TOP OFF THE UNPARTICLE

2008 ◽  
Vol 23 (16n17) ◽  
pp. 2579-2590 ◽  
Author(s):  
DEBAJYOTI CHOUDHURY ◽  
DILIP KUMAR GHOSH
Keyword(s):  
Fixed Point ◽  
Standard Model ◽  
Top Physics ◽  
Energy Scale ◽  
Scale Invariant ◽  
The Standard Model

The existence of an exactly scale invariant sector possessing a nontrivial infrared fixed point at a higher energy scale and its possible communication with the Standard Model particles through a heavy messenger sector has been shown to lead to curious unparticle effects. We demonstrate that top physics at the Tevatron can already constrain such theories. We also consider possible improvements at the LHC and delineate some striking signatures.

scholarly journals Renormalization group equations of Higgs-R2 inflation

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Yohei Ema ◽  
Kyohei Mukaida ◽  
Jorinde van de Vis
Keyword(s):  
Renormalization Group ◽  
Standard Model ◽  
Planck Scale ◽  
Energy Scale ◽  
Einstein Frame ◽  
Ricci Scalar ◽  
Minimal Coupling ◽  
Renormalization Group Equations ◽  
The Standard Model

Abstract We derive one- and two-loop renormalization group equations (RGEs) of Higgs-R2 inflation. This model has a non-minimal coupling between the Higgs and the Ricci scalar and a Ricci scalar squared term on top of the standard model. The RGEs derived in this paper are valid as long as the energy scale of interest (in the Einstein frame) is below the Planck scale. We also discuss implications to the inflationary predictions and the electroweak vacuum metastability.

scholarly journals Sub-GeV-scale signatures of hidden braneworlds up to the Planck scale in a SO(3,1)-broken bulk

2019 ◽  
Vol 34 (05) ◽  
pp. 1950029 ◽  
Author(s):  
Coraline Stasser ◽  
Michaël Sarrazin
Keyword(s):  
Standard Model ◽  
Phenomenological Model ◽  
Quantum Dynamics ◽  
Scale Up ◽  
Planck Scale ◽  
Energy Scale ◽  
Beyond The Standard Model ◽  
Coupling Constant ◽  
The Standard Model ◽  
Gut Scale

Many-brane Universes are at the heart of several cosmological scenarios related to physics beyond the Standard Model. It is then a major concern to constrain these approaches. Two-brane Universes involving [Formula: see text]-broken 5D bulks are among the cosmological models of interest. They also allow considering matter exchange between branes, a possible way to test these scenarios. Neutron disappearance (reappearance) toward (from) the hidden brane is currently tested with high-precision experiments to constrain the coupling constant [Formula: see text] between the visible and hidden neutron sectors. When dealing with the sub-GeV-scale quantum dynamics of fermions, any pair of braneworlds can be described by a noncommutative two-sheeted space–time [Formula: see text] from which [Formula: see text] emerges. Nevertheless, the calculation of the formal link between [Formula: see text] for a neutron and [Formula: see text]-broken 5D bulks remains an open problem until now although necessary to constrain these braneworld scenarios. Thanks to a phenomenological model, we derive [Formula: see text] — for a neutron — between the two braneworlds endowed with their own copy of the Standard Model in an [Formula: see text]-broken 5D bulk. Constraints on interbrane distance and brane energy scale (or brane thickness) are discussed. While brane energy scale below the GUT scale is excluded, energy scale up to the Planck limit allows neutron swapping detection in forthcoming experiments.

scholarly journals GUT PRECURSORS IN SU(3)3-TYPE MODEL AND Ncolour>3

2004 ◽  
Vol 19 (21) ◽  
pp. 1615-1621
Author(s):  
N. D. TRACAS
Keyword(s):  
Standard Model ◽  
Energy Scale ◽  
Type Model ◽  
State Contribution ◽  
The Standard Model ◽  
Wide Energy ◽  
Colour Group ◽  
Gauge Couplings ◽  
Kaluza Klein

