A place for the discussion of all things not closely related to the sport and its competitive side. (Locked down several times a year during the major championships)
JRM wrote:Here's a link to the journal issue (Physics Letters B) in which the official discovery announcement papers from the ATLAS and CMS Collaborations are published (p 1-29 for ATLAS, and p 30-61 for CMS). Also, scroll down and check out paper #11 in the issue's Astrophysics and Cosmology section (p 171-176)!
JRM wrote:Here's a link to the journal issue (Physics Letters B) in which the official discovery announcement papers from the ATLAS and CMS Collaborations are published (p 1-29 for ATLAS, and p 30-61 for CMS). Also, scroll down and check out paper #11 in the issue's Astrophysics and Cosmology section (p 171-176)!
By the way. look at the length of the authors list; the 19th author has a name starting with Ad and they are all alphabetical.
It's also not uncommon for those international collaborations to have authors who are posthumously listed (and I believe there are several in that list). In fact, the entire author listing goes on for at least 10 pages.
The author list starts at page 25. The paper also has the following dedication:
"This paper is dedicated to the memory of our ATLAS colleagues who did not live to see the full impact and significance of their contributions to the experiment."
JRM wrote:Here's a link to the journal issue (Physics Letters B) in which the official discovery announcement papers from the ATLAS and CMS Collaborations are published (p 1-29 for ATLAS, and p 30-61 for CMS). Also, scroll down and check out paper #11 in the issue's Astrophysics and Cosmology section (p 171-176)!
By the way. look at the length of the authors list; the 19th author has a name starting with Ad and they are all alphabetical.
It's also not uncommon for those international collaborations to have authors who are posthumously listed (and I believe there are several in that list). In fact, the entire author listing goes on for at least 10 pages.
My article in Nature had ten authors, and I thought that that was a lot. Yes, I am aware of the issues in big experimental setups, so I am not surprised by that long list.
Results not kind to Super Symmetry. Commentary from JRM needed here for perspective?
The new observation, reported at the Hadron Collider Physics conference in Kyoto, is not consistent with many of the most likely models of SUSY.
Prof Chris Parke, who is the spokesperson for the UK Participation in the LHCb experiment, told BBC News: "Supersymmetry may not be dead but these latest results have certainly put it into hospital."
26mi235 wrote:Results not kind to Super Symmetry. Commentary from JRM needed here for perspective?
The new observation, reported at the Hadron Collider Physics conference in Kyoto, is not consistent with many of the most likely models of SUSY.
Their results suggest that the decays of B0-mesons (neutral particles made of quark - anti-quark pairs of varying flavor) decay to lighter particles (muon and anti-muon) in a fashion consistent with the Standard Model. The bad thing is the statistics of the decay rates (called branching ratios) is what strongly constraints Supersymmetry. That is, supersymmetry predicts a rate they're decidedly not seeing. So, good for Standard Model, bad for Supersymmetry.
That being said, my contacts at CERN inform me that LHCb is stretching the stats a bit, and not to put too much faith in the "sensationalist" press release.
JRM wrote:(neutral particles made of quark - anti-quark pairs of varying flavor) decay to lighter particles (muon and anti-muon)
So I'm reading wiki . . .
There is considerable speculation as to why the observable universe is apparently composed almost entirely of matter (as opposed to a mixture of matter and antimatter), whether there exist other places that are almost entirely composed of antimatter . . .
I'm imagining an anti-universe where left is right, down is up . . .
There is considerable speculation as to why the observable universe is apparently composed almost entirely of matter (as opposed to a mixture of matter and antimatter), whether there exist other places that are almost entirely composed of antimatter . . .
I'm imagining an anti-universe where left is right, down is up . . .
Well, yes and no. Anti-matter does exist in our region of the universe. In fact, high-energy cosmic ray positrons (i.e. anti-electrons) shoot through your body every day. We can also readily manufacture anti-matter in the laboratory, e.g. at CERN. Anti-particles have the opposite properties of their particle counterparts, but those are PARTICLE properties: the two most common are spin and chirality (so, in a sense, right IS left for anti-matter).
But technically, mass is not included: anti-matter has positive mass, and feels gravity the same way normal mass does. Now, in other cases, you can have negative energy particles, but those can't exist for more time than the Heisenberg Uncertainty Principle allows (i.e. they're not around long enough for you to see them).
