Records |
Author |
LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C. |
Title |
Measurement of the Ratio of Branching Fractions B((B)over-bar(0) -> D-*(+)tau(-)(nu)over-bar(tau))/B((B)over-bar(0) -> D-*(+)mu(-)(nu)over-bar(mu)) |
Type |
Journal Article |
Year |
2015 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
115 |
Issue |
11 |
Pages |
111803 - 10pp |
Keywords |
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Abstract |
The branching fraction ratio R(D-*) = B((B) over bar (0) -> D-*(+)tau(-)(nu) over bar (tau))/B((B) over bar (0) -> D-*(+)mu(-)(nu) over bar (mu)) is measured using a sample of proton-proton collision data corresponding to 3.0 fb(-1) of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode tau(-) -> mu(-)(nu) over bar (mu)nu(tau). The semitauonic decay is sensitive to contributions from non-standard-model particles that preferentially couple to the third generation of fermions, in particular, Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate (B) over bar (0) decays gives R(D-*) = 0.336 +/- 0.027(stat) +/- 0.030(syst). This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the standard model. |
Address |
[Bediaga, I.; De Miranda, J. M.; Ferreira Rodrigues, F.; Gomes, A.; Massafferri, A.; Rodrigues, B. Osorio; dos Reis, A. C.; Rodrigues, A. B.] CBPF, Rio De Janeiro, Brazil |
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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 ![sorted by Edition field, descending order (down)](img/sort_desc.gif) |
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ISSN |
0031-9007 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000360894300004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2384 |
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 |
First Observation of Top Quark Production in the Forward Region |
Type |
Journal Article |
Year |
2015 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
115 |
Issue |
11 |
Pages |
112001 - 10pp |
Keywords |
|
Abstract |
Top quark production in the forward region in proton-proton collisions is observed for the first time. The W + b final state with W -> μnu is reconstructed using muons with a transverse momentum, p(T), larger than 25 GeV in the pseudorapidity range 2.0 < eta < 4.5. The b jets are required to have 50 < p(T) < 100 GeV and 2.2 < eta < 4.2, while the transverse component of the sum of the muon and b-jet momenta must satisfy p(T) > 20 GeV. The results are based on data corresponding to integrated luminosities of 1.0 and 2.0 fb(-1) collected at center-of-mass energies of 7 and 8 TeV by LHCb. The inclusive top quark production cross sections in the fiducial region are sigma(top)[7 TeV] = 239 +/- 53(stat) +/- 33(syst) +/- 24(theory) fb; sigma(top)[8 TeV ] = 289 +/- 43(stat) +/- 40(syst) +/- 29(theory) fb: These results, along with the observed differential yields and charge asymmetries, are in agreement with next-to-leading order standard model predictions. |
Address |
[Bediaga, I.; De Miranda, J. M.; Ferreira Rodrigues, F.; Massafferri, A.; Osorio Rodrigues, B.; dos Reis, A. C.; Rodrigues, A. B.] 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 ![sorted by Edition field, descending order (down)](img/sort_desc.gif) |
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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:000360893600006 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2387 |
Permanent link to this record |
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Author |
BABAR and Belle Collaborations (Abdesselam, A. et al); Martinez-Vidal, F.; Oyanguren, A. |
Title |
First Observation of CP Violation in (B)over-bar(0) -> D(CP)((*))h(0) Decays by a Combined Time-Dependent Analysis of BABAR and Belle Data |
Type |
Journal Article |
Year |
2015 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
115 |
Issue |
12 |
Pages |
121604 - 10pp |
Keywords |
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Abstract |
We report a measurement of the time-dependent CP asymmetry of (B) over bar (0) -> D(CP)((*))h(0) decays, where the light neutral hadron h(0) is a pi(0), eta , or omega meson, and the neutral D meson is reconstructed in the CP eigenstates K+K-, K-S(0)pi(0) or K-S(0)omega. The measurement is performed combining the final data samples collected at the Upsilon(4S) resonance by the BABAR and Belle experiments at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain (471 +/- 3) x 10(6) B (B) over bar pairs recorded by the BABAR detector and (772 +/- 11) x 10(6) B (B) over bar pairs recorded by the Belle detector. We measure the CP asymmetry parameters -eta S-f = +0.66 +/- 0.10(stat) +/- 0.06(syst) and C = -0.02 +/- 0.07(stat) +/- 0.03(syst). These results correspond to the first observation of CP violation in (B) over bar (0) -> D(CP)((*))h(0) decays. The hypothesis of no mixing-induced CP violation is excluded in these decays at the level of 5.4 standard deviations. |
