Abstract:

Cosmologically long-lived, composite states arise as natural dark matter candidates in theories with a strongly interacting hidden sector at a scale of 10 - 100 TeV. Light axion-like states, with masses in the 1 MeV - 10 GeV range, are also generic, and can decay via Higgs couplings to light standard model particles. Such a scenario is well motivated in the context of very low energy supersymmetry breaking, where ubiquitous cosmological problems associated with the gravitino are avoided. We investigate the astrophysical and collider signatures of this scenario, assuming that dark matter decays into the axion-like states via dimension six operators, and we present an illustrative model exhibiting these features.

A particle that is its own antiparticle reminds of a man
who can't be distinguished from his own shadow. The neutrino, perhaps
the tiniest bit of reality we can dream of, is still, more than 80 years
after its conception to the world of ideas, as mysterious as the
Majorana himself.

Did Majorana die in the sea? Some scientists --some poets--
prefer to think that he didn't and he lives still, retired from the
World, in some remote and forgotten haven. Perhaps we will never know,
but instead we may find whether the neutrino is its own antiparticle, by
detecting neutrinoless double beta decay events. Those processes, whose
lifetime is many orders of magnitude longer than that of the universe
may hold the key to the question of the nature of the neutrino, and by
extension help us to understand the cosmic asymmetry between matter and
antimatter. The NEXT experiment, largely an Iberian collaboration will
be one of the key knights to bring light into this fundamental question,
perhaps the one to answer if Ettore Majorana will, at the long last,
meet his shadow.

Abstract:

The 5D gauge-Higgs unification models in warped RS framework is
a very attractive idea. It is dual to the 4D pseudo-Goldstone boson model,
known as Georgi-Kaplan model. We study the LHC signal of this type of
model. We point out the robust way to test it is to look for heavy gauge
bosons which carry Higgs quantum number. We discuss the signal and
background and the LHC reach of finding these exotic gauge bosons.

Abstract:

The exchange of electroweak gauginos in the t- or u-channel allows squark pair production at hadron colliders without color exchange between the squarks. This can give rise to events where little or no energy is deposited in the detector between the squark decay products. I will talk about the potential for detection of such rapidity gap events at the Large Hadron Collider (LHC). The numerical analysis is divided into two parts. First, the rapidity gap signal is evaluated in a simplified framework at the parton level. The second part covers an analysis with full event simulation using PYTHIA as well as Herwig++, but without detector simulation. The transverse energy deposited between the jets from squark decay is analyzed, as well as the probability of finding a third jet in between the two hardest jets. For the mSUGRA benchmark point SPS1a we find statistically significant evidence for a color singlet exchange contribution.

Abstract:

The 5D gauge-Higgs unification models in warped RS framework is
a very attractive idea. It is dual to the 4D pseudo-Goldstone boson model,
known as Georgi-Kaplan model. We study the LHC signal of this type of
model. We point out the robust way to test it is to look for heavy gauge
bosons which carry Higgs quantum number. We discuss the signal and
background and the LHC reach of finding these exotic gauge bosons.