Search results for "Weak"
showing 10 items of 1417 documents
Stability of Embankments Resting on Foundation Soils with A Weak Layer
2021
The presence of weak layers in geotechnical systems, including soil or rock masses, both natural and man-made, is more frequent than is normally believed. Weak layers can affect both failure mechanisms, in drained and in undrained conditions, as well as in static and seismic conditions, and the safety factor. In the present study, conducted numerically using the finite-element method (FEM) Plaxis 2D code, the influence of a horizontal thin weak layer on stress and strain distribution, on failure mechanisms and on the overall stability of an embankment was evaluated. The results obtained prove that when the weak layer is located at a significant depth from the foundation plane, the failure m…
Electroweak Gauge-Boson and Higgs Production at Small qT: Infrared Safety from the Collinear Anomaly
2012
We study the differential cross sections for electroweak gauge-boson and Higgs production at small and very small transverse-momentum $q_T$. Large logarithms are resummed using soft-collinear effective theory. The collinear anomaly generates a non-perturbative scale $q_*$, which protects the processes from receiving large long-distance hadronic contributions. A numerical comparison of our predictions with data on the transverse-momentum distribution in Z-boson production at the Tevatron and LHC is given.
Quantum and classical dynamics of heavy quarks in a quark-gluon plasma
2018
We derive equations for the time evolution of the reduced density matrix of a collection of heavy quarks and antiquarks immersed in a quark gluon plasma. These equations, in their original form, rely on two approximations: the weak coupling between the heavy quarks and the plasma, the fast response of the plasma to the perturbation caused by the heavy quarks. An additional semi-classical approximation is performed. This allows us to recover results previously obtained for the abelian plasma using the influence functional formalism. In the case of QCD, specific features of the color dynamics make the implementation of the semi-classical approximation more involved. We explore two approximate…
Determination of the non-abelian Debye screening mass using classical chromodynamics
2014
Tässä työssä tutkitaan gluonin Debye-massaa, ja sen aika- ja miehityslukudis- tribuutioriippuvuutta käyttäen klassista väridynamiikkaa kahdessa paikkaulot- tuvuudessa. Työssä tutkitaan myös ominaista liikemääräskaalaa ja miehitys- lukudistribuutioita. Gluonin Debye-massa määritetään sovittamalla suora glu- onien dispersiorelaatioon pienellä liikemäärällä. Tuloksia verrataan termisestä kenttäteoriasta johdetun kaavan ennusteisiin. Aluksi tutustutaan raskasionifysiikkaan liittyvään viitekehykseen. Tämän jälkeen kerrataan nopeasti klassinen Yang-Mills teoria jatkumossa ja hilalla. Käydään läpi Fourier kiihdytetty Coulombin mitan kiinnitysmenetelmä yk- sityiskohtaisesti jatkumossa ja hilalla. T…
Review of Particle Physics
2020
The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 2,143 new measurements from 709 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. Particle properties and search limits are listed in Summary Tables. We give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology, Particle Detectors, Colliders, …
Pattern formation in hyperbolic reaction-transport systems and applications to dryland ecology
2023
Pattern formation and modulation is an active branch of mathematics, not only from the perspective of fundamental theory but also for its huge applications in many fields of physics, ecology, chemistry, biology, and other sciences. In this thesis, the occurrence of Turing and wave instabilities, giving rise to stationary and oscillatory patterns, respectively, is theoretically investigated by means of two-compartment reaction-transport hyperbolic systems. The goal is to elucidate the role of inertial times, which are introduced in hyperbolic models to account for the finite-time propagation of disturbances, in stationary and transient dynamics, in supercritical and subcritical regimes. In p…
Coincidence and common fixed points of weakly reciprocally continuous and compatible hybrid mappings via an implicit relation and an application
2015
Using the hybrid version of the notion of weakly reciprocal continuous mappings due to Gairola et al. [Coincidence and fixed point for weakly reciprocally continuous single-valued and multi-valued maps, Demonstratio Math. (2013/2014), accepted], we prove a coincidence and common fixed point theorem for a hybrid pair of compatible mappings via an implicit relation. Our main result improves and generalizes a host of previously known theorems. As an application, we give a homotopy theorem which supports our main result.
Precision Measurement of the Mass and Lifetime of the Xi(-)(b) Baryon
2016
We report on measurements of the mass and lifetime of the Ξ[- over b] baryon using about 1800 Ξ[- over b] decays reconstructed in a proton-proton collision data set corresponding to an integrated luminosity of 3.0 fb[superscript -1] collected by the LHCb experiment. The decays are reconstructed in the Ξ[- over b] → Ξ[0 over c]π[superscript -], Ξ[0 over c] → pK[superscript -]K[superscript -]π[superscript +] channel and the mass and lifetime are measured using the Λ[0 over b] → Λ[+ over c]π[superscript -] mode as a reference. We measure M(Ξ[- over b] - M(Λ[0 over b]) = 178.36 ± 0.46 ± 0.16 MeV/c[superscript 2], (τ[subscript Ξ[- over b]/τ[subscript Λ[0 over b]) = 1.089 ± 0.026 ± 0.011, where…
Theoretical study of neutrino scattering off the stable even Mo isotopes at low and intermediate energies
2011
A systematic study of the cross sections of neutral-current neutrino scattering off the stable even Mo isotopes (mass number A = 92, 94, 96, 98, 100), at low and intermediate neutrino energies (E(nu) <= 130 MeV), is presented and discussed. The required wave functions for the initial (ground state) and all accessible final nuclear states are constructed in the context of the quasi-particle random-phase approximation (QRPA) and tested against data on the low-lying energy spectra of the isotopes in question. The individual contributions coming from the polar-vector and axial-vector components of the hadronic current for the coherent and incoherent channels of each isotope are investigated. Th…
Intrinsic spin-orbit interaction in diffusive normal wire Josephson weak links: Supercurrent and density of states
2015
We study the effect of the intrinsic (Rashba or Dresselhaus) spin-orbit interaction in superconductor--nanowire--superconductor (SNS) weak links in the presence of a spin-splitting field that can result either from an intrinsic exchange field or the Zeeman effect of an applied field. We solve the full non-linear Usadel equations numerically and analyze the resulting supercurrent through the weak link and the behavior of the density of states in the center of the wire. We point out how the presence of the spin-orbit interaction gives rise to a long-range spin triplet supercurrent, which remains finite even in the limit of very large exchange fields. In particular, we show how rotating the fi…