Measurement of the Q2 Dependence of the Deuteron Spin Structure Function g1 and its Moments at Low Q2 with CLAS

Adhikari, K. P.; Deur, A.; El Fassi, L.; Kang, H.; Kuhn, S. E.; Ripani, M.; Slifer, K.; Zheng, X.; Adhikari, S.; Akbar, Z.; Amaryan, M. J.; Avakian, H.; Ball, J.; Balossino, I.; Barion, L.; Battaglieri, M.; Bedlinskiy, I.; Biselli, A. S.; Bosted, P.; Briscoe, W. J.; Brock, J.; Bültmann, S.; Burkert, V. D.; Thanh Cao, F.; Carlin, C.; Carman, D. S.; Celentano, A.; Charles, G.; Chen, J. -P.; Chetry, T.; Choi, S.; Ciullo, G.; Clark, L.; Cole, P. L.; Contalbrigo, M.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Defurne, M.; Djalali, C.; Dodge, G. E.; Drozdov, V.; Dupre, R.; Egiyan, H.; El Alaoui, A.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Filippi, A.; Ghandilyan, Y.; Gilfoyle, G. P.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guler, N.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Harrison, N.; Hattawy, M.; Heddle, D.; Hicks, K.; Holtrop, M.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Isupov, E. L.; Jenkins, D.; H. S., Jo; Johnston, S. C.; Joo, K.; Joosten, S.; Kabir, M. L.; Keith, C. D.; Keller, D.; Khachatryan, G.; Khachatryan, M.; Khandaker, M.; Kim, W.; Klein, A.; Klein, F. J.; Konczykowski, P.; Kovacs, K.; Kubarovsky, V.; Lanza, L.; Lenisa, P.; Livingston, K.; Long, E.; Macgregor, I. J. D.; Markov, N.; Mayer, M.; Mckinnon, B.; Meekins, D. G.; Meyer, C. A.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Movsisyan, A.; Munoz Camacho, C.; Nadel-Turonski, P.; Niculescu, G.; Niccolai, S.; Osipenko, M.; Ostrovidov, A. I.; Paolone, M.; Pappalardo, L.; Paremuzyan, R.; Park, K.; Pasyuk, E.; Payette, D.; Phelps, W.; Phillips, S. K.; Pierce, J.; Pogorelko, O.; Poudel, J.; Price, J. W.; Prok, Y.; Protopopescu, D.; Raue, B. A.; Rizzo, A.; Rosner, G.; Rossi, P.; Sabatié, F.; Salgado, C.; Schumacher, R. A.; Sharabian, Y. G.; Shigeyuki, T.; Simonyan, A.; Skorodumina, Iu.; Smith, G. D.; Sparveris, N.; Sokhan, D.; Stepanyan, S.; Strakovsky, I. I.; Strauch, S.; Sulkosky, V.; Taiuti, M.; Tan, J. A.; Ungaro, M.; Voutier, E.; Wei, X.; Weinstein, L. B.; Zhang, J.; Zhao, Z. W.

doi:10.1103/PhysRevLett.120.062501

We measured the g1 spin structure function of the deuteron at low Q2, where QCD can be approximated with chiral perturbation theory (χPT). The data cover the resonance region, up to an invariant mass of W ≈ 1.9 GeV. The generalized Gerasimov-Drell-Hearn sum, the moment Γ1d and the spin polarizability γ0d are precisely determined down to a minimum Q2 of 0.02 GeV2 for the first time, about 2.5 times lower than that of previous data. We compare them to several χPT calculations and models. These results are the first in a program of benchmark measurements of polarization observables in the χPT domain.