Higsov bozon

Jedan mogući trag Higsovog bozona iz simuliranog proton-proton sudara. Raspada se skoro istog trenutka u dva mlaza hadrona i dva elektrona, koji su vidljivi kao linije.

Higsov bozon, ili Braut-Englert-Higsov bozon, jeste elementarna čestica u standardnom modelu fizike čestica, koja nastaje pri kvantnim ekscitacijama Higsovog polja. Imenovana je po fizičaru Piteru Higsu, koji je 1964. godine, zajedno sa još pet fizičara, predložio teoriju koja objašljava poreklo mase elementarnih čestica. Ova teorija, kasnije nazvana Higsov mehanizam, implicira postojanje Higsovog bozona, koji je otkriven tek 2012. godine u ATLAS I CMS eksperimentima na velikom hadronskom sudaraču u Evropskom centru za nuklearna istraživanja (CERN, eng. CERN). Piter Higs i Fransoa Englert nagrađeni su Nobelovom nagradom za fiziku 2013. godine za njihov rad na formuslisanju Higsovog mehanizma.

U popularnoj literaturi, Higsov bozon se takođe naziva i Božijom česticom, nakon naslova knjige fizičara i nobelovca Leona Ledermana Božija Čestica: Ako je svemir odgovor, šta je pitanje? iz 1993. godine. Mnogi naučnici taj naziv odbijaju smatrajući ga senzacionalističkim.

O bozonu

Šest autora PRL radova (PRL symmetry breaking papers), koji su 2010. godine primili Sakurai nagradu za svoj rad. Slijeva nadesno: Kibl, Guralnik, Hagen, Englert, Braut.

Piter Higs, takođe jedan od šest nagrađenih autora PRL radova.

Postojanje Higsovog bozona predviđeno je 1964. godine kao objašnjenje za Higsov mehanizam, mehanizam po kojem elementarne čestice dobijaju masu. Dok se smatra da je potvrđeno postojanje Higsovog mehanizma, sam bozon - kamen temeljac ove teorije - nije posmatran i njegovo postojanje nije bilo potvrđeno. Njegovo privremeno (neutvrđeno) otkriće u julu 2012. godine može potvrditi da je Standardni Model u suštini tačan. Alternativne teorije kao izvori Higsovog mehanizma kojima ne treba Higsov bozon su takođe moguće i bile bi razmotrene u slučaju da je postojanje Higsovog bozona odbačeno.

Higsov bozon nazvan je po Piteru Higsu, koji je 1964. godine napisao jedan od tri revolucionarna rada koji govore o onome što je sada poznato kao Higsov mehanizam i opisuju vezu između Higsovog polja i bozona. Međutim, Higs nije bio prvi koji je opisao ovaj fenomen: mjesec dana prije, Robert Braut i Fransoa Englert napisali su sličan rad.

Zato što je Higsov bozon veoma velika čestica, i raspada se skoro odmah pošto nastane, samo akcelerator čestica velike energije može da ga posmatra i snimi. Eksperimenti koji su potvrdili i odredili prirodu Higsovog bozona koristeći veliki hadronski sudarač (LHC) u CERN-u, počeli su rane 2010. godine, i izvođeni su u tevatronu Fermilab-a do 2011. godine, kada se zatvorio.

Dana 4. jula 2012. godine, dva glavna eksperimenta na velikom hadronskom sudaraču (ATLAS i CMS) su oba, nezavisno jedan od drugog, potvrdili postojanje dotada nepoznate čestice čija je masa oko 125 GeV/c2 (što iznosi oko 133 masa protona, po redu od 10-25 kilograma), što se „poklapa sa Higsovim bozonom“, i široko se veruje da je upravo to Higsov bozon. Objavili su da je potrebno dalje ispitivanje da bi se utvrdilo da je to zaista Higsov bozon, a ne neka druga nepoznata čestica (koja ima teoretski predviđene osobine Higsovog bozona) i, ako je tako, da se odredi koju verziju Standardnog Modela najbolje podržava.

