Professor Chris Hays: Publications

Search for anomalous semileptonic decay of heavy flavor hadrons produced in association with a W boson at CDF II

Physical Review D Particles Fields Gravitation and Cosmology 73:5 (2006)

Authors:

A Abulencia, D Acosta, J Adelman, T Affolder, T Akimoto, MG Albrow, D Ambrose, S Amerio, D Amidei, A Anastassov, K Anikeev, A Annovi, J Antos, M Aoki, G Apollinari, JF Arguin, T Arisawa, A Artikov, W Ashmanskas, A Attal, F Azfar, P Azzi-Bacchetta, P Azzurri, N Bacchetta, H Bachacou, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, V Bartsch, G Bauer, F Bedeschi, S Behari, S Belforte, G Bellettini, J Bellinger, A Belloni, EB Haim, D Benjamin, A Beretvas, J Beringer, T Berry, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, A Bolshov, D Bortoletto, J Boudreau, S Bourov, A Boveia, B Brau, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, K Burkett, G Busetto, P Bussey, KL Byrum, S Cabrera, M Campanelli, M Campbell, F Canelli, A Canepa, D Carlsmith, R Carosi, S Carron, M Casarsa, A Castro, P Catastini, D Cauz, M Cavalli-Sforza, A Cerri, L Cerrito, SH Chang, J Chapman, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, I Cho, K Cho, D Chokheli, JP Chou, PH Chu, SH Chuang, K Chung, WH Chung

Abstract:

We present a search for anomalous semileptonic decays of heavy flavor hadrons produced in association with a W boson in proton-antiproton collisions at s=1.96TeV. We use 162pb-1 of data collected with the CDF II detector at the Fermilab Tevatron Collider. We select events with one W boson and at least one jet with an identified secondary vertex. In the jets with a secondary vertex we look for a semileptonic decay to a muon. We compare the number of jets with both a secondary vertex and a semileptonic decay and the kinematic properties of these jets, with the standard model expectation of W plus heavy flavor production and decay. No discrepancy is seen between the observation and the expectation, and we set limits on the production cross section of a B-like hadron with an anomalously high semileptonic branching ratio. © 2006 The American Physical Society.

Search for second-generation scalar leptoquarks in pp̄ collisions at s=1.96TeV

Physical Review D Particles Fields Gravitation and Cosmology 73:5 (2006)

Authors:

Abstract:

Results on a search for pair production of second-generation scalar leptoquark in pp̄ collisions at s=1.96TeV are reported. The data analyzed were collected by the CDF detector during the 2002-2003 Tevatron Run II and correspond to an integrated luminosity of 198pb-1. Leptoquarks (LQ) are sought through their decay into (charged) leptons and quarks, with final state signatures represented by two muons and jets and one muon, large transverse missing energy and jets. We observe no evidence for LQ production and derive 95% C.L. upper limits on the LQ production cross sections as well as lower limits on their mass as a function of β, where β is the branching fraction for LQ→μq. © 2006 The American Physical Society.

Evidence for the exclusive decay B(c)+- --> J/psi pi+- and measurement of the mass of the B(c)+- meson.

Phys Rev Lett 96:8 (2006) 082002

Authors:

A Abulencia, D Acosta, J Adelman, T Affolder, T Akimoto, MG Albrow, D Ambrose, S Amerio, D Amidei, A Anastassov, K Anikeev, A Annovi, J Antos, M Aoki, G Apollinari, J-F Arguin, T Arisawa, A Artikov, W Ashmanskas, A Attal, F Azfar, P Azzi-Bacchetta, P Azzurri, N Bacchetta, H Bachocou, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, V Bartsch, G Bauer, F Bedeschi, S Behari, S Belforte, G Bellettini, J Bellinger, A Belloni, E Ben-Haim, D Benjamin, A Beretvas, J Beringer, T Berry, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, A Bolshov, D Bortoletto, J Boudreau, S Bourov, A Boveia, B Brau, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, K Burkett, G Busetto, P Bussey, KL Byrum, S Cabrera, M Campanelli, M Campbell, F Canelli, A Canepa, D Carlsmith, R Carosi, S Carron, M Casarsa, A Castro, P Catastini, D Cauz, M Cavalli-Sforza, A Cerri, L Cerrito, SH Chang, J Chapman, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, I Cho, K Cho, D Chokheli, JP Chou, PH Chu, SH Chuang, K Chung, WH Chung, YS Chung, M Cijliak, CI Ciobanu, MA Ciocci, A Clark, D Clark, M Coca, A Connolly, M Convery, J Conway, B Cooper, K Copic, M Cordelli, G Cortiana, J Cranshaw, A Cruz, J Cuevas, R Culbertson, D Cyr, S Da Ronco, S D'Auria, M D'Onofrio, D Dagenhart, P de Barbaro, S De Cecco, A Deisher, G De Lentdecker, M Dell'Orso, S Demers, L Demortier, J Deng, M Deninno, D De Pedis, PF Derwent, T Devlin, C Dionisi, JR Dittmann, P DiTuro, C Dörr, A Dominguez, S Donati, M Donega, P Dong, J Donini, T Dorigo, S Dube, K Ebina, J Efron, J Ehlers, R Erbacher, D Errede, S Errede, R Eusebi, HC Fang, S Farrington, I Fedorko, WT Fedorko, RG Feild, M Feindt, JP Fernandez, R Field, G Flanagan, LR Flores-Castillo, A Foland, S Forrester, GW Foster, M Franklin, JC Freeman, Y Fujii, I Furic, A Gajjar, M Gallinaro, J Galyardt, JE Garcia, M Garcia Sciveres, AF Garfinkel, C Gay, H Gerberich, E Gerchtein, D Gerdes, S Giagu, P Giannetti, A Gibson, K Gibson, C Ginsburg, K Giolo, M Giordani, M Giunta, G Giurgiu, V Glagolev, D Glenzinski, M Gold, N Goldschmidt, J Goldstein, G Gomez, G Gomez-Ceballos, M Goncharov, O González, I Gorelov, AT Goshaw, Y Gotra, K Goulianos, A Gresele, M Griffiths, S Grinstein, C Grosso-Pilcher, U Grundler, J Guimaraes da Costa, C Haber, SR Hahn, K Hahn, E Halkiadakis, A Hamilton, B-Y Han, R Handler, F Happacher, K Hara, M Hare, S Harper, RF Harr, RM Harris, K Hatakeyama, J Hauser, C Hays, H Hayward, A Heijboer, B Heinemann, J Heinrich, M Hennecke, M Herndon, J Heuser, D Hidas, CS Hill, D Hirschbuehl, A Hocker, A Holloway, S Hou, M Houlden, S-C Hsu, BT Huffman, RE Hughes, J Huston, K Ikado, J Incandela, G Introzzi, M Iori, Y Ishizawa, A Ivanov, B Iyutin, E James, D Jang, B Jayatilaka, D Jeans, H Jensen, EJ Jeon, M Jones, KK Joo, SY Jun, TR Junk, T Kamon, J Kang, M Karagoz-Unel, PE Karchin, Y Kato, Y Kemp, R Kephart, U Kerzel, V Khotilovich, B Kilminster, DH Kim, HS Kim, JE Kim, MJ Kim, MS Kim, SB Kim, SH Kim, YK Kim, M Kirby, L Kirsch, S Klimenko, M Klute, B Knuteson, BR Ko, H Kobayashi, K Kondo, DJ Kong, J Konigsberg, K Kordas, A Korytov, AV Kotwal, A Kovalev, J Kraus, I Kravchenko, M Kreps, A Kreymer, J Kroll, N Krumnack, M Kruse, V Krutelyov, SE Kuhlmann, Y Kusakabe, S Kwang, AT Laasanen, S Lai, S Lami, S Lammel, M Lancaster, RL Lander, K Lannon, A Lath, G Latino, I Lazzizzera, C Lecci, T LeCompte, J Lee, J Lee, SW Lee, R Lefèvre, N Leonardo, S Leone, S Levy, JD Lewis, K Li, C Lin, CS Lin, M Lindgren, E Lipeles, TM