DOCSLIB.ORG

Frontiers in Physics and Astrophysics Fermi Lecture 7 –Higgs Particle, Supersymmetry, Future

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Frontiers in Physics and Astrophysics Fermi Lecture 7 –Higgs Particle, Supersymmetry, Future Frontiers in Physics and Astrophysics Fermi Lecture 7 –Higgs Particle, Supersymmetry, Future Barry C Barish 12-December-2019 Fermi Lecture 7 1 Enrico Fermi Fermi Lecture 7 2 Enrico Fermi Lectures 2019-2020 Frontiers of Physics and Astrophysics • Explore frontiers of Physics and Astrophysics from an Experimental Viewpoint • Some History and Background for Each Frontier • Emphasis on Large Facilities and Major Recent Discoveries • Discuss Future Directions and Initiatives ---------------------------------------------------------------------- • Thursdays 4-6 pm • Oct 10,17,24,one week break, Nov 7 • Nov 28, Dec 5,12,19 Jan 9,16,23 • Feb 27, March 5,12,19 Fermi Lecture 7 3 Frontiers Fermi Lectures 2019-2020 - Barry C Barish • Course Title: Large Scale Facilities and the Frontiers of Physics • The Course will consist of 15 Lectures, which will be held from 16:00 to 18:00 in aula Amaldi, Marconi building, according to the following schedule: • 10 October 2019 - Introduction to Physics of the Universe 17 October 2019 - Elementary Particles 24 October 2019 - Quarks 7 November 2019 – Particle Accelerators 28 November 2019 – Big Discoveries and the Standard Model 5 December 2019 – Weak Force Carriers – Z, W: and Higgs Mechanism 12 December 2019 – Higgs Discovery, Supersymmetry?, Future?? 19 December 2019 – Introduction/History of Neutrinos 9 January 2020 – Neutrino(2) 16 January 2020 – Neutrinos(3) 23 January 2020 – Neutrinos (4) 27 February 2020 – Gravitational Waves (1) 5 March 2020 – Gravitational Waves (2) 12 March 2020 – Particle Astrophysics / Experimental Cosmology 19 March 2020 – Future Perspectives • All Lectures and the supporting teaching materials will be published by the Physics Department. Fermi Lecture 7 4 Frontiers 7 Constituents and Forces in the Standard Model Discovery, Features Fermi Lecture 6 5 Frontiers 7 Supersymmetry SPIN ½ SPIN 0 FERMIONS BOSONS u c t u c t d s d s Squarks Quarks b b e e e e Sleptons Leptons The Generations of Matter The Generations of Smatter Fermi Lecture 7 6 Frontiers 7 Future Collider Proposals Fermi Lecture 7 7 Frontiers 7 Next Set of Lectures: Neutrinos Next Set of Lectures NEUTRINOS Particle Physics Astrophysics Cosmology Fermi Lecture 6 8 Frontiers 7 The Higgs Mechanism 1964 Fermi Lecture 7 9 Frontiers 7 1964 Tom Kibble Gerry Guralnik Carl Hagen François Englert Robert Brout Peter Higgs Fermi Lecture 7 10 Frontiers 7 The Higgs Mechanism for ‘theorists.’ Spontaneous symmetry breaking: massless Nambu- Goldstone boson ‘eaten’`eaten’ by by massless massless gaugegauge bosonboson Accompanied by massive particle 11 Frontiers 7 1) If Higgs bosons produced, what will we see? Production Rates Decay Fraction gg ⟶ H ⟶ ZZ ⟶gllllg ⟶ H qq ⟶ qqH gg ⟶ H ⟶ gg • Highest production rate: gg ⟶ H • Easiest decays to see: ZZ and gg Fermi Lecture 7 12 Frontiers 7 2) What other processes can result in four charged leptons? One main background: qq ⟶ ZZ ⟶ llll Plus a small background from “fake” leptons: qq ⟶ Zqq ⟶ ll“ll” Fermi Lecture 