@article{fomin_alarcon_alonzi_askanazi_baessler_balascuta_barron-palos_barzilov_blyth_bowman_et al._2022, title={Measurement of the parity-odd angular distribution of gamma rays from polarized neutron capture on Cl-35}, volume={106}, ISSN={["2469-9993"]}, DOI={10.1103/PhysRevC.106.015504}, abstractNote={We report a measurement of two energy-weighted $\ensuremath{\gamma}$ cascade angular distributions from polarized slow neutron capture on the $^{35}\mathrm{Cl}$ nucleus, one parity-odd correlation proportional to $\stackrel{P\vec}{{s}_{n}}\ifmmode\cdot\else\textperiodcentered\fi{}\stackrel{P\vec}{{k}_{\ensuremath{\gamma}}}$ and one parity-even correlation proportional to $\stackrel{P\vec}{{s}_{n}}\ifmmode\cdot\else\textperiodcentered\fi{}\stackrel{P\vec}{{k}_{n}}\ifmmode\times\else\texttimes\fi{}\stackrel{P\vec}{{k}_{\ensuremath{\gamma}}}$. A parity-violating asymmetry can appear in this reaction due to the weak nucleon-nucleon interaction, which mixes opposite parity S- and P-wave levels in the excited compound $^{36}\mathrm{Cl}$ nucleus formed upon slow neutron capture. If parity-violating (PV) and parity-conserving (PC) terms both exist, the measured differential cross section can be related to them via $\frac{d\ensuremath{\sigma}}{d\mathrm{\ensuremath{\Omega}}}\ensuremath{\propto}1+{A}_{\ensuremath{\gamma},\mathrm{PV}}cos\ensuremath{\theta}+{A}_{\ensuremath{\gamma},\mathrm{PC}}sin\ensuremath{\theta}$. The PV and PC asymmetries for energy-weighted $\ensuremath{\gamma}$ cascade angular distributions for polarized slow neutron capture on $^{35}\mathrm{Cl}$ averaged over the neutron energies from 2.27--9.53 meV were measured to be ${A}_{\ensuremath{\gamma},\mathrm{PV}}=(\ensuremath{-}23.9\ifmmode\pm\else\textpm\fi{}0.7)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$ and ${A}_{\ensuremath{\gamma},\mathrm{PC}}=(0.1\ifmmode\pm\else\textpm\fi{}0.7)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$. These results are consistent with previous experimental results. Systematic errors were quantified and shown to be small compared to the statistical error. These asymmetries in the angular distributions of the $\ensuremath{\gamma}$ rays emitted from the capture of polarized neutrons in $^{35}\mathrm{Cl}$ were used to verify the operation and data analysis procedures for the NPDGamma experiment, which measured the parity-odd asymmetry in the angular distribution of $\ensuremath{\gamma}$s from polarized slow neutron capture on protons.}, number={1}, journal={PHYSICAL REVIEW C}, author={Fomin, N. and Alarcon, R. and Alonzi, L. and Askanazi, E. and Baessler, S. and Balascuta, S. and Barron-Palos, L. and Barzilov, A. and Blyth, D. and Bowman, J. D. and et al.}, year={2022}, month={Jul} }
 @article{blyth_fry_fomin_alarcon_alonzi_askanazi_baessler_balascuta_barron-palos_barzilov_et al._2018, title={First Observation of P-odd gamma Asymmetry in Polarized Neutron Capture on Hydrogen}, volume={121}, ISSN={["1079-7114"]}, DOI={10.1103/PhysRevLett.121.242002}, abstractNote={We report the first observation of the parity-violating gamma-ray asymmetry A_{γ}^{np} in neutron-proton capture using polarized cold neutrons incident on a liquid parahydrogen target at the Spallation Neutron Source at Oak Ridge National Laboratory. A_{γ}^{np} isolates the ΔI=1, ^{3}S_{1}→^{3}P_{1} component of the weak nucleon-nucleon interaction, which is dominated by pion exchange and can be directly related to a single coupling constant in either the DDH meson exchange model or pionless effective field theory. We measured A_{γ}^{np}=[-3.0±1.4(stat)±0.2(syst)]×10^{-8}, which implies a DDH weak πNN coupling of h_{π}^{1}=[2.6±1.2(stat)±0.2(syst)]×10^{-7} and a pionless EFT constant of C^{^{3}S_{1}→^{3}P_{1}}/C_{0}=[-7.4±3.5(stat)±0.5(syst)]×10^{-11}  MeV^{-1}. We describe the experiment, data analysis, systematic uncertainties, and implications of the result.}, number={24}, journal={PHYSICAL REVIEW LETTERS}, author={Blyth, D. and Fry, J. and Fomin, N. and Alarcon, R. and Alonzi, L. and Askanazi, E. and Baessler, S. and Balascuta, S. and Barron-Palos, L. and Barzilov, A. and et al.}, year={2018}, month={Dec} }