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Author Roca, L.; Oset, E. url  doi
openurl 
  Title 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 (up) no  
  Call Number IFIC @ pastor @ Serial 1655  
Permanent link to this record
 

 
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 [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 (up) no  
  Call Number IFIC @ pastor @ Serial 1681  
Permanent link to this record
 

 
Author Aceti, F.; Oset, E.; Roca, L. url  doi
openurl 
  Title Composite nature of the Lambda (1520) resonance Type Journal Article
  Year 2014 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 90 Issue 2 Pages 025208 - 8pp  
  Keywords  
  Abstract Recently, the Weinberg compositeness condition of a bound state was generalized to account for resonant states and higher partial waves. We apply this extension to the case of the Lambda (1520) resonance and quantify the weight of the meson-baryon components in contrast to other possible genuine building blocks. This resonance was theoretically obtained from a coupled channels analysis using the s-wave pi Sigma* and K Xi* and the d-wave (K) over bar N and pi Sigma channels, applying the techniques of the chiral unitary approach. We obtain the result that this resonance is essentially dynamically generated from these meson-baryon channels, leaving room for only 15% weight of other kinds of components in its wave function.  
  Address [Aceti, F.; Oset, E.] Univ Valencia, CSIC, Ctr Mixto, Inst Invest Paterna,Dept Fis Teor, E-46071 Valencia, 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:000341271300006 Approved no  
  Is ISI yes International Collaboration (up) no  
  Call Number IFIC @ pastor @ Serial 1907  
Permanent link to this record
 

 
Author Garzon, E.J.; Oset, E. url  doi
openurl 
  Title Mixing of pseudoscalar-baryon and vector-baryon in the J(P)=1/2(-) sector and the N* (1535) and N* (1650) resonances Type Journal Article
  Year 2015 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 91 Issue 2 Pages 025201 - 7pp  
  Keywords  
  Abstract We study the meson-baryon interaction with J(P) = 1/2 using the hidden-gauge Lagrangians and mixing pseudoscalar meson-baryon with the vector meson-baryon states in a coupled channels scheme with pi N, eta N, K Lambda, K Sigma, rho N, and pi Delta (d wave). We fit the subtraction constants of each channel to the S-11 partial wave amplitude of the pi N scattering data extracted from the partial wave analysis of the George Washington group. We find two poles that we associate to the N*(1535) and the N*(1650) resonances, with negative subtraction constants of natural size, and compare the results with empirical determinations of these pole positions. We calculate the branching ratios for the different channels of each resonance and we find a good agreement with the experimental data. The cross section for the pi(-)p -> eta n scattering is also evaluated and compared with experiment.  
  Address [Garzon, E. J.] Univ Valencia, CSIC, Ctr Mixto, Inst Invest Paterna,Dept Fis Teor, 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 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000349248700003 Approved no  
  Is ISI yes International Collaboration (up) no  
  Call Number IFIC @ pastor @ Serial 2106  
Permanent link to this record
 

 
Author Feijoo, A.; Magas, V.K.; Ramos, A.; Oset, E. url  doi
openurl 
  Title Lambda(b) -> J/psi K Xi decay and the higher order chiral terms of the meson baryon interaction Type Journal Article
  Year 2015 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 92 Issue 7 Pages 076015 - 10pp  
  Keywords  
  Abstract We study the weak decay of the Lambda(b) into J/psi K Xi. and J/psi eta Lambda states, and relate these processes to the Lambda(b) -> J/psi(K) over barN decay mode. The elementary weak transition at the quark level proceeds via the creation of a J/psi meson and an excited sud system with I = 0, which upon hadronization leads to (K) over barN or eta Lambda pairs. These states undergo final-state interaction in coupled channels and produce a final meson-baryon pair. The K. state only occurs via rescattering, hence making the Lambda(b) -> J/psi K Xi process very sensitive to the details of the meson-baryon interaction in strangeness S = -1 and isospin I = 0. We show that the corresponding invariant mass distribution is dominated by the next-to-leading-order terms of the chiral interaction. The I = 0 selectivity of this decay, and its large sensitivity to the higher-order terms, makes its measurement very useful and complementary to the K- p -> K Xi cross section data. The rates of the Lambda(b) -> J/psi K Xi and Lambda(b) -> J/psi eta Lambda invariant mass distributions are sizable compared to those of the Lambda(b) -> J/psi(K) over barN decay, which is measured experimentally, and thus, we provide arguments for an experimental determination of these decay modes that will help us understand better the chiral dynamics at higher energies.  
  Address [Feijoo, A.; Magas, V. K.; Ramos, A.] Univ Barcelona, Dept Estruct & Constituents Mat, E-08028 Barcelona, Spain, Email: feijoo@ecm.ub.edu  
  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:000363792600009 Approved no  
  Is ISI yes International Collaboration (up) no  
  Call Number IFIC @ pastor @ Serial 2432  
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