Transverse-momentum and pseudorapidity distributions of charged hadrons in pp collisions at √s=7TeV

Physical Review Letters 105:2 (2010)

Authors:

V Khachatryan, AM Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, J Erö, C Fabjan, M Friedl, R Frühwirth, VM Ghete, J Hammer, S Hänsel, M Hoch, N Hörmann, J Hrubec, M Jeitler, G Kasieczka, W Kiesenhofer, M Krammer, D Liko, I Mikulec, M Pernicka, H Rohringer, R Schöfbeck, J Strauss, A Taurok, F Teischinger, W Waltenberger, G Walzel, E Widl, CE Wulz, V Mossolov, N Shumeiko, J Suarez Gonzalez, L Benucci, L Ceard, EA De Wolf, M Hashemi, X Janssen, T Maes, L Mucibello, S Ochesanu, B Roland, R Rougny, M Selvaggi, H Van Haevermaet, P Van Mechelen, N Van Remortel, V Adler, S Beauceron, S Blyweert, J D'hondt, O Devroede, A Kalogeropoulos, J Maes, M Maes, S Tavernier, W Van Doninck, P Van Mulders, I Villella, EC Chabert, O Charaf, B Clerbaux, G De Lentdecker, V Dero, APR Gay, GH Hammad, PE Marage, C Vander Velde, P Vanlaer, J Wickens, S Costantini, M Grunewald, B Klein, A Marinov, D Ryckbosch, F Thyssen, M Tytgat, L Vanelderen, P Verwilligen, S Walsh, N Zaganidis, S Basegmez, G Bruno, J Caudron, J De Favereau De Jeneret, C Delaere, P Demin, D Favart, A Giammanco, G Grégoire, J Hollar, V Lemaitre, O Militaru, S Ovyn, D Pagano, A Pin, K Piotrzkowski, L Quertenmont

Abstract:

Charged-hadron transverse-momentum and pseudorapidity distributions in proton-proton collisions at √s=7TeV are measured with the inner tracking system of the CMS detector at the LHC. The charged-hadron yield is obtained by counting the number of reconstructed hits, hit pairs, and fully reconstructed charged-particle tracks. The combination of the three methods gives a charged-particle multiplicity per unit of pseudorapidity dNch/ dη|η|<0.5 = 5.78 ± 0.01(stat)±0.23(syst) for non-single-diffractive events, higher than predicted by commonly used models. The relative increase in charged-particle multiplicity from √s=0.9 to 7 TeV is [66.1±1.0(stat)±4.2(syst)]%. The mean transverse momentum is measured to be 0.545±0.005(stat)±0.015(syst)GeV/c. The results are compared with similar measurements at lower energies. © 2010 The American Physical Society.

Measurement of the ratio σ{tt}/σ{Z/γ{*}→ll} and precise extraction of the tt cross section.

Phys Rev Lett 105:1 (2010) 012001

Authors:

T Aaltonen, J Adelman, B Alvarez González, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, A Apresyan, T Arisawa, A Artikov, J Asaadi, W Ashmanskas, A Attal, A Aurisano, F Azfar, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, P Bartos, G Bauer, P-H Beauchemin, F Bedeschi, D Beecher, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, A Bhatti, M Binkley, D Bisello, I Bizjak, RE Blair, C Blocker, B Blumenfeld, A Bocci, A Bodek, V Boisvert, 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, C Calancha, S Camarda, M Campanelli, M Campbell, F Canelli, A Canepa, B Carls, D Carlsmith, R Carosi, S Carrillo, S Carron, B Casal, M Casarsa, A Castro, P Catastini, D Cauz, V Cavaliere, 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, K Chung, WH Chung, YS Chung, T Chwalek, CI Ciobanu, MA Ciocci, A Clark, D Clark, G Compostella, ME Convery, J Conway, M Corbo, M Cordelli, CA Cox, DJ Cox, 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 Lorenzo, M Dell'orso, C Deluca, L Demortier, J Deng, M Deninno, M d'Errico, A Di Canto, GP di Giovanni, B Di Ruzza, JR Dittmann, M D'Onofrio, S Donati, P Dong, T Dorigo, S Dube, K Ebina, A Elagin, R Erbacher, D Errede, S Errede, N Ershaidat, R Eusebi, HC Fang, S Farrington, WT Fedorko, RG Feild, M Feindt, JP Fernandez, C Ferrazza, R Field, G Flanagan, R Forrest, MJ Frank, M Franklin, JC Freeman, I Furic, M Gallinaro, J Galyardt, F Garberson, JE Garcia, AF Garfinkel, P Garosi, H Gerberich, D Gerdes, A Gessler, S Giagu, V Giakoumopoulou, P Giannetti, K Gibson, JL Gimmell, CM Ginsburg, N Giokaris, M Giordani, P Giromini, M Giunta, G Giurgiu, V Glagolev, D Glenzinski, M Gold, N Goldschmidt, A Golossanov, G Gomez, G Gomez-Ceballos, M Goncharov, O González, I Gorelov, AT Goshaw, K Goulianos, A Gresele, S Grinstein, C Grosso-Pilcher, RC Group, U Grundler, J Guimaraes da Costa, Z Gunay-Unalan, C Haber, SR Hahn, E Halkiadakis, B-Y Han, JY Han, F Happacher, K Hara, D Hare, M Hare, RF Harr, M Hartz, K Hatakeyama, C Hays, M Heck, J Heinrich, M Herndon, J Heuser, S Hewamanage, D Hidas, CS Hill, D Hirschbuehl, A Hocker, S Hou, M Houlden, S-C Hsu, RE Hughes, M Hurwitz, U Husemann, M Hussein, J Huston, J Incandela, G Introzzi, M Iori, A Ivanov, E James, D Jang, B Jayatilaka, EJ Jeon, MK Jha, S Jindariani, W Johnson, M Jones, KK Joo, SY Jun, JE Jung, TR Junk, T Kamon, D Kar, PE Karchin, Y Kato, R Kephart, W Ketchum, J Keung, V Khotilovich, B Kilminster, DH Kim, HS Kim, HW Kim, JE Kim, MJ Kim, SB Kim, SH Kim, YK Kim, N Kimura, L Kirsch, S Klimenko, K Kondo, DJ Kong, J Konigsberg, A Korytov, AV Kotwal, M Kreps, J Kroll, D Krop, N Krumnack, M Kruse, V Krutelyov, T Kuhr, NP Kulkarni, M Kurata, S Kwang, AT Laasanen, S Lami, S Lammel, M Lancaster, RL Lander, K Lannon, A Lath, G Latino, I Lazzizzera, T Lecompte, E Lee, HS Lee, JS Lee, SW Lee, S Leone, JD Lewis, C-J Lin, J Linacre, M Lindgren, E Lipeles, A Lister, DO Litvintsev, C Liu, T Liu, NS Lockyer, A Loginov, L Lovas, D Lucchesi, J Lueck, P Lujan, P Lukens, G Lungu, J Lys, R Lysak, D Macqueen, R Madrak, K Maeshima, K Makhoul, P Maksimovic, S Malde, S Malik, G Manca, A Manousakis-Katsikakis, F Margaroli, C Marino, CP Marino, A Martin, V Martin, M Martínez, R Martínez-Ballarín, P Mastrandrea, M Mathis, ME Mattson, P Mazzanti, KS McFarland, P McIntyre, R McNulty, A Mehta, P Mehtala, A Menzione, C Mesropian, T Miao, D Mietlicki, N Miladinovic, R Miller, C Mills, M Milnik, A Mitra, G Mitselmakher, H Miyake, S Moed, N Moggi, MN Mondragon, CS Moon, R Moore, MJ Morello, J Morlock, P Movilla Fernandez, J Mülmenstädt, A Mukherjee, Th Muller, P Murat, M Mussini, J Nachtman, Y Nagai, J Naganoma, K Nakamura, I Nakano, A Napier, J Nett, C Neu, MS Neubauer, S Neubauer, J Nielsen, L Nodulman, M Norman, O Norniella, E Nurse, L Oakes, SH Oh, YD Oh, I Oksuzian, T Okusawa, R Orava, K Osterberg, S Pagan Griso, C Pagliarone, E Palencia, V Papadimitriou, A Papaikonomou, AA Paramanov, B Parks, S Pashapour, J Patrick, G Pauletta, M Paulini, C Paus, T Peiffer, DE Pellett, A Penzo, TJ Phillips, G Piacentino, E Pianori, L Pinera, K Pitts, C Plager, L Pondrom, K Potamianos, O Poukhov, F Prokoshin, A Pronko, F Ptohos, E Pueschel, G Punzi, J Pursley, J Rademacker, A Rahaman, V Ramakrishnan, N Ranjan, I Redondo, P Renton, M Renz, M Rescigno, S Richter, F Rimondi, L Ristori, A Robson, T Rodrigo, T Rodriguez, E Rogers, S Rolli, R Roser, M Rossi, R Rossin, P Roy, A Ruiz, J Russ, V Rusu, B Rutherford, H Saarikko, A Safonov, WK Sakumoto, L Santi, L Sartori, K Sato, A Savoy-Navarro, P Schlabach, A Schmidt, EE Schmidt, MA Schmidt, MP Schmidt, M Schmitt, T Schwarz, L Scodellaro, A Scribano, F Scuri, A Sedov, S Seidel, Y Seiya, A Semenov, L Sexton-Kennedy, F Sforza, A Sfyrla, SZ Shalhout, T Shears, PF Shepard, M Shimojima, S Shiraishi, M Shochet, Y Shon, I Shreyber, A Simonenko, P Sinervo, A Sisakyan, AJ Slaughter, J Slaunwhite, K Sliwa, JR Smith, FD Snider, R Snihur, A Soha, S Somalwar, V Sorin, P Squillacioti, M Stanitzki, R St Denis, B Stelzer, O Stelzer-Chilton, D Stentz, J Strologas, GL Strycker, JS Suh, A Sukhanov, I Suslov, A Taffard, R Takashima, Y Takeuchi, R Tanaka, J Tang, M Tecchio, PK Teng, J Thom, J Thome, GA Thompson, E Thomson, P Tipton, P Ttito-Guzmán, S Tkaczyk, D Toback, S Tokar, K Tollefson, T Tomura, D Tonelli, S Torre, D Torretta, P Totaro, S Tourneur, M Trovato, S-Y Tsai, Y Tu, N Turini, F Ukegawa, S Uozumi, N van Remortel, A Varganov, E Vataga, F Vázquez, G Velev, C Vellidis, M Vidal, I Vila, R Vilar, M Vogel, I Volobouev, G Volpi, P Wagner, RG Wagner, RL Wagner, W Wagner, J Wagner-Kuhr, T Wakisaka, R Wallny, SM Wang, A Warburton, D Waters, M Weinberger, J Weinelt, WC Wester, B Whitehouse, D Whiteson, AB Wicklund, E Wicklund, S Wilbur, G Williams, HH Williams, P Wilson, BL Winer, P Wittich, S Wolbers, C Wolfe, H Wolfe, T Wright, X Wu, F Würthwein, A Yagil, K Yamamoto, J Yamaoka, UK Yang, YC Yang, WM Yao, GP Yeh, K Yi, J Yoh, K Yorita, T Yoshida, GB Yu, I Yu, SS Yu, JC Yun, A Zanetti, Y Zeng, X Zhang, Y Zheng, S Zucchelli, CDF Collaboration

