Search for $R$-Parity Violating Decays of Sneutrinos to $e\mu$, $\mu \tau$, and $e\tau$ Pairs in $p\overline{p}$ Collisions at $\sqrt{s}=1.96\mathrm{TeV}$

We present a search for supersymmetric neutrino $\tilde{\nu }$ production using the Tevatron $p\overline{p}$ collision data collected with the CDF II detector and corresponding to an integrated luminosity of $1{\mathrm{fb}}^{-1}$. We focus on the scenarios predicted by the $R$-parity violating (RPV) supersymmetric models in which sneutrinos decay to two charged leptons of different flavor. With the data consistent with the standard model expectations, we set upper limits on $\sigma (p\overline{p}\to \tilde{\nu })\times BR(\tilde{\nu }\to e\mu ,\mu \tau ,e\tau )$ and use these results to constrain the RPV couplings as a function of the sneutrino mass.

Figure 1

Expected SM and observed distributions in $M_{\mathrm{ll}}$ for $e\mu$, $\mu \tau$ and $e\tau$ channels. Also shown is an expected ${\tilde{\nu }}_{\tau }$ signal for $M_{{\tilde{\nu }}_{\tau }}=500\mathrm{GeV}/c^2$ and RPV couplings ${\lambda }_{311}^{\prime }=0.10$ and ${\lambda }_{i3k}=0.05$.

Figure 2

The expected and observed 95% C.L. upper limits on $\sigma (p\overline{p}\to {\tilde{\nu }}_{\tau })\times BR({\tilde{\nu }}_{\tau }\to e\mu /\mu \tau /e\tau )$ as a function of $M_{{\tilde{\nu }}_{\tau }}$.