| Records |
| Author |
LHCb Collaboration (Aaij, R. et al); Garcia Martin, L.M.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Valls, P.; Sanchez Mayordomo, C. |
| Title |
Measurement of matter-antimatter differences in beauty baryon decays |
Type |
Journal Article |
| Year |
2017 |
Publication |
Nature Physics |
Abbreviated Journal |
Nat. Phys. |
| Volume |
13 |
Issue |
4 |
Pages |
391-396 |
| Keywords |
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| Abstract |
Differences in the behaviour of matter and antimatter have been observed in K and B meson decays, but not yet in any baryon decay. Such differences are associated with the non-invariance of fundamental interactions under the combined chargeconjugation and parity transformations, known as CP violation. Here, using data from the LHCb experiment at the Large Hadron Collider, we search for CP-violating asymmetries in the decay angle distributions of A(b)(0) baryons decaying to p pi(-)pi(+)pi(-) and p pi-K+K- final states. These four-body hadronic decays are a promising place to search for sources of CP violation both within and beyond the standard model of particle physics. We find evidence for CP violation in A(b)(0) to p pi(-)pi(+)pi(-) decays with a statistical significance corresponding to 3.3 standard deviations including systematic uncertainties. This represents the first evidence for CP violation in the baryon sector. |
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| Corporate Author |
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Thesis |
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| Publisher |
Nature Publishing Group |
Place of Publication |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1745-2473 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000398262900020 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
3170 |
| Permanent link to this record |
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| Author |
LHCb Collaboration (Aaij, R. et al); Oyanguren, A.; Ruiz Valls, P. |
| Title |
First Observation of CP Violation in the Decays of B-s(0) Mesons |
Type |
Journal Article |
| Year |
2013 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
| Volume |
110 |
Issue |
22 |
Pages |
221601 - 9pp |
| Keywords |
|
| Abstract |
Using pp collision data corresponding to an integrated luminosity of 1.0 fb(-1) and collected by LHCb in 2011 at a center-of-mass energy of 7 TeV, we report the measurement of direct CP violation in B-s(0) -> K-pi(+) decays, A(CP) (B-s(0) -> K-pi(+)) = 0.27 +/- 0.04(stat) +/- 0.01(syst), with significance exceeding 5 standard deviations. This is the first observation of CP violation in the decays of B-s(0) mesons. Furthermore, we provide an improved determination of direct CP violation in B-0 -> K+pi(-) decays, A(CP)(B-0 -> K+pi(-) ) = -0.080 +/- 0.007(stat) +/- 0.003(syst), which is the most precise measurement of this quantity to date. |
| Address |
CBPF, Rio De Janeiro, Brazil |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0031-9007 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000319738400003 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1465 |
| Permanent link to this record |
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| Author |
LHCb Collaboration (Aaij, R. et al); Oyanguren, A.; Ruiz Valls, P. |
| Title |
Determination of the X(3872) Meson Quantum Numbers |
Type |
Journal Article |
| Year |
2013 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
| Volume |
110 |
Issue |
22 |
Pages |
222001 - 8pp |
| Keywords |
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| Abstract |
The quantum numbers of the X(3872) meson are determined to be J(PC) = 1(++) based on angular correlations in B+ -> X(3872)K+ decays, where X(3872) -> pi(+) pi(-) j/psi and J/psi -> pi(+) mu(-). The data correspond to 1.0 fb(-1) of pp collisions collected by the LHCb detector. The only alternative assignment allowed by previous measurements J(PC) = 2(-+) is rejected with a confidence level equivalent to more than 8 Gaussian standard deviations using a likelihood-ratio test in the full angular phase space. This result favors exotic explanations of the X(3872) state. |
| Address |
CBPF, Rio De Janeiro, Brazil |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0031-9007 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000319682200007 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1466 |
| Permanent link to this record |
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| |
| Author |
LHCb Collaboration (Aaij, R. et al); Oyanguren, A.; Ruiz Valls, P. |
| Title |
First Measurement of the CP-Violating Phase in B-s(0) -> phi phi Decays |
Type |
Journal Article |
| Year |
2013 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
| Volume |
110 |
Issue |
24 |
Pages |
241802 - 8pp |
| Keywords |
|
| Abstract |
