Precision measurement of the Ξ0 mass and the branching ratios of the decays Ξ0 → Λγ and Ξ0 → ∑0γ

European Physical Journal C 12:1 (2000) 69-76

Authors:

V Fanti, A Lai, D Marras, L Musa, A Nappi, B Hay, KN Moore, RW Moore, DJ Munday, MD Needham, MA Parker, TO White, SA Wotton, G Barr, H Blümer, G Bocquet, J Bremer, A Ceccucci, J Cogan, D Cundy, N Doble, G Fischer, W Funk, L Gatignon, A Gianoli, A Gonidec, G Govi, P Grafström, A Lacourt, S Luitz, V Marzulli, JP Matheys, A Norton, S Palestini, B Panzer-Steindel, D Schinzel, H Taureg, M Velasco, O Vossnack, H Wahl, G Wirrer, A Gaponenko, V Kekelidze, D Madigojine, A Mestvirishvili, N Molokanova, Y Potrebenikov, G Tatishvili, A Tkatchev, A Zinchenko, O Boyle, IG Knowles, VJ Martin, H Parsons, M Contalbrigo, P Dalpiaz, J Duclos, A Formica, PL Frabetti, M Martini, F Petrucci, M Savrie, A Bizzeti, M Calvetti, G Collazuol, G Graziani, E Iacopini, M Lenti, A Michetti, C Talamonti, HG Becker, D Coward, C Ebersberger, H Fox, A Kalter, K Kleinknecht, U Koch, L Köpke, B Renk, J Scheidt, J Schmidt, Y Schue, V Schönharting, R Wilhelm, M Wittgen, JC Chollet, S Crépé, L Fayard, L Iconomidou-Fayard, J Ocariz, G Unal, I Wingerter, G Anzivino, P Cenci, P Lubrano, M Pepe, P Calafiura, R Carosi, R Casali, C Cerri

Abstract:

A new precision measurement of the Ξ0 mass has been performed at the NA48 experiment at the CERN SPS. The value obtained is [1314.82±0.06 (stat.) ±0.2 (syst.)] MeV/c2. The branching ratios of Xi;0 radiative decays have been measured as: Br(Ξ0 → Λγ) = [1.90 ± 0.34(stat.) ± 0.19(syst.)] · 10-3 and Br(Ξ0 → ∑0γ) = [3.14 ± 0.76(stat.) ± 0.32(syst.)] · 10-3.

Search for a fourth-generation quark more massive than the Z0 boson in pp¯ collisions at √s = 1.8 TeV

Physical Review Letters 84:5 (2000) 835-840

Authors:

T Affolder, H Akimoto, A Akopian, MG Albrow, P Amaral, SR Amendolia, D Amidei, J Antos, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, M Atac, F Azfar, P Azzi-Bacchetta, N Bacchetta, MW Bailey, S Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, G Bauer, F Bedeschi, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, S Bertolucci, B Bevensee, A Bhatti, C Bigongiari, M Binkley, D Bisello, RE Blair, C Blocker, K Bloom, B Blumenfeld, BS Blusk, A Bocci, A Bodek, W Bokhari, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, A Brandl, S Van den Brink, C Bromberg, N Bruner, E Buckley-Geer, J Budagov, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, M Campbell, A Caner, W Carithers, J Carlson, D Carlsmith, J Cassada, A Castro, D Cauz, A Cerri, 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, S Cihangir, CI Ciobanu, AG Clark, M Cobal, E Cocca, A Connolly, J Conway, J Cooper, M Cordelli, D Costanzo, J Cranshaw, D Cronin-Hennessy, R Cropp, R Culbertson, D Dagenhart, F DeJongh

Abstract:

We present the results of a search for pair production of a fourth-generation charge -1/3 quark (b′) in √s=1.8 TeV pp¯ collisions using 88 pb−1 of data obtained with the Collider Detector at Fermilab. We assume that both quarks decay via the flavor-changing neutral current process b′→bZ0 and that the b′ mass is greater than mZ+mb. We studied the decay mode b′b′¯→Z0Z0bb¯ where one Z0 decays into e+e− or μ+μ− and the other decays hadronically, giving a signature of two leptons plus jets. An upper limit on the σpp¯→b′b′¯×[B(b′→bZ0)]2 is established as a function of the b′ mass. We exclude at 95% confidence level a b′ quark with mass between 100 and 199 GeV/c2 for B(b′→bZ0)=100%. © 2000 The American Physical Society.

