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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. |
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Title |
Observation of structure in the J/psi-pair mass spectrum |
Type |
Journal Article |
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Year |
2020 |
Publication |
Science Bulletin |
Abbreviated Journal |
Sci. Bull. |
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Volume |
65 |
Issue |
23 |
Pages |
1983-1993 |
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Keywords |
QCD; Exotics; Tetraquark; Spectroscopy; Quarkonium; Particle and resonance production |
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Abstract |
Using proton-proton collision data at centre-of-mass energies of root s = 7, 8 and 13 TeV recorded by the LHCb experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 9 fb(-1), the invariant mass spectrum of J/psi pairs is studied. A narrow structure around 6.9 GeV/c(2) matching the line-shape of a resonance and a broad structure just above twice the J/psi mass are observed. The deviation of the data from nonresonant J/psi-pair production is above five standard deviations in the mass region between 6.2 and 7.4 GeV/c(2), covering predicted masses of states composed of four charm quarks. The mass and natural width of the narrow X(6900) structure are measured assuming a Breit-Wigner lineshape. |
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Address |
[Bediaga, I.; Cruz Torres, M.; De Miranda, J. M.; Gomes, A.; Massafferri, A.; dos Reis, A. C.; Soares Lavra, L.; Tourinho Jadallah Aoude, R.] CBPF, Rio De Janeiro, Brazil, Email: maria.vieites.diaz@cern.ch |
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Publisher  |
Elsevier |
Place of Publication |
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Language |
English |
Summary Language |
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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 |
2095-9273 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000593153200012 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4622 |
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Author |
LHCb Collaboration (Aaij, R. et al); Henry, L.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J. |
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Title |
Evidence of a J/psi Lambda structure and observation of excited Xi(-) states in the Xi(-)(b) -> J/psi Lambda K- decay |
Type |
Journal Article |
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Year |
2021 |
Publication |
Science Bulletin |
Abbreviated Journal |
Sci. Bull. |
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Volume |
66 |
Issue |
13 |
Pages |
1278-1287 |
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Keywords |
QCD; Exotics; Pentaquark; Spectroscopy; Quarkonium; Particle and resonance production |
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Abstract |
First evidence of a structure in the J/psi Lambda invariant mass distribution is obtained from an amplitude analysis of Xi(-)(b) -> J/psi Lambda K- decays. The observed structure is consistent with being due to a charmonium pentaquark with strangeness with a significance of 3.1r including systematic uncertainties and lookelsewhere effect. Its mass and width are determined to be 4458.8 +/- 2.9(-1.1)(+4.7) MeV and 17.3 +/- 6.5(-5.7)(+8.0) MeV, respectively, where the quoted uncertainties are statistical and systematic. The structure is also consistent with being due to two resonances. In addition, the narrow excited Xi(-) states, Xi(-)(1690) and Xi(-)(1820)(-), are seen for the first time in a Xi(-)(b) decay, and their masses and widths are measured with improved precision. The analysis is performed using pp collision data corresponding to a total integrated luminosity of 9 fb(-1), collected with the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV. |
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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 |
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Corporate Author |
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Thesis |
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Publisher |
Elsevier |
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 |
2095-9273 |
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:000668689800009 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4888 |
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Author |
LHCb Collaboration (Aaij, R. et al); Henry, L.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J. |
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Title |
Search for the doubly heavy baryons Omega(0)(bc) and Xi(0)(bc) decaying to Lambda(+)(c)pi(-) and Xi(+)(c)pi- |
Type |
Journal Article |
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Year |
2021 |
Publication |
Chinese Physics C |
Abbreviated Journal |
Chin. Phys. C |
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Volume |
45 |
Issue |
9 |
Pages |
093002 - 12pp |
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Keywords |
B physics; quarkonium; spectroscopy; heavy quark production |
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Abstract |
