A
bstract
The
ϒ
(1
S
)
μ
+
μ
−
invariant-mass distribution is investigated for a possible exotic meson state composed of two
b
quarks and two
b
¯
quarks,
X
b
b
¯
b
b
¯
. The analysis is based on a ...data sample of
pp
collisions recorded with the LHCb detector at centre-of-mass energies
s
=
7
, 8 and 13 TeV, corresponding to an integrated luminosity of 6.3 fb
−1
. No significant excess is found, and upper limits are set on the product of the production cross-section and the branching fraction as functions of the mass of the
X
b
b
¯
b
b
¯
state. The limits are set in the fiducial volume where all muons have pseudorapidity in the range 2
.
0
,
5
.
0, and the
X
b
b
¯
b
b
¯
state has rapidity in the range 2
.
0
,
4
.
5 and transverse momentum less than 15 GeV/
c
.
Overview of the CMD-3 recent results Ryzhenenkov, A E; Akhmetshin, R R; Amirkhanov, A N ...
Journal of physics. Conference series,
04/2020, Volume:
1526, Issue:
1
Journal Article
Peer reviewed
Open access
The CMD-3 detector started data taking at the electron-positron collider VEPP-2000 in December 2010 with a goal to collect about 1 fb−1. The collected data sample corresponds to an integrated ...luminosity of 200 pb−1 in the center-of-mass energy range from 0.32 up to 2 GeV. This paper reports recent results on the hadronic cross sections measurements with the CMD-3 detector.
The updated results of the precise measurements of the processes e+e−→ρ→π+π−, e+e−→ω→π+π−π0 and e+e−→φ→K0LK0S performed by the CMD-2 Collaboration are presented. The update appeared necessary due to ...an overestimate of the integrated luminosity in previous analyses.
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Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The process e+e−→K+K−π+π− has been studied in the center-of-mass energy range from 1500 to 2000 MeV using a data sample of 23 pb−1 collected with the CMD-3 detector at the VEPP-2000 e+e− collider. ...Using about 24 000 selected events, the e+e−→K+K−π+π− cross section has been measured with a systematic uncertainty decreasing from 11.7% at 1500–1600 MeV to 6.1% above 1800 MeV. A preliminary study of K+K−π+π− production dynamics has been performed.
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Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The cross section of the process e + e − → π + π − has been measured in the center of mass energy range from 0.32 to 1.2 GeV with the CMD-3 detector at the electron-positron collider VEPP-2000. The ...measurement is based on a full dataset collected below 1 GeV during three data taking seasons, corresponding to an integrated luminosity of about 62 pb − 1 . In the dominant ρ -resonance region, a systematic uncertainty of 0.7% has been reached. At energies around ϕ -resonance the π + π − production cross section was measured for the first time with high beam energy resolution. The forward-backward charge asymmetry in the π + π − production has also been measured. It shows a strong deviation from the theoretical prediction based on the conventional scalar quantum electrodynamics framework, and it is in good agreement with the generalized vector-meson-dominance and dispersive-based predictions. The impact of the presented results on the evaluation of the hadronic contribution to the anomalous magnetic moment of muon is discussed. Published by the American Physical Society 2024
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
We search for lepton-number- and baryon-number-violating decays τ− → ¯pe+e−, pe−e−, ¯pe+μ−, ¯pe−μ+, ¯pμ+μ−, and pμ−μ− using 921 fb−1 of data, equivalent to (841 ± 12) × 106 τ+τ− events, recorded with ...the Belle detector at the KEKB asymmetric-energy e+e− collider. In the absence of a signal, 90% confidence-level upper limits are set on the branching fractions of these decays in the range (1.8 − 4.0) × 10−8. We set the world's first limits on the first four channels and improve the existing limits by an order of magnitude for the last two channels.
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Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
A search is presented for massive long-lived particles decaying into a muon and two quarks. The dataset consists of proton-proton interactions at centre-of-mass energies of 7 and 8 TeV, corresponding ...to integrated luminosities of 1 and 2
fb
-
1
, respectively. The analysis is performed assuming a set of production mechanisms with simple topologies, including the production of a Higgs-like particle decaying into two long-lived particles. The mass range from 20 to 80
GeV
/
c
2
and lifetimes from 5 to 100
ps
are explored. Results are also interpreted in terms of neutralino production in different R-Parity violating supersymmetric models, with masses in the 23–198 GeV/
c
2
range. No excess above the background expectation is observed and upper limits are set on the production cross-section for various points in the parameter space of theoretical models.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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