scholarly journals Magnetic field driven enhancement of the weak decay width of charged pions

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Maximo Coppola ◽  
Daniel Gomez Dumm ◽  
Santiago Noguera ◽  
Norberto N. Scoccola
Keyword(s):  
Magnetic Field ◽  
Enhancement Factor ◽  
Uniform Magnetic Field ◽  
Weak Decay ◽  
Significant Suppression ◽  
Decay Constants ◽  
A Value ◽  
Njl Model ◽  
Charged Pions ◽  
The Magnetic Field

Abstract We study the effect of a uniform magnetic field $$ \overrightarrow{B} $$ B → on the decays $$ {\pi}^{-}\to {l}^{-}{\overline{\nu}}_l $$ π − → l − ν ¯ l , where l− = e−, μ−, carrying out a general analysis that includes four π− decay constants. Taking the values of these constants from a chiral effective Nambu-Jona-Lasinio (NJL) model, it is seen that the total decay rate gets strongly increased with respect to the B = 0 case, with an enhancement factor ranging from ∼ 10 for eB = 0.1 GeV2 up to ∼ 103 for eB = 1 GeV2. The ratio between electronic and muonic decays gets also enhanced, reaching a value of about 1 : 2 for eB = 1 GeV2. In addition, we find that for large B the angular distribution of outgoing antineutrinos shows a significant suppression in the direction of the magnetic field.

The cut-off characteristic of the single anode magnetron

1939 ◽  
Vol 35 (4) ◽  
pp. 637-651
Author(s):  
A. F. Harvey
Keyword(s):  
Magnetic Field ◽  
Uniform Magnetic Field ◽  
Axial Magnetic Field ◽  
Present Discussion ◽  
A Value ◽  
Field Parallel ◽  
Concentric Cylinders ◽  
Image Position ◽  
The Magnetic Field

For the purpose of the present discussion the magnetron will be defined as a diode thermionic tube, having concentric cylinders as electrodes, in which there is a uniform magnetic field parallel to the axis of the electrodes. An electron emitted from the cathode travels towards the anode in a path which is bent by the action of the magnetic field. If the anode has radius a and is at potential V with respect to the cathode of radius b, then it is well known that electrons emitted without velocity from the cathode will just graze the anode when the uniform and axial magnetic field has a value H such that

The stability of viscous flow in a curved channel in the presence of a magnetic field

1961 ◽  
Vol 264 (1317) ◽  
pp. 155-164 ◽  
Keyword(s):  
Magnetic Field ◽  
Viscous Flow ◽  
Uniform Magnetic Field ◽  
Axial Direction ◽  
Electrical Conductor ◽  
Curved Channel ◽  
Coaxial Cylinders ◽  
Transverse Pressure ◽  
The Stability ◽  
The Magnetic Field

The stability of viscous flow between two coaxial cylinders maintained by a constant transverse pressure gradient is considered when the fluid is an electrical conductor and a uniform magnetic field is impressed in the axial direction. The problem is solved and the dependence of the critical number for the onset of instability on the strength of the magnetic field and the coefficient of electrical conductivity of the fluid is determined.

scholarly journals Spin-1/2 Particles under the Influence of a Uniform Magnetic Field in the Interior Schwarzschild Solution

Universe ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 467
Author(s):  
Fayçal Hammad ◽  
Alexandre Landry ◽  
Parvaneh Sadeghi
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Total Mass ◽  
Uniform Magnetic Field ◽  
Energy Levels ◽  
Relativistic Wave Equation ◽  
Relativistic Wave ◽  
Schwarzschild Solution ◽  
Relativistic Regime ◽  
The Magnetic Field

The relativistic wave equation for spin-1/2 particles in the interior Schwarzschild solution in the presence of a uniform magnetic field is obtained. The fully relativistic regime is considered, and the energy levels occupied by the particles are derived as functions of the magnetic field, the radius of the massive sphere and the total mass of the latter. As no assumption is made on the relative strengths of the particles’ interaction with the gravitational and magnetic fields, the relevance of our results to the physics of the interior of neutron stars, where both the gravitational and the magnetic fields are very intense, is discussed.

scholarly journals Deformation of a magnetic liquid drop in an applied non-stationary uniform magnetic field

2018 ◽  
Vol 185 ◽  
pp. 09006
Author(s):  
Alexander Tyatyushkin
Keyword(s):  
Magnetic Field ◽  
Reynolds Number ◽  
Steady State ◽  
Uniform Magnetic Field ◽  
Liquid Drop ◽  
Magnetic Liquid ◽  
Stationary Approximation ◽  
The Magnetic Field

Small steady-state deformational oscillations of a drop of magnetic liquid in a nonstationary uniform magnetic field are theoretically investigated. The drop is suspended in another magnetic liquid immiscible with the former. The Reynolds number is so small that the inertia can be neglected. The variation of the magnetic field is so slow that the quasi-stationary approximation for the magnetic field and the quasi-steady approximation for the flow may be used.

