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Measurement of W-boson polarization in top-quark decay using the full CDF Run II data set

Physical Review D - Particles, Fields, Gravitation and Cosmology 87:3 (2013)

Authors:

T Aaltonen, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, JA Appel, T Arisawa, A Artikov, J Asaadi, W Ashmanskas, B Auerbach, A Aurisano, F Azfar, W Badgett, T Bae, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, P Bartos, M Bauce, F Bedeschi, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, A Bhatti, KR Bland, B Blumenfeld, A Bocci, A Bodek, D Bortoletto, J Boudreau, A Boveia, L Brigliadori, C Bromberg, E Brucken, J Budagov, HS Budd, K Burkett, G Busetto, P Bussey, P Butti, A Buzatu, A Calamba, S Camarda, M Campanelli, F Canelli, B Carls, D Carlsmith, R Carosi, S Carrillo, B Casal, M Casarsa, A Castro, P Catastini, D Cauz, V Cavaliere, M Cavalli-Sforza, A Cerri, L Cerrito, YC Chen, M Chertok, G Chiarelli, G Chlachidze, K Cho, D Chokheli, MA Ciocci, A Clark, C Clarke, ME Convery, J Conway, M Corbo, M Cordelli, CA Cox, DJ Cox, M Cremonesi, D Cruz, J Cuevas, R Culbertson, N D'Ascenzo, M Datta, P De Barbaro, L Demortier, M Deninno, F Devoto, M D'Errico, A Di Canto, B Di Ruzza, JR Dittmann, M D'Onofrio, S Donati, M Dorigo, A Driutti, K Ebina, R Edgar, A Elagin

Abstract:

We measure the polarization of W bosons from top-quark (t) decays into final states with a charged lepton and jets, tt̄→W+bW -b̄→ℓνbqq̄′b̄, using the full Run II data set collected by the CDF II detector, corresponding to an integrated luminosity of 8.7 fb-1. A model-independent method simultaneously determines the fraction of longitudinal (f0) and right-handed (f+) W bosons to yield f0=0.726±0. 066(stat)±0.067(syst) and f+=-0.045±0.044(stat) ±0.058(syst) with a correlation coefficient of -0.69. Additional results are presented under various standard model assumptions. No significant discrepancies with the standard model are observed. © 2013 American Physical Society.
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Measurement of the Inclusive NuMu Charged Current Cross Section on Carbon in the Near Detector of the T2K Experiment

(2013)

Authors:

T2K Collaboration, K Abe, N Abgrall, H Aihara, T Akiri, JB Albert, C Andreopoulos, S Aoki, A Ariga, T Ariga, S Assylbekov, D Autiero, M Barbi, GJ Barker, G Barr, M Bass, M Batkiewicz, F Bay, SW Bentham, V Berardi, BE Berger, S Berkman, I Bertram, D Beznosko, S Bhadra, FDM Blaszczyk, A Blondel, C Bojechko, S Boyd, D Brailsford, A Bravar, C Bronner, DG Brook-Roberge, N Buchanan, RG Calland, J Caravaca Rodríguez, SL Cartwright, R Castillo, MG Catanesi, A Cervera, D Cherdack, G Christodoulou, A Clifton, J Coleman, SJ Coleman, G Collazuol, K Connolly, L Cremonesi, A Curioni, A Dabrowska, I Danko, R Das, S Davis, M Day, JPAM de Andre, P de Perio, G De Rosa, T Dealtry, SR Dennis, C Densham, F Di Lodovico, S Di Luise, J Dobson, O Drapier, T Duboyski, F Dufour, J Dumarchez, S Dytman, M Dziewiecki, M Dziomba, S Emery, A Ereditato, L Escudero, AJ Finch, E Frank, M Friend, Y Fujii, Y Fukuda, AP Furmanski, V Galymov, A Gaudin, S Giffin, C Giganti, K Gilje, T Golan, JJ Gomez-Cadenas, M Gonin, N Grant, D Gudin, P Guzowski, DR Hadley, A Haesler, MD Haigh, P Hamilton, D Hansen, T Hara, M Hartz, T Hasegawa, NC Hastings, Y Hayato, C Hearty, RL Helmer, M Hierholzer, J Hignight, A Hillairet, A Himmel, T Hiraki, J Holeczek, S Horikawa, K Huang, AK Ichikawa, K Ieki, M Ieva, M Ikeda, J Imber, J Insler, TJ Irvine, T Ishida, T Ishii, SJ Ives, K Iyogi, A Izmaylov, A Jacob, B Jamieson, RA Johnson, JH Jo, P Jonsson, KK Joo, CK Jung, A Kaboth, H Kaji, T Kajita, H Kakuno, J Kameda, Y Kanazawa, D Karlen, I Karpikov, E Kearns, M Khabibullin, F Khanam, A Khotjantsev, D Kielczewska, T Kikawa, A Kilinski, JY Kim, J Kim, SB Kim, B Kirby, J Kisiel, P Kitching, T Kobayashi, G Kogan, A Kolaceke, A Konaka, LL Kormos, A Korzenev, K Koseki, Y Koshio, K Kowalik, I Kreslo, W Kropp, H Kubo, Y Kudenko, S Kumaratunga, R Kurjata, T Kutter, J Lagoda, K Laihem, A Laing, M Laveder, M Lawe, KP Lee, C Licciardi, IT Lim, T Lindner, C Lister, RP Litchfield, A Longhin, GD Lopez, L Ludovici, M Macaire, L Magaletti, K Mahn, M Malek, S Manly, A Marchionni, AD Marino, J Marteau, JF Martin, T Maruyama, J Marzec, P Masliah, EL Mathie, V Matveev, K Mavrokoridis, E Mazzucato, N McCauley, KS McFarland, C McGrew, T McLachlan, M Messina, C Metelko, M Mezzetto, P Mijakowski, CA Miller, A Minamino, O Mineev, S Mine, A Missert, M Miura, L Monfregola, S Moriyama, Th A Mueller, A Murakami, M Murdoch, S Murphy, J Myslik, T Nagasaki, T Nakadaira, M Nakahata, T Nakai, K Nakajima, K Nakamura, S Nakayama, T Nakaya, K Nakayoshi, D Naples, TC Nicholls, C Nielsen, K Nishikawa, Y Nishimura, HM O'Keeffe, Y Obayashi, R Ohta, K Okumura, T Okusawa, W Oryszczak, SM Oser, M Otani, RA Owen, Y Oyama, MY Pac, V Palladino, V Paolone, D Payne, GF Pearce, O Perevozchikov, JD Perkin, ES Pinzon Guerra, P Plonski, E Poplawska, B Popov, M Posiadala, J-M Poutissou, R Poutissou, P Przewlocki, B Quilain, E Radicioni, PN Ratoff, M Ravonel, MAM Rayner, M Reeves, E Reinherz-Aronis, F Retiere, A Robert, PA Rodrigues, E Rondio, S Roth, A Rubbia, D Ruterbories, R Sacco, K Sakashita, F Sanchez, E Scantamburlo, K Scholberg, J Schwehr, M Scott, DI Scully, Y Seiya, T Sekiguchi, H Sekiya, D Sgalaberna, M Shibata, M Shiozawa, S Short, Y Shustrov, P Sinclair, B Smith, RJ Smith, M Smy, JT Sobczyk, H Sobel, M Sorel, L Southwell, P Stamoulis, J Steinmann, B Still, A Suzuki, K Suzuki, SY Suzuki, Y Suzuki, T Szeglowski, M Szeptycka, R Tacik, M Tada, S Takahashi, A Takeda, Y Takeuchi, HA Tanaka, MM Tanaka, M Tanaka, IJ Taylor, D Terhorst, R Terri, LF Thompson, A Thorley, S Tobayama, W Toki, T Tomura, Y Totsuka, C Touramanis, T Tsukamoto, M Tzanov, Y Uchida, K Ueno, A Vacheret, M Vagins, G Vasseur, T Wachala, AV Waldron, CW Walter, J Wang, D Wark, MO Wascko, A Weber, R Wendell, RJ Wilkes, MJ Wilking, C Wilkinson, Z Williamson, JR Wilson, RJ Wilson, T Wongjirad, Y Yamada, K Yamamoto, C Yanagisawa, S Yen, N Yershov, M Yokoyama, T Yuan, A Zalewska, L Zambelli, K Zaremba, M Ziembicki, ED Zimmerman, M Zito, J Zmuda
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Comparisons of annual modulations in MINOS with the event rate modulation in CoGeNT

