摘要：
The time-integrated CP asymmetry in the decay D
0 → K
S
0
K
S
0
is measured using 3 fb−1 of proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The flavour of the D
0 meson is determined by use of the decay D
*+ → D
0
π
+ and its charge conjugate mode. The result is
$$ {\mathcal{A}}_{CP}=-0.029\pm 0.052\pm 0.022, $$
where the first uncertainty is statistical and the second systematic. The result is consistent with Standard Model expectations and improves the uncertainty with respect to the only previous measurement of this quantity by more than a factor of three.
摘要：
The first measurement of CP asymmetries in the decay
$$ {B}_s^0\to J/\psi {\overline{\mathrm{K}}}^{\ast }{(892)}^0 $$
and an updated measurement of its branching fraction and polarisation fractions are presented. The results are obtained using data corresponding to an integrated luminosity of 3.0 fb
−1 of proton-proton collisions recorded with the LHCb detector at centre-of-mass energies of 7 and 8 TeV. Together with constraints from B
0 → J/ψ ρ
0, the results are used to constrain additional contributions due to penguin diagrams in the CP -violating phase ϕ
s
, measured through B
0
decays to charmonium.
摘要：
Angular correlations in $B^+\to X(3872) K^+$ decays, with $X(3872)\to \rho^0 J/\psi$, $\rho^0\to\pi^+\pi^-$ and $J/\psi \to\mu^+\mu^-$, are used to measure orbital angular momentum contributions and to determine the $J^{PC}$ value of the $X(3872)$ meson. The data correspond to an integrated luminosity of 3.0 fb$^{-1}$ of proton-proton collisions collected with the LHCb detector. This determination, for the first time performed without assuming a value for the orbital angular momentum, confirms the quantum numbers to be $J^{PC}=1^{++}$. The $X(3872)$ is found to decay predominantly through S wave and an upper limit of $4\%$ at $95\%$ C.L. is set on the fraction of D wave.
期刊：
Journal of High Energy Physics,2015年2015(4):1-23 ISSN：1029-8479
通讯作者：
Aaij, R.
作者机构：
[Jans, E.; Ketel, T.; Tuning, N.; Tolk, S.; Pellegrino, A.; Syropoulos, V.; van Tilburg, J.; Santos, D. Martinez; Merk, M.; Ali, S.; Koppenburg, P.; Tsopelas, P.; Snoek, H.; de Vries, J. A.; Koopman, R. F.; Heijne, V.; van Leerdam, J.; Raven, G.; Ciezarek, G.; Aaij, R.; Lambert, R. W.; De Bruyn, K.; David, P. N. Y.; van Beuzekom, M.; Farinelli, C.; Hulsbergen, W.] Nikhef, Natl Inst Subatom Phys, Amsterdam, Netherlands.;[Gomes, A.; Osorio Rodrigues, B.; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; De Miranda, J. M.; Ferreira Rodrigues, F.] Ctr Brasileiro Pesquisas Fis, 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.; Francisco, O.; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Salustino Guimaraes, V.; Vieira, D.] Univ Fed Rio de Janeiro, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Zhang, Y.; Zhong, L.; Jing, F.; An, L.; Zhang, L.] Tsinghua Univ, Ctr High Energy Phys, Beijing 100084, Peoples R China.;[Chefdeville, M.; Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph.; Qian, W.; Beaucourt, L.; Tournefier, E.; Pietrzyk, B.; Lees, J. -P.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoic, CNRS, IN2P3, LAPP, Annecy Le Vieux, France.
摘要：
An angular analysis of the B0 → K*0e+e− decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 fb−1, collected by the LHCb experiment in pp collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared (q2) interval between 0.002 and 1.120 GeV2/c4. The angular observables FL and A
T
Re
which are related to the K*0 polarisation and to the lepton forward-backward asymmetry, are measured to be FL = 0.16 ± 0.06 ± 0.03 and A
T
Re
= 0.10 ± 0.18 ± 0.05, where the first uncertainty is statistical and the second systematic. The angular observables A
T
(2)
and A
T
Im
which are sensitive to the photon polarisation in this q2 range, are found to be A
T
(2)
= − 0.23 ± 0.23 ± 0.05 and A
T
Im
= 0.14 ± 0.22 ± 0.05. The results are consistent with Standard Model predictions.
