Detection of electron recoils by dark matter (DM) may reveal the structure of the dark sector. We consider a scenario where a heavier DM particle inelastically scatters off an electron and is ...converted into a lighter DM particle. A small mass difference between the two DM particles is transferred into electron recoil energy. We investigate the DM-electron interaction mediated by a massive dark photon and evaluate the inelastic DM scattering rate, taking account of the atomic structure. It is found that the scattering rate is significantly enhanced because of the small mass splitting, which allows for a small momentum transfer matched with the size of the electron wave function. We show that there exists a viable parameter space which explains the excess of electron recoil events around 2-3 keV recently reported by the XENON1T experiment.
An exact parity replicates the Standard Model giving a Mirror Standard Model, SM
↔
SM
′
. This “Higgs Parity” and the mirror electroweak symmetry are spontaneously broken by the mirror Higgs, 〈
H
′
〉 ...=
v
′
≫ 〈
H
〉, yielding the Standard Model Higgs as a Pseudo-Nambu-Goldstone Boson of an approximate SU (4) symmetry, with a quartic coupling
λ
SM
(
v
′
)
∼
10
−
3
. Mirror electromagnetism is unbroken and dark matter is composed of
e
′
and
e
¯
′
. Direct detection may be possible via the kinetic mixing portal, and in unified theories this rate is correlated with the proton decay rate. With a high reheat temperature after inflation, the
e
t
dark matter abundance is determined by freeze-out followed by dilution from decays of mirror neutrinos,
ν
′
→ ℓH
. Remarkably, this requires
v
′
∼
(10
8
–10
10
) GeV, predicting a Higgs mass of 123
±
3 GeV at 1
σ
and a Standard Model neutrino mass of (10
−
2
–10
−
1
) eV, consistent with observed neutrino masses. The mirror QCD sector exhibits a first order phase transition producing gravitational waves that may be detected by future observations. Mirror glueballs decay to mirror photons giving dark radiation with ∆
N
eff
∼
0
.
03–0
.
4. With a low reheat temperature after inflation, the
e
′
dark matter abundance is determined by freeze-in from the SM sector by either the Higgs or kinetic mixing portal.
A
bstract
We propose a minimal supersymmetric Twin Higgs model that can accommodate tuning of the electroweak scale for heavy stops better than 10% with high mediation scales of supersymmetry ...breaking. A crucial ingredient of this model is a new SU(2)
X
gauge symmetry which provides a
D
-term potential that generates a large SU(4) invariant coupling for the Higgs sector and only small set of particles charged under SU(2)
X
, which allows the model to be perturbative around the Planck scale. The new gauge interaction drives the top yukawa coupling small at higher energy scales, which also reduces the tuning.
Naturally astrophobic QCD axion Badziak, Marcin; Harigaya, Keisuke
The journal of high energy physics,
06/2023, Letnik:
2023, Številka:
6
Journal Article
Recenzirano
Odprti dostop
A
bstract
We present a QCD axion model where the couplings of the axion to nucleons, electrons, and muons are naturally suppressed because of the appropriate choice of the Peccei-Quinn charges of the ...Standard Model fermions. We reexamine next-to-leading order corrections to the couplings of the axion with nucleons and photons and show that the axion decay constant may be as small as 10
7
GeV. It is also possible to suppress the coupling with the photon so that the decay constant is even smaller and minimal axiogenesis works. In this scenario, the axion has a mass above 1 eV and may be directly detected via absorption of axion dark matter. Flavor-violating axion couplings are generically predicted in our model, but we show that they may be naturally and sufficiently suppressed. We discuss the implications of the hints for anomalous cooling in several stellar environments to our model.
Supersymmetric D-term Twin Higgs Badziak, Marcin; Harigaya, Keisuke
The journal of high energy physics,
06/2017, Letnik:
2017, Številka:
6
Journal Article
Recenzirano
Odprti dostop
A
bstract
We propose a new type of supersymmetric Twin Higgs model where the SU(4) invariant quartic term is provided by a
D
-term potential of a new U(1) gauge symmetry. In the model the 125 GeV ...Higgs mass can be obtained for stop masses below 1 TeV, and a tuning required to obtain the correct electroweak scale can be as low as 20%. A stop mass of about 2 TeV is also possible with tuning of order
O
10
%
.
R-parity violation axiogenesis Co, Raymond T.; Harigaya, Keisuke; Johnson, Zachary ...
