Non-mesonic weak decay of hypernuclei in effective field theory
- Pérez-Obiol Castañeda, Axel
- Bruno Juliá Diaz Doktorvater/Doktormutter
- Assumpta Parreño García Doktorvater/Doktormutter
Universität der Verteidigung: Universitat de Barcelona
Fecha de defensa: 11 von Februar von 2014
- Angels Ramos Gómez Präsident/in
- David Rodríguez Entem Sekretär
- Evgeny Epelbaum Vocal
Art: Dissertation
Zusammenfassung
In this thesis we have described the weak Lambda N to NN interaction, which is the main responsible for the decay of heavy hypernuclei, within the effective field theory (EFT) framework. The EFT is developed up to second order in “q”, where “q” is the transferred momentum between the interacting baryons. In particular, all the two-pion exchange diagrams entering at second order in the momentum expansion have been calculated. Numerical values for the leading order low-energy constants are obtained by two means. First, a fit to the hypernuclear decay observables for three light hypernuclei, 5-Lambda/He, 11-lLambda/B i 12/Lambda/C, has been performed. This calculation has involved a proper description of the initial and final nuclear states within a many-body formalism. Second, the EFT has been compared to the one-meson-exchange model describing the same interaction. By expanding the one-meson-exchange potentials in powers of momentum, the low energy constants appearing in the EFT description have been written in terms of the heavy meson parameters. In order to obtain a less model dependent description of the weak decay of hypernuclei we have studied the decay of the lightest hypernucleus, the hypertriton, which can be described within an effective field theory framework in both the strong and the weak sectors.