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.

Multiple spectral splits of supernova neutrinos.

Abstract: Collective oscillations of supernova neutrinos swap the spectra ${f}_{{\ensuremath{ u}}_{e}}(E)$ and ${f}_{{\overline{\ensuremath{ u}}}_{e}}(E)$ with those of another flavor in certain energy intervals bounded by sharp spectral splits. This phenomenon is far more general than previously appreciated: typically one finds one or more swaps and accompanying splits in the $\ensuremath{ u}$ and $\overline{\ensuremath{ u}}$ channels for both inverted and normal neutrino mass hierarchies. Depending on an instability condition, swaps develop around spectral crossings (energies where ${f}_{{\ensuremath{ u}}_{e}}={f}_{{\ensuremath{ u}}_{x}}$, ${f}_{{\overline{\ensuremath{ u}}}_{e}}={f}_{{\overline{\ensuremath{ u}}}_{x}}$ as well as $E\ensuremath{\rightarrow}\ensuremath{\infty}$ where all fluxes vanish), and the widths of swaps are determined by the spectra and fluxes. Washout by multiangle decoherence varies across the spectrum and splits can survive as sharp spectral features.

Gravitational Collapse and Spacetime Singularities

Abstract: Physical phenomena in astrophysics and cosmology involve gravitational collapse in a fundamental way. The final fate of a massive star when it collapses under its own gravity at the end of its life cycle is one of the most important questions in gravitation theory and relativistic astrophysics, and is the foundation of black hole physics. General relativity predicts that continual gravitational collapse gives rise to a space-time singularity. Quantum gravity may take over in such regimes to resolve the classical space-time singularity. This book investigates these issues, and shows how the visible ultra-dense regions arise naturally and generically as an outcome of dynamical gravitational collapse. It will be of interest to graduate students and academic researchers in gravitation physics, fundamental physics, astrophysics, and cosmology. It includes a detailed review of research into gravitational collapse, and several examples of collapse models are investigated in detail.

Measurement of the differential cross section for top quark pair production in pp collisions at √s=8 TeV

Abstract: The normalized differential cross section for top quark pair (tt) production is measured in pp collisions at a centre-of-mass energy of 8TeV at the CERN LHC using the CMS detector in data corresponding to an integrated luminosity of 19.7fb^(−1). The measurements are performed in the lepton+jets (e/μ +jets) and in the dilepton (e^+e^−, μ^+μ^−, and e^±μ^∓) decay channels. The tt cross section is measured as a function of the kinematic properties of the charged leptons, the jets associated to b quarks, the top quarks, and the tt system. The data are compared with several predictions from perturbative quantum chromodynamic up to approximate next-to-next-to-leading-order precision. No significant deviations are observed relative to the standard model predictions.