Spin-polarization observables of deuteron photodisintegration at low energies in pionless effective-field theory

Abstract

Spin polarization observables of the deuteron photodisintegration at low energies are studied in a pionless effective field theory up to next-to-next-to-leading order (NNLO). The total and differential cross sections, induced neutron polarization P y , and tensor analyzing powers T 20 and T 22 of the process are calculated at photon energies from the breakup threshold to 20 MeV. We find that the NNLO corrections in the cross sections and P y converge well whereas they turn out to be important contributions in T 20 and T 22 . We discuss the discrepancy between theory and experiment in P y still persisting as well as an implication of our result to the first measurement of T 20 at low energies in the HIGS facility. PACS numbers: 21.45.Bc, 25.20.-x * Electronic address: hch@daegu.ac.kr 1 arXiv:1701.07163v2 [nucl-th]

Nuclear effective field theory: status and perspectives

“…The related processes of deuteron electro-and photodisintegration are experimentally accessible, and discrepancies between phenomenological potential models and data have been reported. Dibaryon fields implementing a resummation of range effects have been used to N 2 LO for ed → e pn (Christlmeier and Grießhammer, 2008) and dγ → np (Ando et al, 2011;Song et al, 2017a), with results generally supporting phenomenological models. For example, Christlmeier and Grießhammer (2008) concluded that no consistent theoretical calculation could describe the data because the EFT calculation, unlike the potential-model approach, comes with a rigorous uncertainty estimate (see Fig.…”

Complete analysis of beam analyzing powers in d+γ⃗⃗n+p at near threshold energies

“…Induced polarization P y ¢ of the neutron in the deuteron photodisintegration using various potentials was calculated [57] and was found that the predictions are systematically larger than the measured P y ¢ values. Using effective field theory, the induced neutron spin polarization in  d n p g +  + was discussed by Ando et al [58] and Young et al [59] in view of the mismatch between theory [56] and experiment [60]. We may quote Young et al [59] 'Because the measured induced neutron polarization P y ¢ in  d n p g +  + and theoretical calculation using the phenomenological potential model show a discrepancy [56,58,60], it is desirable to have a model independent calculation'.…”

Neutrino-Deuteron Reactions at Solar Neutrino Energies in Pionless Effective Field Theory with Dibaryon Fields

“…These high-precision theories provide a unique opportunity in which we can probe the interactions of neutrino and deuteron with uncertainties due to strong interactions under control. In the publications during the last decade, we have been applying the pionless effective field theory with dibaryon fields (dEFT in short) [16,17] to the low-energy two-nucleon systems and phenomena such as electromagnetic (EM) form factors of the deuteron [18], synthesis of the deuteron at big bang energies [19], proton-proton scattering [20], their fusion [21], neutron-proton scattering [22], spin-dependent polarization [23][24][25], and hadronic parity violation in the radiative neutron-proton fusion or the dissociation of the deuteron [26][27][28][29][30]. We could verify that i) calculational complexity and difficulty are significantly reduced in dEFT compared to the calculations in phenomenological potential models or other EFTs, ii) convergence of the 1 EeV is an initialism of exa-electron volt, 10 18 eV.…”