James Pilcher

James E. Pilcher

Ph.D., Princeton, 1968.
Professor Emeritus, Dept. of Physics, Enrico Fermi Institute, and the College.
Research: Experimental physics, particle physics.

My research involves studying nature at the shortest possible distances and highest energy densities. Our research group has been part of the ATLAS experiment at the CERN Large Hadron Collider for many years, first to build the detector and now to exploit it for physics. We are currently studying proton-proton collisions at a center of mass energy of 7 TeV and will move to 14 TeV in a few years. We are searching for the source of electroweak symmetry breaking, and an understanding of why the Higgs boson is as light as indicated by the precision electroweak data. This facility also has the potential to produce forms of matter never before observed. These include supersymmetric states, dark matter, heavy gauge bosons, and mini black holes. Some of these experimental signatures could also be associated with extra dimensions.

Our research group built much of the readout electronics for the hadron calorimeter of the ATLAS detector. This device measures the direction and energy of final state quarks and gluons and plays an essential role in the search for final states with apparent missing energy. We are currently involved in many of the early physics measurements of final states with multiple quarks and gluons. These are important final states in the search for supersymmetry.

My earlier work involved high precision studies of the electroweak interaction using the OPAL experiment at the LEP e+e- collider. We measured the mass of the W boson to a precision of 0.06% to put new constraints on the electroweak theory and its prediction of the Higgs boson mass. We also made precise measurements of the Z boson total width and its decay rates to quarks and leptons. These results provided important additional tests of the theory.

Selected Publications:

  • Measurement of the production cross section for W-bosons in association with jets in pp collisions at √s = 7 TeV with the ATLAS detector, The ATLAS Collaboration, submitted to Physics Letters B, http://arxiv.org/abs/1012.5382v1.
  • Measurement of the W → _ν and Z/γ* → __ production cross sections in proton-proton collisions at √s = 7 TeV with the ATLAS detector, The ATLAS Collaboration, JHEP 12, 60 (2010).
  • Search for Quark Contact Interactions in Dijet Angular Distributions in 7 TeV Proton-Proton Collisions with the ATLAS Detector at the LHC, The ATLAS Collaboration, Phys. Lett. B 694, 327 (2011).
  • Search for New Particles in Two-Jet Final States in 7 TeV Proton-Proton Collisions with the ATLAS Detector at the LHC, The ATLAS Collaboration, Phys. Rev. Lett. 105, 161801 (2010).
  • Design of the front-end analog electronics for the ATLAS tile calorimeter, K. Anderson et al., Nucl. Instr. and Meth. A551, 469 (2005).
  • Measurement of the Mass and Width of the W Boson, G. Abbiendi et al., Euro. Phys. Journal C45, 307 (2006).
  • Search for the Standard Model Higgs Boson with the OPAL Detector at LEP, G. Abbiendi et al., Euro. Phys. Journal C26, 479 (2003).