Induced proton polarization for pi(0) electroproduction at Q(2)=0.126 GeV2/c(2) around the Delta(1232) resonance

Authors :: Warren, GA Alarcon, R Armstrong, C Asavapibhop, B and Barkhuff, DH Bertozzi, W Burkert, V Chen, J Chen, JP and Comfort, JR Dale, D Dodson, G Dolfini, S Dow, K and Epstein, M Farkhondeh, M Finn, JM Gilad, S Gothe, RW and Jiang, X Jones, M Joo, K Karabarbounis, A Kelly, J and Kowalski, S Kunz, C Liu, D Lourie, RW Madey, R and Margaziotis, D Markowitz, P McIntyre, JI Mertz, C and Milbrath, BD Miskimen, R Mitchell, J Mukhopadhyay, S and Papanicolas, CN Perdrisat, C Punjabi, V Qin, L Rutt, P and Sarty, A Shaw, J Soong, SB Tieger, D Tschalaer, C and Turchinetz, W Ulmer, P Van Verst, S Vellidis, C and Weinstein, LB Williamson, S Woo, RJ Young, A
Publication Year :: 1998
Abstract: We present a measurement of the induced proton polarization P-n in pi(0) electroproduction on the proton around the Delta resonance. The measurement was made at a central invariant mass and a squared four-momentum transfer of W=1231 MeV and Q(2)=0.126 GeV2/c(2), respectively. We measured a large induced polarization, P-n = -0.397 +/- 0.055 +/- 0.009. The data suggest that the scalar background is larger than expected from a recent effective Hamiltonian model. [S0556-2813(98)02012-3].

Tools