Helicity amplitudes A1/2 and A3/2 for the D13(1520) resonance obtained from the gamma-->p-->-->ppi(0) Reaction.
The helicity dependence of the gamma-->p-->-->ppi(0) reaction has been measured for the first time in the photon-energy range from 550 to 790 MeV. The experiment, performed at the Mainz microtron MAMI, used a 4pi-detector system, a circularly polarized, tagged photon beam, and a longitudinally polarized frozen-spin target. These data are predominantly sensitive to the D13(1520) resonance and are used to determine its helicity amplitudes.
Ahrens
J
J
Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany.
Altieri
S
S
Annand
J R M
JR
Anton
G
G
Arends
H-J
HJ
Aulenbacher
K
K
Beck
R
R
Bradtke
C
C
Braghieri
A
A
Degrande
N
N
D'Hose
N
N
Drechsel
D
D
Dutz
H
H
Goertz
S
S
Grabmayr
P
P
Hansen
K
K
Harmsen
J
J
Von Harrach
D
D
Hasegawa
S
S
Hasegawa
T
T
Heid
E
E
Helbing
K
K
Holvoet
H
H
Van Hoorebeke
L
L
Horikawa
N
N
Iwata
T
T
Jahn
O
O
Jennewein
P
P
Kageya
T
T
Kamalov
S
S
Kiel
B
B
Klein
F
F
Kondratiev
R
R
Kossert
K
K
Krimmer
J
J
Lang
M
M
Lannoy
B
B
Leukel
R
R
Lisin
V
V
Matsuda
T
T
McGeorge
J C
JC
Meier
A
A
Menze
D
D
Meyer
W
W
Michel
T
T
Naumann
J
J
Panzeri
A
A
Pedroni
P
P
Pinelli
T
T
Preobrajenski
I
I
Radtke
E
E
Reichert
E
E
Reicherz
G
G
Rohlof
Ch
Ch
Rosner
G
G
Ryckbosch
D
D
Sauer
M
M
Schoch
B
B
Schumacher
M
M
Seitz
B
B
Speckner
T
T
Takabayashi
N
N
Tamas
G
G
Thomas
A
A
Tiator
L
L
Van Vyver
R
R
Wakai
A
A
Weihofen
W
W
Wissmann
F
F
Zapadtka
F
F
Zeitler
G
G