Neutrino scattering as a probe for the strange content of the nucleon

We consider different methods and observables which can be obtained by the measurement of neutrino scattering off nucleons and nuclei with the purpose of finding evidence for the strange form factors of the nucleon, which enter into structure of the nucleonic weak neutral current.Comment: 8 pages, 2 figures Contribution to 20th Max Born Symposium, Wroclaw (Poland), December 7-10, 200

Weak non-mesonic decay of Hypernuclei

We review the mechanism of weak decay of hypernuclei, with emphasis on the non-mesonic decay channels. Various theoretical approaches are discussed and the results are compared with the available experimental data.Comment: 15 pages, 3 figures, Talk presented at XXVIII Mazurian Lakes Conference, Krzyze, Poland, August 31-September 7, 2003. To be published in Acta Physica Pol. B 35 (2004

Weak Decay of Hypernuclei

The focus of these Lectures is on the weak decay modes of hypernuclei, with special attention to Lambda-hypernuclei. The subject involves many fields of modern theoretical and experimental physics, from nuclear structure to the fundamental constituents of matter and their interactions. The various weak decay modes of Lambda-hypernuclei are described: the mesonic mode and the non-mesonic ones. The latter are the dominant decay channels of medium--heavy hypernuclei, where, on the contrary, the mesonic decay is disfavoured by Pauli blocking effect on the outgoing nucleon. In particular, one can distinguish between one-body and two-body induced decays. Theoretical models employed to evaluate the (partial and total) decay widths of hypernuclei are illustrated, and their results compared with existing experimental data. Open problems and recent achievements are extensively discussed, in particular the determination of the ratio Gamma_n/Gamma_p, possible tests of the Delta I=1/2 rule in non-mesonic decays and the puzzling asymmetric non-mesonic decay of polarized hypernuclei.Comment: 59 pages, 13 figures Lectures given at the International School of Physics "Enrico Fermi" Course on: HADRON PHYSICS, Varenna (Lake Como), June 22nd - July 2nd, 200

Screening Masses of Scalar and Pseudo-scalar Excitations in Quark-gluon Plasma

The quark-gluon plasma (QGP) excitations, corresponding to the scalar and pseudoscalar meson quantum numbers, for different temperatures are calculated. Analysis is performed in the Hard Thermal Loop (HTL) Approximation and leads to a better understanding of the excitations of QGP in the deconfined phase and is also of relevance for lattice studies

On a possibility to determine the S-factor of the hep process in experiments with thermal (cold) neutrons

The problem of the magnitude of the S--factor of the hep process $p + {^3\mathrm{He}} \to {^4\mathrm{He}} + e^+ + \nu_e$ is one of the most important unsolved problems in nuclear astrophysics. The magnitude of $S(hep)$ has also an important impact on the interpretation of the Super-Kamiokande solar neutrino results in terms of neutrino oscillations. We point out the possiblity to determine the major hadronic contribution to $S(hep)$ from the measurement of the total cross section of the process $n + {^3\mathrm{H}} \to {^4\mathrm{He}} + e^- + \bar{\nu}_e$ in experiments with high intensity beams of thermal or cold neutrons.Comment: 7 pages, revtex, no figures; note added; final version to be published in Astropart. Phy