Accelerator Neutrinos

Research group

Research theme

Sub department

About

Related research groups

Search for a very light CP-Odd higgs boson in top quark decays from pp̄ collisions at √s=1.96TeV

Physical Review Letters 107:3 (2011)

Authors:

T Aaltonen, B Alvarez 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 present the results of a search for a very light CP-odd Higgs boson a10 originating from top quark decays t→H⊃±b→W⊃± (⊃*)a10b, and subsequently decaying into τ⊃+τ⊃-. Using a data sample corresponding to an integrated luminosity of 2.7fb⊃-1 collected by the CDF II detector in pp̄ collisions at 1.96TeV, we perform a search for events containing a lepton, three or more jets, and an additional isolated track with transverse momentum in the range 3 to 20GeV/c. Observed events are consistent with background sources, and 95% C.L. limits are set on the branching ratio of t→H⊃±b for various masses of H⊃± and a10. © 2011 American Physical Society.
More details from the publisher
More details
More details
Details from ArXiV

First direct observation of muon antineutrino disappearance.

Phys Rev Lett 107:2 (2011) 021801

Authors:

P Adamson, C Andreopoulos, DJ Auty, DS Ayres, C Backhouse, G Barr, M Bishai, A Blake, GJ Bock, DJ Boehnlein, D Bogert, S Cavanaugh, D Cherdack, S Childress, BC Choudhary, JAB Coelho, SJ Coleman, L Corwin, D Cronin-Hennessy, IZ Danko, JK de Jong, NE Devenish, MV Diwan, M Dorman, CO Escobar, JJ Evans, E Falk, GJ Feldman, MV Frohne, HR Gallagher, RA Gomes, MC Goodman, P Gouffon, N Graf, R Gran, N Grant, K Grzelak, A Habig, D Harris, J Hartnell, R Hatcher, A Himmel, A Holin, C Howcroft, X Huang, J Hylen, J Ilic, GM Irwin, Z Isvan, DE Jaffe, C James, D Jensen, T Kafka, SMS Kasahara, G Koizumi, S Kopp, M Kordosky, A Kreymer, K Lang, G Lefeuvre, J Ling, PJ Litchfield, L Loiacono, P Lucas, WA Mann, ML Marshak, N Mayer, AM McGowan, R Mehdiyev, JR Meier, MD Messier, WH Miller, SR Mishra, J Mitchell, CD Moore, J Morfín, L Mualem, S Mufson, J Musser, D Naples, JK Nelson, HB Newman, RJ Nichol, TC Nicholls, JA Nowak, JP Ochoa-Ricoux, WP Oliver, M Orchanian, R Ospanov, J Paley, RB Patterson, G Pawloski, GF Pearce, DA Petyt, S Phan-Budd, RK Plunkett, X Qiu, J Ratchford, TM Raufer, B Rebel, PA Rodrigues, C Rosenfeld, HA Rubin, MC Sanchez, J Schneps, P Schreiner, P Shanahan, A Sousa, P Stamoulis, M Strait, N Tagg, RL Talaga, E Tetteh-Lartey, J Thomas, MA Thomson, G Tinti, R Toner, G Tzanakos, J Urheim, P Vahle, B Viren, A Weber, RC Webb, C White, L Whitehead, SG Wojcicki, T Yang, R Zwaska, MINOS Collaboration

Abstract:

This Letter reports the first direct observation of muon antineutrino disappearance. The MINOS experiment has taken data with an accelerator beam optimized for ν(μ) production, accumulating an exposure of 1.71 × 10²⁰ protons on target. In the Far Detector, 97 charged current ν(μ) events are observed. The no-oscillation hypothesis predicts 156 events and is excluded at 6.3σ. The best fit to oscillation yields |Δm²| = [3.36(-0.40)(+0.46)(stat) ± 0.06(syst)] × 10⁻³ eV², sin²(2θ) = 0.86(-0.12)(+0.11)(stat) ± 0.01(syst). The MINOS ν(μ) and ν(μ) measurements are consistent at the 2.0% confidence level, assuming identical underlying oscillation parameters.
More details from the publisher
More details
More details

Active to sterile neutrino mixing limits from neutral-current interactions in MINOS.

Phys Rev Lett 107:1 (2011) 011802

Authors:

P Adamson, DJ Auty, DS Ayres, C Backhouse, G Barr, M Bishai, A Blake, GJ Bock, DJ Boehnlein, D Bogert, S Cavanaugh, D Cherdack, S Childress, JAB Coelho, SJ Coleman, L Corwin, D Cronin-Hennessy, IZ Danko, JK de Jong, NE Devenish, MV Diwan, M Dorman, CO Escobar, JJ Evans, E Falk, GJ Feldman, MV Frohne, HR Gallagher, RA Gomes, MC Goodman, P Gouffon, N Graf, R Gran, N Grant, K Grzelak, A Habig, D Harris, J Hartnell, R Hatcher, A Himmel, A Holin, X Huang, J Hylen, J Ilic, GM Irwin, Z Isvan, DE Jaffe, C James, D Jensen, T Kafka, SMS Kasahara, G Koizumi, S Kopp, M Kordosky, A Kreymer, K Lang, G Lefeuvre, J Ling, PJ Litchfield, L Loiacono, P Lucas, WA Mann, ML Marshak, N Mayer, AM McGowan, R Mehdiyev, JR Meier, MD Messier, WH Miller, SR Mishra, J Mitchell, CD Moore, J Morfín, L Mualem, S Mufson, J Musser, D Naples, JK Nelson, HB Newman, RJ Nichol, TC Nicholls, JA Nowak, WP Oliver, M Orchanian, J Paley, RB Patterson, G Pawloski, GF Pearce, DA Petyt, S Phan-Budd, R Pittam, RK Plunkett, X Qiu, J Ratchford, TM Raufer, B Rebel, PA Rodrigues, C Rosenfeld, HA Rubin, MC Sanchez, J Schneps, P Schreiner, R Sharma, P Shanahan, A Sousa, P Stamoulis, M Strait, N Tagg, RL Talaga, E Tetteh-Lartey, J Thomas, MA Thomson, G Tinti, R Toner, D Torretta, G Tzanakos, J Urheim, P Vahle, B Viren, JJ Walding, A Weber, RC Webb, C White, L Whitehead, SG Wojcicki, R Zwaska, MINOS Collaboration

