Related papers: Neutralino decay in the $\mu$-problem solvable ext…
Motivated by grand unified theories and string theories we analyze the general structure of the neutralino sector in the USSM, an extension of the Minimal Supersymmetric Standard Model that involves a broken extra U(1) gauge symmetry. This…
We examine the production and the decay modes of neutralinos and charginos in a softly-broken supersymmetric model with an extra Abelian symmetry U(1)'. We perform the study in a U(1)' model with a secluded sector, where the tension between…
The radiative decay Z2-> Z1 gamma proceeds at the one-loop level in the MSSM. It can be the dominant decay mode for the second lightest neutralino Z2 in certain regions of parameter space of supersymmetric models, where either a dynamical…
Radiative neutralino decay $\chi^0_2 -> \chi^0_1\gamma$ is studied in a Split Supersymmetric scenario, and compared with mSUGRA and MSSM. This 1-loop process has a transition amplitude which is often quite small, but has the advantage of…
Neutralinos $\tilde{\chi}^0$ in supersymmetric theories, the spin--1/2 Majorana--type superpartners of the U(1) and SU(2) neutral electroweak gauge bosons and SU(2) neutral Higgs bosons, are expected to be among light supersymmetric…
We perform a comprehensive analysis of the decays of charginos and neutralinos in the Minimal Supersymmetric Standard Model where the neutralino $\chi_1^0$ is assumed to be the lightest supersymmetric particle. We focus, in particular, on…
Charginos $\tilde{\chi}^\pm$ and neutralinos $\tilde{\chi}^0$ in supersymmetric theories can be produced copiously at $e^+e^-$ colliders and their properties can be measured with high accuracy. Consecutively to the chargino system, in which…
The radiative decay of neutrino,such as (\bar{\nu_{\tau}}: \longrightarrow: \nu_{\mu}+\gamma), in the minimal supersymmetric standard model with right-handed neutrinos (MSSMRN) and in the (SU(5)) grand unified theory with right-handed…
We study properties of the lightest neutralino (\chi) and calculate its cosmological relic density in a supersymmetric U(1)' model with a secluded U(1)' breaking sector (the S-model). The lightest neutralino mass is smaller than in the…
The supersymmetric decays of the top quark into charged Higgs plus bottom, $\thb$, and into the supersymmetric partner of the top (${\wti u}_1$) plus the lightest neutralino (${\wti \chi}_1^0$), $\tstopneu$, are discussed within the…
We examine in detail the neutrino masses and mixing patterns in an extension of the minimal supersymmetric standard model with three gauge-singlet neutrinos and R-parity violation. The Majorana masses for the gauge-singlet neutrinos as well…
We study the neutralino radiative decay into the lightest supersymmetric particle (LSP) in the framework of a minimal anomalous U(1)' extension of the MSSM. It turns out that in a suitable decoupling limit the axino, which is present in the…
In the Minimal Supersymmetric Standard Model, neutralinos lighter than 50 GeV are compatible with all accelerator, precision, and cosmological bounds. Such neutralinos might constitute a relevant decay channel for the Higgs boson, modifying…
A complete phenomenological study of the next-to-lightest neutralino decays is performed in the MSSM. The widths and branching ratios for all the possible decay channels (including the radiative decay X0(2) --> X0(1) gamma and the decay…
We consider different patterns of supersymmetry breaking gaugino masses, and implications of these patterns for the phenomenology of neutralinos and charginos in models of low energy supersymmetry. We outline a general procedure for…
Within the framework of the Next-To-Minimal Supersymmetric Standard Model (NMSSM) we study neutralino production $e^+e^- \longrightarrow \tilde{\chi}^0_i \tilde{\chi}^0_j$ ($i,j=1,\ldots ,5$) at center-of-mass energies between 100 and 600…
In the minimal supersymmetric standard model (MSSM), the neutralinos, the spin--1/2 Majorana superpartners of the neutral gauge and Higgs bosons, are expected to be among the light supersymmetric particles that can be produced copiously at…
In an R-parity violating supersymmetric scenario, the lightest neutralino $\tilde \chi^0_1$ is no longer a stable particle. We calculate the branching ratio for the decay mode $\tilde \chi^0_1 \longrightarrow \nu \gamma$ which occurs at the…
We study the neutralino sector of the left-right supersymmetric model. In addition to the possibilities available in the minimal supersymmetric model, the neutralino states can be superpartners of the U(1)_{B-L} gauge boson, the neutral…
Decays of the lightest neutralino are studied in R_p-violating models with operators lambda^{prime} L Q D^c and lambda L L E^c involving third-generation matter fields and with dominant lambda^{prime} and lambda couplings. Generalizations…