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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 (down) 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 Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000360893600006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2387
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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 (down) Phys. Rev. Lett.
Volume 115 Issue 12 Pages 121604 - 10pp
Keywords
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
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000361316500005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2390
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Author LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C.
Title Search for Hidden-Sector Bosons in B-0 -> K*(0)mu(+)mu(-) Decays Type Journal Article
Year 2015 Publication Physical Review Letters Abbreviated Journal (down) Phys. Rev. Lett.
Volume 115 Issue 16 Pages 161802 - 10pp
Keywords
Abstract A search is presented for hidden-sector bosons, chi, produced in the decay B-0 -> K*(892)(0)chi, with K*(892)(0) -> K+pi(-) and chi -> mu(+)mu(-). The search is performed using pp-collision data corresponding to 3.0 fb(-1) collected with the LHCb detector. No significant signal is observed in the accessible mass range 214 <= m(chi) <= 4350 MeV, and upper limits are placed on the branching fraction product B(B-0 -> K*(892)(0)chi) X B(chi -> mu(+)mu(-)) as a function of the mass and lifetime of the chi boson. These limits are of the order of 10(-9) for chi lifetimes less than 100 ps over most of the m(chi) range, and place the most stringent constraints to date on many theories that predict the existence of additional low-mass bosons.
Address [Bediaga, I.; De Miranda, J. M.; Ferreira Rodrigues, F.; Gomes, A.; Massafferri, A.; Osorio Rodrigues, B.; dos Reis, A. C.; Rodrigues, A. B.] CBPF, Rio De Janeiro, Brazil
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000362909100005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2414
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Author LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C.
Title Evidence for the Strangeness-Changing Weak Decay Xi(-)(b) -> Lambda(0)(b)pi(-) Type Journal Article
Year 2015 Publication Physical Review Letters Abbreviated Journal (down) Phys. Rev. Lett.
Volume 115 Issue 24 Pages 241801 - 10pp
Keywords
Abstract Using a pp collision data sample corresponding to an integrated luminosity of 3.0 fb(-1), collected by the LHCb detector, we present the first search for the strangeness-changing weak decay Xi(-)(b) -> Delta(0)(b)pi(-). No b hadron decay of this type has been seen before. A signal for this decay, corresponding to a significance of 3.2 standard deviations, is reported. The relative rate is measured to be f Xi(-)(b)/f Lambda B-0(b)(Xi(-)(b) -> Lambda(0)(b)pi(-)) = (5.7 +/- 1.8(-0.9)(+0.8)) x 10(-4) where f Xi(-)(b) and f Lambda(0)(b) are the b -> Xi(-)(b) and b -> Lambda(0)(b) fragmentation fractions, and B(Xi(-)(b) -> Lambda(0)(b)pi(-)) is the branching fraction. Assuming f Xi(-)(b)/f Lambda(0)(b) is bounded between 0.1 and 0.3, the branching fraction B(Xi(-)(b) -> Lambda(0)(b)pi(-)) would lie in the range from (0.57 +/- 0.21)% to (0.19 +/- 0.07)%.
Address [Bediaga, I.; De Miranda, J. M.; Ferreira Rodrigues, F.; Gomes, A.; Massafferri, A.; Osorio Rodrigues, B.; dos Reis, A. C.; Rodrigues, A. B.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000366171900003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2484
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Author BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A.
Title Observation of (B)over-bar -> D-(*()) pi(+)pi(-)l(-)(nu)over-bar Decays in e(+)e(-) Collisions at the Upsilon(4S) Resonance Type Journal Article
Year 2016 Publication Physical Review Letters Abbreviated Journal (down) Phys. Rev. Lett.
Volume 116 Issue 4 Pages 041801 - 7pp
Keywords
Abstract We report on measurements of the decays of (B) over bar mesons into the semileptonic final states (B) over bar -> D-(*())pi(+)pi(-)l(-)(nu) over bar, where D-(*()) represents a D or D* meson and l(-) is an electron or a muon. These measurements are based on 471 x 10(6) B (B) over bar pairs recorded with the BABAR detector at the SLAC asymmetric B factory PEP-II. We determine the branching fraction ratios R-pi+pi-(()*()) = B((B) over bar -> D-(*())pi(+)pi(-)l(-)(nu) over bar /B (B) over bar -> D-(*())l(-)(nu) over bar) using events in which the second B meson is fully reconstructed. We find R pi+pi- = 0.067 +/- 0.010 +/- 0.008 and R pi+pi-* = 0.019 +/- 0.005 +/- 0.004, where the first uncertainty is statistical and the second is systematic. Based on these results and assuming isospin invariance, we estimate that (B) over bar -> D-(*())pi pi l (nu) over bar decays, where pi denotes either a pi(+/-) and pi(0) meson, account for up to half the difference between the measured inclusive semileptonic branching fraction to charm hadrons and the corresponding sum of previously measured exclusive branching fractions.
