Waves & Packets
Nov. 3, 2012

New form of matter, color glass condensate, possibly spotted by CMS
Physics World
The first proton–lead collision data from CMS include a "ridge" structure in correlations between newly generated particles. That is, when a graph is plotted of the fraction of particles versus the relative transverse emission angle and the relative angle to the beam axis, the correlation appears as a distinct ridge. Besides this new CMS data, data like this have previously been seen in 2005 in gold-gold collisions at RHIC, and in 2010 in proton-proton and lead-lead collisions at CMS. Theorists have been searching for an explanation for this "ridge," and two in the U.S. believe that the ridge correlation is an unusual type of quantum entanglement in which generated particles carry information about the state of protons before those protons collided. The so-called "color glass condensate" is a state where protons fluctuate into quantum states incorporating three quarks and a swarm of accompanying gluons, and this state could explain how particles are generated in collisions.More

What do we want graduate school to be?
Recently, an email that was sent to graduate students at the astronomy department of a U.S. university caught the attention of faculty and students in departments across the country. Perhaps the most important result of this letter is a serious discussion about what the graduate student experience should be like. Recently, Astrobites, a daily blog written by a team of astronomy graduate students covering the latest research literature, asked its readers to comment on expectations and experiences of graduate school in general. The results indicate that the original letter itself was unpopular. There was much discussion on work-life balance, especially the number of hours per week students are expected to work. The comments showed much concern over job prospects, including the impression of a mentoring culture that suggests that tenure-track positions at research-focused universities are only desirable outcome for Ph.D. students in astronomy. The underrepresentation of women and minorities in the field was also a major concern. Overriding all the issues was the very real concern about student mental health, as graduate school can have consequences for the lives of real people. 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

NSBP members descend upon Australia for more than just a total solar eclipse
The Total Solar Eclipse of 2012 is just days away and will cut a path through the South Pacific. In the coming weeks, NSBP members will be traveling to exotic locations to do more than bask in the unique environment of totality. In Cairns, Australia, which is predicted to have the best eclipse viewing, Dr. Hakeem Oluseyi of the Florida Institute of Technology will be using the eclipse to study the lower atmosphere of the sun. He will be working with a group of students, telescopes and cameras to capture scientific images that will augment his research. Dr. Alphonse Sterling, of NASA Marshall Space Flight Center, will be flying in from Tokyo. He too will be taking images of the lower atmosphere of the sun for his scientific research. All of this work is being capture in the film, "Black Sun," made by NSBP member, Dr. Jarita Holbrook. More

NSBP member Stephon Alexander wins 2013 Edward Bouchet Award
For his contributions to theoretical cosmology, in particular the interface between fundamental physics and early universe cosmology, that includes work in leptogenesis, and parity violating effects in quantum gravity, as well as for communicating many ideas of this field to the scientific community and the public, Dr. Stephon Alexander, has received the 2013 Edward A. Bouchet Award. Alexander is the Ernest Everett Just 1907 Professor of Natural Sciences at Dartmouth College. Besides being an accomplished physicist, he is a prodigious jazz saxophonist.More

Lasers cool molecules to their lowest state
American Physical Society
Laser cooling, where photons are absorbed and emitted by matter, which transfers momentum from the matter to the photon, has been around for 30 years. Using the technique to cool atoms and ions has been the subject of two Nobel prizes. It is natural to ask whether laser cooling can be generalized to molecules. Their complex structures can lead to a much richer phenomenology than for atoms. But due to this complex structure, getting them to cool is much more difficult. In a paper published in Physical Review Letters, a team of physicists report on the culmination of their long-standing research efforts to cool (T∼300 microkelvin) molecules with lasers to the electronic, rotational and vibrational ground state.

Laser cooling of molecules was first thought to be impractical, so other approaches were explored to cool molecules. These approaches led to molecules that were kinetically quite cold, but were "internally" hot: they were not necessarily in the electronic ground state and, more importantly, they were mostly in excited vibrational (quantum number v) and rotational (quantum number J) states. In the current work, the 1950s idea of optical pumping was used to produce molecules in the v=0, J=0 ground state. Realizing that vibrational states and rotational states could not be manipulated independently, the researchers' breakthrough came when they combined a pumping laser for the vibrational modes with a narrow-band, continuous-wave diode laser as an additional pumping laser. Sweeping the second laser led to the rotational levels being swept from J=10 to J=0 much in the way one sweeps dust on a staircase from the top step, step-by-step to the bottom. The availability of rotationally-vibrationally cold molecules could be used to test one of the predictions of theories beyond the standard model of particle theory: a nonzero electron electric dipole moment.More

Physicists discover new way to spot malaria using light and magnets
MIT Technology Reviews
When malaria parasites consume blood they produce a molecular complex called hemozoin, an insoluble crystal form of heme, the iron-containing, oxygen-carrying molecule in blood. Hemozoin is paramagnetic, and scientists in Hungary have exploited that fact to develop a new and possibly cheaper way to detect malaria infections. Blood infected with malaria will contain hemozoin crystals. When a sample is put in a magnetic field the crystals will align perpendicular to the field. Rotating the magnetic field at a certain frequency will cause the crystals to overcome thermal disorder to align along the crystals' long axis. The solution of aligned crystals will then polarize light from a laser, which allows for rapid determination of whether or not the sample contains hemozoin crystals, i.e., is infected with malaria. Malaria is the world's No. 1 vector-borne infectious disease. There are over 200 million infections per year and 1 million deaths. This new cheaper and rapid detection method could be crucial in bringing the latter number down.More

