Coulomb gauge QCD as a tool for the excited spectrum

A distinct feature of Coulomb gauge QCD is that it can be formulated in terms of physical, transverse gluons and quarks alone. The state-counting is then transparent, and the gauge is suited for studies of the excited spectrum. Leaving aside exotic spectroscopy, which has been the subject of other publications, in this note I call attention on two recent applications. One is that the running quark mass in the mid-infrared can be probed from excited baryons thanks to parity doubling, a consequence of insensitivity to chiral symmetry breaking. Fast quarks are asymptotically free and behave as massless, so hadrons containing fast quarks decouple from the condensate. Their (power-law) rate of decoupling reflects on the rate of decreasing parity splittings, which can be measured. The second is that, in analogy with the Franck-Condon principle of molecular physics, the velocity distribution of the heavy quarks inside a heavy hadron can be mapped out by the velocity distribution of its open-flavor decay products. This is exemplified by recent data from the Belle collaboration taken at the Upsilon(10860).Comment: 4 pages, 3 figures, contribution to the proceedings of the workshop LightCone2010, Valencia, June 14th-18t

Revisiting Factors Associated with the Success of Ballot Initiatives with a Substantial Rail Transit Component, Research Report 10-13

This report presents the replication of an MTI study conducted in 2001 by Peter Haas and Richard Werbel. That research, itself a continuation of an earlier project completed in 2000, included an analysis of transportation tax elections in 11 urban areas across the nation and culminated in the identification of 17 community-level factors with potential impact on the success of ballot measures for sales tax increases to fund transportation packages with substantial rail components. Trends observed in these more recent case studies were generally highly consistent with the following findings from the 2001 study. Thus this analysis reaffirms the importance for community consensus amongst the business, elected and environmental communities, and accompanying depth of financial support. Once again, the difficulty of passing an initiative without well-funded, effective use of multimedia was validated, as was the importance of utilizing experienced campaign consultants. Some factors seemed less important in the current study than in 2001, including the effectiveness of presenting a multimodal package, the perception of benefits of a package being distributed throughout the voting district, the experience gained in recent transit elections, and the credibility of the transit agency. Finally, this compilation includes an exploration of “rebound” elections – those instances in which a failed measure is quickly followed by a successful one – and the factors that seem linked to achieving success in such instances

Relativistic Quark Model Calculation of the l1, l2 Coefficients of the Chiral Lagrangian

We briefly report on a relativistic quark model scheme to calculate the O(P^4) pion-pion vertex in the planar approximation and in the chiral limit. The calculation is reduced to the solution of simple integral equations (Bethe-Salpeter like) by an effective use of chiral Ward Identities. Specific model computations are provided.Comment: Proc. V Intnal. Conf. on Quark Confinement and the Hadron Spectrum, Gargnano,Italy 200

[Review of] Elizabeth Martinez. De Colores Means All Of Us

Elizabeth Martinez, well known San Franciscan activist, author and journalist, in her most recent work endeavors to connect the movements of the 90s with the crucible of the 60s. Her narrative of the course of contemporary activism and insurgence in the United States gives the reader an introspective look into the underbelly of Chicano/Chicana activism in the 60s and the resultant conflicts which ensued from not initially addressing issues of sexism, classism and machismo within the Movimiento. She provocatively talks about the utilization of chingon politics and the suppression of the Chicana feminist voice which has ultimately led to attempts to redefine and reconstitute the Movimiento

Estimating Workforce Development Needs for High-Speed Rail in California, Research Report 11-16

This study provides an assessment of the job creation and attendant education and training needs associated with the creation of the California High-Speed Rail (CHSR) network, scheduled to begin construction in September 2012. Given the high profile of national and state commitment to the project, a comprehensive analysis that discusses the education, training, and related needs created during the build out of the CHSR network is necessary. This needs assessment is achieved by means of: 1) analyzing current high-speed rail specific challenges pertaining to 220mph trains; 2) using a more accurate and robust “bottom-up” approach to estimate the labor, education, skills, and knowledge needed to complete the CHSR network; and 3) assessing the current capacity of railroad-specific training and education in the state of California and the nation. Through these analyses, the study identifies the magnitude and attributes of the workforce development needs and challenges that lie ahead for California. The results of this research offer new insight into the training and education levels likely to be needed for the emergent high-speed rail workforce, including which types of workers and professionals are needed over the life of the project (by project phase), and their anticipated educational level. Results indicates that although the education attained by the design engineers of the system signifies the most advanced levels of education in the workforce, this group is comparatively small over the life of the project. Secondly, this report identifies vast training needs for the construction workforce and higher education needs for a managerial construction workforce. Finally, the report identifies an extremely limited existing capacity for training and educating the high-speed rail workforce in both California and in the U.S. generally

Geometrical and spectral study of beta-skeleton graphs

We perform an extensive numerical analysis of beta-skeleton graphs, a particular type of proximity graphs. In beta-skeleton graph (BSG) two vertices are connected if a proximity rule, that depends of the parameter beta is an element of (0, infinity), is satisfied. Moreover, for beta > 1 there exist two different proximity rules, leading to lune-based and circle-based BSGs. First, by computing the average degree of large ensembles of BSGs we detect differences, which increase with the increase of beta, between lune-based and circle-based BSGs. Then, within a random matrix theory (RMT) approach, we explore spectral and eigenvector properties of random BSGs by the use of the nearest-neighbor energy-level spacing distribution and the entropic eigenvector localization length, respectively. The RMT analysis allows us to conclude that a localization transition occurs at beta = 1

Soft interactions in jet quenching

We study the collisional aspects of jet quenching in a high energy nuclear collision, especially in the final state pion gas. The jet has a large energy, and acquires momentum transverse to its axis more effectively by multiple soft collisions than by few hard scatterings (as known from analogous systems such as J/\psi production at Hera). Such regime of large E and small momentum transfer corresponds to Regge kinematics and is characteristically dominated by the pomeron. From this insight we estimate the jet quenching parameter in the hadron medium (largely a pion gas) at the end of the collision, which is naturally small and increases with temperature in line with the gas density. The physics in the quark-gluon plasma/liquid phase is less obvious, and here we revisit a couple of simple estimates that suggest indeed that the pomeron-mediated interactions are very relevant and should be included in analysis of the jet quenching parameter. Finally, the ocasional hard collisions produce features characteristic of a L\`evy flight in the q_perp^2 plane perpendicular to the jet axis. We suggest one- and two-particle q_perp correlations as interesting experimental probes.Comment: 14 pages, 16 figure