2,129 research outputs found
Hyperfine splitting in muonic hydrogen constrains new pseudoscalar interactions
We constrain the possibility of a new pseudoscalar coupling between the muon
and proton using a recent measurement of the 2S hyperfine splitting in muonic
hydrogen.Comment: 3 pages, 2 figures. Version to appear in PL
The Decay Rate Asymmetry of the Top Quark
The asymmetries {\cal A}_k \equiv [\Gamma(\twddec) -\Gamma(\tbwddec)]
/[\Gamma(\twddec) + \Gamma(\tbwddec)] in the partial widths of the top quark
decays are discussed within the Standard Model (SM), the Two-Higgs-Doublet
Model (2HDM) and supersymmetric extensions of the SM (SSM). The leading
contributions to these asymmetries in the SM and in the 2HDM are induced by the
up-type quark self-energy diagrams and are found to be very small. However, in
the SSM, the asymmetry can be substantial, , provided the CP-violating phase of gluino-top-stop couplings
is not suppressed. Within the SSM is generated by the vertex
corrections.Comment: 9 pages, 3 figures (not included, postscript files available when
requested). CERN-TH.6941/93,UICHEP-TH/93-1
Physics at e-e- Colliders
An overview of the physics motivations for e-e- colliders is presented.Comment: 10 pages. Opening lecture of the 3nd International Workshop on
Electron-Electron Interactions at TeV Energies (e-e-99), University of
California, Santa Cruz, 10-12 December 199
Generic dark matter signature for gamma-ray telescopes
We describe a characteristic signature of dark matter (DM) annihilation or
decay into gamma-rays. We show that if the total angular momentum of the
initial DM particle(s) vanishes, and helicity suppression operates to prevent
annihilation/decay into light fermion pairs, then the amplitude for the
dominant 3-body final state f^+f^-\gamma has a unique form dictated by gauge
invariance. This amplitude and the corresponding energy spectra hold for
annihilation of DM Majorana fermions or self-conjugate scalars, and for decay
of DM scalars, thus encompassing a variety of possibilities. Within this
scenario, we analyze Fermi LAT, PAMELA and HESS data, and predict a hint in
future Fermi gamma-ray data that portends a striking signal at atmospheric
Cherenkov telescopes (ACTs).Comment: 9 pages, 4 figures. Version to appear in PR
Developmental cues for the maturation of metabolic, electrophysiological and calcium handling properties of human pluripotent stem cell-derived cardiomyocytes
Human pluripotent stem cells (hPSCs), including embryonic and induced pluripotent stem cells, are abundant sources of cardiomyocytes (CMs) for cell replacement therapy and other applications such as disease modeling, drug discovery and cardiotoxicity screening. However, hPSC-derived CMs display immature structural, electrophysiological, calcium-handling and metabolic properties. Here, we review various biological as well as physical and topographical cues that are known to associate with the development of native CMs in vivo to gain insights into the development of strategies for facilitated maturation of hPSC-CMs. © 2014 Keung et al.; licensee BioMed Central Ltd.published_or_final_versio
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