Production of π0 and η mesons at large transverse momenta in pp and pBe interactions at 530 and 800GeV/c

Phys. Rev. D 01/2003; 68(5). DOI: 10.1103/PhysRevD.68.052001

ABSTRACT We present measurements of the production of high transverse momentum π0 and η mesons in pp and pBe interactions at 530 and 800GeV/c. The data span the kinematic ranges: 1<pT<10GeV/c in transverse momentum and 1.5 units in rapidity. The inclusive π0 cross sections are compared with next-to-leading order QCD calculations and to expectations based on a phenomenological parton-kT model.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The cross section data for $\pi^0$ inclusive production in $pp$ collisions is considered in a rather broad kinematic region in energy $\sqrt{s}$, Feynman variable $x_F$ and transverse momentum $p_T$. The analysis of these data is done in the perturbative QCD framework at the next-to-leading order. We find that they cannot be correctly described in the entire kinematic domain and this leads us to conclude that the single-spin asymmetry, $A_N$ for this process, observed several years ago at FNAL by the experiment E704 and the recent result obtained at BNL-RHIC by STAR, are two different phenomena. This suggests that STAR data probes a genuine leading-twist QCD single-spin asymmetry for the first time and finds a large effect.


Available from