Search for selectron and squark production in e+p collisions at HERA

PHYSICS LETTERS B 434:1-2 (1998) 214-230

Authors:

J Breitweg, M Derrick, D Krakauer, S Magill, D Mikunas, B Musgrave, J Repond, R Stanek, RL Talaga, R Yoshida, H Zhang, MCK Mattingly, F Anselmo, P Antonioli, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, GC Romeo, G Castellini, L Cifarelli, F Cindolo, A Contin, N Coppola, M Corradi, S De Pasquale, P Giusti, G Iacobucci, G Laurenti, G Levi, A Margotti, T Massam, R Nania, F Palmonari, A Pesci, A Polini, G Sartorelli, YZ Garcia, A Zichichi, C Amelung, A Bornheim, I Brock, K Coboken, J Crittenden, R Deffner, M Eckert, M Grothe, H Hartmann, K Heinloth, L Heinz, E Hilger, HP Jakob, A Kappes, UF Katz, R Kerger, E Paul, M Pfeiffer, J Stamm, H Wieber, DS Bailey, S Campbell-Robson, WN Cottingham, B Foster, R Hall-Wilton, GP Heath, HF Heath, JD McFall, D Piccioni, DG Roff, RJ Tapper, M Capua, L Iannotti, M Schioppa, G Susinno, JY Kim, JH Lee, IT Lim, MY Pac, A Caldwell, N Cartiglia, Z Jing, W Liu, B Mellado, JA Parsons, S Ritz, S Sampson, F Sciulli, PB Straub, Q Zhu, P Borzemski, J Chwastowski, A Eskreys, J Figiel, K Klimek, MB Przybycien, L Zawiejski, L Adamczyk, B Bednarek, M Bukowy, AM Czermak, K Jelen, D Kisielewska, T Kowalski, M Przybycien, E Rulikowska-Zarebska, L Suszycki, J Zajac, Z Dulinski, A Kotanski, G Abbiendi, LAT Bauerdick, U Behrens, H Beier, JK Bienlein, K Desler, G Drews, U Fricke, I Gialas, F Goebel, P Gottlicher, R Graciani, T Haas, W Hain, GF Hartner, D Hasell, K Hebbel, KF Johnson, M Kasemann, W Koch, U Kotz, H Kowalski, L Lindemann, B Lohr, M Martinez, J Milewski, M Milite, T Monteiro, D Notz, A Pellegrino, F Pelucchi, K Piotrzkowski, M Rohde, J Roldan, JJ Ryan, PRB Saull, AA Savin, U Schneekloth, O Schwarzer, F Selonke, S Stonjek, B Surrow, E Tassi, D Westphal, G Wolf, U Wollmer, C Youngman, W Zeuner, BD Burow, C Coldewey, HJ Grabosch, A Meyer, S Schlenstedt, G Barbagli, E Gallo, P Pelfer, G Maccarrone, L Votano, A Bamberger, S Eisenhardt, P Markun, H Raach, T Trefzger, S Wolfle, JT Bromley, NH Brook, PJ Bussey, AT Doyle, SW Lee, N Macdonald, GJ McCance, DH Saxon, LE Sinclair, IO Skillicorn, E Strickland, R Waugh, I Bohnet, N Gendner, U Holm, A Meyer-Larsen, H Salehi, K Wick, A Garfagnini, LK Gladilin, D Kcira, R Klanner, E Lohrmann, C Poelz, F Zetsche, TC Bacon, I Butterworth, JE Cole, G Howell, L