1,104 research outputs found
Charged Higgs Boson Production at e+e- Colliders in the Complex MSSM: A Full One-Loop Analysis
For the search for additional Higgs bosons in the Minimal Supersymmetric
Standard Model (MSSM) as well as for future precision analyses in the Higgs
sector precise knowledge of their production properties is mandatory. We
evaluate the cross sections for the charged Higgs boson production at e+e-
colliders in the MSSM with complex parameters (cMSSM). The evaluation is based
on a full one-loop calculation of the production mechanism e+e- -> H+H- and
e+e- -> H^\pm W^\mp, including soft and hard QED radiation. The dependence of
the Higgs boson production cross sections on the relevant cMSSM parameters is
analyzed numerically. We find sizable contributions to many cross sections.
They are, depending on the production channel, roughly of 5-10% of the
tree-level results, but can go up to 20% or higher. The full one-loop
contributions are important for a future linear e+e- collider such as the ILC
or CLIC.Comment: 28 pages, 13 figures. arXiv admin note: substantial text overlap with
arXiv:1511.06002, arXiv:1503.02996, arXiv:1410.278
Chargino and Neutralino Production at e+e- Colliders in the Complex MSSM: A Full One-Loop Analysis
For the search for charginos and neutralinos in the Minimal Supersymmetric
Standard Model (MSSM) as well as for future precision analyses of these
particles an accurate knowledge of their production and decay properties is
mandatory. We evaluate the cross sections for the chargino and neutralino
production at e+e- colliders in the MSSM with complex parameters (cMSSM). The
evaluation is based on a full one-loop calculation of the production mechanisms
e+e- -> cha_c cha_c' and e+e- -> neu_n neu_n', including soft and hard photon
radiation. We mostly restricted ourselves to a version of our renormalization
scheme which is valid for |M_1| < |M_2|, |mu| and M_2 != mu to simplify the
analysis, even though we are able to switch to other parameter regions and
correspondingly different renormalization schemes. The dependence of the
chargino/neutralino cross sections on the relevant cMSSM parameters is analyzed
numerically. We find sizable contributions to many production cross sections.
They amount roughly 10-20% of the tree-level results, but can go up to 40% or
higher in extreme cases. Also the complex phase dependence of the one-loop
corrections was found non-negligible. The full one-loop contributions are thus
crucial for physics analyses at a future linear e+e- collider such as the ILC
or CLIC.Comment: 45 pages, 26 figures. arXiv admin note: substantial text overlap with
arXiv:1606.06981, arXiv:1511.0600
Neutral Higgs Boson Production at e+e- Colliders in the Complex MSSM: A Full One-Loop Analysis
For the search for additional Higgs bosons in the Minimal Supersymmetric
Standard Model (MSSM) as well as for future precision analyses in the Higgs
sector a precise knowledge of their production properties is mandatory. We
evaluate the cross sections for the neutral Higgs boson production at e^+e^-
colliders in the MSSM with complex parameters (cMSSM). The evaluation is based
on a full one-loop calculation of the production channels e^+e^- -> h_i Z, h_i
gamma, h_i h_j (i,j = 1,2,3), including soft and hard QED radiation. The
dependence of the Higgs boson production cross sections on the relevant cMSSM
parameters is analyzed numerically. We find sizable contributions to many cross
sections. They are, depending on the production channel, roughly of 10-20% of
the tree-level results, but can go up to 50% or higher. The full one-loop
contributions are important for a future linear e^+e^- collider such as the ILC
or CLIC. There are plans to implement the evaluation of the Higgs boson
production cross sections into the code FeynHiggs.Comment: 34 pages, 16 figures. arXiv admin note: text overlap with
arXiv:1503.02996, arXiv:1410.278
Slepton Production at e+e- Colliders in the Complex MSSM: A Full One-Loop Analysis
For the search for scalar leptons in the Minimal Supersymmetric Standard
Model (MSSM) as well as for future precision analyses of these particles an
accurate knowledge of their production and decay properties is mandatory. We
evaluate the cross sections for the slepton production at e+e- colliders in the
MSSM with complex parameters (cMSSM). The evaluation is based on a full
one-loop calculation of the production mechanisms e+e- -> slepton_s slepton_s'
including soft and hard photon radiation. The dependence of the slepton
production cross sections on the relevant cMSSM parameters is analyzed
numerically. We find sizable contributions to many production cross sections.
