Quantum Physics Stream
http://ir.haramaya.edu.et//hru/handle/123456789/226
Sun, 25 Feb 2024 22:24:02 GMT2024-02-25T22:24:02ZNEUTRINO INDUCED MUON PAIR PRODUCTION IN UNIFORM BACKGROUND MAGNETIC FIELD: CASE OF NEUTRAL CURRENT PROCESS
http://ir.haramaya.edu.et//hru/handle/123456789/6910
NEUTRINO INDUCED MUON PAIR PRODUCTION IN UNIFORM BACKGROUND MAGNETIC FIELD: CASE OF NEUTRAL CURRENT PROCESS
Endeshaw Negash Amdine; (PhD) Gashaw Bekele
Neutrino is core in understanding the weak interaction and it is the only fundamental particle
whose interactions are dominated by the weak interaction. The main goal of this study is to
apply Glashow-Weinberg-Salam theory to study of neutrino-induced muon-antimuon pair
production in the presence of uniform background magnetic field. Within the framework of the
standard model, the determination of scattering amplitude in terms of the lowest order Feynman
diagram and production rate for neutral current reaction are the main goal of this work. In the
presence of magnetic field, the modified Dirac equation is derived for both positive and negative
energy solutions. The Fenman rules, Casmir’s trick and trace theorems have been employed in
constructing the relative description of modulus square of spin averaged invariant amplitude.
In doing so, the modulus square of spin averaged invariant amplitude has been described as the
contraction between lepton tensors enabling straight forward calculation of production rate.
The kinematics of the process is set so that the incident, scattered and produced particles were
confined on the ����plane. By taking into account different values of Landau levels, the
production rate as a function of incident energy has been plotted by using Matlab programming
language; and for numerical integration we have used the Gaussian quadrature with 10
integration points. Besides, we have presented the numerical results for the rate of pair
production for NC process near to the critical field. Different Landau levels considered for a
fixed incident energy production rate has been found to increase as field strength increases.
Even though production rate increases for different Landau levels considered, it increases to a
great extent when the Landau levels of muon and antimuon are equal
112p.
Tue, 01 Aug 2023 00:00:00 GMThttp://ir.haramaya.edu.et//hru/handle/123456789/69102023-08-01T00:00:00ZNEUTRINO-INDUCED ELECTRON-POSITRON PAIR-PRODUCTION IN A UNIFORM BACKGROUND MAGNETIC FIELD: CASE OF CHARGED CURRENT PROCESS
http://ir.haramaya.edu.et//hru/handle/123456789/6908
NEUTRINO-INDUCED ELECTRON-POSITRON PAIR-PRODUCTION IN A UNIFORM BACKGROUND MAGNETIC FIELD: CASE OF CHARGED CURRENT PROCESS
Dejene Tamiru; (PhD) Bekele
This study is to present an electroweak description of neutrino-induced electron-positron pair
production in the presence of a strong background magnetic field. The determination of the
scattering matrix, scattering amplitude and numerical analysis of the rate of electron positron pair production for the charged current reaction within the context of the standard
model were the main focuses of this work. An electromagnetic field has many effects on
neutrino physics due to the interaction with a charged particle in the process. Feynman rules
were applied to calculate the scattering matrix element for a process in a charged current
reactions mediated by . The modified Dirac equation is derived and solved when a
constant magnetic field is present. The modulus square of the invariant matrix element was
manipulated into a contraction between the electron and positron tensors. The kinematic
arrangement was set such that the four-momenta are calculated in the frame in which the
magnetic field is stationary, and the electron-neutrino and positron-neutrino planes of the
process were set to be coplanar constrained on the -plane. Python source code was
developed to generate numerical results. The results of the numerical analysis show that the
production rate attains its peak in the low energy range when both electron and positron are
in their lower Landau levels. Moreover, as the magnetic field strength increases, the peak of
the production increases as well with slight shift to the right. In addition, the contributions of
low Landau levels show relative dominance over a wider range of the incident energy.
112p.
Sat, 01 Jul 2023 00:00:00 GMThttp://ir.haramaya.edu.et//hru/handle/123456789/69082023-07-01T00:00:00ZLEPTONIC DECAY OF NEGATIVELY CHARGED PION IN THE FRAMEWORK OF BETHE-SALPETER EQUATION
http://ir.haramaya.edu.et//hru/handle/123456789/6810
LEPTONIC DECAY OF NEGATIVELY CHARGED PION IN THE FRAMEWORK OF BETHE-SALPETER EQUATION
Getachew Ayalew Liben; Elias Mengesha (PhD
In this paper we employed the BSE methed to study the leptonic decays of -meson. By using lowest-order Feynman diagrams, detailed derivations of the invariant matrix element were made. The Feynman rules and trace algebra have been employed in constructing the relativistic quantum mechanical expression of invariant amplitude. To this process we also calculate the pion invariant scattering amplitude of the two leptonic decay modes of the negatively charged pion using Feynman rules, decay width for the two leptonic decay of -meson and the ratio of two leptonic decay modes.
61
Wed, 01 Feb 2023 00:00:00 GMThttp://ir.haramaya.edu.et//hru/handle/123456789/68102023-02-01T00:00:00ZVERTEX CORRECTION AND SOFT PHOTON EMISSION CONTRIBUTIONS TO THE SCATTERING OF ELECTRON BY COULOMB POTENTIAL
http://ir.haramaya.edu.et//hru/handle/123456789/6594
VERTEX CORRECTION AND SOFT PHOTON EMISSION CONTRIBUTIONS TO THE SCATTERING OF ELECTRON BY COULOMB POTENTIAL
Isak Sufiyan; ELIAS MENGESHA (PhD)
The main purpose of this study is to provide the quantum description for the vertex correction and soft photon emission contributions to the radiative corrections of the scattering of electron by coulomb potential. Using Feynman rules of quantum electrodynamics (QED), we evaluate the leading order scattering matrix from the lowest order Feynman diagram, the next to leading order scattering matrix from the higher order Feynman diagram for the scattering of electron by Coulomb field in the case of vertex correction and also evaluate the scattering matrix for the scattering of electron by Coulomb field with soft photon emission. Next, we evaluate the square of the scattering matrix using Cashimer’s trick and calculate the leading order differential cross section, the next to leading order differential cross sections in the case of vertex correction and soft photon emission and total differential cross section using Fermi Golden rule. Finally compare the next to leading order and total differential cross sections with that of the leading order differential cross section. Of course, the next to leading order differential cross section is very small compared with the leading order differential cross section and the total cross section is comparable with that of the leading order differential cross section. These are of course valid in perturbation theory.
101
Thu, 01 Jun 2023 00:00:00 GMThttp://ir.haramaya.edu.et//hru/handle/123456789/65942023-06-01T00:00:00Z