25,267 research outputs found

### Higgs Boson in RG running Inflationary Cosmology

An intriguing hypothesis is that gravity may be non-perturbatively
renormalizable via the notion of asymptotic safety. We show that the Higgs
sector of the SM minimally coupled to asymptotically safe gravity can generate
the observed near scale-invariant spectrum of the Cosmic Microwave Background
through the curvaton mechanism. The resulting primordial power spectrum places
an upper bound on the Higgs mass, which for finely tuned values of the curvaton
parameters, is compatible with the recently released Large Hadron Collider
data.Comment: 7 pages, no figur

### Interpretation of Quantum Field Theories with a Minimal Length Scale

It has been proposed that the incorporation of an observer independent
minimal length scale into the quantum field theories of the standard model
effectively describes phenomenological aspects of quantum gravity. The aim of
this paper is to interpret this description and its implications for scattering
processes.Comment: replaced with published versio

### Six-dimensional Methods for Four-dimensional Conformal Field Theories

The calculation of both spinor and tensor Green's functions in
four-dimensional conformally invariant field theories can be greatly simplified
by six-dimensional methods. For this purpose, four-dimensional fields are
constructed as projections of fields on the hypercone in six-dimensional
projective space, satisfying certain transversality conditions. In this way
some Green's functions in conformal field theories are shown to have structures
more general than those commonly found by use of the inversion operator. These
methods fit in well with the assumption of AdS/CFT duality. In particular, it
is transparent that if fields on AdS$_5$ approach finite limits on the boundary
of AdS$_5$, then in the conformal field theory on this boundary these limits
transform with conformal dimensionality zero if they are tensors (of any rank),
but with conformal dimension 1/2 if they are spinors or spinor-tensors.Comment: Version accepted for publication in Physical Review D. References to
earlier work added in footnote 2. Minor errors corrected. 24 page

### Unified theory for external and internal attributes and symmetries of fundamental fermions

An unorthodox unified theory is developed to describe external and internal
attributes and symmetries of fundamental fermions, quarks and leptons. Basic
ingredients of the theory are an algebra which consists of all the
triple-direct-products of Dirac gamma-matrices and a triple-spinor-field,
called a triplet field, defined on the algebra. The algebra possesses three
commutative sub-algebras which describe, respectively, the external space-time
symmetry, the family structure and the internal color symmetry of quarks and
leptons. The triplet field includes threefold (fourfold) repetitionary modes of
spin 1/2 component fields with SU(3) (SU(4)) color symmetry. It is possible to
qualify the Yukawa interaction and to make a new interpretation of its coupling
constants naturally in an intrinsic mechanism of the triplet field formalism.
The Dirac mass matrices with quasi-democratic structure are derived as an
illustration

### The resultant parameters of effective theory

This is the 4-th paper in the series devoted to a systematic study of the
problem of mathematically correct formulation of the rules needed to manage an
effective field theory. Here we consider the problem of constructing the full
set of essential parameters in the case of the most general effective
scattering theory containing no massless particles with spin J > 1/2. We
perform the detailed classification of combinations of the Hamiltonian coupling
constants and select those which appear in the expressions for renormalized
S-matrix elements at a given loop order.Comment: 21 pages, 4 LaTeX figures, submitted to Phys. Rev.

### Spontaneous violation of CP symmetry in the strong interactions

Some time ago Dashen pointed out that spontaneous CP violation can occur in
the strong interactions. I show how a simple effective Lagrangian exposes the
remarkably large domain of quark mass parameters for which this occurs. I close
with some warnings for lattice simulations.Comment: 10 pages, 1 figure; final version to appear in PR

### II. The Standard Model in the Isotopic Foldy-Wouthuysen Representation without Higgs Bosons in the Fermion Sector. Spontaneous Breaking of Parity and "Dark Matter" Problems

The Standard Model with massive fermions is formulated in the isotopic
Foldy-Wouthuysen representation. SU(2)xU(1) - invariance of the theory in this
representation is independent of whether fermions possess mass or not, and,
consequently, it is not necessary to introduce interactions between Higgs
bosons and fermions. The study discusses a possible relation between
spontaneous breaking of parity in the isotopic Foldy-Wouthuysen representation
and the composition of elementary particles of "dark matter".Comment: 12 page

### Scattering in D=5 super Yang-Mills theory and the relation to (2,0) theory

Compactifying the A_1 version of (2,0) theory on a circle gives rise to
five-dimensional, maximally supersymmetric Yang-Mills theory. In the Coulomb
branch, where the SU(2) gauge group is spontaneously broken to a U(1) subgroup,
the degrees of freedom are constituted by one massless and two massive vector
multiplets. Because of the relation to the six-dimensional (2,0) theory, we are
then interested in scattering processes where both the in-state and the
out-state consist of one massless and one massive particle. We show that the
corresponding part of the S matrix is determined by the symmetries of the
theory up to a single unknown function, which depends on the energy and mass of
the incoming particles, together with the scattering angle. Performing a
straight forward scattering calculation by means of Feynman diagrams, this
function is determined to leading order in a low-energy approximation. The
result is strikingly simple, and it coincides exactly with the corresponding
function in the (2,0) theory.Comment: 17 pages, 1 figur

### Galilean currents and charges

We derive the Noether currents and charges associated with an internal
galilean invariance---a symmetry recently postulated in the context of
so-called galileon theories. Along the way we clarify the physical
interpretation of the Noether charges associated with ordinary Galileo- and
Lorentz-boosts.Comment: 5 page

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