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Determination of ǀVcb☐from the semileptonic decay B0 → D*-ℓ+ν

European Physical Journal C 71:1 (2011) 539-553

Authors:

P Abreu, W Adam, T Adye, E Agasi, I Ajinenko, R Aleksan, GD Alekseev, R Alemany, PP Allport, S Almehed, U Amaldi, S Amato, A Andreazza, ML Andrieux, P Antilogus, WD Apel, Y Arnoud, B Åsman, JE Augustin, A Augustinus, P Baillon, P Bambade, F Barao, R Barate, M Barbi, G Barbiellini, DY Bardin, A Baroncelli, O Barring, JA Barrio, W Bartl, MJ Bates, M Battaglia, M Baubillier, J Baudot, KH Becks, M Begalli, P Beilliere, Y Belokopytov, AC Benvenuti, M Berggren, D Bertrand, F Bianchi, M Bigi, MS Bilenky, P Billoir, D Bloch, M Blume, S Blyth, T Bolognese, M Bonesini, W Bonivento, PSL Booth, G Borisov, C Bosio, S Bosworth, O Botner, E Boudinov, B Bouquet, C Bourdarios, TJV Bowcock, M Bozzo, P Branchini, KD Brand, T Brenke, RA Brenner, C Bricman, L Brillault, RCA Brown, P Bruckman, JM Brunet, L Bugge, T Buran, T Burgsmueller, P Buschmann, A Buys, S Cabrera, M Caccia, M Calvi, AJC Rozas, T Camporesi, V Canale, M Canepa, K Cankocak, F Cao, F Carena, L Carroll, C Caso, CMV Gimenez, A Cattai, FR Cavallo, L Cerrito, V Chabaud, M Chapkin, P Charpentier, L Chaussard, J Chauveau, P Checchia, GA Chelkov, M Chen

Abstract:

Semileptonic decays B→ D*-ℓ+νX were selected from a sample of 3.1 million hadronic Z decays collected by the DELPHI detector at LEP. A topological search for semileptonic B decays to resonant and non-resonant D*-π+ states was performed and the ratio of the branching fractions: Br(B → D*-ℓ+νX)/Br(B → D*-+νX) + Br(B0 → + D*-ℓ+ν) = 0.19 ± 0.10(stat) ± 0.06(syst) was determined. Taking into account this contribution, the differential decay width of B0 → D*-ℓ+ν was measured as a function of the momentum transfer from the B to the D*- in two separate analyses, using exclusive and inclusive methods of D*- reconstruction. The distributions were fitted over the full momentum transfer range to extract the product of {pipe}Vcb{pipe} times the normalization of the decay form factor F(q2max): F(q2max){pipe}Vcb{pipe} = (35.4 ± 1.9(stat) ± 2.4(syst)) · 10-3. The value of {pipe}Vcb{pipe} was computed using theoretical calculations of F(q2max), giving: {pipe}Vcb{pipe} = (38.9 ± 2.0(stat) ± 2.6(syst) ± 1.7(theory)) · 10-3. The total branching fraction Br(B0 → D*-ℓ+ν) was determined to be: Br(130, D*-ℓ+v) = (5.52 ± 0.17(stat) ± 0.68(syst))%. © Springer-Verlag 1996.

First observation of Bs0→J/Ψf0(980) decays

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 698:2 (2011) 115-122

Authors:

R Aaij, B Adeva, M Adinolfi, C Adrover, A Affolder, Z Ajaltouni, J Albrecht, F Alessio, M Alexander, P Alvarez Cartelle, AA Alves, S Amato, Y Amhis, J Amoraal, J Anderson, RB Appleby, O Aquines Gutierrez, L Arrabito, M Artuso, E Aslanides, G Auriemma, S Bachmann, DS Bailey, V Balagura, W Baldini, RJ Barlow, C Barschel, S Barsuk, A Bates, C Bauer, T Bauer, A Bay, I Bediaga, K Belous, I Belyaev, E Ben-Haim, M Benayoun, G Bencivenni, R Bernet, MO Bettler, M van Beuzekom, S Bifani, A Bizzeti, PM Bjørnstad, T Blake, F Blanc, C Blanks, J Blouw, S Blusk, A Bobrov, V Bocci, A Bondar, N Bondar, W Bonivento, S Borghi, A Borgia, E Bos, TJV Bowcock, C Bozzi, T Brambach, J van den Brand, J Bressieux, S Brisbane, M Britsch, T Britton, NH Brook, H Brown, A Büchler-Germann, A Bursche, J Buytaert, S Cadeddu, JM Caicedo Carvajal, O Callot, M Calvi, M Calvo Gomez, A Camboni, L Camilleri, P Campana, G Capon, A Carbone, G Carboni, R Cardinale, A Cardini, L Carson, K Carvalho Akiba, G Casse, M Cattaneo, M Charles, P Charpentier, N Chiapolini, X Cid Vidal, PJ Clark, PEL Clarke, M Clemencic, HV Cliff, J Closier, C Coca, V Coco, J Cogan, P Collins

Abstract:

Using data collected with the LHCb detector in proton-proton collisions at a centre-of-mass energy of 7 TeV, the hadronic decay Bs0→J/Ψf0(980) is observed. This CP eigenstate mode could be used to measure mixing-induced CP violation in the Bs0 system. Using a fit to the Π+Π- mass spectrum with interfering resonances gives Rf0/Φ≡Γ(Bs0→J/Ψf0,f0→Π+Π -)Γ(Bs0→J/Ψφ,φ →K+K-)=0.252-0.032-0.033+ 0.046+0.027. In the interval ±90 MeV around 980 MeV, corresponding to approximately two full f0 widths we also find R' ≡ Γ(Bs0→J/Ψf0,f0→Π+Π-)-980 Mev < 90 Mev)/Γ(Bs0→J/Ψφ,φ→K +K-)=0.162±0.022±0.016, where in both cases the uncertainties are statistical and systematic, respectively. © 2011 CERN.
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First observation of B0s→D*s2+Xμν̄- decays

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 698:1 (2011) 14-20

Authors:

R Aaij, B Adeva, M Adinolfi, C Adrover, A Affolder, M Agari, Z Ajaltouni, J Albrecht, F Alessio, M Alexander, P Alvarez Cartelle, AA Alves, S Amato, Y Amhis, J Amoraal, J Anderson, R Antunes Nobrega, RB Appleby, O Aquines Gutierrez, A Arefyev, L Arrabito, M Artuso, E Aslanides, G Auriemma, S Bachmann, DS Bailey, V Balagura, W Baldini, RJ Barlow, C Barschel, S Barsuk, S Basiladze, A Bates, C Bauer, T Bauer, A Bay, I Bediaga, K Belous, I Belyaev, M Benayoun, G Bencivenni, R Bernet, M Bettler, M van Beuzekom, S Bifani, A Bizzeti, PM Bjørnstad, T Blake, F Blanc, C Blanks, J Blouw, S Blusk, A Bobrov, V Bocci, B Bochin, A Bondar, N Bondar, W Bonivento, S Borghi, A Borgia, E Bos, T Bowcock, C Bozzi, T Brambach, J van den Brand, J Bressieux, S Brisbane, M Britsch, T Britton, NH Brook, H Brown, A Büchler-Germann, A Bursche, J Buytaert, S Cadeddu, JM Caicedo Carvajal, O Callot, M Calvi, M Calvo Gomez, A Camboni, W Cameron, L Camilleri, P Campana, A Carbone, G Carboni, R Cardinale, A Cardini, L Carson, K Carvalho Akiba, G Casse, M Cattaneo, M Charles, P Charpentier, J Cheng, N Chiapolini, A Chlopik, J Christiansen, P Ciambrone, X Cid Vidal, PJ Clark

Abstract:

Using data collected with the LHCb detector in proton-proton collisions at a centre-of-mass energy of 7 TeV, the semileptonic decays B0s→D+s+Xμν̄ and B0s→D0K+Xμν̄ are detected. Two structures are observed in the D0K+ mass spectrum at masses consistent with the known Ds1(2536)+ and Ds2*(2573)+ mesons. The measured branching fractions relative to the total B-s0 semileptonic rate are B(B0s→Ds2*+Xμν̄)/B(B0s→Xμν̄)=(3.3±1.0±0.4)%, and B(B0s→D+s1Xμν̄)/B(B0s→Xμν̄)=(5.4±1.2±0.5)%, where the first uncertainty is statistical and the second is systematic. This is the first observation of the D*+s2 state in B0s decays; we also measure its mass and width. © 2011 CERN.
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LHCb detector and performance

Proceedings of Science (2011)

Abstract:

The LHCb experiment at the CERN Large Hadron Collider (LHC) will measure the CKM parameters of the Unitarity Triangle with high precision, and is designed to discover physics beyond the Standard Model in rare heavy-flavour decays. The experiment is configured in the forward direction and covers a unique rapidity range at the LHC, 1.9 < & < 4.9. This paper describes the detector components of LHCb and the operating performances, focusing on the vertex locator, particle identification, calorimetry and muon system. In 2010, LHCb recorded a total of 37.7 pb-1 of data at √s = 7 TeV with a data-taking efficiency ofbetterthan90%. A selection of LHCb physics results will be shown, and the prospects for data taking in 2011 will be discussed. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-Non Commercial-Share Alike Licence.
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Measurement of V0 production ratios in pp collisions at s√ = 0.9 and 7TeV

Journal of High Energy Physics 2011:8 (2011)

Authors:

R Aaij, B Adeva, M Adinolfi, C Adrover, A Affolder, Z Ajaltouni, J Albrecht, F Alessio, M Alexander, G Alkhazov, PA Cartelle, AA Alves, S Amato, Y Amhis, J Anderson, RB Appleby, OA Gutierrez, L Arrabito, A Artamonov, M Artuso, E Aslanides, G Auriemma, S Bachmann, JJ Back, DS Bailey, V Balagura, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, A Bates, C Bauer, T Bauer, A Bay, I Bediaga, K Belous, I Belyaev, E Ben-Haim, M Benayoun, G Bencivenni, S Benson, R Bernet, MO Bettler, M Van Beuzekom, A Bien, S Bifani, A Bizzeti, PM Bjørnstad, T Blake, F Blanc, C Blanks, J Blouw, S Blusk, A Bobrov, V Bocci, A Bondar, N Bondar, W Bonivento, S Borghi, A Borgia, TJV Bowcock, C Bozzi, T Brambach, J Van Den Brand, J Bressieux, D Brett, S Brisbane, M Britsch, T Britton, NH Brook, A Büchler-Germann, I Burducea, A Bursche, J Buytaert, S Cadeddu, JMC Carvajal, O Callot, M Calvi, MC Gomez, A Camboni, P Campana, A Carbone, G Carboni, R Cardinale, A Cardini, L Carson, KC Akiba, G Casse, M Cattaneo, M Charles, P Charpentier, N Chiapolini, XC Vidal, G Ciezarek, PEL Clarke, M Clemencic, HV Cliff, J Closier, C Coca

Abstract:

The Ā/A and Ā/K0S production ratios are measured by the LHCb detector from 0.3 nb-1 of pp collisions delivered by the LHC at s√ = 0.9TeV and 1.8 nb-1 at s√ = 7TeV. Both ratios are presented as a function of transverse momentum, pT, and rapidity, y, in the ranges 0.15 < pT < 2.50GeV/c and 2.0 < y < 4.5. Results at the two energies are in good agreement as a function of rapidity loss, Δy = ybeam - y, and are consistent with previous measurements. The ratio Ā/A, measuring the transport of baryon number from the collision into the detector, is smaller in data than predicted in simulation, particularly at high rapidity. The ratio Ā/K0S , measuring the baryon-to-meson suppression in strange quark hadronisation, is significantly larger than expected.
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