| Records |
| Author |
LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C. |
| Title |
Study of chi(b) meson production in pp collisions at root s=7 and 8 TeV and observation of the decay chi(b) (3P) -> gamma(3S)gamma |
Type |
Journal Article |
| Year |
2014 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
| Volume |
74 |
Issue |
10 |
Pages  |
3092 - 13pp |
| Keywords |
|
| Abstract |
A study of chi(b) meson production at LHCb is performed on proton-proton collision data, corresponding to 3.0 fb(-1) of integrated luminosity collected at centre-of-mass energies root s = 7 and 8 TeV. The fraction of gamma(nS) mesons originating from chi(b) decays is measured as a function of the gamma transverse momentum in the rapidity range 2.0 < y(gamma) < 4.5. The radiative transition of the chi(b) (3P) meson to gamma(3S) is observed for the first time. The chi(b)1 (3P) mass is determined to be m chi(b1) (3P) = 10 511.3 +/- 1.7 +/- 2.5MeV/c(2), where the first uncertainty is statistical and the second is systematic. |
| Address |
[Bediaga, I.; De Miranda, J. M.; Rodrigues, F. Ferreira; Gomes, A.; Hicheur, A.; Massafferri, A.; dos Reis, A. C.; Rodrigues, A. B.; Santovetti, E.] CBPF, Rio De Janeiro, Brazil, Email: Ivan.Belyaev@cern.ch |
| 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 |
|
Edition |
|
| ISSN |
1434-6044 |
ISBN |
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Medium |
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| Area |
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Expedition |
|
Conference |
|
| Notes |
WOS:000346417200001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2053 |
| Permanent link to this record |
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| |
| Author |
LHCb Collaboration (Aaij, R. et al); Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J. |
| Title |
Study of the doubly charmed tetraquark T-cc(+) |
Type |
Journal Article |
| Year |
2022 |
Publication |
Nature Communications |
Abbreviated Journal |
Nat. Commun. |
| Volume |
13 |
Issue |
1 |
Pages |
3351 - 19pp |
| Keywords |
|
| Abstract |
Quantum chromodynamics, the theory of the strong force, describes interactions of coloured quarks and gluons and the formation of hadronic matter. Conventional hadronic matter consists of baryons and mesons made of three quarks and quark-antiquark pairs, respectively. Particles with an alternative quark content are known as exotic states. Here a study is reported of an exotic narrow state in the (DD0)-D-0 pi(+) mass spectrum just below the D*+D-0 mass threshold produced in proton-proton collisions collected with the LHCb detector at the Large Hadron Collider. The state is consistent with the ground isoscalar T-cc(+), tetraquark with a quark content of cc (u) over bar(d) over bar and spin-parity quantum numbers J(P) =1(+). Study of the DD mass spectra disfavours interpretation of the resonance as the isovector state. The decay structure via intermediate off-shell D*(+) mesons is consistent with the observed D-0 pi(+) mass distribution. To analyse the mass of the resonance and its coupling to the DID system, a dedicated model is developed under the assumption of an isoscalar axial-vector T-cc(+), state decaying to the D*D channel. Using this model, resonance parameters including the pole position, scattering length, effective range and compositeness are determined to reveal important information about the nature of the T-cc(+), state. In addition, an unexpected dependence of the production rate on track multiplicity is observed. |
| Address |
[Aaij, R.; Butter, J. S.; Akiba, K. Carvalho; Sole, S. Ferreres; Gabriel, E.; Geertsema, R. E.; Greeven, L. M.; Heijhoff, K.; Hulsbergen, W.; Hynds, D.; Jans, E.; Ketel, T.; Klaver, S.; Koppenburg, P.; Kostiuk, I; Kuindersma, H. S.; Martinez, M. Lucio; Lukashenko, V; Mauri, A.; Merk, M.; Pellegrino, A.; Raven, G.; Gras, C. Sanchez; Schubiger, M.; Soares, M. Senghi; Snoch, A.; Tuning, N.; Usachov, A.; van Beuzekom, M.; Veronesi, M.] Nikhef Natl Inst Subatom Phys, Amsterdam, Netherlands, Email: Ivan.Belyaev@cern.ch |
| Corporate Author |
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Thesis |
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| Publisher |
Nature Portfolio |
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 |
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ISBN |
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Medium |
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| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000812556800001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5280 |
| Permanent link to this record |
| |
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| |
| Author |
LHCb Collaboration (Aaij, R. et al); Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J. |
| Title |
Centrality determination in heavy-ion collisions with the LHCb detector |
Type |
Journal Article |
| Year |
