Single Spin Asymmetry ANA_N in Polarized Proton-Proton Elastic Scattering at s=200\sqrt{s}=200 GeV

We report a high precision measurement of the transverse single spin asymmetry $A_N$ at the center of mass energy $\sqrt{s}=200$ GeV in elastic proton-proton scattering by the STAR experiment at RHIC. The $A_N$ was measured in the four-momentum transfer squared $t$ range $0.003 \leqslant |t| \leqslant 0.035$ \GeVcSq, the region of a significant interference between the electromagnetic and hadronic scattering amplitudes. The measured values of $A_N$ and its $t$-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 $\sqrt{s}$, 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

Fluctuations Of Charge Separation Perpendicular To The Event Plane And Local Parity Violation In S Nn = 200 Gev Au + Au Collisions At The Bnl Relativistic Heavy Ion Collider

Previous experimental results based on data (∼15×106 events) collected by the STAR detector at the BNL Relativistic Heavy Ion Collider suggest event-by-event charge-separation fluctuations perpendicular to the event plane in noncentral heavy-ion collisions. Here we present the correlator previously used split into its two component parts to reveal correlations parallel and perpendicular to the event plane. The results are from a high-statistics 200-GeV Au + Au collisions data set (57×106 events) collected by the STAR experiment. We explicitly count units of charge separation from which we find clear evidence for more charge-separation fluctuations perpendicular than parallel to the event plane. We also employ a modified correlator to study the possible P-even background in same- and opposite-charge correlations, and find that the P-even background may largely be explained by momentum conservation and collective motion. © 2013 American Physical Society.886NRF-2012004024; National Research FoundationLee, T.D., Yang, C.N., (1956) Phys. Rev., 104. , 1, 254. 0031-899X PHRVAO 10.1103/PhysRev.104.254Vafa, C., Witten, E., (1984) Phys. Rev. Lett., 53. , 2, 535. 0031-9007 PRLTAO 10.1103/PhysRevLett.53.535Lee, T.D., (1973) Phys. Rev. D, 8. , 3, 1226. 0556-2821 10.1103/PhysRevD.8.1226Lee, T.D., Wick, G.C., (1974) Phys. Rev. D, 9. , 4, 2291. 0556-2821 10.1103/PhysRevD.9.2291Kharzeev, D., Parity violation in hot QCD: Why it can happen, and how to look for it (2006) Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 633 (2-3), pp. 260-264. , DOI 10.1016/j.physletb.2005.11.075, PII S0370269305017430Kharzeev, D., Zhitnitsky, A., (2007) Nucl. Phys. 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Lett., 110. , 11 (ALICE Collaboration), 012301. 0031-9007 PRLTAO 10.1103/PhysRevLett. 110.012301Ackermann, K.H., Adams, N., Adler, C., Ahammed, Z., Ahmad, S., Allgower, C., Amonett, J., Harris, J.W., STAR detector overview (2003) Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 499 (2-3), pp. 624-632. , DOI 10.1016/S0168-9002(02)01960-5Adams, J., Aggarwal, M.M., Ahammed, Z., Amonett, J., Anderson, B.D., Arkhipkin, D., Averichev, G.S., Bai, Y., Directed flow in Au+Au collisions at sNN=62.4 GeV (2006) Physical Review C - Nuclear Physics, 73 (3), pp. 1-7. , http://oai.aps.org/oai?verb=GetRecord&Identifier=oai:aps.org: PhysRevC.73.034903&metadataPrefix=oai_apsmeta_2, DOI 10.1103/PhysRevC.73.034903, 034903Adamczyk, L., (2012) Phys. Rev. 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Degree of market imperfection and the pricing of stock index futures

Capital markets are imperfect. Market imperfections differ among markets. This study uses a theoretical valuation model derived by Hsu and Wang (2004) to estimate the degrees of market imperfection for mature and immature markets, and tests the applicability of the model. Moreover, this study proposes some theoretical hypotheses and empirical tests regarding the relationship between the degree of market imperfection and futures pricing. The evidence indicates that the Hsu and Wang (2004) model appears to provide a reasonable measure of the degree of market imperfection for real capital markets. The theoretical hypotheses and empirical results indicate that larger market imperfections are relatively more mispriced based on the model of perfect-market assumption, suggesting that the impact of market imperfection on the pricing of stock index futures is enormous, and cannot be neglected. Thus, when investors more closely examine the applicability of the cost of carry model for pricing mature and immature futures markets, they should note the degree of imperfection for the markets in which they are participating.

Inflammatory mechanisms underlying the rat pulmonary neutrophil influx induced by airway exposure to staphylococcal enterotoxin type A

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOAssociation between staphylococcal infection and pathogenesis of upper airways disease has been reported. This study aimed to investigate the mechanisms underlying the rat pulmonary inflammation induced by airway exposure to staphylococcal enterotoxin A( SEA). 2 SEA( 0.3 - 10 ng trachea(-1)) caused dose-dependent neutrophil accumulation in BAL fluid, reaching maximal responses at 4 h ( 25-fold increase for 3 ng trachea(-1)). Significant accumulation of both lymphocytes and macrophages in BAL fluid was also observed at 4 h ( 2.1- and 1.9-fold increase, respectively, for 3 ng trachea(-1)). At later times ( 16 h), neutrophil counts in bone marrow ( immature forms) and peripheral blood increased by 63 and 81%, respectively. SEA failed to directly induce chemotaxis and adhesion of isolated neutrophils. 3 Analysis of mRNA expression for iNOS, COX-2 and CINC-2 in lung tissue showed an upregulation of these enzymes, which paralleled elevated levels of LTB4, PGE(2), TNF-alpha, IL-6 and NO2- in BAL fluid. Expression of CINC-1 was unchanged, whereas CINC-3 was reduced in SEA-treated rats. Incubation of isolated alveolar macrophages with SEA( 3 mu g ml(-1)) resulted in significant elevations of TNF-alpha and NO2- levels in the cell supernatants. 4 Dexamethasone ( 0.5 mg kg(-1)), celecoxib ( 3 mg kg(-1)) and compound 1400W ( 5 mg kg(-1)) markedly reduced SEA-induced lung neutrophil influx and NO2- levels in BAL fluid. The lipoxygenase inhibitor AA-861 ( 100 mu g kg(-1)) partly inhibited the neutrophil influx in SEA-treated rats without modifying the NO2- levels. None of these treatments reduced the number of mononuclear cells in BAL fluid ( except of dexamethasone, which abolished the increased lymphocyte counts). 5 Our study shows that airways exposure to SEA results in marked neutrophil influx through mechanisms involving increased expressions of CINC-2, iNOS and COX-2, as well as enhanced production of NO, PGE(2), LTB4, TNF-alpha and IL-61466781791FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOsem informaçã

Fusion enhancement at near and sub-barrier energies in 19O + 12C

Measuring the fusion excitation function for an isotopic chain of projectile nuclei provides a stringent test of a microscopic description of fusion. We report the first measurement of the fusion excitation function at near-barrier energies for the 19O + 12C system. The measured excitation function is compared with the fusion excitation function of 18O + 12C. A significant enhancement in the fusion probability of 19O ions with a 12C target as compared to 18O ions is observed. The experimental cross-sections observed at near-barrier energies are compared with a state-of-the-art microscopic model