期刊：
Journal of High Energy Physics,2014年2014(12):1-25 ISSN：1029-8479
通讯作者：
Aaij, R.
作者机构：
[Jans, E.; Tuning, N.; Pellegrino, A.; van Tilburg, J.; Martinelli, M.; Merk, M.; Ali, S.; Koppenburg, P.; Tsopelas, P.; Snoek, H.; de Vries, J. A.; Heijne, V.; van Leerdam, J.; Aaij, R.; De Bruyn, K.; Oggero, S.; Kozlinskiy, A.; David, P. N. Y.; van Beuzekom, M.; Farinelli, C.; Hulsbergen, W.] Nikhef Natl Inst Subat Phys, Amsterdam, Netherlands.;[Hicheur, A.; 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.;[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.; Szilard, D.; Tostes, D. Martins; 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.;[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.
摘要：
A measurement of the inclusive W → μν production cross-section using data from pp collisions at a centre-of-mass energy of
$$ \sqrt{s}=7 $$
TeV is presented. The analysis is based on an integrated luminosity of about 1.0 fb−1 recorded with the LHCb detector. Results are reported for muons with a transverse momentum greater than 20 GeV/c and pseudorapidity between 2.0 and 4.5. The W
+ and W
− production cross-sections are measured to be
$$ {\sigma}_W{+}_{\to \mu }{+}_{\nu }=861.0\pm 2.0\pm 11.2\pm 14.7\kern0.5em pb, $$
$$ {\sigma}_W{-}_{\to \mu }{-}_{\overline{\nu}}=675.8\pm 1.9\pm 8.8\pm 11.6\kern0.5em pb, $$
where the first uncertainty is statistical, the second is systematic and the third is due to the luminosity determination. Cross-section ratios and differential distributions as functions of the muon pseudorapidity are also presented. The ratio of W
+ to W
− cross-sections in the same fiducial kinematic region is determined to be
$$ \frac{\sigma_W{+_{\to}}_{\mu }{+}_{\nu }}{\sigma_W{-}_{\to \mu }{-}_{\overline{\nu}}}=1.274\pm 0.005\pm 0.009, $$
where the uncertainties are statistical and systematic, respectively. Results are in good agreement with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics.
期刊：
Journal of Instrumentation,2014年9(12):P12005- ISSN：1748-0221
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.; 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 Subatom 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.] CBPF, 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.; Lucchesi, D.; 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.; 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.;[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.
关键词：
Pattern recognition, cluster finding, calibration and fitting methods;Instrumentation for particle accelerators and storage rings - high energy (linear accelerators, synchrotrons)
期刊：
Journal of High Energy Physics,2014年2014(11):1-30 ISSN：1029-8479
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.; Santos, D. Martinez; Merk, M.; Ali, S.; Koppenburg, P.; Tsopelas, P.; Van Leerdam, J.; Snoek, H.; de Vries, J. A.; Koopman, R. F.; Heijne, V.; 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 Subatom Phys, Amsterdam, Netherlands.;[Hicheur, A.; 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.;[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.; Szilard, D.; Tostes, D. Martins; 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.;[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.
摘要：
We report on measurements of the time-dependent CP violating observables in B
0
→ D
∓
K
± decays using a dataset corresponding to 1.0 fb−1 of pp collisions recorded with the LHCb detector. We find the CP violating observables C
f
= 0.53±0.25±0.04, A
= 0.37 ± 0.42 ± 0.20,
$$ {A}_{\overline{f}}^{\varDelta \varGamma }=0.20\pm 0.41\pm 0.20 $$
, S
f
= −1.09±0.33±0.08,
$$ {S}_{\overline{f}}=-0.36\pm 0.34\pm 0.08 $$
, where the uncertainties are statistical and systematic, respectively. Using these observables together with a recent measurement of the B
0
mixing phase −2β
s
leads to the first extraction of the CKM angle γ from B
0
→ D
∓
K
± decays, finding γ = (115
− 43
+ 28
)° modulo 180° at 68% CL, where the error contains both statistical and systematic uncertainties.
