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Measurement of the forward W boson cross-section in pp collisions at √s = 7 TeV

Journal of High Energy Physics 2014:12 (2014)

Authors:

A Zvyagin, 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, A Badalov, 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, 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, T Brambach, J van den Brand, J Bressieux, D Brett, M Britsch, T Britton, J Brodzicka, NH Brook, H Brown, A Bursche, G Busetto, J Buytaert, S Cadeddu, R Calabrese, M Calvi, M Calvo Gomez, P Campana, D Campora Perez, A Carbone, G Carboni, R Cardinale, A Cardini, L Carson, K Carvalho Akiba

Abstract:

Abstract: A measurement of the inclusive W → μν production cross-section using data from pp collisions at a centre-of-mass energy of √s = 7TeV is presented. The analysis is based on an integrated luminosity of about 1.0 fb-1 recorded with the LHCb detector. Results are reported for muons with a transverse momentum greater than 20 GeV/c and pseudorapidity between 2.0 and 4.5. The W+ and W- production cross-sections are measured to be (formula presented.). where the first uncertainty is statistical, the second is systematic and the third is due to the luminosity determination. Cross-section ratios and differential distributions as functions of the muon pseudorapidity are also presented. The ratio of W+ to W- cross-sections in the same fiducial kinematic region is determined to be (formula presented.). where the uncertainties are statistical and systematic, respectively. Results are in good agreement with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics.
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Measurement of the xb(3p) mass and of the relative rate of xb1(1p) and xb2(1p) production

Journal of High Energy Physics 2014:10 (2014)

Authors:

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, AA Alves, S Amato, S Amerio, Y Amhis, L An, L Anderlini, L Anderlini, J Anderson, R Andreassen, M Andreotti, M Andreotti, JE Andrews, RB Appleby, O Aquines Gutierrez, F Archilli, A Artamonov, M Artuso, E Aslanides, G Auriemma, 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, MO Bettler, M van Beuzekom, A Bien, S Bifani, T Bird, A Bizzeti, A Bizzeti, PM Bjørnstad, T Blake, F Blanc, J Blouw, S Blusk, V Bocci, A Bondar, N Bondar, N Bondar, W Bonivento, W Bonivento, S Borghi, A Borgia, M Borsato, TJV Bowcock, E Bowen, C Bozzi, T Brambach, J van den Brand, J Bressieux, D Brett, M Britsch, T Britton, J Brodzicka, NH Brook, H Brown, A Bursche, G Busetto, G Busetto, J Buytaert, S Cadeddu, R Calabrese, R Calabrese, M Calvi

Abstract:

© CERN 2014. All rights reserved. The production of Xb mesons in proton-proton collisions is studied using a data sample collected by the LHCb detector, at centre-of-mass energies of √s = 7 and 8TeV and corresponding to an integrated luminosity of 3.0 fb−1. The Xb mesons are identified through their decays to γ(1S) and γ(2S)γ using photons that converted to e+e− pairs in the detector. The relative prompt production rate of Xb1(1P) and Xb2(1P) mesons is measured as a function of the X(1S) transverse momentum in the Xb rapidity range 2.0 < y < 4.5. A precise measurement of the Xb(3P) mass is also performed. Assuming a mass splitting between the Xb1(3P) and the Xb2(3P) states of 10.5 MeV/c2, the measured mass of the Xb1(3P) meson is m(Xb1(3P)) = 10515.7+2.2−3.9(stat)+1.5−2.1(syst)MeV/c2.
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Measurement of the xb(3p) mass and of the relative rate of xb1(1p) and xb2(1p) production

Journal of High Energy Physics 2014:10 (2014) 1-16

Authors:

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, 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, 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, T Brambach, J van den Brand, J Bressieux, D Brett, M Britsch, T Britton, J Brodzicka, NH Brook, H Brown, A Bursche, G Busetto, J Buytaert, S Cadeddu, R Calabrese

Abstract:

© CERN 2014. All rights reserved. The production of Xb mesons in proton-proton collisions is studied using a data sample collected by the LHCb detector, at centre-of-mass energies of √s = 7 and 8TeV and corresponding to an integrated luminosity of 3.0 fb−1. The Xb mesons are identified through their decays to γ(1S) and γ(2S)γ using photons that converted to e+e− pairs in the detector. The relative prompt production rate of Xb1(1P) and Xb2(1P) mesons is measured as a function of the X(1S) transverse momentum in the Xb rapidity range 2.0 < y < 4.5. A precise measurement of the Xb(3P) mass is also performed. Assuming a mass splitting between the Xb1(3P) and the Xb2(3P) states of 10.5 MeV/c2, the measured mass of the Xb1(3P) meson is m(Xb1(3P)) = 10515.7+2.2 −3.9(stat)+1.5 −2.1(syst)MeV/c2.
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Observation of the ᴧ0b→ J/ψpπ− decay

Journal of High Energy Physics 2014:7 (2014) 1-19

Authors:

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, A B Ă Beanu, S Bachmann, JJ Back, A Badalov, V Balagura, 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, 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, T Bowcock, E Bowen, C Bozzi, T Brambach, J Van Den Brand, J Bressieux, D Brett, M Britsch, T Britton, J Brodzicka, NH Brook, H Brown, A Bursche, G Busetto, J Buytaert, S Cadeddu, R Calabrese, M Calvi

Abstract:

© The Authors. The first observation of the Cabibbo-suppressed decay V0b→ J/ψpπ−is reported using a data sample of proton-proton collisions at 7 and 8TeV, corresponding to an integrated luminosity of 3 fb−1. A prominent signal is observed and the branching fraction relative to the decay mode V0b→ J/ψpK−is determined to be B[Equations Found] A search for direct CP violation is performed. The difference in the CP asymmetries between these two decays is found to be [Equations Found], which is compatible with CP symmetry at the 2.2σ level.
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Search for CP violation in D± → K0 SK± and D± s → K0 Sπ± decays

Journal of High Energy Physics 2014:10 (2014) 1-18

Authors:

R Aaij, 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, A Badalov, V Balagura, 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, 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, T Brambach, J van den Brand, J Bressieux, D Brett, M Britsch, T Britton, J Brodzicka, NH Brook, H Brown, A Bursche, G Busetto, J Buytaert, S Cadeddu, R Calabrese

Abstract:

© 2014, Springer Verlag. All rights reserved. A search for CP violation in Cabibbo-suppressed D± → K0 SK± and D± s → K0 Sπ± decays is performed using pp collision data, corresponding to an integrated luminosity of 3 fb-1, recorded by the LHCb experiment. The individual CP-violating asymmetries are measured to be (Formula presented.) assuming that CP violation in the Cabibbo-favoured decays is negligible. A combination of the measured asymmetries for the four decay modes D± (s) → K0 SK± and D± (s) → K0 Sπ± gives the sum (Formula presented.). In all cases, the first uncertainties are statistical and the second systematic. The results represent the most precise measurements of these asymmetries to date and show no evidence for CP violation.
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