Lamberti, KR Long, DB Miller, N Pavel, A Prinias, JK Sedgbeer, D Sideris, R Walker, U Mallik, SM Wang, JT Wu, P Cloth, D Filges, JI Fleck, T Ishii, M Kuze, I Suzuki, K Tokushuku, S Yamada, K Yamauchi, Y Yamazaki, SJ Hong, SB Lee, SW Nam, SK Park, H Lim, IH Park, D Son, F Barreiro, JP Fernandez, G Garcia, C Glasman, JM Hernandez, L Hervas, L Labarga, J del Peso, J Puga, J Terron, JF de Troconiz, F Corriveau, DS Hanna, J Hartmann, LW Hung, WN Murray, A Ochs, M Riveline, DG Stairs, M St-Laurent, R Ullmann, T Tsurugai, V Bashkirov, BA Dolgoshein, A Stifutkin, GL Bashindzhagyan, PF Ermolov, YA Golubkov, LA Khein, NA Korotkova, IA Korzhavina, VA Kuzmin, OY Lukina, AS Proskuryakov, LM Shcheglova, AN Solomin, SA Zotkin, C Bokel, M Botje, N Brummer, J Engelen, E Koffeman, P Kooijman, A van Sighem, H Tiecke, N Tuning, W Verkerke, J Vossebeld, I Wiggers, E de Wolf, D Acosta, B Bylsma, LS Durkin, J Gilmore, CM Ginsburg, CL Kim, TY Ling, P Nylander, TA Romanowski, HE Blaikley, RJ Cashmore, AM Cooper-Sarkar, RCE Devenish, JK Edmonds, J Grosse-Knetter, N Harnew, C Nath, VA Noyes, A Quadt, O Ruske, JR Tickner, R Walczak, DS Waters, A Bertolin, R Brugnera, R Carlin, F Dal Corso, U Dosselli, S Limentani, M Morandin, M Posocco, L Stanco, R Stroili, C Voci, J Bulmahn, BY Oh, JR Okrasinski, WS Toothacker, JJ Whitmore, Y Iga, G D'Agostini, G Marini, A Nigro, M Raso, JC Hart, NA McCubbin, TP Shah, D Epperson, C Heusch, JT Rahn, HFW Sadrozinski, A Seiden, R Wichmann, DC Williams, H Abramowicz, G Briskin, S Dagan, S Kananov, A Levy, T Abe, T Fusayasu, M Inuzuka, K Nagano, K Umemori, T Yamashita, R Hamatsu, T Hirose, K Homma, S Kitamura, T Matsushita, M Arneodo, R Cirio, M Costa, MI Ferrero, S Maselli, V Monaco, C Peroni, MC Petrucci, M Ruspa, R Sacchi, A Solano, A Staiano, M Dardo, DC Bailey, CP Fagerstroem, R Galea, KK Joo, GM Levman, JFMRS Orr, S Polenz, A Sabetfakhri, D Simmons, JM Butterworth, CD Catterall, ME Hayes, TW Jones, JB Lane, RL Saunders, MR Sutton, M Wing, J Ciborowski, G Grzelak, M Kasprzak, RJ Nowak, JM Pawlak, R Pawlak, B Smalska, T Tymieniecka, AK Wroblewski, JA Zakrzewski, AF Zarnecki, M Adamus, O Deppe, Y Eisenberg, D Hochman, U Karshon, WF Badgett, D Chapin, R Cross, S Dasu, C Foudas, RJ Loveless, S Mattingly, DD Reeder, WH Smith, A Vaiciulis, M Wodarczyk, A Deshpande, S Dhawan, VW Hughes, S Bhadra, WR Frisken, M Khakzad, WB Schmidke

