Home << 1 2 3 4 >>
List View
 | 
Citations
 | 
Details
   web
Records
Author Roca, L.; Oset, E.
Title (up) Isospin 0 and 1 resonances from pi Sigma photoproduction data Type Journal Article
Year 2013 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 88 Issue 5 Pages 055206 - 7pp
Keywords
Abstract Recently we presented a successful strategy to extract the position of the two Lambda ( 1405) poles from experimental photoproduction data on the gamma p -> K+pi(0)Sigma(0) reaction at Jefferson Lab. Following a similar strategy, we extend the previous method to incorporate also the isospin 1 component which allows us to consider in addition the experimental data on gamma p -> K+pi(+/-)Sigma(-/+). The idea is based on considering a production mechanism as model independent as possible and implementing the final state interaction of the final meson-baryon pair based on small modifications of the unitary chiral perturbation theory amplitudes. Good fits to the data are obtained with this procedure, by means of which we can also predict the cross sections for the K- p -> (K) over barN, pi Sigma, and pi Lambda reactions for the different charge channels. Besides the two poles found for the Lambda(1405) resonance, we discuss the possible existence of an isospin 1 resonance in the vicinity of the (K) over barN threshold.
Address [Roca, L.] Univ Murcia, Dept Fis, E-30100 Murcia, Spain
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000327315800008 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1655
Permanent link to this record
 
 
Author Roca, L.; Oset, E.
Title (up) Lambda(1405) poles obtained from pi(0)Sigma(0) photoproduction data Type Journal Article
Year 2013 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 87 Issue 5 Pages 055201 - 8pp
Keywords
Abstract We present a strategy to extract the position of the two Lambda(1405) poles from experimental photoproduction data measured recently at different energies in the gamma p -> K+pi(0)Sigma(0) reaction at Jefferson Laboratory. By means of a chiral dynamics motivated potential with free parameters, we solve the Bethe-Salpeter equation in the coupled channels (K) over barN and pi Sigma in isospin I = 0 and parametrize the amplitude for the photonuclear reaction in terms of a linear combination of the pi Sigma -> pi Sigma and (K) over barN -> pi Sigma scattering amplitudes in I = 0, with a different linear combination for each energy. Good fits to the data are obtained with some sets of parameters, by means of which one can also predict the cross section for the K- p -> pi(0)Sigma(0) reaction. These later results help us decide among the possible solutions. The result is that the different solutions lead to two poles similar to those found in the chiral unitary approach. With the best result we find the two Lambda(1405) poles at 1385 – 68i MeV and 1419 – 22i MeV.
Address Univ Murcia, Dept Fis, E-30100 Murcia, Spain
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000318527400004 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1442
Permanent link to this record
 
 
Author Roca, L.; Nieves, J.; Oset, E.
Title (up) LHCb pentaquark as a (D)over-bar*Sigma(c) – (D)over-bar*Sigma(c)* molecular state Type Journal Article
Year 2015 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 92 Issue 9 Pages 094003 - 6pp
Keywords
Abstract We perform a theoretical analysis of the Lambda(b) -> J/psi K(-)p reaction from where a recent LHCb experiment extracts a Lambda(1405) contribution in the K(-)p spectrum close to threshold and two baryon states of hidden charm in the J/psi p spectrum. We recall that baryon states of this type have been theoretically predicted matching the mass, width and J(P) of the experiment; concretely some states built up from the J/psi N, (D) over bar*Lambda(c), (D) over bar*Sigma(c), (D) over bar Sigma(c)* and (D) over bar*Sigma(c)* coupled channels. We assume that the observed narrow state around 4450 MeV has this nature and we are able to describe simultaneously the shapes and relative strength of the the K(-)p mass distribution close to threshold and the peak of the J/psi p distribution, with values of the J/psi p coupling to the resonance in line with the theoretical ones. The nontrivial matching of many properties gives support to a J(P) = 3/2(-) assignment to this state and to its nature as a molecular state mostly made of (D) over bar*Sigma(c) and (D) over bar*Sigma(c)*.
Address [Roca, L.] Univ Murcia, Dept Fis, E-30100 Murcia, Spain
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000364019700004 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 2448
Permanent link to this record
 