2022 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
| Volume |
17 |
Issue |
5 |
Pages |
P05009 - 31pp |
| Keywords |
Pattern recognition; cluster finding; calibration and fitting methods; Performance of High Energy Physics Detectors; Simulation methods and programs |
| Abstract |
The centrality of heavy-ion collisions is directly related to the created medium in these interactions. A procedure to determine the centrality of collisions with the LHCb detector is implemented for lead-lead collisions root s(NN) = 5 TeV and lead-neon fixed-target collisions at root s(NN) = 69 GeV. The energy deposits in the electromagnetic calorimeter are used to determine and define the centrality classes. The correspondence between the number of participants and the centrality for the lead-lead collisions is in good agreement with the correspondence found in other experiments, and the centrality measurements for the lead-neon collisions presented here are performed for the first time in fixed-target collisions at the LHC. |
| Address |
[Leite, J. Baptista; Bediaga, I; Torres, M. Cruz; De Miranda, J. M.; dos Reis, A. C.; Gomes, A.; Massafferri, A.; Machado, D. Torres] Ctr Brasileiro Pesquisas Fis CBPF, Rio De Janeiro, Brazil |
| Corporate Author |
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Thesis |
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| Publisher |
IOP Publishing Ltd |
Place of Publication |
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Editor |
|
| Language |
English |
Summary Language |
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Original Title |
|
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1748-0221 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000832952600001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5315 |
| 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 |
A new algorithm for identifying the flavour of B-s(0) mesons at LHCb |
Type |
Journal Article |
| Year |
2016 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
| Volume |
11 |
Issue |
|
Pages |
P05010 - 23pp |
| Keywords |
Analysis and statistical methods; Particle identification methods; Pattern recognition; cluster finding; calibration and fitting methods |
| Abstract |
A new algorithm for the determination of the initial flavour of B-s(0) mesons is presented. The algorithm is based on two neural networks and exploits the b hadron production mechanism at a hadron collider. The first network is trained to select charged kaons produced in association with the B-s(0) meson. The second network combines the kaon charges to assign the B-s(0) flavour and estimates the probability of a wrong assignment. The algorithm is calibrated using data corresponding to an integrated luminosity of 3 fb(-1) collected by the LHCb experiment in proton-proton collisions at 7 and 8 TeV centre-of-mass energies. The calibration is performed in two ways: by resolving the B-s(0)-B-s(0) flavour oscillations in B-s(0) -> D-s(-)pi(+) decays, and by analysing flavour-specific B-s2*(5840)(0) -> B+K- decays. The tagging power measured in B-s(0) -> D-s(-)pi(+) decays is found to be (1.80 +/- 0.19 ( stat) +/- 0.18 (syst))%, which is an improvement of about 50% compared to a similar algorithm previously used in the LHCb experiment. |
| Address |
[Bediaga, I.; De Miranda, J. M.; Rodrigues, F. Ferreira; Gomes, A.; Massafferri, A.; Rodrigues, B. Osorio; dos Reis, A. C.; Rodrigues, A. B.] CBPF, Rio De Janeiro, Brazil, Email: mirco.dorigo@cern.ch |
| Corporate Author |
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Thesis |
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| Publisher |
Iop Publishing Ltd |
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 |
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| Series Volume |
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Series Issue |
|
Edition |
|
| ISSN |
1748-0221 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000377851700033 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2731 |
| 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 |
Identification of beauty and charm quark jets at LHCb |
Type |
Journal Article |
| Year |
2015 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
| Volume |
10 |
Issue |
|
Pages |
P06013 - 29pp |
| Keywords |
Performance of High Energy Physics Detectors; Analysis and statistical methods |
| Abstract |
Identification of jets originating from beauty and charm quarks is important for measuring Standard Model processes and for searching for new physics. The performance of algorithms developed to select b- and c-quark jets is measured using data recorded by LHCb from proton-proton collisions at root s = 7TeV in 2011 and at root s = 8TeV in 2012. The efficiency for identifying a b (c) jet is about 65%(25%) with a probability for misidentifying a light-parton jet of 0.3% for jets with transverse momentum pT > 20GeV and pseudorapidity 2 : 2 < eta < 4.2. The dependence of the performance on the pT and eta of the jet is also measured. |
