Introduction

We have discussed inelastic processes from free nucleon targets in Chapters11 and 12. However, most of the early experiments and also the newexperiments on inelastic as well as quasielastic reactions induced by(anti)neutrinos use nuclear targets. In this chapter, we will focus on theinelastic 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 stayin the ground state giving almost all the transferred energy in the reactionto the outgoing meson leading to the coherent production of mesons or can beexcited and/or broken up leading to the incoherent production of meson. Inthe subsequent sections, incoherent and coherent pion production from nucleiin the delta dominance model will be discussed with some comments on theinelastic production of kaons and photons.

The first experiments on inelastic scattering of (anti)neutrinos from nucleiwere done at CERN in the early 1960s using heavy liquid bubble chambers(HLBC) filled with propane, freon and with spark chambers, and at ANL/BNLwith spark and bubble chambers. The importance of nuclear medium effects inthe analysis of these experiments was realized and discussed in the contextof inelastic as well as quasielastic reactions. Some of the mesons, mostlypions, produced in the inelastic reactions could be absorbed in the parentnucleus giving rise to ‘pionless’ lepton events in chargedcurrent (CC) induced reactions enhancing the yield of quasielastic eventsand reducing the yield of ‘pionic’ events as compared to thetheoretical 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 quasielasticreactions (see Chapter 14), no serious efforts were made in the case ofinelastic reactions. Subsequently, many experiments were done at CERN [696,697, 698, 699, 700], SKAT [701, 702, 703, 704], FNAL [705, 706], and CHARM[707], using propane, propane– freon, neon, marble, and aluminiumtargets; only a qualitative description of the nuclear medium effects wasused. Most of these experiments studied the incoherent production of pionswhile some of them also studied the coherent production of pions [698, 699,700, 703, 704, 706, 708, 709] from nuclei.