Design and performance of the level 1 calorimeter trigger for the BABAR detector

IEEE T NUCL SCI 48:3 (2001) 541-546

Authors:

PD Dauncey, JC Andress, TJ Adye, NI Chevalier, BJ Claxton, N Dyce, B Foster, S Galagedera, A Kurup, A Mass, JD McFall, P McGrath, SJ Nash, DR Price, U Schafer, I Scott, DCH Wallom

Abstract:

Since May 1999 the BABAR detector has been taking data at the PEP-II asymmetric electron-positron collider at the Stanford Linear Accelerator Center, CA. This experiment requires a very large data sample and the PEP-Il accelerator uses intense beams to deliver the high collision rates needed. This poses a severe challenge to the BABAR trigger system, which must reject the large rate of background signals resulting from the high beam currents whilst accepting the collisions of interest with very high efficiency. One of the systems that performs this task is the Level 1 Calorimeter Trigger, which identifies energy deposits left by particles in the BABAR calorimeter. It is a digital, custom, fixed latency system which makes heavy use of high-speed FPGA devices to allow flexibility in the choice of data filtering algorithms. Results from several intermediate processing stages are read out, allowing the selection algorithm to be fully analyzed and optimized offline. In addition, the trigger is monitored in real time by sampling these data and cross-checking each stage of the trigger calculation against a software model. The design, implementation, construction and performance of the Level 1 Calorimeter Trigger during the first year of BABAR operation are presented.

Search for Narrow Diphoton Resonances and for gamma-gamma+W/Z Signatures in p\bar p Collisions at sqrt(s)=1.8 TeV

ArXiv hep-ex/0105066 (2001)

Measurement of the two-jet differential cross section inpp¯collisions ats=1800GeV

Physical Review D American Physical Society (APS) 64:1 (2001) 012001

Authors:

T Affolder, H Akimoto, A Akopian, MG Albrow, P Amaral, SR Amendolia, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, F Azfar, P Azzi-Bacchetta, N Bacchetta, MW Bailey, S Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, M Barone, G Bauer, F Bedeschi, S Belforte, WH Bell, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, B Bevensee, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, SR Blusk, A Bocci, A Bodek, W Bokhari, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, A Brandl, S van den Brink, C Bromberg, M Brozovic, N Bruner, E Buckley-Geer, J Budagov, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, P Calafiura, M Campbell, W Carithers, J Carlson, D Carlsmith, W Caskey, J Cassada, A Castro, D Cauz, A Cerri, AW Chan, PS Chang, PT Chang, J Chapman, C Chen, YC Chen, M-T Cheng, M Chertok, G Chiarelli, I Chirikov-Zorin, G Chlachidze, F Chlebana, L Christofek, ML Chu, YS Chung, CI Ciobanu, AG Clark, A Connolly, J Conway, M Cordelli, J Cranshaw, D Cronin-Hennessy, R Cropp, R Culbertson, D Dagenhart, S D’Auria, F DeJongh, S Dell’Agnello, M Dell’Orso, L Demortier, M Deninno, PF Derwent, T Devlin, JR Dittmann, S Donati, J Done, T Dorigo, N Eddy, K Einsweiler, JE Elias, E Engels, R Erbacher, D Errede, S Errede, Q Fan, RG Feild, JP Fernandez, C Ferretti, RD Field, I Fiori, B Flaugher, GW Foster, M Franklin, J Freeman, J Friedman, Y Fukui, I Furic, S Galeotti, M Gallinaro, T Gao, M Garcia-Sciveres, AF Garfinkel, P Gatti, C Gay, DW Gerdes, P Giannetti, P Giromini, V Glagolev, D Glenzinski, M Gold, J Goldstein, A Gordon, I Gorelov, AT Goshaw, Y Gotra, K Goulianos, C Green, G Grim, P Gris, L Groer, C Grosso-Pilcher, M Guenther, G Guillian, J Guimaraes da Costa, RM Haas, C Haber, E Hafen, SR Hahn, C Hall, T Handa, R Handler, W Hao, F Happacher, K Hara, AD Hardman, RM Harris, F Hartmann, K Hatakeyama, J Hauser, J Heinrich, A Heiss, M Herndon, C Hill, KD Hoffman, C Holck, R Hollebeek, L Holloway, R Hughes, J Huston, J Huth, H Ikeda, J Incandela, G Introzzi, J Iwai, Y Iwata, E James, H Jensen, M Jones, U Joshi, H Kambara, T Kamon, T Kaneko, K Karr, H Kasha, Y Kato, TA Keaffaber, K Kelley, M Kelly, RD Kennedy, R Kephart, D Khazins, T Kikuchi, B Kilminster, BJ Kim, DH Kim, HS Kim, MJ Kim, SH Kim, YK Kim, M Kirby, M Kirk, L Kirsch, S Klimenko, P Koehn, A Köngeter, K Kondo, J Konigsberg, K Kordas, A Korn, A Korytov, E Kovacs, J Kroll, M Kruse, SE Kuhlmann, K Kurino, T Kuwabara, AT Laasanen, N Lai, S Lami, S Lammel, JI Lamoureux, J Lancaster, M Lancaster, R Lander, G Latino, T LeCompte, AM Lee, K Lee, S Leone, JD Lewis, M Lindgren, TM Liss, JB Liu, YC Liu, DO Litvintsev, O Lobban, N Lockyer, J Loken, M Loreti, D Lucchesi, P Lukens, S Lusin, L Lyons, J Lys, R Madrak, K Maeshima, P Maksimovic, L Malferrari, M Mangano, M Mariotti, G Martignon, A Martin, JAJ Matthews, J Mayer, P Mazzanti, KS McFarland, P McIntyre, E McKigney, M Menguzzato, A Menzione, C Mesropian, A Meyer, T Miao, R Miller, JS Miller, H Minato, S Miscetti, M Mishina, G Mitselmakher, N Moggi, E Moore, R Moore, Y Morita, T Moulik, M Mulhearn, A Mukherjee, T Muller, A Munar, P Murat, S Murgia, J Nachtman, V Nagaslaev, S Nahn, H Nakada, T Nakaya, I Nakano, C Nelson, T Nelson, C Neu, D Neuberger, C Newman-Holmes, C-YP Ngan, H Niu, L Nodulman, A Nomerotski, SH Oh, T Ohmoto, T Ohsugi, R Oishi, T Okusawa, J Olsen, W Orejudos, C Pagliarone, F Palmonari, R Paoletti, V Papadimitriou, SP Pappas, D Partos, J Patrick, G Pauletta, M Paulini, C Paus, L Pescara, TJ Phillips, G Piacentino, KT Pitts, A Pompos, L Pondrom, G Pope, M Popovic, F Prokoshin, J Proudfoot, F Ptohos, O Pukhov, G Punzi, K Ragan, A Rakitine, D Reher, A Reichold, A Ribon, W Riegler, F Rimondi, L Ristori, M Riveline, WJ Robertson, A Robinson, T Rodrigo, S Rolli, L Rosenson, R Roser, R Rossin, A Roy, A Safonov, R St. Denis, WK Sakumoto, D Saltzberg, C Sanchez, A Sansoni, L Santi, H Sato, P Savard, P Schlabach, EE Schmidt, MP Schmidt, M Schmitt, L Scodellaro, A Scott, A Scribano, S Segler, S Seidel, Y Seiya, A Semenov, F Semeria, T Shah, MD Shapiro, PF Shepard, T Shibayama, M Shimojima, M Shochet, J Siegrist, A Sill, P Sinervo, P Singh, AJ Slaughter, K Sliwa, C Smith, FD Snider, A Solodsky, J Spalding, T Speer, P Sphicas, F Spinella, M Spiropulu, L Spiegel, J Steele, A Stefanini, J Strologas, F Strumia, D Stuart, K Sumorok, T Suzuki, T Takano, R Takashima, K Takikawa, P Tamburello, M Tanaka, B Tannenbaum, W Taylor, M Tecchio, R Tesarek, PK Teng, K Terashi, S Tether, AS Thompson, R Thurman-Keup, P Tipton, S Tkaczyk, K Tollefson, A Tollestrup, H Toyoda, W Trischuk, JF de Troconiz, J Tseng, N Turini, F Ukegawa, T Vaiciulis, J Valls, S Vejcik, G Velev, R Vidal, R Vilar, I Volobouev, D Vucinic, RG Wagner, RL Wagner, J Wahl, NB Wallace, AM Walsh, C Wang, MJ Wang, T Watanabe, D Waters, T Watts, R Webb, H Wenzel, WC Wester, AB Wicklund, E Wicklund, T Wilkes, HH Williams, P Wilson, BL Winer, D Winn, S Wolbers, D Wolinski, J Wolinski, S Wolinski, S Worm, X Wu, J Wyss, A Yagil, W Yao, GP Yeh, P Yeh, J Yoh, C Yosef, T Yoshida, I Yu, S Yu, Z Yu, A Zanetti, F Zetti, S Zucchelli

