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Author Martinez Torres, A.; Garzon, E.J.; Oset, E.; Dai, L.R. url  doi
openurl 
  Title Limits to the fixed center approximation to Faddeev equations: The case of the phi(2170) Type Journal Article
  Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 83 Issue 11 Pages (down) 116002 - 9pp  
  Keywords  
  Abstract The fixed center approximation to the Faddeev equations has been used lately with success in the study of bound systems of three hadrons. It is also important to set the limits of the approach in those problems to prevent proliferation of inaccurate predictions. In this paper, we study the case of the phi(2170), which has been described by means of Faddeev equations as a resonant state of phi and K (K) over bar, and show the problems derived from the use of the fixed center approximation in its study. At the same time, we also expose the limitations of an alternative approach recently proposed.  
  Address [Martinez Torres, A.] Kyoto Univ, Yukawa Inst Theoret Phys, Kyoto 6068502, Japan  
  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:000291151000015 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 637  
Permanent link to this record
 
 
Author Martinez Torres, A.; Oset, E. url  doi
openurl 
  Title Novel Interpretation of the “Theta(+)(1540) Pentaquark” Peak Type Journal Article
  Year 2010 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.  
  Volume 105 Issue 9 Pages (down) 092001 - 4pp  
  Keywords  
  Abstract We use a theoretical model of the gamma d --> K+K- np reaction adapted to the experiment done at LEPS where a peak was observed and associated with the Theta(+)(1540) pentaquark. The study shows that the method used in the experiment to assign momenta to the undetected proton and neutron, together with the chosen cuts, necessarily creates an artificial broad peak in the assumed K(+)n invariant mass in the region of the claimed Theta(+)(1540), such that the remaining strength seen for the experimental peak is compatible with a fluctuation of 2 sigma significance.  
  Address [Martinez Torres, A.] Univ Valencia, Ctr Mixto, CSIC, 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 0031-9007 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000281272700005 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ elepoucu @ Serial 387  
Permanent link to this record
 
 
Author Martinez Torres, A.; Khemchandani, K.P.; Nielsen, M.; Navarra, F.S.; Oset, E. url  doi
openurl 
  Title Exploring the D* rho system within QCD sum rules Type Journal Article
  Year 2013 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 88 Issue 7 Pages (down) 074033 - 14pp  
  Keywords  
  Abstract We present a study of the D* rho system made by using the method of QCD sum rules to determine the mass of possible resonances generated in the same system. Using isospin and spin projectors, we investigate the different configurations and obtain evidences for three D* mesons with isospin I = 1/2, spin S = 0, 1, 2 and with masses 2500 +/- 67, 2523 +/- 60, and 2439 +/- 119 MeV, respectively. The last state can be associated with D-2*(2460) ( spin 2) listed by the Particle Data Group, while one of the first two might be related to D* (2640), with unknown spin parity. In the case of I = 3/2 we also find evidences of three states with spin 0, 1, and 2, respectively, with masses 2467 +/- 82, 2420 +/- 128, and 2550 +/- 56 MeV. The results for the sector I = 1/2 and S 0, 1, 2, are intriguingly similar to a previous study of the D* rho system based on effective field theories, supporting in this way a molecular picture for the resonances D* (2640) and D-2* (2460), while the results for I = 3/2 hint towards the existence of exotic mesons since a multiquark configuration is required to get the quantum numbers of the states found.  
  Address [Torres, A. Martinez; Khemchandani, K. P.; Nielsen, M.; Navarra, F. S.] Univ Sao Paulo, Inst Fis, BR-05389970 Sao Paulo, Brazil, Email: amartine@if.usp.br;  
  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:000326161900004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1644  
Permanent link to this record
 
