Cooling and acceleration rates for protons at the internal shocks of CGRBs for L₀ = 10⁵⁰ erg s⁻¹ and L₀ = 10⁵¹ erg s⁻¹ in the left and right panels, respectively. Top panels correspond to Γ = 100 and the bottom ones to Γ = 300. The different processes are indicated with the following curves: dashed lines are for ϵ_B = 1, solid lines for ϵ_B = 0.1, and short-dashed lines for ϵ_B = 0.01. The blue curves refer to acceleration, orange ones to synchrotron, magenta ones to pp interactions, and black ones to adiabatic cooling. With green, we mark the pγ cooling rates corresponding to a target of external photons (solid lines) and to internal pγ interactions with electron synchrotron photons as targets for a_ep = 1 (long-short dashed lines) and a_ep = 100 (long-short-short dashed lines).