Effect of Magnetic Field on the Laminar Heat Transfer Performance of Hybrid Nanofluid in a Lid Driven Cavity Over Solid Block

2020 ◽  
Author(s):  
Rajesh Nimmagadda ◽  
Durga Prakash Matta ◽  
Rony Reuven ◽  
Lazarus Godson Asirvatham ◽  
Somchai Wongwises ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Uniform Magnetic Field ◽  
Conjugate Heat Transfer ◽  
Heat Transfer Performance ◽  
Hybrid Nanofluid ◽  
Transfer Performance ◽  
Driven Cavity ◽  
The Magnetic Field ◽  
Solid Block

Abstract A 2D numerical investigation has been carried out to obtain the heat transfer performance of hybrid (Al2O3 + Ag) nanofluid in a lid driven cavity over solid block under the influence of uniform as well as non-uniform magnetic field. The geometrical domain consists of a cavity containing nanofluid that is driven by means of lid moving in one direction. This circulating nanofluid will extract enormous amount of heat from the solid block underneath the cavity resulting in conjugate heat transfer. A homogenous solver based on the finite volume method with conjugate heat transfer was developed and adopted in the existing study. The heat efficient hybrid nanofluid (HyNF) pair (2.4 vol.% Ag + 0.6 vol.% Al2O3) obtained by Nimmagadda and Venkatasubbaiah [1] is used in the present investigation. Moreover, efficient non-uniform sinusoidal magnetic field identified by Nimmagadda et al. [2] is also implemented and compared with uniform magnetic field. Furthermore, the magnetic field is applied over the geometrical domain along the two axial directions separately and the effective heat transfer performance is obtained. The significant impact of extensive parameters like Reynolds number, nanoparticle type, nanoparticle concentration, magnetic field type, magnetic field location and the strength of the magnetic field on heat transfer performance are systematically analyzed and presented.

Conduction electron diamagnetism in alloys and magnetic-field-dependent dielectric constant of a Fermi gas

1964 ◽  
Vol 280 (1380) ◽  
pp. 85-96 ◽  
Keyword(s):  
Magnetic Field ◽  
Dielectric Constant ◽  
Free Electrons ◽  
Impurity Potential ◽  
First Order ◽  
Dilute Alloys ◽  
A Value ◽  
Field Dependent ◽  
Self Consistency ◽  
The Magnetic Field

The diamagnetism of free electrons in the presence of charged impurity centres which are sufficiently dilute to be non-interacting is calculated to first order in the strength of the potential of the impurity centre. This is done by combining the density-matrix treatment of Landau diamagnetism with the impurity-screening theory o f March & Murray. The susceptibility involves the integrated value of the impurity potential through the crystal, and its first derivative with respect to the magnetic field, B. If the impurity potential is assumed to have a value appropriate to B — 0, then the result for the change in diamagnetic susceptibility on alloying agrees with that of Kohn & Luming (1963). It is shown, however, that the impurity potential is modified in the presence of the magnetic field, and in particular it has angular dependence. The correction to the dia­magnetic susceptibility due to this self-consistency is shown to be significant (25% ). The relevance of the theory to experimental results on dilute alloys is briefly discussed. Finally, as a by-product of the investigation, we have obtained interesting results about the form of the field-dependent dielectric constant.

