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Measurement of charged-particle multiplicities in gluon and quark jets in pp̄ collisions at √s = 1:8 TeV

Physical Review Letters 94:17 (2005)

Authors:

D Acosta, T Affolder, MG Albrow, D Ambrose, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, A Artikov, W Ashmanskas, F Azfar, P Azzi-Bacchetta, N Bacchetta, H Bachacou, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, M Barone, G Bauer, F Bedeschi, S Behari, S Belforte, WH Bell, G Bellettini, J Bellinger, D Benjamin, A Beretvas, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, A Bocci, A Bodek, G Bolla, A Bolshov, D Bortoletto, J Boudreau, C Bromberg, E Brubaker, J Budagov, HS Budd, K Burkett, G Busetto, KL Byrum, S Cabrera, M Campbell, W Carithers, D Carlsmith, A Castro, D Cauz, A Cerri, L Cerrito, J Chapman, C Chen, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, ML Chu, JY Chung, WH Chung, YS Chung, CI Ciobanu, AG Clark, M Coca, A Connolly, M Convery, J Conway, M Cordelli, J Cranshaw, R Culbertson, D Dagenhart, S D'Auria, P de Barbaro, S de Cecco, S Dell'Agnello, M Dell'Orso, S Demers, L Demortier, M Deninno, D de Pedis, PF Derwent, C Dionisi, JR Dittmann, A Dominguez, S Donati, M D'Onofrio, T Dorigo, N Eddy, R Erbacher, D Errede, S Errede

Abstract:

We report the first largely model independent measurement of charged particle multiplicities in quark and gluon jets, Nq and Ng, produced at the Fermilab Tevatron in pp collisions with a center-of-mass energy of 1.8 TeV and recorded by the Collider Detector at Fermilab. The measurements are made for jets with average energies of 41 and 53 GeV by counting charged particle tracks in cones with opening angles of θc = 0:28, 0.36, and 0.47 rad around the jet axis. The corresponding jet hardness Q = Ejetθc varies in the range from 12 to 25 GeV. At Q = 19:2 GeV, the ratio of multiplicities r = Ng=Nq is found to be 1:64 ± 0:17, where statistical and systematic uncertainties are added in quadrature. The results are in agreement with resummed perturbative QCD calculations.
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Search for ZZ and ZW production in pp̄ collisions at s=1.96TeV

Physical Review D - Particles, Fields, Gravitation and Cosmology 71:9 (2005) 1-7

Authors:

D Acosta, 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, T Arisawa, JF Arguin, A Artikov, W Ashmanskas, A Attal, F Azfar, P Azzi-Bacchetta, N Bacchetta, H Bachacou, W Badgett, A Barbaro-Galtieri, GJ Barker, VE Barnes, BA Barnett, S Baroiant, M Barone, G Bauer, F Bedeschi, S Behari, S Belforte, G Bellettini, J Bellinger, E Ben-Haim, D Benjamin, A Beretvas, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, A Bocci, A Bodek, G Bolla, A Bolshov, PSL Booth, D Bortoletto, J Boudreau, S Bourov, B Brau, C Bromberg, E Brubaker, J Budagov, HS Budd, K Burkett, G Busetto, P Bussey, KL Byrum, S Cabrera, M Campanelli, M Campbell, A Canepa, M Casarsa, D Carlsmith, S Carron, R Carosi, M Cavalli-Sforza, A Castro, P Catastini, D Cauz, A Cerri, L Cerrito, J Chapman, C Chen, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, I Cho, K Cho, D Chokheli, JP Chou, ML Chu, S Chuang, JY Chung, WH Chung, YS Chung, CI Ciobanu, MA Ciocci, AG Clark, D Clark, M Coca, A Connolly

Abstract:

We present a search for ZZ and ZW vector boson pair production in pp̄ collisions at s=1.96TeV using the leptonic decay channels ZZ→llνν, ZZ→lll′l′, and ZW→lll′ν. In a data sample corresponding to an integrated luminosity of 194pb-1 collected with the Collider Detector at Fermilab, 3 candidate events are found with an expected background of 1.0±0.2 events. We set a 95% confidence level upper limit of 15.2pb on the cross section for ZZ plus ZW production, compared to the standard model prediction of 5.0±0.4pb. © 2005 The American Physical Society.
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A study of the Type II-P supernova 2003gd in M74

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 359:3 (2005) 906-926

Authors:

MA Hendry, SJ Smartt, JR Maund, A Pastorello, L Zampieri, S Benetti, M Turatto, E Cappellaro, WPS Meikle, R Kotak, MJ Irwin, PG Jonker, L Vermaas, RF Peletier, H Van Woerden, KM Exter, DL Pollacco, S Leon, S Verley, CR Benn, G Pignata
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Improved measurement of the form factors in the decay lambda+c-->lambda + nue.