Liss, A Lister, DO Litvintsev, T Liu, Y Liu, NS Lockyer, A Loginov, M Loreti, P Loverre, R-S Lu, D Lucchesi, P Lujan, P Lukens, G Lungu, L Lyons, J Lys, R Lysak, E Lytken, P Mack, D MacQueen, R Madrak, K Maeshima, P Maksimovic, G Manca, F Margaroli, R Marginean, C Marino, A Martin, M Martin, V Martin, M Martínez, T Maruyama, H Matsunaga, ME Mattson, R Mazini, P Mazzanti, KS McFarland, D McGivern, P McIntyre, P McNamara, R McNulty, A Mehta, S Menzemer, A Menzione, P Merkel, C Mesropian, A Messina, M von der Mey, T Miao, N Miladinovic, J Miles, R Miller, JS Miller, C Mills, M Milnik, R Miquel, S Miscetti, G Mitselmakher, A Miyamoto, N Moggi, B Mohr, R Moore, M Morello, P Movilla Fernandez, J Mülmenstädt, A Mukherjee, M Mulhearn, Th Muller, R Mumford, P Murat, J Nachtman, S Nahn, I Nakano, A Napier, D Naumov, V Necula, C Neu, MS Neubauer, L Nicolas, J Nielsen, T Nigmanov, L Nodulman, O Norniella, T Ogawa, SH Oh, YD Oh, T Okusawa, R Oldeman, R Orava, K Osterberg, C Pagliarone, E Palencia, R Paoletti, V Papadimitriou, A Papikonomou, AA Paramonov, B Parks, S Pashapour, J Patrick, G Pauletta, M Paulini, C Paus, DE Pellett, A Penzo, TJ Phillips, G Piacentino, J Piedra, K Pitts, C Plager, L Pondrom, G Pope, X Portell, O Poukhov, N Pounder, F Prakoshyn, A Pronko, J Proudfoot, F Ptohos, G Punzi, J Pursley, J Rademacker, A Rahaman, A Rakitin, S Rappoccio, F Ratnikov, B Reisert, V Rekovic, N van Remortel, P Renton, M Rescigno, S Richter, F Rimondi, K Rinnert, L Ristori, WJ Robertson, A Robson, T Rodrigo, E Rogers, S Rolli, R Roser, M Rossi, R Rossin, C Rott, A Ruiz, J Russ, V Rusu, D Ryan, H Saarikko, S Sabik, A Safonov, WK Sakumoto, G Salamanna, O Salto, D Saltzberg, C Sanchez, L Santi, S Sarkar, K Sato, P Savard, A Savoy-Navarro, T Scheidle, P Schlabach, EE Schmidt, MP Schmidt, M Schmitt, T Schwarz, L Scodellaro, AL Scott, A Scribano, F Scuri, A Sedov, S Seidel, Y Seiya, A Semenov, F Semeria, L Sexton-Kennedy, I Sfiligoi, MD Shapiro, T Shears, PF Shepard, D Sherman, M Shimojima, M Shochet, Y Shon, I Shreyber, A Sidoti, A Sill, P Sinervo, A Sisakyan, J Sjolin, A Skiba, AJ Slaughter, K Sliwa, D Smirnov, JR Smith, FD Snider, R Snihur, M Soderberg, A Soha, S Somalwar, V Sorin, J Spalding, M Spezziga, F Spinella, P Squillacioti, M Stanitzki, A Staveris-Polykalas, R St Denis, B Stelzer, O Stelzer-Chilton, D Stentz, J Strologas, D Stuart, JS Suh, A Sukhanov, K Sumorok, H Sun, T Suzuki, A Taffard, R Tafirout, R Takashima, Y Takeuchi, K Takikawa, M Tanaka, R Tanaka, M Tecchio, PK Teng, K Terashi, S Tether, J Thom, AS Thompson, E Thomson, P Tipton, V Tiwari, S Tkaczyk, D Toback, K Tollefson, T Tomura, D Tonelli, M Tönnesmann, S Torre, D Torretta, S Tourneur, W Trischuk, R Tsuchiya, S Tsuno, N Turini, F Ukegawa, T Unverhau, S Uozumi, D Usynin, L Vacavant, A Vaiciulis, S Vallecorsa, A Varganov, E Vataga, G Velev, G Veramendi, V Veszpremi, T Vickey, R Vidal, I Vila, R Vilar, I Vollrath, I Volobouev, F Würthwein, P Wagner, RG Wagner, RL Wagner, W Wagner, R Wallny, T Walter, Z Wan, MJ Wang, SM Wang, A Warburton, B Ward, S Waschke, D Waters, T Watts, M Weber, WC Wester, B Whitehouse, D Whiteson, AB Wicklund, E Wicklund, HH Williams, P Wilson, BL Winer, P Wittich, S Wolbers, C Wolfe, S Worm, T Wright, X Wu, SM Wynne, A Yagil, K Yamamoto, J Yamaoka, Y Yamashita, C Yang, UK Yang, WM Yao, GP Yeh, K Yi, J Yoh, K Yorita, T Yoshida, I Yu, SS Yu, JC Yun, L Zanello, A Zanetti, I Zaw, F Zetti, X Zhang, J Zhou, S Zucchelli, CDF Collaboration

