Nuclear physicist’s work opens intra-atomic world

IU nuclear physicist Mike Snow’s investigations into the weak interactions of low-energy neutrons will advance using equipment funded by the IU Office of the Vice Provost for Research and then be put into use at the National Institute of Standards and Technology.

IU’s Faculty Research Support Program will provide Snow $90,970 toward equipping a new high-precision neutron spin rotation facility at the National Institute of Standards and Technology’s Center for Neutron Research in Gaithersburg, Md.

Achieving precise measurements in low-energy interactions can address issues of fundamental importance in nuclear and particle physics, according to an IU press release.

“These types of weak interactions remain one of the most poorly understood sectors of the Standard Model, and a quantitative description of the weak (nucleon-nucleon) interaction is needed to understand weak interaction phenomena in atomic, nuclear and hadronic systems,” said Snow, who has a master’s degree and a doctorate from Harvard, in a statement.

“This new facility will build upon our laboratory’s recent search for parity-odd neutron spin rotation in liquid helium, which is the most sensitive measurement of its type ever performed, and make possible more precise experiments in helium, deuterium and hydrogen targets. This accuracy is expected to be enough to see clearly the effects of quark-quark weak interactions in these systems for the first time.”

Institutions collaborating with IU in addition to the National Institute of Standards and Technology include University of Washington, George Washington University, North Carolina Central University, Georgia State University and Kazakh National University.


“This support from the Faculty Research Support Program will help provide for the main equipment components needed to repeat a measurement in helium, but with higher precision than before, and also to pursue measurements with deuterium and hydrogen,” Snow said in a statement. “We have already done the first search for this phenomenon in helium and data analysis is nearing completion. Independent of the result of that analysis, we plan to conduct a more sensitive measurement at NIST in the future.”

Snow said data analysis from the first helium experiment should be complete this fall, with the next measurement expected to be conducted in the next few years after a new slow-neutron beamline is constructed there as part of a new cold-neutron guide hall, according to a press release.

“This new facility IU is funding will help put the IU nuclear physics experimental group in strong position to take full advantage of the new science made possible by NIST’s construction of one of the most intense slow-neutron beams for fundamental physics with neutrons in the world,” Snow said in a statement.

“It would also further build upon the several existing IU/NIST collaborations in neutron physics and scattering.”