We investigate the SU (3)3 GUT model when signs of the model (precursors), due to low compactification scale, appear before the gauge couplings of the Standard Model get unified. The Kaluza–Klein state contribution seems to lead the gauge couplings to unification through a wide energy scale only in the case when the colour group is augmented to SU(4).

scholarly journals STANDARD MODEL WITH COSMOLOGICALLY BROKEN QUANTUM SCALE INVARIANCE

2010 ◽  
Vol 25 (03) ◽  
pp. 167-177 ◽  
Author(s):  
PANKAJ JAIN ◽  
SUBHADIP MITRA
Keyword(s):  
Perturbation Theory ◽  
Standard Model ◽  
Particle Physics ◽  
Scale Invariance ◽  
Hierarchy Problem ◽  
Scale Invariant ◽  
Scalar Particles ◽  
Cosmological Observations ◽  
The Standard Model ◽  
Physical Spectrum

We consider a locally scale invariant extension of the Standard Model of particle physics and argue that it fits both the particle and cosmological observations. The model is scale invariant both classically and quantum mechanically. The scale invariance is broken (or hidden) by a mechanism which we refer to as cosmological symmetry breaking. This produces all the dimensionful parameters in the theory. The cosmological constant or dark energy is a prediction of the theory and can be calculated systematically order by order in perturbation theory. It is expected to be finite at all orders. The model does not suffer from the hierarchy problem due to the absence of scalar particles, including the Higgs, from the physical spectrum.

scholarly journals Investigating BSM Models with Large Scale Separation

2018 ◽  
Vol 175 ◽  
pp. 08007 ◽  
Author(s):  
Anna Hasenfratz ◽  
Claudio Rebbi ◽  
Oliver Witzel
Keyword(s):  
Fixed Point ◽  
Standard Model ◽  
Large Scale ◽  
Gauge Coupling ◽  
Model Systems ◽  
Beyond The Standard Model ◽  
Heavy Flavor ◽  
Scale Separation ◽  
The Standard Model ◽  
Effective Description

Mass-split systems based on a conformal infrared fixed point provide a lowenergy effective description of beyond the standard model systems with large scale separation. We report results of exploratory investigations with four light and eight heavy flavors using staggered fermions, and up to five different values for the light flavor mass, five different heavy flavor masses, and two values of the bare gauge coupling.

scholarly journals Exact one-loop running couplings in the standard model

2008 ◽  
Vol 86 (9) ◽  
pp. 1067-1070 ◽  
Author(s):  
F A Chishtie ◽  
M D Lepage ◽  
D GC McKeon ◽  
T G Steele ◽  
I Zakout
Keyword(s):  
Standard Model ◽  
Yukawa Coupling ◽  
Top Quark ◽  
Higgs Mass ◽  
Gauge Coupling ◽  
New Physics ◽  
Energy Scale ◽  
Scalar Coupling ◽  
Upper And Lower Bounds ◽  
The Standard Model

Taking the dominant couplings in the standard model to be the quartic scalar coupling, the Yukawa coupling of the top quark, and the SU(3) gauge coupling, we consider their associated running couplings to one-loop order. Despite the nonlinear nature of the differential equations governing these functions, we show that they can be solved exactly. The nature of these solutions is discussed and their singularity structure is examined. It is shown that for a sufficiently small Higgs mass, the quartic scalar coupling decreases with increasing energy scale and becomes negative, indicative of vacuum instability. This behavior changes for a Higgs mass greater than 168 GeV, beyond which this couplant increases with increasing energy scales and becomes singular prior to the ultraviolet pole of the Yukawa coupling. Upper and lower bounds on the Higgs mass corresponding to new physics at the TeV scale are obtained and compare favourably with the numerical results of the one-loop and two-loop analyses with inclusion of electroweak couplings.PACS Nos.: 11.10.Hi, 14.80.Bn

Sign in / Sign up

Export Citation Format

Share Document