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 ${\cal A}_b$ can be substantial, ${\cal O}(\alpha_{QCD})$, provided the CP-violating phase of gluino-top-stop couplings is not suppressed. Within the SSM ${\cal A}_b$ 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