heavy quark production

Another process which can constrain the gluon helicity distribution is open heavy flavor production. The cross section calculation assuming the dominance of reproduces the TEVATRON data [10] well ( with a K-factor of 2 ). Then the asymmetry for the open heavy flavor production can be formulated as

where the partonic asymmetry is calculated as a function of partonic center-of-mass energy [11].

Open heavy flavor production could be identified with PHENIX detector system by the detection of leptons with relatively higher transverse momenta from semi-leptonic decays of heavy mesons. Studies are underway to reduce the backgrounds with e.g. coincident detection of electrons in Central Arm.

Numerical calculations with PYTHIA suggest that this process identified with the muon with GeV/c will be sensitive to the product of at and at . This process will provide an optional check of existing models on , although further studies of background rejection are necessary.

The production of heavy quarkonium has been regarded as a good probe of the gluon helicity distribution [12,13,14,15]. The production mechanism should be studied more carefully to get a access to the helicity distributions [16].