Two new particles have been discovered by the experiment at CERN’s Large Hadron Collider near Geneva, Switzerland. One of them has a combination of properties that has never been observed before.

The particles, named DS3*(2860)^– and DS1*(2860)^–, are about three times as massive as protons.

Physicists analysed LHCb observations of an energy peak that had been spotted in 2006 by the experiment at Stanford University in California, but whose cause was still unknown.

“Our result shows that the BaBar peak is caused by two new particles,” says of Warwick University, UK, lead author of the discovery.

The force is strong

Mesons are particles that contain two quarks – subatomic particles that make up matter and are thought to be indivisible. These quarks are bound together by the strong force, one of the four fundamental forces that also keeps the constituents of nuclei together within atoms. This force is one of the less well-understood parts of the standard model of particle physics, the incomplete theory that describes how particles interact.

Quarks come in six different flavours known as up, down, strange, charm, bottom and top, in order from lightest to heaviest. The new particles each contain one charm antiquark and one strange quark.

Significantly, DS3*(2860)^– also has a spin value of 3, making this discovery the first ever observation of a spin-3 particle containing a charm quark.

In other mesons, the quarks can be configured in one of several different ways to give the particle an overall spin value less than three, and this makes the quarks’ exact properties ambiguous. However, for a spin value of three there is no such ambiguity, making DS3*(2860)^–‘s precise configuration clear.

Differing decays

Combined with the particle’s charm quark, this may make DS3*(2860)^– a key player for exploring the strong force, because the calculations involved are more straightforward for heavy quarks than for lighter ones.

The LHCb team used a technique known as Dalitz plot analysis to untangle the data peak into its two components, a complex technique that had never before been used on LHC data.

The technique helps separate and visualise the different paths a particle can take as it decays. Now that it has been used successfully on the LHCb dataset, says Gershon, it can hopefully be applied to more LHC data to help discover further particles and understand how they are bound together.

“This is a lovely piece of experimental physics,” says of the Massachusetts Institute of Technology in Cambridge. “Although it doesn’t probe the limits of the standard model, it may shine light on the dynamics of quarks and gluons. The fact that LHCb was able to use Dalitz plot methods is a testimony to the quantity and high quality of the data they’ve accumulated. We can look forward to other similar discoveries in the future using this method.”

Journal references: Physical Review D, DOI forthcoming and Physical Review Letters, DOI forthcoming

Both are also available on ArXiv: and

When potential dwarf planet 2012 VP113 was discovered in March, it joined a handful of unusual rocky objects known to reside beyond the orbit of Pluto. These small objects have curiously aligned orbits, which hints that an unseen planet even further out is influencing their behaviour. ��è����Ƶs calculated that this world would be about 10 times the mass of Earth and would orbit at roughly 250 times Earth’s distance from the sun.

Now Carlos and Raul de la Fuente Marcos at the Complutense University of Madrid in Spain have taken another look at these distant bodies. As well as confirming their bizarre orbital alignment, the pair found additional puzzling patterns. Small groups of the objects have very similar orbital paths. Because they are not massive enough to be tugging on each other, the researchers think the objects are being “shepherded” by a larger object in a pattern known as orbital resonance.

Planet shepherd

For instance, we know that Neptune and Pluto are in orbital resonance – for every two orbits Pluto makes around the sun, Neptune makes three. Similarly, one group of small objects seems to be in lockstep with a much more distant, unseen planet. That world would have a mass between that of Mars and Saturn and would sit about 200 times Earth’s distance from the sun.

Some of the smaller objects have very elongated orbits that would take them out to this distance. It is unusual for a large planet to orbit so close to other bodies unless it is dynamically tied to something else, so the researchers suggest that the large planet is itself in resonance with a more massive world at about 250 times the Earth-sun distance – just like the one predicted in the previous work.

Observing these putative planets will be tricky. The smaller bodies are on very elliptical orbits and were only spotted when they ventured closest to the sun. But the big planets would have roughly circular orbits and would be slow moving and dim, making them tough for current telescopes to see. “It’s not at all surprising that they haven’t been found yet,” says Carlos.

“As there are only a few of these extremely distant objects known, it’s hard to say anything definitive about the number or location of any distant planets,” says at the Carnegie Institution for Science in Washington DC, one of the discoverers of 2012 VP113. “However, in the near future we should have more objects to work with to help us determine the structure of the outer solar system.”

Reference:

“For the first time, we can actually image the motion of individual atoms, and observe the atom-by-atom assembly of crystals,” says at the University of Warwick, UK.

In the nanoscale world, rods, spheres and dots made from the same material have dramatically different chemical and physical properties. But until now, our control over such structures has been limited because they grow too fast for even the best electron microscopes to follow.

Barry and his colleagues fired a beam of electrons at a thin film of molecules containing the metal osmium, carbon and other elements. Most molecules broke down to release single osmium atoms, and the remaining film fused into a graphene lattice that supported the free atoms. Crucially, this graphene support contained impurities.

Mix and match

“It’s doped with boron and sulphur atoms, which slow down the motion of individual metal atoms on the graphene surface,” says Barry. The sluggish atoms move at the same rate as the image-capture speed of electron microscopes, allowing the team to see crystal growth in action.

The team also used a mix of metal atoms to produce an alloy of osmium and ruthenium for the first time, demonstrating that the technique could conceivably create other novel materials with interesting properties.

The method should make it possible to watch how crystals grow from different chemical recipes and figure out how to make customised crystals for use in diverse fields. It could also allow us to introduce desirable defects into crystals.

Sticky problem

“The ability to watch single atoms combine one by one to form nanoparticles is a significant contribution to understanding how materials form at the atomic level,” says at the University of Nottingham, UK.

But the reactivity of the crystal presents a hurdle, he says. Without a stabilising shell covering a particle’s surface, the material will continue to stick to any other particle it encounters, growing larger and becoming less active. “The useful properties of these crystals will change rapidly over time and then cease quite quickly.”

Still, having uncoated “islands” of highly reactive crystals on a graphene grid could be useful, says Barry. Such a set-up could detect gases or drugs at the atomic scale, for instance. “This combination could be extremely efficient for nano-catalytic applications – but we don’t know yet,” he says.

Journal reference: Nature Communications,

THE sun has thrown us a fractal surprise. An unexpected pattern has been glimpsed in the solar wind, the turbulent plasma of charged particles that streams from the sun. It offers clues for handling plasmas that roil inside nuclear fusion reactors on Earth.

Composed of charged particles such as protons and electrons, the solar wind streams from the sun and pervades the solar system. Its flow is turbulent, containing eddies and moving at different speeds in different directions. It was thought that this turbulence was similar to that in a fluid, behaving like mixing ocean currents or the air flows that make aeroplane flights bumpy.

Now, of the University of Warwick, UK, and her colleagues have examined the solar wind’s behaviour using NASA’s twin STEREO spacecraft. One flies just within Earth’s orbit around the sun, the other just outside it, allowing the pair to obtain unique measurements of solar wind behaviour.

STEREO revealed that when the movement of the wind’s particles is perpendicular to the sun’s magnetic field, they resemble a fluid, with sections that are smooth, interrupted by bursts of violence. “If you look out of a plane window you see mountain ranges and then long rolling plains. This is what the perpendicular fluid turbulence is like,” says Chapman.

But when the particles move in parallel with the field lines, they behave very differently, with the turbulence evenly spread, like crinkly mountains that extend as far as the eye can see (see diagram). “It’s a different kind of physics,” says Chapman.

What’s more, that crinkliness is constant, no matter how much you zoom in or out on a patch of wind, making its behaviour fractal (). Snowflakes, shorelines and most recently black holes (see “Turbulent black holes grow fractal skins as they feed“) also exhibit such fractal behaviour.

The result may help to control nuclear fusion reactors. These create energy in the same way as the sun, by fusing a superheated plasma of hydrogen nuclei to form helium.

One problem with optimising their energy output is deducing what is going on inside them – inserting a probe isn’t an option as it would melt. Enter the solar wind. Though less dense and cooler than the hydrogen of a fusion reactor, the wind is a plasma – and can be probed thanks to STEREO. “The great thing about solar wind turbulence is that the satellites sit right inside, so it can be observed in exquisite detail,” says of the Culham Centre for Fusion Energy, UK.

By adding the fractal behaviour to their plasma models, fusion scientists may be able to control turbulence, which can cause plasma to escape the magnetic field containing it in the reactor. They may also be able to use turbulence to disrupt high energy plasma blobs that can rip holes in the reactor. “These results look very promising,” says Todd Evans of nuclear energy firm in San Diego, California.

This article appeared in print under the headline “Sunny surprise for fusion reactors”

This rock’s got some bling. A star that is about to wink out over Africa will give us a good look at the first known asteroid with rings.

Last month, astronomers described icy rings around the asteroid 10199 Chariklo. They were found during an occultation, when the asteroid crossed in front of a star from Earth’s perspective. Seen from South America, the star’s brightness dipped in a distinctive pattern, indicating a set of sharply defined rings.

At 23.14 UTC on 29 April, , an event that will be visible from a narrow path across South Africa, Namibia and possibly Botswana.

The star is the brightest one that Chariklo will cross in 2014, and it should be easy to spot with amateur telescopes. Some of the scientists who helped find the rings are also hoping to watch the event from regional observatories, such as the South African Astronomical Observatory in Cape Town and the International Amateur Sternwarte in Namibia.

Clear skies

The star will seem to vanish for up to 19 seconds, and records of where people saw the event and how long it lasted at their location will be compiled to recreate the asteroid’s “shadow”. This information could help better pin down Chariklo’s size and shape, perhaps giving clues to its composition.

The rings will cast a much wider shadow across southern Africa, visible 300 kilometres out from the centre of the asteroid’s path. “With the right equipment, I would hope an observer could record some variation in the star’s light as the rings occult the star,” says Steve Preston, president of the International Occultation Timing Association. That could tell astronomers more about the rings’ orientation, and perhaps offer clues as to how they have survived.

For instance, the gravitational pull of a “shepherd” moon could be corralling the rings into a tidy shape, akin to what happens in the rings around Saturn and Uranus. Such an orbiting body would cause a further dip in brightness that may be noticeable as the asteroid slips in front of the star.

“It’s a good occultation, as there are major observatories in South Africa and places in the Namibian desert where it is good to observe from,” says at the Max Planck Institute for Solar System Research in Göttingen, Germany, a co-discoverer of Chariklo’s rings. “And the skies will almost certainly be clear.”

Video: See how the space rock’s shiny rings were found

Asteroids with Saturn-envy can deck themselves out with glittering rings. A space rock called 10199 Chariklo is the first asteroid known to have a ring system, revealing an unexpected possibility for small bodies in the solar system. Until now, rings have been found only around giant planets.

of the Max Planck Institute for Solar System Research in Göttingen, Germany, and his colleagues found the rings in June 2013 during an asteroid occultation. This is when a space rock crosses in front of a star as seen from Earth, causing the star to briefly wink out. Seen from sites across South America, the star’s brightness dipped in a distinctive pattern, indicating a set of sharply defined, thin rings.

“We were amazed to see that the star didn’t just blink out and come back – there were very short blinks before and after the main dip, which could only be explained by rings,” says Snodgrass.

Hidden shepherds

Usually the particles in rings would spread out, making them smoother at the edges. To look so sharp, the asteroid’s rings must be constantly shaped by something, most likely unseen “shepherd” satellites that move near the rings and keep their particles confined. “Shepherds have been observed around some of Uranus and Saturn’s narrow rings,” says team member Bruno Sicardy at Pierre-and-Marie-Curie University in Paris, France. “So even if their origins are very different, Chariklo’s rings seem to follow some common rules.”

Chariklo orbits between the paths of Saturn and Uranus, and the asteroid has shown mysterious behaviour in the past. The tiny body was seen dimming and brightening, and its spectrum held hints of water ice disappearing and reappearing. A pair of icy, reflective rings seen from different angles would account for this.

The authors think the rings could have formed in a number of ways, including impacts flinging up debris, or small moons colliding or being broken up by gravity if they spiralled too close to the asteroid.

