4 research outputs found
Heavy Neutral Gauge Bosons at the LHC in an Extended MSSM
Searching for heavy neutral gauge bosons Z', predicted in extensions of the
Standard Model based on a U(1)' gauge symmetry, is one of the challenging
objectives of the experiments carried out at the Large Hadron Collider. In this
paper, we study Z' phenomenology at hadron colliders according to several
U(1)'-based models and in the Sequential Standard Model. In particular,
possible Z' decays into supersymmetric particles are included, in addition to
the Standard Model modes so far investigated. We point out the impact of the
U(1)' group on the MSSM spectrum and, for a better understanding, we consider a
few benchmarks points in the parameter space. We account for the D-term
contribution, due to the breaking of U(1)', to slepton and squark masses and
investigate its effect on Z' decays into sfermions. Results on branching ratios
and cross sections are presented, as a function of the MSSM and U(1)'
parameters, which are varied within suitable ranges. We pay special attention
to final states with leptons and missing energy and make predictions on the
number of events with sparticle production in Z' decays, for a few values of
integrated luminosity and centre-of-mass energy of the LHC.Comment: 53 pages, 23 figures, 25 tables. One Feynman diagram fixed, results
and conclusions unchange
On logarithmic extensions of local scale-invariance
Ageing phenomena far from equilibrium naturally present dynamical scaling and
in many situations this may generalised to local scale-invariance. Generically,
the absence of time-translation-invariance implies that each scaling operator
is characterised by two independent scaling dimensions. Building on analogies
with logarithmic conformal invariance and logarithmic Schr\"odinger-invariance,
this work proposes a logarithmic extension of local scale-invariance, without
time-translation-invariance. Carrying this out requires in general to replace
both scaling dimensions of each scaling operator by Jordan cells. Co-variant
two-point functions are derived for the most simple case of a two-dimensional
logarithmic extension. Their form is compared to simulational data for
autoresponse functions in several universality classes of non-equilibrium
ageing phenomena.Comment: 23 pages, Latex2e, 2 eps figures included, final form (now also
includes discussion of KPZ equation