Neutron-deuteron system and the photon polarization parameter at thermal neutron energies

Abstract

Effective Field Theory(EFT) is, the unique, model independent and systematic low-energy version of QCD for processes involving momenta below the pion mass. A low-energy photo-nuclear observable in three-body systems, photon polarization parameter at thermal neutron energies is calculated by using pionless EFT up to next-to-next to leading order(N 2 LO). In order to make a comparative study of this model, we compared our results for photon polarization parameter with the realistic Argonne v 18 two-nucleon and Urbana IX or Tucson-Melbourne three-nucleon interactions. Three-body currents give small but significant contributions to some of the observables in the neutron-deuteron radiative capture cross section at thermal neutron energies. In this formalism the three-nucleon forces are needed up to N 2 LO for cut-off independent results. Our result converges order by order in low energy expansion and also cut-off independent at this order.

Efimov States in Nuclear and Particle Physics

“…However, a few exploratory calculations have been carried out. Universal properties of the triton charge form factor have been investigated (76), and neutron-deuteron radiative capture has been calculated (77)(78)(79). The electromagnetic properties of the triton were also recently investigated (80,81).…”

Efimov physics from a renormalization group perspective

“…However, a few exploratory calculations have been carried out. Universal properties of the triton charge form factor were investigated by Platter & Hammer (2006) and neutron-deuteron radiative capture was calculated by Sadeghi & Bayegan (2005), Sadeghi et al (2006), Sadeghi (2007). Electromagnetic properties of the triton were recently investigated by Sadeghi & Bayegan (2010).…”

Three-body Calculation of Total Cross Sections of the p d → 3 H e η Reaction From Chiral Dynamics

“…The resulting EFT is considerably simpler than potential models or the pionful version of nuclear EFT (in which pions are kept as explicit degrees of freedom), but its range of validity is reduced to typical momenta below the pion mass. Recently we have calculated the cross section of radiative capture process nd → 3 H γ [17][18][19], triton photodisintegration [21] and electromagnetic form factor of triton [22] using EFT. No new three-nucleon forces are needed up to N 2 LO in order to achieve cut-off independent results, in addition to those fixed by the triton binding energy and nd scattering length in the triton channel.…”