Cosmological Origin of the Grand-Unification Mass Scale

1979 ◽  
Vol 43 (6) ◽  
pp. 417-420 ◽  
Author(s):  
R. Brout ◽  
F. Englert ◽  
P. Spindel
Keyword(s):  
Mass Scale ◽  
Grand Unification

scholarly journals TRAILING EDGE UNIFICATION VIA AN INTERMEDIATE PATI–SALAM GROUP

2006 ◽  
Vol 15 (06) ◽  
pp. 1175-1182
Author(s):  
V. ELIAS ◽  
T. G. STEELE
Keyword(s):  
Mass Scale ◽  
Grand Unification ◽  
Loop Order ◽  
Intermediate Mass ◽  
Trailing Edge ◽  
Gut Scale

We demonstrate to two-loop order that an intermediate symmetrically embedded Pati–Salam SU(2)L×SU(2)R×SU(4) level of symmetry is all that is necessary to accommodate empirical values of α(Mz), αs(Mz) and sin 2θw(Mz) within a grand unification context but with a high (1014 GeV) intermediate mass scale and with a concomitant higher GUT scale.

scholarly journals Opening the 1 Hz axion window

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
David J. E. Marsh ◽  
Wen Yin
Keyword(s):  
Decay Constant ◽  
Mass Scale ◽  
Grand Unification ◽  
A Value ◽  
Relic Density ◽  
Open Window ◽  
Gut Scale ◽  
Near Future ◽  
M Theory ◽  
The Universe

Abstract An axion-like particle (ALP) with mass mϕ ∼ 10−15 eV oscillates with frequency ∼1 Hz. This mass scale lies in an open window of astrophysical constraints, and appears naturally as a consequence of grand unification (GUT) in string/M-theory. However, with a GUT-scale decay constant such an ALP overcloses the Universe, and cannot solve the strong CP problem. In this paper, we present a two axion model in which the 1 Hz ALP constitutes the entirety of the dark matter (DM) while the QCD axion solves the strong CP problem but contributes negligibly to the DM relic density. The mechanism to achieve the correct relic densities relies on low-scale inflation (mϕ ≲ Hinf ≲ 1 MeV), and we present explicit realisations of such a model. The scale in the axion potential leading to the 1 Hz axion generates a value for the strong CP phase which oscillates around $$ {\overline{\theta}}_{\mathrm{QCD}}\sim {10}^{-12} $$ θ ¯ QCD ∼ 10 − 12 , within reach of the proton storage ring electric dipole moment experiment. The 1 Hz axion is also in reach of near future laboratory and astrophysical searches.

Cosmological Origin of Grand-Unification Mass Scale.

1979 ◽  
Vol 43 (12) ◽  
pp. 890-890 ◽  
Author(s):  
R. Brout ◽  
F. Englert ◽  
P. Spindel
Keyword(s):  
Mass Scale ◽  
Grand Unification

scholarly journals FERMION MASSES, NEUTRINO MIXING AND CP VIOLATION FROM THE ANTI-GRAND-UNIFICATION MODEL

1998 ◽  
Vol 13 (29) ◽  
pp. 5037-5074 ◽  
Author(s):  
C. D. FROGGATT ◽  
M. GIBSON ◽  
H. B. NIELSEN ◽  
D. J. SMITH
Keyword(s):  
Cp Violation ◽  
Mass Scale ◽  
Grand Unification ◽  
Neutrino Mixing ◽  
Mixing Angles ◽  
Quantum Numbers ◽  
Fermion Masses ◽  
The Standard Model ◽  
Higgs Fields ◽  
Fundamental Mass

The fermion masses and mixing angles are fitted using only three free parameters in a nonsupersymmetric extension of the Standard Model, with new, approximately conserved chiral gauge quantum numbers broken by a set of Higgs fields. The fundamental mass scale of this anti-grand-unification model is given by the Planck mass. We also calculate neutrino mixing angles and masses, as well as CP violation from the CKM matrix. A good fit to the observed fermion masses is obtained, but our predictions of the neutrino masses are too small to lead to any observable neutrino oscillation effects claimed today, without introducing another mass scale. We also give some arguments in support of this type of model based on the observed fermion masses.

