The 2p–2h electromagnetic response in the quasielastic peak and beyond

✍ Scribed by A. De Pace; M. Nardi; W.M. Alberico; T.W. Donnelly; A. Molinari

• Book ID: 104335722
• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 319 KB
• Volume: 726
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/s0375-9474(03)01625-7

✦ Synopsis

The contribution to the nuclear transverse response function R T arising from two particle-two hole (2p-2h) states excited through the action of electromagnetic meson exchange currents (MEC) is computed in a fully relativistic framework. The MEC considered are those carried by the pion and by ∆ degrees of freedom, the latter being viewed as a virtual nucleonic resonance. The calculation is performed in the relativistic Fermi gas model in which Lorentz covariance can be maintained. All 2p-2h many-body diagrams containing two pionic lines that contribute to R T are taken into account and the relative impact of the various components of the MEC on R T is addressed. The non-relativistic limit of the MEC contributions is also discussed and compared with the relativistic results to explore the role played by relativity in obtaining the 2p-2h nuclear response.