Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Decays of the Lightest Top Squark

C. Boehm, A. Djouadi, Y. Mambrini

Abstract

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.

Decays of the Lightest Top Squark

Abstract

We analyze higher order decay modes of the lightest top squark in the Minimal Supersymmetric extension of the Standard Model (MSSM), where the lightest SUSY particle (LSP) is assumed to be the neutralino . For small 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, , can dominate in a wide range of the MSSM parameter space over the loop-induced decay into a charm quark and the LSP, . This result might affect the experimental searches on this particle, since only the later signal has been considered so far.

Paper Structure

This paper contains 8 sections, 22 equations, 4 figures, 1 table.

Table of Contents

  1. 1. Introduction
  2. 2. The Two--Body Decays
  3. 3. The Four--Body decay mode
  4. 4. Conclusions

Figures (4)

  • Figure 2: The branching ratio BR$(\tilde{t}_1 \rightarrow b\chi_1^0 f \bar{f}')$ as a function of the common squark mass $m_{\tilde{q}}$ for a scalar top mass $m_{\tilde{t}_1}=80$ (a) and 150 GeV (b).
  • Figure 3: The branching ratio BR$(\tilde{t}_1 \rightarrow b\chi_1^0 f \bar{f}')$ as a function of the top squark mass $m_{\tilde{t}_1}$ for a scalar mass $m_{\tilde{q}}=400$ GeV and a gaugino mass $M_2$ of 120 (a) and 200 GeV (b).
  • Figure 4: The branching ratio BR$(\tilde{t}_1 \rightarrow b\chi_1^0 f \bar{f}')$ as a function of the sneutrino mass $m_{\tilde{\nu}}$ for a scalar top mass $m_{\tilde{t}_1}=80$ and two values of $\mu=700$ GeV (a) and 300 GeV (b).
  • Figure 5: The branching ratio BR$(\tilde{t}_1 \rightarrow b\chi_1^0 f \bar{f}')$ as a function of stop mass $m_{\tilde{t}_1}$ in the mSUGRA scenario for $\mu<0$ (a) and $\mu>0$ (b).