F. Κ. Diakonos
A5082391817- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Theoretical and Computational Physics
- Particle physics theoretical and experimental studies
- Quantum chaos and dynamical systems
- Cold Atom Physics and Bose-Einstein Condensates
- Complex Systems and Time Series Analysis
- Nonlinear Photonic Systems
- Chaos control and synchronization
- Nonlinear Dynamics and Pattern Formation
- Quantum optics and atomic interactions
- Quantum Mechanics and Non-Hermitian Physics
- Statistical Mechanics and Entropy
- Topological Materials and Phenomena
- Spectroscopy and Quantum Chemical Studies
- Stochastic processes and statistical mechanics
- Quantum, superfluid, helium dynamics
- Quantum and electron transport phenomena
- Cosmology and Gravitation Theories
- Mathematical Dynamics and Fractals
- Scientific Research and Discoveries
- Advanced Thermodynamics and Statistical Mechanics
- Fractal and DNA sequence analysis
- Quasicrystal Structures and Properties
- stochastic dynamics and bifurcation
National and Kapodistrian University of Athens
2016-2025
Institute of Nuclear and Particle Physics
1991-2022
Institute of Nuclear Physics, Polish Academy of Sciences
2018-2019
SIL International
2019
Stony Brook University
2018
Florida State University
2015
Hellenic Naval Academy
2015
University of Cambridge
2007
Heidelberg University
1989-2006
National Centre of Scientific Research "Demokritos"
1991-2003
Interaction cross sections and charged pion spectra in p+C interactions at 31 GeV/c were measured with the large acceptance NA61/SHINE spectrometer CERN SPS. These data are required to improve predictions of neutrino flux for T2K long baseline oscillation experiment Japan. A set collected during first run 2007 an isotropic graphite target a thickness 4% nuclear interaction length was used analysis. The inelastic production 257.2 +- 1.9 8.9 mb 229.3 9.0 mb, respectively. Inclusive negatively...
Measurements of hadron production in p + C interactions at 31 GeV/c are performed using the NA61/SHINE spectrometer CERN SPS. The analysis is based on full set data collected 2009 a graphite target with thickness 4 % nuclear interaction length. Inelastic and cross sections as well spectra $$\pi ^{\pm }$$ , $$K^{\pm p, $$K^0_S$$ $$\varLambda $$ measured high precision. These measurements essential for improved calculations initial neutrino fluxes T2K long-baseline oscillation experiment...
A method to detect the unstable periodic orbits of a chaotic dynamical system is developed. For given our approach allows us locate cycles of, in principle, arbitrary length with high accuracy. Preknowledge not required. To demonstrate its reliability as well efficiency we apply it several two-dimensional maps. In case short time series develop algorithm which based on mean-field via Voronoi diagram belonging series. This enables low period using very small set data points. The influence...
We explore the dynamical evolution of an ensemble non-interacting particles propagating freely in elliptical billiard with harmonically driven boundaries. The existence Fermi acceleration is shown thereby refuting established assumption that smoothly billiards whose static counterparts are integrable do not exhibit dynamics. underlying mechanism based on intermittent phases laminar and stochastic behavior strongly correlated angular momentum velocity motion identified studied varying...
Spectra of positively charged kaons in p+C interactions at 31 GeV/c were measured with the NA61/SHINE spectrometer CERN SPS. The analysis is based on full set data collected 2007 a graphite target thickness 4% nuclear interaction length. Interaction cross sections and pion spectra already using same data. These new measurements combination published ones are required to improve predictions neutrino flux for T2K long baseline oscillation experiment Japan. In particular, knowledge kaon...
We present experimental results on inclusive spectra and mean multiplicities of negatively charged pions produced in inelastic p+p interactions at incident projectile momenta 20, 31, 40, 80 158 GeV/c ( $$\sqrt{s} = $$ 6.3, 7.7, 8.8, 12.3 17.3 GeV, respectively). The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer CERN super proton synchrotron. Two-dimensional are determined terms rapidity transverse momentum. Their properties such as width distributions...
We propose a fast and robust quantum state transfer protocol employing Su-Schrieffer-Heeger chain, where the interchain couplings vary in time. Based on simple considerations around terms involved definition of adiabatic invariant, we construct an exponential time-driving function that successfully takes advantage resonant effects to speed up process. Using optimal control theory, confirm proposed is close optimal. To unravel crucial aspects our construction, proceed comparison with two...
A remarkable feature of the trimer Su-Schrieffer-Heeger (SSH3) model is that it supports localized edge states. However, in contrast to dimer version model, a change total number states SSH3 without mirror-symmetry not necessarily associated with phase transition, i.e., closing band gap. As such, topological invariant predicted by 10-fold way classification does always coincide present. Moreover, although Zak's remains quantized for case mirror-symmetric chain, known fails take integer...
Fermi acceleration in a Fermi-Ulam model, consisting of an ensemble particles bouncing between two, infinitely heavy, stochastically oscillating hard walls, is investigated. It shown that the widely used approximation, neglecting displacement walls (static wall approximation), leads to systematic underestimation particle acceleration. An improved approximative map introduced, which takes into account effect displacement, and addition allows analytical estimation long term behavior mean...
