Forward and midrapidity like-particle ratios from p+p collisions at $\sqrt{s}$ = 200 GeV

I.G. Bearden , D. Beavis , C. Besliu , B. Budick , H. Boggild , C. Chasman , C.H. Christensen , P. Chrisitansen , J. Cibor , R. Debbe , E. Enger , J.J. Gaardhoje , M. Germinario , K. Hagel , A. Holm , A.K. Holme , H. Ito , E. Jacobsen , A. Jipa , F. Jundt (1) , J.I. Jordre , C.E. Jorgensen , R. Karabowicz , T. Keutgen , E.J. Kim , T. Kozik , T.M. Larsen , J.H. Lee , Y.K. Lee , G. Lovhoiden , Z. Majka , A. Makeev , M. Mikelsen , M.J. Murray , J. Natowitz , B.S. Nielsen , J. Norris , K. Olchanski , D. Ouerdane , R. Planeta , F. Rami (1) , C. Ristea , D. Röhrich , B.H. Samset , D. Sandberg , S.J. Sanders , R.A. Scheetz , P. Staszel , T.S. Tveter , F. Videbaek , R. Wada , A. Wieloch , Z. Yin , I.S. Zgura , Brahms Collaboration

1 IReS - Institut de Recherches Subatomiques

We present a measurement of pi-\pi+, K-/K+ and pbar/p from p+p collisions at sqrt(s) = 20 0GeV over the rapidity range 0 2.0. The pbar/p ratio is very similar for p+p and 20% central Au+Au collisions at all rapidities. In the fragmentation region the three ratios seem to be independent of beam energy when viewed from the rest frame of one of the protons. Theoretical models based on quark-diquark breaking mechanisms overestimate the pbar/p ratio up to y ~< 3. Including additional mechanisms for baryon number transport such as baryon junctions leads to a better description of the data.

Mots clés: proton collisions; particle ratios; forward rapidity; limiting fragmentation; baryon junctions

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

I.G. Bearden, D. Beavis, C. Besliu, B. Budick, H. Boggild, et al.. Forward and midrapidity like-particle ratios from p+p collisions at $\sqrt{s}$ = 200 GeV. Physics Letters B, 2005, 607, pp.42-50. ⟨10.1016/j.physletb.2004.12.064⟩. ⟨in2p3-00023339⟩