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Author Geng, L.S.; Oset, E. url  doi
openurl 
  Title Novel nonperturbative approach for radiative (B)over-bar(0)((B)over-bar(s)(0)) -> J/psi gamma decays Type Journal Article
  Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 94 Issue 1 Pages 014018 - 11pp  
  Keywords  
  Abstract Radiative (B) over bar (0)((B) over bar (0)(s)) -> J/psi gamma decays provide an interesting case to test our understanding of ( non) perturbative QCD and eventually to probe physics beyond the standard model. Recently, the LHCb Collaboration reported an upper bound, updating the results of the BABAR Collaboration. Previous theoretical predictions based on QCD factorization or perturbative QCD have shown large variations due to different treatment of nonfactorizable contributions and meson-photon transitions. In this paper, we report on a novel approach to estimate the decay rates, which is based on a recently proposed model for B decays and the vector meson dominance hypothesis, widely tested in the relevant energy regions. The predicted branching ratios are Br[(B) over bar (0) -> J/psi gamma] = (3.50 +/- 0.34(-0.63)(+1.12)) x 10(-8) and Br[(B) over bar (0)(s) -> J/psi gamma] = (7.20 +/- 0.68(-1.30)(+2.31)) x 10(-7). The first uncertainty is systematic and the second is statistical, originating from the experimental (B) over bar (0)(s) -> J/psi gamma branching ratio.  
  Address [Geng, Li-Sheng] Beihang Univ, Sch Phys & Nucl Energy Engn, Beijing 100191, Peoples R China, Email: lisheng.geng@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 (down) 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000380111000004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2767  
Permanent link to this record
 

 
Author Wang, E.; Chen, H.X.; Geng, L.S.; Li, D.M.; Oset, E. url  doi
openurl 
  Title Hidden-charm pentaquark state in Lambda(0)(b) -> J/psi p pi(-) decay Type Journal Article
  Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 93 Issue 9 Pages 094001 - 10pp  
  Keywords  
  Abstract We study here the A(b)(0) -> J/psi p pi(-) reaction in analogy to the A(b)(0) -> J/psi pK(-) one, and we note that in both decays there is a sharp structure (dip or peak) in the J/psi p mass distribution around 4450 MeV, which is associated in the A(b)(0) -> J/psi pK(-) experiment to an exotic pentaquark baryonic state, although in J/psi p pi(-) it shows up with relatively low statistics. We analyze the A(b)(0) -> J/psi p pi(-) interaction along the same lines as the A(b)(0) -> J/psi pK(-) one, with the main difference stemming from the reduced Cabibbo strength in the former and the consideration of the pi(-)p final state interaction instead of the K(-)p one. We find that with a minimal input, introducing the pi(-)p and J/psi p interaction in S-wave with realistic interactions, and the empirical P-wave and D-wave contributions, one can accomplish a qualitative description of the pi(-)p and J/psi p mass distributions. More importantly, the peak structure followed by a dip of the experimental J/psi p mass distribution is reproduced with the same input as used to describe the data of A(b)(0) -> J/psi pK(-) reaction. The repercussion for the triangular singularity mechanism, invoked in some works to explain the pentaquark peak, is discussed.  
  Address [Wang, En; Li, De-Min] Zhengzhou Univ, Dept Phys, Zhengzhou 450001, Henan, Peoples R China, Email: hxchen@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 (down) 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000375655000003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2668  
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Author Lu, J.X.; Wang, E.; Xie, J.J.; Geng, L.S.; Oset, E. url  doi
openurl 
  Title Lambda(b) -> J/psi K-0 Lambda reaction and a hidden-charm pentaquark state with strangeness Type Journal Article
  Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 93 Issue 9 Pages 094009 - 11pp  
  Keywords  
  Abstract We study the Lambda(b) -> J/psi K-0 Lambda reaction considering both the K-0 Lambda interaction with its coupled channels and the J/psi Lambda interaction. The latter is described by taking into account the fact that there are predictions for a hidden-charm state with strangeness that couples to J/psi Lambda By using the coupling of the resonance to J/psi Lambda from these predictions, we show that a neat peak can be observed in the J/psi Lambda invariant mass distribution, rather stable under changes of unknown magnitudes. In some cases, one finds a dip structure associated to that state, but a signal of the state shows up in the J/psi Lambda spectrum.  
  Address [Lu, Jun-Xu; Geng, Li-Sheng] Beihang Univ, Sch Phys & Nucl Energy Engn, Beijing 100191, Peoples R China, Email: wangen@zzu.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 (down) 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000376001100004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2680  
Permanent link to this record
 

 
Author Lu, J.X.; Chen, H.X.; Guo, Z.H.; Nieves, J.; Xie, J.J.; Geng, L.S. url  doi
openurl 
  Title Lambda(c)(2595) resonance as a dynamically generated state: The compositeness condition and the large N-c evolution Type Journal Article
  Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 93 Issue 11 Pages 114028 - 16pp  
  Keywords  
  Abstract Recent studies have shown that the well-established Lambda(c) (2595) resonance contains a large meson-baryon component, which can vary depending on the specific formalism. In this work, we examine such a picture by utilizing the compositeness condition and the large number of colors (N-c) expansion. We examine three different models fulfilling two body unitarily in coupled-channels, and adopting renormalization schemes where the mass of the Lambda(c)(2595) resonance is well described, but not necessarily its width, since we do not consider three body channels and work at the isospin symmetric limit. Both approximations might have an effect larger on the width than on the mass. In this context, our studies show that the compositeness of the Lambda(c)(2595) depends on the number of considered coupled channels, and on the particular regularization scheme adopted in the unitary approaches and, therefore, is model dependent. In addition, we perform an exploratory study of the Lambda(c)(2595) in the large N-c expansion, within a scheme involving only the pi Sigma(c) and K Xi(c)', channels, whose dynamics is mostly fixed by chiral symmetry. In this context and formulating the leading-order interaction as a function of N-c, we show that for moderate N-c > 3 values, the mass and width of the Lambda(c)(2595) deviate from those of a genuine qqq baryon, implying the relevance of meson-baryon components in its wave function. Furthermore, we study the properties of the Lambda(c)(2595), in the strict N-c -> infinity limit, using an extension of the chiral Weinberg-Tomozawa interaction to an arbitrary number of flavors and colors. This latter study hints at the possible existence of a (perhaps) subdominant qqq component in the Lambda(c)(2595) resonance wave function, which would become dominant when the number of colors gets sufficiently large.  
  Address [Lu, Jun-Xu; Chen, Hua-Xing; Geng, Li-Sheng] Beihang Univ, Sch Phys & Nucl Energy Engn, Beijing 100191, Peoples R China, Email: lisheng.geng@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 (down) 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000378306600004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2745  
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Author Xie, J.J.; Geng, L.S.; Oset, E. url  doi
openurl 
  Title f(2)(1810) as a triangle singularity Type Journal Article
  Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 95 Issue 3 Pages 034004 - 6pp  
  Keywords  
  Abstract We perform calculations showing that a source producing K*K* in J = 2 and L = 0 gives rise to a triangle singularity at 1810 MeV with a width of about 200 MeV from the mechanism K*-> pi K and then KK* merging into the a alpha(1)(1260) resonance. We suggest that this is the origin of the present f(2)(1810) resonance and propose to look at the pa pi alpha(1)(1260) mode in several reactions to clarify the issue.  
  Address [Xie, Ju-Jun; Oset, E.] Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Peoples R China, Email: lisheng.geng@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 (down) 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000393509100003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2960  
Permanent link to this record
 

 
Author Wang, E.; Xie, J.J.; Geng, L.S.; Oset, E. url  doi
openurl 
  Title Analysis of the B+ -> J/Psi phi K+ data at low J/Psi phi invariant masses and the X(4140) and X(4160) resonances Type Journal Article
  Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 97 Issue 1 Pages 014017 - 6pp  
  Keywords  
  Abstract We have studied the J/Psi phi mass distribution of the B+ -> J/Psi phi K+ reaction from threshold to about 4250 MeV, and find that one needs the contribution of the X(4140) with a narrow width, together with the X(4160) which accounts for most of the strength of the distribution in that region. The existence of a clear cusp at the D-s*(D) over bar (s)* threshold indicates that the X(4160) resonance is strongly tied to the D-s*(D) over bar (s)* channel, which finds a natural interpretation in the molecular picture of this resonance.  
  Address [Wang, En] Zhengzhou Univ, Dept Phys, Zhengzhou 450001, Henan, Peoples R China  
  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 (down) 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000423429400007 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3463  
Permanent link to this record
 

 
Author Xie, J.J.; Oset, E.; Geng, L.S. url  doi
openurl 
  Title Photoproduction of the f(2)'(1525), a(2)(1320), and K-2(*) (1430) Type Journal Article
  Year 2016 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 93 Issue 2 Pages 025202 - 8pp  
  Keywords  
  Abstract Assuming that the f(2)'(1525), a(2)(1320), and K-2(*) (1430) resonances are dynamically generated states from vector-meson-vector-meson interactions in the s-wave with spin S = 2, we study the gamma p -> f(2)'(1525)p, gamma p -> a(2)(0)(1320)p, and gamma p -> K-2(*)(1430)Lambda(Sigma) reactions. These reactions proceed in the following way: the incoming photon first mutates into a rho(0), omega, or phi meson via vector-meson dominance, which then interacts with the rho(0), omega, or K* emitted by the incoming proton to form the tensor mesons f(2)(')(1525), a(2)(1320), and K-2(*)(1430). The picture is simple and has no free parameters, as all the parameters of the mechanism have been fixed in previous studies. We predict the differential and total cross sections of these reactions. The results can be tested in future experiments and therefore offer new clues about the nature of these tensor states.  
  Address [Xie, Ju-Jun; Oset, E.] Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Peoples R China, Email: lisheng.geng@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 (down) 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000369729400004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2557  
Permanent link to this record
 