Physical review letters 94:19 (2005) 191801

Authors:

JW Hinson, GS Huang, J Lee, DH Miller, V Pavlunin, R Rangarajan, B Sanghi, EI Shibata, IPJ Shipsey, D Cronin-Hennessy, CS Park, W Park, JB Thayer, EH Thorndike, TE Coan, YS Gao, F Liu, R Stroynowski, M Artuso, C Boulahouache, S Blusk, E Dambasuren, O Dorjkhaidav, R Mountain, H Muramatsu, R Nandakumar, T Skwarnicki, S Stone, JC Wang, SE Csorna, I Danko, G Bonvicini, D Cinabro, M Dubrovin, S McGee, A Bornheim, E Lipeles, SP Pappas, A Shapiro, WM Sun, AJ Weinstein, RA Briere, GP Chen, T Ferguson, G Tatishvili, H Vogel, ME Watkins, NE Adam, JP Alexander, K Berkelman, V Boisvert, DG Cassel, JE Duboscq, KM Ecklund, R Ehrlich, RS Galik, L Gibbons, B Gittelman, SW Gray, DL Hartill, BK Heltsley, L Hsu, CD Jones, J Kandaswamy, DL Kreinick, A Magerkurth, H Mahlke-Krüger, TO Meyer, NB Mistry, JR Patterson, D Peterson, J Pivarski, SJ Richichi, D Riley, AJ Sadoff, H Schwarthoff, MR Shepherd, JG Thayer, D Urner, T Wilksen, A Warburton, M Weinberger, SB Athar, P Avery, L Breva-Newell, V Potlia, H Stoeck, J Yelton, K Benslama, C Cawlfield, BI Eisenstein, GD Gollin, I Karliner, N Lowrey, C Plager, C Sedlack, M Selen, JJ Thaler, J Williams, KW Edwards, D Besson, S Anderson, VV Frolov, DT Gong, Y Kubota, SZ Li, R Poling, A Smith, CJ Stepaniak, J Urheim, Z Metreveli, KK Seth, A Tomaradze, P Zweber, S Ahmed, MS Alam, J Ernst, L Jian, M Saleem, F Wappler, K Arms, E Eckhart, KK Gan, C Gwon, K Honscheid, H Kagan, R Kass, TK Pedlar, E von Toerne, H Severini, P Skubic, SA Dytman, JA Mueller, S Nam, V Savinov, CLEO Collaboration

Abstract:

Using the CLEO detector at the Cornell Electron Storage Ring, we have studied the distribution of kinematic variables in the decay lambda(+)(c)lambda--> e(+)nu(e). By performing a four-dimensional maximum likelihood fit, we determine the form factor ratio, R= f(2)/f(1) = -0.31 +/- 0.05(stat) +/- 0.04(syst), the pole mass, M(pole) = [2.21 +/- 0.08(stat) +/- 0.14(syst)] GeV/c(2), and the decay asymmetry parameter of the lambda(+)(c), alpha (lambda(c)) = -0.86 +/-0.03(stat) +/- 0.02(syst), for q(2) = 0.67 (GeV/c(2))(2). We compare the angular distributions of the lambda(+)(c) and lambda(-)(c) and find no evidence for CP violation: A(lambda(c)) = (alpha(lambda(c)) + alpha (lambda(c)))/(alpha(lambda(c))-alpha(lambda(c))) = 0.00 +/- 0.03(stat) +/- 0.01(syst) +/- 0.02, where the third error is from the uncertainty in the world average of the CP-violating parameter, A(lambda), for ppi(-).
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The luminosity function of Lyα emitters at 2.3 \lt z \lt 4.6 from integral-field spectroscopy$^*$

\mnras 359 (2005) 895-905-895-905

Authors:

C van Breukelen, MJ Jarvis, BP Venemans
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