Literatura

• G.S. Guralnik, C.R. Hagen and T.W.B. Kibble (1964). „Global Conservation Laws and Massless Particles”. Physical Review Letters. 13 (20): 585. Bibcode:1964PhRvL..13..585G. doi:10.1103/PhysRevLett.13.585. 
• F. Englert and R. Brout (1964). „Broken Symmetry and the Mass of Gauge Vector Mesons”. Physical Review Letters. 13 (9): 321. Bibcode:1964PhRvL..13..321E. doi:10.1103/PhysRevLett.13.321. 
• Higgs, P. (1964). „Broken Symmetries, Massless Particles and Gauge Fields”. Physics Letters. 12 (2): 132. Bibcode:1964PhL....12..132H. doi:10.1016/0031-9163(64)91136-9. 
• Higgs, P. (1964). „Broken Symmetries and the Masses of Gauge Bosons”. Physical Review Letters. 13 (16): 508. Bibcode:1964PhRvL..13..508H. doi:10.1103/PhysRevLett.13.508. 
• Higgs, P. (1966). „Spontaneous Symmetry Breakdown without Massless Bosons”. Physical Review. 145 (4): 1156. Bibcode:1966PhRv..145.1156H. doi:10.1103/PhysRev.145.1156. 
• Y. Nambu and G. Jona-Lasinio (1961). „Dynamical Model of Elementary Particles Based on an Analogy with Superconductivity”. Physical Review. 122: 345—358. Bibcode:1961PhRv..122..345N. doi:10.1103/PhysRev.122.345. 
• J. Goldstone, A. Salam and S. Weinberg (1962). „Broken Symmetries”. Physical Review. 127 (3): 965. Bibcode:1962PhRv..127..965G. doi:10.1103/PhysRev.127.965. 
• P.W. Anderson (1963). „Plasmons, Gauge Invariance, and Mass”. Physical Review. 130: 439. Bibcode:1963PhRv..130..439A. doi:10.1103/PhysRev.130.439. 
• A. Klein and B.W. Lee (1964). „Does Spontaneous Breakdown of Symmetry Imply Zero-Mass Particles?”. Physical Review Letters. 12 (10): 266. Bibcode:1964PhRvL..12..266K. doi:10.1103/PhysRevLett.12.266. 
• Gilbert, W. (1964). „Broken Symmetries and Massless Particles”. Physical Review Letters. 12 (25): 713. Bibcode:1964PhRvL..12..713G. doi:10.1103/PhysRevLett.12.713. 
• Bernstein, Jeremy (januar 1974). „Spontaneous symmetry breaking, gauge theories, the Higgs mechanism and all that” (PDF). Reviews of Modern Physics. 46 (1): 7—48. Bibcode:1974RvMP...46..7B . doi:10.1103/RevModPhys.46.7. Arhivirano iz originala (PDF) 21. 1. 2013. g. Pristupljeno 10. 12. 2012. 
• Peskin, Michael E.; Schroeder, Daniel V. (1995). An Introduction to Quantum Field Theory. Reading, MA: Addison-Wesley Publishing Company. ISBN 978-0-201-50397-5. 
• Griffiths, David (2008). Introduction to Elementary Particles (2nd revised izd.). WILEY-VCH. ISBN 978-3-527-40601-2. 
• Tipler, Paul; Llewellyn, Ralph (2003). Modern Physics. W. H. Freeman. ISBN 978-0-7167-4345-3. 
• Guralnik, Gerald S.; Hagen, C.R.; Kibble, Tom W.B. (1968). „Broken Symmetries and the Goldstone Theorem”. Ur.: R.L. Cool and R.E. Marshak. Advances in Physics, Vol. 2. Interscience Publishers. str. 567—708. ISBN 978-0-470-17057-1. Arhivirano iz originala 23. 04. 2012. g. Pristupljeno 05. 07. 2012. 
• Carroll, Sean (2013). The Particle at the End of the Universe: How the Hunt for the Higgs Boson Leads Us to the Edge of a New World. Dutton. ISBN 978-0-14-218030-3. 
• Jakobs, Karl; Seez, Chris (2015). „The Higgs Boson discovery”. Scholarpedia. 10 (9): 32413. doi:10.4249/scholarpedia.32413. 
• Higgs, Peter (2010). „My Life as a Boson” (PDF). Talk given at Kings College, London, Nov 24 2010. Arhivirano iz originala (PDF) 4. 11. 2013. g. Pristupljeno 17. 1. 2013.  (also: Higgs, Peter (24. 11. 2010). „My Life As a Boson: The Story of "the Higgs"”. International Journal of Modern Physics A. 17: 86—88. Bibcode:2002IJMPA..17S..86H. doi:10.1142/S0217751X02013046. )
• Kibble, Tom (2009). „Englert–Brout–Higgs–Guralnik–Hagen–Kibble mechanism (history)”. Scholarpedia. Pristupljeno 17. 1. 2013.  (also: Kibble, Tom (2009). „Englert-Brout-Higgs-Guralnik-Hagen-Kibble mechanism (history)”. Scholarpedia. 4: 8741. Bibcode:2009SchpJ...4.8741K. doi:10.4249/scholarpedia.8741. )
• Guralnik, Gerald (2009). „The History of the Guralnik, Hagen and Kibble development of the Theory of Spontaneous Symmetry Breaking and Gauge Particles”. International Journal of Modern Physics A. 24 (14): 2601—2627. Bibcode:2009IJMPA..24.2601G. arXiv:0907.3466 . doi:10.1142/S0217751X09045431. , Guralnik, Gerald (2011). „The Beginnings of Spontaneous Symmetry Breaking in Particle Physics. Proceedings of the DPF-2011 Conference, Providence, RI, 8–13 August 2011”. arXiv:1110.2253v1  [physics.hist-ph]. ,

