CLAS Physics Database

E99-107

Spokespersons
P. Stoler, V.D.Burkert, R. Minehart, M. Taiuti
Year
2006
Abstract
We report a new measurement of the exclusive electroproduction reaction g* p -> pi0 p$ to explore the evolution from soft non-perturbative physics to hard processes via the Q2 dependence of the magnetic (M1+), electric (E1+) and scalar (S1+) multipoles in the N->Delta transition. 9000 differential cross section data points cover W from threshold to 1.4 GeV/c2, 4pi center-of-mass solid angle, and Q2 from 3 to 6 GeV2/c2, the highest yet achieved. Itis found that the magnetic form factor G*M decreases with Q2 more steeply than the proton magnetic form factor, the ratio E1+/M1+ is small and negative, indicating strong helicity non-conservation, and the ratio S1+/M1+ is negative, while its magnitude increases with Q2.
Publication
  1. M. Ungaro, P. Stoler, and CLAS Collabboration Measurement of the N → Δ+(1232) Transition at High Momentum Transfer by π0 Electroproduction // PRL 97, 112003 (2006)
Quantities
dσ/dΩ

Measurements

ID Quantity Beam Target Final state Q2min,
GeV2
Q2max,
GeV2
Wmin,
GeV
Wmax,
GeV
E37M1 dσ/dΩ e p π0p 3.0 3.0 1.11 1.11
E37M2 dσ/dΩ e p π0p 3.0 3.0 1.13 1.13
E37M3 dσ/dΩ e p π0p 3.0 3.0 1.15 1.15
E37M4 dσ/dΩ e p π0p 3.0 3.0 1.17 1.17
E37M5 dσ/dΩ e p π0p 3.0 3.0 1.19 1.19
E37M6 dσ/dΩ e p π0p 3.0 3.0 1.21 1.21
E37M7 dσ/dΩ e p π0p 3.0 3.0 1.23 1.23
E37M8 dσ/dΩ e p π0p 3.0 3.0 1.25 1.25
E37M9 dσ/dΩ e p π0p 3.0 3.0 1.27 1.27
E37M10 dσ/dΩ e p π0p 3.0 3.0 1.29 1.29
E37M11 dσ/dΩ e p π0p 3.0 3.0 1.31 1.31
E37M12 dσ/dΩ e p π0p 3.0 3.0 1.33 1.33
E37M13 dσ/dΩ e p π0p 3.0 3.0 1.35 1.35
E37M14 dσ/dΩ e p π0p 3.0 3.0 1.37 1.37
E37M15 dσ/dΩ e p π0p 3.0 3.0 1.39 1.39
E37M16 dσ/dΩ e p π0p 3.5 3.5 1.11 1.11
E37M17 dσ/dΩ e p π0p 3.5 3.5 1.13 1.13
E37M18 dσ/dΩ e p π0p 3.5 3.5 1.15 1.15
E37M19 dσ/dΩ e p π0p 3.5 3.5 1.17 1.17
E37M20 dσ/dΩ e p π0p 3.5 3.5 1.19 1.19
E37M21 dσ/dΩ e p π0p 3.5 3.5 1.21 1.21
E37M22 dσ/dΩ e p π0p 3.5 3.5 1.23 1.23
E37M23 dσ/dΩ e p π0p 3.5 3.5 1.25 1.25
E37M24 dσ/dΩ e p π0p 3.5 3.5 1.27 1.27
