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Author |
Xiao, C.W.; Nieves, J.; Oset, E. |
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Title |
Heavy quark spin symmetric molecular states from (D)over-bar(()*())Sigma(()(c)*()) and other coupled channels in the light of the recent LHCb pentaquarks |
Type |
Journal Article |
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Year |
2019 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
100 |
Issue |
1 |
Pages |
014021 - 6pp |
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Keywords |
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Abstract |
We consider the (D) over bar (()*())Sigma(()(c)*()) states, together with J/psi N and other coupled channels, and take an interaction consistent with heavy quark spin symmetry, with the dynamical input obtained from an extension of the local hidden gauge approach. By fitting only one parameter to the recent three pentaquark states reported by the LHCb Collaboration, we can reproduce the three of them in base to the mass and the width, providing for them the quantum numbers and approximate molecular structure as 1/2(-) (D) over bar Sigma(c), 1/2(-) (D) over bar*Sigma(c), and 3/2(-) (D) over bar*Sigma(c), and the isospin I = 1/2. We find another state around 4374 MeV, of the 3/2(-) (D) over bar Sigma(c)* structure, for which indications appear in the experimental spectrum. Two other near degenerate states of a 1/2(-) (D) over bar*Sigma(c)* and 3/2(-) (D) over bar*Sigma(c)* nature are also found around 4520 MeV, which although less clear, are not incompatible with the observed spectrum. In addition, a 5/2(-) (D) over bar*Sigma(c)* state at the same energy appears, which however does not couple to J/psi p in an S wave, and hence, it is not expected to show up in the LHCb experiment. |
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Address |
[Xiao, C. W.] Cent S Univ, Sch Phys & Elect, Changsha 410083, Hunan, Peoples R China |
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Publisher  |
Amer Physical Soc |
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English |
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Series Title |
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Series Volume |
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ISSN |
2470-0010 |
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Conference |
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Notes |
WOS:000476694500003 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4086 |
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Author |
Sobczyk, J.E.; Rocco, N.; Nieves, J. |
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Title |
Polarization of tau in quasielastic (anti)neutrino scattering: The role of spectral functions |
Type |
Journal Article |
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Year |
2019 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
100 |
Issue |
3 |
Pages |
035501 - 14pp |
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Keywords |
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Abstract |
We present a study of the tau polarization in charged-current quasielastic (anti)neutrino-nucleus scattering. The spectral function formalism is used to compute the differential cross section and the polarization components for several kinematical setups, relevant for neutrino-oscillation experiments. The effects of the nuclear corrections in these observables are investigated by comparing the results obtained using two different realistic spectral functions, with those deduced from the relativistic global Fermi gas model, where only statistical correlations are accounted for. We show that the spectral functions, although they play an important role when predicting the differential cross sections, produce much less visible effects on the polarization components of the outgoing tau. |
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Address |
[Sobczyk, J. E.; Nieves, J.] Univ Valencia, Ctr Mixto CSIC, Inst Fis Corpuscular IFIC, Inst Invest Paterna, Apartado 22085, E-46071 Valencia, Spain |
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Publisher |
Amer Physical Soc |
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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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Series Issue |
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ISSN |
2469-9985 |
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Conference |
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Notes |
WOS:000483582500009 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4126 |
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Author |
Penalva, N.; Hernandez, E.; Nieves, J. |
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Title |
Further tests of lepton flavor universality from the charged lepton energy distribution in b -> c semileptonic decays: The case of Lambda(b) -> Lambda(c) l(v)over-bar(l) |
Type |
Journal Article |
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Year |
2019 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
100 |
Issue |
11 |
Pages |
113007 - 11pp |
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Keywords |
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Abstract |
In a general framework, valid for any H -> H' l(-)(v) over bar (l) semileptonic decay, we analyze the d(2)Gamma/(d omega d cos theta(l)) and d(2)Gamma/(d omega dE(l)) distributions, with omega being the product of the hadron four-velocities, theta(l) the angle made by the three-momenta of the charged lepton and the final hadron in the W- center of mass frame and E-l the charged lepton energy in the decaying hadron rest frame. Within the Standard Model (SM), d(2)Gamma/(d omega dE(l)) proportional to (c(0) (omega) c(1) (omega)E-l/M + c(2) (omega)E-l(2)/M-2), with M the initial hadron mass. We find that c(2) (omega) is independent of the lepton flavor and thus it is an ideal candidate to look for lepton flavor universality (LFU) violations. We also find a correlation between the a(2) (omega) structure function, which governs the (cos theta(l))(2) dependence of d(2)Gamma/(d omega d cos theta(l)), and c(2) (omega). Apart from trivial kinematical and mass