The frozen nucleon approximation in two-particle two-hole response functions

We present a fast and efficient method to compute the inclusive two-particle two-hole (2p–2h) electroweak responses in the neutrino and electron quasielastic inclusive cross sections. The method is based on two approximations. The first neglects the motion of the two initial nucleons below the Fermi...

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Detalles Bibliográficos
Autores: Ruiz Simo, I., Amaro Soriano, José Enrique, Barbaro, M. B., Caballero Carretero, Juan Antonio, Megías Vázquez, Guillermo Daniel, Donnelly, T. W.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2017
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/60426
Acceso en línea:http://hdl.handle.net/11441/60426
https://doi.org/10.1016/j.physletb.2017.04.063
Access Level:acceso abierto
Palabra clave:Neutrino scattering
Meson-exchange currents 2p–2h
Descripción
Sumario:We present a fast and efficient method to compute the inclusive two-particle two-hole (2p–2h) electroweak responses in the neutrino and electron quasielastic inclusive cross sections. The method is based on two approximations. The first neglects the motion of the two initial nucleons below the Fermi momentum, which are considered to be at rest. This approximation, which is reasonable for high values of the momentum transfer, turns out also to be quite good for moderate values of the momentum transfer q kF . The second approximation involves using in the “frozen” meson-exchange currents (MEC) an effective -propagator averaged over the Fermi sea. Within the resulting “frozen nucleon approximation”, the inclusive 2p–2h responses are accurately calculated with only a one-dimensional integral over the emission angle of one of the final nucleons, thus drastically simplifying the calculation and reducing the computational time. The latter makes this method especially well-suited for implementation in Monte Carlo neutrino event generators.