Address [Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, CNRS, IN2P3, LAPP, F-749412 Annecy Le Vieux, France
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000369337200004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2546
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Author LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C.
Title Model-Independent Evidence for J/psi p Contributions to Lambda(0)(b) -> J/psi pK(-) Decays Type Journal Article
Year 2016 Publication Physical Review Letters Abbreviated Journal (down) Phys. Rev. Lett.
Volume 117 Issue 8 Pages 082002 - 9pp
Keywords
Abstract The data sample of Lambda(0)(b) -> J/psi pK(-) decays acquired with the LHCb detector from 7 and 8 TeV pp collisions, corresponding to an integrated luminosity of 3 fb(-1), is inspected for the presence of J/psi p or J/psi K- contributions with minimal assumptions about K(-)p contributions. It is demonstrated at more than nine standard deviations that Lambda(0)(b) -> J/psi pK(-) decays cannot be described with K- p contributions alone, and that J/psi K- contributions play a dominant role in this incompatibility. These model-independent results support the previously obtained model-dependent evidence for P-c(+)-> J/psi p charmonium-pentaquark states in the same data sample.
Address [Bediaga, I.; De Miranda, J. M.; Ferreira Rodrigues, F.; Furfaro, E.; Gomes, A.; Massafferri, A.; Rodrigues, B. Osorio; dos Reis, A. C.; Rodrigues, A. B.; Santovetti, E.] CBPF, Rio De Janeiro, Brazil
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000381608500003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2769
Permanent link to this record
 

 
Author LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C.
Title Observation of B-s(0) -> (D)over-bar(0)K(S)(0) and Evidence for B-s(0) -> (D)over-bar*K-0(S)0 Decays Type Journal Article
Year 2016 Publication Physical Review Letters Abbreviated Journal (down) Phys. Rev. Lett.
Volume 116 Issue 16 Pages 161802 - 9pp
Keywords
Abstract The first observation of the B-s(0) -> (D) over bar K-0(S)0 decay mode and evidence for the B-s(0) -> (D) over bar*K-0(S)0 decay mode are reported. The data sample corresponds to an integrated luminosity of 3.0 fb-1 collected in pp collisions by LHCb at center-of-mass energies of 7 and 8 TeV. The branching fractions are measured to be B(B-s(0) -> (D) over bar (0)(K) over bar (0)) = [4.3 +/- 0.5(stat) +/- 0.3 (syst) +/- 0.3(frag) +/- 0.6(norm)] x 10(-4), B(B-s(0) -> (D) over bar*(0)(K) over bar (0)) = [2.8 +/- 1.0(stat) +/- 0.3 (syst) +/- 0.2(frag) +/- 0.4(norm)] x 10(-4), where the uncertainties are due to contributions coming from statistical precision, systematic effects, and the precision of two external inputs, the ratio f(s)/f(d) and the branching fraction of B-0 (D) over bar K-0(S)0, which is used as a calibration channel.
Address [Bediaga, I.; De Miranda, J. M.; Ferreira Rodrigues, F.; Gomes, A.; Lucchesi, D.; Massafferri, A.; Osorio Rodrigues, B.; dos Reis, A. C.; Rodrigues, A. B.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000374559700005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2672
Permanent link to this record
 

 
Author LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C.
Title Measurement of the Difference of Time-Integrated CP Asymmetries in D-0 -> K-K+ and D-0 -> pi(-)pi(+) Decays Type Journal Article
Year 2016 Publication Physical Review Letters Abbreviated Journal (down) Phys. Rev. Lett.
