China to Build Supercollider 2 - 7 Times the Energy of the Swiss Large Hadron Collider

China is planning to enter the Europe- and US-dominated world of experimental physics with (wait for it …) a bang. It has formally announced that it will begin the first phase of construction of an enormous particle accelerator around 2020, which will be twice the size and seven times more powerful than CERN's Large Hadron Collider (LHC).

Europe's LHC is the largest single machine in the world, a huge circular tunnel 17 miles (27 km) in circumference. But China's planned Circular Electron Positron Collider (CEPC) could (almost) literally run rings around it – it will be between 30 and 62 miles in circumference, large enough to circle Manhattan.

Wang Yifang, director of the Institute of High Energy Physics, Chinese Academy of Sciences, has suggested Qinhuangdao, a northern port city near the start of the Great Wall, as an ideal location for the underground facility.

The plan is for the tunnel to house two different super colliders. The first phase project will be the CEPC, designed to study the Higgs boson particle and how it decays following a collision. Super colliders smash atomic particles together at velocities close to the speed of light, to try to recreate the conditions that followed the Big Bang. China's super collider will get closer to these conditions than ever before.

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Teleportation of Quantum Entanglement Over 143 km

Teleportation of entanglement over 143 km

Authors:

Herbst et al

Abstract:

As a direct consequence of the no-cloning theorem, the deterministic amplification as in classical communication is impossible for unknown quantum states. This calls for more advanced techniques in a future global quantum network, e.g., for cloud quantum computing. A unique solution is the teleportation of an entangled state, i.e., entanglement swapping, representing the central resource to relay entanglement between distant nodes. Together with entanglement purification and a quantum memory it constitutes a so-called quantum repeater. Since the aforementioned building blocks have been individually demonstrated in laboratory setups only, the applicability of the required technology in real-world scenarios remained to be proven. Here we present a free-space entanglement-swapping experiment between the Canary Islands of La Palma and Tenerife, verifying the presence of quantum entanglement between two previously independent photons separated by 143 km. We obtained an expectation value for the entanglement-witness operator, more than 6 SDs beyond the classical limit. By consecutive generation of the two required photon pairs and space-like separation of the relevant measurement events, we also showed the feasibility of the swapping protocol in a long-distance scenario, where the independence of the nodes is highly demanded. Because our results already allow for efficient implementation of entanglement purification, we anticipate our research to lay the ground for a fully fledged quantum repeater over a realistic high-loss and even turbulent quantum channel.

Glueball Particle Found?

For decades, scientists have been looking for so-called "glueballs". Now it seems they have been found at last. A glueball is an exotic particle, made up entirely of gluons - the "sticky" particles that keep nuclear particles together. Glueballs are unstable and can only be detected indirectly, by analysing their decay. This decay process, however, is not yet fully understood.

Professor Anton Rebhan and Frederic Brünner from TU Wien (Vienna) have now employed a new theoretical approach to calculate glueball decay. Their results agree extremely well with data from particle accelerator experiments. This is strong evidence that a resonance called "f0(1710)", which has been found in various experiments, is in fact the long-sought glueball. Further experimental results are to be expected in the next few months.

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Tread Carefully Around the Hype: Leptons Behaving Badly at the LHC

Subatomic particles have been found that appear to defy the Standard Model of particle physics. The team working at Cern's Large Hadron Collider have found evidence of leptons decaying at different rates, which could possibly point to some undiscovered forces.

Publishing their findings in the journal Physical Review Letters, the team from the University of Maryland had been searching for conditions and behaviours that do not fit with the Standard Model. The model explains most known behaviours and interactions of fundamental subatomic particles, but it is incomplete – for example it does not adequately explain gravity, dark matter and neutrino masses.

Researchers say the discovery of the non-conforming leptons could provide a big lead in the search for non-standard phenomenon. The Standard Model concept of lepton universality assumes leptons are treated equally by fundamental forces.

They looked at B meson decays including two types of leptons – the tau lepton and the muon, both of which are highly unstable and decay within just a fraction of a second. The tau lepton and muon should decay at the same rate after mass differences are corrected. But the researchers found small but important differences in the predicted rates of decay.

This suggests there are undiscovered forces or particles interfering in the process. Study co-author Hassan Jawahery said: "The Standard Model says the world interacts with all leptons in the same way. There is a democracy there. But there is no guarantee that this will hold true if we discover new particles or new forces. Lepton universality is truly enshrined in the Standard Model. If this universality is broken, we can say that we've found evidence for non-standard physics."

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Check your instruments.  Last tim something like this happened, it turned out to be dirty fiber optics.  

Physicists Propose Experiment to Detect Neutrons From Other Universes

One of the more exciting ideas in high energy physics is the possibility that our three-dimensional universe is embedded in a much bigger multidimensional cosmos. Physicists call these embedded universes “branes” and say that it should be possible for stuff from our brane to leak into other branes nearby and vice versa.

Today, Michael Sarrazin at the University of Namur in Belgium and a few pals say they have worked out to detect this leakage by measuring whether neutrons can bypass barriers by leaping into another brane and back again.

