Department of Physics

My research revolves around the study of the strong force, the force that binds quarks together into larger composites, such as protons and neutrons, or pions and kaons, or other more exotic configurations. To do this, I concentrate on mesons, which are simple bound states of a quark and an anti-quark. The spectrum of mesons is analogous to the energy levels of the hydrogen atom: studying the properties of different quark-antiquark "energy levels" gives important information on how they are bound, similar to the way that the spectroscopy of hydrogen was important for the development of our contemporary picture of electromagnetism.

I am involved with several experimental collaborations. At the BESIII experiment at the Institute of High Energy Physics (Beijing, China), we study bound states of charm and anti-charm quarks. These states are created by the annihilation of electrons and positrons provided by the Beijing Electron Positron Collider (BEPC). They quickly decay and the decay products are then measured with the BESIII detector. I am also working on the GlueX experiment at Jefferson National Laboratory in Newport News, VA. GlueX uses a beam of high energy (9 GeV) photons to produce exotic composites of quarks, antiquarks, and gluons (the particles responsible for the strong force).

M. Ablikim et al. [BESIII Collaboration], "Evidence for e+e- to gamma eta_c at center-of-mass energies between 4.01 and 4.60 GeV," Phys. Rev. D 96, no. 5, 051101 (2017) [arXiv:1705.06853 [hep-ex]].

R. F. Lebed, R. E. Mitchell and E. S. Swanson, "Heavy-Quark QCD Exotica," Prog. Part. Nucl. Phys. 93, 143 (2017) [arXiv:1610.04528 [hep-ph]].

C. Patrignani et al. [Particle Data Group], "Review of Particle Physics," Chin. Phys. C 40, no. 10, 100001 (2016).

M. R. Shepherd, J. J. Dudek and R. E. Mitchell, "Searching for the rules that govern hadron construction," Nature 534, no. 7608, 487 (2016).

R. A. Briere, F. A. Harris and R. E. Mitchell, "Physics Accomplishments and Future Prospects of the BES Experiments at the BEPC Collider," Annual Review of Nuclear and Particle Science 66, 143 (2016) [arXiv:1603.09431 [hep-ex]].

R. A. Briceno et al., "Issues and Opportunities in Exotic Hadrons," Chin. Phys. C 40, no. 4, 042001 (2016) [arXiv:1511.06779 [hep-ph]].

M. Ablikim et al. [BESIII Collaboration], "Observation of a charged charmoniumlike structure in e+e- to pi+pi-J/psi at 4.26 GeV," Phys. Rev. Lett. 110, 252001 (2013) [arXiv:1303.5949 [hep-ex]].

G. S. Adams et al. [CLEO Collaboration], "Amplitude analyses of the decays chi_c1 to eta pi+ pi- and chi_c1 to etaprime pi+ pi-," Phys. Rev. D 84, 112009 (2011) [arXiv:1109.5843 [hep-ex]].

B. D. Schaefer, R. E. Mitchell, P. McChesney, M. R. Shepherd and J. M. Frye, "Radiation Damage of F8 Lead Glass with 20 MeV Electrons," Nucl. Instrum. Meth. B 274, 111 (2012) [arXiv:1107.3332 [physics.ins-det]].

T. K. Pedlar et al. [CLEO Collaboration], "Observation of the h_c(1P) using e+e- collisions above DDbar threshold," Phys. Rev. Lett. 107, 041803 (2011) [arXiv:1104.2025 [hep-ex]].

N. Brambilla et al., "Heavy quarkonium: progress, puzzles, and opportunities," Eur. Phys. J. C 71, 1534 (2011) [arXiv:1010.5827 [hep-ph]].

P. Guo, R. Mitchell and A. P. Szczepaniak, "The role of P-wave inelasticity in J/psi to pi+pi-pi0," Phys. Rev. D {f 82}, 094002 (2010) [arXiv:1006.4371 [hep-ph]].

R.E.Mitchell, et al. [CLEO Collaboration], "J/psi and psi(2S) radiative transitions to eta_c," Physical Review Letters 102, 011801 (2009) [arXiv:0805.0252 [hep-ex]].

J.V.Bennett, et al. [CLEO Collaboration], "Observation of chi_cJ radiative decays to light vector mesons," Physical Review Letters 101, 151801 (2008) [arXiv:0807.3718 [hep-ex]].

R.E.Mitchell, "An Experimental Review of Charmonium," Proceedings of the 34th International Conference of High Energy Physics, Philadelphia, PA (2008) [arXiv:0810.3231 [hep-ex]].

R.E.Mitchell, "Bottomonium and Charmonium at CLEO," Proceedings of the 42nd Recontres de Moriond, La Thuile, Italy (2007) [arXiv:0705.2899 [hep-ex]].

A.R.Dzierba, et al., "A partial wave analysis of the pi-pi-pi+ and pi-pi0pi0 systems and the search for a JPC = 1-+ meson," Physical Review D73, 072001 (2006) [arXiv:hep-ex/0510068].

R.E.Mitchell, "PWA of 3pi final states and a search for the pi1(1600)," Proceedings of Hadron 2005, Rio de Janeiro, Brazil, AIP Conf. Proc. 814, 473 (2006) [arXiv:hep-ex/0510075].

R.E.Mitchell, "Observation of a 1750 MeV State in the Diffractive Photoproduction of K+K-," Proceedings of Photon 2003, Gargnano, Italy, Nuclear Physics B126 (2004).

R.E.Mitchell, "Observation of a 1750 MeV state in the peripheral photoproduction of K+K-," Proceedings of the 8th Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2003), New York, NY, AIP Conf. Proc. 698, 559 (2004).

J.M.Link, et al. [FOCUS Collaboration], "Observation of a 1750 MeV enhancement in the diffractive photoproduction of K+K-," Physics Letters B545, 50 (2002) [arXiv:hep-ex/0208027].