关键词：
B physics;Branching fraction;Hadron-Hadron scattering (experiments)
摘要：
A search for the charmless B
0
→ η′ϕ decay is performed using pp collision data collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb−1. No signal is observed and upper limits on the B
0
→ η′ϕ branching fraction are set to 0.82 × 10−6 at 90% and 1.01 × 10−6 at 95% confidence level.
关键词：
B physics;Branching fraction;Flavor physics;Hadron-Hadron scattering (experiments)
摘要：
The charmless three-body decays B
(
)
0
→ K
S
0
h+h′ − (where h(′) = π, K) are analysed using a sample of pp collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 3 fb−1. The branching fractions are measured relative to that of the B0 → K
S
0
π+π− decay, and are determined to be:
$$ \begin{array}{l}\frac{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{K}^{\pm }{\pi}^{\mp}\right)}{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{K}^{+}{\pi}^{-}\right)}=0.123\pm 0.009\left(\mathrm{stat}\right)\pm 0.015\left(\mathrm{syst}\right),\hfill \\ {}\frac{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{K}^{+}{K}^{-}\right)}{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{\pi}^{+}{\pi}^{-}\right)}=0.549\pm 0.018\left(\mathrm{stat}\right)\pm 0.033\left(\mathrm{syst}\right),\hfill \\ {}\frac{\mathrm{\mathcal{B}}\left({B}_s^0\to {K}_{\mathrm{S}}^0{\pi}^{+}{\pi}^{-}\right)}{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{\pi}^{+}{\pi}^{-}\right)}=0.191\pm 0.027\left(\mathrm{stat}\right)\pm 0.031\left(\mathrm{syst}\right)\pm 0.011\left({f}_s/{f}_d\right),\hfill \\ {}\frac{\mathrm{\mathcal{B}}\left({B}_s^0\to {K}_{\mathrm{S}}^0{K}^{\pm }{\pi}^{\mp}\right)}{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{\pi}^{+}{\pi}^{-}\right)}=1.70\pm 0.07\left(\mathrm{stat}\right)\pm 0.11\left(\mathrm{syst}\right)\pm 0.10\left({f}_s/{f}_d\right),\hfill \\ {}\frac{\mathrm{\mathcal{B}}\left({B}_s^0\to {K}_{\mathrm{S}}^0{K}^{+}{K}^{-}\right)}{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{\pi}^{+}{\pi}^{-}\right)}\in \left[0.008-0.051\right]\kern0.5em \mathrm{at}\kern0.5em 90\%\kern0.5em \mathrm{confidence}\kern0.5em \mathrm{level},\hfill \end{array} $$
where fs/fd represents the ratio of hadronisation fractions of the B
0
and B0 mesons.
作者机构：
[Fohl, K.; Di Canto, A.; Popov, D.; Durante, P.; Matev, R.; Ferro-Luzzi, M.; Cardoso, L. A. Granado; Bozzi, C.; Joram, C.; Fontana, M.; Kvaratskheliya, T.; Altarelli, M. Pepe; Barschel, C.; Karacson, M.; Charpentier, Ph.; Ruf, T.; Hatch, M.; Poikela, T.; Ferrari, F.; Whitehead, M.; Forty, R.; Corti, G.; Schmidt, B.; Gaspar, C.; Voneki, B.; Otto, A.; Perez, H. Campora; Stahl, S.; Bettler, M. -O.; Linn, C.; Roiser, S.; Barter, W.; Schopper, A.; Wyllie, K.; Dordei, F.; Contu, A.; Lacarrere, D.; Couturier, B.; Leflat, A.; Cattaneo, M.; Jost, B.; Farber, C.; Dungs, K.; Dettori, F.; Tonelli, D.; Rihl, M.; Siddi, B. G.; Lindner, R.; Dijkstra, H.; Schindler, H.; Haen, C.; Thomas, E.; Dziurda, A.; Golutvin, A.; Johnson, D.; Lemaitre, F.; Collins, P.; Jacobsson, R.; Neufeld, N.; Schwemmer, R.; Buytaert, J.; Frei, C.; Oyanguren, A.; Aaij, R.; Vagnoni, V.; Mathe, Z.; D'Ambrosio, C.; Grillo, L.; Stagni, F.; Teubert, F.; Bondar, N.; Perazzini, S.; Gys, T.; Cogoni, V.; Wilkinson, G.; Closier, J.; Robbe, P.; Frank, M.; van Herwijnen, E.; Panman, J.; Clemencic, M.; Williams, M.; Coombs, G.; Valat, S.; Valassi, A.; Schiller, M.; Alessio, F.; Sridharan, S.; Trisovic, A.] European Org Nucl Res CERN, Geneva, Switzerland.;[Gomes, A.; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; De Miranda, J. M.; Rodriguez, J. Molina; Vieira, D.] CBPF, Rio De Janeiro, Brazil.;[Hicheur, A.; De Paula, B. Souza; Francisco, O. De Aguiar; de Oliveira, L. Silva; Lopes, J. H.; Marinho, F. Da Cunha; Goicochea, J. M. Otalora; Polycarpo, E.; Potterat, C.; Rodrigues, F. Ferreira; Bursche, A.; Akiba, K. Carvalho; Guimaraes, V. Salustino; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Tostes, D. Martins] Univ Fed Rio de Janeiro UFRJ, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Jiang, F.; Zhu, X.; Li, T.; Zhang, L.; Liu, X.] Tsinghua Univ, Ctr High Energy Phys, Beijing, Peoples R China.;[Chefdeville, M.; Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph.; Beaucourt, L.; Tournefier, E.; Pietrzyk, B.; Lees, J. -P.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie Mt Blanc, CNRS IN2P3, LAPP, Annecy Le Vieux, France.
