Several colliders, including the LHC and the RHIC, will study interesting features of the phase diagram of QCD in the near future. Parts of this phase diagram have been investigated previously in planes of high symmetry using various techniques. I extend these studies to the physical region and argue that there is an unique extension for two-flavour QCD. Whether the same is true of three-flavour QCD can be decided by a single, but expensive, lattice computation.
In this talk I will discuss about the role of the low energy observables, related to mixing and decay of B meson, for the detection of new physics. I will focus on non-leptonic B meson decays which are more interesting and theoretically challenging because there are few data whose apparent inconsistency with the SM may be ascribed to our imperfect knowledge of non-perturbative QCD ; but they may as well be due to indirect effects of new physics. I will also focus on the possibility of large lifetime differences in neutral B-meson system.
The pseudorapidity densities of transverse energy, the charged particle multiplicity and their ratios, (dET/dη)⁄ (dNch/dη) ∼ ET/Nch, have been estimated at mid-rapidity in a statistical-thermal model based on chemical freeze-out criteria, for a wide range of energies from GSI -- AGS -- SPS to RHIC. It has been observed that in nucleus-nucleus collisions, ET/Nch increases rapidly with beam energy and remains approximately constant at about a value of 800 MeV for beam energies from SPS to RHIC. ET/Nch has been observed to be independent of centrality at all measured energies. The statistical-thermal model describes the energy dependence, as well as the centrality independence, qualitatively well. The values of ET/Nch are related to the chemical freeze-out criterion, E/N ≈ 1GeV, valid for primordial hadrons. We have studied the variation of ⟨mass⟩, Ndecays/Nprimordial, Nch/Ndecays and ET/Nch with √sNN for all freeze-out criteria discussed in literature. These observables show saturation around SPS and higher √sNN, like the chemical freeze-out temperature Tch. These observations along with the centrality independence of ET/Nch is consistent with the simultaneity of chemical and kinetic freeze-out at higher energies.
Sterile neutrinos with masses ∼ 0.1 eV or higher, allowed with the current oscillation data, can potentially play an important role in astrophysics and cosmology. We explore possible signatures of such sterile neutrinos at long baseline experiments.
We determine the neutrino conversion probabilities analytically in a 4-neutrino framework, employing perturbative expansion in small quantities. We numerically calculate the signals at a neutrino factory with near and far detectors that can identify the lepton charge, point out observables that can discern the sterile mixing signals, and determine the range of sterile mixing angles that can be probed.
We also generalize the formalism for any number of sterile neutrinos, and demonstrate that only certain combinations of sterile mixing parameters are relevant irrespective of the number of sterile neutrinos. This also leads to a stringent test of the scenario with multiple sterile neutrinos that currently is able to describe all the data from the short baseline experiments, including LSND and MiniBOONE.
We will discuss a simpler inflationary scenario in the minimal left-right symmetric model with spontaneous parity breaking. This model has a natural explanation for neutrino masses and mixing through the celebrated seesaw mechanism. As a result, this model provides a framework to connect the anisotropy in the cosmic microwave background to the observed sub-eV neutrino masses. In this model, we will also discuss the baryogenesis via leptogenesis, an attractive explanation for the present matter anti-matter asymmetry of the Universe.
In this seminar I will formulate the chromoelectric response functions of non-Abelian quark plasma and gluon plasma separately. The formulation is done in semi-classical kinetic theoretical approach. The distribution functions in the color space inherit their form from the parent density operators, leading to distinguishable behavior on the part of quarks and gluons. The non-Abelian response emerges naturally in this formulation.
I will explore the behavior of the Abelian permittivity, the non-Abelian permittivity and the tensor excitations a little bit. A detailed analysis of the screening of heavy quark potential and Landau damping will also be discussed.
The problem of hadronic collisions at high sqrt(s) and moderate momentum transfer can be studied by means of an effective theory -- the Color Glass Condensate -- in which the gauge fields are coupled to external sources that represent the partons contained in the wavefunction of the two projectiles.
In this talk, I will show how observables in this effective theory are related at leading order to solutions of the classical equations of motion, and what is the role of the boundary conditions imposed on these solutions. I will also discuss ongoing work aimed at calculating next-to-leading order corrections in this framework, in order to assess issues such as factorization.
The study of Nuclear Equation of State (EOS) is not only a fundamental problem in nuclear physics, but it also links with other domains such as Astrophysics, Particle Physics and Heavy-ion collisions. Until now, experiments have probed stable nucleonic matter in the vicinity of nuclear saturation density, and so in order to unmask the properties of the enigmatic nuclear force at extremes, we rely heavily on theoretical investigations. Arguably, we present a comprehensive treatise on relativistic Nuclear Equation of State in the mean-field approach using an effective model that embodies the desired ingredients for a complete relativistic description of nuclear matter and neutron stars.
B-factories are producing a large number of charmed mesons and charmonia too. Apparently they are becoming a charm factory. Some of the newly observed resonance states are compatible with the existing charmonium models, but some of them are not. Observation of some of these new states and study of their properties are discussed in this talk. Charmonia or charmoniumlike mesons are produced through B-meson, with an association of ISR photon or in two photon interactions.