factors, the ratio of a(2) (omega)/c(2) (omega) is a universal function that can be measured in any semileptonic decay, involving not only b -> c transitions. These two SM predictions can be used as new tests in the present search for signatures of LFU violations. We also generalize the formalism to account for some new physics (NP) terms, and show that neither c(2) nor a(2) are modified by left and right scalar NP terms, being however sensitive to left and right vector corrections. We also find that the a(2)/c(2) ratio is not modified by these latter NP contributions. Finally, and in order to illustrate our findings, we apply our general framework to the Lambda(b) -> Lambda(c)l (v) over bar (l) decay. We show that a measurement of c(2) (or a(2)) for tau decay would not only be a direct measurement of the possible existence of NP, but it would also allow to distinguish from NP fits to b -> c tau(v) over bar (tau) anomalies in the meson sector, which otherwise give the same total and differential d Gamma/d omega widths. We show that the same occurs for the other two terms, c(0) and c(1), that appear in d(2)Gamma/(d omega dE(l)), and for the cos theta(l) linear term of the angular distribution. |
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Address |
[Penalva, Neus; Nieves, Juan] Ctr Mixto CSIC UV, Inst Invest Paterna, Inst Fis Corpuscular, Apartado 22085, Valencia 46071, Spain |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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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 |
2470-0010 |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000503400600001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
4230 |
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Author |
Nieves, J.; Pavao, R. |
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Title |
Nature of the lowest-lying odd parity charmed baryon Lambda(c)(2595) and Lambda(c)(2625) resonances |
Type |
Journal Article |
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Year |
2020 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
101 |
Issue |
1 |
Pages |
014018 - 17pp |
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Keywords |
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Abstract |
We study the structure of the Lambda(c) (2595) and Lambda(c) (2625) resonances in the framework of an effective field theory consistent with heavy quark spin and chiral symmetries, which incorporates the interplay between Sigma(()(c)*() )pi – ND(*()) baryon-meson degrees of freedom (d.o.f.) and bare P-wave c (u) over bard quark-model states. We show that these two resonances are not heavy quark spin symmetry partners. The J(P) = 3/2(-) Lambda(c) (2625) should be viewed mostly as a dressed three-quark state, whose origin is determined by a bare state, predicted to lie very close to the mass of the resonance. The J(P) = 1/2(-) Lambda(c) (2595) seems to have, however, a predominant molecular structure. This is because it is either the result of the chiral Sigma(c)pi interaction, whose threshold is located much closer than the mass of the bare three-quark state, or because the light d.o.f. in its inner structure are coupled to the unnatural 0(-) quantum numbers. We show that both situations can occur depending on the renormalization procedure used. We find some additional states, but the classification of the spectrum in terms of heavy quark spin symmetry is difficult, despite having used interactions that respect this symmetry. This is because the bare quark-model state and the Sigma(c)pi threshold are located extraordinarily close to the Lambda(c) (2625) and Lambda(c) (2595), respectively, and hence they play totally different roles in each sector. |
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Address |
[Nieves, J.; Pavao, R.] Ctr Mixto CSIC UV, Inst Invest Paterna, Inst Fis Corpuscular, Apartado 22085, Valencia 46071, Spain |
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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 |
2470-0010 |
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:000509494900007 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
4272 |
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Author |
Yao, D.L.; Fernandez-Soler, P.; Guo, F.K.; Nieves, J. |
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Title |
New parametrization of the form factors in (B)over-bar -> Dl(nu)over-bar(l) decays |
Type |
Journal Article |
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Year |
2020 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
101 |
Issue |
3 |
Pages |
034014 - 7pp |
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Keywords |
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Abstract |
A new model-independent parametrization is proposed for the hadronic form factors in the semileptonic (B) over bar -> Dl (nu) over bar (l) decay. By a combined consideration of the recent experimental and lattice QCD data, we determine precisely the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-cb vertical bar = 41.01(75) x 10(-3) and the ratio R-D = BR((B) over bar -> D tau(nu) over bar (tau))/BR((B) over bar -> Dl (nu) over bar (l)) = 0.301(5). The coefficients in this parametrization, related to phase shifts by sumrulelike dispersion relations and hence called phase moments, encode important scattering information of the (B) over bar (D) over bar interactions which are poorly known so far. Thus, we give strong hints about the existence of at least one bound and one virtual (B) over bar (D) over bar S-wave 0(+) states, subject to uncertainties produced by potentially sizable inelastic effects. This formalism is also applicable for any other semileptonic processes induced by the weak b -> c transition. |
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Address |
[Yao, De-Liang] Hunan Univ, Sch Phys & Elect, Changsha 410082, Hunan, Peoples R China |
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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 |
2470-0010 |
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:000513217400004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
4277 |
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| Permanent link to this record |
