Jen-Chieh Peng
Professor of Physics
Professor Peng received his bachelor's degree in physics from Tunghai University in Taiwan in 1970 and his Ph.D. in nuclear physics from the University of Pittsburgh in 1975. He worked as a researcher at the Centre d'Etudes Nucleaires de Saclay and the University of Pittsburgh before joining the Physics Division of Los Alamos National Laboratory in 1978. He became a Laboratory Fellow at Los Alamos in 1996. Professor Peng joined the Department of Physics at the University of Illinois in February 2002.
At Los Alamos, Professor Peng made pioneering contributions to several areas of medium energy physics. He was the first to recognize the feasibility of producing h mesons at the Los Alamos Meson Production Facility (LAMPF) and made the first (p,h) measurements on nuclei. In the early 1980s, Professor Peng proposed the (p+,K+) measurements at Brookhaven National Laboratory's Alternating Gradient Synchrotron (AGS) accelerator, which ultimately identified single-particle states of lambda hypernuclei far beyond what had been possible using the (K-,p-,) reaction. Since the late 1980s, Professor Peng has made seminal contributions to high-energy nuclear physics in a series of experiments at Fermilab (E772, E789, and E866), which pioneered the use of massive lepton pair production to probe the distributions of antiquarks in the nucleons and nuclei. Professor Peng was the spokesperson or co-spokesperson for eight experiments carried out at various laboratories.
Most recently, Professor Peng has led the effort to establish a proton-nucleus experimental program at the Relativistic Heavy Ion Collider (RHIC). He is also actively involved in proposing a new experiment to measure the neutron electric dipole moment (EDM) using the technique of ultra-cold neutron production in superfluid helium. Professor Peng is a Fellow of the American Physical Society.
Research Areas: experimental medium and high energy nuclear physics; Parton structures of the nucleons and nuclei
Description of Current Research
PHENIX experiment at RHIC
We work on the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) in Brookhaven National Laboratory. The primary goals of the PHENIX experiment are:
- Searching for a new state of matter, called the quark-gluon plasma, through the collisions of two energetic heavy-ion beams.
- Understanding the spin structure of the proton, especially the role of the gluons, via the interaction of two colliding polarized proton beams.
- Investigating the antiquark and gluon distributions in nuclei by measuring the nuclear dependence of various hard-processes in proton-nucleus collisions.
Neutron Electric Dipole Moment experiment
An observation of a non-zero neutron electric dipole moment (EDM) would provide direct evidence for time-reversal and CP violation. The present experimental upper limit for neutron EDM is 10-25e.cm , limited by the flux of the ultra-cold neutrons (neutrons having energies less than 200 nano-electron volts). We propose a new measurement using large cells of superfluid helium for producing ultra-cold neutrons and measuring their EDM in situ . The goal of this experiment is to reach a sensitivity of 10-27e.cm, a factor of 100 improvement over the most recent measurement. We plan to use the spallation neutron beam at the Los Alamos Neutron Science Center (LANSCE) for this experiment.
Selected Publications
Adler, SS, et al. (PHENIX Collaboration). Measurement of transverse single-spin asymmetries for mid-rapidity production of neutral pions and charged hadrons in polarized p+p collisions at vs = 200 GeV. Phys. Rev. Lett. 95, 202001-1-6 (2005).
Adler, SS, et al. (PHENIX Collaboration). Midrapidity direct-photon production in p+p collisions at vs = 200 GeV. Phys. Rev. D 71, 071102-1-7 (2005).
Airapetian, A, et al. (HERMES Collaboration). Quark helicity distributions in the nucleon for up, down, and strange quarks from semi-inclusive deep-inelastic scattering. Phys. Rev. D 71, 012003-1-36 (2005).
Adler, SS, et al. (PHENIX Collaboration). Production of f mesons sNN=200 GeV Au+Au collisions at relativistic energies Ö at midrapidity in. Phys. Rev. C 72, 014903-1-23 (2005 ).
Adler, SS, et al. (PHENIX Collaboration). Jet sNN=200 GeV Ö structure of baryon excess in Au+Au collisions at. Phys. Rev. C 71, 51902-1-6 (2005).
Honors and Awards
- Fellow, Los Alamos National Laboratory, 1996
- Fellow, American Physical Society, 1993