作者机构：
[Wilschut, H. W.; Jans, E.; Ketel, T.; Tuning, N.; Ciezare, G.; Tolk, S.; Pellegrino, A.; Syropoulos, V.; van Tilburg, J.; Santos, D. Martinez; Merk, M.; Onderwater, C. J. G.; Ali, S.; Koppenburg, P.; Tsopelas, P.; Snoek, H.; de Vries, J. A.; Koopman, R. F.; Heijne, V.; van Leerdam, J.; Raven, G.; Aaij, R.; Lambert, R. W.; De Bruyn, K.; Oggero, S.; Kozlinskiy, A.; David, P. N. Y.; van Beuzekom, M.; Schiller, M.; Farinelli, C.; Hulsbergen, W.] Nikhef Natl Inst Subat Phys, Amsterdam, Netherlands.;[Kucewicz, W.; Gomes, A.; Rodrigues, F. Ferreira; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; De Miranda, J. M.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil.;[Hicheur, A.; De Paula, B. Souza; Lopes, J. H.; Goicochea, J. M. Otalora; Polycarpo, E.; Potterat, C.; Goebel, C.; Akiba, K. Carvalho; Baesso, C.; Francisco, O.; Guimaraes, V. Salustino; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Rodriguez, J. Molina; Torres, M. Cruz; Tostes, D. Martins; Vieira, D.] Univ Fed Rio de Janeiro, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Li, Y.; Zhang, Y.; Yuan, X.; Zhong, L.; Jing, F.; An, L.; Xie, Y.] Tsinghua Univ, Ctr High Energy Phys, Beijing 100084, Peoples R China.;[Chefdeville, M.; Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph.; Qian, W.; Beaucourt, L.; Tournefier, E.; Pietrzyk, B.; Lees, J. -P.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie, LAPP, CNRS, IN2P3, Annecy Le Vieux, France.
作者机构：
[Jans, E.; Ketel, T.; Tuning, N.; Tolk, S.; Pellegrino, A.; Syropoulos, V.; van Tilburg, J.; Santos, D. Martinez; Merk, M.; Ali, S.; Koppenburg, P.; Bursche, A.; Tsopelas, P.; Snoek, H.; de Vries, J. A.; Koopman, R. F.; Heijne, V.; van Leerdam, J.; Raven, G.; Ciezarek, G.; Aaij, R.; Lambert, R. W.; De Bruyn, K.; David, P. N. Y.; van Beuzekom, M.; Farinelli, C.; Hulsbergen, W.] Nikhef Natl Inst Subat Phys, Amsterdam, Netherlands.;[Gomes, A.; Rodrigues, F. Ferreira; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; De Miranda, J. M.] CBPF, Rio De Janeiro, Brazil.;[Hicheur, A.; De Paula, B. Souza; Lopes, J. H.; Goicochea, J. M. Otalora; Polycarpo, E.; Potterat, C.; Akiba, K. Carvalho; Francisco, O.; Guimaraes, V. Salustino; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Tostes, D. Martins; Vieira, D.] Univ Fed Rio de Janeiro, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Zhang, Y.; Yuan, X.; Zhong, L.; Jing, F.; An, L.; Zhang, L.] Tsinghua Univ, Ctr High Energy Phys, Beijing 100084, Peoples R China.;[Chefdeville, M.; Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph.; Qian, W.; Beaucourt, L.; Tournefier, E.; Pietrzyk, B.; Lees, J. -P.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie, LAPP, CNRS, IN2P3, Annecy Le Vieux, France.
通讯机构：
[Stone, S.] S;Syracuse Univ, Syracuse, NY 13210 USA.
摘要：
Time-dependent CP violation is measured in the (B-0) over bar -> J/psi pi(+)pi(-) p-channel for each pi(+)pi(-) resonant final state using data collected with an integrated luminosity of 3.0 fb(-1) in pp collisions using the LHCb detector. The final state with the largest rate, J/psi rho(0)(770), is used to measure the CP-violating angle 2 beta(eff) to be (41.7 +/- 9.6(-6.3)(+2.8)).. This result can be used to limit the size of penguin amplitude contributions to CPviolation measurements in, for example, (B-0) over bar -> J/psi pi(+)pi(-) decays. Assuming approximate SU(3) flavour symmetry and neglecting higher order diagrams, the shift in the CP-violating phase phi(s) limited to be within the interval [-1.05 degrees, + 1.18 degrees] at 95% confidence level. Changes to the limit due to SU(3) symmetry breaking effects are also discussed. (C) 2015 The Authors. Published by Elsevier B.V.
期刊：
Journal of High Energy Physics,2015年2015(5):1-21 ISSN：1029-8479
通讯作者：
Aaij, R.