These guys are proposing to measure this effect by placing a neutron detector close to a nuclear reactor to see whether neutrons appear unexpectedly as a result of being transported out of the reactor via another braneworld.

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Can Glancing Blows to Nuclei by Neutrinos Summon Particles From the Quantum Foam?

In what they call a “weird little corner” of the already weird world of neutrinos, physicists have found evidence that these tiny particles might be involved in a surprising reaction.

Neutrinos are famous for almost never interacting. As an example, ten trillion neutrinos pass through your hand every second, and fewer than one actually interacts with any of the atoms that make up your hand. However, when neutrinos do interact with another particle, it happens at very close distances and involves a high-momentum transfer.

And yet a new paper, published in Physical Review Letters this week, shows that neutrinos sometimes can also interact with a nucleus but leave it basically untouched – inflicting no more than a “glancing blow” – resulting in a particle being created out of a vacuum.

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China to Build Colossal Particle Collider to Dwarf Large Hadron Collider

For decades, Europe and the United States have led the way when it comes to high-energy particle colliders. But a proposal by China that is quietly gathering momentum has raised the possibility that the country could soon position itself at the forefront of particle physics.

Scientists at the Institute of High Energy Physics (IHEP) in Beijing, working with international collaborators, are planning to build a ‘Higgs factory’ by 2028 — a 52-kilometre underground ring that would smash together electrons and positrons. Collisions of these fundamental particles would allow the Higgs boson to be studied with greater precision than at the much smaller Large Hadron Collider (LHC) at CERN, Europe’s particle-physics laboratory near Geneva, Switzerland.

Physicists say that the proposed US$3-billion machine is within technological grasp and is considered conservative in scope and cost. But China hopes that it would also be a stepping stone to a next-generation collider — a super proton–proton collider — in the same tunnel.

European and US teams have both shown interest in building their own super collider (see Nature 503, 177; 2013), but the huge amount of research needed before such a machine could be built means that the earliest date either can aim for is 2035. China would like to build its electron–positron collider in the meantime, unaided by international funding if needs be, and follow it up as fast as technologically possible with the super proton collider. Because only one super collider is likely to be built, China’s momentum puts it firmly in the driving seat.

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Antihydrogen Properties Measured

The best science — the questions that capture and compel any human being — is enshrouded in mystery. Here’s an example: scientists expect that matter and antimatter were created in equal quantities shortly after the Big Bang. If this had been the case, the two types of particles would have annihilated each other, leaving a Universe permeated by energy.

As our existence attests, that did not happen. In fact, nature seems to have a one-part in 10 billion preference for matter over antimatter. It’s one of the greatest mysteries in modern physics.

But the Large Hadron Collider is working hard, literally pushing matter to the limit, to solve this captivating mystery. This week, CERN created a beam of antihydrogen atoms, allowing scientists to take precise measurements of this elusive antimatter for the first time.

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LBNL Proposing new Laser-Plasma Accelerator

It took every inch of the Large Hadron Collider's 17-mile length to accelerate particles to energies high enough to discover the Higgs boson. Now, imagine an accelerator that could do the same thing in, say, the length of a football field. Or less.

That is the promise of laser-plasma accelerators, which use lasers instead of high-power radio-frequency waves to energize electrons in very short distances. Scientists have grappled with building these devices for two decades, and a new theoretical study predicts that this may be easier than previously thought.

The authors are Carlo Benedetti, Carl Schroeder, Eric Esarey, and Wim Leemans, physicists at Lawrence Berkeley National Laboratory's Berkeley Lab Laser Accelerator (BELLA) Center. Their paper, "Plasma wakefields driven by an incoherent combination of laser pulses: A path towards high-average power laser-plasma accelerators," appears in the May Special Issue of Physics of Plasmas, from AIP Publishing.

If their models prove correct, they could help lower the cost of high-energy physics research -- the Large Hadron Collider cost $9 billion -- as well as many other industrial and medical applications of accelerators.

Laser-plasma accelerators work by blasting a powerful laser beam into a plasma, a cloud of unattached electrons and ions.

"The effect is like the wake of boat speeding down a lake. If the wake was big enough, a surfer could ride it," Leemans, who heads the BELLA Center, explained.

"Imagine that the plasma is the lake and the laser is the motorboat. When the laser plows through the plasma, the pressure created by its photons pushes the electrons out of the way. They wind up surfing the wake, or wakefield, created by the laser as it moves down the accelerator," he said.

The fast moving electrons leave the heavy ions behind. As they separate, they create gigantic electric fields, 100 to 1,000 times larger than those in conventional accelerators.

This is how they accelerate electrons so rapidly. For example, Stanford's Linear Accelerator Center takes two miles to drive an electron to 50 billion electron volts (GeV). Leemans' experimental laser-plasma accelerator takes electrons to more than 1 GeV in slightly more than 1 inch.

It takes a lot of laser power to generate a wakefield. For example, BELLA's petawatt (1 quadrillion watts) laser has a 10 meter x 10 meter footprint. It generates 400 times more power than all the world's power plants combined, though only for 40 femtoseconds (40 quadrillionths of a second).

