Some particle physics news

[WordMan]

So Higgs and Englert won the Nobel for Physics. Cool - given the recent confirmation of the Higg’s Boson, it seems appropriate to this civilian. I know there is discussion about who wall was involved in the discovery…

Anyway, there’s this article behind the paywall at the NY Times. It contains this passage:

It was Yoichiro Nambu of the University of Chicago, who would win a Nobel in 2008, who suggested that the fault might lie not in the laws of physics but in how those laws play out in the real world. By a process called symmetry breaking, a situation that started out balanced can wind up unbalanced.

Imagine, for example, a pencil standing on its tip; it will eventually fall over and point only one way out of many possibilities. The mass of the boson can be thought of as the energy released when the pencil falls.

In 1964, three papers by the different physicists showed how this could work by envisioning a kind of cosmic molasses filling space. Particles trying to go through it would acquire mass.

I am open to hearing that I am Captain Slow (nod to Top Gear), but as science writing, I don’t see how this passage helps explain anything. I am not looking for someone to explain what they mean - just see if other physics-interested folks find this to be sub-par science writing…

ETA: This article behind the subscriber wall is here - http://www.nytimes.com/2013/10/09/science/englert-and-higgs-win-nobel-physics-prize.html?ref=todayspaper

The reporter is Dennis Overbye, who I normally like to read…

[Pasta]

@WordMan

I am not looking for someone to explain what they mean - just see if other physics-interested folks find this to be sub-par science writing…

I would agree that this passage is a bit bumpy. Overbye is good about telling the full story with no lies, not even lies of omission. He’s attempted this here, but the full story is really hard to squeeze into 10 column-inches, and he lost clarity trying to do so. But since he is at least trying to tell the whole truth without the extraneous spin that plagues most science writing, I’d still tag is as “above par” (even if also “not very clear”).

(In case this is part of the confusion: the “boson” in the cited passage is not the Higgs boson but rather the force carriers mentioned a few paragraphs upstream of your excerpt. Since “Higgs boson” is a household phrase now, I could imagine people losing the connection with the intended antecedent by the time they reached this point.)

[deltasigma]

Not sure if this helps or adds to the confusion, but it’s one of many analogies out there.

For decades, experts have been trying to come up with analogies to illustrate how the Higgs mechanism works. One of the best-known was proposed in 1993 by David Miller, a physicist at University College London. Imagine looking down from a balcony in a ballroom, watching a cocktail party below. When just plain folks try to go from one end of the room to the other, they can walk through easily, with no resistance from the party crowd. But when a celebrity like Justin Bieber shows up, other partygoers press around him so tightly that he can hardly move … and once he moves, the crowd moves with him in such a way that the whole group is harder to stop.
The partygoers are like Higgs bosons, the just plain folks are like massless particles, and Bieber is like a massive Z boson.

There’s also a video animation of this someplace which I’m sure you can probably find on youtube.

[deltasigma]

This may not strictly be particle physics news, but hopefully it will still be of interest.

First LUX result negates previous possible dark-matter sighting

In its first three months of running, the world’s most sensitive dark matter experiment saw no signs of dark matter—refuting a previous, inconclusive result from another experiment.
In April, scientists on the Cryogenic Dark Matter Search, or CDMS, experiment announced their detector had caught three candidate dark-matter particles with a mass about nine times that of a proton. This morning, scientists on the Large Underground Xenon, or LUX, experiment announced that, if the particles caught by CDMS really were dark-matter particles, the much larger, more sensitive LUX experiment should have seen about 1600 candidate particles, about one for every 80 minutes of their initial run.
However, the LUX experiment came up empty-handed in its first run, conducted this spring and summer. The worldwide search for dark matter continues.

More at link

Here is another link with more technical info from Ars Technica

[deltasigma]

This looks to be an experimentto study the sea quarks that compose part of the mass of the subatomic particles such as protons and neutrons. The standard 3 quarks and anti-quarks actually only make up about 1% of the static mass of these particles. The remainder is due to the gluons which technically don’t have mass. I think this is where sea quarks come in but I’ve never really had a very good understanding of this and I’ve probably screwed enough up already so I’ll just give you an excerpt from the article and wait for someone to come by and clean this up.

