In this paper , a holographic dark energy model , dubbed Ricci dark energy , is confronted with cosmological observational data from type Ia supernovae ( SN Ia ) , baryon acoustic oscillations ( BAO ) and cosmic microwave background ( CMB ) .
By using maximum likelihood method , it is found out that Ricci dark energy model is a viable candidate of dark energy model with the best fit parameters : \Omega _ { m 0 } = 0.34 \pm 0.04 , \alpha = 0.38 \pm 0.03 with 1 \sigma error .
Here , \alpha is a dimensionless parameter related with Ricci dark energy \rho _ { R } and Ricci scalar R , i.e. , \rho _ { R } \propto \alpha R .