A search for excited fermions in e+p collisions at HERA

Zeitschrift fur Physik C-Particles and Fields 76:4 (1997) 631-646

Authors:

J Breitweg, M Derrick, D Krakauer, S Magill, D Mikunas, B Musgrave, J Repond, R Stanek, RL Talaga, R Yoshida, H Zhang, MCK Mattingly, F Anselmo, P Antonioli, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, G Cara Romeo, G Castellini, L Cifarelli, F Cindolo, A Contin, M Corradi, S De Pasquale, I Gialas, P Giusti, G Iacobucci, G Laurenti, G Levi, A Margotti, T Massam, R Nania, F Palmonari, A Pesci, A Polini, F Ricci, G Sartorelli, Y Zamora Garcia, A Zichichi, C Amelung, A Bornheim, I Brock, K Coböken, J Crittenden, R Deffner, M Eckert, L Feld, M Grothe, H Hartmann, K Heinloth, L Heinz, E Hilger, HP Jakob, UF Katz, R Kerger, E Paul, M Pfeiffer, C Rembser, J Stamm, R Wedemeyer, H Wieber, DS Bailey, S Campbell-Robson, WN Cottingham, B Foster, R Hall-Wilton, ME Hayes, GP Heath, HF Heath, D Piccioni, DG Roff, RJ Tapper, M Arneodo, R Ayad, M Capua, A Garfagnini, L Iannotti, M Schioppa, G Susinno, JY Kim, JH Lee, IT Lim, MY Pac, A Caldwell, N Cartiglia, Z Jing, W Liu, B Mellado, JA Parsons, S Ritz, S Sampson, F Sciulli, PB Straub, Q Zhu, P Borzemski, J Chwastowski, A Eskreys

Abstract:

Using the ZEUS detector at HERA, we have searched for heavy excited states of electrons, neutrinos, and quarks in e+p collisions at a center-of-mass energy of 300 GeV. With an integrated luminosity of 9.4 pb-1, no evidence was found for electroweak production and decay of such states. Limits on the production cross section times branching ratio and on the characteristic couplings, f/Λ, are derived for masses up to 250 GeV. For the particular choice f/Λ = 1/Mf*, we exclude at the 95% confidence level excited electrons with mass between 30 and 200 GeV, excited electron neutrinos with mass between 40 and 96 GeV, and quarks excited electroweakly with mass between 40 and 169 GeV. © Springer-Verlag 1997.

Measurement of inelastic J/ψ photoproduction at HERA

Zeitschrift fur Physik C-Particles and Fields 76:4 (1997) 599-612

Authors:

J Breitweg, M Derrick, D Krakauer, S Magill, D Mikunas, B Musgrave, J Repond, R Stanek, RL Talaga, R Yoshida, H Zhang, MCK Mattingly, F Anselmo, P Antonioli, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, G Cara Romeo, G Castellini, L Cifarelli, F Cindolo, A Contin, M Corradi, S De Pasquale, I Gialas, P Giusti, G Iacobucci, G Laurenti, G Levi, A Margotti, T Massam, R Nania, F Palmonari, A Pesci, A Polini, F Ricci, G Sartorelli, Y Zamora Garcia, A Zichichi, C Amelung, A Bornheim, I Brock, K Coböken, J Crittenden, R Deffner, M Eckert, M Grothe, H Hartmann, K Heinloth, L Heinz, E Hilger, HP Jakob, UF Katz, R Kerger, E Paul, M Pfeiffer, C Rembser, J Stamm, R Wedemeyer, H Wieber, DS Bailey, S Campbell-Robson, WN Cottingham, B Foster, R Hall-Wilton, ME Hayes, GP Heath, HF Heath, D Piccioni, DG Roff, RJ Tapper, M Arneodo, R Ayad, M Capua, A Garfagnini, L Iannotti, M Schioppa, G Susinno, JY Kim, JH Lee, IT Lim, MY Pac, A Caldwell, N Cartiglia, Z Jing, W Liu, B Mellado, JA Parsons, S Ritz, S Sampson, F Sciulli, PB Straub, Q Zhu, P Borzemski, J Chwastowski, A Eskreys, Z Jakubowski

Observation of scaling violations in scaled momentum distributions at HERA

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 414:3-4 (1997) 428-443

Authors:

J Breitweg, M Derrick, D Krakauer, S Magill, D Mikunas, B Musgrave, J Repond, R Stanek, RL Talaga, R Yoshida, H Zhang, MCK Mattingly, F Anselmo, P Antonioli, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, G Cara Romeo, G Castellini, L Cifarelli, F Cindolo, A Contin, M Corradi, S de Pasquale, I Gialas, P Giusti, G Iacobucci, G Laurenti, G Levi, A Margotti, T Massam, R Nania, F Palmonari, A Pesci, A Polini, F Ricci, G Sartorelli, Y Zamora Garcia, A Zichichi, C Amelung, A Bornheim, I Brock, K Coböken, J Crittenden, R Deffner, M Eckert, M Grothe, H Hartmann, K Heinloth, L Heinz, E Hilger, HP Jakob, UF Katz, R Kerger, E Paul, M Pfeiffer, C Rembser, J Stamm, R Wedemeyer, H Wieber, DS Bailey, S Campbell-Robson, WN Cottingham, B Foster, R Hall-Wilton, ME Hayes, GP Heath, HF Heath, JD McFall, D Piccioni, DG Roff, RJ Tapper, M Arneodo, R Ayad, M Capua, A Garfagnini, L Iannotti, M Schioppa, G Susinno, JY Kim, JH Lee, IT Lim, MY Pac, A Caldwell, N Cartiglia, Z Jing, W Liu, B Mellado, JA Parsons, S Ritz, S Sampson, F Sciulli, PB Straub, Q Zhu, P Borzemski, J Chwastowski, A Eskreys

Abstract:

Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of x and Q2 using the ZEUS detector. The evolution of the scaled momentum, xp, with Q2, in the range 10 to 1280 GeV2, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of Q2. © 1997 Elsevier Science B.V.

Observation of isolated high-ET photons in photoproduction at HERA: ZEUS collaboration

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 413:1-2 (1997) 201-216

Authors:

J Breitweg, M Derrick, D Krakauer, S Magill, D Mikunas, B Musgrave, J Repond, R Stanek, RL Talaga, R Yoshida, H Zhang, MCK Mattingly, F Anselmo, P Antonioli, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, G Cara Romeo, G Castellini, L Cifarelli, F Cindolo, A Contin, M Corradi, S de Pasquale, I Gialas, P Giusti, G Iacobucci, G Laurenti, G Levi, A Margotti, T Massam, R Nania, F Palmonari, A Pesci, A Polini, F Ricci, G Sartorelli, Y Zamora Garcia, A Zichichi, C Amelung, A Bornheim, I Brock, K Coböken, J Crittenden, R Deffner, M Eckert, M Grothe, H Hartmann, K Heinloth, L Heinz, E Hilger, HP Jakob, UF Katz, R Kerger, E Paul, M Pfeiffer, C Rembser, J Stamm, R Wedemeyer, H Wieber, DS Bailey, S Campbell-Robson, WN Cottingham, B Foster, R Hall-Wilton, ME Hayes, GP Heath, HF Heath, D Piccioni, DG Roff, RJ Tapper, M Arneodo, R Ayad, M Capua, A Garfagnini, L Iannotti, M Schioppa, G Susinno, JY Kim, JH Lee, IT Lim, MY Pac, A Caldwell, N Cartiglia, Z Jing, W Liu, B Mellado, JA Parsons, S Ritz, S Sampson, F Sciulli, PB Straub, Q Zhu, P Borzemski, J Chwastowski, A Eskreys, Z Jakubowski

Abstract:

Events containing an isolated prompt photon with high transverse energy, together with a balancing jet, have been observed for the first time in photoproduction at HERA. The data were taken with the ZEUS detector, in a γp centre of mass energy range 120-250 GeV. The fraction of the incoming photon energy participating in the production of the prompt photon and the jet, xγ, shows a strong peak near unity, consistent with LO QCD Monte Carlo predictions. In the transverse energy and pseudorapidity range 5 ≤ EγT < 10 GeV, -0.7 ≤ ηγ < 0.8, EjetT ≥ 5 GeV, and -1.5 ≤ ηjet ≤ 1.8, with xOBSγ > 0.8, the measured cross section is 15.3 ± 3.8 ± 1.8 pb, in good agreement with a recent NLO calculation. © 1997 Elsevier Science B.V.