Transverse momentum distributions and yields for $\pi^{\pm}$, $K^{\pm}$, $p$ and $\bar{p}$ in $p+p$ collisions at $\sqrt{s}$=200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC). These data provide important baseline spectra for comparisons with identified particle spectra in heavy ion collisions at RHIC. We present the inverse slope parameter $T_{\rm inv}$, mean transverse momentum $
Invariant cross sections for inclusive PI+ and PI- production in P P collisions at a centre-of-mass energy of 200 GeV. There is an additional normalization uncertainty of 9.7 PCT.
Invariant cross sections for inclusive K+ and K- production in P P collisions at a centre-of-mass energy of 200 GeV. There is an additional normalization uncertainty of 9.7 PCT.
Invariant cross sections for inclusive P and PBAR production in P P collisions at a centre-of-mass energy of 200 GeV with feed-down weak decay corrections NOT applied. There is an additional normalization uncertainty of 9.7 PCT.
The momentum distribution of electrons from decays of heavy flavor (charm and beauty) for midrapidity |y| < 0.35 in p+p collisions at sqrt(s) = 200 GeV has been measured by the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) over the transverse momentum range 0.3 < p_T < 9 GeV/c. Two independent methods have been used to determine the heavy flavor yields, and the results are in good agreement with each other. A fixed-order-plus-next-to-leading-log pQCD calculation agrees with the data within the theoretical and experimental uncertainties, with the data/theory ratio of 1.72 +/- 0.02^stat +/- 0.19^sys for 0.3 < p_T < 9 GeV/c. The total charm production cross section at this energy has also been deduced to be sigma_(c c^bar) = 567 +/- 57^stat +/- 224^sys micro barns.
Heavy-flavor decay electrons invariant differential cross-section An additional 10% normalization uncertainty is to add.
Differential charm cross section To obtain this value, the differential "charm-decay" electrons cross-section, integrated over PT>0.4 GeV/c, has been extrapolated down to PT=0 using the spectrum shape predicted by a fixed-order-plus-next-to-leading-log (FONLL)calculation. The contribution from beauty and beauty cascades, estimated to be 0.1 microbarn, has been substracted, and the c->e branching ratio used was 9.5 +- 1.0%.
Total charm cross section To obtain the total charm cross section, the differential charm cross section has been extrapolated to the whole rapidity range, using a HVQMNR rapidity distribution with aCTEQ5M PDF.
The invariant differential cross section for inclusive neutral pion production in p+p collisions at sqrt(s_NN) = 200 GeV has been measured at mid-rapidity |eta| < 0.35 over the range 1 < p_T <~ 14 GeV/c by the PHENIX experiment at RHIC. Predictions of next-to-leading order perturbative QCD calculations are consistent with these measurements. The precision of our result is sufficient to differentiate between prevailing gluon-to-pion fragmentation functions.
The invariant differential cross section as a function of PT. The mean PT here is defined as the PT for which the cross section equals its average over thebin.
Backward emitted protons with momentump>0.3 GeV/c in interactions of neutrino in the energy range 10–200 GeV with photoemulsion nuclei were investigated. Energy spectrum slope parameter of backward protons was measured to beT0=48.9±7.9 MeV. TheA-dependence power index of relative mean yield of backward protons was found to bea=0.68±0.12. A drop in the mean yield of backward protons at the four momentum squared over ∼15 (GeV/c)2 (the neutrino energy over ∼50 GeV) was observed.
NUCLEUS IS AVERAGE NUCLEI OF NUCLEAR EMULSION, <A> ABOUT 80.
NUCLEUS IS AVERAGE NUCLEI OF NUCLEAR EMULSION, <A> ABOUT 80.
NUCLEUS IS AVERAGE NUCLEI OF NUCLEAR EMULSION, <A> ABOUT 80.