Budzanowski, A.; Chatterjee, A.; Hawranek, P.; Jahn, R.; Jain, B. K.;
Jha, V.; Kailas, S.; Kilian, K.; Kliczewski, S.; Kirillov,
Da.; Roy, B. J.; and others
ABSTRACT
We have studied the reaction p + 27Al
→ 3He + p + π− + X at
recoil-free kinematics. An η meson possibly produced in
this reaction would be thus almost at rest in the laboratory
system and could therefore be bound with high probability, if
nuclear η states exist. The decay of such a state through
the N*(1535)
resonance would lead to a proton-π− pair
emitted in opposite directions. For these conditions we find
some indication of such a bound state. An upper limit of ≈0.5 nb
is found.