|Status||A Higgs boson of mass ≈125 GeV has been tentatively confirmed by CERN on 14 March 2013, although it is unclear as yet which model the particle best supports or whether multiple Higgs bosons exist.
|Theorised||R. Brout, F. Englert, P. Higgs, G. S. Guralnik, C. R. Hagen, and T. W. B. Kibble (1964)|
|Discovered||Large Hadron Collider (2011-2013)|
|Mass||125.09±0.21 (stat.)±0.11 (syst.) GeV/c2 (CMS+ATLAS)|
1.56×10−22 s[Note 2] (predicted)
|Electric charge||0 e|
|Spin||0 (tentatively confirmed at 125 GeV)|
|Parity||+1 (tentatively confirmed at 125 GeV)|
The Higgs boson (or Higgs particle) is a particle in the Standard Model of physics. In the 1960s Peter Higgs was the first person to express the idea. On 14 March 2013, scientists at CERN tentatively confirm that they have found the particle.
It is one of the 17 particles in the Standard Model. The Higgs particle is a boson. Bosons are thought to be particles which are responsible for all physical forces. Other known bosons are the photon, the W and Z bosons, and the gluon. Scientists do not yet know how to combine gravity with the Standard Model.
The Higgs field is a fundamental field of crucial importance to particle physics theory. Unlike other known fields such as the electromagnetic field, the Higgs field takes a non-zero constant value almost everywhere. The question of the Higgs field's existence has been the last unverified part of the Standard Model of particle physics and, according to some, "the central problem in particle physics".
It is difficult to detect the Higgs Boson. Due to their massive size (compared with other particles) it needs vast amounts of energy to create them. The Large Hadron Collider at CERN was built mainly for this. It accelerates two sets of partials to almost light speed (travelling in opposite directions), before setting them on a path to collide with each other.
Each collision produces a flurry of new particles which are detected by detectors around the point where they collide. There is still only a very small chance, one in 10 billion, of a Higgs Boson appearing and being detected, so the LHC needs to smash together trillions of partials, and supercomputers need to sift through a massive amount of data to find the few collisions where evidence of the Higgs boson is.
Higgs bosons obey the conservation of energy law, which states that no energy is created or destroyed, but instead it is transferred. First, the energy starts out in the gauge boson that interacts with the Higgs field. This energy is in the form of kinetic energy as movement. After the gauge boson interacts with the Higgs field, it is slowed down. This slowing reduces the amount of kinetic energy in the gauge boson. However, this energy is not destroyed. Instead, the energy is converted into mass-energy, which is normal mass that comes from energy. The mass created is what we call a Higgs boson. The amount of mass created comes from Einstein's famous equation E=mc2, which states that mass is equal to a large amount of energy (for example, 1 kg of mass is equivalent to almost 90 quadrillion joules of energy—the same amount of energy used by the entire world in roughly an hour and a quarter in 2008). Since the amount of mass-energy created by the Higgs field is equal to the amount of kinetic-energy that the gauge boson lost by being slowed, energy is conserved.
Higgs bosons are used in a variety of science fiction stories. The physicist Leon Lederman called it the "God particle" in 1993. He used this name to get attention and support for experiments to detect the particle. However, most scientists do not like this name, because the particle has nothing to do with any kind of god and the nickname might confuse people.
Possible claims[change | change source]
On 12 December 2011, the two teams at the Large Hadron Collider looking for the Higgs Boson, ATLAS and CMS, announced that they had finally seen results which could suggest the Higgs Boson particle existed; however, they did not know for certain if this was true.
On 4 July 2012, the teams at the Large Hadron Collider declared that they had discovered a particle which they think is the Higgs boson.
On 14 March 2013 the teams had done much more testing, and announced that they now think the new particle was a Higgs boson.
References[change | change source]
- O'Luanaigh, C. (14 March 2013). "New results indicate that new particle is a Higgs boson". CERN. http://home.web.cern.ch/about/updates/2013/03/new-results-indicate-new-particle-higgs-boson. Retrieved 2013-10-09.
- Bryner, J. (14 March 2013). "Particle confirmed as Higgs boson". NBC News. http://science.nbcnews.com/_news/2013/03/14/17311477-particle-confirmed-as-higgs-boson. Retrieved 2013-03-14.
- ATLAS; CMS (26 March 2015). "Combined Measurement of the Higgs Boson Mass in pp Collisions at √s=7 and 8 TeV with the ATLAS and CMS Experiments". arXiv:1503.07589.
- LHC Higgs Cross Section Working Group; Dittmaier; Mariotti; Passarino; Tanaka; Alekhin; Alwall; Bagnaschi et al. (2012). "Handbook of LHC Higgs Cross Sections: 2. Differential Distributions". CERN Report 2 (Tables A.1 – A.20) 1201: 3084.
- Onyisi P. 2012. "Higgs boson FAQ". University of Texas ATLAS group. https://wikis.utexas.edu/display/utatlas/Higgs+boson+FAQ. Retrieved 2013-01-08.
- Strassler M. 2012. "The Higgs FAQ 2.0". ProfMattStrassler.com. http://profmattstrassler.com/articles-and-posts/the-higgs-particle/the-higgs-faq-2-0/. Retrieved 2013-01-08. "[Q] Why do particle physicists care so much about the Higgs particle?
[A] Well, actually, they don’t. What they really care about is the Higgs field, because it is so important. [emphasis in original]"
- The Grand Patchwork. quantum excitation]
- José Luis Lucio and Arnulfo Zepeda (1987). Proceedings of the II Mexican School of Particles and Fields, Cuernavaca-Morelos, 1986. World Scientific. p. 29. ISBN 9971504340. https://books.google.com/?id=jJ-yAAAAIAAJ&q=higgs+%22central+problem+today+in+particle+physics%22&dq=higgs+%22central+problem+today+in+particle+physics%22.
- Gunion, Dawson, Kane, and Haber (199). The Higgs Hunter's Guide (1st ed.). pp. 11 (?). ISBN 9780786743186. https://books.google.com/?id=M5moXN_SA-MC&pg=PA10&dq=higgs+hunter+crucial+central+prediction#v=snippet&q=central&f=false. – quoted as being in the first (1990) edition of the book by Peter Higgs in his talk "My Life as a Boson", 2001, ref#25.
- Rincon, Paul (13 December 2011). "LHC: Higgs Boson 'may have been glimpsed". BBC. http://www.bbc.co.uk/news/science-environment-16158374. Retrieved 13 December 2011.
- BBC News - Higgs boson-like particle discovery claimed at LHC - Retrieved 4 July 2012
Notes[change | change source]
- Note that such events also occur due to other processes. Detection involves a statistically significant excess of such events at specific energies.
- In the Standard Model, the total decay width of a Higgs boson with a mass of 126 GeV/c2 is predicted to be 4.21×10−3 GeV. The mean lifetime is given by .
Other websites[change | change source]
- The Official Website of ATLAS Project, a leading Higgs Boson research project: atlas.ch