my email address | office: CERN Bat. 22 R-003, +41-22-767-3783 | cell: +41-76-487-5562
Me in 2012
Me in Dallas, TX, Jan 2012


Welcome to my website. I am a Ph.D. student with the University of Pennsylvania studying experimental elementary particle physics with the ATLAS detector at the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) near Geneva, Switzerland. Follow the menu above to read about my interests and research.

Students and those interested in physics may find my notes on the documents page helpful. Those who work on ATLAS may find my Athena Notes TWiki helpful. Non-physicists can get a great introduction to the LHC by watching this 60 Minutes news segment, or this BBC documentary about the LHC.

Trying to discover something? My skills are for hire in 2013. I will be writing my thesis this fall.

My Work

ATLAS is one of the multi-purpose experiments built to detect the products of 7-8 TeV proton-proton collisions at the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) near Geneva, Switzerland. Penn helped design, assemble, and install the front end electronics that read out, control, and power the Transition Radiation Tracker (TRT), the outermost sub-detector of the ATLAS tracker. Experiments at the LHC hope to discover the long sought after Higgs boson (evidence of which was announced on the 4th of July 2012) and observe possible signatures of Supersymmetry, among other goals on the frontier of particle physics.

Preparing for the arrival of, and analyzing the data collected by ATLAS since it first started-up in 2009, has been the focus of my graduate research. Between taking graduate courses at Penn, I spent the summers of 2006, 2007, and 2008 at CERN, participating in the commissioning of the TRT. I helped with connectivity tests of the TRT end-caps in the above ground clean room where the TRT was assembled (SR-1), and helped install and debug some of the TRT patch panels in the ATLAS cavern at Point 1. I designed and wrote software that calibrates the analog-to-digital thresholds for the TRT by tuning the thresholds channel-by-channel to reach a uniform noise occupancy, used as part of the regularly scheduled calibration. I moved to work at CERN full-time in January 2009, and helped support the TRT during the start-up of first collisions that fall. I wrote and supported applications used for scanning and archiving detailed TRT performance metrics to a database for tracking long term detector health. I continued to support the operations of the TRT as part of the team rotating the DAQ on-call responsibility through the summer of 2012. For the TRT offline community, I developed an algorithm for calculating the straw hit efficiency by counting straws that should have hits by using track extrapolation tools.

For the last few years, I have been working on tau identification performance and learning/developing an Analysis Model in ATLAS. I developed the minimal cut-based tau identification used with the first ATLAS data in 2010. I contributed to several of the first ATLAS conference notes documenting the performance of tau reconstruction and reporting the first data-Monte Carlo comparisons. I was editor of the first ATLAS conference note documenting systematic uncertainties on the tau identification efficiency and energy scale. I developed further improvements to tau identification including pT-parametrization and contributed to the vertex-dependent pile-up corrections. I was one of the lead developers in the team that documented the first observation of Z → ττ with ATLAS, and measured its cross section with the 2010 dataset. More recently, I have been investigating the performance of high-pT taus and searching for hypothetical high-mass ditau decays, like Z' → ττ, which are predicted in many Grand Unified Theories.

Research Interests

  • Data mining and visualization
  • Hadronic tau reconstruction and identification
  • Searches for the Higgs boson
  • Statistical inference

I am involved in:

  • Tau lepton physics
    • Reconstruction and identification of hadronic tau decays
    • Pile-up robustness
    • TauD3PDMaker - the tau physics ntuple maker
    • Observation and cross section measurement of Z → ττ
    • Searching for Z' → ττ
    • Searching for the SM Higgs boson, H → ττ
    • Liason for the ATLAS Exotics Working Group to the Tau Working Group
  • Commissioning of the TRT
    • Low threshold optimization
    • Long term detector monitoring
    • Straw efficiency studies
    • DAQ on-call support

You can read papers I've written and talks I've given on the documents page.


  • Email: my email address
  • Skype: ryan.reece
  • Cell: +41-76-487-5562


Office Home Institute
Ryan Reece
Bat. 22 R-003
CH-1202 Genève 23
tel: +41-22-767-3783
fax: +41-22-767-8350
Ryan Reece
6 Rue des Hautains
Bat. A1
01630 Saint-Genis-Pouilly
tel: +33-45-682-9080
Ryan Reece
Physics Department
209 S. 33rd St.
University of Pennsylvania
Philadelphia, PA 19104
fax: +1-215-898-8512