7 13 Frontiers 7 3) Differentiate signal from background. For the background, the two Z bosons have basically random momenta. In both cases. the detected leptons came from the Z decay For the signal, the Z bosons come from the decay of the Higgs boson. Fermi Lecture 7 14 15 Frontiers 7 Experimentally searching for the Higgs • The ambitious U.S. initiative - The Superconducting Super Collider (SSC) • The cost was ~ $10B and had a highest energy of 20 TeV to pursue the Higgs Boson and new physics “beyond” the Standard Model. • Killed by newly elected Congress in 1993. Fermi Lecture 7 16 Frontiers 7 Experimentally searching for the Higgs • Fortunately, there was already a large tunnel at CERN (though considerably smaller than SSC). • The 27 km ring is filled with superconducting magnets cooled to just above absolute zero. • Large Hadron Collider (LHC) costs about $10B over 20 years. Note: Hadrons are particles containing quarks. • ATLAS and CMS projects involve over 3,000 physicists Fermi Lecture 7 17 The Large Hadron Collider LHC is located at CERN The LHC collides protons CERN is located near Geneva Center of Mass E=14 TeV ~7X Fermilab Part of CERN is in France Very high luminosity ~100X Fermilab Goal: discover Higgs+SUSY+??? Fermi Lecture 7 18 Frontiers 7 CERN Large Hadron Collider – Aerial View Fermi Lecture 7 19 Frontiers 7 The CERN Large Hadron Collider Fermi Lecture 7 20 The Large Hadron Collider Above Ground Below Ground Fermi Lecture 7 21 The Large Hadron Collider Magnetic field at 7 TeV: 8.33 Tesla Operating temperature: 1.9 K Number of magnets: ~9300 Number of main dipoles: 1232 Number of quadrupoles: ~858 Number of correcting magnets: ~6208 Number of RF cavities: 8 per beam; Field strength at top energy ≈ 5.5 MV/m Power consumption: ~120 MW Fermi Lecture 7 22 How Do We Get 7 TeV Protons? ~7 TeV final beam energy LINAC→PSB→PS→SPS→LHC ~450 GeV ~25 GeV ~1011 protons/beam ~2 GeV ~1 GeV 23 24 The Energy has been increased toThe 13-14 GeV Fermi Lecture 7 25 Fermi Lecture 7 26 Fermi Lecture 7 27 LHC Detectors Fermi Lecture 7 28 Frontiers 7 The Atlas and CMS Detectors at LHC Fermi Lecture 7 29 Frontiers 7 30 Frontiers 7 Fermi Lecture 7 31 Frontiers 7 Fermi Lecture 7 32 Frontiers 7 Fermi Lecture 7 33 Fermi Lecture 7 34 Fermi Lecture 7 35 36 Frontiers 7 LHC – Tunnel and Superconducting Magnets Fermi Lecture 7 37 Frontiers 7 Movie of a collision Fermi Lecture 7 38 Frontiers 7 H → gg Fermi Lecture 7 39 Frontiers 7 Same event, different angle Fermi Lecture 7 40 Frontiers 7 H → ZZ → Fermi Lecture 7 41 Frontiers 7 H → ZZ → eeee Fermi Lecture 7 42 Fermi Lecture 7 43 Fermi Lecture 7 44 Frontiers 7 H → gg ATLAS V 10000 e Selected diphoton sample G 2 Data 2011+2012 8000 / Sig+Bkg Fit (m =126.8 GeV) H s t Bkg (4th order polynomial) n e 6000 v ATLAS Preliminary E H®gg 4000 s = 7 TeV, Ldt = 4.8 fb-1 2000 ò s = 8 TeV, òLdt = 20.7 fb-1 g 500 k 400 b d 300 e t 200 t i F 100 - CMS 0 s t -100 n e -200 v 100 110 120 130 140 150 160 E 45 mgg [GeV] Fermi Lecture 7 46 Fermi Lecture 7 47 Fermi Lecture 7 48 Frontiers 7 Higgs boson summary • Two different experiments (ATLAS and CMS) find a new particle with a mass of 125.6 GeV/c2. • This is a spin 0 boson, with properties consistent with the Standard Model Higgs boson. • The existence of this particle confirms the point of view that mass is an acquired property (through coupling to the Higgs field) and not an intrinsic property of particles. Fermi Lecture 7 49 Frontiers 7 Is it a Higgs Boson? • Is it a single fundamental particle? • Does it have zero intrinsic angular momentum (spin=0)? • Does it have even parity? • Is it electrically neutral? • Does it interact with fermions as predicted? • Probability is directly proportional the the fermion mass. • Does it interact with W and Z bosons as predicted? • Tied the relationship between EM and Weak forces. Fermi Lecture 7 50 Frontiers 7 Interaction Strengths • Studies from both the LHC (CERN) and Tevatron (Fermilab) • LHC collided protons with protons at energies of 7 – 8 TeV • Tevatron collided protons with anti-protons at an energy of 2 TeV • Analyses are like before, but for specific decays • Select events one would expect for a specific Higgs production and decay. • Discriminate that signal from the backgrounds. • Measure the signal rate. • Does it agree with theory? Fermi Lecture 7 51 Higgs Interaction Strengths Fermi Lecture 7 52 Frontiers 7 • Straight blue line gives the standard model predictions. • Range of predictions in models with extra dimensions -- yellow band, (at most 30% below the Standard Model • The red error bars indicate the level of precision attainable at the ILC for each particle 53 Frontiers 7 Testing Spin and Parity • After discriminating signal from background, find distributions that discriminated between different spin and parity hypotheses: SpinParity = 0+, 0-, or 2+ ? Fermi Lecture 7 54 Spin and Parity Results Fermi Lecture 7 55 Frontiers 7 Is it the ‘simple’ Higgs or multiple Higgs or?? • Investigate the properties of the Higgs boson in more detail (e.g. decay paths, coupling to other particles, etc). • Are there other Higgs-like particles? The Standard Model assumes a Higgs field with fourfold symmetry, but there are other models that include more Higgs terms. • Other interesting physics problems to study at the LHC. Physics beyond the Standard Model? Fermi Lecture 7 56 Frontiers 7 Summary • The Standard Model describes the fundamental particles and three of the four forces. • Matter is made from quarks and leptons, which come in three copies of increasing mass. • Ordinary matter is made from the lightest copies. • Forces are caused by exchanging force carrier particles. • The non-zero Higgs field gives mass to particles that interact with it. Fermi Lecture 7 57 Break Supersymmetry, etc Fermi Lecture 7 58 Frontiers 7 What about Super- symmetry? Fermi Lecture 7 59 Frontiers 7 Quote from Ed Witten in preface of Gordon Kane’s book “Supersymmetry” “Supersymmetry, if it holds in nature, is part of the quantum structure of space and time… Discovery of supersymmetry would be one of the real milestones in physics… Indeed, supersymmetry is one of the basic requirements of string theory… Discovery of supersymmetry would surely give string theory an enormous boost… The search for supersymmetry is one of the great dramas in present day physics.” Fermi Lecture 7 60 Frontiers 7 Supersymmetry • In Quantum Mechanics, there is a connection between Global transformations and conserved quantities:.