The SeaQuest experiment, based at Fermilab and managed by a group of scientists from Argonne laboratory, studies the structure of protons and the behavior of the particles of which they’re made.
Protons contain a constantly simmering sea of particles bound together by the aptly named strong force, which is the strongest of the four fundamental interactions of nature—above the weak force, electromagnetism and gravity.
In the experiment, a particle accelerator sends a beam of protons at very high speeds into a target made of either liquid hydrogen or deuterium or solid carbon, iron or tungsten. These bursts of beam come once a minute and each last about 5 seconds.
This causes protons to essentially break apart and release the quarks and antiquarks within. (Antiquarks are the antiparticle of quarks, meaning they have the same mass but opposite charge.)
SeaQuest physicists will then study in great detail the particles that are released during these interactions. Their aim is to resolve questions about the particles that make up the visible mass in our universe.
Initially, experimenters hope to shed light on the internal structure of protons, specifically, the ratio of anti-up quarks to anti-down quarks—two types of antiquarks with different properties.
Results from SeaQuest’s predecessor, NuSea, and DESY’s Hermes experiment, both reported in 1998, found a surprise in measuring the ratio of anti-down quarks to anti-up quarks in the proton; it trended toward a value of less than one. This shook up current assumptions about symmetry between these particles and might hint that we have an incomplete understanding of the strong force.

edit: I’m behind on my reading so there’s probably something in one of the Fermilab newsletters over the past couple of weeks on this which I’ll post as soon as I run across it.

[deltasigma]

Here’s the Fermilab announcement of the SeaQuest start up.

Protons contain a constantly simmering sea of particles called quarks and antiquarks, all bound together by the aptly named strong force, the strongest of the four fundamental interactions of nature. SeaQuest aims to shed light on the structure of protons, specifically, the ratio of up antiquarks to down antiquarks — two types of antiquarks with different properties. The experiment is also intended to study how the strong force binds particles and how those effects are modified when the proton is inside an atom’s nucleus rather than isolated and separated from the rest of the atom.

[deltasigma]

It looks like there might be a whole family of 4 quark hadrons.

A partner to the Zc(3900) – called the “Zc(4020)” – was recently discovered using a method very similar to that used in the discovery of the Zc(3900). Rather than decaying to a charged pion and a J/ψ, the Zc(4020) appeared in a decay to a charged pion and an hc. The hc and J/ψ both consist of a charm quark and an anti-charm quark, only the orientation of the quarks differs. Since the Zc(4020) is also electrically charged, and also decays to a particle consisting of a charm quark and an anti-charm quark, its interpretation is the same – it must also be a four-quark object. Therefore, it appears the BESIII Collaboration has begun to unveil a whole family of these four-quark objects.

[Senegoid]

If only they could make these new particles stay around for longer, and then create them in industrial quantities, think of the the marvelous new materials technology we would have!

If we could generate macroscopic quantities of these stuffs, what kind of chemical and physical properties would they have?

[Count_Blucher]

I’m no where near well versed enough to reply to this, but I have some ideas for some fun Sci-Fi thoughts based on this which I’ll propose for entertainment value only:

Assuming they morph:

1. What if by controlling an external factor you could control which ball they become? Granted its Trinary and not binary, but technically could you not use this as the basis for calculations faster than any other calculations previously recorded?
   Or as a way to control/sustain an energy source? Or even (its the Sci-fi fan in me) as a method of propulsion?

Assuming they DON’T morph:

2. Those balls came from somewhere and your balls went to somewhere… and could those balls have shot / pushed into some-place-else and have pushed the other balls out of that some-place-else… marbles-style?
   If it did, could that not be the basis for a proposal that multiple (infinite?) realms could occupy the same time an space and that some neutrinos, based on some as yet not defined properties specifically unique to those neutrinos, can travel between them?

Assuming that wildly speculative idea, what if under ideal conditions, sufficient neutrinos could be forced from A to B, could that not open up some sort of point for one-way travel of a very small amount of mass from A to B?
Or possibly even from A to A through B?

“Black Mesa Transit Announcement System: Good morning, and welcome to the Black Mesa Transit System. This automated train is provided for the security and convenience of the Black Mesa Research Facility personnel…”

[deltasigma]

As long as we’re speculating, here’s some speculation that may also be of interest. Does the Higgs field raise more issues than it resolves? To put it more technically,is the Standard Model too finely tuned?

