13 research outputs found
Recoil polarization for Delta excitation in pion electroproduction - art. no. 102002
We measured angular distributions of recoil-polarization response
functions for neutral pion electroproduction for W=1.23 GeV at Q(2)=1.0
(GeV/c)(2), obtaining 14 separated response functions plus 2 Rosenbluth
combinations; of these, 12 have been observed for the first time.
Dynamical models do not describe quantities governed by imaginary parts
of interference products well, indicating the need for adjusting
magnitudes and phases for nonresonant amplitudes. We performed a nearly
model-independent multipole analysis and obtained values for Re
(S1+/M1+)= -(6.84 +/- 0.15)% and Re (E1+/M1+)= -(2.91 +/- 0.19)% that
are distinctly different from those from the traditional Legendre
analysis based upon M1+ dominance and l(pi)<= 1 truncation