139 research outputs found
Interpreting The 750 GeV Diphoton Excess Within Topflavor Seesaw Model
We propose to interpret the 750 GeV diphoton excess in a typical topflavor
seesaw model. The new resonance X can be identified as a CP-even scalar
emerging from a certain bi-doublet Higgs field. Such a scalar can couple to
charged scalars, fermions as well as heavy gauge bosons predicted by the model,
and consequently all of the particles contribute to the diphoton decay mode of
the X. Numerical analysis indicates that the model can predict the central
value of the diphoton excess without contradicting any constraints from 8 TeV
LHC, and among the constraints, the tightest one comes from the Z \gamma
channel, \sigma_{8 {\rm TeV}}^{Z \gamma} \lesssim 3.6 {\rm fb}, which requires
\sigma_{13 {\rm TeV}}^{\gamma \gamma} \lesssim 6 {\rm fb} in most of the
favored parameter space.Comment: Major changes, 17 pages, 4 figure, typos corrected, calculation
details adde
Interpreting the 750 GeV diphoton excess by the singlet extension of the Manohar-Wise Model
The evidence of a new scalar particle from the 750 GeV diphoton excess,
and the absence of any other signal of new physics at the LHC so far suggest
the existence of new colored scalars, which may be moderately light and thus
can induce sizable and couplings without resorting to
very strong interactions. Motivated by this speculation, we extend the
Manohar-Wise model by adding one gauge singlet scalar field. The resulting
theory then predicts one singlet dominated scalar as well as three kinds
of color-octet scalars, which can mediate through loops the and interactions. After fitting the model to the diphoton data at
the LHC, we find that in reasonable parameter regions the excess can be
explained at level by the process ,
and the best points predict the central value of the excess rate with
, which corresponds to a -value of . We also
consider the constraints from various LHC Run I signals, and we conclude that,
although these constraints are powerful in excluding the parameter space of the
model, the best points are still experimentally allowed.Comment: 19 pages, 3 figure
Accelerated Light Dark Matter-Earth Inelastic Scattering in Direct Detection
The Earth-stopping effect plays a crucial role in the direct detection of
sub-GeV dark matter. Besides the elastic scattering process, the quasi-elastic
and deep inelastic scatterings between dark matter and nucleus that are usually
neglected can dominate the interaction, especially in the accelerated dark
matter scenarios, which may affect the dark matter detection sensitivity
significantly for the underground experiments. We calculate such inelastic
scattering contributions in the Earth-stopping effect and illustrate the
essence of our argument with the atmospheric dark matter. With the available
data, we find that the resulting upper limits on the atmospheric dark
matter-nucleus scattering cross-section can differ from those only considering
the elastic scattering process by one order of magnitude.Comment: 7 pages, 4 figure
Spin-dependent sub-GeV Inelastic Dark Matter-electron scattering and Migdal effect: (I). Velocity Independent Operator
The ionization signal provide an important avenue of detecting light dark
matter. In this work, we consider the sub-GeV inelastic dark matter and use the
non-relativistic effective field theory (NR-EFT) to derive the constraints on
the spin-dependent DM-electron scattering and DM-nucleus Migdal scattering.
Since the recoil electron spectrum of sub-GeV DM is sensitive to tails of
galactic DM velocity distributions, we also compare the bounds on corresponding
scattering cross sections in Tsallis, Empirical and standard halo models. With
the XENON1T data, we find that the exclusion limits of the DM-proton/neutron
and DM-electron scattering cross sections for exothermic inelastic DM are much
stronger that those for the endothermic inelastic DM. Each limits of the
endothermic inelastic DM can differ by an order of magnitude at most in three
considered DM velocity distributions.Comment: 36 pages, 7 figure
Heavy Bino and Slepton for Muon g-2 Anomaly
In light of very recent E989 experimental result, we investigate the
possibility that heavy sparticles explain the muon g-2 anomaly. We focus on the
bino-smuon loop in an effective SUSY scenario, where a light gravitino plays
the role of dark matter and other sparticles are heavy. Due to the enhancement
of left-right mixing of smuons by heavy higgsinos, the contribution of
bino-smuon loop can sizably increase the prediction of muon g-2 to the
experimental value. Under collider and vacuum stability constraints, we find
that TeV scale bino and smuon can still account for the new muon g-2 anomaly.
The implications for LHC phenomenology are also discussed.Comment: 10 pages,1 figure;Published in:Nucl.Phys.B 969(2021)115481,add some
discussions and references, matches published versio
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