Unitary Approach Research Articles

Theoretical study of N(1535) and Σ*(1/2−) in the Cabibbo-favored process Λc+→pK¯0η

Motivated by the recent experimental measurements, we have investigated the Cabibbo-favored process Λc+→pK¯0η, where the N(1535) resonance is dynamically generated from the S-wave pseudoscalar meson-octet baryon interactions within the chiral unitary approach. The contributions from the intermediate N(1650) and the predicted low-lying baryon Σ*(1/2−) are also considered. In addition, a Breit-Wigner amplitude for the N(1535) resonance is checked. By comparing with the measured ηp, K¯0η, and pK¯0 invariant mass squared distributions, our results support the interpretation of N(1535) as a dynamically generated state. Furthermore, we demonstrate that, with the contribution from Σ*(1/2−) taken into account, the calculated invariant mass distributions agree with the Belle measurements. Future precise measurements of the Λc+→pK¯0η process can further elucidate the existence of the low-lying baryon Σ*(1/2−). Published by the American Physical Society 2024

A0(1710)−f0(1710) mixing effect in the Ds+→KS0KS0π+ decay

With the measurements of the decay Ds+→KS0KS0π+ by the BESIII collaboration, we investigate this three-body weak decay via the chiral unitary approach for the final state interaction, where the resonances S(980) and S(1710) are dynamically reproduced with the interaction of eleven coupled channels, and the W-external and W-internal emission mechanisms are considered at the quark level. Besides, we also take into account the contribution from the P-wave resonance K*(892)+ and make a combined fit of the KS0KS0 and KS0π+ invariant mass spectra measured by the BESIII collaboration. The fitted results show that the enhancement around 1.7 GeV in KS0KS0 mass spectrum is overlapped with two visible peaks, indicating the mixing signal originated from the resonances a0(1710) and f0(1710) due to their different poles (masses). Thus, the decay Ds+→KS0KS0π+ is helpful to reveal their molecular nature with the mixing signal, which can be more precisely measured in the future. Published by the American Physical Society 2024

Renormalized Internally Contracted Multireference Coupled Cluster with Perturbative Triples.

In this work, we combine the many-body formulation of the internally contracted multireference coupled cluster (ic-MRCC) method with Evangelista's multireference formulation of the driven similarity renormalization group (DSRG). The DSRG method can be viewed as a unitary multireference coupled cluster theory, which renormalizes the amplitudes based on a flow equation approach to eliminate numerical instabilities. We extend this approach by demonstrating that the unitary flow equation approach can be adapted for nonunitary transformations, rationalizing the renormalization of ic-MRCC amplitudes. We denote the new approach, the renormalized ic-MRCC (ric-MRCC) method. To achieve high accuracy with a reasonable computational cost, we introduce a new approximation to the Baker-Campbell-Hausdorff expansion. We fully consider the linear commutator while approximating the quadratic commutator, for which we neglect specific contractions involving amplitudes with active indices. Moreover, we introduce approximate perturbative triples to obtain the ric-MRCCSD[T] method. We demonstrate the accuracy of our approaches in comparison to advanced multireference methods for the potential energy curves of H8, F2, H2O, N2, and Cr2. Additionally, we show that ric-MRCCSD and ric-MRCSSD[T] match the accuracy of CCSD(T) for evaluating spectroscopic constants and of full configuration interaction energies for a set of small molecules.

On imperfective suffixes in Russian

This article is concerned with imperfective suffixes in Russian. It argues that there are at least three imperfective suffixes, the progressive morpheme, the iterative marker and the habitual suffix. It is shown that they differ in morphosyntactic and semantic properties. As to their structural properties, the progressive suffix is the lowest marker; the iterative morpheme attaches in a higher position; and the habitual morpheme is structurally the highest element. Thus, the article argues against a unitary approach to the iterative suffix and the habitual morpheme. Semantically, the iterative suffix has a pluractional meaning, whereas the habitual suffix is a vague generic quantifier. As to their phonological properties, the three markers are homophonous; they are spelled out as an -yva- allomorph. In this respect, the suffixes differ from the morphological aspect operator encoding (im)perfectivity in the aspectual head, which is phonologically empty. Further, it is shown that there are certain prefixes in the verbal morphosyntactic structure that are placed between the progressive projection and the iterative projection.