Abstract:

We report the first evidence for a fully reconstructed decay mode of the B(c)+- meson in the channel B(c)+- --> J/psi pi+-, with J/psi --> mu+ mu-. The analysis is based on an integrated luminosity of 360 pb(-1) in pp collisions at 1.96 TeV center of mass energy collected by the Collider Detector at Fermilab. We observe 14.6 +/- 4.6 signal events with a background of 7.1 +/- 0.9 events, and a fit to the J/psi pi+-mass spectrum yields a B(c)+- mass of 6285.7 +/- 5.3(stat) +/- 1.2(syst) MeV/c2. The probability of a peak of this magnitude occurring by random fluctuation in the search region is estimated as 0.012%.

Top quark mass measurement using the template method in the lepton+jets channel at CDF II

Physical Review D Particles Fields Gravitation and Cosmology 73:3 (2006)

Authors:

A Abulencia, D Acosta, J Adelman, T Affolder, T Akimoto, MG Albrow, D Ambrose, S Amerio, D Amidei, A Anastassov, K Anikeev, A Annovi, J Antos, M Aoki, G Apollinari, JF Arguin, T Arisawa, A Artikov, W Ashmanskas, A Attal, F Azfar, P Azzi-Bacchetta, P Azzurri, N Bacchetta, H Bachacou, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, V Bartsch, G Bauer, F Bedeschi, S Behari, S Belforte, G Bellettini, J Bellinger, A Belloni, E Ben-Haim, D Benjamin, A Beretvas, J Beringer, T Berry, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, A Bolshov, D Bortoletto, J Boudreau, S Bourov, A Boveia, B Brau, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, K Burkett, G Busetto, P Bussey, KL Byrum, S Cabrera, M Campanelli, M Campbell, F Canelli, A Canepa, D Carlsmith, R Carosi, S Carron, M Casarsa, A Castro, P Catastini, D Cauz, M Cavalli-Sforza, A Cerri, L Cerrito, SH Chang, J Chapman, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, I Cho, K Cho, D Chokheli, JP Chou, PH Chu, SH Chuang, K Chung, WH Chung

Abstract:

This article presents a measurement of the top quark mass using the CDF II detector at Fermilab. Colliding beams of protons and antiprotons at Fermilab's Tevatron (s=1.96TeV) produce top/antitop pairs, which decay to W+W-bb̄; events are selected where one W decays to hadrons and the other W decays to either e or μ plus a neutrino. The data sample corresponds to an integrated luminosity of approximately 318pb-1. A total of 165 tt̄ events are separated into four subsamples based on jet transverse energy thresholds and the number of b jets identified by reconstructing a displaced vertex. In each event, the reconstructed top quark invariant mass is determined by minimizing a χ2 for the overconstrained kinematic system. At the same time, the mass of the hadronically decaying W boson is measured in the same event sample. The observed W boson mass provides an in situ improvement in the determination of the hadronic jet energy scale. A simultaneous likelihood fit of the reconstructed top quark masses and the W boson invariant masses in the data sample to distributions from simulated signal and background events gives a top quark mass of 173.5-3.8+3.9GeV/c2. © 2006 The American Physical Society.

Precision top-quark mass measurement in the lepton+jets topology in pp̄ collisions at s=1.96TeV

Physical Review Letters 96:2 (2006)

Authors:

A Abulencia, D Acosta, J Adelman, T Affolder, T Akimoto, MG Albrow, D Ambrose, S Amerio, D Amidei, A Anastassov, K Anikeev, A Annovi, J Antos, M Aoki, G Apollinari, JF Arguin, T Arisawa, A Artikov, W Ashmanskas, A Attal, F Azfar, P Azzi-Bacchetta, P Azzurri, N Bacchetta, H Bachacou, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, V Bartsch, G Bauer, F Bedeschi, S Behari, S Belforte, G Bellettini, J Bellinger, A Belloni, E Ben-Haim, D Benjamin, A Beretvas, J Beringer, T Berry, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, A Bolshov, D Bortoletto, J Boudreau, S Bourov, A Boveia, B Brau, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, K Burkett, G Busetto, P Bussey, KL Byrum, S Cabrera, M Campanelli, M Campbell, F Canelli, A Canepa, D Carlsmith, R Carosi, S Carron, M Casarsa, A Castro, P Catastini, D Cauz, M Cavalli-Sforza, A Cerri, L Cerrito, SH Chang, J Chapman, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, I Cho, K Cho, D Chokheli, JP Chou, PH Chu, SH Chuang, K Chung, WH Chung

Abstract:

We report two measurements of the top-quark mass Mtop using the CDF II detector at the Fermilab Tevatron in a 318pb-1 data sample of tt̄ events in the lepton+jets final state. One method uses an event-based likelihood technique resulting in Mtop=173.2-2.4+2.6(stat)±3.2(syst)GeV/c2 or 173.2-4.0+4.1GeV/c2. The second method reconstructs a top-quark mass in each event using the measured invariant mass of the hadronically decaying W boson to constrain the jet energy scale to obtain a value for Mtop of 173.5-3.6+3.7(stat)±1.3(syst)GeV/c2 or 173.5-3.8+3.9GeV/c2. We take the latter, which is more precise, as our result. © 2006 The American Physical Society.

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