Address |
[Lee, M. J.; 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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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 ![sorted by Edition field, descending order (down)](img/sort_desc.gif) |
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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:000361316500005 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2390 |
Permanent link to this record |
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Author |
ATLAS Collaboration (Aad, G. et al); Alvarez Piqueras, D.; Cabrera Urban, S.; Castillo Gimenez, V.; Costa, M.J.; Fernandez Martinez, P.; Ferrer, A.; Fiorini, L.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gonzalez de la Hoz, S.; Hernandez Jimenez, Y.; Higon-Rodriguez, E.; Irles Quiles, A.; Jimenez Pena, J.; Kaci, M.; King, M.; Lacasta, C.; Lacuesta, V.R.; Marti-Garcia, S.; Mitsou, V.A.; Moles-Valls, R.; Oliver Garcia, E.; Pedraza Lopez, S.; Perez Garcia-Estañ, M.T.; Romero Adam, E.; Ros, E.; Salt, J.; Sanchez Martinez, V.; Soldevila, U.; Sanchez, J.; Torro Pastor, E.; Valero, A.; Valladolid Gallego, E.; Valls Ferrer, J.A.; Vos, M. |
Title |
Search for Dark Matter in Events with Missing Transverse Momentum and a Higgs Boson Decaying to Two Photons in pp Collisions at root s=8 TeV with the ATLAS Detector |
Type |
Journal Article |
Year |
2015 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
115 |
Issue |
13 |
Pages |
131801 - 19pp |
Keywords |
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Abstract |
Results of a search for new phenomena in events with large missing transverse momentum and a Higgs boson decaying to two photons are reported. Data from proton-proton collisions at a center-of-mass energy of 8 TeV and corresponding to an integrated luminosity of 20.3 fb(-1) have been collected with the ATLAS detector at the LHC. The observed data are well described by the expected standard model backgrounds. Upper limits on the cross section of events with large missing transverse momentum and a Higgs boson candidate are also placed. Exclusion limits are presented for models of physics beyond the standard model featuring dark-matter candidates. |
Address |
[Jackson, P.; Lee, L.; Soni, N.; White, M. J.] Univ Adelaide, Dept Phys, Adelaide, SA, Australia |
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 ![sorted by Edition field, descending order (down)](img/sort_desc.gif) |
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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:000361677000005 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2393 |
Permanent link to this record |
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Author |
XENON Collaboration (Aprile, E. et al); Orrigo, S.E.A. |
Title |
Search for Event Rate Modulation in XENON100 Electronic Recoil Data |
Type |
Journal Article |
Year |
2015 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
115 |
Issue |
9 |
Pages |
091302 - 6pp |
Keywords |
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Abstract |
We have searched for periodic variations of the electronic recoil event rate in the (2-6) keVenergy range recorded between February 2011 and March 2012 with the XENON100 detector, adding up to 224.6 live days in total. Following a detailed study to establish the stability of the detector and its background contributions during this run, we performed an unbinned profile likelihood analysis to identify any periodicity up to 500 days. We find a global significance of less than 1 sigma for all periods, suggesting no statistically significant modulation in the data. While the local significance for an annual modulation is 2.8 sigma, the analysis of a multiple-scatter control sample and the phase of the modulation disfavor a dark matter interpretation. The DAMA/LIBRA annual modulation interpreted as a dark matter signature with axial-vector coupling of weakly interacting massive particles to electrons is excluded at 4.8 sigma. |
Address |
[Aprile, E.; Anthony, M.; Contreras, H.; de Perio, P.; Goetzke, L. W.; Fernandez, A. J. Melgarejo; Messina, M.; Plante, G.; Rizzo, A.; Weber, M.; Zhang, Y.] Columbia Univ, Dept Phys, New York, NY 10027 USA, Email: feigao.ge@sjtu.edu.cn; |
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 |
|
Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition ![sorted by Edition field, descending order (down)](img/sort_desc.gif) |
|
ISSN |
0031-9007 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000360289000004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2399 |
Permanent link to this record |