2p-2h excitations in neutrino scattering: angular distribution and frozen approximation

28 Aug 2014, 11:50
25m
Western Infirmary Lecture Theatre (University of Glasgow)

Western Infirmary Lecture Theatre

University of Glasgow

University Avenue Glasgow, G12 8QQ, Scotland, UK

Speaker

Dr Ignacio Ruiz Simo (University of Granada)

Description

We study the phase-space dependence of 2p-2h excitations in neutrino scattering using the relativistic Fermi gas model \cite{Rui14}. We follow a similar approach to Refs. \cite{Pace03,Ama10}, but focusing in the phase-space properties, comparing with the non-relativistic model of \cite{Van81}. A careful mathematical analysis of the angular distribution function for the outgoing nucleons is performed. Our goals are to optimize the CPU time of the 7D integral to compute the hadronic tensor in neutrino scattering, and to conciliate the different relativistic and non relativistic models by describing general properties independently of the two-body current. For some emission angles the angular distribution becomes infinite in the Lab system, and we derive a method to integrate analytically around the divergence. Our angular distribution is the same as the one obtained in the Monte Carlo generators by a boost from the CM isotropical distribution. Our formalism is applied to neutrino scattering from C-12, in the particular case of the seagull MEC diagrams. Our results show that the frozen approximation, obtained by neglecting the momenta of the two initial nucleons inside the integral of the hadronic tensor, reproduces fairly the exact response functions. \begin{thebibliography}{expo92} \bibitem{Rui14} I. Ruiz Simo, C. Albertus, J.E. Amaro, M.B. Barbaro, J.A. Caballero, T.W. Donnelly, arXiv:1405.4280 [nucl-th]. \bibitem{Pace03} A. De pace, M. Nardi, W.M. Alberico, T.W. Donnelly, A. Molinari, \bibitem{Ama10} J.E. Amaro, C. Maieron, M.B. Barbaro, J.A. Caballero, T.W. Donnelly, Phys. Rev. C 82, 044601 (2010). \bibitem{Van81} J.W. Van Orden, T.W. Donnelly, Published in Annals Phys. 131 (1981) 451. \end{thebibliography}
WG1: Neutrino Oscillation Physics (Yes/No) No
WG2: Neutrino Scattering Physics (Yes/No) Yes
WG3: Accelerator Physics (Yes/No) No
WG4: Muon Physics (Yes/No) No
Type of presentation Oral presentation

Author

Dr Ignacio Ruiz Simo (University of Granada)

Co-authors

Dr Conrado Albertus (University of Granada) Prof. Jose Enrique Amaro (University of Granada) Prof. Juan Antonio Caballero (University of Sevilla) Prof. Maria Barbaro (University of Torino) Prof. T. William Donnelly (Massachusetts Institute of Technology (MIT))

Presentation materials