Snowmass White Paper: Flavor Model Building

Abstract

In this white paper for the Snowmass process, we summarize the role flavor model building plays in the quest for new physics. We review approaches to address the non-generic flavor structure of the Standard Model and discuss how new physics models can be made compatible with the stringent constraints from flavor changing processes that indirectly probe very high scales. We also give an overview of the persistent anomalies in B decays and the anomalous magnetic moment of the muon and some of their most popular new physics explanations.

Dark matter production through a non-thermal flavon portal

“…We have also verified numerically that our results for the flavon yield from freezein do not change by more than a factor of a few for a different choice of a realistic texture following that study. We illustrate this in the right panel of figure 1 where the yellow dashed line corresponds to the flavon freeze-in production for the following choice of the texture: 3,3). We label this choice by texture 2 in the plot and compare it with the results obtained for the FN texture in eq.…”

“…refs. [1][2][3] for reviews. A particularly popular attempt utilizes the observation that the hierarchy in the masses and mixing matrix elements among the SM fermions can be conveniently reproduced up to order-one factors with simple integer powers of a common JHEP03(2023)149 quantity 0.23, which is of the order of the Cabibbo angle.…”

TASI 2022 lectures on flavor physics

“…In the following, we briefly discuss various ways to generate hierarchical Yukawa couplings. A more detailed discussion can be found, for example, in [53]. Many ideas have been put forward to explain hierarchical Yukawa couplings using new UV dynamics.…”

“…Intriguingly, for a long time, LHCb measurements of LFU ratios gave results significantly below the Standard Model prediction [82,83], creating considerable excitement in the particle physics community. The large flavor model building undertaking that was motivated by the hints for lepton flavor universality violation is summarized, for example, in [53]. The most recent update by LHCb from December 2022, however, gives results that are fully compatible with the Standard Model predictions 1 [84,85] low-q 2 R K = 0.994 +0.090 −0.082 (stat) +0.029 −0.027 (sys) , R K * = 0.927 +0.093 −0.087 (stat) +0.036 −0.035 (sys) , central-q 2 R K = 0.949 +0.042 −0.041 (stat) +0.022 −0.022 (sys) , R K * = 1.027 +0.072 −0.068 (stat) +0.027 −0.026 (sys) , where (stat) and (sys) correspond to statistical and systematic uncertainties, respectively.…”