On the linearity of the MINOS light-injection calibration system

Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 521:2-3 (2004) 361-366

Authors:

P Adamson, L Barrett, A Belias, A Blake, A Cabrera, E Falk, PG Harris, J Hartnell, C Howcroft, M Kordosky, K Lang, R Lee, J Liu, D Michael, R Morse, JK Nelson, R Nichol, G Pearce, K Ruddick, PN Smith, PA Symes, J Thomas, PL Vahle, R Webb, A Weber, RF White

Abstract:

The MINOS light-injection calibration system has been fully documented in a previous article (Nucl. Instr. and Meth. A 492 (2002) 353). Upon commissioning in the MINOS detectors, the system was found to give a non-linear response to variations in the intensity of injected light. The source of this non-linearity has been traced to a small change in the spectrum of the injected light as a function of the current applied to the original blue LEDs, in combination with a rapidly varying spectral response function of the wavelength-shifting fibre used in the detector. Both aspects of the problem have been addressed successfully by use of LEDs with different spectral characteristics, and the system now has a linear response. © 2003 Elsevier B.V. All rights reserved.

Optimized search for single-top-quark production at the Fermilab Tevatron

Physical Review D - Particles, Fields, Gravitation and Cosmology 69:5 (2004)

Authors:

D Acosta, T Affolder, MG Albrow, D Ambrose, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, A Artikov, W Ashmanskas, F Azfar, P Azzi-Bacchetta, N Bacchetta, H Bachacou, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, M Barone, G Bauer, F Bedeschi, S Behari, S Belforte, WH Bell, G Bellettini, J Bellinger, D Benjamin, A Beretvas, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, A Bocci, A Bodek, G Bolla, A Bolshov, D Bortoletto, J Boudreau, C Bromberg, E Brubaker, J Budagov, HS Budd, K Burkett, G Busetto, KL Byrum, S Cabrera, M Campbell, W Carithers, D Carlsmith, A Castro, D Cauz, A Cerri, L Cerrito, J Chapman, C Chen, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, ML Chu, JY Chung, WH Chung, YS Chung, CI Ciobanu, AG Clark, M Coca, A Connolly, M Convery, J Conway, M Cordelli, J Cranshaw, R Culbertson, D Dagenhart, S D’Auria, P Barbaro, S Cecco, S Dell’Agnello, M Dell’Orso, S Demers, L Demortier, M Deninno, D Pedis, PF Derwent, C Dionisi, JR Dittmann, A Dominguez, S Donati, M D’Onofrio, T Dorigo, N Eddy, R Erbacher, D Errede, S Errede

Abstract:

We use a neural-network technique to search for standard model single-top-quark production in the [Formula Presented] dataset accumulated by the Collider Detector at Fermilab detector during the 1992–1995 collider run (“run I”). Using a sample of 64 [Formula Presented] 2, 3 jets events, we set a 95% confidence level upper limit of 24 pb on the W-gluon and [Formula Presented] combined single-top cross section. © 2004 The American Physical Society.

Search for 3- and 4-body decays of the scalar top quark in pp̄ collisions at √s=1.8 TeV

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 581:3-4 (2004) 147-155

Authors:

VM Abazov, B Abbott, A Abdesselam, M Abolins, V Abramov, BS Acharya, DL Adams, M Adams, SN Ahmed, GD Alexeev, A Alton, GA Alves, EW Anderson, Y Arnoud, C Avila, VV Babintsev, L Babukhadia, TC Bacon, A Baden, S Baffioni, B Baldin, PW Balm, S Banerjee, E Barberis, P Baringer, J Barreto, JF Bartlett, U Bassler, D Bauer, A Bean, F Beaudette, M Begel, A Belyaev, SB Beri, G Bernardi, I Bertram, A Besson, R Beuselinck, VA Bezzubov, PC Bhat, V Bhatnagar, M Bhattacharjee, G Blazey, F Blekman, S Blessing, A Boehnlein, NI Bojko, TA Bolton, F Borcherding, K Bos, T Bose, A Brandt, R Breedon, G Briskin, R Brock, G Brooijmans, A Bross, D Buchholz, M Buehler, V Buescher, VS Burtovoi, JM Butler, F Canelli, W Carvalho, D Casey, H Castilla-Valdez, D Chakraborty, KM Chan, SV Chekulaev, DK Cho, S Choi, S Chopra, D Claes, AR Clark, L Coney, B Connolly, WE Cooper, D Coppage, S Crépé-Renaudin, MAC Cummings, D Cutts, H da Motta, GA Davis, K De, SJ de Jong, M Demarteau, R Demina, P Demine, D Denisov, SP Denisov, S Desai, HT Diehl, M Diesburg, S Doulas, LV Dudko, S Duensing, L Duflot, SR Dugad, A Duperrin, A Dyshkant

Abstract:

We have searched for the signature of 3- and 4-body decays of pair-produced scalar top quarks (stop) in the inclusive final state containing an electron, a muon, and significant missing transverse energy using a sample of pp̄ events corresponding to 108.3 pb-1 of data collected with the DØ detector at Fermilab. The search is done in the framework of the minimal supersymmetric standard model assuming that the neutralino (χ̃10) is the lightest supersymmetric particle and is stable. No evidence for a signal is found and we derive cross-section upper limits as a function of stop (t̃) and neutralino masses in different decay scenarios leading to the bℓνχ̃10 final state. © 2004 Published by Elsevier B.V.

