Study of 9Be+12C elastic scattering at energies near the Coulomb barrier

In this work, angular distribution measurements for the elastic channel were performed for the 9Be+12C reaction at the energies ELab=13.0, 14.5, 17.3, 19.0 and 21.0 MeV, near the Coulomb barrier. The data have been analyzed in the framework of the double folding S\~ao Paulo potential. The experimental elastic scattering angular distributions were well described by the optical potential at forward angles for all measured energies. However, for the three highest energies, an enhancement was observed for intermediate and backward angles. This can be explained by the elastic transfer mechanism. Keywords: 9Be+12C, Elastic Scattering, S\~aoo Paulo Potential

6Li direct breakup lifetimes

alpha-d coincidence data were studied for the 6Li + 59Co reaction at E(lab) = 29.6 MeV. By using a kinematic analysis, it was possible to identify which process, leading to the same final state, has the major contribution for each of the selected angular regions. Contributions of the 6Li sequential and direct breakup to the incomplete fusion/transfer process were discussed by considering the lifetimes obtained by using a semiclassical approach, for both breakup components.Comment: 5 pages, 4 figures, Invited Talk (Parrallel Sessions) of A. Szanto de Toledo, prepared for the Proccedings of the 10th International Conference on Nucleus-Nucleus Collisions, August 16-21, 2009, Beijing, China; submitted to Nucl. Phys. A (Proceedings of NN2009

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

Evolution of the differential transverse momentum correlation function with centrality in Au+Au collisions at sNN=200\sqrt{s_{NN}} = 200 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 $\sqrt{s_{NN}} = 200$ 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, $\eta/s$, of the matter formed in central Au+Au interactions. We obtain an upper limit estimate of $\eta/s$ that suggests that the produced medium has a small viscosity per unit entropy.Comment: 7 pages, 4 figures, STAR paper published in Phys. Lett.

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

Measurement Of Charge Multiplicity Asymmetry Correlations In High-energy Nucleus-nucleus Collisions At Snn =200 Gev

