Study of tau decays to six pions and a neutrino.

Physical review letters 86:20 (2001) 4467-4471

Authors:

A Anastassov, JE Duboscq, E Eckhart, KK Gan, C Gwon, T Hart, K Honscheid, D Hufnagel, H Kagan, R Kass, TK Pedlar, H Schwarthoff, JB Thayer, E von Toerne, MM Zoeller, SJ Richichi, H Severini, P Skubic, A Undrus, S Chen, J Fast, JW Hinson, J Lee, DH Miller, EI Shibata, IP Shipsey, V Pavlunin, D Cronin-Hennessy, AL Lyon, EH Thorndike, CP Jessop, V Savinov, TE Coan, V Fadeyev, Y Maravin, I Narsky, R Stroynowski, J Ye, T Wlodek, M Artuso, R Ayad, C Boulahouache, K Bukin, E Dambasuren, S Karamov, G Majumder, GC Moneti, R Mountain, S Schuh, T Skwarnicki, S Stone, G Viehhauser, JC Wang, A Wolf, J Wu, S Kopp, AH Mahmood, SE Csorna, I Danko, KW McLean, Z Xu, R Godang, G Bonvicini, D Cinabro, M Dubrovin, S McGee, GJ Zhou, E Lipeles, SP Pappas, M Schmidtler, A Shapiro, WM Sun, AJ Weinstein, F Würthwein, DE Jaffe, G Masek, HP Paar, EM Potter, S Prell, DM Asner, A Eppich, TS Hill, RJ Morrison, RA Briere, GP Chen, WT Ford, A Gritsan, J Roy, JG Smith, JP Alexander, R Baker, C Bebek, BE Berger, K Berkelman, F Blanc, V Boisvert, DG Cassel, PS Drell, KM Ecklund, R Ehrlich, AD Foland, P Gaidarev, RS Galik, L Gibbons, B Gittelman, SW Gray, DL Hartill, BK Heltsley, PI Hopman, L Hsu, CD Jones, DL Kreinick, M Lohner, A Magerkurth, TO Meyer, NB Mistry, E Nordberg, JR Patterson, D Peterson, D Riley, A Romano, JG Thayer, D Urner, B Valant-Spaight, A Warburton, P Avery, C Prescott, AI Rubiera, H Stoeck, J Yelton, G Brandenburg, A Ershov, YS Gao, DY Kim, R Wilson, T Bergfeld, BI Eisenstein, J Ernst, GE Gladding, GD Gollin, RM Hans, E Johnson, I Karliner, MA Marsh, M Palmer, C Plager, C Sedlack, M Selen, JJ Thaler, J Williams, KW Edwards, R Janicek, PM Patel, AJ Sadoff, R Ammar, A Bean, D Besson, X Zhao, S Anderson, VV Frolov, Y Kubota, SJ Lee, R Mahapatra, JJ O'Neill, R Poling, T Riehle, A Smith, CJ Stepaniak, J Urheim, S Ahmed, MS Alam, SB Athar, L Jian, L Ling, M Saleem, S Timm, F Wappler, CLEO Collaboration

Abstract:

The tau decays to six-pion final states have been studied with the CLEO detector at the Cornell Electron Storage Ring. The measured branching fractions are B(tau(-)-->2pi(-)pi(+)3pi(0)nu(tau)) = (2.2+/-0.3+/-0.4)x10(-4) and B(tau(-)-->3pi(-)2pi(+)pi(0)nu(tau)) = (1.7+/-0.2+/-0.2)x10(-4). A search for substructure in these decays shows that they are saturated by intermediate states with eta or omega mesons. We present the first observation of the decay tau(-)-->2pi(-)pi(+)omega(nu)tau and the branching fraction is measured to be (1.2+/-0.2+/-0.1)x10(-4). The measured branching fractions are in good agreement with the isospin expectations but somewhat below the conserved-vector-current predictions.

Radio flares and plasmon size in Cygnus X-3

(2001)

Authors:

RN Ogley, SJ Bell Burnell, RE Spencer, SJ Newell, AM Stirling, RP Fender

On the origin of the color-magnitude relation in the Virgo Cluster

Astrophysical Journal 551:2 PART 2 (2001)

Authors:

A Vazdekis, H Kuntschner, RL Davies, N Arimoto, O Nakamura, R Peletier

Abstract:

We explore the origin of the color-magnitude relation (CMR) of early-type galaxies in the Virgo Cluster using spectra of very high signal-to-noise ratio for six elliptical galaxies selected along the CMR. The data are analyzed using a new evolutionary stellar population synthesis model to generate galaxy spectra at the resolution given by their velocity dispersions. In particular, we use a new age indicator that is virtually free of the effects of metallicity. We find that the luminosity-weighted mean ages of Virgo ellipticals are greater than ∼8 Gyr and show no clear trend with galaxy luminosity. We also find a positive correlation of metallicity with luminosity, color, and velocity dispersion. We conclude that the CMR is driven primarily by a luminosity-metallicity correlation. However, not all elements increase equally with the total metallicity, and we speculate that the CMR may be driven by both a total metallicity increase and a systematic departure from solar abundance ratios of some elements along the CMR. A full understanding of the role played by the total metallicity, abundance ratios, and age in generating the CMR requires the analysis of spectra of very high quality, such as those reported here, for a larger number of galaxies in Virgo and other clusters.

Microquasars: Hard X-ray/γ-ray emission

AIP Conference Proceedings AIP Publishing 558:1 (2001) 221-233

Search for B → τv and B → Kvv̄

Physical Review Letters 86:14 (2001) 2950-2954

Authors:

TE Browder, Y Li, JL Rodriguez, H Yamamoto, T Bergfeld, BI Eisenstein, J Ernst, GE Gladding, GD Gollin, RM Hans, E Johnson, I Karliner, MA Marsh, M Palmer, C Plager, C Sedlack, M Selen, JJ Thaler, J Williams, KW Edwards, R Janicek, PM Patel, AJ Sadoff, R Ammar, A Bean, D Besson, R Davis, N Kwak, X Zhao, S Anderson, VV Frolov, Y Kubota, SJ Lee, R Mahapatra, JJ O'Neill, R Poling, T Riehle, A Smith, CJ Stepaniak, J Urheim, S Ahmed, MS Alam, SB Athar, L Jian, L Ling, M Saleem, S Timm, F Wappler, A Anastassov, JE Duboscq, E Eckhart, KK Gan, C Gwon, T Hart, K Honscheid, D Hufnagel, H Kagan, R Kass, TK Pedlar, H Schwarthoff, JB Thayer, E von Toerne, MM Zoeller, SJ Richichi, H Severini, P Skubic, A Undrus, S Chen, J Fast, JW Hinson, J Lee, DH Miller, EI Shibata, IPJ Shipsey, V Pavlunin, D Cronin-Hennessy, AL Lyon, EH Thorndike, CP Jessop, H Marsiske, ML Perl, V Savinov, D Ugolini, X Zhou, TE Coan, V Fadeyev, Y Maravin, I Narsky, R Stroynowski, J Ye, T Wlodek, M Artuso, R Ayad, C Boulahouache, K Bukin, E Dambasuren, S Karamov, G Majumder, GC Moneti, R Mountain

Abstract:

An analysis of 9.66 × 106 charged B meson decays which results in a conservative upper limit on the branching fraction B(B → τν) < 8.4 × 10-4. The analysis was slightly modified to establish B(B± → K± νν̄) < 2.4 × 10-4. The method used is optimized for conditions available at Y(4S) experiments, and some application of the method to other rare decay modes with large missing energy was aniticipated.