First observation of the KS → π0γ γ decay

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 578:3-4 (2004) 276-284

Authors:

A Lai, D Marras, JR Batley, RS Dosanjh, TJ Gershon, GE Kalmus, C Lazzeroni, DJ Munday, E Olaiya, MA Parker, TO White, SA Wotton, R Arcidiacono, G Barr, G Bocquet, A Ceccucci, T Cuhadar-Dönszelmann, D Cundy, N Doble, V Falaleev, L Gatignon, A Gonidec, B Gorini, P Grafström, W Kubischta, A Lacourt, A Norton, B Panzer-Steindel, G Tatishvili, H Wahl, C Cheshkov, P Hristov, V Kekelidze, D Madigojine, N Molokanova, Y Potrebenikov, A Zinchenko, V Martin, P Rubin, R Sacco, A Walker, M Contalbrigo, P Dalpiaz, J Duclos, PL Frabetti, A Gianoli, M Martini, F Petrucci, M Savrié, A Bizzeti, M Calvetti, G Collazuol, G Graziani, E Iacopini, M Lenti, F Martelli, M Veltri, M Eppard, A Hirstius, K Holtz, K Kleinknecht, U Koch, L Köpke, P Lopes da Silva, P Marouelli, I Mestvirishvili, I Pellmann, A Peters, SA Schmidt, V Schönharting, Y Schué, R Wanke, A Winhart, M Wittgen, JC Chollet, L Fayard, L Iconomidou-Fayard, G Unal, I Wingerter-Seez, G Anzivino, P Cenci, E Imbergamo, P Lubrano, A Mestvirishvili, A Nappi, M Pepe, M Piccini, R Casali, C Cerri, M Cirilli, F Costantini, R Fantechi, L Fiorini, S Giudici, I Mannelli, G Pierazzini, M Sozzi, JB Cheze, M De Beer, P Debu

Abstract:

Using the NA48 detector at the CERN SPS, 31 KS → π 0γγ candidates with an estimated background of 13.7 ± 3.2 events have been observed. This first observation leads to a branching ratio of BR(KS → π0γγ) z>0.2 = (4.9 ± 1.6stat ± 0.9 syst) × 10-8 in agreement with Chiral Perturbation Theory predictions. © 2003 Elsevier B.V. All rights reserved.

Combination of CDF and D0 results on the W boson mass and width

Physical Review D - Particles, Fields, Gravitation and Cosmology 70:9 (2004)

Authors:

VM Abazov, B Abbott, A Abdesselam, M Abolins, V Abramov, BS Acharya, D Acosta, DL Adams, M Adams, T Affolder, SN Ahmed, H Akimoto, A Akopian, MG Albrow, GD Alexeev, A Alton, GA Alves, P Amaral, D Ambrose, SR Amendolia, D Amidei, K Anikeev, J Antos, G Apollinari, Y Arnoud, T Arisawa, A Artikov, T Asakawa, C Avila, W Ashmanskas, M Atac, F Azfar, P Azzi-Bacchetta, VV Babintsev, L Babukhadia, N Bacchetta, H Bachacou, TC Bacon, A Baden, W Badgett, S Baffioni, MW Bailey, S Bailey, B Baldin, PW Balm, S Banerjee, P de Barbaro, A Barbaro-Galtieri, E Barberis, P Baringer, VE Barnes, BA Barnett, S Baroiant, M Barone, J Barreto, JF Bartlett, U Bassler, D Bauer, G Bauer, A Bean, F Beaudette, F Bedeschi, S Behari, M Begel, S Belforte, WH Bell, G Bellettini, J Bellinger, A Belyaev, D Benjamin, J Bensinger, A Beretvas, JP Berge, SB Beri, G Bernardi, I Bertram, J Berryhill, A Besson, R Beuselinck, B Bevensee, VA Bezzubov, PC Bhat, V Bhatnagar, M Bhattacharjee, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, G Blazey, F Blekman, S Blessing, C Blocker, K Bloom, B Blumenfeld, SR Blusk, A Bocci, A Bodek, A Boehnlein, NI Bojko

Abstract:

The results based on 1992-95 data (Run 1) from the CDF and D0 experiments on the measurements of the W boson mass and width are presented, along with the combined results. We report a Tevatron collider average MW = 80.456 ± 0.059 GeV. We also report the Tevatron collider average of the directly measured W boson width TW = 2.115 ± 0.105 GeV. We describe a new joint analysis of the direct W mass and width measurements. Assuming the validity of the standard model, we combine the directly measured W boson width with the width extracted from the ratio of W and Z boson leptonic partial cross sections. This combined result for the Tevatron is TW = 2.135 ± 0.050 GeV. Finally, we use the measurements of the direct total W width and the leptonic branching ratio to extract the leptonic partial width Γ(W → eν) = 224 ± 13 MeV.