Donal Day

Ph.D., 1979, Virginia
B.A., 1973, University of Virginia

Research Professor

Experimental Nuclear and Particle Physics

Research Interests

Our research program is at the forefront of the studies of the fundamental properties of the nucleons, i.e. the proton and neutron, which are the two building blocks of the atomic nucleus. The interactions of quarks and gluons, the underlying constituents of strongly interacting matter, are well described by the basic theory, Quantum Chromodynamics (QCD). However, the way in which quarks and gluons are confined within the nucleons and the mesons (responsible for nuclear forces), is poorly understood in QCD. We concentrate on experiments that use spin degrees of freedom (i.e. using polarized targets and beams) in electron-nucleon/nucleus interactions to extract new information about the properties of these fundamental building blocks of nature and lend new insights into these basic and longstanding problems. We are unique among university based research groups as we have the capabilities of developing, building and maintaining the cryogenic polarized targets critical for this research which is carried out at the Jefferson Lab  and FermiLab whose unique capabilities make this research possible.

Selected Publications

Searching for three-nucleon short-range correlations
By Misak M. Sargsian, Donal B. Day, Leonid L. Frankfurt, Mark I. Strikman.
[arXiv:1910.14663 [nucl-th]].
Phys.Rev. C100 (2019) no.4, 044320.
Measurement of the cross sections for inclusive electron scattering in the E12-14-012 experiment at Jefferson Lab
By M. Murphy et al..
[arXiv:1908.01802 [hep-ex]].
Phys.Rev. C100 (2019) no.5, 054606.
Probing nucleon’s spin structures with polarized Drell-Yan in the Fermilab SpinQuest experiment
By SeaQuest Collaboration (Andrew Chen et al.).
[arXiv:1901.09994 [nucl-ex]].
PoS SPIN2018 (2019) 164.
First measurement of the Ar(e,e′)X cross section at Jefferson Laboratory
By H. Dai et al..
[arXiv:1810.10575 [nucl-ex]].
Phys.Rev. C99 (2019) no.5, 054608.
Measurements of Nonsinglet Moments of the Nucleon Structure Functions and Comparison to Predictions from Lattice QCD for Q2 = 4 GeV2
By E06-009 Collaboration (I. Albayrak et al.).
[arXiv:1807.06061 [nucl-ex]].
Phys.Rev.Lett. 123 (2019) no.2, 022501.
Revealing Color Forces with Transverse Polarized Electron Scattering
By SANE Collaboration (W. Armstrong et al.).
[arXiv:1805.08835 [nucl-ex]].
Phys.Rev.Lett. 122 (2019) no.2, 022002.
First measurement of the Ti(e,e′)X cross section at Jefferson Lab
By Jefferson Lab Hall A Collaboration (H. Dai et al.).
[arXiv:1803.01910 [nucl-ex]].
Phys.Rev. C98 (2018) no.1, 014617.
Design and Performance of the Spin Asymmetries of the Nucleon Experiment
By J.D. Maxwell et al..
[arXiv:1711.09089 [physics.ins-det]].
Nucl.Instrum.Meth. A885 (2018) 145-159.

News Items

2020 is the 50th anniversary of Physical Review C which was spun-off by its parent publication, The Physical Review, in 1970. As part of its anniversary PRC is creating a collection ......More >
From CBS19: "I really don't think there is much future for Nuclear energy," said Donal Day, a Nuclear Physicist who teaches at University of Virginia. "I ......More >
A PRC paper presenting the results of Prof. Donal Day's work with John Arrington (our recent colloquium speaker), Nadia Fomin (his former graduate student), and a few others on the EMC effect has ......More >
The atomic nucleus is made of confined nucleons in constant motion dominated by their interactions with the mean field of the nucleus - that is the average potential generated the many body ......More >
This paper, coauthored by Nadia Fomin, a former UVa graduate student (and now a research associate at the University of Tennessee), Donal Day (her advisor at UVa), John Arrington of Argonne ......More >


APS Fellow [2012]
For his studies of high momentum transfer quasielastic electron scattering, scaling relations and the short-range structure of nuclei and for his contributions to the use of polarized targets in the study of nucleon form factors and spin structure functions