The mass hierarchy with atmospheric neutrinos at INO

We study the neutrino mass hierarchy at the magnetized Iron CALorimeter (ICAL) detector at India-based Neutrino Observatory with atmospheric neutrino events generated by the Monte Carlo event generator Nuance. We judicially choose the observables so that the possible systematic uncertainties can be reduced. The resolution as a function of both energy and zenith angle simultaneously is obtained for neutrinos and anti-neutrinos separately from thousand years un-oscillated atmospheric neutrino events at ICAL to migrate number of events from neutrino energy and zenith angle bins to muon energy and zenith angle bins. The resonance ranges in terms of directly measurable quantities like muon energy and zenith angle are found using this resolution function at different input values of $\theta_{13}$. Then, the marginalized $\chi^2$s are studied for different input values of $\theta_{13}$ with its resonance ranges taking input data in muon energy and zenith angle bins. Finally, we find that the mass hierarchy can be explored up to a lower value of $\theta_{13}\approx 5^\circ$ with confidence level $>$ 95% in this set up.Comment: some clarifications added, version accepted in PLB, 12 pages, 34 figure

Alpha decay chains from superheavy nuclei

Magic islands for extra-stable nuclei in the midst of the sea of fission-instability were predicted to be around Z=114, 124 or, 126 with N=184, and Z=120, with N=172. Whether these fission-survived superheavy nuclei with high Z and N would live long enough for detection or, undergo alpha-decay in a very short time remains an open question. Alpha-decay half lives of nuclei with 130 < Z < 100 have been calculated in a WKB framework using density-dependent M3Y interaction with Q-values from different mass formulae. The results are in excellent agreement with the experimental data. Fission survived Sg nuclei with Z=106, N=162 is predicted to have the highest alpha-decay half life ~ 3.2 hrs in the Z=106-108, N=160-164 region called, small island/peninsula. Superheavy nuclei with Z > 118 are found to have alpha-decay half lives of the order of microseconds or, less.Comment: Invited Talk presented at the "International School Of Nuclear Physics. 30th Course. Heavy-Ion Collisions from the Coulomb Barrier to the Quark-Gluon Plasma", Erice-Sicily: 16 - 24 September 200

Reply to Comment on Extension of the Bethe-Weizsacker mass formula to light nuclei and some new shell closures

Some properties of the modified Bethe-Weizsacker mass formula (BWM) are discussed. As BWM has no shell effect included, the extra-stability or, magicity in nuclei clearly stands out when experimental mass data are compared with BWM predictions. If the shell effect quenches, the BWM predictions come closer to the experimental data.Comment: 2 pages, no figur

Superheavy Elements in the Magic Islands

Recent microscopic calculation based on the density functional theory predicts long-lived superheavy elements in a variety of shapes, including spherical, axial and triaxial configurations. Only when N=184 is approached one expects superheavy nuclei that are spherical in their ground states. Magic islands of extra-stability have been predicted to be around Z=114, 124 or, 126 with N=184, and Z=120, with N=172. However, the question of whether the fission-survived superheavy nuclei with high Z and N would live long enough for detection or, undergo alpha-decay in a very short time remains open. In this talk I shall present results of our calculations of alpha-decay half lives of heavy and superheavy nuclei. Calculations, carried out in a WKB framework using density-dependent M3Y interaction, have been found to reproduce the experimental data quite well. Fission survived Sg nuclei with Z=106, N=162 is predicted to have the highest alpha-decay half life (~3.2 hrs) in the Z=106-108, N=160-164 region called, small island/peninsula. Neutron-rich (N >170) superheavy nuclei with Z >118 are found to have half-lives of the order of microseconds or, less.Comment: 9 pages, 1 figure, 1 table; Invited Talk presented at the "Fourth International Conference on Fission and Properties of Neutron-Rich nuclei", held at Sanibel Island, Florida, November 11-17, 200