2,420 research outputs found
SIMP dark matter and its cosmic abundances
We give a review on the thermal average of the annihilation cross-sections
for and general higher-order processes. Thermal average of
higher order annihilations highly depend on the velocity of dark matter,
especially, for the case with resonance poles. We show such examples for scalar
dark matter in gauged models.Comment: 5 pages, 2 figures, Prepared for the proceedings of the 13th
International Conference on Gravitation, 3-7 July 201
Cosmic abundances of SIMP dark matter
Thermal production of light dark matter with sub-GeV scale mass can be
attributed to self-annihilation processes. We consider the
thermal average for annihilation cross sections of dark matter at and general higher-order interactions. A correct thermal average for initial
dark matter particles is important, in particular, for annihilation cross
sections with overall velocity dependence and/or resonance poles. We apply our
general results to benchmark models for SIMP dark matter and discuss the
effects of the resonance pole in determining the relic density.Comment: 21 pages, 6 figures, Version to appear in Journal of High Energy
Physic
Quantum-based Mechanical Force Realization in Pico-Newton Range
We propose mechanical force realization based on flux quantization in the
pico-Newton range. By controlling the number of flux quantum in a
superconducting annulus, a force can be created as integer multiples of a
constant step. For a 50 nm-thick Nb annulus with the inner and outer radii of 5
m and 10 m, respectively, and the field gradient of 10 T/m the force
step is estimated to be 184 fN. The stability against thermal fluctuations is
also addressed.Comment: 5 pages; 4 figure
Higgs phenomenology in the Peccei-Quinn invariant NMSSM
We study the Higgs phenomenology in the Peccei-Quinn invariant NMSSM
(PQ-NMSSM) where the low energy mass parameters of the singlet superfield are
induced by a spontaneous breakdown of the Peccei-Quinn symmetry. In the generic
NMSSM, scalar mixing among CP-even Higgs bosons is constrained by the observed
properties of the SM-like Higgs boson, as well as by the LEP bound on the
chargino mass and the perturbativity bound on the singlet Yukawa coupling. In
the minimal PQ-NMSSM, scalar mixing is further constrained due to the presence
of a light singlino-like neutralino. It is noticed that the excess of
the LEP events at 98 GeV can be explained by a
singlet-like 98 GeV Higgs boson in the minimal PQ-NMSSM with low ,
stops around or below 1 TeV, and light doublet-higgsinos around the weak scale.Comment: 31 pages, 4 figures; v2: references added, light stop effects
discussed, bound on the Higgs invisible decay rate correcte
Development of a Chaff Dispense Program for Target Tracking Radar Deception
This study aims to develop an appropriate chaff dispensing program to deceive the target tracking radar (TTR) effectively. Chaff is a countermeasure commonly used by fighter aircraft to deceive TTR. However, there has been a lack of methodology for calculating chaff dispense programs that take into account the specific characteristics of the fighter, chaff, and TTR. This study proposes a methodology that considers these variables to calculate chaff dispense programs and addresses this gap. The proposed method is demonstrated through TESS engagement, which shows its effectiveness in various engagement situations
String theoretic QCD axions in the light of PLANCK and BICEP2
The QCD axion solving the strong CP problem may originate from antisymmetric tensor gauge fields in compactified string theory, with a decay constant around the GUT scale. Such possibility appears to be ruled out now by the detection of tensor modes by BICEP2 and the PLANCK constraints on isocurvature density perturbations. A more interesting and still viable possibility is that the string theoretic QCD axion is charged under an anomalous U(1)A gauge symmetry. In such case, the axion decay constant can be much lower than the GUT scale if moduli are stabilized near the point of vanishing Fayet-Illiopoulos term, and U(1)A-charged matter fields get a vacuum value v ∼ (mSUSYMnPl)1/(n+1) (n ≥ 0) induced by a tachyonic SUSY breaking mass mSUSY. We examine the symmetry breaking pattern of such models during the inflationary epoch with HI ≃ 1014 GeV, and identify the range of the QCD axion decay constant, as well as the corresponding relic axion abundance, consistent with known cosmological constraints. In addition to the case that the PQ symmetry is restored during inflation, i.e. v(tI ) = 0, there are other viable scenarios, including that the PQ symmetry is broken during inflation with v(tI ) ∼ (4HIMnPl)1/(n+1) ∼ 1016–1017 GeV due to the Hubble-induced D-term DA ∼ 82H2 I , while v(t0) ∼ (mSUSYMnPl)1/(n+1) ∼ 109–5×1013 GeV in the present universe, where v(t0) above 1012 GeV requires a fine-tuning of the axion misalignment angle. We also discuss the implications of our results for the size of SUSY breaking soft masses.131211Nsciescopu
Development of a Chaff Dispense Program for Target Tracking Radar Deception
This study aims to develop an appropriate chaff dispensing program to deceive the target tracking radar (TTR) effectively. Chaff is a countermeasure commonly used by fighter aircraft to deceive TTR. However, there has been a lack of methodology for calculating chaff dispense programs that take into account the specific characteristics of the fighter, chaff, and TTR. This study proposes a methodology that considers these variables to calculate chaff dispense programs and addresses this gap. The proposed method is demonstrated through TESS engagement, which shows its effectiveness in various engagement situations
- …