Measurement of dijet production in neutral current deep inelastic scattering at high Q2 and determination of αs

Physics Letters Section B Nuclear Elementary Particle and High Energy Physics 507:1-4 (2001) 70-88

Authors:

J Breitweg, S Chekanov, M Derrick, D Krakauer, S Magill, B Musgrave, A Pellegrino, J Repond, R Stanek, R Yoshida, MCK Mattingly, P Antonioli, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, G Cara Romeo, L Cifarelli, F Cindolo, A Contin, M Corradi, S de Pasquale, P Giusti, G Iacobucci, G Levi, A Margotti, T Massam, R Nania, F Palmonari, A Pesci, G Sartorelli, A Zichichi, G Aghuzumtsyan, C Amelung, I Brock, K Coböken, S Goers, H Hartmann, K Heinloth, E Hilger, P Irrgang, HP Jakob, A Kappes, UF Katz, R Kerger, O Kind, E Paul, J Rautenberg, H Schnurbusch, A Stifutkin, J Tandler, KC Voss, A Weber, H Wieber, DS Bailey, O Barret, NH Brook, JE Cole, B Foster, GP Heath, HF Heath, S Robins, E Rodrigues, J Scott, RJ Tapper, M Capua, A Mastroberardino, M Schioppa, G Susinno, HY Jeoung, JY Kim, JH Lee, IT Lim, KJ Ma, MY Pac, A Caldwell, W Liu, X Liu, B Mellado, S Paganis, S Sampson, WB Schmidke, F Sciulli, J Chwastowski, A Eskreys, J Figiel, K Klimek, K Olkiewicz, MB Przybycień, P Stopa, L Zawiejski, B Bednarek, K Jeleń, D Kisielewska, AM Kowal, T Kowalski, E Rulikowska-Zarebska, L Suszycki

Abstract:

Dijet production has been studied in neutral current deep inelastic e+p scattering for 470 < Q2 < 20000 GeV2 with the ZEUS detector at HERA using an integrated luminosity of 38.4 pb-1. Dijet differential cross sections are presented in a kinematic region where both theoretical and experimental uncertainties are small. Next-to-leading-order (NLO) QCD calculations describe the measured differential cross sections well. A QCD analysis of the measured dijet fraction as a function of Q2 allows both a precise determination of αs(Mz) and a test of the energy-scale dependence of the strong coupling constant. A detailed analysis provides an improved estimate of the uncertainties of the NLO QCD cross sections arising from the paxton distribution functions of the proton. The value of αs(Mz), as determined from the QCD fit, is αs (MZ) = 0.1166 ± 0.0019(stat.)+0.0024 -0.0044 (exp.) +0.0057 0.0044(th.). © 2001 Elsevier Science B.V.

