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Study of B±→J/ψπ± and B±→J/ψK± decays: Measurement of the ratio of branching fractions and search for direct CP-violating charge asymmetries

Physical Review D - Particles, Fields, Gravitation and Cosmology 65:9 (2002) 911011-911017

Authors:

B Aubert, D Boutigny, JM Gaillard, A Hicheur, Y Karyotakis, JP Lees, P Robbe, V Tisserand, A Palano, A Pompili, GP Chen, JC Chen, ND Qi, G Rong, P Wang, YS Zhu, G Eigen, B Stugu, GS Abrams, AW Borgland, AB Breon, DN Brown, J Button-Shafer, RN Cahn, AR Clark, MS Gill, AV Gritsan, Y Groysman, RG Jacobsen, RW Kadel, J Kadyk, LT Kerth, YG Kolomensky, JF Kral, C LeClerc, ME Levi, G Lynch, PJ Oddone, M Pripstein, NA Roe, A Romosan, MT Ronan, VG Shelkov, AV Telnov, WA Wenzel, TJ Harrison, CM Hawkes, DJ Knowles, SW O'Neale, RC Penny, AT Watson, NK Watson, T Deppermann, K Goetzen, H Koch, M Kunze, B Lewandowski, K Peters, H Schmuecker, M Steinke, NR Barlow, W Bhimji, N Chevalier, PJ Clark, WN Cottingham, B Foster, C Mackay, FF Wilson, K Abe, C Hearty, TS Mattison, JA McKenna, D Thiessen, S Jolly, AK McKemey, VE Blinov, AD Bukin, DA Bukin, AR Buzykaev, VB Golubev, VN Ivanchenko, AA Korol, EA Kravchenko, AP Onuchin, SI Serednyakov, YI Skovpen, VI Telnov, AN Yushkov, D Best, M Chao, D Kirkby, AJ Lankford, M Mandelkern, S McMahon, DP Stoker, K Arisaka, C Buchanan, S Chun, DB MacFarlane, S Prell

Abstract:

We have studied the B±→J/ψπ± and B±→J/ψK± decays using a 20.7 fb-1 data set collected with the BABAR detector. We observe a signal of 51±10 B±→J/ψπ± events and determine the ratio B(B± →J/ψπ±)/B(B±→J/ψ K±) to be [3.91±0.78(stat)±0.19(syst)]%. The CP-violating charge asymmetries for the B±→J/ψπ± and B±→J/ψK± decays are determined to be Aπ=0.01±0.22(stat)±0.01(syst) and AK =0.003±0.030(stat)±0.004(syst).
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Measurement of the photon-proton total cross section at a center-of-mass energy of 209 GeV at HERA

Nuclear Physics B 627:1-2 (2002) 3-28

Authors:

S Chekanov, M Derrick, D Krakauer, S Magill, B Musgrave, A Pellegrino, J Repond, R Yoshida, MCK Mattingly, P Antonioli, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, GC Romeo, L Cifarelli, F Cindolo, A Contin, M Corradi, S de Pasquale, P Giusti, G Iacobucci, G Levi, A Margotti, T Massam, R Nania, F Palmonari, A Pesci, G Sartorelli, A Zichichi, G Aghuzumtsyan, D Bartsch, I Brock, J Crittenden, S Goers, H Hartmann, E Hilger, P Irrgang, HP Jakob, A Kappes, UF Katz, R Kerger, O Kind, E Paul, J Rautenberg, R Renner, H Schnurbusch, A Stifutkin, J Tandler, KC Voss, A Weber, H Wessoleck, DS Bailey, NH Brook, JE Cole, B Foster, GP Heath, HF Heath, S Robins, E Rodrigues, J Scott, RJ Tapper, M Wing, M Capua, A Mastroberardino, M Schioppa, G Susinno, HY Jeoung, JY Kim, JH Lee, IT Lim, KJ Ma, MY Pac, A Caldwell, M Helbich, X Liu, B Mellado, S Paganis, WB Schmidke, F Sciulli, J Chwastowski, A Eskreys, J Figiel, K Olkiewicz, MB Przybycień, P Stopa, L Zawiejski, B Bednarek, I Grabowska-Bold, K Jeleń, D Kisielewska, AM Kowal, M Kowal, T Kowalski, B Mindur, E Rulikowska-Zarebska, L Suszycki, D Szuba