| 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 |
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Thesis |
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| Publisher |
Iop Publishing Ltd |
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 |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1748-0221 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000358004200029 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2314 |
| Permanent link to this record |
| |
|
| |
| Author |
LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C. |
| Title |
B flavour tagging using charm decays at the LHCb experiment |
Type |
Journal Article |
| Year |
2015 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
| Volume |
10 |
Issue |
|
Pages |
P10005 - 16pp |
| Keywords |
Performance of High Energy Physics Detectors; Analysis and statistical methods |
| Abstract |
An algorithm is described for tagging the flavour content at production of neutral B mesons in the LHCb experiment. The algorithm exploits the correlation of the flavour of a B meson with the charge of a reconstructed secondary charm hadron from the decay of the other b hadron produced in the proton-proton collision. Charm hadron candidates are identified in a number of fully or partially reconstructed Cabibbo-favoured decay modes. The algorithm is calibrated on the self-tagged decay modes B+ -> J/psi K+ and B-0 -> J/psi K*(0) using 3.0fb(-1) of data collected by the LHCb experiment at pp centre-of-mass energies of 7TeV and 8TeV. Its tagging power on these samples of B -> J/psi X decays is (0.30 +/- 0.01 +/- 0.01) %. |
| 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, Email: jwimberl@cern.ch |
| Corporate Author |
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Thesis |
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| Publisher |
Iop Publishing Ltd |
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 |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1748-0221 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000367674700007 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2519 |
| Permanent link to this record |
| |
|
| |
| Author |
LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C. |
| Title |
Study of the production of A(b)(0) and (B)over-bar(0) hadrons in pp collisions and first measurement of the A(b)(0)-> J/psi pK(-) branching fraction |
Type |
Journal Article |
| Year |
2016 |
Publication |
Chinese Physics C |
Abbreviated Journal |
Chin. Phys. C |
| Volume |
40 |
Issue |
1 |
Pages |
011001 - 16pp |
| Keywords |
production cross-section; branching fraction; b hadrons; proton-proton collisions |
| Abstract |
The product of the A(b)(0) ((B) over bar (0)) differential production cross-section and the branching fraction of the decay A(b)(0)-> J/psi pK(-) ((B) over bar (0)-> J/psi p (K) over bar*(892)(0)) is measured as a function of the beauty hadron transverse momentum, p(T), and rapidity, y. The kinematic region of the measurements is p(T) <20 GeV/c and 2.0 < y < 4.5. The measurements use a data sample corresponding to an integrated luminosity of 3fb(-1) collected by the LHCb detector in pp collisions at centre-of-mass energies root s=7 TeV in 2011 and root s=8 TeV in 2012. Based on previous LHCb results of the fragmentation fraction ratio, f(Ab0)/f(d), the branching fraction of the decay A(b)(0)-> J/psi pK(-) is measured to be B(A(b)(0)-> J/psi pK(-))=(3.17 +/- 0.04 +/- 0.07 +/- 0.34(-0.28)(+0.45))x10(-4) where the first uncertainty is statistical, the second is systematic, the third is due to the uncertainty on the branching fraction of the decay (B) over bar (0)-> J/psi p (K) over bar*(892)(0), and the fourth is due to the knowledge of f(Ab0)/f(d). The sum of the asymmetries in the production and decay between A(b)(0) and (A) over bar (0)(b) is also measured as a function of p(T) and y. The previously published branching fraction of A(b)(0)-> J/psi p pi(-), relative to that of A(b)(0)-> J/psi pK(-), is updated. The branching fractions of A(b)(0)-> P-c(+)(-> J/psi p)K- are determined. |
| Address |
[Bediagal, I.; De Miranda, J. M.; Rodrigues, F. Ferreira; Gomes, A.; Massafferri, A.; Rodrigues, B. Osorio; Dos Reis, A. C.; Rodrigues, A. B.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil |
| Corporate Author |
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Thesis |
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| Publisher |
Chinese Physical Soc |
Place of Publication |
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Editor |
|
| Language |
English |
Summary Language |
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Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1674-1137 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000368221600001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2526 |
