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New Particle Discovered At CERN

Soulskill posted more than 2 years ago | from the lhc-stories-not-about-the-higgs dept.

Science 144

New submitter ph4cr writes with news that a new particle has been discovered at CERN that confirms theoretical predictions. A pre-print of the academic paper is available at the arXiv (PDF). From the article: "Physicists from the University of Zurich have discovered a previously unknown particle composed of three quarks in the Large Hadron Collider (LHC) particle accelerator. A new baryon could thus be detected for the first time at the LHC. The baryon known as Xi_b^* confirms fundamental assumptions of physics regarding the binding of quarks. ... In the course of proton collisions in the LHC at CERN, physicists Claude Amsler, Vincenzo Chiochia and Ernest Aguiló from the University of Zurich's Physics Institute managed to detect a baryon with one light and two heavy quarks. The particle Xi_b^* comprises one 'up,' one 'strange' and one 'bottom' quark (usb), is electrically neutral and has a spin of 3/2 (1.5). Its mass is comparable to that of a lithium atom. The new discovery means that two of the three baryons predicted in the usb composition by theory have now been observed."

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WTF am I supposed to call this thing? (1)

Anonymous Coward | more than 2 years ago | (#39831427)

Are all particles named so oddly?

Bring on the explanation for the lazy, science geeks.

Re:WTF am I supposed to call this thing? (1)

Entropius (188861) | more than 2 years ago | (#39831473)

Wikipedia has a succinct explanation for the baryon naming rules.

It's a holdover from before quarks were known, and all these things were thought to be fundamental.

Re:WTF am I supposed to call this thing? (1, Insightful)

Anonymous Coward | more than 2 years ago | (#39831477)

It's LaTeX, you moron. It's the Greek letter Xi with a "b" in the subscript and a "*" in the superscript. So just call it Xi-b-star or Xi-b-asterix. Simple.

Re:WTF am I supposed to call this thing? (-1)

Anonymous Coward | more than 2 years ago | (#39832017)

Why is the parent modded Troll? Because of the "you moron" bit? Aside from that, the parent has the succinct explanation the grandparent wanted.

Re:WTF am I supposed to call this thing? (5, Insightful)

cyberchondriac (456626) | more than 2 years ago | (#39832149)

I didn't mod it down, but I can answer: probably because there's absolutely no call for calling someone a moron over a simple enough question, especially where something like QM is concerned, but even more because it assumes the OP should have knowledge of LaTex, as though everyone in the world should and anyone who doesn't is stupid.
Funny how the geeks never liked being called "nerd" and "dork" by the jocks in school, but in their own climate, quite a few of them dish it out just as bad. Now who's the bully? Honestly, unprovoked name-calling is just flat-out childish and mean spirited... thus, trollish.

Re:WTF am I supposed to call this thing? (0, Flamebait)

Rinikusu (28164) | more than 2 years ago | (#39832313)

I took my nerd and dork and wore it with pride. My parents gave me a solid enough of an upbringing to be confident in my intelligence.

So, shut the fuck up, nerd. It only hurts if you let it.

Re:WTF am I supposed to call this thing? (0, Troll)

Anonymous Coward | more than 2 years ago | (#39832375)

I don't think you're as proud or confident as you purport to be, or else you wouldn't need to bolster your ego by insulting strangers.

Or in your words:
You're an obnoxious douchebag with nothing of substance to add to the discussion, and should be downmodded as such.

Re:WTF am I supposed to call this thing? (4, Insightful)

Cabriel (803429) | more than 2 years ago | (#39832865)

You are not everyone. I was beaten up about once a week on average for it from grade 2 until grade 8. I wish I was exxagerating, but I'm not. Not everyone is given the lavish life you enjoyed.

So, shut the fuck up, Bully. You didn't live the hardest life evar (and neither did I. I know because I'm still alive).

Re:WTF am I supposed to call this thing? (0)

Anonymous Coward | more than 2 years ago | (#39833339)

Sigh...so sad and silly you have to make up some emotional garbage sob story just to try and win you points. Your still silly.

Re:WTF am I supposed to call this thing? (-1, Troll)

Rinikusu (28164) | more than 2 years ago | (#39833599)

Uh, I got picked on plenty and was probably in more fights than you (a week with only ONE fight was an easy week).

So, shut the fuck up, pussy.

Re:WTF am I supposed to call this thing? (1)

Rinikusu (28164) | more than 2 years ago | (#39833603)

Furthermore... you should also be able to appreciate the difference between what really hurts. Nerd, dork, geek, dweeb, that doesn't hurt. Fists and feet (and once a brick) hurt.

