| Records |
| Author |
LHCb Collaboration (Aaij, R. et al); Henry, L.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J. |
| 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 |
| Year |
2021 |
Publication |
Science Bulletin |
Abbreviated Journal |
Sci. Bull. |
| Volume |
66 |
Issue |
13 |
Pages |
1278-1287 |
Keywords  |
QCD; Exotics; Pentaquark; Spectroscopy; Quarkonium; Particle and resonance production |
| 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. |
| 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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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 |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4888 |
| 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 |
Observation of charmonium pairs produced exclusively in pp collisions |
Type |
Journal Article |
| Year |
2014 |
Publication |
Journal of Physics G |
Abbreviated Journal |
J. Phys. G |
| Volume |
41 |
Issue |
11 |
Pages |
115002 - 17pp |
| Keywords |
QCD; diffraction; charmonia |
| Abstract |
A search is performed for the central exclusive production of pairs of charmonia produced in proton-proton collisions. Using data corresponding to an integrated luminosity of 3 fb(-1) collected at centre-of-mass energies of 7 and 8 TeV, J/psi J/psi and J/psi psi (2S) pairs are observed, which have been produced in the absence of any other activity inside the LHCb acceptance that is sensitive to charged particles in the pseudorapidity ranges (-3.5,-1.5) and (1.5, 5.0). Searches are also performed for pairs of P-wave charmonia and limits are set on their production. The cross-sections for these processes, where the dimeson system has a rapidity between 2.0 and 4.5, are measured to be sigma (J/psi J/psi) = 58 +/- 10(stat) +/- 6(syst) pb, sigma(J/psi psi(2S)) = 63(-18)(+27)(stat) +/- 10(syst) pb, sigma(psi(2S)psi(2S)) < 237 pb, sigma(chi)(chi)(C0)(C0) < 69 nb, sigma(chi)(chi)(C1)(C1) < 45 pb, sigma(chi)(chi)(C2)(C2) < 141 pb, where the upper limits are set at the 90% confidence level. The measured J/psi J/psi and J/psi psi (2S) cross-sections are consistent with theoretical expectations. |
| Address |
[Bediaga, I.; De Miranda, J. M.; Rodrigues, F. Ferreira; Gomes, A.; Hicheur, A.; Massafferri, A.; Rodrigues, B. Osorio; dos Reis, A. C.; Rodrigues, A. B.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil, Email: ronan.mcnulty@ucd.ie |
| 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 |
0954-3899 |
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:000344090500011 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1992 |
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| Author |
LHCb Collaboration (Aaij, R. et al); Jaimes Elles, S.J.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Rebollo De Miguel, M.; Remon Alepuz, C.; Ruiz Vidal, J.; Sanderswood, I. |
| Title |
Search for the doubly heavy baryon Ξbc+ decaying to J/ψΞc+ |
Type |
Journal Article |
| Year |
2023 |
Publication |
Chinese Physics C |
Abbreviated Journal |
Chin. Phys. C |
| Volume |
47 |
Issue |
9 |
Pages |
093001 - 13pp |
| Keywords |
QCD; B physics; charm physics; spectroscopy |
| Abstract |
A first search for the Xi(+)(bc) -> J/psi Xi c+ decay is performed by the LHCb experiment with a data sample of proton-proton collisions, corresponding to an integrated luminosity of 9 fb(-1) recorded at centre-of-mass energies of 7, 8, and 13 TeV. Two peaking structures are seen with a local (global) significance of and standard deviations at masses of 6571 and 6694 MeV/c(2), respectively. Upper limits are set on the Xi(+)(bc) baryon production cross-section times the branching fraction relative to that of the B-c(+) -> J/psi Xi(+)(c) decay at centre-of-mass energies of 8 and 13 TeV, in the Xi(+)(bc) and in the rapidity and transverse-momentum ranges from 2.0 to 4.5 and 0 to, respectively. Upper limits are presented as a function of the Xi(+)(bc) mass and lifetime. |
| Address |
[Baptista De Souza Leite, J.; Bediaga, I. B.; Torres, M. Cruz; De Freitas Carneiro Da Graca, U.; De Miranda, J. M.; dos Reis, A. C.; Falcao, L. N.; Gomes, A.; Massafferri, A.; Torres Machado, D.] Ctr Brasileiro Pesquisas Fisicas CBPF, Rio De Janeiro, Brazil |
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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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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:001062113700001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5751 |
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| Author |
Greynat, D.; de Rafael, E.; Vulvert, G. |
| Title |
Asymptotic behaviour of pion-pion total cross-sections |
Type |
Journal Article |
| Year |
2014 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
03 |
Issue |
3 |
Pages |
107 - 21pp |
| Keywords |
QCD Phenomenology; Phenomenological Models |
| Abstract |
