Axion Like Particles ( ALPs ) are one promising kind of dark matter candidate particles that are predicted to couple with photons in the presence of magnetic fields .
The oscillations between photons and ALPs travelling in the magnetic fields have been used to constrain ALP properties .
In this work , we obtain some new constraints on the ALP mass m _ { a } and the photon-ALP coupling constant g with two different magnetic field models through TeV photons from PKS 2155-304 .
One is the discrete- \varphi model that the magnetic field has the orientation angle \varphi changes discretely and randomly from one coherent domain to the next , another is the linearly-continuous- \varphi model that the magnetic field orientation angle \varphi varies continuously across neighboring coherent domains .
For the discrete- \varphi model , we can obtain the best constraints on the ALP mass m _ { 1 } = m _ { a } / ( 1 { neV } ) = 0.1 and on the photon-ALP coupling constant g _ { 11 } = g / ( 10 ^ { -11 } { GeV ^ { -1 } } ) = 5 , the reasonable range of the ALP mass m _ { 1 } is 0.08 \thicksim 0.2 when g _ { 11 } =5 , and the only reasonable value of the photon-ALP coupling constant is g _ { 11 } =5 when m _ { 1 } =0.1 .
For the linearly-continuous- \varphi model , we can obtain the best constraints on the ALP mass m _ { 1 } = 0.1 and on the photon-ALP coupling constant g _ { 11 } = 0.7 , the reasonable range of the ALP mass m _ { 1 } is 0.05 \thicksim 0.4 when g _ { 11 } =0.7 , and the reasonable range of the photon-ALP coupling constant g _ { 11 } is 0.5 \thicksim 1 when m _ { 1 } =0.1 .
All the results are consistent with the upper bound ( g < 6.6 \times 10 ^ { -11 } { GeV ^ { -1 } } , i.e . g _ { 11 } < 6.6 ) set by the CAST experiment .