Abstract:

We report a measurement of the ratio of the tt to Z/γ{*} production cross sections in sqrt[s]=1.96  TeV pp collisions using data corresponding to an integrated luminosity of up to 4.6  fb{-1}, collected by the CDF II detector. The tt cross section ratio is measured using two complementary methods, a b-jet tagging measurement and a topological approach. By multiplying the ratios by the well-known theoretical Z/γ{*}→ll cross section predicted by the standard model, the extracted tt cross sections are effectively insensitive to the uncertainty on luminosity. A best linear unbiased estimate is used to combine both measurements with the result σ{tt}=7.70±0.52  pb, for a top-quark mass of 172.5  GeV/c{2}.

Erratum: Measurement of the W+W- production cross section and search for anomalous WWγ and WWZ couplings in pp̄ collisions at √s=1.96 TeV (Phys. Rev. Lett. (2010) 104 (201801))

Physical Review Letters 105:1 (2010)

Authors:

T Aaltonen, J Adelman, B Álvarez Gonzalez, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, A Apresyan, T Arisawa, A Artikov, J Asaadi, W Ashmanskas, A Attal, A Aurisano, F Azfar, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, P Bartos, G Bauer, PH Beauchemin, F Bedeschi, D Beecher, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, A Bhatti, M Binkley, D Bisello, I Bizjak, RE Blair, C Blocker, B Blumenfeld, A Bocci, A Bodek, V Boisvert, 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, C Calancha, S Camarda, M Campanelli, M Campbell, F Canelli, A Canepa, B Carls, D Carlsmith, R Carosi, S Carrillo, S Carron, B Casal, M Casarsa, A Castro, P Catastini, D Cauz, V Cavaliere, 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, K Chung, WH Chung, YS Chung, T Chwalek, CI Ciobanu, MA Ciocci, A Clark, D Clark, G Compostella, ME Convery, J Conway, M Corbo