 
Author Dai, L.R.; Oset, E.; Feijoo, A.; Molina, R.; Roca, L.; Martinez Torres, A.; Khemchandani, K.P.
Title (up) Masses and widths of the exotic molecular B-(s)(()*B-)((s))(*()) states Type Journal Article
Year 2022 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 105 Issue 7 Pages 074017 - 11pp
Keywords
Abstract We study the interaction of the doubly bottom systems BB, B*B, BsB, B-s*B, B*B*, B*B-S, B*B-s*, BsBs, BsBs*, B-s*B-s* by means of vector meson exchange with Lagrangians from an extension of the local hidden gauge approach. The full s-wave scattering matrix is obtained implementing unitarity in coupled channels by means of the Bethe-Salpeter equation. We find poles below the channel thresholds for the attractively interacting channels B*B in I = 0, B-s*B – B*B-s in I = 1/2, B* B* in I = 0, and B-s*B* in I = 1/2, all of them with J(P) = 1(+). For these cases the widths are evaluated identifying the dominant source of imaginary part. We find binding energies of the order of 10-20 MeV, and the widths vary much from one system to the other: of the order of 10-100 eV for the B* B system and B-s*B – B* B-s, about 6 MeV for the B*B* system and of the order of 0.5 MeV for the B-s*B* system.
Address [Dai, L. R.] Huzhou Univ, Sch Sci, Huzhou 313000, Zhejiang, Peoples R China, Email: dailianrong@zjhu.edu.cn;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000809898400002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5317
Permanent link to this record
 
 
Author Roca, L.; Song, J.; Oset, E.
Title (up) Molecular pentaquarks with hidden charm and double strangeness Type Journal Article
Year 2024 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 109 Issue 9 Pages 094005 - 8pp
Keywords
Abstract We analyze theoretically the coupled-channel meson-baryon interaction with global flavor c<overline>cssn and c<overline>csss, where mesons are pseudoscalars or vectors, and baryons have JP = 1/2+ or 3/2+. The aim is to explore whether the nonlinear dynamics inherent in the unitarization process within coupled channels can dynamically generate double- and triple-strange pentaquark-type states (Pcss and Pcsss, respectively), for which there is no experimental evidence to date. We evaluate the s-wave scattering matrix by implementing unitarity in coupled channels, using potential kernels obtained from t-channel vector meson exchange. The required PPV and VVV vertices are obtained from Lagrangians derived through appropriate extensions of the local hidden gauge symmetry approach to the charm sector, while capitalizing on the symmetry of the spin and flavor wave function to evaluate the BBV vertex. We find four different poles in the double strange sector, some of them degenerate in spin. For the triple-strange channel, we find the meson-baryon interaction insufficient to generate a bound or resonance state through the unitary coupled-channel dynamics.
Address [Roca, L.] Univ Murcia, Dept Fis, E-30100 Murcia, Spain, Email: luisroca@um.es;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:001224715500002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6135
Permanent link to this record
 
 
Author Yamagata-Sekihara, J.; Roca, L.; Oset, E.
Title (up) Nature of the K-2*(1430), K-3*(1780), K-4*(2045), K-5*(2380), and K-6* as K*-multi-rho states Type Journal Article
Year 2010 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 82 Issue 9 Pages 094017 - 8pp
Keywords
Abstract We show that the K-2*(1430), K-3*(1780), K-4*(2045), K-5*(2380), and a not-yet-discovered K-6* resonance are basically molecules made of an increasing number of rho(770) and one K*(892) mesons. The idea relies on the fact that the vector-vector interaction in the s wave with spins aligned is very strong for both rho rho and K*rho. We extend a recent work, where several resonances showed up as multi-rho(770) molecules, to the strange sector including the K*(892) into the system. The resonant structures show up in the multibody scattering amplitudes, which are evaluated in terms of the unitary two-body vector-vector scattering amplitudes by using the fixed center approximation to the Faddeev equations.
Address [Yamagata-Sekihara, J.; Oset, E.] Univ Valencia, CSIC, Dept Fis Teor IFIC, Ctr Mixto,Inst Invest Paterna, Valencia 46071, Spain
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes ISI:000284206500003 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ elepoucu @ Serial 323
Permanent link to this record
 
