3,281 research outputs found
Adiabatic Electroweak Baryogenesis Driven by an Axion-like Particle
An axion-like particle (ALP) offers a new direction in electroweak
baryogenesis because the periodic nature enables it to trigger a strong
first-order phase transition insensitively to the decay constant . For
much above TeV, the ALP-induced electroweak phase transition is approximately
described by adiabatic processes, distinguishing our scenario for electroweak
baryogenesis from the conventional ones. We show that, coupled to the
electroweak anomaly, the ALP can naturally realize spontaneous electroweak
baryogenesis to solve the matter-antimatter asymmetry problem for in the
range between about GeV and GeV. In such an ALP window, the
violation for baryogenesis is totally free from the experimental constraints,
especially from the recently improved limit on the electron electric dipole
moment. Future searches for ALPs could probe our scenario while revealing the
connection between electroweak symmetry breaking and baryogenesis.Comment: 12 pages, 5 figures, appendices added, published versio
Nanoscale Heat Transfer from Magnetic Nanoparticles and Ferritin in an Alternating Magnetic Field
Recent suggestions of nanoscale heat confinement on the surface of synthetic and biogenic magnetic nanoparticles during heating by radio frequency-alternating magnetic fields have generated intense interest because of the potential utility of this phenomenon for noninvasive control of biomolecular and cellular function. However, such confinement would represent a significant departure from the classical heat transfer theory. Here, we report an experimental investigation of nanoscale heat confinement on the surface of several types of iron oxide nanoparticles commonly used in biological research, using an all-optical method devoid of the potential artifacts present in previous studies. By simultaneously measuring the fluorescence of distinct thermochromic dyes attached to the particle surface or dissolved in the surrounding fluid during radio frequency magnetic stimulation, we found no measurable difference between the nanoparticle surface temperature and that of the surrounding fluid for three distinct nanoparticle types. Furthermore, the metalloprotein ferritin produced no temperature increase on the protein surface nor in the surrounding fluid. Experiments mimicking the designs of previous studies revealed potential sources of the artifacts. These findings inform the use of magnetic nanoparticle hyperthermia in engineered cellular and molecular systems
Dark matter filtering-out effect during a first-order phase transition
If the mass of dark matter is generated from a cosmological phase transition
involving the nucleation of bubbles, the corresponding bubble walls can filter
out dark matter particles during the phase transition. Only particles with
sufficient momentum to overcome their mass inside the bubbles can pass through
the walls. As a result, the dark matter number density after the phase
transition has a suppression factor , where
is the dark matter mass, and and are the Lorentz
factor and temperature of the incoming fluid in the bubble wall rest frame,
respectively. Under certain assumptions, we show that the filtering-out process
can naturally provide a large suppression consistent with the observed dark
matter density for a wide range of dark matter masses up to the Planck scale.
Since the first-order phase transition is the decisive ingredient in our
mechanism, a new connection is made between heavy dark matter scenarios and
gravitational wave observations.Comment: 6 pages, 2 figures, minor change, presentation improve
Finite rings with identity having GL(2m) as the group of units
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๊ตฐ์ ์ด๋ฃฌ๋ค. ์ด ๊ณฑ์
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ผ๋ฌธ์์๋ ๋ค์ ์ ๋ฆฌ๋ฅผ ์ฆ๋ช
ํ๋ค. ์ ๋ฆฌ (3. 1) ๊ฐ์ญ์ ์ ์ฒด๋ก ์ด๋ฃจ์ด์ง ๊ณฑ์
๊ตฐ์ด ์ผ๋ฐ์ ํ๊ตฐ GLโ(2m)๊ณผ ๋ํ์ธ ์ ํํ R์ ๋ค์๊ณผ ๊ฐ๋ค. ์ฆ, Rโ
Mโ(2m)โZโโโฆโฆโZโ
Rheological method for alpha test evaluation of developing superplasticizers' performance: Channel flow test
Advance in high-range water-reducing admixture revolutionizes the workability and constructability of conventional vibrated concrete as well as self-consolidating concrete. Its need from construction fields has increased, and consequently a variety of new-type polycarboxylates, base polymers for the admixture, are being formulated in these days. Synthesizing new polymers needs a quick, but reliable, test to evaluate its performance on concrete. The test is also asked for selecting the best applicable brand of them before a test concrete will be mixed. This paper proposes a channel flow test and its usage for the purpose. The proposed procedure for the test includes the mix proportion of a test mortar, the test method, and rheological interpretation of the test results.ope
Nanoscale Heat Transfer from Magnetic Nanoparticles and Ferritin in an Alternating Magnetic Field
Recent suggestions of nanoscale heat confinement on the surface of synthetic and biogenic magnetic nanoparticles during heating by radio frequency-alternating magnetic fields have generated intense interest because of the potential utility of this phenomenon for noninvasive control of biomolecular and cellular function. However, such confinement would represent a significant departure from the classical heat transfer theory. Here, we report an experimental investigation of nanoscale heat confinement on the surface of several types of iron oxide nanoparticles commonly used in biological research, using an all-optical method devoid of the potential artifacts present in previous studies. By simultaneously measuring the fluorescence of distinct thermochromic dyes attached to the particle surface or dissolved in the surrounding fluid during radio frequency magnetic stimulation, we found no measurable difference between the nanoparticle surface temperature and that of the surrounding fluid for three distinct nanoparticle types. Furthermore, the metalloprotein ferritin produced no temperature increase on the protein surface nor in the surrounding fluid. Experiments mimicking the designs of previous studies revealed potential sources of the artifacts. These findings inform the use of magnetic nanoparticle hyperthermia in engineered cellular and molecular systems
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