43 research outputs found
Clifford-based spectral action and renormalization group analysis of the gauge couplings
The Spectral Action Principle in noncommutative geometry derives the actions
of the Standard Model and General Relativity (along with several other
gravitational terms) by reconciling them in a geometric setting, and hence
offers an explanation for their common origin. However, one of the requirements
in the minimal formalism, unification of the gauge coupling constants, is not
satisfied, since the basic construction does not introduce anything new that
can change the renormalization group (RG) running of the Standard Model. On the
other hand, it has been recently argued that incorporating structure of the
Clifford algebra into the finite part of the spectral triple, the main object
that encodes the complete information of a noncommutative space, gives rise to
five additional scalar fields in the basic framework. We investigate whether
these scalars can help to achieve unification. We perform a RG analysis at the
one-loop level, allowing possible mass values of these scalars to float from
the electroweak scale to the putative unification scale. We show that out of
twenty configurations of mass hierarchy in total, there does not exist even a
single case that can lead to unification. In consequence, we confirm that the
spectral action formalism requires a model-construction scheme beyond the
(modified) minimal framework.Comment: 20 pages, 1 figure, 1 table of results; matches the published versio
Dynamical Four-Form Fields
We present an example of a gauge-invariant Lagrangian that contains four
derivatives and describes one massive, non-ghostlike, degree of freedom.Comment: 5 page
Gauge non-invariance as tests of emergent gauge symmetry
We motivate the concept of emergent gauge symmetry and discuss ways that this
concept can be tested. The key idea is that if a symmetry is emergent, one
should look for small violations of this symmetry because the underlying
fundamental theory does not contain the symmetry. We describe our recent work
implementing this idea in the gravity sector. We also describe the reasons why
violations of gauge symmetry may well be linked to violations of Lorentz
invariance.Comment: 5 pages, Invited talk presented at the Fifth Meeting on CPT and
Lorentz Symmetry, Bloomington, Indiana, June 28-July 2, 201
-decay anomalies and scalar leptoquarks in unified Pati-Salam models from noncommutative geometry
Motivated by possible scalar-leptoquark explanations of the recently reported
-decay anomalies, we investigate whether the required leptoquarks can be
accommodated within models based on noncommutative geometry (NCG). The models
considered have the gauge structure of Pati-Salam models, , with gauge coupling unification at a single scale. In
one of the models, we find a unique scalar leptoquark with quantum numbers
, originating from a complex multiplet
, which can potentially explain the -decay anomalies if its
mass is on the order of a few TeV. The unification of couplings can be realized
with the inclusion of a single step of intermediate symmetry breaking. The
scalar leptoquark under consideration does not contribute to proton decay due
to the absence of diquark couplings, as dictated by the underlying
noncommutative geometry.Comment: 40 pages, 5 figures; references added, typos corrected, minor
clarifications made. Published version in JHE