Search results for "ATZ"

showing 10 items of 256 documents

Nuclear-structure input to r-process calculations

1998

Abstract By comparing results from r-process parameter studies within the classical waiting-point approximation with the observed solar-system r-abundance distribution N r ,⊙ , in-formation on nuclear-structure phenomena on neutron-rich isotopes far off the stability line can be obtained. Such information is — to a large extent — experimentally not accessible. Investigations in the early 1990's, making use of QRPA β-decay properties and nuclear masses from the macroscopic-microscopic FRDM and ETFSI-1 models, showed r-abundance deficiencies around A ⋍115 and 180 , indicating overly strong N=82 and 126 shell strengths far from stability. Recent experiments in the A ⋍110–130 region as well as …

Nuclear physicsPhysicsNuclear and High Energy PhysicsStarsFormalism (philosophy of mathematics)IsotopeNuclear TheoryNuclear structurer-processNeutronHaloAnsatzNuclear Physics A
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Thermodynamics of Toda lattice models: application to DNA

1993

Abstract Our generalised Bethe ansatz method is used to formulate the statistical mechanics of the classical Toda lattice in terms of a set of coupled integral equations expressed in terms of appropriate action-angle variables. The phase space as coordinatised by these action-angle variables is constrained; and both the soliton number density and the soliton contribution to the free energy density can be shown to decouple from the phonon degrees of freedom and to depend only on soliton-soliton interactions. This makes it possible to evaluate the temperature dependence of the soliton number density which, to leading order, is found to be proportional to T 1 3 .

Number densityDegrees of freedom (physics and chemistry)Statistical and Nonlinear PhysicsStatistical mechanicsCondensed Matter PhysicsBethe ansatzNonlinear Sciences::Exactly Solvable and Integrable SystemsPhase spaceSolitonPerturbation theory (quantum mechanics)Toda latticeNonlinear Sciences::Pattern Formation and SolitonsMathematicsMathematical physicsPhysica D: Nonlinear Phenomena
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Energy dependence of event shapes and of $\alpha_s$ at LEP 2

1999

Infrared and collinear safe event shape distributions and their mean values are determined using the data taken at five different centre of mass energies above M-Z with the DELPHI detector at LEP. From the event shapes, the strong coupling alpha(s) is extracted in O(alpha(s)(2)), NLLA and a combined scheme using hadronisation corrections evaluated with fragmentation model generators as well as using an analytical power ansatz. Comparing these measurements to those obtained at M-Z, the energy dependence (running) of alpha(s) is accessible. The logarithmic energy slope of the inverse strong coupling is measured to be d alpha(s)(-1)/d log(E-cm) = 1.39 +/- 0.34 (stat) +/- 0.17(syst), in good ag…

Particle physicsNuclear and High Energy PhysicsE+E ANNIHILATIONZ(0) RESONANCELogarithmInfraredElectron–positron annihilationMonte Carlo methodTRISTANInversePREDICTIONS01 natural sciencesPartícules (Física nuclear)Nuclear physicsMONTE-CARLO0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]010306 general physicsAnsatzDELPHIQuantum chromodynamicsPhysics010308 nuclear & particles physicsDetectorHigh Energy Physics::PhenomenologyLARGE ELECTRON POSITRON COLLIDERHADRONIC Z-DECAYSPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIQCD MODELSPARTICLE PHYSICSHADRONIC Z-DECAYS; E+E ANNIHILATION; Z(0) RESONANCE; MONTE-CARLO; QCD MODELS; FRAGMENTATION; PREDICTIONS; TRISTANFísica nuclearHigh Energy Physics::ExperimentFRAGMENTATIONParticle Physics - Experiment
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Paternitātes noteikšana un apstrīdēšana

2015

Maģistra darba tēma ir „Paternitātes noteikšana un apstrīdēšana”. Paternitātes jautājums mūsdienās kļūst aktuāls arvien lielākam personu lokam. Katram bērnam ir tiesības zināt savus vecākus un prasīt tiesisku noteiktību attiecībā uz viņa personas identitāti. Likumdošana paternitātes jomā arvien tiek pilnveidota un meklēti jauni risinājumi. Maģistra darba mērķis ir izpētīt pastāvošo likumdošanu un judikatūru paternitātes noteikšanā un apstrīdēšanā, apzināt pastāvošās problēmas un izvērtēt likumu grozījumu ietekmi uz jomas sakārtošanu. No vienas puses īpaši pēdējos trijos gados šajā jomā ir paveikts daudz, piemēram, paternitātes atzīšana ir kļuvusi iespējama uz trīspusēja iesnieguma pamata; p…

PaternitātePrezumpcijaAtzīšanaNoteikšanaIzcelšanāsJuridiskā zinātne
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Iepazīt ekslibri kā grafikas mākslas veidu vizuālās mākslas stundā 9.klasē

