Search results for "Mathematical physics"
showing 10 items of 2687 documents
Pseudobosons, Riesz bases, and coherent states
2010
In a recent paper, Trifonov suggested a possible explicit model of a PT-symmetric system based on a modification of the canonical commutation relation. Although being rather intriguing, in his treatment many mathematical aspects of the model have just been neglected, making most of the results of that paper purely formal. For this reason we are re-considering the same model and we repeat and extend the same construction paying particular attention to all the subtle mathematical points. From our analysis the crucial role of Riesz bases clearly emerges. We also consider coherent states associated to the model.
Comment on “Scaling behavior in explosive fragmentation”
2002
We discuss the data analysis and the conclusions based upon the analysis given in the paper by Diehl et al. Following the suggestion in the Comment on our previous work by Astrom, Linna, and Timonen [Phys. Rev. E 65,048101 (2002)], we performed extensive molecular-dynamics simulations to confirm that our numerical results for the mass distribution of fragments after the "explosion" of thermalized samples are consistent with the scaling form n(m)∼m - ( α + 1 ) f(m/M 0 ), where ∫(m/M 0 ) is a cutoff function, M 0 is a cutoff parameter, and the exponent a is close to zero.
K --> pi pi matrix elements beyond the leading-order chiral expansion
2002
We propose an approach for calculating $K\to\pi\pi$ decays to the next-to-leading order in chiral expansion. A detailed numerical study of this approach is being performed.
Quons, coherent states and intertwining operators
2009
We propose a differential representation for the operators satisfying the q-mutation relation $BB^\dagger-q B^\dagger B=\1$ which generalizes a recent result by Eremin and Meldianov, and we discuss in detail this choice in the limit $q\to1$. Further, we build up non-linear and Gazeau-Klauder coherent states associated to the free quonic hamiltonian $h_1=B^\dagger B$. Finally we construct almost isospectrals quonic hamiltonians adopting the results on intertwining operators recently proposed by the author.
Extended SUSY quantum mechanics, intertwining operators and coherent states
2009
Abstract We propose an extension of supersymmetric quantum mechanics which produces a family of isospectral Hamiltonians. Our procedure slightly extends the idea of intertwining operators. Several examples of the construction are given. Further, we show how to build up vector coherent states of the Gazeau–Klauder type associated to our Hamiltonians.
Dissipation evidence for the quantum damped harmonic oscillator via pseudo-bosons
2011
It is known that a self-adjoint, time-independent hamiltonian can be defined for the quantum damped harmonic oscillator. We show here that the two vacua naturally associated to this operator, when expressed in terms of pseudo-bosonic lowering and raising operators, appear to be non square-integrable. This fact is interpreted as the evidence of the dissipation effect of the classical oscillator at a purely quantum level.
Study of the DKK and DKK¯ systems
2017
Using the fixed center approximation to Faddeev equations, we investigate the $DKK$ and $DK\overline{K}$ three-body systems, considering that the $DK$ dynamically generates, through its $I=0$ component, the ${D}_{s0}^{*}(2317)$ molecule. According to our findings, for the $DK\overline{K}$ interaction we find evidence of a state $I({J}^{P})=1/2({0}^{\ensuremath{-}})$ just above the ${D}_{s0}^{*}(2317)\overline{K}$ threshold and around the $D{f}_{0}(980)$ threshold, with mass of about 2833--2858 MeV, made mostly of $D{f}_{0}(980)$. On the other hand, no evidence related to a state from the $DKK$ interaction is found. The state found could be seen in the $\ensuremath{\pi}\ensuremath{\pi}D$ inv…
A three body state with J=3 in the ρB*B̅N* interaction
2016
We study the ρB * BN * system solving the Faddeev equations in the fixed center approximation. The B * BN * system will be considered forming a cluster, and using the two-body ρB * unitarized scattering amplitudes in the local Hidden Gauge approach we find a new I ( J PC ) = 1(3 −− ) state. The mass of the new state corresponds to a two particle invariant mass of the ρB * system close to the resonant energy of the B * 2 (5747), indicating that the role of this J = 2 resonance is important in the dynamical generation of the new state.
Binding of the BDD¯ and BDD systems
2017
We study theoretically the $BD\overline{D}$ and $BDD$ systems to see if they allow for possible bound or resonant states. The three-body interaction is evaluated implementing the fixed center approximation to the Faddeev equations which considers the interaction of a $D$ or $\overline{D}$ particle with the components of a $BD$ cluster, previously proved to form a bound state. We find an $I({J}^{P})=1/2({0}^{\ensuremath{-}})$ bound state for the $BD\overline{D}$ system at an energy around 8925--8985 MeV within uncertainties, which would correspond to a bottom hidden-charm meson. In contrast, for the $BDD$ system, which would be bottom double-charm and hence manifestly exotic, we have found h…
Position space formulation for Dirac fermions on honeycomb lattice
2014
We study how to construct Dirac fermion defined on the honeycomb lattice in position space. Starting from the nearest neighbor interaction in tight binding model, we show that the Hamiltonian is constructed by kinetic term and second derivative term of three flavor Dirac fermions in which one flavor has a mass of cutoff order and the other flavors are massless. In this formulation the structure of the Dirac point is simplified so that its uniqueness can be easily shown even if we consider the next-nearest neighbor interaction. We also show the chiral symmetry at finite lattice spacing, which protects the masslessness of the Dirac fermion, and discuss the analogy with the staggered fermion f…