作者机构：
Laboratory of Information Technologies, Joint Institute for Nuclear Research (JINR-LIT), Dubna, Russian Federation;GSI Helmholtzzentrum für Schwerionenforschung GmbH (GSI), Darmstadt, Germany;Institut für Kernphysik, Goethe Universität Frankfurt, Frankfurt, Germany;Department of Physics, Bose Institute, Kolkata, India;Marian Smoluchowski Institute of Physics, Jagiellonian University, Kraków, Poland
摘要：
The paper shows the advances of research carroed out by the CBM (Compressed Barionic Matter) Collaboration at FAIR/GSI in Darmstadt.
会议名称：
12th Workshop on Resistive Plate Chambers and Related Detectors
会议时间：
FEB 23-28, 2014
会议地点：
Tsinghua Univ, Beijing, PEOPLES R CHINA
会议主办单位：
Tsinghua Univ
关键词：
Particle identification methods;Detector design and construction technologies and materials;Resistive-plate chambers;Instrumentation and methods for time-of-flight (TOF) spectroscopy
作者机构：
[Jans, E.; Ketel, T.; Pesen, E.; 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.; 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.; Molina Rodriguez, J.; Carvalho Akiba, K.; Polycarpo, E.; Potterat, C.; Goebel, C.; Souza De Paula, B.; Cruz Torres, M.; 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.; Luo, H.; 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.;[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.
摘要：
We report on measurements of the mass and lifetime of the Xi(-)(b) baryon using about 1800 Xi(-)(b) decays reconstructed in a proton-proton collision data set corresponding to an integrated luminosity of 3.0 fb(-1) collected by the LHCb experiment. The decays are reconstructed in the Xi(-)(b) -> Xi(0)(c)pi(-), Xi(0)(c) -> pK(-)K(-)pi(+) channel and the mass and lifetime are measured using the Lambda(0)(b) -> Lambda(+)(c)pi(-) mode as a reference. We measure M(Xi(-)(b)) - M(Lambda(0)(b)) = 178.36 +/- 0.46 +/- 0.16 MeV/c(2), (tau Xi(-)(b)/tau Lambda(0)(b)) = 1.089 +/- 0.026 +/- 0.011, where the uncertainties are statistical and systematic, respectively. These results lead to a factor of 2 better precision on the Xi(-)(b) mass and lifetime compared to previous best measurements, and are consistent with theoretical expectations.
期刊：
Journal of High Energy Physics,2014年2014(10):1-21 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.; Martinelli, M.; Santos, D. Martinez; Merk, M.; Ali, S.; Koppenburg, P.; Dettori, F.; 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.; Rodrigues, F. Ferreira; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; De Miranda, J. M.; Nasteva, I.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil.;[De Paula, B. Souza; Otalora Goicochea, J. M.; Souza, D.; Lopes, J. H.; Polycarpo, E.; Akiba, K. Carvalho; Francisco, O.; Guimaraes, V. Salustino; Gandelman, M.; Amato, S.; Rangel, M. S.; Szilard, D.; 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.; Lu, H.] Tsinghua Univ, Ctr High Energy Phys, Beijing 100084, Peoples R China.;[Tisserand, V.; Decamp, D.; Ghez, Ph.; Qian, W.; Tournefier, E.; Pietrzyk, B.; Lees, J. -P.; T'Jampens, S.; Minard, M. -N.; Deleage, N.; De Bruyn, K.] Univ Savoie, CNRS, IN2P3, LAPP, Annecy Le Vieux, France.
摘要：
A search for CP violation using T-odd correlations is performed using the four-body D
0 → K
+
K
−π+π− decay, selected from semileptonic B decays. The data sample corresponds to integrated luminosities of 1.0 fb−1 and 2.0 fb−1 recorded at the centre-of-mass energies of 7 TeV and 8 TeV, respectively. The CP -violating asymmetry a
‐ odd
is measured to be (0.18 ± 0.29 (stat) ± 0.04 (syst))%. Searches for CP violation in different regions of phase space of the four-body decay, and as a function of the D
0 decay time, are also presented. No significant deviation from the CP conservation hypothesis is found.