通讯机构：
[Aaij, R.] E;European Org Nucl Res CERN, Geneva, Switzerland.
摘要：
A search for the CP-violating strong decays eta -> pi(+)pi(-) and eta ' (958) -> pi(+)pi(-) has been performed using approximately 2.5 x 10(7) events of each of the decays D+ -> pi(+)pi(+)pi(-) and D-s(+) -> pi(+)pi(+)pi(-), recorded by the LHCb experiment. The data set corresponds to an integrated luminosity of 3.0 fb(-1) of pp collision data recorded during LHC Run 1 and 0.3fb(-1) recorded in Run 2. No evidence is seen for D-(s)(+) -> pi(+)eta((')) with eta((')) -> pi(+)pi(-), and upper limits at 90% confidence level are set on the branching fractions, B(eta -> pi(+)pi(-)) < 1.6 x 10(-5) and B(eta' -> pi(+)pi(-)) < 1.8 x 10(-5). The limit for the eta decay is comparable with the existing one, while that for the eta' is a factor of three smaller than the previous limit. (C) 2016 The Author. Published by Elsevier B.V.
期刊：
Journal of High Energy Physics,2017年2017(5):1-43 ISSN：1029-8479
通讯作者：
A. Poluektov
作者机构：
[Fohl, K.; Di Canto, A.; Popov, D.; Durante, P.; Matev, R.; Ferro-Luzzi, M.; Cardoso, L. A. Granado; Bozzi, C.; Joram, C.; Fontana, M.; Kvaratskheliya, T.; Altarelli, M. Pepe; Barschel, C.; Karacson, M.; Charpentier, Ph.; Ruf, T.; Hatch, M.; Poikela, T.; Ferrari, F.; Whitehead, M.; Forty, R.; Corti, G.; McCann, M.; Schmidt, B.; Gaspar, C.; Perez, D. H. Campora; Voneki, B.; Otto, A.; Stahl, S.; Bettler, M. -O.; Linn, C.; Roiser, S.; Schopper, A.; Wyllie, K.; Dordei, F.; Contu, A.; Lacarrere, D.; Couturier, B.; Leflat, A.; Cattaneo, M.; Jost, B.; Farber, C.; Dungs, K.; Dettori, F.; Tonelli, D.; Rihl, M.; Siddi, B. G.; Prisciandaro, J.; Lindner, R.; Dijkstra, H.; Schindler, H.; Haen, C.; Barbosa, J. V. Viana; Thomas, E.; Funk, W.; Dziurda, A.; Golutvin, A.; Johnson, D.; Lemaitre, F.; Collins, P.; Jacobsson, R.; Neufeld, N.; Schwemmer, R.; Buytaert, J.; Frei, C.; Aaij, R.; Vagnoni, V.; Mathe, Z.; D'Ambrosio, C.; Grillo, L.; Stagni, F.; Pearce, A.; Teubert, F.; Bondar, N.; Lupton, O.; Perazzini, S.; Gys, T.; Cogoni, V.; Wilkinson, G.; Closier, J.; Robbe, P.; Frank, M.; van Herwijnen, E.; Clemencic, M.; Williams, M.; Coombs, G.; Valat, S.; Valassi, A.; Alessio, F.; Sridharan, S.; Trisovic, A.] European Org Nucl Res CERN, Geneva, Switzerland.;[Gomes, A.; Molina Rodriguez, J.; Dos Reis, A. C.; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; De Miranda, J. M.; Soares Lavra, L.; Salustino Guimaraes, V.] CBPF, Rio De Janeiro, Brazil.;[Hicheur, A.; Otalora Goicochea, J. M.; Lopes, J. H.; Martins Tostes, D.; Silva De Oliveira, L.; Carvalho Akiba, K.; Polycarpo, E.; Potterat, C.; Souza De Paula, B.; Bursche, A.; De Paula, L.; Nasteva, I.; Gandelman, M.; Da Cunha Marinho, F.; Amato, S.; Rangel, M. S.; Ferreira Rodrigues, F.] Univ Fed Rio de Janeiro, Rio de Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Jiang, F.; Zhu, X.; Li, T.; An, L.; Davis, A.; Zhang, L.; Liu, X.] Tsinghua Univ, Ctr High Energy Phys, Beijing, Peoples R China.;[Chefdeville, M.; Marchand, J. F.; Tisserand, V.; Xu, Z.; Decamp, D.; Ghez, Ph.; Beaucourt, L.; Tournefier, E.; Pietrzyk, B.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie Mt Blanc, CNRS, IN2P3, LAPP, Annecy Le Vieux, France.