作者机构：
[Jans, E.; Tuning, N.; Pellegrino, A.; van Tilburg, J.; Merk, M.; Ali, S.; Koppenburg, P.; Tsopelas, P.; Snoek, H.; de Vries, J. A.; Heijne, V.; van Leerdam, J.; Ciezarek, G.; Aaij, R.; De Bruyn, K.; David, P. N. Y.; van Beuzekom, M.; Farinelli, C.; Hulsbergen, W.] Nikhef Natl Inst Subat Phys, Amsterdam, Netherlands.;[Gomes, A.] CBPF, Rio De Janeiro, Brazil.;[Hicheur, A.; Otalora Goicochea, J. M.; Lopes, J. H.; Martins Tostes, D.; Polycarpo, E.; Potterat, C.; Souza De Paula, B.; Francisco, O.; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Salustino Guimaraes, V.; Vieira, D.] Univ Fed Rio de Janeiro, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Zhang, Y.; Jing, F.; An, L.; Zhang, L.] Tsinghua Univ, Ctr High Energy Phys, Beijing 100084, Peoples R China.;[Chefdeville, M.; Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph; Qian, W.; Beaucourt, L.; Tournefier, E.; Minard, M. N.; Pietrzyk, B.; Lees, J. -P.; T'Jampens, S.; Deleage, N.] Univ Savoie Mt Blanc, CNRS, IN2P3, LAPP, Annecy Le Vieux, France.
摘要：
A measurement of the cross-section for Z-boson production in the forward region of pp collisions at 8 TeV centre-of-mass energy is presented. The measurement is based on a sample of Z → e+e− decays reconstructed using the LHCb detector, corresponding to an integrated luminosity of 2.0 fb−1. The acceptance is defined by the requirements 2.0 < η < 4.5 and p
T > 20 GeV for the pseudorapidities and transverse momenta of the leptons. Their invariant mass is required to lie in the range 60-120 GeV. The cross-section is determined to be
$$ \sigma \left(\mathrm{pp}\to \mathrm{Z}\to {\mathrm{e}}^{+}{\mathrm{e}}^{-}\right)=93.81\pm 0.41\left(\mathrm{stat}\right)\pm 1.48\left(\mathrm{syst}\right)\pm 1.14\left(\mathrm{lumi}\right)\mathrm{p}\mathrm{b}, $$
where the first uncertainty is statistical and the second reflects all systematic effects apart from that arising from the luminosity, which is given as the third uncertainty. Differential cross-sections are presented as functions of the Z-boson rapidity and of the angular variable ϕ
∗, which is related to the Z-boson transverse momentum.
摘要：
The production of Υ mesons in pp collisions at
$$ \sqrt{s}=7 $$
and 8 TeV is studied with the LHCb detector using data samples corresponding to an integrated luminosity of 1 fb−1 and 2 fb−1 respectively. The production cross-sections and ratios of cross-sections are measured as functions of the meson transverse momentum p and rapidity y, for p < 30 GeV/c and 2.0 < y < 4.5.
期刊：
Journal of Instrumentation,2015年10(2):P02007 ISSN：1748-0221
通讯作者：
Aaij, R.
作者机构：
[Jans, E.; Ketel, T.; van den Brand, J.; Tuning, N.; Tolk, S.; Pellegrino, A.; Syropoulos, V.; van Tilburg, J.; Martinelli, M.; Santos, D. Martinez; Merk, M.; Ali, S.; Koppenburg, P.; Tsopelas, P.; Snoek, H.; de Vries, J. A.; Koopman, R. F.; Heijne, V.; van Leerdam, J.; Raven, G.; Aaij, R.; Lambert, R. W.; De Bruyn, K.; Oggero, S.; Kozlinskiy, A.; David, P. N. Y.; van Beuzekom, M.; Schiller, M.; Farinelli, C.; Hulsbergen, W.] Nikhef Natl Inst Subat Phys, Amsterdam, Netherlands.;[Hicheur, A.; Gomes, A.; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; De Miranda, J. M.; Ferreira Rodrigues, F.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil.;[Otalora Goicochea, J. M.; Lopes, J. H.; Martins Tostes, D.; Carvalho Akiba, K.; Polycarpo, E.; Potterat, C.; Souza De Paula, B.; Francisco, O.; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Szilard, D.; Salustino Guimaraes, V.; Vieira, D.] Univ Fed Rio de Janeiro, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Wu, S.; Li, Y.; Zhang, Y.; Yuan, X.; Zhong, L.; Jing, F.; An, L.; Lu, H.] Tsinghua Univ, Ctr High Energy Phys, Beijing 100084, Peoples R China.;[Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph.; Qian, W.; Beaucourt, L.; Tournefier, E.; Pietrzyk, B.; Lees, J. -P.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie, CNRS, IN2P3, LAPP, Annecy Le Vieux, France.
