Search results for "Unitary state"
showing 10 items of 133 documents
Relativistic Corrections and Unitary Equivalence
1992
Model calculations of the charge and quadrupole deuteron form factors were performed starting from a class of approximately unitary equivalent Hamiltonians and using consistent charge density operators. The approximate unitary equivalence was tested numerically and found to break down already for rather small values of momentum transfer.
N*(1920)(1/2+) STATE IN THE $NK\bar{K}$ SYSTEM
2013
We study the three body $N \bar{K} K$ system by using the fixed center approximation to the Faddeev equations, taking the interaction between $N$ and $\bar{K}$, $N$ and $K$, and $\bar{K}$ and $K$ from the chiral unitary approach. Our results suggest that a $N\bar{K}K$ hadron state, with spin-parity $J^P=1/2^+$, and mass around 1920 MeV, can be formed.
A MOLECULAR INTERPRETATION FOR THE $D^*_{s2}(2573)$, THE PREDICTION OF NOVEL EXOTIC CHARMED MESONS AND NARROW N*, Λ* RESONANCES AROUND 4.3 GeV
2011
In this talk we review the vector-vector and vector-baryon interaction within the hidden gauge formalism in a coupled channel unitary approach. The vector-vector interaction is studied 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. We find nine states, four of them in the C = 1; S = 1 sector, where one can be identified with the [Formula: see text] 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 [Formula: see text], D* D* and [Formula: see text] molecular states. …
Unitary chiral dynamics of two hadrons in a finite volume: theKD,ηDssystem and theDs*0(2317) resonance
2012
We investigate the KD and ηDs system in a finite volume and study the properties of the Ds*0(2317) resonance, which is generated in this coupled channel system. We calculate the energy levels in a cubic box and considering them as synthetic lattice data we solve the inverse problem of determining the bound states and phase shifts in the infinite volume. We observe that it is possible to obtain accurate KD phase shifts and the position of the Ds*0(2317) state from the synthetic lattice data considered and that a careful analysis of the finite volume data can shed some light on the nature of the Ds*0(2317) resonance as a KD molecule or otherwise.
Vector meson–vector meson interaction and dynamically generated resonances
2012
We report upon 11 composite meson states, dynamically generated from the vector meson–vector meson interaction using the local hidden gauge formalism within a unitary approach. Six of these states are associated to the f0(1370), f0(1710), f2(1270), f'2(1525), a2(1320) and K*2(1430) resonances. At the same time we predict five other states with the quantum numbers of h1, a0, b1, K*0, and K1 which could be tested by future experiments.
Dissipative effects on a generation scheme of a W state in an array of coupled Josephson junctions
2011
The dynamics of an open quantum system, consisting of three superconducting qubits interacting with independent reservoirs, is investigated to elucidate the effects of the environment on a unitary generation scheme of W states (Migliore R et al 2006 Phys. Rev. B 74 104503). To this end a microscopic master equation is constructed and its exact resolution predicts the generation of a Werner-like state instead of the W state. A comparison between our model and a more intuitive phenomenological model is also considered, in order to find the limits of the latter approach in the case of structured reservoirs.
Observation of a unitary cusp in the thresholdγp→π0preaction
1997
A rigorous multipole analysis of the recent $\ensuremath{\gamma}p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}p$ cross-section measurement is presented. The data were taken using the photon spectrometer TAPS at the tagged photon beam of the Mainz microtron. The $s$ and $p$ wave multipoles were extracted using minimal model assumptions. The predicted unitary cusp for the $s$-wave multipole ${E}_{0+}$ due to the two step $\ensuremath{\gamma}p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}n\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}p$ reaction was observed. The results are consistent with one-loop chiral perturbation theory calculations for which three low-energy constants have been determi…
Sigma Exchange in the NN interaction within the chiral unitary approach
2000
We study the nucleon-nucleon interaction in the isoscalar-scalar channel using t he chiral unitary approach. The $t$-matrix of the pion-pion scattering in this c hannel is summed up to all orders using the B-S equation. We find that the calcu lated results at long distances are close to those of the $\sigma$-exchange inte raction. In addition, there appears a shorter range repulsion in this channel.
The In-Medium \barK NInteraction within a Chiral Unitary Approach
2007
The s- and p-wave contributions to the $\bar K N$ interaction in dense nuclear matter are obtained using a chiral unitary approach. We perform a self-consistent calculation of the $\bar K$ self-energy including Pauli blocking effects, meson self-energies modified by short-range correlations and baryon binding potentials. We find that the on-shell factorization cannot be applied to evaluate the in-medium corrections to p-wave amplitudes. Furthermore, the $\Lambda$ and $\Sigma$ develop a mass shift of -30 MeV at saturation density while the $\Sigma^*$ width increases to 80 MeV. We conclude that no deep and narrow $\bar K$ bound states could be observed.
Resonances, chiral symmetry, coupled channel unitarity and effective Lagrangians
1999
By means of a coupled channel non-perturbative unitary approach, it is possible to extend the strong constrains of Chiral Perturbation Theory to higher energies. In particular, it is possible to reproduce the lowest lying resonances in meson-meson scattering up to 1.2 GeV using the parameters of the O(p^2) and O(p^4) Chiral Lagrangian. We report on an update of these results examining their possible relevance for meson spectroscopy.