Open charm meson in nuclear matter at finite temperature beyond the zero range approximation

The properties of open charm mesons, $D$, $\bar D$, $D_s$ and $\bar D_s$ in nuclear matter at finite temperature are studied within a self-consistent coupled-channel approach. The interaction of the low lying pseudoscalar mesons with the ground state baryons in the charm sector is derived from a $t$-channel vector-exchange model. The in-medium scattering amplitudes are obtained by solving the Lippmann-Schwinger equation at finite temperature including Pauli blocking effects, as well as $D$, $\bar D$, $D_s$ and $\bar D_s$ self-energies taking their mutual influence into account. We find that the in-medium properties of the $D$ meson are affected by the $D_s$-meson self-energy through the intermediate $D_s Y$ loops coupled to $DN$ states. Similarly, dressing the $\bar{D}$ meson in the $\bar{D}Y$ loops has an influence over the properties of the $\bar{D}_s$ meson.Comment: 23 pages, 9 figures, 2 table

Dynamically generated open charmed baryons beyond the zero range approximation

The interaction of the low lying pseudo-scalar mesons with the ground state baryons in the charm sector is studied within a coupled channel approach using a t-channel vector-exchange driving force. The amplitudes describing the scattering of the pseudo-scalar mesons off the ground-state baryons are obtained by solving the Lippmann--Schwinger equation. We analyze in detail the effects of going beyond the $t=0$ approximation. Our model predicts the dynamical generation of several open charmed baryon resonances in different isospin and strangeness channels, some of which can be clearly identified with recently observed states.Comment: 7 figures, 8 table

An atom-doped photon engine: Extracting mechanical work from a quantum system via radiation pressure

The possibility of efficiently converting heat into work at the microscale has triggered an intense research effort to understand quantum heat engines, driven by the hope of quantum superiority over classical counterparts. In this work, we introduce a model featuring an atom-doped optical quantum cavity propelling a classical piston through radiation pressure. The model, based on the Jaynes-Cummings Hamiltonian of quantum electrodynamics, demonstrates the generation of mechanical work through thermal energy injection. We establish the equivalence of the piston expansion work with Alicki's work definition, analytically for quasistatic transformations and numerically for finite time protocols. We further employ the model to construct quantum Otto and Carnot engines, comparing their performance in terms of energetics, work output, efficiency, and power under various conditions. This model thus provides a platform to extract useful work from an open quantum system to generate net motion, and sheds light on the quantum concepts of work and heat.Comment: Updated version. 15 pages, 8 figure

Charmed nuclei within a microscopic many-body approach

Single-particle energies of the $\Lambda_c$ chamed baryon are obtained in several nuclei from the relevant self-energy constructed within the framework of a perturbative many-body approach. Results are presented for a charmed baryon-nucleon ($Y_cN$) potential based on a SU(4) extension of the meson-exchange hyperon-nucleon potential $\tilde A$ of the J\"{u}lich group. Three different models (A, B and C) of this interaction, that differ only on the values of the couplings of the scalar $\sigma$ meson with the charmed baryons, are considered. Phase shifts, scattering lengths and effective ranges are computed for the three models and compared with those predicted by the $Y_cN$ interaction derived in Eur. Phys. A {\bf 54}, 199 (2018) from the extrapolation to the physical pion mass of recent results of the HAL QCD Collaboration. Qualitative agreement is found for two of the models (B and C) considered. Our results for $\Lambda_c$-nuclei are compatible with those obtained by other authors based on different models and methods. We find a small spin-orbit splitting of the $p-, d-$ and $f-$wave states as in the case of single $\Lambda$-hypernuclei. The level spacing of $\Lambda_c$ single-particle energies is found to be smaller than that of the corresponding one for hypernuclei. The role of the Coulomb potential and the effect of the coupling of the $\Lambda_cN$ and $\Sigma_cN$ channels on the single-particle properties of $\Lambda_c-$nuclei are also analyzed. Our results show that, despite the Coulomb repulsion between the $\Lambda_c$ and the protons, even the less attractive one of our $Y_cN$ models (model C) is able to bind the $\Lambda_c$ in all the nuclei considered. The effect of the $\Lambda_cN-\Sigma_cN$ coupling is found to be almost negligible due to the large mass difference of the $\Lambda_c$ and $\Sigma_c$ baryons.Comment: 10 pages, 6 figures, 4 table

Generalized transverse resonance analysis of planar discontinuities considering the edge effect

Mode-matching related techniques such as the Generalized Transverse Resonance Method (GTR) suffer from the relative convergence phenomenon. To reduce its influence, we present a technique consisting of the application of basis functions incorporating the singular behavior of fields at edges and an optimal modal ratio. We present the results obtained analyzing a uniform finline and a short-circuited finline which demonstrate the minimization of the relative convergence phenomenon, allowing a fast and accurate analysis on a low-cost personal computer.Peer Reviewe

La coxartrosis en los pacientes con osteopetrosis: su tratamiento quirúrgico

Se presentan un caso de osteopetrosis en un paciente de 22 años de edad que consultó por dolor en la cadera izquierda, siendo diagnosticado de coxartrosis izquierda secundaria a la osteopetrosis. Fue tratado inicialmente de forma quirúrgica realizándosele una osteotomía de la cadera afectada. Varios años después, tras la reaparición del dolor se procedió a la implantación de una prótesis total de cadera que evolucionó satisfactoriamente.A case of osteopetrosis in a 22-year-old patient who consulted by pain in the left hip is presented. He was diagnosed of degenerative osteoarthritis of the left hip secondary to osteopetrosis. Initially, it was treated surgically by an osteotomy of the proximal femur. Several years later\ after the pain reappearance, the authors treated the patient by a total hip arthroplasty with satisfactory outcome