First measurement of the fraction of top-quark pair production through gluon-gluon fusion

Physical Review D - Particles, Fields, Gravitation and Cosmology 78:11 (2008)

Authors:

T Aaltonen, J Adelman, T Akimoto, MG Albrow, B Álvarez González, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, M Aoki, G Apollinari, A Apresyan, T Arisawa, A Artikov, W Ashmanskas, A Attal, A Aurisano, F Azfar, P Azzi-Bacchetta, P Azzurri, N Bacchetta, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, V Bartsch, G Bauer, PH Beauchemin, F Bedeschi, P Bednar, S Behari, G Bellettini, J Bellinger, A Belloni, D Benjamin, A Beretvas, J Beringer, T Berry, A Bhatti, M Binkley, D Bisello, I Bizjak, RE Blair, C Blocker, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, A Bolshov, D Bortoletto, J Boudreau, A Boveia, B Brau, A Bridgeman, L Brigliadori, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, K Burkett, G Busetto, P Bussey, A Buzatu, KL Byrum, S Cabrera, M Campanelli, M Campbell, F Canelli, A Canepa, D Carlsmith, R Carosi, S Carrillo, S Carron, B Casal, M Casarsa, A Castro, P Catastini, D Cauz, 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, CI Ciobanu

Abstract:

We present the first measurement of σ(gg→tt̄)/ σ(pp̄→tt̄). We use 0.96fb-1 of s=1.96TeV pp̄ collision data recorded with the CDF II detector at Fermilab. Using charged particles with low transverse momentum in tt̄ events, we find σ(gg→ tt̄)/σ(pp̄→tt̄)=0.07±0.14(stat)±0. 07(syst), corresponding to a 95% confidence level upper limit of 0.33, in agreement with the standard model next-to-leading-order prediction of 0.15±0.05. © 2008 The American Physical Society.

Recent results from the minos experiment

Frascati Physics Series 47:SPEC. ISS. (2008) 133-140

Abstract:

MINOS is a long baseline neutrino oscillation experiment. Protons from the Fermilab main injector are used to generate an intense muon neutrino beam, which is directed at the Soudan underground laboratory in Northern Minnesota. The result from two years of running with a total exposure of 2.5 × 10 20 protons on target from the NuMI beam is reported. We made a preliminary measurement by comparing the event rate and energy spectra of charge current muon neutrino interactions in the two detectors, which are 1 and 735 km from the neutrino production target. The data is consistent with νμ to ντ oscillation in the so-called atmospheric parameter range with Δm2 = (2.38+0.20-0.16) * 10-3eV2 and sin2 2θ = 1-0.08. Copyright © 2008, by INFN.

Search for charged current coherent pion production on carbon in a few-GeV neutrino beam

Physical Review D American Physical Society (APS) 78:11 (2008) 112004

Authors:

K Hiraide, JL Alcaraz-Aunion, SJ Brice, L Bugel, J Catala-Perez, G Cheng, JM Conrad, Z Djurcic, U Dore, DA Finley, AJ Franke, C Giganti, JJ Gomez-Cadenas, P Guzowski, A Hanson, Y Hayato, G Jover-Manas, G Karagiorgi, T Katori, YK Kobayashi, T Kobilarcik, H Kubo, Y Kurimoto, WC Louis, PF Loverre, L Ludovici, KBM Mahn, C Mariani, S Masuike, K Matsuoka, W Metcalf, G Mills, G Mitsuka, Y Miyachi, S Mizugashira, CD Moore, Y Nakajima, T Nakaya, R Napora, P Nienaber, V Nguyen, D Orme, M Otani, AD Russell, F Sanchez, MH Shaevitz, T-A Shibata, M Sorel, RJ Stefanski, H Takei, H-K Tanaka, M Tanaka, R Tayloe, IJ Taylor, RJ Tesarek, Y Uchida, R Van de Water, JJ Walding, MO Wascko, H White, MJ Wilking, M Yokoyama, GP Zeller, ED Zimmerman

The ATLAS experiment at the CERN large hadron collider

Journal of Instrumentation 3:8 (2008)

Authors:

