摘要
在２５ＭｅＶ／ｕ４０Ａｒ＋１１５Ｉｎ反应的在平面和出平面大角度关联测量中，提取了碎片和α粒子之间的方位角关联函数和方位角非对称性因子．φ＝９０时，方位角关联函数呈现为最小值，表明在集体类转动效应影响下，反应产生的轻带电粒子和碎片优先在反应平面内发射．随着关联对质量的增加，在平面关联粒子的发射相对于束流轴不对称性逐渐增大．随着关联对质量的增加，相继衰变和粒子末态相互作用对φ＝０的关联粒子对方位角关联函数值的影响逐渐降低并直至消失，同时集体转动效应增强，方位角非对称性增加．
The large angle correlations for in-plane and out-of-plane have been measured for the pairs of the fragments and light charged particles (LCPs) in the reaction of 25MeV/u 40 Ar+115 In. The azimuthal correlation functions and the azimuthal asymmetry factors were obtained. The azimuthal correlation functions of all pairs between fragments and a particles are of minimum value in = 90 plane. It indicates that the LCPs and fragments formed in the reaction exhibit an enhanced emission in the reaction plane due to collective rotation-like effect induced by attractive mean field. The more heavier the masses of the coincident LCPs and fragments are, the more stronger the left-right asymmetries of the coincident particles with respect to the beam direction in the reaction plane are, the more preferential the particle emission to the direction opposite to the coincident reaction products is. Along with the increase of the mass of the coincident LCPs and fragments, the influences of the sequential decay and particle final state interactions on the azimuthal correlation functions of the correlated pairs in the = 0 plane decrease and vanish at last, the collective rotation-like effect is enhanced, and the azimuthal asymmetries increase.
出处
《高能物理与核物理》
EI
CSCD
北大核心
2001年第1期16-22,共7页
High Energy Physics and Nuclear Physics
基金
国家自然科学基金资助!(1947505)&&
