Some peculiarities of formation of ⁴He nuclei in ¹⁶Op collisions at 3.25A GeV/c

Abstract

The new experimental data on dependences of the mean multiplicities and kinematical characteristics of 4 He nuclei, formed in 16 Op collisions at 3.25A GeV/c, on degree of excitation of the fragmenting nucleus are presented. It is shown that the initial (α cluster) structure of oxygen nucleus is retained at small excitation levels. It is established that the kinematical characteristics of 1 H, 2 H, 3 H and 3 He fragments do not depend on availability or absence of α particles in a collision event, which indicates the independence of mechanisms of formation of such fragments and 4 He nuclei. Keywords: Fragmentation of nuclei; structure of nuclei; excitation of nuclei; formation of light nuclei. PACS Number(s): 25.10.+s, 27.20.+nIt is known that α cluster structure prevails in even-even light nuclei. This structure should manifest itself mainly in fragmentation processes of such relativistic nuclei at peripheral collisions with nucleons and nuclei when the excitation energy of fragmenting nucleus slightly exceeds the value of threshold energy of nucleus breakup into the constituents of initial structure. ‡ Corresponding author. 1450086-1 Int. J. Mod. Phys. E 2014.23. Downloaded from www.worldscientific.com by UNIVERSITY OF CALIFORNIA @ DAVIS on 02/08/15. For personal use only. 1450086-2 Int. J. Mod. Phys. E 2014.23. Downloaded from www.worldscientific.com by UNIVERSITY OF CALIFORNIA @ DAVIS on 02/08/15. For personal use only. Some peculiarities of formation of 4 He nuclei