
Supersymmetry theory in doubt. Researchers detect rare particle decay at LHC. - pepsi_can
http://www.bbc.co.uk/news/science-environment-20300100
======
Steuard
This article conflates all sorts of loosely connected ideas and buzzwords
without really giving a solid explanation of any of them (least of all this
new result). A more focused look at this particular (but quite preliminary)
result can be found at

[http://www.science20.com/quantum_diaries_survivor/lhcb_evide...](http://www.science20.com/quantum_diaries_survivor/lhcb_evidence_rare_decay_bs_dimuons-96311)

From the sound of it, many of the details won't become available until a
seminar tomorrow. (Nevertheless, it sounds like this really will constrain
many forms of "new physics" by quite a bit.)

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InclinedPlane
I would just like to take a moment here to draw attention to the fact that the
planned Superconducting Supercollider would have been even more capable at
probing supersymmetry than the LHC and had it not been cancelled it would have
been operating for well over a decade by now.

~~~
jessriedel
That time frame is not really accurate. Big accelerators, like many massive
projects, are always years behind schedule. Back before the SSC was canceled,
it and the LHC were both scheduled to turn on about a decade ago. But since
the LHC actually got built, it experienced the real-life hiccups that would
have delayed the SSC by years too.

~~~
InclinedPlane
I believe you are mistaken. The LEP and the SSC started early construction at
about the same time, and the SSC was cancelled in the early 90s while the LEP
started operations in '89. Construction of the LHC did not begin until the
late 90s, well after the SSC had been cancelled and operations began about a
decade after construction started. Even taking into account thee advantage the
LHC had in being able to reuse the LEP tunnels and some of the existing
infrastructure the likelihood of the SSC being able to become operational in
the early 2000s is fairly high.

~~~
jessriedel
I guess we'll continue to disagree in the absence of an expert. My information
comes from a discussion I had with two professors who migrated to CMS at LHC
after the SSC was canceled. They agreed that the real tragedy of the loss of
the SSC was the higher energy, and that with realistic estimates for the SSC
schedule the timing advantage would have been minimal.

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ISL
Useful links here:

[http://profmattstrassler.com/2012/11/12/first-news-from-
kyot...](http://profmattstrassler.com/2012/11/12/first-news-from-kyoto-
conference/)

<http://www.math.columbia.edu/~woit/wordpress/?p=5264>

Talk is here (follow password instructions):
[http://kds.kek.jp/getFile.py/access?contribId=61&session...](http://kds.kek.jp/getFile.py/access?contribId=61&sessionId=25&resId=0&materialId=slides&confId=9237)

~~~
mlmilleratmit
I can personally vouch for Matt Strassler's writing, he is one of the most
trusted and readable theorists in the field.

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mercuryrising
Humans are running in a relay marathon of knowledge. Physics always seems to
stagnate, then jump. The jumps come when a bunch of smart people can collocate
and communicate. That's the recipe, and that's the only recipe. It's hard to
share the energy in the room when you are not in the same room.

The cause of the jump though is not a bunch of people getting together, it's
someone crazy enough to throw the first stone. It's someone crazy enough to
question the structure science has created. It's someone daring enough to
break it all apart, for the benefit of humanity, to let us rebuild and get
closer to the correct path. One person starts a revolution. All the smart
people look at all the pieces that broke and see how they can fit together in
a new way.

