A5033426004- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Black Holes and Theoretical Physics
- Quantum, superfluid, helium dynamics
- Physics of Superconductivity and Magnetism
- Nuclear physics research studies
- Advanced NMR Techniques and Applications
- Cosmology and Gravitation Theories
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Atomic and Subatomic Physics Research
- Seismic Imaging and Inversion Techniques
- Particle accelerators and beam dynamics
- Molecular spectroscopy and chirality
- Computational Physics and Python Applications
- Advanced Algebra and Geometry
- Pulsars and Gravitational Waves Research
- Geophysics and Gravity Measurements
- Neutrino Physics Research
- Quantum chaos and dynamical systems
- Atomic and Molecular Physics
- Spectroscopy and Quantum Chemical Studies
- Electron Spin Resonance Studies
Universidad Complutense de Madrid
2016-2025
University of Bonn
2025
William & Mary
2024
Williams (United States)
2024
Thomas Jefferson National Accelerator Facility
2024
Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas
2023
University of Bern
2018
Universidad de Salamanca
2018
Institute of Nuclear Physics, Polish Academy of Sciences
2006-2012
Institut National de Physique Nucléaire et de Physique des Particules
2010
A nonperturbative method which combines constraints from chiral symmetry breaking and coupled channel unitarity is used to describe the meson-meson interaction up about 1.2 GeV. The approach uses $\mathcal{O}{(p}^{2})$ $\mathcal{O}{(p}^{4})$ Lagrangians. seven free parameters of Lagrangian are fitted data. results in good agreement with a vast amount experimental analyses. amplitudes develop poles complex plane corresponding ${f}_{0}, {a}_{0}, \ensuremath{\rho}, {K}^{*},...
We improve our description of pion-pion scattering data by imposing additional requirements to previous fits, in the form once-subtracted Roy-like equations, while extending analysis up 1100 MeV. provide simple and ready use parametrizations amplitude. In addition, we present a detailed derivation these dispersion relations that, 450 MeV region, an constraint which is much stronger than Forward Dispersion Relations standard Roy equations. The ensuing constrained amplitudes describe existing...
This paper presents a comprehensive review of both the theory and experimental successes Quantum Chromodynamics, starting with its emergence as well defined in 1972-73 following developments results up to present day. Topics include earliest theoretical foundations; fundamental constants QCD; an introductory discussion lattice QCD, only known method for obtaining exact predictions from methods approximating special focus on effective field theories; QCD under extreme conditions; measurements...
We develop a coupled channel unitary approach describing the behavior at higher energies of systems whose low-energy dynamics is given by effective $O({p}^{2})$ and $O({p}^{4})$ chiral Lagrangians. Our free parameters are those Lagrangian. When applied to meson-meson interaction, it yields remarkable agreement with data up $\sqrt{s}\ensuremath{\simeq}1.2\mathrm{GeV}$, dynamically generating $\ensuremath{\sigma}$, ${f}_{0}$, ${a}_{0}$, $\ensuremath{\rho}$, ${K}^{*}$ resonances. Further...
Based on a dispersive approach, we apply the inverse amplitude method to unitarize one-loop SU(2) and SU(3) Chiral Perturbation Theory. Numerically, find that this unitarization technique yields correct complex analytic structure in terms of cuts poles. Indeed, using chiral parameter estimates obtained from low energy experiments obtain poles associated with rho(770) K^*(982) resonances. Just by fixing their actual masses parametrization pi-pi pi-K phase shifts eight different channels. With...
We show how to obtain information about the states of an effective field theory in terms underlying fundamental theory. In particular, we analyze spectroscopic nature meson resonances from meson-meson scattering amplitudes QCD low energy theory, combined with expansion large number colors. The vectors follow a $\overline{q}q$ behavior, whereas $\ensuremath{\sigma}$, $\ensuremath{\kappa}$, and ${f}_{0}(980)$ scalars disappear for ${N}_{c}$, support $\overline{q}\overline{q}qq$-like nature....
We present a complete one-loop calculation of all the two-meson scattering amplitudes within framework SU(3) chiral perturbation theory, which includes pions, kaons, and eta. In addition, we have unitarized these with coupled channel inverse amplitude method, simultaneously ensures good low energy properties theory unitarity. show how this method provides remarkable description meson-meson data up to 1.2 GeV including lengths generation seven light resonances, is consistent previous...
We use our latest dispersive analysis of ππ scattering data and the very recent K(ℓ4) experimental results to obtain mass, width, couplings two lightest scalar-isoscalar resonances. These parameters are defined from their associated poles in complex plane. The analytic continuation plane is made a model-independent way by means once- twice-subtracted dispersion relations for partial waves, without any other theoretical assumption. find f(0)(600) pole at (457(-13))+14))-i(279(-7)(+11)) MeV...
By using unitarized two-loop chiral perturbation theory partial waves to describe pion-pion scattering we find that the dominant component of lightest scalar meson does not follow qq dependence on number colors that, in contrast, is obeyed by vectors. The method suggests a subdominant f0(600) possibly originates around 1 GeV.
