Star formation from matter including the hot CNO processed ejecta of asymptotic giant branch ( AGB ) winds is regarded as a plausible scenario to account for the chemical composition of a stellar second generation ( SG ) in Globular Clusters ( GCs ) .
The chemical evolution models , based on this hypothesis , so far included only the yields available for the massive AGB stars , while the possible role of super–AGB ejecta was either extrapolated or not considered .
In this work , we explore in detail the role of super–AGB ejecta on the formation of the SG abundance patterns using yields recently calculated by Ventura and D ’ Antona .

An application of the model to clusters showing extended Na–O anticorrelations , like NGC 2808 , indicates that a SG formation history similar to that outlined in our previous work is required : formation of an Extreme population with very large helium content from the pure ejecta of super–AGB stars , followed by formation of an Intermediate population by dilution of massive AGB ejecta with pristine gas .
The present models are able to account for the very O-poor Na-rich Extreme stars once deep-mixing is assumed in SG giants forming in a gas with helium abundance Y > 0.34 , which significantly reduces the atmospheric oxygen content , while preserving the sodium abundance .
On the other hand , for clusters showing a mild O–Na anticorrelation , like M 4 , the use of the new yields broadens the range of SG formation routes leading to abundance patterns consistent with observations .
Specifically , our study shows that a model in which SG stars form only from super–AGB ejecta promptly diluted with pristine gas can reproduce the observed patterns .
We briefly discuss the variety of ( small ) helium variations occurring in this model and its relevance for the horizontal branch morphology .

In some of these models , the duration of the SG formation episode can be as short as \sim 10 Myr ; the formation time of the SG is therefore compatible with the survival of a cooling flow in the cluster core , previous to the explosion of the SG core collapse supernovae .
We also explore models characterized by the formation of multiple populations in individual bursts , each lasting no longer than \sim 10 Myr .