关键词：
Large detector-systems performance;Pattern recognition, cluster finding, calibration and fitting methods;Performance of High Energy Physics Detectors
作者机构：
[Fohl, K.; Di Canto, A.; Popov, D.; Durante, P.; Matev, R.; Ferro-Luzzi, M.; Cardoso, L. A. Granado; Joram, C.; Campora Perez, D.; Tuning, N.; Altarelli, M. Pepe; Faerber, C.; Vidal, X. Cid; Baldini, W.; Barschel, C.; Karacson, M.; Charpentier, Ph.; Kenzie, M.; Marino, P.; Ruf, T.; Bettler, M-O.; He, J.; Poikela, T.; Forty, R.; Corti, G.; Schmidt, B.; Gaspar, C.; Carvalho Akiba, K.; Otto, A.; Stahl, S.; Linn, C.; Roiser, S.; Rauschmayr, N.; Barter, W.; Schopper, A.; Wyllie, K.; Van Herwijnen, E.; Langhans, B.; Mapelli, A.; Contu, A.; Lacarrere, D.; Couturier, B.; Leflat, A.; Cattaneo, M.; Archilli, F.; Jost, B.; Koppenburg, P.; Dettori, F.; Khanji, B.; Tonelli, D.; Rihl, M.; Lindner, R.; Dijkstra, H.; Schindler, H.; Haen, C.; Garcia, L. Castillo; Thomas, E.; Lohn, S.; Gallorini, S.; Golutvin, A.; Johnson, D.; Collins, P.; Jacobsson, R.; Neufeld, N.; Gligorov, V. V.; Schwemmer, R.; Buytaert, J.; Frei, C.; Aaij, R.; Mathe, Z.; D'Ambrosio, C.; Stagni, F.; Teubert, F.; Bondar, N.; Gys, T.; Sokoloff, M. D.; Wilkinson, G.; Closier, J.; Robbe, P.; Szczypka, P.; Frank, M.; Fiore, M.; Guz, Yu.; Panman, J.; Easo, S.; Karbach, T. M.; Clemencic, M.; Williams, M.; Schiller, M.; Benson, S.; Alessio, F.; Coco, V.; 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.; Rodrigues, B. Osorio; Ferreira Rodrigues, F.] CBPF, Rio De Janeiro, Brazil.;[Hicheur, A.; Otalora Goicochea, J. M.; Lopes, J. H.; Martins Tostes, D.; Molina Rodriguez, J.; Carvalho Akiba, K.; Polycarpo, E.; Potterat, C.; Goebel, C.; Souza De Paula, B.; Cruz Torres, M.; Baesso, C.; Francisco, O.; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Salustino Guimaraes, V.; Vieira, D.] Univ Fed Rio de Janeiro, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Yu, J.; Zhang, Y.; Zhong, L.; Jing, F.; An, L.; Xie, Y.; Zhang, L.; Liu, X.] Tsinghua Univ, Ctr High Energy Phys, Beijing 100084, Peoples R China.;[Minard, M-N.; Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph.; Qian, W.; Lees, J-P.; Beaucourt, L.; Tournefier, E.; Pietrzyk, B.; T'Jampens, S.; Deleage, N.] Univ Savoie Mont Blanc, CNRS, IN2P3, LAPP, Annecy Le Vieux, France.
通讯机构：
[Aaij, R.] E;European Org Nucl Res CERN, Geneva, Switzerland.
摘要：
The branching fraction ratio R(D-*) = B((B) over bar (0) -> D-*(+)tau(-)(nu) over bar (tau))/B((B) over bar (0) -> D-*(+)mu(-)(nu) over bar (mu)) is measured using a sample of proton-proton collision data corresponding to 3.0 fb(-1) of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode tau(-) -> mu(-)(nu) over bar (mu)nu(tau). The semitauonic decay is sensitive to contributions from non-standard-model particles that preferentially couple to the third generation of fermions, in particular, Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate (B) over bar (0) decays gives R(D-*) = 0.336 +/- 0.027(stat) +/- 0.030(syst). This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the standard model.
