Experimental study of the <Emphasis Type="Italic">πh</Emphasis><Subscript>11/2</Subscript> band in <Superscript>113</Superscript>Sb

In the present work, the excited states of ¹¹³Sb were populated in the ¹⁰⁰Mo(²⁰Ne, p6n) reaction at a beam energy of 136 MeV. States only up to 59/2⁻ were observed in the ΔJ = 2 band. Mean lifetimes for the five states (from 4460 to 7998 keV) were measured for the first time using Doppler shift attenuation method. An upper limit of the lifetime (0.14 ps) was estimated for the 9061 keV, 47/2⁻ state. The B(E2) values, derived from the present lifetime results, correspond to a large quadrupole deformation of β ₂ = 0.32. The observed reduction in the experimental B(E2) values for the 918.4 keV (spin 39/2⁻ → 35/2⁻) and 985 keV (spin 43/2⁻ → 39/2⁻) transitions may be interpreted as due to the proton alignement in the g _7/2 orbital. The dynamic moment of inertia was observed to be about half of the rigid body value at the highest observed frequency.     

Quillen bundle and geometric prequantization of non-abelian vortices on a Riemann surface

In this paper we prequantize the moduli space of non-abelian vortices. We explicitly calculate the symplectic form arising from L ² metric and we construct a prequantum line bundle whose curvature is proportional to this symplectic form. The prequantum line bundle turns out to be Quillen’s determinant line bundle with a modified Quillen metric. Next, as in the case of abelian vortices, we construct line bundles over the moduli space whose curvatures form a family of symplectic forms which are parametrized by Ψ₀, a section of a certain bundle. The equivalence of these prequantum bundles are discussed.     

Effect of Na＋, K＋ and Ca2＋ Ions on Physico-chemical Properties of Thymine, Cytosine, Thymidine and Cytidine in Aqueous Urea Solution

Experimental determination of density, ultrasonic velocity and viscosity of two pyrimidine bases thymine and cytosine along with their respective nucleosides, thymidine and cytidine has been carried out in aqueous urea solutions in the presence of different concentrations of three salts, viz. NaCl, KCl and CaCl₂. The experimental data have been used for the computation of various thermodynamic parameters, viz. apparent molar volume, apparent molar compressibility, coefficients A and B of the Jones-Dole equation, internal pressure, acoustic impedance, etc. Structural studies of solutions under investigation have also been carried out by ultraviolet spectroscopy, and an attempt has been made to collaborate the findings of ultraviolet spectroscopy with results obtained thermodynamically.     

One-parameter family of solitons from minimal surfaces

In this paper, we discuss a one parameter family of complex Born–Infeld solitons arising from a one parameter family of minimal surfaces. The process enables us to generate a new solution of the B–I equation from a given complex solution of a special type (which are abundant). We illustrate this with many examples. We find that the action or the energy of this family of solitons remains invariant in this family and find that the well-known Lorentz symmetry of the B–I equations is responsible for it.     

Estimate of stellar masses from their QPO frequencies

Kilohertz quasiperiodic oscillations (kHz QPOs) are observed in binary stellar systems. For such a system, the stellar radius is very close to the marginally stable orbit R _ms as predicted by Einstein’s general relativity. Many models have been proposed to explain the origin of the kHz QPO features in the binaries. Here we start from the work of Li et al (Phys. Rev . Lett. 83, 3776 (1999)) who in 1999, from the unique millisecond X-ray pulsations, suggested SAX J1808.4−3658 to be a strange star, from an accurate determination of its rotation period. It showed kHz QPOs eight years ago and so far it is the only set that has been observed. We suggest that the mass of four compact stars SAX J1808.4−3658, KS 1731−260, SAX J1750.8−2900 and IGR J17191−2821 can be determined from the difference in the observed kHz QPOs of these stars. It is exciting to be able to give an estimate of the mass of the star and three other compact stars in low-mass X-ray binaries using their observed kHz QPOs.