A first flavor-tagged measurement of the time-dependent CP-violating asymmetry in B-s(0) -> phi phi decays is presented. In this decay channel, the CP-violating weak phase arises due to CP violation in the interference between B-s(0)-(B) over bar (0)(s) mixing and the b -> s (s) over bars gluonic penguin decay amplitude. Using a sample of pp collision data corresponding to an integrated luminosity of 1.0 fb(-1) and collected at a center-of-mass energy of 7 TeV with the LHCb detector, 880 B-s(0) -> phi phi signal decays are obtained. The CP-violating phase is measured to be in the interval [-2.46, -0.76] rad at a 68% confidence level. The p value of the standard model prediction is 16%. |
| Address |
CBPF, Rio De Janeiro, Brazil |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0031-9007 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000320307400005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1472 |
| Permanent link to this record |
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| Author |
LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C. |
| Title |
Measurement of forward Z -> e(+)e(-) production at root s=8 TeV |
Type |
Journal Article |
| Year |
2015 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
05 |
Issue |
5 |
Pages |
109 - 21pp |
| Keywords |
Electroweak interaction; QCD; Forward physics; Hadron-Hadron Scattering; proton-proton scattering |
| Abstract |
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 < eta < 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(pp -> Z -> e(+)e(-)) = 93.81 +/- 0.41(stat) +/- 1.48(syst) +/- 1.14(lumi) pb, 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 phi*, which is related to the Z-boson transverse momentum. |
| Address |
CBPF, Rio De Janeiro, Brazil, Email: drw1@cam.ac.uk |
| Corporate Author |
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Thesis |
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| Publisher |
Springer |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1029-8479 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000354977800001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2236 |
| Permanent link to this record |
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| Author |
LHCb Collaboration (Aaij, R. et al); Oyanguren, A.; Ruiz Valls, P. |
| Title |
Observation of the suppressed ADS modes B-+/- -> [pi K-+/-(-/+)pi(+)pi(-)](D)K-+/- and B-+/- -> [pi K-+/-(-/+)pi(+)pi(-)](D)pi(+/-) |
Type |
Journal Article |
| Year |
2013 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
723 |
Issue |
1-3 |
Pages |
44-53 |
| Keywords |
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| Abstract |
An analysis of and B-+/- -> DK +/- and B-+/- -> D pi(+/-) decays is presented where the D meson is reconstructed in the four-body final state K-+/-pi(-/+)pi(+)pi(-). Using LHCb data corresponding to an integrated luminosity of 1.0 fb(-1), first observations are made of the suppressed ADS modes B-+/- ->[pi K-+/-(-/+)pi(+)pi(-)](D)K-+/- and B +/- -> [pi K-+/-(-/+)pi(+)pi(-)](D)pi(+/-) with a significance of 5.1 sigma and greater than 10 sigma, respectively. Measurements of CP asymmetries and CP-conserving ratios of partial widths from this family of decays are also performed. The magnitude of the ratio between the suppressed and favoured B-+/- -> DK +/- amplitudes is determined to be r(B)(K) = 0.097 +/- 0.011. |
| Address |
CBPF, Rio De Janeiro, Brazil, Email: guy.wilkinson@cern.ch |
| Corporate Author |
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Thesis |
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| Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0370-2693 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000320206500005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1475 |
| Permanent link to this record |
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| |
| Author |
LHCb Collaboration (Aaij, R. et al); Oyanguren, A.; Ruiz Valls, P. |
| Title |
Observation of the decay B-c(+) -> psi(2S)pi(+) |
Type |
Journal Article |
| Year |
2013 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
87 |
Issue |
7 |
Pages |
071103 - 7pp |
| Keywords |
|
| Abstract |
The decay B-c(+) -> psi(2S)pi(+) with psi(2S) -> mu(+)mu(-) is observed with a significance of 5.2 sigma using pp collision data corresponding to an integrated luminosity of 1.0 fb(-1) collected by the LHCb experiment. The branching fraction of B-c(+) -> psi(2S)pi(+) decays relative to that of the B-c(+) -> J/psi pi(+) mode is measured to be B(B-c(+) -> psi(2S)pi(+))/B(B-c(+) -> J/psi pi(+)) = 0.250 +/- 0.068(stat) +/- 0.014(syst) +/- 0.006(B). The last term is the uncertainty on the ratio B(psi(2S) -> mu(+)mu(-))/B(J/psi -> mu(+)mu(-)). |
| Address |
Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1550-7998 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000318183700001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1419 |
| Permanent link to this record |
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| |
| Author |