Physical Review D - Particles, Fields, Gravitation and Cosmology 87:3 (2013)

Authors:

P Adamson, I Anghel, G Barr, M Bishai, A Blake, GJ Bock, D Bogert, SV Cao, S Childress, JAB Coelho, L Corwin, D Cronin-Hennessy, JK De Jong, AV Devan, NE Devenish, MV Diwan, CO Escobar, JJ Evans, E Falk, GJ Feldman, MV Frohne, HR Gallagher, RA Gomes, MC Goodman, P Gouffon, N Graf, R Gran, K Grzelak, A Habig, J Hartnell, R Hatcher, A Himmel, A Holin, J Hylen, GM Irwin, Z Isvan, DE Jaffe, C James, D Jensen, T Kafka, SMS Kasahara, G Koizumi, S Kopp, M Kordosky, A Kreymer, K Lang, J Ling, PJ Litchfield, P Lucas, WA Mann, ML Marshak, M Mathis, N Mayer, AM McGowan, MM Medeiros, R Mehdiyev, JR Meier, MD Messier, WH Miller, SR Mishra, S Moed Sher, CD Moore, L Mualem, J Musser, D Naples, JK Nelson, HB Newman, RJ Nichol, JA Nowak, J O'Connor, WP Oliver, M Orchanian, RB Pahlka, J Paley, RB Patterson, G Pawloski, S Phan-Budd, RK Plunkett, X Qiu, A Radovic, B Rebel, C Rosenfeld, HA Rubin, MC Sanchez, J Schneps, A Schreckenberger, P Schreiner, R Sharma, A Sousa, N Tagg, RL Talaga, J Thomas, MA Thomson, R Toner, D Torretta, G Tzanakos, J Urheim, P Vahle, B Viren, A Weber

Abstract:

The CoGeNT Collaboration has recently published results from a fifteen month data set which indicate an annual modulation in the event rate similar to what is expected from weakly interacting massive particle interactions. It has been suggested that the CoGeNT modulation may actually be caused by other annually modulating phenomena, specifically the flux of atmospheric muons underground or the radon level in the laboratory. We have compared the phase of the CoGeNT data modulation to that of the concurrent atmospheric muon and radon data collected by the MINOS experiment which occupies an adjacent experimental hall in the Soudan Underground Laboratory. The results presented are obtained by performing a shape-free χ2 data-to-data comparison and from a simultaneous fit of the MINOS and CoGeNT data to phase-shifted sinusoidal functions. Both tests indicate that the phase of the CoGeNT modulation is inconsistent with the phases of the MINOS muon and radon modulations at the 3.0σ level. © 2013 American Physical Society.
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Observation of the production of a W boson in association with a single charm quark

Physical Review Letters 110:7 (2013)

Authors:

T Aaltonen, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, JA Appel, T Arisawa, A Artikov, J Asaadi, W Ashmanskas, B Auerbach, A Aurisano, F Azfar, W Badgett, T Bae, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, P Bartos, M Bauce, F Bedeschi, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, A Bhatti, KR Bland, B Blumenfeld, A Bocci, A Bodek, D Bortoletto, J Boudreau, A Boveia, L Brigliadori, C Bromberg, E Brucken, J Budagov, K Burkett, G Busetto, P Bussey, P Butti, A Buzatu, A Calamba, S Camarda, M Campanelli, F Canelli, B Carls, D Carlsmith, R Carosi, S Carrillo, B Casal, M Casarsa, A Castro, P Catastini, D Cauz, V Cavaliere, M Cavalli-Sforza, A Cerri, L Cerrito, YC Chen, M Chertok, G Chiarelli, G Chlachidze, K Cho, JP Chou, D Chokheli, A Clark, C Clarke, ME Convery, J Conway, M Corbo, M Cordelli, CA Cox, DJ Cox, M Cremonesi, J Cuevas, R Culbertson, N D'Ascenzo, M Datta, L Demortier, M Deninno, F Devoto, M D'Errico, A Di Canto, B Di Ruzza, JR Dittmann, M D'Onofrio, S Donati, M Dorigo, A Driutti, K Ebina, R Edgar, A Elagin, R Erbacher, S Errede, B Esham