作者机构：
[Jans, E.; Ketel, T.; van den Brand, J.; 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.; 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 Subatom 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.;[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.
期刊：
Journal of High Energy Physics,2014年2014(10):1-18 ISSN：1029-8479
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.; Martinelli, M.; Santos, D. Martinez; Merk, M.; Ali, S.; Koppenburg, P.; Dettori, F.; 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.; Nasteva, I.; 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.
摘要：
First observations of the rare decays B
+ → K
+
π
+
π
−
μ
+
μ
−
and B
+→ ϕK
+μ+μ− are presented using data corresponding to an integrated luminosity of 3.0 fb−1, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The branching fractions of the decays are
$$ \begin{array}{c}\hfill \mathrm{\mathcal{B}}\left({B}^{+}\to {K}^{+}{\pi}^{+}{\pi}^{-}{\mu}^{+}{\mu}^{-}\right)=\left(4.{36}_{-0.27}^{-0.29}\left(\mathrm{stat}\right)\pm 0.21\ \left(\mathrm{syst}\right)\pm 0.18\left(\mathrm{norm}\right)\right)\times 1{0}^{-7},\hfill \\ {}\hfill \mathrm{\mathcal{B}}\left({B}^{+}\to \phi {K}^{+}{\mu}^{+}{\mu}^{-}\right)=\left(0.{82}_{-0.17}^{-0.19}{\left(\mathrm{stat}\right)}_{-0.04}^{-0.10}\left(\mathrm{syst}\right)\pm 0.27\left(\mathrm{norm}\right)\right)\times 1{0}^{-7},\hfill \end{array} $$
where the uncertainties are statistical, systematic, and due to the uncertainty on the branching fractions of the normalisation modes. A measurement of the differential branching fraction in bins of the invariant mass squared of the dimuon system is also presented for the decay B
+ → K
+
π
+
π
−
μ
+
μ
−
.
期刊：
Journal of High Energy Physics,2014年2014(9):1-17 ISSN：1029-8479
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.; Martinelli, M.; Santos, D. Martinez; Merk, M.; Ali, S.; Koppenburg, P.; Dettori, F.; Tsopelas, P.; Van Leerdam, J.; Snoek, H.; de Vries, J. A.; Koopman, R. F.; Heijne, V.; 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 Subatom Phys, Amsterdam, Netherlands.;[Hicheur, A.; Gomes, A.; Rodrigues, F. Ferreira; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; De Miranda, J. M.; Nasteva, I.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil.;[De Paula, B. Souza; Otalora Goicochea, J. M.; Lopes, J. H.; Polycarpo, E.; Akiba, K. Carvalho; Francisco, O.; Guimaraes, V. Salustino; De Paula, L.; Gandelman, M.; Amato, S.; Rangel, M. S.; Szilard, D.; Tostes, D. Martins; 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.; Lu, H.] Tsinghua Univ, Ctr High Energy Phys, Beijing 100084, Peoples R China.;[Tisserand, V.; Decamp, D.; Ghez, Ph.; Qian, W.; 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：
Electroweak interaction;Heavy Ions;Heavy-ion collision;Particle and resonance production;Forward physics
摘要：
The first observation of Z boson production in proton-lead collisions at a centre-of-mass energy per proton-nucleon pair of
$$ \sqrt{s_{N\;N}} $$
= 5 TeV is presented. The data sample corresponds to an integrated luminosity of 1.6 nb−1 collected with the LHCb detector. The Z candidates are reconstructed from pairs of oppositely charged muons with pseudorapidities between 2.0 and 4.5 and transverse momenta above 20 GeV/c. The invariant dimuon mass is restricted to the range 60 − 120 GeV/c. The Z production cross-section is measured to be
$$ {\sigma_Z}_{\to {\mu}^{+}{\mu}^{-}}\left(\mathrm{fwd}\right)={13.5}_{-4.0}^{+5.4}\left(\mathrm{stat}.\right)\pm 1.2\left(\mathrm{syst}.\right)\mathrm{nb} $$
in the direction of the proton beam and
$$ {\sigma}_{Z\to {\mu}^{+}{\mu}^{-}}\left(\mathrm{bwd}\right)={10.7}_{-5.1}^{+8.4}\left(\mathrm{stat}.\right)\pm 1.0\left(\mathrm{syst}.\right)\mathrm{nb} $$
in the direction of the lead beam, where the first uncertainty is statistical and the second systematic.
