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.; Forty, R.; Corti, G.; McCann, M.; Gaspar, C.; Perez, D. H. Campora; Voneki, B.; Seyfert, P.; Wyllie, K.; Dordei, F.; Lacarrere, D.; Leflat, A.; Cattaneo, M.; Jost, B.; Hasse, C.; Farber, C.; Rihl, M.; Bettler, M. O.; 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.; Ciezarek, G.; Frei, C.; Aaij, R.; Mathe, Z.; Stagni, F.; Pearce, A.; Teubert, F.; Lupton, O.; Perazzini, S.; Gys, T.; Frank, M.; De Bruyn, K.; Clemencic, M.; Borghi, S.; Pisani, F.; Valassi, A.; Alessio, F.; Popov, D.; Matev, R.; Romero Vidal, A.; Cardoso, L. A. Granado; Joram, C.; Altarelli, M. Pepe; Barschel, C.; Charpentier, Ph.; Neri, N.; Whitehead, M.; Stahl, S.; Gruber, L.; Schopper, A.; 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.; van Herwijnen, E.; Coombs, G.; Valat, S.; Coco, V.; Sridharan, S.; Colombo, T.] European Org Nucl Res CERN, Geneva, Switzerland.;[Tourinho Jadallah Aoude, R.; Massafferri, A.; De Miranda, J. M.; Rodriguez, J. Molina; Torres, M. Cruz; Gomes, A.; Lavra, L. Soares; Bediaga, I.; dos Reis, A. C.] CBPF, Rio De Janeiro, Brazil.;[De Paula, B. Souza; de Oliveira, L. Silva; 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.] Univ Fed Rio de Janeiro, Rio de Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Jiang, F.; Li, T.; Xu, Z.; 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.; Xu, Z.; Ghez, Ph.; Tournefier, E.; Pietrzyk, B.; Minard, M. -N.] Univ Grenoble Alpes, Univ Savoie Mont Blanc, CNRS, LAPP IN2P3, Annecy, France.
通讯机构：
[Aaij, R.] E;European Org Nucl Res CERN, Geneva, Switzerland.
摘要：
We report measurements of charm-mixing parameters based on the decay-time-dependent ratio of D-0 -> K+pi(-) to D-0 -> K-pi(+) rates. The analysis uses a data sample of proton-proton collisions corresponding to an integrated luminosity of 5.0 fb(-1) recorded by the LHCb experiment from 2011 through 2016. Assuming charge-parity (CP) symmetry, the mixing parameters are determined to be x'(2) = (3.9 +/- 2.7) x 10(-5), y' = (5.28 +/- 0.52) x 10(-3), and R-D = (3.454 +/- 0.031) x 10(-3). Without this assumption, the measurement is performed separately for D-0 and (D) over bar (0) mesons, yielding a direct CP-violating asymmetry A(D) = (-0.1 +/- 9.1) x 10(-3), and magnitude of the ratio of mixing parameters 1.00 < vertical bar q/p vertical bar < 1.35 at the 68.3% confidence level. All results include statistical and systematic uncertainties and improve significantly upon previous single-measurement determinations. No evidence for CP violation in charm mixing is observed.
期刊：
EUROPEAN PHYSICAL JOURNAL C,2018年78(6):1-31 ISSN：1434-6044
通讯作者：
Aaij, R.
