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19 results on '"Bjørnstad, PM"'

1. Search for long-lived particles decaying to jet pairs

Author

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

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, hep-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

A search is presented for long-lived particles with a mass between 25 and 50 [Formula: see text] and a lifetime between 1 and 200[Formula: see text] in a sample of proton-proton collisions at a centre-of-mass energy of [Formula: see text] TeV, corresponding to an integrated luminosity of 0.62 [Formula: see text], collected by the LHCb detector. The particles are assumed to be pair-produced by the decay of a standard model-like Higgs boson. The experimental signature of the long-lived particle is a displaced vertex with two associated jets. No excess above the background is observed and limits are set on the production cross-section as a function of the long-lived particle mass and lifetime.

Published
2015

2. Measurement of the Bc+ meson lifetime using Bc+→J/ψμ+νμX decays

Author

The LHCb Collaboration, Aaij, R, Adeva, B, Adinolfi, M, Affolder, A, Ajaltouni, Z, Albrecht, J, Alessio, F, Alexander, M, Ali, S, Alkhazov, G, Cartelle, P Alvarez, Alves, AA, Amato, S, Amerio, S, Amhis, Y, Anderlini, L, Anderson, J, Andreassen, R, Andreotti, M, Andrews, JE, Appleby, RB, Gutierrez, O Aquines, Archilli, F, Artamonov, A, Artuso, M, Aslanides, E, Auriemma, G, Baalouch, M, Bachmann, S, Back, JJ, Badalov, A, Balagura, V, Baldini, W, Barlow, RJ, Barschel, C, Barsuk, S, Barter, W, Batozskaya, V, Bauer, Th, Bay, A, Beddow, J, Bedeschi, F, Bediaga, I, Belogurov, S, Belous, K, Belyaev, I, Ben-Haim, E, Bencivenni, G, Benson, S, Benton, J, Berezhnoy, A, Bernet, R, Bettler, M-O, van Beuzekom, M, Bien, A, Bifani, S, Bird, T, Bizzeti, A, Bjørnstad, PM, Blake, T, Blanc, F, Blouw, J, Blusk, S, Bocci, V, Bondar, A, Bondar, N, Bonivento, W, Borghi, S, Borgia, A, Borsato, M, Bowcock, TJV, Bowen, E, Bozzi, C, Brambach, T, van den Brand, J, Bressieux, J, Brett, D, Britsch, M, Britton, T, Brook, NH, Brown, H, Bursche, A, Busetto, G, Buytaert, J, Cadeddu, S, Calabrese, R, Callot, O, Calvi, M, Calvo Gomez, M, Camboni, A, Campana, P, Campora Perez, D, Carbone, A, Carboni, G, Cardinale, R, Cardini, A, Carranza-Mejia, H, Carson, L, and Carvalho Akiba, K

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, LHCb Collaboration, hep-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

The lifetime of the [Formula: see text] meson is measured using semileptonic decays having a [Formula: see text] meson and a muon in the final state. The data, corresponding to an integrated luminosity of [Formula: see text], are collected by the LHCb detector in [Formula: see text] collisions at a centre-of-mass energy of 8 TeV. The measured lifetime is [Formula: see text]where the first uncertainty is statistical and the second is systematic.

Published
2014

3. Measurement of charged particle multiplicities and densities in pp collisions at s=7TeV in the forward region

Author

The LHCb Collaboration, Aaij, R, Adeva, B, Adinolfi, M, Affolder, A, Ajaltouni, Z, Albrecht, J, Alessio, F, Alexander, M, Ali, S, Alkhazov, G, Alvarez Cartelle, P, Alves, AA, Amato, S, Amerio, S, Amhis, Y, Anderlini, L, Anderson, J, Andreassen, R, Andreotti, M, Andrews, JE, Appleby, RB, Aquines Gutierrez, O, Archilli, F, Artamonov, A, Artuso, M, Aslanides, E, Auriemma, G, Baalouch, M, Bachmann, S, Back, JJ, Badalov, A, Balagura, V, Baldini, W, Barlow, RJ, Barschel, C, Barsuk, S, Barter, W, Batozskaya, V, Bauer, Th, Bay, A, Beddow, J, Bedeschi, F, Bediaga, I, Belogurov, S, Belous, K, Belyaev, I, Ben-Haim, E, Bencivenni, G, Benson, S, Benton, J, Berezhnoy, A, Bernet, R, Bettler, M-O, van Beuzekom, M, Bien, A, Bifani, S, Bird, T, Bizzeti, A, Bjørnstad, PM, Blake, T, Blanc, F, Blouw, J, Blusk, S, Bocci, V, Bondar, A, Bondar, N, Bonivento, W, Borghi, S, Borgia, A, Borsato, M, Bowcock, TJV, Bowen, E, Bozzi, C, Brambach, T, vanden Brand, J, Bressieux, J, Brett, D, Britsch, M, Britton, T, Brook, NH, Brown, H, Bursche, A, Busetto, G, Buytaert, J, Cadeddu, S, Calabrese, R, Callot, O, Calvi, M, Calvo Gomez, M, Camboni, A, Campana, P, Campora Perez, D, Carbone, A, Carboni, G, Cardinale, R, Cardini, A, Carranza-Mejia, H, Carson, L, and Carvalho Akiba, K

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, LHCb Collaboration, hep-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

Charged particle multiplicities are studied in proton-proton collisions in the forward region at a centre-of-mass energy of [Formula: see text]TeV with data collected by the LHCb detector. The forward spectrometer allows access to a kinematic range of [Formula: see text] in pseudorapidity, momenta greater than [Formula: see text] and transverse momenta greater than [Formula: see text]. The measurements are performed using events with at least one charged particle in the kinematic acceptance. The results are presented as functions of pseudorapidity and transverse momentum and are compared to predictions from several Monte Carlo event generators.