Abstract:

The photon-proton total cross section has been measured in the process e+ p → e+ γp → e+ X with the ZEUS detector at HERA. Events were collected with photon virtuality Q2 < 0.02 GeV2 and average γp center-of-mass energy Wγp = 209 GeV in a dedicated run, designed to control systematic effects, with an integrated luminosity of 49 nb-1. The measured total cross section is σtot γp = 174 ± 1 (stat.) ± 13 (syst.) μb. The energy dependence of the cross section is compatible with parameterizations of high-energy pp and pap data. © 2002 Elsevier Science B.V. All rights reserved.
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High-mass dijet cross sections in photoproduction at HERA

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 531:1-2 (2002) 9-27

Authors:

S Chekanov, M Derrick, D Krakauer, S Magill, B Musgrave, A Pellegrino, J Repond, R Yoshida, MCK Mattingly, P Antonioli, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, G Cara Romeo, L Cifarelli, F Cindolo, A Contin, M Corradi, S De Pasquale, P Giusti, G Iacobucci, G Levi, A Margotti, T Massam, R Nania, F Palmonari, A Pesci, G Sartorelli, A Zichichi, G Aghuzumtsyan, D Bartsch, I Brock, J Crittenden, S Goers, H Hartmann, E Hilger, P Irrgang, HP Jakob, A Kappes, UF Katz, R Kerger, O Kind, E Paul, J Rautenberg, R Renner, H Schnurbusch, A Stifutkin, J Tandler, KC Voss, A Weber, H Wessoleck, DS Bailey, NH Brook, JE Cole, B Foster, GP Heath, HF Heath, S Robins, E Rodrigues, J Scott, RJ Tapper, M Wing, M Capua, A Mastroberardino, M Schioppa, G Susinno, HY Jeoung, JY Kim, JH Lee, IT Lim, KJ Ma, MY Pac, A Caldwell, M Helbich, X Liu, B Mellado, S Paganis, WB Schmidke, F Sciulli, J Chwastowski, A Eskreys, J Figiel, K Olkiewicz, MB Przybycien, P Stopa, L Zawiejski, B Bednarek, I Grabowska-Bold, K Jeleń, D Kisielewska, AM Kowal, M Kowal, T Kowalski, B Mindur, E Rulikowska-Zarebska, L Suszycki, D Szuba

Abstract:

Dijet differential cross sections for the reaction e+ p → e+ + jet + jet + X in the photoproduction regime have been measured with the ZEUS detector at HERA using an integrated luminosity of 42.7 pb-. The cross sections are given for photon-proton centre-of-mass energies in the range 134 < W < 277 GeV. The differential cross sections as a function of the dijet mass, MJJ, and of the dijet angular variables have been measured for 47 < MJJ < 160 GeV and compared to next-to-leading-order QCD calculations. The dijet events in the region 75 < MJJ < 100 GeV have been used to derive a 95% C.L. upper limit on the cross section for Z0 photoproduction of σ e+p→e+Z0X < 5.9 pb. Upper limits on the photoproduction of new heavy resonances decaying into two jets are also presented for masses in the range between 60 GeV and 155 GeV. © 2002 Elsevier Science B.V. All rights reserved.
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Dijet photoproduction at HERA and the structure of the photon

European Physical Journal C 23:4 (2002) 615-631

Authors:

S Chekanov, M Derrick, D Krakauer, S Magill, B Musgrave, A Pellegrino, J Repond, R Yoshida, MCK Mattingly, P Antonioli, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, G Cara Romeo, L Cifarelli, F Cindolo, A Contin, M Corradi, S de Pasquale, P Giusti, G Iacobucci, G Levi, A Margotti, T Massam, R Nania, F Palmonari, A Pesci, G Sartorelli, A Zichichi, G Aghuzumtsyan, D Bartsch, I Brock, J Crittenden, S Goers, H Hartmann, E Hilger, P Irrgang, HP Jakob, A Kappes, UF Katz, R Kerger, O Kind, E Paul, J Rautenberg, R Renner, H Schnurbusch, A Stifutkin, J Tandler, KC Voss, A Weber, H Wessoleck, DS Bailey, NH Brook, JE Cole, B Foster, GP Heath, HF Heath, S Robins, E Rodrigues, J Scott, RJ Tapper, M Wing, M Capua, A Mastroberardino, M Schioppa, G Susinno, HY Jeoung, JY Kim, JH Lee, IT Lim, KJ Ma, MY Pac, A Caldwell, M Helbich, X Liu, B Mellado, S Paganis, WB Schmidke, F Sciulli, J Chwastowski, A Eskreys, J Figiel, K Olkiewicz, MB Przybycień, P Stopa, L Zawiejski, B Bednarek, I Grabowska-Bold, K Jeleń, D Kisielewska, AM Kowal, M Kowal, T Kowalski, B Mindur, E Rulikowska-Zarȩbska, L Suszycki, D Szuba

Abstract:

The dijet cross section in photoproduction has been measured with the ZEUS detector at HERA using an integrated luminosity of 38.6 pb-1. The events were required to have a virtuality of the incoming photon, Q2, of less than 1 GeV2 and a photon-proton centre-of-mass energy in the range 134 < Wγp < 277 GeV. Each event contains at least two jets satisfying transverse-energy requirements of ETjet1 > 14 GeV and ETjet2 > 11 GeV and pseudorapidity requirements of -1 < ηjet1,2 < 2.4. The measurements are compared to next-to-leading-order QCD predictions. The data show particular sensitivity to the density of partons in the photon, allowing the validity of the current parameterisations to be tested.
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Measurement of B → K*γ branching fractions and charge asymmetries

Physical Review Letters 88:10 (2002) 1018051-1018057

Authors:

B Aubert, D Boutigny, JM Gaillard, A Hicheur, Y Karyotakis, JP Lees, P Robbe, V Tisserand, A Palano, GP Chen, JC Chen, ND Qi, G Rong, P Wang, YS Zhu, G Eigen, PL Reinertsen, B Stugu, B Abbott, GS Abrams, AW Borgland, AB Breon, DN Brown, J Button-Shafer, RN Cahn, AR Clark, MS Gill, AV Gritsan, Y Groysman, RG Jacobsen, RW Kadel, J Kadyk, LT Kerth, S Kluth, YG Kolomensky, JF Kral, C LeClerc, ME Levi, T Liu, G Lynch, AB Meyer, M Momayezi, PJ Oddone, A Perazzo, M Pripstein, NA Roe, A Romosan, MT Ronan, VG Shelkov, AV Telnov, WA Wenzel, MS Zisman, PG Bright-Thomas, TJ Harrison, CM Hawkes, DJ Knowles, SW O'Neale, RC Penny, AT Watson, NK Watson, T Deppermann, K Goetzen, H Koch, J Krug, M Kunze, B Lewandowski, K Peters, H Schmuecker, M Steinke, JC Andress, NR Barlow, W Bhimji, N Chevalier, PJ Clark, WN Cottingham, N de Groot, N Dyce, B Foster, JD McFall, D Wallom, FF Wilson, K Abe, C Hearty, TS Mattison, JA McKenna, D Thiessen, S Jolly, AK McKemey, J Tinslay, VE Blinov, AD Bukin, DA Bukin, AR Buzykaev, VB Golubev, VN Ivanchenko, AA Korol, EA Kravchenko, AP Onuchin, AA Salnikov, SI Serednyakov

Abstract:

The branching fraction of the exclusive decays B0 → K*0γ and B+ → K*+γ measured from a sample of BB̄ decays collected with the BABAR detector at the PEP-II asymetric e+e- collider was discussed. It was found that the weighted average of the measured CP-violating charged asymmetries was Acp(B → K*γ) = -0.044 + 0.076 (stat) ± 0.012 (syst). The results showed the CP-violating charge asymmetry to be constrained to -0.170 < Acp(B → K*γ) < 0.082 at 90% C.L.