Search for neutral supersymmetric Higgs bosons in pp collisions at sqrt[s] = 1.8TeV.

Phys Rev Lett 86:20 (2001) 4472-4478

Authors:

T Affolder, H Akimoto, A Akopian, MG Albrow, P Amaral, SR Amendolia, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, F Azfar, P Azzi-Bacchetta, N Bacchetta, MW Bailey, S Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, M Barone, G Bauer, F Bedeschi, S Belforte, WH Bell, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, B Bevensee, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, SR Blusk, A Bocci, A Bodek, W Bokhari, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, A Brandl, S van Den Brink, C Bromberg, M Brozovic, N Bruner, E Buckley-Geer, J Budagov, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, P Calafiura, M Campbell, W Carithers, J Carlson, D Carlsmith, W Caskey, J Cassada, A Castro, D Cauz, A Cerri, AW Chan, PS Chang, PT Chang, J Chapman, C Chen, YC Chen, MT Cheng, M Chertok, G Chiarelli, I Chirikov-Zorin, G Chlachidze, F Chlebana, L Christofek, ML Chu, YS Chung, CI Ciobanu, AG Clark, A Connolly, J Conway, M Cordelli, J Cranshaw, D Cronin-Hennessy, R Cropp, R Culbertson, D Dagenhart, S D'Auria, F DeJongh, S Dell'Agnello, M Dell'Orso, L Demortier, M Deninno, PF Derwent, T Devlin, JR Dittmann, S Donati, J Done, T Dorigo, N Eddy, K Einsweiler, JE Elias, E Engels, D Errede, S Errede, Q Fan, RG Feild, JP Fernandez, C Ferretti, RD Field, I Fiori, B Flaugher, GW Foster, M Franklin, J Freeman, J Friedman, Y Fukui, I Furic, S Galeotti, M Gallinaro, T Gao, M Garcia-Sciveres, AF Garfinkel, P Gatti, C Gay, DW Gerdes, P Giannetti, P Giromini, V Glagolev, M Gold, J Goldstein, A Gordon, I Gorelov, AT Goshaw, Y Gotra, K Goulianos, C Green, G Grim, P Gris, L Groer, C Grosso-Pilcher, M Guenther, G Guillian, J Guimaraes da Costa, RM Haas, C Haber, E Hafen, SR Hahn, C Hall, T Handa, R Handler, W Hao, F Happacher, K Hara, AD Hardman, RM Harris, F Hartmann, K Hatakeyama, J Hauser, J Heinrich, A Heiss, M Herndon, C Hill, KD Hoffman, C Holck, R Hollebeek, L Holloway, R Hughes, J Huston, J Huth, H Ikeda, J Incandela, G Introzzi, J Iwai, Y Iwata, E James, H Jensen, M Jones, U Joshi, H Kambara, T Kamon, T Kaneko, K Karr, H Kasha, Y Kato, TA Keaffaber, K Kelley, M Kelly, RD Kennedy, R Kephart, D Khazins, T Kikuchi, B Kilminster, BJ Kim, DH Kim, HS Kim, MJ Kim, SH Kim, YK Kim, M Kirby, M Kirk, L Kirsch, S Klimenko, P Koehn, A Köngeter, K Kondo, J Konigsberg, K Kordas, A Korn, A Korytov, E Kovacs, J Kroll, M Kruse, SE Kuhlmann, K Kurino, T Kuwabara, AT Laasanen, N Lai, S Lami, S Lammel, JI Lamoureux, J Lancaster, M Lancaster, R Lander, G Latino, T LeCompte, AM Lee, K Lee, S Leone, JD Lewis, M Lindgren, TM Liss, JB Liu, YC Liu, N Lockyer, J Loken, M Loreti, D Lucchesi, P Lukens, S Lusin, L Lyons, J Lys, R Madrak, K Maeshima, P Maksimovic, L Malferrari, M Mangano, M Mariotti, G Martignon, A