Evidence for a kaon-bound state K(-)pp produced in K(-) absorption reactions at rest

M Agnello; G Beer; L Benussi; M Bertani; S Bianco; E Botta; T Bressani; L Busso; D Calvo; P Camerini; P Cerello; B Dalena; F De Mori; G D'Erasmo; D Di Santo; F L Fabbri; D Faso; A Feliciello; A Filippi; V Filippini; E M Fiore; H Fujioka; P Gianotti; N Grion; V Lucherini; S Marcello; T Maruta; N Mirfakhrai; O Morra; T Nagae; A Olin; H Outa; E Pace; M Palomba; A Pantaleo; A Panzarasa; V Paticchio; S Piano; F Pompili; R Rui; G Simonetti; H So; S Tomassini; A Toyoda; R Wheadon; A Zenoni; FINUDA Collaboration

doi:10.1103/PhysRevLett.94.212303

Evidence for a kaon-bound state K(-)pp produced in K(-) absorption reactions at rest

Phys Rev Lett. 2005 Jun 3;94(21):212303. doi: 10.1103/PhysRevLett.94.212303. Epub 2005 Jun 3.

Affiliation

¹ Dipartimento di Fisica del Politecnico di Torino, I-10129 Torino, Italy and INFN Sezione di Torino, I-10125 Torino, Italy.

PMID: 16090313
DOI: 10.1103/PhysRevLett.94.212303

Abstract

We have searched for a deeply bound kaonic state by using the FINUDA spectrometer installed at the e(+)e(-) collider DAPhiNE. Almost monochromatic K(-)'s produced through the decay of phi(1020) mesons are used to observe K(-) absorption reactions stopped on very thin nuclear targets. Taking this unique advantage, we have succeeded to detect a kaon-bound state K(-)pp through its two-body decay into a Lambda hyperon and a proton. The binding energy and the decay width are determined from the invariant-mass distribution as 115(+6)(-5)(stat)(+3)(-4)(syst) MeV and 67(+14)(-11)(stat)(+2)(-3)(syst) MeV, respectively.