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First physics results from the sPHENIX particle detector

The sPHENIX particle detector, the newest experiment at the Relativistic Heavy Ion Collider (RHIC) at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, has released its first physics results: precision measurements of the number and energy density of thousands of particles streaming from collisions of near-light-speed gold ions.

As described in two papers recently accepted for publication in Physical Review C and the Journal of High Energy Physics, these measurements lay the foundation for the ’s detailed exploration of the quark–gluon plasma (QGP), a unique state of matter that existed just microseconds after the Big Bang some 14 billion years ago. Both studies are available on the arXiv preprint server.

The new measurements reveal that the more head-on the nuclear smashups are, the more charged particles they produce and the more total energy those firework-like sprays of particles carry. That matches nicely with results from other detectors that have tracked QGP-generating collisions at RHIC since 2000, confirming that the new detector is performing as promised.

OLEDs light the way to faster longer-distance wireless communication

In the race to develop faster and more flexible wireless communication technologies, researchers are turning to an unexpected source: the same organic light-emitting diodes (OLEDs) found in smartphone screens and TVs.

A recent study by scientists at the University of St Andrews and the University of Cambridge, published in Advanced Photonics, shows that OLEDs can be engineered to transmit data at record-breaking speeds over surprisingly long distances—potentially transforming how we connect devices in the future.

The paper is titled “High-speed based on dinaphthylperylene achieving 4-Gbps communication.”

World’s First Hybrid Chip Combines Electronics, Photonics, and Quantum Power

An interdisciplinary academic team has successfully integrated quantum light sources and control electronics onto a single silicon chip. In a significant advancement for quantum technology, researchers from Boston University, UC Berkeley, and Northwestern University have developed the first chip

Different Bacterial Genes Have Different Turn-Ons

Not all genes respond in the same way to regulation by the same molecule—a property that might enable cells to produce complex genetic responses.

Genes in living cells may become active or may be suppressed in response to environmental stimuli such as heat or the availability of nutrients. For bacteria, this gene regulation often appears to be a simple “on-off switch” controlled by regulatory proteins called transcription factors (TFs). But researchers have now found that different genes might respond differently to the same stimulus even if they are regulated by the same TF [1]. The team activated genes involved in DNA repair and observed gene-to-gene variations in their protein production patterns. Such differences might have been exploited by evolution to achieve complex responses with relatively few molecular components, the researchers suggest.

In the typical scenario, a TF binds to a region of a so-called promoter, a DNA sequence next to a gene. If the TF is the type that blocks gene expression, it prevents the enzyme RNA polymerase from binding and thus from beginning the process of producing the protein that the gene encodes. Because of thermal fluctuations (noise), the TF may spontaneously unbind, allowing gene expression to proceed until it rebinds. The rate of TF binding depends on its concentration, so fluctuations in concentration will cause changes in gene expression.

Unusual Plasma Waves Above Jupiter’s North Pole

A spacecraft observes a new oscillation mode in the low-density plasma.

The Juno space probe has spent the past nine years observing Jupiter and its moons. As the spacecraft’s mission draws to a close, the precession of its orbit has caused its closest approach to the gas giant to shift toward the north pole, enabling it to uncover a surprise: an unusual pattern of plasma waves in the planet’s magnetosphere. Now Robert Lysak of the University of Minnesota and his colleagues describe these waves and propose a mechanism for generating them [1]. Their theory offers a new component to include in planetary magnetosphere models and opens a new plasma regime to further exploration.

According to textbook plasma physics, collective waves of electrons in a plasma called Langmuir waves tend to oscillate parallel to magnetic-field lines at a so-called plasma frequency that’s much greater than the ions’ angular frequency around these field lines, their gyrofrequency. Meanwhile, ions tend to oscillate perpendicular to magnetic-field lines as Alfvén waves, with an upper frequency limit corresponding to the ion gyrofrequency. The waves detected by Juno, however, departed from that paradigm: The Alfven waves’ frequency extended only to the plasma frequency, which was less than the ion gyrofrequency. And the waves’ frequency never exceeded the plasma frequency.