Observation of exclusive electron-positron production in hadron-hadron collisions

Physical Review Letters 98:11 (2007)

Authors:

A Abulencia, J Adelman, T Affolder, T Akimoto, MG Albrow, D Ambrose, S Amerio, D Amidei, A Anastassov, K Anikeev, A Annovi, J Antos, M Aoki, G Apollinari, JF Arguin, T Arisawa, A Artikov, W Ashmanskas, A Attal, F Azfar, P Azzi-Bacchetta, P Azzurri, N Bacchetta, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, V Bartsch, G Bauer, F Bedeschi, S Behari, S Belforte, G Bellettini, J Bellinger, A Belloni, D Benjamin, A Beretvas, J Beringer, T Berry, A Bhatti, M Binkley, D Bisello, RE Blair, C Blocker, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, A Bolshov, D Bortoletto, J Boudreau, A Boveia, B Brau, L Brigliadori, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, S Budroni, K Burkett, G Busetto, P Bussey, KL Byrum, S Cabrera, M Campanelli, M Campbell, F Canelli, A Canepa, S Carillo, D Carlsmith, B Caron, R Carosi, 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, I Cho, K Cho, D Chokheli, JP Chou, G Choudalakis, SH Chuang, K Chung, WH Chung, YS Chung, M Ciljak, CI Ciobanu, MA Ciocci

Abstract:

We present the first observation of exclusive e+e- production in hadron-hadron collisions, using pp̄ collision data at s=1.96TeV taken by the run II Collider Detector at Fermilab, and corresponding to an integrated luminosity of 532pb-1. We require the absence of any particle signatures in the detector except for an electron and a positron candidate, each with transverse energy ET>5GeV and pseudorapidity |η|<2. With these criteria, 16 events are observed compared to a background expectation of 1.9±0.3 events. These events are consistent in cross section and properties with the QED process pp̄→p+e+e-+p̄ through two-photon exchange. The measured cross section is 1.6-0.3+0.5(stat)±0.3(syst)pb. This agrees with the theoretical prediction of 1.71±0.01pb. © 2007 The American Physical Society.

Inclusive-jet and dijet cross sections in deep inelastic scattering at HERA

Nuclear Physics B 765:1-2 (2007) 1-30

Authors:

S Chekanov, M Derrick, S Magill, S Miglioranzi, B Musgrave, D Nicholass, J Repond, R Yoshida, MCK Mattingly, N Pavel, AG Yagües Molina, S Antonelli, P Antonioli, G Bari, M Basile, L Bellagamba, M Bindi, D Boscherini, A Bruni, G Bruni, L Cifarelli, F Cindolo, A Contin, M Corradi, S De Pasquale, G Iacobucci, A Margotti, R Nania, A Polini, L Rinaldi, G Sartorelli, A Zichichi, G Aghuzumtsyan, D Bartsch, I Brock, S Goers, H Hartmann, E Hilger, HP Jakob, M Jüngst, OM Kind, E Paul, J Rautenberg, R Renner, U Samson, V Schönberg, M Wang, M Wlasenko, NH Brook, GP Heath, JD Morris, T Namsoo, M Capua, S Fazio, A Mastroberardino, M Schioppa, G Susinno, E Tassi, JY Kim, KJ Ma, ZA Ibrahim, B Kamaluddin, WAT Wan Abdullah, Y Ning, Z Ren, F Sciulli, J Chwastowski, A Eskreys, J Figiel, A Galas, M Gil, K Olkiewicz, P Stopa, L Zawiejski, L Adamczyk, T Bołd, I Grabowska-Bołd, D Kisielewska, J Łukasik, M Przybycień, L Suszycki, A Kotański, W Słomiński, V Adler, U Behrens, I Bloch, A Bonato, K Borras, N Coppola, J Fourletova, A Geiser, D Gladkov, P Göttlicher, I Gregor, O Gutsche, T Haas, W Hain, C Horn, B Kahle, U Kötz

Abstract:

Inclusive-jet and dijet differential cross sections have been measured in neutral current deep inelastic ep scattering for exchanged boson virtualities Q2 > 125   GeV2 with the ZEUS detector at HERA using an integrated luminosity of 82 pb-1. Jets were identified in the Breit frame using the kT cluster algorithm. Jet cross sections are presented as functions of several kinematic and jet variables. The results are also presented in different regions of Q2. Next-to-leading-order QCD calculations describe the measurements well. Regions of phase space where the theoretical uncertainties are small have been identified. Measurements in these regions have the potential to constrain the gluon density in the proton when used as inputs to global fits of the proton parton distribution functions. © 2006.

Measurement of sigma Lambda b0/sigma B0 x B(Lambda b0-->Lambda c+pi-)/B(B0-->D+pi-) in pp collisions at square root s=1.96 TeV.

