The ϕ-meson leptonic widths, Γee and Γμμ, are obtained, respectively, from the e+e− forward–backward asymmetry and the μ+μ− cross section around the ϕ-mass energy. We find Γee=1.32±0.05±0.03 keV and ...ΓeeΓμμ=1.320±0.018±0.017 keV. These results, compatible with Γee=Γμμ, provide a precise test of lepton universality. Combining the two results gives Γℓℓ(ϕ)=1.320±0.023 keV.
We have searched with the KLOE detector for the P and CP violating decay η→π+π− in a sample of 1.55×107η's from the decay ϕ→ηγ of ϕ-mesons produced in e+e− annihilations at DAΦNE. No signal is found. ...We obtain the upper limit BR(η→π+π−)<1.3×10−5 at 90% confidence level.
We have searched for the C-violating decay η→γγγ in a sample of ∼18 million η mesons produced in φ→ηγ decays, collected with the KLOE detector at the Frascati φ-factory DAΦNE. No signal is observed ...and we obtain the upper limit BR(η→γγγ)⩽1.6×10−5 at 90% CL.
Data acquisition and monitoring for the KLOE detector Aloisio, A.; Ambrosino, F.; Antonelli, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2004, Volume:
516, Issue:
2
Journal Article
Peer reviewed
The Data Acquisition system for the KLOE experiment, presently running at the Laboratori Nazionali di Frascati DAΦNE collider, has been designed to sustain an acquisition throughput of
50
Mbyte/
s
...for an event rate of
10
kHz
. Its two major components are the front end data readout, based on custom buses, and a complex network of computers and storage devices hosting a set of distributed processes. The end result is a seamless data transport from the readout system to the storage library, accompanied by concurrent on line calibrations and data quality control.
We present the first observation of quantum interference in the process ϕ→KSKL→π+π−π+π−, using the KLOE detector at the Frascati e+e− collider DAΦNE. From about 5×104 neutral kaon pairs both decaying ...to π+π− pairs we obtain the distribution of Δt, the difference between the two kaon decay times, which allows testing the validity of quantum mechanics and CPT invariance: no violation of either is observed. New or improved limits on coherence loss and CPT violation are presented.
We have measured the ratio
R
S
π
=
Γ(
K
S
→
π
+
π
−(
γ))/
Γ(
K
S
→
π
0
π
0) with the KLOE detector at the DA
ΦNE
e
+
e
− collider. This measurement is fully inclusive with respect to the
π
+
π
−
γ ...final state. The sample of over 10
6 two-pion decays of tagged
K
S
mesons allows a statistical error as low as ∼0.1% to be obtained. The accuracy is limited by systematic uncertainties, which are estimated primarily from data. We find
R
S
π
=2.236±0.003
stat±0.015
syst.
We have studied the Dalitz plot of the e+e-→π0π0γ events (Nπ0π0γ∼65000) collected at \(\sqrt{s} \simeq{M}_{\phi}\) with the KLOE detector. In the dipion invariant mass (Mππ) region below 700 MeV, the ...process under study is dominated by the non-resonant process e+e-→ωπ0 with ω→π0γ whereas, for higher Mππ values, the radiative φ decay to the f0(980) is the dominant mechanism. Different theoretical models are used to fit the Dalitz plot, taking also into account a possible contribution of the σ(600). For each model, we extract the f0(980) mass and its coupling to ππ, KK̄ and to the φ.
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