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Archive for the ‘particle physics’ category: Page 323

Apr 3, 2021

The invisible Higgs bosons

Posted by in category: particle physics

This is the best estimate scientists have made for the size of the invisible Higgs sector. The next step is to collect more data and hone their techniques to narrow in on these invisible decays.

“It’s like looking at something very small,” Rifki says. “Right now, we can’t see anything other than what we already know. But that doesn’t mean there is nothing new there. It could just mean that we need a more powerful lens.”

Lindert sees this collaboration as a good example of what theorists and experimentalists can accomplish when they combine their skills and work together.

Apr 3, 2021

Antimatter cooled by laser light

Posted by in category: particle physics

A step towards ultra-precise measurements of antihydrogen.


These two constraints are so fundamental that it would be difficult to formulate a consistent understanding of nature without them. Nevertheless, it is worth testing whether they really hold up in ultra-precise measurements carried out using the most modern technologies, because any deviation, however small, would force scientists to radically rethink the basis of our theories of physics. Writing in Nature, Baker et al.1 (members of the ALPHA collaboration) report a major step towards this goal. They have slowed down atoms of antihydrogen — the antimatter counterpart of hydrogen — to unprecedentedly low velocities by bathing them in a beam of ultraviolet laser light. This could allow measurements of the atoms to be made with exceptionally high precision.

Antihydrogen is the simplest stable atom that consists only of antimatter particles, namely an antiproton and an antielectron (a positron). Measurements of antihydrogen therefore provide an ideal way to test the symmetry between matter and antimatter, but such experiments present formidable obstacles. In 1995, 11 antihydrogen atoms were produced from reactions in a particle accelerator at CERN, Europe’s particle-physics laboratory near Geneva, Switzerland, and hurtled down a 10-metre-long vacuum tube at nine-tenths of the speed of light2. Each atom existed for barely a few tens of nanoseconds before being destroyed by striking a particle detector.

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Apr 2, 2021

Surprising Evidence for PeVatrons, the Milky Way’s Most Powerful Particle Accelerators

Posted by in categories: nuclear energy, particle physics, space

The Tibet ASγ experiment, a China-Japan joint research project on cosmic-ray observation, has discovered ultra-high-energy diffuse gamma rays from the Milky Way galaxy. The highest energy detected is estimated to be unprecedentedly high, nearly 1 Peta electronvolts (PeV, or one million billion eV).

Surprisingly, these gamma rays do not point back to known high-energy gamma-ray sources, but are spread out across the Milky Way (see Figure 1).

Scientists believe these gamma rays are produced by the nuclear interaction between cosmic rays escaping from the most powerful galactic sources (“PeVatrons”) and interstellar gas in the Milky Way galaxy. This observational evidence marks an important milestone in revealing the origin of cosmic rays, which has puzzled mankind for more than a century.

Apr 2, 2021

NASA’s Juno spacecraft detects strange new auroras on Jupiter

Posted by in categories: particle physics, space

NASA’s Juno spacecraft captured a new aurora feature on Jupiter that is characterized by faint ring-shaped emissions that expand rapidly over time. These auroral emissions are believed to be triggered by charged particles coming from the edge of the planet’s magnetosphere.


NASA’s Juno mission has detected new auroral emissions on Jupiter which appear to ripple over the planet’s poles.

The Ultraviolet Spectrograph (UVS) on the Juno spacecraft captured this glowing phenomenon, which is characterized by faint ring-shaped emissions that expand rapidly over time at speeds between 2 and 4.8 miles per second (3.3 and 7.7 kilometers per second). Researchers from the Southwest Research Institute (SwRI), where Juno’s UVS instrument was built, suggest these auroral emissions are triggered by charged particles coming from the edge of Jupiter’s massive magnetosphere, according to a statement from the institute.

