121681055
Inhomogeneous and intrinsic damping of giant dipole resonance in hot rotating nuclei with A ~ 150
High-energy gamma rays in the range of ~4–28 MeV were measured in the reaction 28Si+124Sn at E(28Si) ~ 185 MeV in coincidence with low-energy gamma ray multiplicities and evaporation residues. The centroid energy and width of the giant dipole resonance were extracted for various multiplicity windows from the statistical model analysis. These extracted widths, along with those from an earlier measurement at E(28Si) ~ 149 MeV, show a discrepancy with the results of a calculation under the thermal shape fluctuation model which describes the inhomogeneous damping of the resonance. An empirical form of the temperature and angular momentum dependence of the width, describing the data at both the beam energies, has been derived. The present results suggest that the contributions from both the inhomogeneous damping and the intrinsic collisional damping processes should be included.
14314222
A Large area plastic scintillator detector array for fast neutron measurements
Abstract A large area plastic scintillator detector array ( ∼ 1 × 1 m 2 ) has been set up for fast neutron spectroscopy at the BARC-TIFR Pelletron laboratory, Mumbai. The energy, time and position response has been measured for electrons using radioactive sources and for monoenergetic neutrons using the 7 Li ( p , n 1 ) 7 Be * ( 0.429 MeV ) reaction at proton energies between 6.3 and 19 MeV. A Monte Carlo simulation of the energy dependent efficiency of the array for neutron detection is in agreement with the 7 Li ( p , n 1 ) measurements. The array has been used to measure the neutron spectrum, in the energy range of 4–12 MeV, in the reaction C 12 + Nb 93 at E ( C 12 ) = 40 MeV . This is in reasonable agreement with a statistical model calculation.
118511593
Influence of density-dependent symmetry energy on elliptical flow
Abstract.The effect of density-dependent symmetry energy on elliptical flow is studied using the isospin-dependent quantum molecular dynamics model (IQMD). We have used the reduced isospin-dependent cross-section with hard (H) equation of state to study the sensitivity of the elliptical flow to symmetry energy in the energy range 50-1000MeV/nucleon. The elliptical flow becomes zero at a particular energy termed as transition energy. A systematic effort has been made to pin down the transition energy for the density-dependent symmetry energy.
118577769
Effect of density dependent symmetry energy on Elliptical flow
Nuclear Physics in general and heavy-ion collisions in particular is of central interest in investigating the matter under the extreme conditions of temperature and compression. Among the different observables, collective flow and its various forms enjoys a special status, due to its sensitivity towards model ingredients that define equation of state. The elliptical flow, which is the squeeze out of spectator matter out of the reaction plane, is more suited to study the collective flow,, as compared to the directed flow, which is constrained only along the reaction plane.
119277312
Mass dependence of various fragments in multi-fragmentation
Based on the isospin-dependent quantum molecular dynamics (IQMD) model, we aim to understand the effect of target fragmentation on various quantities i.e. collision rate, fragments multiplicity etc by simulating the collision between $Au^{197}$ projectile and $C^{12}$, $Al^{26}$, $Cu^{63}$, and $Pb^{208}$ as targets at incident energy 600 MeV/nucleon. The collision geometry is varied from central to peripheral. Our results indicate the rise and fall in the production of intermediate mass fragments with ${Z_{bound}}$ which is in agreement with the experimental data of Aladin collaboration at lower impact parameters, while, some deviation is seen at higher impact parameters.
119117378
Hadron energy response of the Iron Calorimeter detector at the India-based Neutrino Observatory
The results of a Monte Carlo simulation study of the hadron energy response for the magnetized Iron CALorimeter detector, ICAL, proposed to be located at the India-based Neutrino Observatory (INO) is presented. Using a GEANT4 modeling of the detector ICAL, interactions of atmospheric neutrinos with target nuclei are simulated. The detector response to hadrons propagating through it is investigated using the hadron hit multiplicity in the active detector elements. The detector response to charged pions of fixed energy is studied first, followed by the average response to the hadrons produced in atmospheric neutrino interactions using events simulated with the NUANCE event generator. The shape of the hit distribution is observed to fit the Vavilov distribution, which reduces to a Gaussian at high energies. In terms of the parameters of this distribution, we present the hadron energy resolution as a function of hadron energy, and the calibration of hadron energy as a function of the hit multiplicity. The energy resolution for hadrons is found to be in the range 85% (for 1 GeV) – 36% (for 15 GeV).
14812310
Strings in twistor superspace and mirror symmetry
Abstract We obtain the super-Landau–Ginzburg mirror of the A-twisted topological sigma model on a twistor superspace—the quadric in CP 3 | 3 × CP 3 | 3 which is a Calabi–Yau supermanifold. We show that the B-model mirror has a geometric interpretation. In a particular limit for one of the Kahler parameters of the quadric, we show that the mirror can be interpreted as the twistor superspace CP 3 | 4 . This agrees with the recent conjecture of Neitzke and Vafa proposing a mirror equivalence between the two twistor superspaces.