Strong evidence for ZZ production in pp[over] collisions at sqrt[s]=1.96 TeV.
Phys Rev Lett 100:20 (2008) 201801
Authors:
T Aaltonen, J Adelman, T Akimoto, MG Albrow, B Alvarez Gonz谩lez, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, M Aoki, G Apollinari, A Apresyan, T Arisawa, A Artikov, W Ashmanskas, A Attal, A Aurisano, F Azfar, P Azzi-Bacchetta, P Azzurri, N Bacchetta, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, V Bartsch, G Bauer, P-H Beauchemin, F Bedeschi, P Bednar, S Behari, G Bellettini, J Bellinger, A Belloni, D Benjamin, A Beretvas, J Beringer, T Berry, A Bhatti, M Binkley, D Bisello, I Bizjak, RE Blair, C Blocker, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, A Bolshov, D Bortoletto, J Boudreau, A Boveia, B Brau, A Bridgeman, L Brigliadori, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, K Burkett, G Busetto, P Bussey, A Buzatu, KL Byrum, S Cabrera, M Campanelli, M Campbell, F Canelli, A Canepa, D Carlsmith, R Carosi, S Carrillo, S Carron, B Casal, M Casarsa, A Castro, P Catastini, D Cauz, M Cavalli-Sforza, A Cerri, L Cerrito, SH Chang, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, K Cho, D Chokheli, JP Chou, G Choudalakis, SH Chuang, K Chung, WH Chung, YS Chung, CI Ciobanu, MA Ciocci, A Clark, D Clark, G Compostella, ME Convery, J Conway, B Cooper, K Copic, M Cordelli, G Cortiana, F Crescioli, C Cuenca Almenar, J Cuevas, R Culbertson, JC Cully, D Dagenhart, M Datta, T Davies, P de Barbaro, S De Cecco, A Deisher, G De Lentdecker, G De Lorenzo, M Dell'Orso, L Demortier, J Deng, M Deninno, D De Pedis, PF Derwent, GP Di Giovanni, C Dionisi, B Di Ruzza, JR Dittmann, M D'Onofrio, S Donati, P Dong, J Donini, T Dorigo, S Dube, J Efron, R Erbacher, D Errede, S Errede, R Eusebi, HC Fang, S Farrington, WT Fedorko, RG Feild, M Feindt, JP Fernandez, C Ferrazza, R Field, G Flanagan, R Forrest, S Forrester, M Franklin, JC Freeman, I Furic, M Gallinaro, J Galyardt, F Garberson, JE Garcia, AF Garfinkel, K Genser, H Gerberich, D Gerdes, S Giagu, V Giakoumopolou, P Giannetti, K Gibson, JL Gimmell, CM Ginsburg, N Giokaris, M Giordani, P Giromini, M Giunta, V Glagolev, D Glenzinski, M Gold, N Goldschmidt, A Golossanov, G Gomez, G Gomez-Ceballos, M Goncharov, O Gonz谩lez, I Gorelov, AT Goshaw, K Goulianos, A Gresele, S Grinstein, C Grosso-Pilcher, U Grundler, J Guimaraes da Costa, Z Gunay-Unalan, C Haber, K Hahn, SR Hahn, E Halkiadakis, A Hamilton, B-Y Han, JY Han, R Handler, F Happacher, K Hara, D Hare, M Hare, S Harper, RF Harr, RM Harris, M Hartz, K Hatakeyama, J Hauser, C Hays, M Heck, A Heijboer, B Heinemann, J Heinrich, C Henderson, M Herndon, J Heuser, S Hewamanage, D Hidas, CS Hill, D Hirschbuehl, A Hocker, S Hou, M Houlden, S-C Hsu, BT Huffman, RE Hughes, U Husemann, J Huston, J Incandela, G Introzzi, M Iori, A Ivanov, B Iyutin, E James, B Jayatilaka, D Jeans, EJ Jeon, S Jindariani, W Johnson, M Jones, KK Joo, SY Jun, JE Jung, TR Junk, T Kamon, D Kar, PE Karchin, Y Kato, R Kephart, U Kerzel, V Khotilovich, B Kilminster, DH Kim, HS Kim, JE Kim, MJ Kim, SB Kim, SH Kim, YK Kim, N Kimura, L Kirsch, S Klimenko, M Klute, B Knuteson, BR Ko, SA Koay, K Kondo, DJ Kong, J Konigsberg, A Korytov, AV Kotwal, J Kraus, M Kreps, J Kroll, N Krumnack, M Kruse, V Krutelyov, T Kubo, SE Kuhlmann, T Kuhr, NP Kulkarni, Y Kusakabe, S Kwang, AT Laasanen, S Lai, S Lami, S Lammel, M Lancaster, RL Lander, K Lannon, A Lath, G Latino, I Lazzizzera, T LeCompte, J Lee, J Lee, YJ Lee, SW Lee, R Lef猫vre, N Leonardo, S Leone, S Levy, JD Lewis, C Lin, CS Lin, J Linacre, M Lindgren, E Lipeles, A Lister, DO Litvintsev, T Liu, NS Lockyer, A Loginov, M Loreti, L Lovas, R-S Lu, D Lucchesi, J Lueck, C Luci, P Lujan, P Lukens, G Lungu, L Lyons, J Lys, R Lysak, E Lytken, P Mack, D MacQueen, R Madrak, K Maeshima, K Makhoul, T Maki, P Maksimovic, S Malde, S Malik, G Manca, A Manousakis, F Margaroli, C Marino, CP Marino, A Martin, M Martin, V Martin, M Mart铆nez, R