Probing space-time structure of new physics with polarized beams at the ILC

At the International Linear Collider large beam polarization of both the electron and positron beams will enhance the signature of physics due to interactions that are beyond the Standard Model. Here we review our recently obtained results on a general model independent method of determining for an arbitary one-particle inclusive state the space-time structure of such new physics through the beam polarization dependence and angular distribution of the final state particle.Comment: 6 pages, plain latex, Talk given at LCWS06, Linear Collider Workshop, 9-13 March 2006, Bangalore, Indi

The Nobel Prize in Physics 2002 for the observation of cosmic neutrinos

A brief description of the work for which the first half of the Nobel prize for physics for the year 2002 is presented.Comment: 2 pages plain latex, to appear in Resonance, Journal of Science Educatio

Fundamental particles and their interactions

In this article the current understanding of fundamental particles and their interactions is presented for the interested non-specialist, by adopting a semi-historical path. A discussion on the unresolved problems is also presented.Comment: 10 pages, plain late

Lectures on Unification

In these lectures we review the motivation, principles of and (circumstantial) evidence for the program of unification of the fundamental forces. In an appendix, we review the group theory pertinent to the program.Comment: 28 pages plain LaTeX, to be run twice. Lectures given at the Sixth ICTP-BCSPIN School on Current Trends in High Energy Physics and Cosmology, Kathmandu, Nepal, May 19-June 3 199

A note on the heat kernel coefficients for nonminimal operators

We consider certain results for the heat kernel of nonminimal operators. The general expressions provided by Gusynin and Kornyak resulting from symbolic computation programmes for n dimensions are evaluated for 4 dimensions which are checked against results given by Barvinsky and Vilkovisky. We also check that the results in flat space are consistent with earlier results of Guendelmen et al. We then consider a powerful construction of the Green function of a nonminimal operator by Shore for covariantly constantly gauge fields in flat spacetime, and employ dimensional arguments to produce a check on the gauge parameter dependence of a certain coefficient. The connection of the results for heat kernel coefficients emanating from the construction of Shore, to those from other techniques is hereby established for the first time.Comment: 9 pages, plain latex, accepted for publication by Journal of Physics

Radiative Electroweak Breaking with Pseudogoldstone Higgs Doublets

We consider a realistic example of supersymmetric grand unification based on $SU(3)_c \times SU(3)_L \times SU(3)_R$ in which the electroweak (EW) higgs doublets are `light' as a consequence of the `pseudogoldstone' mechanism. We discuss radiative EW breaking in this model, exploring in particular the `small' (order unity) and `large' $(\approx m_t/m_b)$ $\tan \beta$ regions by studying the variations of $r (\equiv \sqrt{\mu^2_{1,2}/\mu^2_3})$, where $\mu^2_{1,2,3}$ are the well known MSSM parameters evaluated at the GUT scale. For $r$ sufficiently close to unity the quantity $\tan \beta$ can be of order unity, but the converse is not always true.Comment: 18 pages plain LaTeX (to be run twice) and 11 figures available separately from uuencoded file

Comparison of Pion-Kaon Scattering in SU(3) Chiral Perturbation Theory and Dispersion Relations

We establish the framework for the comparison of $\pi K$ scattering amplitudes from SU(3) chiral perturbation theory with suitable dispersive representations which result from the combination of certain fixed-t dispersion relations with dispersion relations on hyperbolic curves. This allows for predictions for some combinations of low energy constants appearing in higher order calculations of chiral perturbation theory. Using a simple parametrization for the lowest partial waves, first estimates for some combinations are presented.Comment: 20 pages, LaTeX2e; replaced with version to appear in European Physical Journal C; typographical errors removed, minor stylistic change

Optimal renormalization and the extraction of the strange quark mass from moments of the τ\tau-decay spectral function

We introduce an optimal renormalization group analysis pertinent to the analysis of polarization functions associated with the $s$-quark mass relevant in $\tau$-decay. The technique is based on the renormalization group invariance constraints which lead to closed form summation of all the leading and next-to-leading logarithms at each order in perturbation theory. The new perturbation series exhibits reduced sensitivity to the renormalization scale and improved behavior in the complex plane along the integration contour. Using improved experimental and theory inputs, we have extracted the value of the strange quark mass $m_s(2{\rm GeV}) = 106.70 \pm 9.36~{\rm MeV}$ and $m_s(2{\rm GeV}) = 74.47 \pm 7.77~{\rm MeV}$ from presently available ALEPH and OPAL data respectively. These determinations are in agreement with the determinations in other phenomenological methods and from the lattice.Comment: 12 pages, 4 tables, 7 figures, v2 corresponds to version to appear in Physical Review