My current interest in QCD is related to energy loss of a colored parton in a colored medium. This has a close connection with the problem of energy loss of charged particles through matter (charged medium), one of the first non-trivial fundamental problems studied in QED. The non-Albelian nature of QCD results in slightly different behavior of the emitted gluon spectrum, path length dependence, etc. Results from RHIC have unambiguously shown that jet quenching occurs, which should be indicative of QCD energy loss. However, none of the models of energy loss can be reconciled with all of the data.
In my thesis, advised by Craig Ogilvie at Iowa State University, I performed the first systematic study of jet properties in p+p, d+Au, and Au+Au collisions. These data showed that d+Au jet properties are similar to p+p jet properties - important to establish that any modification in Au+Au is due entirely to those collisions and not a nuclear modification which exists in d+Au collisions. Jet properties from Au+Au collisions, however, show a marked difference between those in the simpler systems: their yield is suppressed and the correlation shape is strongly distorted. Both of these qualitative results are in agreement with expectation from QCD energy loss models.
One drawback from understanding energy loss from RHIC data is that full jet reconstruction is only now being seriously considered. All results to this point have been from multi-particle correlations which seem to have a serious bias against energy loss. Therefore, one aspect of my research focuses on reconstructing full jets with the ATLAS detector at the LHC. Currently, I maintain the software that I had a large part in designing to reconstruct jets in heavy ion collisions in ATLAS. You can see the code in the ATLAS code repository here. I have also continued to study jet modification with PHENIX data by pushing further on the analysis from my thesis and to extend the measurements to forward rapidity to measure effects from the jet energy loss.
While waiting for data from the LHC, I am currently pursuing an analysis on full jet reconstruction in PHENIX in d+Au collisions. In this analysis I would like to extend the work in my thesis which used two-particle correlations to infer the jet properties. At a recent Division of Nuclear Physics Meeting, I presented the first results from this analysis on di-jet azimuthal correlations.
I also have a general interest in QCD. I am currently working with a graduate student on her thesis work in measuring electron-muon correlations in p+p collisions in PHENIX - work which will elucidate heavy quark (charm and bottom) production mechanisms. I have worked with another graduate student in her measurement of fragmentation photons in p+p in PHENIX. I am also studying jet fragmentation in p+p by using several identified particle correlations: h-π0, h-η, and h-ω.
For a list of publications see my publication list page.