Production of Mesons and Baryons at High Rapidity and High pT in Proton-Proton Collisions at $\sqrt(s)$=200 GeV

• Published in: Physical review letters 2007, Vol.98
• Main Authors: Arsene, I., Bearden, I.G., Beavis, D., Bekele, S., Besliu, C., Budick, B., Boggild, H., Chasman, C., Christensen, C.H., Dalsgaard, H.H., Debbe, R., Gaardhoje, J.J., Hagel, K., Ito, H., Jipa, A., Johnson, E.B., Jorgensen, C.E., Karabowicz, R., Katrynska, N., Kim, E.J., Larsen, T.M., Lee, J.H., Lindal, S., Lovhoiden, G., Majka, Z., Murray, M., Natowitz, J., Nielsen, B.S., Nygaard, C., Planeta, R., Rami, F., Renault, F., Ristea, C., Ristea, O., Rohrich, D., Samset, B.H., Sanders, S.J., Scheetz, R.A., Staszel, P., Tveter, T.S., Videbaek, F., Wada, R., Yin, Z., Yang, H., Zgura, I.S.
• Format: Article
• Language: English
• Subjects: High Energy Physics - Experiment; Physics
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.98.252001

We present particle spectra for charged hadrons pi(+/-), K-+/-, p, and (p) over bar from pp collisions at root s=200 GeV measured for the first time at forward rapidities (2.95 and 3.3). The kinematics of these measurements are skewed in a way that probes the small momentum fraction in one of the protons and large fractions in the other. Large proton to pion ratios are observed at values of transverse momentum that extend up to 4 GeV/c, where protons have momenta up to 35 GeV. Next-to-leading order perturbative QCD calculations describe the production of pions and kaons well at these rapidities, but fail to account for the large proton yields and small (p) over bar /p ratios