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.; Forty, R.; Corti, G.; McCann, M.; Schmidt, B.; Gaspar, C.; Perez, D. H. Campora; Voneki, B.; Roiser, S.; Seyfert, P.; Wyllie, K.; Dordei, F.; Lacarrere, D.; Leflat, A.; Cattaneo, M.; Jost, B.; Hasse, C.; Farber, C.; Rihl, M.; Bettler, M. O.; Lindner, R.; Dijkstra, H.; Vidal, A. Romero; Thomas, E.; Funk, W.; Belyaev, I.; Lemaitre, F.; Collins, P.; Jacobsson, R.; Neufeld, N.; Buytaert, J.; Ciezarek, G.; Frei, C.; Aaij, R.; Mathe, Z.; Stagni, F.; Pearce, A.; Teubert, F.; Lupton, O.; Perazzini, S.; Gys, T.; Frank, M.; De Bruyn, K.; Clemencic, M.; Borghi, S.; Pisani, F.; Valassi, A.; Alessio, F.; Popov, D.; Matev, R.; Cardoso, L. A. Granado; Joram, C.; Altarelli, M. Pepe; Barschel, C.; Charpentier, Ph.; Ruf, T.; Neri, N.; Whitehead, M.; Stahl, S.; Gruber, L.; Schopper, A.; 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.; Chitic, S-G.; D'Ambrosio, C.; Gomez, R. Vazquez; Declara, P. Fernandez; Closier, J.; van Herwijnen, E.; Coombs, G.; Valat, S.; Coco, V.; Sridharan, S.; Colombo, T.] European Org Nucl Res CERN, Geneva, Switzerland.;[Massafferri, A.; Alfonso Albero, A.; De Miranda, J. M.; Rodriguez, J. Molina; Torres, M. Cruz; Gomes, A.; Lavra, L. Soares; Bediaga, I.; Aoude, R. Tourinho Jadallah; dos Reis, A. C.] Ctr Brasileiro Pesquisas Fis CBPF, Rio De Janeiro, Brazil.;[De Paula, B. Souza; de Oliveira, L. Silva; 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.] Univ Fed Rio de Janeiro UFRJ, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Jiang, F.; Li, T.; Xu, Z.; 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.; Xu, Z.; Ghez, Ph.; Tournefier, E.; Pietrzyk, B.; Minard, M. -N.] Univ Savoie Mont Blanc, Univ Grenoble Alpes, CNRS, IN2P3 LAPP, Annecy, France.
通讯机构：
[Aaij, R.] E;European Org Nucl Res CERN, Geneva, Switzerland.
摘要：
Amplitude models are constructed to describe the resonance structure of
$${D^{0}\rightarrow K^{-}\pi ^{+}\pi ^{+}\pi ^{-}}$$
and
$${D^{0} \rightarrow K^{+}\pi ^{-}\pi ^{-}\pi ^{+}}$$
decays using pp collision data collected at centre-of-mass energies of 7 and 8 TeV with the LHCb experiment, corresponding to an integrated luminosity of 3.0
$$fb^{-1}$$
. The largest contributions to both decay amplitudes are found to come from axial resonances, with decay modes
$$D^{0} \rightarrow a_1(1260)^{+} K^{-}$$
and
$$D^{0} \rightarrow K_1(1270/1400)^{+} \pi ^{-}$$
being prominent in
$${D^{0}\rightarrow K^{-}\pi ^{+}\pi ^{+}\pi ^{-}}$$
and
$$D^{0}\rightarrow K^{+}\pi ^{-}\pi ^{-}\pi ^{+}$$
, respectively. Precise measurements of the lineshape parameters and couplings of the
$$a_1(1260)^{+}$$
,
$$K_1(1270)^{-}$$
and
$$K(1460)^{-}$$
resonances are made, and a quasi model-independent study of the
$$K(1460)^{-}$$
resonance is performed. The coherence factor of the decays is calculated from the amplitude models to be
$$R_{K3\pi } = 0.459\pm 0.010\,(\mathrm {stat}) \pm 0.012\,(\mathrm {syst}) \pm 0.020\,(\mathrm {model})$$
, which is consistent with direct measurements. These models will be useful in future measurements of the unitary-triangle angle
$$\gamma $$
and studies of charm mixing and
$$C\!P$$
violation.
期刊：
Journal of Physics: Conference Series,2018年1113(1) ISSN：1742-6588
作者机构：
School of Economics and Management, Sichuan Normal University, Chengdu, 61010, China;Key Laboratory of Quark and Lepton Physics (MOE), Institute of Particle Physics, Central China Normal University, Wuhan, 430079, China;College of International Studies, Sichuan University, Chengdu, 610074, China
摘要：
The measurements of A(pi pi) and RKK in B-+/- -> DK*(+/-) decays were incorrectly reported in the paper [1], due to a transposition of the systematic uncertainties. This error was present in the reporting of the individual systematic uncertainties, the correlation matrix, and in the calculation of RCP+. In this erratum, all tables and final values that need correction are reported, with identical numbering and captions to those in the original publication. As the affected systematic uncertainties are substantially smaller than the statistical uncertainties there is no change to the interpretation of these results and the conclusions. The corrected CP observables are A(pi pi) = 0.15 +/- 0.13 +/- 0.01 R-KK = 1.22 +/- 0.09 +/- 0.02 RCP+ = 1.18 +/- 0.08 +/- 0.02 where the first uncertainty is statistical and the second is systematic.
