Experimental Study Of The Low Energy Cross Section Of6li(p, γ)~7Be

6Li(p, γ)7Be reaction and its reverse reaction are closely related to the big bangnucleosynthesis (BBN). It is worthwhile to make a experimental study of thelow-energy cross-section of6Li(p, γ)7Be, which has not been studied well. A newexperimental setup for nuclear astrophysics study has been established in Lanzhouby our group. The setup is driven by a320kV high voltage platform, which canprovide intense currents of proton, alpha and many heavy ion beams. The energy of aproton beam has been calibrated against the nominal platform high voltage by usinga well-known resonant reaction of11B(p, γ)12C and a non-resonant reaction of12C(p,γ)13N. The accuracy was achieved to be better than0.5keV. The detection systemconsists of a Clover-type high-purity germanium detector, a silicon detector and aplastic scintillator. The absolute efficiency of the Clover detector was given by thestandard γ-ray sources of60Co and152Eu with known activites combined with aresonant reaction of14N(p, γ)15O. The plastic scintillator can suppress thebackground of cosmic-rays efficiently, and background suppression factors wereobtained for different energy regions.The low-energy astrophysical S-factors of the6Li(p, γ)7Be reaction have beeninvestigated on the new experimental setup. The yields of γ-rays from γ-channel andcharge particles from α-channel were measured simultaneously. The astrophysicalS-factors of6Li(p, γ)7Be were determined relatively to the well-known S-factors of6Li(p, α)3He reaction at50～250keV energy region. The experimental S-factor ofthis reaction shows an interesting sizable drop contrary to any existing theoreticalexpectations at energies below200keV. Our R-matrix calculation shows that theremay be an interesting new positive-parity3/2+resonance at ER≈195keV in7Be. Such a resonance state of7Be can not only fit the structure of the obtained S-factorsbut also interpret the nonzero coefficient of a1in6Li(p, α)3He reaction. Although, ourresults discussed in a SUSY assisted BBN model hardly change the abundance of6Liand7Be, the new cross section based on a solid experimental ground is a good startfor the realistic calculations.