Physical-Continuum Limit of the Nucleon Gluon Parton Distribution from Lattice QCD

We present the key results from the first study of the $x$-dependent nucleon gluon distribution from lattice QCD extrapolated to the physical-continuum limit. We use ensembles with $2+1+1$ flavors of highly improved staggered quarks (HISQ) generated by the MILC Collaboration with clover fermions for the valence action on three different lattice spacings and three different pion masses. We took up to $O(10^6)$ measurements of two-point correlators, obtaining good signal at boost momenta up to 3~GeV. We extrapolated the reduced pseudo-ITD matrix elements to the physical-continuum limit before extracting $xg(x)/\langle x \rangle_g$. Then using the gluon momentum fraction $\langle x \rangle_g$ calculated on the same configurations, we determine the unpolarized nucleon gluon PDF $xg(x)$ and compare results with other lattice and selected global fits.Comment: 10 pages, 3 figures, DIS2023 conference proceedings, based on full paper: arXiv:2210.0998

The Kansas Court of Industrial Relations

Call number: LD2668 .T4 1933 H8

Hadrons and Nuclei

This document is one of a series of whitepapers from the USQCD collaboration. Here, we discuss opportunities for lattice QCD calculations related to the structure and spectroscopy of hadrons and nuclei. An overview of recent lattice calculations of the structure of the proton and other hadrons is presented along with prospects for future extensions. Progress and prospects of hadronic spectroscopy and the study of resonances in the light, strange and heavy quark sectors is summarized. Finally, recent advances in the study of light nuclei from lattice QCD are addressed, and the scope of future investigations that are currently envisioned is outlined.Comment: 45 page

The Gluon Moment and Parton Distribution Function of the Pion from Nf=2+1+1N_f = 2 + 1 + 1 Lattice QCD

We present the first calculation of the pion gluon moment from lattice QCD in the continuum-physical limit. The calculation is done using clover fermions for the valence action with three pion masses, 220, 310 and 690 MeV, and three lattice spacings, 0.09, 0.12, and 0.15 fm, using ensembles generated by MILC Collaboration with 2+1+1 flavors of highly improved staggered quarks (HISQ). On the lattice, we nonperturbatively renormalize the gluon operator in RI/MOM scheme using the cluster-decomposition error reduction (CDER) technique to enhance the signal-to-noise ratio of the renormalization constant. We extrapolate the pion gluon moment to the continuum-physical limit and obtain $0.364(38)_{\text{stat}+\text{NPR}}(36)_\text{mixing}$ in the $\overline{\text{MS}}$ scheme at 2 GeV, with first error being the statistical error and uncertainties in nonperturbative renormalization, and the second being a systematic uncertainty estimating the effect of ignoring quark mixing. Our pion gluon momentum fraction has a central value lower than two recent single-ensemble lattice-QCD results near physical pion mass but is consistent with the recent global fits by JAM and xFitter and with most QCD-model estimates.Comment: 13 pages, 5 figure

Chemoenzymatic elaboration of monosaccharides using engineered cytochrome P450_(BM3) demethylases

Polysaccharides comprise an extremely important class of biopolymers that play critical roles in a wide range of biological processes, but the synthesis of these compounds is challenging because of their complex structures. We have developed a chemoenzymatic method for regioselective deprotection of monosaccharide substrates using engineered Bacillus megaterium cytochrome P450 (P450_(BM3)) demethylases that provides a highly efficient means to access valuable intermediates, which can be converted to a wide range of substituted monosaccharides and polysaccharides. Demethylases displaying high levels of regioselectivity toward a number of protected monosaccharides were identified using a combination of protein and substrate engineering, suggesting that this approach ultimately could be used in the synthesis of a wide range of substituted mono- and polysaccharides for studies in chemistry, biology, and medicine

A closer look at the hedonics of everyday meaning and satisfaction

Ministry of Education, Singapore under its Academic Research Funding Tier

Automation of Hubble Space Telescope Mission Operations

On June 13, 2011, after more than 21 years, 115 thousand orbits, and nearly 1 million exposures taken, the operation of the Hubble Space Telescope successfully transitioned from 24x7x365 staffing to 815 staffing. This required the automation of routine mission operations including telemetry and forward link acquisition, data dumping and solid-state recorder management, stored command loading, and health and safety monitoring of both the observatory and the HST Ground System. These changes were driven by budget reductions, and required ground system and onboard spacecraft enhancements across the entire operations spectrum, from planning and scheduling systems to payload flight software. Changes in personnel and staffing were required in order to adapt to the new roles and responsibilities required in the new automated operations era. This paper will provide a high level overview of the obstacles to automating nominal HST mission operations, both technical and cultural, and how those obstacles were overcome

Effect of Metal Alloys, Degradation Inhibitors, Temperatures on Thermal Oxidative Stability of CF3O(CF2O)(sub x)(CF2O)(sub y)CF3 Fluids

Degradation-promoting action of a series of ferrous and titanium alloys on CF3O(CF2O)(sub x)(CF2-CF2O)(sub y)CF3-based Z25 fluids and the inhibition effectiveness of several classes of additives were investigated. Four types of additives-phosphines, phosphates, phospha-s-triazines, and diphosphatetraazacyclooctatetraene-were studied in two batches of Z25 fluid, P28 and P151. In the absence of inhibitors, titanium alloys were more detrimental than the ferrous metals, but the additives were more effective in the presence of titanium alloys. Phosphate esters totally inhibited the decomposition of P151 at 330 C over 24 h in both types of alloys. The other additives were effective at lower temperatures. The responsiveness of fluid to an additive was found to be batch dependent

Extraversion and agreeableness: Divergent routes to daily satisfaction with social relationships

Ministry of Education, Singapore under its Academic Research Funding Tier 1, 08-C242-SMU-020, 09-C242-SMU-019, 10-C242-SMU-02