We derive a sum rule which shows that the Froissart-Martin bound for the asymptotic behaviour of the pi pi total cross sections at high energies, if modulated by the Lukaszuk-Martin coefficient of the leading log(2)s behaviour, cannot be an optimal bound in QCD. We next compute the total cross sections for pi(+)pi(-), pi(+/-)pi(0) and pi(0)pi(0) scattering within the framework of the constituent chiral quark model (C chi QM) in the limit of a large number of colours N-c and discuss their asymptotic behaviours. The same pi pi cross sections are also discussed within the general framework of Large-N-c QCD and we show that it is possible to make an Ansatz for the isospin I = 1 and I = 0 spectrum which satisfy the Froissart-Martin bound with coefficients which, contrary to the Lukaszuk-Martin coefficient, are not singular in the chiral limit and have the correct Large-N-c counting. We finally propose a simple phenomenological model which matches the low energy behaviours of the sigma(total)(pi +/-pi 0)(s) cross section predicted by the CxQM with the high energy behaviour predicted by the Large-N-c Ansatz. The magnitude of these cross sections at very high energies is of the order of those observed for the pp and pp scattering total cross sections. |
| Address |
[Greynat, David] Univ Naples Federico II, Dipartimento Sci Fis, I-80126 Naples, Italy, Email: david.greynat@gmail.com; |
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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:000333803000003 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1747 |
| Permanent link to this record |
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| Author |
Du, M.L.; Baru, V.; Guo, F.K.; Hanhart, C.; Meissner, U.G.; Oller, J.A.; Wang, Q. |
| Title |
Revisiting the nature of the P-c pentaquarks |
Type |
Journal Article |
| Year |
2021 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
08 |
Issue |
8 |
Pages |
157 - 50pp |
| Keywords |
QCD Phenomenology; Non-perturbative renormalization |
| Abstract |
The nature of the three narrow hidden-charm pentaquark P-c states, i.e., P-c (4312), P-c (4440) and P-c (4457), is under intense discussion since their discovery from the updated analysis of the process Lambda(0)(b) -> I ) J/psi pK(-) by LHCb. In this work we extend our previous coupled-channel approach [Phys. Rev. Lett. 124, 072001 (2020)], in which the Pc states are treated as Sigma(()(c)*()) (D) over bar (()*()) molecules, by including the Lambda(c)(D) over bar (()*()) and eta(c)p as explicit inelastic channels in addition to the J/psi p, as required by unitarity and heavy quark spin symmetry (HQSS), respectively. Since inelastic parameters are very badly constrained by the current data, three calculation schemes are considered: (a) scheme I with pure contact interactions between the elastic, i.e., Sigma(()(c)*()) (D) over bar (()*()), and inelastic channels and without the Lambda(c)(D) over bar (()*()) interactions, (b) scheme II, where the one-pion exchange (OPE) is added to scheme I, and (c) scheme III, where the Lambda(c)(D) over bar (()*()) interactions are included in addition. It is shown that to obtain cutoff independent results, OPE in the multichannel system is to be supplemented with S-wave-to-D-wave mixing contact terms. As a result, in line with our previous analysis, we demonstrate that the experimental data for the J/psi p invariant mass distribution are consistent with the interpretation of the P-c(4312) and P-c(4440)/P-c(4457) as Sigma(c)(D) over bar and Sigma(c)(D) over bar* hadronic molecules, respectively, and that the data show clear evidence for a new narrow state, P-c(4380), identified as a Sigma(c)*(D) over bar molecule, which should exist as a consequence of HQSS. While two statistically equally good solutions are found in scheme I, only one of these solutions with the quantum numbers of the P-c (4440) and P-c (4457) being J(P) = 3/2(-) and 1/2(-), respectively, survives the requirement of regulator independence once the OPE is included. Moreover, we predict the line shapes in the elastic and inelastic channels and demonstrate that those related to the P-c (4440) and the P-c (4457) in the Sigma(()(c)*())<(D)over ( )anf eta(c)p mass distributions from Lambda(0)(b) ->( )Sigma(()(c)*()) (D) over barK(-) and Lambda(0)(b) -> eta(c)pK(-) will shed light on the quantum numbers of those states, once the data are available. We also investigate possible pentaquark signals in the Lambda(c)(D) over bar (()*()) final states. |
| Address |
[Du, Meng-Lin; Meissner, Ulf-G.] Univ Bonn, Helmholtz Inst Strahlen & Kernphys, D-53115 Bonn, Germany, Email: du@hiskp.uni-bonn.de |
| 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 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:000693090600001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4958 |
| Permanent link to this record |