Load more

Recommended publications
  • Nobel Lectures™ 2001-2005
    World Scientific Connecting Great Minds 逾10 0 种 诺贝尔奖得主著作 及 诺贝尔奖相关图书 我们非常荣幸得以出版超过100种诺贝尔奖得主著作 以及诺贝尔奖相关图书。 我们自1980年代开始与诺贝尔奖得主合作出版高品质 畅销书。一些得主担任我们的编辑顾问、丛书编辑， 并于我们期刊发表综述文章与学术论文。 世界科技与帝国理工学院出版社还邀得其中多位作了公 开演讲。 Philip W Anderson Sir Derek H R Barton Aage Niels Bohr Subrahmanyan Chandrasekhar Murray Gell-Mann Georges Charpak Nicolaas Bloembergen Baruch S Blumberg Hans A Bethe Aaron J Ciechanover Claude Steven Chu Cohen-Tannoudji Leon N Cooper Pierre-Gilles de Gennes Niels K Jerne Richard Feynman Kenichi Fukui Lawrence R Klein Herbert Kroemer Vitaly L Ginzburg David Gross H Gobind Khorana Rita Levi-Montalcini Harry M Markowitz Karl Alex Müller Sir Nevill F Mott Ben Roy Mottelson 诺贝尔奖相关图书 THE PERIODIC TABLE AND A MISSED NOBEL PRIZES THAT CHANGED MEDICINE NOBEL PRIZE edited by Gilbert Thompson (Imperial College London) by Ulf Lagerkvist & edited by Erling Norrby (The Royal Swedish Academy of Sciences) This book brings together in one volume fifteen Nobel Prize- winning discoveries that have had the greatest impact upon medical science and the practice of medicine during the 20th “This is a fascinating account of how century and up to the present time. Its overall aim is to groundbreaking scientists think and enlighten, entertain and stimulate. work. This is the insider’s view of the process and demands made on the Contents: The Discovery of Insulin (Robert Tattersall) • The experts of the Nobel Foundation who Discovery of the Cure for Pernicious Anaemia, Vitamin B12 assess the originality and significance (A Victor Hoffbrand) • The Discovery of
    [Show full text]
  • Fermi Lecture 6 Weak Force Carriers W, Z and Origin of Mass: Higgs Particle
    Frontiers in Physics and Astrophysics Fermi Lecture 6 Weak Force carriers W, Z and Origin of Mass: Higgs Particle Barry C Barish 5-December-2019 Fermi Lecture 6 1 Enrico Fermi Fermi Lecture 6 2 Enrico Fermi Lectures 2019-2020 Frontiers of Physics and Astrophysics • Explore frontiers of Physics and Astrophysics from an Experimental Viewpoint • Some History and Background for Each Frontier • Emphasis on Large Facilities and Major Recent Discoveries • Discuss Future Directions and Initiatives ---------------------------------------------------------------------- • Thursdays 4-6 pm • Oct 10,17,24,one week break, Nov 7 • Nov 28, Dec 5,12,19 Jan 9,16,23 • Feb 27, March 5,12,19 Fermi Lecture 6 3 Frontiers Fermi Lectures 2019-2020 - Barry C Barish • Course Title: Large Scale Facilities and the Frontiers of Physics • The Course will consist of 15 Lectures, which will be held from 16:00 to 18:00 in aula Amaldi, Marconi building, according to the following schedule: • 10 October 2019 - Introduction to Physics of the Universe 17 October 2019 - Elementary Particles 24 October 2019 - Quarks 7 November 2019 – Particle Accelerators 28 November 2019 – Big Discoveries and the Standard Model 5 December 2019 – Weak Force Carriers – Z, W: and Higgs Mechanism 12 December 2019 – Higgs Discovery; Supersymmetry? Intro to Neutrinos 19 December 2019 – Neutrinos 9 January 2020 – Neutrino Oscillations and Future Perspectives (2) 16 January 2020 - Gravitational Waves (1) 23 January 2020 - Gravitational Waves (2) 27 February 2020 – Gravitational Waves – Future Perspectives 5 March 2020 – Dark Matter 12 March 2020 – Particle Astrophysics, Experimental Cosmology 19 March 2020 - The Future • All Lectures and the supporting teaching materials will be published by the Physics Department.
