73 research outputs found
Status of Composite Higgs
In these proceedings I will briefly describe the Composite Higgs constructions and then discuss their current experimental status
Flavor Physics in the Models with Warped Extra Dimension
I will first briefly review the Standard Model and gauge hierarchy problem.
Then I will present the Randall-Sundrum model with warped extra dimension, which
provides an elegant geometrical solution to the hierarchy problem. The main focus of
this thesis will be an analysis of the flavor violation in the models with warped extra
dimension. First I will discuss the bounds on the scale of the extra dimension arising
from the low energy physics. I will show that there is a tension in the parameter
space coming from different low energy observables, and I will also discuss possible
ways to relax these bounds. Another interesting feature of the warped models is that
they generically predict flavor violation in the Higgs sector. I will discuss low energy
flavor constraints on the Higgs mediated flavor violation as well as its signatures at
the collider experiments. In the last part of this thesis I will discuss the physics of
radion, a scalar degree of freedom of the five dimensional gravity multiplet, and I will
show why it has interactions which are generically flavor misaligned leading to the
observable flavor violation. This, combined with the fact that radion is likely to be
the lightest new physics degree of freedom will lead to the interesting phenomenology
both from perspective of collider phenomenology and low energy observables
Challenges of EFT at the LHC
I will discuss the difficulties of putting constraints on the Effective Field Theories (EFT) at the Large Hadron Collider (LHC). In particular, I will analyse the generic properties of the 2 ! 2 scattering in the presence of the higher dimensional operators indicating that some of the beyond Standard Model effects are parametrically smaller than naive expectations
The higgs boson beyond standard model
We will review the status of the Higgs boson beyond Standard Model. This proceeding will be focused on the experimental and theoretical status of the Higgs boson in the Composite Higgs models. In particular we will discuss implications on the beyond Standard Model (BSM) Higgs coming from the observed excess at 125 GeV
Contextualizing the Higgs at the LHC
Recent excesses across different search modes of the collaborations at the
LHC seem to indicate the presence of a Higgs-like scalar particle at 125 GeV.
Using the current data sets, we review and update analyses addressing the
extent to which this state is compatible with the Standard Model, and provide
two contextual answers for how it might instead fit into alternative scenarios
with enlarged electroweak symmetry breaking sectors.Comment: Contribution to the proceedings of PLHC 2012, Vancouver, BC, June
4-9, 201
Superconformal Technicolor
In supersymmetric theories with a strong conformal sector, soft supersymmetry
breaking at the TeV scale naturally gives rise to confinement and chiral
symmetry breaking at the same scale. We investigate models where such a sector
dynamically breaks electroweak symmetry. We consider two scenarios, one where
the strong dynamics induces vacuum expectation values for elementary Higgs
fields, and another where the strong dynamics is solely responsible for
electroweak symmetry breaking. In both cases there is no fine tuning required
to explain the absence of a Higgs boson below the LEP bound, solving the
supersymmetry naturalness problem. A good precision electroweak fit can be
obtained, and quark and lepton masses are generated without flavor-changing
neutral currents. Electroweak symmetry breaking may be dominated either by the
elementary Higgs bosons or by the strong dynamics. In addition to standard
superymmetry collider signals, these models predict production of multiple
heavy standard model particles (t, W, Z, and b) from decays of resonances in
the strong sector.Comment: 4 pages; v2: minor changes, references adde
Early Higgs Hints for Non-Minimal Supersymmetry
We discuss the role that Higgs coupling measurements can play in
differentiating supersymmetric extensions of the Standard Model. Fitting
current LHC data to the Higgs couplings, we find that the likelihood fit shows
a preference in the direction of suppressed (enhanced) bottom (top) quark
couplings. In the minimal supersymmetric Standard Model, we demonstrate that
for tan beta > 1, there is tension in achieving such fermion couplings due to
the structure of the Higgs quartic couplings. In anticipation of interpreting
supersymmetric models with future data, we determine a single straightforward
condition required to access the region of coupling space preferred by current
data.Comment: 6 pages, 3 figures; v3: updated fits to include post-discovery data,
references and discussion modified accordingl
Radion Mediated Flavor Changing Neutral Currents
In the context of a warped extra-dimension with Standard Model fields in the
bulk, we obtain the general flavor structure of the Radion couplings to
fermions and show that the result is independent on the particular nature of
the Higgs mechanism (bulk or brane localized). These couplings will be
generically misaligned with respect to the fermion mass matrix when the fermion
bulk mass parameters are not all degenerate. When the Radion is light enough,
the generic size of these tree-level flavor changing couplings will be strongly
constrained by the experimental bounds on processes. At the LHC
the possibility of a heavier Radion decaying into top and charm quarks is then
considered as a promising signal to probe the flavor structure of both the
Radion sector and the whole scenario.Comment: 4 pages, 2 figures, 1 tabl
Bubble wall velocity: heavy physics effects
We analyse the dynamics of the relativistic bubble expansion during the first order phase transition focusing on the ultra relativistic velocities \u3b3 1. We show that fields much heavier than the scale of the phase transition can significantly contribute to the friction and modify the motion of the bubble wall leading to interesting phenomenological consequences. NLO effects on the friction due to the soft vector field emission are reviewed as well
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