The muons from the beam dump make the CSCs fire. The reconstruction algorithm looks at these hits and tries to make a centrally generated muon (Red Lines). However, these muons aren’t coming from the center, so the reconstruction is invalid.

Thanks for sharing this unusual “event” with us. For the benefit of your audience would you explain how you know the muons are incorrectly reconstructed and why the software makes this “mistake”. (You did say that muons were present. What’s incorrect about the reconstruction?) This would give your audience several insights into the workings of a collider detector and the associated reconstruction software.

Alternatively you could challenge your non-particle physics portion of your audience to come up with an explanation to see what sort of discussion ensues over the next 2-3 days.

Thanks,
Pat

I’m just catching-up on Doug’s blog posts this past month. I’m glad to see he corralled you to give us an overview of the ongoing and upcoming system commissioning efforts especially in the photon sector.

Thanks for your remarks. You gave us a nice glimpse into the early stages of the data quality checks that you and your colleagues are conducting.

Pat

You said and your photo shows that there was no one else in the Meyrin CMS Center when you took the photo at 7am. I’m surprised the night shift wasn’t still there? Was the beam off the night before? The CMS Center looks like a comfortable and well-equipped area to work.

Pat