A study is reported of the same- and opposite-sign charge-dependent azimuthal correlations with respect to the event plane in Au+Au collisions at sNN=200 GeV. The charge multiplicity asymmetries between the up/down and left/right hemispheres relative to the event plane are utilized. The contributions from statistical fluctuations and detector effects were subtracted from the (co-)variance of the observed charge multiplicity asymmetries. In the mid- to most-central collisions, the same- (opposite-) sign pairs are preferentially emitted in back-to-back (aligned on the same-side) directions. The charge separation across the event plane, measured by the difference, Δ, between the like- and unlike-sign up/down-left/right correlations, is largest near the event plane. The difference is found to be proportional to the event-by-event final-state particle ellipticity (via the observed second-order harmonic v2obs), where Δ=[1.3±1.4(stat)-1.0+4.0(syst)]×10- 5+[3.2±0.2(stat)-0.3+0.4(syst)]×10-3v2obs for 20-40% Au+Au collisions. The implications for the proposed chiral magnetic effect are discussed. © 2014 American Physical Society.894NRF-2012004024; National Research FoundationArsene, I., (2005) Nucl. Phys. A, 757, p. 1. , (BRAHMS Collaboration),. NUPABL 0375-9474 10.1016/j.nuclphysa.2005.02.130Back, B.B., (2005) Nucl. Phys. A, 757, p. 28. , (PHOBOS Collaboration),. NUPABL 0375-9474 10.1016/j.nuclphysa.2005.03.084Adams, J., (2005) Nucl. Phys. A, 757, p. 102. , (STAR Collaboration),. NUPABL 0375-9474 10.1016/j.nuclphysa.2005.03.085Adcox, K., (2005) Nucl. Phys. A, 757, p. 184. , (PHENIX Collaboration),. NUPABL 0375-9474 10.1016/j.nuclphysa.2005.03.086Lee, T.D., (1973) Phys. Rev. D, 8, p. 1226. , 0556-2821 10.1103/PhysRevD.8.1226Lee, T.D., Wick, G.C., (1974) Phys. Rev. D, 9, p. 2291. , 0556-2821 10.1103/PhysRevD.9.2291Morley, P.D., Schmidt, I.A., (1985) Z. Phys. C, 26, p. 627. , ZPCFD2 0170-9739 10.1007/BF01551807Kharzeev, D., Pisarski, R.D., Tytgat, M.H.G., (1998) Phys. Rev. Lett., 81, p. 512. , PRLTAO 0031-9007 10.1103/PhysRevLett.81.512Kharzeev, D., (2006) Phys. Lett. B, 633, p. 260. , PYLBAJ 0370-2693 10.1016/j.physletb.2005.11.075Kharzeev, D., Zhitnitsky, A., (2007) Nucl. Phys. A, 797, p. 67. , NUPABL 0375-9474 10.1016/j.nuclphysa.2007.10.001Fukushima, K., Kharzeev, D.E., Warringa, H.J., (2008) Phys. Rev. D, 78, p. 074033. , PRVDAQ 1550-7998 10.1103/PhysRevD.78.074033Kharzeev, D.E., McLerran, L.D., Warringa, H.J., (2008) Nucl. Phys. A, 803, p. 227. , NUPABL 0375-9474 10.1016/j.nuclphysa.2008.02.298Voloshin, S.A., (2004) Phys. Rev. C, 70, p. 057901. , PRVCAN 0556-2813 10.1103/PhysRevC.70.057901Abelev, B.I., (2009) Phys. Rev. Lett., 103, p. 251601. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.103.251601Abelev, B.I., (2010) Phys. Rev. C, 81, p. 054908. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.81.054908Abelev, B., (2013) Phys. Rev. Lett., 110, p. 012301. , (ALICE Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.110.012301Wang, Q., (2012), http://drupal.star.bnl.gov/STAR/theses/phd/quanwang, Ph.D. thesis, Purdue University, arXiv:1205.4638Ackermann, K.H., (2003) Nucl. Instrum. Methods A, 499, p. 624. , (STAR Collaboration),. NIMAER 0168-9002 10.1016/S0168-9002(02)01960-5Bieser, F.S., (2003) Nucl. Instrum. Methods A, 499, p. 766. , (STAR Collaboration),. NIMAER 0168-9002 10.1016/S0168-9002(02)01974-5Adler, C., (2003) Nucl. Instrum. Methods A, 499, p. 433. , NIMAER 0168-9002 10.1016/j.nima.2003.08.112Adams, J., (2004) Phys. Rev. Lett., 92, p. 112301. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.92.112301Abelev, B.I., (2009) Phys. Rev. C, 79, p. 034909. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.79.034909Ackermann, K.H., (1999) Nucl. Phys. A, 661, p. 681. , (STAR Collaboration),. NUPABL 0375-9474 10.1016/S0375-9474(99)85117-3Anderson, M., (2003) Nucl. Instrum. Methods A, 499, p. 659. , NIMAER 0168-9002 10.1016/S0168-9002(02)01964-2Poskanzer, A.M., Voloshin, S.A., (1998) Phys. Rev. C, 58, p. 1671. , PRVCAN 0556-2813 10.1103/PhysRevC.58.1671Wang, G., (2005), http://drupal.star.bnl.gov/STAR/theses/ph-d/gang-wang, Ph.D. thesis, UCLAAdamczyk, L., (2012) Phys. Rev. Lett., 108, p. 202301. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.108.202301Wang, F., (2010) Phys. Rev. C, 81, p. 064902. , PRVCAN 0556-2813 10.1103/PhysRevC.81.064902Pratt, S., Schlichting, S., Gavin, S., (2011) Phys. Rev. C, 84, p. 024909. , PRVCAN 0556-2813 10.1103/PhysRevC.84.024909Adams, J., (2005) Phys. Rev. Lett., 95, p. 152301. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.95.152301Aggarwal, M.M., (2010) Phys. Rev. C, 82, p. 024912. , (STAR collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.82.024912Abelev, B.I., (2009) Phys. Rev. Lett., 102, p. 052302. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.102.052302Abelev, B.I., (2009) Phys. Rev. C, 80, p. 064912. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.80.064912Abelev, B.I., (2010) Phys. Rev. Lett., 105, p. 022301. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.105.022301Agakishiev, H., (STAR Collaboration), arXiv:1010.0690Petersen, H., Renk, T., Bass, S.A., (2011) Phys. Rev. C, 83, p. 014916. , PRVCAN 0556-2813 10.1103/PhysRevC.83.014916Adamczyk, L., (2013) Phys. Rev. C, 88, p. 064911. , (STAR Collaboration),. 10.1103/PhysRevC.88.064911Asakawa, M., Majumder, A., Müller, B., (2010) Phys. Rev. C, 81, p. 064912. , PRVCAN 0556-2813 10.1103/PhysRevC.81.064912Bzdak, A., Koch, V., Liao, J., (2010) Phys. Rev. C, 81, pp. 031901R. , PRVCAN 0556-2813 10.1103/PhysRevC.81.031901Liao, J., Koch, V., Bzdak, A., (2010) Phys. Rev. C, 82, p. 054902. , PRVCAN 0556-2813 10.1103/PhysRevC.82.054902Ma, G.-L., Zhang, B., (2011) Phys. Lett. B, 700, p. 39. , PYLBAJ 0370-2693 10.1016/j.physletb.2011.04.057Voloshin, S.A., (2010) Phys. Rev. Lett., 105, p. 172301. , PRLTAO 0031-9007 10.1103/PhysRevLett.105.17230

