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Measurement of D*± production and the charm contribution to F2 in deep inelastic scattering at HERA

European Physical Journal C 12:1 (2000) 35-52

Authors:

J Breitweg, S Chekanov, M Derrick, D Krakauer, S Magill, B Musgrave, A Pellegrino, J Repond, R Stanek, R Yoshida, MCK Mattingly, G Abbiendi, 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, 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, Y Zamora Garcia, A Zichichi, C Amelung, A Bornheim, I Brock, K Coböken, J Crittenden, R Deffner, M Eckert, H Hartmann, K Heinloth, E Hilger, HP Jakob, A Kappes, UF Katz, R Kerger, E Paul, J Rautenberg, H Schnurbusch, A Stifutkin, J Tandler, A Weber, H Wieber, DS Bailey, O Barret, WN Cottingham, B Foster, GP Heath, HF Heath, JD McFall, D Piccioni, J Scott, RJ Tapper, M Capua, A Mastroberardino, M Schioppa, G Susinno, HY Jeoung, JY Kim, JH Lee, IT Lim, KJ Ma, MY Pac, A Caldwell, W Liu, X Liu, B Mellado, JA Parsons, S Ritz, R Sacchi, S Sampson, F Sciulli, J Chwastowski, A Eskreys, J Figiel, K Klimek, K Olkiewicz, MB Przybycień, P Stopa, L Zawiejski, L Adamczyk

Abstract:

The production of D*± (2010) mesons in deep inelastic scattering has been measured in the ZEUS detector at HERA using an integrated luminosity of 37 pb-1. The decay channels D*+ → D0π+ (+c.c.), with D0 → K-π+ or D0 → K-π-π+π+, have been used to identify the D mesons. The e+p cross section for inclusive D*± production with 1 < Q2 < 600 GeV2 and 0.02 < y < 0.7 is 8.31±0.31(stat.)+0.30-0.50 (syst.) nb in the kinematic region 1.5 < pT(D*±) < 15 GeV and \η(D*±)\ < 1.5. Differential cross sections are consistent with a next-to-leading-order perturbative-QCD calculation when using charm-fragmentation models which take into account the interaction of the charm quark with the proton remnant. The observed cross section is extrapolated to the full kinematic region in pT(D*±) and η(D*±) in order to determine the charm contribution, Fcc̄2 (x, Q2), to the proton structure function. The ratio Fcc̄2/F2 rises from ≃10% at Q2 ≃ 1.8GeV2 to ≃30% at Q2 ≃130GeV2 for x values in the range 10-4 to 10-3.
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Measurement of J/ψ and ψ(2S) polarization in pp collisions at √ s = 1.8 Tev

Physical Review Letters 85:14 (2000) 2886-2891

Authors:

T Affolder, H Akimoto, A Akopian, MG Albrow, P Amaral, SR Amendolia, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, M Atac, F Azfar, P Azzi-Bacchetta, N Bacchetta, MW Bailey, S Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, G Bauer, F Bedeschi, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, B Bevensee, A Bhatti, M Binkley, D Bisello, RE Blair, C Blocker, K Bloom, B Blumenfeld, SR Blusk, A Bocci, A Bodek, W Bokhari, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, A Brandl, S van den Brink, C Bromberg, M Brozovic, N Bruner, E Buckley Geer, J Budagov, HS Budd, K Burkett, G Busetto, A Byon Wagner, KL Byrum, P Calafiura, M Campbell, W Carithers, J Carlson, D Carlsmith, J Cassada, A Castro, D Cauz, A Cerri, AW Chan, PS Chang, PT Chang, J Chapman, C Chen, YC Chen, MT Cheng, M Chertok, G Chiarelli, I Chirikov Zorin, G Chlachidze, F Chlebana, L Christofek, ML Chu, CI Ciobanu, AG Clark, A Connolly, J Conway, J Cooper, M Cordelli, J Cranshaw, D Cronin Hennessy, R Cropp, R Culbertson, D Dagenhart, F De Jongh, S Dell Agnello, M Dell Orso, R Demina

Abstract:

We have measured the polarization of J/ψ and ψ(2S) mesons produced in pp collisions at √ = 1.8 TeV using data collected at the Collider Detector at Fermilab during 1992–1995. The polarization of promptly produced J/ψ [ψ(2S)] mesons is isolated from those produced in B-hadron decay and measured over the kinematic range 4 [5.5] < PT < 20 GeV/c and |y| < 0.6. For PT ≾ 12 GeV/c we do not observe significant polarization in the prompt component. © 2000 The American Physical Society.
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Measurement of [formula presented] rapidity correlations in [formula presented] collisions at [formula presented]

Physical Review D - Particles, Fields, Gravitation and Cosmology 61:3 (2000)

Authors:

