23 research outputs found
KK Parity in Warped Extra Dimension
We construct models with a Kaluza-Klein (KK) parity in a five- dimensional
warped geometry, in an attempt to address the little hierarchy problem present
in setups with bulk Standard Model fields. The lightest KK particle (LKP) is
stable and can play the role of dark matter. We consider the possibilities of
gluing two identical slices of 5D AdS in either the UV (IR-UV-IR model) or the
IR region (UV-IR-UV model) and discuss the model-building issues as well as
phenomenological properties in both cases. In particular, we find that the
UV-IR-UV model is not gravitationally stable and that additional mechanisms
might be required in the IR-UV-IR model in order to address flavor issues.
Collider signals of the warped KK parity are different from either the
conventional warped extra dimension without KK parity, in which the new
particles are not necessarily pair-produced, or the KK parity in flat universal
extra dimensions, where each KK level is nearly degenerate in mass. Dark matter
and collider properties of a TeV mass KK Z gauge boson as the LKP are
discussed.Comment: 35 pages, 11 figure
PYTHIA 6.4 Physics and Manual
The PYTHIA program can be used to generate high-energy-physics `events', i.e.
sets of outgoing particles produced in the interactions between two incoming
particles. The objective is to provide as accurate as possible a representation
of event properties in a wide range of reactions, within and beyond the
Standard Model, with emphasis on those where strong interactions play a role,
directly or indirectly, and therefore multihadronic final states are produced.
The physics is then not understood well enough to give an exact description;
instead the program has to be based on a combination of analytical results and
various QCD-based models. This physics input is summarized here, for areas such
as hard subprocesses, initial- and final-state parton showers, underlying
events and beam remnants, fragmentation and decays, and much more. Furthermore,
extensive information is provided on all program elements: subroutines and
functions, switches and parameters, and particle and process data. This should
allow the user to tailor the generation task to the topics of interest.Comment: 576 pages, no figures, uses JHEP3.cls. The code and further
information may be found on the PYTHIA web page:
http://www.thep.lu.se/~torbjorn/Pythia.html Changes in version 2: Mistakenly
deleted section heading for "Physics Processes" reinserted, affecting section
numbering. Minor updates to take into account referee comments and new colour
reconnection option