13,686 research outputs found
N_c and m_pi dependence of rho and sigma mesons from unitarized Chiral Perturbation Theory
We review our work on the rho and sigma resonances derived from the Inverse
Amplitude Method. In particular, we study the leading 1/N_c behavior of the
resonances masses and widths and their evolution with changing m_pi. The 1/N_c
expansion gives a clear definition of quark-antiquark states, which is neatly
satisfied by the rho but not by the sigma, showing that its dominant component
is not quark-antiquark. The m_pi dependence of the resonance properties is
relevant to connect with lattice studies. We show that our predictions compare
well with some lattice results and we find that the rho-pi-pi coupling constant
is m_pi independent, in contrast with the sigma-pi-pi coupling, that shows a
strong m_pi dependence.Comment: To appear in the Proceedings of the Chiral10 Workshop, June 21-24
2010. Valencia, Spai
Moving frames for cotangent bundles
Cartan's moving frames method is a standard tool in riemannian geometry. We
set up the machinery for applying moving frames to cotangent bundles and its
sub-bundles defined by non-holonomic constraints.Comment: 13 pages, to appear in Rep. Math. Phy
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