Resummations in QCD hard-scattering at large and small x

We discuss different resummations of large logarithms that arise in hard-scattering cross sections of quarks and gluons in regions of large and small x. The large-x logarithms are typically dominant near threshold for the production of a specified final state. These soft and collinear gluon corrections produce large enhancements of the cross section for many processes, notably top quark and Higgs production, and typically the higher-order corrections reduce the factorization and renormalization scale dependence of the cross section. The small-x logarithms are dominant in the regime where the momentum transfer of the hard sub-process is much smaller than the total collision energy. These logarithms are important to describe multijet final states in deep inelastic scattering and hadron colliders, and in the study of parton distribution functions. The resummations at small and large x are linked by the eikonal approximation and are dominated by soft gluon anomalous dimensions. We will review their role in both contexts and provide some explicit calculations at one and two loops.Comment: 36 pages, 12 figures, invited contribution to the edited book "The Physics of Quarks"; Eqs. 31 and 47 corrected, references update

Probing Unified Origin of Dark Matter and Baryon Asymmetry at PAMELA/Fermi

We propose an unified model of dark matter and baryon asymmetry in a lepto-philic world above the electroweak scale. We provide an example where the inflaton decay products subsequently generate a lepton asymmetry and a dark matter abundance with an unique coupling in the early universe, while the present day decay of the dark matter through the same coupling gives rise the observed cosmic ray anomalies at PAMELA and Fermi Large Area Telescope.Comment: 6 pages (minor revision), revtex, 3 figure

The role of 'S' level mathematics

The role of 'S' level mathematic

Status of Eikonal Two-Loop Calculations with Massive Quarks

We present results for two-loop diagrams with massive quarks in the eikonal approximation. Explicit expressions are given for the UV poles in dimensional regularization of several of the required integrals.Comment: 5 pages, 3 figures; presented at DIS 2008, London, England, April 7-11, 2008; corrections in I_2, I_2^UV, and I_ql^U

Oral mucosal progenitor cell clones resist In Vitro myogenic differentiation

Abstract Progenitor cells derived from the oral mucosa lamina propria (OMLP-PCs) demonstrate an ability to differentiate into tissue lineages removed from their anatomical origin. This clonally derived population of neural-crest cells have demonstrated potential to differentiate along mesenchymal and neuronal cell lineages. Objective Significant efforts are being made to generate functioning muscle constructs for use in research and clinical tissue engineering. In this study we aimed to determine the myogenic properties of clonal populations of expanded OMLP-PCs. Design PCs were subject to several in vitro culture conditions in an attempt to drive myogenic conversion. Methodologies include use of demethylation gene-modifying reagents, mechanical conditioning of tissue culture substrates, tuneable polyacrylamide gels and a 3-dimensional construct as well as published myogenic media compositions. PCR and immunostaining for the muscle cell markers Desmin and MyoD1 were used to assess muscle differentiation