Virtual annihilation contribution to orthopositronium decay rate

Order alpha^2 contribution to the orthopositronium decay rate due to one-photon virtual annihilation is found to be delta Gamma = (alpha/pi)^2 (pi^2 ln(alpha) - 0.8622(9))Gamma_LO.Comment: 2 pages, no figure

Looking for magnetic monopoles at LHC with diphoton events

Magnetic monopoles have been a subject of interest since Dirac established the relation between the existence of monopoles and charge quantization. The intense experimental search carried thus far has not met with success. The Large Hadron Collider is reaching energies never achieved before allowing the search for exotic particles in the TeV mass range. In a continuing effort to discover these rare particles we propose here other ways to detect them. We study the observability of monopoles and monopolium, a monopole-antimonopole bound state, at the Large Hadron Collider in the $\gamma \gamma$ channel for monopole masses in the range 500-1000 GeV. We conclude that LHC is an ideal machine to discover monopoles with masses below 1 TeV at present running energies and with 5 fb$^{-1}$ of integrated luminosity.Comment: This manuscript contains information appeared in Looking for magnetic monopoles at LHC, arXiv:1104.0218 [hep-ph] and Monopolium detection at the LHC.,arXiv:1107.3684 [hep-ph] by the same authors, rewritten for joint publication in The European Physica Journal Plus. 26 pages, 22 figure

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

Beam-energy Dependence Of Charge Balance Functions From Au + Au Collisions At Energies Available At The Bnl Relativistic Heavy Ion Collider

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Balance functions have been measured in terms of relative pseudorapidity (Δη) for charged particle pairs at the BNL Relativistic Heavy Ion Collider from Au + Au collisions at sNN=7.7GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the CERN Large Hadron Collider from Pb + Pb collisions at sNN=2.76TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark gluon plasma (QGP). The narrowing of the balance function in central collisions at sNN=7.7 GeV implies that a QGP is still being created at this relatively low energy. © 2016 American Physical Society.942CNPq, Conselho Nacional de Desenvolvimento Científico e TecnológicoMinistry of Education and Science of the Russian FederationMOE, Ministry of Education of the People's Republic of ChinaMOST, Ministry of Science and Technology of the People's Republic of ChinaNRF-2012004024, National Research FoundationNSF, National Stroke FoundationConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

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

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. Commun., 174. , 21, 669. 0010-4655 CPHCBZ 10.1016/j.cpc.2005.11.010Bzdak, A., Koch, V., Liao, J., (2011) Phys. Rev. C, 83. , 22, 014905. 0556-2813 PRVCAN 10.1103/PhysRevC.83.014905Adams, J., Aggarwal, M.M., Ahammed, Z., Amonett, J., Anderson, B.D., Arkhipkin, D., Averichev, G.S., Grebenyuk, O., Azimuthal anisotropy in Au+Au collisions at sNN=200GeV (2005) Physical Review C - Nuclear Physics, 72 (1), pp. 1-23. , http://oai.aps.org/oai/?verb=ListRecords&metadataPrefix= oai_apsmeta_2&set=journal:PRC:72, DOI 10.1103/PhysRevC.72.014904, 014904Ray, R.L., Longacre, R.S., 24, arXiv:nucl-ex/0008009 and private communicationKopylov, G.I., Podgoretsky, M.I., Kopylov, G.I., Podgoretsky, M.I., (1972) Sov. J. Nucl. Phys., 15. , 25a, 219 ()25b, Phys. Lett. B. 50, 472 (1974) 0370-2693 PYLBAJ 10.1016/0370-2693(74)90263-925c, Sov. J. Part. Nucl. 20, 266 (1989)Goldhaber, G., Goldhaber, S., Lee, W., Pais, A., (1960) Phys. Rev., 120. , 26, 325. 0031-899X PHRVAO 10.1103/PhysRev.120.32

Search for gravitational-wave transients associated with magnetar bursts in advanced LIGO and advanced Virgo data from the third observing run

Gravitational waves are expected to be produced from neutron star oscillations associated with magnetar giant f lares and short bursts. We present the results of a search for short-duration (milliseconds to seconds) and longduration (∼100 s) transient gravitational waves from 13 magnetar short bursts observed during Advanced LIGO, Advanced Virgo, and KAGRA’s third observation run. These 13 bursts come from two magnetars, SGR1935 +2154 and SwiftJ1818.0−1607. We also include three other electromagnetic burst events detected by FermiGBM which were identified as likely coming from one or more magnetars, but they have no association with a known magnetar. No magnetar giant flares were detected during the analysis period. We find no evidence of gravitational waves associated with any of these 16 bursts. We place upper limits on the rms of the integrated incident gravitational-wave strain that reach 3.6 × 10−²³ Hz at 100 Hz for the short-duration search and 1.1 ×10−²² Hz at 450 Hz for the long-duration search. For a ringdown signal at 1590 Hz targeted by the short-duration search the limit is set to 2.3 × 10−²² Hz. Using the estimated distance to each magnetar, we derive upper limits upper limits on the emitted gravitational-wave energy of 1.5 × 1044 erg (1.0 × 1044 erg) for SGR 1935+2154 and 9.4 × 10^43 erg (1.3 × 1044 erg) for Swift J1818.0−1607, for the short-duration (long-duration) search. Assuming isotropic emission of electromagnetic radiation of the burst fluences, we constrain the ratio of gravitational-wave energy to electromagnetic energy for bursts from SGR 1935+2154 with the available fluence information. The lowest of these ratios is 4.5 × 103