Search

We study the relation between the existence of the logarithmic prefactor and spacetime dimensionality in black hole entropy relation by a detailed study of a TeV-scale black hole entropy. In a model universe with large extra dimensions and within the Generalized Uncertainty Principle (GUP) framework, we show that probability of black hole production in the Large Hadronic Collider (LHC) decreases for sufficiently large values of the GUP parameter. In this regard, even observation of micro-black holes may be suppressed at TeV energy scale. We determine also the GUP parameter in an extra dimensional scenario by comparing black hole entropy calculated within the GUP and loop quantum gravity frameworks. [ABSTRACT FROM AUTHOR]

A particle scattered off by a rotating black hole can be amplified when the system is in the superradiant regime. If the system is surrounded by a mirror which reflects the particle back to the black hole the whole system forms a black-hole bomb, amplifying the original field exponentially. We show in this paper that higher-dimensional black holes can also form black-hole bombs at the LHC. For a pion the e-folding time for the field amplification is tc ~ 10-23-10-24sec. If the lifetime of the black hole is long enough compared with tc, we can observe severely amplified fields. [ABSTRACT FROM AUTHOR]

In curved space-time near TeV black holes many gluons and quarks produced by the Unruh effect interact with each other and create Higgs bosons. We study the Unruh effect and show that, for gluons and quarks, the internal stationary state of a Schwarzschild black hole can be represented by a maximally entangled two-mode squeezed state of outgoing and infalling Hawking radiation. We consider different channels for Higgs boson production near event horizons of mini black holes at the Large Hadron Collider (LHC) and obtain the cross section in each channel. We observe that the cross section of a Higgs boson produced via gluon fusion near a single black hole is much larger for smaller black hole masses. This is because the temperature of the black hole becomes larger as the mass becomes smaller and the thermal radiation of the gluons is enhanced. At lower mass, MBH < 4 TeV, the black hole will not be able to emit Higgs, but will still be able to produce a quark; for MBH < 3 TeV the black hole can only emit massless gluons. We show that as the black hole mass at the LHC increases (4 TeV < MBH < 8 TeV) most of the Higgs boson production is due to the Unruh effect near the event horizon of the black hole. Comparing these Higgs boson cross sections with Higgs boson cross sections in perturbative quantum chromodynamics, we find that micro black holes can be a source of Higgs production at the LHC. Finally, we calculate the effects of Higgs boson radiation due to mini black holes on the hadronic cross section at the LHC. We observe that as the order of perturbation theory increases this effect becomes systematically more significant because at higher orders there exist more channels for Higgs production and, in our calculations, Higgs decay into massive quark-antiquark pairs. At smaller masses, MBH < 2 TeV, the hadronic cross section at leading order is large while the cross sections at next-to-leading order and at next-to-next-to-leading order are rising at MBH ∼ 2 and 3 TeV, respectively, and exhibit a turn-over at moderate values of black hole mass. [ABSTRACT FROM AUTHOR]

Abstract: A search for microscopic black hole production and decay in pp collisions at a center-of-mass energy of 7 TeV has been conducted by the CMS Collaboration at the LHC, using a data sample corresponding to an integrated luminosity of 35 pb−1. Events with large total transverse energy are analyzed for the presence of multiple high-energy jets, leptons, and photons, typical of a signal expected from a microscopic black hole. Good agreement with the standard model backgrounds, dominated by QCD multijet production, is observed for various final-state multiplicities and model-independent limits on new physics in these final states are set. Using simple semi-classical approximation, limits on the minimum black hole mass are derived as well, in the range 3.5–4.5 TeV. These are the first direct limits on black hole production at a particle accelerator. [Copyright &y& Elsevier]

brief survey of the present-day status of the problem of multidimensional-black-hole production at accelerators according to models featuring large extra dimensions is given. The respective production cross section and the Hawking temperature and decay rate are estimated versus model parameters. Possible flaws and assumptions whose accurate inclusion can reduce significantly the probability of blackhole production at accelerators in relation to earlier optimistic estimates are also discussed. [ABSTRACT FROM AUTHOR]

We study the unitarity of models with low scale quantum gravity both in four dimensions and in models with a large extra-dimensional volume. We find that models with low scale quantum gravity have problems with unitarity below the scale at which gravity becomes strong. An important consequence of our work is that their first signal at the Large Hadron Collider would not be of a gravitational nature such as graviton emission or small black holes, but rather would be linked to the mechanism which fixes the unitarity problem. We also study models with scalar fields with non-minimal couplings to the Ricci scalar. We consider the strength of gravity in these models and study the consequences for inflation models with non-minimally coupled scalar fields. We show that a single scalar field with a large non-minimal coupling can lower the Planck mass in the TeV region. In that model, it is possible to lower the scale at which gravity becomes strong down to 14 TeV without violating unitarity below that scale. [ABSTRACT FROM AUTHOR]

The framework of large extra dimensions provides a way to explain why gravity is weaker than the other forces in nature. A consequence of this model is the possible production of D-dimensional black holes in high energy p–p collisions at the Large Hadron Collider. The present work uses the CATFISH black hole generator to study quantitatively how these events could be observed in the hadronic channel at midrapidity using a particle-tracking detector. [ABSTRACT FROM AUTHOR]

Abstract: The upcoming high energy experiments at the LHC are one of the most outstanding efforts for a better understanding of nature. It is associated with great hopes in the physics community. But there is also some fear in the public, that the conjectured production of mini black holes might lead to a dangerous chain reaction. In this Letter we summarize the most straightforward arguments that are necessary to rule out such doomsday scenarios. [Copyright &y& Elsevier]

Searches for transient astrophysical pulses could open an exciting new window into the fundamental physics of quantum gravity. In particular, an evaporating primordial black hole in the presence of an extra dimension can produce a detectable transient pulse. Observations of such a phenomenon can in principle explore the electroweak energy scale, indicating that astrophysical probes of quantum gravity can successfully complement the exciting new physics expected to be discovered in the near future at the Large Hadron Collider. [ABSTRACT FROM AUTHOR]

Black hole production at the Large Hadron Collider (LHC) was first discussed in 1999. Since then, much work has been performed in predicting the black hole cross-section. In light of the start up of the LHC, it is now timely to review the state of these calculations. We review the uncertainties in estimating the black hole cross-section in higher dimensions. One would like to make this estimate as precise as possible since the predicted values, or lower limits, obtain for the fundamental Planck scale and number of extra dimensions from experiments will depend directly on the accuracy of the cross-section. Based on the current knowledge of the cross-section, we give a range of lower limits on the fundamental Planck scale that could be obtained at LHC energies. [ABSTRACT FROM AUTHOR]

Recently, a model for charged black hole production and decay at LHC has been constructed. These results can be extended to multiverse. Because, it is obviously that there a enough energy in the cosmic rays to produce charged Universe. It is observed that these Universes are defined by their gauge charges. Consequently, gauge charges should be produced before charged Universes in multiverse. There are different methods for producing gauge charges in multiverse. However, it seems that more charges are created due to curved space-time near one bigger horizon that multiverse is located in it. The thermal distributions for gauge charges is more for higher charge energy and less for lower charge energy in multiverse. [ABSTRACT FROM AUTHOR]