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.; Onderwater, G.; 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.; Rodrigues, F. Ferreira; Bediaga, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; De Miranda, J. M.] CBPF, Rio De Janeiro, Brazil.;[De Paula, B. Souza; Lopes, J. H.; Goicochea, J. M. Otalora; Polycarpo, E.; Potterat, C.; Goebel, C.; Akiba, K. Carvalho; Francisco, O.; Guimaraes, V. Salustino; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Szilard, D.; Rodriguez, J. Molina; Torres, M. Cruz; Tostes, D. Martins; 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.; Xie, Y.] 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.
摘要：
An analysis of B-0 --> DK*(0) decays is presented, where D represents an admixture of D-0 and (D) over bar (0) mesons reconstructed in four separate final states: K-pi(+), pi K--(+), K+K- and pi(+)pi(-). The data sample corresponds to 3.0 fb(-1) of proton-proton collision, collected by the LHCb experiment. Measurements of several observables are performed, including CP asymmetries. The most precise determination is presented of r(B)(DK*(0)), the magnitude of the ratio of the amplitudes of the decay B-0 --> DK+pi(-) with a b --> u or a b --> c transition, in a K pi mass region of +/- 50 MeV/c(2) around the K*(892) mass and for an absolute value of the cosine of the K*(0) helicity angle larger than 0.4.
期刊：
New Journal of Physics,2014年16(12):123001 ISSN：1367-2630
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.; 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 Subatom Phys, Amsterdam, Netherlands.;[Hicheur, A.; Carboni, G.; Gomes, A.; Rodrigues, F. Ferreira; Bediaga, I.; Massafferri, A.; Furfaro, E.; Rodrigues, A. B.; dos Reis, A. C.; De Miranda, J. M.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil.;[De Paula, B. Souza; Otalora Goicochea, J. M.; Lopes, J. H.; Polycarpo, E.; Potterat, C.; Akiba, K. Carvalho; Francisco, O.; Guimaraes, V. Salustino; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Szilard, D.; Tostes, D. Martins; 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.;[Chefdeville, M.; Lees, J-P; Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph; Qian, W.; Beaucourt, L.; Tournefier, E.; Pietrzyk, B.; T'Jampens, S.; Minard, M-N; Deleage, N.] Univ Savoie, CNRS, IN2P3, LAPP, Annecy Le Vieux, France.
摘要：
Measurements of the branching fractions of B-s(0) -> K*K-+/-(-/+) and B-s(0) -> K*(+/-) pi(-/+) decays are performed using a data sample corresponding to 1.0 fb(-1) of protonproton collision data collected with the LHCb detector at a centre-of- mass energy of 7 TeV, where the K*(+/-) mesons are reconstructed in the K-s(0) pi(+/-) final state. The first observation of the B-s(0) -> K*(+/-) K--/+ decay and the first evidence for the B-s(0) -> K*(-) pi(+) decay are reported with branching fractions B(B-s(0) -> K*K-+/-(-/+)) = (12.7 +/- 1.9 +/- 1.9) x 10(-6) , B(B-s(0) -> K*(-) pi(+)) = (3.3 +/- 1.1 +/- 0.5) x 10(-6) , where the first uncertainties are statistical and the second are systematic. In addition, an upper limit of B(B-0 -> K*K-+/-(-/+)) < 0.4 (0.5) x 10(-6) is set at 90% (95%) confidence level.
