Professor Chris Hays: Publications

Doubly-charged Higgs bosons

Chapter in The Large Hadron Collider and Higgs Boson Research, (2011) 259-283

Abstract:

The standard model includes a Higgs weak doublet whose vacuum expectation value results in the masses of the observed particles. A number of models also predict a Higgs weak triplet, which includes a doubly-charged Higgs boson (H±±). The existence of such a boson could be inferred indirectly by its exchange in measured processes, or observed directly through its production and decay. Measurements of Bhabha scattering, tau decay, muon decay, and (g - 2)μ provide indirect limits on H±± couplings to charged leptons. Direct H±± searches have been performed in e+e- collisions at the Large Electron Positron collider (LEP) and in p-p collisions at the Fermilab Tevatron. The highest mass limits for exclusive H±± couplings to electrons and muons, and for long-lived H±±, are obtained by the Collider Detector at Fermilab (CDF), while the DELPHI detector at CERN obtains the highest mass limits for H±± couplings to taus. Future data at the Tevatron, Large Hadron Collider, and International Linear Collider will increase sensitivity to H±± mass and couplings by about an order of magnitude. © 2011 by Nova Science Publishers, Inc. All rights reserved.

Measurements of branching fraction ratios and CP-asymmetries in suppressed B^-→D(→K⁺π^-)K^- and B^-→D(→K⁺π^-)π^- decays

Physical Review D - Particles, Fields, Gravitation and Cosmology 84:9 (2011)

Authors:

T Aaltonen, B Álvarez González, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, JA Appel, A Apresyan, T Arisawa, A Artikov, J Asaadi, W Ashmanskas, B Auerbach, A Aurisano, F Azfar, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, P Bartos, M Bauce, G Bauer, F Bedeschi, D Beecher, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, A Bhatti, M Binkley, D Bisello, I Bizjak, KR Bland, B Blumenfeld, A Bocci, A Bodek, D Bortoletto, J Boudreau, A Boveia, L Brigliadori, A Brisuda, C Bromberg, E Brucken, M Bucciantonio, J Budagov, HS Budd, S Budd, K Burkett, G Busetto, P Bussey, A Buzatu, 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, JP Chou, WH Chung, YS Chung, CI Ciobanu, MA Ciocci, A Clark, C Clarke, G Compostella, ME Convery, J Conway, M Corbo, M Cordelli, CA Cox, DJ Cox, F Crescioli, C Cuenca Almenar, J Cuevas, R Culbertson, D Dagenhart

Abstract:

We report the first reconstruction in hadron collisions of the suppressed decays B-→D(→K+π-)K- and B-→D(→K+π-)π-, sensitive to the Cabibbo-Kobayashi-Maskawa phase γ, using data from 7fb-1 of integrated luminosity collected by the CDF II detector at the Tevatron collider. We reconstruct a signal for the B -→D(→K+π-)K- suppressed mode with a significance of 3.2 standard deviations, and measure the ratios of the suppressed to favored branching fractions R(K)=[22.0±8.6(stat) ±2.6(syst)]×10-3, R+(K)=[42.6±13. 7(stat)±2.8(syst)]×10-3, R-(K)=[3. 8±10.3(stat)±2.7(syst)]×10-3 as well as the direct CP-violating asymmetry A(K)=-0.82±0.44(stat)±0.09(syst) of this mode. Corresponding quantities for B-→D(→K +π-)π- decay are also reported. © 2011 American Physical Society.

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Top-quark mass measurement using events with missing transverse energy and jets at CDF

Physical Review Letters 107:23 (2011)

Authors:

Abstract:

We present a measurement of the top-quark mass using a sample of tt̄ events in 5.7fb-1 of integrated luminosity from pp̄ collisions at the Fermilab Tevatron with √s=1.96TeV and collected by the CDF II Detector. We select events having large missing transverse energy, and four, five, or six jets with at least one jet tagged as coming from a b quark, and reject events with identified charged leptons. This analysis considers events from the semileptonic tt̄ decay channel, including events that contain tau leptons. The measurement is based on a multidimensional template method. We fit the data to signal templates of varying top-quark masses and background templates, and measure a top-quark mass of Mtop=172.32±2. 4(stat)±1.0(syst)GeV/c2. © 2011 American Physical Society.

