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Author |
BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A. |
![goto web page (via DOI) doi](img/doi.gif)
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Title |
Evidence for an Excess of (B)over-bar -> D-(*()) tau(-)(nu)over-bar(tau) Decays |
Type |
Journal Article |
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Year |
2012 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
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Volume |
109 |
Issue |
10 |
Pages |
101802 - 8pp |
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Abstract |
Based on the full BABAR data sample, we report improved measurements of the ratios R(D-(*())) = B((B) over bar -> D-(*()) tau(-)(nu) over bar (tau))/B((B) over bar -> D-(*()) l(l)(-)(nu) over bar (l), where l is either e or mu. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure R(D) = 0.440 +/- 0.058 +/- 0.042 and R(D*) = 0.332 +/- 0.024 +/- 0.018, which exceed the standard model expectations by 2.0 sigma and 2.7 sigma, respectively. Taken together, our results disagree with these expectations at the 3.4 sigma level. This excess cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model. |
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Address ![sorted by Address field, descending order (down)](img/sort_desc.gif) |
[Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, LAPP, CNRS, IN2P3, F-74941 Annecy Le Vieux, France |
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Amer Physical Soc |
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English |
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0031-9007 |
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Notes |
WOS:000308394900005 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
1163 |
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Permanent link to this record |
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Author |
BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A. |
![goto web page (via DOI) doi](img/doi.gif)
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Title |
Search for Invisible Decays of a Dark Photon Produced in e(+)e(-) Collisions at BABAR |
Type |
Journal Article |
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Year |
2017 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
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Volume |
119 |
Issue |
13 |
Pages |
131804 - 7pp |
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Keywords |
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Abstract |
We search for single-photon events in 53 fb(-1) of e(+)e(-) collision data collected with the BABAR detector at the PEP-II B-Factory. We look for events with a single high-energy photon and a large missing momentum and energy, consistent with production of a spin-1 particle A' through the process e(+)e(-) -> gamma A'; A' -> invisible. Such particles, referred to as “dark photons,” are motivated by theories applying a U(1) gauge symmetry to dark matter. We find no evidence for such processes and set 90% confidence level upper limits on the coupling strength of A' to e(+)e(-) in the mass range m(A') <= 8 GeV. In particular, our limits exclude the values of the A' coupling suggested by the dark-photon interpretation of the muon (g – 2)(mu) anomaly, as well as a broad range of parameters for the dark-sector models. |
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Address ![sorted by Address field, descending order (down)](img/sort_desc.gif) |
[Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, LAPP, CNRS, IN2P3, F-74941 Annecy Le Vieux, France |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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English |
Summary Language |
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Original Title |
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Series Editor |
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0031-9007 |
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Notes |
WOS:000411996200004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3315 |
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Permanent link to this record |
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Author |
BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A. |
![goto web page (via DOI) doi](img/doi.gif)
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Title |
Search for Rare or Forbidden Decays of the D-0 Meson |
Type |
Journal Article |
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Year |
2020 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
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Volume |
124 |
Issue |
7 |
Pages |
071802 - 8pp |
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Abstract |
We present a search for nine lepton-number-violating and three lepton-flavor-violating neutral charm decays of the type D-0 -> h'(-) h(-) l'(+) l(+) and D-0 -> h'(-) h(+) l'(+/-) l(-/+), where h and h' represent a K or pi meson and l and l' an electron or muon. The analysis is based on 468 fb(-1) of e(+) e(-) annihilation data collected at or close to the Upsilon(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory. No significant signal is observed for any of the twelve modes, and we establish 90% confidence level upper limits on the branching fractions in the range (1.0-30.6) x 10(-7). The limits are between 1 and 3 orders of magnitude more stringent than previous measurements. |
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Address ![sorted by Address field, descending order (down)](img/sort_desc.gif) |
[Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, LAPP, CNRS, IN2P3, F-74941 Annecy Le Vieux, France |
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Amer Physical Soc |
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0031-9007 |
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Notes |
WOS:000515063000004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4301 |
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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. |
![goto web page (via DOI) doi](img/doi.gif)
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Title |
Search for a Dark Photon in e(+)e(-) Collisions at BABAR |
Type |
Journal Article |
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Year |
2014 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
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Volume |
113 |
Issue |
20 |
Pages |
201801 - 8pp |
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Keywords |
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Abstract |
Dark sectors charged under a new Abelian interaction have recently received much attention in the context of dark matter models. These models introduce a light new mediator, the so-called dark photon (A'), connecting the dark sector to the standard model. We present a search for a dark photon in the reaction e(+)e(-) ->gamma A', A' -> e(+)e(-), mu(+) mu(-) using 514 fb(-1) of data collected with the BABAR detector. We observe no statistically significant deviations from the standard model predictions, and we set 90% confidence level upper limits on the mixing strength between the photon and dark photon at the level of 10(-4) – 10(-3) for dark photon masses in the range 0.02-10.2 GeV. We further constrain the range of the parameter space favored by interpretations of the discrepancy between the calculated and measured anomalous magnetic moment of the muon. |
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Address ![sorted by Address field, descending order (down)](img/sort_desc.gif) |
[Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, Lab Annecy le Vieux Phys Particules LAPP, IN2P3, CNRS, F-74941 Annecy Le Vieux, France |
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Publisher |
Amer Physical Soc |
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English |
Summary Language |
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0031-9007 |
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Notes |
WOS:000344919200001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
2004 |
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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. |
![goto web page (via DOI) doi](img/doi.gif)
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Title |
Measurement of the B -> X(s)l(+)l(-) Branching Fraction and Search for Direct CP Violation from a Sum of Exclusive Final States |
Type |
Journal Article |
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Year |
2014 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
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Volume |
112 |
Issue |
21 |
Pages |
211802 - 8pp |
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Keywords |
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Abstract |
We measure the total branching fraction of the flavor-changing neutral-current process B -> X(s)l(+)l(-), along with partial branching fractions in bins of dilepton and hadronic system (X-s) mass, using a sample of 471 x 10(6)Upsilon(4S) -> B (B) over bar events recorded with the BABAR detector. The admixture of charged and neutral B mesons produced at PEP-II2 are reconstructed by combining a dilepton pair with 10 different X-s final states. Extrapolating from a sum over these exclusive modes, we measure a lepton-flavor-averaged inclusive branching fraction B(B -> X(s)l(+)l(-)) = [6.73(-0.64)(+0.70)(stat)(-0.25)(+0.34)(exp syst) +/- 0.50(model syst)] x 10(-6) for m(l+l-)(2) > 0.1 GeV2/c(4). Restricting our analysis exclusively to final states from which a decaying B meson's flavor can be inferred, we additionally report measurements of the direct CP asymmetry A(CP) in bins of dilepton mass; over the full dilepton mass range, we find A(CP) = 0.04 +/- 0.11 +/- 0.01 for a leptonflavor-averaged sample. |
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Address ![sorted by Address field, descending order (down)](img/sort_desc.gif) |
[Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, Lab Annecy le Vieux Phys Particules LAPP, CNRS, IN2P3, F-74941 Annecy Le Vieux, France |
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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:000338034400002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
1827 |
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Permanent link to this record |