Photo-Production of Neutral Mesons in Nuclear Electric Fields and the Mean Life of the Neutral Meson

1951 ◽  
Vol 81 (5) ◽  
pp. 899-899 ◽  
Author(s):  
H. Primakoff
Keyword(s):  
Electric Fields ◽  
Neutral Meson ◽  
Neutral Mesons ◽  
The Mean ◽  
Photo Production

scholarly journals The behaviour of electrolytes in mixed solvents. Part I.—The free energies and heat contents of hydrogen chloride in water—Ethyl alcohol solutions

1929 ◽  
Vol 125 (799) ◽  
pp. 694-712 ◽  
Keyword(s):  
Hydrogen Chloride ◽  
Electric Fields ◽  
Mixed Solvents ◽  
Dielectric Constants ◽  
Free Energies ◽  
Dissolved Ions ◽  
Uniform Medium ◽  
The Mean ◽  
Solvent Molecules ◽  
Water Alcohol

Previous studies on the effect of a change of medium on tire properties of dissolved electrolytes have aimed at correlating the behaviour of the electrolyte with the mean physical properties, e. g ., dielectric constants, of the medium. While this approach may be justified in the case of solvents containing molecules of only one kind, it is not sufficient to regard a mixed solvent as a uniform medium affecting the dissolved ions solely through the effect of its dielectric constant on the electric forces between them. For the electric fields of ions exert a differential attraction on molecules possessing different degrees of polarisability and since tire more polarisable molecules must tend to congregate round the ions, the properties of the latter cannot depend solely on tire mean properties of tire medium. Studies on the behaviour of ions in such cases will throw light on the interaction between ions and solvent molecules. The present paper gives tire results of measurements of the free energies and heat contents of hydrogen chloride in water-alcohol solutions, obtained by determining the electromotive forces of cells of the type:— H 2 ( g ) | HCl ( m ), AgCl ( s ) | Ag water-alcohol

On a phenomenological approach to meson production in nucleon-nucleon collisions

1951 ◽  
Vol 210 (1100) ◽  
pp. 85-98 ◽  
Keyword(s):  
Meson Production ◽  
Phenomenological Approach ◽  
Nucleon Nucleon ◽  
Neutral Meson ◽  
No Production ◽  
Distorted Wave ◽  
Proton Proton ◽  
Neutral Mesons ◽  
Valid Comparison ◽  
Charged Mesons

The validity of certain phenomenological approaches to spin zero meson production in nucleon-nucleon collisions is considered. It is shown that, to first-order perturbation theory, a method analogous to the distorted wave approximation is valid. Comparison is made with a bremsstrahlung-like calculation which, for neutral mesons with non-derivative coupling to the spinor field, gives no production, since the nucleon recoil is neglected. Application of the distorted wave approach to neutral meson production in proton-neutron collisions, and comparison with the results for production of charged mesons in proton-proton collisions is sketched. Results are quoted for simple inverse processes.

Simulation of Electron Transport in Silicon using Monte Carlo Method

2011 ◽  
Vol 284-286 ◽  
pp. 871-874
Author(s):  
Zan Wang ◽  
Lei Quan ◽  
Yi Wu Ruan
Keyword(s):  
Monte Carlo ◽  
Electron Transport ◽  
Monte Carlo Method ◽  
Electric Fields ◽  
Phonon Scattering ◽  
Mean Free Path ◽  
Intervalley Scattering ◽  
The Mean ◽  
Simulation Time ◽  
Electron Phonon Scattering

A Monte Carlo method is employed to investigate the properties of electron transport with considerations of electron-phonon scattering including intervalley scattering and intravalley scattering. Under different electric fields, the coupling relations between electrons and phonons are studied, and the behaviors of absorbing and releasing phonons from electrons are also analyzed. The results show the scattering events of absorbing phonons from electrons decrease with the increasing simulation time. At the same temperature, the mean free path of electron increases initially and then decreases with the increasing electric field intensity, and finally approaches an asymptotic value.

scholarly journals Magnetospheric energy inputs into the upper atmospheres of the giant planets

2005 ◽  
Vol 23 (5) ◽  
pp. 1943-1947 ◽  
Author(s):  
C. G. A. Smith ◽  
S. Miller ◽  
A. D. Aylward
Keyword(s):  
Electric Fields ◽  
Joule Heating ◽  
Energy Input ◽  
Giant Planets ◽  
Energy Inputs ◽  
Additional Input ◽  
Planetary Ionosphere ◽  
The Mean ◽  
Auroral Phenomena ◽  
Electric Fields And Currents

Abstract. We revisit the effects of Joule heating upon the upper atmospheres of Jupiter and Saturn. We show that in addition to direct Joule heating there is an additional input of kinetic energy – ion drag energy – which we quantify relative to the Joule heating. We also show that fluctuations about the mean electric field, as observed in the Earth's ionosphere, may significantly increase the Joule heating itself. For physically plausible parameters these effects may increase previous estimates of the upper atmospheric energy input at Saturn from ~10 TW to ~20 TW. Keywords. Ionosphere (Electric fields and currents; Planetary ionosphere) – Magnetospheric physics (Auroral phenomena)

scholarly journals A Quantum Charged Particle under Sudden Jumps of the Magnetic Field and Shape of Non-Circular Solenoids

2019 ◽  
Vol 1 (2) ◽  
pp. 193-207 ◽  
Author(s):  
Viktor V. Dodonov ◽  
Matheus B. Horovits
Keyword(s):  
Magnetic Field ◽  
Charged Particle ◽  
Magnetic Fields ◽  
Electric Fields ◽  
Cross Sections ◽  
Magnetic Moment ◽  
Landau Gauge ◽  
Time Dependent ◽  
The Mean ◽  
The Magnetic Field

