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First determination of the CP content of D -> pi(+)pi(-)pi(0) and D -> K+K-pi(0)

Physics Letters B Elsevier 740 (2015) 1-7

Authors:

M Nayak, J Libby, Sneha Malde, C Thomas, Guy Wilkinson, Et al.

Abstract:

Quantum-correlated ψ(3770)→DD decays collected by the CLEO-c experiment are used to perform first measurements of F+, the fractional CP-even content of the self-conjugate decays D→π+π-π0 and D→K+K-π0. Values of 0.968±0.017±0.006 and 0.731±0.058±0.021 are obtained for π+π-π0 and K+K-π0, respectively. It is demonstrated how modes of this sort can be cleanly included in measurements of the unitarity triangle angle γ using B∓→DK∓ decays. The high CP-even content of D→π+π-π0, in particular, makes this a promising mode for improving the precision on γ.
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Development of scalable electronics for the TORCH time-of-flight detector

Journal of Instrumentation IOP Publishing 10:2 (2015) C02028

Authors:

Rui Gao, N Brook, LC Garcia, EN Cowie, D Cussans, R Forty, C Frei, T Gys, Neville Harnew, D Piedigrossi, M Van Dijk

Abstract:

The TORCH detector is proposed for the low-momentum particle identification upgrade of the LHCb experiment. It combines Time-Of-Flight and Cherenkov techniques to achieve charged particle separation up to 10 GeV/c. This requires a time resolution of 70 ps for single photons. Existing electronics has already demonstrated a 26 ps intrinsic time resolution; however the channel count and density need improvements for future micro-channel plate devices. This paper will report on a scalable design using custom ASICs (NINO-32 and HPTDC). The system provides up to 8 × 64 channels for a single micro-channel plate device. It is also designed to read out micro-channel plate tubes with charge-sharing technique.
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Erratum: Updated measurements of absolute D+ and D0 hadronic branching fractions and σ(e+e-→DD¯) at Ecm=3774 MeV [Phys. Rev. D 89, 072002 (2014)]

Physical Review D American Physical Society (APS) 91:1 (2015) 019903

Authors:

G Bonvicini, D Cinabro, MJ Smith, P Zhou, P Naik, J Rademacker, KW Edwards, RA Briere, H Vogel, JL Rosner, JP Alexander, DG Cassel, R Ehrlich, L Gibbons, SW Gray, DL Hartill, BK Heltsley, DL Kreinick, VE Kuznetsov, JR Patterson, D Peterson, D Riley, A Ryd, AJ Sadoff, X Shi, WM Sun, S Das, J Yelton, P Rubin, N Lowrey, S Mehrabyan, M Selen, J Wiss, J Libby, M Kornicer, RE Mitchell, D Besson, TK Pedlar, D Cronin-Hennessy, J Hietala, S Dobbs, Z Metreveli, KK Seth, A Tomaradze, T Xiao, A Powell, C Thomas, G Wilkinson, DM Asner, G Tatishvili, JY Ge, DH Miller, IPJ Shipsey, B Xin, GS Adams, J Napolitano, KM Ecklund, J Insler, H Muramatsu, LJ Pearson, EH Thorndike, M Artuso, S Blusk, R Mountain, T Skwarnicki, S Stone, JC Wang, LM Zhang, PUE Onyisi
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Measurement of the CP-violating phase βin B0→J/Ψπ+π-decays and limits on penguin effects

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 742:1 (2015) 38-49

Authors:

R Aaij, B Adeva, M Adinolfi, A Affolder, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, S Ali, G Alkhazov, P AlvarezCartelle, AA Alves, S Amato, S Amerio, Y Amhis, L An, L Anderlini, J Anderson, R Andreassen, M Andreotti, JE Andrews, RB Appleby, O AquinesGutierrez, F Archilli, A Artamonov, M Artuso, E Aslanides, G Auriemma, M Baalouch, S Bachmann, JJ Back, A Badalov, C Baesso, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, V Batozskaya, V Battista, A Bay, L Beaucourt, J Beddow, F Bedeschi, I Bediaga, S Belogurov, K Belous, I Belyaev, E Ben-Haim, G Bencivenni, S Benson, J Benton, A Berezhnoy, R Bernet, AB Bertolin, MO Bettler, M vanBeuzekom, A Bien, S Bifani, T Bird, A Bizzeti, PM Bjørnstad, T Blake, F Blanc, J Blouw, S Blusk, V Bocci, A Bondar, N Bondar, W Bonivento, S Borghi, A Borgia, M Borsato, TJV Bowcock, E Bowen, C Bozzi, D Brett, M Britsch, T Britton, J Brodzicka, NH Brook, A Bursche, J Buytaert, S Cadeddu, R Calabrese, M Calvi, M CalvoGomez, P Campana, D CamporaPerez, A Carbone, G Carboni, R Cardinale, A Cardini, L Carson, K CarvalhoAkiba, RCM CasanovaMohr, G Casse, L Cassina, L CastilloGarcia

Abstract:

Time-dependent CPviolation is measured in the B0→J/Ψπ+π-channel for each π+π-resonant final state using data collected with an integrated luminosity of 3.0fb-1in ppcollisions using the LHCb detector. The final state with the largest rate, J/Ψρ0(770), is used to measure the CP-violating angle 2βeffto be (41.7 ±9.6+2.8-6.3)°. This result can be used to limit the size of penguin amplitude contributions to CPviolation measurements in, for example, B0s→J/Ψϕdecays. Assuming approximate SU(3) flavour symmetry and neglecting higher order diagrams, the shift in the CP-violating phase ϕsis limited to be within the interval [-1.05°, +1.18°] at 95% confidence level. Changes to the limit due to SU(3) symmetry breaking effects are also discussed.
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Measurement of the Z+b-jet cross-section in pp collisions at(Formula presented.)= 7 TeV in the forward region

Journal of High Energy Physics 2015:1 (2015) 1-15

Authors:

L Zhong, R Aaij, B Adeva, M Adinolfi, A Affolder, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, S Ali, G Alkhazov, P Alvarez Cartelle, AA Alves, S Amato, S Amerio, Y Amhis, L An, L Anderlini, J Anderson, R Andreassen, M Andreotti, JE Andrews, RB Appleby, O Aquines Gutierrez, F Archilli, A Artamonov, M Artuso, E Aslanides, G Auriemma, M Baalouch, S Bachmann, JJ Back, S Eidelman, C Baesso, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, V Batozskaya, V Battista, A Bay, L Beaucourt, J Beddow, F Bedeschi, I Bediaga, S Belogurov, K Belous, I Belyaev, E Ben-Haim, G Bencivenni, S Benson, J Benton, A Berezhnoy, R Bernet, AB Bertolin, MO Bettler, M van Beuzekom, A Bien, S Bifani, T Bird, A Bizzeti, PM Bjørnstad, T Blake, F Blanc, J Blouw, S Blusk, V Bocci, A Bondar, N Bondar, W Bonivento, S Borghi, A Borgia, M Borsato, TJV Bowcock, E Bowen, C Bozzi, D Brett, M Britsch, T Britton, J Brodzicka, NH Brook, A Bursche, J Buytaert, S Cadeddu, R Calabrese, M Calvi, M Calvo Gomez, P Campana, D Campora Perez, L Capriotti, A Carbone, G Carboni, R Cardinale, A Cardini, L Carson, K Carvalho Akiba, RCM Casanova Mohr, G Casse

Abstract:

Abstract: The associated production of a Z boson or an off-shell photon γ* with a bottom quark in the forward region is studied using proton-proton collisions at a centre-of-mass energy of 7 TeV. The Z bosons are reconstructed in the Z/γ* → μ+μ− final state from muons with a transverse momentum larger than 20 GeV, while two transverse momentum thresholds are considered for jets (10 GeV and 20 GeV). Both muons and jets are reconstructed in the pseudorapidity range 2.0 < η < 4.5. The results are based on data corresponding to 1.0 fb−1 recorded in 2011 with the LHCb detector. The measurement of the Z+b-jet cross-section is normalized to the Z+jet cross-section. The measured cross-sections are(Formula presented.)for pT(jet) > 10 GeV, and(Formula presented.)for pT(jet) > 20 GeV.[Figure not available: see fulltext.].
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