Mart铆nez-Ballar铆n, T Maruyama, P Mastrandrea, T Masubuchi, ME Mattson, P Mazzanti, KS McFarland, P McIntyre, R McNulty, A Mehta, P Mehtala, S Menzemer, A Menzione, P Merkel, C Mesropian, A Messina, T Miao, N Miladinovic, J Miles, R Miller, C Mills, M Milnik, A Mitra, G Mitselmakher, H Miyake, S Moed, N Moggi, CS Moon, R Moore, M Morello, P Movilla Fernandez, J M眉lmenst盲dt, A Mukherjee, Th Muller, R Mumford, P Murat, M Mussini, J Nachtman, Y Nagai, A Nagano, J Naganoma, K Nakamura, I Nakano, A Napier, V Necula, C Neu, MS Neubauer, J Nielsen, L Nodulman, M Norman, O Norniella, E Nurse, SH Oh, YD Oh, I Oksuzian, T Okusawa, R Oldeman, R Orava, K Osterberg, S Pagan Griso, C Pagliarone, E Palencia, V Papadimitriou, A Papaikonomou, AA Paramonov, B Parks, S Pashapour, J Patrick, G Pauletta, M Paulini, C Paus, DE Pellett, A Penzo, TJ Phillips, G Piacentino, J Piedra, L Pinera, K Pitts, C Plager, L Pondrom, X Portell, O Poukhov, N Pounder, F Prakoshyn, A Pronko, J Proudfoot, F Ptohos, G Punzi, J Pursley, J Rademacker, A Rahaman, V Ramakrishnan, N Ranjan, I Redondo, B Reisert, V Rekovic, P Renton, M Rescigno, S Richter, F Rimondi, L Ristori, A Robson, T Rodrigo, E Rogers, S Rolli, R Roser, M Rossi, R Rossin, P Roy, A Ruiz, J Russ, V Rusu, H Saarikko, A Safonov, WK Sakumoto, G Salamanna, O Salt贸, L Santi, S Sarkar, L Sartori, K Sato, A Savoy-Navarro, T Scheidle, P Schlabach, EE Schmidt, MA Schmidt, MP Schmidt, M Schmitt, T Schwarz, L Scodellaro, AL Scott, A Scribano, F Scuri, A Sedov, S Seidel, Y Seiya, A Semenov, L Sexton-Kennedy, A Sfyrla, SZ Shalhout, MD Shapiro, T Shears, PF Shepard, D Sherman, M Shimojima, M Shochet, Y Shon, I Shreyber, A Sidoti, P Sinervo, A Sisakyan, AJ Slaughter, J Slaunwhite, K Sliwa, JR Smith, FD Snider, R Snihur, M Soderberg, A Soha, S Somalwar, V Sorin, J Spalding, F Spinella, T Spreitzer, P Squillacioti, M Stanitzki, R St Denis, B Stelzer, O Stelzer-Chilton, D Stentz, J Strologas, D Stuart, JS Suh, A Sukhanov, H Sun, I Suslov, T Suzuki, A Taffard, R Takashima, Y Takeuchi, R Tanaka, M Tecchio, PK Teng, K Terashi, J Thom, AS Thompson, GA Thompson, E Thomson, P Tipton, V Tiwari, S Tkaczyk, D Toback, S Tokar, K Tollefson, T Tomura, D Tonelli, S Torre, D Torretta, S Tourneur, W Trischuk, Y Tu, N Turini, F Ukegawa, S Uozumi, S Vallecorsa, N van Remortel, A Varganov, E Vataga, F V谩zquez, G Velev, C Vellidis, V Veszpremi, M Vidal, R Vidal, I Vila, R Vilar, T Vine, M Vogel, I Volobouev, G Volpi, F W眉rthwein, P Wagner, RG Wagner, RL Wagner, J Wagner-Kuhr, W Wagner, T Wakisaka, R Wallny, SM Wang, A Warburton, D Waters, M Weinberger, WC Wester, B Whitehouse, D Whiteson, AB Wicklund, E Wicklund, G Williams, HH Williams, P Wilson, BL Winer, P Wittich, S Wolbers, C Wolfe, T Wright, X Wu, SM Wynne, A Yagil, K Yamamoto, J Yamaoka, T Yamashita, C Yang, UK Yang, YC Yang, WM Yao, GP Yeh, J Yoh, K Yorita, T Yoshida, GB Yu, I Yu, SS Yu, JC Yun, L Zanello, A Zanetti, I Zaw, X Zhang, Y Zheng, S Zucchelli, CDF Collaboration, RC Group
Abstract:
We report the first evidence of Z boson pair production at a hadron collider with a significance exceeding 4 standard deviations. This result is based on a data sample corresponding to 1.9 fb(-1) of integrated luminosity from pp[over] collisions at sqrt[s]=1.96 TeV collected with the Collider Detector at Fermilab II detector. In the lll'l' channel, we observe three ZZ candidates with an expected background of 0.096(-0.063)+0.092 events. In the llnunu channel, we use a leading-order calculation of the relative ZZ and WW event probabilities to discriminate between signal and background. In the combination of lll'l' and llnunu channels, we observe an excess of events with a probability of 5.1 x 10(-6) to be due to the expected background. This corresponds to a significance of 4.4 standard deviations. The measured cross section is sigma(pp[over]-->ZZ)=1.4(-0.6)+0.7(stat+syst) pb, consistent with the standard model expectation.