4,415 research outputs found
Black Hole Production at the Large Hadron Collider
Black hole production at the Large Hadron Collider (LHC) is an interesting
consequence of TeV-scale gravity models. The predicted values, or lower limits,
for the fundamental Planck scale and number of extra dimensions will depend
directly on the accuracy of the black hole production cross-section. We give a
range of lower limits on the fundamental Planck scale that could be obtained at
LHC energies. In addition, we examine the effects of parton electric charge on
black hole production using the trapped-surface approach of general relativity.
Accounting for electric charge of the partons could reduce the black hole
cross-section by one to four orders of magnitude at the LHC.Comment: CTP Symposium on Supersymmetry at LHC: Theoretical and Experimental
Perspectives at the British University in Egypt 11-14 March 200
Negative Refraction Gives Rise to the Klein Paradox
Electromagnetic negative refraction in metamaterials has attracted
increasingly great interest, since its first experimental verification in 2001.
It potentially leads to the applications superior to conventional devices
including compact antennas for mobile stations, imaging beyond the diffraction
limit, and high-resolution radars, not to mention the anamolous wave
propagation in fundamental optics. Here, we report how metamaterials could be
used to simulate the "negative refraction of spin-zero particles interacting
with a strong potential barrier", which gives rise to the Klein paradox--a
counterintuitive relativistic process. We address the underlying physics of
analogous wave propagation behaviours in those two entirely different domains
of quantum and classical.Comment: 4 journal pages, 2 figure
Microcanonical treatment of black hole decay at the Large Hadron Collider
This study of corrections to the canonical picture of black hole decay in
large extra dimensions examines the effects of back-reaction corrected and
microcanonical emission at the LHC. We provide statistical interpretations of
the different multiparticle number densities in terms of black hole decay to
standard model particles. Provided new heavy particles of mass near the
fundamental Planck scale are not discovered, differences between these
corrections and thermal decay will be insignificant at the LHC.Comment: small additions and clarifications, format for J. Phys.
Missing energy in black hole production and decay at the Large Hadron Collider
Black holes could be produced at the Large Hadron Collider in TeV-scale
gravity scenarios. We discuss missing energy mechanisms in black hole
production and decay in large extra-dimensional models. In particular, we
examine how graviton emission into the bulk could give the black hole enough
recoil to leave the brane. Such a perturbation would cause an abrupt
termination in Hawking emission and result in large missing-energy signatures.Comment: addressed reviewer comments and updated reference
Bursts of low-energy electron-positron pairs in TeV-range collider physics
In this Letter we investigate the possible emission of low-energy electron
neutrinos and electron-positron pairs of anomalously large multiplicity in
close-to-central collisions at LHC. The scenario is based on confining
SU(2) Yang-Mills dynamics of Hagedorn temperature keV being
responsible for the emergence of the lightest lepton family and the weak
interactions of the Standard Model. Although cut off by LHC's detectors these
electrons-positron bursts would be seen indirectly by a large defect energy and
thus an anomalously strong decrease of events with interesting high-energy
secondaries for increasing . This is because the formation of
superconducting (preconfining) SU(2) hot-spots `steals' a large fraction of
subsequently transferring it to a thermal spectrum of electron
neutrinos, electrons, and positrons liberated through evaporation. We thus
propose the detection of electrons and positrons of kinetic energy
and photons of energy .Comment: 7 pages and 2 figure
Entangled Light in Moving Frames
We calculate the entanglement between a pair of polarization-entangled photon
beams as a function of the reference frame, in a fully relativistic framework.
We find the transformation law for helicity basis states and show that, while
it is frequency independent, a Lorentz transformation on a momentum-helicity
eigenstate produces a momentum-dependent phase. This phase leads to changes in
the reduced polarization density matrix, such that entanglement is either
decreased or increased, depending on the boost direction, the rapidity, and the
spread of the beam.Comment: 4 pages and 3 figures. Minor corrections, footnote on optimal basis
state
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