Dissociation of relativistic⁷Li in photoemulsion and structure of⁷Li nucleus

Abstract

The dissociation of relativistic 7Li nuclei was studied with the photoemulsion technique. The nuclear photoemulsions have been exposed in the beam of 7Li at the momentum of 3 A GeV/c at the JINR synchrophasotron in Dubna. Along the scanned length 239.76 m of 7Li tracks, 1675 inelastic interactions have been found. For the first time the coherent dissociation of the relativistic 7Li nuclei into the (α + t) channel in the nuclear photoemulsion has been detected. The mean free path of this channel in emulsion is equal to 5.4 m and corresponds to the cross section which is equal to 23 ± 5 mb. Previously in the dissociation of the relativistic 6Li nuclei it was found that the main di-cluster configuration of the ground state of 6Li manifests itself as the main channel of coherent dissociation into α-particle and deuteron. The close values of relative yields and kinematic features of these two-particle dissociation channels of 7Li and 6Li suggest that a similar di-cluster configuration consisting of α-particle core and bound together outer nucleons predominates in the dissociating nuclei at relativistic energies also. The data presented prove the validity of the relativistic nuclei dissociation as an effective complementary method for the study of nuclear structure.

Peripheral interactions of relativistic 14N nuclei with emulsion nuclei

“…The results of these measurements were utilized to identify the hydrogen and helium isotopes involved in the 14 N fragment composition. [2] are displayed in Table I in which there are also the λ A values calculated by the Bradt-Peters equation [3].…”

Dissociation of relativistic 7Be nuclei through the 3He+4He channel on a proton target

“…Commensurate contributions come from the decay of the giant dipole resonance in the projectile nucleus to nucleons, and this is of particular interest for studying collective excitations in radioactive nuclei. More recent investigations devoted to the fragmentation of relativistic nuclei and performed at the synchrophasotron and nuclotron of the Joint Institute for Nuclear Research (JINR, Dubna) with a propane bubble chamber [2,3] and photoemulsions [4][5][6][7][8] were aimed primarily at detecting events involving the emission of protons and extremely light nuclei, including deuterons, tritons, 3 He nuclei, and alpha particles, and at determining to a considerable extent the cluster structure of light nuclei. An extensive survey of investigations on the subject is given in [9].…”

“…In order to study the electromagnetic and nuclear interaction mechanisms in such processes, it is reasonable to measure the transverse-momentum-transfer (Q) distribution of events. Such reactions include the dissociation of 6 Li, 7 Li, and 7 Be nuclei to pairs of extremely light nuclei-2 H+ 4 He, 3 H+ 4 He, and 3 He+ 4 He, respectivelyin which case a theoretical analysis of data is much more straightforward than in the case of multiparticle processes. A comparatively large number of such events observed in a nuclear emulsion [6,7,10,11] is indicative of a high probability for two-cluster components in the wave functions that describe primary nuclei.…”

Clustering in light nuclei in fragmentation above 1 A GeV

“…Experimental data on the charged topology for the final states of a number of light nuclei have been described in [2,3,4,5,6]. More specific studies were performed for the leading channels like 12 C → 3α [7], 16 O → 4α [8,9], 6 Li → dα [10,11], 7 Li → tα [12], 10 B → dαα [13], and 7 Be → 3 Heα [14]. A collection of appropriate reaction images can be found in [15,16].…”