## Saturday, April 02, 2005

### Supersplit supersymmetry

This paper by eight phenomenologists

is well done. You have to read the abstract - or the paper - quite carefully to become sure that it is an April fool's day hoax. Alternatively, you must know that some of the 8 authors are known to dislike supersymmetry.

What do these guys do? They take the models of split supersymmetry and improve it a little bit so that all remaining superpartners are sent to the Planck scale. This solves about 15 different problems of SUSY breaking - such as the gaugino decay problem, the flavor changing neutral currents, and so on. :-) The resulting model may resemble a model by Glashow, Salam, Weinberg at low (sub-Planckian) energies, but their motivation was not quite correct, the present authors say.

I think that such form of criticism is healthy, and despite my belief that SUSY is beautiful, realistic, and worth considering, I sympathize with many points of their paper. Let's hope that Nima and Savas won't be too upset. ;-) Let's also emphasize that the supersplit supersymmetry fails to reproduce some successes of split (and other) supersymmetry - at least one of them, namely the gauge coupling unification.

1. Lubos, that's a good one. I never realized that it was a paper specifically written for April Fools day, until after I read your above comments.

No, that's NOT because I did not realize it was a joke. I DO fully realize the paper was a joke at first glanz. So when some one on Peter's blog refered the paper as a joke, I agreed and did not think more. The problem is I did NOT realize that the authors were MEANT to make a joke, which is a bit un-usual, instead of the more common cases where the authors thought they published something serious but it was just jokes.

Seriously, it's no longer april 1st, the sad fact is 99% of publications on ARXIV these days are all jokes. So it is sometimes hard to determine whether the author intend to make a joke, or are they un-intentionally making themselves a joke.

Quantoken

2. This comment has been removed by a blog administrator.

3. Lubos:

Want to comment on recent discovery of a extra-solar planet by direct photon detection?

First confirmed picture of a planet beyond the solar system

http://space.com/

It is also reported on CNN, too Astronomers capture photo of extrasolar planet
http://www.cnn.com/2005/TECH/space/04/01/extrasolar.planet.photo/index.html

Quantoken

4. Quantoken's word unification: "glanz" stands equally well for glance as for glands. The latter in turn may be the core of the problem. A hyperactive thyroid gland can cause strange behaviour and psychiatric problems, like Quantoken's. So please, Quantoken, go to a doctor and have hime have a glanz at your glanz, will you!?

5. If he spells "glance" as "glanz", it mostly likely means he has an accent. "glance" is pronounced with an 's', not a 'z'.

6. This reminds me of a favorite model building tactic:

1. Come up with a model which gives rise to an MSSM or SM spectrum at low energies.

2. Tweak the field content and/or parameters of the model so that new physics only occurs at high enough energy scales.

3. Compute the phenomenological constraints. A low proton decay lifetime? Tweak, tweak, tweak. A doublet-triplet splitting problem? Tweak, tweak, tweak. Too large a CKM mixing angle? Tweak, tweak, tweak. Monoples and cosmic strings? Oh, they'll be inflated away; don't worry.

4. In most models, there is often a region in parameter space which satisfies these constraints. It corresponds to the case where the model looks like MSSM/SM up to some arbitrarily high scale, and that scale can always be pushed higher if needed.

5. So, having satisfied the constraints, write up yet a paper.

7. Are these models a 'tweak category' (or is it too late for April's Fooling around? :-)?

8. Gauge coupling strength unification is no big deal especially when we don't even have any evidence for Grand Unification (what a silly name). Even if there is Grand Unification, who knows about threshold effects? And besides, with the orbifold theories all in rage nowadays, we can always add a brane localized term to "correct" for (oops, did I say correct? I meant "fit") any mismatches.