Published
2014

4. Observation of B0s – B0s mixing and measurement of mixing frequencies using semileptonic B decays

Author

Aaij, R, Adeva, B, Adinolfi, M, Adrover, C, Affolder, A, Ajaltouni, Z, Albrecht, J, Alessio, F, Alexander, M, Ali, S, Alkhazov, G, Cartelle, PA, Alves, AA, Amato, S, Amerio, S, Amhis, Y, Anderlini, L, Anderson, J, Andreassen, R, Andrews, JE, Andrianala, F, Appleby, RB, Gutierrez, OA, Archilli, F, Artamonov, A, Artuso, M, Aslanides, E, Auriemma, G, Baalouch, M, Bachmann, S, Back, JJ, Baesso, C, Balagura, V, Baldini, W, Barlow, RJ, Barschel, C, Barsuk, S, Barter, W, Bauer, T, Bay, A, Beddow, J, Bedeschi, F, Bediaga, I, Belogurov, S, Belous, K, Belyaev, I, Ben-Haim, E, Bencivenni, G, Benson, S, Benton, J, Berezhnoy, A, Bernet, R, Bettler, MO, Van Beuzekom, M, Bien, A, Bifani, S, Bird, T, Bizzeti, A, Bjørnstad, PM, Blake, T, Blanc, F, Blouw, J, Blusk, S, Bocci, V, Bondar, A, Bondar, N, Bonivento, W, Borghi, S, Borgia, A, Bowcock, TJV, Bowen, E, Bozzi, C, Brambach, T, Van Den Brand, J, Bressieux, J, Brett, D, Britsch, M, Britton, T, Brook, NH, Brown, H, Burducea, I, Bursche, A, Busetto, G, Buytaert, J, Cadeddu, S, Callot, O, Calvi, M, Gomez, MC, Camboni, A, Campana, P, Perez, DC, Carbone, A, Carboni, G, Cardinale, R, Cardini, A, Carranza-Mejia, H, Carson, L, Akiba, KC, Casse, G, and Garcia, LC

Subjects
hep-ex, Nuclear & Particles Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

The B0s and B0 mixing frequencies, Δms and Δmd, are measured using a data sample corresponding to an integrated luminosity of 1.0 fb−1 collected by the LHCb experiment in pp collisions at a centre of mass energy of 7 TeV during 2011. Around 1.8 × 106 candidate events are selected of the type B0(s) → D−(s)μ+ (+ anything), where about half are from peaking and combinatorial backgrounds. To determine the B decay times, a correction is required for the momentum carried by missing particles, which is performed using a simulation-based statistical method. Associated production of muons or mesons allows us to tag the initialstate flavour and so to resolve oscillations due to mixing. We obtain Δms = (17.93 ± 0.22 (stat) ± 0.15 (syst)) ps−1, Δmd = (0.503 ± 0.011 (stat) ± 0.013(syst)) ps−1. The hypothesis of no oscillations is rejected by the equivalent of 5.8 standard deviations for B0s and 13.0 standard deviations for B0. This is the first observation of B0s mixing to be made using only semileptonic decays.

Published
2013

5. Observation of – mixing and measurement of mixing frequencies using semileptonic B decays

Author

The LHCb Collaboration, Aaij, R, Adeva, B, Adinolfi, M, Adrover, C, Affolder, A, Ajaltouni, Z, Albrecht, J, Alessio, F, Alexander, M, Ali, S, Alkhazov, G, Alvarez Cartelle, P, Alves, AA, Amato, S, Amerio, S, Amhis, Y, Anderlini, L, Anderson, J, Andreassen, R, Andrews, JE, Andrianala, F, Appleby, RB, Aquines Gutierrez, O, Archilli, F, Artamonov, A, Artuso, M, Aslanides, E, Auriemma, G, Baalouch, M, Bachmann, S, Back, JJ, Baesso, C, Balagura, V, Baldini, W, Barlow, RJ, Barschel, C, Barsuk, S, Barter, W, Bauer, Th, Bay, A, Beddow, J, Bedeschi, F, Bediaga, I, Belogurov, S, Belous, K, Belyaev, I, Ben-Haim, E, Bencivenni, G, Benson, S, Benton, J, Berezhnoy, A, Bernet, R, Bettler, M-O, van Beuzekom, M, Bien, A, Bifani, S, Bird, T, Bizzeti, A, Bjørnstad, PM, Blake, T, Blanc, F, Blouw, J, Blusk, S, Bocci, V, Bondar, A, Bondar, N, Bonivento, W, Borghi, S, Borgia, A, Bowcock, TJV, Bowen, E, Bozzi, C, Brambach, T, van den Brand, J, Bressieux, J, Brett, D, Britsch, M, Britton, T, Brook, NH, Brown, H, Burducea, I, Bursche, A, Busetto, G, Buytaert, J, Cadeddu, S, Callot, O, Calvi, M, Calvo Gomez, M, Camboni, A, Campana, P, Campora Perez, D, Carbone, A, Carboni, G, Cardinale, R, Cardini, A, Carranza-Mejia, H, Carson, L, Carvalho Akiba, K, and Casse, G