Two states for the Ξ(1820) resonance

We recall that the chiral unitary approach for the interaction of pseudoscalar mesons with the baryons of the decuplet predicts two states for the Ξ(1820) resonance, one with a narrow width and the other one with a large width. We contrast this fact with the recent BESIII measurement of the K−Λ mass distribution in the ψ(3686) decay to K−ΛΞ¯+, which demands a width much larger than the average of the PDG, and show how the consideration of the two Ξ(1820) states provides a natural explanation to the experimental data.

The Miami Framework for ALS and related neurodegenerative disorders: an integrated view of phenotype and biology.

Increasing appreciation of the phenotypic and biological overlap between amyotrophic lateral sclerosis (ALS) and frontotemporal dementia, alongside evolving biomarker evidence for a pre-symptomatic stage of disease and observations that this stage of disease might not always be clinically silent, is challenging traditional views of these disorders. These advances have highlighted the need to adapt ingrained notions of these clinical syndromes to include both the full phenotypic continuum - from clinically silent, to prodromal, to clinically manifest - and the expanded phenotypic spectrum that includes ALS, frontotemporal dementia and some movement disorders. The updated clinical paradigms should also align with our understanding of the biology of these disorders, reflected in measurable biomarkers. The Miami Framework, emerging from discussions at the Second International Pre-Symptomatic ALS Workshop in Miami (February 2023; a full list of attendees and their affiliations appears in the Supplementary Information) proposes a classification system built on: first, three parallel phenotypic axes - motor neuron, frontotemporal and extrapyramidal - rather than the unitary approach of combining all phenotypic elements into a single clinical entity; and second, biomarkers that reflect different aspects of the underlying pathology and biology of neurodegeneration. This framework decouples clinical syndromes from biomarker evidence of disease and builds on experiences from other neurodegenerative diseases to offer a unified approach to specifying the pleiotropic clinical manifestations of disease and describing the trajectory of emergent biomarkers.

Study of the B−→K−ηηc decay due to the DD¯ bound state

We study the B−→K−ηηc decay by taking into account the S-wave contributions from the pseudoscalar meson-pseudoscalar meson interactions within the unitary coupled-channel approach, where the DD¯ bound state is dynamically generated. In addition, the contribution from the intermediate resonance K0*(1430)−, with K0*(1430)−→K−η, is also considered. Our results show that there is a clear peak around 3720 MeV in the ηηc invariant mass distribution, which could be associated with the DD¯ bound state. The future precise measurements of the B−→K−ηηc process at the Belle II and LHCb experiments could be, therefore, used to check the existence of the DD¯ bound state, and to deepen our understanding of the hadron-hadron interactions. Published by the American Physical Society 2024

Interactions of the pseudoscalar meson octet and the baryon decuplet in the continuum and a finite volume

This study focuses on the interaction of the pseudoscalar meson octet and the baryon decuplet. In the continuum, it is observed that several JP=32-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$J^{P}=\\frac{3}{2}^-$$\\end{document} baryon resonances can be produced by the Weinberg-Tomozawa interaction in unitarized chiral perturbation theory, including the N(1875), Σ(1670)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Sigma (1670)$$\\end{document}, Σ(1910)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Sigma (1910)$$\\end{document}, Ξ(1820)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Xi (1820)$$\\end{document} and Ω(2012)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Omega (2012)$$\\end{document}. Among them, the Ξ(1820)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Xi (1820)$$\\end{document} and Σ(1670)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Sigma (1670)$$\\end{document} may exhibit a potential two-pole structures. The unitarized chiral perturbation approach is then applied as the underlying theory to predict the energy levels of these systems in a finite volume. These energy levels are well described by the K-matrix parameterization constrained by flavor SU(3) symmetry. With the parameters from the best fits, the poles extracted from the K-matrix parameterization closely correspond to those derived from the underlying chiral effective field theory, as long as they are close to physical region and not significantly higher than the lowest relevant threshold.

