Evidence for a kaon-bound state K(-)pp produced in K(-) absorption reactions at rest.
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.
Agnello
M
M
Dipartimento di Fisica del Politecnico di Torino, I-10129 Torino, Italy and INFN Sezione di Torino, I-10125 Torino, Italy.
Beer
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G
Benussi
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L
Bertani
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M
Bianco
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Botta
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E
Bressani
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T
Busso
L
L
Calvo
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D
Camerini
P
P
Cerello
P
P
Dalena
B
B
De Mori
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F
D'Erasmo
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Di Santo
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Fabbri
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Faso
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Feliciello
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Filippi
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Filippini
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Fiore
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Fujioka
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Gianotti
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P
Grion
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N
Lucherini
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Marcello
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Maruta
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T
Mirfakhrai
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N
Morra
O
O
Nagae
T
T
Olin
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Outa
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H
Pace
E
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Palomba
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M
Pantaleo
A
A
Panzarasa
A
A
Paticchio
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Piano
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S
Pompili
F
F
Rui
R
R
Simonetti
G
G
So
H
H
Tomassini
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S
Toyoda
A
A
Wheadon
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R
Zenoni
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A