Records |
Author |
LHCb Collaboration (Aaij, R. et al); Oyanguren, A.; Ruiz Valls, P. |
Title |
Searches for violation of lepton flavour and baryon number in tau lepton decays at LHCb |
Type |
Journal Article |
Year |
2013 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume |
724 |
Issue |
1-3 |
Pages |
36-45 |
Keywords |
|
Abstract |
Searches for the lepton flavour violating decay tau(-) -> mu(-)mu(+)mu(-) and the lepton flavour and baryon number violating decays tau(-) -> (p) over bar mu(+)mu(-) and tau(-) -> p mu(-)mu(-) have been carried out using proton-proton collision data, corresponding to an integrated luminosity of 1.0 fb(-1), taken by the LHCb experiment at root s = 7 TeV. No evidence has been found for any signal, and limits have been set at 90% confidence level on the branching fractions: B(tau(-) -> mu(-)mu(+)mu(-) < 8.0 x 10(-8), B(tau(-) -> <(p)over bar>mu(+)mu(-)) < 3.3 x 10(-7) and B(tau(-) -> p mu(-)mu(-)) < 4.4 x 10(-7). The results for the tau(-) -> (p) over bar mu(+)mu(-) and tau(-) -> p mu(-)mu(-) decay modes represent the first direct experimental limits on these channels. |
Address |
[Bediaga, I.; De Miranda, J. M.; Ferreira Rodrigues, F.; Massafferri, A.; Nasteva, I.; dos Reis, A. C.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil, Email: jonathan.harrison@hep.manchester.ac.uk |
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 ![sorted by Notes field, ascending order (up)](img/sort_asc.gif) |
WOS:000321538300007 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1686 |
Permanent link to this record |
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Author |
BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A.; Villanueva-Perez, P. |
Title |
Measurement of CP-violating asymmetries in B-0 -> (rho pi)(0) decays using a time-dependent Dalitz plot analysis |
Type |
Journal Article |
Year |
2013 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
88 |
Issue |
1 |
Pages |
012003 - 26pp |
Keywords |
|
Abstract |
We present results for a time-dependent Dalitz plot measurement of CP-violating asymmetries in the mode B-0 -> pi(+)pi(-)pi(0). The data set is derived from the complete sample of 471 x 10(6) B (B) over bar meson pairs collected with the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider at the SLAC National Accelerator Laboratory operating on the Upsilon(4S) resonance. We extract parameters describing the time-dependent B-0 -> rho pi decay probabilities and CP asymmetries, including C = 0.016 +/- 0.059 +/- 0.036, Delta C = 0.234 +/- 0.061 +/- 0.048, S = 0.053 +/- 0.081 +/- 0.034, and Delta S = 0.054 +/- 0.082 +/- 0.039, where the uncertainties are statistical and systematic, respectively. We perform a two-dimensional likelihood scan of the direct CP-violation asymmetry parameters for B-0 -> rho(+/-)pi(-/+) decays, finding the change in chi(2) between the minimum and the origin (corresponding to no direct CP violation) to be Delta chi(2) = 6.42. We present information on the CP-violating parameter alpha in a likelihood scan that incorporates B-+/- -> rho pi measurements. To aid in the interpretation of our results, statistical robustness studies are performed to assess the reliability with which the true values of the physics parameters can be extracted. Significantly, these studies indicate that alpha cannot be reliably extracted with our current sample size, though the other physics parameters are robustly extracted. |
Address |
[Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, CNRS, IN2P3, Lab Annecy Le Vieux Phys Particules LAPP, F-74941 Annecy Le Vieux, France |
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 ![sorted by Notes field, ascending order (up)](img/sort_asc.gif) |
WOS:000322084100001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1492 |
Permanent link to this record |
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Author |
LHCb Collaboration (Aaij, R. et al); Oyanguren, A.; Ruiz Valls, P. |
Title |
Search for D-(s)(+) -> pi(+)mu(+)mu(-) and D-(s)(+) -> pi(-)mu(+)mu(+) decays |
Type |
Journal Article |
Year |
2013 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume |
724 |
Issue |
4-5 |
Pages |
203-212 |
Keywords |
|
Abstract |
