scholarly journals Two-loop renormalization group restrictions on the standard model and the fourth chiral family

1999 ◽  
Vol 10 (4) ◽  
pp. 629-638 ◽  
Author(s):  
Yu.F. Pirogov ◽  
O.V. Zenin
2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Yohei Ema ◽  
Kyohei Mukaida ◽  
Jorinde van de Vis

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.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Minyuan Jiang ◽  
Teng Ma ◽  
Jing Shu

Abstract We describe the on-shell method to derive the Renormalization Group (RG) evolution of Wilson coefficients of high dimensional operators at one loop, which is a necessary part in the on-shell construction of the Standard Model Effective Field Theory (SMEFT), and exceptionally efficient based on the amplitude basis in hand. The UV divergence is obtained by firstly calculating the coefficients of scalar bubble integrals by unitary cuts, then subtracting the IR divergence in the massless bubbles, which can be easily read from the collinear factors we obtained for the Standard Model fields. Examples of deriving the anomalous dimensions at dimension six are presented in a pedagogical manner. We also give the results of contributions from the dimension-8 H4D4 operators to the running of V+V−H2 operators, as well as the running of B+B−H2D2n from H4D2n+4 for general n.


2015 ◽  
Vol 93 (9) ◽  
pp. 988-994 ◽  
Author(s):  
Pietro Donà ◽  
Astrid Eichhorn ◽  
Roberto Percacci

We discuss the compatibility of quantum gravity with dynamical matter degrees of freedom. Specifically, we present bounds we obtained in Donà et al. (Phys. Rev. D, 89, 084035 (2014) doi:10.1103/PhysRevD.89.084035 ) on the allowed number and type of matter fields within asymptotically safe quantum gravity. As a novel result, we show bounds on the allowed number of spin-3/2 (Rarita–Schwinger) fields (e.g., the gravitino). These bounds, obtained within truncated renormalization group flows, indicate the compatibility of asymptotic safety with the matter fields of the standard model. Further, they suggest that extensions of the matter content of the standard model are severely restricted in asymptotic safety. This means that searches for new particles at colliders could provide experimental tests for this particular approach to quantum gravity.


2013 ◽  
Vol 28 (11) ◽  
pp. 1330007 ◽  
Author(s):  
A. S. CORNELL ◽  
ALDO DEANDREA ◽  
LU-XIN LIU ◽  
AHMAD TARHINI

We review the renormalization group evolution of quark and lepton masses, mixing angles and phases both in the UED extension of the Standard Model (SM) and of the Minimal Supersymmetric Standard Model (MSSM). We consider two typical scenarios: all matter fields propagating in the bulk and matter fields constrained to the brane. The resulting renormalization group evolution equations in these scenarios are compared with the existing results in the literature, together with their implications.


2016 ◽  
Vol 31 (28n29) ◽  
pp. 1645033
Author(s):  
Grigorii B. Pivovarov

I define a naturalness criterion formalizing the intuitive notion of naturalness discussed in the literature. After that, using [Formula: see text] as an example, I demonstrate that a theory may be natural in the [Formula: see text]-scheme and, at the same time, unnatural in the Gell-Mann–Low scheme. Finally, I discuss the prospects of using a version of the Gell-Mann–Low scheme in the Standard Model.


1991 ◽  
Vol 06 (04) ◽  
pp. 325-332
Author(s):  
C.E. VAYONAKIS

We examine the renormalization group equations for the standard model interactions realized at higher Kac-Moody levels, as derived from superstring theories. We try to find constraints on these levels, considering both perturbative and non-perturbative unification.


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