Re:WTF am I supposed to call this thing? (0)

Anonymous Coward | more than 2 years ago | (#39833857)

Uh, I got picked on plenty and was probably in more fights than you (a week with only ONE fight was an easy week).

So, shut the fuck up, pussy.

Then

Furthermore... you should also be able to appreciate the difference between what really hurts. Nerd, dork, geek, dweeb, that doesn't hurt. Fists and feet (and once a brick) hurt.

Now who's the sobbing pussy?
Not to mention the hypocrisy and lies of claiming you wore your geek/nerd badge with pride, when clearly you have no curiosity or interest in science. Hell you should at least respect science for all it has given you even if you don't understand it at all. Clearly not a geek, no matter what you try to claim you are.

Likely just a wanna be jock who's too ugly to hang with Chuck, Porterhouse, and Ribeye.

Stating you are secure with yourself when your posts clearly show you are anything but, if you truely have no feelings on the subject then the only possibility is you are a 12 year old troll who gets bricked in the face due to the offensive lies that pour nonstop out of your mouth.

Have fun crying yourself to sleep at night!

Re:WTF am I supposed to call this thing? (0)

Anonymous Coward | more than 2 years ago | (#39833335)

Wore? you mean you did...but not now? tool.

Re:WTF am I supposed to call this thing? (0)

Anonymous Coward | more than 2 years ago | (#39832555)

The rudeness was started with the "what the fuck" attitude of the original question.

Re:WTF am I supposed to call this thing? (0)

Anonymous Coward | more than 2 years ago | (#39832823)

The "moron" was in jest. Relax, dumbass.

Re:WTF am I supposed to call this thing? (0)

Anonymous Coward | more than 2 years ago | (#39833133)

there's absolutely no call for calling someone a moron over a simple enough question...

...particularly by someone who thinks that "asterix" is a word. :-)

Re:WTF am I supposed to call this thing? (1)

kikito (971480) | more than 2 years ago | (#39832981)

Well, aside for the "you moron" bit, it wasn't modded Troll.

Re:WTF am I supposed to call this thing? (4, Funny)

maxwell demon (590494) | more than 2 years ago | (#39833157)

It's LaTeX, you moron. It's the Greek letter Xi with a "b" in the subscript and a "*" in the superscript. So just call it Xi-b-star or Xi-b-asterix. Simple.

And how would you write Xi-b-obelix? ;-)

Sadly, I just ran out of mod points (4, Funny)

Kupfernigk (1190345) | more than 2 years ago | (#39833297)

In fact this particle is pretty massive already, as TFA notes (around the mass of a lithium atom). So presumably a Xi_b^obelix would mass as much as a menhir.

Re:WTF am I supposed to call this thing? (4, Funny)

zAPPzAPP (1207370) | more than 2 years ago | (#39831625)

USB quark (1.0)

Re:WTF am I supposed to call this thing? (2)

mindwhip (894744) | more than 2 years ago | (#39831919)

NO!

This is the second usb quark they found so its USB 2.0!

They still haven't found the third one...

Re:WTF am I supposed to call this thing? (1)

mindwhip (894744) | more than 2 years ago | (#39831929)

Argh! And of course I meant...

NO!

This is the second usb configuration baryon they found so its USB 2.0!

They still haven't found the third one...

I fell into a trap :(

Re:WTF am I supposed to call this thing? (1)

zAPPzAPP (1207370) | more than 2 years ago | (#39832175)

After giving it extra thought, I am sure it's actually USB 1.5.

(which, as they also found out, is 3/2)

Re:WTF am I supposed to call this thing? (1)

Danzigism (881294) | more than 2 years ago | (#39831783)

baryon, also known as O_o

Re:WTF am I supposed to call this thing? (3, Informative)

physburn (1095481) | more than 2 years ago | (#39832529)

It names after the Gell Mann's group of all particles that you can make with up,down and strange quarks, the Xi^0 particle is the name for the Baryon for the particle with two strange quarks and an a up quark. For heavier quarks, physicists write as a subsubscript the letter for an heavy quark replacing the strange quark.

The Baryon multiplets are.

Spin 1/2 (you can draw this as a hexagon)
Xi^0 Xi^-
Sigma^- Sigma^0 Sigma^+
Lambda
Neutron Proton

Spin 3/2 (draw this as a triangle)
Omega^-
Xi^0 Xi^-
Sigma^- Sigma^0 Sigma^+
Delta^- Delta^0 Delta^+ Delta^++

There are plenty of Baryons yet to be found, including most massively of all, the Omega Triple Bottom, which is (bbb) instead of (sss)

Re:WTF am I supposed to call this thing? (0)

Anonymous Coward | more than 2 years ago | (#39832937)

> There are plenty of Baryons yet to be found, including most massively of all, the Omega Triple Bottom

You might have better luck finding a super-heavy Omega Triple Bottom on a cruise for gay bears. ;-)

Re:WTF am I supposed to call this thing? (3, Funny)

kevingolding2001 (590321) | more than 2 years ago | (#39833085)

Physicists from the University of Zurich have discovered a previously unknown particle

I'm going to go with "The particle formerly known as unknown", or just "The particle".

