TASI 2009 Lectures - Flavor Physics

Abstract

The standard model picture of flavor and CP violation is now experimentally verified, hence strong bounds on the flavor structure of new physics follow. We begin by discussing in detail the unique way that flavor conversion and CP violation arise in the standard model. The description provided is based on a spurion, symmetry oriented, analysis, and a covariant basis for describing flavor transition processes is introduced, in order to make the discussion transparent for non-experts. We show how to derive model independent bounds on generic new physics models. Furthermore, we demonstrate, using the covariant basis, how recent data and LHC projections can be applied to constrain models with an arbitrary mechanism of alignment. Next, we discuss the various limits of the minimal flavor violation framework and their phenomenological aspects, as well as the implications to the underlying microscopic origin of the framework. We also briefly discuss aspects of supersymmetry and warped extra dimension flavor violation. Finally we speculate on the possible role of flavor physics in the LHC era.

Ultravisible warped model from flavor triviality and improved naturalness

“…As a result of the large top mass, we actually expect higher powers of the up Yukawa to be important, and these would shift the eigenvalues of the bulk masses [39,84]. The impact of top Yukawa resummation is subtle, but can be observed in flavor violation involving lefthanded currents in the first two generations.…”

Just a Taste: Lectures on Flavor Physics

“…Since an orthogonal matrix is just a unitary matrix "without the phases," we may subtract the latter from the former to find that an N × N unitary matrix has 1 2 N (N + 1) phases and 1 2 N (N − 1) real parameters. Thus our U(N ) 3 kinetic term symmetry gives 9 real parameters and 18 phases. The Yukawas break this to U(1) B so that there are 9 broken real generators and 17 broken complex phases.…”

“…If y e = 0, then the Lagrangian would enjoy a larger global symmetry: the global symmetry of the kinetic term, L kin ⊃ Ēi / DE i + Li / DL i . This is a U(3) E × U(3) L global symmetry associated with the rotation between the three generations of E and L. The Yukawa term breaks the global symmetry down to U(1) 3 , corresponding to the phases of the mass eigenstate fields. We may use the now-broken U(3) E × U(3) L symmetry to rotate the symmetry-breaking order parameter y e to a convenient direction.…”

“…In this set of lectures, we introduce basics of flavor physics, that is, the part of Nature where the differences between the quarks plays a role. While this writeup includes more material than presented at the lectures, this write up is still just a taste of the entire field; for more in-depth reading we refer to other recent tasi lectures [1][2][3], reviews [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] and books [20,21] on the subject.…”

CP violation tests of alignment models at LHCII

“…This could either arise when the flavor mediation scale is very high leading to minimal flavor violation [1,2], or possibly when non-abelian flavor symmetries are involved [3]. In both cases, however, flavor non-universality effects involving the first two generations are suppressed, both in the luminosity and energy frontiers (see, e.g., [2,4,5]).…”