通讯机构：
[A. Poluektov] D;Department of Physics, University of Warwick, Coventry, United Kingdom<&wdkj&>Budker Institute of Nuclear Physics (SB RAS), Novosibirsk, Russia
关键词：
B physics;Charm physics;Hadron-Hadron scattering (experiments);QCD;Spectroscopy
摘要：
An amplitude analysis of the decay Λ
0
→ D
0
pπ
− is performed in the part of the phase space containing resonances in the D
0
p channel. The study is based on a data sample corresponding to an integrated luminosity of 3.0 fb−1 of pp collisions recorded by the LHCb experiment. The spectrum of excited Λ
+
states that decay into D
0
p is studied. The masses, widths and quantum numbers of the Λc(2880)+ and Λc(2940)+ resonances are measured. The constraints on the spin and parity for the Λc(2940)+ state are obtained for the first time. A near-threshold enhancement in the D
0
p amplitude is investigated and found to be consistent with a new resonance, denoted the Λc(2860)+, of spin 3/2 and positive parity.
期刊：
Journal of High Energy Physics,2017年2017(4):1-18 ISSN：1029-8479
通讯作者：
Rodrigues, A. B.
作者机构：
[Fohl, K.; Di Canto, A.; Popov, D.; Durante, P.; Matev, R.; Ferro-Luzzi, M.; Cardoso, L. A. Granado; Bozzi, C.; Joram, C.; Fontana, M.; Kvaratskheliya, T.; Altarelli, M. Pepe; Faerber, C.; Barschel, C.; Karacson, M.; Charpentier, Ph.; Ruf, T.; Hatch, M.; Poikela, T.; Ferrari, F.; Whitehead, M.; Forty, R.; Corti, G.; Schmidt, B.; Gaspar, C.; Perez, D. H. Campora; Voneki, B.; Otto, A.; Stahl, S.; Bettler, M. -O.; Linn, C.; Roiser, S.; Barter, W.; Schopper, A.; Wyllie, K.; Dordei, F.; Contu, A.; Lacarrere, D.; Couturier, B.; Cattaneo, M.; Jost, B.; Dungs, K.; Dettori, F.; Tonelli, D.; Rihl, M.; Siddi, B. G.; Prisciandaro, J.; Lindner, R.; Dijkstra, H.; Schindler, H.; Haen, C.; Thomas, E.; Funk, W.; Dziurda, A.; Golutvin, A.; Johnson, D.; Lemaitre, F.; Collins, P.; Jacobsson, R.; Neufeld, N.; Schwemmer, R.; Buytaert, J.; Frei, C.; Aaij, R.; Vagnoni, V.; Mathe, Z.; D'Ambrosio, C.; Grillo, L.; Stagni, F.; Teubert, F.; Bondar, N.; Perazzini, S.; Gys, T.; Cogoni, V.; Wilkinson, G.; Closier, J.; Robbe, P.; Frank, M.; van Herwijnen, E.; Panman, J.; Clemencic, M.; Williams, M.; Coombs, G.; Valat, S.; Valassi, A.; Alessio, F.; Sridharan, S.; Trisovic, A.] European Org Nucl Res CERN, Geneva, Switzerland.;[Gomes, A.; Bediaga, I.; Molina Rodriguezl, J.; Rodrigues, A. B.; dos Reis, A. C.; Massafferril, A.; Salustino Guimaraes, V.; Lavra, I. Soares; De Mirandal, J. M.; Vieira, D.] CBPF, Rio De Janeiro, Brazil.;[Hicheur, A.; Otalora Goicochea, J. M.; Lopes, J. H.; Martins Tostes, D.; Silva De Oliveira, L.; Carvalho Akiba, K.; Polycarpo, E.; De Aguiar Francisco, O.; Potterat, C.; Souza De Paula, B.; Bursche, A.; Nasteva, I.; Gandelman, M.; Da Cunha Marinho, F.; Amato, S.; Rangel, M. S.; Ferreira Rodrigues, F.] Univ Fed Rio de Janeiro, Rio de Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Jiang, F.; Zhu, X.; Li, T.; Zhang, L.; Liu, X.] Tsinghua Univ, Ctr High Energy Phys, Beijing, Peoples R China.;[Chefdeville, M.; Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph.; Beaucourt, L.; Tournefier, E.; Pietrzyk, B.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie Mont Blanc, CNRS IN2P3, LAPP, Annecy Le Vieux, France.