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, hep-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

The B0s and B0 mixing frequencies, Δms and Δmd, are measured using a data sample corresponding to an integrated luminosity of 1.0 fb−1 collected by the LHCb experiment in pp collisions at a centre of mass energy of 7 TeV during 2011. Around 1.8 × 106 candidate events are selected of the type B0(s) → D−(s)μ+ (+ anything), where about half are from peaking and combinatorial backgrounds. To determine the B decay times, a correction is required for the momentum carried by missing particles, which is performed using a simulation-based statistical method. Associated production of muons or mesons allows us to tag the initialstate flavour and so to resolve oscillations due to mixing. We obtain Δms = (17.93 ± 0.22 (stat) ± 0.15 (syst)) ps−1, Δmd = (0.503 ± 0.011 (stat) ± 0.013(syst)) ps−1. The hypothesis of no oscillations is rejected by the equivalent of 5.8 standard deviations for B0s and 13.0 standard deviations for B0. This is the first observation of B0s mixing to be made using only semileptonic decays.

Published
2013

6. Measurement of J/ψ polarization in pp collisions at

Author

The LHCb Collaboration, Aaij, R, Abellan Beteta, C, Adeva, B, Adinolfi, M, Adrover, C, Affolder, A, Ajaltouni, Z, Albrecht, J, Alessio, F, Alexander, M, Ali, S, Alkhazov, G, Alvarez Cartelle, P, Alves, AA, Amato, S, Amerio, S, Amhis, Y, Anderlini, L, Anderson, J, Andreassen, R, Appleby, RB, Aquines Gutierrez, O, Archilli, F, Artamonov, A, Artuso, M, Aslanides, E, Auriemma, G, Bachmann, S, Back, JJ, Baesso, C, Balagura, V, Baldini, W, Barlow, RJ, Barschel, C, Barsuk, S, Barter, W, Bauer, Th, Bay, A, Beddow, J, Bedeschi, F, Bediaga, I, Belogurov, S, Belous, K, Belyaev, I, Ben-Haim, E, Benayoun, M, Bencivenni, G, Benson, S, Benton, J, Berezhnoy, A, Bernet, R, Bettler, M-O, van Beuzekom, M, Bien, A, Bifani, S, Bird, T, Bizzeti, A, Bjørnstad, PM, Blake, T, Blanc, F, Blouw, J, Blusk, S, Bocci, V, Bondar, A, Bondar, N, Bonivento, W, Borghi, S, Borgia, A, Bowcock, TJV, Bowen, E, Bozzi, C, Brambach, T, van den Brand, J, Bressieux, J, Brett, D, Britsch, M, Britton, T, Brook, NH, Brown, H, Burducea, I, Bursche, A, Busetto, G, Buytaert, J, Cadeddu, S, Callot, O, Calvi, M, Calvo Gomez, M, Camboni, A, Campana, P, Campora Perez, D, Carbone, A, Carboni, G, Cardinale, R, Cardini, A, Carranza-Mejia, H, Carson, L, Carvalho Akiba, K, Casse, G, and Castillo Garcia, L

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, LHCb Collaboration, hep-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

An angular analysis of the decay J/ψ→μ+μ- is performed to measure the polarization of prompt J/ψ mesons produced in pp collisions at [Formula: see text]. The dataset corresponds to an integrated luminosity of 0.37 fb-1 collected with the LHCb detector. The measurement is presented as a function of transverse momentum, pT, and rapidity, y, of the J/ψ meson, in the kinematic region 2

Published
2013

7. Measurement of the forward energy flow in pp collisions at

Author

The LHCb Collaboration, Aaij, R, Abellan Beteta, C, Adametz, A, Adeva, B, Adinolfi, M, Adrover, C, Affolder, A, Ajaltouni, Z, Albrecht, J, Alessio, F, Alexander, M, Ali, S, Alkhazov, G, Alvarez Cartelle, P, Alves, AA, Amato, S, Amhis, Y, Anderlini, L, Anderson, J, Appleby, RB, Aquines Gutierrez, O, Archilli, F, Artamonov, A, Artuso, M, Aslanides, E, Auriemma, G, Bachmann, S, Back, JJ, Baesso, C, Balagura, V, Baldini, W, Barlow, RJ, Barschel, C, Barsuk, S, Barter, W, Bates, A, Bauer, Th, Bay, A, Beddow, J, Bediaga, I, Belogurov, S, Belous, K, Belyaev, I, Ben-Haim, E, Benayoun, M, Bencivenni, G, Benson, S, Benton, J, Berezhnoy, A, Bernet, R, Bettler, M-O, van Beuzekom, M, Bien, A, Bifani, S, Bird, T, Bizzeti, A, Bjørnstad, PM, Blake, T, Blanc, F, Blanks, C, Blouw, J, Blusk, S, Bobrov, A, Bocci, V, Bondar, A, Bondar, N, Bonivento, W, Borghi, S, Borgia, A, Bowcock, TJV, Bozzi, C, Brambach, T, van den Brand, J, Bressieux, J, Brett, D, Britsch, M, Britton, T, Brook, NH, Brown, H, Büchler-Germann, A, Burducea, I, Bursche, A, Buytaert, J, Cadeddu, S, Callot, O, Calvi, M, Calvo Gomez, M, Camboni, A, Campana, P, Carbone, A, Carboni, G, Cardinale, R, Cardini, A, Carranza-Mejia, H, Carson, L, Carvalho Akiba, K, Casse, G, Cattaneo, M, and Cauet, Ch