Astronomers spot superluminous explosions triggered by light being converted into matter/antimatter particles in the early universe
Ars Technica
As the theory goes, in cores of very early, very massive stars, the density of gamma-ray light would reach levels that were so high that some of it would spontaneously convert into pairs of particles and antiparticles. The matter/anti-matter annihilation plus the loss of outward radiation pressure would result in the star's sudden collapse. The subsequent thermonuclear explosion would leave nothing behind but a rapidly expanding gas cloud. These types of stellar explosions are brighter than normal supernovae, so are thus called superluminous supernovae. They also produce electron-positron pairs in a process completely different from all other types of supernovae. Examples of superluminal supernovae have been detected only over the last 10 years. Though highly luminous, they are intrinsically rare, thus require large surveys to be detected. Superluminous supernovae are associated with high red-shifts, and with massive gas clouds. An international team of astrophysicists and cosmologists have reported via Nature the detection of two new superluminous supernovae, at redshifts of 2.05 and 3.90. This new detection extends the redshift limit for supernova detection, and the extreme luminosities provide a way of investigating the deaths of the first generation of stars to form after the Big Bang.More

Astronomers spot leftover light from 1st stars
Science News
Astronomers using data from NASA's Fermi Gamma-ray Space Telescope have made the most accurate measurement of starlight in the universe and used it to establish the total amount of light from all of the stars that have ever shone. Studying the entire history of cosmic star formation, including the very first epochs of star formation will help astronomers learn more about the universe's earliest years — and its first objects, which are too far away to be seen directly. By using the space-based gamma-ray telescope, astronomers were able to study blazars. Blazars are powered by supermassive black holes that emit enormous jets of gamma rays (amongst other things). Gamma rays interact with photons from the early stars. Photons colliding with a blazar's gamma rays are converted into electrons and positrons. The transition produces a dimming effect that the Fermi telescope can detect, and the amount of dimming corresponds to amount of photons between Earth and the blazar. Blazars are distributed across the universe, astronomers can use them to measure the "photon fog" at different ages, and calculate the contributions from early stars. This knowledge provides a constraint on total number of stars ever formed. This work is reported in Science, and the results so far suggest that that early stars may have formed a bit more slowly than previously thought. More

3-D modeling of stellar core collapse
Astronomers studying supernovae have long pursued a challenging goal: an end-to-end simulation of a core-collapse supernova, from the beginnings of collapse to the explosion. Core-collapse supernovae occur when a massive star reaches the end of its life and its dense iron core can no longer support itself. The core collapses on itself (hence the name) and becomes a neutron star or black hole, while an outgoing shock wave explodes the rest of the star in a fiery display. Modeling convection and turbulence on small scales in 3-D is already very difficult. Add in the necessary physics of neutrino reheating, which heretofore has only been simulated in 2-D, and you have a nearly insolvable computational model. So a team of researchers has investigated whether there are systematic differences in fluid behavior between 2-D and 3-D models in order to figure out whether a 2-D model can really stand in for a 3-D one. In results submitted to the Astrophysical Journal, the authors found the 2-D models have higher integrated net heating rates and more mass being heated by neutrinos, while the 3-D models have larger shock radii (the position of the stalled shock). All of these parameters influence when — and if — a CCSN will actually take place. They found that when their models did lead to an CCSN, the 3-D CCSN models exploded earlier than their 2-D models. They also found that 2-D models showed too much energy in long wavelength disturbances.More

Stirred-pot synthesis of iron-selenide compound leads to a superconducting boost
R&D Magazine
In a paper published in the European Journal of Physics B, a team of physicists describe how they have synthesized a new iron-selenide compound, LixFe2Se2(NH3)y. This material has a superconducting transition temperature of 44 K at ambient pressure, thus improving upon traditional copper-based high-temperature superconductors. A key target for superconductivity research is a transition temperature of liquid nitrogen (77 K), which is the benchmark temperature to make them attractive for applications. The researchers used a "stirred pot" chemical synthesis method to intercalate lithium atoms between layers of iron and selenium. They found that superconductivity properties are controlled by electronic doping and expansion of the iron-selenium material's lattice structure, which is gained by intercalating the lithium-based electronic donor molecules. In particular, the high onset temperatures of 44 K and shielding fractions of almost 80 percent were only obtained in samples containing exclusively Lix(NH3)y moieties acting simultaneously as electron donors and spacer units. These results could be the starting point to employ tailor-made electronic donor molecules (e.g. metallocenes), which allow for a systematic variation of the donor capabilities of the guest species and the interlayer separation in Fe2Se2 hybrids and thus a systematic control of the critical temperatures.More

