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in creator/contributor: "Lawrence Berkeley National Laboratory. Nuclear Science Division."  
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Energy dependence of pi, p and pbar transverse momentum spectra for Au+Au collisions at sqrt sNN = 62.4 and 200 GeV

Description: We study the energy dependence of the transverse momentum (pT) spectra for charged pions, protons and anti-protons for Au+Au collisions at sqrt sNN = 62.4 and 200 GeV. Data are presented at mid-rapidity (lbar y rbar< 0.5) for 0.2< pT< 12 GeV/c. In the intermediate pT region (2< pT< 6 GeV/c), the nuclear modification factor is higher at 62.4 GeV than at 200 GeV, while at higher pT (pT> 7 GeV/c) the modification is similar for both energies. The p/pi+ and pbar/pi- ratios for cen… more
Date: March 26, 2007
Creator: Ritter, H
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Partner: UNT Libraries Government Documents Department
open access

Forward Neutral Pion Transverse Single Spin Asymmetries in p+p Collisions at sqrt s = 200 GeV

Description: We report precision measurements of the Feynman-x (x{sub F}) dependence, and first measurements of the transverse momentum (p{sub T}) dependence, of transverse single spin asymmetries for the production of {pi}{sup 0} mesons from polarized proton collisions at {radical}s = 200 GeV. The x{sub F} dependence of the results are in fair agreement with perturbative QCD (pQCD) model calculations that identify orbital motion of quarks and gluons within the proton as the origin of the spin effects. Resu… more
Date: November 26, 2008
Creator: STAR Collaboration
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Partner: UNT Libraries Government Documents Department
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Collins Fragmentation and the Single Transverse Spin Asymmetry

Description: We study the Collins mechanism for the single transverse spin asymmetry in the collinear factorization approach. The correspondent twist-three fragmentation function is identified. We show that the Collins function calculated in this approach is universal.We further examine its contribution to the single transverse spin asymmetry of semi-inclusive hadron production in deep inelastic scattering and demonstrate that the transverse momentum dependent and twist-three collinear approaches are consis… more
Date: March 26, 2009
Creator: Yuan, Feng & Zhou, Jian
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Partner: UNT Libraries Government Documents Department
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A New Limit on Time-Reversal Violation in Beta Decay

Description: We report the results of an improved determination of the triple correlation DP {center_dot} (p{sub e} x p{sub v}) that can be used to limit possible time-reversal invariance in the beta decay of polarized neutrons and constrain extensions to the Standard Model. Our result is D = (-0.96 {+-} 1.89(stat) {+-} 1.01(sys)) x 10{sup -4}. The corresponding phase between g{sub A} and g{sub V} is {phi}{sub AV} = 180.013{sup o} {+-} 0.028{sup o} (68% confidence level). This result represents the most sen… more
Date: April 26, 2011
Creator: Mumm, H P; Chupp, T E; Cooper, R L; Coulter, K P; Freedman, S J; Fujikawa, B K et al.
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Partner: UNT Libraries Government Documents Department
open access

The Case for the Younger Dryas Extraterrestrial Impact Event: Mammoth, Megafauna and Clovis Extinction

Description: The onset of>1000 years of Younger Dryas cooling, broad-scale extinctions, and the disappearance of the Clovis culture in North America simultaneously occurred 12,900 years ago followed immediately by the appearance of a carbon-rich black layer at many locations. In situ bones of extinct megafauna and Clovis tools occur only beneath this black layer and not within or above it. At the base of the black mat at 9 Clovis-age sites in North America and a site in Belgium numerous extraterrestrial imp… more
Date: October 26, 2009
Creator: Firestone, Richard B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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