通讯机构：
[Rodrigues, A. B.] C;CBPF, Rio De Janeiro, Brazil.
关键词：
B physics;Branching fraction;Flavor physics;Hadron-Hadron scattering (experiments)
摘要：
A search for the rare two-body charmless baryonic decay
$$ {B}^{+}\to p\overline{\varLambda} $$
is performed with pp collision data, corresponding to an integrated luminosity of 3 fb−1, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. An excess of
$$ {B}^{+}\to p\overline{\varLambda} $$
candidates with respect to background expectations is seen with a statistical significance of 4.1 standard deviations, and constitutes the first evidence for this decay. The branching fraction, measured using the B
+ → K
S
0
π
+ decay for normalisation, is
$$ \mathrm{\mathcal{B}}\left({B}^{+}\to p\overline{\varLambda}\right)=\left(2.{4}_{-0.8}^{+1.0}\pm 0.3\right)\times 1{0}^{-7}, $$
where the first uncertainty is statistical and the second systematic.
期刊：
Journal of High Energy Physics,2017年2017(12):1-25 ISSN：1029-8479
通讯作者：
Yin, H.
作者机构：
[Di Canto, A.; Durante, P.; Ferro-Luzzi, M.; Bozzi, C.; Fontana, M.; Francisco, O. De Aguiar; Tuning, N.; Kvaratskheliya, T.; Ponce, S.; Karacson, M.; Merli, A.; Byczynski, W.; Hatch, M.; Stah, S.; Rih, M.; Forty, R.; Corti, G.; McCann, M.; Schmidt, B.; Gaspar, C.; Perez, D. H. Campora; Voneki, B.; Roiser, S.; Seyfert, P.; Wyllie, K.; Dordei, F.; Chobanova, V.; Contu, A.; Lacarrere, D.; Leflat, A.; Cattaneo, M.; Jost, B.; Hasse, C.; Farber, C.; Lindner, R.; Dijkstra, H.; Chitic, S. -G.; Thomas, E.; Funk, W.; Palutan, M.; Belyaev, I.; Lemaitre, F.; Collins, P.; Jacobsson, R.; Neufeld, N.; Buytaert, J.; Frei, C.; Aaij, R.; Mathe, Z.; Stagni, F.; Pearce, A.; Teubert, F.; Lupton, O.; Perazzini, S.; Gys, T.; Frank, M.; Clemencic, M.; Pisani, F.; Valassi, A.; Alessio, F.; Trisovic, A.; Popov, D.; Matev, R.; Cardoso, L. A. Granado; Joram, C.; Altarelli, M. Pepe; Barschel, C.; Charpentier, Ph.; Ruf, T.; Neri, N.; Ukleja, A.; Whitehead, M.; Foh, K.; Bettler, M. -O.; Gruber, L.; Schopper, A.; Van Herwijnen, E.; Couturier, B.; Cavallero, G.; Wilson, F. F.; Maev, O.; Salzgeber, M. Ravonel; Schindler, H.; Haen, C.; Barbosa, J. V. Viana; Dziurda, A.; Johnson, D.; Dorigo, M.; Passaleva, G.; Schwemmer, R.; Vagnoni, V.; D'Ambrosio, C.; Gomez, R. Vazquez; Declara, P. Fernandez; Closier, J.; Coombs, G.; Valat, S.; Sridharan, S.; Colombo, T.] European Org Nucl Res CERN, Geneva, Switzerland.;[Aoudel, R. Tourinho Jadallah; De Miranda, J. M.; Massafferril, A.; Rodriguez, J. Molina; Torres, M. Cruz; Gomes, A.; Ukleja, A.; Dos Reis, A. C.; Bediaga, I.; Rodrigues, A. B.; Lavral, O. Soares] CBPF, Rio De Janeiro, Brazil.;[De Paula, B. Souza; Lopes, J. H.; Marinho, F. Da Cunha; Goicochea, J. M. Otalora; Polycarpo, E.; Gandelman, M.; Rangel, M. S.; Hicheur, A.; Potterat, C.; Rodrigues, F. Ferreira; Akiba, K. Carvalho; De Paula, L.; Nasteva, I.; Amato, S.; De Oliveira, L. Silva] Univ Fed Rio de Janeiro, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Jiang, F.; Li, T.; Sun, J.; Zhu, X.; An, L.; Davis, A.; Zhang, L.; Liu, X.] Tsinghua Univ, Ctr High Energy Phys, Beijing, Peoples R China.;[Chefdeville, M.; Decamp, D.; Reboud, M.; Beaucourt, L.; T'Jampens, S.; Marchand, J. F.; Tisserand, V.; Xu, Z.; Ghez, Ph.; Tournefier, E.; Pietrzyk, B.; Minard, M. -N.] Univ Savoie Mont Blanc, CNRS, IN2P3, LAPP, Annecy Le Vieux, France.
