Speaker
Description
Heavy quark measurements in hadronic collisions are useful tests of perturbative Quantum Chromodynamics (pQCD) calculations given their large mass ($m_{c,b}\gg\Lambda_{\mathrm{QCD}}$). These measurements can also probe the gluon distribution in protons at a relatively large $Q^2$. At RHIC energies, $b$-quark production is dominated by the leading order gluon-gluon fusion in contrast of the production mechanism at Tevatron and LHC which are dominated by next-to-leading order processes. Different kinematic region of the nucleon parton distribution function is also accessed by RHIC measurements.
PHENIX has measured the production of $B$-mesons through the $B \rightarrow J/\psi \rightarrow \mu^{+}\mu^{-}$ decays in $1.2 < |y| < 2.2$ rapidity at 200 and 510 GeV $p+p$ collisions, by the analysis of displaced vertex of muons with the Forward Silicon Vertex Detector (FVTX). These measurements can access $B$-mesons with $p_{\mathrm{T}} > 0$ allowing a direct measurement of $b\bar{b}$ total cross section. The PHENIX $p + p$ measurements will be presented in comparison to Tevatron and LHC results, providing a understanding of the energy dependent $B$ hadron production and the transition between LO to NLO dominant $b$-quark production.