DS9 2/3? (0)

GearheadShemTov (208950) | more than 2 years ago | (#39831433)

WTF! This just bows me away. I know he is small, but how in the world did they manage to fit three Ferengi into a USB!?

Or maybe there are other Quarks out there?

I'm not ready for this. (2, Funny)

ScentCone (795499) | more than 2 years ago | (#39831437)

I'm only just now using devices ready for usb 3.0, and here comes another one.

Very cool... (1)

SgtXaos (157101) | more than 2 years ago | (#39831439)

I just wish they had named it something pronounceable. "Chi b to the asterix" just doesn't flow off the tongue too well.. :)

Re:Very cool... (2)

SQL Error (16383) | more than 2 years ago | (#39831461)

Kibitoaster.

Re:Very cool... (0)

Anonymous Coward | more than 2 years ago | (#39831519)

asterisk

chi b star (5, Informative)

Roger W Moore (538166) | more than 2 years ago | (#39831541)

It's pronounced "chi b star" and the discovery was by the CMS collaboration. The analysis was done by physicists from Zurich (apparently including one of my former postdocs) but they require data generated by the experiment so typically we credit the experiment. The discovery is of a new bound state of 3-quarks - not a new fundamental particle - so while interesting and definitely worthwhile it is not particularly exciting.

Re:chi b star (0)

Anonymous Coward | more than 2 years ago | (#39831603)

Article: "The baryon known as Xi_b^* confirms fundamental assumptions of physics regarding the binding of quarks."

Roger W. Moore: "It's pronounced "chi b star" ".

My first thought is this is a strange set of characters to have to type in all publications going forward. It could pass for a password!

JJ

Re:chi b star (5, Funny)

zAPPzAPP (1207370) | more than 2 years ago | (#39831635)

So it was named after a Sailormoon character?

Re:chi b star (4, Informative)

Snowtred (1334453) | more than 2 years ago | (#39831945)

Actually, this is the "Xi B Star" or "Cascade B Star". The "Chi b" particle has already been found, but is a completely different type of particle (meson, with quark and antiquark) than the "Xi b" (baryon, with 3 quarks)

Re:chi b star (5, Informative)

FrootLoops (1817694) | more than 2 years ago | (#39833483)

This discussion made me wonder where the new particle falls in standard particle classifications. I've always been curious so I finally looked it up. My notes are below if anyone else is curious. I abbreviated the fundamental forces as (G)ravity, (E)lectromagnetic, (W)eak, (S)trong.

(1) Elementary particles: indivisible (probably). Includes fundamental fermions and bosons.
        (A) Fundamental fermions: obey Pauli exclusion principle and Fermi-Dirac statistics. Includes quarks and leptons.
                (I) Quarks: six flavors; combine in groups of two or three; interacts with GEWS. The "S" allows atomic nuclei to exist.
                (II) Leptons: six types, three charged, three not.
                          (a) Charged leptons: mostly, the electron. Interacts with GEW. The "E" there makes chemistry work.
                          (b) Uncharged leptons: neutrinos. Interacts with GW, so not much with ordinary matter.

        (B) Fundamental bosons: obey Bose-Einstein statistics, disobey Pauli exclusion principle. Includes gauge bosons, Higgs boson, and gluons.
                (I) Gauge bosons: force carrying particles. Photons carry E, W- and Z-bosons carry W, gluons carry S.
                (II) Higgs boson: would explain the non-masslessness of some fundamental particles. Currently the only unobserved standard model particle.
                (III) Graviton: would carry G. Theoretical status somewhat uncertain; not a standard model particle; currently unobserved.

(2) Composite particles: composed of multiple elementary particles. Includes hadrons, atoms, molecules.
        (A) Hadrons: two or three quarks held together by S. Includes baryons and mesons.
                (I) Baryons: fermions made of three quarks. Most famous examples are protons and neutrons. Huge variety--~hundreds or more depending on how you count.
                (II) Mesons: bosons made of two quarks. All unstable. Huge variety--~hundreds or more depending on how you count..

Note that each particle has an anti-particle, where each composite particle's anti-particle is obtained by replacing the constituent elementary particles with corresponding anti-particles.

The \Xi_b^{*0} particle (the summary left off the 0 for some reason...) is a baryon, so it falls under (2AI) in the above list. In light of the variety of the hadrons and their composite particle nature, this story isn't terribly exciting (at least to me).

