1112.5230 (S. V. Demidov et al.)

Flavor violating processes with sgoldstino pair production    [PDF]

S. V. Demidov, D. S. Gorbunov

In supersymmetric extensions of the Standard Model of particle physics (SM), goldstino superpartners --- scalar and pseudoscalar sgoldstinos --- can be light enough for emerging in decays of SM particles. Sgoldstino interaction with SM fields is suppressed by the scale of supersymmetry breaking in the whole theory. Hence, searches for sgoldstinos give an opportunity to probe the underlying mechanism of supersymmetry breaking. Sgoldstino couplings to SM fields are proportional to the supersymmetry breaking parameters --- MSSM soft terms --- and therefore can lead to flavor violating processes in quark and lepton sectors. We consider flavor violating processes involving sgoldstino pair production which are driven by sgoldstino couplings proportional to squark and slepton soft mass terms, \tilde{m^2_{LL}} and \tilde{m^2_{RR}}. We find that present limits on off-diagonal entries in squark and slepton squared mass matrices allow t-, b-, c-quark and \tau-lepton decays at levels available for study with existing data (BaBar, Belle, CLEOc) and in ongoing experiments (LHCb, CMS, ATLAS). In particular, we obtain the following branching ratios Br(t--> c SP)\lesssim 10^{-7}, Br(\tau--> \mu SP) \lesssim 10^{-7}, Br(B_s--> SP) \lesssim 10^{-4}, Br(B--> K^{(*)} SP) \lesssim 10^{-4}, Br(D--> SP) \lesssim 10^{-7} with sgoldstino subsequent decays into kinematically allowed pairs of SM particles \gamma\gamma, e^+e^-, \mu^+\mu^-, etc. Remarkably, the prominent signature of sgoldstino pair production is two muon pairs with pair momenta peaked at sgoldstino masses.

View original: http://arxiv.org/abs/1112.5230