作者机构：
[Jans, E.; Ketel, T.; Ruiz Valls, P.; Tuning, N.; Bel, L. J.; Sanchez Mayordomo, C.; Tolk, S.; Pellegrino, A.; Syropoulos, V.; van Tilburg, J.; Santos, D. Martinez; Merk, M.; Onderwater, C. J. G.; Ali, S.; Koppenburg, P.; Tsopelas, P.; Snoek, H.; de Vries, J. A.; Koopman, R. F.; Heijne, V.; Martinez Vidal, F.; van Leerdam, J.; Raven, G.; Ciezarek, G.; Oyanguren, A.; Aaij, R.; Lambert, R. W.; De Bruyn, K.; David, P. N. Y.; van Beuzekom, M.; Farinelli, C.; Hulsbergen, W.] Nikhef Natl Inst Subat Phys, Amsterdam, Netherlands.;[Gomes, A.; Osorio Rodrigues, B.; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; De Miranda, J. M.; Ferreira Rodrigues, F.] CBPF, Rio De Janeiro, Brazil.;[Hicheur, A.; Otalora Goicochea, J. M.; Lopes, J. H.; Martins Tostes, D.; Molina Rodriguez, J.; Carvalho Akiba, K.; Polycarpo, E.; Potterat, C.; Goebel, C.; Souza De Paula, B.; Cruz Torres, M.; Baesso, C.; Francisco, O.; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Salustino Guimaraes, V.; Vieira, D.] Univ Fed Rio de Janeiro, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Zhang, Y.; Zhong, L.; Jing, F.; An, L.; Xie, Y.; Zhang, L.] Tsinghua Univ, Ctr High Energy Phys, Beijing 100084, Peoples R China.;[Chefdeville, M.; Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph.; Qian, W.; Beaucourt, L.; Tournefier, E.; Pietrzyk, B.; Lees, J. -P.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie Mont Blanc, CNRS, IN2P3, LAPP, Annecy Le Vieux, France.
摘要：
The resonant substructures of B-0 --> (D) over bar (0)pi(+)pi(-) decays are studied with the Dalitz plot technique. In this study a data sample corresponding to an integrated luminosity of 3.0 fb(-1) of pp collisions collected by the LHCb detector is used. The branching fraction of the B-0 --> (D) over bar (0)pi(+)pi(-) decay in the region m((D) over bar (0)pi(+/-)) > 2.1 GeV/c(2) is measured to be (8.46 +/- 0.14 +/- 0.29 +/- 0.40) x 10(-4), where the first uncertainty is statistical, the second is systematic and the last arises from the normalization channel B-0 --> D*(2010)(-)pi(+). The pi(+)pi(-) S-wave components are modeled with the isobar and K-matrix formalisms. Results of the Dalitz plot analyses using both models are presented. A resonant structure at m((D) over bar (0)pi(-)) approximate to 2.8 GeV/c(2) is confirmed and its spin-parity is determined for the first time as J(P) = 3(-). The branching fraction, mass and width of this structure are determined together with those of the D-0*(2400)(-) and D-2*(2460)(-) resonances. The branching fractions of other B-0 --> (D) over bar (0)h(0) decay components with h(0) --> pi(+)pi(-) also reported. Many of these branching fraction measurements are the most precise to date. The first observation of the decays B0 --> (D) over bar (0)f(0)(500), B-0 --> (D) over bar (0)f(0)(980), B-0 --> (D) over bar (0)rho(1450), B-0 --> D-3(*)(2760)(-)pi(+) and the first evidence of B-0 --> (D) over bar (0)f(0)(2020) are presented.
期刊：
Journal of High Energy Physics,2015年2015(6):1-29 ISSN：1029-8479
通讯作者：
Aaij, R.
作者机构：
[Jans, E.; Ketel, T.; Tuning, N.; Bel, L. J.; Pellegrino, A.; Syropoulos, V.; van Tilburg, J.; Santos, D. Martinez; Merk, M.; Ali, S.; Koppenburg, P.; Tsopelas, P.; Snoek, H.; de Vries, J. A.; Koopman, R. F.; Heijne, V.; van Leerdam, J.; Raven, G.; Ciezarek, G.; Aaij, R.; Lambert, R. W.; De Bruyn, K.; David, P. N. Y.; van Beuzekom, M.; Farinelli, C.; Hulsbergen, W.] Nikhef Natl Inst Subat Phys, Amsterdam, Netherlands.;[Gomes, A.; Osorio Rodrigues, B.; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; De Miranda, J. M.; Ferreira Rodrigues, F.] Ctr Brasileiro Pesquisas Fisicas 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.; Francisco, O.; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Salustino Guimaraes, V.; Vieira, D.] Univ Fed Rio de Janeiro, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Zhang, Y.; Zhong, L.; Jing, F.; An, L.; Zhang, L.] Tsinghua Univ, Ctr High Energy Phys, Beijing 100084, Peoples R China.;[Chefdeville, M.; Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph.; Qian, W.; Beaucourt, L.; Tournefier, E.; Pietrzyk, B.; Lees, J. -P.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie Mont Blanc, CNRS, IN2P3, LAPP, Annecy Le Vieux, France.
