Constraint of broken charge-conjugation invariance on the baryon asymmetry in grand unified theories

1982 ◽  
Vol 25 (5) ◽  
pp. 1400-1416 ◽  
Author(s):  
H. E. Haber ◽  
G. Segrè ◽  
S. K. Soni
2019 ◽  
Vol 79 (11) ◽  
Author(s):  
K. Sravan Kumar ◽  
Paulo Vargas Moniz

AbstractIn this paper, we generalize Coleman–Weinberg (CW) inflation in grand unified theories (GUTs) such as $$\text {SU}(5)$$SU(5) and $$\text {SO}(10)$$SO(10) by means of considering two complex singlet fields with conformal invariance. In this framework, inflation emerges from a spontaneously broken conformal symmetry. The GUT symmetry implies a potential with a CW form, as a consequence of radiative corrections. The conformal symmetry flattens the above VEV branch of the CW potential to a Starobinsky plateau. As a result, we obtain $$n_{s}\sim 1-\frac{2}{N}$$ns∼1-2N and $$r\sim \frac{12}{N^2}$$r∼12N2 for $$N\sim $$N∼ 50–60 e-foldings. Furthermore, this framework allow us to estimate the proton lifetime as $$\tau _{p}\lesssim 10^{40}$$τp≲1040 years, whose decay is mediated by the superheavy gauge bosons. Moreover, we implement a type I seesaw mechanism by weakly coupling the complex singlet, which carries two units of lepton number, to the three generations of singlet right handed neutrinos (RHNs). The spontaneous symmetry breaking of global lepton number amounts to the generation of neutrino masses. We also consider non-thermal leptogenesis in which the inflaton dominantly decays into heavy RHNs that sources the observed baryon asymmetry. We constrain the couplings of the inflaton field to the RHNs, which gives the reheating temperature as $$10^{6}\text { GeV}\lesssim T_{R}<10^{9}$$106GeV≲TR<109 GeV.


1983 ◽  
Vol 104 ◽  
pp. 437-445
Author(s):  
F. W. Stecker

To the gods alone belongs it never to be old or die. But all things else melt with all-powerful time….SophoclesWith the advent of grand unified theories (GUTs) has come the concept (among others) that baryons (protons, etc.) can decay by changing into leptons (“Diamonds are not forever.”) and vice versa, baryonic matter can be created from the thermal blackbody radiation in the early universe (provided, of course, that the hot big-bang model is basically correct). Using this concept, models have been suggested to generate a universal baryon asymmetry, with the consequence that no important amount of antimatter would be left in the universe at the present time (see, e.g. Langacker 1981 and references therein). These models have been motivated by observational constraints on antimatter, at least in our little corner of the universe (Steigman 1976). However, some of these constraints have been shown to be overrestrlctive (Stecker 1978, Allen 1981) and an alternative model, also based on GUTs, has been suggested which maintains matter-antimatter (I.e., baryon) symmetry on a universal scale, but results in separate “fossil domains” of clusters of matter galaxies and clusters of antimatter galaxies.


1979 ◽  
Vol 87 (1-2) ◽  
pp. 114-116 ◽  
Author(s):  
A.Yu. Ignatiev ◽  
V.A. Kuzmin ◽  
M.E. Shaposhnikov

Author(s):  
Steven E. Vigdor

Chapter 4 deals with the stability of the proton, hence of hydrogen, and how to reconcile that stability with the baryon number nonconservation (or baryon conservation) needed to establish a matter–antimatter imbalance in the infant universe. Sakharov’s three conditions for establishing a matter–antimatter imbalance are presented. Grand unified theories and experimental searches for proton decay are described. The concept of spontaneous symmetry breaking is introduced in describing the electroweak phase transition in the infant universe. That transition is treated as the potential site for introducing the imbalance between quarks and antiquarks, via either baryogenesis or leptogenesis models. The up–down quark mass difference is presented as essential for providing the stability of hydrogen and of the deuteron, which serves as a crucial stepping stone in stellar hydrogen-burning reactions that generate the energy and elements needed for life. Constraints on quark masses from lattice QCD calculations and violations of chiral symmetry are discussed.


2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Luca Di Luzio

Abstract An accidental U(1) Peccei-Quinn (PQ) symmetry automatically arises in a class of SO(10) unified theories upon gauging the SU(3)f flavour group. The PQ symmetry is protected by the ℤ4 × ℤ3 center of SO(10) × SU(3)f up to effective operators of canonical dimension six. However, high-scale contributions to the axion potential posing a PQ quality problem arise only at d = 9. In the pre-inflationary PQ breaking scenario the axion mass window is predicted to be ma ∈ [7 × 10−8, 10−3] eV, where the lower end is bounded by the seesaw scale and the upper end by iso-curvature fluctuations. A high-quality axion, that is immune to the PQ quality problem, is obtained for ma ≳ 2 0.02 eV. We finally offer a general perspective on the PQ quality problem in grand unified theories.


1982 ◽  
Vol 26 (9) ◽  
pp. 2396-2419 ◽  
Author(s):  
R. W. Robinett ◽  
Jonathan L. Rosner

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