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, LHCb Collaboration, hep-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

The energy flow created in pp collisions at [Formula: see text] is studied within the pseudorapidity range 1.9

Published
2013

8. Measurement of prompt hadron production ratios in pp collisions at √s = 0.9 and 7 TeV

Author

Aaij, R, Beteta, CA, Adametz, A, Adeva, B, Adinolfi, M, Adrover, C, Affolder, A, Ajaltouni, Z, Albrecht, J, Alessio, F, Alexander, M, Ali, S, Alkhazov, G, Cartelle, PA, Alves, AA, Amato, S, Amhis, Y, Anderson, J, Appleby, RB, Gutierrez, OA, Archilli, F, Artamonov, A, Artuso, M, Aslanides, E, Auriemma, G, Bachmann, S, Back, JJ, Balagura, V, Baldini, W, Barlow, RJ, Barschel, C, Barsuk, S, Barter, W, Bates, A, Bauer, C, Bauer, T, Bay, A, Beddow, J, Bediaga, I, Belogurov, S, Belous, K, Belyaev, I, Ben-Haim, E, Benayoun, M, Bencivenni, G, Benson, S, Benton, J, Berezhnoy, A, Bernet, R, Bettler, MO, Van Beuzekom, M, Bien, A, Bifani, S, Bird, T, Bizzeti, A, Bjørnstad, PM, Blake, T, Blanc, F, Blanks, C, Blouw, J, Blusk, S, Bobrov, A, Bocci, V, Bondar, A, Bondar, N, Bonivento, W, Borghi, S, Borgia, A, Bowcock, TJV, Bozzi, C, Brambach, T, Van Den Brand, J, Bressieux, J, Brett, D, Britsch, M, Britton, T, Brook, NH, Brown, H, Büchler-Germann, A, Burducea, I, Bursche, A, Buytaert, J, Cadeddu, S, Callot, O, Calvi, M, Gomez, MC, Camboni, A, Campana, P, Carbone, A, Carboni, G, Cardinale, R, Cardini, A, Carson, L, Akiba, KC, Casse, G, Cattaneo, M, Cauet, C, Charles, M, Charpentier, P, and Chen, P

Subjects
hep-ex, Nuclear & Particles Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

The charged−particle production ratios p/p, K −/K +, π −/π +, (p + p)/(π ++π −), (K ++K −)/(π + + π −) and (p+ p)/(K + + K −) are measured with the LHCb detector using 0.3 nb−1 of pp collisions delivered by the LHC at √s = 0.9 TeV and 1.8 nb−1 at √s = 7 TeV. The measurements are performed as a function of transverse momentum pT and pseudorapidity η. The production ratios are compared to the predictions of several Monte Carlo generator settings, none of which are able to describe adequately all observables. The ratio p/p is also considered as a function of rapidity loss, Δy ≡ ybeam − y, and is used to constrain models of baryon transport.

Published
2012

9. Measurement of prompt hadron production ratios in pp collisions at

Author

The LHCb Collaboration, Aaij, R, Abellan Beteta, C, Adametz, A, Adeva, B, Adinolfi, M, Adrover, C, Affolder, A, Ajaltouni, Z, Albrecht, J, Alessio, F, Alexander, M, Ali, S, Alkhazov, G, Alvarez Cartelle, P, Alves, AA, Amato, S, Amhis, Y, Anderson, J, Appleby, RB, Aquines Gutierrez, O, Archilli, F, Artamonov, A, Artuso, M, Aslanides, E, Auriemma, G, Bachmann, S, Back, JJ, Balagura, V, Baldini, W, Barlow, RJ, Barschel, C, Barsuk, S, Barter, W, Bates, A, Bauer, C, Bauer, Th, Bay, A, Beddow, J, Bediaga, I, Belogurov, S, Belous, K, Belyaev, I, Ben-Haim, E, Benayoun, M, Bencivenni, G, Benson, S, Benton, J, Berezhnoy, A, Bernet, R, Bettler, M-O, van Beuzekom, M, Bien, A, Bifani, S, Bird, T, Bizzeti, A, Bjørnstad, PM, Blake, T, Blanc, F, Blanks, C, Blouw, J, Blusk, S, Bobrov, A, Bocci, V, Bondar, A, Bondar, N, Bonivento, W, Borghi, S, Borgia, A, Bowcock, TJV, Bozzi, C, Brambach, T, van den Brand, J, Bressieux, J, Brett, D, Britsch, M, Britton, T, Brook, NH, Brown, H, Büchler-Germann, A, Burducea, I, Bursche, A, Buytaert, J, Cadeddu, S, Callot, O, Calvi, M, Calvo Gomez, M, Camboni, A, Campana, P, Carbone, A, Carboni, G, Cardinale, R, Cardini, A, Carson, L, Carvalho Akiba, K, Casse, G, Cattaneo, M, Cauet, Ch, Charles, M, and Charpentier, Ph

