scholarly journals Finite-volume corrections to low-energy constants from the partially quenched effective theory

2010 ◽  
Author(s):  
Christoph Lehner ◽  
Tilo Wettig
2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Andrey Yu. Kotov ◽  
Daniel Nogradi ◽  
Kalman K. Szabo ◽  
Lorinc Szikszai

Abstract In previous work, [arXiv:1905.01909], we have calculated the mϱ/fπ ratio in the chiral and continuum limit for SU(3) gauge theory coupled to Nf = 2, 3, 4, 5, 6 fermions in the fundamental representation. The main result was that this ratio displays no statistically significant Nf-dependence. In the present work we continue the study of the Nf-dependence by extending the simulations to Nf = 7, 8, 9, 10. Along the way we also study in detail the Nf-dependence of finite volume effects on low energy observables and a particular translational symmetry breaking unphysical, lattice artefact phase specific to staggered fermions.


2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Martin Bauer ◽  
Matthias Neubert ◽  
Sophie Renner ◽  
Marvin Schnubel ◽  
Andrea Thamm

Abstract Axions and axion-like particles (ALPs) are well-motivated low-energy relics of high-energy extensions of the Standard Model, which interact with the known particles through higher-dimensional operators suppressed by the mass scale Λ of the new-physics sector. Starting from the most general dimension-5 interactions, we discuss in detail the evolution of the ALP couplings from the new-physics scale to energies at and below the scale of electroweak symmetry breaking. We derive the relevant anomalous dimensions at two-loop order in gauge couplings and one-loop order in Yukawa interactions, carefully considering the treatment of a redundant operator involving an ALP coupling to the Higgs current. We account for one-loop (and partially two-loop) matching contributions at the weak scale, including in particular flavor-changing effects. The relations between different equivalent forms of the effective Lagrangian are discussed in detail. We also construct the effective chiral Lagrangian for an ALP interacting with photons and light pseudoscalar mesons, pointing out important differences with the corresponding Lagrangian for the QCD axion.


Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 191
Author(s):  
Alexander Bednyakov ◽  
Alfiia Mukhaeva

Flavour anomalies have attracted a lot of attention over recent years as they provide unique hints for possible New Physics. Here, we consider a supersymmetric (SUSY) extension of the Standard Model (SM) with an additional anomaly-free gauge U(1) group. The key feature of our model is the particular choice of non-universal charges to the gauge boson Z′, which not only allows a relaxation of the flavour discrepancies but, contrary to previous studies, can reproduce the SM mixing matrices both in the quark and lepton sectors. We pay special attention to the latter and explicitly enumerate all parameters relevant for our calculation in the low-energy effective theory. We find regions in the parameter space that satisfy experimental constraints on meson mixing and LHC Z′ searches and can alleviate the flavour anomalies. In addition, we also discuss the predictions for lepton-flavour violating decays B+→K+μτ and B+→K+eτ.


2010 ◽  
Vol 73 (3) ◽  
pp. 389-404 ◽  
Author(s):  
K. S. Gupta ◽  
A. Samsarov ◽  
S. Sen
Keyword(s):  

2014 ◽  
Vol 23 (13) ◽  
pp. 1443003 ◽  
Author(s):  
Yasuho Yamashita ◽  
Antonio De Felice ◽  
Takahiro Tanaka

In this paper, we discuss the ghost freeness in the case when we add matter coupled to two metrics to the ghost-free bigravity. In this paper we show that the Boulware–Deser ghost generally revives in the presence of doubly coupled matter and that ghost freeness strongly restricts the model of kinetically doubly coupled matter. This result may anticipate difficulties in the attempt to derive the ghost-free bigravity as a low-energy effective theory, starting with a model applicable at high energies.


2008 ◽  
Vol 53 (9(2)) ◽  
pp. 1152-1157
Author(s):  
J. W. Shin ◽  
S. Ando ◽  
C. H. Hyun ◽  
S. W. Hong

2013 ◽  
Vol 41 (1) ◽  
pp. 015105 ◽  
Author(s):  
A Rokash ◽  
E Epelbaum ◽  
H Krebs ◽  
D Lee ◽  
U-G Meißner

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