ATLAS

Research group

Research theme

Sub department

About

Related research groups

Search for pair production of first or second generation leptoquarks in proton-proton collisions at sqrt(s)=7 TeV using the ATLAS detector at the LHC

ArXiv 1104.4481 (2011)
Details from ArXiV

Progress with the single-sided module prototypes for the ATLAS tracker upgrade stave

Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 636:1 SUPPL. (2011)

Authors:

PP Allport, AA Affolder, F Anghinolfi, R Bates, C Betancourt, C Buttar, JR Carter, G Casse, H Chen, A Chilingarov, JV Civera, A Clark, AP Colijn, W Dabrowski, N Dawson, B Dewilde, S Dhawan, N Dressnandt, M Dwužnik, L Eklund, V Fadeyev, P Farthouat, D Ferrère, H Fox, R French, B Gallop, C García, M Gerling, M Gibson, M Gilchriese, S Gonzalez Sevilla, M Goodrick, A Greenall, AA Grillo, CH Haber, NP Hessey, R Holt, LBA Hommels, K Jakobs, TJ Jones, J Kaplon, J Kierstead, E Koffeman, M Köhler, C Lacasta, D La Marra, Z Li, S Lindgren, D Lynn, P Maddock, K Mahboubi, F Martinez-Mckinney, J Matheson, R Maunu, R McCarthy, M Newcomer, R Nickerson, V O'Shea, S Paganis, U Parzefall, S Pernecker, P Phillips, K Poltorak, D Puldon, D Robinson, HFW Sadrozinski, D Santoyo, S Sattari, D Schamberger, A Seiden, P Sutcliffe, K Swientek, D Tsionou, M Tyndel, Y Unno, G Viehhauser, EG Villani, J Von Wilpert, R Wastie, M Weber, A Weidberg, L Wiik, I Wilmut, M Wormald, J Wright, D Xu

Abstract:

The ATLAS experiment is preparing for the planned luminosity upgrade of the LHC (the super-luminous LHC or sLHC) with a programme of development for tracking able to withstand an order of greater magnitude radiation fluence and much greater hit occupancy rates than the current detector. This has led to the concept of an all-silicon tracker with an enhanced performance pixel-based inner region and short-strips for much of the higher radii. Both sub-systems employ many common technologies, including the proposed stave concept for integrated cooling and support. For the short-strip region, use of this integrated stave concept requires single-sided modules mounted on either side of a thin central lightweight support. Each sensor is divided into four rows of 23.82 mm length strips; within each row, there are 1280 strips of 74.5μm pitch. Well over a hundred prototype sensors are being delivered by Hamamatsu Photonics (HPK) to Japan, Europe and the US. We present results of the first 20 chip ABCN25 ASIC hybrids for these sensors, results of the first prototype 5120 strip module built with 40 ABCN25 read-out ASICs, and the status of the hybrids and modules being developed for the ATLAS tracker upgrade stave programme. © 2010 Elsevier B.V.
More details from the publisher
More details

Measurement of the Polarization of W Bosons with Large Transverse Momenta in W+Jets Events at the LHC

ArXiv 1104.3829 (2011)
Details from ArXiV

Charged particle transverse momentum spectra in pp collisions at sqrt(s) = 0.9 and 7 TeV

ArXiv 1104.3547 (2011)
Details from ArXiV

Measurement of the forward-backward asymmetry in the B→K(*) μ+μ- decay and first observation of the Bs0→μ+μ- decay

Physical Review Letters 106:16 (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 reconstruct the rare decays B+→K+μ +μ-, B0→K*(892)0μ +μ-, and Bs0→(1020)μ+μ - in a data sample corresponding to 4.4fb-1 collected in pp̄ collisions at √s=1.96TeV by the CDF II detector at the Tevatron Collider. Using 121±16 B+→K+μ +μ- and 101±12 B0→K*0μ +μ- decays we report the branching ratios. In addition, we report the differential branching ratio and the muon forward-backward asymmetry in the B+ and B0 decay modes, and the K*0 longitudinal polarization fraction in the B0 decay mode with respect to the squared dimuon mass. These are consistent with the predictions, and most recent determinations from other experiments and of comparable accuracy. We also report the first observation of the Bs0→μ+μ- decay and measure its branching ratio BR(Bs0→μ+μ-)= [1.44±0.33±0.46]×10-6 using 27±6 signal events. This is currently the most rare Bs0 decay observed. © 2011 American Physical Society.
More details from the publisher