谁来讲十分钟：QUARKS INFLUENCED BY THEIR NEIGHBORHOOD

The internal structure of a proton or neutron is not
completely fixed--experiments going back decades suggest
that the particles are slightly different when inside a
nucleus. Now results in the 13 November Physical Review
Letters show that the effect is not dependent on the
mass or on the density of the entire nucleus, as some
theories have predicted. Instead, neutrons and protons
appear to change according to their immediate neighborhood
within the nucleus.

J. Seely et al., Phys. Rev. Lett. 103, 202301
Link to the paper: http://link.aps.org/abstract/PRL/v103/e202301
COMPLETE Focus story at http://focus.aps.org/story/v24/st20