We have discussed inelastic processes from free nucleon targets in Chapters 11 and 12. However, most of the early experiments and also the new experiments on inelastic as well as quasielastic reactions induced by (anti)neutrinos use nuclear targets. In this chapter, we will focus on the inelastic process of producing mesons and photons from the nuclear targets. When inelastic processes like
(discussed in Chapter 12) take place inside a nucleus, the nucleus can stay in the ground state giving almost all the transferred energy in the reaction to the outgoing meson leading to the coherent production of mesons or can be excited and/or broken up leading to the incoherent production of meson. In the subsequent sections, incoherent and coherent pion production from nuclei in the delta dominance model will be discussed with some comments on the inelastic production of kaons and photons.
The first experiments on inelastic scattering of (anti)neutrinos from nuclei were done at CERN in the early 1960s using heavy liquid bubble chambers (HLBC) filled with propane, freon and with spark chambers, and at ANL/BNL with spark and bubble chambers. The importance of nuclear medium effects in the analysis of these experiments was realized and discussed in the context of inelastic as well as quasielastic reactions. Some of the mesons, mostly pions, produced in the inelastic reactions could be absorbed in the parent nucleus giving rise to ‘pionless’ lepton events in charged current (CC) induced reactions enhancing the yield of quasielastic events and reducing the yield of ‘pionic’ events as compared to the theoretical predictions for these reactions from free nucleon targets (Chapter 12). While some theoretical calculations were made to estimate, quantitatively, the effect of nuclear medium effects in quasielastic reactions (see Chapter 14), no serious efforts were made in the case of inelastic reactions. Subsequently, many experiments were done at CERN [696, 697, 698, 699, 700], SKAT [701, 702, 703, 704], FNAL [705, 706], and CHARM , using propane, propane– freon, neon, marble, and aluminium targets; only a qualitative description of the nuclear medium effects was used. Most of these experiments studied the incoherent production of pions while some of them also studied the coherent production of pions [698, 699, 700, 703, 704, 706, 708, 709] from nuclei.