Context : The Milky Way bulge is an important tracer of the early formation and chemical enrichment of the Galaxy .
The abundances of different iron-peak elements in field bulge stars can give information on the nucleosynthesis processes that took place in the earliest supernovae .
Cobalt ( Z=27 ) and copper ( Z=29 ) are particularly interesting .

Aims : We aim to identify the nucleosynthesis processes responsible for the formation of the iron-peak elements Co and Cu .

Methods : We derived abundances of the iron-peak elements cobalt and copper in 56 bulge giants , 13 of which were red clump stars .
High-resolution spectra were obtained using FLAMES-UVES at the ESO Very Large Telescope by our group in 2000-2002 , which appears to be the highest quality sample of high-resolution data on bulge red giants obtained in the literature to date .
Over the years we have derived the abundances of C , N , O , Na , Al , Mg ; the iron-group elements Mn and Zn ; and neutron-capture elements .
In the present work we derive abundances of the iron-peak elements cobalt and copper .
We also compute chemodynamical evolution models to interpret the observed behaviour of these elements as a function of iron .

Results : The sample stars show mean values of [ Co/Fe ] \sim 0.0 at all metallicities , and [ Cu/Fe ] \sim 0.0 for [ Fe/H ] \geq -0.8 and decreasing towards lower metallicities with a behaviour of a secondary element .

Conclusions : We conclude that [ Co/Fe ] varies in lockstep with [ Fe/H ] , which indicates that it should be produced in the alpha-rich freezeout mechanism in massive stars .
Instead [ Cu/Fe ] follows the behaviour of a secondary element towards lower metallicities , indicating its production in the weak s-process nucleosynthesis in He-burning and later stages .
The chemodynamical models presented here confirm the behaviour of these two elements ( i.e .
[ Co/Fe ] vs. [ Fe/H ] \sim constant and [ Cu/Fe ] decreasing with decreasing metallicities ) .