Search for color singlet technicolor particles in pp¯ Collisions at √s = 1.8TeV

Physical Review Letters 84:6 (2000) 1110-1115

Authors:

T Affolder, H Akimoto, A Akopian, MGG Albrow, P Amaral, SR Amendolia, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, M Atac, F Azfar, P Azzi-Bacchetta, N Bacchetta, MW Bailey, S Bailey, P De Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, G Bauer, F Bedeschi, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, S Bertolucci, B Bevensee, A Bhatti, C Bigongiari, M Binkley, D Bisello, RE Blair, C Blocker, K Bloom, B Blumenfeld, BS 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, M Campbell, A Caner, W Carithers, J Carlson, D Carlsmith, 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, S Cihangir, CI Ciobanu, AG Clark, M Cobal, E Cocca, A Connolly, J Conway, J Cooper, M Cordelli, D Costanzo, J Cranshaw, D Cronin-Hennessy, R Cropp

Abstract:

We search for color singlet technirho and technipion production in pp¯ Collisions at √s = 1.8TeVrecorded with the Collider Detector at Fermilab. These exotic technimesons are present in a model of walking technicolor. The signatures studied are lepton plus two jets plus ET and multijet final states. No excess of events is seen in either final state. We set an upper limit on the technirho production cross section and exclude a region in the technipion mass versus technirho mass plane. © 2000 American Physical Society.

The NA481 LKr calorimeter readout electronics

IEEE Transactions on Nuclear Science 47:2 PART 1 (2000) 136-141

Authors:

A Gianoli, F Bal, G Barr, P Brodier-Yourstone, P Buchholz, A Ceccucci, C Cerri, A Chlopik, F Costantini, R Fantechi, F Forment, W Funk, S Giudici, B Gorini, Z Guzik, B Hailgren, Y Kozhevnikov, W Iwansky, C De La Taille, A Lacourt, G Laverriere, C Ljuslin, Mannelli, G Martin-Chassard, M Martini, A Papi, N Seguin-Moreau, M Sozzi, JC Tarle, M Velasco, O Vossnack, H Wahl, M Ziolkowsky

Abstract:

The NA48 experiment at the CERN SPS accelerator is making a measurement of the direct CP violation parameter e//£by compari ng the four rates of decay of Kä andKJ. into 2n° and 7i+7iT. To reconstruct the decays into 27C11 the information from the almost 13500 channels of a quasi-homogeneous liquid krypton electromagnetic calorimeter is used. The readout electronics of the calorimeter has been designed to provide a dynamic range from a few MeV to about 50 GeV energy deposition per cell, and to sustain a high rate of incident particles. The system is made by cold charge preamplifiers (working at 120°K), low-noise fast shapers followed by digitizer electronics at 40 MHz sampling rate that employs a gain switching technique to expand the dynamic range, where the gain can be selected for each sample individually (i. e. every 25 ns). To reduce the amount of data collected the system contains a zero suppression circuit based on halo expansion. © 2000 IEEE.

Cross section for b-jet production in (p)over-barp collisions at √s=1.8 TeV

PHYSICAL REVIEW LETTERS 85:24 (2000) 5068-5073

Authors:

B Abbott, M Abolins, V Abramov, BS Acharya, DL Adams, M Adams, GA Alves, N Amos, EW Anderson, MM Baarmand, VV Babintsev, L Babukhadia, A Baden, B Baldin, PW Balm, S Banerjee, J Bantly, E Barberis, P Baringer, JF Bartlett, U Bassler, A Bean, M Begel, A Belyaev, SB Beri, G Bernardi, I Bertram, A Besson, VA Bezzubov, PC Bhat, V Bhatnagar, M Bhattacharjee, G Blazey, S Blessing, A Boehnlein, NI Bojko, F Borcherding, 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, Z Casilum, H Castilla-Valdez, D Chakraborty, KM Chan, SV Chekulaev, DK Cho, S Choi, S Chopra, JH Christenson, M Chung, D Claes, AR Clark, J Cochran, L Coney, B Connolly, WE Cooper, D Coppage, MAC Cummings, D Cutts, OI Dahl, GA Davis, K Davis, K De, K Del Signore, M Demarteau, R Demina, P Demine, D Denisov, SP Denisov, S Desai, HT Diehl, M Diesburg, G Di Loreto, S Doulas, P Draper, Y Ducros, LV Dudko, S Duensing, SR Dugad, A Dyshkant, D Edmunds, J Ellison, VD Elvira, R Engelmann, S Eno, G Eppley, P Ermolov, OV Eroshin, J Estrada, H Evans, VN Evdokimov, T Fahland, S Feher, D Fein, T Ferbel, HE Fisk, Y Fisyak, E Flattum, F Fleuret, M Fortner, KC Frame, S Fuess, E Gallas, AN Galyaev, P Gartung, V Gavrilov, RJII Genik, K Genser, CE Gerber, Y Gershtein, B Gibbard, R Gilmartin, G Ginther, B Gómez, G Gómez, PI Goncharov, JLG Solís, H Gordon, LT Goss, K Gounder, A Goussiou, N Graf, G Graham, PD Grannis, JA Green, H Greenlee, S Grinstein, L Groer, P Grudberg, S Grünendahl, A Gupta, SN Gurzhiev, G Gutierrez, P Gutierrez, NJ Hadley, H Haggerty, S Hagopian, V Hagopian, KS Hahn, RE Hall, P Hanlet, S Hansen, JM Hauptman, C Hays, C Hebert, D Hedin, AP Heinson, U Heintz, T Heuring, R Hirosky, JD Hobbs, B Hoeneisen, JS Hoftun, S Hou, Y Huang, AS Ito, SA Jerger, R Jesik, K Johns, M Johnson, A Jonckheere, M Jones, H Jöstlein, A Juste, S Kahn, E Kajfasz, D Karmanov, D Karmgard, R Kehoe, SK Kim, B Klima, C Klopfenstein, B Knuteson, W Ko, JM Kohli, AV Kostritskiy, J Kotcher, AV Kotwal, AV Kozelov, EA Kozlovsky, J Krane, MR Krishnaswamy, S Krzywdzinski, M Kubantsev, S Kuleshov, Y Kulik, S Kunori, VE Kuznetsov, G Landsberg, A Leflat, F Lehner, J Li, QZ Li, JGR Lima, D Lincoln, S Linn, J Linnemann, R Lipton, A Lucotte, L Lueking, C Lundstedt, AKA Maciel, RJ Madaras, V Manankov, HS Mao, T Marshall, MI Martin, RD Martin, KM Mauritz, B May, AA Mayorov, R McCarthy, J McDonald, T McMahon, HL Melanson, XC Meng, M Merkin, KW Merritt, C Miao, H Miettinen, D Mihalcea, A Mincer, CS Mishra, N Mokhov, NK Mondal, HE Montgomery, RW Moore, M Mostafa, H da Motta, E Nagy, F Nang, M Narain, VS Narasimham, HA Neal, JP Negret, S Negroni, D Norman, L Oesch, V Oguri, B Olivier, N Oshima, P Padley, LJ Pan, A Para, N Parashar, R Partridge, N Parua, M Paterno, A Patwa, B Pawlik, J Perkins, M Peters, O Peters, R Piegaia, H Piekarz, BG Pope, E Popkov, HB Prosper, S Protopopescu, J Qian, PZ Quintas, R Raja, S Rajagopalan, E Ramberg, PA Rapidis, NW Reay, S Reucroft, J Rha, M Rijssenbeek, T Rockwell, M Roco, P Rubinov, R Ruchti, J Rutherfoord, A Santoro, L Sawyer, RD Schamberger, H Schellman, A Schwartzman, J Sculli, N Sen, E Shabalina, HC Shankar, RK Shivpuri, D Shpakov, M Shupe, RA Sidwell, V Simak, H Singh, JB Singh, V Sirotenko, P Slattery, E Smith, RP Smith, R Snihur, GR Snow, J Snow, S Snyder, J Solomon, V Sorín, M Sosebee, N Sotnikova, K Soustruznik, M Souza, NR Stanton, G Steinbrück, RW Stephens, ML Stevenson, F Stichelbaut, D Stoker, V Stolin, DA Stoyanova, M Strauss, K Streets, M Strovink, L Stutte, A Sznajder, W Taylor, S Tentindo-Repond, J Thompson, D Toback, SM Tripathi, TG Trippe, AS Turcot, PM Tuts, P van Gemmeren, V Vaniev, R Van Kooten, N Varelas, AA Volkov, AP Vorobiev, HD Wahl, H Wang, ZM Wang, J Warchol, G Watts, M Wayne, H Weerts, A White, JT White, D Whiteson, JA Wightman, DA Wijngaarden, S Willis, SJ Wimpenny, JVD Wirjawan, J Womersley, DR Wood, R Yamada, P Yamin, T Yasuda, K Yip, S Youssef, J Yu, Z Yu, M Zanabria, H Zheng, Z Zhou, ZH Zhu, M Zielinski, D Zieminska, A Zieminski, V Zutshi, EG Zverev, A Zylberstejn