# Jonathan R. Sapirstein

**Professor
Theoretical Physics**

**B.S., Stanford University, 1973
Ph.D., ibid., 1979**

E-mail: jsapirst (at) nd (dot) edu

Address: Nieuwland Science Hall 319

Phone: (574) 631-5570

Fax: (574) 631-5952

#### Research Interests

Professor Sapirstein’s current research interests involve higher order corrections in quantum field theories. Extremely precise measurements in atomic systems such as hydrogen, helium, and positronium are now requiring Quantum Electrodynamic calculations accurate to better than a part per million. Several such calculations, which require extensive use of computers, are in progress.

Another area of research is parity violation in heavy atoms. This requires solution of the many-electron Schrödinger equation in these complex systems. Large-scale computer calculations then allow the interpretation of experiments measuring parity violation in terms of fundamental particle physics. Similar calculations in highly charged many-electron ions probe quantum electrodynamics in extreme environments.

#### Selected Publications

“Contributions to helium fine structure of order ma^{7},” K. Pachucki and J. Sapirstein, J. Phys. B **33**, 5297 (2000).

“Determination of the two-loop Lamb shift in lithiumlike bismuth,” J. Sapirstein and K.T. Cheng, Phys. Rev. A **64**, 022502 (2001).

“Order ma^{8} contribution to the orthopositronium decay rate,” G.S. Adkins, R.N. Fell, and J. Sapirstein, Annals of Physics **295**, 136 (2002).

“Parity Violation,” J. Sapirstein in Relativistic Electronic Structure Theory: Part I, Fundamentals, Elsevier Science, P. Schwerdtfeger, Ed. (2002).

“Calculation of Radiative Corrections to Hyperfine Splittings in the Neutral Alkalis,” J. Sapirstein, K.T. Cheng, Phys. Rev. A **67**, 022512 (2003).

#### Honors and Activities:

- Fellow, American Physical Society