LHC's first heavy-ion collision yields intriguing results
35 replies, posted
[quote]Z bosons produced in collisions of heavy ions have been observed for the first time by the CMS experiment at CERN’s Large Hadron Collider (LHC). CMS observed 10 events containing a distinctive candidate Z boson reconstructed from a pair of electrons or a pair of muons (see figures 1 and 2 respectively), whose invariant mass is consistent with the Z boson mass.
The Z boson was discovered at CERN in 1983 but has never before been seen in heavy ion collisions. Zs production in heavy ion collisions will provide an important benchmark against which to compare various probes such as the production of J/Psi and Upsilon particles, or the energy of transversally balanced jets of hadrons. All these can signify the formation of small amounts of the quark-gluon plasma, a hot dense state of matter that is similar to the conditions in the very early Universe.
On the 8th of November the LHC first started colliding Lead-Lead collisions at a centre-of-mass energy of 2.76 TeV per nucleon pair – 14 times higher than previously achieved by the Relativistic Heavy Ion Collider (RHIC, Brookhaven, USA) where the quark-gluon plasma is studied since 10 years. Already on the second night of LHC heavy ion collisions, a Z boson was observed decaying to two muons in CMS.[/quote]
[url=http://cms.web.cern.ch/cms/News/2010/FirstZs-HeavyIons/index.html]Source[/url]
EXTREME SCIENCE :science:
Frankly, I'm surprised it hasn't been destroyed by a stray slice of ham carelessly thrown by a Belgian tourist or something.
Didn't they also stabilize antihydrogen for like, 1/6 of a second?
[QUOTE=fenwick;26158314]Didn't they also stabilize antihydrogen for like, 1/6 of a second?[/QUOTE]
1/6 of a second is very long for these kind of experiments
3 days after CERN traps anti-matter and are able to study them, we have another discovery.
God damn, and people say scientist are slow.
I have no idea what this means, so I'm just going to rate OP "informative"
[QUOTE=Raiskauskone V2;26158409]I have no idea what this means, so I'm just going to rate OP "informative"[/QUOTE]
They found something when they collided something, which they also found in colliding something else!
I think :v:
[QUOTE=B1N4RY!;26158336]1/6 of a second is very long for these kind of experiments[/QUOTE]
That's what I was getting at.
:science:
Anything is possible with a good catch phrase, such as [B][I]FOR SCIENCE![/I][/B]
[QUOTE=Madman_Andre;26159220]:science:
Anything is possible with a good catch phrase, such as [B][I]FOR SCIENCE![/I][/B][/QUOTE]
LHC! Come experience our [B]Z BOSONS!!![/B]
[QUOTE=fenwick;26158314]Didn't they also stabilize antihydrogen for like, 1/6 of a second?[/QUOTE]
1/10 of a second
Those aren't really discoveries. As you can read in the text, even CERN itself already produced these z boson particles previously, only using more painful method and with smaller efficiency.
Same goes with antimatter. We already were able to produce and trap it, but CERN is able to do it at rate no other experiment ever did before.
[editline]20th November 2010[/editline]
Cool, nonetheless. It's good to see there's progress, with the constant fuckups they constantly have to face. I am often checking the direct information feeds from them, which show the momentary state of the whole thing and such, and bad shit happens on weekly, sometimes daily basis.
so they can make bosons
but they can't make bosoms
Can somebody clever please explain what this means in more laymen's terms. I'm as good at particle physics as Glaber is good at making reasonable posts.
[QUOTE=MrEndangered;26165909]Can somebody clever please explain what this means in more laymen's terms. I'm as good at particle physics as Glaber is good at making reasonable posts.[/QUOTE]
They found more experimental evidence of an elusive boson (a kind of subatomic level force-mediating particle). That's pretty much all.
Cool though.
i love you large hadron collider
[QUOTE=MrEndangered;26165909]Can somebody clever please explain what this means in more laymen's terms. I'm as good at particle physics as Glaber is good at making reasonable posts.[/QUOTE]
The Z-Boson is one of the force-particles of the weak force (W+,W-,Z0). The weak force is responsible for particles (mainly quarks) being able to decay to others. Here you see a proton decaying to a neutron in a Feynman-Diagram:
[img]http://upload.wikimedia.org/wikipedia/commons/thumb/8/89/Beta_Negative_Decay.svg/310px-Beta_Negative_Decay.svg.png[/img]
The neutron consists of an up and two down quarks (bottom) and one down quark decays to an up-quark. Due to conservation of quantum-numbers (here especially the charge), a gauge-boson has to be emitted. This later decays to an electron and an anti-electron neutrino.
Why is this experiment at CERN important?: Before, we never saw a Z-Boson in lead-ion collisions.
How does that time arrow work? Is the neutron at an earlier stage?
[QUOTE=MrAfroShark70;26158391]3 days after CERN traps anti-matter and are able to study them, we have another discovery.
God damn, and people say scientist are slow.[/QUOTE]
They've been doing that for years.
[QUOTE=aVoN;26174521]The Z-Boson is one of the force-particles of the weak force (W+,W-,Z0). The weak force is responsible for particles (mainly quarks) being able to decay to others. Here you see a proton decaying to a neutron in a Feynman-Diagram:
[img_thumb]http://upload.wikimedia.org/wikipedia/commons/8/89/Beta_Negative_Decay.svg[/img_thumb]
The proton consists of an up and two down quarks (bottom) and one down quark decays to an up-quark. Due to conservation of quantum-numbers (here especially the charge), a gauge-boson has to be emitted. This later decays to an electron and an anti-electron neutrino.