Abstract:

The first observation of the production of a W boson with a single charm quark (c) jet in pp̄ collisions at √s=1.96 TeV is reported. The analysis uses data corresponding to 4.3 fb-1, recorded with the CDF II detector at the Fermilab Tevatron. Charm quark candidates are selected through the identification of an electron or muon from charm-hadron semileptonic decay within a hadronic jet, and a Wc signal is observed with a significance of 5.7 standard deviations. The production cross section σ Wc(pTc>20 GeV/c,|ηc|<1.5) ×B(W→ℓν) is measured to be 13.6-3.1+3.4 pb and is in agreement with theoretical expectations. From this result the magnitude of the quark-mixing matrix element Vcs is derived, |Vcs|=1. 08±0.16 along with a lower limit of |Vcs|>0.71 at the 95% confidence level, assuming that the Wc production through c to s quark coupling is dominant. © 2013 American Physical Society.
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Measurement of the flavour composition of dijet events in pp collisions at √s = 7 TeV with the ATLAS detector

European Physical Journal C 73:2 (2013)

Authors:

G Aad, T Abajyan, B Abbott, J Abdallah, SA Khalek, AA Abdelalim, O Abdinov, R Aben, B Abi, M Abolins, OSA Zeid, H Abramowicz, H Abreu, E Acerbi, BS Acharya, L Adamczyk, DL Adams, TN Addy, J Adelman, S Adomeit, P Adragna, T Adye, S Aefsky, JA Aguilar-Saavedra, M Agustoni, M Aharrouche, SP Ahlen, F Ahles, A Ahmad, M Ahsan, G Aielli, T Akdogan, TPA Åkesson, G Akimoto, AV Akimov, MS Alam, MA Alam, J Albert, S Albrand, M Aleksa, IN Aleksandrov, F Alessandria, C Alexa, G Alexander, G Alexandre, T Alexopoulos, M Alhroob, M Aliev, G Alimonti, J Alison, BMM Allbrooke, PP Allport, SE Allwood-Spiers, J Almond, A Aloisio, R Alon, A Alonso, F Alonso, BA Gonzalez, MG Alviggi, K Amako, C Amelung, VV Ammosov, SPA Dos Santos, A Amorim, N Amram, C Anastopoulos, LS Ancu, N Andari, T Andeen, CF Anders, G Anders, KJ Anderson, A Andreazza, V Andrei, ML Andrieux, XS Anduaga, P Anger, A Angerami, F Anghinolfi, A Anisenkov, N Anjos, A Annovi, A Antonaki, M Antonelli, A Antonov, J Antos, F Anulli, M Aoki, S Aoun, LA Bella, R Apolle, G Arabidze, I Aracena, Y Arai, ATH Arce, S Arfaoui, JF Arguin, E Arik, M Arik

Abstract:

This paper describes a measurement of the flavour composition of dijet events produced in pp collisions at √s = 7 TeV using the ATLAS detector. The measurement uses the full 2010 data sample, corresponding to an integrated luminosity of 39 pb−1. Six possible combinations of light, charm and bottom jets are identified in the dijet events, where the jet flavour is defined by the presence of bottom, charm or solely light flavour hadrons in the jet. Kinematic variables, based on the properties of displaced decay vertices and optimised for jet flavour identification, are used in a multidimensional template fit to measure the fractions of these dijet flavour states as functions of the leading jet transverse momentum in the range 40 GeV to 500 GeV and jet rapidity |y| < 2.1. The fit results agree with the predictions of leading- and next-to-leading-order calculations, with the exception of the dijet fraction composed of bottom and light flavour jets, which is underestimated by all models at large transverse jet momenta. The ability to identify jets containing two b-hadrons, originating from e.g. gluon splitting, is demonstrated. The difference between bottom jet production rates in leading and subleading jets is consistent with the next-to-leading-order predictions.
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