Demonstration of the Equivalence of Soft and Zero-Bin Subtractions

Calculations of collinear correlation functions in perturbative QCD and Soft-Collinear Effective Theory (SCET) require a prescription for subtracting soft or zero-bin contributions in order to avoid double counting the contributions from soft modes. At leading order in $\lambda$, where $\lambda$ is the SCET expansion parameter, the zero-bin subtractions have been argued to be equivalent to convolution with soft Wilson lines. We give a proof of the factorization of naive collinear Wilson lines that is crucial for the derivation of the equivalence. We then check the equivalence by computing the non-Abelian two-loop mixed collinear-soft contribution to the jet function in the quark form factor. These results provide strong support for the equivalence, which can be used to give a nonperturbative definition of the zero-bin subtraction at lowest order in $\lambda$.Comment: 14 pages, 3 figure

Transverse parton distribution functions at next-to-next-to-leading order: the quark-to-quark case

We present a calculation of the perturbative quark-to-quark transverse parton distribution function at next-to-next-to-leading order based on a gauge invariant operator definition. We demonstrate for the first time that such a definition works beyond the first non-trivial order. We extract from our calculation the coefficient functions relevant for a next-to-next-to-next-to-leading logarithmic $Q_T$ resummation in a large class of processes at hadron colliders.Comment: 4 pages, 1 figure, revised version, accepted for publication in PR

Combining Semi-Analytic Models of Galaxy Formation with Simulations of Galaxy Clusters: the Need for AGN Heating

We present hydrodynamical N-body simulations of clusters of galaxies with feedback taken from semi-analytic models of galaxy formation. The advantage of this technique is that the source of feedback in our simulations is a population of galaxies that closely resembles that found in the real universe. We demonstrate that, to achieve the high entropy levels found in clusters, active galactic nuclei must inject a large fraction of their energy into the intergalactic/intracluster media throughout the growth period of the central black hole. These simulations reinforce the argument of Bower et al. (2008), who arrived at the same conclusion on the basis of purely semi-analytic reasoning.Comment: 4 pages, 1 figure. To appear in the proceedings of "The Monster's Fiery Breath", Eds. Sebastian Heinz and Eric Wilcots (AIP conference series

Distribution of red deepsea crab (Chaceon quinquedens) by size and sex in the Gulf of Mexico

The red deepsea crab (Chaceon quinquedens (Smith, 1879)) has supported a commercial fishery off the coast of New England since the 1970s (Wigley et al., 1975) and has had annual harvests from 400 metric tons (t) (1996) to 4000 t (2001) (NEFMC, 2002). In 2002, a fishery management plan for the northeast fishery on the Atlantic coast was implemented and total allowable catch was reduced to approximately 2500 t (NEFMC, 2002). Although there are management plans for the golden crab (C. fenneri) and the red deep sea crab for Atlantic coast regions, there is no fishery management plan for red deepsea crabs in the Gulf of Mexico. Successful management for sustainable harvests should be based on a knowledge of the life history of the species, but C. quinquedens has been a difficult species for which to obtain life history and abundance information because of its deep distribution

Prediction of gas leakage of environmental control systems

Mathematical models of leakage configurations and various flow theories are presented with the substantive experimental test data to provide background material for future design and failure analysis. Normal-rate leakage and emergency, high-rate leakage are considered

Our Commitment to Economic Development

When I arrived at UNLV, I gave considerable thought to how the university could better embrace the identity of our city. What I didn’t quite anticipate at the time was just how much the city wanted to embrace UNLV

Potential Milk Production in the Point MacKenzie Area of Southcentral Alaska

Point MacKenzie is an area northwest of Anchorage directly across the Knik Arm of Cook Inlet (Figure 1 ). This area contains a substantial amount of latent agricultural land and discussion regarding its potential has been going on for some time. The catalyst which activated the recent planning process directed at Point MacKenzie was concern over potential loss of the southcentral Alaska dairy industry expressed on May 4, 1979, in a letter from Jack Flint, General Manager, Matanuska Maid, Inc., to Governor Jay Hammond: "It is my opinion that if we do not take immediate steps to stabilize this important phase of agriculture, [the dairy industry] will pass from the scene. I think that if it should occur, it would be a serious blow to the State of Alaska, economically and socially. I believe we should also realize that if the dairy industry should cease to exist within the state, it is going to be very difficult to re-establish it." Mr. Flint's letter and corresponding action by the Matanuska-Susitna Borough have directed planning processes of the State of Alaska toward Poinr Mac- Kenzie. The Alaska Agricultural Action Council, created by the 1979 state legislature to plan, recommend, and administer agricultural development projects on state lands in Alaska, held a meeting in the Matanuska Valley in September, 1979, and determined that an economic feasibility study, directed toward dairy production, should be undertaken for the Point MacKenzie area. This report is that feasibility study.The information presented in this bulletin is part of a report prepared for the Agricultural Action Council of the State of Alaska. The group was formed in 1979 by legislative action and is chaired by W. I. "Bob" Palmer, Special Projects Director, Office of the Governor. The purpose of the group is to plan and manage agricultural development projects within the state. The report on the feasibility of milk production in the Point MacKenzie Area presented to Governor Hammond through the Alaska Agricultural Action Council was prepared by the authors of this bulletin and Dr. Boyd Buxton, Agricultural Economist, U.S. D.A., stationed at the University of Minnesota at St. Paul and Dr. Paul Fuglestad, Agricultural Economist, U.S.D .A., stationed in Anchorage, Alaska, both of whom are acknowledged with gratitude. The authors also wish to thank Cathy Warren who reviewed extensively the tabular data