Unfortunately, it takes BELLA's laser a full second to recharge and send a second pulse. High-energy physics research requires tens of thousands of pulses per second. Many other applications would benefit from multiple pulses per second.

BELLA's laser has the highest repetition rate of any petawatt laser in the world. Building a faster petawatt laser would require a heroic feat of engineering.

Several European researchers have suggested using an array of smaller lasers to produce one enormous pulse. Since less powerful lasers recharge faster, they could produce hundreds or even thousands of pulses per second and sustain a wakefield over many meters.

The hurdle they needed to overcome was how to synchronize hundreds of lasers so they all pulsed within less than a femtosecond of one another.

Such precision would be expensive and presents serious technical problems. But the concept of combining lasers got Leemans' team thinking.

What if the beam was not perfect? What if it were just good enough to rapidly raise the photon pressure on the electrons? Could we get away with it, they wondered.

According to the model presented in Physics of Plasmas, they could. Leemans compares it to pushing a swing.

"Instead of one big push, we would give it many smaller pushes at roughly the same time. It's not quite perfect, but the swing doesn't really care. It averages over all these little pushes and up it goes."

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Physicists Discover Method to Create Matter From Light

Imperial College London physicists have discovered how to create matter from light - a feat thought impossible when the idea was first theorised 80 years ago.

In just one day over several cups of coffee in a tiny office in Imperial's Blackett Physics Laboratory, three physicists worked out a relatively simple way to physically prove a theory first devised by scientists Breit and Wheeler in 1934.

Breit and Wheeler suggested that it should be possible to turn light into matter by smashing together only two particles of light (photons), to create an electron and a positron – the simplest method of turning light into matter ever predicted. The calculation was found to be theoretically sound but Breit and Wheeler said that they never expected anybody to physically demonstrate their prediction. It has never been observed in the laboratory and past experiments to test it have required the addition of massive high-energy particles.

The new research, published in Nature Photonics, shows for the first time how Breit and Wheeler's theory could be proven in practice. This 'photon-photon collider', which would convert light directly into matter using technology that is already available, would be a new type of high-energy physics experiment. This experiment would recreate a process that was important in the first 100 seconds of the universe and that is also seen in gamma ray bursts, which are the biggest explosions in the universe and one of physics' greatest unsolved mysteries.

The scientists had been investigating unrelated problems in fusion energy when they realised what they were working on could be applied to the Breit-Wheeler theory. The breakthrough was achieved in collaboration with a fellow theoretical physicist from the Max Planck Institute for Nuclear Physics, who happened to be visiting Imperial.

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CERN Hears Snowmass and Wants to Build 80 km, 100TeV TLEP Collider

Not content with the 27-kilometre-round Large Hadron Collider, researchers at CERN have their sights set on a new beast of a particle collider that could have a circumference of 80 to 100 kilometres.

The nuclear research organisation announced that it was hatching plans for an ambitious successor to the LHC with an international study called the Future Circular Colliders (FCC) programme, which will kick off with a meeting next week.

The idea is to consider different hadron collider designs similar to the existing LHC but more powerful—much more powerful. CERN wrote it was looking for a collider “capable of reaching unprecedented energies in the region of 100 TeV.” The existing LHC will reach a maximum of around 14 TeV (tera electron Volts).

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Sounds like the SSC!  Even down to the length!  Our tunnel is partially built!  C'mon!  Let's get into a science race with the Euros!  F*ck the EU!  Ahem.  ;)

Snowmass Results: Planning the Future of U.S. Particle Physics

Snowmass meeting on planning the future of United States efforts in particle physics.

Reports.

1. Summary.
2. Intensity Frontier. 
3. Energy Frontier 
4. Cosmic Frontier

There will be more as I understand it.

Snowmass: Let us Have the Very Large Hadron Collider!

When Europe’s Large Hadron Collider (LHC) started up in 2008, particle physicists would not have dreamt of asking for something bigger until they got their US$5-billion machine to work. But with the 2012 discovery of the Higgs boson, the LHC has fulfilled its original promise — and physicists are beginning to get excited about designing a machine that might one day succeed it: the Very Large Hadron Collider (VLHC).

“It’s only prudent to try to sketch a vision decades into the future,” says Michael Peskin, a theoretical physicist at SLAC National Accelerator Laboratory in Menlo Park, California, who presented the VLHC concept to a US government advisory panel on 2 November.

The giant machine would dwarf all of its predecessors (see ‘Lord of the rings’). It would collide protons at energies around 100 teraelectronvolts (TeV), compared with the planned 14 TeV of the LHC at CERN, Europe’s particle-physics lab near Geneva in Switzerland. And it would require a tunnel 80–100 kilometers around, compared with the LHC’s 27-km circumference. For the past decade or so, there has been little research money available worldwide to develop the concept. But this summer, at the Snowmass meeting in Minneapolis, Minnesota — where hundreds of particle physicists assembled to dream up machines for their field’s long-term future — the VLHC concept stood out as a favorite.

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The diameter sounds suspiciously like the old SSC.  Perhaps some crazy person in Texas ought to pitch their congress critter...;)