We present high-quality , Keck spectroscopic data for a sample of 20 globular clusters ( GCs ) in the massive E0 galaxy NGC 1407 .
A subset of twenty line-strength indices of the Lick/IDS system have been measured for both the GC system and the central integrated star-light of the galaxy .
Ages , metallicities and [ \alpha /Fe ] ratios have been derived using several different approaches .
The majority GCs in NGC 1407 studied are old , follow a tight metallicity sequence reaching values slightly above solar , and exhibit mean [ \alpha /Fe ] ratios of \sim 0.3 dex .
In addition , three GCs are formally derived to be young ( \sim 4 Gyr ) , but we argue that they are actually old GCs hosting blue horizontal branches .
We report , for the first time , evidence for the existence of two chemically-distinct subpopulations of metal-rich ( MR ) GCs .
We find some MR GCs exhibit significantly larger [ Mg/Fe ] and [ C/Fe ] ratios .
Different star formation time-scales are proposed to explain the correlation between Mg and C abundances .
We also find striking CN overabundances over the entire GC metallicity range .
Interestingly , the behavior of C and N in metal-poor ( MP ) GCs clearly deviates from the one in MR GCs .
In particular , for MR GCs , N increases dramatically while C essentially saturates .
This may be interpreted as a consequence of the increasing importance of the CNO cycle with increasing metallicity .