Probing $(g-2{)}_{\mu }$ at the LHC in the paradigm of $R$-parity violating MSSM

The measurement of the anomalous magnetic moment of the muon exhibits a long-standing discrepancy compared to the standard model prediction. In this paper, we concentrate on this issue in the framework of the $R$-parity violating minimal supersymmetric standard model. Such a scenario provides a substantial contribution to the anomalous magnetic moment of the muon while satisfying constraints from low energy experimental observables as well as the neutrino mass. In addition, we point out that the implication of such operators satisfying muon $g-2$ are immense from the perspective of the LHC experiment, leading to a spectacular four muon final state. We propose an analysis in this particular channel which might help to settle the debate of $R$-parity violation as a probable explanation for $(g-2{)}_{\mu }$.

Figure 1

The most dominant diagrams that contribute to $(g-2{)}_{\mu }$ in the RPV MSSM scenario.

Figure 2

Trilinear ${\cancel{R}}_p$ violating contribution to neutrino masses.

Figure 3

1 and $2\sigma$ limits on $\mathrm{\Delta }{a}_{\mu }$ are shown in red and yellow colours respectively in the $m_{{\tilde{\nu }}_1}-{\lambda }_{322}$ plane where $m_{{\tilde{\nu }}_1}\equiv m_{{\tilde{\nu }}_{\tau }}$.

Figure 4

Decay branching ratios of the lightest sneutrino for bino-line neutralino mass parameters of $M_1=300\mathrm{GeV}$ and $M_1=10\mathrm{GeV}$, respectively. The points are consistent within the $2\sigma$ error of the $\mathrm{\Delta }{a}_{\mu }$ parameter.

Figure 5

Present 95% C.L. upper limits on the $\sigma \times BR$ for different values of heavy resonance masses.

Figure 6

Upper: The $p_T$ distribution of the leading muon for the two benchmark points BP1 and BP2 along with the three dominant SM backgrounds. The signal muons are seen to be harder compared to that of the SM ones. Lower: Di-muon invariant mass distribution for the signal and background events. Sharp resonance peaks can be observed for the signal benchmark points, while a clear peak at $M_Z\sim 91\mathrm{GeV}$ is also visible for the mass distribution.

Figure 7

Contour plot in the $\mathcal{L}-m_{{\tilde{\nu }}_1}$ plane for the binolike neutralino mass parameter of $M_1=300\mathrm{GeV}$. A similar distribution can be obtained for $M_1=10\mathrm{GeV}$.