 
Author Dai, L.R.; Oset, E.; Feijoo, A.; Molina, R.; Roca, L.; Martinez Torres, A.; Khemchandani, K.P. url  doi
openurl 
  Title 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 (down) 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 Xie, J.J.; Martinez Torres, A.; Oset, E. url  doi
openurl 
  Title Faddeev fixed-center approximation to the N K K(bar) system and the signature of a N*(1920)(1/2+) state Type Journal Article
  Year 2011 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 83 Issue 6 Pages (down) 065207 - 8pp  
  Keywords  
  Abstract We perform a calculation for the three-body N (K) over barK scattering amplitude by using the fixed-center approximation to the Faddeev equations, taking the interaction between N and (K) over bar, N and K, and (K) over bar and K from the chiral unitary approach. The resonant structures show up in the modulus squared of the three-body scattering amplitude and suggest that a N (K) over barK hadron state can be formed. Our results are in agreement with others obtained in previous theoretical works, which claim a new N* resonance around 1920 MeV with spin-parity J(P) = 1/2(+). The existence of these previous works allows us to test the accuracy of the fixed center approximation in the present problem and sets the grounds for possible application in similar problems, as an explorative tool to determine bound or quasibound three-hadron systems.  
  Address [Xie, Ju-Jun; Oset, E.] Univ Valencia, Ctr Mixto CSIC, Inst Fis Corpuscular IFIC, Inst Invest Paterna, E-46071 Valencia, Spain, Email: xiejujun@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 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000291984800004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 665  
Permanent link to this record
 
 
Author Xie, J.J.; Martinez Torres, A.; Oset, E.; Gonzalez, P. url  doi
openurl 
  Title Plausible explanation for the Delta(5/2)+(2000) puzzle Type Journal Article
  Year 2011 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 83 Issue 5 Pages (down) 055204 - 11pp  
  Keywords  
  Abstract From a Faddeev calculation for the pi-(Delta rho)(N5/2)-(1675) system we show the plausible existence of three dynamically generated I (J(P)) = 3/2(5/2(+)) baryon states below 2.3 GeV, whereas only two resonances, Delta(5/2)+ (1905)( ) and Delta(5/2)+(2000)(**), are cataloged in the Particle Data Book Review. Our results give theoretical support to data analyses extracting two distinctive resonances, Lambda(5/2)+(similar to 1740) and Lambda(5/2)+(similar to 2200), from which the mass of Delta(5/2)+ (2000) is estimated. We propose that these two resonances should be cataloged instead of Delta(5/2)+(2000). This proposal gets further support from the possible assignment of the other baryon states found in the approach in the I = 1/2, 3/2 with J(P) = 1/2(+), 3/2(+), 5/(2)+ sectors to known baryonic resonances. In particular, Delta(1/2)+(1750)(*) is naturally interpreted as a pi N-1/2-(1650) bound state.  
  Address [Xie, Ju-Jun; Oset, E.; Gonzalez, P.] Univ Valencia, Ctr Mixto CSIC, Inst Fis Corpuscular IFIC, Inst Invest Paterna, E-46071 Valencia, Spain, Email: xiejujun@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 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000290522200010 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 626  
Permanent link to this record
 
 
Author Martinez Torres, A.; Oset, E. url  doi
openurl 
  Title The gamma d -> K(+)K(-)np reaction and an alternative explanation for the “Theta(+)(1540) pentaquark” peak Type Journal Article
  Year 2010 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 81 Issue 5 Pages (down) 055202 - 16pp  
  Keywords  
  Abstract We present a calculation of the gamma d -> K(+)K(-)np reaction with the aim of seeing whether the experimental peak observed in the K(+)n invariant mass around 1526 MeV, from where evidence for the existence of the Theta(+) has been claimed, can be obtained without this resonance as a consequence of the particular dynamics of the process and the cuts applied in the experimental setup. We find that a combination of facts leads indeed to a peak around 1530 MeV for the invariant mass of K(+)n without the need to invoke any new resonance around this energy. This, together with statistical fluctuations that we prove to be large with the statistics of the experiment, is likely to produce the narrower peak observed there.  
  Address [Martinez Torres, A.] Univ Politecn Valencia, CSIC, Ctr Mixto, Dept Fis Teor, E-46071 Valencia, Spain, Email: amartine@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 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000278144800057 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ elepoucu @ Serial 443  
Permanent link to this record
 
