We have searched for 14.4 keV solar axions or more general axion-like particles (ALPs), that may be emitted in the M1 nuclear transition of 57Fe, by using the axion-to-photon conversion in the CERN Axion Solar Telescope (CAST) with evacuated magnet bores (Phase I). From the absence of excess of the monoenergetic X-rays when the magnet was pointing to the Sun, we set model-independent constraints on the coupling constants of pseudoscalar particles that couple to two photons and to a nucleon g_{ a\gamma} |-1.19 g_{ aN}^{ 0}+g_{ aN}^{ 3}|<1.36\times 10^{ -16} GeV^{ -1} for m_{ a}<0.03 eV at the 95% confidence level.
Categories: hep-ex