[Please correct any mistakes; I'm not a physicist.]

Re:chi b star (4, Interesting)

Snowtred (1334453) | more than 2 years ago | (#39833621)

Your summary seems good. Although for your Hadrons, its better to understand that, a Baryon contains 3 quarks and an Antibaryon contains 3 anti-quarks. The meson, however, contains a quark and an antiquark. Two quarks or two anti-quarks are never stable. This is due to Color Confinement.

A quark can contain a Red, Blue, or Green color. An antiquark can contain an Anti-red, Anti-blue, or Anti-green color. Any stable particle must be colorless, or white. You can make White with Red+Green+Blue (Baryons), Anti-Red+Anti-Green+Anti-Blue (Anti-Baryons), or Red+Anti-Red, Green+Anti-Green, or Blue+Anti-Blue (Mesons)

Re:chi b star (2)

jandoedel (1149947) | more than 2 years ago | (#39831969)

while interesting and definitely worthwhile it is not particularly exciting.

maybe not. But the asterisk tells us the baryon itself is excited.

Re:chi b star (0)

Anonymous Coward | more than 2 years ago | (#39833383)

Sigh i wish i was a scientist....my penis tells me when I'm excited....

Re:chi b star (0)

Anonymous Coward | more than 2 years ago | (#39832315)

To be pedantic, not chi, xi [wikipedia.org] .

Re:chi b star (1)

blue_teeth (83171) | more than 2 years ago | (#39833565)

If it has anything remotely to do with Chi-Square symbol (the X which I cannot reproduce here), then it is pronounced as Kai-Square.

Just saying.

Re:Very cool... (1)

Anonymous Coward | more than 2 years ago | (#39831611)

The "Xi" greek letter is quite often refered to as "cascade" by particle physicists. I would say "cascade b zero star" when discussing this particle with colleagues.

Re:Very cool... (1)

AngryDill (740460) | more than 2 years ago | (#39831811)

It kind of flows when you pronounce each character...

Zion Der Scorby Kara Tasterisk

Re:Very cool... (1)

quenda (644621) | more than 2 years ago | (#39832225)

I just wish they had named it something pronounceable. "Chi b to the asterix" just doesn't flow off the tongue too well.. :)

They ran out of cool names, so they started using obscure smileys, it would appear.

Big whoop (0)

Anonymous Coward | more than 2 years ago | (#39831453)

This is a bit of cool and all, but do we really need a /. post for every new particle over which the high-energy people trip?

Re:Big whoop (2)

arth1 (260657) | more than 2 years ago | (#39831999)

There aren't that many of them.

It's news for nerds, and whatever kind of stuff it is, baryons comprise matter.

Re:Big whoop (0)

Anonymous Coward | more than 2 years ago | (#39832203)

Please go back to your basement and read some science books.

Its mass is comparable to that of a lithium atom. (3, Interesting)

olsmeister (1488789) | more than 2 years ago | (#39831479)

I don't understand much about particle physics, but perhaps someone could give a quick explanation of how a particle made of three quarks has a mass equivalent to an entire atom of atomic number 3 and atomic weight almost 7? Is it because a bottom quark is one of its constituents?

Re:Its mass is comparable to that of a lithium ato (1)

MartinSchou (1360093) | more than 2 years ago | (#39831507)

I can't claim to understand much about particle physics, but I would guess that this particular arrangement of quarks has a bigger interaction with the Higgs field, thus making it more massive.

Re:Its mass is comparable to that of a lithium ato (5, Informative)

Anonymous Coward | more than 2 years ago | (#39831511)

Protons and neutrons are composed of strictly up and down quarks, in (uud) and (udd) combinations for protons and neutrons respectively. Up quarks weigh about 2.5 MeV and down quarks weigh about 5.0 MeV. A strange quark weighs about 100 MeV, and a bottom Quark weighs (very) roughly 4.2 GeV. It's because of the bottom quark that Xi_b^* weighs so much.

Source: http://pdglive.lbl.gov/Rsummary.brl?nodein=Q123
                        http://pdglive.lbl.gov/Rsummary.brl?nodein=Q005

Re:Its mass is comparable to that of a lithium ato (4, Informative)

BlueParrot (965239) | more than 2 years ago | (#39831865)

It gets even more amusing when you consider that a proton has a mass of about 938MeV/c , whereas the three quarks it is made up doesn't even add up to 10MeV/c. The binding energy of protons and neutrons is immense compared to the particles they are composed of.

Re:Its mass is comparable to that of a lithium ato (0)

Anonymous Coward | more than 2 years ago | (#39833307)

So would the next stage of nuclear power after fusion be proton/neutron fission that extracts their binding energy?

