A study of P wave charm mesons, a search for radially excited charm mesons and a study of microstrip gas chambers with polymer substrates

Naresh Nandrumar Menon, Purdue University

Abstract

Using approximately 4 × 106e +e− → cc¯ events at [special characters omitted] = 10.5GeVc2 obtained with the CLEO II.V detector at the Cornell Electron Storage Ring, we have investigated properties of the two narrow L = 1 charmed mesons, D 1(2420)0 and [special characters omitted](2460)0. We observe and measure the mass and decay width of the two mesons in the charmed continuum by studying D +π− and D*+π − final states. We measure [special characters omitted] = 2.94 ± 0.40(stat.) ± 0.44( sys.) ± 0.25([special characters omitted]). All these parameters have historically been poorly determined and our measurements have precisions which are better than the combined world average. We also search for the forbidden decay mode D 1 → D+π− and find no evidence for this ([special characters omitted]([special characters omitted] → D+π−)/[special characters omitted]([special characters omitted] → D*+π−) ≤ 0.069 at 90% C.L.). Using approximately 107e+ e− → cc¯ events at [special characters omitted] = 10.5GeV/c2 obtained with the CLEO II and CLEO II. V detectors we present our results for the search for a narrow radially excited charmed meson [special characters omitted]. The DELPHI collaboration presented first evidence for a narrow radially excited charm meson in the summer of 1997 by comparing their [special characters omitted] signal to their DJ0 production [special characters omitted] = 0.49 ± 0.18(stat.) ± 0.10( syst.). We find no evidence for a narrow [special characters omitted] signal in the decay modes of [special characters omitted] ≤ 0.09 at 90% C.L.) and [special characters omitted] ≤ 0.053 at 90% C.L.). For the latter analysis we use data obtained with the CLEO II.V detector only. We presented preliminary results with the CLEO II data set at ICHEP'98. The upper limits presented above supersedes the previous results and is approximately 60% smaller. We report on the study of Microstrip Gas Chambers (MSGCs) with Polymer substrates. We discuss the applicability of these detectors to two dimensional imaging of photons (X-rays) and demonstrate the first two dimensional images obtained with an ion implanted Kapton substrate MSGC with PCB readout of the second dimension.

Degree

Ph.D.

Advisors

Shipsey, Purdue University.

Subject Area

Particle physics

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