Reinhard Schumacher

Professor, Physics

Education

Ph.D., Massaschusetts Institute of Technology

Research

Medium energy physics explores the interactions of few- and many-particle systems at the interface between the quark-gluon and meson-baryon descriptions of matter. Medium energy physics tends to address questions that, as a practical matter, do not require the highest beam energies or luminosities, but do call for high-precision measurements using specialized equipment. At Carnegie Mellon we have a large research group doing Medium Energy Physics. 

Currently, my main area of work is in the electromagnetic production of strange particles (kaons and hyperons).  The production of strange-quark pairs via the well-known electromagnetic interaction (via photon and electron-induced reactions) gives us an avenue for refining our knowledge of baryon resonances and coupling constants; the results are compared with modern quark model calculations. This work is being done at the Thomas Jefferson National Accelerator Facility . More exactly, my work is done using the CEBAF Large Acceptance Spectrometer (CLAS) in Hall B at Jefferson Lab. 

At Carnegie Mellon I teach a number of different courses, and this comprises a very important part of my work. 

Selected Publications

• Kei Moriya and Reinhard Schumacher, Properties of the Λ(1405) Measured at CLAS. AIP Conf. Proc. 1432, 371 (2012).
• R. A. Schumacher, M. M. Sargsian, Scaling and resonances in elementary K⁺Λ photoproduction, Physical Review C 83, 025207 (2011)
• R. Schumacher, Polarization in hyperon photo- and electro-production, The European Physical Journal A 35, 299 (2008)
• R. Bradford et al., First measurement of beam-recoil observables Cx and Cz in hyperon photoproduction, Physical Review C 75, 035205 (2007)
• R. Bradford et al., Differential cross sections for γ+p→K⁺+Y for Λ and Σ⁰ hyperons, Physical Review C 73, 035202 (2006)
• Reinhard Schumacher, The Rise and Fall of Pentaquarks in Experiments, AIP Conf. Proc. 842, 409 (2006).
• J. McNabb et al., Hyperon photoproduction in the nucleon resonance region, Physical Review C 69, 042201 (2004)
• R. A. Schumacher, Strangeness production and other recent results from Hall B at Jefferson Lab, The European Physical Journal A - Hadrons and Nuclei 18, 371 (2003)
• B.A. Mecking et al., The CEBAF large acceptance spectrometer (CLAS), Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 503, 513 (2003)
• Reinhard Schumacher, Photoproduction evidence for and against hidden-strangeness states near 2 GeV, Physical Review C 56, 2774 (1997)
• Stephan A. Roth, Reinhard A. Schumacher, A computer-controlled tension monitoring system for drift chamber wires, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 369, 215 (1996)
• Reinhard A. Schumacher, Special relativity and the Michelson–Morley interferometer, American Journal of Physics 62, 609 (1994)