Super black hole as spinning particle: Supersymmetric baglike core

We consider particlelike solutions to supergravity based on the Kerr-Newman black hole (BH) solution. The BH singularity is regularized by means of a phase transition to a new vacuum state near the core region confining a dual gauge field. Supersymmetric BPS-saturated domain wall model is suggested which can provide this phase transition and formation the stable charged superconducting core. For spinning particle the core takes the form of thin, relativistically rotaiting disk.Comment: 9 pages, Latex, plenary talks given at the School-Workshop Praha-Spin-2001 (Prague,July 15-28,2001) and at the XXIV International Workshop on Fundamental Problems of HEP and Field Theory (IHEP, June 2001, Protvino

Global Superdiffusion of Weak Chaos

A class of kicked rotors is introduced, exhibiting accelerator-mode islands (AIs) and {\em global} superdiffusion for {\em arbitrarily weak} chaos. The corresponding standard maps are shown to be exactly related to generalized web maps taken modulo an ``oblique cylinder''. Then, in a case that the web-map orbit structure is periodic in the phase plane, the AIs are essentially {\em normal} web islands folded back into the cylinder. As a consequence, chaotic orbits sticking around the AI boundary are accelerated {\em only} when they traverse tiny {\em ``acceleration spots''}. This leads to chaotic flights having a quasiregular {\em steplike} structure. The global weak-chaos superdiffusion is thus basically different in nature from the strong-chaos one in the usual standard and web maps.Comment: REVTEX, 4 Figures: fig1.jpg, fig2.ps, fig3.ps, fig4.p

Symmetrized models of last passage percolation and non-intersecting lattice paths

It has been shown that the last passage time in certain symmetrized models of directed percolation can be written in terms of averages over random matrices from the classical groups $U(l)$, $Sp(2l)$ and $O(l)$. We present a theory of such results based on non-intersecting lattice paths, and integration techniques familiar from the theory of random matrices. Detailed derivations of probabilities relating to two further symmetrizations are also given.Comment: 21 pages, 5 figure

The scientific potential of space-based gravitational wave detectors

The millihertz gravitational wave band can only be accessed with a space-based interferometer, but it is one of the richest in potential sources. Observations in this band have amazing scientific potential. The mergers between massive black holes with mass in the range 10 thousand to 10 million solar masses, which are expected to occur following the mergers of their host galaxies, produce strong millihertz gravitational radiation. Observations of these systems will trace the hierarchical assembly of structure in the Universe in a mass range that is very difficult to probe electromagnetically. Stellar mass compact objects falling into such black holes in the centres of galaxies generate detectable gravitational radiation for several years prior to the final plunge and merger with the central black hole. Measurements of these systems offer an unprecedented opportunity to probe the predictions of general relativity in the strong-field and dynamical regime. Millihertz gravitational waves are also generated by millions of ultra-compact binaries in the Milky Way, providing a new way to probe galactic stellar populations. ESA has recognised this great scientific potential by selecting The Gravitational Universe as its theme for the L3 large satellite mission, scheduled for launch in ~2034. In this article we will review the likely sources for millihertz gravitational wave detectors and describe the wide applications that observations of these sources could have for astrophysics, cosmology and fundamental physics.Comment: 18 pages, 2 figures, contribution to Gravitational Wave Astrophysics, the proceedings of the 2014 Sant Cugat Forum on Astrophysics; v2 includes one additional referenc

Supergravity Inflation Free from Harmful Relics

We present a realistic supergravity inflation model which is free from the overproduction of potentially dangerous relics in cosmology, namely moduli and gravitinos which can lead to the inconsistencies with the predictions of baryon asymmetry and nucleosynthesis. The radiative correction turns out to play a crucial role in our analysis which raises the mass of supersymmetry breaking field to intermediate scale. We pay a particular attention to the non-thermal production of gravitinos using the non-minimal Kahler potential we obtained from loop correction. This non-thermal gravitino production however is diminished because of the relatively small scale of inflaton mass and small amplitudes of hidden sector fields.Comment: 10 pages, revtex, 1 eps figure, references added, conclusion section expande

