1,477 research outputs found
Emerging Jets
In this work, we propose a novel search strategy for new physics at the LHC
that utilizes calorimeter jets that (i) are composed dominantly of displaced
tracks and (ii) have many different vertices within the jet cone. Such emerging
jet signatures are smoking guns for models with a composite dark sector where a
parton shower in the dark sector is followed by displaced decays of dark pions
back to SM jets. No current LHC searches are sensitive to this type of
phenomenology. We perform a detailed simulation for a benchmark signal with two
regular and two emerging jets, and present and implement strategies to suppress
QCD backgrounds by up to six orders of magnitude. At the 14 TeV LHC, this
signature can be probed with mediator masses as large as 1.5 TeV for a range of
dark pion lifetimes, and the reach is increased further at the high-luminosity
LHC. The emerging jet search is also sensitive to a broad class of long-lived
phenomena, and we show this for a supersymmetric model with R-parity violation.
Possibilities for discovery at LHCb are also discussed.Comment: 45 pages, 22 figures. v2: Typos fixed. v3: Minor modifications,
references added, version accepted in JHEP. Supplementary code can be found
at github.com/pedroschwaller/EmergingJet
Light third-generation squarks from flavour gauge messengers
We study models of gauge-mediated supersymmetry breaking with a gauged
horizontal SU(3)_F symmetry acting on the quark superfields. If SU(3)_F is
broken non-supersymmetrically by F-term vacuum expectation values, the massive
gauge bosons and gauginos become messengers for SUSY breaking mediation. These
gauge messenger fields induce a flavour-dependent, negative contribution to the
soft masses of the squarks at one loop. In combination with the soft terms from
standard gauge mediation, one obtains large and degenerate first- and
second-generation squark masses, while the stops and sbottoms are light. We
discuss the implications of this mechanism for the superparticle spectrum and
for flavour precision observables. We also provide an explicit realization in a
model with simultaneous SUSY and SU(3)_F breaking.Comment: 25 pages, 7 figure
Little composite dark matter
We examine the dark matter phenomenology of a composite electroweak singlet
state. This singlet belongs to the Goldstone sector of a well-motivated
extension of the Littlest Higgs with -parity. A viable parameter space,
consistent with the observed dark matter relic abundance as well as with the
various collider, electroweak precision and dark matter direct detection
experimental constraints is found for this scenario. -parity implies a rich
LHC phenomenology, which forms an interesting interplay between conventional
natural SUSY type of signals involving third generation quarks and missing
energy, from stop-like particle production and decay, and composite Higgs type
of signals involving third generation quarks associated with Higgs and
electroweak gauge boson, from vector-like top-partners production and decay.
The composite features of the dark matter phenomenology allows the composite
singlet the produce the correct relic abundance while interacting weakly with
the Higgs via the usual Higgs portal coupling , thus evading direct detection.Comment: 27 pages + appendices and references, 7 figure
Syntax-based skill extractor for job advertisements
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Towards reproducible research of event detection techniques for Twitter
© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works
Fastlim: a fast LHC limit calculator
Fastlim is a tool to calculate conservative limits on extensions of the
Standard Model from direct LHC searches without performing any Monte Carlo
event generation. The program reconstructs the visible cross sections from
pre-calculated efficiency tables and cross section tables for simplified event
topologies. As a proof of concept of the approach, we have implemented searches
relevant for supersymmetric models with R-parity conservation. Fastlim takes
the spectrum and coupling information of a given model point and provides, for
each signal region of the implemented analyses, the visible cross sections
normalised to the corresponding upper limit, reported by the experiments, as
well as the exclusion -value. To demonstrate the utility of the program we
study the sensitivity of the recent ATLAS missing energy searches to the
parameter space of natural SUSY models. The program structure allows the
straight-forward inclusion of external efficiency tables and can be generalised
to R-parity violating scenarios and non-SUSY models. This paper serves as a
self-contained user guide, and indicates the conventions and approximations
used.Comment: 39 pages, 43 figure
Charged Composite Scalar Dark Matter
We consider a composite model where both the Higgs and a complex scalar
, which is the dark matter (DM) candidate, arise as light pseudo
Nambu-Goldstone bosons (pNGBs) from a strongly coupled sector with TeV scale
confinement. The global symmetry structure is , and the DM is
charged under an exact that ensures its
stability. Depending on whether the shift symmetry is respected or
broken by the coupling of the top quark to the strong sector, the DM can be
much lighter than the Higgs or have a weak-scale mass. Here we focus primarily
on the latter possibility. We introduce the lowest-lying composite resonances
and impose calculability of the scalar potential via generalized Weinberg sum
rules. Compared to previous analyses of pNGB DM, the computation of the relic
density is improved by fully accounting for the effects of the fermionic top
partners. This plays a crucial role in relaxing the tension with the current DM
direct detection constraints. The spectrum of resonances contains exotic top
partners charged under the , whose LHC phenomenology is
analyzed. We identify a region of parameters with and
that satisfies
all existing bounds. This DM candidate will be tested by XENON1T in the near
future.Comment: 36 pages + appendices and references, 10 figures. v2: minor
modifications, references added. Matches version published in JHE
Hypercharged Naturalness
We present an exceptional twin-Higgs model with the minimal symmetry
structure for an exact implementation of twin parity along with custodial
symmetry. Twin particles are mirrors of the Standard Model yet they carry
hypercharge, while the photon is identified with its twin. We thoroughly
explore the phenomenological signatures of hypercharged naturalness: long-lived
charged particles, a colorless twin top with electric charge that once
pair-produced, bounds via twin-color interactions and can annihilate to
dileptons or a Higgs plus a photon or a , and glueballs produced from Higgs
decays and twin-quarkonium annihilation that either decay displaced, or are
stable on collider scales and eventually decay to diphotons. Prospects for
detection of these signatures are also discussed.Comment: 37 pages, 7 figure
Charming Higgs
We present a simple supersymmetric model where the dominant decay mode of the
lightest Higgs boson is h->2eta->4c where eta is a light pseudoscalar and c is
the charm quark. For such decays the Higgs mass can be smaller than 100 GeV
without conflict with experiment. Together with the fact that both the Higgs
and the pseudoscalar eta are pseudo-Goldstone bosons, this resolves the little
hierarchy problem.Comment: 6 pages, 2 figure
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