 
Author Martinez Torres, A.; Bayar, M.; Jido, D.; Oset, E. url  doi
openurl 
  Title Strategy to find the two Lambda (1405) states from lattice QCD simulations Type Journal Article
  Year 2012 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 86 Issue 5 Pages (down) 055201 - 13pp  
  Keywords  
  Abstract Theoretical studies within the chiral unitary approach, and recent experiments, have provided evidence of the existence of two isoscalar states in the region of the Lambda(1405). In this paper we use the same chiral approach to generate energy levels in a finite box. In a second step, assuming that these energies correspond to lattice QCD results, we devise the best strategy of analysis to obtain the two states in the infinite-volume case, with sufficient precision to distinguish them. We find out that by using energy levels obtained with asymmetric boxes and/or with a moving frame, with reasonable errors in the energies, one has a successful scheme to get the two Lambda(1405) poles.  
  Address [Torres, A. Martinez; Jido, D.] Kyoto Univ, Yukawa Inst Theoret Phys, Kyoto 6068502, Japan  
  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:000310685400008 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1226  
Permanent link to this record
 
 
Author Malabarba, B.B.; Khemchandani, K.P.; Martinez Torres, A.; Oset, E. url  doi
openurl 
  Title D1(2420) and its interactions with a kaon: Open charm states with strangeness Type Journal Article
  Year 2023 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 107 Issue 3 Pages (down) 036016 - 12pp  
  Keywords  
  Abstract In this work we present an attempt to describe the X1(2900) found by the LHCb collaboration, in the experimental data on the invariant mass spectrum of D-K+, as a three-meson molecular state of the KpD over line system. We discuss that the interactions in all the subsystems are attractive in nature, with the pD over line interaction generating over line D1(2420) and the Kp resonating as K1(1270). We find that the system can form a three-body state but with a mass higher than that of X1(2900). We investigate the KpD system too, finding that the three-body dynamics generates an isoscalar state, which can be related to D*s1(2860), and an exotic isovector state. This latter state has a mass similar to that of the X0(2900) and X1(2900) states found by LHCb, but a very small width (similar to 7.4 +/- 0.9 MeV) and necessarily requires more than two quarks to describe its properties. We hope that our findings will encourage experimental investigations of the isovector KpD state. Finally, in the pursuit of finding a description for X1(2900), we study the K over line K*D* system where over line K*D* forms 0+, 1+, and 2+ states. We do not find a state that can be associated with X1(2900).  
  Address [Malabarba, Brenda B.; Torres, A. Martinez] Univ Sao Paulo, Inst Fis, BR-05389970 Sao Paulo, Brazil, Email: brenda@if.usp.br;  
  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:000989327600013 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5562  
Permanent link to this record
 
 
Author Martinez Torres, A.; Khemchandani, K.P.; Oset, E. url  doi
openurl 
  Title Theoretical study of the gamma d -> pi(0)eta d reaction Type Journal Article
  Year 2023 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 107 Issue 2 Pages (down) 025202 - 24pp  
  Keywords  
  Abstract We have done a theoretical study of the gamma d -> pi(0)eta d reaction starting with a realistic model for the gamma N -> pi(0)eta N reaction that reproduces cross sections and polarization observables at low energies and involves the gamma N -> Delta(1700) -> eta Delta(1232) -> eta pi N-0 process. For the coherent reaction in the deuteron we considered the impulse approximation together with the rescattering of the pions and the eta on a different nucleon than the one where they are produced. We found this second mechanism very important since it helps share between two nucleons the otherwise large momentum transfer of the reaction. Other contributions to the gamma d -> pi(0)eta d reaction, involving the gamma N -> pi(+/-)pi N-0' process, followed by the rescattering of the pi(+/-) with another nucleon to give eta and a nucleon, have also been included. We find a natural explanation, tied to the dynamics of our model, for the shift of the eta-d mass distribution to lower invariant masses, and of the pi(0)-d mass distribution to larger invariant masses, compared to a phase space calculation. We also study theoretical uncertainties related to the large momenta of the deuteron wave function involved in the process as well as to the couplings present in the model. Striking differences are found with the experimental angular distribution and further theoretical investigations might be necessary.  
  Address [Torres, A. Martinez] Univ Sao Paulo, Inst Fis, BR-05389970 Sao Paulo, Brazil, Email: amartine@if.usp.br;  
  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 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000981821500002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5563  
Permanent link to this record
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