Paper available at link
Theoretical survey of tidal-charged black holes at the LHC
Roberto Casadio, Sergio Fabi, Benjamin Harms, Octavian Micu
(Submitted on 10 Nov 2009)
Abstract: We analyse a family of brane-world black holes which solve the effective four-dimensional Einstein equations for a wide range of parameters related to the unknown bulk/brane physics. We first constrain the parameters using known experimental bounds and, for the allowed cases, perform a numerical analysis of their time evolution, which includes accretion through the Earth. The study is aimed at predicting the typical behavior one can expect if such black holes were produced at the LHC. Most notably, we find that, under no circumstances, the black holes would reach the (hazardous) regime of Bondi accretion. Nonetheless, the possibility remains that black holes live long enough to escape from the accelerator (and even from the Earth's gravitational field) and result in missing energy from the detectors.
http://arxiv.org/abs/0911.1884v1
From
Man-Made (But Very Tiny) Black Holes Possible (Discovery News, Ian O'Neill, Nov 12)
...
So, what did the researchers from Italy, US and Germany find out?
"First, we found that tidal black holes would evaporate (almost) instantly," says Roberto Casadio from the University of Bologna, Italy, and his three colleagues in their publication titled Theoretical survey of tidal-charged black holes at the LHC.
This is all well and good, but what if a micro-black hole shoots through the Earth at high speed?
"[We] show that the black holes with a large value of the initial momentum would cross the Earth in a matter of seconds and come out with velocities much larger than the Earth's escape velocity," say Casadio et al.
Once these speeding black holes pop out the other side of the Earth, they stop accreting mass (from the Earth's interior) and are flung into space and evaporate as they radiate Hawking Radiation. But don't worry about these welterweights punching a hole in the ground beneath you, on the entire trip through our planet, a single black hole will have swept up a meager 10-22 kg of rock.
10-22 kg is the mass of a hemoglobin molecule inside a red blood cell.
But say if the black hole isn't very speedy and it drops like a stone into the Earth... and stays there?
The researchers point out that the slower the black hole, the less mass it accretes; so although it might pop out of the LHC and sink into our planet, it will suck up very little mass.
If a slow-moving micro-black hole set up home inside Earth and sat there for 13.7 billion years (the age of the Universe), it would weigh in at a puny 10-18 kg (the mass of a virus).
"Our overall conclusion is therefore that the tidal charged black holes are a viable model of micro-black holes which might be produced at the LHC. The model predicts that such black holes cannot grow to catastrophic size, but might live long enough to escape the detectors and result in significant amounts of missing energy." --Casadio et al., 2009
When the LHC gets fired up in the coming weeks, let's see if any energy goes "missing" after a particle collision, it might be a sign of black hole birth (but not of the "Earth-munching" variety).
http://news.discovery.com/space/the-lhc ... raner.html
