Re: No Higgs Boson will be found...
Large Hardon Collider has a lot of other uses then searching for the Higgs particle.
Large Hardon Collider has a lot of other uses then searching for the Higgs particle.
GENEVA | Fri Sep 17, 2010 12:32pm EDT
The Linac 2 (Linear Accelerator 2) is pictured at the European Organisation for Nuclear Research (CERN) in Meyrin near Geneva October 16, 2008.
Credit: Reuters/Denis Balibouse
(Reuters) - Europe's particle research center CERN unveiled budget cuts Friday that will force it to temporarily close its accelerators for a year in 2012, but said its flagship "Big Bang" machine will mainly be unaffected.
...Sep 21st, 2010
by Nancy Atkinson
Image of a 7 TeV proton-proton collision in CMS producing more than 100 charged particles. Credit: CERN
Scientists at the Large Hadron Collison reported today they apparently have discovered a previously unobserved phenomenon in proton-proton collisions. One of the detectors shows that the colliding particles appear to be intimately linked in a way not seen before in proton collisions. The correlations were observed between particles produced in 7 TeV collisions. “The new feature has appeared in our analysis around the middle of July,” physicist Guido Tonelli told fellow CERN scientists at a seminar to present the findings from the collider’s CMS (Compact Muon Solenoid) detector.
The scientists said the effect is subtle and they have performed several detailed crosschecks and studies to ensure that it is real. It bears some similarity to effects seen in the collisions of nuclei at the RHIC facility located at the US Brookhaven National Laboratory, which have been interpreted as being possibly due to the creation of hot dense matter formed in the collisions.
...The scientists stressed that there are several potential explanations to be considered and the they presented their news to the physics community at CERN today in hopes of “fostering a broader discussion on the subject.”
24 September 2010
A long period of machine development paid dividends last night with a game-changing fill in the LHC. As I write this, the fill, which started colliding at 19:00 yesterday evening, has just wound down. Both ATLAS and CMS have posted integrated luminosities of over 680 inverse nanobarns, and the initial luminosity for the fill doubles the previous record at 2×10[super]31[/super]cm-2s-1.
But it’s not the records that are important this time – it’s normal that in the start-up phase of a new machine, records will fall like autumn leaves – what’s significant here is that the LHC’s performance this fill significantly exceeded some crucial design parameters, opening up the path to much better still to come.
Last night’s fill was the first with 56 bunches arranged in trains of eight bunches per train. The significance of bunch train running is that we can configure the orbits such that more bunches collide in the experiments, so even though the number of bunches may not be much higher, the collision rate is. For example, last night’s 56-bunch fill had 47 bunches colliding at ATLAS, CMS and LHCb, with 16 colliding in ALICE, whose needs are lower. This compares to a maximum of 36 colliding bunches out of 48 total before we introduced bunch trains.
A big jump in luminosity was clearly expected in moving to bunch trains and colliding more bunches. What came as a pleasant surprise is that it was accompanied by an exceptional beam lifetime of 40 hours, and less disruption to the beams caused by packing more protons into a smaller space (in technical terms, the beam-beam tune shift was much less destructive to the beams than anticipated). This result means that the LHC operators have more leeway in operational parameters in the quest for higher luminosity.
The plan for today and the weekend is to run for one more fill with 56 bunches in trains of eight before moving on to 104 bunches in 13 trains of eight, with 93 bunches colliding in ATLAS and CMS. Ultimately, the LHC will run with 2808 bunches in each beam, so there’s still a long way to go. We’ll get there slowly but surely by adding bunches to each train until the trains meet in a single machine-filling train. That will take time, but for the moment, last night’s fill puts us well on the way to achieving the main objective for 2010: a luminosity of 10[super]32[/super]cm-2s-1
From http://blogs.uslhc.us/a-great-fill:EarthlingX":3t28sah5 said:
[youtube]http://www.youtube.com/watch?v=_NMqPT6oKJ8[/youtube]September 21st, 2010 7:05 AM
by Phil Plait
There are a lot of questions in science that seem simple, but in fact lead to profound concepts. Why is the sky dark at night? Why does gravity pull me down? Why is the Sun hot?