The first search for the doubly heavy Omega(0)(bc) baryon and a search for the Xi(0)(bc) baryon are performed using collision data collected via the experiment from 2016 to 2018 at a centre-of-mass energy of, corresponding to an integrated luminosity of 5.2 fb(-1). The baryons are reconstructed via their decays to Lambda(+)(-)(c)(pi) and Xi(+)(c)pi(-). No significant excess is found for invariant masses between 6700 and 7300 MeV/c(2), in a rapidity range from 2.0 to 4.5 and a transverse momentum range from 2 to 20 MeV/c. Upper limits are set on the ratio of the Omega(0)(bc) and Xi(0)(bc) production cross-section times the branching fraction to Lambda(+)(c)pi(-)(Xi(+)(c)pi(-)) relative to that of the Lambda(0)(b)(Xi(0)(b)) baryon, for different lifetime hypotheses, at 95% confidence level. The upper limits range from 0.5x10(-4) to 2.5x10(-4) for the Omega(0)(bc) -> Lambda(+)(c)pi(-) (Xi(0)(bc) -> Lambda(+)(c)pi(-)) decay, pending on the considered mass and lifetime of the Omega(0)(bc) (Xi(0)(bc)) baryon. |
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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, Email: shiyang.li@cern.ch |
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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 |
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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 |
1674-1137 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000693209400001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4974 |
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Author |
LHCb Collaboration (Aaij, R. et al); Oyanguren, A.; Ruiz Valls, P. |
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Title |
Production of J/psi and Y mesons in pp collisions at root s=8 TeV |
Type |
Journal Article |
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Year |
2013 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
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Volume |
06 |
Issue |
6 |
Pages |
064 - 31pp |
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Keywords |
Quarkonium; Heavy quark production; Particle and resonance production; Hadron-Hadron Scattering; Flavor physics |
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Abstract |
The production of J/psi and gamma mesons in pp collisions at root s = 8 TeV is studied with the LHCb detector. The J/psi and gamma mesons are reconstructed in the mu(+)mu(-) decay mode and the signal yields are determined with a fit to the mu(+)mu(-) invariant mass distributions. The analysis is performed in the rapidity range 2.0 < y < 4.5 and transverse momentum range 0 < PT < 14 (15) GeV/c of the J/psi (gamma) mesons. The J/psi and gamma production cross-sections and the fraction of J/psi mesons from b-hadron decays are measured as a function of the meson P-T and y. |
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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: Ciulia.Manca@cern.ch |
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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 |
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Edition |
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ISSN |
1029-8479 |
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:000321381800010 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
1536 |
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| 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. |
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Title |
Study of production and cold nuclear matter effects in pPb collisions at=5 TeV |
Type |
Journal Article |
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Year |
2014 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
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Volume |
07 |
Issue |
7 |
Pages |
094 - 19pp |
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Keywords |
Relativistic heavy ion physics; Quarkonium; Heavy quark production; Heavy Ions; Particle and resonance production |
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Abstract |
Production of mesons in proton-lead collisions at a nucleon-nucleon centre-of-mass energy = 5 TeV is studied with the LHCb detector. The analysis is based on a data sample corresponding to an integrated luminosity of 1.6 nb(-1). The mesons of transverse momenta up to 15 GeV/c are reconstructed in the dimuon decay mode. The rapidity coverage in the centre-of-mass system is 1.5 < y < 4.0 (forward region) and -5.0 < y < -2.5 (backward region). The forward-backward production ratio and the nuclear modification factor for (1S) mesons are determined. The data are compatible with the predictions for a suppression of (1S) production with respect to proton-proton collisions in the forward region, and an enhancement in the backward region. The suppression is found to be smaller than in the case of prompt J/psi mesons. |
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Address |
[Bediaga, I.; De Miranda, J. M.; Ferreira Rodrigues, F.; Gomes, A.; Hicheur, A.; Massafferri, A.; dos Reis, A. C.; Rodrigues, A. B.] CBPF, Rio De Janeiro, Brazil, Email: yangzhw@tsinghua.edu.cn |
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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 |
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Edition |
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ISSN |
1029-8479 |
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:000339818500001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
1883 |
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