Following a question from a student, I thought all of you might benefit from this guidance:
You don’t need an
abstract or acknowledgements or a contents list. You need to have a
brief introduction to the overall experiment and then discuss in detail
those sub-systems that are critical for selecting and reconstructing the
events you are concerned with.
One possible section heading, amongst a number, in your report might be “Lepton energy measurement”.
This published, open-access paper on the CMS electromagnetic calorimeter shows the appropriate style:
https://iopscience.iop.org/article/10.1088/1748-0221/5/03/T03010