This series consists of talks in the areas of Particle Physics, High Energy Physics & Quantum Field Theory.
Physics
is at a crossroad that leads either to Naturalness or the Multiverse. While the
confirmation of gauge coupling unification in the early 90s gave a tremendous
boost to naturalness and to low energy SUSY, the lack of evidence
for new physics beyond the standard model at the LHC points to a paucity of new
particles near the weak scale. This suggests that the weak scale is tuned and
that supersymmetry, if present at all, is realized at higher energies. This
I introduce a new
nonrelativistic effective field theory which systematically accounts for the finite lifetime effects in production of unstable
particles.
The theory is applied to the threshold production of top quark-antiquark
pairs.
The Standard Model Higgs boson may be mixed
with another scalar that does not couple singly to gauge bosons or fermions.
The electroweak quantum numbers of such an additional scalar can be determined
by measuring the quartic Higgs-Higgs-vector-vector couplings, which
contribute—along with the coveted triple Higgs coupling—to double Higgs
production in e+e− collisions. We show that simultaneous sensitivity
to the quartic Higgs-Higgs-vector-vector coupling and the triple Higgs coupling
The Standard Model Higgs boson may be mixed
with another scalar that does not couple singly to gauge bosons or fermions.
The electroweak quantum numbers of such an additional scalar can be determined
by measuring the quartic Higgs-Higgs-vector-vector couplings, which
contribute—along with the coveted triple Higgs coupling—to double Higgs
production in e+e− collisions. We show that simultaneous sensitivity
to the quartic Higgs-Higgs-vector-vector coupling and the triple Higgs coupling
We have made a new
measurement of the electron’s electric dipole moment (EDM) using a beam of YbF
molecules. By measuring atto-eV energy shifts in a molecule, this
experiment probes new physics at the tera-eV energy scale. According to the
standard model, this EDM is d_e=10^(-38) e.cm
– some eleven orders of magnitude below the current experimental limit.
However, most extensions to the standard model predict much larger values,
It is known that the correlator
of one axial and two vector currents, that receives leading contributions
through one-loop fermion triangle diagrams, is not modified by QCD radiative
corrections at two loops. It was suggested that this non-renormalization of the
VVA correlator persists in higher orders in perturbative QCD as well. To check
this assertion, I compute the three-loop QCD corrections to the
VAA-correlator using the technique of asymptotic expansions. I find that
Last year strong evidence was
claimed for a 130 GeV gamma ray line from the galactic center in the FERMI
telescope data. In the first half of the talk I will review the status of
the evidence, including recent suggestions which call it into question.
In the second half of the talk, under the bold assumption that the line
is a genuine signature of dark matter, I will review some of the properties
required of dark matter to explain the line and the general features of models
The
interpretation of events with jets is often ambiguous, especially for the sort
of highly complex events one encounters at the LHC. One often finds that
an event interpreted as signal-like using one choice of jet algorithm and
radius parameter is no longer signal-like with another, even if the two are
very similar. Here we present an extension of the Qjets procedure
designed to account for this ambiguity and assign each plausible interpretation
of an event a weight, so that events which are unambiguously signal-like carry
There is overwhelming evidence that non-baryonic dark
matter constitutes ~23% of the energy density of the universe. Weakly Interacting Massive Particles (WIMPs)
are promising dark matter candidates that may produce gamma rays via
annihilation or decay detectable by the Fermi Large Area Telescope (Fermi
LAT). A detection of WIMPs would also
indicate the existence of physics beyond the Standard Model. I will present recent results from indirect
WIMP searches by the Fermi LAT Collaboration.