University of Rajasthan

About: University of Rajasthan is a education organization based out in Jaipur, India. It is known for research contribution in the topics: Chemical shift & Derivative (chemistry). The organization has 15058 authors who have published 15733 publications receiving 117400 citations. The organization is also known as: Rajasthan University.

Observation of an Antimatter Hypernucleus

Abstract: Nuclear collisions recreate conditions in the universe microseconds after the Big Bang. Only a very small fraction of the emitted fragments are light nuclei, but these states are of fundamental interest. We report the observation of antihypertritons-comprising an antiproton, an antineutron, and an antilambda hyperon-produced by colliding gold nuclei at high energy. Our analysis yields 70 +/- 17 antihypertritons (3/Lambda(H) over bar) and 157 +/- 30 hypertritons ((3)(Lambda)H). The measured yields of (3)(Lambda)H (3/Lambda(H) over bar) and (3)He ((3)(He) over bar) are similar, suggesting an equilibrium in coordinate and momentum space populations of up, down, and strange quarks and antiquarks, unlike the pattern observed at lower collision energies. The production and properties of antinuclei, and of nuclei containing strange quarks, have implications spanning nuclear and particle physics, astrophysics, and cosmology.

Activation energy and crystallization kinetics of untreated and treated oil palm fibre reinforced phenol formaldehyde composites

Abstract: In this paper, oil palm fiber reinforced phenol formaldehyde (PF) treated, as well as untreated, composites have been taken for the study. The untreated sample (sample 1) contains oil palm fiber reinforced in the PF matrix, and the same fiber is treated with silane (sample 2) and with alkali (sample 3) to produce two types of treated fibers. These treated fibers were then reinforced in the matrix to produce two treated samples. Differential scanning calorimetry has been employed to study the crystallization kinetics and the energy of crystallization for all the samples. All the samples show the well-defined peaks of crystallization. In the case of silane-treated sample, double crystallization is observed. The crystallization data are analyzed in terms of a modified Kissinger’s equation to determine the activation energy. The activation energy and other crystallization parameters have also been determined using Matusita’s equation and are compared with the values obtained from other equations. It has also been found that various treatments have improved the thermal stability of the composites to different extents.

J/psi Suppression at Forward Rapidity in Pb-Pb Collisions at root s(NN)=2.76 TeV

Abstract: The ALICE experiment has measured the inclusive J/psi production in Pb-Pb collisions at root s(NN) = 2.76 TeV down to zero transverse momentum in the rapidity range 2.5 < y < 4. A suppression of the inclusive J/psi yield in Pb-Pb is observed with respect to the one measured in pp collisions scaled by the number of binary nucleon-nucleon collisions. The nuclear modification factor, integrated over the 0%-80% most central collisions, is 0.545 +/- 0.032(stat) +/- 0.083dsyst_ and does not exhibit a significant dependence on the collision centrality. These features appear significantly different from measurements at lower collision energies. Models including J/psi production from charm quarks in a deconfined partonic phase can describe our data.

Pion interferometry in Au+Au collisions at √ sNN = 200 GeV

Abstract: We present a systematic analysis of two-pion interferometry in Au+Au collisions at {radical}(s{sub NN})=200 GeV using the STAR detector at Relativistic Heavy Ion Collider. We extract the Hanbury-Brown and Twiss radii and study their multiplicity, transverse momentum, and azimuthal angle dependence. The Gaussianness of the correlation function is studied. Estimates of the geometrical and dynamical structure of the freeze-out source are extracted by fits with blast-wave parametrizations. The expansion of the source and its relation with the initial energy density distribution is studied.