Reinhard A. Schumacher
Emeritus Professor of Physics
Nuclear & Particle Physics
Quark Interaction Experiment
Wean Hall 8406
Education & Professional Experience
Ph.D.: Massaschusetts Institute of Technology (1983)
B.S.: Case Western Reserve University (1978)
Fellow, American Physical Society
Professor of Physics, Carnegie Mellon University, 1999–
Indefinite Tenure, Carnegie Mellon University, 1995
Associate Professor, Carnegie Mellon University, 1993–99
Assistant Professor, Carnegie Mellon University, 1987–93
Post-doctoral Research: Paul-Scherrer Institute (Switzerland), 1983–87
Quark interaction physics explores sub-atomic particle systems at the boundary between the quark-gluon and meson-baryon descriptions of matter. The field addresses questions that 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 Nuclear and Quark Interaction Physics.
Currently, my main area of research is in the electromagnetic production of strange particles (kaons and hyperons). The production of strange-quark pairs via the well-known electromagnetic interaction is our avenue for refining understanding of baryon resonances, mesonic resonances, and various polarization observables. Experimental results are compared with modern quark models and unitarized chiral perturbation theory with the use of partial wave analysis. We seek evidence for particle states that fall outside the traditional quark model classification scheme on account of active gluonic configurations.
This work is being done at the Thomas Jefferson National Accelerator Facility. My experimental work is done using the CEBAF Large Acceptance Spectrometer (CLAS) in Hall B and using the GlueX detector (GlueX) in Hall D at Jefferson Lab.
Another research direction is using fMRI methods to study the encoding of scientific concept in the human brain, particularly those that do not have classical analogues. The neuroscience of advanced physics concepts in the brains of PhD Physicists versus young students can be compared, for example, to see their cognitive foundations and development during learning.
At Carnegie Mellon I teach a number of different courses, and this comprises a very important part of my work. Recently I have taught Modern Essentials (33.211) (Relativity and Quantum Physics) in the fall and Modern Physics Laboratory (33.340) in the spring. I have produced some less technical YouTube videos on physics topics, such as A Diffusion Cloud Chamber and The Kelvin Water Dropper with Electroscope.
R. A. Mason, R. A. Schumacher, M. A. Just, The neuroscience of advanced scientific concepts , npj Science of Learning 6, 29 (2021)
D. Ho, R. A. Schumacher, et al., Beam-Target Helicity Asymmetry for γ n → π- p in the N* Resonance Region (CLAS Collaboration) Physical Review Letters 118, 242002 (2017)
R. Dickson, R. A. Schumacher, et al., Photoproduction of the f1(1285) meson (CLAS Collaboration) Physical Review C 93, 065202 (2016)
K. Moriya et al., Spin and parity measurement of the Λ(1405) baryon, Physical Review Letters 112, 82004 (2014)
K. Moriya et al., Differential photoproduction cross sections of the Σ0(1385), Λ(1405), and Λ(1520), Phys. Rev. C 88, 45201 (2013)
K. Moriya et al., Measurement of the Σπ photoproduction line shapes near the Λ(1405), Phys. Rev. C 87, 35206 (2013)
G Bernero, J Olitsky, R A Schumacher, Atmospheric dependence of the stopping cosmic ray muon rate at ground level, J. Phys. G: Nucl. Part. Phys. 40, 65203 (2013)
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)