Quark Coalescence with Quark Number Conservation and the Effect on Quark-Hadron Scaling

We develop a new formulation of the quark coalescence model by including the quark number conservation in order to describe the hadronization of the bulk of the quark-gluon plasma. The scalings between hadron and quark phase space distributions are shown to depend on the transverse momentum. For hard quarks, our general scalings reproduce the usual quadratic scaling relation for mesons and the cubic scaling relation for baryons. For softer quarks, however, the inclusion of the quark number conservation leads to a linear scaling for the hadron species that dominates the quark number of each flavor, while the scalings of non-dominant hadrons depend on the coalescence dynamics. For charm mesons, we find that the distribution of soft $D$ mesons does not depend on the light quark distribution but the distribution of soft $J/\psi$ mesons is inversely correlated to the light quark distribution.Comment: Added 6 more equations to explain the derivations; added discussions; final published versio

Holonomic Quantum Computing Based on the Stark Effect

We propose a spin manipulation technique based entirely on electric fields applied to acceptor states in $p$-type semiconductors with spin-orbit coupling. While interesting in its own right, the technique can also be used to implement fault-resilient holonomic quantum computing. We explicitly compute adiabatic transformation matrix (holonomy) of the degenerate states and comment on the feasibility of the scheme as an experimental technique.Comment: 5 page

Geometry and Representations of the Quantum Supergroup OSPq(1|2n)

The quantum supergroup OSPq(1|2n) is studied systematically. A Haar functional is constructed, and an algebraic version of the Peter - Weyl theory is extended to this quantum supergroup. Quantum homogeneous superspaces and quantum homogeneous supervector bundles are defined following the strategy of Connes' theory. Parabolic induction is developed by employing the quantum homogeneous supervector bundles. Quantum Frobenius reciprocity and a generalized Borel - Weil theorem are established for the induced representations.Comment: Latex, 20 page

Magnetars and pulsars: a missing link

There is growing evidence that soft gamma-ray repeaters (SGRs) and anomalous X-ray pulsars (AXPs) are isolated neutron stars with superstrong magnetic fields, i.e., magnetars, marking them a distinguished species from the conventional species of spindown-powered isolated neutron stars, i.e., radio pulsars. The current arguments in favor of the magnetar interpretation of SGR/AXP phenomenology will be outlined, and the two energy sources in magnetars, i.e. a magnetic dissipation energy and a spindown energy, will be reviewed. I will then discuss a missing link between magnetars and pulsars, i.e., lack of the observational evidence of the spindown-powered behaviors in known magnetars. Some recent theoretical efforts in studying such behaviors will be reviewed along with some predictions testable in the near future.Comment: Invited talk at the Sixth Pacific Rim Conference on Stellar Astrophysics, a tribute to Helmut A. Abt, July 11-17, 2002, Xi'an. To appear in the proceedings (eds. K. S. Cheng, K. C. Leung & T. P. Li

The heavy-element abundances of AGB stars and the angular momentum conservation model of wind accretion for barium stars

Adpoting new s-process nucleosynthesis scenario and branch s-process path, we calculate the heavy-element abundances and C/O ratio of solar metallicity 3M_sun TP-AGB stars. The evolutionary sequence from M to S to C stars of AGB stars is explained naturally by the calculated results. Then combining the angular momentum conservation model of wind accretion with the heavy-element abundances on the surface of TP-AGB stars, we calculate the heavy-element overabundances of barium stars via successive pulsed accreting and mixing. Our results support that the barium stars with longer orbital period, P>1600 days, form through wind accretion scenario.Comment: 14 pages, LaTex, 17 PS figures included, accepted for publication in A &

Effective-Field-Theory Approach to Top-Quark Production and Decay

We discuss new physics in top-quark interactions, using an effective field theory approach. We consider top-quark decay, single top production, and top-quark pair production. We identify 15 dimension-six operators that contribute to these processes, and we compute the deviation from the Standard Model induced by these operators. The results provide a systematic way of searching for (or obtaining bounds on) physics beyond the Standard Model.Comment: 24 pages, 12 figures; references added, typos correcte

A finite-strain hyperviscoplastic model and undrained triaxial tests of peat

This paper presents a finite-strain hyperviscoplastic constitutive model within a thermodynamically consistent framework for peat which was categorised as a material with both rate-dependent and thermodynamic equilibrium hysteresis based on the data reported in the literature. The model was implemented numerically using implicit time integration and verified against analytical solutions under simplified conditions. Experimental studies on the undrained relaxation and loading-unloading-reloading behaviour of an undisturbed fibrous peat were carried out to define the thermodynamic equilibrium state during deviatoric loading as a prerequisite for further modelling, to fit particularly those model parameters related to solid matrix properties, and to validate the proposed model under undrained conditions. This validation performed by comparison to experimental results showed that the hyperviscoplastic model could simulate undrained triaxial compression tests carried out at five different strain rates with loading/unloading relaxation steps.Comment: 30 pages, 16 figures, 4 tables. This is a pre-peer reviewed version of manuscript submitted to the International Journal of Numerical and Analytical Methods in Geomechanic

Optimal provision of distributed reserves under dynamic energy service preferences

We propose and solve a stochastic dynamic programming (DP) problem addressing the optimal provision of regulation service reserves (RSR) by controlling dynamic demand preferences in smart buildings. A major contribution over past dynamic pricing work is that we pioneer the relaxation of static, uniformly distributed utility of demand. In this paper we model explicitly the dynamics of energy service preferences leading to a non-uniform and time varying probability distribution of demand utility. More explicitly, we model active and idle duty cycle appliances in a smart building as a closed queuing system with price-controlled arrival rates into the active appliance queue. Focusing on cooling appliances, we model the utility associated with the transition from idle to active as a non-uniform time varying function. We (i) derive an analytic characterization of the optimal policy and the differential cost function, and (ii) prove optimal policy monotonicity and value function convexity. These properties enable us to propose and implement a smart assisted value iteration (AVI) algorithm and an approximate DP (ADP) that exploits related functional approximations. Numerical results demonstrate the validity of the solution techniques and the computational advantage of the proposed ADP on realistic, large-state-space problems