Spoljašnje veze

Popularne nauke, masovni mediji i opšta pokrivenost

• Higgs Boson observation at CERN
• Hunting the Higgs Boson at C.M.S. Experiment, at CERN
• The Higgs Boson by the CERN exploratorium.
• Particle Fever, documentary film about the search for the Higgs Boson.
• The Atom Smashers, documentary film about the search for the Higgs Boson at Fermilab.
• Collected Articles at the Guardian
• Video (04:38) – CERN Announcement on 4 July 2012, of the discovery of a particle which is suspected will be a Higgs Boson.
• Video1 (07:44) + Video2 (07:44) – Higgs Boson Explained by CERN Physicist, Dr. Daniel Whiteson (16 June 2011).
• HowStuffWorks: What exactly is the Higgs Boson?
• Carroll, Sean. „Higgs Boson with Sean Carroll”. Sixty Symbols. University of Nottingham. 
• Overbye, Dennis (5. 3. 2013). „Chasing the Higgs Boson: How 2 teams of rivals at CERN searched for physics' most elusive particle”. New York Times Science pages. Pristupljeno 22. 7. 2013.  – New York Times "behind the scenes" style article on the Higgs' search at ATLAS and CMS
• "Heretical Ideas that Provided the Cornerstone for the Standard Model of Particle Physics". Arhivirano na sajtu Wayback Machine (15. oktobar 2013) SPG Mitteilungen March 2013, No. 39, (p. 14), and Talk at Brown University about the 1964 PRL papers
• Philip Anderson (not one of the PRL authors) on symmetry breaking in superconductivity and its migration into particle physics and the PRL papers
• Cartoon about the search
• Cham, Jorge (19. 2. 2014). „True Tales from the Road: The Higgs Boson Re-Explained”. Piled Higher and Deeper. Pristupljeno 25. 2. 2014. 
• Higgs Boson, BBC Radio 4 discussion with Jim Al-Khalili, David Wark & Roger Cashmore (In Our Time, 18 Nov. 2004)

Značajne publikacije i drugo

• „Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC”. Physics Letters B. 716 (2012): 1—29. 2012. Bibcode:2012PhLB..716....1A. arXiv:1207.7214 . doi:10.1016/j.physletb.2012.08.020. 
• „Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC”. Physics Letters B. 716 (2012): 30—61. 2012. Bibcode:2012PhLB..716...30C. arXiv:1207.7235 . doi:10.1016/j.physletb.2012.08.021. 
• Particle Data Group: Review of searches for Higgs Bosons.
• {cite book|last=Conference|first=Michigan Center for Theoretical Physics. Inaugural|title=2001, a Spacetime Odyssey: Proceedings of the Inaugural Conference of the Michigan Center for Theoretical Physics : Michigan, USA, 21-25 May 2001|url=https://books.google.com/books?id=ONhnbpq00xIC&pg=PA86%7Cyear=2002%7Cpublisher=World Scientific|isbn=978-981-238-231-3|pages=86–}}
• Migdal, A. A.; Polyakov, A. M. (1966). „Spontaneous Breakdown of Strong Interaction Symmetry and the Absence of Massless Particles” (PDF). Soviet Physics JETP. 24 (1): 91. Arhivirano iz originala (PDF) 21. 09. 2018. g. Pristupljeno 08. 01. 2019.  – example of a 1966 Russian paper on the subject.

Uvod u polje

• For a pedagogic introduction to electroweak symmetry breaking with step by step derivations, not found in texts, of many key relations, see http://www.quantumfieldtheory.info/Electroweak_Sym_breaking.pdf
• Spontaneous symmetry breaking, gauge theories, the Higgs mechanism and all that (Bernstein, Reviews of Modern Physics Jan 1974) – an introduction of 47 pages covering the development, history and mathematics of Higgs theories from around 1950 to 1974.