New signals of a R-parity violating model of neutrino mass at the Tevatron

Abstract

In a variety models of neutrino masses and mixings the lighter top squark decays into competing R - parity violating and R - parity conserving channels. Using Pythia we have estimated in a model independent way the minimum value of P $\equiv$ BR($\widetilde t_1 \to c \widetilde χ_1^0 $) $\times$ BR($\widetilde t_1 \to l^+_i b$), where $l_i = e^+$ and $μ^+$, corresponding to an observable signal involving the final state 1$l$ + jets +$\met$ (carried by the neutrinos from the $\tilde χ_1^0$ decay) at Tevatron Run II. For the kinematical cuts designed in this paper P depends on $m_{\widetilde t_1}$ only. We then compute P for representative choices of the model parameters constrained by the oscillation data and find that over a significant region of the allowed parameter space P is indeed larger than $P_{min}$. This signal is complementary to the dilepton + dijet signal studied in several earlier experimental and phenomenological analyses and may be observed even if BR($\widetilde t_1 \to l^+_i b$) is an order of magnitude smaller than BR($\widetilde t_1 \to c \widetilde χ_1^0$). The invariant mass distribution of the hardest lepton and the hardest jet may determine $m_{\widetilde t_1}$ and reveal the lepton number violating nature of the underlying interaction. The invariant mass distribution of the two lowest energy jets may determine $m_{\widetilde χ_1^0}$.

Some minor changes in language are made at pages 1,2,8 and 18 respectively