IMPLEMENTAREA UNEI DOCTRINE A SPRIJINULUI PRIN FOC DE NIVEL ÎNTRUNIT – CERINȚĂ A OPERAȚIEI ÎNTRUNITE

Implementing a Joint Fire Support Doctrine – Requirement for the Joint OperationAbstract: In this paper we wanted to highlight the importance of developing and implementing in the Romanian Army a jointfire support doctrine that will serve as foundation for common and coherent understanding of specific concepts and terminology forfire support in every branch of the armed forces. The unitary approach and understanding of these concepts constitute a fundamentalneed to provide timely, integrated and synchronized fire support in a joint operation.Although, at Land Forces level, “F.T.-6 – Fire support manual for group force operations” was developed in 2018, and comprisesfire support fundamentals, this manual cannot be sufficient and, in our opinion, a dedicated norm that implements fire support specificprinciples, tactics, techniques and procedures at every armed force branch is required, for responsible personnel with fire support andalso with joint targeting, no matter what force structures are generated for the joint operation. In order to achieve this requirement,we believe it is necessary to develop a dedicated doctrine at the highest national military authority regarding joint fire support, inorder to implement fire support fundamentals in every army branch of the Romanian Army – aspects that currently exist in the landforces manual, as every army branch can contribute with force structures or specialized elements to providing fire support in a jointoperation.

Dynamical generation of the scalar f0(500) , f0(980) , and K0*(700) resonances in the Ds+→K+π+π− reaction

We develop a model aimed at understanding the three mass distributions of pairs of mesons in the Cabibbo-suppressed Ds+→K+π+π− decay recently measured with high statistics by the BESIII collaboration. The largest contributions to the process come from the Ds+→K+ρ0 and Ds+→K*0π+ decay modes, but the Ds+→K0*(1430)π+ and Ds+→K+f0(1370) modes also play a moderate role and all of them are introduced empirically. Instead, the contribution of the f0(500), f0(980), and K0*(700) resonances is introduced dynamically by looking at the decay modes at the quark level, hadronizing qq¯ pairs to give two mesons, and allowing these mesons to interact, for which we follow the chiral unitary approach, to finally produce the K+π+π− final state. While the general features of the mass distributions are fairly obtained, we pay special attention to the specific effects created by the light scalar resonances, which are visible in the low mass region of the π+π−(f0(500)) and K+π−(K0*(700)) mass distributions and a narrow peak for π+π− distribution corresponding to f0(980) excitation. The contribution of these three resonances is generated by only one parameter. We see the agreement found in these regions as further support for the nature of the light scalar states as dynamically generated from the interaction of pseudoscalar mesons. Published by the American Physical Society 2024

Correlation functions for the N*(1535) and the inverse problem

The N*(1535) can be dynamically generated in the chiral unitary approach with the coupled channels, K0Σ+,K+Σ0,K+Λ, and ηp. In this work, we evaluate the correlation functions for every channel and face the inverse problem. Assuming the correlation functions to correspond to real measurements, we conduct a fit to the data within a general framework in order to extract the information contained in these correlation functions. The bootstrap method is used to determine the uncertainties of the different observables, and we find that, assuming errors of the same order than in present measurements of correlation functions, one can determine the scattering length and effective range of all channels with a very good accuracy. Most remarkable is the fact that the method predicts the existence of a bound state of isospin 12 nature around the mass of the N*(1535) with an accuracy of 6 MeV. These results should encourage the actual measurement of these correlation functions (only the K+Λ one is measured so far), which can shed valuable light on the relationship of the N*(1535) state to these coupled channels, a subject of continuous debate. Published by the American Physical Society 2024

Unitarity, real-intermediate states, and fixed-order approach to resonant dark matter annihilation

We study the role of perturbative unitarity in the resonant annihilation of two dark matter particles into the standard model bath. Systematically including all kinematically allowed holomorphic cuts of the corresponding forward-scattering diagram, cancellation of the singularities occurs, resulting in a fixed-order correction to the narrow-width approximation for the annihilation cross section. Unlike the standard approach based on including the finite width of the mediator, no double counting of intermediate states occurs. Published by the American Physical Society 2024

Modeling the effect of shape deformation induced by gravity on the evaporation of pendant and sessile drops

