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Correlated inclusive ΛΛ̄ production in e +e- annihilations at √s∼10.5 GeV

Physical Review D 66:5 (2002)

Authors:

Z Metreveli, KK Seth, A Tomaradze, P Zweber, S Ahmed, MS Alam, L Jian, M Saleem, F Wappler, E Eckhart, KK Gan, C Gwon, T Hart, K Honscheid, D Hufnagel, H Kagan, R Kass, TK Pedlar, JB Thayer, T Wilksen, MM Zoeller, H Muramatsu, SJ Richichi, H Severini, P Skubic, SA Dytman, JA Mueller, S Nani, V Savinov, S Chen, JW Hinson, J Lee, DH Miller, V Pavlunin, EI Shibata, IPJ Shipsey, D Cronin-Hennessy, AL Lyon, CS Park, W Park, EH Thorndike, TE Coan, YS Gao, F Liu, Y Maravin, I Narsky, R Stroynowski, M Artuso, C Boulahouache, K Bukin, E Dambasuren, K Khroustalev, GC Moneti, R Mountain, R Nandakumar, T Skwarnicki, S Stone, JC Wang, AH Mahmood, SE Csorna, I Danko, Z Xu, G Bonvicini, D Cinabro, M Dubrovin, S McGee, A Bornheim, E Lipeles, SP Pappas, A Shapiro, WM Sun, AJ Weinstein, G Masek, HP Paar, R Mahapatra, RA Briere, GP Chen, T Ferguson, G Tatishvili, H Vogel, NE Adam, JP Alexander, K Berkelman, F Blanc, V Boisvert, DG Cassel, PS Drell, JE Duboscq, KM Ecklund, R Ehrlich, RS Galik, L Gibbons, B Gittelman, SW Gray, DL Hartill, BK Heltsley, L Hsu, CD Jones, J Kandaswamy

Abstract:

Using a 13.7 fb-1 sample of continuum two-jet e +e- → qq̄ events collected with the CLEO detector, we have searched for correlations between Λ and Λ̄ particles, specifically in cases where the opening angle between the two particles is large and each has momentum > 1 GeV/c. Such correlations may indicate the presence of baryon number conservation at the primary quark level. A previous CLEO study of ΛcΛc correlations indicated direct, associated production of primary charmed baryons Λc: e+e- → cc̄ → ΛcΛ̄c. That effect was not observed in Monte Carlo simulations. Our current search for similar direct, associated production of Λ baryons at the primary quark level (e+e - → ss̄ → ΛΛ̄, e.g.) qualitatively indicates a similar effect, although it relies on a Monte Carlo dependent subtraction of background ΛΛ̄ production (based on the default JETSET 7.4 event generator). © 2002 The American Physical Society.
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Cross section and heavy quark composition of γ+μ events produced in pp̄ collisions

Physical Review D Particles Fields Gravitation and Cosmology 65:1 (2002) 120031-120037

Authors:

T Affolder, H Akimoto, A Akopian, MG Albrow, P Amaral, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, F Azfar, P Azzi-Bacchetta, N Bacchetta, MW Bailey, S Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, M Barone, G Bauer, F Bedeschi, S Belforte, WH Bell, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, B Bevensee, A Bhatti, M Binkley, D Bisello, M Bishai, 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, W Caskey, 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, YS Chung, CI Ciobanu, AG Clark, A Connolly, J Conway, M Cordelli, J Cranshaw, D Cronin-Hennessy, R Cropp, R Culbertson, D Dagenhart, S D'Auria, F DeJongh

Abstract:

We present a measurement of the cross section and the first measurement of the heavy flavor content of associated direct photon + muon events produced in hadronic collisions. These measurements come from a sample of 1.8 TeV pp̄ collisions recorded with the Collider Detector at Fermilab. Quantum chromodynamics (QCD) predicts that these events are primarily due to the Compton scattering process cg→cγ, with the final-state charm quark producing a muon. The cross section for events with a photon transverse momentum between 12 and 40 GeV/c is measured to be 46.8±6.3±7.5 pb, which is two standard deviations below the most recent theoretical calculation. A significant fraction of the events in the sample contain a final-state bottom quark. The ratio of charm to bottom production is measured to be 2.4±1.2, in good agreement with QCD models.
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Cross section for forward j/ψ production in pp collisions at √s=1.8 tev

Physical Review D Particles Fields Gravitation and Cosmology 66-9 (2002)

Authors:

D Acosta, T Affolder, H Akimoto, MG Albrow, D Ambrose, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, A Artikov, T Asakawa, W Ashmanskas, F Azfar, P Azzi-Bacchetta, N Bacchetta, H Bachacou, W Badgett, S Bailey, P De Barbaro, 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, J Bensinger, A Beretvas, J Berryhill, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, SR Blusk, A Bocci, A Bodek, G Bolla, A Bolshov, Y Bonushkin, D Bortoletto, J Boudreau, A Brandl, C Bromberg, E Brubaker, N Bruner, J Budagov, HS Budd, K Burkett, G Busetto, KL Byrum, S Cabrera, P Calafiura, M Campbell, W Carithers, J Carlson, D Carlsmith, W Caskey, A Castro, D Cauz, A Cerri, L Cerrito, 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, JY Chung, WH Chung, YS Chung, CI Ciobanu, AG Clark, M Coca, AP Colijn, A Connolly, M Convery, J Conway, M Cordelli, J Cranshaw, R Culbertson, D Dagenhart

Abstract:

The inclusive cross section for J/Ψ production times the branching ratio B(J/Ψ→μ + μ - ) has been measured in the forward pseudorapidity region: B×dσ[p - +p→J/Ψ(p T >10 GeV/c,2.1<|η|<2.6)+X]/dη = 192±9(stat) ±29(syst) pb. The results are based on 74.1±5.2 pb -1 of data collected by the CDF Collaboration at the Fermilab Tevatron Collider. The measurements extend earlier measurements of the D0 Collaboration to higher p T J/Ψ . In the kinematic range where the experiments partially overlap, these data are in good agreement with previous measurements.
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First observation of B̄0→ D*0π+π+π-π -decays

Physical Review D 65:1 (2002)

Authors:

KW Edwards, AJ Sadoff, R Ammar, A Bean, D Besson, X Zhao, S Anderson, VV Frolov, Y Kubota, SJ Lee, R Poling, A Smith, CJ Stepaniak, J Urheim, S Ahmed, MS Alam, SB Athar, L Jian, L Ling, M Saleem, S Timm, F Wappler, A Anastassov, E Eckhart, KK Gan, C Gwon, T Hart, K Honscheid, D Hufnagel, H Kagan, R Kass, TK Pedlar, JB Thayer, E Von Toerne, MM Zoeller, SJ Richichi, H Severini, P Skubic, A Undrus, V Savinov, S Chen, JW Hinson, J Lee, DH Miller, EI Shibata, IPJ Shipsey, V Pavlunin, D Cronin-Hennessy, AL Lyon, EH Thorndike, TE Coan, YS Gao, Y Maravin, I Narsky, R Stroynowski, J Ye, T Wlodek, M Artuso, K Benslama, C Boulahouache, K Bukin, E Dambasuren, G Majumder, R Mountain, T Skwarnicki, S Stone, JC Wang, A Wolf, S Kopp, M Kostin, AH Mahmood, SE Csorna, I Danko, KW McLean, Z Xu, R Godang, G Bonvicini, D Cinabro, M Dubrovin, S McGee, A Bornheim, E Lipeles, SP Pappas, A Shapiro, WM Sun, AJ Weinstein, DE Jaffe, R Mahapatra, G Masek, HP Paar, A Eppich, RJ Morrison, RA Briere, GP Chen, T Ferguson, H Vogel, JP Alexander, C Bebek, BE Berger

Abstract:

We report on the observation of B̄0→D* 0π+π+π- π-decays. The branching ratio is (0.30±0.07 ±0.06)%. Interest in this particular mode was sparked by Ligeti, Luke and Wise who propose it as a way to check the validity of factorization tests in B̄0→D*+π+π -π-π0 decays. © 2001 The American Physical Society.
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Gemini-north multiobject spectrograph: Integral field unit

Proceedings of SPIE the International Society for Optical Engineering 4841:3 (2002) 1750-1759

Authors:

G Murray, J Allington-Smith, R Content, R Davies, G Dodsworth, B Miller, I Jorgensen, I Hook, D Crampton, R Murowinski

Abstract:

The Gemini-North Multiobject Spectrograph (CMOS) includes a powerful capability for integral field spectroscopy - the first to be installed and used on an 8-10m telescope. CMOS is switched to this mode by the remote insertion of an integral field unit (IFU) into the focal plane in place of the masks used for multiobject spectroscopy. With 1500 lenslet-coupled fibres, it provides a total field of view exceeding 50 square arcseconds, including a separate field dedicated to background subtraction. We describe the design, construction and testing of the IFU and present performance results obtained during commissioning.
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