Delaware State University breaks ground for new optics research building
Laser Focus World
Delaware State University, one of the US' historically black universities, has broken ground on its future Optical Science Center for Applied Research building, which was made possible initially by the support of Governor Jack Markell, who earmarked $10 million in the fiscal 2012 budget for the project. The four-story, 70,000-square-foot building will be the new home of DSU's Optics Program, which since 2006 has been the recipient of $23 million in research grants, produced the university's two first two intellectual properties, and is currently involved with NASA in its current Mars Curiosity Rover mission. The OSCAR Building will provide for wet chemistry, nanochemistry, conventional and confocal microscopy, scanning electronic and atomic force microscopy, as well as a complete image analysis suite. More

Optical 3-D metrology in industrial opthalmic applications
With hundreds of millions of people choosing contacts for either visual or aesthetic reasons, and millions more having surgery to solve vision problems associated with aging, there is a growing need for high-volume manufacturing process control for ophthalmic products. Proper process control will improve yield and comfort for the wearers as well as ensure quality manufacturing. This application note discusses the manufacture and production of various contact lenses and intraocular implantable lenses and how properly deployed metrology, using advanced 3-D optical microscopes provide a high return on investment to manufacturers in this space. More

What else could the Higgs be?
Symmetry Magazine
According to the Standard Model, the mass of the Higgs boson should be enormous. But recent experimental results suggest it's quite small, indicating that scientists might need to go beyond the Standard Model to explain the new particle. If the particle is indeed a Higgs boson, then theories beyond the Standard Model can account for its low mass. Three popular explanations involve the ideas of supersymmetry, compositeness and extra dimensions. More

Medical physics research round-up
Medical Physics Web
An international team of researchers have developed an improved breast scanning technique based on phase contrast imaging with high-energy X-rays. The method produces 3-D images with a spatial resolution two to three times higher than current hospital scanners, and a radiation dose of about 25 times lower.

A new study shows that within three months of completing proton therapy for prostate cancer, men reported identical urinary and bowel function as before treatment. These findings suggest that proton therapy for prostate cancer is successful in avoiding treatment-related side effects that are common with other forms of radiation therapy.

Using an atomic force microscope tip to measure the local nanomechanical properties of cancerous breast cells can help quickly determine metastasis has occurred. As reported in Nature Nanotechnology, specific structural alterations in cancer cells and the surrounding extracellular matrix of malignant breast tumors were found to be markedly different from that of healthy tissue and benign tumors.

The first two patients have been treated in a clinical trial investigating the use of magnetic resonance guided focused ultrasound to treat tremor-dominant Parkinson's disease. In this procedure, ultrasound is used to create a small heat-induced lesion an area of the brain associated with Parkinson's tremor. Previous trials on patients with essential tremor resulted in tremor reduction for all 15 patients.

Optical coherence tomography scans of the back of the eye can accurately assess brain damage in people with multiple sclerosis and offer clues regarding disease progress. In one study, researchers demonstrated that increased inflammation and swelling in the retinas of MS patients correlated with more inflammation in brain MRIs, affirming the value of retinal scans as a stand-alone surrogate for brain damage. In another study, researchers showed that cell wasting in deep retinal layers was strongly correlated with more grey matter damage in the brain. This finding is particularly important as neurodegeneration is difficult to accurately gauge, and OCT uses no ionizing radiation and is one-tenth the cost of an MRI.More

National Society of Black Physicists jobs board postings
Tenure Track Assistant Professor in Evolution
National Radio Astronomy Observatory Research Experience for Undergraduates LIGO Livingston Operations Manager
Astronomy Faculty Position at University of Arizona
Tenure Track Position in Experimental Quantum/Nano-Optics at the University of New Mexico
Associate Professor in Geometry and Topology in Physics at the University of Chicago Member-Advisory Committee on Reactor Safeguards
Post Doctoral (12-0164)
Renewable Energy REU at Colorado School of Mines
Tenure-Track Faculty Position, Physics
Post Doctoral Research Associate - Space Telescope Science Institute
Assistant Professor, Experimental Physics
Tenure-track Position Applied Physics — #18557
Assistant Professor, Astrophysics
Tenure-Track Assistant Professor — University of Maryland Baltimore County
Experimental Particle Physics Faculty
Cornell University Tenure Track Assistant Professor in Experimental Physics
National Radio Astronomy Observatory Jansky Fellowship Program

Latest research from Reports on Progress in Physics
IOP Publishing
Black holes in the early universe

Photonic crystal light-emitting sources

Orbital upper critical field and its anisotropy of clean one- and two-band superconductors

Physically based principles of cell adhesion mechanosensitivity in tissues

Overview on the physics and materials of the new superconductor KxFe2−ySe2More

Latest research from Optics Express
Optical Society of America
Noncollinear parametric fluorescence by chirped quasi-phase matching for monocycle temporal entanglement

Noise models for low counting rate coherent diffraction imaging

Multispectral integral imaging acquisition and processing using a monochrome camera and a liquid crystal tunable filter

Evidence of speckle in extreme-UV lithography

Laser divided-aperture differential confocal sensing technology with improved axial resolutionMore