Precision study of the eta3He system using the dp--> 3Heeta reaction.
The differential and total cross sections for the dp--> 3Heeta reaction have been measured in a high precision high statistics COSY-ANKE experiment near threshold using a continuous beam energy ramp up to an excess energy Q of 11.3 MeV with essentially 100% acceptance. The kinematics allowed the mean value of Q to be determined to about 9 keV. Evidence is found for the effects of higher partial waves for Q >or= 4 MeV. The very rapid rise of the total cross section to its maximum value within 0.5 MeV of threshold implies a very large eta3He scattering length and hence the presence of a quasibound state extremely close to threshold.
Institut für Kernphysik, Universität Münster, 48149 Münster, Germany.
T
T
Mersmann
A
A
Khoukaz
M
M
Büscher
D
D
Chiladze
S
S
Dymov
M
M
Hartmann
V
V
Hejny
A
A
Kacharava
I
I
Keshelashvili
P
P
Kulessa
Y
Y
Maeda
M
M
Mielke
S
S
Mikirtychiants
H
H
Ohm
M
M
Papenbrock
D
D
Prasuhn
F
F
Rathmann
T
T
Rausmann
R
R
Schleichert
V
V
Serdyuk
H-J
HJ
Stein
H
H
Ströher
A
A
Täschner
Yu
Y
Valdau
C
C
Wilkin
A
A
Wrońska