Ab initio calculation of the $np \to d γ$ radiative capture process

Silas R. Beane; Emmanuel Chang; William Detmold; Kostas Orginos; Assumpta Parreño; Martin J. Savage; Brian C. Tiburzi

doi:10.1103/PhysRevLett.115.132001

paper

Ab initio calculation of the $n p \to d γ$ radiative capture process

arXiv:1505.02422 · doi:10.1103/PhysRevLett.115.132001

Abstract

Lattice QCD calculations of two-nucleon systems are used to isolate the short-distance two-body electromagnetic contributions to the radiative capture process $n p \to d γ$ , and the photo-disintegration processes $γ^{(*)} d \to n p$ . In nuclear potential models, such contributions are described by phenomenological meson-exchange currents, while in the present work, they are determined directly from the quark and gluon interactions of QCD. Calculations of neutron-proton energy levels in multiple background magnetic fields are performed at two values of the quark masses, corresponding to pion masses of $m_{π} \sim 450$ and 806 MeV, and are combined with pionless nuclear effective field theory to determine these low-energy inelastic processes. Extrapolating to the physical pion mass, a cross section of $σ^{l q c d} (n p \to d γ) = 332.4 (+ 5.4 - 4.7) mb$ is obtained at an incident neutron speed of $v = 2, 200 m / s$ , consistent with the experimental value of $σ^{e x pt} (n p \to d γ) = 334.2 (0.5) mb$ .

Ab initio calculation of the $n p \to d γ$ radiative capture process

Abstract

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Ab initio calculation of the np→dγ radiative capture process

Abstract

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Cited by in corpus (60)

Ab initio calculation of the $n p \to d γ$ radiative capture process