#### ${{\mathit \Delta}{(1232)}}$ BREIT-WIGNER PHOTON DECAY AMPLITUDES

Papers on ${{\mathit \gamma}}{{\mathit N}}$ amplitudes predating 1981 may be found in our 2006 edition, Journal of Physics G33 1 (2006).

#### ${{\mathit \Delta}{(1232)}}$ $\rightarrow$ ${{\mathit N}}{{\mathit \gamma}}$ , helicity-3/2 amplitude A$_{3/2}$

VALUE (GeV${}^{−1/2}$) DOCUMENT ID TECN  COMMENT
 $\bf{ -0.262\text{ to }-0.248\text{ }(\approx-0.255) }$ OUR ESTIMATE
$-0.250$ $\pm0.002$ 1
 2019
DPWA Multichannel
$-0.254$ $\pm0.005$
 2012 A
DPWA Multichannel
$-0.262$ $\pm0.003$
 2012 A
DPWA ${{\mathit \gamma}}$ ${{\mathit N}}$ $\rightarrow$ ${{\mathit N}}{{\mathit \pi}}$
$-0.258$ $\pm0.005$
 2007
DPWA ${{\mathit \gamma}}$ ${{\mathit N}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit N}}$
$-0.256$ $\pm0.003$
 2004 A
DPWA $\vec\gamma\vec {{\mathit p}}$ $\rightarrow$ ${{\mathit N}}{{\mathit \pi}}$
$-0.2669$ $\pm0.0016$ $\pm0.0078$
 2001
LEGS ${{\mathit \gamma}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \gamma}}$ , ${{\mathit p}}{{\mathit \pi}^{0}}$ , ${{\mathit n}}{{\mathit \pi}^{+}}$
$-0.251$ $\pm0.001$
 2000
IPWA $\vec\gamma$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \pi}^{0}}$ , ${{\mathit n}}{{\mathit \pi}^{+}}$
$-0.258$ $\pm0.006$
 1999
DPWA ${{\mathit \gamma}}$ ${{\mathit N}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit N}}$
$-0.2466$ $\pm0.0013$
 1998
IPWA ${{\mathit \gamma}}$ ${{\mathit N}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit N}}$
$-0.2524$ $\pm0.0013$
 1997
DPWA ${{\mathit \gamma}}$ ${{\mathit N}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit N}}$
• • We do not use the following data for averages, fits, limits, etc. • •
$-0.251$ $\pm0.001$ 1
 2012 A
DPWA Multichannel
$-0.267$ $\pm0.008$
 2010
DPWA Multichannel
$-0.265$
 2007
DPWA ${{\mathit \gamma}}$ ${{\mathit N}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit N}}$
$-0.243$ $\pm0.001$
 2002
DPWA ${{\mathit \gamma}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit N}}{{\mathit \pi}}$
$-0.247$
 2002 D
DPWA Multichannel
$-0.2522$
 1998
DPWA ${{\mathit \gamma}}$ ${{\mathit N}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit N}}$
 1 Statistical error only.
References:
 HUNT 2019
PR C99 055205 Updated determination of $N^*$ resonance parameters using a unitary, multichannel formalism
 ANISOVICH 2012A
EPJ A48 15 Properties of Baryon Resonances from a Multichannel Partial Wave Analysis
 SHRESTHA 2012A
PR C86 055203 Multichannel Parametrization of ${{\mathit \pi}}{{\mathit N}}$ Scattering Amplitudes and Extraction of Resonance Parameters
 WORKMAN 2012A
PR C86 015202 Unified Chew-Mandelstam SAID Analysis of Pion Photoproduction Data
 ANISOVICH 2010
EPJ A44 203 Photoproduction of Pions and Properties of Baryon Resonances from a Bonn-Gatchina Partial-Wave Analysis
 DRECHSEL 2007
EPJ A34 69 Unitary Isobar Model $−$ MAID2007
 DUGGER 2007
PR C76 025211 ${{\mathit \pi}^{0}}$ Photoproduction on the Proton for Photon Energies from 0.675 to 2.875 GeV
 AHRENS 2004A
EPJ A21 323 Helicity Dependence of the ${{\mathit \gamma}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit N}}{{\mathit \pi}}$ Channels and Multipole Analysis in the ${{\mathit \Delta}}$ Region
 ARNDT 2002
PR C66 055213 Analysis of Pion Photoproduction Data
 PENNER 2002D
PR C66 055212 Vector Meson Production and Nucleon Resonance Analysis in a Coupled Channel Approach for Energies ${\mathit m}_{{{\mathit N}}}$ $<$ $\sqrt {s }$ $<$ 2 GeV. 2. Photon Induced Results
 BLANPIED 2001
PR C64 025203 ${{\mathit N}}$ $\rightarrow$ ${{\mathit \Delta}}$ Transition and Proton Polarizabilities from Measurements of ${{\mathit p}}$ (${{\mathit \gamma}}$ $↑$, ${{\mathit \gamma}}$ ), ${{\mathit p}}$ (${{\mathit \gamma}}$ $↑$, ${{\mathit \pi}^{0}}$ ), and ${{\mathit p}}$ (${{\mathit \gamma}}$ $↑$, ${{\mathit \pi}^{+}}$ )
 BECK 2000
PR C61 035204 Determination of the $\mathit E2/\mathit M$1 Ratio in the ${{\mathit \gamma}}$ ${{\mathit N}}$ $\rightarrow$ ${{\mathit \Delta}{(1232)}}$ Transition from a Simultaneous Measurement of ${{\mathit p}}$ (${{\mathit \gamma}}$ $↑$, ${{\mathit p}}$ )${{\mathit \pi}^{0}}$ and ${{\mathit p}}$ (${{\mathit \gamma}}$ $↑$, ${{\mathit \pi}^{+}}$ )${{\mathit n}}$
 KAMALOV 1999
PRL 83 4494 Pion Cloud and the $\mathit Q{}^{2}$ Dependence of ${{\mathit \gamma}^{*}}{{\mathit N}}$ $\leftrightarrow$ ${{\mathit \Delta}}$ Transition Form Factors
 HANSTEIN 1998
NP A632 561 Multipole Analysis of Pion Photoproduction Based on Fixed $\mathit t$ Dispersion Relations and Unitarity
 DAVIDSON 1997
PRL 79 4509 Mainz Measurement of the $\mathit E2/\mathit M$1 Ratio in the ${{\mathit N}}$ $−$ ${{\mathit \Delta}}$ Transition. (A Comment on the Letter by R.Beck $\mathit et~al$, PRL 78, 606 (BECK 1997 ))