Re:Its mass is comparable to that of a lithium ato (0)

Anonymous Coward | more than 2 years ago | (#39832433)

holly shit

Re:Its mass is comparable to that of a lithium ato (-1)

Anonymous Coward | more than 2 years ago | (#39833197)

Up quarks weigh about 2.5 MeV

Very unscientific. In the scientific metric system we weigh things in grams, not in mevs, whatever they are.

Re:Its mass is comparable to that of a lithium ato (0)

Anonymous Coward | more than 2 years ago | (#39833793)

So you are claiming the "mega" prefix is not from SI nor a metric unit?

Gram is a unit of mass. Electron Volts are a unit of energy directly comparable to a Jule.

You must be a product of the American educational system...

Re:Its mass is comparable to that of a lithium ato (1)

Zocalo (252965) | more than 2 years ago | (#39831637)

Firstly, remember that mass != weight. Mass is all to do with energy (as in e=mc^2), and bottom quarks have lots of energy - just over 4GeV compared to the ~2.5MeV (up) and ~5MeV (down) of the quarks that protons and neutrons consist of.

Re:Its mass is comparable to that of a lithium ato (3, Interesting)

Immerman (2627577) | more than 2 years ago | (#39832043)

It's worth noting that the composite particle's masses are generally due primarily to the massless gluons who's immense energy contributes to the bound particle
Proton (uud): ~10MeV/c^2 in quarks , 938MeV total
Neutron (udd): ~12.5MeV in quarks, 940MeV total
  Xi_b^* (usb): ~4293MeV in quarks, ~6517MeV total (7amu * 931 MeV/amu)
So not only is Xi_b^* composed of much higher mass quarks, but it would appear to have roughly twice the binding energy as well.

But why mention mass != weight? In a uniform gravitational field mass and weight are directly proportional to each other and can be used interchangeably using the gravitational acceleration as the conversion factor. The distinction is only relevant if you're either
1) operating within a non-constant gravitational field (i.e. in space) or comparing weights of different planets
or
2) You've discovered the first matter ever detected with different gravitational mass and inertial mass
Since (1) doesn't apply, and (2) almost certainly doesn't the distinction seems irrelevant

Re:Its mass is comparable to that of a lithium ato (0)

Anonymous Coward | more than 2 years ago | (#39833749)

Yes its the bottom quark, up and down quark have very little mass, and baryons make of those, get most of the mass, from the
trapped energy of quark motion in the QCD glue (at any one time this will be part QCD potential energy (glue) and part kinetic equation (velocity)), but the bottom quark is quite massive itself around 4.6GeV and gets its mass directly from interacting with the Higg boson. So its the bottom quark that give the Xi_b star most of its mass. Another 150MeV comes from the strange quark which again gets its mass from the Higgs, but the star adds at least 200MeV, and come from the particle have all the quark spins in the same direction, its a chromomagnetic energy, (the spin of the particles making the color equilivent of a magnetic field).

So it's a USB... (0)

zammer990 (2225956) | more than 2 years ago | (#39831515)

Can I store DS9 episodes on it and how long before "Will it Blend" are allowed to blend it?

Re:So it's a USB... (1)

thereitis (2355426) | more than 2 years ago | (#39832897)

And where can I get one so I can try these experiments?

USB sticks are cool (-1)

Anonymous Coward | more than 2 years ago | (#39831539)

oh wait ....

Funny. (5, Insightful)

Milharis (2523940) | more than 2 years ago | (#39831545)

I find it funny that TFS talks about a Xi_b^* baryon with usb quarks, and goes on about its spin, as if it was common knowlegde, but has to precise that 3/2 is 1.5.

Re:Funny. (0)

Anonymous Coward | more than 2 years ago | (#39831643)

Now combine that with the earlier story of how the use of numbered lines is surely not innate and you'll begin to wonder if that simple math is what ruins most people's ability to conceptualize quarks.... But if we don't use the number lines we have virtually NO way to meaningfully communicate with each other. I love the Universe!

Re:Funny. (1)

VortexCortex (1117377) | more than 2 years ago | (#39831701)

>_<

I can confirm it! (5, Funny)

Anonymous Coward | more than 2 years ago | (#39831581)

... and has a spin of 3/2 (1.5). ...

I don't know about the rest of the summary, but I can confirm that 3/2 is in fact 1.5.

Re:I can confirm it! (0)

Anonymous Coward | more than 2 years ago | (#39831873)

... and has a spin of 3/2 (1.5). ...

I don't know about the rest of the summary, but I can confirm that 3/2 is in fact 1.5.

Well I used to be sure of that, until I read it on Slashdot.

Well that was certainly worth €10 billion (0)

Shavano (2541114) | more than 2 years ago | (#39831785)

Tiny little particle; huge godlike pricetag.

