Waves & Packets
Jul. 14, 2012

Have we observed the Higgs (imposter)? Signal may not be standard model Higgs boson after all
Digital Journal
In a paper posted on arXiv, a trio of physicists are interpreting the new "Higgs-like" particle as a CP-even scalar and investigate its electroweak quantum number. They show that the LHC data gathered heretofore already strongly disfavors both the dilatonic and nondilatonic singlet imposters. Relying on custodial SU(2) symmetry constructions, they argue that the new particle could very well be a part of the Higgs triplet rather than the usual Higgs doublet. But they emphasize that more precise measurements of the ratio of event rates in the WW over ZZ channels, as well as the event rates in bb and tau tau channels, are needed to distinguish the Higgs doublet from the triplet imposter.More

Further evidence that 'charge-density-wave instability' competes with superconductivity
Canadian Light Source
Charge density waves compete with superconductivity, whenever they meet on the same Fermi surface. This is an experimental fact, which agrees qualitatively with a number of theories. But getting direct experimental evidence has been a challenge. In a paper published in Science, an international team of scientists report using resonant soft X-ray scattering and no less than four different synchrotrons to find experimental evidence that charge-density-wave instability competes with superconductivity with long-range incommensurate charge fluctuations in cuprates.More

Black hole shines a light on dark galaxies
Ars Technica
According to our best models, the early universe was filled with clouds of gas that were the source of its current galaxies. However, not all of these protogalactic nebulas were massive enough to compress their gas sufficiently to make stars. This means a number of "dark galaxies" should exist: galaxy-sized clouds of gas with few or no stars. This lack of stars makes dark galaxies extremely hard to find. But a group of astronomers using the Very Large Telescope in Chile have identified 12 candidates from the early days of the universe via the UV light emitted from the black hole rather than star light. The UV light from the quasar fluorscently illuminates the gas in the otherwise dark galaxies. The findings are reported in Monthly Notices of the Royal Astronomical Society. More

5th moon found orbiting Pluto
Hubble Site
Astronomers using the Hubble Space Telescope have reported that they have spotted a fifth moon orbiting Pluto. The moon is estimated to be irregular in shape and six to 15 miles across. It is in a 58,000-mile-diameter circular orbit around Pluto that is assumed to be co-planar with the other satellites in the system. The Pluto team is intrigued that such a small planet can have such a complex collection of satellites. The new discovery provides additional clues for unraveling how the Pluto system formed and evolved. The favored theory is that all the moons are relics of a collision between Pluto and another large Kuiper belt object billions of years ago.More

Mechanical waves mediate wound repair and tumor growth
Physics World
Researchers in Spain and the U.S. have reported in Nature Physics that ultraslow mechanical waves occur during the expansion of living tissue. These waves could explain how cells migrate to the right places for an organism to grow, repair itself or develop tumors. Growth, repair and the development of tumors are all processes that involve the expansion of a monolayer of cells, or "epithelial expansion." If you have a small wound, for example, the wound will form a scab and, beneath that, a matrix for the construction of new tissue. But in the final stage, a monolayer of cells will migrate from undamaged tissue to form a new outer-boundary layer.More

Quantum-dot mixture could boost solar cells
Physics World
A new way to extend the lifetimes of charge carriers in solar cells has been unveiled by researchers in Spain. The technique involves creating an aggregate of two different kinds of quantum dots, which can be made using low-cost solution-processing techniques. As detailed in a paper in Nature Photonics, the method could be used to boost the performance of solar cells — even those based on photovoltaic materials that have relatively poor optoelectronic properties. Solution-processed inorganic solar cells are made by depositing layers of quantum dots — tiny pieces of semiconductor — in colloidal suspension. The devices have shown much promise because they can absorb light over a wide spectrum of wavelengths. This is a result of the fact that the electronic band gaps in a quantum dot can be tuned over a large energy range by simply changing the size of the dot.More

Multicore fiber becomes 'photonic lantern' filter for telescopes
Laser Focus News
When fiber Bragg gratings are written into all 120 cores of a multicore optical fiber, great things can happen. Specifically, such an arrangement can become a "photonic lantern" filter that serves as an ultranarrow band line blocker for astronomy. Photonic lanterns couple the functions of single-spatial-mode optical devices (in this case, FBGs) to multimode fiber inputs and outputs. To do this, they combine many single mode fibers together (or in some cases, rely on integrated photonics). Photonic lanterns based on the combination of many single mode fibers with FBGs have been constructed with as many as 61 identical FBGs, with at least one already under test with a telescope. More

Peering into supernovae: Simulation points out how to detect a rapidly spinning stellar core
California Institute of Technology
Each century, about two massive stars in our own galaxy explode, producing magnificent supernovae. These stellar explosions send neutrinos streaming our way and generate gravitational waves in the fabric of space-time. Here on Earth, large, sensitive neutrino and gravitational-wave detectors have the ability to detect these respective signals, which will provide information about what happens in the core of collapsing massive stars just before they explode. In a paper appearing in Physical Review D, Caltech astrophysicists predict an unmistakable signature of a feature of such an event: If the interior of the dying star is spinning rapidly just before it explodes, the emitted neutrino and gravitational-wave signals will oscillate together at the same frequency.More