Pendant and sessile drops form a spherical cap only in the absence of gravity. The effect of gravity on drop shape is often neglected on the basis of the assumption that the drop size is smaller than the capillary length [Lc=(σ/gρ)1/2], although the deformation may not be fully negligible even in those cases. This paper focuses on evaluation of the effect that deformation due to gravity has on the evaporation characteristics of pendant and sessile drops. The drop shape is described by the Bashforth–Adams equation, a non-linear second order ordinary differential equation, which is solved numerically using a Runge–Kutta method with variable time steps. Under quasi-steady approximation, the species and energy conservation equations in the gas phase have analytical solutions, even for temperature-dependent gas thermophysical properties, once the solution of a basic Laplace problem is known. The Laplace equation is solved in axial symmetric geometry by using COMSOL Multiphysics®, for a wide range of drop sizes and contact angles, yielding vapor distribution, vapor fluxes, and evaporation rates. Comparison with the results from drops of same size in microgravity (i.e., having a spherical cap shape) shows that the effect is also perceptible for drops with a size smaller than the capillary length and that it can become quite important for those with larger sizes. Complementary results are found for sessile and pendant drops with respect to wall wettability, suggesting that the phenomenon can be analyzed using a unitary approach.

A unified approach to three themes in harmonic analysis (I & II): (I) The linear Hilbert transform and maximal operator along variable curves (II) Carleson type operators in the presence of curvature

This paper constitutes the first part of a study that addresses three rich historical themes in harmonic analysis that, in the non-zero curvature setting, investigate the boundedness properties along variable curves for(I) the linear Hilbert transform and analogous maximal operator,(II) the Carleson-type operators, and(III) the bilinear Hilbert transform and analogous maximal operator.Our Main Theorem in this paper states that, given a general variable curve γ(x,t) in the plane that is assumed only to be measurable in x and to satisfy suitable non-zero curvature in t and extra (mild) non-degeneracy conditions, the operators at (I) and (II) defined along the curve γ are Lp-bounded for 1<p<∞.Our result provides a new and unified treatment of the first two themes as well as a unitary approach within the x-variable setting for both the singular integral and the maximal operator versions of (I).At the heart of our approach is the LGC–methodology introduced here, which encompasses three key ingredients:(1)phase/space discretization that confines the phase of the multiplier to oscillate at the linear level,(2)adapted Gabor frame discretization of the input function(s), and(3)cancelation extraction via the analysis of the time-frequency correlation(s) capturing the non-zero curvature of γ.

Spin-Adapted Externally Contracted Multireference Configuration Interaction Method Based on Selected Reference Configurations.

As one kind of approximation of the full configuration interaction solution, the selected configuration interaction (sCI) methods have been shown to be valuable for large active spaces. However, the inclusion of dynamic correlation beyond large active spaces is necessary for more quantitative results. Since the sCI wave function can provide a compact reference for multireference methods, previously, we proposed an externally contracted multireference configuration interaction method using the sCI reference reconstructed from the density matrix renormalization group wave function [J. Chem. Theory Comput. 2018, 14, 4747-4755]. The DMRG2sCI-EC-MRCI method is promising for dealing with more than 30 active orbitals and large basis sets. However, it suffers from two drawbacks: spin contamination and low efficiency when using Slater determinant bases. To solve these problems, in this work, we adopt configuration state function bases and introduce a new algorithm based on the hybrid of tree structure for convenient configuration space management and the graphical unitary group approach for efficient matrix element calculation. The test calculation of naphthalene shows that the spin-adapted version could achieve a speed-up of 6.0 compared with the previous version based on the Slater determinant. Examples of dinuclear copper(II) compound as well as Ln(III) and An(III) complexes show that the sCI-EC-MRCI can give quantitatively accurate results by including dynamic correlation over sCI for systems with large active spaces and basis sets.

Analysis of the Ξ(1620) resonance and K¯Λ scattering length with a chiral unitary approach

We study the Ξ(1620) resonance near the K¯Λ threshold in the light of recent experimental constraints. The Belle Collaboration have found a resonance peak of Ξ(1620) slightly below the K¯0Λ threshold in the π+Ξ− invariant mass spectrum, and the ALICE Collaboration have determined the K−Λ scattering length from the measurement of the momentum correlation functions in heavy ion collisions. Using the effective range expansion, we classify the nature of the pole of the near-threshold eigenstate in terms of the scattering length, in the presence of the decay channel. It is shown that the quasibound state below the threshold can be described by only the scattering length, while the description of the resonance above the threshold requires the contribution from the effective range. Based on the chiral unitary approach, we construct a theoretical model which generates the pole of Ξ(1620) below the K¯Λ threshold with relatively narrow width, as reported by the Belle Collaboration. It is quantitatively demonstrated that the spectrum of the Ξ(1620) quasibound state is distorted by the effect of the nearby K¯Λ threshold. We then construct another model which reproduces the K−Λ scattering length by the ALICE Collaboration. In this case, the eigenstate pole does not appear in the physically relevant Riemann sheet, and the spectrum shows a cusp structure at the K¯Λ threshold. We finally examine the compatibility of the value of the K¯Λ scattering length and the subthreshold pole of Ξ(1620) including the experimental uncertainties. Published by the American Physical Society 2024

