8,758 research outputs found
Minimal Walking Technicolor
I report on our construction and analysis of the effective low energy
Lagrangian for the Minimal Walking Technicolor (MWT) model. The parameters of
the effective Lagrangian are constrained by imposing modified Weinberg sum
rules and by imposing a value for the S parameter estimated from the underlying
Technicolor theory. The constrained effective Lagrangian allows for an inverted
vector vs. axial-vector mass spectrum in a large part of the parameter space.Comment: Submitted for the SUSY07 proceedings, 4 pages, LaTeX, 3 eps figure
Discovering a Light Scalar or Pseudoscalar at The Large Hadron Collider
The allowed standard model Higgs mass range has been reduced to a region
between 114 and 130 GeV or above 500 GeV, at the 99% confidence level, since
the Large Hadron Collider (LHC) program started. Furthermore some of the
experiments at Tevatron and LHC observe excesses that could arise from a spin-0
particle with a mass of about 125 GeV. It is therefore timely to compare the
standard model Higgs predictions against those of a more general new spin-0
state, either scalar or pseudo-scalar. Using an effective Lagrangian approach
we investigate the ability to discriminate between a scalar or pseudoscalar,
stemming from several extensions of the standard model, at the LHC. We also
discuss how to use experimental results to disentangle whether the new state is
elementary or composite.Comment: 28 pages, 21 figure
Asymmetric dark matter and the Sun
Cold dark matter particles with an intrinsic matter-antimatter asymmetry do
not annihilate after gravitational capture by the Sun and can affect its
interior structure. The rate of capture is exponentially enhanced when such
particles have self-interactions of the right order to explain structure
formation on galactic scales. A `dark baryon' of mass 5 GeV is a natural
candidate and has the required relic abundance if its asymmetry is similar to
that of ordinary baryons. We show that such particles can solve the `solar
composition problem'. The predicted small decrease in the low energy neutrino
fluxes may be measurable by the Borexino and SNO+ experiments.Comment: 4 pages, 3 figures (RevTex); Capture rate corrected to obey the
geometrical bound; Changes in adopted cross-sections and particle physics
motivation; Conclusions concerning helioseismology and solar neutrino fluxes
unchange
The Up-Shot of Inelastic Down-Scattering at CDMS-Si
We study dark matter that inelastically scatters and de-excites in direct
detection experiments, as an interpretation of the CDMS-Si events in light of
the recent LUX data. The constraints from LUX and XENON10 require the
mass-splitting between the DM excited and de-excited states to be keV. At the same time, the CDMS-Si data itself do not allow for a
consistent DM interpretation for mass splittings larger than 200 keV. We find that a low threshold analysis will be needed to rule out this
interpretation of the CDMS-Si events. In a simple model with a kinetically
mixed dark photon, we show that the CDMS-Si rate and the thermal relic
abundance can both be accommodated.Comment: 10 pages, 3 figures; updated to match PRD versio
125 GeV Higgs from a not so light Technicolor Scalar
Assuming that the observed Higgs-like resonance at the Large Hadron Collider
is a technicolor isosinglet scalar (the technicolor Higgs), we argue that the
standard model top-induced radiative corrections reduce its dynamical mass
towards the desired experimental value. We then discuss conditions for the
spectrum of technicolor theories to feature a technicolor Higgs with the
phenomenologically required dynamical mass. We use scaling laws coming from
modifying the technicolor matter representation, number of technicolors,
techniflavors as well as the number of doublets gauged under the electroweak
theory. Finally we briefly summarize the potential effects of walking dynamics
on the technicolor Higgs.Comment: ReVTex, 15 pages, 3 figures. Version to match the published on
Corrigan-Ramond Extension of QCD at Nonzero Baryon Density
We investigate the Corrigan-Ramond extension of one massless flavor Quantum
Chromo Dynamics at nonzero quark chemical potential. Since the extension
requires the fermions to transform in the two index antisymmetric
representation of the gauge group, one finds that the number of possible
channels is richer than in the 't Hooft limit. We first discuss the diquark
channels and show that for a number of colors larger than three a new diquark
channel appears. We then study the infinite number of color limit and show that
the Fermi surface is unstable to the formation of the
Deryagin-Grigoriev-Rubakov chiral waves. We discover, differently from the 't
Hooft limit, the possibility of a colored chiral wave breaking the color
symmetry as well as translation invariance.Comment: RevTeX, 14 pages, 2 figure
- …