Document Type
Report
Publication Date
2014
Pages
37 pp.
Abstract
We propose to perform the first measurements of the spin-dependent EMC effect utilizing CLAS12 in Hall B with 11 GeV polarized electrons and polarized nuclear targets. Our target of choice is ⁷Li (in the form of dynamically polarized ⁷LiD) in which a highly polarized proton is embedded in the nuclear medium. Simultaneously, we will also measure the double spin asymmetry on the proton with a ⁶LiH target, to minimize systematic uncertainties. The experiment will obtain the double spin asymmetry A ⁷IILi ≈ g⁷₁Li from the measurement on ⁷LiD, after correcting for the small contribution from other polarized species (D) and the beam and target polarization as well as the dilution by unpolarized target components. Using the simultaneous measurement on ⁶LiH, we can form the ratio of the double spin asymmetries as well as the cross section differences directly (with many systematic uncertainties canceling), both of which contain direct information on any medium effect on spin structure functions and asymmetries. Together with the unpolarized structure function (to be measured in Hall C), we can also extract gp₁ | ⁷Li for a proton bound in ⁷LiD. We will cover a kinematic range of 1 < Q² < 15 GeV² and 0.06 < x < 0.8. These data will provide new constraints on models for the EMC effect, some of which predict that medium modifications of quark distributions depend strongly on the quark helicities.
We request 50 days of 11 GeV beam on the longitudinal polarized target and 5 additional days for auxiliary measurements.
Rights
© 2014 The authors. All rights reserved.
Included with the kind written permission of the authors.
Original Publication Citation
Brooks, W., Hakobyan, H., Kopeliovich, B., Kuleshov, S., Mancilla, S., Mendez, R., Adhikari, K., Dodge, G., El Fassi, L., Kuhn, S., Weinstein, L., Avakian, H., Deur, A., Higinbotham, D., Keith, C., Melnitchouk, W., Pierce, J., Crabb, D., Keller, D.,…Tarutina, T. (2019). The EMC effect of spin structure functions (No. PR12-14-001). Thomas Jefferson National Accelerator Facility. https://www.jlab.org/exp_prog/proposals/14/PR12-14-001.pdf
ORCID
0000-0003-1582-2376 (Dodge), 0000-0003-2243-6836 (Kuhn)
Repository Citation
Brooks, W. K.; Hakobyan, H.; Kopeliovich, B.; Kuleshov, S.; Mancilla, S.; Mendez, R.; Adhikari, K.; Dodge, G.; Fassi, L. El; Kuhn, S.; Weinstein, L.; Avakian, H.; Deur, A.; Higinbotham, D.; Keith, C.; Melnitchouk, W.; Pierce, J.; Crabb, D.; Keller, D.; Tkachenko, S.; Zhang, J.; Bosted, P. E.; Griffioen, K.; Hicks, K.; Dupré, R.; Badman, T.; Li, S.; Long, E.; Slifer, K.; Solvignon, P.; Zielinski, R.; Kalantarians, N.; Klein, F. J.; Thomas, A. W.; Bentz, W.; Cloet, I.; Wiringa, R. B.; Ciofi degli Atti, C.; Fanchiotti, H.; Garcia Canal, C. A.; Tarutina, T.; and Vento, V., "The EMC Effect in Spin Structure Functions" (2014). Physics Faculty Publications. 956.
https://digitalcommons.odu.edu/physics_fac_pubs/956