Accurate Determination of the Neutron Skin Thickness of ^{208}Pb 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 ^{208}Pb. 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 ^{208}Pb: 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.

J. Napolitano | C. Clarke | B. Quinn | C. Horowitz | M. Thiel | G. Leverick | M. Thiel | G. Urciuoli | C. Clarke | M. Mondal | S. Malace | D. Gaskell | C. Keppel | A. Narayan | H. Bhatt | V. Bellini | K. Kumar | D. Jones | S. Johnston | P. Souder | C. Feldman | H. Liu | D. King | Y. Tian | C. Palatchi | D. McNulty | S. Jian | C. Gal | R. Michaels | M. Mondal | A. Deshpande | D. Dutta | J. Pan | P. Reimer | A. Shahinyan | A. Zec | P. Datta | K. Paschke | S. Barcus | A. Camsonne | S. Dusa | E. Fuchey | T. Gautam | J. Hansen | F. Hauenstein | D. Meekins | B. Pandey | A. Puckett | L. Tang | B. Wojtsekhowski | K. Aniol | T. Averett | Y. Roblin | L. Tang | J. Zhang | C. A. Gayoso | B. Reed | W. Zhang | Y. Chen | D. Androić | D. Armstrong | R. Beminiwattha | J. Benesch | G. Cates | J. Cornejo | M. Gericke | P. King | J. Mammei | M. Pitt | E. W. Wertz | B. Karki | S. Riordan | B. Yale | P. Datta | S. Covrig Dusa | T. Kutz | M. Rashad | R. Mammei | Y. Tian | S. Park | Binod Karki | W. Zhang | D. Bhetuwal | N. Lashley-Colthirst | H. Albataineh | Q. Campagna | S. Jian | V. Owen | S. Premathilake | W. Henry | X. Zheng | D. Adhikari | D. Pathak | B. Blaikie | C. Ghosh | I. Halilovic | C. Jantzi | S. Katugampola | C. Metts | J. Napolitano | D. Nikolaev | M. Petrusky | R. Radloff | S. Rahman | A. Rathnayake | R. Richards | S. Seeds | T. Ye | A. Yoon | M. Knauss | D. Bhatta Pathak | M. Knauss | N. Liyange | D. Androic | M. McCaughan | J. Pan | S. Park | T. Ye | C. Ayerbe Gayoso | S. Seeds | X. Zheng | D. Jones | X. Zheng | C. Gayoso | D. Mcnulty | J. Hansen | G. Leverick

[1]  C. Horowitz,et al.  Insights into nuclear saturation density from parity-violating electron scattering , 2020 .

[2]  C. Horowitz,et al.  Measuring the surface thickness of the weak charge density of nuclei , 2020, 2009.06664.

[3]  S. Novario,et al.  Charge radii of exotic neon and magnesium isotopes , 2020, 2007.06684.

[4]  C. Horowitz,et al.  GW190814: Impact of a 2.6 solar mass neutron star on nucleonic equations of state , 2020, 2007.03799.

[5]  K. Chatziioannou Neutron-star tidal deformability and equation-of-state constraints , 2020, General Relativity and Gravitation.

[6]  J. Melendez,et al.  How Well Do We Know the Neutron-Matter Equation of State at the Densities Inside Neutron Stars? A Bayesian Approach with Correlated Uncertainties. , 2020, Physical review letters.

[7]  Min Liu,et al.  Constraints on the symmetry energy and its associated parameters from nuclei to neutron stars , 2020, Physical Review C.

[8]  L. Fabbietti,et al.  Strangeness in nuclei and neutron stars , 2020, Progress in Particle and Nuclear Physics.

[9]  G. Burgio,et al.  Are nuclear matter properties correlated to neutron star observables? , 2020, The European Physical Journal A.

[10]  E. Khan,et al.  Multimessenger and multiphysics Bayesian inference for the GW170817 binary neutron star merger , 2020, 2001.10259.

[11]  K. Sumiyoshi,et al.  Effects of Symmetry Energy on the Equation of State for Simulations of Core-collapse Supernovae and Neutron-star Mergers , 2020, The Astrophysical Journal.

[12]  C. Providencia,et al.  Relativistic hypernuclear compact stars with calibrated equations of state , 2020, Physical Review D.

[13]  Keith C. Gendreau,et al.  A NICER View of PSR J0030+0451: Millisecond Pulsar Parameter Estimation , 2019, The Astrophysical Journal.

[14]  C. Horowitz Neutron rich matter in the laboratory and in the heavens after GW170817 , 2019, Annals of Physics.

[15]  Lie-Wen Chen,et al.  Probing the Neutron Skin with Ultrarelativistic Isobaric Collisions. , 2019, Physical review letters.

[16]  J. Piekarewicz,et al.  Electroweak probes of ground state densities , 2019, Physical Review C.

[17]  G. Burgio,et al.  Are nuclear matter properties correlated to neutron star observables? , 2019, The European Physical Journal A.