作者机构：
[Su, Chenliang; Li, Ying; Tian, Bingbing; Qu, Gan] Shenzhen Univ, Coll Optoelect Engn, SZU NUS Collaborat Ctr, Shenzhen 518060, Peoples R China.;[Su, Chenliang; Li, Ying; Tian, Bingbing; Qu, Gan] Shenzhen Univ, Int Collaborat Lab Mat Optoelect Sci & Technol 2D, Engn Technol Res Ctr Mat Informat Funct Devices &, Coll Optoelect Engn, Shenzhen 518060, Peoples R China.;[Tang, Yiwen; Qu, Gan] Cent China Normal Univ, Dept Phys & Technol, Inst Nanosci & Technol, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Tang, Yiwen] C;[Li, Ying] S;Shenzhen Univ, Coll Optoelect Engn, SZU NUS Collaborat Ctr, Shenzhen 518060, Peoples R China.;Shenzhen Univ, Int Collaborat Lab Mat Optoelect Sci & Technol 2D, Engn Technol Res Ctr Mat Informat Funct Devices &, Coll Optoelect Engn, Shenzhen 518060, Peoples R China.;Cent China Normal Univ, Dept Phys & Technol, Inst Nanosci & Technol, Wuhan 430079, Hubei, Peoples R China.
摘要：
Herein, gas bubbles generated in situ from precursors assist the rapid construction of hollow sycamore fruit-like CoMoO4 spheres (HSCSs). This bubble-assisted fabrication strategy is easy to operate, ultra-fast, low cost and post-treatment-free, showing great potential for the large-scale production of HSCSs. The growth mechanism of HSCSs is discussed to reveal the evolution process, which may be generalized to the construction of a series of hollow ternary Mo-based oxides. The obtained HSCSs exhibit a superior specific capacitance and outstanding cyclic stability when applied in supercapacitors.
期刊：
Journal of High Energy Physics,2018年2018(3):1-20 ISSN：1029-8479
通讯作者：
Aaij, R.
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.; Forty, R.; Corti, G.; McCann, M.; Marinho, F. Da Cunha; Schmidt, B.; 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.; Rihl, M.; 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.; Fohl, K.; Popov, D.; Matev, R.; Cardoso, L. A. Granado; Joram, C.; Altarelli, M. Pepe; Barschel, C.; Charpentier, Ph.; Ruf, T.; Neri, N.; Whitehead, M.; Stahl, S.; Bettler, M. -O.; Gruber, L.; Schopper, A.; 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.; Fernandez Declara, P.; Passaleva, G.; Schwemmer, R.; Vagnoni, V.; D'Ambrosio, C.; Gomez, R. Vazquez; Closier, J.; van Herwijnen, E.; Coombs, G.; Valat, S.; Sridharan, S.; Colombo, T.] European Org Nucl Res CERN, Geneva, Switzerland.;[Tourinho Jadallah Aoude, R.; Massafferri, A.; Cruz Torres, M.; De Miranda, J. M.; Soares Lavra, L.; Rodriguez, J. Molina; Gomes, A.; Bediaga, I.; Rodrigues, A. B.; dos Reis, A. C.] CBPF, Rio De Janeiro, Brazil.;[Lopes, J. H.; Martins Tostes, D.; Polycarpo, E.; Souza De Paula, B.; Petruzzo, M.; Gandelman, M.; Rangel, M. S.; Ferreira Rodrigues, F.; Hicheur, A.; Otalora Goicochea, J. M.; Carvalho Akiba, K.; Potterat, C.; 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.; Sun, J.; 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.; Gavardi, L.; Marchand, J. F.; Tisserand, V.; Xu, Z.; Ghez, Ph.; Tournefier, E.; Pietrzyk, B.; Minard, M. -N.] Univ Savoie Mt Blanc, LAPP, CNRS, IN2P3, Annecy Le Vieux, France.
通讯机构：
[Aaij, R.] E;European Org Nucl Res CERN, Geneva, Switzerland.
