Observation of D0-D0bar Mixing using the CDF II Detector

ArXiv 1309.4078 (2013)

Authors:

CDF Collaboration, 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, 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, L Marchese, 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, S Farrington, JP Fern谩ndez Ramos, R Field, G Flanagan, R Forrest, M Franklin, JC Freeman, H Frisch, Y Funakoshi, C Galloni, AF Garfinkel, P Garosi, H Gerberich, E Gerchtein, S Giagu, V Giakoumopoulou, K Gibson, CM Ginsburg, N Giokaris, P Giromini, G Giurgiu, V Glagolev, D Glenzinski, M Gold, D Goldin, A Golossanov, G Gomez, G Gomez-Ceballos, M Goncharov, O Gonz谩lez L贸pez, I Gorelov, AT Goshaw, K Goulianos, E Gramellini, S Grinstein, C Grosso-Pilcher, RC Group, J Guimaraes da Costa, SR Hahn, JY Han, F Happacher, K Hara, M Hare, RF Harr, T Harrington-Taber, K Hatakeyama, C Hays, J Heinrich, M Herndon, A Hocker, Z Hong, W Hopkins, S Hou, RE Hughes, U Husemann, M Hussein, J Huston, G Introzzi, M Iori, A Ivanov, E James, D Jang, B Jayatilaka, EJ Jeon, S Jindariani, M Jones, KK Joo, SY Jun, TR Junk, M Kambeitz, T Kamon, PE Karchin, A Kasmi, Y Kato, W Ketchum, J Keung, B Kilminster, DH Kim, HS Kim, JE Kim, MJ Kim, SB Kim, SH Kim, YK Kim, YJ Kim, N Kimura, M Kirby, K Knoepfel, K Kondo, DJ Kong, J Konigsberg, AV Kotwal, M Kreps, J Kroll, M Kruse, N Kulkarni, T Kuhr, M Kurata, AT Laasanen, S Lammel, M Lancaster, K Lannon, G Latino, HS Lee, JS Lee, S Leo, S Leone, JD Lewis, A Limosani, E Lipeles, A Lister, H Liu, Q Liu, T Liu, S Lockwitz, A Loginov, A Luc脿, D Lucchesi, J Lueck, P Lujan, P Lukens, G Lungu, J Lys, R Lysak, R Madrak, P Maestro, S Malik, G Manca, A Manousakis-Katsikakis, F Margaroli, P Marino, M Mart铆nez, K Matera, ME Mattson, A Mazzacane, P Mazzanti, R McNulty, A Mehta, P Mehtala, C Mesropian, T Miao, D Mietlicki, A Mitra, H Miyake, S Moed, N Moggi, CS Moon, R Moore, MJ Morello, A Mukherjee, Th Muller, P Murat, M Mussini, J Nachtman, Y Nagai, J Naganoma, I Nakano, A Napier, J Nett, C Neu, T Nigmanov, L Nodulman, SY Noh, O Norniella, L Oakes, SH Oh, YD Oh, I Oksuzian, T Okusawa, R Orava, L Ortolan, C Pagliarone, E Palencia, P Palni, V Papadimitriou, W Parker, G Pauletta, M Paulini, C Paus, TJ Phillips, G Piacentino, E Pianori, J Pilot, K Pitts, C Plager, L Pondrom, S Poprocki, K Potamianos, F Prokoshin, A Pranko, F Ptohos, G Punzi, N Ranjan, I Redondo Fern谩ndez, P Renton, M Rescigno, F Rimondi, L Ristori, A Robson, T Rodriguez, S Rolli, M Ronzani, R Roser, JL Rosner, F Ruffini, A Ruiz, J Russ, V Rusu, WK Sakumoto, Y Sakurai, L Santi, K Sato, V Saveliev, A Savoy-Navarro, P Schlabach, EE Schmidt, T Schwarz, L Scodellaro, F Scuri, S Seidel, Y Seiya, A Semenov, F Sforza, SZ Shalhout, T Shears, PF Shepard, M Shimojima, M Shochet, I Shreyber-Tecker, A Simonenko, K Sliwa, JR Smith, FD Snider, V Sorin, H Song, M Stancari, R St Denis, D Stentz, J Strologas, Y Sudo, A Sukhanov, I Suslov, K Takemasa, Y Takeuchi, J Tang, M Tecchio, PK Teng, J Thom, E Thomson, V Thukral, D Toback, S Tokar, K Tollefson, T Tomura, D Tonelli, S Torre, D Torretta, P Totaro, M Trovato, F Ukegawa, S Uozumi, F V谩zquez, G Velev, C Vellidis, C Vernieri, M Vidal, R Vilar, J Viz谩n, M Vogel, G Volpi, P Wagner, R Wallny, SM Wang, D Waters, WC Wester, D Whiteson, AB Wicklund, S Wilbur, HH Williams, JS Wilson, P Wilson, BL Winer, P Wittich, S Wolbers, H Wolfe, T Wright, X Wu, Z Wu, K Yamamoto, D Yamato, T Yang, UK Yang, YC Yang, W-M Yao, GP Yeh, K Yi, J Yoh, K Yorita, T Yoshida, GB Yu, I Yu, AM Zanetti, Y Zeng, C Zhou, S Zucchelli

