Seminar on Jan. 23rd, 2009
Back to Home (Japanese)
Back-Numbers etc.
Title:
Low energy constants of Chiral Perturbation Theory
from the instanton vacuum model
Speaker:
Mirzayusuf Musakhanov
(Uzbekistan National University)
Abstract:
In the framework of the instanton vacuum model it was derived the partition
function for the light quarks. We make expansion over the current mass m
and number of colors Nc and evaluate O(1/Nc, m, m/Nc, m/Nc ln m)-corrections
to the dynamical quark mass M, the quark condensate <bar q q>, the pion
mass Mpi and decay constant Fpi. There are several sources of these corrections:
meson loops, finite size of the instanton distribution and the quark-quark "tensor"
interaction terms. In contrast to the expectations, we found that numerically the
1/Nc-corrections to dynamical mass are large and mostly come from meson loops.
As a consequence, we have large 1/Nc-corrections to all the other quantities.
To provide the values of Fpi(m=0), <bar q q(m=0)> in agreement with ChPT,
we offer a new set of parameters - average instanton size rho and average
inter-instanton distance R. Finally, we find the ChPT SU(2)_f low-energy
constants bar l_3, bar l_4 in a good correspondence with the phenomenology
and lattice results.
Publications:
1. Improved effective action for light quarks beyond chiral limit.
M. Musakhanov, Eur.Phys.J.C9:235-243,1999. e-Print: hep-ph/9810295.
2. A Test of the instanton vacuum with low-energy theorems of the axial anomaly.
M.M. Musakhanov, Hyun-Chul Kim, Phys.Lett.B572:181-188,2003. e-Print: hep-ph/0206233.
3. Magnetic susceptibility of the QCD vacuum.
H.C.Kim, M.Musakhanov, M.Siddikov, Phys. Lett. B { 608}, 95 (2005). [hep-ph/0411181].
4. Quark condensate of the QCD vacuum beyond the chiral limit.
H.C.Kim, M.Musakhanov, M.Siddikov, Phys. Lett. B { 633}, 701 (2006). [hep-ph/0508211].
5. Low energy constants of chiPT from the instanton vacuum model.
K.Goeke, M.Musakhanov, M.Siddikov, Phys. Rev. D { 76}, 076007 (2007). [0707.1997 [hep-ph]].
6. 1/N_c corrections to the magnetic susceptibility of the QCD vacuum.
K.Goeke, H.C.Kim, M.Musakhanov, M.Siddikov, Phys. Rev. D{76}, 0116007(2007). [0708.3526 [hep-ph]].