506 research outputs found
Boosted Event Topologies from TeV Scale Light Quark Composite Partners
We propose a new search strategy for quark partners which decay into a
boosted Higgs and a light quark. As an example, we consider phenomenologically
viable right handed up-type quark partners of mass TeV in composite
pseudo-Nambu-Goldstone-boson Higgs models within the context of flavorful
naturalness. Our results show that and signal significance of is achievable at TeV LHC with 35 of
integrated luminosity, sufficient to claim discovery of a new particle. A
combination of a multi-dimensional boosted Higgs tagging technique, kinematics
of pair produced heavy objects and -tagging serves to efficiently diminish
the large QCD backgrounds while maintaining adequate levels of signal
efficiency. We present the analysis in the context of effective field theory,
such that our results can be applied to any future search for pair produced
vector-like quarks with decay modes to Higgs and a light jet.Comment: 18 pages, 7 figures, 5 tables, v2: short discussion added in Sec. 2,
references added, corresponds to version published in JHE
Spatial urban health equity indicators – a framework-based approach supporting spatial decision making
Hadronic Calorimeter Shower Size: Challenges and Opportunities for Jet Substructure in the Superboosted Regime
Hadrons have finite interaction size with dense material, a basic feature
common to known forms of hadronic calorimeters (HCAL). We argue that
substructure variables cannot use HCAL information to access the microscopic
nature of jets much narrower than the hadronic shower size, which we call
superboosted massive jets. It implies that roughly 15% of their transverse
energy profile remains inaccessible due to the presence of long-lived neutral
hadrons. This part of the jet substructure is also subject to order-one
fluctuations. We demonstrate that the effects of the fluctuations are not
reduced when a global correction to jet variables is applied. The above leads
to fundamental limitations in the ability to extract intrinsic information from
jets in the superboosted regime. The neutral fraction of a jet is correlated
with its flavor. This leads to an interesting and possibly useful difference
between superboosted W/Z/h/t jets and their corresponding backgrounds. The QCD
jets that form the background to the signal superboosted jets might also be
qualitatively different in their substructure as their mass might lie at or
below the Sudakov mass peak. Finally, we introduce a set of zero-cone
longitudinal jet substructure variables and show that while they carry
information that might be useful in certain situations, they are not in general
sensitive to the jet substructure.Comment: 6 pages, 4 figures; v2: minor improvements of presentation; published
versio
Light Non-degenerate Composite Partners at the LHC
We study the implications of a large degree of compositeness for the light
generation quarks in composite pseudo-Nambu-Goldstone-boson Higgs models. We
focus in particular on viable scenarios where the right-handed up-type quarks
have a sizable mixing with the strong dynamics. For concreteness we assume the
latter to be characterized by an SO(5)/SO(4) symmetry with fermionic resonances
in the SO(4) singlet and fourplet representations. Singlet partners dominantly
decay to a Higgs boson and jets. As no dedicated searches are currently looking
for these final states, singlet partners can still be rather light. Conversely,
some fourplet partners dominantly decay to an electroweak gauge boson and a
jet, a signature which has been analyzed at the LHC. To constrain the parameter
space of this scenario we have reinterpreted various LHC analyses. In the limit
of first two generation degeneracy, as in minimal flavor violation or
U(2)-symmetric flavor models, fourplet partners need to be relatively heavy,
with masses above 1.8 TeV, or the level of compositeness needs to be rather
small. The situation is rather different in models that deviate from the first
two generation degeneracy paradigm, as the charm parton distribution functions
are suppressed relative to the up quark ones. The right-handed charm quark can
be composite and its partners being as light as 600 GeV, while the right-handed
up quark needs either to be mostly elementary or to have its partners as heavy
as 2 TeV. Models with fully composite singlet fermions are also analyzed,
leading to similar conclusions. Finally, we consider the case where both the
fourplet and the singlet states are present. In this case the bounds could be
significantly weaken due to a combination of smaller production rates and the
opening of new channels including cascade processes.Comment: 49 pages, 18 figure
Towards supporting collaborative spatial planning:Conceptualization of a maptable tool through user stories
Older adults’ outdoor walking and inequalities in neighbourhood green spaces characteristics
Anarchic Yukawas and top partial compositeness: the flavour of a successful marriage
The top quark can be naturally singled out from other fermions in the
Standard Model due to its large mass, of the order of the electroweak scale. We
follow this reasoning in models of pseudo Nambu Goldstone Boson composite
Higgs, which may derive from an underlying confining dynamics. We consider a
new class of flavour models, where the top quark obtains its mass via partial
compositeness, while the lighter fermions acquire their masses by a deformation
of the dynamics generated at a high flavour scale. One interesting feature of
such scenario is that it can avoid all the flavour constraints without the need
of flavour symmetries, since the flavour scale can be pushed high enough. We
show that both flavour conserving and violating constraints can be satisfied
with top partial compositeness without invoking any flavour symmetry for the
up-type sector, in the case of the minimal SO(5)/SO(4) coset with top partners
in the four-plet and singlet of SO(4). In the down-type sector, some degree of
alignment is required if all down-type quarks are elementary. We show that
taking the bottom quark partially composite provides a dynamical explanation
for the hierarchy causing this alignment. We present explicit realisations of
this mechanism which do not require to include additional bottom partner
fields. Finally, these conclusions are generalised to scenarios with
non-minimal cosets and top partners in larger representations.Comment: 37 pages, 1 figure, v2: typos fixed, Eq. (3.44) added, version
corresponds to published article in JHE
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