Re:Well that was certainly worth €10 billion (4, Insightful)

jo_ham (604554) | more than 2 years ago | (#39831817)

Indeed, without having that massive boondoggle at CERN we could have funded at least 1 more month of the Iraq war!

Re:Well that was certainly worth €10 billion (0)

Anonymous Coward | more than 2 years ago | (#39832165)

Not defending the OPs complaint, but a little good came out of the Iraq "war" -actually a resumption of the Desert War ceasefire- the world got rid of S Hussein and his two totally fucking psychopathic sons. On the other hand.. Iraq held the militant Shia from Iran in check. Umm ..what was my argument again?

Re:Well that was certainly worth €10 billion (2)

Shavano (2541114) | more than 2 years ago | (#39832533)

And that only cost a $1-2 Trillion and about 150,000 to 600,00 lives. How long would it have taken Saddam and his psychopathic sons to kill that many people?

Re:Well that was certainly worth €10 billion (3, Interesting)

Snowtred (1334453) | more than 2 years ago | (#39831977)

I know this is slightly in jest, but this paper is not the sum-total of all of the work at the LHC.

There are 6 projects, each with hundreds of scientists, all of whom are juggling many papers at once. This Xi stuff is completely independent from Higgs searches, and it is one of many particles already discovered or confirmed at the LHC. So this isn't a Higgs-worthy discovery, although I think it is pumped-up a bit because CERN has really good press, and it looks good that the LHC is finding new physics.

Otherwise, this would just be a normal story. New Baryons or Mesons (like this one) are found a few times a year.

Re:Well that was certainly worth €10 billion (2)

Shavano (2541114) | more than 2 years ago | (#39832497)

I know this is slightly in jest, but this paper is not the sum-total of all of the work at the LHC.

There are 6 projects, each with hundreds of scientists, all of whom are juggling many papers at once. This Xi stuff is completely independent from Higgs searches, and it is one of many particles already discovered or confirmed at the LHC. So this isn't a Higgs-worthy discovery, although I think it is pumped-up a bit because CERN has really good press, and it looks good that the LHC is finding new physics.

Otherwise, this would just be a normal story. New Baryons or Mesons (like this one) are found a few times a year.

I know this is slightly in jest, but this paper is not the sum-total of all of the work at the LHC.

There are 6 projects, each with hundreds of scientists, all of whom are juggling many papers at once. This Xi stuff is completely independent from Higgs searches, and it is one of many particles already discovered or confirmed at the LHC. So this isn't a Higgs-worthy discovery, although I think it is pumped-up a bit because CERN has really good press, and it looks good that the LHC is finding new physics.

Otherwise, this would just be a normal story. New Baryons or Mesons (like this one) are found a few times a year.

It's interesting that it's yet another confirmation of the standard model. Calling it "new physics" is probably a little bit of an overstatement, since everybody expected that this particle was one of the ones that they would be able to prove out. It's a new and confirming result. I would go so far as to say something is "new physics" if it was weird enough to call the standard model into doubt, or if a neutrino really did travel faster than the speed of light, or if it looked like confirmation of a new theory.

As for the fact that it employs hundreds of scientists, that's really irrelevant. Since when do we do science as a jobs program for the very smart?

Science is for two things:

  1. the pursuit of knowledge to satisfy our curiosity about the universe
  2. the pursuit of useful knowledge to improve our lives

This is an example of the former.

Re:Well that was certainly worth €10 billion (2)

Snowtred (1334453) | more than 2 years ago | (#39832869)

The "hundreds of scientists" bit wasn't an argument for the LHC producing jobs, but just that there are hundreds of scientists each working on several papers that are all producing interesting results. So the fact that we see "New particle at LHC" articles everywhere after several months of running is misleading, as several LHC-related papers are put on the arxiv each week.

Re:Well that was certainly worth €10 billion (0)

Anonymous Coward | more than 2 years ago | (#39832513)

just like there was no reason to go to the moon. what did they actually do up there, jack shit right? how much did it cost, throw in some inflation for good measure? i think we should all just spend our tax dollars on better soap operas, i need my stories.

The name of the particle (5, Informative)

krzysz00 (1842280) | more than 2 years ago | (#39831803)

Xi_b^* is actually the LaTeX code needed to generate the name of the particle. The particle's name is actually this (png image) [equationater.com]

a LaTeX particle (1)

ndverdo (799508) | more than 2 years ago | (#39831833)

\Xi_b^*0 is part LaTeX for greek capital xi which gives the particle a Unicode identity of subscript b superscript * 0 - \Xi_b^{*0} ;)

Question: (0)

Anonymous Coward | more than 2 years ago | (#39831883)

How does the peer review system come into play with something like this?