通讯机构：
[Yin, H.] C;Cent China Normal Univ, Inst Particle Phys, Wuhan, Hubei, Peoples R China.
关键词：
B physics;Hadron-Hadron scattering (experiments);Particle and resonance production
摘要：
The production of B± mesons is studied in pp collisions at centre-of-mass energies of 7 and 13 TeV, using B± → J/ψ K± decays and data samples corresponding to 1.0 fb−1 and 0.3 fb−1, respectively. The production cross-sections summed over both charges and integrated over the transverse momentum range 0 < pT < 40 GeV/c and the rapidity range 2.0 < y < 4.5 are measured to be
$$ \begin{array}{l}\sigma \left( pp\to {B}^{\pm }X,\sqrt{s}=7\kern0.5em \mathrm{T}\mathrm{e}\mathrm{V}\right)=43.0\pm 0.2\pm 2.5\pm 1.7\kern0.5em \upmu \mathrm{b},\hfill \\ {}\sigma \left( pp\to {B}^{\pm }X,\sqrt{s}=13\kern0.5em \mathrm{T}\mathrm{e}\mathrm{V}\right)=86.6\pm 0.5\pm 5.4\pm 3.4\kern0.5em \upmu \mathrm{b},\hfill \end{array} $$
where the first uncertainties are statistical, the second are systematic, and the third are due to the limited knowledge of the B± → J/ψ K± branching fraction. The ratio of the cross-section at 13 TeV to that at 7 TeV is determined to be 2.02 ± 0.02 (stat) ± 0.12 (syst). Differential cross-sections are also reported as functions of pT and y. All results are in agreement with theoretical calculations based on the state-of-art fixed next-to-leading order quantum chromodynamics.
期刊：
EUROPEAN PHYSICAL JOURNAL C,2017年77(4):238- ISSN：1434-6044
通讯作者：
Calvi, M.
作者机构：
[Fohl, K.; Di Canto, A.; Popov, D.; Durante, P.; Dettori, E.; Matev, R.; Ferro-Luzzi, M.; Cardoso, L. A. Granado; Bozzi, C.; Joram, C.; Fontana, M.; Marchand, J. F.; Kvaratskheliya, T.; Altarelli, M. Pepe; Karacson, M.; Charpentier, Ph.; Ruf, T.; Hatch, M.; Poikela, T.; Ferrari, F.; Whitehead, M.; Forty, R.; Corti, G.; Schmidt, B.; Gaspar, C.; Perez, D. H. Campora; Voneki, B.; Otto, A.; Stahl, S.; Bettler, M. -O.; Linn, C.; Roiser, S.; Barter, W.; Schopper, A.; Wyllie, K.; Contu, A.; Lacarrere, D.; Couturier, B.; Leflat, A.; Cattaneo, M.; Jost, B.; Farber, C.; Barsche, C.; Dungs, K.; Khanji, B.; Tonelli, D.; Rihl, M.; Siddi, B. G.; Lindner, R.; Dijkstra, H.; Schindler, H.; Haen, C.; Thomas, E.; Dordei, E.; Dziurda, A.; Golutvin, A.; Johnson, D.; Lemaitre, F.; Jacobsson, R.; Neufeld, N.; Collins, R.; Schwemmer, R.; Buytaert, J.; Frei, C.; Aaij, R.; Vagnoni, V.; Mathe, Z.; Stagni, F.; Teubert, F.; Bondar, N.; Perazzini, S.; Gys, T.; Cogoni, V.; Wilkinson, G.; Closier, J.; Robbe, P.; Frank, M.; van Herwijnen, E.; Panman, J.; Perez, D. Campora; Clemencic, M.; Williams, M.; Grillo, I.; Coombs, G.; Valat, S.; Valassi, A.; Schiller, M.; Alessio, F.; D'Ambrosie, C.; Sridharan, S.; Trisovic, A.] CERN, European Org Nucl Res, Geneva, Switzerland.;[Gomes, A.; Rodrigues, F. Ferreira; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; De Miranda, J. M.; Rodriguez, J. Molina; Vieira, D.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil.;[Hicheur, A.; De Paula, B. Souza; Francisco, O. De Aguiar; de Oliveira, L. Silva; Lopes, J. H.; Marinho, F. Da Cunha; Goicochea, J. M. Otalora; Polycarpo, E.; Potterat, C.; Bursche, A.; Akiba, K. Carvalho; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Guimaraes, V. Saluslino; Tostes, D. Martins] Univ Fed Rio de Janeiro, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Jiang, F.; Zhu, X.; Zhang, L.; Liu, X.] Tsinghua Univ, Ctr High Energy Phys, Beijing, Peoples R China.;[Chefdeville, M.; Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph.; Beaucourt, L.; Tournefier, E.; Pietrzyk, B.; Lees, J. -P.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie Mt Blanc, LAPP, CNRS, IN2P3, Annecy Le Vieux, France.
