Search for standard model Higgs boson production in association with a W boson using a neural network discriminant at CDF

Physical Review D - Particles, Fields, Gravitation and Cosmology 80:1 (2009)

Authors:

T Aaltonen, J Adelman, T Akimoto, BA González, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, A Apresyan, T Arisawa, A Artikov, W Ashmanskas, A Attal, A Aurisano, F Azfar, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, V Bartsch, G Bauer, PH Beauchemin, F Bedeschi, D Beecher, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, J Beringer, A Bhatti, M Binkley, D Bisello, I Bizjak, RE Blair, C Blocker, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, D Bortoletto, J Boudreau, A Boveia, B Brau, A Bridgeman, L Brigliadori, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, S Burke, K Burkett, G Busetto, P Bussey, A Buzatu, KL Byrum, S Cabrera, C Calancha, 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, SH Chang, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, K Cho, D Chokheli, JP Chou, G Choudalakis, SH Chuang, K Chung, WH Chung, YS Chung, T Chwalek, CI Ciobanu, MA Ciocci, A Clark, D Clark

Abstract:

We present a search for standard model Higgs boson production in association with a W boson in proton-antiproton collisions (pp ↠W±H↠â.,"Î bbÂ) at a center of mass energy of 1.96 TeV. The search employs data collected with the CDF II detector that correspond to an integrated luminosity of approximately 1.9 fb-1. We select events consistent with a signature of a single charged lepton (e±/Π±), missing transverse energy, and two jets. Jets corresponding to bottom quarks are identified with a secondary vertex tagging method, a jet probability tagging method, and a neural network filter. We use kinematic information in an artificial neural network to improve discrimination between signal and background compared to previous analyses. The observed number of events and the neural network output distributions are consistent with the standard model background expectations, and we set 95% confidence level upper limits on the production cross section times branching fraction ranging from 1.2 to 1.1 pb or 7.5 to 102 times the standard model expectation for Higgs boson masses from 110 to 150 GeV/c2, respectively. © 2009 The American Physical Society.

Search for the production of narrow tb̄ resonances in 1.9fb-1 of pp̄ collisions at s=1.96TeV

Physical Review Letters 103:4 (2009)

Authors:

T Aaltonen, J Adelman, T Akimoto, B Álvarez González, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, A Apresyan, T Arisawa, A Artikov, W Ashmanskas, A Attal, A Aurisano, F Azfar, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, P Bartos, V Bartsch, G Bauer, PH Beauchemin, F Bedeschi, D Beecher, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, J Beringer, A Bhatti, M Binkley, D Bisello, I Bizjak, RE Blair, C Blocker, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, D Bortoletto, J Boudreau, A Boveia, B Brau, A Bridgeman, L Brigliadori, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, S Burke, K Burkett, G Busetto, P Bussey, A Buzatu, KL Byrum, S Cabrera, C Calancha, 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, SH Chang, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, K Cho, D Chokheli, JP Chou, G Choudalakis, SH Chuang, K Chung, WH Chung, YS Chung, T Chwalek, CI Ciobanu, MA Ciocci, A Clark

Abstract:

We present new limits on resonant tb̄ production in pp̄ collisions at s=1.96TeV, using 1.9fb-1 of data recorded with the CDFII detector at the Fermilab Tevatron. We reconstruct a candidate tb̄ mass in events with a lepton, neutrino candidate, and two or three jets, and search for anomalous tb̄ production as modeled by W′→tb̄. We set a new limit on a right-handed W′ with standard model-like coupling, excluding any mass below 800GeV/c2 at 95% C.L. The cross section for any narrow, resonant tb̄ production between 750 and 950GeV/c2 is found to be less than 0.28pb at 95% C.L. We also present an exclusion of the W′ coupling strength versus W′ mass over the range 300-950GeV/c2. © 2009 The American Physical Society.

Searching the inclusive l γe T+b-quark signature for radiative top quark decay and non-standard-model processes

Physical Review D - Particles, Fields, Gravitation and Cosmology 80:1 (2009)

Authors:

T Aaltonen, J Adelman, T Akimoto, B Álvarez González, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, A Apresyan, T Arisawa, A Artikov, W Ashmanskas, A Attal, A Aurisano, F Azfar, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, V Bartsch, G Bauer, PH Beauchemin, F Bedeschi, D Beecher, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, J Beringer, A Bhatti, M Binkley, D Bisello, I Bizjak, RE Blair, C Blocker, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, D Bortoletto, J Boudreau, A Boveia, B Brau, A Bridgeman, L Brigliadori, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, S Burke, K Burkett, G Busetto, P Bussey, A Buzatu, KL Byrum, S Cabrera, C Calancha, 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, SH Chang, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, K Cho, D Chokheli, JP Chou, G Choudalakis, SH Chuang, K Chung, WH Chung, YS Chung, T Chwalek, CI Ciobanu, MA Ciocci, A Clark, D Clark

Abstract:

We compare the inclusive production of events containing a lepton (á), a photon (γ), significant transverse momentum imbalance (E T), and a jet identified as containing a b-quark, to SM predictions. The search uses data produced in proton-antiproton collisions at s=1.96TeV corresponding to 1.9fb-1 of integrated luminosity taken with the CDF detector. We find 28 áγbET events versus an expectation of 31.0-3.5+4.1 events. If we further require events to contain at least three jets and large total transverse energy, the largest SM source is radiative top-quark pair production, tt̄+γ. In the data we observe 16 tt̄γ candidate events versus an expectation from SM sources of 11.2-2.1+2.3. Assuming the difference between the observed number and the predicted non-top-quark total of 6.8-2.0+2.2 is due to SM top-quark production, we estimate the tt̄γ cross section to be 0.15±0.08pb. © 2009 The American Physical Society.

Measurement of the ratio of the numu charged-current single-pion production to quasielastic scattering with a 0.8 GeV neutrino beam on mineral oil.

Physical review letters 103:8 (2009) 081801

Authors:

AA Aguilar-Arevalo, CE Anderson, AO Bazarko, SJ Brice, BC Brown, L Bugel, J Cao, L Coney, JM Conrad, DC Cox, A Curioni, Z Djurcic, DA Finley, BT Fleming, R Ford, FG Garcia, GT Garvey, C Green, JA Green, TL Hart, E Hawker, R Imlay, RA Johnson, G Karagiorgi, P Kasper, T Katori, T Kobilarcik, I Kourbanis, S Koutsoliotas, EM Laird, SK Linden, JM Link, Y Liu, Y Liu, WC Louis, KBM Mahn, W Marsh, VT McGary, G McGregor, W Metcalf, PD Meyers, F Mills, GB Mills, J Monroe, CD Moore, RH Nelson, P Nienaber, JA Nowak, B Osmanov, S Ouedraogo, RB Patterson, D Perevalov, CC Polly, E Prebys, JL Raaf, H Ray, BP Roe, AD Russell, V Sandberg, R Schirato, D Schmitz, MH Shaevitz, FC Shoemaker, D Smith, M Soderberg, M Sorel, P Spentzouris, J Spitz, I Stancu, RJ Stefanski, M Sung, HA Tanaka, R Tayloe, M Tzanov, R Van de Water, MO Wascko, DH White, MJ Wilking, HJ Yang, GP Zeller, ED Zimmerman, MiniBooNE Collaboration

Abstract:

Using high statistics samples of charged-current numu interactions, the MiniBooNE [corrected] Collaboration reports a measurement of the single-charged-pion production to quasielastic cross section ratio on mineral oil (CH2), both with and without corrections for hadron reinteractions in the target nucleus. The result is provided as a function of neutrino energy in the range 0.4 GeV

Search for muon neutrino and antineutrino disappearance in MiniBooNE.

Physical review letters 103:6 (2009) 061802

Authors:

AA Aguilar-Arevalo, CE Anderson, AO Bazarko, SJ Brice, BC Brown, L Bugel, J Cao, L Coney, JM Conrad, DC Cox, A Curioni, Z Djurcic, DA Finley, BT Fleming, R Ford, FG Garcia, GT Garvey, J Grange, C Green, JA Green, TL Hart, E Hawker, R Imlay, RA Johnson, G Karagiorgi, P Kasper, T Katori, T Kobilarcik, I Kourbanis, S Koutsoliotas, EM Laird, SK Linden, JM Link, Y Liu, Y Liu, WC Louis, KBM Mahn, W Marsh, C Mauger, VT McGary, G McGregor, W Metcalf, PD Meyers, F Mills, GB Mills, J Monroe, CD Moore, J Mousseau, RH Nelson, P Nienaber, JA Nowak, B Osmanov, S Ouedraogo, RB Patterson, Z Pavlovic, D Perevalov, CC Polly, E Prebys, JL Raaf, H Ray, BP Roe, AD Russell, V Sandberg, R Schirato, D Schmitz, MH Shaevitz, FC Shoemaker, D Smith, M Soderberg, M Sorel, P Spentzouris, J Spitz, I Stancu, RJ Stefanski, M Sung, HA Tanaka, R Tayloe, M Tzanov, RG Van de Water, MO Wascko, DH White, MJ Wilking, HJ Yang, GP Zeller, ED Zimmerman, MiniBooNE Collaboration

Abstract:

The MiniBooNE Collaboration reports a search for nu_{micro} and nu[over]_{micro} disappearance in the Deltam;{2} region of 0.5-40 eV;{2}. These measurements are important for constraining models with extra types of neutrinos, extra dimensions, and CPT violation. Fits to the shape of the nu_{micro} and nu[over]_{micro} energy spectra reveal no evidence for disappearance at the 90% confidence level (C.L.) in either mode. The test of nu[over]_{micro} disappearance probes a region below Deltam;{2} = 40 eV;{2} never explored before.