Engineering topics
Molina, R
Publications and source records attributed to Molina, R.
Prediction of narrow N* and {Lambda}* with hidden charm
The interaction between various charmed mesons and charmed baryons, such as D-bar{Sigma}{sub c}-D-bar{Lambda}{sub c}, D-bar*{Sigma}{sub c}-D-bar*{Lambda}{sub c}, and related strangeness channels, are studied within the framework of the coupled channel unitary approach with the local hidden gauge formalism. Six narrow N* and {Lambda}* resonances are dynamically generated with mass above 4 GeV and width smaller than 100 MeV. These predicted new resonances definitely cannot be accommodated by quark models with three constituent quarks. We make estimates of production cross sections of these predicted resonances in p-barp collisions for PANDA at the forthcoming FAIR facility.
N* production from pp and p-barp collisions
With an effective Lagrangian approach, we give a full analysis on the NN{yields}NN{pi}{pi} and pp{yields}pn{pi}{sup +} reactions for proton beam energy from 1 to 1.5 GeV. The results are very consistent with the experiment data from CELSIUS, KEK, COSY, and so on. Based on these results, we consider the N-barN{yields}N-barN{pi}{pi} and p-barp{yields}p-barn{pi}{sup +} for proton beam energy up to 4 GeV. Compare to the pp collisions, there are many benefits to study N* resonances in these two reactions. And for the high proton beam energy up to 15 GeV, we consider some new resonances with hidden charm which are definitely beyond three constituent quarks model in the p-barp{yields}p-barpJ/{psi} and p-barp{yields}p-barp{eta}{sub c}, where there are very nice places to find these new N{sub cc}-bar*. The predicted results about p-barp collisions can be looked for at the forthcoming PANDA/FAIR experiments.
Dynamically generated N* and {Lambda}* resonances in the hidden charm sector around 4.3 GeV
The interactions of D-bar{Sigma}{sub c}-D-bar{Lambda}{sub c}, D-bar*{Sigma}{sub c}-D-bar*{Lambda}{sub c}, and related strangeness channels, are studied within the framework of the coupled-channel unitary approach with the local hidden gauge formalism. A series of meson-baryon dynamically generated relatively narrow N* and {Lambda}* resonances are predicted around 4.3 GeV in the hidden charm sector. We make estimates of production cross sections of these predicted resonances in p-barp collisions for the experiment of antiproton annihilation at Darmstadt (PANDA) at the forthcoming GSI Facility for Antiproton and Ion Research (FAIR) facility.
The Y(3940), Z(3930) and the X(4160) as dynamically generated resonances from the vector-vector interaction
We apply a unitary approach together with a set of hidden-gauge Lagrangians to study the vector-vector interaction. Concretely, we focus on the sector with quantum numbers charm C = 0 and strangeness S = 0 in the region around 4000 MeV. We get five poles, three of which could be identified with the Y(3940), Z(3930) and X(4160). These poles appear with quantum numbers I = 0 and J{sup PC} = 0{sup ++},2{sup ++} and 2{sup ++}, respectively, and can be considered as hadronic molecules made of D*D-bar*, D{sub s}*D-bar{sub s}*, decaying to a pair of light vectors, light-heavy vector or pseudoscalar-pseudoscalar.
Decay of vector-vector resonances into {gamma} and a pseudoscalar meson
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{sub 2}{sup *+}(1430){yields}K{sup +}{gamma} and K{sub 2}{sup *0}(1430){yields}K{sup 0}{gamma} and find a good agreement with the data for the K{sub 2}{sup *+}(1430) case and a width considerably smaller than the upper bound measured for the K{sub 2}{sup *0}(1430) meson. We also investigate the decay into {pi}{sup +{gamma}} of one a{sub 2} state, tentatively associated to the a{sub 2}(1320), obtaining qualitative agreement with data.
The f{sub 0}(1370), f{sub 0}(1710), f{sub 2}(1270), f{sub 2}{sup '}(1525), and K{sub 2}{sup *}(1430) as dynamically generated states from vector meson-vector meson interaction
We report on some recent developments in understanding the nature of the low-lying mesonic resonances f{sub 0}(1370), f{sub 0}(1710), f{sub 2}(1270), f{sub 2}{sup '}(1525), and K{sub 2}*(1430). In particular we show that these five resonances can be dynamically generated from vector meson-vector meson interaction in a coupled-channel unitary approach, which utilizes the phenomenologically very successful hidden-gauge Lagrangians to produce the interaction kernel between two vector mesons, which is then unitarized by the Bethe-Salpeter-equation method. The data on the strong decay branching ratios, total decay widths, and radiative decay widths of these five states, and on related J/{psi} decay processes can all be well described by such an approach. We also make predictions, compare them with the results of earlier studies, and highlight observables that if measured can be used to distinguish different pictures of these resonances.