A search for non-resonant D-(s)(+) -> pi(+)mu(+)mu(-) and D-(s)(+) -> pi(-)mu(+)mu(+) decays is performed using protonproton collision data, corresponding to an integrated luminosity of 1.0 fb(-1), at root s = 7 TeV recorded by the LHCb experiment in 2011. No signals are observed and the 90% (95%) confidence level (CL) limits on the branching fractions are found to be B(D+ -> pi(+)mu(+)mu(-)) < 7.3 (8.3) x 10(-8), B(D-s(+) -> pi(+)mu(+)mu(-)) < 4.1 (4.8) x 10(-7), B(D-s(+) -> pi(+)mu(+)mu(-)) < 2.2 (2.5) x 10(-8), B(D-s(+) -> pi(+)mu(+)mu(-)) < 1.2 (1.4) x 10(-7). These limits are the most stringent to date. |
Address |
[Bediaga, I.; De Miranda, J. M.; Rodrigues, F. Ferreira; Massafferri, A.; Nasteva, I.; dos Reis, A. C.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil, Email: ed.greening@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 ![sorted by Notes field, ascending order (up)](img/sort_asc.gif) |
WOS:000322358500004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1525 |
Permanent link to this record |
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Author |
BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A.; Villanueva-Perez, P. |
Title |
Search for a light Higgs boson decaying to two gluons or s(s)over-bar in the radiative decays of Upsilon(1S) |
Type |
Journal Article |
Year |
2013 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
88 |
Issue |
3 |
Pages |
031701 - 7pp |
Keywords |
|
Abstract |
We search for the decay Upsilon(1S) -> A(0), A(0) -> gg or s (s) over bar, where A(0) is the pseudoscalar light Higgs boson predicted by the next-to-minimal supersymmetric Standard Model. We use a sample of (17.6 +/- 0.3) x 10(6) Upsilon(1S) mesons produced in the BABAR experiment via e(+)e(-) -> Upsilon(2S) -> pi(+)pi(-)Upsilon(1S). We see no significant signal and set 90%-confidence-level upper limits on the product branching fraction B(Upsilon(1S) -> gamma A(0)) . B(A(0) -> gg or s (s) over bar ranging from 10(-6) to 10(-2) for A(0) masses in the range 0.5-9.0 GeV/c(2). |
Address |
[Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, CNRS, LAPP, IN2P3, F-74941 Annecy Le Vieux, France |
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 |
|
Medium |
|
Area |
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Expedition |
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Conference |
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Notes ![sorted by Notes field, ascending order (up)](img/sort_asc.gif) |
WOS:000322785400001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1549 |
Permanent link to this record |
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Author |
BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A. |
Title |
Evidence of B+ -> tau(+)nu decays with hadronic B tags |
Type |
Journal Article |
Year |
2013 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
88 |
Issue |
3 |
Pages |
031102 - 9pp |
Keywords |
|
Abstract |
We present a search for the decay B+ -> tau(+)nu using 467.8 x 10(6) B (B) over bar pairs collected at the Upsilon(4S) resonance with the BABAR detector at the SLAC PEP-II B-Factory. We select a sample of events with one completely reconstructed B- in the hadronic decay mode (B- -> D-(*X-)0(-) and B- -> J/psi X-). We examine the rest of the event to search for a B+ -> tau(+)nu decay. We identify the tau(+) lepton in the following modes: tau(+) -> e(+)nu(nu) over bar, tau(+) -> mu(+)nu(nu) over bar, tau(+) -> pi(+)(nu) over bar and tau(+) -> rho(+)(nu) over bar. We find an excess of events with respect to the expected background, which excludes the null signal hypothesis at the level of 3.8 sigma (including systematic uncertainties) and corresponds to a branching fraction value of B(B+ -> tau(+)nu) = (1.83(-0.49)(+0.53)(stat) +/- 0.24(syst)) x 10(-4). |
Address |
[Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, CNRS IN2P3, Lab Annecy le Vieux Phys Particules LAPP, F-74941 Annecy Le Vieux, France |
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 |
|
Edition |
|
ISSN |
1550-7998 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
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Notes ![sorted by Notes field, ascending order (up)](img/sort_asc.gif) |
WOS:000322916300001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1547 |
Permanent link to this record |