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Search for high-mass resonances decaying into ZZ in p$\bar{p}$ collisions at $\sqrt{s}=1.96$\,TeV

(2011)

Authors:

CDF Collaboration, T Aaltonen, B Alvarez Gonzalez, 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, A Di Canto, B Di Ruzza, JR Dittmann, M D'Onofrio, S Donati, P Dong, M Dorigo, T Dorigo, K Ebina, A Elagin, A Eppig, R Erbacher, S Errede, N Ershaidat, R Eusebi, S Farrington, M Feindt, JP Fernandez, R Field, G Flanagan, R Forrest, MJ Frank, M Franklin, JC Freeman, Y Funakoshi, I Furic, M Gallinaro, JE Garcia, AF Garfinkel, P Garosi, H Gerberich, E Gerchtein, S Giagu, V Giakoumopoulou, P Giannetti, K Gibson, CM Ginsburg, N Giokaris, P Giromini, G Giurgiu, V Glagolev, D Glenzinski, M Gold, D Goldin, N Goldschmidt, A Golossanov, G Gomez, G Gomez-Ceballos, M Goncharov, O González, I Gorelov, AT Goshaw, K Goulianos, S Grinstein, C Grosso-Pilcher, RC Group, J Guimaraes da Costa, SR Hahn, E Halkiadakis, A Hamaguchi, JY Han, F Happacher, K Hara, D Hare, M Hare, RF Harr, K Hatakeyama, C Hays, M Heck, J Heinrich, M Herndon, S Hewamanage, A Hocker, W Hopkins, D Horn, S Hou, RE Hughes, M Hurwitz, U Husemann, N Hussain, 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, T Kamon, PE Karchin, A Kasmi, Y Kato, W Ketchum, J Keung, V Khotilovich, B Kilminster, DH Kim, HS Kim, JE Kim, MJ Kim, SB Kim, SH Kim, YK Kim, YJ Kim, N Kimura, M Kirby, S Klimenko, K Knoepfel, K Kondo, DJ Kong, J Konigsberg, AV Kotwal, M Kreps, J Kroll, D Krop, M Kruse, V Krutelyov, T Kuhr, M Kurata, S Kwang, AT Laasanen, S Lami, S Lammel, M Lancaster, RL Lander, K Lannon, A Lath, G Latino, T LeCompte, E Lee, HS Lee, JS Lee, SW Lee, S Leo, S Leone, JD Lewis, A Limosani, C-J Lin, M Lindgren, E Lipeles, A Lister, DO Litvintsev, C Liu, 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, K Maeshima, P Maestro, S Malik, G Manca, A Manousakis-Katsikakis, F Margaroli, C Marino, M Martinez, P Mastrandrea, K Matera, ME Mattson, A Mazzacane, P Mazzanti, KS McFarland, P McIntyre, R McNulty, A Mehta, P Mehtala, C Mesropian, T Miao, D Mietlicki, A Mitra, H Miyake, S Moed, N Moggi, MN Mondragon, CS Moon, R Moore, MJ Morello, J Morlock, P Movilla Fernandez, A Mukherjee, Th Muller, P Murat, M Mussini, J Nachtman, Y Nagai, J Naganoma, I Nakano, A Napier, J Nett, C Neu, MS Neubauer, J Nielsen, L Nodulman, SY Noh, O Norniella, L Oakes, SH Oh, YD Oh, I Oksuzian, T Okusawa, R Orava, L Ortolan, S Pagan Griso, C Pagliarone, E Palencia, V Papadimitriou, AA Paramonov, J Patrick, G Pauletta, M Paulini, C Paus, DE Pellett, A Penzo, 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, A Rahaman, V Ramakrishnan, N Ranjan, I Redondo, P Renton, M Rescigno, T Riddick, F Rimondi, L Ristori, A Robson, T Rodrigo, T Rodriguez, E Rogers, S Rolli, R Roser, 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, A Schmidt, EE Schmidt, T Schwarz, L Scodellaro, A Scribano, 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, P Sinervo, K Sliwa, JR Smith, FD Snider, A Soha, V Sorin, H Song, P Squillacioti, M Stancari, R St Denis, B Stelzer, O Stelzer-Chilton, D Stentz, J Strologas, GL Strycker, Y Sudo, A Sukhanov, I Suslov, K Takemasa, Y Takeuchi, J Tang, M Tecchio, PK Teng, J Thom, J Thome, GA Thompson, E Thomson, D Toback, S Tokar, K Tollefson, T Tomura, D Tonelli, S Torre, D Torretta, P Totaro, M Trovato, F Ukegawa, S Uozumi, A Varganov, F Vazquez, G Velev, C Vellidis, M Vidal, I Vila, R Vilar, J Vizan, M Vogel, G Volpi, P Wagner, RL Wagner, T Wakisaka, R Wallny, SM Wang, A Warburton, D Waters, WC Wester, D Whiteson, AB Wicklund, E Wicklund, S Wilbur, F Wick, 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, SS Yu, JC Yun, A Zanetti, Y Zeng, C Zhou, S Zucchelli

