Experimental Particle Physics with Electronic Detectors

This is a proposal to fund a research program to investigate the constituent structure of matter by colliding leptons (specifically electrons and positrons) with protons.

The experiment is being done by physicists from PSU and collaborators using the ZEUS detector at the HERA accelerator of the DESY laboratory in Hamburg, Germany. This experiment is a study of electron/positron-proton deep inelastic scattering (DIS) collisions at a center-of-mass energy of 318 GeV.

Intellectual Merit

The primary aim of the experiment is the study of DIS at the highest available exchanged photon virtualities (Q-squared up to 90,000 GeV^2), in order to probe electron and quark substructure down to distances of 10^(-18) cm, and to search for new families of excited leptons and quarks indicative of physics beyond the Standard Model. The PSU group expects to study heavy quark production as well as the electroweak properties at high Q-squared that could be observed with the advent of polarized electrons and positrons.

In addition, the PSU group has been invited to participate in a cosmic ray experiment (CORAL) to determine the energy spectrum and primary particle chemical composition in the energy range of the 'knee', i.e., cosmic ray primary energies of 10^15 to 10^16 eV. The experiment will involve the simultaneous determination of both the electron/photon and muon components of cosmic ray air showers, using a surface array of scintillation counters and an underground muon drift chamber system, where the muon momentum cutoff is about 70 GeV.

Broader Impacts

Education/outreach activities include taking typically two REU students to work on the ZEUS experiment in the summers. The group will also participate in the cosmic ray 'school' effort already in an advanced planning stage with a group at CERN that is working with the schools in Dusseldorf.