Determination of the nuclear weak axial charge radius of 12C via the 12C(νe, e−) 12Ng.s. reaction

Abstract A recent measurement of the charged current reaction 12 C (ν e , e − ) 12 N g.s. has been used to investigate the weak axial vector form factor F A ( q 2 ) for 12 C in the range | q 2 | ≤ 0.4 m 2 π . The analysis yields a rms radius of the weak axial charge R A =(3.7 +1.3 −1.8 ) fm corresponding in a dipole form to a mass parameter M A =(180 +200 −45 ) MeV/ c 2 in agreement with results deduced from inelastic electron scattering. From the total number of observed events the value at q 2 =0, F A (0)=0.73 +0.11 −0.10 , was derived.