Precision calculation of np→dγ cross section for big-bang nucleosynthesis

✍ Scribed by Gautam Rupak

• Book ID: 104333686
• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 184 KB
• Volume: 678
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/s0375-9474(00)00323-7

✦ Synopsis

An effective field theory calculation of the np → dγ cross section accurate to 1% for center of mass energies E 1 MeV is presented. At these energies, which are relevant for big-bang nucleosynthesis, isovector magnetic dipole transitions M1 V and isovector electric dipole transitions E1 V give the dominant contributions. The M1 V amplitude is calculated up to next-to-next-toleading order (N 2 LO), and the contribution from the associated four-nucleon-one-photon operator is determined from the cold neutron capture rate. The E1 V amplitude is calculated up to N 4 LO. The four-nucleon-one-photon operator contribution to E1 V is determined from the related deuteron photodisintegration reaction γ d → np.