- Physical Review Journals
All JournalsPhysics Magazine
Access Provided by Xinjiang University

Physical Review D

Export citation

Export citation

Choose format for download:

Download Citation
  • Access by Xinjiang University

Gluon saturation and energy dependence of hadron multiplicity in pp and AA collisions at the LHC

Eugene Levin1,2 and Amir H. Rezaeian1

  • 1Departamento de Física, Universidad Técnica Federico Santa María, Avda. España 1680, Casilla 110-V, Valparaiso, Chile
  • 2Department of Particle Physics, Tel Aviv University, Tel Aviv 69978, Israel

PDF

Phys. Rev. D 83, 114001 – Published 1 June, 2011

DOI: https://doi.org/10.1103/PhysRevD.83.114001

Abstract

The recent results in s=2.76  TeV Pb+Pb collisions at the Large Hadron Collider (LHC) reported by the ALICE collaboration shows that the power-law energy-dependence of charged hadron multiplicity in Pb+Pb collisions is significantly different from p+p collisions. We show that this different energy-dependence can be explained by inclusion of a strong angular-ordering in the gluon-decay cascade within the color glass condensate (or gluon saturation) approach. This effect is more important in nucleus-nucleus collisions where the saturation scale is larger than 1 GeV. Our prescription gives a good description of the LHC data both in p+p and Pb+Pb collisions.

View figure in article

Article Text

References (64)

