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Author Ramos, A.; Oset, E. url  doi
openurl 
  Title The role of vector-baryon channels and resonances in the gamma p -> K-0 Sigma(+) and gamma n -> K-0 Sigma(0) reactions near the K*Lambda threshold Type Journal Article
  Year 2013 Publication Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 727 Issue 1-3 Pages 287-292  
  Keywords  
  Abstract We have studied the gamma p -> K-0 Sigma(+) reaction in the energy region around the K*Lambda and K*Sigma thresholds, where the CBELSA/TAPS cross section shows a sudden drop and the differential cross section experiences a transition from a forward-peaked distribution to a flat one. Our coupled-channel model incorporates the dynamics of the vector meson-baryon interaction which is obtained from the hidden gauge formalism. We find that the cross section in this energy region results from a delicate interference between amplitudes having K*Lambda and K*Sigma intermediate states. The sharp downfall is dictated by the presence of a nearby N* resonance produced by our model, a feature that we have employed to predict its properties. We also show results for the complementary gamma n -> K-0 Sigma(0) reaction, the measurement of which would test the mechanism proposed in this work.  
  Address (up) [Ramos, A.] Univ Barcelona, Dept Estruct & Constituents Mat, E-08028 Barcelona, Spain, Email: ramos@ecm.ub.edu  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0370-2693 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000328518400041 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 1681  
Permanent link to this record
 

 
Author Ramos, A.; Tolos, L.; Molina, R.; Oset, E. url  doi
openurl 
  Title The width of the omega meson in the nuclear medium Type Journal Article
  Year 2013 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A  
  Volume 49 Issue 11 Pages 148 - 16pp  
  Keywords  
  Abstract We evaluate the width of the omega meson in nuclear matter. We consider the free decay mode of the omega into three pions, which is dominated by rho IEuro decay, and replace the rho and pi propagators by their medium-modified ones. We also take into account the quasielastic and inelastic processes induced by a vector-baryon interaction dominated by vector meson exchange, as well as the contributions coming from the mechanism with medium-modified K , propagators. We obtain a substantial increase of the omega width in the medium, reaching a value of 121 +/- 10 MeV at normal nuclear matter density for an omega at rest, which comes mainly from omega N -> pi pi N, omega NN -> pi NN processes associated to the dominant omega -> rho IEuro decay mode. The value of the width increases moderately with momentum, reaching values of around 200MeV at 600MeV/c.  
  Address (up) [Ramos, A.] Univ Barcelona, Dept Estruct & Constituents Mat, E-08028 Barcelona, Spain, Email: ramos@ecm.ub.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 1434-6001 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000327460400001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1654  
Permanent link to this record
 

 
Author Oset, E.; Ramos, A. url  doi
openurl 
  Title Chiral unitary approach to eta ' N scattering at low energies Type Journal Article
  Year 2011 Publication Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 704 Issue 4 Pages 334-342  
  Keywords  
  Abstract We study the eta'N interaction within a chiral unitary approach which includes pi N, eta N and related pseudoscalar meson-baryon coupled channels. Since the SU(3) singlet does not contribute to the standard interaction and the eta' is mostly a singlet, the resulting scattering amplitude is very small and inconsistent with the experimental scattering length. The additional consideration of vector meson-baryon states into the coupled channel scheme, via normal and anomalous couplings of pseudoscalar to vector mesons, enhances substantially the eta'N amplitude. We also exploit the freedom of adding to the Lagrangian a new term, allowed by the symmetries of QCD, which couples baryons to the singlet meson of SU(3). Adjusting the unknown strength to the eta'N scattering length, we obtain predictions for the elastic eta'N -> eta'N and inelastic eta'N -> eta N, pi N, K Lambda, K Sigma cross sections at low eta' energies, and discuss their significance.  
  Address (up) [Ramos, A] Univ Barcelona, Dept Estruct & Constituents Mat, E-08028 Barcelona, Spain, Email: ramos@ecm.ub.es  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0370-2693 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000296175500015 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ elepoucu @ Serial 783  
Permanent link to this record
 