Physical review letters 98:12 (2007) 122002

Authors:

A Abulencia, J Adelman, T Affolder, T Akimoto, MG Albrow, D Ambrose, S Amerio, D Amidei, A Anastassov, K Anikeev, A Annovi, J Antos, M Aoki, G Apollinari, J-F Arguin, T Arisawa, A Artikov, W Ashmanskas, A Attal, F Azfar, P Azzi-Bacchetta, P Azzurri, N Bacchetta, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, V Bartsch, G Bauer, F Bedeschi, S Behari, S Belforte, G Bellettini, J Bellinger, A Belloni, D Benjamin, A Beretvas, J Beringer, T Berry, A Bhatti, M Binkley, D Bisello, RE Blair, C Blocker, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, A Bolshov, D Bortoletto, J Boudreau, A Boveia, B Brau, L Brigliadori, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, S Budroni, K Burkett, G Busetto, P Bussey, KL Byrum, S Cabrera, M Campanelli, M Campbell, F Canelli, A Canepa, S Carillo, D Carlsmith, R Carosi, 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, I Cho, K Cho, D Chokheli, JP Chou, G Choudalakis, SH Chuang, K Chung, WH Chung, YS Chung, M Ciljak, CI Ciobanu, MA Ciocci, A Clark, D Clark, M Coca, 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 Cyr, S DaRonco, S D'Auria, T Davies, M D'Onofrio, D Dagenhart, P de Barbaro, S De Cecco, A Deisher, G De Lentdecker, M Dell'Orso, F Delli Paoli, L Demortier, J Deng, M Deninno, D De Pedis, PF Derwent, GP Di Giovanni, C Dionisi, B Di Ruzza, JR Dittmann, P DiTuro, C Dörr, S Donati, M Donega, P Dong, J Donini, T Dorigo, S Dube, J Efron, R Erbacher, D Errede, S Errede, R Eusebi, HC Fang, S Farrington, I Fedorko, WT Fedorko, RG Feild, M Feindt, JP Fernandez, R Field, G Flanagan, A Foland, S Forrester, GW Foster, M Franklin, JC Freeman, I Furic, M Gallinaro, J Galyardt, JE Garcia, F Garberson, AF Garfinkel, C Gay, H Gerberich, D Gerdes, S Giagu, P Giannetti, A Gibson, K Gibson, JL Gimmell, C Ginsburg, N Giokaris, M Giordani, P Giromini, M Giunta, G Giurgiu, V Glagolev, D Glenzinski, M Gold, N Goldschmidt, J Goldstein, G Gomez, G Gomez-Ceballos, M Goncharov, O González, I Gorelov, AT Goshaw, K Goulianos, A Gresele, M Griffiths, S Grinstein, C Grosso-Pilcher, RC Group, 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, M Hare, S Harper, RF Harr, RM Harris, M Hartz, K Hatakeyama, J Hauser, A Heijboer, B Heinemann, J Heinrich, C Henderson, M Herndon, J Heuser, D Hidas, CS Hill, D Hirschbuehl, A Hocker, A Holloway, S Hou, M Houlden, S-C Hsu, BT Huffman, RE Hughes, U Husemann, J Huston, J Incandela, G Introzzi, M Iori, Y Ishizawa, A Ivanov, B Iyutin, E James, D Jang, B Jayatilaka, D Jeans, H Jensen, EJ Jeon, S Jindariani, M Jones, KK Joo, SY Jun, JE Jung, TR Junk, T Kamon, PE Karchin, Y Kato, Y Kemp, 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, K Kondo, DJ Kong, J Konigsberg, A Korytov, AV Kotwal, A Kovalev, AC Kraan, J Kraus, I Kravchenko, M Kreps, J Kroll, N Krumnack, M Kruse, V Krutelyov, T Kubo, SE Kuhlmann, T Kuhr, Y Kusakabe, S Kwang, AT Laasanen, S Lai, S Lami, S Lammel, M Lancaster, RL Lander, K Lannon, A Lath, G Latino, I Lazzizzera, Y Le, T LeCompte, J Lee, J Lee, YJ Lee, SW Lee, R Lefèvre, N Leonardo, S Leone, S Levy, JD Lewis, C Lin, CS Lin, M Lindgren, E Lipeles, A Lister, DO Litvintsev, T Liu, NS Lockyer, A Loginov, M Loreti, P Loverre, R-S Lu, D Lucchesi, 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, G Manca, F Margaroli, R Marginean, C Marino, CP Marino, A Martin, M Martin, V Martin, M Martínez, T Maruyama, P Mastrandrea, T Masubuchi, H Matsunaga, ME Mattson, R Mazini, 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, A Miyamoto, S Moed, N Moggi, B Mohr, R Moore, M Morello, P Movilla Fernandez, J Mülmenstädt, A Mukherjee, Th Muller, R Mumford, P Murat, J Nachtman, A Nagano, J Naganoma, I Nakano, A Napier, V Necula, C Neu, MS Neubauer, J Nielsen, T Nigmanov, L Nodulman, O Norniella, E Nurse, SH Oh, YD Oh, I Oksuzian, T Okusawa, R Oldeman, R Orava, K Osterberg, C Pagliarone, E Palencia, V Papadimitriou, 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, N Ranjan, S Rappoccio, 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, A Ruiz, J Russ, V Rusu, H Saarikko, S Sabik, A Safonov, WK Sakumoto, G Salamanna, O Saltó, D Saltzberg, C Sánchez, L Santi, S Sarkar, L Sartori, K Sato, P Savard, A Savoy-Navarro, T Scheidle, P Schlabach, EE 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, MD Shapiro, T Shears, PF Shepard, D Sherman, M Shimojima, M Shochet, Y Shon, I Shreyber, A Sidoti, P Sinervo, A Sisakyan, J Sjolin, 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, A Staveris-Polykalas, R St Denis, B Stelzer, O Stelzer-Chilton, D Stentz, J Strologas, D Stuart, JS Suh, A Sukhanov, H Sun, T Suzuki, A Taffard, R Takashima, Y Takeuchi, K Takikawa, M Tanaka, R Tanaka, M Tecchio, PK Teng, K Terashi, J Thom, AS 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, J Tseng, R Tsuchiya, S Tsuno, N Turini, F Ukegawa, T Unverhau, S Uozumi, D Usynin, S Vallecorsa, N van Remortel, A Varganov, E Vataga, F Vázquez, G Velev, G Veramendi, V Veszpremi, R Vidal, I Vila, R Vilar, T Vine, I Vollrath, I Volobouev, G Volpi, F Würthwein, P Wagner, RG Wagner, RL Wagner, J Wagner, W Wagner, R Wallny, SM Wang, A Warburton, S Waschke, D Waters, 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, J Zhou, S Zucchelli, CDF Collaboration

