Question

Higgs production and detection

a) Explain in a few short sentences how protons are accelerated at LHC to the high energy needed to produce Higgs bosons

b) Draw a likely Feynman diagram for Higgs production in a proton-proton collisions

c) Draw a likely Feynman diagram for Higgs decay to two photons

d) Draw a sketch of how such a decay would be detected in the detector

e) The Higgs invariant mass peak is sitting on a large two-photon background. Draw a Feynman diagram of a likely background process that occurs in proton-proton collisions.

Answer 1

a. The LHC means large hadron collider is a particle accelarator which pushes protons to the near speed of light.it consists of 27km ring of the superconducting magnets with a number of accelerating structures that boost energy of particles along the way. Here "Large" refers to its size, approximately 27km in circumferenc and "Hadron" because it accelerates protons or ions, which belong to the group of particles called hadrons Collider" because the particles form two beams travelling in opposite directions, which are made to collide at four points around the machine. Accelerating a particle like a proton requires different sorts of components along the way — The LHC accelerates protons around its 17-mile circumference to just under the speed of light and then brings them into head-on collisions at four intersections along its ring. As such, the LHC itself is fed by an elaborate collection of particle accelerators, working in sequence to achieve a final particle energy of 7 tera-electron volts (TeV) or more. Higgs bosons can be produced only by particles that interact with the Higgs field—in other words, particles with mass.As two active protons pass through each other, it’s usually pairs of massless gluons they can momentarily smash their energy to a virtual particle, which converts the gluon’s energy into mass. If two gluons produce a pair of virtual top quarks, the tops can recombine and annihilate into a Higgs boson.

b) fenyman diagram for higgs production in a proton-proton collisions

b. fenyman diagram for higgsdecay to two photon

.