Molecular Branching Topology & Quantum Mechanical Quantities

183-18

The Lamb shift contribution of very light millicharged particles

The leading order vacuum polarization contribution of very light millicharged fermions and scalar (spin-0) particles with charge \epsilon e and mass \mu to the Lamb shift of the hydrogen atom is shown to imply universal, i.e. \mu-independent, upper bounds on \epsilon: \epsilon \lsim 10^{-4} for \mu \lsim 1 keV in the case of fermions, and for scalars this bound is increased by a factor of 2. This is in contrast to expectations based on the commonly used approximation to the Uehling potential relevant only for conventionally large fermion (and scalar) masses.Comment: 10 pages including 3 figures, version to appear in Physical Review D (Rapid Communications

Effect of Thermal Annealing on Boron Diffusion, Micro-structural, Electrical and Magnetic properties of Laser Ablated CoFeB Thin Films

We report on Boron diffusion and subsequent crystallization of Co$_{40}$Fe$_{40}$B$_{20}$ (CoFeB) thin films on SiO$_2$/Si(001) substrate using pulsed laser deposition. Secondary ion mass spectroscopy reveals Boron diffusion at the interface in both amorphous and crystalline phase of CoFeB. High-resolution transmission electron microscopy reveals a small fraction of nano-crystallites embedded in the amorphous matrix of CoFeB. However, annealing at 400$^\circ$C results in crystallization of CoFe with \textit{bcc} structure along (110) orientation. As-deposited films are non-metallic in nature with the coercivity (H$_c$) of 5Oe while the films annealed at 400$^\circ$C are metallic with a H$_c$ of 135Oe.Comment: 16 pages, 6 figure

On the transport equations of cosmic neutrinos passing through Earth and secondary nu_mu fluxes

The convergence of the iterative solutions of the transport equations of cosmic muon and tau neutrinos propagating through Earth is studied and analyzed. For achieving a fast convergence of the iterative solutions of the coupled transport equations of nu_tau, nubar_tau and the associated tau^{\pm} fluxes, a new semi-analytic input algorithm is presented where the peculiar tau-decay contributions are implemented already in the initial zeroth order input. Furthermore, the common single transport equation for muon neutrinos is generalized by taking into account the contributions of secondary nu_mu and nubar_mu fluxes due to the prompt tau-decay tau -> nu_mu initiated by the associated tau flux. Differential and total nadir angle integrated upward-going mu^- + mu^+ event rates are presented for underground neutrino telescopes and compared with the muon rates initiated by the primary nu_mu, nu_tau and tau fluxes.Comment: Version to appear in PR