Abstract:

We measure the time dependence of the ratio of decay rates for D0 -> K+ pi- to the Cabibbo-favored decay D0 -> K- pi+. The charge conjugate decays are included. A signal of 3.3 x 10^4 D*+ -> pi+ D0, D0 -> K+ pi- decays is obtained with D0 proper decay times between 0.75 and 10 mean D0 lifetimes. The data were recorded with the CDF II detector at the Fermilab Tevatron and correspond to an integrated luminosity of 9.6 fb-1 for p-pbar collisions at sqrt(s) = 1.96 TeV. Assuming CP conservation, we search for D0-D0bar mixing and measure the mixing parameters to be R_D = (3.51 +/- 0.35) x 10^{-3}, y' = (4.3 +/- 4.3) x 10^{-3}, and x'^2 = (0.08 +/- 0.18) x 10^{-3}. We report Bayesian probability intervals in the x'^2 - y' plane and find that the significance of excluding the no-mixing hypothesis is equivalent to 6.1 Gaussian standard deviations, providing the second observation of D0-D0bar mixing from a single experiment.

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 726:1-3 (2013) 88-119

Authors:

G Aad, T Abajyan, B Abbott, J Abdallah, S AbdelKhalek, O Abdinov, R Aben, B Abi, M Abolins, OS AbouZeid, H Abramowicz, H Abreu, Y Abulaiti, BS Acharya, L Adamczyk, DL Adams, TN Addy, J Adelman, S Adomeit, T Adye, S Aefsky, JA Aguilar-Saavedra, M Agustoni, SP Ahlen, A Ahmad, M Ahsan, G Aielli, TPA 脜kesson, G Akimoto, AV Akimov, MA Alam, J Albert, S Albrand, MJ Alconada Verzini, M Aleksa, IN Aleksandrov, F Alessandria, C Alexa, G Alexander, G Alexandre, T Alexopoulos, M Alhroob, M Aliev, G Alimonti, L Alio, J Alison, BMM Allbrooke, LJ Allison, PP Allport, SE Allwood-Spiers, J Almond, A Aloisio, R Alon, A Alonso, F Alonso, A Altheimer, B Alvarez Gonzalez, MG Alviggi, K Amako, Y Amaral Coutinho, C Amelung, VV Ammosov, SP Amor Dos Santos, A Amorim, S Amoroso, N Amram, C Anastopoulos, LS Ancu, N Andari, T Andeen, CF Anders, G Anders, KJ Anderson, A Andreazza, V Andrei, XS Anduaga, S Angelidakis, P Anger, A Angerami, F Anghinolfi, AV Anisenkov, N Anjos, A Annovi, A Antonaki, M Antonelli, A Antonov, J Antos, F Anulli, M Aoki, L Aperio Bella, R Apolle, G Arabidze, I Aracena, Y Arai, ATH Arce, S Arfaoui, JF Arguin, S Argyropoulos, E Arik, M Arik

Abstract:

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H鈫捨澄�, H鈫抁Z*鈫�4鈩� and H鈫扺W*鈫掆創谓鈩撐�. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of s=7 TeV and s=8 TeV, corresponding to an integrated luminosity of about 25 fb-1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson. 漏 2013 CERN.

Hyper-Kamiokande Physics Opportunities

ArXiv 1309.0184 (2013)

Performance of jet substructure techniques for large-R jets in proton-proton collisions at 鈭歴=7 TeV using the ATLAS detector

Journal of High Energy Physics 2013:9 (2013)

Authors:

G Aad, T Abajyan, B Abbott, J Abdallah, S Abdel Khalek, AA Abdelalim, O Abdinov, R Aben, B Abi, M Abolins, OS Abouzeid, H Abramowicz, H Abreu, Y Abulaiti, BS Acharya, L Adamczyk, DL Adams, TN Addy, J Adelman, S Adomeit, T Adye, S Aefsky, JA Aguilar-Saavedra, M Agustoni, SP Ahlen, F Ahles, A Ahmad, M Ahsan, G Aielli, TPA 脜kesson, G Akimoto, AV Akimov, 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, LJ Allison, PP Allport, SE Allwood-Spiers, J Almond, A Aloisio, R Alon, A Alonso, F Alonso, A Altheimer, B Alvarez Gonzalez, MG Alviggi, K Amako, Y Amaral Coutinho, C Amelung, VV Ammosov, SP Amor Dos Santos, A Amorim, S Amoroso, N Amram, C Anastopoulos, LS Ancu, N Andari, T Andeen, CF Anders, G Anders, KJ Anderson, A Andreazza, V Andrei, XS Anduaga, S Angelidakis, P Anger, A Angerami, F Anghinolfi, AV Anisenkov, N Anjos, A Annovi, A Antonaki, M Antonelli, A Antonov, J Antos, F Anulli, M Aoki, L Aperio Bella, R Apolle, G Arabidze, I Aracena, Y Arai, ATH Arce, S Arfaoui, JF Arguin, S Argyropoulos, E Arik, M Arik

Abstract:

This paper presents the application of a variety of techniques to study jet substructure. The performance of various modified jet algorithms, or jet grooming techniques, for several jet types and event topologies is investigated for jets with transverse momentum larger than 300 GeV. Properties of jets subjected to the mass-drop filtering, trimming, and pruning algorithms are found to have a reduced sensitivity to multiple proton-proton interactions, are more stable at high luminosity and improve the physics potential of searches for heavy boosted objects. Studies of the expected discrimination power of jet mass and jet substructure observables in searches for new physics are also presented. Event samples enriched in boosted W and Z bosons and top-quark pairs are used to study both the individual jet invariant mass scales and the efficacy of algorithms to tag boosted hadronic objects. The analyses presented use the full 2011 ATLAS dataset, corresponding to an integrated luminosity of 4.7 卤 0.1 fb-1 from proton-proton collisions produced by the Large Hadron Collider at a centre-of-mass energy of 鈭歴=7 TeV. [Figure not available: see fulltext.] 漏 2013 Cern for the benefit of the ATLAS collaboration.

Search for excited electrons and muons in 鈭歴=8 TeV proton-proton collisions with the ATLAS detector

New Journal of Physics 15 (2013)

Authors:

G Aad, T Abajyan, B Abbott, J Abdallah, S Abdel Khalek, O Abdinov, R Aben, B Abi, M Abolins, OS Abouzeid, H Abramowicz, H Abreu, Y Abulaiti, BS Acharya, L Adamczyk, DL Adams, TN Addy, J Adelman, S Adomeit, T Adye, S Aefsky, T Agatonovic-Jovin, JA Aguilar-Saavedra, M Agustoni, SP Ahlen, A Ahmad, F Ahmadov, M Ahsan, G Aielli, TPA 脜kesson, G Akimoto, AV Akimov, MA Alam, J Albert, S Albrand, MJ Alconada Verzini, M Aleksa, IN Aleksandrov, F Alessandria, C Alexa, G Alexander, G Alexandre, T Alexopoulos, M Alhroob, M Aliev, G Alimonti, L Alio, J Alison, BMM Allbrooke, LJ Allison, PP Allport, SE Allwood-Spiers, J Almond, A Aloisio, R Alon, A Alonso, F Alonso, A Altheimer, B Alvarez Gonzalez, MG Alviggi, K Amako, Y Amaral Coutinho, C Amelung, VV Ammosov, SP Amor Dos Santos, A Amorim, S Amoroso, N Amram, C Anastopoulos, LS Ancu, N Andari, T Andeen, CF Anders, G Anders, KJ Anderson, A Andreazza, V Andrei, XS Anduaga, S Angelidakis, P Anger, A Angerami, F Anghinolfi, AV Anisenkov, N Anjos, A Annovi, A Antonaki, M Antonelli, A Antonov, J Antos, F Anulli, M Aoki, L Aperio Bella, R Apolle, G Arabidze, I Aracena, Y Arai, ATH Arce, S Arfaoui, JF Arguin, S Argyropoulos

Abstract:

The ATLAS detector at the Large Hadron Collider is used to search for excited electrons and excited muons in the channel pp 鈫� 鈩撯創* 鈫� 鈩撯創纬, assuming that excited leptons are produced via contact interactions. The analysis is based on 13 fb-1 of pp collisions at a centre-of-mass energy of 8 TeV. No evidence for excited leptons is found, and a limit is set at the 95% credibility level on the cross section times branching ratio as a function of the excited-lepton mass m鈩�*. For m鈩�* 0.8 TeV, the respective upper limits on 蟽B(鈩�* 鈫� 鈩撐�) are 0.75 and 0.90 fb for the e* and 渭* searches. Limits on 蟽B are converted into lower bounds on the compositeness scale 螞. In the special case where 螞 = m 鈩�*, excited-electron and excited-muon masses below 2.2 TeV are excluded. 漏 CERN 2013.