The Naked Scientists

The Naked Scientists Forum

Author Topic: Large Hadron Collider, how did know they saw the Higgs Boson?  (Read 623 times)

Offline Alan McDougall

  • Neilep Level Member
  • ******
  • Posts: 1285
  • Thanked: 14 times
    • View Profile
As a crude comparison if we collided two cars at an enormous speed and the task was to find a piece of the carburetor among the shattered remains if we searched long enough we would find it because we would know exactly what we were looking for. The same goes for the "Black Box" of airplane disasters.

We have been informed that the LHC scientists that they have found (identified) the elusive Higgs Boson, but how did they know that among the billions of hadrons that among them were/was a Higgs Boson,(s) having never observed this unique animal before??

Alan   


 

Offline Bill S

  • Neilep Level Member
  • ******
  • Posts: 1830
  • Thanked: 12 times
    • View Profile
As I understand it, they didn't see the Higgs particle.  The Higgs particle is so short-lived that it cannot directly be detected by any currently available technique or equipment.  The only way in which the existence of the Higgs particle can be inferred is by the identification of the smaller particles into which it decays. 

Around half a century of theoretical work has enabled scientists to identify, theoretically, these decay products and find ways of distinguishing them from the vast numbers of particles produced in the billions of collisions generated in the LHC.  It is these decay products that were detected, and identified by the international group of scientists gathered at CERN.                   
 

Offline Alan McDougall

  • Neilep Level Member
  • ******
  • Posts: 1285
  • Thanked: 14 times
    • View Profile
As I understand it, they didn't see the Higgs particle.  The Higgs particle is so short-lived that it cannot directly be detected by any currently available technique or equipment.  The only way in which the existence of the Higgs particle can be inferred is by the identification of the smaller particles into which it decays. 

Around half a century of theoretical work has enabled scientists to identify, theoretically, these decay products and find ways of distinguishing them from the vast numbers of particles produced in the billions of collisions generated in the LHC.  It is these decay products that were detected, and identified by the international group of scientists gathered at CERN.                   

I am by no means a particle physicists so correct me if I am wrong?

Excuse my wrong rather crude analogy of two cars crashing into each other and then searching for the shattered remains of a piece of the carburetor.

A closer analogy one would be smashing billiard balls of different properties and masses and from the traces, they make outward, deduce their original properties from, the paths and distances the took after the collision between them etc?

In this hypothetic case, you are not looking to capture the actual balls and measure them because the force of the collision has destroyed them or putting them forever out of reach.

Among these hypothetical balls, someone has included a ball with which they call the "Higgs Ball". The task being to measure the paths left by the all of the balls and from the left over "Mess" confirm Mr. Higgs had indeed included his ball, with the predicted properties he had said it would have, if the experiment, were successful?

Am I close, put in my crude layman terms?

Alan
« Last Edit: 15/07/2016 09:07:17 by Alan McDougall »
 

Offline evan_au

  • Neilep Level Member
  • ******
  • Posts: 4130
  • Thanked: 249 times
    • View Profile
Quote from: Alan McDougall
how did know they saw the Higgs Boson?
There are a large number of subatomic events that occur every microsecond in the LHC.

CERN has some high-powered computers that collect the detector data every time a bunch of protons collide (about every 40 nanoseconds), and weeds out the "boring" ones, passing on the "interesting" ones for more detailed analysis by other (slower) computers.

As well as looking for particle "jets" representing the decay of massive particles, they are also looking for the decay of micro-black holes, and other theoretical particles outside the Standard Model.

There are many jets which could be produced by different mechanisms, so they focused on the jets with composition most likely to come from the hypothetical Higgs, and unlikely to come from other particles.

By varying the collision energy of the beams, they can see that there are certain energies where the output of the relevant events is enhanced. This gives clues about the energy of the particle which produced these interesting jets.

See: https://en.wikipedia.org/wiki/Higgs_boson#Discovery_of_candidate_boson_at_CERN
 

The Naked Scientists Forum


 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums