## Friday, June 10, 2011

### CMS at 190/pb: LHC avoids black hole production

The CMS Collaboration has published a new paper that also answers the question whether the Earth is going to be swallowed by a man-made black hole.

You can be sure that everything is fine and the Earth isn't being eaten yet. To be sure, here are the webcams near the CMS experiment and the LHC building. You may watch it to get assured that our planet is safe. ;-)

If you want to check that the LHC is safe with some music...

Indeed, even after 190 inverse picobarns, there's no black hole:
Search for black holes in pp collisions at sqrt(s) = 7 TeV
They studied final states with many - e.g. 10 - objects such as jets, leptons, and photons which carry a high energy such as 1 TeV or more. They would be a sign of an evaporating black hole. An agreement with the Standard Model background is found. I choose not to get excited by some occasional 2-sigma-like excess etc.

If there were low-energy string theory in Nature around us, I would still expect the string scale to be of order 3 TeV but the quantum gravity scale - the mass of the lightest black holes worth the name - would probably be significantly greater than that (an order of magnitude or more) and inaccessible at 7 TeV and maybe even at 14 TeV. So I personally view this experiment as a formality. But surprises may come at unexpected times...