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T. S. Biró

Publications and source records attributed to T. S. Biró.

At least 19 recordsLinked to original sources

Radiation pattern and source size of particles in nanoplasmonic fusion

For the angular radiation patterns of proton, deuteron or alpha emission we present a way using particle-in-cell simulation of laser induced nanoplasmonic fusion. The differential Hanbury-Brown and Twiss analysis is widely used in astrophysics and in relativistic heavy ion physics to determine the source size of emitted particles. Here, we show how this method could be adopted for inertial confinement fusion. This method aims to determine the parameters of emitted nuclei after the fusion target ignition. In addition to spatial volume, the method can detect specific space-time correlation patterns connected to the collective flow post-ignition. In the NAPLIFE project our aim is to avoid thermalization and fluidization as much as possible at each stage of the fusion process. As the original laser beam is non-thermal and not equilibrated in any way it is obvious that we can minimize energy loss if we exploit the initial available energy in a non-thermal way. The detailed dynamics of deuterium and alpha production is not aimed at and not addressed by this paper.

physics.plasm-ph↗

Indication of p + 11B Reaction in Laser Induced Nanofusion Experiment

The NanoPlasmonic Laser Induced Fusion Energy (NAPLIFE) project proposed fusion by regulating the laser light absorption via resonant nanorod antennas implanted into hydrogen rich urethane acrylate methacrylate (UDMA) and triethylene glycol dimethylacrylate (TEGDMA) copolymer targets. In part of the tests, boron-nitride (BN) was added to the polymer. Our experiments with resonant nanoantennas accelerated protons up to 225 keV energy. Some of these protons then led to p + 11B fusion, indicated by the sharp drop of observed backward proton emission numbers at the 150 keV resonance energy of the reaction. The generation of alpha particles was verified by CR-39 (Columbia Resin #39) nuclear plastic track detectors.

physics.plasm-ph↗

Monitoring of nanoplasmonics-assisted deuterium production in a polymer seeded with resonant Au nanorods using in situ femtosecond laser induced breakdown spectroscopy

In this brief report, we present laser induced breakdown spectroscopy (LIBS) evidence of deuterium (D) production in a 3:1 urethane dimethacrylate (UDMA) and triethylene glycol dimethacrylate (TEGDMA) polymer doped with resonant gold nanorods, induced by intense, 40 fs laser pulses. The in situ recorded LIBS spectra revealed that the D/(2D+H) increased to 4-8% in the polymer samples in selected events. The extent of transmutation was found to linearly increase with the laser pulse energy (intensity) between 2 and 25 mJ (up to 3x10^17 W/cm). The observed effect is attributed only to the field enhancing effects due to excited localized surface plasmons on the gold nanoparticles.

physics.plasm-ph↗

Undersaturation of quarks at early stages of relativistic nuclear collisions: the hot glue initial scenario and its observable signatures

The early stage of high multiplicity nuclear collisions is represented by a nearly quarkless, hot, deconfined pure gluon plasma. This new scenario should be characterized by a suppression of high $p_T$ photons and dileptons as well as by reduced baryon to meson ratios. We present the numerical results for central Pb+Pb collisions at the LHC energies by using the ideal Bjorken hydrodynamics with time-dependent quark fugacity. It is shown that about 25\% of final total entropy is generated during the hydrodynamic evolution of chemically undersaturated quark-gluon plasma.

hep-ph↗

Elliptic flow due to radiation in heavy-ion collisions

In this paper we demonstrate that radiation patterns could cause flow-like behaviour without any reference to hydrodynamic description. For that purpose we use a statistical ensemble of radiating dipoles, motivated by the investigation of the equivalent photon yield produced by decelerating charges. For the elliptic asymmetry factor we find a reasonable agreement with experimental data.

hep-ph↗

Splitting the source term for the Einstein equation to classical and quantum parts

We consider the special and general relativistic extensions of the action principle behind the Schrödinger equation distinguishing classical and quantum contributions. Postulating a particular quantum correction to the source term in the classical Einstein equation we identify the conformal content of the above action and obtain classical gravitation for massive particles, but with a cosmological term representing off-mass-shell contribution to the energy-momentum tensor. In this scenario the - on the Planck scale surprisingly small - cosmological constant stems from quantum bound states (gravonium) having a Bohr radius $a$ as being Λ=3/a^2.

gr-qc↗

$v_2$ of charged hadrons in a`soft + hard' model for PbPb collisions at $\sqrt s$ = 2.76 ATeV

We describe transverse spectra as well as azimuthal anisotropy ($v_2$) of charged hadrons stemming from various centrality PbPb collisions at $\sqrt s$ = 2.76 ATeV analytically in a `soft + hard' model. In this model, we propose that hadron yields produced in heavy-ion collisions are simply the sum of yields stemming from jets (hard yields) and yields stemming from the Quark-Gluon Plasma (soft yields). The hadron spectra in both types of yields are approximated by the Tsallis distribution. It is found that the anisotropy decreases for more central collisions.

