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Y. Mambrini

Publications and source records attributed to Y. Mambrini.

39 records · Page 3Linked to original sources

Three-Body Decays of SUSY Particles

We analyze the decays of charginos, neutralinos, gluinos and the first/second generation squarks in the Minimal Supersymmetric extension of the Standard Model, focusing on the three-body decays in scenarios where the ratio $\tan β$ of vacuum expectation values of the two Higgs doublet fields is large. We show that the three-body decays of the next-to-lightest neutralinos (lightest charginos) into $b\bar{b},τ^+τ^-$ ($τν$) final states, where third generation sfermion and Higgs boson exchange diagrams play an important role, are dominant. Furthermore, we show that decays of gluinos into $b\bar{b}$ final states and squark decays into lighter sbottoms through gluino exchange can also have sizeable branching fractions, especially in scenarios where the soft SUSY breaking gaugino mass parameters are not unified at the GUT scale.

hep-ph↗

Decays of the Lightest Top Squark

We analyze higher order decay modes of the lightest top squark $\tilde{t}_1$ in the Minimal Supersymmetric extension of the Standard Model (MSSM), where the lightest SUSY particle (LSP) is assumed to be the neutralino $χ_1^0$. For small $\tilde{t}_1$ masses accessible at LEP2 and the Tevatron, we show that the four-body decay mode into the LSP, a bottom quark and two massless fermions, $\tilde{t}_1 \ra b χ_1^0 f\bar{f}'$, can dominate in a wide range of the MSSM parameter space over the loop-induced decay into a charm quark and the LSP, $\tilde{t}_1 \ra c χ_1^0$. This result might affect the experimental searches on this particle, since only the later signal has been considered so far.

hep-ph↗