Thermal Radiation from Nucleons and Mesons

Thermal photon emission rates due to meson-nucleon interactions have been evaluated. An exhaustive set of reactions involving p(\bar p), n(\bar n), rho, omega, a_1, pi and eta is seen to provide a sizeable contribution to the emission rate from hot hadronic matter. Contributions from baryonic resonances are found to be negligibly small

Physics Prospects at the Hadron Colliders

I start with a brief introduction to the elementary particles and their interactions, Higgs mechanism and supersymmetry. The major physics objectives of the Tevatron and LHC colliders are identified. The status and prospects of the top quark, charged Higgs boson and superparticle searches are discussed in detail, while those of the neutral Higgs boson(s) are covered in a parallel talk by R.J.N. Phillips at this workshop.Comment: 16 pages Latex + 15 figures (available on request

Constraints on the Charged Higgs Sector from the Tevatron Collider Data on Top Quark Decay

The top quark data in the lepton plus $\tau$ channel offers a viable probe for the charged Higgs boson signal. We analyse the recent Tevatron collider data in this channel to obtain a significant limit on the $H^\pm$ mass in the large $\tan\beta$ region.Comment: 8 pages, LaTeX file; 2 figures included (PS files

Using Tau Polarization to Discriminate between SUSY Models and Determine SUSY Parameters at ILC

In many SUSY models the first SUSY signal in the proposed International Linear Collider is expected to come from the pair production of $\tilde\tau_1$, followed by its decay into $\tau$+LSP. We study a simple and robust method of measuring the polarization of this $\tau$ in its 1-prong hadronic decay channel,and show how it can be used to discriminate between SUSY models and to determine SUSY parameters.Comment: 9 pages, 5 figures, minor corrections; version published in Phys. Lett.

Radiative corrections to the Casimir effect for the massive scalar field

We compute the $O(\lambda)$ correction to the Casimir energy for the massive $\lambda\phi^4$ model confined between a pair of parallel plates. The calculations are made with Dirichlet and Neumann boundary conditions. The correction is shown to be sensitive to the boundary conditions, except in the zero mass limit, in which case our results agree with those found in the literature.Comment: 6 pages. Work presented at the XXIII Brazilian National Meeting on Particles and Fields (Aguas de Lindoia, Brazil, 15-19 Oct 2002). Also available at http://www.sbf1.if.usp.br/eventos/enfpc/xxiii/procs/RES142.pd

A model for the degradation of polyimides due to oxidation

Polyimides, due to their superior mechanical behavior at high temperatures, are used in a variety of applications that include aerospace, automobile and electronic packaging industries, as matrices for composites, as adhesives etc. In this paper, we extend our previous model in [S. Karra, K. R. Rajagopal, Modeling the non-linear viscoelastic response of high temperature polyimides, Mechanics of Materials, In press, doi:10.1016/j.mechmat.2010.09.006], to include oxidative degradation of these high temperature polyimides. Appropriate forms for the Helmholtz potential and the rate of dissipation are chosen to describe the degradation. The results for a specific boundary value problem, using our model compares well with the experimental creep data for PMR-15 resin that is aged in air.Comment: 13 pages, 2 figures, submitted to Mechanics of Time-dependent Material

Optical spin-transfer-torque-driven domain-wall motion in a ferromagnetic semiconductor

We demonstrate optical manipulation of the position of a domain wall in a dilute magnetic semiconductor,GaMnAsP. Two main contributions are identified. First, photocarrier spin exerts a spin-transfer torque on the magnetization via the exchange interaction. The direction of the domain-wall motion can be controlled using the helicity of the laser. Second, the domain wall is attracted to the hot spot generated by the focused laser. Unlike magnetic-field-driven domain-wall depinning, these mechanisms directly drive domain-wall motion, providing an optical tweezerlike ability to position and locally probe domain walls

Recent developments in unconventional superconductivity theory

The review of recent developments in the unconventional superconductivity theory is given. In the fist part I consider the physical origin of the Kerr rotation polarization of light reflected from the surface of superconducting $Sr_2RuO_4$. Then the comparison of magneto-optical responses in superconductors with orbital and spin spontaneous magnetization is presented. The latter result is applied to the estimation of the magneto-optical properties of neutral superfluids with spontaneous magnetization. The second part is devoted to the natural optical activity or gyrotropy properties of noncentrosymmetric metals in their normal and superconducting states. The temperature behavior of the gyrotropy coefficient is compared with the temperature behavior of paramagnetic susceptibility determining the noticeable increase of the paramagnetic limiting field in noncentrosymmetric superconductors. In the last chapter I describe the order parameter and the symmetry of superconducting state in the itinerant ferromagnet with orthorhombic symmetry. Finally the Josephson coupling between two adjacent ferromagnet superconducting domains is discussed.Comment: 15 page

Towards Activity Context using Software Sensors

Service-Oriented Computing delivers the promise of configuring and reconfiguring software systems to address user's needs in a dynamic way. Context-aware computing promises to capture the user's needs and hence the requirements they have on systems. The marriage of both can deliver ad-hoc software solutions relevant to the user in the most current fashion. However, here it is a key to gather information on the users' activity (that is what they are doing). Traditionally any context sensing was conducted with hardware sensors. However, software can also play the same role and in some situations will be more useful to sense the activity of the user. Furthermore they can make use of the fact that Service-oriented systems exchange information through standard protocols. In this paper we discuss our proposed approach to sense the activity of the user making use of software

Charged and Pseudoscalar Higgs production at a Muon Collider

We consider single charged Higgs ($H^{\pm}$) and pseudoscalar Higgs ($A^0$) production in association with a gauge boson at $\mu^+\mu^-$ colliders. We find that the tree-level t-channel and s-channel contributions to $\mu^+\mu^-\to H^{\pm}W^{\mp}, A^0Z$ are enhanced for large values of $\tan\beta$, allowing sizeable cross-sections whose analogies at $e^+e^-$ colliders would be very small. These processes provide attractive new ways of producing such particles at $\mu^+\mu^-$ colliders and are superior to the conventional methods in regions of parameter space.Comment: 11 pages Latex, 5 figures, formulae added in sections 2.2 and 2.3, extra discussion in section 2.3, references adde