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, hep-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

The charged−particle production ratios p/p, K −/K +, π −/π +, (p + p)/(π ++π −), (K ++K −)/(π + + π −) and (p+ p)/(K + + K −) are measured with the LHCb detector using 0.3 nb−1 of pp collisions delivered by the LHC at √s = 0.9 TeV and 1.8 nb−1 at √s = 7 TeV. The measurements are performed as a function of transverse momentum pT and pseudorapidity η. The production ratios are compared to the predictions of several Monte Carlo generator settings, none of which are able to describe adequately all observables. The ratio p/p is also considered as a function of rapidity loss, Δy ≡ ybeam − y, and is used to constrain models of baryon transport.

Published
2012

10. Measurement of ψ(2S) meson production in pp collisions at

Author

The LHCb Collaboration, Aaij, R, Abellan Beteta, C, Adeva, B, Adinolfi, M, Adrover, C, Affolder, A, Ajaltouni, Z, Albrecht, J, Alessio, F, Alexander, M, Alkhazov, G, Alvarez Cartelle, P, Alves, AA, Amato, S, Amhis, Y, Anderson, J, Appleby, RB, Aquines Gutierrez, O, Archilli, F, Arrabito, L, Artamonov, A, Artuso, M, Aslanides, E, Auriemma, G, Bachmann, S, Back, JJ, Bailey, DS, Balagura, V, Baldini, W, Barlow, RJ, Barschel, C, Barsuk, S, Barter, W, Bates, A, Bauer, C, Bauer, Th, Bay, A, Bediaga, I, Belogurov, S, Belous, K, Belyaev, I, Ben-Haim, E, Benayoun, M, Bencivenni, G, Benson, S, Benton, J, Bernet, R, Bettler, M-O, van Beuzekom, M, Bien, A, Bifani, S, Bird, T, Bizzeti, A, Bjørnstad, PM, Blake, T, Blanc, F, Blanks, C, Blouw, J, Blusk, S, Bobrov, A, Bocci, V, Bondar, A, Bondar, N, Bonivento, W, Borghi, S, Borgia, A, Bowcock, TJV, Bozzi, C, Brambach, T, van den Brand, J, Bressieux, J, Brett, D, Britsch, M, Britton, T, Brook, NH, Brown, H, de Bruyn, K, Büchler-Germann, A, Burducea, I, Bursche, A, Buytaert, J, Cadeddu, S, Callot, O, Calvi, M, Calvo Gomez, M, Camboni, A, Campana, P, Carbone, A, Carboni, G, Cardinale, R, Cardini, A, Carson, L, Carvalho Akiba, K, Casse, G, Cattaneo, M, Cauet, Ch, Charles, M, Charpentier, Ph, and Chiapolini, N

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, LHCb Collaboration, hep-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

The differential cross-section for the inclusive production of ψ(2S) mesons in pp collisions at [Formula: see text] has been measured with the LHCb detector. The data sample corresponds to an integrated luminosity of 36 pb-1. The ψ(2S) mesons are reconstructed in the decay channels ψ(2S)→μ+μ- and ψ(2S)→J/ψπ+π-, with the J/ψ meson decaying into two muons. Results are presented both for promptly produced ψ(2S) mesons and for those originating from b-hadron decays. In the kinematic range pT(ψ(2S))≤16 GeV/c and 2

Published
2012

11. Measurement of relative branching fractions of B decays to ψ(2S) and J/ψ mesons

Author

The LHCb Collaboration, Aaij, R, Abellan Beteta, C, Adametz, A, Adeva, B, Adinolfi, M, Adrover, C, Affolder, A, Ajaltouni, Z, Albrecht, J, Alessio, F, Alexander, M, Ali, S, Alkhazov, G, Alvarez Cartelle, P, Alves, AA, Amato, S, Amhis, Y, Anderson, J, Appleby, RB, Aquines Gutierrez, O, Archilli, F, Artamonov, A, Artuso, M, Aslanides, E, Auriemma, G, Bachmann, S, Back, JJ, Balagura, V, Baldini, W, Barlow, RJ, Barschel, C, Barsuk, S, Barter, W, Bates, A, Bauer, C, Bauer, Th, Bay, A, Beddow, J, Bediaga, I, Belogurov, S, Belous, K, Belyaev, I, Ben-Haim, E, Benayoun, M, Bencivenni, G, Benson, S, Benton, J, Bernet, R, Bettler, M-O, van Beuzekom, M, Bien, A, Bifani, S, Bird, T, Bizzeti, A, Bjørnstad, PM, Blake, T, Blanc, F, Blanks, C, Blouw, J, Blusk, S, Bobrov, A, Bocci, V, Bondar, A, Bondar, N, Bonivento, W, Borghi, S, Borgia, A, Bowcock, TJV, Bozzi, C, Brambach, T, van den Brand, J, Bressieux, J, Brett, D, Britsch, M, Britton, T, Brook, NH, Brown, H, Büchler-Germann, A, Burducea, I, Bursche, A, Buytaert, J, Cadeddu, S, Callot, O, Calvi, M, Calvo Gomez, M, Camboni, A, Campana, P, Carbone, A, Carboni, G, Cardinale, R, Cardini, A, Carson, L, Carvalho Akiba, K, Casse, G, Cattaneo, M, Cauet, Ch, Charles, M, Charpentier, Ph, and Chiapolini, N

