94 research outputs found
Single Spin Asymmetry in Polarized Proton-Proton Elastic Scattering at GeV
We report a high precision measurement of the transverse single spin
asymmetry at the center of mass energy GeV in elastic
proton-proton scattering by the STAR experiment at RHIC. The was measured
in the four-momentum transfer squared range \GeVcSq, the region of a significant interference between the
electromagnetic and hadronic scattering amplitudes. The measured values of
and its -dependence are consistent with a vanishing hadronic spin-flip
amplitude, thus providing strong constraints on the ratio of the single
spin-flip to the non-flip amplitudes. Since the hadronic amplitude is dominated
by the Pomeron amplitude at this , we conclude that this measurement
addresses the question about the presence of a hadronic spin flip due to the
Pomeron exchange in polarized proton-proton elastic scattering.Comment: 12 pages, 6 figure
High non-photonic electron production in + collisions at = 200 GeV
We present the measurement of non-photonic electron production at high
transverse momentum ( 2.5 GeV/) in + collisions at
= 200 GeV using data recorded during 2005 and 2008 by the STAR
experiment at the Relativistic Heavy Ion Collider (RHIC). The measured
cross-sections from the two runs are consistent with each other despite a large
difference in photonic background levels due to different detector
configurations. We compare the measured non-photonic electron cross-sections
with previously published RHIC data and pQCD calculations. Using the relative
contributions of B and D mesons to non-photonic electrons, we determine the
integrated cross sections of electrons () at 3 GeV/10 GeV/ from bottom and charm meson decays to be = 4.0({\rm
stat.})({\rm syst.}) nb and =
6.2({\rm stat.})({\rm syst.}) nb, respectively.Comment: 17 pages, 17 figure
Evolution of the differential transverse momentum correlation function with centrality in Au+Au collisions at GeV
We present first measurements of the evolution of the differential transverse
momentum correlation function, {\it C}, with collision centrality in Au+Au
interactions at GeV. {\it C} exhibits a strong dependence
on collision centrality that is qualitatively similar to that of number
correlations previously reported. We use the observed longitudinal broadening
of the near-side peak of {\it C} with increasing centrality to estimate the
ratio of the shear viscosity to entropy density, , of the matter formed
in central Au+Au interactions. We obtain an upper limit estimate of
that suggests that the produced medium has a small viscosity per unit entropy.Comment: 7 pages, 4 figures, STAR paper published in Phys. Lett.
Longitudinal scaling property of the charge balance function in Au + Au collisions at 200 GeV
We present measurements of the charge balance function, from the charged
particles, for diverse pseudorapidity and transverse momentum ranges in Au + Au
collisions at 200 GeV using the STAR detector at RHIC. We observe that the
balance function is boost-invariant within the pseudorapidity coverage [-1.3,
1.3]. The balance function properly scaled by the width of the observed
pseudorapidity window does not depend on the position or size of the
pseudorapidity window. This scaling property also holds for particles in
different transverse momentum ranges. In addition, we find that the width of
the balance function decreases monotonically with increasing transverse
momentum for all centrality classes.Comment: 6 pages, 3 figure
Measurement of the Bottom contribution to non-photonic electron production in collisions at =200 GeV
The contribution of meson decays to non-photonic electrons, which are
mainly produced by the semi-leptonic decays of heavy flavor mesons, in
collisions at 200 GeV has been measured using azimuthal
correlations between non-photonic electrons and hadrons. The extracted
decay contribution is approximately 50% at a transverse momentum of GeV/. These measurements constrain the nuclear modification factor for
electrons from and meson decays. The result indicates that meson
production in heavy ion collisions is also suppressed at high .Comment: 6 pages, 4 figures, accepted by PR
J/ψ polarization in p+p collisions at s=200 GeV in STAR
