Hot QCD equations of state and relativistic heavy ion collisions

We study two recently proposed equations of state (EOS) which are obtained from high temperature QCD, and show how they can be adapted to use them for making predictions for relativistic heavy ion collisions. The method involves extracting equilibrium distribution functions for quarks and gluons from the EOS, which in turn will allow a determination of the transport and other bulk properties of the quark gluon plasma. Simultaneously, the method also yields a quasi particle description of interacting quarks and gluons. The first EOS is perturbative in the QCD coupling constant and has contributions of $O(g^5)$. The second EOS is an improvement over the first, with contributions upto $O(g^6 ln(\frac{1}{g}))$; it incorporates the nonperturbative hard thermal contributions. The interaction effects are shown to be captured entirely by the effective chemical potentials for the gluons and the quarks, in both the cases. The chemical potential is seen to be highly sensitive to the EOS. As an application, we determine the screening lengths which are, indeed the most important diagnostics for QGP. The screening lengths are seen to behave drastically differently depending on the EOS considered., and yield, therefore, a way to distinguish the two equations of state in heavy ion collisions.Comment: 11 pages, fifteen figures, two column, accepted for publication in PR

Identification of Top Performing Economies

Using seven indicators of the economic performance of 187 countries, the paper identifies the top 50 performers during the decades of 1981-90 and 1991-2000. Five of these indicators are the trend rates of growth over a decade in imports, FDI, capital formation, per capita income and forex reserves. Average inflation rate and HDI are the remaining indicators. Comparison of top performers of the 1980s and the 1990s suggest that high performance in inflation and HDI are the precondition for consistency of high overall performance over time. The paper also examines the interrelationship among the indicators over time.

Petrology and tectonic development of supracrustal sequence of Kerala Khondalite Belt, Southern India

The granulite terrain of southern India, of which the Kerala Khondalite belt (KKB) is a part, is unique in exposing crustal sections with arrested charnockite growth in different stages of transformation and in varied lithological association. The KKB with rocks of surficial origin and incipient charnockite development, poses several problems relating to the tectonics of burial of vast area and mechanisms involved in expelling initial H2O (causes of dryness) for granulite facies metamorphism. It is possible to infer the following sequence of events based on the field and laboratory studies: (1) derivation of protoliths of KKB from granitic uplands and deposition in fault bounded basin (cratonic rift); (2) subhorizontal deep burial of sediments; (3) intense deformation of infra and supracrustal rocks; (4) early granulite facies metamorphism predating F sub 2 - loss of primary structure in sediments and formation of charnockites from amphibole bearing gneisses and khondalites from pelites; (5) migmatisation and deformation of metasediments and gneisses; (6) second event of charnockite formation probably aided by internal CO2 build-up; and (7) isothermal uplift, entrapment of late CO2 and mixed CO2-H2O fluids, formation of second generation cordierites and cordierite symplectites

Multiple Triple-Point Fermions in Heusler Compounds

Using the density functional theoretical calculations, we report a new set of topological semimetals X$_{2}$YZ (X = \{Cu, Rh, Pd, Ag, Au, Hg\}, Y = \{Li, Na, Sc, Zn, Y, Zr, Hf, La, Pr, Pm, Sm, Tb, Dy, Ho, Tm\} and Z =\{Mg, Al, Zn, Ga, Y, Ag, Cd, In, Sn, Ta, Sm\}), which show the existence of multiple topological triple point fermions along four independent $C_{3}$ axes. These fermionic quasiparticles have no analogues elementary particle in the standard model. The angle-resolved photoemission spectroscopy is simulated to obtain the exotic topological surface states and the characteristic Fermi arcs. The inclusion of spin-orbit coupling splits the triple-point into two Dirac points. The triple-point fermions are exhibited on the easily cleavable (111) surface and are well separated from the surface $\bar{\Gamma}$ point, allowing them to be resolved in the surface spectroscopic techniques. This intermediate linearly dispersive degeneracy between Weyl and Dirac points may offer prospective candidates for quantum transport applications