3 research outputs found
Naturalness and theoretical constraints on the Higgs boson mass
Arbitrary regularization dependent parameters in Quantum Field Theory are
usually fixed on symmetry or phenomenology grounds. We verify that the
quadratically divergent behavior responsible for the lack of naturalness in the
Standard Model (SM) is intrinsically arbitrary and regularization dependent.
While quadratic divergences are welcome for instance in effective models of low
energy QCD, they pose a problem in the SM treated as an effective theory in the
Higgs sector. Being the very existence of quadratic divergences a matter of
debate, a plausible scenario is to search for a symmetry requirement that could
fix the arbitrary coefficient of the leading quadratic behavior to the Higgs
boson mass to zero. We show that this is possible employing consistency of
scale symmetry breaking by quantum corrections. Besides eliminating a
fine-tuning problem and restoring validity of perturbation theory, this
requirement allows to construct bounds for the Higgs boson mass in terms of
(where is the renormalized Higgs mass and
is the 1-loop Higgs mass correction). Whereas
(perturbative regime) in this scenario allows the Higgs boson mass around the
current accepted value, the inclusion of the quadratic divergence demands
arbitrarily large to reach that experimental value.Comment: 6 pages, 4 figure
Pair Production of the Lightest Chargino via Gluon-Gluon Collisions
The production of the lightest chargino pair from gluon-gluon fusion is
studied in the minimal supersymmetric model(MSSM) at proton-proton colliders.
We find that with the chosen parameters, the production rate of the subprocess
can be over 2.7 femto barn when the chargino is higgsino-like, and the
corresponding total cross section in proton-proton collider can reach 56 femto
barn at the LHC in the CP-conserving MSSM. It shows that this loop mediated
subprocess can be competitive with the standard Drell-Yan subprocess in
proton-proton colliders, especially at the LHC. Furthermore, our calculation
shows it would be possible to extract information about some CP-violating phase
parameters, if we collected enough chargino pair events.Comment: 39 pages, LaTex, 8 figure