Agnello M, Beer G, Benussi L, Bertani M, Bianco S, Botta E, Bressani T, Busso L, Calvo D, Camerini P, Cerello P, Dalena B, De Mori F, D'Erasmo G, Di Santo D, Fabbri F L, Faso D, Feliciello A, Filippi A, Filippini V, Fiore E M, Fujioka H, Gianotti P, Grion N, Lucherini V, Marcello S, Maruta T, Mirfakhrai N, Morra O, Nagae T, Olin A, Outa H, Pace E, Palomba M, Pantaleo A, Panzarasa A, Paticchio V, Piano S, Pompili F, Rui R, Simonetti G, So H, Tomassini S, Toyoda A, Wheadon R, Zenoni A
Dipartimento di Fisica del Politecnico di Torino, I-10129 Torino, Italy and INFN Sezione di Torino, I-10125 Torino, Italy.
Phys Rev Lett. 2005 Jun 3;94(21):212303. doi: 10.1103/PhysRevLett.94.212303.
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.
我们利用安装在正负电子对撞机DAPhiNE上的FINUDA谱仪寻找深度束缚的奇异介子态。通过φ(1020)介子衰变产生的几乎单色的K⁻，用于观测在非常薄的核靶上停止的K⁻吸收反应。利用这一独特优势，我们成功地通过其两体衰变到一个Λ超子和一个质子中探测到一个奇异介子束缚态K⁻pp。结合能和衰变宽度分别根据不变质量分布确定为115(+6)(-5)(统计)(+3)(-4)(系统)兆电子伏特和67(+14)(-11)(统计)(+2)(-3)(系统)兆电子伏特。