J/ψ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\varvec{J/\\psi }$$\\end{document} decays into ω(ϕ)f1(1285)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\omega (\\phi ) f_1(1285)$$\\end{document} and ω(ϕ)``f1(1420)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\omega (\\phi ) ``f_1(1420)$$\\end{document}”

We perform a theoretical study of the J/ψ→ω(ϕ)K∗K¯+c.c.→ω(ϕ)K0π+K-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$J/\\psi \\rightarrow \\omega (\\phi ) K^* \\bar{K} + c.c. \\rightarrow \\omega (\\phi ) K^0 \\pi ^+ K^-$$\\end{document} reactions with the assumption that the f1(1285)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$f_1(1285)$$\\end{document} is dynamically generated from a single channel K∗K¯+c.c\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$K^* \\bar{K} + c.c$$\\end{document} interaction in the chiral unitary approach. Two peaks in the K0π+K-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$K^0 \\pi ^+ K^-$$\\end{document} invariant mass distribution are observed, one clear peak locates at the f1(1285)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$f_1(1285)$$\\end{document} nominal mass, the other peak locates at around 1420MeV\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$1420 \ ext {MeV}$$\\end{document} with about 70MeV\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$70 \ ext {MeV}$$\\end{document} width. We conclude that the former peak is associated with the f1(1285)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$f_1(1285)$$\\end{document} and the latter peak is not a genuine resonance but a manifestation of the kinematic effect in the higher energy region caused by the K∗K¯+c.c.\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$K^* \\bar{K} + c.c.$$\\end{document} decay mode of the f1(1285)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$f_1(1285)$$\\end{document}.

Dynamically generated states from the ηK*K¯* , πK*K¯* , and KK*K¯* systems within the fixed-center approximation

The three-body systems ηK*K¯*, πK*K¯*, and KK*K¯* are further investigated within the framework of fixed-center approximation, where K*K¯* is treated as the fixed-center, corresponding to the possible scalar meson a0(1780) or the tensor meson f2′(1525). The interactions between η, π, K, and K* are taken from the chiral unitary approach. The resonance structures appear in the modulus squared of the three-body scattering amplitude and suggest that η/π/K−(K*K¯*)a0(1780)/f2′(1525) hadron state can be formed. By scattering the η meson on the fixed-center (K*K¯*)a0(1780), it is found that there is a distinct peak around 2100 MeV, as shown in the modulus squared of the three-body scattering amplitude, which can be associated with the meson π(2070). For the scattering of the η meson on the (K*K¯*)f2′(1525), a resonance structure around 1890 MeV is found and it can be associated with the η2(1870) meson. Other resonance structures are also found and can be associated with π2(1880) and η(2010). Published by the American Physical Society 2024

Analysis of 𝚵(1620) resonance with chiral unitary approach

Abstract. Recently, the ξ(1620) resonance has attracted much attention, thanks to detailed experimental data by the Belle and ALICE collaborations. This experimental progress has prepared us to conduct theoretical analyses based on experimental data. In this study, we analyze the ξ(1620) resonance using the chiral unitary model and discuss the properties of the ξ(1620) resonance and the K−Λ scattering length.

Continuous unitary transformation approach to the Kondo–Majorana interplay

We analyze a setup composed of a correlated quantum dot (QD) coupled to one metallic lead and one end of topological chain hosting a Majorana zero mode (MZM). In such a hybrid structure, a leakage of the MZM into the region of the QD competes with the Kondo resonance appearing as a consequence of the spin-exchange interactions between the dot and the lead. In the work, we use the nontrivial technique called the continuous unitary transformation (CUT) to analyze this competition. Using the CUT technique, we inspect the influence of the coupling between the QD and the chain on effective exchange and density–density interactions.