First observation of excited omega(-)(b) states
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
We report four narrow peaks in the
Ξ
0
b
K
−
mass spectrum obtained using
p
p
collisions at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of
9
fb
−
1
recorded by the LHCb experiment. Referring to these states by their mass, the mass values are
m
[
Ω
b
(
6316
)
−
]
=
6315.64
±
0.31
±
0.07
±
0.50
MeV
,
m
[
Ω
b
(
6330
)
−
]
=
6330.30
±
0.28
±
0.07
±
0.50
MeV
,
m
[
Ω
b
(
6340
)
−
]
=
6339.71
±
0.26
±
0.05
±
0.50
MeV
,
m
[
Ω
b
(
6350
)
−
]
=
6349.88
±
0.35
±
0.05
±
0.50
MeV
, where the uncertainties are statistical, systematic, and the last is due to the knowledge of the
Ξ
0
b
mass. The natural widths of the three lower mass states are consistent with zero, and the 90% confidence-level upper limits are determined to be
Γ
[
Ω
b
(
6316
)
−
]
<
2.8
MeV
,
Γ
[
Ω
b
(
6330
)
−
]
<
3.1
MeV
and
Γ
[
Ω
b
(
6340
)
−
]
<
1.5
MeV
. The natural width of the
Ω
b
(
6350
)
−
peak is
1.4
+
1.0
−
0.8
±
0.1
MeV
, which is
2.5
σ
from zero and corresponds to an upper limit of 2.8 MeV. The peaks have local significances ranging from
3.6
σ
to
7.2
σ
. After accounting for the look-elsewhere effect, the significances of the
Ω
b
(
6316
)
−
and
Ω
b
(
6330
)
−
peaks are reduced to
2.1
σ
and
2.6
σ
, respectively, while the two higher mass peaks exceed
5
σ
. The observed peaks are consistent with expectations for excited
Ω
−
b
resonances.
Ξ
0
b
K
−
mass spectrum obtained using
p
p
collisions at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of
9
fb
−
1
recorded by the LHCb experiment. Referring to these states by their mass, the mass values are
m
[
Ω
b
(
6316
)
−
]
=
6315.64
±
0.31
±
0.07
±
0.50
MeV
,
m
[
Ω
b
(
6330
)
−
]
=
6330.30
±
0.28
±
0.07
±
0.50
MeV
,
m
[
Ω
b
(
6340
)
−
]
=
6339.71
±
0.26
±
0.05
±
0.50
MeV
,
m
[
Ω
b
(
6350
)
−
]
=
6349.88
±
0.35
±
0.05
±
0.50
MeV
, where the uncertainties are statistical, systematic, and the last is due to the knowledge of the
Ξ
0
b
mass. The natural widths of the three lower mass states are consistent with zero, and the 90% confidence-level upper limits are determined to be
Γ
[
Ω
b
(
6316
)
−
]
<
2.8
MeV
,
Γ
[
Ω
b
(
6330
)
−
]
<
3.1
MeV
and
Γ
[
Ω
b
(
6340
)
−
]
<
1.5
MeV
. The natural width of the
Ω
b
(
6350
)
−
peak is
1.4
+
1.0
−
0.8
±
0.1
MeV
, which is
2.5
σ
from zero and corresponds to an upper limit of 2.8 MeV. The peaks have local significances ranging from
3.6
σ
to
7.2
σ
. After accounting for the look-elsewhere effect, the significances of the
Ω
b
(
6316
)
−
and
Ω
b
(
6330
)
−
peaks are reduced to
2.1
σ
and
2.6
σ
, respectively, while the two higher mass peaks exceed
5
σ
. The observed peaks are consistent with expectations for excited
Ω
−
b
resonances.
Date Issued
2020-02-25
Date Acceptance
2020-02-01
Citation
Physical Review Letters, 2020, 124 (8), pp.082002-1-082002-12
ISSN
0031-9007
Publisher
American Physical Society
Start Page
082002-1
End Page
082002-12
Journal / Book Title
Physical Review Letters
Volume
124
Issue
8
Copyright Statement
© 2020 CERN, for the LHCb Collaboration. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license (https://creativecommons.org/licenses/by/4.0/). Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000515707700003&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Physical Sciences
Physics, Multidisciplinary
Physics
HEAVY BARYONS
DECAY
Publication Status
Published
Article Number
ARTN 082002
Date Publish Online
2020-02-25