An Upper Bound on Parity Violating Neutron Spin Rotation in He-4

Published

January 31, 2011

Author(s)

Jeffrey S. Nico, William M. Snow, Christopher D. Bass, Tiffany D. Bass, B. E. Crawford, K. F. Gan, B R. Heckel, D Lou, D M. Markoff, A M. Micherdzinska, Hans P. Mumm, A. K. Opper, M Sarsour, E I. Sharapov, H E. Swanson, S. C. Walbridge, V Zhumabekova

Abstract

We report an upper bound on parity violating neutron spin rotation in He-4. This experiment is the most sensitive search for neutron weak optical activity yet performed. Our result for the neutron spin rotation angle per unit length in He-4 is dphi/dz = (+1.7 +/- 9.1(stat) +/- 1.4(sys))x10^{-7} rad/m. The statistical uncertainty is smaller than the best current estimates of the range of possible values of dphi/dz in n+He-4. The systematic uncertainty achieved using our experimental technique is small enough to encourage more precise measurements.

Citation

Physics Letters B

Pub Type

Journals

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Keywords

cold neutron, effective field theory, hadronic parity violation, weak interaction

Citation

Nico, J. , Snow, W. , Bass, C. , Bass, T. , Crawford, B. , Gan, K. , Heckel, B. , Lou, D. , Markoff, D. , Micherdzinska, A. , Mumm, H. , Opper, A. , Sarsour, M. , Sharapov, E. , Swanson, H. , Walbridge, S. and Zhumabekova, V. (2011), An Upper Bound on Parity Violating Neutron Spin Rotation in He-4, Physics Letters B, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=906487 (Accessed October 6, 2025)