Heavy quark diffusion in perturbative QCD at next-to-leading order

We compute the momentum diffusion coefficient of a nonrelativistic heavy quark in a hot QCD plasma, to next-to-leading order in the weak coupling expansion. Corrections arise at O(g); physically they represent interference between overlapping scatterings, as well as soft, electric scale ($p\sim gT$) gauge field physics, which we treat using the hard thermal loop (HTL) effective theory. In 3-color, 3-flavor QCD, the momentum diffusion constant of a fundamental representation heavy quark at NLO is $\kappa = \frac{16\pi}{3} \alpha_s^2 T^3 (\ln \frac{1}{g} + 0.07428 + 1.8869 g)$. The convergence of the weak coupling expansion is poor.Comment: 4 pages, 3 figure

An inventory of state natural resources information systems

The status of a project to inventory state natural resources information systems is summarized. All tasks accomplished are described, and tasks remaining to be completed are outlined

A fluid flow perspective on the diagenesis of Te Aute limestones

Pliocene cool-water, bioclastic Te Aute limestones in East Coast Basin, New Zealand, accumulated either in shelfal shoal areas or about structurally shallow growth fold structures in the tectonically active accretionary forearc prism. Up to five stages of carbonate cementation are recognised, based on cement sequence-stratigraphic concepts, that formed on the seafloor during exposure of the limestones before burial, during burial, uplift, and deformation. Two principal fluid types are identified--topography-driven meteoric fluids and compaction-driven fluids. We have developed conceptual and quantitative models that attempt to relate the physical characteristics of fluid flow to the cement paragenesis. In particular, we have simulated the effects of uplift of the axial ranges bordering East Coast Basin in terms of the degree of penetration of a meteoric wedge into the basin. The dynamics of meteoric flow changed dramatically during uplift over the last 2 m.y. such that the modelled extent of the meteoric wedge is at least 40 km across the basin, and the penetration depth 1500 m or more corresponding with measured freshwater intersections in some oil wells. Cement-fluid relationships include: (1) true marine cements that precipitated in areas remote from shallow freshwater lenses; (2) pre-compaction cements that formed in shallow freshwater lenses beneath limestone "islands"; (3) post-compaction cements derived from compaction-driven flow during burial; (4) early uplift-related fracture-fill cements formed during deformation of the accretionary prism and uplift of the axial ranges; and (5) late uplift-related cements associated with uplift into a shallow meteoric regime

Academic-Community Partnerships: Effectiveness Evaluated Beyond the Ivory Walls

Community-based participatory research (CBPR) has furthered our understanding of the working principles required for academic-community partnerships to address persistent public health problems. However, little is known about how effective these partnerships have been in eliminating or reducing community-based public health issues. To contribute to the literature in this area, the authors conducted a survey of U.S. schools and programs in public health and community groups working with these academic partners to: (1) identify the most common local public health issues addressed; (2) examine the characteristics of the partnership and the actual or perceived benefits and challenges for each partner; (3) assess the perceived effectiveness of the partnership and their evaluation techniques; and (4) analyze the intent to continue or dissolve the partnership and the associated factors that influence this decision. The authors provide recommendations that can improve the development, functioning, and effectiveness of academic-community collaborations aimed at addressing a variety of public health concerns

On the Hierarchy of Block Deterministic Languages

A regular language is $k$-lookahead deterministic (resp. $k$-block deterministic) if it is specified by a $k$-lookahead deterministic (resp. $k$-block deterministic) regular expression. These two subclasses of regular languages have been respectively introduced by Han and Wood ($k$-lookahead determinism) and by Giammarresi et al. ($k$-block determinism) as a possible extension of one-unambiguous languages defined and characterized by Br\"uggemann-Klein and Wood. In this paper, we study the hierarchy and the inclusion links of these families. We first show that each $k$-block deterministic language is the alphabetic image of some one-unambiguous language. Moreover, we show that the conversion from a minimal DFA of a $k$-block deterministic regular language to a $k$-block deterministic automaton not only requires state elimination, and that the proof given by Han and Wood of a proper hierarchy in $k$-block deterministic languages based on this result is erroneous. Despite these results, we show by giving a parameterized family that there is a proper hierarchy in $k$-block deterministic regular languages. We also prove that there is a proper hierarchy in $k$-lookahead deterministic regular languages by studying particular properties of unary regular expressions. Finally, using our valid results, we confirm that the family of $k$-block deterministic regular languages is strictly included into the one of $k$-lookahead deterministic regular languages by showing that any $k$-block deterministic unary language is one-unambiguous

Heavy Quark Thermalization in Classical Lattice Gauge Theory: Lessons for Strongly-Coupled QCD

Thermalization of a heavy quark near rest is controlled by the correlator of two electric fields along a temporal Wilson line. We address this correlator within real-time, classical lattice Yang-Mills theory, and elaborate on the analogies that exist with the dynamics of hot QCD. In the weak-coupling limit, it can be shown analytically that the dynamics on the two sides are closely related to each other. For intermediate couplings, we carry out non-perturbative simulations within the classical theory, showing that the leading term in the weak-coupling expansion significantly underestimates the heavy quark thermalization rate. Our analytic and numerical results also yield a general understanding concerning the overall shape of the spectral function corresponding to the electric field correlator, which may be helpful in subsequent efforts to reconstruct it from Euclidean lattice Monte Carlo simulations.Comment: 22 pages. v2: a reference and clarifications added; published versio

Alien Registration- Caron, Georgiana D. (Lewiston, Androscoggin County)

https://digitalmaine.com/alien_docs/29229/thumbnail.jp