scholarly journals UPPER BOUND ON THE MASS SCALE OF SUPERPARTNERS IN MINIMAL N = 2 SUPERSYMMETRY

2007 ◽  
Vol 22 (33) ◽  
pp. 2539-2547 ◽  
Author(s):  
BISWAJOY BRAHMACHARI
Keyword(s):  
Renormalization Group ◽  
Gauge Theory ◽  
Upper Bound ◽  
Threshold Effect ◽  
Mass Scale ◽  
Low Energy ◽  
Intermediate Scale ◽  
Central Value ◽  
Renormalization Group Equations ◽  
Group Evolution

If N = 2 supersymmetry breaks to N = 1 supersymmetry at an intermediate scale m2 and then, later on, N = 1 supersymmetry breaks and produces standard model at a scale m susy such that m2>m susy , renormalization group evolution of three gauge couplings are altered above the scale m2, changing the unification scale and the unified coupling. We show that when we enforce this general condition m2>m susy on the solutions of the renormalization group equations, the condition is translated into an upper bound on the scale m susy . Using presently favored values of α1(mz), α2(mz), α3(mz), we get m susy < 4.5 ×109 GeV for the central value of α3(mZ). When low energy threshold effect is present, this bound gets smeared yet remains generally stable in the 109–1010 GeV range. We also show that if we demand string unification instead of having a unified gauge theory, this constraint can be changed by exotic hypercharge normalizations.

scholarly journals Threshold effects and renormalization group evolution of neutrino parameters in TeV scale seesaw models

2014 ◽  
Vol 29 (22) ◽  
pp. 1450114 ◽  
Author(s):  
Srubabati Goswami ◽  
Subrata Khan ◽  
Sasmita Mishra
Keyword(s):  
Renormalization Group ◽  
Numerical Study ◽  
Threshold Effect ◽  
Factorization Method ◽  
Neutrino Masses ◽  
Threshold Effects ◽  
Mixing Angles ◽  
Group Evolution ◽  
Analytic Expressions

We consider the threshold effect on the renormalization group (RG) evolution of the neutrino masses and mixing angles in TeV scale seesaw models. We obtain the analytic expressions using the factorization method in the presence of threshold effects. We also perform numerical study of RG effects in two specific low scale seesaw models following the bottom-up approach and ascertain the role of seesaw thresholds in altering the values of masses and mixing angles during RG evolution.

scholarly journals Renormalization Scheme and Mass Scale Independence

2021 ◽  
Author(s):  
F.A. Chishtie ◽  
D.G.C. McKeon
Keyword(s):  
Renormalization Group ◽  
Cross Section ◽  
Mass Scale ◽  
Renormalization Scheme ◽  
Perturbative Expansion ◽  
Explicit Dependence ◽  
Renormalization Group Equations ◽  
The Cross ◽  
Implicit And Explicit

We demonstrate that in the mass independent renormalization scheme, the renormalization group equations associated with the unphysical parameters that characterize the renormalization scheme and the mass scale leads to summation that results in a cancellation between the implicit and explicit dependence on these parameters. The resulting perturbative expansion is consequently independent of these arbitrary parameters. We illustrate this by considering R, the cross section for e+e− → hadrons.

scholarly journals DsixTools 2.0: the effective field theory toolkit

2021 ◽  
Vol 81 (2) ◽  
Author(s):  
Javier Fuentes-Martín ◽  
Pedro Ruiz-Femenía ◽  
Avelino Vicente ◽  
Javier Virto
Keyword(s):  
Field Theory ◽  
Renormalization Group ◽  
Cross Sections ◽  
Effective Field Theory ◽  
Degrees Of Freedom ◽  
Effective Field ◽  
Low Energy ◽  
Weak Basis ◽  
The Standard Model ◽  
Group Evolution

Abstract is a package for the handling of the standard model effective field theory (SMEFT) and the low-energy effective field theory (LEFT) with operators up to dimension six, both at the algebraic and numerical level. contains a visually accessible and operationally convenient repository of all operators and parameters of the SMEFT and the LEFT. This repository also provides information concerning symmetry categories and number of degrees of freedom, and routines that allow to implement this information on global expressions (such as decay amplitudes and cross-sections). also performs weak basis transformations, and implements the full one-loop Renormalization Group Evolution in both EFTs (with SM beta functions up to five loops in QCD), and the full one-loop SMEFT-LEFT matching at the electroweak scale.