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, LHCb Collaboration, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

The relative rates of B-meson decays into J/ψ and ψ(2S) mesons are measured for the three decay modes in pp collisions recorded with the LHCb detector. The ratios of branching fractions ([Formula: see text]) are measured to be [Formula: see text] where the third uncertainty is from the ratio of the ψ(2S) and J/ψ branching fractions to μ+μ-.

Published
2012

12. Opposite-side flavour tagging of B mesons at the LHCb experiment

Author

The LHCb Collaboration, Aaij, R, Abellan Beteta, C, Adeva, B, Adinolfi, M, Adrover, C, Affolder, A, Ajaltouni, Z, Albrecht, J, Alessio, F, Alexander, M, Alkhazov, G, Alvarez Cartelle, P, Alves, AA, Amato, S, Amhis, Y, Anderson, J, Appleby, RB, Aquines Gutierrez, O, Archilli, F, Arrabito, L, Artamonov, A, Artuso, M, Aslanides, E, Auriemma, G, Bachmann, S, Back, JJ, Bailey, DS, Balagura, V, Baldini, W, Barlow, RJ, Barschel, C, Barsuk, S, Barter, W, Bates, A, Bauer, C, Bauer, Th, Bay, A, Bediaga, I, Belogurov, S, Belous, K, Belyaev, I, Ben-Haim, E, Benayoun, M, Bencivenni, G, Benson, S, Benton, J, Bernet, R, Bettler, M-O, van Beuzekom, M, Bien, A, Bifani, S, Bird, T, Bizzeti, A, Bjørnstad, PM, Blake, T, Blanc, F, Blanks, C, Blouw, J, Blusk, S, Bobrov, A, Bocci, V, Bondar, A, Bondar, N, Bonivento, W, Borghi, S, Borgia, A, Bowcock, TJV, Bozzi, C, Brambach, T, van den Brand, J, Bressieux, J, Brett, D, Britsch, M, Britton, T, Brook, NH, Brown, H, de Bruyn, K, Büchler-Germann, A, Burducea, I, Bursche, A, Buytaert, J, Cadeddu, S, Callot, O, Calvi, M, Calvo Gomez, M, Camboni, A, Campana, P, Carbone, A, Carboni, G, Cardinale, R, Cardini, A, Carson, L, Carvalho Akiba, K, Casse, G, Cattaneo, M, Cauet, Ch, Charles, M, Charpentier, Ph, and Chiapolini, N

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, LHCb Collaboration, hep-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

The calibration and performance of the opposite-side flavour tagging algorithms used for the measurements of time-dependent asymmetries at the LHCb experiment are described. The algorithms have been developed using simulated events and optimized and calibrated with B+→J/ψK+, B0→J/ψK∗0 and B0→D∗-μ+νμ decay modes with 0.37 fb-1 of data collected in pp collisions at [Formula: see text] during the 2011 physics run. The opposite-side tagging power is determined in the B+→J/ψK+ channel to be (2.10±0.08±0.24) %, where the first uncertainty is statistical and the second is systematic.

Published
2012

13. Measurement of ϒ production in pp collisions at

Author

The LHCb Collaboration, Aaij, R, Abellan Beteta, C, Adeva, B, Adinolfi, M, Adrover, C, Affolder, A, Ajaltouni, Z, Albrecht, J, Alessio, F, Alexander, M, Alkhazov, G, Alvarez Cartelle, P, Alves, AA, Amato, S, Amhis, Y, Anderson, J, Appleby, RB, Aquines Gutierrez, O, Archilli, F, Arrabito, L, Artamonov, A, Artuso, M, Aslanides, E, Auriemma, G, Bachmann, S, Back, JJ, Bailey, DS, Balagura, V, Baldini, W, Barlow, RJ, Barschel, C, Barsuk, S, Barter, W, Bates, A, Bauer, C, Bauer, Th, Bay, A, Bediaga, I, Belogurov, S, Belous, K, Belyaev, I, Ben-Haim, E, Benayoun, M, Bencivenni, G, Benson, S, Benton, J, Bernet, R, Bettler, M-O, van Beuzekom, M, Bien, A, Bifani, S, Bird, T, Bizzeti, A, Bjørnstad, PM, Blake, T, Blanc, F, Blanks, C, Blouw, J, Blusk, S, Bobrov, A, Bocci, V, Bondar, A, Bondar, N, Bonivento, W, Borghi, S, Borgia, A, Bowcock, TJV, Bozzi, C, Brambach, T, van den Brand, J, Bressieux, J, Brett, D, Britsch, M, Britton, T, Brook, NH, Brown, H, de Bruyn, K, Büchler-Germann, A, Burducea, I, Bursche, A, Buytaert, J, Cadeddu, S, Callot, O, Calvi, M, Calvo Gomez, M, Camboni, A, Campana, P, Carbone, A, Carboni, G, Cardinale, R, Cardini, A, Carson, L, Carvalho Akiba, K, Casse, G, Cattaneo, M, Cauet, Ch, Charles, M, Charpentier, Ph, and Chiapolini, N

