Create a beautifully simple personal or academic website in under 10 minutes.
Selected Publications
Accurate Determination of the Neutron Skin Thickness of through Parity-Violation in Electron Scattering
We report a precision measurement of the parity-violating asymmetry A PV in the elastic scattering of longitudinally polarized electrons from Pb 208. We measure A PV= 550±16 (stat)±8 (syst) parts per billion, leading to an extraction of the neutral weak form factor F W (Q 2= 0.00616 GeV 2)= 0.368±0.013. Combined with our previous measurement, the extracted neutron skin thickness is R n− R p= 0.283±0.071 fm. The result also yields the first significant direct measurement of the interior weak density of Pb 208: ρ W 0=− 0.0796±0.0036 (exp)±0.0013 (theo) fm− 3 leading to the interior baryon density ρ b 0= 0.1480±0.0036 (exp)±0.0013 (theo) fm− 3. The measurement accurately constrains the density dependence of the symmetry energy of nuclear matter near saturation density, with implications for the size and composition of neutron stars.
Physics Review Letters
Precision measurement of the weak charge of the proton
The Qweak experiment has made possible the first determination of the weak charge of the proton QWp by incorporating earlier parity-violating electron scattering (PVES) data at higher Q2 to constrain hadronic corrections. The value of QWp obtained in this way is QWp(PVES)=0.0719±0.0045, which is in good agreement with the standard model prediction of QWp(SM)=0.0710±0.0007.
Nature
Measurement of parity violation in electron–quark scattering
The experiment provides a measurement of the parity-violating asymmetry in electron–quark scattering, which yields a determination of $2C_{2u} − C_{2d}$ (where u and d denote up and down quarks, respectively) with a precision increased by a factor of five relative to the earlier result. These results provide evidence with greater than 95 percent confidence that the C2q couplings are non-zero, as predicted by the electroweak theory.
Nature Journal
First Determination of Weak Charge of Proton
The Qweak experiment has made possible the first determination of the weak charge of the proton QWp by incorporating earlier parity-violating electron scattering (PVES) data at higher Q2 to constrain hadronic corrections. The value of QWp obtained in this way is QWp(PVES)=0.064±0.012, which is in good agreement with the standard model prediction of QWp(SM)=0.0710±0.0007.
Physics Review Letters
Measurement of the Neutron Radius of 208Pb Through Parity-Violation in Electron Scattering
The skin thikness of 208Pb, difference between the radii of the neutron and proton distributions Rn - Rp = 0.33 +0.16 -0.18 fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.
Physics Review Letters