通讯机构：
[Calvi, M.] S;Sez INFN Milano Bicocca, Milan, Italy.
关键词：
Transverse Momentum;Systematic Uncertainty;Calibration Parameter;Multivariate Classifier;Mistag Probability
摘要：
Two new algorithms for use in the analysis of
$$pp$$
collision are developed to identify the flavour of
$${\mathrm {B}} ^0$$
mesons at production using pions and protons from the hadronization process. The algorithms are optimized and calibrated on data, using
$${{\mathrm {B}} ^0} \!\rightarrow D^{-}\pi ^{+}$$
decays from
$$pp$$
collision data collected by LHCb at centre-of-mass energies of 7 and 8TeV. The tagging power of the new pion algorithm is 60% greater than the previously available one; the algorithm using protons to identify the flavour of a
$${\mathrm {B}} ^0$$
meson is the first of its kind.
期刊：
Journal of High Energy Physics,2017年2017(3):1-18 ISSN：1029-8479
通讯作者：
X. Yuan
作者机构：
[Di Canto, A.; Durante, P.; Ferro-Luzzi, M.; Bozzi, C.; Fontana, M.; Kvaratskheliya, T.; Ponce, S.; Karacson, M.; Hatch, M.; Ferrari, F.; Forty, R.; Corti, G.; McCann, M.; Schmidt, B.; Gaspar, C.; Perez, D. H. Campora; Voneki, B.; Otto, A.; Roiser, S.; Wyllie, K.; Dordei, F.; Contu, A.; Lacarrere, D.; Leflat, A.; Cattaneo, M.; Jost, B.; Farber, C.; Dungs, K.; Rihl, M.; Siddi, B. G.; Lindner, R.; Dijkstra, H.; Thomas, E.; Funk, W.; Golutvin, A.; Lemaitre, F.; Collins, P.; Jacobsson, R.; Neufeld, N.; Buytaert, J.; Frei, C.; Aaij, R.; Mathe, Z.; Grillo, L.; Stagni, F.; Pearce, A.; Teubert, F.; Bondar, N.; Lupton, O.; Perazzini, S.; Gys, T.; Cogoni, V.; Wilkinson, G.; Robbe, P.; Frank, M.; Clemencic, M.; Williams, M.; Valassi, A.; Alessio, F.; Trisovic, A.; Fohl, K.; Popov, D.; Matev, R.; Cardoso, L. A. Granado; Joram, C.; Altarelli, M. Pepe; Barschel, C.; Charpentier, Ph.; Ruf, T.; Poikela, T.; Whitehead, M.; Stahl, S.; Bettler, M. -O.; Linn, C.; Schopper, A.; Couturier, B.; Dettori, F.; Tonelli, D.; Schindler, H.; Haen, C.; Barbosa, J. V. Viana; Dziurda, A.; Johnson, D.; Schwemmer, R.; Vagnoni, V.; D'Ambrosio, C.; Closier, J.; van Herwijnen, E.; Coombs, G.; Valat, S.; Sridharan, S.] European Org Nucl Res CERN, Geneva, Switzerland.;CERN, CH-1211 Geneva 23, Switzerland.;[Massafferri, A.; De Miranda, J. M.; Soares Lavra, L.; Salustino Guimaraes, V.; Rodriguez, J. Molina; Kucewicz, W.; Gomes, A.; Bediaga, I.; Rodrigues, A. B.; Baszczyk, M.; dos Reis, A. C.] CBPF, Rio De Janeiro, Brazil.;[Lopes, J. H.; Marinho, F. Da Cunha; Goicochea, J. M. Otalora; Polycarpo, E.; Souza De Paula, B.; Gandelman, M.; Rangel, M. S.; Tostes, D. Martins; Hicheur, A.; Potterat, C.; Rodrigues, F. Ferreira; Akiba, K. Carvalho; Silva de Oliveira, L.; De Paula, L.; Nasteva, I.; Amato, S.] Univ Fed Rio de Janeiro, Rio de Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Jiang, F.; Li, T.; Zhu, X.; An, L.; Davis, A.; Zhang, L.; Liu, X.] Tsinghua Univ, Ctr High Energy Phys, Beijing, Peoples R China.