Nab: Measurement Principles, Apparatus and Uncertainties

The Nab collaboration will perform a precise measurement of 'a', the electron-neutrino correlation parameter, and 'b', the Fierz interference term in neutron beta decay, in the Fundamental Neutron Physics Beamline at the SNS, using a novel electric/magnetic field spectrometer and detector design. The experiment is aiming at the 10^{-3} accuracy level in (Delta a)/a, and will provide an independent measurement of lambda = G_A/G_V, the ratio of axial-vector to vector coupling constants of the nucleon. Nab also plans to perform the first ever measurement of 'b' in neutron decay, which will provide an independent limit on the tensor weak coupling.Comment: 12 pages, 6 figures, 1 table, talk presented at the International Workshop on Particle Physics with Slow Neutrons, Grenoble, 29-31 May 2008; to appear in Nucl. Instrum. Meth. in Physics Research

Physics Implications of Flat Directions in Free Fermionic Superstring Models II: Renormalization Group Analysis

We continue the investigation of the physics implications of a class of flat directions for a prototype quasi-realistic free fermionic string model (CHL5), building upon the results of the previous paper in which the complete mass spectrum and effective trilinear couplings of the observable sector were calculated to all orders in the superpotential. We introduce soft supersymmetry breaking mass parameters into the model, and investigate the gauge symmetry breaking patterns and the renormalization group analysis for two representative flat directions, which leave an additional $U(1)'$ as well as the SM gauge group unbroken at the string scale. We study symmetry breaking patterns that lead to a phenomenologically acceptable $Z-Z'$ hierarchy, $M_{Z^{'}} \sim {\cal O}(1~{\rm TeV})$ and $10^{12}~{\rm GeV}$ for electroweak and intermediate scale $U(1)^{'}$ symmetry breaking, respectively, and the associated mass spectra after electroweak symmetry breaking. The fermion mass spectrum exhibits unrealistic features, including massless exotic fermions, but has an interesting $d$-quark hierarchy and associated CKM matrix in one case. There are (some) non-canonical effective $\mu$ terms, which lead to a non-minimal Higgs sector with more than two Higgs doublets involved in the symmetry breaking, and a rich structure of Higgs particles, charginos, and neutralinos, some of which, however, are massless or ultralight. In the electroweak scale cases the scale of supersymmetry breaking is set by the $Z^{'}$ mass, with the sparticle masses in the several TeV range.Comment: 38 pages, 5 figures, LaTex. Minor correction

Novel Phases in the Field Induced Spin Density Wave State in (TMTSF)_2PF_6

Magnetoresistance measurements on the quasi one-dimensional organic conductor (TMTSF)_2PF_6 performed in magnetic fields B up to 16T, temperatures T down to 0.12K and under pressures P up to 14kbar have revealed new phases on its P-B-T phase diagram. We found a new boundary which subdivides the field induced spin density wave (FISDW) phase diagram into two regions. We showed that a low-temperature region of the FISDW diagram is characterized by a hysteresis behavior typical for the first order transitions, as observed in a number of studies. In contrast to the common believe, in high temperature region of the FISDW phase diagram, the hysteresis and, hence, the first order transitions were found to disappear. Nevertheless, sharp changes in the resistivity slope are observed both in the low and high temperature domains indicating that the cascade of transitions between different subphases exists over all range of the FISDW state. We also found that the temperature dependence of the resistance (at a constant B) changes sign at about the same boundary. We compare these results with recent theoretical models.Comment: LaTex, 4 pages, 4 figure

Leptogenesis and rescattering in supersymmetric models

The observed baryon asymmetry of the Universe can be due to the $B-L$ violating decay of heavy right handed (s)neutrinos. The amount of the asymmetry depends crucially on their number density. If the (s)neutrinos are generated thermally, in supersymmetric models there is limited parameter space leading to enough baryons. For this reason, several alternative mechanisms have been proposed. We discuss the nonperturbative production of sneutrino quanta by a direct coupling to the inflaton. This production dominates over the corresponding creation of neutrinos, and it can easily (i.e. even for a rather small inflaton-sneutrino coupling) lead to a sufficient baryon asymmetry. We then study the amplification of MSSM degrees of freedom, via their coupling to the sneutrinos, during the rescattering phase which follows the nonperturbative production. This process, which mainly influences the (MSSM) $D-$flat directions, is very efficient as long as the sneutrinos quanta are in the relativistic regime. The rapid amplification of the light degrees of freedom may potentially lead to a gravitino problem. We estimate the gravitino production by means of a perturbative calculation, discussing the regime in which we expect it to be reliable.Comment: (20 pages, 6 figures), references added, typos corrected. Final version in revte