New Features in the Electromagnetic Structure of the Neutron

Le résumé fourni par la source

Here we present new results for the Born cross section and the effective form factor of the neutron at the center-of-mass energies ${\\bf \\sqrt{s}}$ between 2.0 and 3.08 GeV, using 18 data sets corresponding to an integrated luminosity of 647.9 pb${\\bf ^{-1}}$ from e${\\bf ^+}$e${\\bf ^-}$ annihilation reactions collected at the BESIII experiment. The process $e^{+}e^{-}\\to n\\bar{n}$ is analyzed with three individual categories to improve the efficiency of $n\\bar{n}$ reconstruction. The cross section of $e^{+}e^{-}\\to n\\bar{n}$ is measured at 18 c.m. energies where the best precision is 8.1\\% at $\\sqrt{s}=2.396$ GeV. The corresponding effective form factors are extracted under the assumption $|G_{E}|=|G_{M}|$. Our results improve the statistical precision on the neutron form factor by more than a factor of 60 over previous measurements from the FENICE and DM2 experiments and usher in a new era where neutron form factor data from annihilation in the time-like regime is on par with that from electron scattering experiments. In addition, an oscillatory behavior of the effective form factor observed for the proton is discussed for the neutron.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.