Analysis of the first RHIC results in the String Fusion Model.pdfVIP

October 2001 UCOFIS 3/01 US-FT/5-01 LPT Orsay 01-39 Analysis of the first RHIC results in the String Fusion Model 2 N. Armestoa,† , C. Pajaresb,‡ and D. Sousac,§ 0 0 a 2 Departamento de F´ısica, M´odulo C2, Planta baja, Campus de Rabanales, n Universidad de C´ordoba, E-14071 C´ordoba, Spain a J b Departamento de F´ısica de Part´ıculas, Universidade de Santiago de Compostela, 8 E-15706 Santiago de Compostela, Spain 2 v c Laboratoire de Physique Th´eorique, Universit´e de Paris XI, 9 6 Baˆtiment 210, F-91405 Orsay Cedex, France 2 4 0 † E-mail: fa1arpen@uco.es ‡ E-mail: pajares@fpaxp1.usc.es 1 0 § E-mail: Dolores.Sousa@th.u-psud.fr / h p - p e h : v i X r a Abstract First results from RHIC on charged multiplicities, evolution of multiplicities with central- ity, particle ratios and transverse momentum distributions in central and minimum bias col- lisions, are analyzed in a string model which includes hard collisions, collectivity in the initial state considered as string fusion, and rescattering of the produced secondaries. Multiplici- ties and their evolution with centrality are successfully reproduced. Transverse momentum distributions in the model show a larger pT -tail than experimental data, disagreement wh