hep-ph↗

A `soft + hard' model for heavy-ion collisions

We describe the spectra of neutral pions stemming from AuAu collisions at $\sqrt s$ = 200 AGeV in a `soft + hard' model. The model is based on the assumptions that hadrons stemming from hard processes are described via perturbative quantum chromodynamics improved parton model calculations, while those stemming from the Quark-Gluon Plasma (we refer to as soft yields) can be described in a super-statistical model induced by multiplicity fluctuations. The obtained dependence of the parameters of the model on the event centrality is compared to what is observed in PbPb collisions at $\sqrt s$ = 2.76 ATeV.

hep-ph↗

Multicomponent Modified Boltzmann Equation and Thermalization

The existence of stationary distributions in a multicomponent Boltzmann equation using a non-additive kinetic energy composition rule for binary collisions is discussed. It is found that detailed balance is not achieved when -- in contrast to the case of a single rule -- several different composition rules are considered. The long-time behaviour of a simple momentum space model is explored numerically: saturating, heating and cooling solutions are presented.

cond-mat.stat-mech↗

Statistical Power-Law Spectra due to Reservoir Fluctuations

LHC ALICE data are interpreted in terms of statistical power-law tailed pT spectra. As explanation we derive such statistical distributions for particular particle number fluctuation patterns in a finite heat bath exactly, and for general thermodynamical systems in the subleading canonical expansion approximately. Our general result, $q = 1 - 1/C + ΔT^2 / T^2$, demonstrates how the heat capacity and the temperature fluctuation effects compete, and cancel only in the standard Gaussian approximation.

hep-ph↗

Thermodynamics and flow-frames for dissipative relativistic fluids

A general thermodynamic treatment of dissipative relativistic fluids is introduced, where the temperature four vector is not parallel to the velocity field of the fluid. Generic stability and kinetic equilibrium points out a particular thermodynamics, where the temperature vector is parallel to the enthalpy flow vector and the choice of the flow fixes the constitutive functions for viscous stress and heat. The linear stability of the homogeneous equilibrium is proved in a mixed particle-energy flow-frame.

gr-qc↗

Dissipation flow-frames: particle, energy, thermometer

We associate the following physical co-mover conditions of to different frame choices: i) Eckart: particle flow, ii) Landau-Lifshitz: energy flow, iii) Jüttner: moving thermometer frame. The role of fixing a flow-frame is analysed with respect to local equilibrium concentrating on dissipative currents and forces in single component relativistic fluids. The special role of a "Jüttner frame" is explored and contrasted to the more common Eckart and Landau-Lifshitz choices.

gr-qc↗

Microcanonical Jet-fragmentation in proton-proton collisions at LHC Energy

In this paper, we show that the distribution of the longitudinal momentum fraction of charged hadrons $dN/dz$ inside jets stemming from proton-proton collisions at $\sqrt{s}$ = 7 TeV center of mass energy can be described by a statistical jet-fragmentation model. This model combines microcanonical statistics and super-statistics induced by multiplicity fluctuations. The resulting scale dependence of the parameters of the model turns out to be similar to what was observed in electron-positron annihilations in Urmossy, Barnaföldi, and Biró.

hep-ph↗

Nonadditive thermostatistics and thermodynamics

Nonadditive composition rules for several physical quantities are treated in thermodynamics. It is argued that the zeroth law defines the existence of their additive forms, the formal logarithms. A further principle, the universal thermostat independence leads to a particular formal logarithm, equivalent to Tsallis entropy S_q. We connect q with generalized susceptibilities of the thermostat.

cond-mat.stat-mech↗

Thermodynamic Derivation of the Tsallis and Rényi Entropy Formulas and the Temperature of Quark-Gluon Plasma

We derive Tsallis entropy, Sq, from universal thermostat independence and obtain the functional form of the corresponding generalized entropy-probability relation. Our result for finite thermostats interprets thermodynamically the subsystem temperature, T1, and the index q in terms of the temperature, T, entropy, S, and heat capacity, C of the reservoir as T1 = T exp(-S/C) and q = 1 - 1/C. In the infinite C limit, irrespective to the value of S, the Boltzmann-Gibbs approach is fully recovered. We apply this framework for the experimental determination of the original temperature of a finite thermostat, T, from the analysis of hadron spectra produced in high energy collisions, by analyzing frequently considered simple models of the quark-gluon plasma.

hep-ph↗

Non-extensive statistics, relativistic kinetic theory and fluid dynamics

Experimental particle spectra can be successfully described by power-law tailed energy distributions characteristic to canonical equilibrium distributions associated to Rényi's or Tsallis' entropy formula - over a wide range of energies, colliding system sizes, and produced hadron sorts. In order to derive its evolution one needs a corresponding dynamical description of the system which results in such final state observables. The equations of relativistic fluid dynamics are obtained from a non-extensive Boltzmann equation consistent with Tsallis' non-extensive $q$-entropy formula. The transport coefficients like shear viscosity, bulk viscosity, and heat conductivity are evaluate based on a linearized collision integral.

nucl-th↗

First order and stable relativistic dissipative hydrodynamics

Relativistic thermodynamics is derived from kinetic equilibrium in a general frame. Based on a novel interpretation of Lagrange multipliers in the equilibrium state we obtain a generic stable but first order relativistic dissipative hydrodynamics. Although this was believed to be impossible, we circumvent this difficulty by a specific handling of the heat flow.

nucl-th↗