Theories of the Origin of the Universe Theological “Theories”: Greek Mythology (Chaos) Hindu Mythology(Cosmic sleep of gods) Chinese creation myth (Pangu) Biblical account of the creation (God) Scientific Theories: Steady State Plasma theory Inflation Universe Big Bounce Cyclic Universe Big Bang
Evidence for the Big Bang Theory predicts an expanding universe Confirm by Red Shift (Doppler effect) in spectrum Theory predicts cosmic background radiation Background radiation was discovered in 1964 by Arno Penzias and Robert Wilson, who later won the Nobel Prize for this discovery
The Big Bang• The universe does not expand into space – space itself expands• Extrapolating back, space was small – the Big Bang• Other dimensions could exist but still be small. String theory requires 6 extra dimensions.• How can we test this possibility?
The Large Hadron ColliderLHC is located at CERN The LHC collides protonsCERN is located near Geneva Center of Mass E=14 TeV ~7X FermilabPart of CERN is in France Very high luminosity ~100X Fermilab
The Large Hadrons ColliderMagnetic field at 7 TeV: 8.33 TeslaOperating temperature: 1.9 KNumber of magnets: ~9300Number of main dipoles: 1232Number of quadrupoles: ~858Number of correcting magnets: ~6208Number of RF cavities: 8 per beam; Field strength at top energy ≈ 5.5 MV/m Power consumption: ~120 MW
The LHC what for ? Particle physics needs proton-proton centre of mass energy in the 1 TeV region where the Standard Model without Higgs Sector is expected to fail. Need for a exploratory machine (= high discovery potential) to search for Higgs and the spectrum of SUSY particles.
Why large ? Colliders use magnetic fields in order to keep particles on a circular orbit with radius R R [m] = 3.33 p [GeV] / B [T] B limited by technology, cost, power consumption to < 10 T For p = 10000 GeV, R > 3 km (circumference C > 20 km) Not all the circumference can be covered by dipoles
Why a hadron (pp) collider ? Hadron colliders are exploratory machines giving access to a diversity of physics processes Hadronic Protonic (gg, qg, qq) proton-proton centre of mass energy Not fixed = covers wide energy range (“broad band”) Lower than the pp center of mass energy (~1/6) Need pp center of mass energy of O(10 TeV) to reach 1 TeV proton-proton centre of mass energy. Proton luminosity Depending on the proton luminosity and the proton distribution function (pdf) of the proton.
Why collider ? Proton beam on fixed target √s = √(2pmp) ~ √p p Two protons of equal energy colliding √s = 2p ~ p p p
Already today, beams are availableclose to the nominal beam parametersrequired for the LHC ! 450 GeV 26 GeV LEAR => LEIR
Superconducting Cables ∅1 mm ∅6 µm Typical value for operation at 8 T and 1.9 K: 800 A Rutherford cable