期刊：
Journal of High Energy Physics,2014年2014(7):1-19 ISSN：1029-8479
通讯作者：
Aaij, R.
作者机构：
[Jans, E.; Tuning, N.; Tolk, S.; Pellegrino, A.; Syropoulos, V.; van Tilburg, J.; Merk, M.; Ali, S.; Koppenburg, P.; Dettori, F.; Brand, J. van den; Tsopelas, P.; Snoek, H.; de Vries, J. A.; Koopman, R. F.; Heijne, V.; van Leerdam, J.; Beuzekom, M. van; Raven, G.; Aaij, R.; Martinez Santos, D.; Lambert, R. W.; De Bruyn, K.; Oggero, S.; Kozlinskiy, A.; David, P. N. Y.; 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.; Aaij, R.; Ferreira Rodrigues, F.] CBPF, Rio De Janeiro, Brazil.;[Otalora Goicochea, J. M.; Lopes, J. H.; Martins Tostes, D.; Polycarpo, E.; Potterat, C.; Souza De Paula, B.; Akiba, K. Carvalho; 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.; Zhang, F.] 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, LAPP, CNRS IN2P3, Annecy Le Vieux, France.
通讯机构：
[Aaij, R.] C;CBPF, Rio De Janeiro, Brazil.
关键词：
Relativistic heavy ion physics;Quarkonium;Heavy quark production;Heavy Ions;Particle and resonance production
摘要：
Production of
$$ \varUpsilon $$
mesons in proton-lead collisions at a nucleon-nucleon centre-of-mass energy
$$ \sqrt{s_{NN}} $$
= 5 TeV is studied with the LHCb detector. The analysis is based on a data sample corresponding to an integrated luminosity of 1.6 nb−1. The
$$ \varUpsilon $$
mesons of transverse momenta up to 15 GeV/c are reconstructed in the dimuon decay mode. The rapidity coverage in the centre-of-mass system is 1.5 < y < 4.0 (forward region) and −5.0 < y < −2.5 (backward region). The forward-backward production ratio and the nuclear modification factor for
$$ \varUpsilon $$
(1S) mesons are determined. The data are compatible with the predictions for a suppression of
$$ \varUpsilon $$
(1S) production with respect to proton-proton collisions in the forward region, and an enhancement in the backward region. The suppression is found to be smaller than in the case of prompt J/ψ mesons.
期刊：
EUROPEAN PHYSICAL JOURNAL C,2014年74(5):1-12 ISSN：1434-6044
通讯作者：
Aaij, R.
作者机构：
[Jans, E.; Tuning, N.; Pellegrino, A.; van Tilburg, J.; Martinelli, M.; Bauer, Th; Merk, M.; Ali, S.; Koppenburg, P.; Tsopelas, P.; Snoek, H.; de Vries, J. A.; Wiggers, L.; Heijne, V.; van Leerdam, J.; Aaij, R.; De Bruyn, K.; Oggero, S.; Kozlinskiy, A.; David, P. N. Y.; van Beuzekom, 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.; Nasteva, I.; Ferreira Rodrigues, F.] CBPF, Rio De Janeiro, Brazil.;[Otalora Goicochea, J. M.; Lopes, J. H.; Martins Tostes, D.; Carvalho Akiba, K.; Polycarpo, E.; Souza De Paula, B.; Francisco, O.; De Paula, L.; 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.; Zhang, F.] Tsinghua Univ, Ctr High Energy Phys, Beijing 100084, Peoples R China.;[Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph; Qian, W.; Tournefier, E.; Pietrzyk, B.; Lees, J. -P.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie, CNRS IN2P3, LAPP, Annecy Le Vieux, France.