摘要：
The differential branching fraction of the rare decay Lambda(0)(b) -> Lambda mu(+)mu(-) is measured as a function of q(2), the square of the dimuon invariant mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb(-1), collected by the LHCb experiment. Evidence of signal is observed in the q(2) region below the square of the J/psi mass. Integrating over 15 < q(2) < 20 GeV2/c(4) the differential branching fraction is measured as dB(Lambda(0)(b) -> Lambda mu(+)mu(-))/dq(2) = (1.18(-0.08)(+0.09) +/- 0.03 +/- 0.27) x 10(-7) (GeV2/c(4))(-1) where the uncertainties are statistical, systematic and due to the normalisation mode Lambda(0)(b) -> J/psi Lambda , respectively. In the q(2) intervals where the signal is observed, angular distributions are studied and the forward-backward asymmetries in the dimuon (A(FB)(l)) and hadron (A(FB)(h)) systems are measured for the first time. In the range 15 < q(2) < 20GeV(2)/c(4) they are found to be A(FB)(l) = -0.05 +/- 0.09 (stat) +/- 0.03 (syst) and A(FB)(h) = -0.29 +/- 0.07 (stat) +/- 0.03 (syst).
期刊：
Journal of High Energy Physics,2015年2015(2):1-20 ISSN：1029-8479
通讯作者：
Aaij, R.
作者机构：
[Jans, E.; Ketel, T.; Tuning, N.; Faerber, C.; Tolk, S.; Pellegrino, A.; Syropoulos, V.; van Tilburg, J.; Santos, D. Martinez; Merk, M.; Ali, S.; Koppenburg, P.; Tsopelas, P.; Snoek, H.; de Vries, J. A.; Koopman, R. F.; Heijne, V.; van Leerdam, J.; Raven, G.; Ciezarek, G.; Aaij, R.; Lambert, R. W.; De Bruyn, K.; Oggero, S.; Kozlinskiy, A.; David, P. N. Y.; van Beuzekom, M.; Schiller, M.; Hulsbergen, W.] Nikhef Natl Inst Subat Phys, Amsterdam, Netherlands.;[Gomes, A.; Rodrigues, F. Ferreira; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; De Miranda, J. M.; Aaij, R.] CBPF, Rio De Janeiro, Brazil.;[Hicheur, A.; De Paula, B. Souza; Lopes, J. H.; Goicochea, J. M. Otalora; Polycarpo, E.; Potterat, C.; Akiba, K. Carvalho; Francisco, O.; Guimaraes, V. Salustino; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Tostes, D. Martins; Vieira, D.] Univ Fed Rio de Janeiro, Rio de Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Li, Y.; Zhang, Y.; Yuan, X.; Zhong, L.; Jing, F.; An, L.] Tsinghua Univ, Ctr High Energy Phys, Beijing 100084, Peoples R China.;[Chefdeville, M.; Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph.; Qian, W.; Beaucourt, L.; Tournefier, E.; Pietrzyk, B.; Lees, J. -P.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie, CNRS, LAPP, IN2P3, Annecy Le Vieux, France.
摘要：
A search for the lepton flavour violating decay tau(-) -> mu(-)mu(+)mu(-) is performed with the LHCb experiment. The data sample corresponds to an integrated luminosity of 1.0 fb(-1) of proton-proton collisions at a centre-of-mass energy of 7 TeV and 2.0 fb(-1) at 8 TeV. No evidence is found for a signal, and a limit is set at 90% confidence level on the branching fraction, B(tau(-) -> mu(-)mu(+)mu(-)) < 4.6 x 10(-8).
作者机构：
[Wilschut, H. W.; Jans, E.; Ketel, T.; Tuning, N.; Tolk, S.; Pellegrino, A.; Syropoulos, V.; van Tilburg, J.; Santos, D. Martinez; Merk, M.; Onderwater, C. J. G.; Ali, S.; Koppenburg, P.; Tsopelas, P.; Snoek, H.; de Vries, J. A.; Koopman, R. F.; Heijne, V.; van Leerdam, J.; Raven, G.; Ciezarek, G.; Aaij, R.; Lambert, R. W.; De Bruyn, K.; David, P. N. Y.; van Beuzekom, M.; Farinelli, C.; Hulsbergen, W.] Nikhef Natl Inst Subat Phys, Amsterdam, Netherlands.;[Gomes, A.; Rodrigues, F. Ferreira; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; De Miranda, J. M.] CBPF, Rio De Janeiro, Brazil.;[Hicheur, A.; De Paula, B. Souza; Lopes, J. H.; Goicochea, J. M. Otalora; Polycarpo, E.; Potterat, C.; Goebel, C.; Akiba, K. Carvalho; Baesso, C.; Francisco, O.; Guimaraes, V. Salustino; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Rodriguez, J. Molina; Torres, M. Cruz; Tostes, D. Martins; Vieira, D.] Univ Fed Rio de Janeiro, Rio de Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Zhang, Y.; Yuan, X.; Zhong, L.; Jing, F.; An, L.; Xie, Y.; Zhang, L.] Tsinghua Univ, Ctr High Energy Phys, Beijing 100084, Peoples R China.;[Chefdeville, M.; Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph.; Qian, W.; Beaucourt, L.; Tournefier, E.; Pietrzyk, B.; Lees, J. -P.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie, CNRS, IN2P3, LAPP, Annecy Le Vieux, France.
