Indication of a deeply bound and compact K- pp state formed in the pp- -> pLambdaK+ reaction at 2.85 GeV.
We have analyzed data of the DISTO experiment on the exclusive pp --> pLambdaK+ reaction at 2.85 GeV to search for a strongly bound compact K- pp(approximately = X) state to be formed in the pp --> K+ + X reaction. The observed spectra of the K+ missing mass and the pLambda invariant-mass with high transverse momenta of p and K+ revealed a broad distinct peak of 26-sigma confidence with a mass M(X)=2267+/-3(stat)+/-5(syst) MeV/c2 and a width Gamma(X)=118+/-8(stat)+/-10(syst) MeV. The enormously large cross section indicates formation of a compact K- pp with a large binding energy of B(K)=103 MeV, which can be a possible gateway toward cold and dense kaonic nuclear matter.
Yamazaki
T
T
Department of Physics, University of Tokyo, Tokyo, 116-0033 Japan.
Maggiora
M
M
Kienle
P
P
Suzuki
K
K
Amoroso
A
A
Alexeev
M
M
Balestra
F
F
Bedfer
Y
Y
Bertini
R
R
Bland
L C
LC
Brenschede
A
A
Brochard
F
F
Bussa
M P
MP
Choi
Seonho
S
Colantoni
M L
ML
Dressler
R
R
Dzemidzic
M
M
Faivre
J-Cl
JC
Ferrero
L
L
Foryciarz
J
J
Fröhlich
I
I
Frolov
V
V
Garfagnini
R
R
Grasso
A
A
Heinz
S
S
Jacobs
W W
WW
Kühn
W
W
Maggiora
A
A
Panzieri
D
D
Pfaff
H-W
HW
Pontecorvo
G
G
Popov
A
A
Ritman
J
J
Salabura
P
P
Sosio
S
S
Tchalyshev
V
V
Vigdor
S E
SE