Final-state interactions in the high-energy proton-deuteron charge exchange reaction

The charge exchange reaction dp → (pp)n

“…Moreover experimental investigations of final state interactions (FSI) showed that the backwardforward asymmetries of the cos α = ( )/(| || |) dis- * E-mail: martinska.gabriela@upjs.sk tributions are very sensitive to FSI, where -is the momentum of the spectator with respect to the deuteron frame, and -is the three-dimensional momentum transfer from the incident nucleon to the scattered one. In the works [6,7] it has been shown that for the values of | | < 0 1(GeV/c) 2 and spectator momenta | | < 0 1 GeV/c the asymmetries caused by FSI are practically absent, this is well demonstrated for both charge retention and charge exchange deuteron break-up channels in Fig. 1.…”

“…In connection with the appreciable contribution of events with intermediate ∆-isobar [7,19], the main part of which comes from quasi-pp collisions (proceeding mainly via ∆ ++ and ∆ + -isobars) see diagrams a) and b) in the Fig. 4, it would be necessary to introduce a correction for this effect.…”

Analysis of Δ0(1232) production in collisions of protons with carbon nuclei at 4.2 GeV/c

“…Interpreting the distribution D(M) as a pure ∆ 0 signal, it was fitted in region 1092 -1407 MeV/ 2 by a relativistic Breit-Wigner function [38] …”

“…p [26,27] or 3 He [28] induced reactions at around 2 GeV bombarding energy, the pπ correlations were successfully analyzed and the mass distribution of ∆(1232) was extracted. The resonance mass was found to be shifted by about −25 MeV/ 2 towards lower masses in reactions on various targets, compared to those on protons [26][27][28]. The mass reduction of ∆(1232) in +A collisions (A =C, Nb, Pb) at 0 8 and 1 6 GeV incident energy [26] was related to the effects of Fermi motion, NN scattering, and pion reabsorption in nuclear matter.…”

“…As was pointed out in [11], the nuclear environment causes, in general, a mass shift which can be either positive or negative and depends on the hadronic density. For example, in near-central Ni+Ni and Au+Au collisions [11,24] at energies between 1 and 2 A GeV the average mass shift of ∆(1232) was −60 and −80 MeV/ 2 , respectively, the obtained widths being of the order of 50 MeV/ 2 . The mass shift of ∆(1232) in nucleus-nucleus collisions was found to be roughly proportional to the number of participants that became smaller with increasing impact parameter [11,23,25].…”