 
Author Ren, X.L.; Geng, L.S.; Oset, E.; Meng, J. url  doi
openurl 
  Title Test of h(1)(1830) made of K*K* with the eta(c) ->phi K*K* decay Type Journal Article
  Year 2014 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A  
  Volume 50 Issue 8 Pages 133 - 5pp  
  Keywords  
  Abstract We present a new reaction, complementary to from which an h (1) resonance with mass around 1830 MeV was reported from a BESIII experiment. The new reaction is , or . Using the information from the analysis of , we find that the invariant mass distribution for those two Iu decays exhibits a clear peak around 1830 MeV perfectly distinguishable from what one obtains with pure phase space. We suggest the implementation of these reactions to assert the existence of this elusive resonance which, by its nature as a vector-vector molecule with 0(-)(1(+-)) quantum numbers, only couples to the channel.  
  Address (up) [Ren, Xiu-Lei; Geng, Li-Sheng; Oset, E.; Meng, Jie] Beihang Univ, Sch Phys & Nucl Energy Engn, Beijing 100191, Peoples R China, Email: lisheng.geng@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 1434-6001 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000341425400001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1921  
Permanent link to this record
 

 
Author Ren, X.L.; Oset, E.; Alvarez-Ruso, L.; Vicente Vacas, M.J. url  doi
openurl 
  Title Antineutrino induced Lambda(1405) production off the proton Type Journal Article
  Year 2015 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 91 Issue 4 Pages 045201 - 11pp  
  Keywords  
  Abstract We have studied the strangeness-changing antineutrino-induced reactions (v) over bar (l)p -> l(+)phi B, with phi B = K(-)p, (K) over bar (0)n, pi(0)Lambda, pi(0)Sigma(0), eta Lambda, eta Sigma(0), pi(+)Sigma(-), pi(-)Sigma(+), K+Xi(-), and K-0 Xi(0), using a chiral unitary approach. These ten coupled channels are allowed to interact strongly, using a kernel derived from the chiral Lagrangians. This interaction generates two Lambda(1405) poles, leading to a clear single peak in the pi Sigma invariant mass distributions. At backward scattering angles in the center-of-mass frame, (nu) over bar (mu)p -> mu(+)pi(0)Sigma(0) is dominated by the Lambda(1405) state at around 1420 MeV while the lighter state becomes relevant as the angle decreases, leading to an asymmetric line shape. In addition, there are substantial differences in the shape of pi Sigma invariant mass distributions for the three charge channels. If observed, these differences would provide valuable information on a claimed isospin I = 1, strangeness S = -1 baryonic state around 1400 MeV. Integrated cross sections have been obtained for the pi Sigma and (K) over barN channels and the impact of unitarization in the results has been investigated. The number of events with Lambda(1405) excitation in (nu) over bar μp collisions in the recent antineutrino run at the Main Injector Experiment for nu-A (MINER nu A) has also been obtained. We find that this reaction channel is relevant enough to be investigated experimentally and to be taken into account in the simulation models of future experiments with antineutrino beams.  
  Address (up) [Ren, Xiu-Lei] Beihang Univ, Sch Phys & Nucl Energy Engn, Beijing 100191, Peoples R China, Email: xiulei.ren@buaa.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 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000352190300006 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2191  
Permanent link to this record
 

 
Author Roca, L.; Oset, E. url  doi
openurl 
  Title Description of the f(2)(1270), rho(3)(1690), f(4)(2050), rho(5)(2350), f(6)(2510) resonances as multi-rho(770) states Type Journal Article
  Year 2010 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 82 Issue 5 Pages 054013 - 11pp  
  Keywords  
  Abstract In a previous work regarding the interaction of two rho(770) resonances, the f(2)(1270) (J(PC) = 2(++)) resonance was obtained dynamically as a two-rho molecule with a very strong binding energy, 135 MeV per rho particle. In the present work we use the rho rho interaction in spin 2 and isospin 0 channel to show that the resonances rho(3)(1690) (3(--)), f(4)(2050) (4(++)), rho(5)(2350) (5(--)), and f(6)(2510) (6(++)) are basically molecules of increasing number of rho(770) particles. We use the fixed center approximation of the Faddeev equations to write the multibody interaction in terms of the two-body scattering amplitudes. We find the masses of the states very close to the experimental values and we get an increasing value of the binding energy per rho as the number of rho mesons is increased.  
  Address (up) [Roca, L.] Univ Murcia, Dept Fis, E-30071 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 ISI:000281791100002 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ elepoucu @ Serial 381  
Permanent link to this record
 