摘要：
The polarisation of prompt
$$\psi {(2S)} $$
mesons is measured by performing an angular analysis of
$$\psi {(2S)} \!\rightarrow \mu ^+\mu ^- $$
decays using proton-proton collision data, corresponding to an integrated luminosity of 1.0
$$\,\text{ fb }^{-1} $$
, collected by the LHCb detector at a centre-of-mass energy of 7TeV. The polarisation is measured in bins of transverse momentum
$$p_\mathrm{T} $$
and rapidity
$$y$$
in the kinematic region
$$3.5< p_\mathrm{T} <15{\mathrm {\,GeV\!/}c} $$
and
$$2.0<y<4.5$$
, and is compared to theoretical models. No significant polarisation is observed.
期刊：
Journal of High Energy Physics,2014年2014(7):1-19 ISSN：1029-8479
通讯作者：
Aaij, R.
作者机构：
[Jans, E.; van den Brand, J.; Tuning, N.; Tolk, S.; Pellegrino, A.; Syropoulos, V.; Kozinskiy, A.; van Tilburg, J.; Martinelli, M.; Merk, M.; Ali, S.; Koppenburg, P.; Tsopelas, P.; Van Leerdam, J.; Snoek, H.; de Vries, J. A.; Koopman, R. F.; Heijne, V.; Raven, G.; Aaij, R.; Martinez Santos, D.; Lambert, R. W.; De Bruyn, K.; Oggero, S.; David, P. N. Y.; van Beuzekom, M.; Schiller, M.; Farinelli, C.; Hulsbergen, W.] Nikhef Natl Inst Subat Phys, Amsterdam, Netherlands.;[Gomes, A.; Bediagal, I.; Massafferri, A.; Rodrigues, A. B.; dos Reis, A. C.; Hicheuri, A.; De Miranda, J. M.; Ferreira Rodrigues, F.] CBPF, Rio De Janeiro, Brazil.;[De Paula, B. Souza; Lopes, J. H.; Martins Tostes, D.; Carvalho Akiba, K.; Goicochea, J. M. Otalora; Polycarpo, E.; Potterat, C.; Francisco, O.; Guimaraes, V. Salustino; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Szilard, D.; Vieira, D.] Univ Fed Rio de Janeiro UFRJ, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Wu, S.; Li, Y.; Zhang, Y.; Yuan, X.; Zhong, L.; Jing, F.; An, L.; Lu, H.; Akar, S.] 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, LAPP, IN2P3, Annecy Le Vieux, France.
关键词：
B physics;CP violation;Branching fraction;Flavor physics;Hadron-Hadron Scattering
摘要：
The first observation of the Cabibbo-suppressed decay Λ
0
→ J/ψpπ
− is reported using a data sample of proton-proton collisions at 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb−1. A prominent signal is observed and the branching fraction relative to the decay mode Λ
0
→ J/ψpK
− is determined to be
$$ \frac{\mathrm{\mathcal{B}}\left({\varLambda}_b^0\to J/\psi p{\pi}^{-}\right)}{\mathrm{\mathcal{B}}\left({\varLambda}_b^0\to J/\psi p{K}^{-}\right)} = 0.0824\pm 0.0025\ \left(\mathrm{stat}\right)\pm 0.0042\ \left(\mathrm{syst}\right). $$
A search for direct CP violation is performed. The difference in the CP asymmetries between these two decays is found to be
$$ {\mathcal{A}}_{CP}\left({\varLambda}_b^0\to J/\psi p{\pi}^{-}\right) - {\mathcal{A}}_{CP}\left({\varLambda}_b^0\to J/\psi p{K}^{-}\right)=\left(+5.7\pm 2.4\ \left(\mathrm{stat}\right)\pm 1.2\ \left(\mathrm{syst}\right)\right)\%, $$
which is compatible with CP symmetry at the 2.2σ level.
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.; Dettori, F.; 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.; Hulsbergen, W.] Nikhef Natl Inst Subatom 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.;[Qian, S. W.; 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, CNRS, IN2P3, LAPP, Annecy Le Vieux, France.
