We present a measurement of the branching ratio of the CP violating decay KL→π+π− performed by the KLOE experiment at the ϕ factory DAΦNE. We use 328 pb−1 of data collected in 2001 and 2002, ...corresponding to ∼150 million tagged KL mesons. We find BR(KL→π+π−)=(1.963±0.012stat.±0.017syst.)×10−3. This branching ratio measurement is fully inclusive of final-state radiation. Using the above result, we determine the modulus of the amplitude ratio |η+−| to be (2.219±0.013)×10−3 and |ϵ| to be (2.216±0.013)×10−3.
We present the result of a direct search for the decay KS→e+e−, obtained with a sample of e+e−→ϕ→KSKL events produced at DAΦNE, the Frascati ϕ-factory, for an integrated luminosity of 1.9 fb−1. The ...search has been performed using a pure KS beam tagged by the simultaneous detection of a KL interaction in the calorimeter. Background rejection has been optimized by using both kinematic and particle identification cuts. We find BR(KS→e+e−)<9×10−9 at 90% CL, which improves by an order of magnitude on the previous best limit.
Calibration and performances of the KLOE calorimeter Ambrosino, F.; Antonelli, A.; Antonelli, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2009, 2009-1-00, Volume:
598, Issue:
1
Journal Article
Peer reviewed
The KLOE experiment uses a fine sampling lead-scintillating fibre calorimeter to measure energy, time and position of neutral and charged particles. The overall detector consists of 88 modules ...organised in a barrel and two end-caps, for a total granularity of 2440 cells, read-out by photo-multipliers at both fibre ends. The chosen design of a high sampling fraction with the usage of thin lead layers and fast scintillating fibres allows to reach good efficiency for photon energies down to few
MeV, good energy resolution and excellent time resolution. The design, calibration and performances of the calorimeter on efficiency, time/position/energy resolution and particle identification is reviewed. The overall calorimeter impact on kaon tagging and on physics results is also presented.
We have measured the cross section of the radiative process esuper+esuper---pisuper+pisuper- gamma with the KLOE detector at the Frascati phi-factory DAPhiNE, from events taken at a CM energy W=1 ...GeV. Initial state radiation allows us to obtain the cross section for esuper+esuper---pisuper+pisuper-, the pion form factor
We have measured the cross section of the radiative process e+e−→π+π−γ with the KLOE detector at the Frascati ϕ-factory DAΦNE, from events taken at a CM energy W=1 GeV. Initial state radiation allows ...us to obtain the cross section for e+e−→π+π−, the pion form factor |Fπ|2 and the dipion contribution to the muon magnetic moment anomaly, Δaμππ=(478.5±2.0stat±5.0syst±4.5th)×10−10 in the range 0.1<Mππ2<0.85 GeV2, where the theoretical error includes a SU(3) χPT estimate of the uncertainty on photon radiation from the final pions. The discrepancy between the Standard Model evaluation of aμ and the value measured by the Muon g-2 collaboration at BNL is confirmed.
The High Luminosity LHC phase includes an upgrade to the muon stations for the CMS Experiment. CMS trigger and muon identification performance will be crucial, and it is, therefore, necessary to ...install new GEM stations to extend acceptance in the high-{\eta} region. An explanation of the quality control test and an update on the status of production will be provided.
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