关键词：
B physics;Branching fraction;Flavor physics;Hadron-Hadron scattering (experiments);Rare decay
摘要：
A search for the lepton-flavour violating decays B
0
→ e±μ∓ and B0 → e±μ∓ is performed based on a sample of proton-proton collision data corresponding to an integrated luminosity of 3 fb−1, collected with the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The observed yields are consistent with the background-only hypothesis. Upper limits on the branching fraction of the B
0
→ e±μ∓ decays are evaluated both in the hypotheses of an amplitude completely dominated by the heavy eigenstate and by the light eigenstate. The results are
$$ \frac{@}{@}\mathrm{\mathcal{B}}\left({B}_s^0\to {e}^{\pm }{\mu}^{\mp}\right)<6.3(5.4)\times 1{0}^{-9} $$
and
$$ \frac{@}{@}\mathrm{\mathcal{B}}\left({B}_s^0\to {e}^{\pm }{\mu}^{\mp}\right)<7.2(6.0)\times 1{0}^{-9} $$
at 95% (90%) confidence level, respectively. The upper limit on the branching fraction of the B0 → e±μ∓ decay is also evaluated, obtaining
$$ \frac{@}{@}\mathrm{\mathcal{B}}\left({B}^0\to {e}^{\pm }{\mu}^{\mp}\right)<1.3(1.0)\times 1{0}^{-9} $$
at 95% (90%) confidence level. These are the strongest limits on these decays to date.
期刊：
Journal of High Energy Physics,2018年2018(7):1-27 ISSN：1029-8479
通讯作者：
Qin, J.
作者机构：
[Ketel, T.; Mulder, M.; Tuning, N.; van Tilburg, J.; Ali, S.; de Vries, J. A.; Aaij, R.; Greim, R.; van Beuzekom, M.; Dufour, L.; Jans, E.; Bel, L. J.; Dall'Occo, E.; Pellegrino, A.; Vitkovskiy, A.; Merk, M.; Archilli, F.; van Veghel, M.; Koppenburg, P.; Raven, G.; Sierra, C. Vazquez; Govorkova, E.; Syropoulos, V; Benson, S.; Hulsbergen, W.] Nikhef Natl Inst Subatom Phys, Amsterdam, Netherlands.;[Tourinho Jadallah Aoude, R.; Massafferri, A.; Cruz Torres, M.; De Miranda, J. M.; Soares Lavra, I; Gomes, A.; Molina Rodriguez, J.; dos Reis, A. C.; Bediaga, I] CBPF, Rio De Janeiro, Brazil.;[Lopes, J. H.; Polycarpo, E.; Souza De Paula, B.; Gandelman, M.; Rangel, M. S.; Ferreira Rodrigues, F.; Hicheur, A.; Nasteva, I; Otalora Goicochea, J. M.; Carvalho Akiba, K.; Potterat, C.; Silva de Oliveira, L.; De Paula, L.; Da Cunha Marinho, F.; Amato, S.] Univ Fed Rio de Janeiro UFRJ, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Jiang, F.; Li, T.; Tang, Z.; Xu, Z.; Wang, M.; 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.; Ghez, Ph; Reboud, M.; T'Jampens, S.; Minard, M-N; Marchand, J. F.; Xu, Z.; Tournefier, E.; Pietrzyk, B.] Univ Savoie Montt Blanc, Univ Grenoble Alpes, CNRS, IN2P3,LAPP, Annecy, France.
通讯机构：
[Qin, J.] U;Univ Chinese Acad Sci, Beijing, Peoples R China.
摘要：
The production cross-sections of ϒ(1S), ϒ(2S) and ϒ(3S) mesons in proton-proton collisions at
$$ \sqrt{s}=13 $$
TeV are measured with a data sample corresponding to an integrated luminosity of 277 ± 11 pb−1 recorded by the LHCb experiment in 2015. The ϒ mesons are reconstructed in the decay mode ϒ → μ+μ−. The differential production cross-sections times the dimuon branching fractions are measured as a function of the ϒ transverse momentum, pT, and rapidity, y, over the range 0 < pT < 30 GeV/c and 2.0 < y < 4.5. The ratios of the cross-sections with respect to the LHCb measurement at
$$ \sqrt{s}=8 $$
TeV are also determined. The measurements are compared with theoretical predictions based on NRQCD.