If you want to go full-weird, however, you can adopt Richard Feynman's interpretation of anti-particles: they are negative-energy (negative mass) particles that travel backward in time!
JRM wrote:1. high-energy cosmic ray positrons (i.e. anti-electrons) shoot through your body every day. 2. they're not around long enough for you to see them. 3. anti-particles: they are negative-energy (negative mass) particles that travel backward in time!
1. I wondered what that tingling sensation was! 2. um . . . then how do we know . . . never mind 3. What happens when they get back to the Big Bang?!
[quote="Marlow" 3. What happens when they get back to the Big Bang?! [/quote]
Given what 'Dark Energy' does, it seems like there will be no return to the Big Bang in the future (it is never coming back together in a point), if that is what you meant.
If you meant what it looks like when you look back far enough, there is no really looking back passed about 300,000 from BB because the radiation was dominant and it was all a haze.
yahoo news wrote:Collisions between particles inside the Large Hadron Collider atom smasher have created what looks like a new form of matter. The new kind of matter is called color-glass condensate, and is a liquidlike wave of gluons, which are elementary particles related to the strong force that sticks quarks together inside protons and neutrons (hence they are like "glue"). In this case, the collisions create what's called quark-gluon plasma — a superhot soup of particles similar to the state of the universe just after the Big Bang.
Heisenberg and Schrödinger are speeding in a car and get pulled over. Heisenberg is in the driver's seat, so the officer asks him, "Do you know how fast you were going?" Heisenberg replies, "No, but I know exactly where I am!" The officer looks at him confused and says, "You were going 108 miles per hour!" Heisenberg throws his arms up and cries, "Great! Now I'm lost!" The officer, now more confused and frustrated, orders the men outside of the car, and proceeds to inspect the vehicle. He opens the trunk and yells at the two men, "Hey! Did you guys know you have a dead cat back here?" Schrödinger angrily yells back, "Well, we do now!"
Heisenberg and Schrödinger are speeding in a car and get pulled over. Heisenberg is in the driver's seat, so the officer asks him, "Do you know how fast you were going?" Heisenberg replies, "No, but I know exactly where I am!" The officer looks at him confused and says, "You were going 108 miles per hour!" Heisenberg throws his arms up and cries, "Great! Now I'm lost!" The officer, now more confused and frustrated, orders the men outside of the car, and proceeds to inspect the vehicle. He opens the trunk and yells at the two men, "Hey! Did you guys know you have a dead cat back here?" Schrödinger angrily yells back, "Well, we do now!"
Awesome. Can't believe I haven't heard that before.
Heisenberg and Schrödinger are speeding in a car and get pulled over. Heisenberg is in the driver's seat, so the officer asks him, "Do you know how fast you were going?" Heisenberg replies, "No, but I know exactly where I am!" The officer looks at him confused and says, "You were going 108 miles per hour!" Heisenberg throws his arms up and cries, "Great! Now I'm lost!" The officer, now more confused and frustrated, orders the men outside of the car, and proceeds to inspect the vehicle. He opens the trunk and yells at the two men, "Hey! Did you guys know you have a dead cat back here?" Schrödinger angrily yells back, "Well, we do now!"
Awesome. Can't believe I haven't heard that before.
This thread has been a bit quiet since the fall. Perhaps I can reactivate it by asking what's up with the ITER (the pilot fusion reactor)? Weren't they supposed to be installing the kit by now?
Peter Woit and Matt Strassler both have interesting and generally accessible blogs on the physics. Both are somewhat dubious on string theory and supersymmetry.
added 3/16 Both, but especially MS have discussions because of the updating of the results from the LHC, which seem to continue (even more over time) to affirm the SM (Standard Model) and show nothing of numerous extensions or alterations.
Last edited by 26mi235 on Sat Mar 16, 2013 6:30 pm, edited 1 time in total.
Quick Silver wrote:This thread has been a bit quiet since the fall. Perhaps I can reactivate it by asking what's up with the ITER (the pilot fusion reactor)? Weren't they supposed to be installing the kit by now?
Quick Silver Hong Kong
I can't say a lot about the progress of this project. It is unrelated to the LHC. Fusion as a returnable energy source has been problematic for decades. It would be nice to see some breakthroughs on that front, but it will require significant advances in engineering, more than physics. On paper, no-cost fusion is easy. In practice... not so much.
Awesome. Can't believe I haven't heard that before.