Volume 116 Issue 19 Pages 191601 - 10pp
Keywords
Abstract A search for CP violation in D-0 -> K-K+ and D-0 -> pi(-)pi(+) decays is performed using pp collision data, corresponding to an integrated luminosity of 3 fb(-1), collected using the LHCb detector at center-of-mass energies of 7 and 8 TeV. The flavor of the charm meson is inferred from the charge of the pion in D*(+) -> D-0 pi(+) and D*(-) -> (D) over bar (0)pi(-) decays. The difference between the CP asymmetries in D-0 -> K-K+ and D-0 -> pi(-)pi(+) decays, Delta A(CP) A(CP)(K-K+) – A(CP)(pi(-)pi(+)), is measured to be [-0.10 +/- 0.08(stat) +/- 0.03(syst)]%. This is the most precise measurement of a time-integrated CP asymmetry in the charm sector from a single experiment.
Address [Bediaga, I.; De Miranda, J. M.; Ferreira Rodrigues, F.; Fleuret, F.; Gomes, A.; Massafferri, A.; Osorio Rodrigues, B.; dos Reis, A. C.; Rodrigues, A. B.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000376011400003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2681
Permanent link to this record
 

 
Author LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C.
Title Search for violations of Lorentz invariance and CPT symmetry in B-(s)(0) mixing Type Journal Article
Year 2016 Publication Physical Review Letters Abbreviated Journal (down) Phys. Rev. Lett.
Volume 116 Issue 24 Pages 241601 - 10pp
Keywords
Abstract Violations of CPT symmetry and Lorentz invariance are searched for by studying interference effects in B-0 mixing and in B-s(0) mixing. Samples of B-0 -> J/psi K-S(0) and B-0(s) -> J/psi K+K- decays are recorded by the LHCb detector in proton-proton collisions at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb(-1). No periodic variations of the particle-antiparticle mass differences are found, consistent with Lorentz invariance and CPT symmetry. Results are expressed in terms of the standard model extension parameter Delta a(mu) with precisions of O(10(-15)) and O(10(-14)) GeV for the B-0 and B-s(0) systems, respectively. With no assumption on Lorentz (non) invariance, the CPT-violating parameter z in the B-s(0) system is measured for the first time and found to be Re(z) = -0.022 +/- 0.033 +/- 0.005 and Im(z) = 0.004 +/- 0.011 +/- 0.002, where the first uncertainties are statistical and the second systematic.
Address [Bediaga, I.; De Miranda, J. M.; Ferreira Rodrigues, F.; Gomes, A.; Massafferri, A.; Osorio Rodrigues, B.; dos Reis, A. C.; Rodrigues, A. B.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000377813100002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2725
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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 D-0 – (D)over-bar(0) Oscillations in D-0 -> K+pi(-)pi(+)pi(-) Decays and Measurement of the Associated Coherence Parameters Type Journal Article
Year 2016 Publication Physical Review Letters Abbreviated Journal (down) Phys. Rev. Lett.
Volume 116 Issue 24 Pages 241801 - 10pp
Keywords
Abstract Charm meson oscillations are observed in a time-dependent analysis of the ratio of D-0 -> K+pi(-)pi(+)pi(-) to D-0 -> K-pi(+)pi(-)pi(+) decay rates, using data corresponding to an integrated luminosity of 3.0 fb(-1) recorded by the LHCb experiment. The measurements presented are sensitive to the phase-space averaged ratio of doubly Cabibbo-suppressed to Cabibbo-favored amplitudes r(D)(K3 pi) and the product of the coherence factor R-D(K3 pi) and a charm mixing parameter y'(K3 pi). The constraints measured are r(D)(K3 pi) = (5.67 +/- 0.12) x 10(-2), which is the most precise determination to date, and R-D(K3 pi) y'(K3 pi) = (0.3 +/- 1.8) x 10(-3), which provides useful input for determinations of the CP-violating phase gamma in B-+/- -> DK +/-, D -> K--/+pi(+/-)pi(-/+)pi(+/-) decays. The analysis also gives the most precise measurement of the D-0 -> K+pi(-)pi(+)pi(-) branching fraction, and the first observation of D-0-(D) over bar (0) oscillations in this decay mode, with a significance of 8.2 standard deviations.
Address [Bediaga, I.; De Miranda, J. M.; Ferreira Rodrigues, F.; Gomes, A.; Osorio Rodrigues, B.; Dos Reis, A. C.; Rodrigues, A. B.; Tomassetti, L.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000378059500006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2734
Permanent link to this record