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, LHCb Collaboration, hep-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

The production of ϒ(1S), ϒ(2S) and ϒ(3S) mesons in proton-proton collisions at the centre-of-mass energy of [Formula: see text] is studied with the LHCb detector. The analysis is based on a data sample of 25 pb-1 collected at the Large Hadron Collider. The ϒ mesons are reconstructed in the decay mode ϒ→μ+μ- and the signal yields are extracted from a fit to the μ+μ- invariant mass distributions. The differential production cross-sections times dimuon branching fractions are measured as a function of the ϒ transverse momentum pT and rapidity y, over the range pT

Published
2012

14. Observation of X(3872) production in pp collisions at

Author

Aaij, R, Abellan Beteta, C, Adeva, B, Adinolfi, M, Adrover, C, Affolder, A, Ajaltouni, Z, Albrecht, J, Alessio, F, Alexander, M, Alkhazov, G, Alvarez Cartelle, P, Alves, AA, Amato, S, Amhis, Y, Anderson, J, Appleby, RB, Aquines Gutierrez, O, Archilli, F, Arrabito, L, Artamonov, A, Artuso, M, Aslanides, E, Auriemma, G, Bachmann, S, Back, JJ, Bailey, DS, Balagura, V, Baldini, W, Barlow, RJ, Barschel, C, Barsuk, S, Barter, W, Bates, A, Bauer, C, Bauer, Th, Bay, A, Bediaga, I, Belogurov, S, Belous, K, Belyaev, I, Ben-Haim, E, Benayoun, M, Bencivenni, G, Benson, S, Benton, J, Bernet, R, Bettler, M-O, van Beuzekom, M, Bien, A, Bifani, S, Bird, T, Bizzeti, A, Bjørnstad, PM, Blake, T, Blanc, F, Blanks, C, Blouw, J, Blusk, S, Bobrov, A, Bocci, V, Bondar, A, Bondar, N, Bonivento, W, Borghi, S, Borgia, A, Bowcock, TJV, Bozzi, C, Brambach, T, van den Brand, J, Bressieux, J, Brett, D, Britsch, M, Britton, T, Brook, NH, Brown, H, Büchler-Germann, A, Burducea, I, Bursche, A, Buytaert, J, Cadeddu, S, Callot, O, Calvi, M, Calvo Gomez, M, Camboni, A, Campana, P, Carbone, A, Carboni, G, Cardinale, R, Cardini, A, Carson, L, Carvalho Akiba, K, Casse, G, Cattaneo, M, Cauet, Ch, Charles, M, Charpentier, Ph, Chiapolini, N, Ciba, K, and Cid Vidal, X

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, hep-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

Using 34.7 pb−1of data collected with the LHCb detector, the inclusive production of the X(3872) meson in pp collisions at √s = 7 TeV is observed for the first time. Candidates are selected in the X(3872)→J/ψπ+π−decay mode, and used to measure σ(pp→X(3872)+anything)B(X(3872)→J/ψπ+π−) = 5.4 ± 1.3 (stat) ± 0.8 (syst) nb, where σ(pp →X(3872) + anything) is the inclusive production cross section of X(3872) mesons with rapidity in the range 2.5–4.5 and transverse momentum in the range 5–20 GeV/c. In addition the masses of both the X(3872) and ψ(2S) mesons, reconstructed in the J/ψπ+π−final state, are measured to be mX(3872) = 3871.95 ± 0.48 (stat) ± 0.12 (syst) MeV/c2and mψ(2S) = 3686.12± 0.06 (stat) ± 0.10 (syst) MeV/c2.