2018

Diplomdarba tēma ir ‘’Iepazīt ekslibri kā grafikas mākslas veidu vizuālajā mākslā 9.klasē’’. Darba mērķis ir iepazīt devītās klases skolēnus ar vienu no grafikas mākslas veidiem, ekslibri. Ekslibris vizuālās mākslas sundās tiek pieminēts ļoti mazs vai pat nemaz. Jo skolotājas uzkata šo mākslas veidu par sarežģītu pamatskolas klasēs, ka ir vajadzīgi dārgi materiāli darba izpildei. Bet tā nemaz nav, ekslibris var būt arī zīmējums kuram nav vajadzīgi materiāli un tehniskais aprīkojums. Darbs ietver sevī teorētisko daļu un prakstisko daļu. Teorētiskajā daļā tiek runāts par vizuālo mākslu par grafikas tehnikas grupām, par ekslibri un to vēsturisko gaitu un māksliniekiem. Prakstiskajā daļā balsto…

Pedagoģijagrafikaiespiedgrafikaekslibrisgrāmatzīmeradošums
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Energy fluctuations and the singularity of specific heat in a 3D Ising model

2004

We study the energy fluctuations in 3D Ising model near the phase transition point. Specific heat is a relevant quantity which is directly related to the mean squared amplitude of the energy fluctuations in the system. We have made extensive Monte Carlo simulations in 3D Ising model to clarify the character of the singularity of the specific heat C v based on the finite-size scaling of its maximal values C v max depending on the linear size of the lattice L . An original iterative method has been used which automatically finds the pseudocritical temperature corresponding to the maximum of C v . The simulations made up to L ≤ 128 with application of the Wolff's cluster algorithm allowed us t…

Phase transitionSingularityCritical phenomenaIsing modelSquare-lattice Ising modelStatistical physicsScalingCritical exponentAnsatzMathematicsSPIE Proceedings
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CP symmetries as guiding posts: Revamping tribimaximal mixing. II.

2019

In this follow up of arXiv:1812.04663 we analyze the generalized CP symmetries of the charged lepton mass matrix compatible with the complex version of the Tri-Bi-Maximal (TBM) lepton mixing pattern. These symmetries are used to `revamp' the simplest TBM \textit{Ansatz} in a systematic way. Our generalized patterns share some of the attractive features of the original TBM matrix and are consistent with current oscillation experiments. We also discuss their phenomenological implications both for upcoming neutrino oscillation and neutrinoless double beta decay experiments.

Physics010308 nuclear & particles physicsPhysics beyond the Standard ModelHigh Energy Physics::PhenomenologyFOS: Physical sciences01 natural sciencesHigh Energy Physics - ExperimentHigh Energy Physics - Experiment (hep-ex)High Energy Physics - PhenomenologyTheoretical physicsMatrix (mathematics)High Energy Physics - Phenomenology (hep-ph)Mixing patterns0103 physical sciencesHomogeneous spaceCP violationHigh Energy Physics::Experiment010306 general physicsNeutrino oscillationMixing (physics)AnsatzPhysical Review D
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Solutions via double wave ansatz to the 1-D non-homogeneous gas-dynamics equations

2020

Abstract In this paper classes of double wave solutions of the 1D Euler system describing a ideal fluid in the non-homogeneous case have been determined. In order that the analytical procedure under interest to hold, suitable model laws for the source term involved in the governing model were characterized. Finally such a class of exact double wave solutions has been used for solving some problems of interest in nonlinear wave propagation.

PhysicsApplied MathematicsMechanical EngineeringMathematical analysisPerfect fluid02 engineering and technologyGas dynamicsDouble wave solutionsNonlinear wave interactionsEuler system021001 nanoscience & nanotechnologyRiemann problemDouble wave solutions; Hyperbolic systems; Nonlinear wave interactions; Riemann problemTerm (time)Nonlinear wave propagationHyperbolic systems020303 mechanical engineering & transports0203 mechanical engineeringMechanics of MaterialsNon homogeneousOrder (group theory)0210 nano-technologySettore MAT/07 - Fisica MatematicaAnsatz
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Dipole soliton solution for the homogeneous high-order nonlinear Schrödinger equation with cubic–quintic–septic non-Kerr terms

2015

Abstract We consider a high-order nonlinear Schrodinger equation with third- and fourth-order dispersions, cubic–quintic–septic nonlinearities, self-steepening, and instantaneous Raman response. This equation models describes ultra-short optical pulse propagation in highly-nonlinear media. The ansatz solution of Choudhuri and Porsezian (in Ref. [16]) is adapted to investigate solutions composed of the product of bright and dark solitary waves. Parametric conditions for the existence of the derived soliton solutions are given and their stabilities are numerically discussed. These exact solutions provide insight into balance mechanisms between several high-order nonlinearities of different na…

PhysicsApplied MathematicsSoliton (optics)Quintic functionDipolesymbols.namesakeClassical mechanicsModeling and SimulationProduct (mathematics)Quantum mechanicssymbolsRaman spectroscopyNonlinear Schrödinger equationParametric statisticsAnsatzApplied Mathematical Modelling
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From supersymmetric to non-supersymmetric black holes

2012

Methods similar to those used for obtaining supersymmetric black hole solutions can be employed to find also non-supersymmetric solutions. We briefly review some of them, with the emphasis on the non-extremal deformation ansatz of [1].

PhysicsBlack holeGeneral Relativity and Quantum CosmologyHigh Energy Physics::TheoryTheoretical physicsParticle physicsAstrophysics::High Energy Astrophysical PhenomenaSupergravityHigh Energy Physics::PhenomenologyExtremal black holeGeneral Physics and AstronomyDeformation (meteorology)AnsatzFortschritte der Physik
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