Renormalization of infrared contributions to the QCD pressure

Thanks to dimensional reduction, the infrared contributions to the QCD pressure can be obtained from two different three-dimensional effective field theories, called the Electrostatic QCD (Yang-Mills plus adjoint Higgs) and the Magnetostatic QCD (pure Yang-Mills theory). Lattice measurements have been carried out within these theories, but a proper interpretation of the results requires renormalization, and in some cases also improvement, i.e. the removal of terms of O(a) or O(a^2). We discuss how these computations can be implemented and carried out up to 4-loop level with the help of Numerical Stochastic Perturbation Theory.Comment: 7 pages, 4 figures, talk presented at Lattice 2006 (High temperature and density

The leading non-perturbative coefficient in the weak-coupling expansion of hot QCD pressure

Using Numerical Stochastic Perturbation Theory within three-dimensional pure SU(3) gauge theory, we estimate the last unknown renormalization constant that is needed for converting the vacuum energy density of this model from lattice regularization to the MSbar scheme. Making use of a previous non-perturbative lattice measurement of the plaquette expectation value in three dimensions, this allows us to approximate the first non-perturbative coefficient that appears in the weak-coupling expansion of hot QCD pressure.Comment: 16 pages. v2: published versio

3-d Lattice QCD Free Energy to Four Loops

We compute the expansion of the 3-d Lattice QCD free energy to four loop order by means of Numerical Stochastic Perturbation Theory. The first and second order are already known and are correctly reproduced. The third and fourth order coefficients are new results. The known logarithmic divergence in the fourth order is correctly identified. We comment on the relevance of our computation in the context of dimensionally reduced finite temperature QCD.Comment: 8 pages, 3 figures, latex typeset with JHEP3.cl

Towards 4-loop NSPT result for a 3-dimensional condensate-contribution to hot QCD pressure

Thanks to dimensional reduction, the contributions to the hot QCD pressure coming from so-called soft modes can be studied via an effective three-dimensional theory named Electrostatic QCD (spatial Yang-Mills fields plus an adjoint Higgs scalar). The poor convergence of the perturbative series within EQCD suggests to perform lattice measurements of some of the associated gluon condensates. These turn out, however, to be plagued by large discretization artifacts. We discuss how Numerical Stochastic Perturbation Theory can be exploited to determine the full lattice spacing dependence of one of these condensates up to 4-loop order, and sharpen our tools on a concrete 2-loop example.Comment: Presented at 25th International Symposium on Lattice Field Theory, Regensburg, Germany, 30 Jul - 4 Aug 2007, 7 page

Comparing single-frequency bioelectrical impedance analysis against deuterium dilution to assess total body water.

Background/Objectives: In this study, we aimed to validate the accuracy of single-frequency bioelectrical impedance analysis (SF-BIA) at 50 kHz to assess total body water (TBW) against the reference technique deuterium dilution (D(2)O) and to explore if the simple clinical parameters extracellular fluid (ECF) composition and body shape explain individual differences between D(2)O and SF-BIA (Diff(BIA-D(2)O)). Subjects/Methods: We assessed TBW with D(2)O and SF-BIA in 26 women and 26 men without known disease or anomalous body shapes. In addition, we measured body shape with anthropometry and ECF composition (osmolality, albumin, glucose, urea, creatinine, sodium and potassium). Results: On group average, SF-BIA to predict TBW agreed well with D(2)O (SF-BIA, 39.8±10.1 l; D(2)O, 40.4±10.2 l; and Diff(BIA-D(2)O) -0.7 l). In four individuals ('outliers'; 15% of the study population), Diff(BIA-D(2)O) was high (-6.8 to +3.8 l). Diff(BIA-D(2)O) was associated with individual variations in body shape rather than ECF composition. Using gender-specific analysis, we found that individual variability of waist circumference in men and arm length in women significantly contributed to Diff(BIA-D(2)O). When removing the four 'outliers', these associations were lost. Conclusions: In the majority of our sample, BIA agreed well with D(2)O. Adjusting for individual variability in body shape by anthropometrical assessment could possibly improve the accuracy of SF-BIA for individuals who deviate from mean values with respect to body shape. However, further studies with higher subject numbers are needed to confirm our findings

An East to West Mineralogical Trend in Mars Exploration Rover Spirit Moessbauer Spectra of Home Plate

Home Plate is a light-toned plateau approx.90 m in diameter within the Inner Basin of the Columbia Hills in Gusev crater on Mars. It is the most extensive exposure of layered bedrock encountered by Spirit to date, and it is composed of clastic rocks of moderately altered alkali basalt composition, enriched in some highly volatile elements. Textural observations suggest an explosive origin and geochemical observations favor volcanism, probably a hydrovolcanic explosion [1]. Since it first arrived at Home Plate on sol 744, Spirit has circumnavigated the plateau (Fig. 1) and is now, since sol 1410, resting at its Winter Haven 3 location at the north end of Home Plate. Results: The MER Moessbauer spectrometers determine Fe oxidation states, identify Fe-bearing mineral phases and quantify the distribution of Fe among oxidation states and mineral phases [2]. Moessbauer spectra of Home Plate bedrock were obtained in five different locations from nine different targets (Fig. 1): Barnhill Ace, Posey Manager, and James Cool Papa Bell Stars at the northwest side of Home Plate; Pesapallo, June Emerson, and Elizabeth Emery on the east side; Texas Chili on the south side; Pecan Pie on the west side; and Chanute on the north side

Cygnus X-2: the Descendant of an Intermediate-Mass X-Ray Binary

The X-ray binary Cygnus X-2 (Cyg X-2) has recently been shown to contain a secondary that is much more luminous and hotter than is appropriate for a low-mass subgiant. We present detailed binary-evolution calculations which demonstrate that the present evolutionary state of Cyg X-2 can be understood if the secondary had an initial mass of around 3.5 M_sun and started to transfer mass near the end of its main-sequence phase (or, somewhat less likely, just after leaving the main sequence). Most of the mass of the secondary must have been ejected from the system during an earlier rapid mass-transfer phase. In the present phase, the secondary has a mass of around 0.5 M_sun with a non-degenerate helium core. It is burning hydrogen in a shell, and mass transfer is driven by the advancement of the burning shell. Cyg X-2 therefore is related to a previously little studied class of intermediate-mass X-ray binaries (IMXBs). We suggest that perhaps a significant fraction of X-ray binaries presently classified as low-mass X-ray binaries may be descendants of IMXBs and discuss some of the implications