Abstract:

Results are reported from a search for active to sterile neutrino oscillations in the MINOS long-baseline experiment, based on the observation of neutral-current neutrino interactions, from an exposure to the NuMI neutrino beam of 7.07×10(20) protons on target. A total of 802 neutral-current event candidates is observed in the Far Detector, compared to an expected number of 754 ± 28(stat) ± 37(syst) for oscillations among three active flavors. The fraction f(s) of disappearing ν(μ) that may transition to ν(s) is found to be less than 22% at the 90% C.L.
More details from the publisher
More details
More details

Measurement of K+ production cross section by 8 GeV protons using high-energy neutrino interactions in the SciBooNE detector

Physical Review D American Physical Society (APS) 84:1 (2011) 012009

Authors:

G Cheng, C Mariani, JL Alcaraz-Aunion, SJ Brice, L Bugel, J Catala-Perez, JM Conrad, Z Djurcic, U Dore, DA Finley, AJ Franke, C Giganti, JJ Gomez-Cadenas, P Guzowski, A Hanson, Y Hayato, K Hiraide, G Jover-Manas, G Karagiorgi, T Katori, YK Kobayashi, T Kobilarcik, H Kubo, Y Kurimoto, WC Louis, PF Loverre, L Ludovici, KBM Mahn, S Masuike, K Matsuoka, VT McGary, W Metcalf, GB Mills, G Mitsuka, Y Miyachi, S Mizugashira, CD Moore, Y Nakajima, T Nakaya, R Napora, P Nienaber, 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, HB White, M Yokoyama, GP Zeller, ED Zimmerman
More details from the publisher
More details

Search for an excess of events with an identical flavour lepton pair and significant missing transverse momentum in √s = TeV proton-proton collisions with the ATLAS detector

European Physical Journal C 71:7 (2011) 1-18

Authors:

G Aad, B Abbott, J Abdallah, AA Abdelalim, A Abdesselam, O Abdinov, B Abi, M Abolins, H Abramowicz, H Abreu, E Acerbi, BS Acharya, DL Adams, TN Addy, J Adelman, M Aderholz, S Adomeit, P Adragna, T Adye, S Aefsky, JA Aguilar-Saavedra, M Aharrouche, SP Ahlen, F Ahles, A Ahmad, M Ahsan, G Aielli, T Akdogan, TPA Åkesson, G Akimoto, AV Akimov, A Akiyama, MS Alam, MA Alam, S Albrand, M Aleksa, IN Aleksandrov, F Alessandria, C Alexa, G Alexander, G Alexandre, T Alexopoulos, M Alhroob, M Aliev, G Alimonti, J Alison, M Aliyev, PP Allport, SE Allwood-Spiers, J Almond, A Aloisio, R Alon, A Alonso, MG Alviggi, K Amako, P Amaral, C Amelung, VV Ammosov, A Amorim, G Amorós, N Amram, C Anastopoulos, T Andeen, CF Anders, KJ Anderson, A Andreazza, V Andrei, ML Andrieux, XS Anduaga, A Angerami, F Anghinolfi, N Anjos, A Annovi, A Antonaki, M Antonelli, S Antonelli, A Antonov, J Antos, F Anulli, S Aoun, L Aperio Bella, R Apolle, G Arabidze, I Aracena, Y Arai, ATH Arce, JP Archambault, S Arfaoui, JF Arguin, E Arik, M Arik, AJ Armbruster, O Arnaez, C Arnault, A Artamonov, G Artoni, D Arutinov, S Asai, R Asfandiyarov, S Ask

Abstract:

Results are presented of a search for particles decaying into final states with significant missing transverse momentum and exactly two identical flavour leptons (e, μ) of opposite charge in √s = TeV collisions at the Large Hadron Collider. This channel is particularly sensitive to supersymmetric particle cascade decays producing flavour correlated lepton pairs. Flavour uncorrelated backgrounds are subtracted using a sample of opposite flavour lepton pair events. Observation of an excess beyond Standard Model expectations following this subtraction procedure would offer one of the best routes to measuring the masses of supersymmetric particles. In a data sample corresponding to an integrated luminosity of 35 pb-1 no such excess is observed. Model-independent limits are set on the contribution to these final states from supersymmetry and are used to exclude regions of a phenomenological supersymmetric parameter space. © 2011 CERN for the benefit of the ATLAS collaboration.
More details from the publisher
More details