High-pT pion and proton yields in p+p collisions at sqrt(s)=200GeV

Identified hadrons(pions, protons, and anti-protons) in mid-rapidity at high transverse momentum (pT$\sim $=10GeV) can be used to test the validity of pQCD in p+p collisions. They also provide a baseline for the study of color charge effect of parton energy loss in heavy ion collisions. However, with current event statistics from minimum-bias triggered p+p collisions the proton+anti-proton spectra are limited to pT$<\sim $7GeV/c. We report a study of charged hadron production in events triggered by high deposit energy in electromagnetic calorimeter positioned at mid-rapidity. Preliminary results on particle ratios and their pT dependence up to pT$\sim $12GeV/c will be presented. The effect of the above trigger can lead to relative enhancement/suppression of one of the sub-process (qq, qg, gg) of jet production, these aspects will also be discussed.