Thanks, I see. Was thinking too complicatd Have a nice weekend, B.

Discovering mirror particles at the Large Hadron Collider and the implied cold universe

The Mirror Matter or Exact Parity Model sees every standard particle, including the physical neutral Higgs boson, paired with a parity partner. The unbroken parity symmetry forces the mass eigenstate Higgs bosons to be maximal mixtures of the ordinary and mirror Higgs bosons. Each of these mass eigenstates will therefore decay 50% of the time into invisible mirror particles, providing a clear and interesting signature for the Large Hadron Collider (LHC) which could thus establish the existence of the mirror world. However, for this effect to be observable the mass difference between the two eigenstates must be sufficiently large. In this paper, we study cosmological constraints from Big Bang Nucleosynthesis on the mass difference parameter. We find that the temperature of the radiation dominated (RD) phase of the universe should never have exceeded a few 10’s of GeV if the mass difference is to be observable at the LHC. Chaotic inflation with very inefficient reheating provides an example of how such a cosmology could arise. We conclude that the LHC could thus discover the mirror world and simultaneously establish an upper bound on the temperature of the RD phase of the universe.

The masses of the KK graviton excitations in the Randall-Sundrum model are proportional to the roots of the J_1 Bessel function. The first root, which sets the scale for the first excitation, has a value of 3.83. One of the main signatures for a warped extra dimension is that the KK states are not evenly spaced, but have spacings proportional to roots of Bessel functions. As I said, ‘Graviton383′ clearly knows his/her Randall-Sundrum phenomenology.

well, I was about to give you the reference, but I guess you are familiar with it

I don’t necessarity believe that microscopic BH physics is T invariant… Even macroscopic BH physics is not T invariant since Hawking radiation is a statistical process but stellar collapse is not.

Yep, that’s the same answer I give when someone comes up with that point. That’s what my brain says. However, my stomach expects the universe to be nice and pretty, such that it allows elementary process back as well as forth. So, I agree with you that relics aren’t excluded, but to be honest, I just don’t believe in it.

Best, B.

PS
JoAnne: the fact that the very name graviton383 shows intimate and deep knowledge of the phenomenology of the Randall-Sundrum model
I don’t get it, can you give me a hint?

That would be extraordinarily bad for a number of reasons.

But yea the nondiscovery of the Higgs or alternatives (and im skeptical about some of those proposals) would be catastrophic. If for no other reason than they are more or less guarenteed to be there by no lose theorems. The electroweak sector would then be formally inconsistent and we would be stuck.

Hack, comment #1: The real problem is that almost nobody is expecting the unexpected. The majority think that not only will SUSY show up, but it will be our most studied benchmark point SUSY SPS1a! If SUSY shows up and it’s not the benchmark point in parameter space we have studied well (i.e., point SPS1a) we might be terribly confused.

Thanks for you comments, I have heard these arguments
but I don’t necessarity believe that microscopic BH physics is T invariant… Even macroscopic BH physics is not T invariant since Hawking radiation is a statistical process but stellar collapse is not. Thanks for the
reference to the work of Rizzo..I am very familiar with it..I wrote it.

I see no reason based on existing data why such things can’t exist since we don’t know the threshold mass scale or the number of extra dimensions

Yep I agree, there is a lot we don’t know, and we certainly don’t know for sure whether black hole relics can exist or not. Imo we know even much less about black hole evaporation than is commonly believed to be “true”. However, the question relics or not has not a priory anything to do with the threshold or the # of extra dims (unless you think of higher curvature corrections to GR, see e.g. work by Rizzo, there the # of extra dims is crucial).

The most common arguments against relics (both of which I think don’t hold) are the necessity for an arbitrarily large information content (based on a misinterpretation of the black hole’s entropy) and an enormous phase space for the pair production (which follows from the first argument, and therefore is also a misconception).

The reason why I don’t like black hole relics is that their existence breaks time-reversal symmetry. If a black hole can be formed in a collision of two particles, I expect it should be able to decay in the reverse process.

Hi Tony,

right. But that is not the patent Horst holds. He does not want to extract energy from the hole. He just wants to use it to convert energy. Like a very efficient fire place, with the extra virtue that it absolutely does not care what you throw in.

Best,

B.