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.

scholarly journals RENORMALIZATION GROUP EVOLUTION OF NEUTRINO MASSES AND MIXING IN SEESAW MODELS

2010 ◽  
Vol 25 (23) ◽  
pp. 4339-4384 ◽  
Author(s):  
SHAMAYITA RAY
Keyword(s):  
Renormalization Group ◽  
High Energy ◽  
Energy Scale ◽  
Low Energy ◽  
Effective Theory ◽  
Neutrino Masses ◽  
Mixing Parameters ◽  
Group Evolution ◽  
High Energy Scale ◽  
The Masses

We consider different extensions of the Standard Model which can give rise to the small active neutrino masses through seesaw mechanisms, and their mixing. These tiny neutrino masses are generated at some high energy scale by the heavy seesaw fields which then get sequentially decoupled to give an effective dimension-5 operator at the low energy. The renormalization group evolution of the masses and the mixing parameters of the three active neutrinos in the high energy as well as the low energy effective theory is reviewed in this paper.

scholarly journals Running in the ALPs

2021 ◽  
Vol 81 (2) ◽  
Author(s):  
Mikael Chala ◽  
Guilherme Guedes ◽  
Maria Ramos ◽  
Jose Santiago
Keyword(s):  
Field Theory ◽  
Renormalization Group ◽  
Effective Field Theory ◽  
New Physics ◽  
Effective Field ◽  
Electroweak Scale ◽  
Renormalization Group Equations ◽  
Group Evolution ◽  
The Alps

AbstractThe couplings of axion-like particles are probed by different experiments across a huge range of energy scales. Accordingly, a consistent analysis of the corresponding constraints requires the use of the renormalization group equations. We compute the full one-loop renormalization group evolution of all – relevant and marginal – parameters in the effective field theory for axion-like particles up to dimension five, above and below the electroweak scale, assuming only that new physics does not violate CP. We also include a detailed discussion of the different bases used in the literature, the relations among them and the interplay of the CP and shift symmetries.

ON THE CALCULATION OF THE LOW ENERGY SOFT SUPERSYMMETRY BREAKING TERMS

1993 ◽  
Vol 08 (27) ◽  
pp. 2579-2583 ◽  
Author(s):  
N.V. KRASNIKOV
Keyword(s):  
Renormalization Group ◽  
Supersymmetry Breaking ◽  
Low Energy ◽  
Planck Mass ◽  
Renormalization Group Equations ◽  
Soft Supersymmetry Breaking

We show that in supergravity theories with soft supersymmetry breaking it is necessary to take into account the terms in the Lagrangian which are suppressed by the inverse powers of the Planck mass in the calculation of the low energy soft supersymmetry breaking terms. Such terms are discarded in the standard calculations based on the use of the renormalization group equations.

FLAVOR GAUGE THEORY, AND MASSES OF TOP AND NEUTRINO

1994 ◽  
Vol 09 (04) ◽  
pp. 289-297 ◽  
Author(s):  
G. CVETIČ ◽  
C.S. KIM
Keyword(s):  
Renormalization Group ◽  
Gauge Theory ◽  
Standard Model ◽  
Boundary Conditions ◽  
Yukawa Couplings ◽  
Tau Neutrino ◽  
Renormalization Group Equations ◽  
The Standard Model

We assume that the standard model (SM) breaks down around some energy Λ, and is replaced by a new (Higgsless) flavor gauge theory (FGT). We investigate this possibility by studying the renormalization group equations for the Yukawa couplings of SM with two Higgs doublets for various mt and υU/υD. With appropriate flavor democratic boundary conditions at Λ FGT , we derive the bounds on masses of top and tau-neutrino, which are compatible with experimental bounds.

Recent results on renormalization-group evolution of theories with gauge, fermion, and scalar fields

2017 ◽  
Vol 32 (35) ◽  
pp. 1747007
Author(s):  
R. Shrock
Keyword(s):  
Renormalization Group ◽  
Gauge Theory ◽  
Anomalous Dimension ◽  
Beta Function ◽  
Scalar Fields ◽  
Group Behavior ◽  
Abelian Gauge ◽  
Dimension Formula ◽  
Technicolor Model ◽  
Group Evolution

We discuss recent results on renormalization-group evolution of several types of theories. First, we consider asymptotically free vectorial gauge theories with various fermion contents and discuss higher-loop calculations of the UV to IR evolution in these theories, including an IR zero of the beta function and the value of the anomalous dimension [Formula: see text] at this point, together with comparisons with lattice measurements. Effects of scheme transformations are discussed. We then present a novel way to determine the value of [Formula: see text] in an [Formula: see text] technicolor model from a particular embedding in an extended technicolor theory. Finally, we analyze the renormalization-group behavior of several non-asymptotically free theories, including a U(1) gauge theory, a non-Abelian gauge theory with many fermions, an [Formula: see text] [Formula: see text] scalar theory, and Yukawa theories.

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