Published
2012

15. Measurement of charged particle multiplicities in pp collisions at in the forward region

Author

The LHCb Collaboration, Aaij, R, Abellan Beteta, C, Adeva, B, Adinolfi, M, Adrover, C, Affolder, A, Ajaltouni, Z, Albrecht, J, Alessio, F, Alexander, M, Alkhazov, G, Alvarez Cartelle, P, Alves, AA, Amato, S, Amhis, Y, Anderson, J, Appleby, RB, Aquines Gutierrez, O, Archilli, F, Arrabito, L, Artamonov, A, Artuso, M, Aslanides, E, Auriemma, G, Bachmann, S, Back, JJ, Bailey, DS, Balagura, V, Baldini, W, Barlow, RJ, Barschel, C, Barsuk, S, Barter, W, Bates, A, Bauer, C, Bauer, Th, Bay, A, Bediaga, I, Belogurov, S, Belous, K, Belyaev, I, Ben-Haim, E, Benayoun, M, Bencivenni, G, Benson, S, Benton, J, Bernet, R, Bettler, M-O, van Beuzekom, M, Bien, A, Bifani, S, Bird, T, Bizzeti, A, Bjørnstad, PM, Blake, T, Blanc, F, Blanks, C, Blouw, J, Blusk, S, Bobrov, A, Bocci, V, Bondar, A, Bondar, N, Bonivento, W, Borghi, S, Borgia, A, Bowcock, TJV, Bozzi, C, Brambach, T, van den Brand, J, Bressieux, J, Brett, D, Britsch, M, Britton, T, Brook, NH, Brown, H, Büchler-Germann, A, Burducea, I, Bursche, A, Buytaert, J, Cadeddu, S, Callot, O, Calvi, M, Calvo Gomez, M, Camboni, A, Campana, P, Carbone, A, Carboni, G, Cardinale, R, Cardini, A, Carson, L, Carvalho Akiba, K, Casse, G, Cattaneo, M, Cauet, Ch, Charles, M, Charpentier, Ph, Chiapolini, N, and Ciba, K

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, hep-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

Charged particle production in proton-proton collisions is studied with the LHCb detector at a centre-of-mass energy of √s = 7 TeV in different intervals of pseudorapidity η. Charged particles are reconstructed close to the interaction region in the vertex detector, which provides high reconstruction efficiency in the η ranges −2.5 < η

Published
2012

16. Observation of X (3872) production in pp collisions at √s =7 TeV

Author

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

Subjects
hep-ex, Nuclear & Particles Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

Using 34.7 pb−1of data collected with the LHCb detector, the inclusive production of the X(3872) meson in pp collisions at √s = 7 TeV is observed for the first time. Candidates are selected in the X(3872)→J/ψπ+π−decay mode, and used to measure σ(pp→X(3872)+anything)B(X(3872)→J/ψπ+π−) = 5.4 ± 1.3 (stat) ± 0.8 (syst) nb, where σ(pp →X(3872) + anything) is the inclusive production cross section of X(3872) mesons with rapidity in the range 2.5–4.5 and transverse momentum in the range 5–20 GeV/c. In addition the masses of both the X(3872) and ψ(2S) mesons, reconstructed in the J/ψπ+π−final state, are measured to be mX(3872) = 3871.95 ± 0.48 (stat) ± 0.12 (syst) MeV/c2and mψ(2S) = 3686.12± 0.06 (stat) ± 0.10 (syst) MeV/c2.

Published
2012

17. Measurement of charged particle multiplicities in pp collisions at √s = 7 TeV in the forward region

Author

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

Subjects
hep-ex, Nuclear & Particles Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

Charged particle production in proton-proton collisions is studied with the LHCb detector at a centre-of-mass energy of √s = 7 TeV in different intervals of pseudorapidity η. Charged particles are reconstructed close to the interaction region in the vertex detector, which provides high reconstruction efficiency in the η ranges −2.5 < η

Published
2012

18. Measurement of J/Ψ production in pp collisions at TeV

Author

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

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, hep-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

The production of J/ψ mesons in proton-proton collisions at √S = 7 TeV is studied with the LHCb detector at the LHC. The differential cross-section for prompt J/ψ production is measured as a function of the J/ψ transverse momentum pT and rapidity y in the fiducial region pT ∈ [0; 14] GeV/c and y ∈ [2.0; 4.5]. The differential cross-section and fraction of J/ψ from b-hadron decays are also measured in the same pT and y ranges. The analysis is based on a data sample corresponding to an integrated luminosity of 5.2 pb&-1. The measured cross-sections integrated over the fiducial region are 10.52 ± 0.04 ± 1.40+1.64 &-2.20 μb for prompt J/ψ production and 1.14 ± 0.01 ± 0.16 μb for J/ψ from b-hadron decays, where the first uncertainty is statistical and the second systematic. The prompt J/ψ production cross-section is obtained assuming no J/ψ polarisation and the third error indicates the acceptance uncertainty due to this assumption.

Published
2011

19. Measurement of J/ψ production in pp collisions at √S = 7 TeV

Author

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

Subjects
hep-ex, Nuclear & Particles Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

The production of J/ψ mesons in proton-proton collisions at √S = 7 TeV is studied with the LHCb detector at the LHC. The differential cross-section for prompt J/ψ production is measured as a function of the J/ψ transverse momentum pT and rapidity y in the fiducial region pT ∈ [0; 14] GeV/c and y ∈ [2.0; 4.5]. The differential cross-section and fraction of J/ψ from b-hadron decays are also measured in the same pT and y ranges. The analysis is based on a data sample corresponding to an integrated luminosity of 5.2 pb&-1. The measured cross-sections integrated over the fiducial region are 10.52 ± 0.04 ± 1.40+1.64 &-2.20 μb for prompt J/ψ production and 1.14 ± 0.01 ± 0.16 μb for J/ψ from b-hadron decays, where the first uncertainty is statistical and the second systematic. The prompt J/ψ production cross-section is obtained assuming no J/ψ polarisation and the third error indicates the acceptance uncertainty due to this assumption.

Published
2011

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