Quark-Gluon Plasma: Present and Future

We review a sample of the experimental results from AGS to SPS and RHIC and their interpretations towards understanding of the Quark-Gluon Plasma. We discuss extrapolations of these results to the upcoming LHC experiments. Finally, we present the plans to probe the QCD critical point with an energy scan at RHIC and FAIR facilities.Comment: Invited talk at the DAE Symposium on Nuclear Physics (December 2007) at Sambalpur University, India. 9 page

A history of the Lonar crater, India: An overview

The origin of the circular structure at Lonar, India, described variously as cauldron, pit, hollow, depression, and crater, has been a controversial subject since the early nineteenth century. A history of its origin and other aspects from 1823 to 1990 are overviewed. The structure in the Deccan Trap Basalt is nearly circular with a breach in the northeast, 1830 m in diameter, 150 m deep, with a saline lake in the crater floor. Over the years, the origin of the Lonar structure has risen from volcanism, subsidence, and cryptovolcanism to an authentic meteorite impact crater. Lonar is unique because it is probably the only terrestrial crater in basalt and is the closest analog with the Moon's craters. Some unresolved questions are suggested. The proposal is made that the young Lonar impact crater, which is less than 50,000 years old, should be considered as the best crater laboratory analogous to those of the Moon, be treated as a global monument, and preserved for scientists to comprehend more about the mysteries of nature and impact cratering, which is now emerging as a fundamental ubiquitous geological process in the evolution of the planets

Wave Propagation in 1-D Spiral geometry

In this article, we investigate the wave equation in spiral geometry and study the modes of vibrations of a one-dimensional (1-D) string in spiral shape. Here we show that the problem of wave propagation along a spiral can be reduced to Bessel differential equation and hence, very closely related to the problem of radial waves of two-dimensional (2-D) vibrating membrane in circular geometry

Singlet Fermion Assisted Dominant Seesaw with Lepton Flavor and Number Violations and Leptogenesis

In a recent review Mohapatra has discussed how type-I seesaw mechanism suppressed by fine tuning of Yukawa couplings, or specific textures of associated fermion mass matrices, can form the basis of neutrino masses in TeV scale $W_R$ boson models. In this paper we review recent works in another class of theories where the added presence of fermion singlets manifesting as sterile neutrinos render the type-I seesaw contribution vanishing but extended seesaw dominant where the light neutrino mass formula is same as the classic inverse seesaw but all massive neutrinos are Majorana fermions. We also show domunance of linear seesaw, or double seesaw, or type-II seesaw in due to cancellation of type-I seesaw. Embeddings of this mechnism in supersymmetric as well as non-supersymmetric SO(10) with low or intermediate masses of $W_R$ or $Z_R$ bosons are discussed. We also discuss how this cancellation criteria has led to a new mechanism of type-II seesaw dominance which permits $U(1)_{B-L}$ breaking scale much smaller than the left-handed triplet mass. Out of a number of new observable predictions, the most visible ones are the dominant contribution to LFV decays and neutrinoless double beta decay mediated by light sterile neutrinos in the $W_L-W_L$ channel. These seesaw dominance mechanisms are applicable in the extensions of the SM and high, intermediate, or low scale left-right gauge theories with or without their SO(10) origin. Other recent works on the applications of this mechanism covering dark matter and leptogenesis are noted..Comment: 66 pages pdfLatex, 9 figures; Review Artile on Neutrino Physics, Seesaw Mechanisms, and Beyond SM Physics Including GUT

Measuring radial flow of partonic and hadronic phases in relativistic heavy ion collision

It has been shown that the thermal photon and the lepton pair spectra can be used to estimate the radial velocity of different phases of the matter formed in nuclear collisions at ultra-relativistic energies. We observe a non-monotonic variation of the flow velocity with invariant mass of the lepton pair which is indicative of two different sources of thermal dilepton sources at early and late stage of the dynamically evolving system. We also show that the study of radial velocity through electromagnetic probes may shed light on the nature of the phase transition from hadrons to QGP.Comment: 0ne figure added, minor modification in tex

Fundamental String (Membrane) Orbiting D5(M5)-branes

We study fundamental string (F-string) dynamics near D5-brane in some limits. We find that when the angular momentum of the probe is proportional to string length (l_s) and square root of string coupling constant {g_s}, the F-string lies in its metastable orbit at a finite distance from D5-branes. We further study the metastable orbits of a M2-brane in M5-brane background.Comment: 13 pages, In JHEP Styl