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Archive for the ‘particle physics’ category: Page 14

Oct 15, 2024

Higgs Particles And Tiny Black Holes Could Have Destroyed Our Universe

Posted by in categories: cosmology, particle physics

Although our universe may seem stable, having existed for a whopping 13.7 billion years, several experiments suggest that it is at risk—walking on the edge of a very dangerous cliff. And it’s all down to the instability of a single fundamental particle: the Higgs boson.

In new research by me and my colleagues, just accepted for publication in Physical Letters B, we show that some models of the early universe, those which involve objects called light primordial black holes, are unlikely to be right because they would have triggered the Higgs boson to end the cosmos by now.

The Higgs boson is responsible for the mass and interactions of all the particles we know of. That’s because particle masses are a consequence of elementary particles interacting with a field, dubbed the Higgs field. Because the Higgs boson exists, we know that the field exists.

Oct 14, 2024

World’s most powerful X-ray laser set for massive upgrade that will help us better understand the atomic world

Posted by in categories: chemistry, particle physics

Researchers will be able to analyze chemical compounds and atoms in greater detail than ever before using the brightest, clearest laser of its kind anywhere in the world.

Oct 14, 2024

Heavy Element Formation Limited in Failed Supernovae

Posted by in categories: cosmology, particle physics

Despite its intensity, the gravitational collapse of certain massive stars does not produce an abundance of heavy elements.

About half of the elements heavier than iron are made by the r, or rapid, process. A nucleus captures neutrons so quickly that radioactive decay is forestalled until the neutron-heavy nucleus finally emits electrons and neutrinos and settles at a new, higher atomic number. Besides normal supernovae and neutron-star mergers, the r process is also suspected to occur in so-called collapsars. These are rapidly rotating massive stars that collapse without producing a regular supernova once they exhaust their fuel. However, simulations by Coleman Dean and Rodrigo Fernández of the University of Alberta, Canada, have now undermined that r-process conjecture [1].

A collapsar’s progenitor is massive enough that it forms a black hole. To shed its prodigious angular momentum, it also forms a thick, unstable accretion disk. During the collapse, nuclei in the stellar envelope break apart, and their protons combine with electrons in the envelope to produce neutrons and neutrinos in large numbers. These neutrons could turn the disk into a favorable, if fleeting, site for the r process to forge and disperse heavy elements—provided that this neutron-rich matter can be ejected.

Oct 14, 2024

Cleaning Intense Laser Pulses with Plasma

Posted by in category: particle physics

When two laser beams converge on a volume of gas, their interference creates a diffraction grating made of plasma that can divert and shape a third beam.

Once a laser pulse packs more than 1018 W/cm2 or so of power, its electric field strips electrons from atoms and accelerates them to near light speed. This effect could lead to compact and highly efficient particle accelerators (see Viewpoint: Shooting Ahead with Wakefield Acceleration). But for various reasons to do with pulse generation, the main pulse is unavoidably preceded by weaker prepulses, which can muddle an experiment’s initial conditions and frustrate anticipated results. Now Matthew Edwards of Stanford University, working at Julia Mikhailova’s lab at Princeton University, and collaborators have demonstrated a setup that can delete meddlesome prepulses with unprecedented effectiveness [1].

A key component of the researchers’ setup was demonstrated in 2009 [2]. Two pulsed beams of the same wavelength converged on a volume of gas contained in a cell, ionizing the gas where the beams constructively interfered. The difference in refractive index between the plasma and the neutral gas created an instant and switchable diffraction grating.

Oct 14, 2024

Scientists build world’s thinnest lens, measuring just 3 atoms thick

Posted by in categories: materials, particle physics

The world’s thinnest lens diffracts light of specific wavelengths instead of refracting it.


By arranging a special material in concentric rings, researchers have built the world’s thinnest lens at just three atoms thickness.

Oct 13, 2024

Avoided quasiparticle decay from strong quantum interactions

Posted by in categories: particle physics, quantum physics

Immortality particles called quasiparticles face_with_colon_three


A collective excitation behaving as a single emergent entity, known as a quasiparticle, often becomes unstable when encountering a continuum of many-body excited states. However, under certain conditions, the result can be totally different.

Oct 12, 2024

Brookhaven National Laboratory Scientists Explore Ways to Synchronize Magnetic Spins for Nanoscale Electronic Devices

Posted by in categories: computing, mobile phones, nanotechnology, particle physics

Brookhaven National Laboratory researchers are working to develop ways to synchronize the magnetic spins in nanoscale devices to build tiny signal-generating or receiving antennas and other electronics.

Upton, New York — Scientists at the U.S. Department of Energy’s Brookhaven National Laboratory are seeking ways to synchronize the magnetic spins in nanoscale devices to build tiny yet more powerful signal-generating or receiving antennas and other electronics. Their latest work, published in Nature Communications, shows that stacked nanoscale magnetic vortices separated by an extremely thin layer of copper can be driven to operate in unison, potentially producing a powerful signal that could be put to work in a new generation of cell phones, computers, and other applications.

The aim of this “spintronic” technology revolution is to harness the power of an electron’s “spin,” the property responsible for magnetism, rather than its negative charge.

Oct 12, 2024

Unique Particles — With Stickiness of Gecko Feet — Formed by Harnessing Chaos

Posted by in categories: chemistry, engineering, food, nanotechnology, particle physics

New research from North Carolina State University shows that unique materials with distinct properties akin to those of gecko feet – the ability to stick to just about any surface – can be created by harnessing liquid-driven chaos to produce soft polymer microparticles with hierarchical branching on the micro-and nanoscale.

The findings, published today (October 14, 2019) in the journal Nature Materials, hold the potential for advances in gels, pastes, foods, nonwovens, and coatings, among other formulations.

The soft dendritic particle materials with unique adhesive and structure-building properties can be created from a variety of polymers precipitated from solutions under special conditions, says Orlin Velev, S. Frank and Doris Culberson Distinguished Professor of Chemical and Biomolecular Engineering at NC State and corresponding author of the paper.

Oct 12, 2024

Soft dendritic microparticles with unusual adhesion and structuring properties

Posted by in categories: materials, particle physics

Polymer precipitation under turbulent flows generates soft microparticles with branched dendritic coronas and high adhesive properties.

Oct 12, 2024

Twenty years after its discovery, graphene is finally living up to the hype

Posted by in categories: computing, particle physics, space

Manchester, England— On a rare sunny day in northern England, the National Graphene Institute (NGI) here gleams like a five-story block of obsidian. Squeezed into the University of Manchester’s sprawling downtown campus, the research center is clad in almost 2000 lustrous black panels with small hexagonal perforations—an architectural nod to the structure of the atom-thin sheet of carbon that gives the building its name.

NGI exists because graphene was first isolated a short walk away in a University of Manchester lab. Andre Geim and Konstantin Novoselov presented it to the world 20 years ago this month and later won a Nobel Prize for the work. Since its unveiling, billions of dollars of R&D funding have flowed to graphene, in a global race to exploit its peerless properties. It is better at carrying electricity than any metal, a superb heat conductor, and hundreds of times stronger than steel—selling points trumpeted in the marketing materials of universities and companies alike.

Early on, researchers were not shy about promising graphene breakthroughs, with predictions that it would enable superthin rollable TVs and space elevators, and even supplant silicon in computer chips. “Expectations were very, very high,” Geim says. “The companies I was involved in were mostly based on hype.”

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