[18]  L. Baiotti Gravitational waves from neutron star mergers and their relation to the nuclear equation of state , 2019, Progress in Particle and Nuclear Physics.

[19]  J. Piekarewicz,et al.  Neutron-rich matter in heaven and on Earth , 2019, Physics Today.

[20]  C. Tsang,et al.  Symmetry energy constraints from GW170817 and laboratory experiments , 2019, Physics Letters B.

[21]  C. Horowitz,et al.  Neutron skins of atomic nuclei: per aspera ad astra , 2019, Journal of Physics G: Nuclear and Particle Physics.

[22]  V. Ferrari,et al.  Constraining the Neutron Star Equation of State Using Multiband Independent Measurements of Radii and Tidal Deformabilities. , 2019, Physical review letters.

[23]  K. Aulenbacher,et al.  Precision electron beam polarimetry for next generation nuclear physics experiments , 2018, International Journal of Modern Physics E.

[24]  Nicolas Produit,et al.  The P2 experiment , 2018, The European Physical Journal A.

[25]  S. Klein,et al.  Observation of coherent elastic neutrino-nucleus scattering , 2017, Science.

[26]  E. Chicken,et al.  Power of two: Assessing the impact of a second measurement of the weak-charge form factor of $^{208}$Pb , 2016, 1604.07799.

[27]  V. Tioukine,et al.  The MOLLER Experiment: An Ultra-Precise Measurement of the Weak Mixing Angle Using M{\o}ller Scattering , 2014, 1411.4088.

[28]  Nuruzzaman,et al.  The Q(weak) experimental apparatus , 2014, 1409.7100.

[29]  J. Piekarewicz,et al.  Has a thick neutron skin in 208Pb been ruled out? , 2013, Physical review letters.

[30]  J. Erler,et al.  The Weak Neutral Current , 2013, 1303.5522.

[31]  Nicolas Produit,et al.  Weak charge form factor and radius of 208Pb through parity violation in electron scattering , 2012, 1202.1468.

[32]  Nicolas Produit,et al.  Measurement of the Neutron Radius of 208Pb Through Parity Violation in Electron Scattering , 2012, 1201.2568.

[33]  C. Horowitz,et al.  Model dependence of the γZ dispersion correction to the parity-violating asymmetry in elastic ep scattering , 2011, 1102.3910.

[34]  C. Horowitz,et al.  Relativistic effective interaction for nuclei, giant resonances, and neutron stars , 2010, 1008.3030.

[35]  C. Horowitz,et al.  Dispersion gammaZ-box correction to the weak charge of the proton. , 2008, Physical review letters.

[36]  P. Hartmann,et al.  Development of a high average current polarized electron source with long cathode operational lifetime , 2007 .

[37]  J. Piekarewicz,et al.  Neutron-rich nuclei and neutron stars: a new accurately calibrated interaction for the study of neutron-rich matter. , 2005, Physical review letters.

[38]  D. Kim,et al.  Parity violating electroweak asymmetry in polarized-e p scattering , 2004 .

[39]  C. Horowitz Parity Violating Measurements of Neutron Densities and Nuclear Structure , 2000, nucl-th/0010010.

[40]  C. Horowitz Parity violating elastic electron scattering and Coulomb distortions , 1998, nucl-th/9801011.

[41]  R. Schaeffer,et al.  A Skyrme parametrization from subnuclear to neutron star densities , 1997 .

[42]  D. Sprung,et al.  The symmetrized Fermi function and its transforms , 1997 .

[43]  P. Ring,et al.  New parametrization for the Lagrangian density of relativistic mean field theory , 1996, nucl-th/9607039.

[44]  I. Sick,et al.  Isospin dependences in parity-violating electron scattering , 1989 .

[45]  C. Papanicolas,et al.  Electron scattering and nuclear structure , 1987 .

[46]  C. Vries,et al.  Nuclear charge-density-distribution parameters from elastic electron scattering , 1987 .

[47]  P. Quentin,et al.  Nuclear ground-state properties and self-consistent calculations with the skyrme interaction: (I). Spherical description , 1975 .

[48]  J. Walecka ELECTRON SCATTERING AND NUCLEAR STRUCTURE. , 1968 .

[49]  A. Hewish,et al.  Observation of a Rapidly Pulsating Radio Source , 1968, Nature.

[50]  Aaas News,et al.  Book Reviews , 1893, Buffalo Medical and Surgical Journal.

[51]  P. K. Panda,et al.  GW190814: Gravitational Waves from the Coalescence of a 23 Solar Mass Black Hole with a 2.6 Solar Mass Compact Object , 2020 .

[52]  P. Markowitz,et al.  Precision Measurement of Parity-violation in Deep Inelastic Scattering Over a Broad Kinematic Range , 2009 .

[53]  Nicolas Produit,et al.  Basic instrumentation for Hall A at Jefferson Lab , 2004, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.