Heavy Quarkonium

I review heavy quarkonium physics in view of recent experimental results. In particular, I discuss new results on spin singlet states, photon and hadronic transitions, D-states and discovery of yet unexplained narrow X(3872) state.Comment: 15 pages, 16 figures. 2nd version: minor changes in references and text. Invited talk presented at the 21st International Symposium On Lepton And Photon Interactions At High Energies (LP03) 11-16 August 2003, Batavia, Illinoi

Comment on 'Quantum inversion of cold atoms in a microcavity: spatial dependence'

In a recent work, Abdel-Aty and Obada [2002 J. Phys. B 35 807-813] analyzed the quantum inversion of cold atoms in a microcavity, the motion of the atoms being described quantum mechanically. Two-level atoms were assumed to interact with a single mode of the cavity, and the off-resonance case was considered (namely the atomic transition frequency is detuned from the single mode cavity frequency). We demonstrate in this paper that this case is incorrectly treated by these authors and we question therefore their conclusions.Comment: 4 pages, no figure

Tsallis' deformation parameter q quantifies the classical-quantum transition

We investigate the classical limit of a type of semiclassical evolution, the pertinent system representing the interaction between matter and a given field. On using as a quantifier of the ensuing dynamics Tsallis q-entropy, we encounter that it not only appropriately describes the quantum-classical transition, but that the associated deformation-parameter q itself characterizes the different regimes involved in the process, detecting the most salient fine details of the changeover.Comment: 19 pages, 7 figure

Cultivating knowledge sharing through the relationship management maturity model

Purpose - The purpose of this paper is to present the development of the relationship management maturity model (RMMM), the output of an initiative aimed at bridging the gap between business units and the IT organisation. It does this through improving and assessing knowledge sharing between business and IT staff in Finco, a large financial services organisation. Design/methodology/approach - The objectives were achieved by undertaking ethnographic research with the relationship managers (RMs) as they carried out their activities, and developing the RMMM by visualizing the development of a community of practice (CoP) between business and IT. Findings - The RMMM demonstrates a learning mechanism to bridge the business/IT gap through an interpretive approach to knowledge sharing by defining knowledge sharing processes between business and IT and defining the tasks of the relationship managers as facilitators of knowledge sharing. Research limitations/implications - More research is necessary to determine whether the RMMM is a useful tool on which Finco can base the development of RM over the next few years. Practical implications - The RMMM acts as a practical knowledge management tool, and will act as a future reference for the RMs as they attempt to further develop the business/IT relationship. Originality/value - The findings provide an initial endorsement of the knowledge sharing perspective to understand the business/IT relationship. Also, the RMMM can be used to identify problematic issues and develop processes to address them

Numerical residual perturbation solution applied to an earth satellite including luni-solar effects

Mathematical model and computer program for numerical solution of earth orbit differential equations of motio

Experimental constraints on the polarizabilities of the 6s^2 1S0 and 6s6p 3P0 states of Yb

We utilize accurate experimental data available in the literature to yield bounds on the polarizabilities of the ground and first excited states of atomic Yb. For the 6s^2 1S0 ground state, we find the polarizability alpha to be constrained to 134.4<alpha<144.2 in atomic units, while for the 6s6p 3P0 excited state we find 280.1<alpha<289.9. The uncertainty in each of these values is 1.0. These constraints provide a valuable check for ab initio and semi-empirical methods used to compute polarizabilities and other related properties in Yb.Comment: 7 pages, 1 figur

Polarized heat current generated by quantum pumping in two-dimensional topological insulators

We consider transport properties of a two dimensional topological insulator in a double quantum point contact geometry in presence of a time-dependent external field. In the proposed setup an external gate is placed above a single constriction and it couples only with electrons belonging to the top edge. This asymmetric configuration and the presence of an ac signal allow for a quantum pumping mechanism, which, in turn, can generate finite heat and charge currents in an unbiased device configuration. A microscopic model for the coupling with the external time-dependent gate potential is developed and the induced finite heat and charge currents are investigated. We demonstrate that in the non-interacting case, heat flow is associated with a single spin component, due to the helical nature of the edge states, and therefore a finite and polarized heat current is obtained in this configuration. The presence of e-e interchannel interactions strongly affects the current signal, lowering the degree of polarization of the system. Finally, we also show that separate heat and charge flows can be achieved, varying the amplitude of the external gate.Comment: 13 pages, 5 figure

An electronic Mach-Zehnder interferometer in the Fractional Quantum Hall effect

We compute the interference pattern of a Mach-Zehnder interferometer operating in the fractional quantum Hall effect. Our theoretical proposal is inspired by a remarkable experiment on edge states in the Integer Quantum Hall effect (IQHE). The Luttinger liquid model is solved via two independent methods: refermionization at nu=1/2 and the Bethe Ansatz solution available for Laughlin fractions. The current differs strongly from that of single electrons in the strong backscattering regime. The Fano factor is periodic in the flux, and it exhibits a sharp transition from sub-Poissonian (charge e/2) to Poissonian (charge e) in the neighborhood of destructive interferences