Professor Longo's primary research activities have been experiments at Fermilab, including E871 (HyperCP), an experiment designed to perform a sensitive search for direct CP violation in the decays of Xi and Lambda hyperons by looking for an asymmetry between particle and antiparticle decay parameters. A difference between the decay parameters for particle and antiparticle is direct evidence that CP-symmetry is violated. His research group is analyzing one of the largest data sets ever acquired in a high-energy physics experiment. Research Fellow H.K. Park prepared a paper with results on rare decays of kaons involving two muons, which was the first published result from HyperCP (//ppd.fnal.gov/experiments/e871).

Professor Longo is also working on the MIPP experiment at Fermilab. This is an experiment to measure cross sections for production of protons, neutrons, pions, kaons etc. by beams of particles with energies up to 100 GeV (//ppd.fnal.gov/experiments/e907).

Professor Longo's group consists of postdoctoral scientists H.K. Park and D. Rajaram and research scientist H.R. Gustafson.

Professor Longo is a Fellow of the American Physical Society.

Measurement of the Atmospheric Neutrino Induced Upgoing Muon Flux Using MACRO, (MACRO Collaboration), Phys. Lett. B 434, 451-457 (1998).

Atmospheric Neutrino Flux Measurement Using Upgoing Muons, (MACRO Collaboration), Phys. Lett. B 357, 481-486 (1995).

First Supermodule of the MACRO Detector at Gran Sasso, (MACRO Collaboration), Nucl. Instrum. Meth. A 324, 337-362 (1993).

Demonstration of Megavoltage and Diagnostic X-ray Imaging with Hydrogenated Amorphous Silicon Arrays, (L. E. Antonuk, J. Boudry, W. Huang, D. L. McShan, E. J. Morton, J. Yorkston, M. J. Longo, and R. A. Street), Med. Phys. 19, 1455-1466 (1992).

New Precision Tests of the Einstein Equivalence Principle From SN1987A, (Michael J. Longo), Phys. Rev. Lett. 60, 173 (1988).

A-Dependence of Charm Production, (M.E. Duffy, G.K. Fanourakis, R.J. Loveless, D.D. Reeder, E.S. Smith, S. Childress, C. Castoldi, G. Conforto, R.C. Ball, C.T. Coffin, H.R. Gustafson, L.W. Jones, M.J. Longo, T.J. Roberts, B.P. Roe, E. Wang, M.B. Crisler, J.S. Hoftun, T.Y. Ling, T.A. Romanowski, J.T. Volk), Phys. Rev. Lett. 55, 1816-1819 (1985).

Observation of Charmed Baryon Production in e⁺e^- Collisions, (G.S. Abrams et al.), Phys. Rev. Lett. 44, 10 (1980).

Neutron Total Cross Section on Nuclei at Fermilab Energies, (P.V. Ramana Murthy, Cyril A. Ayre, H. Richard Gustafson, Lawrence W. Jones, Michael J. Longo), Nucl. Phys. B 92, 269-308 (1975).