https://doi.org/10.1051/epjconf/20100307014
The investigation of Λ(1405) state in the stopped K− reaction on deuterium
1
Department of Physics, The University of Tokyo,
Tokyo
113-0033,
Japan
2
RIKEN Nishina Center, RIKEN, Saitama
351-0198,
Japan
3
Department of Physics, Isfahan University of
Technology, Isfahan
84156-83111,
Iran
4
College of Science and Technology, Nihon
University, Chiba
274-8501,
Japan
a e-mail: tsuzuki@phys.s.u-tokyo.ac.jp
Nowadays, extensive studies of the problem of the deeply bound 
nuclei stimulate the reconsid eration of Λ(1405) state as the
theoretical basis of the binding of nuclei, and the old
question of the nature of Λ(1405) becomes a modern subject by
the new interest. In contrast to one of conventional interpretations of
Λ(1405) as the N quasi-bound state at
1405 MeV/c2 , a two-pole hypothesis, by which
Λ(1405) consists of two poles at 1420 and 1390
MeV/c2 couple mainly with N
and Σπ channels, respectively, was proposed recently. On the
other hand, a very recent theoretical analysis has clarified that the (Σπ)0 invariant mass spectra after
K− absorption in d reflect
strikingly resonant formation of Λ(1405) (or
Λ(1420)) and thus are capable of distinguishing different
Ansatz’s. We have proposed a new experiment by means of the stopped
K− reaction on liquid deuterium at J-PARC K1.8BR
beamline with E15/E17 experimental devices, so as to give a new precision- and
high-statistics-data of (Σπ)0 mass spectra to
examine the issue, Λ(1405) or Λ(1420), in the
most reliable way, and thus to answer the most fundamental questions of
N interaction and nuclei.
© Owned by the authors, published by EDP Sciences, 2010