Physics confirms sprinters are performing better than ever before
Institute of Physics
Steve Haake, director of the Centre for Sports Engineering at Sheffield Hallam University in the U.K., discusses his "performance-improvement index," which uses very simple physics to compare the relative improvement of top athletes in different sports over the last 100 years. Some of the reasons for these changes, which Haake describes in this feature, are because of technological interventions that have changed the face of the sport. The performance of javelin throwers, for example, was improving drastically up until the mid-1980s, to a point where officials were concerned for crowd safety. In recognition of the summer 2012 games being in London, IOP is making the July 2012 edition of Physics World, which focuses on physics of sports, freely available as a download. More

Calculation of the electric field resulting from human body rotation in a magnetic field
Medical Physics Web
The electric field and current density induced in the human body by movement in and around magnetic resonance imaging installations can sometimes exceed regulatory levels. Good theoretical models would help medical physicists plan procedures that stay within safety and regulatory limits. Using simple electromagnetic analysis, a trio of researchers have shown in a paper appearing in Physics in Medicine and Biology that v  ×  B rather than −(v   ∇)A should be used as the driving term in potential-based modeling of induced fields under rotational motion. They also show that it is necessary to take account of the volume charge density that is generated when the magnetic field and axis of rotation are not perpendicular in all locations.More

ALICE tracks charm energy loss in the QGP
CERN Courier
When heavy nuclei collide at high energies, a high-density color-deconfined state of strongly interacting matter is expected to form. According to lattice QCD calculations, the confinement of colored quarks and gluons into colorless hadrons vanishes under the conditions of high-energy density and temperature that are reached in these collisions and a phase transition to a quark–gluon plasma occurs. High-momentum partons are created in hard-scattering processes that occur in the early stage of the nuclear collision. They subsequently traverse the hot QGP, losing energy as they interact with its constituents. The first direct observation of the suppression of charmed mesons at high-transverse momentum in head-on nucleus–nucleus collisions indicates that charm quarks suffer a strong loss of energy in hot quark–gluon plasma. More

Commentary: Open questions on transitioning to open access
Waves and Packets
A longtime veteran of the scientific publishing industry, Darrell Gunter has held senior positions with Collexis Holdings, Elsevier and the American Institute of Physics. In this commentary, special for Waves and Packets, he comments on the recent Finch report out of the U.K. and on open questions in the proposed transition from the subscription-based model to an author-pays open access business model. More

Webinar:Acing the Physics GRE: Tips and Strategies, July 17, 3-4 p.m.
American Physical Society
Many physics students are intimidated by the prospect of taking the physics GRE subject exam. What should you expect? How should you prepare? Which strategies will give you the best edge on the exam? In this interactive webinar, GRE prep course leader Jeremy Dodd will describe the content and format of the Physics GRE subject test, provide advice and tips on how best to prepare for the test, and offer test-taking strategies. More

Caltech's John Johnson advice on graduate school admission
Society of Physics Students
According to professor John Johnson, no one should care about your physics GRE score. While admissions committees do not like to see below-average scores, there is nothing unusual about students that scored below the 50th percentile on the physics GRE going on to become professors at an elite university. The physics GRE tests a very specific problem-solving skill set and is simply not a good predictor of the success of graduate students. In fact, at least one study has shown that relying on the physic GRE in admissions can actually work against departmental quality and diversity goals, both ethnic and gender. But the fact remains that at least half of the graduate programs in physics and astronomy do require you physics GRE scores, and some professors on admissions committees may take that score very seriously. Still, Johnson advises that while students should take the GRE seriously, the most important thing to do for a successful graduate school application is to participate in research. More

Increase your options for graduate or REU program admissions
The NSBP GradApps and REUApps services are open to all students and allows them to upload all the elements of an admissions application, including academic and work history, transcripts, letters of recommendation and a personal statement. Graduate and REU programs can subscribe to these databases to increase the programs' applicant pool, while at the same time allowing students can put their credentials in front of more programs than to which they would otherwise apply.More

National Society of Black Physicists jobs board postings
Deputy Director, National High Magnet Field Laboratory
Research Associate
Faculty Position in Astrophysics
Faculty Position in Biophysics
SKA Project Scientist
National Astrophysics and Space Science Program
Postdoctoral Research Associate PositionsMore

Latest research from Chemical Physics Letters
Ultrafast electron crystallography of monolayer adsorbates on clean surfaces: Structural dynamics

Ultrafast electron crystallography of heterogeneous structures: Gold-graphene bilayer and ligand-encapsulated nanogold on graphene

A DFT study of magnetic interactions in photoswitchable systems

Performance of the coupled cluster and DFT methods for through-space magnetic interactions of nitroxide dimer

A quantum mechanical study of alkylimidazolium halide ionic liquidsMore

Latest research from Classical and Quantum Gravity
IOP Publishing
Scalar field cosmology: I. Asymptotic freedom and the initial-value problem

Self-force as probe of internal structure

On the existence of solutions to the relativistic Euler equations in two spacetime dimensions with a vacuum boundary

Quantization of Lorentzian 3-D gravity by partial gauge fixing

The gravity dual of a density matrixMore