Search for rare and forbidden decays of charm and charmed-strange mesons to final states h±e e+

Physical Review D - Particles, Fields, Gravitation and Cosmology 82:9 (2010)

Authors:

P Rubin, N Lowrey, S Mehrabyan, M Selen, J Wiss, J Libby, M Kornicer, RE Mitchell, MR Shepherd, CM Tarbert, D Besson, TK Pedlar, J Xavier, D Cronin-Hennessy, J Hietala, P Zweber, S Dobbs, Z Metreveli, KK Seth, A Tomaradze, T Xiao, S Brisbane, L Martin, A Powell, P Spradlin, G Wilkinson, H Mendez, JY Ge, DH Miller, IPJ Shipsey, B Xin, GS Adams, D Hu, B Moziak, J Napolitano, KM Ecklund, J Insler, H Muramatsu, CS Park, LJ Pearson, EH Thorndike, F Yang, S Ricciardi, C Thomas, M Artuso, S Blusk, R Mountain, T Skwarnicki, S Stone, JC Wang, LM Zhang, G Bonvicini, D Cinabro, A Lincoln, MJ Smith, P Zhou, J Zhu, P Naik, J Rademacker, DM Asner, KW Edwards, K Randrianarivony, G Tatishvili, RA Briere, H Vogel, PUE Onyisi, JL Rosner, JP Alexander, DG Cassel, S Das, R Ehrlich, L Fields, L Gibbons, SW Gray, DL Hartill, BK Heltsley, DL Kreinick, VE Kuznetsov, JR Patterson, D Peterson, D Riley, A Ryd, AJ Sadoff, X Shi, WM Sun, J Yelton

Abstract:

We have searched for flavor-changing neutral current decays and lepton-number-violating decays of D+ and Ds+ mesons to final states of the form h±e e+, where h is either π or K. We use the complete samples of CLEO-c open-charm data, corresponding to integrated luminosities of 818pb-1 at the center-of-mass energy E CM=3.774GeV containing 2.4×106 D+D- pairs and 602pb-1 at ECM=4.170GeV containing 0.6×106 Ds*±Ds pairs. No signal is observed in any channel, and we obtain 90% confidence level upper limits on branching fractions B(D +→π+e+e-)<5. 9×10-6, B(D+→π-e +e+)<1.1×10-6, B(D+→ K+e+e-)<3.0×10-6, B(D +→K-e+e+)<3.5×10 -6, B(Ds+→π+e+e-)<2. 2×10-5, B(Ds+→π-e+e +)<1.8×10-5, B(Ds+→K+e +e-)<5.2×10-5, and B(Ds+→K -e+e+)<1.7×10-5. © 2010 The American Physical Society.

The sudden death of the nearest quasar

Astrophysical Journal Letters 724:1 PART 2 (2010)

Authors:

K Schawinski, DA Evans, S Virani, CM Urry, WC Keel, P Natarajan, CJ Lintott, A Manning, P Coppi, S Kaviraj, SP Bamford, GIG Józsa, M Garrett, H Van Arkel, P Gay, L Fortson

Abstract:

Galaxy formation is significantly modulated by energy output from supermassive black holes at the centers of galaxies which grow in highly efficient luminous quasar phases. The timescale on which black holes transition into and out of such phases is, however, unknown. We present the first measurement of the shutdown timescale for an individual quasar using X-ray observations of the nearby galaxy IC 2497, which hosted a luminous quasar no more than 70,000 years ago that is still seen as a light echo in "Hanny's Voorwerp," but whose present-day radiative output is lower by at least two, and more likely by over four, orders of magnitude. This extremely rapid shutdown provides new insight into the physics of accretion in supermassive black holes and may signal a transition of the accretion disk to a radiatively inefficient state. © 2010. The American Astronomical Society. All rights reserved.

ULTRA-BRIGHT OPTICAL TRANSIENTS ARE LINKED WITH TYPE Ic SUPERNOVAE

The Astrophysical Journal Letters American Astronomical Society 724:1 (2010) l16-l21

Authors:

A Pastorello, SJ Smartt, MT Botticella, K Maguire, M Fraser, K Smith, R Kotak, L Magill, S Valenti, DR Young, S Gezari, F Bresolin, R Kudritzki, DA Howell, A Rest, N Metcalfe, S Mattila, E Kankare, KY Huang, Y Urata, WS Burgett, KC Chambers, T Dombeck, H Flewelling, T Grav, JN Heasley, KW Hodapp, N Kaiser, GA Luppino, RH Lupton, EA Magnier, DG Monet, JS Morgan, PM Onaka, PA Price, PH Rhoads, WA Siegmund, CW Stubbs, WE Sweeney, JL Tonry, RJ Wainscoat, MF Waterson, C Waters, CG Wynn-Williams

On the nature of the "radio quiet" black hole binaries

(2010)

Authors:

Paolo Soleri, Rob Fender

Search for dijet resonances in 7 TeV pp collisions at CMS

Physical Review Letters 105:21 (2010)

Authors:

V Khachatryan, AM Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, J Erö, C Fabjan, M Friedl, R Frühwirth, VM Ghete, J Hammer, S Hänsel, C Hartl, M Hoch, N Hörmann, J Hrubec, M Jeitler, G Kasieczka, W Kiesenhofer, M Krammer, D Liko, I Mikulec, M Pernicka, H Rohringer, R Schöfbeck, J Strauss, A Taurok, F Teischinger, W Waltenberger, G Walzel, E Widl, CE Wulz, V Mossolov, N Shumeiko, J Suarez Gonzalez, L Benucci, L Ceard, EA De Wolf, X Janssen, T Maes, L Mucibello, S Ochesanu, B Roland, R Rougny, M Selvaggi, H Van Haevermaet, P Van Mechelen, N Van Remortel, V Adler, S Beauceron, S Blyweert, J D'Hondt, O Devroede, A Kalogeropoulos, J Maes, M Maes, S Tavernier, W Van Doninck, P Van Mulders, I Villella, EC Chabert, O Charaf, B Clerbaux, G De Lentdecker, V Dero, APR Gay, GH Hammad, T Hreus, PE Marage, L Thomas, C Vander Velde, P Vanlaer, J Wickens, S Costantini, M Grunewald, B Klein, A Marinov, D Ryckbosch, F Thyssen, M Tytgat, L Vanelderen, P Verwilligen, S Walsh, N Zaganidis, S Basegmez, G Bruno, J Caudron, J De Favereau De Jeneret, C Delaere, P Demin, D Favart, A Giammanco, G Grégoire, J Hollar, V Lemaitre, O Militaru, S Ovyn, D Pagano, A Pin

Abstract:

A search for narrow resonances in the dijet mass spectrum is performed using data corresponding to an integrated luminosity of 2.9pb⊃-1 collected by the CMS experiment at the Large Hadron Collider. Upper limits at the 95% confidence level are presented on the product of the resonance cross section, branching fraction into dijets, and acceptance, separately for decays into quark-quark, quark-gluon, or gluon-gluon pairs. The data exclude new particles predicted in the following models at the 95% confidence level: string resonances, with mass less than 2.50 TeV, excited quarks, with mass less than 1.58 TeV, and axigluons, colorons, and E6 diquarks, in specific mass intervals. This extends previously published limits on these models. Copyright © 2010 American Physical Society.