摘要：
The difference between the CP asymmetries in the decays Λ
+
→ pK−K+ and Λ
+
→ pπ−π+ is presented. Proton-proton collision data taken at centre-of-mass energies of 7 and 8 TeV collected by the LHCb detector in 2011 and 2012 are used, corresponding to an integrated luminosity of 3 fb−1. The Λ
+
candidates are reconstructed as part of the Λ
0
→ Λ
+
μ−X decay chain. In order to maximize the cancellation of production and detection asymmetries in the difference, the final-state kinematic distributions of the two samples are aligned by applying phase-space-dependent weights to the Λ
+
→ pπ−π+ sample. This alters the definition of the integrated CP asymmetry to A
wgt
(pπ−π+). Both samples are corrected for reconstruction and selection efficiencies across the five-dimensional Λ
+
decay phase space. The difference in CP asymmetries is found to be
$$ \begin{array}{c}\hfill \Delta {A}_{CP}^{\mathrm{wgt}}={A}_{CP}\left(p{K}^{-}{K}^{+}\right) - {A}_{CP}^{\mathrm{wgt}}\left(p{\pi}^{-}{\pi}^{+}\right)\hfill \\ {}\hfill = \left(0.30 \pm 0.91 \pm 0.61\right)\ \%,\hfill \end{array} $$
where the first uncertainty is statistical and the second is systematic.
期刊：
Journal of High Energy Physics,2017年2017(8):1-28 ISSN：1029-8479
通讯作者：
Zhang, L.
作者机构：
[Durante, P.; Ferro-Luzzi, M.; Bozzi, C.; Fontana, M.; Kvaratskheliya, T.; Ponce, S.; Karacson, M.; Hatch, M.; Forty, R.; Corti, G.; Schmidt, B.; Gaspar, C.; Voneki, B.; Roiser, S.; Wyllie, K.; Dordei, F.; Contu, A.; Lacarrere, D.; Leflat, A.; Cattaneo, M.; Jost, B.; Farber, C.; Dungs, K.; Rihl, M.; Campora Perez, D. H.; Siddi, B. G.; Lindner, R.; Dijkstra, H.; Thomas, E.; Funk, W.; Palutan, M.; 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.; Williams, M.; Valassi, A.; Alessio, F.; Trisovic, A.; Fohl, K.; Pepe Altarelli, M.; Popov, D.; Matev, R.; Joram, C.; Barschel, C.; Herwijnen, E. van; Charpentier, Ph.; Ruf, T.; Neri, N.; Poikela, T.; Whitehead, M.; Canto, A. Di; Stahl, S.; Bettler, M. -O.; Schopper, A.; Couturier, B.; Granado Cardoso, L. A.; Schindler, H.; Haen, C.; Dziurda, A.; Johnson, D.; Schwemmer, R.; Vagnoni, V.; D'Ambrosio, C.; Closier, J.; Viana Barbosa, J. V.; Coombs, G.; Valat, S.; Sridharan, S.] CERN, European Org Nucl Res, Geneva, Switzerland.;[Tourinho Jadallah Aoude, R.; Massafferri, A.; Miranda, J. M. De; Salustino Guimaraes, V.; Soares Lavra, I.; Molina Rodriguez, J.; Bediaga, I.; Rodrigues, A. B.; Reis, A. C. dos] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil.;[Lopes, J. H.; Martins Tostes, D.; Polycarpo, E.; Souza De Paula, B.; Gandelman, M.; Rangel, M. S.; Paula, L. De; Ferreira Rodrigues, F.; Hicheur, A.; Otalora Goicochea, J. M.; Cunha Marinho, F. Da; Carvalho Akiba, K.; Potterat, C.; Bursche, A.; Silva de Oliveira, L.; Nasteva, I.; Amato, S.] Univ Fed Rio Janeiro UFRJ, 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.;[Chefdeville, M.; Dlage, N.; Decamp, D.; 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, LAPP, Annecy Le Vieux, France.
通讯机构：
[Zhang, L.] T;Tsinghua Univ, Ctr High Energy Phys, Beijing, Peoples R China.