Apr 2, 2021

CERN Is Betting Big on Exascale

Posted by in categories: computing, particle physics

The European Organization for Nuclear Research (CERN) involves 23 countries, 15000 researchers, billions of dollars a year, and the biggest machine in the world: the Large Hadron Collider. Even with so much organizational and mechanical firepower behind it, though, CERN and the LHC are outgrowing their current computing infrastructure, demanding big shifts in how the world’s biggest physics experiment collects, stores and analyzes its data. At the 2021 EuroHPC Summit Week, Maria Girone, CTO of the CERN openlab, discussed how those shifts will be made.

The answer, of course: HPC.

The Large Hadron Collider – a massive particle accelerator – is capable of collecting data 40 million times per second from each of its 150 million sensors, adding up to a total possible data load of around a petabyte per second. This data describes whether a detector was hit by a particle, and if so, what kind and when.

Apr 2, 2021

Physicists observe new phase in Bose-Einstein condensate of light particles

Posted by in categories: particle physics, quantum physics

About 10 years ago, researchers at the University of Bonn produced an extreme aggregate photon state, a single “super-photon” made up of many thousands of individual light particles, and presented a completely new light source. The state is called an optical Bose-Einstein condensate and has captivated many physicists ever since, because this exotic world of light particles is home to its very own physical phenomena. Researchers led by Prof. Dr. Martin Weitz, who discovered the super photon, and theoretical physicist Prof. Dr. Johann Kroha now report a new observation: a so-called overdamped phase, a previously unknown phase transition within the optical Bose-Einstein condensate. The study has been published in the journal Science.

The Bose-Einstein is an extreme physical state that usually only occurs at very low temperatures. The particles in this system are no longer distinguishable and are predominantly in the same quantum mechanical state; in other words, they behave like a single giant “superparticle.” The state can therefore be described by a single wave function.

In 2010, researchers led by Martin Weitz succeeded for the first time in creating a Bose-Einstein condensate from particles (photons). Their special system is still in use today: Physicists trap light particles in a resonator made of two curved mirrors spaced just over a micrometer apart that reflect a rapidly reciprocating beam of light. The space is filled with a liquid dye solution, which serves to cool down the photons. The dye molecules “swallow” the photons and then spit them out again, which brings the light particles to the temperature of the dye solution—equivalent to room temperature. The system makes it possible to cool light particles because their natural characteristic is to dissolve when cooled.

Apr 1, 2021

Non-destructive detection could speed up cold-atom quantum sensors

Posted by in categories: particle physics, quantum physics

Researchers use microwaves to observe an atomic sample 30000 times a second without destroying it.

Apr 1, 2021

Artificial Life Forged in a Lab? Scientists Create Synthetic Cell That Grows and Divides Normally

Posted by in category: particle physics

New findings shed light on mechanisms controlling the most basic processes of life.

Five years ago, scientists created a single-celled synthetic organism that, with only 473 genes, was the simplest living cell ever known. However, this bacteria-like organism behaved strangely when growing and dividing, producing cells with wildly different shapes and sizes.

Now, scientists have identified seven genes that can be added to tame the cells’ unruly nature, causing them to neatly divide into uniform orbs. This achievement, a collaboration between the J. Craig Venter Institute (JCVI), the National Institute of Standards and Technology (NIST) and the Massachusetts Institute of Technology (MIT) Center for Bits and Atoms, is described in the journal Cell.

Apr 1, 2021

Particles of a Meteor Explosion From 430,000 Years Ago Found Hidden in Antarctic Ice

Posted by in categories: asteroid/comet impacts, existential risks, particle physics

Approximately 430000 years ago, a meteorite exploded over Antarctica.

The only reason we know about it now is because scientists have just found tiny, once-molten particles of space rock that have been hidden away in the ice ever since.

Based on an analysis of those particles, the event was an unusual one — not quite powerful enough to produce an impact crater, but nor was it a lightweight. The jet of melted and vaporized material that blasted from the mid-air explosion would have been more hazardous than the Tunguska event that flattened a Siberian forest in 1908.

Mar 31, 2021

Frog skin cells turned themselves into living machines

Posted by in category: particle physics

The “xenobots” can swim, navigate tubes, move particles into piles and even heal themselves after injury, a new study reports.