The Standard Model is finely tuned in several ways, but the most significant is the fact that it does not explain why gravity is so much weaker than the other forces. Here’s a more technical statement of the problem: Why is the Higgs mass (now known to be 125 GeV) about 100 quintillion times less than the characteristic energy scale of quantum gravity? When physicists tried to predict the Higgs mass mathematically, they found that the largest terms in the equation are due to ultra-high energy effects, the regime of quantum gravity. Since we know very little about quantum gravity, the equation could not be solved and the Higgs mass could not be predicted. However, it is highly suspicious that some combination of these unknown yet ultra-high energy terms result in something that is known to be 100 quintillion times smaller.

Here’s a NYT article that goes into the issue in more depth. I found this particularly titillating.

There is a third way, he says, to keep the Higgs mass in bounds. That is by saying that its mass comes entirely from the virtual particles winking in and out of life around the particle. To make this scheme work, however, physicists have to abandon popular speculations of how the forces of nature are unified at “superhigh energies,” Dr. Lykken admitted in an email.

[deltasigma]

Some more cool speculation from Fermilab - are quarks and leptons the ultimate building blocks of matter? A youtube video.

The Standard Model of particle physics treats quarks and leptons as having no size at all. Quarks are found inside protons and neutrons and the most familiar lepton is the electron. While the best measurements to date support that idea, there is circumstantial evidence that suggests that perhaps the these tiny particles might be composed of even smaller building blocks. This video explains this circumstantial evidence and introduces some very basic ideas of what those building blocks might be.

It interesting to note the scale of things here. At the 6min mark he notes that if quarks have a size, they are 10^-19m. For reference, the Planck length is 1.616 x 10^-35m

[deltasigma]

Again some ‘not technically particle physics news’ but very close. A method had been devised for encoding qubits that allows them to remain viable for as long as 39 minutes at room temperature. The downside is that you have to cool them back down to around 4K to read or write them, but as it turns out, that make them even ahem cooler (sorry). From Physics World:

Quantum states have been shown to endure in a room-temperature solid-state device for a whopping 39 minutes, shattering the previous record of 2 s. The feat was achieved by physicists in Canada, the UK and Germany, who used phosphorus atoms in silicon as their quantum bits – or qubits. The breakthrough offers hope that normally fragile quantum states could be made robust enough to be used in practical quantum computers or even in “quantum money”.

[squeegee]

Following this. Thanks deltasigma.

[deltasigma]

Thanks - mainly for giving me an excuse to post this somewhat more comprehensible announcement of what seems to be the new family of tetraquark hadrons.

[WordMan]

Like I always say, you can never have too many tetraquark hadrons.

As always, ds, thanks for these updates.

[OldGuy]

@deltasigma

Thanks - mainly for giving me an excuse to post this somewhat more comprehensible announcement of what seems to be the new family of tetraquark hadrons.

I assume all tetraquark hadrons are to quarks and two anti-quarks so their net charge is integral, but I don’t see that the article says this to be the case.

[deltasigma]

@OldGuy

I assume all tetraquark hadrons are to quarks and two anti-quarks so their net charge is integral, but I don’t see that the article says this to be the case.

The article I referenced in post 27 (link here) goes into more detail but is more technical.

Decay paths seem to be into 2 mesons, one charged and one neutral (j/psi or h-sub-c) - but honestly this stuff is still a little confusing.

[deltasigma]

Here is an article from CERN that gives some very intimate details about the newly revamped accelerator complex at Fermilab. It’s really fascinating and will tell you more than you could probably ever hope to learn anywhere in such a short amount of time.

There is also this wonderful aerial shot and schematic of the complex.

[deltasigma]

I’m not sure I completely understand this, but it seems that the last decay channel for the Higgs boson has finally been “discovered” to high enough degree of confidence that physicists are sure that it explains everything it was designed to explain. As the articlenotes, it still doesn’t explain why neutrinos have mass or dark matter either, but things are copacetic as far as the Standard Model goes.

What seemed to be missing was a decay into pairs of particles called taus (sometimes tauons). These particles are members of a group that includes the familiar electron and its heavier relative, the muon. Muons are also negatively charged, weigh nearly as much as a proton, and decay in about 10-6 seconds. Taus weigh over 10 times more and decay in about 10-13 seconds. Typically, these heavier particles decay down to the next-lighter version, releasing some energy in the process.

[deltasigma]

Tour the LHC online