Records |
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 |
Evidence for Modification of b Quark Hadronization in High-Multiplicity pp Collisions at √s=13 TeV |
Type |
Journal Article |
Year |
2023 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
131 |
Issue |
6 |
Pages |
061901 - 11pp |
Keywords |
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Abstract |
The production rate of B-s(0) mesons relative to B-0 mesons is measured by the LHCb experiment in pp collisions at a center-of-mass energy root s = 13 TeV over the forward rapidity interval 2 < y < 4.5 as a function of the charged particle multiplicity measured in the event. Evidence at the 3.4 sigma level is found for an increase of the ratio of B-s(0) to B-0 cross sections with multiplicity at transverse momenta below 6 GeV=c, with no significant multiplicity dependence at higher transverse momentum. Comparison with data from e(+)e(-) collisions implies that the density of the hadronic medium may affect the production rates of B mesons. This is qualitatively consistent with the emergence of quark coalescence as an additional hadronization mechanism in high-multiplicity collisions. |
Address |
[Baptista de Souza Leite, J.; Bediaga, I. B.; Cruz Torres, M.; 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 Fis, Rio De Janeiro, Brazil, Email: juan.baptista.leite@cern.ch |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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English |
Summary Language |
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Original Title |
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Abbreviated Series Title |
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Series Volume |
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Edition |
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ISSN ![sorted by ISSN field, descending order (down)](img/sort_desc.gif) |
0031-9007 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:001162017900001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
6007 |
Permanent link to this record |
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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 Rare Decays of D0 Mesons into Two Muons |
Type |
Journal Article |
Year |
2023 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
131 |
Issue |
4 |
Pages |
041804 - 13pp |
Keywords |
|
Abstract |
A search for the very rare D-0 -> mu(+)mu(-) decay is performed using data collected by the LHCb experiment in proton-proton collisions at root s = 7, 8, and 13 TeV, corresponding to an integrated luminosity of 9 fb(-1). The search is optimized for D-0 mesons from D*(+) -> D-0 pi(+) decays but is also sensitive to D-0 mesons from other sources. No evidence for an excess of events over the expected background is observed. An upper limit on the branching fraction of this decay is set at B(D-0 -> mu(+)mu(-)) < 3.1 x 10(-9) at a 90% C.L. This represents the world's most stringent limit, constraining models of physics beyond the standard model. |
Address |
[Leite, J. Baptista de Souza; Bediaga, I. B.; Torres, M. Cruz; Da Graca, U. De Freitas Carneiro; De Miranda, J. M.; dos Reis, A. C.; Falcao, L. N.; Gomes, A.; Massafferri, A.; Torres Machado, D.] 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 |
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ISSN ![sorted by ISSN field, descending order (down)](img/sort_desc.gif) |
0031-9007 |
ISBN |
|
Medium |
|
Area |
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Expedition |
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Conference |
|
Notes |
WOS:001257153800001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
6216 |
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 |
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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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ISSN ![sorted by ISSN field, descending order (down)](img/sort_desc.gif) |
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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:000812556800001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
5280 |
Permanent link to this record |