Inclusive-jet cross sections in NC DIS at HERA and a comparison of the kT, anti-kT and SIScone jet algorithms

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 691:3 (2010) 127-137

Authors:

H Abramowicz, I Abt, L Adamczyk, M Adamus, R Aggarwal, S Antonelli, P Antonioli, A Antonov, M Arneodo, V Aushev, Y Aushev, O Bachynska, A Bamberger, AN Barakbaev, G Barbagli, G Bari, F Barreiro, D Bartsch, M Basile, O Behnke, J Behr, U Behrens, L Bellagamba, A Bertolin, S Bhadra, M Bindi, C Blohm, T Bołd, EG Boos, M Borodin, K Borras, D Boscherini, D Bot, SK Boutle, I Brock, E Brownson, R Brugnera, N Brümmer, A Bruni, G Bruni, B Brzozowska, PJ Bussey, JM Butterworth, B Bylsma, A Caldwell, M Capua, R Carlin, CD Catterall, S Chekanov, J Chwastowski, J Ciborowski, R Ciesielski, L Cifarelli, F Cindolo, A Contin, AM Cooper-Sarkar, N Coppola, M Corradi, F Corriveau, M Costa, G D'Agostini, FD Corso, J de Favereau, J de Peso, RK Dementiev, S De Pasquale, M Derrick, RCE Devenish, D Dobur, BA Dolgoshein, AT Doyle, V Drugakov, LS Durkin, S Dusini, Y Eisenberg, PF Ermolov, A Eskreys, S Fang, S Fazio, J Ferrando, MI Ferrero, J Figiel, M Forrest, B Foster, S Fourletov, G Gach, A Galas, E Gallo, A Garfagnini, A Geiser, I Gialas, LK Gladilin, D Gladkov, C Glasman, O Gogota, Y Golubkov, P Göttlicher, I Grabowska-Bołd, J Grebenyuk, I Gregor

Abstract:

For the first time, differential inclusive-jet cross sections have been measured in neutral current deep inelastic ep scattering using the anti-kT and SIScone algorithms. The measurements were made for boson virtualities Q2>125 GeV2 with the ZEUS detector at HERA using an integrated luminosity of 82 pb-1 and the jets were identified in the Breit frame. The performance and suitability of the jet algorithms for their use in hadron-like reactions were investigated by comparing the measurements to those performed with the kT algorithm. Next-to-leading-order QCD calculations give a good description of the measurements. Measurements of the ratios of cross sections using different jet algorithms are also presented; the measured ratios are well described by calculations including up to O(αs3) terms. Values of αs(MZ) were extracted from the data; the results are compatible with and have similar precision to the value extracted from the kT analysis. © 2010 Elsevier B.V.

Design and performance of improved Column Parallel CCD, CPC2

Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 621:1-3 (2010) 192-204

Authors:

Y Banda, P Coulter, D Cussans, C Damerell, E Devetak, J Fopma, B Foster, R Frost, R Gao, J Goldstein, T Greenshaw, K Harder, B Hawes, S Hillert, B Jeffery, JJ John, N Kundu, Y Li, P Murray, A Nomerotski, C Perry, K Stefanov, S Thomas, J Velthuis, T Wolliscroft, S Worm, J Yow, Z Zhang

Abstract:

The Linear Collider Flavour Identification (LCFI) Collaboration is developing the sensors, readout electronics and mechanical support structures for the vertex detector of the International Linear Collider (ILC). High speed readout is needed to ensure that the occupancy due to the pair production background at the ILC is kept below the 1% level. In order to satisfy this requirement, Column Parallel CCDs (CPCCDs), Column Parallel Readout chips (CPRs) and Column Parallel Driver chips (CPDs) have been developed. The CPCCD has to operate at a clock frequency of 50 MHz, which represents a difficult technical challenge due to the large sensor capacitance. The design and performance of the second generation CPCCD sensors, CPC2, and the new driver chip, CPD1, which meet these challenging requirements, are described. © 2010 Elsevier B.V. All rights reserved.