通讯机构：
[X. Yuan] B;Budker Institute of Nuclear Physics (SB RAS), Novosibirsk, Russia<&wdkj&>Novosibirsk State University, Novosibirsk, Russia
关键词：
B physics;Branching fraction;CP violation;Hadron-Hadron scattering (experiments)
摘要：
The ratio of branching fractions and the difference in CP asymmetries of the decays B
+ → J/ψπ
+ and B
+ → J/ψK
+ are measured using a data sample of pp collisions collected by the LHCb experiment, corresponding to an integrated luminosity of 3 fb−1 at centre-of-mass energies of 7 and 8 TeV. The results are
$$ \frac{\mathrm{\mathcal{B}}\left({B}^{+}\to J/\psi {\pi}^{+}\right)}{\mathrm{\mathcal{B}}\left({B}^{+}\to J/\psi {K}^{+}\right)}=\left(3.83\pm 0.03\pm 0.03\right)\times {10}^{-2}, $$
$$ {\mathcal{A}}^{\mathrm{CP}}\left({B}^{+}\to J/\psi {\pi}^{+}\right)-{\mathcal{A}}^{\mathrm{CP}}\left({B}^{+}\to J/\psi {K}^{+}\right)=\left(1.82\pm 0.86\pm 0.14\right)\times {10}^{-2}, $$
where the first uncertainties are statistical and the second are systematic. Combining this result with a recent LHCb measurement of
$$ {\mathcal{A}}^{\mathrm{CP}}\left({B}^{+}\to J/{\psi K}^{+}\right) $$
provides the most precise estimate to date of CP violation in the decay B
+ → J/ψπ
+,
$$ {\mathcal{A}}^{\mathrm{CP}}\left({B}^{+}\to J/{\psi \pi}^{+}\right)=\left(1.91\pm 0.89\pm 0.16\right)\times 1{0}^{-2}. $$
摘要：
A search is made for the highly-suppressed B meson decays B+ -> K+K+pi(-) and B+ -> pi(+)pi K-+(-) using a data sample corresponding to an integrated luminosity of 3.0 fb(-1) collected by the LHCb experiment in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV. No evidence is found for the decays, and upper limits at 90% confidence level are determined to be B(B+ -> K+K+pi(-))< 1.1 x 10(-8) and B(B+ -> pi(+)pi K-+(-)) < 4.6 x 10(-8). (C) 2016 The Author. Published by Elsevier B.V. This is an open access article under the CC BY license.
作者机构：
[Fohl, K.; Di Canto, A.; Popov, D.; Matev, R.; Ferro-Luzzi, M.; Cardoso, L. A. Granado; Durante, R.; Bozzi, C.; Joram, C.; Fontana, M.; Kvaratskheliya, T.; Altarelli, M. Pepe; Barschel, C.; Karacson, M.; Charpentier, Ph.; Ruf, T.; Hatch, M.; Poikela, T.; Ferrari, F.; Rih, M.; Whitehead, M.; Forty, R.; Corti, G.; McCann, M.; Schmidt, B.; Gaspar, C.; Perez, D. H. Campora; Voneki, B.; Otto, A.; Stahl, S.; Bettler, M. -O.; Linn, C.; Roiser, S.; Barter, W.; Schopper, A.; Wyllie, K.; Dordei, F.; Contu, A.; Lacarrere, D.; Couturier, B.; Leflat, A.; Cattaneo, M.; Jost, B.; Farber, C.; Dungs, K.; Dettori, F.; Siddi, B. G.; Lindner, R.; Dijkstra, H.; Schindler, H.; Haen, C.; Barbosa, J. V. Viana; Thomas, E.; Funk, W.; Dziurda, A.; Golutvin, A.; Johnson, D.; Lemaitre, F.; Robbe, R.; Collinsol, R.; Jacobsson, R.; Neufeld, N.; Schwemmer, R.; Buytaert, J.; Frei, C.; Aaij, R.; Vagnoni, V.; Mathe, Z.; D'Ambrosio, C.; Grillo, L.; Stagni, F.; Pearce, A.; Teubert, F.; Bondar, N.; Lupton, O.; Perazzini, S.; Gys, T.; Cogoni, V.; Wilkinson, G.; Closier, J.; Frank, M.; van Herwijnen, E.; Clemencic, M.; Williams, M.; Coombs, G.; Valat, S.; Valassi, A.; Alessio, F.; Sridharan, S.; Trisovic, A.] European Org Nucl Res CERN, Geneva, Switzerland.;[Gomes, A.; Lavra, L. Soares; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; Guimaraes, V. Salustino; De Miranda, J. M.; Rodriguez, J. Molina] CBPF, Rio De Janeiro, Brazil.;[Hicheur, A.; De Paula, B. Souza; Otalora Goicochea, J. M.; de Oliveira, L. Silva; Lopes, J. H.; Marinho, F. Da Cunha; Polycarpo, E.; Potterat, C.; Rodrigues, F. Ferreira; Bursche, A.; Akiba, K. Carvalho; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Tostes, D. Martins] Univ Fed Rio de Janeiro, Rio de Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Jiang, F.; Zhu, X.; Li, T.; An, L.; Davis, A.; Zhang, L.; Liu, X.] Tsinghua Univ, Ctr High Energy Phys, Beijing, Peoples R China.;[Chefdeville, M.; Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph.; Beaucourt, L.; Tournefier, E.; Pietrzyk, B.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie Mt Blanc, CNRS, IN2P3, LAPP, Annecy Le Vieux, France.
通讯机构：
[Liu, X.] T;Tsinghua Univ, Ctr High Energy Phys, Beijing, Peoples R China.