  1. V. Khachatryan et al. (CMS Collaboration), Phys. Rev. Lett. 105, 022002 (2010); J. High Energy Phys. 02 (2010) 041; 01 (2011) 079.
  2. G. Aad et al. (ATLAS Collaboration), Phys. Lett. B 688, 21 (2010).
  3. K. Aamodt et al. (ALICE Collaboration), Eur. Phys. J. C 65, 111 (2009); arXiv:1004.3034; Eur. Phys. J. C 68, 89 (2010).
  4. K. Aamodt et al. (ALICE Collaboration), Phys. Rev. Lett. 105, 252301 (2010).
  5. K. Aamodt et al. (ALICE Collaboration), Phys. Rev. Lett. 106, 032301 (2011).
  6. L. V. Gribov, E. M. Levin, and M. G. Ryskin, Phys. Rep. 100, 1 (1983); A. H. Mueller and J. Qiu, Nucl. Phys. B268, 427 (1986); M. A. Braun, Phys. Lett. B 632, 297 (2006); Eur. Phys. J. C 48, 511 (2006); arXiv:hep-ph/0504002.
  7. L. McLerran and R. Venugopalan, Phys. Rev. D 49, 2233 (1994); 49, 3352 (1994); 50, 2225 (1994); 53, 458 (1996); 59, 094002 (1999).
  8. J. Jalilian-Marian, A. Kovner, A. Leonidov, and H. Weigert, Phys. Rev. D 59, 014014 (1998); Nucl. Phys. B 504, 415 (1997); J. Jalilian-Marian, A. Kovner, and H. Weigert, Phys. Rev. D 59, 014015 (1998); A. Kovner, J. G. Milhano, and H. Weigert, 62, 114005 (2000); E. Iancu, A. Leonidov, and L. D. McLerran, Phys. Lett. B 510, 133 (2001); Nucl. Phys. A 692, 583 (2001); E. Ferreiro, E. Iancu, A. Leonidov, and L. McLerran, Nucl. Phys. A703, 489 (2002); H. Weigert, A703, 823 (2002).
  9. For a recent review see: R. Venugopalan, Proc. Sci.ICHEP2010 (2010) 567 [arXiv:1012.4699]; L. McLerran, Acta Phys. Pol. B 41, 2799 (2010); F. Gelis, E. Iancu, J. Jalilian-Marian, and R. Venugopalan, arXiv:1002.0333.
  10. I. Balitsky, Nucl. Phys. B463, 99 (1996); Phys. Rev. D 60, 014020 (1999); Y. V. Kovchegov, 60, 034008 (1999).
  11. E. Levin and A. H. Rezaeian, Phys. Rev. D 82, 014022 (2010); see also arXiv:1011.3591.
  12. L. McLerran and M. Praszalowicz, Acta Phys. Pol. B 41, 1917 (2010); P. Tribedy and R. Venugopalan, Nucl. Phys. A850, 136 (2011).
  13. D. Kharzeev, E. Levin, and M. Nardi, Nucl. Phys. A747, 609 (2005).
  14. N. Armesto, C. A. Salgado, and U. A. Wiedemann, Phys. Rev. Lett. 94, 022002 (2005).
  15. E. Levin and A. H. Rezaeian, Phys. Rev. D 82, 054003 (2010).
  16. J. L. Albacete and A. Dumitru, arXiv:1011.5161.
  17. Y. V. Kovchegov and K. Tuchin, Phys. Rev. D 65, 074026 (2002).
  18. Yu. V. Kovchegov and A. H. Mueller, Nucl. Phys. B529, 451 (1998); M. A. Braun, Phys. Lett. B 483, 105 (2000); A. Dumitru and L. McLerran, Nucl. Phys. A700, 492 (2002); J. P. Blaizot, F. Gelis, and R. Venugopalan, A743, 13 (2004); R. Baier, A. Kovner, M. Nardi, and U. A. Wiedemann, Phys. Rev. D 72, 094013 (2005).
  19. A. Kovner and U. A. Wiedemann, Phys. Lett. B 551, 311 (2003); Phys. Rev. D 66, 034031 (2002); 66, 051502 (2002).
  20. K. J. Golec-Biernat and A. M. Stasto, Nucl. Phys. B668, 345 (2003).
  21. A. Kormilitzin and E. Levin, Nucl. Phys. A849, 98 (2011).
  22. J. Berger and A. Stasto, Phys. Rev. D 83, 034015 (2011).
  23. J. L. Albacete, N. Armesto, J. G. Milhano, P. Quiroga Arias, and C. A. Salgado, arXiv:1012.4408.
  24. A. Krasnitz, Y. Nara, and R. Venugopalan, Nucl. Phys. A727, 427 (2003); Nucl. Phys. A717, 268 (2003); Phys. Rev. Lett. 87, 192302 (2001).
  25. J. P. Blaizot, T. Lappi, and Y. Mehtar-Tani, Nucl. Phys. A846, 63 (2010).
  26. E. Levin, Phys. Rev. D 82, 101704 (2010).
  27. D. Kharzeev, E. Levin, and M. Nardi, Nucl. Phys. A730, 448 (2004); Nucl. Phys. A743, 329(E) (2004); Phys. Rev. C 71, 054903 (2005); D. Kharzeev and E. Levin, Phys. Lett. B 523, 79 (2001); D. Kharzeev and M. Nardi, 507, 121 (2001); D. Kharzeev, E. Levin, and L. McLerran, Nucl. Phys. A748, 627 (2005); Phys. Lett. B 561, 93 (2003).
  28. For example: I. Arsene et al. (BRAHMS collaboration), Nucl. Phys. A757, 1 (2005); B. B. Back et al. (PHOBOS collaboration), A757, 28 (2005); J. Adams et al. (STAR collaboration), A757, 102 (2005).
  29. UA1 collaboration, Nucl. Phys. B335, 261 (1990); UA5 collaboration, Z. Phys. C 33, 1 (1986); CDF collaboration, Phys. Rev. D 41, 2330 (1990); CDF collaboration, Phys. Rev. Lett. 61, 1819 (1988).
