相关论文: Radiative Neutralino Decay in Split Supersymmetry
We present a re-analysis of the decay $\bsgamma$ in the Minimal Supersymmetric Standard Model with radiatively induced breaking of $SU(2) \times U(1)$. We extend this analysis to regions of the supersymmetric parameter space wider than…
We study the distribution of lepton pairs from the second lightest neutralino decay \tchi^0_2\to\tchi^0_1 l^+l^-. This decay mode is important to measure the mass difference between \tchi^0_2 and the lightest neutralino \tchi^0_1, which…
We discuss three-body supersymmetric top decays, in schemes both with and without R-parity conservation, assuming that sfermion masses are larger than m_t. We find that MSSM top decays into chargino/neutralino pairs have a strong kinematic…
We investigate the prospects for neutralino dark matter within the Supersymmetric Standard Model (SSM) including the constraints from universal soft supersymmetry breaking and radiative breaking of the electroweak symmetry. The latter is…
We evaluate two-body decay modes of neutralinos in the Minimal Supersymmetric Standard Model with complex parameters (cMSSM). Assuming heavy scalar quarks we take into account all two-body decay channels involving charginos, neutralinos,…
The radiative decay of the massive neutrino $\nu_i \rightarrow \nu_j \gamma$ is investigated in the framework of the Standard Model in external electromagnetic fields of various configurations: constant crossed field, constant uniform…
We study all tree-level neutralino annihilation processes concerning energy-dependence at the mSUGRA benchmark point SPS1a using tree-level calculators MadGraph and CompHEP as well as FormCalc. We further investigate the total tree-level…
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.…
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…
The lighter chargino three body decays $\tilde{\chi}_1^\pm\to \tilde{\chi}_1^0 f f^\prime$ via the $W^\pm$ boson and the charged Higgs boson $H^\pm$ are studied in the R-parity conserved Minimal Supersymmetric Standard Model (MSSM). We…
In this paper, we present the branching ratios of the two lightest CP-even Higgses, $h_1$ and $h_2$, and of the lightest CP-odd Higgs, $a_1$, in the context of the Non-Minimal Supersymmetric Standard Model (NMSSM). We find that for some…
The radiative decay of the massive neutrino $\nu_i \rightarrow \nu_j \gamma ( m_i > m_j )$ in the external electromagnetic field is analyzed in detail in the framework of the standard model with lepton mixing. It is shown, that a sort of a…
Neutralino as the lightest supersymmetric particle (LSP) is a candidate for supersymmetric dark matter. It is known that coannihilation effects could be important in neutralino relic density calculation. Here we present some results on…
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…
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…
We perform a study of neutrinoless double beta ($0\nu\beta\beta$) decay mediated by the lightest neutralino of arbitrary mass in the Minimal Supersymmetric Standard Model (MSSM) under the presence of R-parity violating trilinear…
A stable neutralino $\chi_1^0$, assumed to be the lightest supersymmetric particle, is a favored particle physics candidate for the cosmological Dark Matter. We study co-annihilation of the lightest neutralino with the lighter scalar top…
We present a detailed analysis together with exact numerical calculations on one-loop contributions to the branching ratio of the radiative decay of $\mu$ and $\tau$, namely $\mu \to e \gamma$, $\tau \to e \gamma$, and $\tau \to\mu \gamma$…
The 1-loop computation of the processes $\tchi_i \tchi_j \to \gamma Z$ has been performed at an arbitrary c.m. energy for any pair of MSSM neutralinos. As an application suitable for Dark Matter (DM) searches, the neutralino-neutralino…
Once supersymmetric neutralinos $\tilde{\chi}^0$ are produced copiously at $e^+e^-$ linear colliders, their characteristics can be measured with high precision. In particular, the fundamental parameters in the gaugino/higgsino sector of the…