Jet physics

Jet physics is a research project funded by the University of Helsinki for 2013-2016 and lead by Mikko Voutilainen accompanied by graduate student Juska Pekkanen and MSc student Hannu Siikonen. The project aims to take advantage of the highly precise jet energy scale at CMS to do precision QCD measurements. The first analysis looked at the ratio of inclusive jet cross sections with two jet clustering radii (R=0.5 and R=0.7) at 7 TeV to better understand the role of final state radiation and theory scale uncertainties. The results of this novel analysis were first presented at Lepton-Photon in June, and the corresponding paper is now in the final stages before being submitted to Physical Review D.

The HIP Jet physics team has taken an active role in the CMS Run 2 Exotica Dijet Resonance Search that is one of the most anticipated early analyses in 13 TeV LHC Run 2. Helsinki responsibilities include developing the analysis tools, the production of processed data files for the entire group, studying the effect of jet energy corrections to dijet mass and making various data quality cross-checks for ensuring unbiased physics results.