How does Savas Dimopoulos' latest paper challenge current SUSY collider limits?

[twistor]

http://arxiv.org/pdf/1412.0805.pdf
Auto-Concealment of Supersymmetry in Extra
Dimensions
Savas Dimopoulos,a Kiel Howe,a,b John March-Russell,c,a James Scovillec,d
aStanford Institute for Theoretical Physics, Department of Physics,
Stanford University, Stanford, CA 94305, USA
bSLAC National Accelerator Laboratory
Menlo Park, CA 94025 USA
cRudolf Peierls Centre for Theoretical Physics, University of Oxford
1 Keble Road, Oxford, OX1 3NP, UK
dUnited States Air Force Institute of Technology
Wright-Patterson Air Force Base, OH 45433, USA
E-mail: savas@stanford.edu, howek@stanford.edu, jmr@thphys.ox.ac.uk,
james.scoville@physics.ox.ac.uk
Abstract: In supersymmetric (SUSY) theories with extra dimensions the visible energy
in sparticle decays can be significantly reduced and its energy distribution broadened, thus
significantly weakening the present collider limits on SUSY. The mechanism applies when
the lightest supersymmetric particle (LSP) is a bulk state—e.g. a bulk modulino, axino, or
gravitino—the size of the extra dimensions >∼ 10−14 cm, and for a broad variety of visible sparticle
spectra. In such cases the lightest ordinary supersymmetric particle (LOSP), necessarily
a brane-localised state, decays to the Kaluza-Klein (KK) discretuum of the LSP. This dynamically
realises the compression mechanism for hiding SUSY as decays into the more numerous
heavier KK LSP states are favored. We find LHC limits on right-handed slepton LOSPs evaporate,
while LHC limits on stop LOSPs weaken to ∼ 350 ÷ 410 GeV compared to ∼ 700 GeV
for a stop decaying to a massless LSP. Similarly, for the searches we consider, present limits
on direct production of degenerate first and second generation squarks drop to ∼ 450 GeV
compared to ∼ 800 GeV for a squark decaying to a massless LSP. Auto-concealment typically
works for a fundamental gravitational scale of M∗ ∼ 10 ÷ 100 TeV, a scale sufficiently
high that traditional searches for signatures of extra dimensions are mostly avoided. If superpartners
are discovered, their prompt, displaced, or stopped decays can also provide new
search opportunities for extra dimensions with the potential to reach M∗ ∼ 109 GeV. This
mechanism applies more generally than just SUSY theories, pertaining to any theory where
there is a discrete quantum number shared by both brane and bulk sectors.
It seems amazing and gives me hope :) I was missing you, SUSY

 

[twistor]

Why hasn't my post been replied to?

 

[MTd2]

Because SUSY looks like crying wolf at a dead horse. What is so good here that made you hopeful?

 

[ChrisVer]

I think section 3, with the weakening of SUSY searches...

 

[Haelfix]

Because SUSY looks like crying wolf at a dead horse. What is so good here that made you hopeful?

Perhaps it may be to you, but certainly not to the vast majority of high energy theorists and working phenomenologists out there; this sort of thing has been the topic of several big conferences of late. This paper's explicit model is part of a more general way that supersymmetry can be difficult to detect, even at well trodden energy ranges, which is known as a compressed spectrum.

Unfortunately it will be a very long time before we have any sort of final say on these matters, it just takes a lot of work and very careful searches to eliminate the enormous parameter space that is out there.

 

[MTd2]

Unfortunately the vast majority(?) does not post here. So, to the vast majority(?) of casual observers, this is like beating a dead horse. And it may be just a matter of time until young casual observers get fed up with this and just give up.

 

[ChrisVer]

Well it's not a dead horse. The fact that SUSY gets disfavored as a candidate solution to the Hierarchy problem, doesn't mean it gets disfavored in general [in fact it's needed in lots of applications].