Speaker
Yue Shi Lai
(Columbia University-Unknown-Unknown)
Description
The Relativistic Heavy Ion Collider uses the collision of heavy nuclei to create a strongly interacting, partonic medium, while the collision of $p + p$ provides a baseline measurement to determine the medium modification effect. Direct jet reconstruction applied to these collision systems offers a crucial constraint on the mechanism for in-medium parton energy loss and jet-medium interactions. However, traditional jet reconstruction algorithms operating in the large soft background at RHIC give rise to fake jets well above the intrinsic production rate of high-$p_T$ partons, impeding the detection of the low cross section jet signal at RHIC energies. We developed a new jet reconstruction algorithm that uses a Gaussian filter to locate and reconstruct the jet energy. This algorithm is combined with a fake jet rejection scheme that provides efficient jet reconstruction with acceptable fake rate in a background environment up to the central $\mathrm{Au} + \mathrm{Au}$ collision at $\sqrt{s_{NN}} = 200\,\mathrm{GeV}$~[1]. We present results of its application in $p + p$ and $\mathrm{Cu} + \mathrm{Cu}$ collisions using data from the PHENIX detector, including jet spectra, jet--jet angular correlation, and the nuclear modification factor. We discuss the comparison and implication for models, and further outline our future program for jet physics using the PHENIX detector.
[1] Y.-S.~Lai and B.A.~Cole, arXiv:0806.1499 (2008).
Author
Yue Shi Lai
(Columbia University-Unknown-Unknown)
