Precision Determination of the Neutral Weak Form Factor of Ca 48

Journal Article · 19 July 2022 · Physical Review Letters

DOI: https://doi.org/10.1103/physrevlett.129.042501 · OSTI ID:1877582

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

In this work, we report a precise measurement of the parity-violating asymmetry $$A_{\rm PV}$$ in the elastic scattering of longitudinally polarized electrons from $$^{48}{\rm Ca}$$. We measure $$A_{\rm PV} =2668\pm 106\ {\rm (stat)}\pm 40\ {\rm (syst)}$$ parts per billion, leading to an extraction of the neutral weak form factor $$F_{\rm W} (q=0.8733$$ fm$$^{-1}) = 0.1304 \pm 0.0052 \ {\rm (stat)}\pm 0.0020\ {\rm (syst)}$$ and the charge minus the weak form factor $$F_{\rm ch} - F_{\rm W} = 0.0277\pm 0.0055$$. The resulting neutron skin thickness $$R_n-R_p=0.121 \pm 0.026\ {\rm (exp)} \pm 0.024\ {\rm (model)}$$~fm is relatively thin yet consistent with many model calculations. The combined CREX and PREX results will have implications for future energy density functional calculations and on the density dependence of the symmetry energy of nuclear matter.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States); College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
• Sponsoring Organization: National Science Foundation (NSF); USDOE Office of Science (SC), Nuclear Physics (NP)
• Contributing Organization: CREX Collaboration
• Grant/Contract Number: AC02-06CH11357; AC05-06OR23177; FG02-96ER41003
• OSTI ID: 1877582
• Report Number(s): DOE/OR/23177-5521; JLAB-PHY-22-3642; arXiv:2205.11593
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 4 Vol. 129; ISSN 0031-9007
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English