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LHC News July 3, 2009

Posted by gordonwatts in CERN, LHC.

Sorry if this is old news…

CERN management recently had a council meeting. These meetings take place between the council and the CERN directory general. Big funding changes, new projects, major schedule changes, a new country wants to join CERN, etc., all have to be approved by this council. As you might imagine the recent council meetings have been dominated by the “schedule changes” (I don’t actually know as a function of time if that is true, but I would imagine).

What is nice about the current CERN DG is that he usually immediately sends a message out to the public and the the CERN folks. Much better than reading about an updated CERN LHC schedule in the Geneva newspaper. Even better, a presentation to all of CERN (and an open webcast) is schedule. The last one just happened (there is a video link and slides link at the top of the agenda, just under the main agenda title).

Everyone is eager for data. I’ve discussed what I think are some of the pressures on the accelerator division previously. This meeting is a continuing part of that conversation.

It is clear they are doing a huge amount of work. They have a lot done. A huge amount. From a physicist’s point of view, the most frustrating thing about Steve Myers’ talk was there is no date and no energy. It wasn’t clear to me what the plan was until someone asked a question at the very end of the talk. Basically – they will have measured the splices (electrical connections) in all of the LHC in early August. Those splices are what caused the disaster last September – so it is important that all of them be carefully measured. And once they have measured everything – then they can start a discussion with the experiments on start up schedule and energy.

Next time something on the trade offs…



1. Energy vs Power vs Heat vs Oh no! « Life as a Physicist - July 5, 2009

[…] vs Power vs Heat vs Oh no! July 5, 2009 Posted by gordonwatts in CERN, LHC. trackback Last post I mentioned the LHC update that was given at a recent meeting at CERN. One cool thing Steve […]

2. Mario E. de Souza - October 28, 2011

Sorry, guys, but the Higgs is just a chimera because quarks are composite. You may say now ‘come on, we haven’t seen it’, and the truth is that we have seen several indications of it. The first one was found in 1956 by Hofstadter when he determined the charge distributions of both nucleons. (one can see them around p. 450 (depending on edition) of the Berkeley Physics Course, vol. 1 (Mechanics)). We clearly see that both nucleons have two layers of internal constituents. Unfortunately these results were put aside from 1964 on due to the success of the quark model and of QCD later on. From 1985 on we began to see more indications of compositeness, but we were so enthusiastic with the SM that we didn’t pay much attention to them. A partial list of them: 1) in 1983 the European Muon Collaboration (EMC) at CERN found that the quarks of nucleons are slower when the nucleons are inside nuclei; 2) in 1988 the SLAC E143 Collaboration and the Spin Muon Collaboration found that the three quarks of the proton account for only half of its total spin (other subsequent collaborations (EMC in 1989 and Hermes in 2007) have confirmed this result which is called the proton spin puzzle); 3) in 1995 CDF at Fermilab found hard collisions among quarks indicating that they have constituents (this was not published because CDF didn’t reach a final consensus); 4) Gerald Miller at Argonne (Phys. Rev. Lett. 99, 112001 (2007)) found that close to its center the neutron has a negative charge equal to -1/3e (inside the positive region with +1/2e); 5) new measurements of the EMC effect have been carried out by J. Arrington et al. at Jefferson Lab and they have shown that the effect is much stronger than was previously observed; etc.
Gerald Miller wrongly attibuted to d quarks the -1/3 charge at the neutron center, but as the neutron ia a udd system we know (even from QCD) that none of the 3 quarks spends much time at the center.
The relevant paper on this subject is Weak decays of hadrons reveal compositeness of quarks which can be accessed from Google (it is at the top on the subjects Weak decays of hadrons, Decays of Hadrons and Weak decays).

Therefore, we should go back and probe further the nucleons in the low energy scale, and carry on Miller’s experiment with the proton.

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