The BABAR Collaboration BABAR, the detector for the SLAC PEP-II asymmetric e + e − B Factory operating at the Υ (4S) resonance, was designed to allow comprehensive studies of CP -violation in B-meson decays. Charged particle tracks are measured in a multi-layer silicon vertex tracker surrounded by a cylindrical wire drift chamber. Electromagnetic showers from electrons and photons are detected in an array of CsI crystals located just inside the solenoidal coil of a superconducting magnet. Muons and neutral hadrons are identified by arrays of resistive plate chambers inserted into gaps in the steel flux return of the magnet. Charged hadrons are identified by dE/dx measurements in the tracking detectors and in a ring-imaging Cherenkov detector surrounding the drift chamber. The trigger, data acquisition and data-monitoring systems , VME-and network-based, are controlled by custom-designed online software. Details of the layout and performance of the detector components and their associated electronics and software are presented.

Using the CLEO II detector, we have measured the differential cross sections for exclusive two-photon production of light pseudoscalar mesons 0 , , and Ј. From our measurements we have obtained the form factors associated with the electromagnetic transitions ␥*␥→meson. We have measured these form factors in the momentum transfer ranges from 1.5 to 9, 20, and 30 GeV 2 for 0 , , and Ј, respectively, and have made comparisons to various theoretical predictions. ͓S0556-2821͑98͒01001-7͔

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We have observed the decays B° -» K*(892)°j and B~ -> K*(892)~ry, which are evidence for the quark-level process b -• 57. The average branching fraction is (4.5 ± 1.5 ± 0.9) x 10~5. This value is consistent with standard model predictions from electromagnetic penguin diagrams. PACS numbers: 13.40.Hq, 14.40.Jz One-loop, flavor-changing neutral current diagrams, meson decays [1]. They were later identified as a possible known as penguins, were originally introduced into the source of direct CP violation in kaon decay, and hence as theory of weak decays to explain the AI = \ rule in K a contribution to e! /e [2]. Their importance in B meson 674 0031 -9007/93/71 (5)/674(5)$06.00

The MINOS CollaborationArgonne -Athens -Caltech -Chicago -Dubna -Fermilab -Harvard IHEP-Beijing -Indiana -ITEP-Moscow -Lebedev Livermore VCL-London Minnesota -Oxford -Pittsburgh -Protvino -Rutherford -Stanford -SussexTexas A&M -Texas-Austin -Tufts -Western Washington - Executive summaryThe MINOS (Main Injector Neutrino Oscillation Search) experiment is designed to search for neutrino oscillations with a sensitivity significantly greater than has been achieved to date. The phenomenon of neutrino oscillations, whose existence has not been proven convincingly so far, allows neutrinos of one "flavor" (type) to slowly transform themselves into another flavor, and then back again to the original flavor, as they propagate through space or matter.The MINOS experiment is optimized to explore the region of neutrino oscillation "para meter space" (values of the !:l.m 2 and sin 2 29 parameters) suggested by previous investigations of atmospheric neutrinos: the Kamiokande, 1MB, Super-Kamiokande and Soudan 2 experi ments. The study of oscillations in this region with a neutrino beam from the Main Injector requires measurements of the beam after a very long flight path. This in turn requires an intense neutrino beam and a massive detector in order to have an adequate event rate at a great distance from the source.We propose to enhance significantly the physics capabilities of the MINOS experiment by the addition of a Hybrid Emulsion Detector at Soudan, capable of unambigous identification of the neutrino flavor. Recent developments in emulsion experiments make such a detector possible, although significant technological challenges must be overcome. We propose to initiate an R&D effort to identify major potential problems and to develop practical solutions to them.In addition to this primary motivation for this R&D work, we note that the strong and growing interest in studies of neutrino oscillations using neutrino beams from future muon storage rings provides another potential application. These beams will offer significantly higher intensities, albeit of mixed 1I1J-and lie, beams. In order to take full advantage of these beams for neutrino oscillation studies it will be necessary that the detector be capable of determination of the flavor of the final state lepton, and the lepton's charge in a significant fraction of the interactions. At present, an emulsion detector in an external magnetic field appears best suited to offer such capabilities. The R&D effort discussed here will be an important step towards a design of such a future detector. This document is organized as follows:• Chapter 1 summarizes the physics motivation for the proposed emulsion detector,• Chapter 2 briefly reviews the status of the emulsion technology and its aplication to particle physics experiments,• Chapter 3 discusses design considerations for an emulsion detector,• Chapter 4 describes some of the details of a possible detector as well as results from the work up to date,• Chapter 5 outlines the proposed R&D program and summarizes the resources req...