E37M25 dσ/dΩ e p π0p 3.5 3.5 1.29 1.29
E37M26 dσ/dΩ e p π0p 3.5 3.5 1.31 1.31
E37M27 dσ/dΩ e p π0p 3.5 3.5 1.33 1.33
E37M28 dσ/dΩ e p π0p 3.5 3.5 1.35 1.35
E37M29 dσ/dΩ e p π0p 3.5 3.5 1.37 1.37
E37M30 dσ/dΩ e p π0p 3.5 3.5 1.39 1.39
E37M31 dσ/dΩ e p π0p 4.2 4.2 1.11 1.11
E37M32 dσ/dΩ e p π0p 4.2 4.2 1.13 1.13
E37M33 dσ/dΩ e p π0p 4.2 4.2 1.15 1.15
E37M34 dσ/dΩ e p π0p 4.2 4.2 1.17 1.17
E37M35 dσ/dΩ e p π0p 4.2 4.2 1.19 1.19
E37M36 dσ/dΩ e p π0p 4.2 4.2 1.21 1.21
E37M37 dσ/dΩ e p π0p 4.2 4.2 1.23 1.23
E37M38 dσ/dΩ e p π0p 4.2 4.2 1.25 1.25
E37M39 dσ/dΩ e p π0p 4.2 4.2 1.27 1.27
E37M40 dσ/dΩ e p π0p 4.2 4.2 1.29 1.29
E37M41 dσ/dΩ e p π0p 4.2 4.2 1.31 1.31
E37M42 dσ/dΩ e p π0p 4.2 4.2 1.33 1.33
E37M43 dσ/dΩ e p π0p 4.2 4.2 1.35 1.35
E37M44 dσ/dΩ e p π0p 4.2 4.2 1.37 1.37
E37M45 dσ/dΩ e p π0p 3.0 3.0 1.39 1.39
E37M46 dσ/dΩ e p π0p 4.2 4.2 1.39 1.39
E37M47 dσ/dΩ e p π0p 5.0 5.0 1.11 1.11
E37M48 dσ/dΩ e p π0p 5.0 5.0 1.13 1.13
E37M49 dσ/dΩ e p π0p 5.0 5.0 1.15 1.15
E37M50 dσ/dΩ e p π0p 5.0 5.0 1.17 1.17
E37M51 dσ/dΩ e p π0p 5.0 5.0 1.19 1.19
E37M52 dσ/dΩ e p π0p 5.0 5.0 1.21 1.21
E37M53 dσ/dΩ e p π0p 5.0 5.0 1.23 1.23
E37M54 dσ/dΩ e p π0p 5.0 5.0 1.25 1.25
E37M55 dσ/dΩ e p π0p 5.0 5.0 1.27 1.27
E37M56 dσ/dΩ e p π0p 5.0 5.0 1.29 1.29
E37M57 dσ/dΩ e p π0p 5.0 5.0 1.31 1.31
E37M58 dσ/dΩ e p π0p 5.0 5.0 1.33 1.33
E37M59 dσ/dΩ e p π0p 5.0 5.0 1.35 1.35
E37M60 dσ/dΩ e p π0p 5.0 5.0 1.37 1.37
E37M61 dσ/dΩ e p π0p 5.0 5.0 1.39 1.39
E37M62 dσ/dΩ e p π0p 6.0 6.0 1.11 1.11
E37M63 dσ/dΩ e p π0p 6.0 6.0 1.13 1.13
E37M64 dσ/dΩ e p π0p 6.0 6.0 1.15 1.15
E37M65 dσ/dΩ e p π0p 6.0 6.0 1.17 1.17
E37M66 dσ/dΩ e p π0p 6.0 6.0 1.19 1.19
E37M67 dσ/dΩ e p π0p 6.0 6.0 1.21 1.21
E37M68 dσ/dΩ e p π0p 6.0 6.0 1.23 1.23
E37M69 dσ/dΩ e p π0p 6.0 6.0 1.25 1.25
E37M70 dσ/dΩ e p π0p 6.0 6.0 1.27 1.27
E37M71 dσ/dΩ e p π0p 6.0 6.0 1.29 1.29
E37M72 dσ/dΩ e p π0p 6.0 6.0 1.31 1.31
E37M73 dσ/dΩ e p π0p 6.0 6.0 1.33 1.33
E37M74 dσ/dΩ e p π0p 6.0 6.0 1.35 1.35
E37M75 dσ/dΩ e p π0p 6.0 6.0 1.37 1.37
E37M76 dσ/dΩ e p π0p 6.0 6.0 1.39 1.39