120263892
Inclusive K0 production in e+ e− annihilation at the upsilon resonances
We report on inclusive K0 production in the region of the upsilon resonances (9.4–10.6 GeV). The K0 yield for the resonances and continuum below the BB threshold is found to be constant at 0.82 ± 0.10 K0 per observed hadronic event. At the ϒ(4S), however, the K0 yield is significantly higher, 1.58 ± 0.35. This increase in K0 production and the differential cross section dσ/dp of kaons are consistent with BB decay of the ϒ(4S) resonance with the bottom quarks subsequently decaying primarily into charmed quarks.
126286321
Observation of the Upsilon''' at CESR
117830203
Observation of Upsilon, Upsilon', and Upsilon'' at the Cornell electron Storage Ring
The UPSILON, UPSILON', and UPSILON'' states have been observed at the Cornell Electron Storage Ring as narrow peaks in sigma(e/sup +/e/sup -/ ..-->.. hadrons) versus beam energy. Data were collected during a run of 1000 nb/sup -1/, using the Columbia University--Stony Brook segmented NaI detector. The measured mass differences are M(UPSILON')-M(UPSILON)=559 +- 1( +- 3) MeV and M(UPSILON'')-M(UPSILON)=889 +- 1( +- 5) MeV, where the errors in parentheses represent systematic uncertainties. Preliminary values for the leptonic width ratios were also obtained.
117089603
Measurements of the A2- and A2+ Mass Spectra
120228621
Observation of the Transition $\Upsilon^\prime \to \Upsilon \pi^+ \pi^- \to e^+ e^- \pi^+ \pi^-$
121331255
Experimental tests of limiting fragmentation at the ISR
Abstract We present direct tests of the hypothesis of limiting fragmentation from an experiment at the CERN Intersecting Storage Rings at centre-of-mass energies between 31 and 53 GeV. Single-particle inclusive distributions and partial multiplicity distributions are observed for the case in which the energy of one beam is fixed while varying the energy of the other beam. Within cones around the beam, limiting fragmentation is shown to be valid.
110466342
Performance and Aging Studies of BaBar Resistive Plate Chambers
The BaBar detector is currently operating nearly 200 Resistive Plate Chambers (RPCs), constructed as part of an upgrade of the forward endcap muon detector in 2002. Although the average RPC efficiency remains high, numerous changes in the RPC performance (increased currents and rates) have been observed. A few of the highest rate RPCs have suffered efficiency losses of more than 15%. Several types of efficiency loss have been observed. Tests with humidified gas have shown that some of the lost efficiency is recoverable. However, efficiency losses in the highest rate regions have not yet improved with humid gases.
52216370
Measuring propagation speed of Coulomb fields
The problem of gravity propagation has been subject of discussion for quite a long time: Newton, Laplace and, in relatively more modern times, Eddington pointed out that, if gravity propagated with finite velocity, planet motion around the sun would become unstable due to a torque originating from time lag of the gravitational interactions. Such an odd behavior can be found also in electromagnetism, when one computes the propagation of the electric fields generated by a set of uniformly moving charges. As a matter of fact the Liénard–Weichert retarded potential leads to the same formula as the one obtained assuming that the electric field propagate with infinite velocity. The Feynman explanation for this apparent paradox was based on the fact that uniform motions last indefinitely. To verify such an explanation, we performed an experiment to measure the time/space evolution of the electric field generated by an uniformly moving electron beam. The results we obtain, on a finite lifetime kinematical state, are compatible with an electric field rigidly carried by the beam itself.
56098294
Review of measurements of the angles of the CKM matrix from the BaBar experiment
Experimental results on CP violation measurements in the B meson system from the BABAR experiment at the PEP-II asymmetric B Factory are reviewed.
120292237
Test of a small prototype of the KLOE drift chamber in magnetic field
Abstract We report on a beam test of a small prototype of the KLOE drift chamber in magnetic field. The chamber was operated with a 90% He–10% iC 4 H 10 gas mixture. Drift space–time relations were studied. The average spatial resolution is about 110 μm in the absence of magnetic field and 120 μm in a 0.6 T magnetic field. Measurements of the primary ionization and drift velocity are reported. The measurement of d E /d x in a He-based gas mixture is also discussed.
16384620
CKM-UT Angles: Mixing And CP Violation at the B Factories
We review the experimental status of the angles of the Unitarity Triangle of the CKM matrix, as measured by the BABAR and Belle experiments. The B Factories have demonstrated since the beginning of this decade that CP violation in the B meson system is consistent with the Standard Model (SM) description in terms of the complex phase in the three-by-three Cabibbo-Kobayashi-Maskawa (CKM) matrix. With one single phase, the SM predicts clear patterns for quark mixing and CP violations, to be satisfied by all processes.