Why is this experiment at CERN important?: Before, we never saw a Z-Boson in lead-ion collisions.[/QUOTE]
You read the Feynman diagram incorrectly.
Time passes going upwards, and the neutron is on the bottom.
The neutron is made up of two down and one up quarks, not the proton
[QUOTE=Swebonny;26174690]How does that time arrow work? Is the neutron at an earlier stage?[/QUOTE]
Yes, the timeline is from botton to top. First there is the neutron, then one of it's quarks decays. Everything which exists at the same time but has an horizontal extension is a virtual particle (here it's the Z0 Boson): This simply means, it is a gauge-boson in a field, responsible for carrying a force from one to another place. The important thing is, that in a particle accelerator, the Z0 Boson can manifest as a real particle. At least that's what I remember from my particle-physics lesson. Correct me if I'm wrong, too long ago.
[editline]20th November 2010[/editline]
[QUOTE=LF9000;26175641]You read the Feynman diagram incorrectly.
Time passes going upwards, and the neutron is on the bottom.
The neutron is made up of two down and one up quark, not the proton[/QUOTE]
I was mixing up proton and neutron when writing. Obviously I was reading the graph correctly, cause I said "one up and two down-quarks, where one down decays to up" - This is the correct process but I named udd = "proton". Sorry. At least someone paid attention, thanks :)
[QUOTE=Swebonny;26174690]How does that time arrow work? Is the neutron at an earlier stage?[/QUOTE]
As far as I'm aware QM is linear and is time reversal symmetric, so if you face the arrow down all you have to do is change all the other arrow pointers and it would still be accurate. As it is now, I think it would be showing a neutron decaying into a proton.
[QUOTE=aVoN;26174521]The Z-Boson is one of the force-particles of the weak force (W+,W-,Z0). The weak force is responsible for particles (mainly quarks) being able to decay to others. Here you see a proton decaying to a neutron in a Feynman-Diagram:
[img_thumb]http://upload.wikimedia.org/wikipedia/commons/thumb/8/89/Beta_Negative_Decay.svg/310px-Beta_Negative_Decay.svg.png[/img_thumb]
The neutron consists of an up and two down quarks (bottom) and one down quark decays to an up-quark. Due to conservation of quantum-numbers (here especially the charge), a gauge-boson has to be emitted. This later decays to an electron and an anti-electron neutrino.
Why is this experiment at CERN important?: Before, we never saw a Z-Boson in lead-ion collisions.[/QUOTE]
Thank you everything is now much less clear
[QUOTE=aVoN;26174521]The Z-Boson is one of the force-particles of the weak force (W+,W-,Z0). The weak force is responsible for particles (mainly quarks) being able to decay to others. Here you see a proton decaying to a neutron in a Feynman-Diagram:
[img_thumb]http://upload.wikimedia.org/wikipedia/commons/thumb/8/89/Beta_Negative_Decay.svg/310px-Beta_Negative_Decay.svg.png[/img_thumb]
The neutron consists of an up and two down quarks (bottom) and one down quark decays to an up-quark. Due to conservation of quantum-numbers (here especially the charge), a gauge-boson has to be emitted. This later decays to an electron and an anti-electron neutrino.
Why is this experiment at CERN important?: Before, we never saw a Z-Boson in lead-ion collisions.[/QUOTE]
Every time you post I regret not taking math more seriously when I was younger. I'm never going to know all this awesome universe-governing shit!
[QUOTE=B1N4RY!;26158336]1/6 of a second is very long for these kind of experiments[/QUOTE]
I accidentally rated you disagree, so I refreshed the thread and rated you agree.
[QUOTE=Dazza;26181357]Every time you post I regret not taking math more seriously when I was younger. I'm never going to know all this awesome universe-governing shit![/QUOTE]
You need to have studied physics more deeply to get into it. I posted a few basics there which can be "accepted" by a normal person. But to understand it, you need the background and that is quantum chromo dynamics, the standard model with all the freaking gauge symmetries.
I couldn't read the OP because I was too distracted by his avatar. :saddowns:
If they really want to do this quickly they need to build an accelerator that orbits the sun and can collide blocks of tungsten the size of cars. Now thats science for you.
Have we reached the part like in the movies where the scientists know they shouldn't go further with the research but are doing it anyway?
[QUOTE=angelangel;26217162]Have we reached the part like in the movies where the scientists know they shouldn't go further with the research but are doing it anyway?[/QUOTE]
If we can go further, you definitely should. Otherwise, science wouldn't make any sense.
[QUOTE=aVoN;26174521]The Z-Boson is one of the force-particles of the weak force (W+,W-,Z0). The weak force is responsible for particles (mainly quarks) being able to decay to others. Here you see a proton decaying to a neutron in a Feynman-Diagram:
[img_thumb]http://upload.wikimedia.org/wikipedia/commons/thumb/8/89/Beta_Negative_Decay.svg/310px-Beta_Negative_Decay.svg.png[/img_thumb]
The neutron consists of an up and two down quarks (bottom) and one down quark decays to an up-quark. Due to conservation of quantum-numbers (here especially the charge), a gauge-boson has to be emitted. This later decays to an electron and an anti-electron neutrino.
Why is this experiment at CERN important?: Before, we never saw a Z-Boson in lead-ion collisions.[/QUOTE]
Sooooo..... The collision of Pudu and Nudd equals _Ve into W- that's something of a e¨.
That's what I got out of this.
[editline]22nd November 2010[/editline]
And I love your avatar aVoN.
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