Speaker
Kwangbok Lee
(Losalamos National Laboratory)
Description
$\Upsilon(1S+2S+3S)$ are measured in $d$ + Au and $p$ + $p$ collisions
at $\sqrt{s_{NN}} $= 200 GeV by the PHENIX experiment in the di-muon decay channel
at 1.2 < |y| < 2.2. Compared to the $J/\psi$, the $Upsilon$'s heavier mass makes it possible to
study the nuclear effects on the gluon distribution in different kinematic regions than those
probed by the $J/\psi$. The measured results are compared to a nuclear shadowing model, EPS09
combined with a final state absorption cross section, $\sigma_{br}$, and contrasted with the PHENIX
$J/psi$ results. We also will compare to lower energy $p$ + A results. Conclusive findings on
$\sigma_{br}$ are difficult to obtain due to the large experimental uncertainties. However the
degree of suppression is found to agree within uncertainties with the lower energy measurement
as well as the $J/\psi$. In this poster, the details of the analysis procedure will be shown.
Primary author
Kwangbok Lee
(Losalamos National Laboratory)