They amount to roughly 15% of the tree-level results but can go up to 40% or
higher in extreme cases. Also the complex phase dependence of the one-loop
corrections for charged slepton production was found non-negligible. The full
one-loop contributions are thus crucial for physics analyses at a future linear
e+e- collider such as the ILC or CLIC.Comment: 41 pages, 20 figures. arXiv admin note: substantial text overlap with
arXiv:1704.07627, arXiv:1606.06981, arXiv:1511.0600
Heavy Scalar Tau Decays in the Complex MSSM: A Full One-Loop Analysis
We evaluate all two-body decay modes of the heavy scalar tau in the Minimal
Supersymmetric Standard Model with complex parameters (cMSSM) and no generation
mixing. The evaluation is based on a full one-loop calculation of all decay
channels, also including hard and soft QED radiation. The renormalization of
the relevant sectors is briefly reviewed. The dependence of the heavy scalar
tau decay on the relevant cMSSM parameters is analyzed numerically, including
also the decay to Higgs bosons and another scalar lepton or to a tau and the
lightest neutralino. We find sizable contributions to many partial decay widths
and branching ratios. They are mostly of O(5-10%) of the tree-level results,
but can go up to 20%. These contributions are potentially important for the
correct interpretation of scalar tau decays at the LHC and, if kinematically
allowed, at the ILC or CLIC. The evaluation of the branching ratios of the
heavy scalar tau will be implemented into the Fortran code FeynHiggs.Comment: 57 pages, 31 figures. arXiv admin note: substantial text overlap with
arXiv:1111.7289, 1112.0760, 1112.283
Proposals for Bottom Quark/Squark Renormalization in the Complex MSSM
We present a consistent renormalization of the top and bottom quark/squark
sector of the MSSM with complex parameters (cMSSM). Various renormalization
schemes are defined, analyzed analytically and tested numerically in the decays
Stop_2 -> Sbot_i H+/W+ (i = 1,2). No scheme is found that produces numerically
acceptable results over all the cMSSM parameter space, where problems occur
mostly already for real parameters. Two schemes are identified that show the
most robust behavior. A numerical analysis of the four partial stop decay
widths is performed in our "preferred" scheme, "m_b, A_b DRbar". The full
one-loop corrections to the corresponding partial decay widths are evaluated
including hard QED and QCD radiation. We find mostly modest corrections at the
one-loop level.Comment: 47 pages, 12 figure
Precise prediction for the Higgs-Boson Masses in the SSM
The SSM is a simple supersymmetric extension of the Standard Model
(SM) capable of predicting neutrino physics in agreement with experiment. In
this paper we perform the complete one-loop renormalization of the neutral
scalar sector of the SSM with one generation of right-handed neutrinos
in a mixed on-shell/ scheme. The renormalization
procedure is discussed in detail, emphasizing conceptual differences to the
minimal (MSSM) and next-to-minimal (NMSSM) supersymmetric standard model
regarding the field renormalization and the treatment of non-flavor-diagonal
soft mass parameters, which have their origin in the breaking of -parity in
the SSM. We calculate the full one-loop corrections to the neutral
scalar masses of the SSM. The one-loop contributions are supplemented
by available MSSM higher-order corrections. We obtain numerical results for a
SM-like Higgs boson mass consistent with experimental bounds. We compare our
results to predictions in the NMSSM to obtain a measure for the significance of
genuine SSM-like contributions. We only find minor corrections due to
the smallness of the neutrino Yukawa couplings, indicating that the Higgs boson
mass calculations in the SSM are at the same level of accuracy as in
the NMSSM. Finally we show that the SSM can accomodate a Higgs boson
that could explain an excess of events at as reported by CMS, as well as the excess of events observed at LEP at a similar mass scale.Comment: Version published in EPJC. Numerical analysis improved, numerical
results for NMSSM comparison changed accordingly, overall conclusions
unchanged. 56 pages, 12 figure
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