Constraining Anomaly Mediated Supersymmetry Breaking Framework via Ongoing Muon g-2 Experiment at Brookhaven

The ongoing high precision E821 Brookhaven National Laboratory experiment on muon g-2 is promising to probe a theory involving supersymmetry. We have studied the constraints on the minimal Anomaly Mediated Supersymmetry Breaking (AMSB) model using the current data of muon g-2 from Brookhaven. A scenario of seeing no deviation from the Standard Model is also considered, within a $2\sigma$ limit of the combined error from the Standard Model result and the Brookhaven predicted uncertainty level. The resulting constraint is found to be complementary to what one obtains from $b \to s+ \gamma$ bounds within the AMSB scenario, since only a definite sign of $\mu$ is effectively probed via $b \to s+ \gamma$. A few relevant generic features of the model are also described for disallowed regions of parameter space.Comment: 24 pages, LaTeX, 5 postscript figures. A few references added. Final version to appear in Phys. Rev.

Characteristic Wino Signals in a Linear Collider from Anomaly Mediated Supersymmetry Breaking

Though the minimal model of anomaly mediated supersymmetry breaking has been significantly constrained by recent experimental and theoretical work, there are still allowed regions of the parameter space for moderate to large values of $\tan\beta$. We show that these regions will be comprehensively probed in a ${\sqrt s} =1$ TeV $e^+e^-$ linear collider. Diagnostic signals to this end are studied by zeroing in on a unique and distinct feature of a large class of models in this genre: a neutral winolike Lightest Supersymmetric Particle closely degenerate in mass with a winolike chargino. The pair production processes $e^+e^- \to {\tilde e}_L^\pm {\tilde e}_L^\mp$, ${\tilde e}_R^\pm {\tilde e}_R^\mp$, ${\tilde e}_L^\pm {\tilde e}_R^\mp$, ${\tilde \nu} {\bar {\tilde \nu}}$, $\widetilde \chi^0_1 \widetilde \chi^0_2$, $\widetilde \chi^0_2 \widetilde \chi^0_2$ are all considered at $\sqrt s = 1$ TeV corresponding to the proposed TESLA linear collider in two natural categories of mass ordering in the sparticle spectra. The signals analysed comprise multiple combinations of fast charged leptons (any of which can act as the trigger) plus displaced vertices $X_D$ (any of which can be identified by a heavy ionizing track terminating in the detector) and/or associated soft pions with characteristic momentum distributions.Comment: 25 pages, LaTeX, three PS figures and one EPS figur

Electroweak Phase Transition in a Right-Handed Neutrino Superfield Extended NMSSM

Supersymmetric models with singlet extensions can accommodate single- or multi-step first-order phase transitions (FOPT) along the various constituent field directions. Such a framework can also produce Gravitational Waves, detectable at the upcoming space-based interferometers, e.g., U-DECIGO. We explore the dynamics of electroweak phase transition and the production of Gravitational Waves in an extended set-up of the Next-to-Minimal Supersymmetric Standard Model (NMSSM) with a Standard Model singlet right-handed neutrino superfield. We examine the role of the new parameters compared to NMSSM on the phase transition dynamics and observe that the occurrence of a FOPT, an essential requirement for Electroweak Baryogenesis, typically favours a right-handed sneutrino state below 125 GeV. Our investigation shows how the analysis can offer complementary probes for physics beyond the Standard Model besides the collider searches.Comment: 77 pages, 17 figures, 4 tables, discussion on semi-analytic computation and gauge dependency added, version accepted for publication in JHE