  30. M. C. Abreu et al. (NA50 Collaboration), Phys. Lett. B 530, 43 (2002).
  31. B. B. Back et al. (PHOBOS collaboration), Phys. Rev. Lett. 91, 052303 (2003); C. Adler et al. (STAR collaboration), 87, 112303 (2001).
  32. I. G. Bearden et al. (BRAHMS collaboration), Phys. Lett. B 523, 227 (2001); Phys. Rev. Lett. 88, 202301 (2002).
  33. C. Adler et al. (STAR collaboration), Phys. Rev. Lett. 87, 112303 (2001).
  34. K. Adcox et al. (PHENIX collaboration), Phys. Rev. Lett. 86, 3500 (2001); Phys. Rev. C 71, 034908 (2005); 71, 049901(E) (2005).
  35. S. Eidelman et al. (Particle Data Group Collaboration), Phys. Lett. B 592, 1 (2004).
  36. G. Abbiendi et al. (OPAL collaboration), Phys. Rev. D 69, 032002 (2004).
  37. G. Abbiendi et al. (OPAL collaboration), Eur. Phys. J. C 23, 597 (2002).
  38. Y. L. Dokshitzer, V. A. Khoze, and S. I. Troian, J. Phys. G 17, 1585 (1991); V. A. Khoze, W. Ochs, and J. Wosiek, arXiv:hep-ph/0009298; V. A. Khoze and W. Ochs, Int. J. Mod. Phys. A 12, 2949 (1997) and reference therein.
  39. J. Jalilian-Marian and Y. V. Kovchegov, Phys. Rev. D 70, 114017 (2004); 71, 079901(E) (2005).
  40. C. Marquet, Nucl. Phys. B705, 319 (2005).
  41. A. Kovner and M. Lublinsky, J. High Energy Phys. 11 (2006) 083.
  42. E. Levin and A. Prygarin, Phys. Rev. C 78, 065202 (2008).
  43. A. E. Chudakov, Izv. Akad. Nauk SSSR, Ser. Fiz. 19, 650 (1955).
  44. A. Bassetto, M. Ciafaloni, and G. Marchesini, Phys. Rep. 100, 201 (1983); Yu. L. Dokshitzer, V. A. Khoze, A. H. Mueller, and S. I. Troyan, Basics of Perturbative QCD (Editions Frontieres, Gif-sur-Yvette, 1991).
  45. A. Capella et al., Phys. Rev. D 61, 074009 (2000); P. Eden and G. Gustafson, J. High Energy Phys. 09 (1998) 015; P. Eden, G. Gustafson, and V. A. Khoze, Eur. Phys. J. C 11, 345 (1999).
  46. I. M. Dremin and J. W. Gary, Phys. Lett. B 459, 341 (1999).
  47. W. Ochs, Acta Phys. Pol. B 41, 2839 (2010); W. Ochs and R. P. Ramos, Phys. Rev. D 78, 034010 (2008); S. Lupia and W. Ochs, Phys. Lett. B 418, 214 (1998).
  48. J. Bartels and E. Levin, Nucl. Phys. B387, 617 (1992); K. Golec-Biernat and M. Wusthoff, Phys. Rev. D 59, 014017 (1998); 60, 114023 (1999); J. Bartels, K. Golec-Biernat, and H. Kowalski, 66, 014001 (2002).
  49. A. H. Mueller and D. N. Triantafyllopoulos, Nucl. Phys. B640, 331 (2002); D. N. Triantafyllopoulos, B648, 293 (2003).
  50. S. Munier and R. B. Peschanski, Phys. Rev. D 70, 077503 (2004); 69, 034008 (2004); Phys. Rev. Lett. 91, 232001 (2003).
  51. E. Iancu, K. Itakura, and S. Munier, Phys. Lett. B 590, 199 (2004).
  52. G. Watt and H. Kowalski, Phys. Rev. D 78, 014016 (2008).
  53. E. Levin and K. Tuchin, Nucl. Phys. B573, 833 (2000).
  54. H. Kowalski, L. Motyka, and G. Watt, Phys. Rev. D 74, 074016 (2006).
  55. B. Z. Kopeliovich, E. Levin, A. H. Rezaeian, and I. Schmidt, Phys. Lett. B 675, 190 (2009).
  56. A. H. Mueller, Nucl. Phys. A724, 223 (2003); Nucl. Phys. B 558, 285 (1999); E. M. Levin and M. G. Ryskin, Nucl. Phys. B304, 805 (1988); Sov. J. Nucl. Phys. 41, 472 (1985).
  57. C. W. De Jagier, H. De Vries, and C. De Vries, At. Data Nucl. Data Tables 14, 479 (1974).
  58. For example see: D. Kharzeev, C. Lourenco, M. Nardi, and H. Satz, Z. Phys. C 74, 307 (1997); U. A. Wiedemann, in Heavy-ion collisions: Selected topics, Trest, 2007 p. 277.
  59. E. Gotsman, E. Levin, U. Maor, and J. S. Miller, Eur. Phys. J. C 57, 689 (2008).
  60. A. H. Rezaeian and A. Schaefer, Phys. Rev. D 81, 114032 (2010).
  61. B. B. Back et al. (PHOBOS collaboration), Phys. Rev. C 65, 061901(R) (2002).
  62. T. Lappi, arXiv:1104.3725.
  63. B. I. Abelev et al. (STAR collaboration), Phys. Rev. C 79, 034909 (2009).
  64. D. H. Rischke, D. T. Son, and M. A. Stephanov, Phys. Rev. Lett. 87, 062001 (2001).

Outline

Information

Phys. Rev. D 83, 114001– Published 1 June, 2011
  • Received 15 February 2011

© 2011 American Physical Society

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation