481 research outputs found
Uncover Compressed Supersymmetry via Boosted Bosons from the Heavier Stop/Sbottom
A light stop around the weak scale is a hopeful messenger of natural
supersymmetry (SUSY), but it has not shown up at the current stage of LHC. Such
a situation raises the question of the fate of natural SUSY. Actually, a
relatively light stop can easily be hidden in a compressed spectra such as mild
mass degeneracy between stop and neutralino plus top quark. Searching for such
a stop at the LHC is a challenge. On the other hand, in terms of the argument
of natural SUSY, other members in the stop sector, including a heavier stop
and lighter sbottom (both assumed to be
left-handed-like), are also supposed to be relatively light and therefore
searching for them would provide an alternative method to probe natural SUSY
with a compressed spectrum. In this paper we consider quasi-natural SUSY which
tolerates relatively heavy colored partners near the TeV scale, with a
moderately large mass gap between the heavier members and the lightest stop.
Then as companions of and decaying into
generically are well boosted, and they, along with other visible
particles from decay, are a good probe to study compressed SUSY.
We find that the resulting search strategy with boosted bosons can have better
sensitivity than those utilizing multi-leptons.Comment: 19 pages, 6 figures, to appear in EPJ
The Nelson-Seiberg theorem revised
The well-accepted Nelson-Seiberg theorem relates R-symmetries to
supersymmetry (SUSY) breaking vacua, and provides a guideline for SUSY model
building which is the most promising physics beyond the Standard Model. In the
case of Wess-Zumino models with perturbative superpotentials, we revise the
theorem to a combined necessary and sufficient condition for SUSY breaking
which can be easily checked before solving the vacuum. The revised theorem
provides a powerful tool to construct either SUSY breaking or SUSY vacua, and
offers many practicable applications in low energy SUSY model building and
string phenomenology.Comment: 5 pages; v2: abstract and introduction revised; v3: condition of
perturbative superpotentials added, JHEP published versio
New Avenues to Heavy Right-handed Neutrinos with Pair Production at Hadronic Colliders
In many models incorporating the type-I seesaw mechanism, the right-handed
neutrino () couples to heavy vector/scalar bosons and thereby has resonant
pair production. It barely receives attention thus far, however, it may provide
the best avenue to probe TeV scale without requiring anomalously large
mixing between and the active neutrino . In this paper we explore
the discovery prospects of (mainly heavy) pair production at the 14 TeV LHC
and future 100 TeV collider, based on the three signatures: 1) trilepton
from with the
leptonically/hadronically decaying ; 2) boosted di-Higgs boson plus MET from
; 3) a single boosted Higgs with
leptons and MET from . At the
100 TeV collider, we also consider the situation when the Higgs boson is over
boosted thus losing its jet substructure. Interpreting our tentative results in
the benchmark model, the local model, we find that the (multi-) TeV scale
can be probed at the (100) 14 TeV colliders.Comment: 34 pages, 8 figures, version to be published in Phys. Rev.
Simplified Supersymmetry with Sneutrino LSP at 8 TeV LHC
The current searches of supersymmetry (SUSY) are based on the neutralino
lightest sparticle (LSP). In this article we instead focus on SUSY with
sneutrino LSP. It is well motivated in many contexts, especially in which
sneutrino services as a dark matter candidate. We first develop a simplified
model, which contains the stop, chagino/neutralino and sneutrino, to describe
the LHC phenomenologies of a large class of models with sneutrino LSP. Then we
investigate bounds on the model using the SUSY searches at the 8 TeV LHC.
Strong exclusion limits are derived, e.g., masses of stop and chargino can be
excluded up to about 900 GeV and 550 GeV, respectively. We also propose
optimizations for some searches without turning to higher energy and
luminosity.Comment: 26 pages, 8 figures,Minor corrections,References adde
Probing the CP-even Higgs Sector via in the Natural NMSSM
After the discovery of a Standard Model (SM) like Higgs boson, naturalness
strongly favors the next to the Minimal Supersymmetric SM (NMSSM). In this
letter, we point out that the most natural NMSSM predicts the following CP-even
Higgs sector: (A) is the SM-like Higgs boson with mass
pushed-upward by a lighter with mass overwhelmingly within
; (B) GeV; (C)
has a significant coupling to top quarks and can decay to with a
large branching ratio. Using jet substructure we show that all the three Higgs
bosons can be discovered via at
the 14 TeV LHC. Especially, the LEP-LHC scenario with GeV has a
very good discovery potential.Comment: 5 pages, 2 figures. Some typos corrected and reference adde
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