Energy dependence of pion double charge exchange

Abstract

The energy dependence of forward angle pion double charge exchange is calculated in the energy range of 0-250 MeV. The most striking feature is a peak around 40 MeV which is in excellent agreement with the data when distorted waves obtained from a realistic optical model are used. Two possible short-range corrections to the reaction mechanism are addressed. ͓S0556-2813͑98͒07410-X͔

Double charge exchange and configuration mixing

“…The energy dependence of the forward angle cross section for pion-nucleus double charge exchange (DCX) reactions has been shown to contain important information on the fundamental pion-nucleon charge exchange process and has been investigated extensively both experimentally [1,2,3] and theoretically [4,5]. See Ref.…”

Double charge exchange on medium mass nuclei

“…There have been controversial theoretical explanations of this peak. While some authors [2] have claimed that the peak is evidence for the existence of a dibaryon, we explained [3,4] this peak as the consequence of pion distortion based on a two-step sequential process which involves nucleons solely. It has been also shown that the energy dependence of the forward transition of DCX is sensitive to the configuration mixing [4].…”

“…The purpose of present work is to extend our previous studies [3,4] to medium mass nuclei, for which calculations are rare. To be specific, we study the DCX reactions 56 Fe(π…”

“…[10]. In our previous work [3,4] the parameters of the optical model are taken from the fits to elastic scattering. However, for the targets studied in this paper, there exist no such fits.…”

Resonant behaviour in double charge exchange reaction of πmesons on the nuclear photoemulsion

“…Later, attempts were made [17], [18] to explain the peaks qualitatively by nuclear medium effects, but no explanation based on conventional nuclear physics exists, however, for the whole set of data on DCX, and, in particular, for nuclei with N = Z. A series of experiments in search of the d ′ has been performed at JINR [19], [20] and at TRIUMF [21], [22], where the DCX π + + 4 He → pppp π − was measured.…”