We apply the one-loop results of $\mathrm{SU}{(3)}_{L}\ifmmode\times\else\texttimes\fi{}\mathrm{SU}{(3)}_{R}$ chiral perturbation theory supplemented with inverse-amplitude method to fit available experimental data on $\ensuremath{\pi}\ensuremath{\pi}$ and $\ensuremath{\pi}K$ scattering. With essentially only three parameters we describe accurately corresponding six different channels: namely, $(I, J)=(0, 0), (2, (1, 1), (\frac{1}{2}, (\frac{3}{2}, \mathrm{and} 1)$. In addition reproduce...
We use the one-loop chiral perturbation theory pipi-scattering amplitude and dispersion in form of inverse method to study quark-mass dependence two lightest resonances strong interactions, f(0)(600) (sigma) rho meson. As main results, we find that rhopipi coupling constant is almost quark mass independent shows a smooth while sigma nonanalyticity. These findings are important for studies meson spectrum on lattice.
We obtain reliable $\ensuremath{\pi}\ensuremath{\pi}$ scattering amplitudes consistent with experimental data, both at low and high energies, fulfilling appropriate analyticity properties. do this by first fitting energy (${s}^{1/2}\ensuremath{\le}1.42\text{ }\mathrm{GeV}$) phase shifts inelasticities expressions that incorporate unitarity. In particular, for the S wave isospin 0, we discuss in detail several sets of data. This provides partial summarize known information. Then, impose Regge...
We complete and improve the fits to experimental $\ensuremath{\pi}\ensuremath{\pi}$ scattering amplitudes, both at low high energies, that we performed in previous papers of this series. then verify corresponding amplitudes satisfy analyticity requirements, form partial wave forward dispersion relations (FDR) all Roy equations below$\overline{K}K$ threshold; first by construction, last two, inside errors. Then repeat including as constraints FDR equations. The ensuing central values various...
We study the light quark mass dependence of ${f}_{0}(600)$, $\ensuremath{\kappa}(800)$, $\ensuremath{\rho}(770)$, and ${K}^{*}(892)$ resonance parameters generated from elastic meson-meson scattering using unitarized one-loop chiral perturbation theory. First, we show that it is possible to fit simultaneously all experimental data up 0.8--1 GeV together with lattice results on decay constants lengths a pion 400 MeV, compatible existing determinations. Then, strange nonstrange masses are...
The quark mass dependences of light-element binding energies and nuclear scattering lengths are derived using chiral perturbation theory in combination with nonperturbative methods. In particular, we present new, improved values for the dependence meson resonances that enter force. A detailed analysis theoretical uncertainties arising this determination is presented. As an application, derive from a comparison observed calculated primordial deuterium helium abundances stringent limit on...
We discuss in general terms pole trajectories of resonances coupling to a continuum channel as some strength parameter is varied. It demonstrated that, regardless the underlying dynamics, poles that couple partial wave higher than s-wave are qualitatively same, while case s-waves trajectory can reveal important information on internal structure resonance. In addition we show only molecular (or extraordinary) states appear near thresholds naturally, more compact structures need significant...
By means of unitarized Chiral Perturbation Theory it is possible to obtain a remarkable description meson-meson scattering amplitudes up 1.2 GeV, and generate poles associated scalar vector resonances. Since the QCD low energy effective theory, then study its large Nc limit where qqbar states are easily identified. The vectors thus generated follow closely behavior, whereas light behavior expected for dominant tetraquark or two-meson structure.
The experimental results obtained in the last few years on kaon decays ($K\ensuremath{\rightarrow}2\ensuremath{\pi}$ and, above all, Ke4 decays) allow a reliable, model-independent determination of low energy $\ensuremath{\pi}\ensuremath{\pi}$ scattering S0 wave. Using them eventually, other sets data, it is possible to give precise parametrization wave as well find length and effective range parameter. One can also perform an extrapolation pole ``sigma resonance'' [${f}_{0}(600)$]. We...
The inverse amplitude method is a powerful unitarization technique to enlarge the energy applicability region of effective Lagrangians. It has been widely used describe resonances in hadronic physics, combined with chiral perturbation theory, as well strongly interacting symmetry breaking sector. In this work we show how it can be slightly modified also account for subthreshold region, incorporating correctly Adler zeros required by and eliminating spurious poles. These improvements produce...
We study the pion mass dependence of $\ensuremath{\rho}(770)$ and ${f}_{0}(600)$ masses widths from one two-loop unitarized chiral perturbation theory (ChPT). show consistency one-loop calculations with lattice results for ${M}_{\ensuremath{\rho}}$, ${f}_{\ensuremath{\pi}}$, isospin-2 scattering length ${a}_{20}$. Then, we develop apply modified inverse amplitude method formalism ChPT. In contrast to ${f}_{0}(600)$, is rather sensitive ChPT parameters---our main source systematic...