Abstract:

We present the first observation of the baryon decay Lambda b0-->Lambda c+pi- followed by Lambda c+-->pK-pi+ in 106 pb-1 pp collisions at square root s=1.96 TeV in the CDF experiment. In order to reduce systematic error, the measured rate for Lambda b0 decay is normalized to the kinematically similar meson decay B0-->D+pi- followed by D+-->pi+K-pi+. We report the ratio of production cross sections (sigma) times the ratio of branching fractions (B) for the momentum region integrated above pT>6 GeV/c and pseudorapidity range |eta|<1.3: sigma(pp-->Lambda b0X)/sigma(pp-->B0X)xB(Lambda b0-->Lambda c+pi-)/B(B0-->D+pi-)=0.82+/-0.08(stat)+/-0.11(syst)+/-0.22[B(Lambda c+-->pK-pi+)].

Precision determination of the D0 mass.

Physical review letters 98:9 (2007) 092002

Authors:

C Cawlfield, BI Eisenstein, I Karliner, D Kim, N Lowrey, P Naik, M Selen, EJ White, J Wiss, RE Mitchell, MR Shepherd, D Besson, TK Pedlar, D Cronin-Hennessy, KY Gao, J Hietala, Y Kubota, T Klein, BW Lang, R Poling, AW Scott, A Smith, P Zweber, S Dobbs, Z Metreveli, KK Seth, A Tomaradze, J Ernst, KM Ecklund, H Severini, W Love, V Savinov, O Aquines, Z Li, A Lopez, S Mehrabyan, H Mendez, J Ramirez, GS Huang, DH Miller, V Pavlunin, B Sanghi, IPJ Shipsey, B Xin, GS Adams, M Anderson, JP Cummings, I Danko, D Hu, B Moziak, J Napolitano, Q He, J Insler, H Muramatsu, CS Park, EH Thorndike, F Yang, TE Coan, YS Gao, M Artuso, S Blusk, J Butt, J Li, N Menaa, R Mountain, S Nisar, K Randrianarivony, R Sia, T Skwarnicki, S Stone, JC Wang, K Zhang, G Bonvicini, D Cinabro, M Dubrovin, A Lincoln, DM Asner, KW Edwards, RA Briere, T Ferguson, G Tatishvili, H Vogel, ME Watkins, JL Rosner, NE Adam, JP Alexander, DG Cassel, JE Duboscq, R Ehrlich, L Fields, RS Galik, L Gibbons, R Gray, SW Gray, DL Hartill, BK Heltsley, D Hertz, CD Jones, J Kandaswamy, DL Kreinick, VE Kuznetsov, H Mahlke-Krüger, PUE Onyisi, JR Patterson, D Peterson, J Pivarski, D Riley, A Ryd, AJ Sadoff, H Schwarthoff, X Shi, S Stroiney, WM Sun, T Wilksen, SB Athar, R Patel, V Potlia, J Yelton, P Rubin, CLEO Collaboration

Abstract:

A precision measurement of the D0 meson mass has been made using approximately 281 pb(-1) of e+e- annihilation data taken with the CLEO-c detector at the psi(3770) resonance. The exclusive decay D0-->K_{S}phi has been used to obtain M(D0)=1864.847+/-0.150(stat)+/-0.095(syst) MeV. This corresponds to M(D0D*0)=3871.81+/-0.36 MeV, and leads to a well-constrained determination of the binding energy of the proposed D0D*0 molecule X(3872), as Eb=0.6+/-0.6 MeV.

Status of Flavor Physics

AIP Conference Proceedings 892:1 (2007) 107-120