摘要：
The mixing-induced CP-violating phase phi(s) in B-s(0) and (B) over bar (0)(s) decays is measured using the J / psi pi(+)pi(-) final state in data, taken from 3 fb(-1) of integrated luminosity, collected with the LHCb detector in 7 and 8 TeV centre-of-mass pp collisions at the LHC. A time-dependent flavour-tagged amplitude analysis, allowing for direct CP violation, yields a value for the phase phi(s) = 70 +/- 68 +/- 8 mrad. This result is consistent with the Standard Model expectation and previous measurements. (C) 2014 The Authors. Published by Elsevier B.V.
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 de Savoie, CNRS/IN2P3, Annecy-Le-Vieux, France;Clermont Université, Université Blaise Pascal, LPC, Clermont-Ferrand, France
作者机构：
[Jans, E.; Ketel, T.; van den Brand, J.; Tuning, N.; Tolk, S.; Pellegrino, A.; Syropoulos, V.; Martinelli, M.; Santos, D. Martinez; Merk, M.; Ali, S.; Koppenburg, P.; Dettori, F.; Tsopelas, P.; Snoek, H.; Bauer, Th.; 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.; Nasteva, I.; 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.; Souza De Paula, B.; Francisco, O.; De Paula, L.; 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.; Zhang, F.] Tsinghua Univ, Beijing 100084, Peoples R China.;[Tisserand, V.; Decamp, D.; Ghez, Ph.; Tournefier, E.; Qian, W. W.; Pietrzyk, B.; Lees, J. -P.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie, CNRS, IN2P3, LAPP, Annecy Le Vieux, France.
摘要：
Evidence for the decay mode X(3872) -> psi(2S)gamma in B+ -> X(3872)K+ decays is found with a significance of 4.4 standard deviations. The analysis is based on a data sample of proton proton collisions, corresponding to an integrated luminosity of 3 fb(-1), collected with the LHCb detector, at centre-of-mass energies of 7 and 8 TeV. The ratio of the branching fraction of the X(3872) -> psi(2S)gamma decay to that of the X(3872) -> J/psi gamma decay is measured to be B(X(3872) -> psi(2S)gamma)/B(X(3872) -> J/psi gamma) = 2.46 +/- 0.64 +/- 0.29, where the first uncertainty is statistical and the second is systematic. The measured value does not support a pure D (D) over bar* molecular interpretation of the X(3872) state. (C) 2014 CERN for the benefit of the LHCb Collaboration. Published by Elsevier B.V.
作者机构：
[Jans, E.; Ketel, T.; van den Brand, J.; Tuning, N.; Tolk, S.; Pellegrino, A.; Syropoulos, V.; van Tilburg, J.; Vanleerdam, J.; Merk, M.; Ali, S.; Koppenburg, P.; Dettori, F.; Tsopelas, P.; Snoek, H.; Bauer, Th.; de Vries, J. A.; Koopman, R. F.; Heijne, V.; Vanbeuzekom, M.; Raven, G.; Aaij, R.; Martinez Santos, D.; Lambert, R. W.; De Bruyn, K.; Oggero, S.; Kozlinskiy, A.; David, P.; Schiller, M.; Farinelli, C.; Hulsbergen, W.] Nikhef Natl Inst Subat Phys, Amsterdam, Netherlands.;[Hicheur, A.; 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.;[Lopes, J. H.; Goicochea, J. M. Otalora; Polycarpo, E.; Potterat, C.; Souza De Paula, B.; Akiba, K. Carvalho; Francisco, O.; Guimaraes, V. Salustino; De Paula, L.; Nasteva, I.; Gandelman, M.; Amato, S.; Rangel, M. S.; Szilard, D.; Tostes, D. Martins; Vieira, D.] Univ Fed Rio de Janeiro UFRJ, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Wu, S.; Li, Y.; Zhang, Y.; Yuan, X.; Zhong, L.; Jing, F.; An, L.; Lu, H.; Zhang, F.] Tsinghua Univ, Ctr High Energy Phys, Beijing 100084, Peoples R China.;[Marchand, J. F.; Tisserand, V.; Decamp, D.; Ghez, Ph.; Qian, W.; Tournefier, E.; Pietrzyk, B.; Lees, J. -P.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie, LAPP, CNRS IN2P3, Annecy Le Vieux, France.
