ﻻ يوجد ملخص باللغة العربية
We study the threshold production of two pions induced by neutrinos in nucleon targets. The contribution of nucleon, pion and contact terms are calculated using a chiral Lagrangian. The contribution of the Roper resonance, neglected in earlier studies, has also been taken into account. The numerical results for the cross sections are presented and compared with the available experimental data. It has been found that in the two pion channels with $pi^+pi^-$ and $pi^0pi^0$ in the final state, the contribution of the $N^*(1440)$ is quite important and could be used to determine the $N^*(1440)$ electroweak transition form factors if experimental data with better statistics become available in the future.
We have studied quasielastic charged current hyperon production induced by $bar u_mu$ on free nucleon and the nucleons bound inside the nucleus and the results are presented for several nuclear targets like $^{40}Ar$, $^{56}Fe$ and $^{208}Pb$. The hy
Using a covariant spectator quark model we estimate valence quark contributions to the F1*(Q2) and F2*(Q2) transition form factors for the gamma N -> P11(1440) reaction. The Roper resonance, P11(1440), is assumed to be the first radial excitation of
We study the threshold production of two pions induced by neutrinos in nucleon targets. The contribution of nucleon pole, pion and contact terms is calculated using a chiral Lagrangian. The contribution of the Roper resonance, neglected in earlier studies, has also been taken into account.
We calculate the axial $Nto Delta(1232)$ and $Nto N^{star}(1440)$ transition form factors in a chiral constituent quark model. As required by the partial conservation of axial current ($PCAC$) condition, we include one- and two-body axial exchange cu
We present Standard Model predictions for the complete set of phenomenologically relevant electroweak precision pseudo-observables related to the Z-boson: the leptonic and bottom-quark effective weak mixing angles $sin^2theta_{rm eff}^ell$, $sin^2the