Martin, JA Matthews, J Mayer, P Mazzanti, KS McFarland, P McIntyre, E McKigney, M Menguzzato, A Menzione, C Mesropian, A Meyer, T Miao, R Miller, JS Miller, H Minato, S Miscetti, M Mishina, G Mitselmakher, N Moggi, E Moore, R Moore, Y Morita, M Mulhearn, A Mukherjee, T Muller, A Munar, P Murat, S Murgia, J Nachtman, S Nahn, H Nakada, T Nakaya, I Nakano, C Nelson, T Nelson, C Neu, D Neuberger, C Newman-Holmes, CY Ngan, H Niu, L Nodulman, A Nomerotski, SH Oh, T Ohmoto, T Ohsugi, R Oishi, T Okusawa, J Olsen, W Orejudos, C Pagliarone, F Palmonari, R Paoletti, V Papadimitriou, SP Pappas, D Partos, J Patrick, G Pauletta, M Paulini, C Paus, L Pescara, TJ Phillips, G Piacentino, KT Pitts, A Pompos, L Pondrom, G Pope, M Popovic, F Prokoshin, J Proudfoot, F Ptohos, O Pukhov, G Punzi, K Ragan, A Rakitine, D Reher, A Reichold, A Ribon, W Riegler, F Rimondi, L Ristori, M Riveline, WJ Robertson, A Robinson, T Rodrigo, S Rolli, L Rosenson, R Roser, R Rossin, A Safonov, R St Denis, WK Sakumoto, D Saltzberg, C Sanchez, A Sansoni, L Santi, H Sato, P Savard, P Schlabach, EE Schmidt, MP Schmidt, M Schmitt, L Scodellaro, A Scott, A Scribano, S Segler, S Seidel, Y Seiya, A Semenov, F Semeria, T Shah, MD Shapiro, PF Shepard, T Shibayama, M Shimojima, M Shochet, J Siegrist, G Signorelli, A Sill, P Sinervo, P Singh, AJ Slaughter, K Sliwa, C Smith, FD Snider, A Solodsky, J Spalding, T Speer, P Sphicas, F Spinella, M Spiropulu, L Spiegel, J Steele, A Stefanini, J Strologas, F Strumia, D Stuart, K Sumorok, T Suzuki, T Takano, R Takashima, K Takikawa, P Tamburello, M Tanaka, B Tannenbaum, W Taylor, M Tecchio, PK Teng, K Terashi, S Tether, AS Thompson, R Thurman-Keup, P Tipton, S Tkaczyk, K Tollefson, A Tollestrup, H Toyoda, W Trischuk, JF de Troconiz, J Tseng, N Turini, F Ukegawa, T Vaiciulis, J Valls, S Vejcik, G Velev, R Vidal, R Vilar, I Volobouev, D Vucinic, RG Wagner, RL Wagner, J Wahl, NB Wallace, AM Walsh, C Wang, MJ Wang, T Watanabe, D Waters, T Watts, R Webb, H Wenzel, WC Wester, AB Wicklund, E Wicklund, T Wilkes, HH Williams, P Wilson, BL Winer, D Winn, S Wolbers, D Wolinski, J Wolinski, S Wolinski, S Worm, X Wu, J Wyss, A Yagil, W Yao, GP Yeh, P Yeh, J Yoh, C Yosef, T Yoshida, I Yu, S Yu, Z Yu, A Zanetti, F Zetti, S Zucchelli, CDF Collaboration

Abstract:

We present the results of a search for neutral Higgs bosons produced in association with b quarks in pp-->bb(phi)-->bbb final states with 91+/-7 pb(-1) of pp collisions at sqrt[s] = 1.8 TeV recorded by the Collider Detector at Fermilab. We find no evidence of such a signal and the data are interpreted in the context of the neutral Higgs sector of the minimal supersymmetric extension of the standard model. With basic parameter choices for the supersymmetric scale and the stop-quark mixing, we derive 95% C.L. lower mass limits for neutral Higgs bosons for tan(beta) values in excess of 35.