fermion and sfermion massesfermion and sfermion masses

Melina Gómez Bock

Mini-Workshop on flavor physics: Mexican taste 24-25 November 2008

...el sabor leptónico nació con el descubrimiento del muón y la famosa pregunta de I.I. Rabi: ¿ quién ordenó esto? [W. Marciano:97]

flavor history

Una vez que Gell-Mann y yo ibamos camino a un restaurant en Pasadena para comer, pasamos por un lugar de helados Baskin & Robins, donde anunciaban 32 sabores diferentes. De repente, a Murray se le ocurri¶o una propuesta para usar el término “sabor" (...) para distinguir entre los diferentes grados de libertad de los quarks.[Fritzsch:01]

contentscontents

SUSY

Flavor in SUSY

Sfermions masses

Radiative generation of lepton masses

Flavor violation processes

x

1019GeV Planck Scale

GU

1GeV = 1.2 13 K

10-33cm10-44s

EM

StandardModel

EW

weak

246 MeV

SUSY

t

E

strong gravity

CPVFV FCNC

bosonsfermions

SusyQ

Q | > = | >

Q | > = | >

Chiral supermultipletChiral supermultiplet

Fermión de Weyl

Campo escalar complejo

Flavor in SUSYFlavor in SUSY

Sfermion mass matrixSfermion mass matrix

General contributions to sfermion massGeneral contributions to sfermion mass

From Soft SUSY breaking terms Direct contribution to sfermion masses

Contribution through Higgs interaction

Trilineal scalar couplingsTrilineal scalar couplingsOff-diagonal mass terms

trilineal mass terms

Mass contribution from auxiliary field FMass contribution from auxiliary field F

Mass contribution from auxiliary field DMass contribution from auxiliary field D

sfermion massessfermion masses

A

Trilineal terms

degenerationdegeneration, where different sfermion families have the same mass;

proportionalityproportionality, here the trilinear A-terms are proportional to the Yukawa couplings (SUGRA)[Hall:86] ;

decouplingdecoupling, where the superpartners are too heavy to affect the low energy physics(Split SUSY, focus point SUSY, inverted hierarchy)[Feng:05];

alignmentalignment, in this case the same physics that plains the fermion mass spectra and mixing angles also would explain the pattern of sfermions mass spectra [Nir:1993]

Several conditions or scenarios have been proposed , which reduce the number of free parameters and safely fit the experimental restrictions.

Trilineal term Ansatz

1.We have a defined mixing angle for sfermions2.Analitic expresions for FV processes3.We have no dependence on renormalization scale Q4.We are able to compare with low scale data5.Bound the parameter space of the model6.We have expresions for mass values of different sfermions -> non-universality

advantages:

LO mass matrix

Sfermion massesSfermion masses

Radiative generation of leptons masses

1 1 2 21 ( )2

f ffM vY v Y

Radiative generation of leptons masses

Flavor violation

if~

jf~

if jfB

Flavor violation in leptons

sabor!!!!

h0

h0

Hierarchy problem