Search for supersymmetry in events with large missing transverse momentum, jets, and at least one tau lepton in 7 TeV proton-proton collision data with the ATLAS detector

European Physical Journal C 72:11 (2012)

Authors:

G Aad, T Abajyan, B Abbott, J Abdallah, SA Khalek, AA Abdelalim, O Abdinov, R Aben, B Abi, M Abolins, OSA Zeid, H Abramowicz, H Abreu, BS Acharya, L Adamczyk, DL Adams, TN Addy, J Adelman, S Adomeit, P Adragna, T Adye, S Aefsky, JAA Saavedra, M Agustoni, M Aharrouche, SP Ahlen, F Ahles, A Ahmad, M Ahsan, G Aielli, T Akdogan, TPA Åkesson, G Akimoto, AV Akimov, MS Alam, MA Alam, J Albert, S Albrand, M Aleksa, IN Aleksandrov, F Alessandria, C Alexa, G Alexander, G Alexandre, T Alexopoulos, M Alhroob, M Aliev, G Alimonti, J Alison, BMM Allbrooke, PP Allport, SEA Spiers, J Almond, A Aloisio, R Alon, A Alonso, F Alonso, A Altheimer, BA Gonzalez, MG Alviggi, K Amako, C Amelung, VV Ammosov, SPA Dos Santos, A Amorim, N Amram, C Anastopoulos, LS Ancu, N Andari, T Andeen, CF Anders, G Anders, KJ Anderson, A Andreazza, V Andrei, ML Andrieux, XS Anduaga, S Angelidakis, P Anger, A Angerami, F Anghinolfi, A Anisenkov, N Anjos, A Annovi, A Antonaki, M Antonelli, A Antonov, J Antos, F Anulli, M Aoki, S Aoun, LA Bella, R Apolle, G Arabidze, I Aracena, Y Arai, ATH Arce, S Arfaoui, JF Arguin, E Arik

Abstract:

A search for supersymmetry (SUSY) in events with large missing transverse momentum, jets, and at least one hadronically decaying τ lepton, with zero or one additional light lepton (e/μ), has been performed using 4.7 fb−1of proton-proton collision data at √s = 7 TeV recorded with the ATLAS detector at the Large Hadron Collider. No excess above the Standard Model background expectation is observed and a 95 % confidence level visible cross-section upper limit for new phenomena is set. In the framework of gauge-mediated SUSY-breaking models, lower limits on the mass scale Λ are set at 54 TeV in the regions where the τ1is the next-to-lightest SUSY particle (tanβ > 20). These limits provide the most stringent tests to date of GMSB models in a large part of the parameter space considered.

A complex state transition from the black hole candidate Swift J1753.5-0127

(2012)

Authors:

P Soleri, T Muñoz-Darias, S Motta, T Belloni, P Casella, M Méndez, D Altamirano, M Linares, R Wijnands, R Fender, M van der Klis

Automated rapid follow-up of Swift GRBs with AMI-LA

(2012)

Authors:

TD Staley, DJ Titterington, RP Fender, JD Swinbank, AJ van der Horst, A Rowlinson, AMM Scaife, KJB Grainge, GG Pooley

Jet spectral breaks in black hole X-ray binaries

(2012)

Authors:

DM Russell, S Markoff, P Casella, AG Cantrell, R Chatterjee, RP Fender, E Gallo, P Gandhi, J Homan, D Maitra, JCA Miller-Jones, K O'Brien, T Shahbaz

Measurements of the top-quark mass and the tt̄ cross section in the hadronic τ+jets decay channel at √s=1.96TeV

Physical Review Letters 109:19 (2012)

Authors:

T Aaltonen, B Álvarez González, 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

Abstract:

We present the first direct measurement of the top-quark mass using tt̄ events decaying in the hadronic τ+jets decay channel. Using data corresponding to an integrated luminosity of 2.2fb-1 collected by the CDF II detector in pp̄ collisions at √s=1.96TeV at the Fermilab Tevatron, we measure the tt̄ cross section, σtt̄, and the top-quark mass, Mtop. We extract Mtop from a likelihood based on per-event probabilities calculated with leading-order signal and background matrix elements. We measure σtt̄=8. 8±3.3(stat)±2.2(syst)pb and Mtop=172.7±9.3(stat) ±3.7(syst)GeV/c2. © 2012 American Physical Society.