| Permanent link to this record |
| |
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| |
| Author |
LHCb Collaboration (Aaij, R. et al); Garcia Martin, L.M.; Henry, L.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.; Sanchez Mayordomo, C. |
| Title |
Measurement of the electron reconstruction efficiency at LHCb |
Type |
Journal Article |
| Year |
2019 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
| Volume |
14 |
Issue |
|
Pages |
P11023 - 20pp |
| Keywords |
Pattern recognition, cluster finding, calibration and fitting methods; Performance of High Energy Physics Detectors |
| Abstract |
The single electron track-reconstruction efficiency is calibrated using a sample corresponding to 1.3 fb(-1) of pp collision data recorded with the LHCb detector in 2017. This measurement exploits B+ -> J/psi (e(+)e(-))K+ decays, where one of the electrons is fully reconstructed and paired with the kaon, while the other electron is reconstructed using only the information of the vertex detector. Despite this partial reconstruction, kinematic and geometric constraints allow the B meson mass to be reconstructed and the signal to be well separated from backgrounds. This in turn allows the electron reconstruction efficiency to be measured by matching the partial track segment found in the vertex detector to tracks found by LHCb's regular reconstruction algorithms. The agreement between data and simulation is evaluated, and corrections are derived for simulated electrons in bins of kinematics. These correction factors allow LHCb to measure branching fractions involving single electrons with a systematic uncertainty below 1%. |
| Address |
[Bediaga, I; Cruz Torres, M.; De Miranda, J. M.; dos Reis, A. C.; Gomes, A.; Massafferri, A.; Soares Lavra, L.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil, Email: laurent.dufour@cern.ch |
| Corporate Author |
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Thesis |
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| Publisher |
Iop Publishing Ltd |
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 |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1748-0221 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000507589800023 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4253 |
| Permanent link to this record |
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| Author |
BABAR Collaboration (del Amo Sanchez, P. et al); Lopez-March, N.; Martinez-Vidal, F.; Milanes, D.A.; Oyanguren, A. |
| Title |
Evidence for the decay X(3872) -> J/psi omega |
Type |
Journal Article |
| Year |
2010 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
82 |
Issue |
1 |
Pages |
011101 - 8pp |
| Keywords |
|
| Abstract |
We present a study of the decays B-0,B-+ -> J/psi pi(+)pi(-)pi K-0(0,+), using 467 x 106 B (B) over bar pairs recorded with the BABAR detector. We present evidence for the decay mode X(3872) -> J/psi omega, with product branching fractions B(B+ -> X(3872K(+)) x B(X(3872) -> J/psi omega) = [0.6 +/- 0.2(stat) +/- 0.1(syst)] x 10(-5), and B(B-0 -> X(3872)K-0) x B(X(3872) -> J/psi omega) = [0.6 +/- 0.3(stat) +/- 0.1(syst)] x 10(-5). A detailed study of the pi(+) pi(-) pi(0) mass distribution from X(3872) decay favors a negative-parity assignment. |
| Address |
[del Amo Sanchez, P.; Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.] Univ Savoie, Lab Annecy Le Vieux Phys Particules LAAP, CNRS, 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 |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1550-7998 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
ISI:000279691200001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ elepoucu @ |
Serial |
414 |
| Permanent link to this record |
| |
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| |
| Author |
BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A. |
| Title |
Measurement of the semileptonic branching fraction of the B(s) meson |
Type |
Journal Article |
| Year |
2012 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
85 |
Issue |
1 |
Pages |
011101 - 9pp |
| Keywords |
|
| Abstract |
We report a measurement of the inclusive semileptonic branching fraction of the B(s) meson using data collected with the BABAR detector in the center-of-mass energy region above the Y(4S) resonance. We use the inclusive yield of phi mesons and the phi yield in association with a high-momentum lepton to perform a simultaneous measurement of the semileptonic branching fraction and the production rate of B(s) mesons relative to all B mesons as a function of center-of-mass energy. The inclusive semileptonic branching fraction of the B(s) meson is determined to be B(B(s) -> l nu X) = 9.5(-2.0)(+2.5)(stat)(-1.9)(+1.1)(syst)% where l indicates the average of e and mu. |
| 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 |
|
| Notes |
WOS:000298925300001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
872 |
| Permanent link to this record |