LHCb Collaboration (Aaij, R. et al); Oyanguren, A.; Ruiz Valls, P. |
| Title |
Search for the decay B-s(0) -> D*(-/+)pi(+/-) |
Type |
Journal Article |
| Year |
2013 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
87 |
Issue |
7 |
Pages |
071101 - 8pp |
| Keywords |
|
| Abstract |
A search for the decay B-s(0) -> D*(-/+)pi(+/-) is presented using a data sample corresponding to an integrated luminosity of 1.0 fb(-1) of pp collisions collected by LHCb. This decay is expected to be mediated by a W-exchange diagram, with little contribution from rescattering processes, and therefore a measurement of the branching fraction will help us to understand the mechanism behind related decays such as B-s(0) -> pi(+)pi(-) and B-s(0) -> D (D) over bar. Systematic uncertainties are minimized by using B-0 -> D*(-/+)pi(+/-) as a normalization channel. We find no evidence for a signal, and set an upper limit on the branching fraction of B(B-s(0) -> D*(-/+)pi(+/-) < 6.1(7.8) x 10(-6) at 90% (95%) confidence level. |
| Address |
Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1550-7998 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:000317912600001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1422 |
| Permanent link to this record |
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| Author |
LHCb Collaboration (Aaij, R. et al); Oyanguren, A.; Ruiz Valls, P. |
| Title |
First observations of (B)over-bar(s)(0) -> D+D-, Ds+D- and D-0(D)over-bar(0) decays |
Type |
Journal Article |
| Year |
2013 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
87 |
Issue |
9 |
Pages |
092007 - 12pp |
| Keywords |
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| Abstract |
First observations and measurements of the branching fractions of the (B) over bar (0)(s) -> D+D-, (B) over bar (0)(s) -> Ds+D- and (B) over bar (0)(s) -> D-0(D) over bar (0) decays are presented using 1.0 fb(-1) of data collected by the LHCb experiment. These branching fractions are normalized to those of (B) over bar (0) -> D+D-, B-0 -> D-Ds+ and B- -> (DDs-)-D-0, respectively. An excess of events consistent with the decay (B) over bar (0) -> D-0(D) over bar (0) is also seen, and its branching fraction is measured relative to that of B- -> D0Ds-. Improved measurements of the branching fractions B((B) over bar (0)(s) -> Ds+Ds-) and B(B- -> (DDs-)-D-0) are reported, each relative to B(B-0 -> D-Ds+). The ratios of branching fractions are B((B) over bar (0)(s) -> D+D-)/B((B) over bar (0) -> D+D-) = 1.08 +/- 0.20 +/- 0.10, B((B) over bar (0)(s) -> Ds+D-)/B(B-0 -> D-Ds+) = 0.050 +/- 0.008 +/- 0.004, B((B) over bar (0)(s) -> D-0(D) over bar (0))/B((B) over bar (-) -> (DDs-)-D-0) = 0.019 +/- 0.003 +/- 0.003, B((B) over bar (0) -> D-0(D) over bar (0))/B(B- -> (DDs-)-D-0) < 0.0024 at 90% CL, B(<(B)over bar>(0)(s) -> D-s(+)(D) over bar (-)(s))/B(B-0 -> D-Ds+) = 0.56 +/- 0.03 +/- 0.04, B(B -> (DDs)-D-0)/B(B-0 -> D-Ds+) = 1.22 +/- 0.02 +/- 0.07, where the uncertainties are statistical and systematic, respectively. |
| Address |
Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1550-7998 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000319283500001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1460 |
| Permanent link to this record |
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| Author |
LHCb Collaboration (Aaij, R. et al); Oyanguren, A.; Ruiz Valls, P. |
| Title |
Observations of B-S(0) ->psi(2S)eta and B-(s)(0) ->psi(2S)pi(+)pi(-) decays |
Type |
Journal Article |
| Year |
2013 |
Publication |
Nuclear Physics B |
Abbreviated Journal |
Nucl. Phys. B |
| Volume |
871 |
Issue |
3 |
Pages |
403-419 |
| Keywords |
|
| Abstract |
First observations of the B-S(0) ->psi(2S)eta, B-(s)(0) ->psi(2S)pi(+)pi(-) decays are made using a dataset corresponding to an integrated luminosity of 1.0 fb(-1) collected by the LHCb experiment in proton proton collisions at a centre-of-mass energy of root s = 7 TeV. The ratios of the branching fractions of each of the *(2S) modes with respect to the corresponding J/psi decays are B(B-s(0) ->psi(2S)eta)/B(B-s(0) -> J(2S)eta) = 0.83 +/- 0.14 (stat) +/- 0.12 (B), B(B0 ->psi(2S)pi(+)pi(-))/B(B0 -> J/psi pi(+)pi(-)) = 0.56 +/- 0.07 (stat) +/- 0.05 (syst) +/- 0.01 (B), B(B0 ->psi(2S)pi(+)pi(-))/B(B-s(0) -> J/psi pi(+)pi(-)) = 0.34 +/- 0.04 (stat) +/- 0.03 (syst) +/- 0.01 (B). where the third uncertainty corresponds to the uncertainties of the dilepton branching fractions of the J/* and psi(28) meson decays. |
| Address |
Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil, Email: Ivan.Belyaev@itep.ru |
| Corporate Author |
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Thesis |
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| Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0550-3213 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000317450600001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1400 |
| Permanent link to this record |
