362 research outputs found
Natural Inflation with Hidden Scale Invariance
We propose a new class of natural inflation models based on a hidden scale
invariance. In a very generic Wilsonian effective field theory with an
arbitrary number of scalar fields, which exhibits scale invariance via the
dilaton, the potential necessarily contains a flat direction in the classical
limit. This flat direction is lifted by small quantum corrections and inflation
is realised without need for an unnatural fine-tuning. In the conformal limit,
the effective potential becomes linear in the inflaton field, yielding to
specific predictions for the spectral index and the tensor-to-scalar ratio,
being respectively:
and , where
is a number of efolds during observable inflation.
This predictions are in reasonable agreement with cosmological measurements.
Further improvement of the accuracy of these measurements may turn out to be
critical in falsifying our scenario.Comment: 8 pages, minor revision, to be published in PL
Low temperature electroweak phase transition in the Standard Model with hidden scale invariance
We discuss a cosmological phase transition within the Standard Model which
incorporates spontaneously broken scale invariance as a low-energy theory. In
addition to the Standard Model fields, the minimal model involves a light
dilaton, which acquires a large vacuum expectation value (VEV) through the
mechanism of dimensional transmutation. Under the assumption of the
cancellation of the vacuum energy, the dilaton develops a very small mass at
2-loop order. As a result, a flat direction is present in the classical
dilaton-Higgs potential at zero temperature while the quantum potential admits
two (almost) degenerate local minima with unbroken and broken eletroweak
symmetry. We found that the cosmological electroweak phase transition in this
model can only be triggered by a QCD chiral symmetry breaking phase transition
at low temperatures, MeV. Furthermore, unlike the standard
case, the universe settles into the chiral symmetry breaking vacuum via a
first-order phase transition which gives rise to a stochastic gravitational
background with a peak frequency Hz as well as triggers the
production of approximately solar mass primordial black holes. The observation
of these signatures of cosmological phase transitions together with the
detection of a light dilaton would provide a strong hint of the fundamental
role of scale invariance in particle physics
Exotic Lepton Searches via Bound State Production at the LHC
Heavy long-lived multi-charged leptons (MCLs) are predicted by various new
physics models. These hypothetical MCLs can form bound states, due to their
high electric charges and long life times. In this work, we propose a novel
strategy of searching for MCLs through their bound state productions and
decays. By utilizing LHC-8 TeV data in searching for resonances in the diphoton
channel, we exclude the masses of isospin singlet heavy leptons with electric
charge (in units of electron charge) lower than 1.2 TeV,
which are much stronger than the corresponding 8 TeV LHC bounds from analysing
the high ionisation and the long time-of-flight of MCLs. By utilising the
current 13 TeV LHC diphoton channel measurements the bound can further exclude
MCL masses up to 1.6 TeV for . Also, we demonstrate that the
conventional LHC limits from searching for MCLs produced via Drell-Yan
processes can be enhanced by including the contribution of photon fusion
processes.Comment: 9 pages, 3 figures, Updated to match PL
Vague and weak convergence of signed measures
Necessary and sufficient conditions for weak and vague convergence of
measures are important for a diverse host of applications. This paper aims to
give a comprehensive description of the relationship between the two modes of
convergence when the measures are signed, which is largely absent from the
literature. Furthermore, when the underlying space is , we study
the relationship between vague convergence of signed measures and the pointwise
convergence of their distribution functions.Comment: 16 pages, 3 figure
HC-030031, a TRPA1 selective antagonist, attenuates inflammatory- and neuropathy-induced mechanical hypersensitivity