We look for fluctuations expected the QCD critical point using an intermittency analysis in transverse momentum phase space of protons produced around midrapidity 12.5 % most central C+C, Si+Si and Pb+Pb collisions at maximum SPS energy 158A GeV. find evidence power-law data. The fitted exponent $$\phi _{2} = 0.96^{+0.38}_{-0.25}\text { (stat.)}$$ $$\pm $$ $$0.16\text (syst.)}$$ is consistent with value fluctuations. Power-law had previously also been observed low-mass $$\pi ^+ \pi ^-$$...
Measurements of multiplicity and transverse momentum fluctuations charged particles were performed in inelastic p+p interactions at 20, 31, 40, 80, 158 $$\text{ GeV }\!/\!c$$ beam momentum. Results for the scaled variance distribution three strongly intensive measures $$\varDelta [P_{T},N]$$ , $$\varSigma $$\varPhi _{p_T}$$ are presented. For first time results on fully corrected experimental biases. The significantly deviate from expectations independent particle production. They also...
We study the interaction of dark solitons with a localized impurity in Bose-Einstein condensates. apply soliton perturbation theory developed earlier optics for describing dynamics and soliton-impurity analytically, then verify results by direct numerical simulations Gross-Pitaevskii equation. find that can be reflected from or transmitted through repulsive controllable manner, while near critical point quasitrapped impurity. Additionally, we demonstrate an immobile may captured dragged...
We argue that the fluctuations of order parameter in a complex system at critical point can be described terms intermittent dynamics type I. Based on this observation we develop an algorithm to calculate isothermal exponent delta for "thermal" system. apply successfully our approach 3D Ising model. The character these "critical" guides introduction new which extends notion nonthermal systems.
We present a method to detect the unstable periodic orbits of multidimensional chaotic dynamical system. Our approach allows us locate in an efficient way cycles of, principle, arbitrary length with high accuracy. Based on universal set linear transformations originally are transformed into stable ones, and can consequently be detected analyzed easily. This is applicable systems any dimension, requires no preknowledge respect solutions original As example application our method, we...
We show that critical opalescence, a clear signature of second-order phase transition in conventional matter, manifests itself as intermittency QCD matter produced experiments with nuclei. This behavior is revealed transverse momentum spectra pattern power laws factorial moments, to all orders, associated baryon production. phenomenon together similar effect the isoscalar sector pions (sigma mode) provide us set observables search for point nuclei at high energies.
Abstract Topological physics has revolutionized materials science, introducing topological phases of matter in diverse settings ranging from quantum to photonic and phononic systems. Herein, we present a family systems, which term “strain metamaterials”, whose properties are hidden unveiled only under higher-order (strain) coordinate transformations. We firstly show that the canonical mass dimer, model can describe various such as electrical circuits optics, among others, belongs this where...
Spike structures appear in several phenomena, whereas spike trains (STs) are of particular importance, since they can carry temporal encoding information. Regarding the STs biological neuron type, models have already been proposed. While existing effectively simulate generation, fail to capture dynamics high-frequency spontaneous membrane potential fluctuations observed during relaxation intervals between consecutive spikes, dismissing them as random noise. This is eventually an important...
We investigate the electronic structure of helium atom in a magnetic field between B = 0 and . The is treated as nonrelativistic system with two interacting electrons fixed nucleus. Scaling laws are provided connecting fixed-nucleus Hamiltonian to one for case finite nuclear mass. Respecting symmetries presence field, we represent this matrix respect two-particle basis composed one-particle states Gaussian set. corresponding generalized eigenvalue problem solved numerically, providing...
The electronic structure of the hydrogen molecule is investigated for parallel configuration. ground states Sigma manifold are studied ungerade and gerade parity as well singlet triplet covering a broad regime field strengths from B = 0 up to 100a.u. A variety interesting phenomena can be observed. For ^1Sigma_g state we found monotonous decrease equilibrium distance simultaneously increase dissociation energy with growing magnetic strength. ^3\Sigma_g shown develop an additional minimum...
Pion production in nuclear collisions at the SPS is investigated with aim to search, a restricted domain of phase diagram, for power-laws behavior correlations which are compatible critical QCD. We have analyzed interactions nuclei different size (p+p, C+C, Si+Si, Pb+Pb) 158$A$ GeV adopting, as appropriate observables, scaled factorial moments search intermittent fluctuations transverse dimensions. The analysis performed $\pi^+\pi^-$ pairs invariant mass very close two-pion threshold. In...
We develop a classification of perfectly transmitting resonances occurring in effectively one-dimensional optical media which are decomposable into locally reflection symmetric parts. The local symmetries the medium shown to yield piecewise translation-invariant quantities, used distinguish with arbitrary field profile from following symmetries. Focusing on light scattering aperiodic multilayer structures, we demonstrate this for representative setups, providing insight origin perfect...
The parity and Bloch theorems are generalized to the case of broken global symmetry. Local inversion or translation symmetries shown yield invariant currents that characterize wave propagation. These map function from an arbitrary spatial domain any symmetry-related domain. Our approach addresses combination local symmetries, thus applying in particular acoustic, optical matter waves. Nonvanishing values provide a systematic pathway breaking discrete symmetries.