucleon interaction that is generated by the isovector spin-flip $\pi \pi NN$ contact-vertex proportional to the large low-energy constant $c_4\simeq 3.4$GeV${}^{-1}$. We find that the respective $2\pi \gamma$-exchange potentials contain sizeable isospin-breaking components which reach up to -4% of corresponding isovector $2\pi$-exchange potentials. The typical values of these novel charge-independence breaking spin-spin and tensor potentials are $-0.11$MeV and $0.09$MeV, at a nucleon distance of $r=m_{\pi }^{-1}=1.4$fm. The charge-symmetry breaking spin-spin and tensor potentials come out a factor of 2.4 smaller. Our analytical results for these presumably dominant isospin-violating spin-spin and tensor NN-forces are in a form such that they can be easily implemented into phase-shift analyses and few-body calculations.

7 pages, 1 figure, 2 tables, to be published in Physical Review C: Brief reports

References in corpus (2)

• Pion-photon exchange nucleon-nucleon potentials
• Electromagnetic corrections to the dominant two-pion exchange nucleon-nucleon potential

Cited by in corpus (2)

• Isospin-breaking two-nucleon force with explicit Delta-excitations
• A Two Potential Formula and its Application to Proton-Proton Scattering