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Author Martinez Torres, A.; Oset, E.
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 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 (up) 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 Oset, E.; Martinez Torres, A.; Khemchandani, K.P.; Roca, L.; Yamagata-Sekihara, J.
Title Two, three, many body systems involving mesons Type Journal Article
Year 2012 Publication Progress in Particle and Nuclear Physics Abbreviated Journal Prog. Part. Nucl. Phys.
Volume 67 Issue 2 Pages 455-460
Keywords Meson many body; Chiral dynamics; Dynamically generated resonances
Abstract In this talk we show recent developments on few body systems involving mesons. We report on an approach to Faddeev equations using chiral unitary dynamics, where an explicit cancellation of the two body off shell amplitude with three body forces stemming from the same chiral Lagrangians takes place. This removal of the unphysical off shell part of the amplitudes is most welcome and renders the approach unambiguous, showing that only on shell two body amplitudes need to be used. Within this approach, systems of two mesons and one baryon are studied, reproducing properties of the low lying 1/2(+) states. On the other hand we also report on multirho and K* multirho states which can be associated to known meson resonances of high spin.
Address [Oset, E.; Yamagata, J.] Ctr Mixto CSIC UV, Inst Fis Corpuscular, Inst Invest Paterna, Valencia 46071, Spain, Email: oset@ific.uv.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 (up) 0146-6410 ISBN Medium
Area Expedition Conference
Notes WOS:000303282200060 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 998
Permanent link to this record
 
 
Author Martinez Torres, A.; Prelovsek, S.; Oset, E.; Ramos, A.
Title Effective Field Theories in a Finite Volume Type Journal Article
Year 2018 Publication Few-Body Systems Abbreviated Journal Few-Body Syst.
Volume 59 Issue 6 Pages 139 - 5pp
Keywords
Abstract In this talk I present the formalism we have used to analyze Lattice data on two meson systems by means of effective field theories. In particular I present the results obtained from a reanalysis of the lattice data on the KD(*()) systems, where the states D-s0*(2317) and D-s1*(2460) are found as bound states of KD and KD *, respectively. We confirm the presence of such states in the lattice data and determine the contribution of the KD channel in the wave function of D-s0*(2317) and that of KD* in the wave function of D-s1*(2460). Our findings indicate a large meson-meson component in the two cases.
Address [Martinez Torres, A.] Univ Sao Paulo, Inst Fis, Rua Matao 1371, BR-05508090 Sao Paulo, SP, Brazil, Email: amartine@if.usp.br
Corporate Author Thesis
Publisher Springer Wien Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 0177-7963 ISBN Medium
Area Expedition Conference
Notes WOS:000448041400002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3772
Permanent link to this record
 
 
Author Martinez Torres, A.; Khemchandani, K.P.; Roca, L.; Oset, E.
Title Few-body systems consisting of mesons Type Journal Article
Year 2020 Publication Few-Body Systems Abbreviated Journal Few-Body Syst.
Volume 61 Issue 4 Pages 35 - 16pp
Keywords
Abstract We present a work which is meant to inspire the few-body practitioners to venture into the study of new, more exotic, systems and to hadron physicists, working mostly on two-body problems, to move in the direction of studying related few-body systems. For this purpose we devote the discussions in the introduction to show how the input two-body amplitudes can be easily obtained using techniques of the chiral unitary theory, or its extensions to the heavy quark sector. We then briefly explain how these amplitudes can be used to solve the Faddeev equations or a simpler version obtained by treating the three-body scattering as that of a particle on a fixed center. Further, we give some examples of the results obtained by studying systems involving mesons. We have also addressed the field of many meson systems, which is currently almost unexplored, but for which we envisage a bright future. Finally, we give a complete list of works dealing with unconventional few-body systems involving one or several mesons, summarizing in this way the findings on the topic, and providing a motivation for those willing to investigate such systems.
Address [Martinez Torres, A.] Univ Sao Paulo, Inst Fis, BR-05389970 Sao Paulo, Brazil, Email: amartine@if.usp.br;
Corporate Author Thesis
Publisher Springer Wien Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 0177-7963 ISBN Medium
Area Expedition Conference
Notes WOS:000572646500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4546
Permanent link to this record
 
 
Author Martinez Torres, A.; Khemchandani, K.P.; Navarra, F.S.; Nielsen, M.; Oset, E.
Title The role of f(0)(1710) in the phi omega threshold peak of J/Psi -> gamma phi omega Type Journal Article
Year 2013 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 719 Issue 4-5 Pages 388-393
Keywords
Abstract We study the process J/Psi -> gamma phi omega, measured by the BES experiment, where a neat peak close to the phi omega threshold is observed and is associated to a scalar meson resonance around 1800 MeV. We make the observation that a scalar resonance coupling to phi omega unavoidably couples strongly to K (K) over bar, but no trace of a peak is seen in the K (K) over bar spectrum of the J/Psi -> gamma K (K) over bar at this energy. This serves us to rule out the interpretation of the observed peak as a signal of a new resonance. After this is done, a thorough study is performed on the production of a pair of vector mesons and how its interaction leads necessarily to a peak in the J/Psi -> gamma phi omega reaction close to the phi omega threshold, due to the dynamical generation of the f(0)(1710) resonance by the vector-vector interaction. We then show that both the shape obtained for the phi omega mass distribution, as well as the strength are naturally reproduced by this mechanism. The work also explains why the phi omega peak is observed in the BES experiment and not in other reactions, like B-+/- -> K-+/-phi omega of Belle.
Address [Martinez Torres, A.; Khemchandani, K. P.; Navarra, F. S.; Nielsen, M.; Oset, E.] Univ Sao Paulo, Inst Fis, BR-05389970 Sao Paulo, Brazil, Email: amartine@if.usp.br
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 (up) 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000315316900020 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1377
Permanent link to this record
 
 
Author Martinez Torres, A.; Khemchandani, K.P.; Jido, D.; Kanada-En'yo, Y.; Oset, E.
Title Three-body hadron systems with strangeness Type Journal Article
Year 2013 Publication Nuclear Physics A Abbreviated Journal Nucl. Phys. A
Volume 914 Issue Pages 280-288
Keywords Unitary chiral theories; Few-body systems
Abstract Recently, many efforts are being put in studying three-hadron systems made of mesons and baryons and interesting results are being found. In this talk, we summarize the main features of the formalism used to study such three hadron systems with strangeness S = -1, 0 within a framework built on the basis of unitary chiral theories and solution of the Faddeev equations. In particular, we present the results obtained for the pi(K) over barN, K (K) over barN and KK (K) over bar systems and their respective coupled channels. In the first case, we find four Sigma's and two A's with spin-parity J(P) = 1/2(+), in the 1500-1800 MeV region, as two meson-one baryon s-wave resonances. In the second case, a 1/2(+) N* around 1900 MeV is found. For the last one a kaon close to 1420 MeV is formed, which can be identified with K(1460).
Address [Torres, A. Martinez; Khemchandani, K. P.] Univ Sao Paulo, Inst Fis, BR-05314970 Sao Paulo, Brazil, Email: amartine@if.usp.br;
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 (up) 0375-9474 ISBN Medium
Area Expedition Conference
Notes WOS:000324847700036 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1596
Permanent link to this record
 
 
Author Xie, J.J.; Martinez Torres, A.; Oset, E.; Gonzalez, P.
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 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 (up) 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.
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 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 (up) 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 Xie, J.J.; Martinez Torres, A.; Oset, E.
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 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 (up) 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 Martinez Torres, A.; Bayar, M.; Jido, D.; Oset, E.
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 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 (up) 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