scholarly journals Control of quantum dynamics of electron transfer in molecular loop structures: Spontaneous breaking of chiral symmetry under strong decoherence

2019 ◽  
Vol 99 (6) ◽  
Author(s):  
Nguyen Thanh Phuc ◽  
Akihito Ishizaki
Keyword(s):  
Electron Transfer ◽  
Chiral Symmetry ◽  
Quantum Dynamics ◽  
Spontaneous Breaking

DIMENSIONAL DEPENDENCE OF CHIRAL-SYMMETRY- BREAKING PHASE TRANSITION IN QUENCHED PLANAR QED

1989 ◽  
Vol 04 (22) ◽  
pp. 2155-2166 ◽  
Author(s):  
KEI-ICHI KONDO ◽  
HAJIME NAKATANI
Keyword(s):  
Phase Transition ◽  
Chiral Symmetry ◽  
Chiral Symmetry Breaking ◽  
Scaling Law ◽  
Mean Field ◽  
Dyson Equation ◽  
Essential Singularity ◽  
Spontaneous Breaking ◽  
Planar Approximation ◽  
Singularity Type

We consider the critical behavior of the phase transition associated with the spontaneous breaking of chiral-symmetry in (QED) D, in the framework of the Schwinger-Dyson equation. Special attention is paid on the scaling law. While it is well known that quenched planar QED 4 obeys the Miransky scaling of the essential singularity type, our numerical calculations show that QED 5 and QED 6 do obey the mean-field type scaling, even in the quenched planar approximation. Thus the essential singularity type scaling in the cutoff QED is considered to be possible only when D=4 under the quenched planar approximation.

scholarly journals A road towards a beyond the Standard Model model

2022 ◽  
Vol 258 ◽  
pp. 06003
Author(s):  
Giancarlo Rossi
Keyword(s):  
Standard Model ◽  
Chiral Symmetry ◽  
Top Quark ◽  
Gauge Coupling ◽  
Spontaneous Breaking ◽  
Strong Interactions ◽  
Fermion Mass ◽  
Mass Hierarchy ◽  
Strongly Interacting ◽  
Fermion Masses

In this talk we describe examples of renormalizable strongly interacting field theories where chiral symmetry, broken at the UV cutoff by the presence of some irrelevant d > 4 operators in the fundamental Lagrangian, is recovered at low energy owing to the tuning of certain Lagrangian parameters. The interference of UV effects with IR features coming from the spontaneous breaking of the recovered chiral symmetry yields non perturbatively generated elementary fermion masses parametrically expressed by formulae of the kind mq ~ Cq(α)ΛRGI with α the gauge coupling constant and ΛRGI the RGI scale of the theory. Upon introducing EW interactions, this mechanism can be extended to give mass to EW bosons and leptons and can thus be used as an alternative to the Higgs scenario. In order to give the top quark and the weak gauge bosons a mass of the phenomenologically correct order of magnitude, the model must necessarily include (yet unobserved) super-strongly interacting massive fermions endowed, besides ordinary Standard Model interactions, with super-strong interactions with a RGI scale, ΛT ΛQCD in the few TeV range. Though limited in its scope (here we ignore hypercharge and leptons and discuss only the case of one family neglecting weak isospin splitting), the model opens the way to a solution of the naturalness problem and an understanding of the fermion mass hierarchy.

Chiral Symmetry

2019 ◽  
pp. 217-230
Author(s):  
Michael E. Peskin
Keyword(s):  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Chiral Symmetry ◽  
Goldstone Boson ◽  
Spontaneous Breaking ◽  
Quark Masses ◽  
Zero Mass ◽  
K Mesons ◽  
The Masses

This chapter introduces chiral symmetry, the extra symmetry that QCD acquires when the masses of quarks are set to zero. It introduces the concept of spontaneous symmetry breaking and explains the spontaneous breaking of chiral symmetry in QCD. It introduces the concept of a Goldstone boson, a particle that has zero mass as the result of spontaneous symmetry breaking, and explains how this concept explains properties of the pi and K mesons and allows us to determine the underlying values of the quark masses.

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