AbstractWe report on a polarization measurement of inclusive J/ψ mesons in the di-electron decay channel at mid-rapidity at 2<pT<6 GeV/c in p+p collisions at s=200 GeV. Data were taken with the STAR detector at RHIC. The J/ψ polarization measurement should help to distinguish between different models of the J/ψ production mechanism since they predict different pT dependences of the J/ψ polarization. In this analysis, J/ψ polarization is studied in the helicity frame. The polarization parameter λθ measured at RHIC becomes smaller towards high pT, indicating more longitudinal J/ψ polarization as pT increases. The result is compared with predictions of presently available models
American Society of Hematology living guidelines on the use of anticoagulation for thromboprophylaxis in patients with COVID-19: May 2021 update on the use of intermediate-intensity anticoagulation in critically ill patients
Background: COVID-19-related critical illness is associated with an increased risk of venous thromboembolism (VTE). Objective: These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in making decisions about the use of anticoagulation for thromboprophylaxis in patients with COVID-19-related critical illness who do not have confirmed or suspected VTE.Methods: ASH formed a multidisciplinary guideline panel that included 3 patient representatives and applied strategies to minimize potential bias from conflicts of interest. The McMaster University Grading of Recommendations Assessment, Development and Evaluation (GRADE) Centre supported the guideline development process by performing systematic evidence reviews (up to 5 March 2021). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the GRADE approach to assess evidence and make recommendations, which were subject to public comment. This is an update on guidelines published in February 2021.Results: The panel agreed on 1 additional recommendation. The panel issued a conditional recommendation in favor of prophylactic-intensity over intermediate-intensity anticoagulation in patients with COVID-19-related critical illness who do not have confirmed or suspected VTE.Conclusions: This recommendation was based on low certainty in the evidence, which underscores the need for additional high-quality, randomized, controlled trials comparing different intensities of anticoagulation in critically ill patients. Other key research priorities include better evidence regarding predictors of thrombosis and bleeding risk in critically ill patients with COVID-19 and the impact of nonanticoagulant therapies (eg, antiviral agents, corticosteroids) on thrombotic risk.Thrombosis and Hemostasi
Dielectron Azimuthal Anisotropy At Mid-rapidity In Au+au Collisions At Snn =200 Gev
We report on the first measurement of the azimuthal anisotropy (v2) of dielectrons (e+e- pairs) at mid-rapidity from sNN=200 GeV Au+Au collisions with the STAR detector at the Relativistic Heavy Ion Collider (RHIC), presented as a function of transverse momentum (pT) for different invariant-mass regions. In the mass region Mee<1.1 GeV/c2 the dielectron v2 measurements are found to be consistent with expectations from π0,η,ω, and φ decay contributions. In the mass region 1.1<Mee<2.9GeV/c2, the measured dielectron v2 is consistent, within experimental uncertainties, with that from the cc¯ contributions.906Adams, J., (2005) Nucl. Phys. A, 757, p. 102. , NUPABL 0375-9474Arsene, I., (2005) Nucl. Phys. A, 757, p. 1. , NUPABL 0375-9474Adcox, K., (2005) Nucl. Phys. A, 757, p. 184. , NUPABL 0375-9474Back, B.B., (2005) Nucl. Phys. A, 757, p. 28. , NUPABL 0375-9474Rapp, R., Wambach, J., (2002) Adv. Nucl. Phys., 25, p. 1. , 0065-2970David, G., Rapp, R., Xu, Z., (2008) Phys. Rep., 462, p. 176. , PRPLCM 0370-1573Agakichiev, G., (2005) Eur. Phys. J. C, 41, p. 475. , EPCFFB 1434-6044Arnaldi, R., (2006) Phys. Rev. Lett., 96, p. 162302. , PRLTAO 0031-9007Brown, G.E., Rho, M., (1996) Phys. Rep., 269, p. 333. , PRPLCM 0370-1573Rapp, R., Wambach, J., (1999) Eur. Phys. J. A, 6, p. 415. , EPJAFV 1434-6001Dusling, K., Teaney, D., Zahed, I., (2007) Phys. Rev. C, 75, p. 024908. , PRVCAN 0556-2813Van Hees, H., Rapp, R., (2008) Nucl. Phys. A, 806, p. 339. , NUPABL 0375-9474Renk, T., Ruppert, J., (2008) Phys. Rev. C, 77, p. 024907. , PRVCAN 0556-2813Adare, A., (2010) Phys. Rev. C, 81, p. 034911. , PRVCAN 0556-2813Adamczyk, L., (2014) Phys. Rev. Lett., 113, p. 022301. , a longer version (unpublished). PRLTAO 0031-9007Rapp, R., Wambach, J., Van Hees, H., (2010) Relativistic Heavy-Ion Physics, , in, edited by R. Stock, Landolt Börnstein New Series I/23A (Springer, Berlin), Chap. 4-1Linnyk, O., Cassing, W., Manninen, J., Bratkovskaya, E.L., Ko, C.M., (2012) Phys. Rev. C, 85, p. 024910. , PRVCAN 0556-2813Xu, J.