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Search for supersymmetry in events with large missing transverse momentum, jets, and at least one tau lepton in 7 TeV proton-proton collision data with the ATLAS detector

European Physical Journal C 72:11 (2012)

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, BS Acharya, L Adamczyk, DL Adams, TN Addy, J Adelman, S Adomeit, P Adragna, T Adye, S Aefsky, JAA 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, SEA Spiers, J Almond, A Aloisio, R Alon, A Alonso, F Alonso, A Altheimer, 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, S Angelidakis, 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

Abstract:

A search for supersymmetry (SUSY) in events with large missing transverse momentum, jets, and at least one hadronically decaying τ lepton, with zero or one additional light lepton (e/μ), has been performed using 4.7 fb−1of proton-proton collision data at √s = 7 TeV recorded with the ATLAS detector at the Large Hadron Collider. No excess above the Standard Model background expectation is observed and a 95 % confidence level visible cross-section upper limit for new phenomena is set. In the framework of gauge-mediated SUSY-breaking models, lower limits on the mass scale Λ are set at 54 TeV in the regions where the τ1is the next-to-lightest SUSY particle (tanβ > 20). These limits provide the most stringent tests to date of GMSB models in a large part of the parameter space considered.
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Measurements of the top-quark mass and the tt̄ cross section in the hadronic τ+jets decay channel at √s=1.96TeV

Physical Review Letters 109:19 (2012)

Authors:

T Aaltonen, B Álvarez González, 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, D Bisello, I Bizjak, 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, A Buzatu, A Calamba, C Calancha, S Camarda, M Campanelli, M Campbell, F Canelli, B Carls, D Carlsmith, R Carosi, S Carrillo, S Carron, 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, F Chlebana, K Cho, D Chokheli, WH Chung, YS Chung, MA Ciocci, A Clark, C Clarke, G Compostella, ME Convery, J Conway, M Corbo, M Cordelli, CA Cox, DJ Cox, F Crescioli, J Cuevas, R Culbertson, D Dagenhart, N D'Ascenzo, M Datta, P De Barbaro, M Dell'Orso, L Demortier, M Deninno, F Devoto, M D'Errico

Abstract:

We present the first direct measurement of the top-quark mass using tt̄ events decaying in the hadronic τ+jets decay channel. Using data corresponding to an integrated luminosity of 2.2fb-1 collected by the CDF II detector in pp̄ collisions at √s=1.96TeV at the Fermilab Tevatron, we measure the tt̄ cross section, σtt̄, and the top-quark mass, Mtop. We extract Mtop from a likelihood based on per-event probabilities calculated with leading-order signal and background matrix elements. We measure σtt̄=8. 8±3.3(stat)±2.2(syst)pb and Mtop=172.7±9.3(stat) ±3.7(syst)GeV/c2. © 2012 American Physical Society.
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Search for neutral Higgs bosons in events with multiple bottom quarks at the Tevatron

Physical Review D - Particles, Fields, Gravitation and Cosmology 86:9 (2012)

Authors:

T Aaltonen, VM Abazov, B Abbott, BS Acharya, M Adams, T Adams, GD Alexeev, G Alkhazov, A Alton, B Lvarez González, G Alverson, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, JA Appel, T Arisawa, A Artikov, J Asaadi, W Ashmanskas, A Askew, S Atkins, B Auerbach, K Augsten, A Aurisano, C Avila, F Azfar, F Badaud, W Badgett, T Bae, L Bagby, B Baldin, DV Bandurin, S Banerjee, A Barbaro-Galtieri, E Barberis, P Baringer, VE Barnes, BA Barnett, P Barria, JF Bartlett, P Bartos, U Bassler, M Bauce, V Bazterra, A Bean, F Bedeschi, M Begalli, S Behari, L Bellantoni, G Bellettini, J Bellinger, D Benjamin, A Beretvas, SB Beri, G Bernardi, R Bernhard, I Bertram, M Besançon, R Beuselinck, PC Bhat, S Bhatia, V Bhatnagar, A Bhatti, M Binkley, D Bisello, I Bizjak, KR Bland, G Blazey, S Blessing, K Bloom, B Blumenfeld, A Bocci, A Bodek, A Boehnlein, D Boline, EE Boos, G Borissov, D Bortoletto, T Bose, J Boudreau, A Boveia, A Brandt, O Brandt, L Brigliadori, R Brock, C Bromberg, A Bross, D Brown, J Brown, E Brucken, J Budagov, XB Bu, HS Budd, M Buehler, V Buescher, V Bunichev, S Burdin

Abstract:

The combination of searches performed by the CDF and D0 collaborations at the Fermilab Tevatron Collider for neutral Higgs bosons produced in association with b quarks is reported. The data, corresponding to 2.6fb -1 of integrated luminosity at CDF and 5.2fb -1 at D0, have been collected in final states containing three or more b jets. Upper limits are set on the cross section multiplied by the branching ratio varying between 44 pb and 0.7 pb in the Higgs boson mass range 90 to 300 GeV, assuming production of a narrow scalar boson. Significant enhancements to the production of Higgs bosons can be found in theories beyond the standard model, for example, in supersymmetry. The results are interpreted as upper limits in the parameter space of the minimal supersymmetric standard model in a benchmark scenario favoring this decay mode. © 2012 American Physical Society.
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Measurement of the top quark forward-backward production asymmetry and its dependence on event kinematic properties

(2012)

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, 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, R Eusebi, S Farrington, JP Fernández Ramos, R Field, G Flanagan, R Forrest, M Franklin, JC Freeman, H Frisch, Y Funakoshi, 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 González López, 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, T Kuhr, M Kurata, AT Laasanen, S Lammel, M Lancaster, K Lannon, G Latino, HS Lee, JS Lee, S Leone, JD Lewis, A Limosani, E Lipeles, H Liu, Q Liu, T Liu, S Lockwitz, A Loginov, 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 Martínez, 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 Fernández, P Renton, M Rescigno, T Riddick, F Rimondi, L Ristori, A Robson, T Rodriguez, S Rolli, M Ronzani, R Roser, JL Rosner, F Ruffini, A Ruiz, J Russ, V Rusu, A Safonov, WK Sakumoto, Y Sakurai, L Santi, K Sato, V Saveliev, A Savoy-Navarro, P Schlabach, EE Schmidt, T Schwarz, L Scodellaro, S Seidel, Y Seiya, A Semenov, F Sforza, SZ Shalhout, T Shears, PF Shepard, M Shimojima, M Shochet, I Shreyber-Tecker, A Simonenko, P Sinervo, K Sliwa, JR Smith, FD Snider, V Sorin, H Song, M Stancari, R St Denis, B Stelzer, O Stelzer-Chilton, 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 Vázquez, G Velev, C Vellidis, C Vernieri, M Vidal, R Vilar, J Vizán, M Vogel, G Volpi, P Wagner, R Wallny, SM Wang, A Warburton, 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
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Measurement of the top quark forward-backward production asymmetry and its dependence on event kinematic properties

ArXiv 1211.1003 (2012)

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, 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, R Eusebi, S Farrington, JP Fernández Ramos, R Field, G Flanagan, R Forrest, M Franklin, JC Freeman, H Frisch, Y Funakoshi, 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 González López, 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, T Kuhr, M Kurata, AT Laasanen, S Lammel, M Lancaster, K Lannon, G Latino, HS Lee, JS Lee, S Leone, JD Lewis, A Limosani, E Lipeles, H Liu, Q Liu, T Liu, S Lockwitz, A Loginov, 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 Martínez, 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 Fernández, P Renton, M Rescigno, T Riddick, F Rimondi, L Ristori, A Robson, T Rodriguez, S Rolli, M Ronzani, R Roser, JL Rosner, F Ruffini, A Ruiz, J Russ, V Rusu, A Safonov, WK Sakumoto, Y Sakurai, L Santi, K Sato, V Saveliev, A Savoy-Navarro, P Schlabach, EE Schmidt, T Schwarz, L Scodellaro, S Seidel, Y Seiya, A Semenov, F Sforza, SZ Shalhout, T Shears, PF Shepard, M Shimojima, M Shochet, I Shreyber-Tecker, A Simonenko, P Sinervo, K Sliwa, JR Smith, FD Snider, V Sorin, H Song, M Stancari, R St Denis, B Stelzer, O Stelzer-Chilton, 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 Vázquez, G Velev, C Vellidis, C Vernieri, M Vidal, R Vilar, J Vizán, M Vogel, G Volpi, P Wagner, R Wallny, SM Wang, A Warburton, D Waters, WC Wester III, 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 present new measurements of the inclusive forward-backward ttbar production asymmetry, AFB, and its dependence on several properties of the ttbar system. The measurements are performed with the full Tevatron data set recorded with the CDF II detector during ppbar collisions at sqrt(s) = 1.96 TeV, corresponding to an integrated luminosity of 9.4 fb^(-1). We measure the asymmetry using the rapidity difference Delta-y=y_(t)-y_(tbar). Parton-level results are derived, yielding an inclusive asymmetry of 0.164+/-0.047 (stat + syst). We observe a linear dependence of AFB on the top-quark pair mass M(ttbar) and the rapidity difference |Delta-y| at detector and parton levels. Assuming the standard model, the probabilities to observe the measured values or larger for the detector-level dependencies are 7.4*10^(-3) and 2.2*10^(-3) for M(ttbar) and |Delta-y| respectively. Lastly, we study the dependence of the asymmetry on the transverse momentum of the ttbar system at the detector level. These results are consistent with previous lower-precision measurements and provide additional quantification of the functional dependencies of the asymmetry.
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