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.

Evidence for transverse-momentum- and pseudorapidity-dependent event-plane fluctuations in PbPb and pPb collisions

Abstract: A systematic study of the factorization of long-range azimuthal two-particle correlations into a product of single-particle anisotropies is presented as a function of pT and nu of both particles and as a function of the particle multiplicity in PbPb and pPb collisions. The data were taken with the CMS detector for PbPb collisions at root sNN = 2.76 TeV and pPb collisions at root sNN = 5.02 TeV, covering a very wide range of multiplicity. Factorization is observed to be broken as a function of both particle pT and nu. When measured with particles of different pT, the magnitude of the factorization breakdown for the second Fourier harmonic reaches 20% for very central PbPb collisions but decreases rapidly as the multiplicity decreases. The data are consistent with viscous hydrodynamic predictions, which suggest that the effect of factorization breaking is mainly sensitive to the initial-state conditions rather than to the transport properties (e.g., shear viscosity) of the medium. The factorization breakdown is also computed with particles of different nu. The effect is found to be weakest for mid-central PbPb events but becomes larger for more central or peripheral PbPb collisions, and also for very-high-multiplicity pPb collisions. The nu-dependent factorization data provide new insights to the longitudinal evolution of the medium formed in heavy ion collisions.

On the critical end point of QCD

Abstract: In this talk I present the logic behind, and examine the reliability of, estimates of the critical end point (CEP) of QCD using the Taylor expansion method.

Improved measurement of the electroweak penguin process B→Xs+-

Abstract: Reference EPFL-ARTICLE-154446doi:10.1103/PhysRevD.72.092005View record in Web of Science Record created on 2010-11-05, modified on 2017-05-12

Continuing search for new physics in b → sμμ decays: two operators at a time

Abstract: The anomalies in the measurements of observables involving b → sμμ decays, namely RK, RK*, P 5 ′ , and B , may be addressed by adding lepton-universality-violating new physics contributions to the effective operators $$ {\mathcal{O}}_{\mathcal{9}},{\mathcal{O}}_{10},{\mathcal{O}}_9^{\prime },{\mathcal{O}}_{10}^{\prime } $$ . We analyze all the scenarios where the new physics contributes to a pair of these operators at a time. We perform a global fit to all relevant data in the b → s sector to estimate the corresponding new Wilson coefficients, $$ {\mathcal{O}}_9^{\mathrm{NP}},{\mathcal{O}}_{10}^{\mathrm{NP}},{\mathcal{O}}_9^{\prime },{\mathcal{O}}_{10}^{\prime } $$ . In the light of the new data on RK, and RK*, presented in Moriond 2019, we find that the scenarios with new physics contributions to the $$ \left({\mathcal{O}}_9^{\mathrm{NP}},{\mathcal{O}}_9^{\prime}\right) $$ or $$ \left({\mathcal{O}}_9^{\mathrm{NP}},{\mathcal{O}}_{10}^{\prime}\right) $$ pair remain the most favored ones. On the other hand, though the competing scenario $$ \left({\mathcal{O}}_9^{\mathrm{NP}},{\mathcal{O}}_{10}^{\mathrm{NP}}\right) $$ remains attractive, its advantage above the SM reduces significantly due to the tension that emerges between the RK and RK* measurements with the new data. The movement of the RK measurement towards unity would also result in the re-emergence of the one-parameter scenario C 9 NP = − C 9 ′ .