6,594 research outputs found
Minimal Z' models and the early LHC
We consider a class of minimal extensions of the Standard Model with an extra
massive neutral gauge boson Z'. They include both family-universal models,
where the extra U(1) is associated with (B-L), and non-universal models where
the Z' is coupled to a non-trivial linear combination of B and the lepton
flavours. After giving an estimate of the range of parameters compatible with a
Grand Unified Theory, we present the current experimental bounds, discussing
the interplay between electroweak precision tests and direct searches at the
Tevatron. Finally, we assess the discovery potential of the early LHC.Comment: 6 pages, 2 figures. Talk given at the 2nd Young Researchers Workshop
"Physics Challenges in the LHC Era", Frascati, May 10 and 13, 201
Classical and quantum mechanics via supermetrics in time
Koopman-von Neumann in the 30's gave an operatorial formululation of
Classical Mechanics. It was shown later on that this formulation could also be
written in a path-integral form. We will label this functional approach as CPI
(for classical path-integral) to distinguish it from the quantum mechanical
one, which we will indicate with QPI. In the CPI two Grassmannian partners of
time make their natural appearance and in this manner time becomes something
like a three dimensional supermanifold. Next we introduce a metric in this
supermanifold and show that a particular choice of the supermetric reproduces
the CPI while a different one gives the QPI.Comment: To appear in the proceedings of the conference held in Trieste in
October 2008 with title: "Theoretical and Experimental aspects of the spin
statistics connection and related symmetries
Cartan-Calculus and its Generalizations via a Path-Integral Approach to Classical Mechanics
In this paper we review the recently proposed path-integral counterpart of
the Koopman-von Neumann operatorial approach to classical Hamiltonian
mechanics. We identify in particular the geometrical variables entering this
formulation and show that they are essentially a basis of the cotangent bundle
to the tangent bundle to phase-space. In this space we introduce an extended
Poisson brackets structure which allows us to re-do all the usual Cartan
calculus on symplectic manifolds via these brackets. We also briefly sketch how
the Schouten-Nijenhuis, the Fr\"olicher- Nijenhuis and the Nijenhuis-Richardson
brackets look in our formalism.Comment: 6 pages, amste
- …