Naslov
Neutro-Neutron Effective Range Parameters

Autori
Šlaus, Ivo ; Akaishi, Yoshimori ; Tanaka, Hajime

Izvornik
Physics Rreports (0370-1573) 173 (1989), 5; 257-300

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Three-nucleon force; nucleon.nucleonfinal state interaction; charge symmetry breaking; charge dependence

Sažetak
We present a comprehensive review of information on the neutron-neutron effective range parameters in the 1^S_0 state. A critical evaluation of the neutron-neutron scattering length, anm, extracted from the reactions D(pi^-, gamma)2n and D(n, nn)p demontrates an appreciable discrepancy between the values obtained from these processes. It is shown that the semi-phenomenological Fujita-Mayazawa three-nucleon force can explain these discrepancies as well as the discrepancy between a_nm obtained from pickup and knockon D(n, nm)p processes. We discuss evidence for three-nucleon force effects in other processes. The small effect of the three-nucleon force in certain kinematic configurations of the D(n, nm)p reaction allows one to combine the values from different processes, resulting in new recommended values: a_nm=− 18.5&plusmn ; ; 0.3 fm and r_nm=2.75&plusmn ; ; 0.11 fm. An investigation of the nucleon-nucleon final state interacation region gives information on the central part of the three-nucleon force. These neutron-neutron effective range parameters are compared with those for the neutron-proton and proton-proton systems and it is shown that they are compatible with the 3^H− 3^He binding energy difference. Charge dependence and charge symmetry breaking in the 1^S_0 state are discussed.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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