Tata Institute of Fundamental Research

About: Tata Institute of Fundamental Research is a education organization based out in Mumbai, Maharashtra, India. It is known for research contribution in the topics: Magnetization & Large Hadron Collider. The organization has 7786 authors who have published 21742 publications receiving 622368 citations. The organization is also known as: TIFR.

Equivalence between the Abelian sandpile model and the q→0 limit of the Potts model

Abstract: We establish an equivalence between the undirected Abelian sandpile model and the q→0 limit of the q-state Potts model. The equivalence is valid for arbitrary finite graphs. Two-dimensional Abelian sandpile models, thus, correspond to a conformal field theory with central charge c = −2. The equivalence also gives a Monte Carlo algorithm to generate random spanning trees. We study the growth process of the spread of fire under the burning algorithm in the background of a random recurrent configuration of the Abelian sandpile model. The average number of sites burnt upto time t varies at ta. In two dimensions our numerically determined value of a agrees with the theoretical prediction a = 8 5 . We relate this exponent to the conventional exponents characterizing the distributions of avalanche sizes.

Heavy-flavour and quarkonium production in the LHC era: from proton-proton to heavy-ion collisions

Abstract: This report reviews the study of open heavy-flavour and quarkonium production in high-energy hadronic collisions, as tools to investigate fundamental aspects of Quantum Chromodynamics, from the proton and nucleus structure at high energy to deconfinement and the properties of the Quark-Gluon Plasma. Emphasis is given to the lessons learnt from LHC Run 1 results, which are reviewed in a global picture with the results from SPS and RHIC at lower energies, as well as to the questions to be addressed in the future. The report covers heavy flavour and quarkonium production in proton-proton, proton-nucleus and nucleus-nucleus collisions. This includes discussion of the effects of hot and cold strongly interacting matter, quarkonium photo-production in nucleus-nucleus collisions and perspectives on the study of heavy flavour and quarkonium with upgrades of existing experiments and new experiments. The report results from the activity of the SaporeGravis network of the I3 Hadron Physics programme of the European Union 7th Framework Programme.

Seismic measurement of the depth of the solar convection zone

Abstract: The observed frequencies of solar oscillations have been used to determine the depth of the convection zone. The effect of diffusion of helium and heavy elements on this measurement is studied and it is found that the discontinuity in the composition gradient at the base of the CZ due to diffusion gives rise to some systematic errors in this measurement. Taking into account these systematic errors the base of the CZ is estimated to be at a radial distance of (0.713 ± 0_001) R0 . Further, the estimated opacity at the base of the CZ is found to be consistent with that calculated from the OPAL opacity tables using the current value of Z/X. Assuming that the OPAL tables correctly represent the opacity of solar material the surface Z/X is estimated to be 0.0245 ± 0.0008.