摘要：
The observation of the decay Xi(-)(b)-> J/psi Lambda K- is reported, using a data sample corresponding to an integrated luminosity of 3 fb(-1), collected by the LHCb detector in pp collisions at centre-of-mass energies of 7 and 8 TeV. The production rate of Xi(-)(b) baryons detected in the decay Xi(-)(b) -> J/psi Lambda K- is measured relative to that of Lambda(0)(b) baryons using the decay Lambda(0)(b) -> J/psi Lambda. Integrated over the b-baryon transverse momentum p(T) < 25 GeV/c and rapidity 2.0 < y < 4.5, the measured ratio is f Xi(-)(b/) f Lambda(0)(b) B(Xi(-)(b)-> J/psi Lambda K-) / B(Lambda(0)(b)-> J/psi Lambda) = (4.19 +/- 0.29 (stat) +/- 0.15 (syst)) x 10(-2), where f(Xi)(b)(-) band f(Lambda)(b)(0)are the fragmentation fractions of b ->Xi(-)(b)and b ->Lambda(0)(b)transitions, and ss represents the branching fraction of the corresponding b- baryon decay. The mass difference between Xi(-)(b) and Lambda(0)(b) baryons is measured to be M(Xi(-)(b))-M(Lambda(0)(b)) = 177.08 +/- 0.47 (stat) +/- 0.16 (syst) MeV/c(2). (C) 2017 The Author(s). Published by Elsevier B.V.
期刊：
EUROPEAN PHYSICAL JOURNAL C,2017年77(10):1-12 ISSN：1434-6044
通讯作者：
Aaij, R.
作者机构：
[Di Canto, A.; Popov, D.; Durante, P.; Bozzi, C.; Fontana, M.; Kvaratskheliya, T.; Barschel, C.; Charpentier, Ph.; Merli, A.; Neri, N.; Whitehead, M.; Corti, G.; McCann, M.; Perez, D. H. Campora; Voneki, B.; Stahl, S.; Bettler, M. -O.; Wyllie, K.; Dordei, F.; Contu, A.; Couturier, B.; Leflat, A.; Cattaneo, M.; Cavallero, G.; Dungs, K.; Siddi, B. G.; Dijkstra, H.; Barbosa, J. V. Viana; Thomas, E.; Golutvin, A.; Collins, P.; Buytaert, J.; Aaij, R.; Vagnoni, V.; D'Ambrosio, C.; Grillo, L.; Teubert, F.; Wilkinson, G.; Closier, J.; Clemencic, M.; Williams, M.; Coombs, G.; Valat, S.; Valassi, A.; Alessio, F.; Trisovic, A.] European Org Nucl Res CERN, Geneva, Switzerland.;[Tourinho Jadallah Aoude, R.; Gomes, A.; Molina Rodriguez, J.; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; De Miranda, J. M.; Soares Lavra, L.; Aaij, R.; Salustino Guimaraes, V.] CBPF, Rio De Janeiro, Brazil.;[Hicheur, A.; Otalora Goicochea, J. M.; Lopes, J. H.; Martins Tostes, D.; Carvalho Akiba, K.; Polycarpo, E.; Potterat, C.; Souza De Paula, B.; Silva de Oliveira, L.; De Paula, L.; Nasteva, I.; Gandelman, M.; Da Cunha Marinho, F.; Amato, S.; Rangel, M. S.; Ferreira Rodrigues, F.] Univ Fed Rio de Janeiro UFRJ, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Jiang, F.; Zhu, X.; Li, T.; An, L.; Davis, A.; Zhang, L.; Liu, X.] Tsinghua Univ, Ctr High Energy Phys, Beijing, Peoples R China.;[Chefdeville, M.; Marchand, J. F.; Tisserand, V.; Xu, Z.; Decamp, D.; Ghez, Ph.; Beaucourt, L.; Tournefier, E.; Pietrzyk, B.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie Mont Blanc, LAPP, CNRS, IN2P3, Annecy Le Vieux, France.
通讯机构：
[Aaij, R.] C;CBPF, Rio De Janeiro, Brazil.
摘要：
A search for the decay
$${{K} ^0_{\mathrm { \scriptscriptstyle S}}} \rightarrow \mu ^+\mu ^-$$
is performed, based on a data sample of proton-proton collisions corresponding to an integrated luminosity of
$$3\,\text{ fb }^{-1} $$
, collected by the LHCb experiment at centre-of-mass energies of 7and8
$$\mathrm {\,TeV}$$
. The observed yield is consistent with the background-only hypothesis, yielding a limit on the branching fraction of
$$\mathcal{B}({{K} ^0_{\mathrm { \scriptscriptstyle S}}} \rightarrow \mu ^+\mu ^-) < 0.8~(1.0) \times 10^{-9}$$
at
$$90\%~(95\%)$$
confidence level. This result improves the previous upper limit on the branching fraction by an order of magnitude.
