الفهرس 
Theoretical Context
Supersymmetric Extensions of the Standard ModelOnly 14 pages are availabe for public view
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Abstract
The aim of this thesis is devoted to a detailed phenomenological analysis of the
production of the lightest neutral Higgs boson 0 h in association with pairs of
sleptons which are muon-sneutrino 0 e e h and tau-sneutrino
0 e e h at future e e colliders in the context of the minimal
supersymmetric standard model (MSSM).
The dependence of the lowest order and the virtual one loop radiative
corrected total cross sections on the center of mass energy and the other model
parameters in the framework of the MSSM would be discussed. The
phenomenological analyses are based on the CP-conserving MSSM with real
parameters. Numerical results at the SPS1b and SPS 4 benchmark points as
proposed in the Supersymmetry Parameter Analysis (SPA) project are presented
for demonstration.
This thesis consists of five Chapters:
Chapter 1 gives an overview of the Standard Model (SM) with emphasis on the
Higgs sector. An important component of the SM is the Higgs mechanism which
enables gauge bosons to have non-zero mass while preserving gauge symmetry.
The constraints on the Standard Model Higgs boson mass from the direct searches
and from precision measurements in addition to shortcomings of the Standard
Model are briefly introduced.
Chapter 2 presents the leading candidate for physics beyond the standard model
which is supersymmetry (SUSY) theory. The Minimal Supersymmetric Standard
Model (MSSM) is introduced as an extension of the Standard Model and
differences between the MSSM and SM Higgs sectors are described. The Chapter
sheds lights on the mass spectrum and the renormalization of the MSSM.
Chapter 3 provides the basic modern tools for the calculation of loop diagrams
which are the dimensional regularization (DR) and Passarino–Veltman functions.
A brief introduction about QuantumElectroDynamics (QED) corrections at one
loop and renormalization in QED are presented.
Chapter 4 is devoted to study the associated production of the lightest 0 h boson
along with a muon-sneutrino pair at future e e colliders in the context of the
MSSM in each of the SPS 1b and SPS 4 scenarios. The calculation of the Born
cross section contribution as well as the full virtual one loop electroweak
corrections to the 0 e e h process are presented. The QED contributions
can be isolated as a separate subclass.
In the numerical calculation, the MSSM parameters at the two reference points
SPS 1b and SPS 4 defined in the SPA project are adopted. Our numerical results
show that in each of the SPS 1b and SPS 4 scenarios, the full virtual electroweak
corrected total cross sections are always more than the corresponding tree-level
cross sections clearly.
The EW relative correction / 0 for the 0 e e h channel can be
either positive or negative with the increment of the colliding energy s and the
/ 0 is always positive with the increment of the supersymmetric Higgs mass
parameter of the two chosen scenarios.
In the numerical results, one found that SUSY M has evidently a considerable
impact on the muon-sneutrino and the lightest neutral Higgs particle masses (m
and 0 h
m ) in addition to its considerable effect on the Born cross section 0 of
each of the our chosen scenarios. There is weakly effect of tan parameter on the
muon-sneutrino and the lightest neutral Higgs particle masses (m
and 0 h
m ).
One concludes that the cross section values and the EW relative correction for
the 0 e e h channel in SPS 1b scenario are always higher than the
corresponding values in the SPS 4 scenario and these corrections are so remarkable
and cannot be neglected in the precise experiment analysis.
Chapter 5 presents the 0 e e h channel where the associated production
of the lightest boson 0 h along with a tau-sneutrino pair at future e e colliders in
the context of the MSSM in each of the SPS 1b and SPS 4 scenarios is discussed.
The dependence of the Born cross section, the full electroweak corrected cross
sections and the relative correction on the colliding energy s are analyzed.
Our numerical results show clearly that the radiative corrections for the
0 e e h channel for the two reference points SPS 1b and SPS 4 are always
more than the corresponding tree-level cross sections, i.e., the radiative corrections
are always positive in our chosen parameter spaces. The relative correction varies
in the range of the SPS 1b and SPS 4 scenarios are of order of 90% and 8%,
respectively. This is consistent with our numerical results in the corresponding
reaction 0 e e h .
The effect of the parameter on the total cross section value as a function of
the c.m.s energy at the values = 150, 200 and 250 GeV is rather minute at the
Born approximation level or at the full virtual electroweak corrected total cross
section for the two scenarios SPS 1b and SPS 4, respectively. Similar results
obtained for the reaction 0 e e h where the parameter in each of SPS
1b and SPS 4 scenarios in the same range, from 150 GeV to 250 GeV, has a small
effect on the / 0 .
The influence of the soft-breaking squark mass SUSY M parameter on
the tau-sneutrino and the lightest neutral Higgs particle masses at the tree
level 0 is considerable.
The influence of the vacuum expectation value tan parameter at
the tree level on the tau-sneutrino mass m
is minimal (1 GeV) and its
effect on the lightest neutral Higgs particle mass 0 h
m is considerable
when the tan value is less than 8 for the two chosen parameter spaces.
These results are consistent with what we got for the 0 e e h
process.
from our numerical calculations, we conclude that the cross section
values and the EW relative corrections for the 0 e e h channel are
in favor of the SPS 1b scenario and these corrections are so remarkable
and they that cannot be neglected if precise experiment of analysis are
sought.