“This work is very consistent with all previous data, and provides an explanation which is quite unexpected,” says of the European Space Research and Technology Centre in the Netherlands, who did not contribute to the study. “It opens a new and unique perspective on the processes dominating the history of small bodies.”

Journal reference: Nature, DOI: 10.1038/nature13155

A surprise monster may be lurking in our solar system. A newly discovered dwarf planet has grabbed the crown as the most distant known object in our solar system – and its orbit hints at a giant, unseen rocky world, 10 times the mass of Earth and orbiting far beyond Pluto.

The dwarf planet, for now dubbed 2012 VP113 because it was spotted in images taken in November 2012 – is an interesting discovery in itself. of the Carnegie Institution for Science in Washington DC and his colleagues found that it is a lump of rock and ice 450 kilometres wide and lies at 80 astronomical units from the sun at its closest approach (1 AU is Earth’s distance from the sun).

That’s twice as far as the most famous dwarf planet, Pluto, which is 2340 kilometres wide and also beats the previous record holder, a 1000-kilometre-wide planetoid called Sedna, discovered in 2003, with a closest approach of 76 AU out.

Objects orbiting this far from the sun, in the “inner Oort cloud”, are useful to probe the early solar system. That’s because they lie too far away to be perturbed by the gas planets, but too close to the sun to be affected by the gravity of other stars in our galaxy – so their orbits and behaviour are thought to be almost unchanged since they first formed. “Once we find more objects in this region, we’ll be able to start to strongly constrain the possible formation scenarios,” says Sheppard.

Distant puppeteer

The discovery of 2012 VP113 instantly doubles the number of objects known in this part of space, from 1 to 2 – and the team estimates that many more exist in this region and are just waiting to be discovered. “We thought Pluto was unique for over 70 years, but we now know that it shares its orbit with thousands of other objects,” says Sheppard. “Sedna was unique for about 10 years but it’s now clear that Sedna and 2012 VP113 are just the tip of the iceberg.”

Intriguingly, Sheppard’s team also found a strange alignment when they looked at the orbits of 2012 VP113, Sedna and 10 other objects that lie closer to the sun. “It was a big surprise to us,” he says.

One explanation for the alignment could be the tug of a rocky planet that is 10 times the mass of Earth that orbits the sun at 250 AU, the team calculate. That world would be cold and faint – and would push and pull at the closer objects like a distant but powerful puppeteer.

Click for a larger version

scoured this region of space in 2010 and 2011 searching for a so-called Planet X and came up empty.

However, WISE was looking for the tell-tale warmth of gas giants – a rocky “super-Earth”, like the one Sheppard’s team suggest, would be too cold for the telescope to pick up. “This is too faint for WISE,” says Ned Wright, the space telescope’s principal investigator. Even if the planet has a small internal heat source – and absorbs some sunlight, it would still not generate enough heat to register, he adds.

Rogue planets

Nonetheless, if it exists, how could such a monster possibly have escaped notice until now? It may seem strange, particularly given our recent ability to spot more than 1000 far more distant planets, in alien solar systems. But instruments such as NASA’s Kepler space telescope, which has had particular success in finding such exoplanets, would have no chance of spotting a planet like this one.

Kepler is designed to spot tell-tale dips in the brightness of alien stars as planets pass in front of them. “No way would Kepler find this planet,” says of San Diego State University, a member of the Kepler team.

The only method currently available that might have a chance is gravitational microlensing, suggests Welsh, where the gravity of a massive object lying between us and the planet could be used as a cosmic magnifying glass. Recently this method was used to spot an object that might be the first moon glimpsed outside our solar system.

However, there are other ways to explain the orbital alignment that Sheppard’s team found, including the pull of stars or “rogue” planets kicked out of our solar system eons ago.

For that reason, of the California Institute of Technology, a co-discoverer of Sedna, isn’t holding out hope of a giant planet just yet. “It is possible that some undiscovered large object out there is doing this, but there are likely many other explanations, too, most of them sadly more mundane.”

Journal reference: Nature, DOI: 10.1038/nature13156