On sgoldstino interpretation of HyperCP events

We discuss possible sgoldstino interpretation of the observation, reported by HyperCP collaboration, of three $\Sigma^+\to p\mu^+\mu^-$ decay events with dimuon invariant mass 214.3 MeV within detector resolution. We find that this interpretation is consistent in models with (i) parity conservation in sgoldstino interactions, (ii) pseudoscalar sgoldstino $P$ of mass 214 MeV and heavier scalar sgoldstino, and (iii) low supersymmetry breaking scale, \sqrt{F} = 2.5-60 TeV. In these models, sgoldstino can be observed in decays $K^+\to\pi^+\pi^0 P$, $K_L\to\pi\pi P$ and $K_S\to\pi\pi P$ at the branching ratios of at least of order 10^{-12}, 10^{-8} and 10^{-11}, respectively. The model can be probed also at e^+e^- colliders in the channels $e^+e^-\to\gamma P$ and $e^+e^-\to e^+e^-P$, where the cross section is likely to be in the range 1 pb - 5 ab.Comment: 14 pages, 1 figure; v2: replaced with journal version, predictions for kaons refine

Stoponium Search at Photon Linear Collider

In some supersymmetric extensions of the Standard Model fairly light superpartner of t-quark is predicted, which may form bound states ({\it stoponiums}) under certain conditions. We study prospects of search for stoponium at the future Photon Linear Collider. It is found that this machine could be the best machine for discovery and study of these resonances at some scenarios of supersymmetric extension of the Standard Model. In particular, if the $hh$ decay channel is dominant stoponium could be observed at the beginning of PLC run with collision energy tuned at the stoponium mass. If this channel is kinematically closed stoponium could be discovered in $gg$, $\gamma\gamma$ and $ZZ$ decay channels but higher statistics are needed. Effects of the stoponium-Higgs mixing and degeneracy are briefly discussed.Comment: 11 pages, 2 figures added, corrections taken into account result in increasing of signal significanc

Gravity waves from inflating brane or Mirrors moving in adS5_5

We study tensor perturbations in a model with inflating Randall--Sundrum-type brane embedded in five-dimensional anti-de Sitter (adS$_5$) bulk. In this model, a natural {\it in}-vacuum of gravitons is the vacuum defined in static adS$_5$ frame. We show that this vacuum is, in fact, the same as the {\it in}-vacuum defined in the frame with de Sitter (dS$_4$) slicing, in which the brane is at rest. Thus, during inflation, gravitons on and off the brane remain in their vacuum state. We then study graviton creation by the brane on which inflation terminates at some moment of time. We mostly consider gravitons whose wavelengths at the end of inflation exceed both the horizon size and the adS$_5$ radius. Creation of these gravitons is dominated by (zero mode)--(zero mode) Bogoliubov coefficients and, apart from an overall factor, the spectrum of produced gravitons is the same as in four-dimensional theory. ``Kaluza--Klein'' gravitons are also produced, but this effect is subdominant. Graviton spectra at somewhat higher momenta are also presented for completeness.Comment: 33 pages, 1 figur

Hidden supersymmetry and Berezin quantization of N=2, D=3 spinning superparticles

The first quantized theory of N=2, D=3 massive superparticles with arbitrary fixed central charge and (half)integer or fractional superspin is constructed. The quantum states are realized on the fields carrying a finite dimensional, or a unitary infinite dimensional representation of the supergroups OSp(2|2) or SU(1,1|2). The construction originates from quantization of a classical model of the superparticle we suggest. The physical phase space of the classical superparticle is embedded in a symplectic superspace $T^\ast({R}^{1,2})\times{L}^{1|2}$, where the inner K\"ahler supermanifold ${L}^{1|2}=OSp(2|2)/[U(1)\times U(1)]=SU(1,1|2)/[U(2|2)\times U(1)]$ provides the particle with superspin degrees of freedom. We find the relationship between Hamiltonian generators of the global Poincar\'e supersymmetry and the ``internal'' SU(1,1|2) one. Quantization of the superparticle combines the Berezin quantization on ${L}^{1|2}$ and the conventional Dirac quantization with respect to space-time degrees of freedom. Surprisingly, to retain the supersymmetry, quantum corrections are required for the classical N=2 supercharges as compared to the conventional Berezin method. These corrections are derived and the Berezin correspondence principle for ${L}^{1|2}$ underlying their origin is verified. The model admits a smooth contraction to the N=1 supersymmetry in the BPS limit.Comment: 43 pages, LaTeX Version 2.0

Evidence for a connection between the gamma-ray and the highest energy cosmic-ray emissions by BL Lacertae objects

A set of potentially gamma-ray--loud BL Lac objects is selected by intersecting the EGRET and BL Lac catalogs. Of the resulting 14 objects, eight are found to correlate with arrival directions of ultra--high-energy cosmic rays (UHECRs), with significance of the order of 5 sigma. This suggests that gamma-ray emission can be used as a distinctive feature of those BL Lac objects that are capable of producing UHECR.Comment: 11 pages, 1 figure, version published in APJ Letter