And some questions seem silly and frivolous, but it turns out are really hard to answer, and in fact scientists might disagree on the answer. Case in point: what happens if you put your hand in the beam of the Large Hadron Collider?
So the folks at Sixty Symbols asked this of several scientists, and the first four minutes of this video are the result:
..It’s complicated! You have to think about the energy of the beam, of course, but also the energy of a given proton as it moves at 99.9999% the speed of light. But that number doesn’t mean anything if the proton doesn’t actually interact with the matter in your hand, so you have to consider the "cross-section" of the atoms in your hand. Think of it this way: if you shoot a gun at a target, you make a hole. But if you shoot a gun at a fishing net, it might pass right through. Most of the area of a fishing net is holes! The nuclei of atoms are very small compared to the atoms themselves, so in a sense most of you is empty space.
...September 27, 2010 | 11:24 am
On August 7, more than 200 photographers had the rare opportunity to go behind the scenes at five laboratories in Asia, Europe and North America, as part of the first Global Particle Physics Photowalk. Thousands of photographs were submitted to the laboratories for local and global competitions. The laboratories have made their choices, each nominating three photographs for global competition. Now it’s your turn – starting today, you may vote for up to three of your favorite photographs as part of the “people’s choice” global photowalk competition.
..The five participating Photowalk laboratories have made their selections, and now it's time to cast your vote! Each laboratory nominated three photographs for this global competition; the winners will be featured in the particle physics magazines symmetry and the CERN Courier and exhibited at the Photowalk laboratories.
To cast your vote, click on the button below your favorite three photographs. Click on any photo to see a larger version.
A. Hamilton (the ATLAS Collaboration)
(Submitted on 30 Sep 2010)
Abstract: The ATLAS trigger has been used very successfully to collect collision data during 2009 and 2010 LHC running at centre of mass energies of 900 GeV, 2.36 TeV, and 7 TeV. This paper presents the ongoing work to commission the ATLAS trigger with proton collisions, including an overview of the performance of the trigger based on extensive online running. We describe how the trigger has evolved with increasing LHC luminosity and give a brief overview of plans for forthcoming LHC running.
14 October 2010
by Rolf Heuer
When we started running the LHC at the end of March, we set ourselves the objective of reaching a luminosity of 10[super]32[/super] by the end of 2010 proton running. Last night, we achieved that goal. The beams that went in at around 2:00am, were colliding with a luminosity of 1.01 × 10[super]32[/super] by 3:38am in both ATLAS and CMS, and had delivered an integrated luminosity of over 2 inverse picobarns to ATLAS, CMS and LHCb by midday today. It’s a great achievement by all concerned to reach this important milestone with over two weeks to spare. The remainder of this year’s proton running will be devoted to maximising the LHC 2010 data set and preparing for 2011 proton running before we switch to lead ions in November.
The significance of this milestone can’t be underestimated, since it is a necessary step on the way to the larger goal of delivering an integrated luminosity of one inverse femtobarn to the experiments by the end of 2011. That’s the amount of data we need to ensure that if nature has put new physics in our path at the LHC’s current collision energy, we’ll have a good chance of seeing it.
At the moment, we’re running the LHC with 248 bunches per beam in a configuration that allows us to go much higher. As 2011 proton running gets underway early next year we’ll continue increasing the number of bunches, since a factor of two or so more luminosity is still needed if we’re to reach our one inverse femtobarn goal. That, however, is for next year. In the meantime, the objective we set ourselves for this year was realistic, but tough, and it’s very gratifying to see it achieved in such fine style.
...Geneva, 8 November 2010.
An event recorded by the ALICE experiment from the first lead-ion collisions, at a centre-of-mass energy of 2.76 TeV per nucleon pair.
Four days is all it took for the LHC operations team at CERN1 to complete the transition from protons to lead ions in the LHC. After extracting the final proton beam of 2010 on 4 November, commissioning the lead-ion beam was underway by early afternoon. First collisions were recorded at 00:30 CET on 7 November, and stable running conditions marked the start of physics with heavy ions at 11:20 CET today.