Search

Your search keyword '"R.D. Appuhn"' showing total 5 results
Start Over Author "R.D. Appuhn" Publisher elsevier bv
5 results on '"R.D. Appuhn"'

1. A measurement of asymmetry in the decay Λc+ → Λπ+

Author

H. Albrecht, H. Ehrlichmann, T. Hamacher, A. Krüger, A. Nau, A. Nippe, M. Reidenbach, M. Schäfer, H. Schröder, H.D. Schulz, F. Sefkow, R. Wurth, R.D. Appuhn, C. Hast, G. Herrera, H. Kolanoski, A. Lange, A. Lindner, R. Mankel, M. Schieber, T. Siegmund, B. Spaan, H. Thurn, D. Töpfer, A. Walther, D. Wegener, M. Paulini, K. Reim, U. Volland, H. Wegener, R. Mundt, W. Schmidt-Parzefall, W. Funk, J. Stiewe, S. Werner, S. Ball, J.C. Gabriel, C. Geyer, A. Hölscher, W. Hofmann, B. Holzer, S. Khan, K.T. Knöpfle, J. Spengler, D.I. Britton, C.E.K. Charlesworth, K.W. Edwards, H. Kapitza, P. Krieger, R. Kutschke, D.B. MacFarlane, R.S. Orr, P.M. Patel, J.D. Prentice, S.C. Seidel, G. Tsipolitis, K. Tzamariudaki, R.G. Van de Water, T.-S. Yoon, D. Reßing, S. Schael, K.R. Schubert, K. Strahl, R. Waldi, S. Weseler, B. Boštjančič, G. Kernel, P. Križan, E. Križnič, T. Podobnik, T. Živko, H.I. Cronström, L. Jönsson, V. Balagura, M. Danilov, A. Droutskoy, B. Fominykh, A. Golutvin, I. Gorelov, F. Ratnikov, V. Lubinov, P. Pakhlov, A. Rostovtsev, A. Semenov, S. Semenov, V. Shevchenko, V. Soloshenko, I. Tichomirov, Yu. Zaitsev, R. Childers, and C.W. Darden

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Argus, media_common.quotation_subject, Electron–positron annihilation, DESY, Parity (mathematics), Asymmetry, computer, Storage ring, media_common, computer.programming_language
Abstract

Using the ARGUS detector at the e + e − storage ring DORIS II at DESY, we have observed parity violation in the decay Λ ± c → Λπ ± . We measure the coefficient of parity violation, α Λ c , to be −0.96±0.42. In addition, we measure σ BR ( Λ + c → Λπ + and σ BR ( Λ + c → Σ 0 π + ) to be, respectively, (2.2±0.3±0.4) pb and (2.0±0.7±0.4) pb.

Published
1992

2. Transition radiation detectors for electron identification beyond 1 GeV/c

Author

A. Schlösser, K. Heinloth, E. Lange, R.D. Appuhn, and R. Oedingen

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Wire chamber, Pion, Photon, Transition radiation, Physics::Instrumentation and Detectors, DESY, Electron, Instrumentation, Particle identification, Particle detector
Abstract

Transition radiation detectors (TRDs) have been tested for the separation of electrons from pions in the momentum range between 1 and 6 GeV/c. Foams as well as fibres and foils served as radiator materials while two types of chambers, a longitudinal drift chamber (DC) and a multiwire proportional chamber (MWPC), both of 16 mm depth and dominantly filled with xenon, were used for detecting the transition radiation photons with a setup of four chambers. Analyzing the data we compared the methods of mean, truncated mean and of maximum likelihood of the total charge measurements and several methods of cluster analysis. As a result of the total charge measurements performed at test beams at CERN and DESY we obtained about 1% pion contamination at 90% electron efficiency for the polypropylene materials in the configuration of four modules with a total length of 40 cm. An improvement by a factor of about two for the electron/pion discrimination can be obtained in the case of a detailed analysis of the clusters.

Published
1988

3. Monte Carlo simulation of a transition radiation detector

Author

R.D. Appuhn, E. Lange, R. Oedingen, and E. Paul

Subjects
Physics, Nuclear physics, Hybrid Monte Carlo, Nuclear and High Energy Physics, Transition radiation detector, Spectrometer, Monte Carlo method, Dynamic Monte Carlo method, High Energy Physics::Experiment, Monte Carlo method in statistical physics, Context (language use), Instrumentation, Particle detector
Abstract

This paper employs Monte Carlo simulations of the performance of a transition radiation detector (TRD). The program has been written for the TRD in the ZEUS spectrometer, which separates electrons from hadrons in the momentum range between 1 and 30 GeV/ c . Both, total charge method and cluster counting method were simulated taking into account various experimental parameters. In particular, it was found that the cluster counting method relies on a quantitative understanding of the background originating from the production of δ-electrons by charged particles. The results of the Monte Carlo calculations are in agreement with experimental data obtained with prototypes within a systematic uncertainty of 20%. We applied our Monte Carlo program to studies in order to find an optimum layout for the TRD within available space in the ZEUS spectrometer. In this context, the performance of TRD layouts with different geometries and materials has been evaluated comprehensively. The geometry found by optimization promises an improvement on hadron suppression by a factor of about two for both methods compared with present results from test measurements. Applying algorithms for a detailed analysis of the energy and space distributions of the clusters in the TRD, hadrons in the momentum range from 1 to 30 GeV/ c can be suppressed to a level of less than 2%. This method of cluster analysing improves the suppression of hadrons by a factor of about two compared to the total charge method.

Published
1988

4. Search for b→sγ in exclusive decays of B mesons

Author

H. Albrecht, R. Gläser, G. Harder, A. Krüger, A. Nippe, T. Oest, M. Reidenbach, M. Schäfer, W. Schmidt-Parzefall, H. Schröder, H.D. Schulz, F. Sefkow, R. Wurth, R.D. Appuhn, A. Drescher, C. Hast, G. Herrera, H. Kolanoski, A. Lange, A. Lindner, R. Mankel, H. Scheck, G. Schweda, B. Spaan, A. Walther, D. Wegener, M. Paulini, K. Reim, U. Volland, H. Wegener, W. Funk, J. Stiewe, S. Werner, S. Ball, J.C. Gabriel, C. Geyer, A. Hölscher, W. Hofmann, B. Holzer, S. Khan, J. Spengler, C.E.K. Charlesworth, K.W. Edwards, W.R. Frisken, H. Kapitza, P. Krieger, R. Kutschke, D.B. MacFarlane, K.W. McLean, R.S. Orr, J.A. Parsons, P.M. Patel, J.D. Prentice, S.C. Seidel, J.D. Swain, G. Tsipolitis, T.-S. Yoon, R. Davis, T. Ruf, S. Schael, K.R. Schubert, K. Strahl, R. Waldi, S. Weseler, B. Bos̆tjanc̆ic̆, G. Kernel, P. Kriz̆an, E. Kriz̆nic̆, M. Ples̆ko, H.I. Cronström, L. Jönsson, A.W. Nilsson, A. Babaev, M. Danilov, B. Fominykh, A. Golutvin, I. Gorelov, V. Lubimov, A. Rostovtsev, A. Semonov, S. Semenov, V. Shevchenko, V. Soloshenko, V. Tchistilin, I. Tichomirov, Yu. Zaitsev, R. Childers, and C.W. Darden

Subjects
Nuclear and High Energy Physics
Published
1989

5. Measurement of the decay B0→D−ℓ+ν

Author

H. Albrecht, R. Gläser, G. Harder, A. Krüger, A. Nippe, T. Oest, M. Reidenbach, M. Schäfer, W. Schmidt-Parzefall, H. Schröder, H.D. Schulz, F. Sefkow, R. Wurth, R.D. Appuhn, A. Drescher, C. Hast, G. Herrera, H. Kolanoski, A. Lange, A. Lindner, R. Mankel, H. Scheck, G. Schweda, B. Spaan, A. Walther, D. Wegener, M. Paulini, K. Reim, U. Volland, H. Wegener, W. Funk, J. Stiewe, S. Werner, S. Ball, J.C. Gabriel, C. Geyer, A. Hölscher, W. Hofmann, B. Holzer, S. Khan, J. Spengler, C.E.K. Charlesworth, K.W. Edwards, W.R. Frisken, H. Kapitza, P. Krieger, R. Kutschke, D.B. MacFarlane, K.W. McLean, R.S. Orr, J.A. Parsons, P.M. Patel, J.D. Prentice, S.C. Seidel, J.D. Swain, G. Tsipolitis, T.-S. Yoon, R. Davis, T. Ruf, S. Schael, K.R. Schubert, K. Strahl, R. Waldi, S. Weseler, B. Boštjančič, G. Kernel, P. Križan, E. Križnič, M. Pleško, H.I. Cronström, L. Jönsson, A.W. Nilsson, A. Babaev, M. Danilov, B. Fominykh, A. Golutvin, I. Gorelov, V. Lubimov, A. Rostovtsev, A. Semenov, S. Semenov, V. Shevchenko, V. Soloshenko, V. Tchistilin, I. Tichomirov, Yu. Zaitsev, R. Childers, and C.W. Darden

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Argus, Particle physics, Meson, Branching fraction, Electron–positron annihilation, computer, Storage ring, computer.programming_language
Abstract

Using the ARGUS detector at the e + e − storage ring DORIS II, we have investigated the decay B 0 →D − l + ν, where l + is e + or μ + . The B 0 mesons were produced in 150 000 ϒ(4S) decays. Assuming electron-muon universality we obtain a branching ratio BR(B 0 →D − e + ν )=BR(B 0 →D − μ + ν )=(1.8±0.6±0.5)%.

Published
1989

Catalog

Books, media, physical & digital resources
See catalog results