-H., Chen, H.F., Dong, X., Wang, Q., Zhang, Y.F., (2012) Phys. Rev. C, 85, p. 024906. , PRVCAN 0556-2813Adare, A., (2010) Phys. Rev. Lett., 104, p. 132301. , PRLTAO 0031-9007Poskanzer, A.M., Voloshin, S.A., (1998) Phys. Rev. C, 58, p. 1671. , PRVCAN 0556-2813Adare, A., (2012) Phys. Rev. Lett., 109, p. 122302. , PRLTAO 0031-9007Van Hees, H., Gale, C., Rapp, R., (2011) Phys. Rev. C, 84, p. 054906. , PRVCAN 0556-2813Chatterjee, R., Srivastava, D.K., Heinz, U., Gale, C., (2007) Phys. Rev. C, 75, p. 054909. , PRVCAN 0556-2813Adare, A., (2009) Phys. Lett. B, 670, p. 313. , PYLBAJ 0370-2693Bonner, B., (2003) Nucl. Instrum. Methods A, 508, p. 181. , NIMAER 0168-9002Shao, M., (2002) Nucl. Instrum. Methods A, 492, p. 344Wu, J., (2005) Nucl. Instrum. Methods A, 538, p. 243. , NIMAER 0168-9002Landgraf, J.M., (2003) Nucl. Instrum. Methods A, 499, p. 762. , NIMAER 0168-9002Ackermann, K.H., (2003) Nucl. Instrum. Methods A, 499, p. 624. , NIMAER 0168-9002Anderson, M., (2003) Nucl. Instrum. Methods A, 499, p. 659. , NIMAER 0168-9002Bichsel, H., (2006) Nucl. Instrum. Methods A, 562, p. 154. , NIMAER 0168-9002Xu, Y., (2010) Nucl. Instrum. Methods A, 614, p. 28. , NIMAER 0168-9002Shao, M., (2006) Nucl. Instrum. Methods A, 558, p. 419. , NIMAER 0168-9002Adams, J., (2005) Phys. Lett. B, 616, p. 8. , PYLBAJ 0370-2693Ruan, L., Ph.D. thesis, University of Science and Technology of China, 2005, arXiv:nucl-ex/0503018 (unpublished)Llope, W.J., (2004) Nucl. Instrum. Methods A, 522, p. 252. , NIMAER 0168-9002Adler, C., (2002) Phys. Rev. Lett., 89, p. 202301. , PRLTAO 0031-9007Adams, J., (2005) Phys. Rev. Lett., 94, p. 062301. , PRLTAO 0031-9007Adamczyk, L., (2012) Phys. Rev. C, 86, p. 024906. , PRVCAN 0556-2813Zhao, J., (2013), https://drupal.star.bnl.gov/STAR/theses/phd-32, Ph.D. thesis, Shanghai Institute of Applied Physics, (unpublished)Voloshin, S.A., Poskanzer, A.M., Snellings, R., (2010) Relativistic Heavy Ion Physics, pp. 5-54. , in, Landolt-Börnstein Vol. 1/23 (Springer-Verlag, Berlin), ppAdamczyk, L., (2013) Phys. Rev. C, 88, p. 014902. , PRVCAN 0556-2813Abelev, B.I., (2008) Phys. Rev. C, 77, p. 054901. , PRVCAN 0556-2813Abelev, B.I., (2006) Phys. Rev. Lett., 97, p. 152301. , PRLTAO 0031-9007Abelev, B.I., (2009) Phys. Rev. C, 79, p. 034909. , PRVCAN 0556-2813Abelev, B.I., (2009) Phys. Rev. C, 79, p. 064903. , PRVCAN 0556-2813Adams, J., (2005) Phys. Lett. B, 612, p. 181. , PYLBAJ 0370-2693Adler, S.S., (2007) Phys. Rev. C, 75, p. 024909. , PRVCAN 0556-2813Tang, Z., Xu, Y., Ruan, L., Van Buren, G., Wang, F., Xu, Z., (2009) Phys. Rev. C, 79, p. 051901. , (R) () PRVCAN 0556-2813Shao, M., Yi, L., Tang, Z., Chen, H., Li, C., Xu, Z., (2010) J. Phys. G, 37, p. 085104. , JPGPED 0954-3899Afanasiev, S., (2009) Phys. Rev. C, 80, p. 054907. , PRVCAN 0556-2813Adams, J., (2005) Phys. Rev. C, 72, p. 014904. , PRVCAN 0556-2813Abelev, B.I., (2007) Phys. Rev. Lett., 99, p. 112301. , PRLTAO 0031-9007Kroll, N.M., Wada, W., (1955) Phys. Rev., 98, p. 1355. , PHRVAO 0031-899XRuan, L., (2011) Nucl. Phys. A, 855, p. 269. , NUPABL 0375-9474Huang, B., (2011), Ph.D. thesis, University of Science and Technology of China, (unpublished)Sjöstrand, T., (2001) Comput. Phys. Commun., 135, p. 238. , CPHCBZ 0010-4655Adamczyk, L., (2012) Phys. Rev. D, 86, p. 072013. , PRVDAQ 1550-7998Agakishiev, H., (2011) Phys. Rev. D, 83, p. 052006. , PRVDAQ 1550-7998Adare, A., (2011) Phys. Rev. C, 84, p. 044905. , PRVCAN 0556-2813Adare, A., (2012) Phys. Rev. C, 85, p. 064914. , PRVCAN 0556-2813Adare, A., (2007) Phys. Rev. Lett., 98, p. 162301. , PRLTAO 0031-9007Adams, J., (2004) Phys. Rev. Lett., 92, p. 052302. , PRLTAO 0031-9007Vujanovic, G., Young, C., Schenke, B., Jeon, S., Rapp, R., Gale, C., (2013) Nucl. Phys. A, 904-905, p. 557c. , NUPABL 0375-9474Vujanovic, G., Young, C., Schenke, B., Jeon, S., Rapp, R., Gale, C., (2014) Phys. Rev. C, 89, p. 034904. , PRVCAN 0556-281
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