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Observation of the baryonic flavor-changing neutral current decay Λb0→Λμ⁺μ^-

Physical Review Letters 107:20 (2011)

Authors:

T Aaltonen, B Álvarez González, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, JA Appel, A Apresyan, T Arisawa, A Artikov, J Asaadi, W Ashmanskas, B Auerbach, A Aurisano, F Azfar, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, P Bartos, M Bauce, G Bauer, F Bedeschi, D Beecher, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, A Bhatti, M Binkley, D Bisello, I Bizjak, KR Bland, C Blocker, B Blumenfeld, A Bocci, A Bodek, D Bortoletto, J Boudreau, A Boveia, B Brau, L Brigliadori, A Brisuda, C Bromberg, E Brucken, M Bucciantonio, J Budagov, HS Budd, S Budd, K Burkett, G Busetto, P Bussey, A Buzatu, S Cabrera, C Calancha, S Camarda, M Campanelli, M Campbell, F Canelli, A Canepa, 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, JP Chou, WH Chung, YS Chung, CI Ciobanu, MA Ciocci, A Clark, D Clark, G Compostella, ME Convery, J Conway, M Corbo, M Cordelli, CA Cox, DJ Cox, F Crescioli

Abstract:

We report the first observation of the baryonic flavor-changing neutral current decay Λb0→Λμ+μ- with 24 signal events and a statistical significance of 5.8 Gaussian standard deviations. This measurement uses a pp̄ collisions data sample corresponding to 6.8fb-1 at √s=1.96TeV collected by the CDF II detector at the Tevatron collider. The total and differential branching ratios for Λb0→Λμ+μ- are measured. We find B(Λb0→Λμ+μ-)=[1.73±0. 42(stat)±(syst)]×10-6. We also report the first measurement of the differential branching ratio of Bs0→μ+μ -, using 49 signal events. In addition, we report branching ratios for B+→K+μ+μ-, B0→K0μ+μ-, and B→K*(892) μ+μ- decays. © 2011 American Physical Society.

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Professor Chris Hays

Research theme

Sub department

Doubly-charged Higgs bosons

Abstract:

Measurements of branching fraction ratios and CP-asymmetries in suppressed B^-→D(→K⁺π^-)K^- and B^-→D(→K⁺π^-)π^- decays

Authors:

Abstract:

Top-quark mass measurement using events with missing transverse energy and jets at CDF

Authors:

Abstract:

Search for high-mass resonances decaying into ZZ in p$\bar{p}$ collisions at $\sqrt{s}=1.96$\,TeV

Authors:

Observation of the baryonic flavor-changing neutral current decay Λb0→Λμ⁺μ^-

Authors:

Abstract:

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Professor Chris Hays

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Sub department

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Doubly-charged Higgs bosons

Abstract:

Measurements of branching fraction ratios and CP-asymmetries in suppressed B-→D(→K+π-)K- and B-→D(→K+π-)π- decays

Authors:

Abstract:

Top-quark mass measurement using events with missing transverse energy and jets at CDF

Authors:

Abstract:

Search for high-mass resonances decaying into ZZ in p$\bar{p}$ collisions at $\sqrt{s}=1.96$\,TeV

Authors:

Observation of the baryonic flavor-changing neutral current decay Λb0→Λμ+μ-

Authors:

Abstract:

Measurements of branching fraction ratios and CP-asymmetries in suppressed B^-→D(→K⁺π^-)K^- and B^-→D(→K⁺π^-)π^- decays

Observation of the baryonic flavor-changing neutral current decay Λb0→Λμ⁺μ^-