We consider a quantum charged particle moving in the x y plane under the action of a time-dependent magnetic field described by means of the linear vector potential of the form A = B ( t ) − y ( 1 + β ) , x ( 1 − β ) / 2 . Such potentials with β ≠ 0 exist inside infinite solenoids with non-circular cross sections. The systems with different values of β are not equivalent for nonstationary magnetic fields or time-dependent parameters β ( t ) , due to different structures of induced electric fields. Using the approximation of the stepwise variations of parameters, we obtain explicit formulas describing the change of the mean energy and magnetic moment. The generation of squeezing with respect to the relative and guiding center coordinates is also studied. The change of magnetic moment can be twice bigger for the Landau gauge than for the circular gauge, and this change can happen without any change of the angular momentum. A strong amplification of the magnetic moment can happen even for rapidly decreasing magnetic fields.

VELOCITY DISTRIBUTION IN THE DUKE–RUBINSTEIN MODEL

2002 ◽  
Vol 13 (06) ◽  
pp. 829-835
Author(s):  
P. PAŚCIAK ◽  
M. J. KRAWCZYK ◽  
K. KUŁAKOWSKI
Keyword(s):  
Velocity Distribution ◽  
Electric Fields ◽  
Gel Electrophoresis ◽  
Dna Molecules ◽  
Mean Velocity ◽  
The Mean ◽  
High Fields ◽  
High Electric Fields

The Duke–Rubinstein model of gel electrophoresis is applied to calculate the velocity of DNA molecules. We have found that the velocity distribution becomes flat at high electric fields. Simultaneously, the percentage of immobile molecules increases. Effectively, the mean velocity starts to decrease at high fields. The field value, where the mean velocity is maximal, decreases with the molecule length. The results are compared with those from similar calculations obtained by Heukelum and Beljaars within the cage model.

scholarly journals THE FOCUSING OF VACUUM FLUCTUATIONS

2002 ◽  
Vol 17 (29) ◽  
pp. 4393-4402
Author(s):  
L. H. FORD ◽  
N. F. SVAITER
Keyword(s):  
Energy Density ◽  
Electric Field ◽  
Electromagnetic Fields ◽  
Electric Fields ◽  
Negative Energy ◽  
Parabolic Mirror ◽  
Vacuum Fluctuations ◽  
Negative Energy Density ◽  
Cylindrical Mirror ◽  
The Mean

The quantization of the scalar and electromagnetic fields in the presence of a parabolic mirror is developed in the context of a geometric optics approximation. We calculate the mean squared scalar and electric fields near the focal line of a parabolic cylindrical mirror. These quantities are found to grow as inverse powers of the distance from the focus. We give a combination of analytic and numerical results for the mean squared fields. In particular, we find that the mean squared electric field can be either negative or positive, depending upon the choice of parameters. The case of a negative mean squared electric field corresponds to a repulsive Van der Waals force on an atom near the focus, and to a region of negative energy density. Similarly, a positive value corresponds to an attractive force and a possibility of atom trapping in the vicinity of the focus.

scholarly journals Dealing with T and CPT violations in mixing as well as direct and indirect CP violations for neutral mesons decaying to two vectors

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Anirban Karan
Keyword(s):  
Decay Rate ◽  
New Physics ◽  
Neutral Meson ◽  
Final State ◽  
Cp Violations ◽  
Neutral Mesons ◽  
Special Cases ◽  
Complete Set ◽  
Vector Particles

Abstract A large number of observables can be constructed from differential decay rate based on the polarization of final state while considering decay of a neutral meson $$(P^{0} \text { or } {\bar{P}}^{0})$$(P0orP¯0) to two vector particles. But all of these observables are not independent to each other since there are only a few independent theoretical parameters controlling the whole dynamics and therefore various relations among observables emerge. In this paper, we have studied the behaviour of observables for neutral meson decaying to two vectors in presence of $$T$$T and $$C\!P T$$CPT violations in mixing accompanied by both direct and indirect $$C\!P$$CP violations. We have expressed all of the fourteen unknown theoretical parameters for this scenario in terms observables only and constructed the complete set of thirty four relations among observables whose violation would signify the existence of some new Physics involving direct violation of $$C\!P T$$CPT. In addition, using this formalism we have studied three special cases too: (a) SM scenario, (b) SM plus direct $$C\!P$$CP violation (c) SM plus $$T$$T and $$C\!P T$$CPT violation in mixing.

scholarly journals Neutral Meson and Direct Photon Measurements with the ALICE Experiment

2019 ◽  
Vol 64 (7) ◽  
pp. 602
Author(s):  
O. Kovalenko
Keyword(s):  
Parton Distribution ◽  
Heavy Ion ◽  
Distribution Functions ◽  
Direct Photon ◽  
Neutral Meson ◽  
Parton Distribution Functions ◽  
Alice Experiment ◽  
Neutral Mesons ◽  
Wide Range ◽  
Aa Collisions

The ALICE experiment is designed to study the properties of the matter created in proton-proton and heavy-ion collisions at the LHC. Neutral mesons can be reconstructed in ALICE in a wide range of transverse momenta via two-photon decays. Neutral meson measurements in pp collisions give an opportunity to validate the NLO or NNLO pQCD calculations and to constrain the parton distribution functions and the parton fragmentation functions. Neutral meson spectra measured in pA and AA collisions allow us to test a modification of the parton distribution functions in nuclei and the parton energy loss in the hot matter created in AA collisions. The recent results from ALICE on direct photon measurements in the Pb–Pb, neutral pion and n meson productions in pp, p-Pb, and Pb–Pb collisions are presented.

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