Construction of a Cost Effective Current Balance for Physics Teaching

2013 ◽  
Vol 770 ◽  
pp. 374-377
Author(s):  
Apichart Sankote ◽  
Kheamrutai Thamaphat ◽  
Supanee Limsuwan
Keyword(s):  
Magnetic Field ◽  
Uniform Magnetic Field ◽  
Magnetic Force ◽  
Magnetic Field Direction ◽  
Horizontal Segment ◽  
Applied Current ◽  
Copper Sheet ◽  
Physics Teaching ◽  
The Magnetic Field ◽  
A Current

In this work, a method to measuring the magnitude of a uniform magnetic field in space using current balance was described. A simple experimental set was designed and constructed using low-cost materials. This constructed current balance consists of copper sheet, weight pan, and acrylic sheet. A copper sheet was cut into a U-shape and attached at the end of acrylic balance arm. A weight pan was hanged in the opposite side of the balance arm with high sensitivity to a small torque. The horizontal segment of the U-shaped copper sheet, which the length l was 3 cm, was located inside the influence of an uniform magnetic field produced by two parallel bar magnets with opposite poles facing each other. The magnetic field direction was perpendicular to the horizontal segment. When a current was supplied to the copper sheet, the magnetic force acting on a horizontal segment of length l carrying a current I in a magnetic field B was given by. In the experiment, the current was varied from 0 1 A. For each value of applied current, the magnetic force on a thin straight sheet of length l was measured by adding masses to the pan until the balance arm moved to the equilibrium between opposing gravitational and magnetic forces. The results showed that the magnetic force increased linearly with increasing applied current. By plotting a linear graph of magnetic force versus applied current, the magnetic field B can be calculated from . The calculated and actual values of B were 100.32 and 100.13 mT, respectively. This constructed current balance is an excellent tool for high school and undergraduate fundamental physics courses. Students will be excited when they see the balance arm rising or going down due to magnitude and direction of current flowing in a conductor wire.

Diffusion eines Plasmas in Abhängigkeit von Magnetfeld und Drude und von der Längs-Ausdehnung in Magnetfeldrichtung

1963 ◽  
Vol 18 (8-9) ◽  
pp. 889-895
Author(s):  
F. Schwirzke
Keyword(s):  
Magnetic Field ◽  
Density Profile ◽  
Plasma Column ◽  
Uniform Magnetic Field ◽  
Radial Density ◽  
Radial Density Profile ◽  
Radial Density Distribution ◽  
Field Lines ◽  
Different Gases ◽  
The Magnetic Field

The radial density distribution for a plasma in a uniform magnetic field was studied in dependence of pressure and distance of the conducting end plates. It was possible to confirm experimentally the dependence of the radial distribution of the finite length in direction of the field lines. The influence of the magnetic field, of the pressure, and of the length of the plasma column on the radial density profile is, in different gases, qualitatively in accordance with the “short-circuiting” theory of A. SIMON.

scholarly journals Neutral Pion Pole Mass Calculation in a Strong Magnetic Field: Lattice QCD Versus NJL Model

2017 ◽  
Vol 45 ◽  
pp. 1760060 ◽  
Author(s):  
Ricardo L. S. Farias ◽  
Sidney S. Avancini ◽  
Marcus Benghi Pinto ◽  
William R. Tavares ◽  
Varese S. Timóteo
Keyword(s):  
Magnetic Field ◽  
Lattice Qcd ◽  
Neutral Pion ◽  
Baryon Density ◽  
Pion Pole ◽  
Meson Mass ◽  
Pole Mass ◽  
Njl Model ◽  
The Magnetic Field ◽  
Good Agreement

Within the framework of cold magnetized SU(2) Nambu-Jona-Lasinio model we evaluate the [Formula: see text] and [Formula: see text] pole mass, as well as, [Formula: see text], [Formula: see text] at zero baryon density. We employ a magnetic field dependent coupling, [Formula: see text], fitted to reproduce lattice QCD results for the quark condensates. In particular, we find that the [Formula: see text] meson mass systematically decreases when the magnetic field increases, in good agreement with recent lattice calculations.

scholarly journals ENERGY ASSOCIATED WITH SCHWARZSCHILD BLACK HOLE IN A MAGNETIC UNIVERSE

2000 ◽  
Vol 15 (19) ◽  
pp. 2979-2986 ◽  
Author(s):  
S. S. XULU
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Uniform Magnetic Field ◽  
Relativistic Effect ◽  
Rest Mass ◽  
Mass Energy ◽  
Schwarzschild Black Hole ◽  
General Relativistic ◽  
The Magnetic Field ◽  
General Relativistic Effect

In this paper we obtain the energy distribution associated with the Ernst space–time (geometry describing Schwarzschild black hole in Melvin's magnetic universe) in Einstein's prescription. The first term is the rest-mass energy of the Schwarzschild black hole, the second term is the classical value for the energy of the uniform magnetic field and the remaining terms in the expression are due to the general relativistic effect. The presence of the magnetic field is found to increase the energy of the system.

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