作者机构：
[Jans, E.; Ketel, T.; Tuning, N.; Tolk, S.; Pellegrino, A.; Syropoulos, V.; van Tilburg, J.; Santos, D. Martinez; Merk, M.; Ali, S.; Koppenburg, P.; Bursche, A.; Tsopelas, P.; Snoek, H.; de Vries, J. A.; Koopman, R. F.; Heijne, V.; van Leerdam, J.; Raven, G.; Ciezarek, G.; Aaij, R.; Lambert, R. W.; De Bruyn, K.; David, P. N. Y.; van Beuzekom, M.; Farinelli, C.; Hulsbergen, W.] Nikhef Natl Inst Subat Phys, Amsterdam, Netherlands.;[Gomes, A.; Rodrigues, F. Ferreira; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; De Miranda, J. M.] CBPF, Rio De Janeiro, Brazil.;[Hicheur, A.; De Paula, B. Souza; Lopes, J. H.; Goicochea, J. M. Otalora; Polycarpo, E.; Potterat, C.; Akiba, K. Carvalho; Francisco, O.; Guimaraes, V. Salustino; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Tostes, D. Martins; Vieira, D.] Univ Fed Rio de Janeiro, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Zhang, Y.; Yuan, X.; Zhong, L.; Jing, F.; An, L.; Zhang, L.] Tsinghua Univ, Ctr High Energy Phys, Beijing 100084, Peoples R China.;[Chefdeville, M.; Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph.; Qian, W.; Beaucourt, L.; Tournefier, E.; Pietrzyk, B.; Lees, J. -P.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie, LAPP, CNRS, IN2P3, Annecy Le Vieux, France.
通讯机构：
[Stone, S.] S;Syracuse Univ, Syracuse, NY 13210 USA.
摘要：
Time-dependent CP violation is measured in the (B-0) over bar -> J/psi pi(+)pi(-) p-channel for each pi(+)pi(-) resonant final state using data collected with an integrated luminosity of 3.0 fb(-1) in pp collisions using the LHCb detector. The final state with the largest rate, J/psi rho(0)(770), is used to measure the CP-violating angle 2 beta(eff) to be (41.7 +/- 9.6(-6.3)(+2.8)).. This result can be used to limit the size of penguin amplitude contributions to CPviolation measurements in, for example, (B-0) over bar -> J/psi pi(+)pi(-) decays. Assuming approximate SU(3) flavour symmetry and neglecting higher order diagrams, the shift in the CP-violating phase phi(s) limited to be within the interval [-1.05 degrees, + 1.18 degrees] at 95% confidence level. Changes to the limit due to SU(3) symmetry breaking effects are also discussed. (C) 2015 The Authors. Published by Elsevier B.V.
摘要：
The density functional perturbation theory (DFPT) is employed to study the structure, optical phonon modes and dielectric properties for wurtzite GaN and AlN under hydrostatic pressure. In order to calculate accurately the Born effective charges and high frequency dielectric tensors, we utilize two sum rules to monitor this calculation. The calculated optical phonon frequencies and longitudinal-transverse splitting show an increasing with pressure, whereas the Born effective charges, and high frequency dielectric tensors are found to decrease with pressure. In particular, we analysed the reason for discrepancy between this calculation and previous experimental determination of pressure dependence of the LO-TO splitting in AlN. The different pressure behavior of the structural and lattice-dynamical properties of GaN and AlN is discussed in terms of the strengths of the covalent bonds and crystal anisotropy. Our results regarding dielectric Grüneisen parameter are predictions and may serve as a reference.
