Black Holes at the LHC

Abstract

If the scale of quantum gravity is near a TeV, the LHC will be producing one black hole (BH) about every second. The BH decays into prompt, hard photons and charged leptons is a clean signature with low background. The absence of significant missing energy allows the reconstruction of the mass of the decaying BH. The correlation between the BH mass and its temperature, deduced from the energy spectrum of the decay products, can test experimentally the higher dimensional Hawking evaporation law. It can also determine the number of large new dimensions and the scale of quantum gravity.

Figures (3)

• Figure 1: a) Parton-level production cross section, b) differential cross section $d\sigma/d\hbox{$M_{\rm BH}$}$ at the LHC, c) Hawking temperature, and d) average decay multiplicity for a Schwarzschild black hole. The number of extra spatial dimensions $n=4$ is used for a)-c). The dependence of the cross section and Hawking temperature on $n$ is weak and would be hardly noticable on the logarithmic scale.
• Figure 2: Number of BHs produced at the LHC in the electron or photon decay channels, with 100 fb$^{-1}$ of integrated luminosity, as a function of the BH mass. The shaded regions correspond to the variation in the number of events for $n$ between 2 and 7. The dashed line shows total SM background (from inclusive $Z(ee)$ and direct photon production). The dotted line corresponds to the $Z(ee)+X$ background alone.
• Figure 3: Determination of the dimensionality of space via Wien's displacement law at the LHC with 100 fb$^{-1}$ of data.