2011/12/31 by S. V. Demidov, D. S. Gorbunov · 1 citation
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Branching fraction #Electron #Lepton #Neutrino Physics Research #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Production (economics) #Pseudoscalar #Quark #Scalar (mathematics) #Standard Model (mathematical formulation) #Supersymmetry #Supersymmetry breaking #hep-ex #hep-ph
paper · pdf · doi:10.1103/physrevd.85.077701
6 pages, 3 figures, updated version to appear in Physical Review D
arxiv created 2012/04/17 · arxiv updated 2013/05/29
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, \stackrel\texttildelowmLL2 and \stackrel\texttildelowmRR2. We find that present limits on off-diagonal entries in squark and slepton squared mass matrices allow t-, b-, c-quark and \ensuremathτ-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\ensuremath→cSP)\ensuremath\lesssim10^\ensuremath-7, Br(\ensuremathτ\ensuremath→\ensuremathμSP)\ensuremath\lesssim10^\ensuremath-7, Br(Bs\ensuremath→SP)\ensuremath\lesssim10^\ensuremath-4, Br(B\ensuremath→K(*)SP)\ensuremath\lesssim10^\ensuremath-4, Br(D\ensuremath→SP)\ensuremath\lesssim10^\ensuremath-7 with sgoldstino subsequent decays into kinematically allowed pairs of SM particles \ensuremathγ\ensuremathγ, e+e^\ensuremath-, \ensuremathμ+\ensuremathμ^\ensuremath-, etc. Remarkably, the prominent signature of sgoldstino pair production is two muon pairs with pair momenta peaked at sgoldstino masses.