Strings in magnetic fields in extra-dimensions and the Standard Model
by
Paolo Di Vecchia(Nordita)
→
Europe/Stockholm
FB51
FB51
Description
I will start discussing the ideas presently used for connecting
string theory to particle phenomenology. They are based on the existence in
string theory of non-perturbative objects called D branes. I will give a brief
description of them. Then, in order to
be able to describe chiral matter as leptons and quarks, I will
introduce the magnetized D branes that have the property of having
magnetic fields living on the compact extra dimensions. I will then
determine the spectrum of open strings connected to D branes having
different magnetizations and I will show that this spectrum reduces,
in the field theory limit, to that of an electron in an external
magnetic field. The degeneracy of the Landau levels corresponds to
the different families of quarks and leptons. Finally, I will discuss the Kaluza-Klein
reduction of the low-energy effective action living on a stack of D9 branes and I will
show how to compute the parameters of the low-energy Lagrangian as
the Kähler metrics and Yukawa couplings that enter in the
determination of the
masses of quarks and leptons.