Spin-isospin responses of 71Ga for solar neutrinos studied by 71Ga(3He,tγ)71Ge reaction

Precision evaluation of theGa71(νe,e−)solar neutrino capture rate from theFrekers1, Adachi2, Akimune3 et al. 2015Phys. Rev. CSelf Cite

“…This integrated value is lower by nearly 25% compared to earlier (3He,r) measurements reported in Ref. [17], which is attributed to the different analysis performed in Ref. [17], in which the non-GT part of the zero-degree cross section could not be as accurately determined.…”

“…[17], which is attributed to the different analysis performed in Ref. [17], in which the non-GT part of the zero-degree cross section could not be as accurately determined. The effect on the solar neutrino capture rate is, however, much less pronounced, as shown below.…”

“…2 and 3). A capture rate of 0.32 SNU was evaluated for excitation energies above the neutron threshold, E x > S" [17], Errors are statistical errors from the present measurements. E 122.4 (16) speccross.f written by Bahcall, which contains corrections for (i) forbidden transitions, (ii) overlap between initial and final atomic states, (iii) exchange effects among electrons, (iv) electron screening, and (v) the nuclear size [31,32], If we use the same B(GT)-strength spectrum as was used by Bahcall, we obtain results identical to those in Ref.…”

“…In a second step, angular distributions were generated for A E = 0.5 MeV excitation-energy bins up to an excitation energy of ^8.5 MeV. This is the effective neutron threshold, because the decay of s-wave neutrons is forbidden [17], These angular distributions are described separately, and because of unknown spins and parities, a slightly more general set of transition amplitudes is assumed. For the low-energy overlap region between 0 and 3 MeV the two sets allow a consistency check for the £(GT) extraction.…”

“…[ 14] em phasis was on accurate extraction o f G am ow -Teller (GT) strength from the 7lG a(3H e ,f)7lGe reaction to the three low est-lying states accessible to the 5lC r calibration neutrinos, i.e., the 7 77 = 1 /2 " ground state (g.s. ), the 1 7 5 -keV (5/2" ) state, and the 5 0 0 k e V (3 /2 " ) state, we present here the entire G T-strength distribution up to an effective neutron-separation energy of 8.46 M eV [17]. This allows for an accurate evaluation o f the 7iG a(ve,e ) response to the full solar neutrino spectrum seen by the SAG E and G A LLEX detectors.…”