<p>Abstract</p> <p>Background</p> <p>Safe and effective treatment for chronic inflammatory and neuropathic pain remains a key unmet medical need for many patients. The recent discovery and description of the transient receptor potential family of receptors including TRPV1 and TRPA1 has provided a number of potential new therapeutic targets for treating chronic pain. Recent reports have suggested that TRPA1 may play an important role in acute formalin and CFA induced pain. The current study was designed to further explore the therapeutic potential of pharmacological TRPA1 antagonism to treat inflammatory and neuropathic pain.</p> <p>Results</p> <p>The <it>in vitro </it>potencies of HC-030031 versus cinnamaldehyde or allyl isothiocyanate (AITC or Mustard oil)-induced TRPA1 activation were 4.9 ± 0.1 and 7.5 ± 0.2 μM respectively (IC<sub>50</sub>). These findings were similar to the previously reported IC<sub>50 </sub>of 6.2 μM against AITC activation of TRPA1 <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>. In the rat, oral administration of HC-030031 reduced AITC-induced nocifensive behaviors at a dose of 100 mg/kg. Moreover, oral HC-030031 (100 mg/kg) significantly reversed mechanical hypersensitivity in the more chronic models of Complete Freunds Adjuvant (CFA)-induced inflammatory pain and the spinal nerve ligation model of neuropathic pain.</p> <p>Conclusion</p> <p>Using oral administration of the selective TRPA1 antagonist HC-030031, our results demonstrated that TRPA1 plays an important role in the mechanisms responsible for mechanical hypersensitivity observed in inflammatory and neuropathic pain models. These findings suggested that TRPA1 antagonism may be a suitable new approach for the development of a potent and selective therapeutic agent to treat both inflammatory and neuropathic pain.</p
HC-030031, a TRPA1 selective antagonist, attenuates inflammatory- and neuropathy-induced mechanical hypersensitivity
<p>Abstract</p> <p>Background</p> <p>Safe and effective treatment for chronic inflammatory and neuropathic pain remains a key unmet medical need for many patients. The recent discovery and description of the transient receptor potential family of receptors including TRPV1 and TRPA1 has provided a number of potential new therapeutic targets for treating chronic pain. Recent reports have suggested that TRPA1 may play an important role in acute formalin and CFA induced pain. The current study was designed to further explore the therapeutic potential of pharmacological TRPA1 antagonism to treat inflammatory and neuropathic pain.</p> <p>Results</p> <p>The <it>in vitro </it>potencies of HC-030031 versus cinnamaldehyde or allyl isothiocyanate (AITC or Mustard oil)-induced TRPA1 activation were 4.9 ± 0.1 and 7.5 ± 0.2 μM respectively (IC<sub>50</sub>). These findings were similar to the previously reported IC<sub>50 </sub>of 6.2 μM against AITC activation of TRPA1 <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>. In the rat, oral administration of HC-030031 reduced AITC-induced nocifensive behaviors at a dose of 100 mg/kg. Moreover, oral HC-030031 (100 mg/kg) significantly reversed mechanical hypersensitivity in the more chronic models of Complete Freunds Adjuvant (CFA)-induced inflammatory pain and the spinal nerve ligation model of neuropathic pain.</p> <p>Conclusion</p> <p>Using oral administration of the selective TRPA1 antagonist HC-030031, our results demonstrated that TRPA1 plays an important role in the mechanisms responsible for mechanical hypersensitivity observed in inflammatory and neuropathic pain models. These findings suggested that TRPA1 antagonism may be a suitable new approach for the development of a potent and selective therapeutic agent to treat both inflammatory and neuropathic pain.</p
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Isolation of Discrete Nanoparticle-DNA Conjugates for Plasmonic Applications
Discrete DNA-gold nanoparticle conjugates with DNA lengths as short as 15 bases for both 5 nm and 20 nm gold particles have been purified by anion-exchange HPLC. Conjugates comprising short DNA (_ 20 nm) are difficult to purify by other means, and are potential substrates for plasmon coupling experiments. Conjugate purity is demonstrated by hybridizing complementary conjugates to form discrete structures, which are visualized by TEM
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Enzymatic Ligation Creates Discrete Multi-Nanoparticle Building Blocks for Self-Assembly
Enzymatic ligation of discrete nanoparticle?DNA conjugates creates nanoparticle dimer and trimer structures in which the nanoparticles are linked by single-stranded DNA, rather than double-stranded DNA as in previous experiments. Ligation is verified by agarose gel and small-angle X-ray scattering. This capability is utilized in two ways: first to create a new class of multiparticle building blocks for nanoscale self-assembly; second to develop a system which can amplify a population of discrete nanoparticle assemblies
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