 
Author Roca, L.; Oset, E. url  doi
openurl 
  Title Asymmetry observables in e(+)e(-) -> pi(+) pi(-) gamma in the phi region within a chiral unitary approach Type Journal Article
  Year 2010 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 81 Issue 1 Pages 014010 - 8pp  
  Keywords  
  Abstract We make a theoretical study of the charge and forward-backward pion asymmetries in the e(+)e(-) -> pi(+) pi(-) gamma process on and off the phi resonance energy. These observables are rather sensitive to the inner details of the theoretical models to describe the reaction. In addition to the standard implementation of the initial state radiation and the bremsstrahlung contribution to the final state radiation, we use the techniques of the chiral unitary approach to evaluate the contribution from the mechanisms of phi decay into pi(+) pi(-) gamma. This contribution involves the implementation of final state interaction from direct chiral loops, the exchange of vector and axial-vector resonances and the final state interaction through the consideration of the meson-meson unitarized amplitudes, which were found important in a previous work describing the phi -> pi pi gamma. We find a good reproduction of the experimental data from KLOE for the forward-backward asymmetry, both at the phi peak and away from it. We also make predictions for the angular distributions of the charge asymmetry and show that this observable is very sensitive to the chiral loops involved in phi radiative decay.  
  Address (up) [Roca, L.] Univ Murcia, Dept Fis, E-30071 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 ISI:000274002800021 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ elepoucu @ Serial 503  
Permanent link to this record
 

 
Author Roca, L.; Oset, E. url  doi
openurl 
  Title Scattering of unstable particles in a finite volume: The case of pi rho scattering and the a(1)(1260) resonance Type Journal Article
  Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 85 Issue 5 Pages 054507 - 13pp  
  Keywords  
  Abstract We present a way to evaluate the scattering of unstable particles quantized in a finite volume with the aim of extracting physical observables for infinite volume from lattice data. We illustrate the method with the pi rho scattering which generates dynamically the axial-vector a(1)(1260) resonance. Energy levels in a finite box are evaluated both considering the rho as a stable and unstable resonance and we find significant differences between both cases. We discuss how to solve the problem to get the physical scattering amplitudes in the infinite volume, and hence phase shifts, from possible lattice results on energy levels quantized inside a finite box.  
  Address (up) [Roca, L.] Univ Murcia, Dept Fis, E-30071 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:000301706700004 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 941  
Permanent link to this record
 

 
Author Roca, L.; Oset, E. url  doi
openurl 
  Title Scalar resonances in the D+ -> K-K+K+ decay Type Journal Article
  Year 2021 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 103 Issue 3 Pages 034020 - 9pp  
  Keywords  
  Abstract We study theoretically the resonant structure of the double Cabibbo suppressed D+ -> K-K+K+ decay. We start from an elementary production diagram, considered subleading in previous approaches, which cannot produce a final K-K+ pair at the tree level but which we show to be able to provide the strength of the decay through final meson-meson state interaction. The different meson-meson elementary productions are related through SU(3), and the final rescattering is implemented from a suitable implementation of unitary extensions of chiral perturbation theory, which generate dynamically the scalar resonances1 f(0)(980) and a(0)(980). We obtain a good agreement with recent experimental data from the LHCb Collaboration with a minimal freedom in the fit and show the dominance of the a(0)(980) contribution close to the threshold of the K-K+ spectrum.  
  Address (up) [Roca, L.] Univ Murcia, Dept Fis, E-30071 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:000621332000004 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 4742  
Permanent link to this record
 

 
Author Roca, L.; Liang, W.H.; Oset, E. url  doi
openurl 
  Title Inconsistency of the data on the K-1(1270) -> pi K-0*(1430) decay width Type Journal Article
  Year 2022 Publication Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 824 Issue Pages 136827 - 3pp  
  Keywords  
  Abstract We show, using the same Lagrangian for the K-1(1270) -> pi K-0*(1430) and K-0*(1430) -> K-1 (1270)pi decays, that the present PDG data on the partial decay width of K-1 (1270) -> pi K-0*(1430) implies a width for K-0*(1430) -> K-1 (1270)pi decay which is about one order of magnitude larger than the total K-0*(1430) width. A discussion on this inconsistency is done, stressing its relationship to the existence of two K-1(1270) states obtained with the chiral unitary theory, which are not considered in the experimental analyses of K pi pi data.  
  Address (up) [Roca, L.] Univ Murcia, Dept Fis, E-30071 Murcia, Spain, Email: luisroca@um.es;  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0370-2693 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000734123200006 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5061  
Permanent link to this record
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