P-wave meson properties with Wilson quarks

We describe two calculations involving P-wave mesons made of Wilson quarks: the strong coupling constant $\alpha_s$ in the presence of two flavors of light dynamical fermions and the mass and decay constant of the $a_1$ meson.Comment: Poster presented at Lattice '94, September 27--October 1, 1994, Bielefeld, Germany (no changes to manuscript, but correction of Authors list above

Dissecting Galaxy Formation: II. Comparing Substructure in Pure Dark Matter and Baryonic Models

We compare the substructure evolution in pure dark matter (DM) halos with those in the presence of baryons (PDM and BDM). The prime halos have been analyzed by Romano-Diaz et al (2009). Models have been evolved from identical initial conditions using Constrained Realizations, including star formation and feedback. A comprehensive catalog of subhalos has been compiled and properties of subhalos analyzed in the mass range of 10^8 Mo - 10^11 Mo. We find that subhalo mass functions are consistent with a single power law, M_sbh^{alpha}, but detect a nonnegligible shift between these functions, alpha -0.86 for the PDM, and -0.98 for the BDM. Overall, alpha const. in time with variations of +-15%. Second, we find that the radial mass distribution of subhalos can be approximated by a power law, R^{gamma} with a steepening around the radius of a maximal circular velocity, Rvmax, in the prime halos. Gamma ~-1.5 for the PDM and -1 for the BDM, inside Rvmax, and is steeper outside. We detect little spatial bias between the subhalo populations and the DM of the main halos. The subhalo population exhibits much less triaxiality with baryons, in tandem with the prime halo. Finally, we find that, counter-intuitively, the BDM population is depleted at a faster rate than the PDM one within the central 30kpc of the prime. Although the baryons provide a substantial glue to the subhalos, the main halos exhibit the same trend. This assures a more efficient tidal disruption of the BDM subhalos. This effect can be reversed for a more efficient feedback from stellar evolution and supermassive black holes, which will expel baryons from the center and decrease the concentration of the prime halo. We compare our results with via Lactea and Aquarius simulations and other published results.Comment: 12 pages, 9 figures, to be published by the Astrophysical Journa

2+1 flavor simulations of QCD with improved staggered quarks

The MILC collaboration has been performing realistic simulations of full QCD with 2+1 flavors of improved staggered quarks. Our simulations allow for controlled continuum and chiral extrapolations. I present results for the light pseudoscalar sector: masses and decay constants, quark masses and Gasser-Leutwyler low-energy constants. In addition I will present some results for heavy-light mesons, decay constants and semileptonic form factors, obtained in collaboration with the HPQCD and Fermilab lattice collaborations. Such calculations will help in the extraction of CKM matrix elements from experimental measurements.Comment: To appear in the proceedings of QNP06, IVth International Conference on Quarks and Nuclear Physics, Madrid, June 200

The Evolution of Dynamical Screening in the Parton Cacade Model

We determine the time evolution of the colour screening mass in high energy nuclear collisions, as provided by the parton cascade model. Using our result, we discuss the onset of deconfinement and the onset of quarkonium suppression in a general, not necessarily equilibrated environment of strongly interacting constituents.Comment: 11 pages, including 4 figure

Exotic meson spectroscopy from the clover action at beta = 5.85 and 6.15

We repeat our original simulations of the hybrid meson spectrum using the clover action, as a check on lattice artifacts. Our results for the 1-+ masses do not substantially change. We present preliminary results for the wave function of the 1-+ state in Coulomb gauge.Comment: LATTICE98(spectrum) 3 latex pages and two postscript figures. Contribution to lattice 9

Two-loop Perturbative Quark Mass Renormalization from Large Beta Monte Carlo

We present the calculation of heavy Wilson quark mass renormalization constants from large beta Monte Carlo simulations. Simulations were performed at various beta larger than 9, each on several spatial lattice sizes to allow for an infinite volume extrapolation. We use twisted boundary conditions to suppress tunneling and work in Coulomb gauge with appropriate adjustments for the temporal links. The one-loop coefficient obtained from this method is in agreement with the analytical result and a preliminary result for the second order coefficient is reported.Comment: Lattice 2000 (Perturbation Theory), 4 pages,4 figures, uses espcrc2.st

Point-of-Care Ultrasound Assessment of Tropical Infectious Diseases—A Review of Applications and Perspectives

The development of good quality and affordable ultrasound machines has led to the establishment and implementation of numerous point-of-care ultrasound (POCUS) protocols in various medical disciplines. POCUS for major infectious diseases endemic in tropical regions has received less attention, despite its likely even more pronounced benefit for populations with limited access to imaging infrastructure. Focused assessment with sonography for HIV-associated TB (FASH) and echinococcosis (FASE) are the only two POCUS protocols for tropical infectious diseases, which have been formally investigated and which have been implemented in routine patient care today. This review collates the available evidence for FASH and FASE, and discusses sonographic experiences reported for urinary and intestinal schistosomiasis, lymphatic filariasis, viral hemorrhagic fevers, amebic liver abscess, and visceral leishmaniasis. Potential POCUS protocols are suggested and technical as well as training aspects in the context of resource-limited settings are reviewed. Using the focused approach for tropical infectious diseases will make ultrasound diagnosis available to patients who would otherwise have very limited or no access to medical imaging

Heavy-light meson decay constants with N_f=3

During the past year the MILC Collaboration has continued its study of heavy-light meson decay constants with three dynamical quarks. Calculations have been extended to a second lattice spacing of about 0.09 fm. At this lattice spacing, there are results in the quenched approximation and for three sets of dynamical quark mass: m_l=m_s; m_l=0.4 m_s and m_l=0.2 m_s, where m_l is the light mass for the u and d quarks and m_s is the strange quark mass. At the coarser lattice spacing, for which results were presented at Lattice 2001, statistics have been increased for two sets of quark masses and three additional sets of quark masses have been studied, giving a total of eight combinations used to interpolate between the quenched and chiral limits. When these calculations are completed, we can study the decay constants taking into account both chiral and continuum extrapolations.Comment: Lattice2002(heavyquark), 3 pages, 3 color figures, to appear in the proceedings of Lattice 200

Scaling Properties of the Energy Density in SU(2) Lattice Gauge Theory

The lattice data for the energy density of $SU(2)$ gauge theory are calculated with \nop~derivatives of the coupling constants. These derivatives are obtained from two sources : i) a parametrization of the \nop~beta function in accord with the measured critical temperature and $\Delta\beta-$values and ii) a \nop~calculation of the presssure. We then perform a detailed finite size scaling analysis of the energy density near $T_c$. It is shown that at the critical temperature the energy density is scaling as a function of $VT^3$ with the corresponding $3d$ Ising model critical exponents. The value of $\epsilon(T_c)/T^4_c$ in the continuum limit is estimated to be 0.256(23). In the high temperature regime the energy density is approaching its weak coupling limit from below, at $T/T_c \approx 2$ it has reached only about $70\%$ of the limit.Comment: 15 pages + 9 figures, BI-TP 94/3