作者机构：
[K. De Bruyn; A. Pellegrino; P. Koppenburg; M. Merk; G. Ciezarek; E. Jans; H. Snoek; V. Heijne; P. Tsopelas; W. Hulsbergen; J. van Leerdam; J. A. de Vries; S. Ali; J. van Tilburg; M. van Beuzekom; P. N. Y. David; N. Tuning; L. J. Bel; C. Farinelli; L. Dufour] Nikhef National Institute for Subatomic Physics, Amsterdam, The Netherlands;[J. Maratas; O. Deschamps; P. Henrard; V. Niess; M. Hoballah; G. Gazzoni; E. Cogneras; Z. Ajaltouni; M. Baalouch; P. Perret; R. Lefèvre; I. El Rifai; S. Monteil; M. Grabalosa Gándara] Clermont Université, Université Blaise Pascal, CNRS/IN2P3, LPC, Clermont-Ferrand, France;[R. Dzhelyadin; A. Novoselov; O. Yushchenko; V. Obraztsov; A. Popov; O. Stenyakin; V. Romanovsky; M. Shapkin; A. Artamonov] Institute for High Energy Physics (IHEP), Protvino, Russia;[J. Closier; S. Gallorini; F. Dettori; R. Matev; H. Schindler; E. Thomas; W. Barter; K. Wyllie; J. V. Viana Barbosa; C. Joram; H. Dijkstra; M. Frank; P. Robbe; K. Carvalho Akiba; S. Sridharan; S. Benson; M. Ferro-Luzzi; A. Di Canto; D. Lacarrere; R. Jacobsson; C. D’Ambrosio; D. Tonelli; B. Langhans; M. Clemencic; M. Rihl; M. Karacson; F. Alessio; N. Neufeld; D. Campora Perez; A. Contu; L. Castillo Garcia; A. Otto; J. He; A. Trisovic; L. A. Granado Cardoso; M. Schiller; C. Frei; T. M. Karbach; M. Pepe Altarelli; P. Collins; F. Archilli; S. Stahl; Yu. Guz; B. Jost; T. Poikela; W. Baldini; M. Kenzie; T. Ruf; C. Linn; C. Haen; G. Corti; J. Buytaert; B. Couturier; A. Mapelli; R. Schwemmer; P. Durante; R. Aaij; F. Stagni; X. Cid Vidal; D. Johnson; C. Barschel; S. Roiser; V. V. Gligorov; R. Lindner; J. Panman; T. Gys; V. Coco; F. Teubert; C. Gaspar; N. Rauschmayr; M.-O. Bettler; Ph. Charpentier; E. van Herwijnen; S. Lohn; Z. Mathe; R. Forty; N. Bondar; B. Schmidt; M. Cattaneo; A. Schopper] European Organization for Nuclear Research (CERN), Geneva, Switzerland;[M. Szczekowski; V. Batozskaya; A. Ukleja; K. Klimaszewski; K. Kurek; W. Wislicki] National Center for Nuclear Research (NCBJ), Warsaw, Poland
通讯机构：
Imperial College London, London, United Kingdom
期刊：
Journal of High Energy Physics,2015年2015(7):1-28 ISSN：1029-8479
通讯作者：
Aaij, R.
作者机构：
[Jans, E.; Tuning, N.; Bel, L. J.; Pellegrino, A.; van Tilburg, J.; Merk, M.; Ali, S.; Koppenburg, P.; Tsopelas, P.; Snoek, H.; de Vries, J. A.; Heijne, V.; van Leerdam, J.; Ciezarek, G.; Aaij, R.; De Bruyn, K.; David, P. N. Y.; van Beuzekom, M.; Farinelli, C.; Hulsbergen, W.] Nikhef Natl Inst Subatom Phys, Amsterdam, Netherlands.;[Gomes, A.; Osorio Rodrigues, B.; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; De Miranda, J. M.; Ferreira Rodrigues, F.] Ctr Brasileiro Pesquisas Fis, 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.; Francisco, O.; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Salustino Guimaraes, V.; Vieira, D.] Univ Fed Rio de Janeiro, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Zhang, Y.; Zhong, L.; Jing, F.; An, L.; Zhang, L.] Tsinghua Univ, Ctr High Energy Phys, Beijing 100084, Peoples R China.;[Chefdeville, M.; Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph.; Qian, W.; 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.
摘要：
An angular analysis of the decay
$$ {B}_s^0\to {K}^{\ast 0}{\overline{K}}^{\ast 0} $$
is performed using pp collisions corresponding to an integrated luminosity of 1.0 fb−1 collected by the LHCb experiment at a centre-of-mass energy
$$ \sqrt{s}=7 $$
TeV. A combined angular and mass analysis separates six helicity amplitudes and allows the measurement of the longitudinal polarisation fraction f
L
= 0.201 ± 0.057 (stat.) ± 0.040 (syst.) for the
$$ {B}_s^0\to {K}^{\ast }{(892)}^0{\overline{K}}^{\ast }{(892)}^0 $$
decay. A large scalar contribution from the K
0
∗
(1430) and K
0
∗
(800) resonances is found, allowing the determination of additional CP asymmetries. Triple product and direct CP asymmetries are determined to be compatible with the Standard Model expectations. The branching fraction
$$ \mathrm{\mathcal{B}}\left({B}_s\to {K}^{\ast }{(892)}^0{\overline{K}}^{\ast }{(892)}^0\right) $$
is measured to be (10.8 ± 2.1 (stat.) ± 1.4 (syst.) ± 0.6 (f
d
/f
s
)) × 10−6.
