Correlation of B_s -> mu^+ mu^- and (g-2)_mu in Minimal Supergravity

TL;DR

It is found that the recently measured excess in (g-2)(mu), if interpreted within mSUGRA, is correlated with a substantial enhancement of the branching ratio Beta(B(s)-->mu(+)mu(-)), which is larger by a factor of 10-100 and within reach of Run-II of the Tevatron.

Abstract

We analyse the rare decay mode B_s -> mu^+ mu^- in the minimal supergravity scenario (mSUGRA). We find a strong correlation with the muon anomalous magnetic moment (g-2)_mu. An interpretation of the recently measured excess in (g-2)_mu in terms of mSUGRA corrections implies a substantial supersymmetric enhancement of the branching ratio Br(B_s -> mu^+ mu^-): if (g-2)_mu exceeds the Standard Model prediction by 4*10^{-9}, Br(B_s -> mu^+ mu^-) is larger by a factor of 10-100 than in the Standard Model and within reach of Run-II of the Tevatron. Thus an experimental search for B_s -> mu^+ mu^- is a stringent test of the mSUGRA GUT scale boundary conditions. If the decay B_s -> mu^+ mu^- is observed at Run-II of the Tevatron, then we predict the mass of the lightest supersymmetric Higgs boson to be less than 120 GeV. The decay B_s -> mu^+ mu^- can also significantly probe the favoured parameter range in SO(10) SUSY GUT models.

Figures (3)

• Figure 1: $(\delta a_\mu)_{SUSY}$, versus ${\cal B}(B_s\rightarrow\mu^+\mu^-)$ for $\tan\beta$ (top) and $M_{1/2}$=450, $M_0=350, A_0=0, \mu>0, m_t=175$ GeV. Shown also, the SM prediction, the present bound by CDF CDFbmumu, on ${\cal B}(B_s\rightarrow\mu^+\mu^-)$ as well as the present 1$\sigma$ and 2$\sigma$ bound on $\delta a_\mu$ from BNL BNL. We used $f_{B_s}=230$ MeV.
• Figure 2: Contours of ${\cal B}(B_s\rightarrow\mu^+\mu^-)$ (solid) and $(\delta a_\mu)_{SUSY}$ (in units $10^{-10})$ (dashed) in the $M_{1/2}$-$\tan\beta$ plane. The lightest neutral CP-even Higgs mass is shown as well (dot-dashed). The shaded regions are excluded, as described in the text. The mSUGRA parameters are given at the top.
• Figure 3: Contour plots of the ${\cal B}(B_s\rightarrow\mu^+\mu^-)$ (solid) and on $(\delta a_ \mu)_{SUSY}$ (dashed) in the ($M_{0},M_{1/2}$)-plane for mSUGRA parameter values as shown. The shaded regions are excluded as described in the text. Contours of the light Higgs boson mass (dot-dash line) are also shown.