摘要：
Measurements of the effective lifetimes in the B-s(0) -> K+K-, B-0 -> K+pi(-) and B-s(0) -> pi K-+(-) decays are presented using 1.0 fb(-1)of pp collision data collected at a centre-of-mass energy of 7 TeV by the LHCb experiment. The analysis uses a data-driven approach to correct for the decay time acceptance. The measured effective lifetimes are tau(Bs0 -> K+K-) = 1.407 +/- 0.016 (stat) +/- 0.007 (syst) ps, tau(Bs0 -> K+pi-) = 1.524 +/- 0.011 (stat) +/- 0.004 (syst) ps, tau(Bs0 ->pi+K-) = 1.60 +/- 0.06 (stat) +/- 0.01 (syst) ps. This is the most precise determination to date of the effective lifetime in the B-s(0) -> K+K- decay and provides constraints on contributions from physics beyond the Standard Model to the B-s(0) mixing phase and the width difference Delta Gamma(s). (C) 2014 The Authors. Published by Elsevier B.V.
作者机构：
[Jans, E.; Ketel, T.; van den Brand, J.; Tuning, N.; Tomassetti, L.; Syropoulos, V.; Martinelli, M.; Santos, D. Martinez; Merk, M.; Bauer, T.; Ali, S.; Van Tilburg, J.; Koppenburg, P.; Dettori, F.; Snoek, H.; de Vries, J. A.; Koopman, R. F.; Onderwater, G.; Heijne, V.; van Leerdam, J.; Raven, G.; Aaij, R.; Garcia, M. Ubeda; 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 Subatom 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.] CBPF, Rio De Janeiro, Brazil.;[De Paula, B. Souza; Otalora Goicochea, J. M.; Lopes, J. H.; Martins Tostes, D.; Molina Rodriguez, J.; Carvalho Akiba, K.; Polycarpo, E.; Potterat, C.; Goebel, C.; Cruz Torres, M.; 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.; Zhang, F.; Xie, Y.] Tsinghua Univ, Ctr High Energy Phys, Beijing 100084, Peoples R China.;[Marchand, J. F.; Tisserand, V.; Decamp, D.; Tourneur, S.; Ghez, P.; Qian, W.; Beaucourt, L.; Pietrzyk, B.; Lees, J. -P.; T'Jampens, S.; Minard, M. -N.; Deleage, N.] Univ Savoie, LAPP, CNRS IN2P3, Annecy Le Vieux, France.
摘要：
The resonant structure of the reaction (B) over bar (0) --> J/psi pi(+)pi(-) is studied using data from 3 fb(-1) of integrated luminosity collected by the LHCb experiment, one third at 7 TeV center-of-mass energy and the remainder at 8 TeV. The invariant mass of the pi(+)pi(-) pair and three decay angular distributions are used to determine the fractions of the resonant and nonresonant components. Six interfering pi(+)pi(-) states, rho(770), f(0)(500), f(2)(1270), rho(1450), omega(782) and rho(1700), are required to give a good description of invariant mass spectra and decay angular distributions. The positive and negative charge parity fractions of each of the resonant final states are determined. The f(0)(980) meson is not seen and the upper limit on its presence, compared with the observed f(0)(500) rate, is inconsistent with a model where these scalar mesons are formed from two quarks and two antiquarks (tetraquarks) at the eight standard deviation level. In the q (q) over bar model, the absolute value of the mixing angle between the f(0)(980) and the f(0)(500) scalar mesons is limited to be less than 17 degrees at 90% confidence level.