关键词：
B physics;CP violation;Spectroscopy;Hadron-Hadron scattering (experiments)
摘要：
The decays of B
0
and
$$ {\overline{B}}_s^0 $$
mesons into the J/ψK
+
K
− final state are studied in the K
+
K
− mass region above the ϕ(1020) meson in order to determine the resonant substructure and measure the CP-violating phase, ϕ
s
, the decay width, Γ
s
, and the width difference between light and heavy mass eigenstates, ΔΓ
s
. A decay-time dependent amplitude analysis is employed. The data sample corresponds to an integrated luminosity of 3 fb−1 produced in 7 and 8 TeV pp collisions at the LHC, collected by the LHCb experiment. The measurement determines ϕ
s
= 119 ± 107 ± 34 mrad. A combination with previous LHCb measurements using similar decays into the J/ψπ
+
π
− and J/ψϕ(1020) final states gives ϕ
s
= 1 ± 37 mrad, consistent with the Standard Model prediction.
关键词：
B physics;CKM angle beta;CP violation;Flavor physics;Hadron-Hadron scattering (experiments)
摘要：
A measurement is presented of decay-time-dependent CP violation in the decays B0 → J/ψ K
S
0
and B0 → ψ(2S)K
S
0
, where the J/ψ is reconstructed from two electrons and the ψ(2S) from two muons. The analysis uses a sample of pp collision data recorded with the LHCb experiment at centre-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb−1. The CP -violation observables are measured to be
$$ \begin{array}{l}C\left({B}^0\to J/\psi \kern0.5em {K}_{\mathrm{S}}^0\right)=0.12\pm 0.07\pm 0.02,\\ {}S\left({B}^0\to J/\psi \kern0.5em {K}_{\mathrm{S}}^0\right)=0.83\pm 0.08\pm 0.01,\\ {}C\left({B}^0\to \psi (2S){K}_{\mathrm{S}}^0\right)=-0.05\pm 0.10\pm 0.01,\\ {}S\left({B}^0\to \psi (2S){K}_{\mathrm{S}}^0\right)=0.84\pm 0.10\pm 0.01,\end{array} $$
where C describes CP violation in the direct decay, and S describes CP violation in the interference between the amplitudes for the direct decay and for the decay after
$$ {B}^0-{\overline{B}}^0 $$
oscillation. The first uncertainties are statistical and the second are systematic. The two sets of results are compatible with the previous LHCb measurement using B0 → J/ψ K
S
0
decays, where the J/ψ meson was reconstructed from two muons. The averages of all three sets of LHCb results are
$$ \begin{array}{l}C\left({B}^0\to \left[c\overline{c}\right]{K}_{\mathrm{S}}^0\right)=-0.017\pm 0.029,\\ {}S\left({B}^0\to \left[c\overline{c}\right]{K}_{\mathrm{S}}^0\right)=0.760\pm 0.034,\end{array} $$
under the assumption that higher-order contributions to the decay amplitudes are negligible. The uncertainties include statistical and systematic contributions.
作者机构：
Centro Brasileiro de Pesquisas Físicas (CBPF), Rio de Janeiro, Brazil;Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil;Center for High Energy Physics, Tsinghua University, Beijing, China;LAPP, Université Savoie Mont-Blanc, CNRS/IN2P3, Annecy-Le-Vieux, France;Clermont Université, Université Blaise Pascal, CNRS/IN2P3, LPC, Clermont-Ferrand, France
关键词：
B physics;Branching fraction;Flavour Changing Neutral Currents;Hadron-Hadron scattering (experiments);Rare decay
摘要：
The suppressed decay Λ
0
→ pπ
−
μ
+
μ
−, excluding the J/ψ and ψ(2S) → μ
+
μ
− resonances, is observed for the first time with a significance of 5.5 standard deviations. The analysis is performed with proton-proton collision data corresponding to an integrated luminosity of 3 fb−1 collected with the LHCb experiment. The Λ
0
→ pπ
−
μ
+
μ
− branching fraction is measured relative to the Λ
0
→ J/ψ(→μ
+
μ
−)pπ
− branching fraction giving
$$ \frac{\mathrm{\mathcal{B}}\left({\Lambda}_b^0\to p{\pi}^{-}{\mu}^{+}{\mu}^{-}\right)}{\mathrm{\mathcal{B}}\left({\Lambda}_b^0\to \mathrm{J}/\psi \left(\to {\mu}^{+}{\mu}^{-}\right)p{\pi}^{-}\right)}=0.044\pm 0.012\pm 0.007, $$
where the first uncertainty is statistical and the second is systematic. This is the first observation of a b → d transition in a baryonic decay.
