학술논문
New Measurements of the Beam-Normal Single Spin Asymmetry in Elastic Electron Scattering Over a Range of Spin-0 Nuclei
Document Type
Working Paper
Author
PREX; Collaborations, CREX; Adhikari, D.; Albataineh, H.; Androic, D.; Aniol, K.; Armstrong, D. S.; Averett, T.; Gayoso, C. Ayerbe; Barcus, S.; Bellini, V.; Beminiwattha, R. S.; Benesch, J. F.; Bhatt, H.; Pathak, D. Bhatta; Bhetuwal, D.; Blaikie, B.; Boyd, J.; Campagna, Q.; Camsonne, A.; Cates, G. D.; Chen, Y.; Clarke, C.; Cornejo, J. C.; Dusa, S. Covrig; 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.; Hauenstein, F.; Henry, W.; Horowitz, C. J.; Jantzi, C.; Jian, S.; Johnston, S.; Jones, D. C.; Karki, B.; Kakkar, S.; Katugampola, S.; Keppel, C. E.; 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, J.; Mammei, R.; McCaughan, M.; McNulty, D.; Meekins, D.; Metts, C.; Michaels, R.; Mihovilovic, M.; Mondal, M. M.; Napolitano, J.; Nikolaev, D.; Rashad, M. N. H.; Owen, V.; Palatchi, C.; Pan, 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. A.; Tang, L.; Thiel, M.; Tian, Y.; Urciuoli, G. M.; Wertz, E. W.; Wojtsekhowski, B.; Xiong, W.; Yale, B.; Ye, T.; Zec, A.; Zhang, W.; Zhang, J.; Zheng, X.
Source
Phys.Rev.Lett. 128 (2022) 14, 142501
Subject
Language
Abstract
We report precision determinations of the beam normal single spin asymmetries ($A_n$) in the elastic scattering of 0.95 and 2.18~GeV electrons off $^{12}$C, $^{40}$Ca, $^{48}$Ca, and $^{208}$Pb at very forward angles where the most detailed theoretical calculations have been performed. The first measurements of $A_n$ for $^{40}$Ca and $^{48}$Ca are found to be similar to that of $^{12}$C, consistent with expectations thus demonstrating the validity of theoretical calculations for nuclei with Z~$\leq20$. We also report $A_n$ for $^{208}$Pb at two new momentum transfers (Q$^2$) extending the previous measurement. Our new data confirm the surprising result previously reported, with all three data points showing significant disagreement with the results from the $Z\leq 20$ nuclei. These data confirm our basic understanding of the underlying dynamics that govern $A_n$ for nuclei containing $\lesssim 50$ nucleons, but point to the need for further investigation to understand the unusual $A_n$ behaviour discovered for scattering off $^{208}$Pb.
Comment: 7 pages, 2 figures
Comment: 7 pages, 2 figures