 
Author Roca, L.; Oset, E.
Title (up) On the hidden charm pentaquarks in Lambda(b) -> J/psi K- p decay Type Journal Article
Year 2016 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 76 Issue 11 Pages 591 - 12pp
Keywords
Abstract In a previous work we presented a theoretical analysis of the Lambda(b) -> J/psi K- p reaction based on which a recent experiment by the LHCb collaboration at CERN claimed the existence of two hidden charm pentaquarks, P-c(4380)(+) and P-c(4450)(+). In that work we focused only on the Lambda(1405) and P-c(4450)(+) signals and discussed the possible explanation of this pentaquark state within the picture of a dynamical meson-baryon molecule made up mostly from (D) over bar*Sigma(c) and (D) over bar*Sigma(c)* components. In the present work we improve upon the previous one by considering the total K- p and J/psi p data including all the relevant resonances contributing to the spectra, and discuss the possible nature of both P-c(4380)(+) and P-c(4450)(+). We also discuss several important topics, like the effect of the contact term in the reaction, the viability of reproducing the data without the P-c(4380)(+) and the possible quantum number assignment to these pentaquarks.
Address [Roca, L.] Univ Murcia, Dept Fis, E-30100 Murcia, Spain, Email: luisroca@um.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000399930700001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3065
Permanent link to this record
 
 
Author Song, J.; Duan, M.Y.; Roca, L.; Oset, E.
Title (up) Pentaquark molecular states with hidden bottom and double strangeness Type Journal Article
Year 2024 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 84 Issue 10 Pages 1055 - 8pp
Keywords
Abstract We investigate the meson-baryon interaction in coupled channels with the quantum numbers of the pentaquarks Pbss and Pbsss. The interaction is derived from an extension of the local hidden gauge approach to the heavy quark sector, which has demonstrated accurate results compared to experiments involving Ωb, Ξb states, and pentaquarks Pc and Pcs. In our study, we identify several molecular states with small decay widths within the chosen set of coupled channels. The spin-parity (JP) of these states is as follows: JP=12− for pseudoscalar-baryon (12+) coupled channels, JP=32− for pseudoscalar-baryon (32+) coupled channels, JP=12− and 32− for vector-baryon (12+) coupled channels, and JP=12−, 32−, 52− for vector-baryon (32+) coupled channels. We search for the poles of these states and evaluate their couplings to the different channels.
Address [Song, Jing] Beihang Univ, Sch Phys, Beijing 102206, Peoples R China, Email: Song-Jing@buaa.edu.cn
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:001331230600005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6333
Permanent link to this record
 
 
Author Dias, J.M.; Roca, L.; Sakai, S.
Title (up) Prediction of new states from D(*)B(*)(B)over-bar(*) three-body interactions Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 97 Issue 5 Pages 056019 - 8pp
Keywords
Abstract We study three-body systems composed of D(*), B(*), and (B) over bar(*) in order to look for possible bound states or resonances. In order to solve the three-body problem, we use the fixed center approach for the Faddeev equations considering that the B*(B) over bar*(B (B) over bar) are clusterized systems, generated dynamically, which interact with a third particle D((D) over bar) whose mass is much smaller than the two-body bound states forming the cluster. In the DB*(B) over bar*, D*B*(B) over bar*, DB (B) over bar, and D*B (B) over bar systems with I = 1/2, we found clear bound state peaks with binding energies typically a few tens MeV and more uncertain broad resonant states about ten MeV above the threshold with widths of a few tens MeV.
Address [Dias, J. M.; Sakai, S.] Ctr Mixto Univ Valencia CSIC, Dept Fis Teor, Inst Invest Paterna, Apartado 22085, Valencia 46071, Spain, Email: jorgivan.morais@ific.uv.es;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000428240900017 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3536
Permanent link to this record
 
 
Author Roca, L.; Mai, M.; Oset, E.; Meissner, U.G.
Title (up) Predictions for the Lambda(b) -> J/psi Lambda (1405) decay Type Journal Article
Year 2015 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 75 Issue 5 Pages 218 - 9pp
Keywords
Abstract We calculate the shape of the pi Sigma and (K) over bar N invariant mass distributions in the Lambda(b) -> J/psi pi Sigma and Lambda(b) -> J/psi (K) over bar N decays that are dominated by the Lambda (1405) resonance. The weak interaction part is the same for both processes and the hadronization into the different meson-baryon channels in the final state is given by symmetry arguments. The most important feature is the implementation of the meson-baryon final-state interaction using two chiral unitary models from different theoretical groups. Both approaches give a good description of antikaon-nucleon scattering data, the complex energy shift in kaonic hydrogen and the line shapes of pi Sigma K in photoproduction, based on the two-pole scenario for the Lambda (1405). We find that this reaction reflects more the higher mass pole and we make predictions of the line shapes and relative strength of the meson-baryon distributions in the final state.
Address [Roca, L.] Univ Murcia, Dept Fis, Murcia 30100, Spain, Email: luisroca@um.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000355678900006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2271
Permanent link to this record