So I have learned today what kind of work I will be doing for Professor B. I will be making samples (carbon nanotubes) and taking electrical measurements on them. Since the work involves several sophisticated experimental procedures, such as AFM, SEM, evaporation... i will have to get trained on these techniques first, which can take a few weeks. The project will largely be a repetition of these procedures, cycles of making samples, taking measurements, making more samples and taking the same measurements again. The goal is to get enough data for the grad student's analysis, who might use it in his potential paper. So as you can see, the project can become a little tedius and quite time consuming: in addition to several weeks of training in the beginning, each procedure in each cycle can also take days. My eight weeks of work in the summer will probably just get me started on taking some data, let alone getting anywhere close to doing anything publishable.
So there is no possible way now that I can do two researches this summer. It's either Prof B or Prof A this summer. Would you guys still recommend B even if the chance of publication with Prof A is almost a sure bet or +70%