120513565
Measurement of inclusive two-particle rapidity correlations at the ISR
Abstract We present data on two-particle distributions in the approximate rapidity variable η = −1n tan θ /2 for secondaries produced in proton-proton collisions at the CERN Intersecting Storage Rings (ISR). The data at centre-of-mass energies of 23 and 62 GeV show the existence of energy-independent positive, short-range correlations between secondaries within the central region. Deviations from short-range correlation exist when one (or both) of the particles is near the boundary of the available phase space. In part, such deviations are interpreted as the effect of a diffractive-like component in multiparticle production.
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.
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.
120228621
Observation of the Transition $\Upsilon^\prime \to \Upsilon \pi^+ \pi^- \to e^+ e^- \pi^+ \pi^-$
126286321
Observation of the Upsilon''' at CESR
117089603
Measurements of the A2- and A2+ Mass Spectra
14677203
Study of Solid State Photon Detectors Read Out of Scintillator Tiles
We present preliminary results on efficiency and light collection uniformity read out performances of different assemblies of scintillator tiles, coupled with solid state photon detectors of different make. Our test beam data suggest that the use of 2 mm scintillator tiles without wavelength shifting fibers may be possible in an ILC hadron calorimeter.
123565774
Alpha and Beta at the B Factories
We review recent experimental results on time-dependent CP asymmetries in the B system from the BABAR and Belle experiments. Measurements of the {alpha} and {beta} angles of the Unitarity Triangle of the CKM matrix are discussed. These measurements constitute stringent tests of the Standard Model, and are also used to search for new physics.
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.
121829651
Beam test of scintillation tiles with MPPC readout
Abstract This paper describes measurements made using counters composed of a small (3 by 3 by 0.5 cm 3 ) scintillation tile coupled to a Multi-Photon Pixel Counter (MPPC) produced by Hamamatsu and exposed to an electron beam at the Beam Test Facility in Frascati. We show our first results for charge spectra and efficiency, and a very preliminary measurement of device linearity.
120063494
High precision limited streamer drift tubes
Abstract 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 4 H 10 gas mixture at atmospheric pressure. The tube cells, with a 100 μm thick CuBe wire strung along the axis, enter streamer mode operation at V = 4.6 kV, and feature full efficiency and local resolution of ≤60 μm.