2,145 research outputs found
Indirect Probe of Electroweak-Interacting Particles with Mono-Lepton Signatures at Hadron Colliders
Electroweak-interacting massive particles (EWIMPs) exist in a broad class of
new physics models beyond the Standard Model. Searching for such particles is
one of most primary goal at the LHC and future colliders. The EWIMP generally
affects the LHC signatures through quantum corrections even without direct
productions. By measuring the Standard Model processes precisely, we can
indirectly probe the EWIMPs. In this paper, we study the current constraint and
future prospect of the EWIMPs by using the precision measurements of
mono-lepton production from the charged Drell-Yan processes at hadron
colliders. We found the mono-lepton signature can be a better probe than
dilepton signature from the neutral Drell-Yan processes.Comment: 10 pages, 7 figure
Wino Dark Matter in light of the AMS-02 2015 Data
The AMS-02 collaboration has recently reported the antiproton to proton ratio
with improved accuracy. In view of uncertainties of the production and the
propagation of the cosmic rays, the observed ratio is still consistent with the
secondary astrophysical antiproton to proton ratio. However, it is nonetheless
enticing to examine whether the observed spectrum can be explained by a
strongly motivated dark matter, the wino dark matter. As we will show, we find
that the antiproton flux from the wino annihilation can explain the observed
spectrum well for its mass range 2.5-3 TeV. The fit to data becomes
particularly well compared to the case without the annihilation for the thermal
wino dark matter case with a mass about 3 TeV. The ratio is predicted to be
quickly decreased at the energy several hundreds of GeV, if this possibility is
true, and it will be confirmed or ruled out in near future when the AMS-02
experiment accumulates enough data at this higher energy region.Comment: 6 pages, 2 figures, version accepted for publication in PRD (Rapid
Communication
Mass of Decaying Wino from AMS-02 2014
We revisit the decaying wino dark matter scenario in the light of the updated
positron fraction, electron and positron fluxes in cosmic ray recently reported
by the AMS-02 collaboration. We show the AMS-02 results favor the mass of the
wino dark matter at around a few TeV, which is consistent with the prediction
on the wino mass in the pure gravity mediation model.Comment: 10 pages, 1 figur
Indirect Probe of Electroweak-Interacting Particles at Future Lepton Colliders
Various types of electroweak-interacting particles, which have non-trivial
charges under the gauge symmetry,
appear in various extensions of the Standard Model. These particles are good
targets of future lepton colliders, such as the International Linear Collider
(ILC), the Compact LInear Collider (CLIC) and the Future Circular Collider of
electrons and positrons (FCC-ee). An advantage of the experiments is that, even
if their beam energies are below the threshold of the production of the new
particles, quantum effects of the particles can be detected through high
precision measurements. We estimate the capability of future lepton colliders
to probe electroweak-interacting particles through the quantum effects, with
particular focus on the wino, the Higgsino and the so-called minimal dark
matters, and found that a particle whose mass is greater than the beam energy
by 100-1000 GeV is detectable by measuring di-fermion production cross sections
with \% accuracy. In addition, with the use of the same analysis, we
also discuss the sensitivity of the future colliders to model independent
higher dimensional operators, and found that the cutoff scales corresponding to
the operators can be probed up to a few ten TeV
A new circuitry model for electric double layer capacitor
A new circuitry model, which consists of constant phase elements is proposed to simply describe the charge storage mechanism of an electric double layer capacitor (EDLC). The model is developed based on previously reported experimental data of cellulose- and glass wool-based capacitors measured by electrochemical impedance spectroscopy. As a result, with a considerably small normalized error, the proposed model fitted the experimental data well for the whole frequency range (from mHz to kHz). The model is capable of providing beneficial information on the charge storage mechanism inside the tested capacitors for each frequency region; low, medium and high frequency region separately. Interestingly, the fitted parameters from the model are consistent with the static EDLC parameters; in particular, the specific capacitance (corresponds to double layer capacitance) and internal resistance values attained from dc properties characterization
A note on no-hair properties of static black holes in four and higher dimensional spacetimes with cosmological constant
We study no-hair properties of static black holes in four and higher
dimensional spacetimes with a cosmological constant. For the vanishing
cosmological constant case, we show a no-hair theorem and also a no-short-hair
theorem under certain conditions for the energy-momentum of matter fields. For
the positive cosmological constant case, we discuss conditions for hairy static
black holes to exist in terms of the energy density of matter fields evaluated
at the black hole horizon and the cosmological horizon. For the negative
cosmological constant case, we study conditions for hairy black holes by
presenting a no-hair theorem in which the asymptotic structure is assumed to be
determined by the true cosmological constant
Non-contact respiratory measurement in a horse in standing position using millimeter-wave array radar
飼育ウマの呼吸数を非接触で測定することに成功 --ミリ波レーダを用いた非接触バイタル測定技術の確立へ--. 京都大学プレスリリース. 2022-08-10.This study aimed to apply radar technology to a large quadruped animal. We first developed a non-contact respiration measurement system using millimeter-wave array radar for a horse in standing position. Specifically, we measured the respiration of a stationary domestic horse in stables. Simultaneously, we measured the respiration rate using infrared thermography and developed a method for analyzing the radar information while verifying the rate of agreement. Our results suggested that the radar technology detected breathing and accurately measured the respiration of a horse, despite variation in the breathing frequency. To the best of our knowledge, this is the first study to apply a non-contact respiration measurement system using millimeter-wave array radar has been applied to large animals in an upright position, thereby demonstrating its potential application in animal husbandry and welfare
Impact of the passive component structure for high efficiency and fast response POL using Power Supply on Chip
Power-SoC, which integrates MCU, power device, control circuits and passive devices on the same chip has been attracted attention. In this paper, we discuss the impact of passive component structure for high efficiency and fast response POL using 3D Power-SoC (Supply on Chip). We propose the optimal structure according to the switching frequency based on simulations
Experimental investigation of pulsed entangled photons and photonic quantum channels
The development of key devices and systems in quantum information technology,
such as entangled particle sources, quantum gates and quantum cryptographic
systems, requires a reliable and well-established method for characterizing how
well the devices or systems work. We report our recent work on experimental
characterization of pulsed entangled photonic states and photonic quantum
channels, using the methods of state and process tomography. By using state
tomography, we could reliably evaluate the states generated from a two-photon
source under development and develop a highly entangled pulsed photon source.
We are also devoted to characterization of single-qubit and two-qubit photonic
quantum channels. Characterization of typical single-qubit decoherence channels
has been demonstrated using process tomography. Characterization of two-qubit
channels, such as classically correlated channels and quantum mechanically
correlated channels is under investigation. These characterization techniques
for quantum states and quantum processes will be useful for developing photonic
quantum devices and for improving their performances.Comment: 12 pages, 8 figures, in Quantum Optics in Computing and
Communications, Songhao Liu, Guangcan Guo, Hoi-Kwong Lo, Nobuyuki Imoto,
Eds., Proceedings of SPIE Vol. 4917, pp.13-24 (2002
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