scholarly journals Renormalization-group evolution of new physics contributions to (semi)leptonic meson decays

2017 ◽  
Vol 772 ◽  
pp. 777-785 ◽  
Author(s):  
Martín González-Alonso ◽  
Jorge Martin Camalich ◽  
Kin Mimouni
Keyword(s):  
Renormalization Group ◽  
New Physics ◽  
Meson Decays ◽  
Group Evolution

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.

scholarly journals Renormalization Group evolution from on-shell SMEFT

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Minyuan Jiang ◽  
Teng Ma ◽  
Jing Shu
Keyword(s):  
Field Theory ◽  
Renormalization Group ◽  
Standard Model ◽  
Effective Field Theory ◽  
Effective Field ◽  
High Dimensional ◽  
Anomalous Dimensions ◽  
The Standard Model ◽  
Group Evolution

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.

scholarly journals Another SMEFT story: Z′ facing new results on ε′/ε, ∆MK and K → $$ \pi \nu \overline{\nu} $$

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Jason Aebischer ◽  
Andrzej J. Buras ◽  
Jacky Kumar
Keyword(s):  
Renormalization Group ◽  
Mass Difference ◽  
Branching Ratios ◽  
New Physics ◽  
Matrix Elements ◽  
Isospin Breaking ◽  
Left Handed ◽  
The Standard Model ◽  
First Time ◽  
Group Effects

Abstract Recently the RBC-UKQCD lattice QCD collaboration presented new results for the hadronic matrix elements relevant for the ratio ε′/ε in the Standard Model (SM) albeit with significant uncertainties. With the present knowledge of the Wilson coefficients and isospin breaking effects there is still a sizable room left for new physics (NP) contributions to ε′/ε which could both enhance or suppress this ratio to agree with the data. The new SM value for the K0 − $$ {\overline{K}}^0 $$ K ¯ 0 mass difference ∆MK from RBC-UKQCD is on the other hand by 2σ above the data hinting for NP required to suppress ∆MK. Simultaneously the most recent results for K+ → $$ {\pi}^{+}\nu \overline{\nu} $$ π + ν ν ¯ from NA62 and for KL → $$ {\pi}^0\nu \overline{\nu} $$ π 0 ν ν ¯ from KOTO still allow for significant NP contributions. We point out that the suppression of ∆MK by NP requires the presence of new CP-violating phases with interesting implications for K → $$ \pi \nu \overline{\nu} $$ πν ν ¯ , KS → μ+μ− and KL → π0ℓ+ℓ− decays. Considering a Z′-scenario within the SMEFT we analyze the dependence of all these observables on the size of NP still allowed by the data on ε′/ε. The hinted ∆MK anomaly together with the εK constraint implies in the presence of only left-handed (LH) or right-handed (RH) flavour-violating Z′ couplings strict correlation between K+ → $$ {\pi}^{+}\nu \overline{\nu} $$ π + ν ν ¯ and KL → $$ {\pi}^0\nu \overline{\nu} $$ π 0 ν ν ¯ branching ratios so that they are either simultaneously enhanced or suppressed relative to SM predictions. An anticorrelation can only be obtained in the presence of both LH and RH couplings. Interestingly, the NP QCD penguin scenario for ε′/ε is excluded by SMEFT renormalization group effects in εK so that NP effects in ε′/ε are governed by electroweak penguins. We also investigate for the first time whether the presence of a heavy Z′ with flavour violating couplings could generate through top Yukawa renormalization group effects FCNCs mediated by the SM Z-boson. The outcome turns out to be very interesting.

scholarly journals Renormalization group evolution of neutrino masses and mixing in the Type-III seesaw mechanism

2009 ◽  
Vol 820 (1-2) ◽  
pp. 116-147 ◽  
Author(s):  
Joydeep Chakrabortty ◽  
Amol Dighe ◽  
Srubabati Goswami ◽  
Shamayita Ray
Keyword(s):  
Renormalization Group ◽  
Neutrino Masses ◽  
Seesaw Mechanism ◽  
Type Iii ◽  
Group Evolution

scholarly journals Renormalization group evolution of the CKM matrix

1999 ◽  
Vol 9 (2) ◽  
pp. 197-211 ◽  
Author(s):  
C. Balzereit ◽  
T. Hansmann ◽  
T. Mannel ◽  
B. Plümper
Keyword(s):  
Renormalization Group ◽  
Ckm Matrix ◽  
Group Evolution

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.

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