학술논문
Accurate Determination of the Neutron Skin Thickness of $^{208}$Pb through Parity-Violation in Electron Scattering
Document Type
Working Paper
Author
Adhikari, D.; Albataineh, H.; Androic, D.; Aniol, K.; Armstrong, D. S.; Averett, T.; Barcus, S.; Bellini, V.; Beminiwattha, R. S.; Benesch, J. F.; Bhatt, H.; Pathak, D. Bhatta; Bhetuwal, D.; Blaikie, B.; Campagna, Q.; Camsonne, A.; Cates, G. D.; Chen, Y.; Clarke, C.; Cornejo, J. C.; Dusa, S. Covrig; Datta, P.; Deshpande, A.; Dutta, D.; Feldman, C.; Fuchey, E.; Gal, C.; Gaskell, D.; Gautam, T.; Gayoso, C. Ayerbe; Gericke, M.; Ghosh, C.; Halilovic, I.; Hansen, J. -O.; Hauenstein, F.; Henry, W.; Horowitz, C. J.; Jantzi, C.; Jian, S.; Johnston, S.; Jones, D. C.; Karki, B.; Katugampola, S.; Keppel, C.; King, P. M.; King, D. E.; Knauss, M.; Kumar, K. S.; Kutz, T.; Lashley-Colthirst, N.; Leverick, G.; Liu, H.; Liyange, N.; Malace, S.; Mammei, R.; Mammei, J.; McCaughan, M.; McNulty, D.; Meekins, D.; Metts, C.; Michaels, R.; Mondal, M. M.; Napolitano, J.; Narayan, A.; Nikolaev, D.; Rashad, M. N. H.; Owen, V.; Palatchi, C.; Pan, 14 J.; Pandey, B.; Park, S.; Paschke, K. D.; Petrusky, M.; Pitt, M. L.; Premathilake, S.; Puckett, A. J. R.; Quinn, B.; Radloff, R.; Rahman, S.; Rathnayake, A.; Reed, B. T.; Reimer, P. E.; Richards, R.; Riordan, S.; Roblin, Y.; Seeds, S.; Shahinyan, A.; Souder, P.; Tang, L.; Thiel, 16 M.; Tian, Y.; Urciuoli, G. M.; Wertz, E. W.; Wojtsekhowski, B.; Yale, B.; Ye, T.; Yoon, A.; Zec, A.; Zhang, W.; Zhang, J.; Zheng, X.
Source
Phys. Rev. Lett. 126, 172502 (2021)
Subject
Language
Abstract
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 $A_{PV}=550\pm 16 {\rm (stat)}\pm 8\ {\rm (syst)}$ parts per billion, leading to an extraction of the neutral weak form factor $F_W(Q^2 = 0.00616\ {\rm GeV}^2) = 0.368 \pm 0.013$. Combined with our previous measurement, the extracted neutron skin thickness is $R_n-R_p=0.283 \pm 0.071$~fm. The result also yields the first significant direct measurement of the interior weak density of $^{208}$Pb: $\rho^0_W = -0.0796\pm0.0036\ {\rm (exp.)}\pm0.0013\ {\rm (theo.)}\ {\rm fm}^{-3}$ leading to the interior baryon density $\rho^0_b = 0.1480\pm0.0036\ {\rm (exp.)}\pm0.0013\ {\rm (theo.)}\ {\rm fm}^{-3}$. 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.