Mass scale of grand unification in N = 8 extended supergravity

1981 ◽  
Vol 105 (1) ◽  
pp. 30-32 ◽  
Author(s):  
M. Glück ◽  
E. Reya
Keyword(s):  
Mass Scale ◽  
Grand Unification

TWO-LOOP RENORMALIZATION GROUP CORRECTIONS IN SO(10) AXION MODELS AND PROTON LIFETIME

1989 ◽  
Vol 04 (03) ◽  
pp. 607-615 ◽  
Author(s):  
XING-MIN WANG
Keyword(s):  
Renormalization Group ◽  
Experimental Error ◽  
Mass Scale ◽  
Grand Unification ◽  
Error Range ◽  
Renormalization Group Equations ◽  
Proton Lifetime

A simplified way to calculate the two-loop corrections to the renormalization group equations is investigated and applied to two SO(10) axion models. It is found that the grand unification mass scale Mx is reduced by a factor ~ 1.5 – 3. And in both models, there exist solutions with Mx ~ 1015 Gev , corresponding to a proton lifetime [Formula: see text] when sin 2 θw, αs and αe are chosen within the experimental error range.

RUNNING COUPLING CONSTANTS AND GRAND UNIFICATION MODELS

1991 ◽  
Vol 06 (19) ◽  
pp. 1745-1755 ◽  
Author(s):  
C. GIUNTI ◽  
C. W. KIM ◽  
U. W. LEE
Keyword(s):  
Standard Deviation ◽  
Gauge Coupling ◽  
Intermediate Energy ◽  
Proton Decay ◽  
Mass Scale ◽  
Energy Scale ◽  
Coupling Constants ◽  
Grand Unification ◽  
Running Coupling ◽  
Supersymmetric Version

The evolution of the gauge coupling constants in the SU (N) and SO (N) grand unification models is examined. It is shown that the three coupling constants αs, α2, α1 in the minimal SU(5) model do not merge into one at 99% confidence level when they are extrapolated from the values at the mass scale MZ, whereas in its supersymmetric version, the coupling constants do merge into one within one standard deviation. In the SU (N) (with N > 5) models with a two-step symmetry breaking the coupling constants can merge into one, but these models are ruled out by the constraint imposed on the unification mass scale from the absence of proton decay. The SO (N) models with N ≥ 10 are shown to be consistent with the proton decay constraint. In particular, the unification scale for the SO(10) model is shown to be 1015~1016 GeV and the intermediate energy scale is 1013~1014 GeV .

SO(10) FOR GRAND UNIFICATION?

1992 ◽  
Vol 07 (08) ◽  
pp. 641-651 ◽  
Author(s):  
S.F. TUAN
Keyword(s):  
Neutrino Mass ◽  
Solar Neutrino ◽  
Mass Scale ◽  
Grand Unification ◽  
Problem Model ◽  
Solar Neutrino Problem ◽  
The Status ◽  
Standard Picture ◽  
Invisible Axion ◽  
Physical Phenomena

In this brief review, we present the arguments both theoretical and experimental in favor of the simple group SO(10) as the first approximation towards grand unification. The physical phenomena of the solar neutrino problem which motivate existence of neutrino mass, the recent LEP data which rule out the simple SU(5) (and perhaps supersymmetric SU(5) if tied also to the solar neutrino problem) model for which vanishing neutrino masses would be logical, coupled with attractive features like accommodating the invisible axion and a τ neutrino mass acceptable to cosmology, converge towards a two-step SO(10) model with intermediate mass scale of order 1011 GeV . We comment on the status of a second Z′ in a model of the spontaneous breakdown of SO(10) which is particularly conservative in that very little of the standard picture is altered.

RHYNCHOLITES AND THE PROBLEM OF NARROW AND BROAD CONCEPTION OF TAXONS

2018 ◽  
pp. 12-17 ◽  
Author(s):  
I. R. Khuzina ◽  
V. N. Komarov
Keyword(s):  
Sexual Dimorphism ◽  
Morphological Characteristics ◽  
Mass Scale ◽  
Individual Variability ◽  
Point Of View ◽  
The Other ◽  
New Taxon ◽  
Artificial System ◽  
Broad Understanding

The paper considers a point of view, based on the conception of the broad understanding of taxons. According to this point of view, rhyncholites of the subgenus Dentatobeccus and Microbeccus are accepted to be synonymous with the genus Rhynchoteuthis, and subgenus Romanovichella is considered to be synonymous with the genus Palaeoteuthis. The criteria, exercising influence on the different approaches to the classification of rhyncholites, have been analyzed (such as age and individual variability, sexual dimorphism, pathological and teratological features, degree of disintegration of material), underestimation of which can lead to inaccuracy. Divestment of the subgenuses Dentatobeccus, Microbeccus and Romanovichella, possessing very bright morphological characteristics, to have an independent status and denomination to their synonyms, has been noted to be unjustified. An artificial system (any suggested variant) with all its minuses is a single probable system for rhyncholites. The main criteria, minimizing its negative sides and proving the separation of the new taxon, is an available mass-scale material. The narrow understanding of the genus, used in sensible limits, has been underlined to simplify the problem of the passing the view about the genus to the other investigators and recognition of rhyncholites for the practical tasks.

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