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. A, 797. , 6, 67. 0375-9474 NUPABL 10.1016/j.nuclphysa.2007.10.001Kharzeev, D., McLerran, L.D., Warringa, H.J., (2008) Nucl. Phys. A, 803. , 7, 227. 0375-9474 NUPABL 10.1016/j.nuclphysa.2008.02.298Fukushima, K., Kharzeev, D.E., Warringa, H.J., (2008) Phys. Rev. D, 78. , 8, 074033. 1550-7998 PRVDAQ 10.1103/PhysRevD.78.074033Abelev, B.I., (2009) Phys. Rev. Lett., 103. , 9 (STAR Collaboration), 251601. 0031-9007 PRLTAO 10.1103/PhysRevLett.103. 251601Abelev, B.I., (2010) Phys. Rev. C, 81. , 10 (STAR Collaboration), 054908. 0556-2813 PRVCAN 10.1103/PhysRevC.81. 054908Abelev, B.I., (2013) Phys. Rev. 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. Lett., 108. , 14 (STAR Collaboration), 202301. 0031-9007 PRLTAO 10.1103/PhysRevLett. 108.202301Voloshin, S.A., Parity violation in hot QCD: How to detect it (2004) Physical Review C - Nuclear Physics, 70 (5), pp. 0579011-0579012. , DOI 10.1103/PhysRevC.70.057901, 057901Poskanzer, A.M., Voloshin, S.A., Methods for analyzing anisotropic flow in relativistic nuclear collisions (1998) Physical Review C - Nuclear Physics, 58 (3), pp. 1671-1678. , DOI 10.1103/PhysRevC.58.1671Ollitrault, J.-Y., Poskanzer, A.M., Voloshin, S.A., (2009) Phys. Rev. C, 80. , 17, 014904. 0556-2813 PRVCAN 10.1103/PhysRevC.80.014904Pratt, S., Schlichting, S., Gavin, S., (2011) Phys. Rev. C, 84. , 18, 024909. 0556-2813 PRVCAN 10.1103/PhysRevC.84.024909Schlichting, S., Pratt, S., (2011) Phys. Rev. C, 83. , 19, 014913. 0556-2813 PRVCAN 10.1103/PhysRevC.83.014913Selyuzhenkov, I., Voloshin, S., (2008) Phys. Rev. C, 77. , 20, 034904. 0556-2813 PRVCAN 10.1103/PhysRevC.77.034904Kisiel, A., (2006) Comput. Phys. 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Validação do Lipe® como método para determinar a digestibilidade dos nutrientes em eqüinos Validation of Lipe® as method to evaluate the apparent digestibility of nutrients in equines

Avaliou-se a eficiência da lignina purificada e enriquecida (Lipe®) como indicador externo para estimar a digestibilidade dos nutrientes de dietas em eqüinos em comparação aos métodos de coleta total de fezes e do indicador óxido crômico. Foram utilizadas seis potras Mangalarga Marchador, com média de 2 anos de idade e 345 kg de peso vivo, alimentadas com feno de alfafa e concentrado comercial na proporção de 50:50, para ingestão de matéria seca de 3,1%PV, e sal mineral. O experimento teve duração de 29 dias, de modo que os 24 dias iniciais foram destinados à adaptação dos animais à dieta e às instalações e os cinco finais para coleta total das fezes. Utilizou-se delineamento em blocos casualizados, no qual cada animal constituiu um bloco e cada método de determinação da digestibilidade, um tratamento. Os cálculos de produção fecal e digestibilidade de cada nutriente foram feitos utilizando-se os indicadores e a taxa de recuperação fecal de cada nutriente. Os coeficientes de digestibilidade dos nutrientes obtidos utilizando-se o óxido crômico foram superiores aos da coleta total e Lipe®. Os resultados obtidos com Lipe® foram similares aos determinados por coleta total. O método do óxido crômico é inadequado, enquanto o Lipe® é eficiente para estimar a digestibilidade de nutrientes da dieta em eqüinos.<br>The objective of this work was to test the efficiency of enriched and purified lignin, Lipe®, as external indicator in order to estimate the apparent digestibility of the nutrients in equine diets, compared with the total feces collection and the chromic oxide methods. Six female Mangalarga Marchador with average of two years of age and average weight of 331 kg were used. The diet was alfalfa hay, commercial grain and mineral salt. The experimental period was of 29 days, the first 24 used for the adaptation of animals to the diet and facilities and the last five days for feed estimation and total feces collection. A random blocks design was used in which each animal constituted one block and each digestibility determination method, one treatment. The digestibility of nutrients using chromic oxide were smaller than those from the total collection and Lipe®, and those estimated by the Lipe® were similar to those from the total collection. Chromic oxide revealed to be inadequate and Lipe® was considered efficient to estimate the apparent digestibility in equine