Near-barrier fission of the system12C+232Th

The fission fragment angular distributions for the system¹²C +²³²Th have been measured in the energy range 0.97<>_c.m./V_B<1.22. the=" measured=" anisotropies=" have=" been=" compared=" with=" the=" predictions=" of=" the=" standard=" saddle=" point=" statistical=" model,=" using=" the=" second=" moment=" of=" the=" compound=" nucleus=" spin=" distribution=">l² deduced from a Wong model fit to the fission excitation function. While the measured anisotropies agree with the standard saddle point statistical model for E_c.m./V_B>1.05, they are abnormally large at lower energies. This is also true for the existing measurements of¹⁶O and¹⁹F +²³²Th systems. Since for this system pre-equilibrium fission contributions are not expected, this anomaly indicates strong channel coupling effects leading to an increase in l² at sub-barrier energies.The authors thank Drs. R.K. Choudhury and A. Saxena for useful discussions, Dr. R.J. Singh for making the thorium target and the Pellectron operation staff for excellent operation of the machine.     

Crystal and molecular structure of a new biguanide metal complex, [Cu(AMNH)2]Cl2

The crystal structure of C₆H₁₆N₈O₂·CuCl₂, a biguanide metal complex, has been determined by X-ray diffraction data using MoK radiation. The compound crystallizes in the monoclinic space groupP2₁/a, witha=11.074(4),b=12.061(4),c=5.312(3)Å and=102.8(1)°.The structure was solved by direct methods and refined by full-matrix least-squares to a finalR value 0.037 with 1245 unique reflections. The complex molecule is centrosymmetric, with the Cu atom (0.5,0.5,0.5) on a crystallographic center of symmetry. The complex molecule is rhombic planar with a trans configuration.     

Determinants of parabolic bundles on Riemann surfaces

LetX be a compact Riemann surface andM _s ^p (X) the moduli space of stable parabolic vector bundles with fixed rank, degree, rational weights and multiplicities. There is a natural Kähler metric onM _s ^p (X). We obtain a natural metrized holomorphic line bundle onM _s ^p (X) whose Chern form equalsmr times the Kähler form, wherem is the common denominator of the weights andr the rank.