Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

“K−pp” a K‾-meson nuclear bound state, observed in 3He(K−,Λp)n reactions

Ajimura, S. ; Tatsuno, H. LU and Zmeskal, J. (2019) In Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 789. p.620-625
Abstract
We observed a distinct peak in the Λp invariant mass spectrum of He3(K−,Λp)n, well below mK+2mp, i.e., the mass threshold of the K− to be bound to two protons. By selecting a relatively large momentum-transfer region q=350∼650 MeV/c, one can kinematically separate the peak from the quasi-free process, K‾N→K‾N followed by the non-resonant absorption by the two spectator-nucleons K‾NN→ΛN. We found that the simplest fit to the observed peak gives us a Breit–Wigner pole position at BKpp=47±3(stat.)−6 +3(sys.) MeV having a width ΓKpp=115±7(stat.)−20 +10(sys.) MeV, and the S-wave Gaussian reaction form-factor parameter QKpp=381±14(stat.)−0 +57(sys.) MeV/c, as a new form of the nuclear bound system with strangeness – “K−pp”.
Please use this url to cite or link to this publication:
author
; and
author collaboration
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Kaon, Mesonic nuclear bound state, Strangeness
in
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
volume
789
pages
6 pages
publisher
Elsevier
external identifiers
  • scopus:85059823166
ISSN
0370-2693
DOI
10.1016/j.physletb.2018.12.058
language
English
LU publication?
yes
id
b3b39cf4-331c-489a-b32c-63277711893d
date added to LUP
2022-04-07 10:35:23
date last changed
2023-11-29 01:42:36
@article{b3b39cf4-331c-489a-b32c-63277711893d,
  abstract     = {{We observed a distinct peak in the Λp invariant mass spectrum of He3(K−,Λp)n, well below mK+2mp, i.e., the mass threshold of the K− to be bound to two protons. By selecting a relatively large momentum-transfer region q=350∼650 MeV/c, one can kinematically separate the peak from the quasi-free process, K‾N→K‾N followed by the non-resonant absorption by the two spectator-nucleons K‾NN→ΛN. We found that the simplest fit to the observed peak gives us a Breit–Wigner pole position at BKpp=47±3(stat.)−6 +3(sys.) MeV having a width ΓKpp=115±7(stat.)−20 +10(sys.) MeV, and the S-wave Gaussian reaction form-factor parameter QKpp=381±14(stat.)−0 +57(sys.) MeV/c, as a new form of the nuclear bound system with strangeness – “K−pp”.}},
  author       = {{Ajimura, S. and Tatsuno, H. and Zmeskal, J.}},
  issn         = {{0370-2693}},
  keywords     = {{Kaon; Mesonic nuclear bound state; Strangeness}},
  language     = {{eng}},
  pages        = {{620--625}},
  publisher    = {{Elsevier}},
  series       = {{Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics}},
  title        = {{“K−pp” a K‾-meson nuclear bound state, observed in 3He(K−,Λp)n reactions}},
  url          = {{http://dx.doi.org/10.1016/j.physletb.2018.12.058}},
  doi          = {{10.1016/j.physletb.2018.12.058}},
  volume       = {{789}},
  year         = {{2019}},
}