    [Show full text]
  • Highlights of Modern Physics and Astrophysics
    Highlights of Modern Physics and Astrophysics How to find the “Top Ten” in Physics & Astrophysics? - List of Nobel Laureates in Physics - Other prizes? Templeton prize, … - Top Citation Rankings of Publication Search Engines - Science News … - ... Nobel Laureates in Physics Year Names Achievement 2020 Sir Roger Penrose "for the discovery that black hole formation is a robust prediction of the general theory of relativity" Reinhard Genzel, Andrea Ghez "for the discovery of a supermassive compact object at the centre of our galaxy" 2019 James Peebles "for theoretical discoveries in physical cosmology" Michel Mayor, Didier Queloz "for the discovery of an exoplanet orbiting a solar-type star" 2018 Arthur Ashkin "for groundbreaking inventions in the field of laser physics", in particular "for the optical tweezers and their application to Gerard Mourou, Donna Strickland biological systems" "for groundbreaking inventions in the field of laser physics", in particular "for their method of generating high-intensity, ultra-short optical pulses" Nobel Laureates in Physics Year Names Achievement 2017 Rainer Weiss "for decisive contributions to the LIGO detector and the Kip Thorne, Barry Barish observation of gravitational waves" 2016 David J. Thouless, "for theoretical discoveries of topological phase transitions F. Duncan M. Haldane, and topological phases of matter" John M. Kosterlitz 2015 Takaaki Kajita, "for the discovery of neutrino oscillations, which shows that Arthur B. MsDonald neutrinos have mass" 2014 Isamu Akasaki, "for the invention of
    [Show full text]
  • Discovery of a New Particle
    Discovery of a New Particle! Experimental High-Energy Physics Group! McGill! Homer’s Physics 101! 2012.September.28! ! http://nonsensibleshoes.com http://twitter.com! 2! Leon Lederman Quotations! ! ! “god particle” nickname: because the particle ! “…is so central to the state of physics today, so crucial to our final understanding of the structure of matter, yet so elusive…”! 1993! http://wikipedia.org! A second reason: because “…the publisher wouldn’t let us call it the Goddamn Particle, though that might be a more appropriate title, given its villainous nature and the expense it is causing.”! 3! Reductionism Epitomised! Condensed-Matter! &" Low Energies! Atomic Physics! Nuclear" Physics! High-Energy" Particle Physics! 4! The (known) Fundamental Particles & Forces! Note: gravity is (temporarily) omitted! 5! What gives masses to fundamental particles such as quarks and electrons, and why are they so different? Important Distinction:! ! We already know how composite matter! (e.g., atoms, fish, pizza, planets, people)! gets most of its mass:! binding E = mc2! ! ! 6! ! So why should you care about the fundamental stuff?! ! ! Q: If your fundamental particles had no mass, what" would they be doing?! ! ! A: They’d all be zipping around at the speed of light.! !!- no fish! !!- no pizza! No us…! !!- no planets! ! 7! ! But the issue of masses of fundamental particles" really takes its origins from the time of Rutherford! Nuclear Physics! Radioactivity:! atoms transmute! Lord Rutherford" ! ! Particle Physics! Force is weak because W particle is massive!!
