Search for the tetraneutron using the reaction <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi mathvariant="normal">He</mi></mrow><mprescripts></mprescripts><mrow></mrow><mrow><mn>4</mn></mrow><mrow></mrow><mrow></mrow></mmultiscripts></mrow></math>(<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>π</mi></mrow><mrow><mi mathvariant="normal">−</mi></mrow></msup></mrow></math>,<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup></mrow></math><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mo>)</mo></mrow><mrow><mn>4</mn></mrow></msup></mrow></math>n

T. P. Gorringe; S. Ahmad; D. S. Armstrong; R. A. Burnham; M. D. Hasinoff; A. J. Larabee; C. E. Waltham; G. Azuelos; J. A. Macdonald; J-M. Poutissou; M. Blecher; D. H. Wright; P. Depommier; R. Poutissou; E. T. H. Clifford

doi:10.1103/PhysRevC.40.2390

Search for the tetraneutron using the reaction ${}^{4}{He}$ ( $π^{-}$ , $π^{+}$ $)^{4}$ n

T. P. Gorringe, S. Ahmad, D. S. Armstrong, R. A. Burnham, M. D. Hasinoff, A. J. Larabee, C. E. Waltham, G. Azuelos, J. A. Macdonald, J-M. Poutissou, M. Blecher, D. H. Wright, P. Depommier, R. Poutissou, and E. T. H. Clifford

Phys. Rev. C 40, 2390 – Published 1 November 1989

Abstract

A search for the production of bound tetraneutrons has been carried out with a time projection chamber using the reaction ${}^{4}{He}$ ( $π^{-}$ , $π^{+}$ $)^{4}$ n at &=80 MeV and at &<130°. No evidence for tetraneutron formation was found, and a 90% confidence level upper limit for the production cross section of dσ/dΩ≤13 nb ${sr}^{- 1}$ was obtained.