 
Author Chen, H.X.; Geng, L.S.; Liang, W.H.; Oset, E.; Wang, E.; Xie, J.J. url  doi
openurl 
  Title Looking for a hidden-charm pentaquark state with strangeness S =-1 from Xi(-)(b) decay into J/Psi K- Lambda Type Journal Article
  Year 2016 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 93 Issue 6 Pages 065203 - 9pp  
  Keywords  
  Abstract Assuming that the recently observed hidden-charm pentaquark state, P-c(4450), is of molecular nature as predicted in the unitary approach, we propose to study the decay of Xi(-)(b) -> J/psi K-Lambda to search for the strangeness counterpart of the P-c(4450). There are three ingredients in the decay mechanism: the weak decay mechanism, the hadronization mechanism, and the final state interactions in the meson-baryon system of strangeness S = -2 and isospin I = 1/2 and of the J/psi Lambda. All these have been tested extensively. As a result, we provide a genuine prediction of the invariant mass distributions where a strangeness hidden-charm pentaquark state, the counterpart of the P-c(4450), can be clearly seen. The decay rate is estimated to be of similarmagnitude as the Lambda(0)(b) -> J/psi K(-)p measured by the LHCb Collaboration.  
  Address [Chen, Hua-Xing; Geng, Li-Sheng] Beihang Univ, Sch Phys & Nucl Energy Engn, Beijing 100191, Peoples R China, Email: lisheng.geng@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 (down) 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000377803500002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2726  
Permanent link to this record
 

 
Author Molina, R.; Geng, L.S.; Oset, E. url  doi
openurl 
  Title Comments on the dispersion relation method to vector-vector interaction Type Journal Article
  Year 2019 Publication Progress of Theoretical and Experimental Physics Abbreviated Journal Prog. Theor. Exp. Phys.  
  Volume Issue 10 Pages 103B05 - 16pp  
  Keywords  
  Abstract We study in detail the method proposed recently to study the vector-vector interaction using the N/D method and dispersion relations, which concludes that, while, for J = 0, one finds bound states, in the case of J = 2, where the interaction is also attractive and much stronger, no bound state is found. In that work, approximations are done for N and D and a subtracted dispersion relation for D is used, with subtractions made up to a polynomial of second degree in s – s(th), matching the expression to 1 – VG at threshold. We study this in detail for the rho rho interaction and to see the convergence of the method we make an extra subtraction matching 1 – VG at threshold up to (s – s(th))(3). We show that the method cannot be used to extrapolate the results down to 1270 MeV where the f(2)(1270) resonance appears, due to the artificial singularity stemming from the “on-shell” factorization of the rho exchange potential. In addition, we explore the same method but folding this interaction with the mass distribution of the rho, and we show that the singularity disappears and the method allows one to extrapolate to low energies, where both the (s – s(th))(2) and (s – s(th))(3) expansions lead to a zero of Re D(s), at about the same energy where a realistic approach produces a bound state. Even then, the method generates a large Im D(s) that we discuss is unphysical.  
  Address [Molina, R.] Univ Complutense Madrid, Fac Fis, Dept Fis Teor 2, Plaza Ciencias 1, E-28040 Madrid, Spain, Email: ramolinape@gmail.com  
  Corporate Author Thesis  
  Publisher Oxford Univ Press Inc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) 2050-3911 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000493500800006 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4190  
Permanent link to this record
 

 
Author Geng, L.S.; Molina, R.; Oset, E. url  doi
openurl 
  Title On the chiral covariant approach to rho rho scattering Type Journal Article
  Year 2017 Publication Chinese Physics C Abbreviated Journal Chin. Phys. C  
  Volume 41 Issue 12 Pages 124101 - 9pp  
  Keywords rho-rho scattering; unitary chiral approaches; on-shell approximations  
  Abstract We examine in detail a recent work (D. Gulmez, U. G. Meibner and J. A. Oller, Eur. Phys. J. C, 77: 460 (2017)), where improvements to make rho rho scattering relativistically covariant are made. The paper has the remarkable conclusion that the J=2 state disappears with a potential which is much more attractive than for J=0, where a bound state is found. We trace this abnormal conclusion to the fact that an “on-shell” factorization of the potential is done in a region where this potential is singular and develops a large discontinuous and unphysical imaginary part. A method is developed, evaluating the loops with full rho propagators, and we show that they do not develop singularities and do not have an imaginary part below threshold. With this result for the loops we define an effective potential, which when used with the Bethe-Salpeter equation provides a state with J=2 around the energy of the f(2)(1270). In addition, the coupling of the state to is evaluated and we find that this coupling and the T matrix around the energy of the bound state are remarkably similar to those obtained with a drastic approximation used previously, in which the q(2) terms of the propagators of the exchanged rho mesons are dropped, once the cut-off in the rho rho loop function is tuned to reproduce the bound state at the same energy.  
  Address [Geng, Li-Sheng] Beihang Univ, Sch Phys & Nucl Energy Engn, Beijing 100191, Peoples R China, Email: lisheng.geng@buaa.edu.cn  
  Corporate Author Thesis  
  Publisher Chinese 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 (down) 1674-1137 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000417112000005 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3398  
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