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Author Sekihara, T.; Martinez Torres, A.; Jido, D.; Oset, E.
Title Theoretical study of incoherent phi photoproduction on a deuteron target Type Journal Article
Year 2012 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 48 Issue 1 Pages 10 - 17pp
Keywords
Abstract We study the photoproduction of phi mesons in deuteron, paying attention to the modification of the cross-section from bound protons to the free ones. For this purpose we take into account Fermi motion in single scattering and rescattering of phi to account for phi absorption on a second nucleon as well as the rescattering of the proton on the neutron. We find that the contribution of the double scattering for phi is much smaller than the typical cross-section of gamma p -> phi p in free space, which implies a very small screening of the phi production in deuteron. The contribution from the proton rescattering, on the other hand, is found to be not negligible compared to the cross-section of gamma p -> phi p in free space, and leads to a moderate reduction of the phi photoproduction cross-section on a deuteron at forward angles if the LEPS set-up is taken into account. The Fermi motion allows contribution of the single scattering in regions forbidden by phase-space in the free case. In particular, we find that for momentum transfer squared close to the maximum value, the Fermi motion changes drastically the shape of d sigma/dt, to the point that the ratio of this cross-section to the free one becomes very sensitive to the precise value of t chosen, or the size of the bin used in an experimental analysis. Hence, this particular region of t does not seem to be the most indicated to find effects of a possible phi absorption in the deuteron. This reaction is studied theoretically as a function of t and the results are contrasted with recent experiments at LEPS and Jefferson Lab. The effect of the experimental angular cuts at LEPS is also discussed, providing guidelines for future experimental analyses of the reaction.
Address [Sekihara, T.] Kyoto Univ, Grad Sch Sci, Dept Phys, Kyoto 6068502, Japan, Email: sekihara@th.phys.titech.ac.jp
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:000300285400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 912
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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 0031-9007 ISBN Medium
Area Expedition Conference
Notes ISI:000281272700005 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ elepoucu @ Serial 387
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Author Molina, R.; Nagahiro, H.; Hosaka, A.; Oset, E.
Title Decay of vector-vector resonances into gamma and a pseudoscalar meson Type Journal Article
Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 83 Issue 9 Pages 094030 - 12pp
Keywords
Abstract We study the decay of dynamically generated resonances from the interaction of two vectors into a gamma and a pseudoscalar meson. The dynamics requires anomalous terms involving vertices with two vectors and a pseudoscalar, which renders it special. We compare our result with data on K-2*(+) (1430) -> K+ gamma and K-2*(0) (1430) -> K-0 gamma and find a good agreement with the data for the K-2*(+) (1430) case and a width considerably smaller than the upper bound measured for the K-2*(0) (1430) meson. We also investigate the decay into pi(+) gamma of one a(2) state, tentatively associated to the a(2)(1320), obtaining qualitative agreement with data.
Address [Molina, R.; Oset, E.] 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 1550-7998 ISBN Medium
Area Expedition Conference
Notes ISI:000291006200002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 636
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Author Yamagata-Sekihara, J.; Roca, L.; Oset, E.
Title 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
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Author Branz, T.; Molina, R.; Oset, E.
Title Radiative decays of the Y(3940), Z(3930), and the X(4160) as dynamically generated resonances Type Journal Article
Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 83 Issue 11 Pages 114015 - 9pp
Keywords
Abstract We study the radiative decay properties of the charmoniumlike X, Y, and Z mesons generated dynamically from vector-meson-vector-meson interaction in the framework of a unitarized hidden-gauge formalism. In the present work, we calculate the one-and two-photon decay widths of the hidden-charm Y(3940), Z(3930) [or X(3915)], and X(4160) mesons in the framework of the vector-meson dominance formalism. We obtain good agreement with the experiment in case of the two-photon width of the X(3915), which we associate to the 2(+) resonance that we find at 3922 MeV. However, in view of discrepancies with a different approach that also considers the resonances as molecular states, we urge independent calculations along the same lines to further clarify the issue.
Address [Branz, Tanja] Univ Tubingen, Inst Theoret Phys, Kepler Ctr Astro & Particle Phys, D-72076 Tubingen, Germany
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:000291312200002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 639
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Author Oset, E.; Ramos, A.
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 [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
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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 0556-2813 ISBN Medium
Area Expedition Conference
Notes ISI:000291984800004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 665
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Author Martinez Torres, A.; Garzon, E.J.; Oset, E.; Dai, L.R.
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 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
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Author Xie, J.J.; Chen, H.X.; Oset, E.
Title The pp -> p Lambda K(+) and pp -> p Sigma(0)K(+) reactions with chiral dynamics Type Journal Article
Year 2011 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 84 Issue 3 Pages 034004 - 8pp
Keywords
Abstract We report on a theoretical study of the pp -> p Lambda K(+) and pp -> p Sigma(0)K(+) reactions near threshold using a chiral dynamical approach. The production process is described by single-pion and single-kaon exchange. The final state interactions of nucleon-hyperon, K-hyperon, and K-nucleon systems are also taken into account. We show that our model leads to a fair description of the experimental data on the total cross section of the pp -> p Lambda K(+) and pp -> p Sigma(0)K(+) reactions. We find that the experimental observed strong suppression of Sigma(0) production compared to Lambda production at the same excess energy can be explained. However, ignorance of phases between some amplitudes does not allow one to properly account for the nucleon-hyperon final state interaction for the pp -> p Sigma(0)K(+) reaction. We also demonstrate that the invariant mass distribution and the Dalitz plot provide direct information about the Lambda and Sigma(0) production mechanisms and may be tested by experiments at COSY or HIRFL-CSR.
Address [Xie, JJ; Chen, HX; Oset, E] Univ Valencia, Inst Fis Corpuscular IFIC, Ctr Mixto CSIC, 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 WOS:000294925700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 757
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Author Xiao, C.W.; Bayar, M.; Oset, E.
Title NDK, (K)over-barDN, and ND(K)over-bar molecules Type Journal Article
Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 84 Issue 3 Pages 034037 - 8pp
Keywords
Abstract We investigate theoretically baryon systems made of three hadrons which contain one nucleon and one D meson, and in addition another meson, (D) over tilde, K, or (K) over tilde. The systems are studied using the fixed center approximation to the Faddeev equations. The study is made assuming scattering of a K or a (K) over tilde on a DN cluster, which is known to generate the Lambda(c)(2595), or the scattering of a nucleon on the D (D) over tilde cluster, which has been shown to generate a hidden charm resonance named X(3700). We also investigate the configuration of scattering of N on the KD cluster, which is known to generate the D*(s0)(2317). In all cases we find bound states, with the NDK system, of exotic nature, more bound than the (K) over tilde DN.
Address [Xiao, CW; Bayar, M; Oset, E] Univ Valencia, Dept Fis Teor, Ctr Mixto, 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 WOS:000294135400007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 725
Permanent link to this record