The dependence of the mass accretion rate on the stellar properties is a key constraint for star formation and disk evolution studies .
Here we present a study of a sample of stars in the Chamaeleon I star-forming region carried out using spectra taken with the ESO VLT/X-Shooter spectrograph .
The sample is nearly complete down to stellar masses ( M _ { \star } ) \sim 0.1 M _ { \odot } for the young stars still harboring a disk in this region .
We derive the stellar and accretion parameters using a self-consistent method to fit the broadband flux-calibrated medium resolution spectrum .
The correlation between accretion luminosity to stellar luminosity , and of mass accretion rate to stellar mass in the logarithmic plane yields slopes of 1.9 \pm 0.1 and 2.3 \pm 0.3 , respectively .
These slopes and the accretion rates are consistent with previous results in various star-forming regions and with different theoretical frameworks .
However , we find that a broken power-law fit , with a steeper slope for stellar luminosity lower than \sim 0.45 L _ { \odot } and for stellar masses lower than \sim 0.3 M _ { \odot } is slightly preferred according to different statistical tests , but the single power-law model is not excluded .
The steeper relation for lower mass stars can be interpreted as a faster evolution in the past for accretion in disks around these objects , or as different accretion regimes in different stellar mass ranges .
Finally , we find two regions on the mass accretion versus stellar mass plane that are empty of objects : one region at high mass accretion rates and low stellar masses , which is related to the steeper dependence of the two parameters we derived .
The second region is located just above the observational limits imposed by chromospheric emission , at M _ { \star } \sim 0.3 - 0.4 M _ { \odot } .
These are typical masses where photoevaporation is known to be effective .
The mass accretion rates of this region are \sim 10 ^ { -10 } M _ { \odot } /yr , which is compatible with the value expected for photoevaporation to rapidly dissipate the inner disk .