The journal of high energy physics,
11/2021, Letnik:
2021, Številka:
11
Journal Article
Recenzirano
Odprti dostop
A
bstract
We show that the rotation of the QCD axion field, aided by
B−L
violation from supersymmetric
R
-parity violating couplings, can yield the observed baryon abundance. Strong sphaleron ...processes transfer the angular momentum of the axion field into a quark chiral asymmetry, which
R
-parity violating couplings convert to the baryon asymmetry of the Universe. We focus on the case of dimensionless
R
-parity violating couplings with textures motivated by grand unified theories and comment on more general scenarios. The axion decay constant and mass spectrum of supersymmetric particles are constrained by Big Bang nucleosynthesis, proton decay from the
R
-parity violation, and successful thermalization of the Peccei-Quinn symmetry breaking field. Axion dark matter may be produced by the axion rotation via the kinetic misalignment mechanism for axion decay constants below 10
10
GeV, or by the conventional misalignment mechanism for 10
11-12
GeV. The viable parameter region can be probed by proton decay and axion searches. This scenario may also have connections with collider experiments, including searches for long-lived particles, and observations of gravitational waves.
A
bstract
The twin Higgs mechanism is a solution to the little hierarchy problem in which the top partner is neutral under the Standard Model (SM) gauge group. The simplest mirror twin Higgs (MTH) ...model — where a
Z
2
symmetry copies each SM particle — has too many relativistic degrees of freedom to be consistent with cosmological observations. We demonstrate that MTH models can have an observationally viable cosmology if the twin mass spectrum leads to twin neutrino decoupling before the SM and twin QCD phase transitions. Our solution requires the twin photon to have a mass of
∼
20 MeV and kinetically mix with the SM photon to mediate entropy transfer from the twin sector to the SM. This twin photon can be robustly discovered or excluded by future experiments. Additionally, the residual twin degrees of freedom present in the early Universe in this scenario would be detectable by future observations of the cosmic microwave background.
A
bstract
The standard model Higgs quartic coupling vanishes at (10
9
− 10
13
) GeV. We study SU(2)
L
×
SU(2)
R
×
U(1)
B−L
theories that incorporate the Higgs Parity mechanism, where this becomes the ...scale of Left-Right symmetry breaking,
v
R
. Furthermore, these theories solve the strong CP problem and predict three right-handed neutrinos. We introduce cosmologies where SU(2)
R
×
U(1)
B−L
gauge interactions produce right-handed neutrinos via the freeze-out or freeze-in mechanisms. In both cases, we find the parameter space where the lightest right-handed neutrino is dark matter and the decay of a heavier one creates the baryon asymmetry of the universe via leptogenesis. A theory of flavor is constructed that naturally accounts for the lightness and stability of the right-handed neutrino dark matter, while maintaining sufficient baryon asymmetry. The dark matter abundance and successful natural leptogenesis require
v
R
to be in the range (10
10
−
10
13
) GeV for freeze-out, in remarkable agreement with the scale where the Higgs quartic coupling vanishes, whereas freeze-in requires
v
R
≳ 10
9
GeV. The allowed parameter space can be probed by the warmness of dark matter, precise determinations of the top quark mass and QCD coupling by future colliders and lattice computations, and measurement of the neutrino mass hierarchy.
A
bstract
A
Z
2
symmetry that extends the weak interaction, SU(2)
L
→ SU(2)
L
×SU(2)
′
, and the Higgs sector,
H
(2) →
H
(2
,
1) +
H
′
(1
,
2), yields a Standard Model quartic coupling that vanishes ...at scale
v
′
= 〈
H
′
〉 ≫ 〈
H
〉. Near
v
′
, theories either have a “prime” sector, or possess “Left-Right” (LR) symmetry with SU(2)
′
= SU(2)
R
. If the
Z
2
symmetry incorporates spacetime parity, these theories can solve the strong CP problem. The LR theories have all quark and lepton masses arising from operators of dimension 5 or more, requiring Froggatt-Nielsen structures. Two-loop contributions to
θ
¯
are estimated and typically lead to a neutron electric dipole moment of order 10
−27
e cm that can be observed in future experiments. Minimal models, with gauge group SU(3) × SU(2)
L
× SU(2)
L
× U(1)
B
−
L
, have precise gauge coupling unification for
v
′
= 10
10±1
GeV, successfully correlating gauge unification with the observed Higgs mass of 125 GeV. With SU(3) × U(1)
B
−
L
embedded in SU(4), the central value of the unification scale is reduced from 10
16−17
GeV to below 10
16
GeV, improving the likelihood of proton decay discovery. Unified theories based on SO(10) ×
CP
are constructed that have
H
+
H
′
in a
16
or
144
and generate higher-dimensional flavor operators, while maintaining perturbative gauge couplings.
Abstract We consider a supersymmetric mirror Twin Higgs model in a gravity-mediated supersymmetry-breaking scenario. We point out that the Polonyi field can be odd under the Z 2 symmetry exchanging ...the Standard Model with the mirror sector while gaugino masses are generated at tree-level. We discuss the dynamics of the Polonyi field during and after inflation and show that the Polonyi problem is absent. The Polonyi field couples to the two sectors with opposite signs, which may serve as origin of the Z 2-breaking of the Higgs potential in Twin Higgs models. We also estimate the Z 2-breaking in soft masses of supersymmetric particles.
PDF