G Aad, E Abat, J Abdallah, AA Abdelalim, A Abdesselam, O Abdinov, BA Abi, M Abolins, H Abramowicz, E Acerbi, BS Acharya, R Achenbach, M Ackers, DL Adams, F Adamyan, TN Addy, M Aderholz, C Adorisio, P Adragna, M Aharrouche, SP Ahlen, F Ahles, A Ahmad, H Ahmed, G Aielli, PF Åkesson, TPA Akesson, AV Akimov, SM Alam, J Albert, S Albrand, M Aleksa, IN Aleksandrov, M Aleppo, F Alessandria, C Alexa, G Alexander, T Alexopoulos, G Alimonti, M Aliyev, PP Allport, SE Allwood-Spiers, A Aloisio, J Alonso, R Alves, MG Alviggi, K Amako, P Amaral, SP Amaral, G Ambrosini, G Ambrosio, C Amelung, VV Ammosov, A Amorim, N Amram, C Anastopoulos, B Anderson, KJ Anderson, EC Anderssen, A Andreazza, V Andrei, L Andricek, ML Andrieux, XS Anduaga, F Anghinolfi, A Antonaki, M Antonelli, S Antonelli, R Apsimon, G Arabidze, I Aracena, Y Arai, ATH Arce, JP Archambault, JF Arguin, E Arik, M Arik, KE Arms, SR Armstrong, M Arnaud, C Arnault, A Artamonov, S Asai, S Ask, B Åsman, D Asner, L Asquith, K Assamagan, A Astbury, B Athar, T Atkinson, B Aubert, B Auerbach, E Auge, K Augsten, VM Aulchenko, N Austin, G Avolio, R Avramidou, A Axen

Search for active neutrino disappearance using neutral-current interactions in the MINOS long-baseline experiment.

Phys Rev Lett 101:22 (2008) 221804

Authors:

P Adamson, C Andreopoulos, KE Arms, R Armstrong, DJ Auty, DS Ayres, C Backhouse, B Baller, G Barr, WL Barrett, BR Becker, A Belias, RH Bernstein, D Bhattacharya, M Bishai, A Blake, GJ Bock, J Boehm, DJ Boehnlein, D Bogert, C Bower, E Buckley-Geer, S Cavanaugh, JD Chapman, D Cherdack, S Childress, BC Choudhary, JH Cobb, SJ Coleman, AJ Culling, JK de Jong, M Dierckxsens, MV Diwan, M Dorman, SA Dytman, CO Escobar, JJ Evans, E Falk Harris, GJ Feldman, MV Frohne, HR Gallagher, A Godley, MC Goodman, P Gouffon, R Gran, EW Grashorn, N Grossman, K Grzelak, A Habig, D Harris, PG Harris, J Hartnell, R Hatcher, K Heller, A Himmel, A Holin, L Hsu, J Hylen, GM Irwin, M Ishitsuka, DE Jaffe, C James, D Jensen, T Kafka, SMS Kasahara, JJ Kim, MS Kim, G Koizumi, S Kopp, M Kordosky, DJ Koskinen, SK Kotelnikov, A Kreymer, S Kumaratunga, K Lang, J Ling, PJ Litchfield, RP Litchfield, L Loiacono, P Lucas, J Ma, WA Mann, A Marchionni, ML Marshak, JS Marshall, N Mayer, AM McGowan, JR Meier, MD Messier, CJ Metelko, DG Michael, WH Miller, SR Mishra, CD Moore, J Morfín, L Mualem, S Mufson, S Murgia, J Musser, D Naples, JK Nelson, HB Newman, RJ Nichol, TC Nicholls, JP Ochoa-Ricoux, WP Oliver, R Ospanov, J Paley, V Paolone, A Para, T Patzak, Z Pavlović, G Pawloski, GF Pearce, CW Peck, DA Petyt, R Pittam, RK Plunkett, A Rahaman, RA Rameika, TM Raufer, B Rebel, J Reichenbacher, PA Rodrigues, C Rosenfeld, HA Rubin, VA Ryabov, MC Sanchez, N Saoulidou, J Schneps, P Schreiner, P Shanahan, W Smart, C Smith, A Sousa, B Speakman, P Stamoulis, M Strait, N Tagg, RL Talaga, MA Tavera, J Thomas, MA Thomson, JL Thron, G Tinti, I Trostin, VA Tsarev, G Tzanakos, J Urheim, P Vahle, B Viren, DR Ward, M Watabe, A Weber, RC Webb, A Wehmann, N West, C White, SG Wojcicki, DM Wright, T Yang, K Zhang, R Zwaska, MINOS Collaboration

Abstract:

We report the first detailed comparisons of the rates and spectra of neutral-current neutrino interactions at two widely separated locations. A depletion in the rate at the far site would indicate mixing between nu(mu) and a sterile particle. No anomalous depletion in the reconstructed energy spectrum is observed. Assuming oscillations occur at a single mass-squared splitting, a fit to the neutral- and charged-current energy spectra limits the fraction of nu(mu) oscillating to a sterile neutrino to be below 0.68 at 90% confidence level. A less stringent limit due to a possible contribution to the measured neutral-current event rate at the far site from nu(e) appearance at the current experimental limit is also presented.