F Abe, H Akimoto, A Akopian, MG Albrow, A Amadon, SR Amendolia, D Amidei, J Antos, S Aota, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, M Atac, P Azzi-Bacchetta, N Bacchetta, S Bagdasarov, MW Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, G Bauer, T Baumann, F Bedeschi, S Behrends, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, S Bertolucci, S Bettelli, B Bevensee, A Bhatti, K Biery, C Bigongiari, M Binkley, D Bisello, RE Blair, C Blocker, K Bloom, S Blusk, A Bodek, W Bokhari, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, L Breccia, C Bromberg, N Bruner, R Brunetti, E Buckley-Geer, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, M Campbell, A Caner, W Carithers, D Carlsmith, J Cassada, A Castro, D Cauz, A Cerri, PS Chang, PT Chang, HY Chao, J Chapman, MT Cheng, M Chertok, G Chiarelli, CN Chiou, F Chlebana, L Christofek, R Cropp, ML Chu, S Cihangir, AG Clark, M Cobal, E Cocca, M Contreras, J Conway, J Cooper, M Cordelli, D Costanzo, C Couyoumtzelis, D Cronin-Hennessy, R Culbertson, D Dagenhart, T Daniels, F DeJongh, S Dell’Agnello, M Dell’Orso

Abstract:

We report the first direct measurement of (Formula presented) rapidity correlations in (Formula presented) collisions at (Formula presented) We select events with a high transverse momentum muon accompanied by a jet, and a second jet associated with a decay vertex displaced from the (Formula presented) interaction vertex. Two independent samples are obtained corresponding to events with a forward (Formula presented) or central (Formula presented) muon. We measure the ratio of forward to central (Formula presented) production to be (Formula presented) in good agreement with the next-to-leading order QCD prediction (Formula presented) © 1999 The American Physical Society.
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Measurement of diffractive photoproduction of vector mesons at large momentum transfer at HERA

European Physical Journal C 14:2 (2000) 213-238

Authors:

J Breitweg, S Chekanov, M Derrick, D Krakauer, S Magill, B Musgrave, A Pellegrino, J Repond, R Stanek, R Yoshida, MCK Mattingly, G Abbiendi, 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, 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, Y Zamora Garcia, A Zichichi, C Amelung, A Bornheim, I Brock, K Coböken, J Crittenden, R Deffner, H Hartmann, K Heinloth, E Hilger, HP Jakob, A Kappes, UF Katz, R Kerger, E Paul, J Rautenberg, H Schnurbusch, A Stifutkin, J Tandler, KC Voss, A Weber, H Wieber, DS Bailey, O Barret, NH Brook, B Foster, GP Heath, HF Heath, JD McFall, D Piccioni, E Rodrigues, J Scott, RJ Tapper, M Capua, A Mastroberardino, M Schioppa, G Susinno, HY Jeoung, JY Kim, JH Lee, IT Lim, KJ Ma, MY Pac, A Caldwell, W Liu, X Liu, B Mellado, R Sacchi, S Sampson, F Sciulli, J Chwastowski, A Eskreys, J Figiel, K Klimek, K Olkiewicz, MB Przybycień, P Stopa, L Zawiejski, L Adamczyk, B Bednarek
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Measurement of high-Q2 charged-current e+p deep inelastic scattering cross sections at HERA

European Physical Journal C 12:3 (2000) 411-428

Authors:

J Breitweg, S Chekanov, M Derrick, D Krakauer, S Magill, B Musgrave, A Pellegrino, J Repond, R Stanek, R Yoshida, MCK Mattingly, G Abbiendi, 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, 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, Y Zamora Garcia, A Zichichi, C Amelung, A Bornheim, I Brock, K Coböken, J Crittenden, R Deffner, M Eckert, H Hartmann, K Heinloth, E Hilger, HP Jakob, A Kappes, UF Katz, R Kerger, E Paul, J Rautenberg, H Schnurbusch, A Stifutkin, J Tandler, A Weber, H Wieber, DS Bailey, O Barret, WN Cottingham, B Foster, GP Heath, HF Heath, JD McFall, D Piccioni, J Scott, RJ Tapper, M Capua, A Mastroberardino, M Schioppa, G Susinno, HY Jeoung, JY Kim, JH Lee, IT Lim, KJ Ma, MY Pac, A Caldwell, N Cartiglia, Z Jing, W Liu, B Mellado, JA Parsons, S Ritz, R Sacchi, S Sampson, F Sciulli, Q Zhu, J Chwastowski, A Eskreys, J Figiel, K Klimek, K Olkiewicz, MB Przybycień, P Stopa

Abstract:

The e+p charged-current deep inelastic scattering cross sections, dσ/dQ2 for Q2 between 200 and 60000 GeV2, and dσ/dx and dσ/dy for Q2 > 200 GeV2, have been measured with the ZEUS detector at HERA. A data sample of 47.7 pb-1, collected at a center-of-mass energy of 300 GeV, has been used. The double-differential cross-section dσ/dQ2 falls by a factor of about 50000 as Q2 increases from 280 to 30000 GeV2. The double differential cross section d2σ/dxdQ2 has also been measured. A comparison between the data and Standard Model (SM) predictions shows that contributions from antiquarks (ū and c̄) and quarks (d and s) are both required by the data. The predictions of the SM give a good description of the full body of the data presented here. A comparison of the charged-current cross-section dσ/dQ2 with the recent ZEUS results for neutral-current scattering shows that the weak and electromagnetic forces have similar strengths for Q2 above M2W, M2Z. A fit to the data for dσ/dQ2 with the Fermi constant GF and MW as free parameters yields GF = (1.171±0.034 (stat.)+0.026-0.032 (syst.)+0.016-0.015 (PDF)) × 10-5 Gev-2 and MW = 80.8+4.9-4.5 (stat.)+5.0-4.3(syst.)+1.4-1.3 (PDF) GeV. Results For MW, where the propagator effect alone or the SM constraint between GF and MW have been considered, are also presented.
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