2017-03-02 CERN gets ready to obtain measurements for the Standard Model by replacing huge solenoid magnet that bends paths of particles from LHC collisions


@IN2P3_CNRS quote of @CERN tweet

@infobook tweet



Figure: Image from CERN live on facebook. Giant detector found at one of four collision sites cf cms.cern/detector  (Extend muon path towards detector)





After accomplishing a successful restart, “new Physics” started on 2015-06-03 at CERN


CERNpress @CERNpress


[Press Release] LHC experiments are back in business at a new record energy #13TeV cern.ch/go/P6jz





We have collisions! LHC experiments begin data-taking at #13TeV cern.ch/go/13TeV "Thanks to everybody, time for new physics!" CERN DG



Footnote from the Press Release

1. CERN, the European Organization for Nuclear Research, is the world's leading laboratory for particle physics. It has its headquarters in Geneva. At present, its member states are Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Israel, Italy, the Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. Romania is a Candidate for Accession. Serbia is an Associate Member in the pre-stage to Membership. Turkey is an Associate Member. India, Japan, the Russian Federation, the United States of America, the European Union, JINR and UNESCO have observer status.


A very happy #ATLAS Control Room! (Image: Pierre Descombe/CERN) #13TeV

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Theoretical background


Making the protons that will collide

"The proton source is a simple bottle of hydrogen gas"






"To make the protons", physicists inject hydrogen gas into the metal cylinder -Duoplasmatron-  then surround it with an electrical field to break down the gas into its constituent protons and electrons. 



The proton source is a simple bottle of hydrogen gas. An electric field is used to strip hydrogen atoms of their electrons to yield protons. Linac 2, the first accelerator in the chain, accelerates the protons to the energy of 50 MeV. The beam is then injected into the Proton Synchrotron Booster (PSB), which accelerates the protons to 1.4 GeV, followed by the Proton Synchrotron (PS), which pushes the beam to 25 GeV. Protons are then sent to the Super Proton Synchrotron (SPS) where they are accelerated to 450 GeV.

The protons are finally transferred to the two beam pipes of the LHC. The beam in one pipe circulates clockwise while the beam in the other pipe circulates anticlockwise.



The Proton



 A proton “is composed of three valence quarks: two up quarks and one down quark. The rest masses of the quarks contribute only about 1% of the proton's mass, however.[2] The remainder of the proton mass is due to the kinetic energy of the quarks and to the energy of the gluon fields that bind the quarks together.”



Gluons /ˈɡlɒnz/ are elementary particles that act as the exchange particles (or gauge bosons) for the strong force between quarks, analogous to the exchange of photons in the electromagnetic force between two charged particles.[6]



When Protons Collide



"The graphic below pictures two protons about to collide. Inside each proton you can find a "sea" of quarks and gluons. Why so many? Haven't you learned that there are only 3 quarks inside a proton? Well, we say that a proton consists of 3 "valence" quarks, but also a whole bunch of “sea” or “virtual” quarks and anti-quarks stemming from gluons.


"All the energy we put into the collision can come out as mass instead!"



When Protons Collide in stars or at CERN


In stars, fusion reactions occur when protons collide. Do those same fusion reactions occur when two protons collide at the LHC supercollider at CERN?  If not, why not?