A SQUID-based microwave cavity search for dark-matter axions

Axions in the micro eV mass range are a plausible cold dark matter candidate and may be detected by their conversion into microwave photons in a resonant cavity immersed in a static magnetic field. The first result from such an axion search using a superconducting first-stage amplifier (SQUID) is reported. The SQUID amplifier, replacing a conventional GaAs field-effect transistor amplifier, successfully reached axion-photon coupling sensitivity in the band set by present axion models and sets the stage for a definitive axion search utilizing near quantum-limited SQUID amplifiers.Comment: 4 pages, 5 figures, submitted to PR

Move of a large but delicate apparatus on a trailer with air-ride suspension

When valuable delicate goods are shipped by truck, attention must be paid to vibrations that may cause damage. We present a case study of moving an extremely delicate 6230-kg superconducting magnet, immersed in liquid nitrogen, from Livermore, CA to Seattle, WA showing the steps of fatigue analysis of the load, a test move, and acceleration monitoring of the final move to ensure a successful damage-free transport

A Search for Scalar Chameleons with ADMX

Scalar fields with a "chameleon" property, in which the effective particle mass is a function of its local environment, are common to many theories beyond the standard model and could be responsible for dark energy. If these fields couple weakly to the photon, they could be detectable through the "afterglow" effect of photon-chameleon-photon transitions. The ADMX experiment was used in the first chameleon search with a microwave cavity to set a new limit on scalar chameleon-photon coupling excluding values between 2*10^9 and 5*10^14 for effective chameleon masses between 1.9510 and 1.9525 micro-eV.Comment: 4 pages, 3 figure

Distributed flow optimization and cascading effects in weighted complex networks

We investigate the effect of a specific edge weighting scheme $\sim (k_i k_j)^{\beta}$ on distributed flow efficiency and robustness to cascading failures in scale-free networks. In particular, we analyze a simple, yet fundamental distributed flow model: current flow in random resistor networks. By the tuning of control parameter $\beta$ and by considering two general cases of relative node processing capabilities as well as the effect of bandwidth, we show the dependence of transport efficiency upon the correlations between the topology and weights. By studying the severity of cascades for different control parameter $\beta$, we find that network resilience to cascading overloads and network throughput is optimal for the same value of $\beta$ over the range of node capacities and available bandwidth

Axion-Higgs Unification

In theories with no fundamental scalars, one gauge group can become strong at a large scale Lambda and spontaneously break a global symmetry, producing the Higgs and the axion as composite pseudo-Nambu-Goldstone bosons. We show how KSVZ and DFSZ axion models can be naturally realised. The assumption Lambda around 10^{11} GeV is phenomenologically favoured because: a) The axion solves the QCD theta problem and provides the observed DM abundance; b) The observed Higgs mass is generated via RGE effects from a small Higgs quartic coupling at the compositeness scale, provided that the Higgs mass term is fine-tuned to be of electroweak size; c) Lepton, quark as well as neutrino masses can be obtained from four-fermion operators at the compositeness scale. d) The extra fermions can unify the gauge couplings.Comment: 19 pages. Refs. added and eq. 3.6 fixe

Superdeformation in 198^{198}Po

The $^{174}$Yb($^{29}$Si,5n) reaction at 148 MeV with thin targets was used to populate high-angular momentum states in $^{198}$Po. Resulting $\gamma$ rays were observed with Gammasphere. A weakly-populated superdeformed band of 10 $\gamma$-ray transitions was found and has been assigned to $^{198}$Po. This is the first observation of a SD band in the $A \approx 190$ region in a nucleus with $Z > 83$. The ${\cal J}^{(2)}$ of the new band is very similar to those of the yrast SD bands in $^{194}$Hg and $^{196}$Pb. The intensity profile suggests that this band is populated through states close to where the SD band crosses the yrast line and the angular momentum at which the fission process dominates.Comment: 10 pages, revtex, 2 figs. available on request, submitted to Phys. Rev. C. (Rapid Communications

Astrophysical Axion Bounds

Axion emission by hot and dense plasmas is a new energy-loss channel for stars. Observational consequences include a modification of the solar sound-speed profile, an increase of the solar neutrino flux, a reduction of the helium-burning lifetime of globular-cluster stars, accelerated white-dwarf cooling, and a reduction of the supernova SN 1987A neutrino burst duration. We review and update these arguments and summarize the resulting axion constraints.Comment: Contribution to Axion volume of Lecture Notes in Physics, 20 pages, 3 figure

Maternal outcomes at 3 months after planned caesarean section versus planned vaginal birth for twin pregnancies in the Twin Birth Study: a randomised controlled trial

OBJECTIVE: To compare outcomes at 3 months post partum for women randomised to give birth by planned caesarean section (CS) or by planned vaginal birth (VB) in the Twin Birth Study (TBS). DESIGN: We invited women in the TBS to complete a 3-month follow-up questionnaire. SETTING: Two thousand and eight hundred and four women from 25 countries. POPULATION: Two thousand and five hundred and seventy women (92% response rate). METHODS: Women randomised between 13 December 2003 and 4 April 2011 in the TBS completed a questionnaire and outcomes were compared using an intention-to-treat approach. MAIN OUTCOME AND MEASURES: Breastfeeding, quality of life, depression, fatigue and urinary incontinence. RESULTS: We found no clinically important differences between groups in any outcome. In the planned CS versus planned VB groups, breastfeeding at any time after birth was reported by 84.4% versus 86.4% (P = 0.13); the mean physical and mental Short Form (36) Health Survey (SF-36) quality of life scores were 51.8 versus 51.6 (P = 0.65) and 46.7 versus 46.0 (P = 0.09), respectively; the mean Multidimensional Assessment of Fatigue score was 20.3 versus 20.8 (P = 0.14); the frequency of probable depression on the Edinburgh Postnatal Depression Scale was 14.0% versus 14.8% (P = 0.57); the rate of problematic urinary incontinence was 5.5% versus 6.4% (P = 0.31); and the mean Incontinence Impact Questionnaire-7 score was 20.5 versus 20.4 (P = 0.99). Partner relationships, including painful intercourse, were similar between the groups. CONCLUSION: For women with twin pregnancies randomised to planned CS compared with planned VB, outcomes at 3 months post partum did not differ. The mode of birth was not associated with problematic urinary incontinence or urinary incontinence that affected the quality of life. Contrary to previous studies, breastfeeding at 3 months was not increased with planned VB. TWEETABLE ABSTRACT: Planned mode of birth for twins doesn't affect maternal depression, wellbeing, incontinence or breastfeeding