We have measured the radiative decays
φ→
ηγ,
φ→
η′
γ selecting
π
+
π
−
γγγ final state in a sample of ∼5×10
7
φ-mesons produced at the Frascati
φ-factory DA
ΦNE. We obtain
Γ(
φ→
η′
γ)/
Γ(
φ→
...ηγ)=(4.70±0.47±0.31)×10
−3. From this result we derive new accurate values for the branching ratio BR(
φ→
η′
γ)=(6.10±0.61±0.43)×10
−5 and the mixing angle of pseudoscalar mesons in the flavour basis
ϕ
P
=(41.8
+1.9
−1.6)°.
The full-length prototype of the KLOE drift chamber Andryakov, A.; Avanzini, C.; Bacci, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
1998, Letnik:
404, Številka:
2
Journal Article
Recenzirano
The main goal of the KLOE experiment is the study of CP violation in the K mesons system, with an accuracy of 10
−4 in the measurement of
Re(
ε′
ε
)
. This task imposes strong constraints on the ...design and operation of the drift chamber, which must reconstruct the charged decays of low momentum K
L's and K
S's with high efficiency and high resolution. A full-length prototype of the chamber has been built and tested on a 50 GeV/
c beam. The analysis of the large sample of data has allowed a detailed study of the time to distance relations as a function of the track parameters and of the peculiar geometry of the drift cell. The detector performance, in terms of efficiency, spatial resolutions and
dE
dχ
resolution, is illustrated and discussed.
dE/dx measurement in a He-based gas mixture Andryakov, A; Antonelli, A; Baldini-Ferroli, R ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/1998, Letnik:
409, Številka:
1-3
Journal Article
Recenzirano
The performance of a prototype drift chamber operating in a He-based gas mixture as a specific ionisation detector is presented. In spite of the small number of primary ions, Helium performs quite ...satisfactorily in measuring energy losses for charged particles: with 50GeV/c pions, we have measured in a 90%He–10%iC4H10 mixture a relative energy loss resolution of 3.1% with 75 samples 3cm long, using a modified Truncated Mean technique with 80% accepted fraction.
The dependence of the resolution on several parameters such as the operating voltage, the truncation fraction, the number and length of the samples is discussed.
The KLOE Drift Chamber construction Bencivenni, G.; Andryakov, A.; Antonelli, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/1998, Letnik:
419, Številka:
2-3
Journal Article
Recenzirano
The tracking detector of the KLOE experiment is a large volume drift chamber designed to contain most of the decays of KL produced at the DAFNE Φ factory. The design of the chamber, choice of ...materials, stringing technique are described in detail as well as the quality tests performed during the construction.
A resistive plate chamber operated at low gas amplification has been exposed to photon and neutron sources to study the detection efficiency and the time response in conditions close to those ...expected in experiments at the Large Hadron Collider. Results on the sensitivity to photons and neutrons of energy around 1 MeV are presented.
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.
High precision limited streamer drift tubes Avanzini, C; Bacci, C; Calcaterra, A ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/1995, Letnik:
367, Številka:
1
Journal Article
Recenzirano
A tracking telescope employing six layers of Al drift tubes 50 cm long, with diameter
d = 3 cm and wall thickness 500 μm, has been built and successfully operated with a 40% Ar-60% iC
4H
10 gas ...mixture at atmospheric pressure. The tube cells, with a 100 μm thick CuBe wire strung along the axis, enter streamer mode operation at
V = 4.6 kV, and feature full efficiency and local resolution of ≤60 μm.
Results from the full-length prototype of the KLOE Drift Chamber Andryakov, A.; Antonelli, A.; Baldini-Ferroli, R. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/1998, Letnik:
409, Številka:
1-3
Journal Article
Recenzirano
A full-size prototype of the KLOE drift chamber has been built and successfully exposed to a 50GeV/c pion beam at CERN. The performances of the detector are presented.
Study of resistive plate chambers for muon detection at hadron colliders
Nuclear instruments and methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment/Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/1994
Journal Article
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