A molecular interpretation for the D{sub s2}*(2573) and the prediction of novel exotic charmed mesons
In this talk we review the vector-vector interaction within the hidden gauge formalism in a coupled channel unitary approach. We study the vector-vector interaction for all the sectors not studied before: C = 0; S 1(hidden-charm), C = 1, S = 1, and the flavor exotic sectors C = 1; S = -1,2 and C = 2; S = 0,1,2. By looking for poles in the complex plane, we find nine states, four of them in the C = 1; S = 1 sector, where one can be identified with the D{sub s2}{sup *}(2573) and it is interpreted as a D*K* molecular state. The other five resonances are found in the flavor exotic sectors C = 1; S = -1, C = 2; S = 0,1 and can be considered as D*K-bar*, D*D* and D{sub s}{sup *}D* molecular states. Nevertheless, there is not experimental evidence of such states yet.
Prediction of Narrow N* and {Lambda}* Resonances with Hidden Charm above 4 GeV
The interaction between various charmed mesons and charmed baryons is studied within the framework of the coupled-channel unitary approach with the local hidden gauge formalism. Several meson-baryon dynamically generated narrow N{sup *} and {Lambda}{sup *} resonances with hidden charm are predicted with mass above 4 GeV and width smaller than 100 MeV. The predicted new resonances definitely cannot be accommodated by quark models with three constituent quarks and can be looked for in the forthcoming PANDA/FAIR experiments.
K-bar* mesons in dense matter
We study the properties of K-bar* mesons in nuclear matter using a unitary approach in coupled channels within the framework of the local hidden gauge formalism and incorporating the K-bar{pi} decay channel in matter. The in-medium K-bar*N interaction accounts for Pauli blocking effects and incorporates the K-bar* self-energy in a self-consistent manner. We also obtain the K-bar* (off-shell) spectral function and analyze its behavior at finite density and momentum. At a normal nuclear matter density, the K-bar* meson feels a moderately attractive potential, while the K-bar* width becomes five times larger than in free space. We estimate the transparency ratio of the {gamma}A{yields}K{sup +}K*{sup -}A{sup '} reaction, which we propose as a feasible scenario at the present facilities to detect changes in the properties of the K-bar* meson in nuclear medium.
Vector meson-vector meson interaction and dynamically generated resonances
Using the local hidden gauge formalism for the vector meson-vector meson interaction within a unitary approach we find that 11 states get dynamically generated. Five of them are associated to the f{sub 0}(1370), f{sub 0}(1710), f{sub 2}(1270), f{sub 2}'(1525), and K{sub 2}*(1430) resonances, by comparing the mass, width, and decay pattern of these states with those of their experimental counterparts. At the same time we predict six other states with the quantum numbers of h{sub 1}, a{sub 0}, b{sub 1}, a{sub 2}, K{sub 0}*, and K{sub 1} which could be tested by future experiments.
The Y(3940), Z(3930) and the X(4160) as dynamically generated resonances from the vector-vector interaction
We study the vector-vector interaction within the framework of the hidden gauge formalism for the sector with quantum numbers charm C = 0 and strangeness S = 0 in the region around 4000 MeV. We get five poles, three of which could be identified with the Y(3940), Z(3930) and X(4160). These poles appear with quantum numbers I = 0 and J{sup PC} = 0{sup ++}, 2{sup ++} and 2{sup ++}, respectively, and can be considered as hadronic molecules made of D*D-bar*,D{sub s}* D{sub s}-bar*
Scalar, axial-vector and tensor resonances from the {rho}D*, {omega}D* interaction in the hidden gauge formalism
We apply a unitary approach together with a set of hidden-gauge Lagrangians to study the vector-vector interaction. We study the case of the {rho}({omega})D* interaction within the model. In I = 1/2 we get strong enough attraction to bind the system. Concretely, we get one resonance for each spin J =0,1,2. For J = 1 and 2 these resonances can be easily identified with the D*(2460) and D*(2640). Whereas the state for J = 0 with mass M{approx}2600 MeV is a prediction of the model. In I = 3/2 we get a repulsive interaction and hence no exotic dynamically generated states.
Charmed mesons in nuclear matter
We obtain the properties of charmed mesons in dense matter using a coupled-channel approach which accounts for Pauli blocking effects and meson self-energies in a self-consistent manner. We study the behaviour of dynamically-generated baryonic resonances together with the open-charm meson spectral functions in this dense nuclear environment. We discuss the implications of the in-medium properties of open-charm mesons on the D{sub s0}(2317) and the predicted X(3700) scalar resonances, and on the formation of D-mesic nuclei.