Neutron skin of lead measured by PREX

Publication date: Sun, Jan 29, 2012 - 12:50pm
The PREX experiment housed in Hall A at Jefferson Lab in Virginia (including faculty Krishna Kumar, postdocs Juliette Mammei and Seamus Riordan and graduate students Luis Mercado, Jon Wexler and Sereres Johnston) has measured the neutron skin of a heavy nucleus for the first time using the parity-violating elastic scattering of polarized electrons. The radius of the neutron shell of Pb-208 is found to be about 6% larger than that the proton, with the difference between the two of 0.33 fm. This result, to appear in Phys. Rev. Lett. (arXiv:1201.2568), provides insight into nuclear symmetry energy, nuclear equations of state, and into the size and cooling processes of neutron stars.