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Measuring the Neutron's Mean Square Charge Radius Using Neutron Interferometry

F. E. Wietfeldt·M. Huber·T. C. Black·H. Kaiser·M. Arif·D. L. Jacobson·S. A. Werner
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Abstract

The neutron is electrically neutral, but its substructure consists of charged quarks so it may have an internal charge distribution. In fact it is known to have a negative mean square charge radius (MSCR), the second moment of the radial charge density. In other words the neutron has a positive core and negative skin. In the first Born approximation the neutron MSCR can be simply related to the neutron-electron scattering length b_ne. In the past this important quantity has been extracted from the energy dependence of the total transmission cross-section of neutrons on high-Z targets, a very difficult and complicated process. A few years ago S.A. Werner proposed a novel approach to measuring b_ne from the neutron's dynamical phase shift in a perfect crystal close to the Bragg condition. We are conducting an experiment based on this method at the NIST neutron interferometer which may lead to a five-fold improvement in precision of b_ne and hence the neutron MSCR.

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F. E. Wietfeldt, M. Huber, T. C. Black, H. Kaiser, M. Arif, D. L. Jacobson, S. A. Werner. 2005-09-14. Measuring the Neutron's Mean Square Charge Radius Using Neutron Interferometry. https://doi.org/10.1016/j.physb.2006.05.187

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