Abstract
We present cross-sections for the black hole and string ball production in proton-proton collisions in a TeV-scale gravity model with split fermions in two dimensions. The cross-section for black hole and string ball production in the split-fermion model is smaller than in the non-split-fermion model. The drop of the cross-section for the string ball production can be one to two orders of magnitude with the increase of the width of the brane from $L=0$ to 15 $\text{TeV}^{-1}$. The cross-section for string ball production in two-dimensional split fermion model reduces more in comparison to black holes. Black holes are quite hard to be observed at the LHC. In fact, taking into account the current experimental limits on the fundamental Planck scale, black holes cannot be produced at the LHC. Cross-section for string ball production depends significantly on string coupling constant, making it very model dependent. We investigate the range of values of string coupling constant from 0.02 to 0.4. There has been no evidence for production of string balls at $\sqrt{s}=8$ TeV. A two-dimensional split fermion model with a extremely thick brane can account for the absence of signature of string balls for a world with the value of fundamental Planck scale even as low as 1 TeV.
Highlights
IntroductionThe analysis of black hole production in colliders range from using a simple πrg form for the cross-section, where rg is the gravitational radius of the black hole formed in the parton scattering process [12,13,14], to calculations based on classical general relativity using the trapped-surface approach [15,16,17]
We present cross-sections for the black hole and string ball production in proton-proton collisions in a TeV-scale gravity model with split fermions in two dimensions
The analysis of black hole production in colliders range from using a simple πrg2 form for the cross-section, where rg is the gravitational radius of the black hole formed in the parton scattering process [12,13,14], to calculations based on classical general relativity using the trapped-surface approach [15,16,17]
Summary
The analysis of black hole production in colliders range from using a simple πrg form for the cross-section, where rg is the gravitational radius of the black hole formed in the parton scattering process [12,13,14], to calculations based on classical general relativity using the trapped-surface approach [15,16,17]. If the black hole is produced at the LHC, it would decay to final states with a relatively high multiplicity. The black hole could make a transition to a highly-excited string state as it evaporates. As the black hole shrinks, it eventually reaches the “correspondence point” Mmin ∼ Ms/gs, (where Ms is the string scale related to the fundamental Planck mass and gs is the dimensionless string coupling constant), and makes a transition to a configuration dominated by a highly-excited long string called a string ball [31,32,33]. If the Planck scale is a few TeV, the mass of the black hole has to be close to the maximum LHC energy for it to be described by general relativity. ATLAS collaboration has performed a search for an excess of events with multiple high transverse momentum objects including charged leptons and jets, using 20.3 fb−1 of proton-proton collision data recorded by the ATLAS detector at the Large Hadron Collider
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