How do you do double-blind testing with CERN?

What does this say about the scientific method?

Re:Question: (0)

Anonymous Coward | more than 2 years ago | (#39831921)

Double-blind testing is for biology - you can't put a blindfold on a particle.
CERN does its experiments over and over to build statistical significance.

Re:Question: (2)

bunratty (545641) | more than 2 years ago | (#39832003)

So you think particle detectors are susceptible to the placebo effect?

Re:Question: (5, Informative)

jmtpi (17834) | more than 2 years ago | (#39832317)

You're asking a couple distinct, and reasonable, questions. About "blind testing" -- I don't know the details for this particular result, but particle physicists put quite a bit of effort into making sure that they aren't fooling themselves. One of the best ways of doing it is so-called "blind analysis". The idea there is to define your entire data analysis strategy based solely on simulated data. There are pretty good simulations available of both the expected backgrounds, and of the process you are trying to actually find (the signal). So you define all of the methods you are going to use using these simulations before you look at the data. This ensures that you don't bias yourself into "finding something" in the data that isn't really there. (I don't know if a strict blinding procedure was used for this analysis, but likely something similar was done.)

The formal peer review system will come into effect now that the result is submitted to a journal. The paper will be distributed to some anonymous referees who will try to judge the merits of the physics and decide whether it merits publication. But I should note that the peer review process in modern particle physics actually starts long before the result is made public. Although there are only 3 or 4 main analysts, the paper is signed by the entire 3000 person CMS Collaboration (of which I am a member). So we have a very stringent internal review process to ensure that the result is sound before we release it with 3000 names taking responsibility. That doesn't mean that particle physics collaborations never make mistakes, but it does mean that results are scrutinized by a number of more or less unbiased eyes before they are made public.

Re:Question: (4, Informative)

kyrsjo (2420192) | more than 2 years ago | (#39832505)

Additionally, if the results are real, they can be replicated. LHC collides particles not only in the heart of the CMS detector, but there is also (among others) the ATLAS detector. This detector has more or less the same goals as CMS, but is built and operated by different people using a different detector design (both on the level of individual electronic chips and sensors, and on overall design choices), as well as different and mostly independently written software.

So I guess someone with access to ATLAS data should now write up the analysis and see if they can find it too.

--- Physicist who did his master thesis with sensors for ATLAS tracker, now doing a PhD on accelerator cavities for the CLIC future high-energy electron-positron collider.

Re:Question: (1)

Anonymous Coward | more than 2 years ago | (#39833079)

Additionally, if the results are real, they can be replicated."

    Replicated, definitely. That is what I used to live for.
    The use of a rapidly depreciating, OK, OK, I'll use the current popular term, deprecating, LaTex phraseology is most irritating. Name it properly. Just look up _why_ the little wigglies are named Quarks in the first place. Early Physicists actually had a sense of humor. And they drank beer. And one even put a glass of beer in a particle beam to observe the formation of bubbles. At CERN.
    Name the God-Damned thing, (See origin of the name God Particle), Ghiorsoroni. He deserves at least that much.

Re:Question: (0)

Anonymous Coward | more than 2 years ago | (#39832809)

Thanks. I was always curious about this.

Re:Question: (0)

Anonymous Coward | more than 2 years ago | (#39832845)

indeed some people (not sure if people in cms are blinding freaks) try to do blinded analyses. compared to medicine: we make the physicist=physician blind, we do not blind the particle=patient.

This is done by setting up the entire analysis without looking at the data. (you have to define which events to select and which to truncate). thereby you're safe (1) not to make the selection such that you select background events such that your data looks like the signal you seek because you picked up the "right" statistical fluctuations. It is still possible to see a signal due to statistical fluctuations, but in that blinded way, the fluctuations are correctly described by the laws of statistics which are used to quote the certainty of the discovery.

The same way analysis tools provide blinding, such that a hidden random number is added to the outcome of the calculations. that way one can investigate the size of the effect of changing something in the analysis -- and thereby identify critical points -- without knowing whether the change pushes the result in the "right" or "wrong" direction. (= you don't know whether the change improves your discovery or dilutes it)

concerning reviews: usually a small part (say 20 people) within a collaboration are involved in such an analysis. the rest is working on different studies. before publishing one needs approval by the entire collaboration, with dedicated referees. since nobody wants to be author of a wrong result due to a mistake someone else did, these referees are usually very strict. Ingredients to those analyses are used by several subgroups and often independently developed. Thereby crosschecks are available to many parts of the analysis and conveners are supposed to block publications if these checks are failed.

Still there are lists of measurements of parameters over the last decades around which suggest that a) usually error are underestimated b) analyses tend to be in agreement with previous results independent whether these previous results were right or wrong. Unfortunately these lists only allow to say something like: at least 5 out of you 7 did something wrong but don't allow to blame any individual experiment.

(1) smallprint: it is often still possible to make an biased analysis even if it's blinded. however it gives you a believed-to-be-comfortable layer of safety not to bias the study unintentionally.

Xi_b^* ? (3, Funny)

DJCouchyCouch (622482) | more than 2 years ago | (#39831979)

Someone's been looking at my coworker's variable names.

Re:Xi_b^* ? (2)

mrbester (200927) | more than 2 years ago | (#39832761)

I'll have to change my online banking password now...

Baryon Discoveries (5, Insightful)

Snowtred (1334453) | more than 2 years ago | (#39832025)

I just want to provide a little context to this announcement. As shown in the article, this is a Baryon, made up of 3 quarks. With 6 possible types of quarks, and 3 spots, this makes for many possible combinations of Baryons, a lot that have been found. Here is a current list of baryons:

PDG Baryon List [lbl.gov]

The proton and neutron are the p and n in the top left. The new Cascade (Xi_b) will be in the bottom right, in the "Bottom quark" section.

So this is neat and all, but hyped up a bit because its the LHC. A couple of these new Baryon (and also Mesons) are confirmed every year.

Re:Baryon Discoveries (1)

cyberchondriac (456626) | more than 2 years ago | (#39832235)

The thing I don't get is, how can a single particle comprised of just 3 quarks be comparable in mass to an entire atom (lithium atom) as stated in the summary? I realize lithium is low on the scale with only 3 protons, but still, even protons, being fermions, are comprised of 3 quarks each, as I understand it..seems counter intuitive. Does it depend on the combination of the types of quarks?

Re:Baryon Discoveries (1)

Snowtred (1334453) | more than 2 years ago | (#39832267)

Most of the energy is the "binding energy" or in this case, the energy of the gluons mediating the strong force that holds the quarks together. The actual sum of the 3 quarks is only a small part of the total mass. But with E=mc^2, Mass and Energy are equivalent, and the large amount of energy binding the 3 quarks together becomes the mass.

Re:Baryon Discoveries (2)

K. S. Kyosuke (729550) | more than 2 years ago | (#39832371)

Different quarks have different masses. The ones forming protons and neutrons (u, d) happen to be the most lightweight of all.

Re:Baryon Discoveries (1)

kyrsjo (2420192) | more than 2 years ago | (#39832549)

And also different combinations of quarks has different energy, which begets different total mass - the whole is greater than the sum of its parts.

Take for example the proton or the neutron, where the mass of the elementary u/d quarks are only a couple of MeV each, while the whole composite particle clock in at almost 1000 GeV. This is due to energy trapped in the binding- and kinetic energy inside the protons and neutrons.

Additionally, you can also "gain" mass without adding or changing particles, by exiting the particles already there to a higher orbit, similarly to how you can exite the electrons in an atom to a higher state with a photon:
http://en.wikipedia.org/wiki/Nucleon#Nucleon_resonances [wikipedia.org]

Re:Baryon Discoveries (0)

Anonymous Coward | more than 2 years ago | (#39833561)

Read this instead:

http://profmattstrassler.com/2012/04/27/cms-finds-a-new-expected-composite-particle/

Unfortunately.. (0)

Anonymous Coward | more than 2 years ago | (#39832295)

.. before the particle could be identified, a janitor swept it up and dumped it in the dust-bin.

underwhelming (0)

Anonymous Coward | more than 2 years ago | (#39832737)

unknown is not how I would call it. It has been expected, its description was already there, one knew where to search. if the higgs was discovered, one wouldn't call it unknown since it's in textbooks for a long time already.
Furthermore, be honest, another particle found in a spectroscopy study is .... boring... what's interesting is having the entire / a large part of the spectrum.
Making rumours on this particle is like making rumours on one single CKM-triangle angle. it's boring unless you have the other three and see either consistency or inconsistency.
Therefore, please find the other _sb baryons first and then tell us about the entire story.

PS: html also support superscript and greek letters, so please newspages call it & Xi ; sub b /sub sup *0 /sup
PPS: how do I get html tags through slashdot?

Who ordered that? (1)

reluctantjoiner (2486248) | more than 2 years ago | (#39833447)

Whenever new particles are discovered I always think of this comment regarding the Muon [wikipedia.org]

Still invoking the *Not Dead Yet* clause (1)

Trikenstein (571493) | more than 2 years ago | (#39833469)

bah humbug g'me an event horizon to bewonderlment at

Meh. (1)

JustNiz (692889) | more than 2 years ago | (#39833517)

Meh. They could make it spin twice as fast just by using usb2.

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