I can't see this happening in 'new physics'. Yes, they are doing amazing
things, things no one has ever been daring enough to do before. But quite
frankly, they aren't diverse enough to solve their own problems they created.
It's incredibly hard to solve the problems you made. There are no analogies to
the problems physics is asking as of yet. To get analogies, you have to have
people wander into your problem and say 'Hey! I was doing something like that
for my Neuroscience research yesterday, maybe there's a connection!'. We
aren't going to get that though, Physics has gone too far down the hole to
relate to other fields. Unless they do what they always do, and just make new
ones.

~~~
Daniel_Newby
You must be watching different physics research than me. I see a huge variety
of crazy-ass physics proposed all the time. Unfortunately it all keeps turning
out to be wrong.

The problem with physics these days is that no "sharp" new data is turning up.
Instead of turning up a new family of particles in an accelerator, we find big
invisible blobs of dark matter. We are getting loads of fascinating
unexplained data, but there are few bright line tests that can use it to rule
in or out new theories.

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pepsi_can
There is an interesting discussion about this on Reddit:

[http://www.reddit.com/r/science/comments/13293t/supersymmetr...](http://www.reddit.com/r/science/comments/13293t/supersymmetry_theory_dealt_a_blow_researchers_at/)

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andrewcooke
can anyone confirm my understanding of the basic physics here?

they are observing a transition from one particle to another that involves a
process whose probability depends on "all particles" in some weird sense,
because it includes particle-antiparticle pairs (so is affected by vacuum
fluctuations?).

because of this, they have a weird situation where an experimental result
depends on all possible particles (below some energy cutoff i guess).

and that is why it's a good test for standard model v super-symmetry. because
super-symmetry (to be symmetric) predicts a bunch more particles. and if those
are real, we would see something different.

i am not sure where i got this from, but it seemed to be implied by one of the
links here...

~~~
mlmilleratmit
Yep, you've pretty much got it right. It is an indirect probe of new physics,
not a direct probe. However, that method is well established. Some of the
strongest constraints for new physics come from things like neutron dipole
moment and studies of the g-factor of the muon (see g-2 or "g minus 2"
online). These indirect methods make use of the virtual particles that arise
from vacuum fluctuations in ways that are cleanly calculable (and thus make
quantitative predictions).

All that said, SUSY has about 100 free parameters in the model, and all of
these LHC searches hoped to find SUSY in the easiest of places, even though
there is no firm prediction from the theory. Simply put, for a long time to
come, SUSY can be "tuned" to remain consistent with all existing physical
data.

------
jasondavies
The "doubt" seems to have been refuted here:

[http://motls.blogspot.cz/2012/11/superstringy-
compactificati...](http://motls.blogspot.cz/2012/11/superstringy-
compactifications.html)

------
wheelerwj
Patience my good people. We all remember what happened the last time there was
a rare particle delay...

~~~
stingraycharles
Out of curiosity: what are you referring to?

~~~
louthy
The barman says "We don't serve neutrinos here"

A neutrino walks into a bar.

~~~
giardini
Isn't that a tachyon?

~~~
xentronium
The news was that neutrino was measured to have FTL speed.

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pyrotechnick
Tesla was right.

------
Create
just for the record and to please the prospective downvoting mob, in order to
warn any non-westerners:

"The cost [...] has been evaluated, taking into account realistic labor prices
in different countries. The total cost is X (with a western equivalent value
of Y) [where Y>X]

source: LHCb calorimeters : Technical Design Report

ISBN: 9290831693 <http://cdsweb.cern.ch/record/494264>

<http://cdsweb.cern.ch/record/1127343?ln=en>

~~~
Symmetry
I've gotta say, you sound sort of like you think you have a point and that you
think it might be controversial, but I have no idea what it might be.

~~~
scott_s
Search for any post about CERN, and you'll find his posts like the above.

From what I can tell, he's claiming that CERN discriminates against non-
Western people. His evidence is a budget report, where they estimate how much
something will cost based on the amount of people involved. The calculation
adjusts for where the people are located, and the cost is higher if they're in
a Western country.

~~~
DiabloD3
There are Japanese and Indians who work for CERN, so I think hes just
trolling.

~~~
Create
Japan and India (China, Russia, Brazil) are not CERN member states.

But there are Eastern European, CERN member states. Some from there work for
CERN, in Switzerland.

Do not think, that value as in monetary value just stays in a spreadsheet cell
at HR. The evaluation has consequences in all other evaluations, peer
evaluations etc. It does contribute to the evaluation of contributions etc.