    [Show full text]
  • Edit Winter 2012/13
    Winter 2012|13 THE ALUMNI MAGAZINE + billet & general COUNCIL PAPERS prOfessor pETEr HIGGS on breakthroughs, the boson and the best of edinburgh TIDE Of INNOvation our energy experts embrace the ocean’s poWer ALSO INSIDE 300 years of chemistry, and counting | our iconic library unveiled | careers in the spotlight winter 2012|13 contents foreWord contents elcome to the winter 2012/13 issue of Edit. It’s 16 10 Walways interesting to hear your stories about how your time at Edinburgh helped you stand out from the crowd, and in this edition we take the opportunity to introduce you to just a few of your fellow trailblazing academics and alumni. Professor Peter Higgs, whose 1964 theory led 48 years later to the discovery of the Higgs boson, is now a name known worldwide – but many 04 08 of his passions remain close to home (p8). The unique marine testing facility due to open at King’s Buildings in 2013 (p14) is another Edinburgh breakthrough with a debt to the past. Inside, we also celebrate the many milestones of the School of Chemistry (p22), take you on 30 a tour of our revamped Main Library (p10), and highlight how our innovative online teaching programmes continue to break new ground for today’s students (p26). Whether you’re a recent graduate or studied at Edinburgh long ago, we’d love for you to share your stories and memories with us. With all best wishes for the holiday season. 08 the interview 04 update Professor Peter Higgs on Kirsty MacDonald breakthroughs, the boson 20 alumni profiles and the best of Edinburgh Director of Development
    [Show full text]
  • Topological Defects in Cosmology 1 1.1 Introduction
    Topological Defects in Cosmology 1 Alejandro Gangui Instituto de Astronom´ıay F´ısica del Espacio, Ciudad Universitaria, 1428 Buenos Aires, Argentina and Dept. de F´ısica, Universidad de Buenos Aires, Ciudad Universitaria – Pab. I, 1428 Buenos Aires, Argentina Abstract Topological defects are ubiquitous in condensed–matter physics but only hypothetical in the early universe. In spite of this, even an indirect evidence for one of these cosmic objects would revolu- tionize our vision of the cosmos. We give here an introduction to the subject of cosmic topological defects and their possible observable signatures. Beginning with a review of the basics of general defect formation and evolution, we then focus on mainly two topics in some detail: conducting strings and vorton formation, and some specific imprints in the cosmic microwave background radiation from simulated cosmic strings. arXiv:astro-ph/0110285v1 11 Oct 2001 1Lecture Notes for the First Bolivian School on Cosmology La Paz, 24–28 September, 2001 http://www.umsanet.edu.bo/fisica/cosmo2k1.html i ii Contents 1 Topological Defects in Cosmology 1 1.1 Introduction...................................... .. 1 1.1.1 Howdefectsform ................................. 2 1.1.2 Phase transitions and finite temperature field theory . ...... 4 1.1.3 TheKibblemechanism.............................. 5 1.1.4 Asurveyoftopologicaldefects. ... 6 1.1.5 Conditions for their existence: topological criteria . ...... 8 1.2 Defectsintheuniverse ............................... ... 9 1.2.1 Local and global monopoles and domain walls . 10 1.2.2 Aredefectsinflatedaway? . .. .. .. 11 1.2.3 Cosmicstrings .................................. 12 1.2.4 String loops and scaling . 14 1.2.5 Globaltextures .................................. 17 1.2.6 Evolution of global textures . 18 1.3 Currentsalongstrings ..............................
    [Show full text]
  • When Past Becomes Future: Physics in the 21St Century
    Towards a New Enlightenment? A Transcendent Decade When Past Becomes Future: Physics in the 21st Century José Manuel Sánchez Ron José Manuel Sánchez Ron holds a Bachelor’s degree in Physical Sciences from the Universidad Complutense de Madrid (1971) and a PhD in Physics from the University of London (1978). He is a senior Professor of the History of Science at the Universidad Autónoma de Madrid, where he was previously titular Professor of Theoretical Physics. He has been a member of the Real Academia Española since 2003 and a member of the International Academy of the History of Science in Paris since 2006. He is the author of over four hundred publications, of which forty-five are books, including El mundo des- pués de la revolución. La física de la segunda mitad del siglo XX (Pasado & José Manuel Sánchez Ron Presente, 2014) for which he received Spain’s National Literary Prize in the Universidad Autónoma de Essay category. In 2011 he received the Jovellanos International Essay Prize Madrid for La Nueva Ilustración: Ciencia, tecnología y humanidades en un mundo interdisciplinar (Ediciones Nobel, 2011), and, in 2016, the Julián Marías Prize for a scientific career in humanities from the Municipality of Madrid. Recommended book: El mundo después de la revolución. La física de la segunda mitad del siglo XX, José Manuel Sánchez Ron, Pasado & Presente, 2014. In recent years, although physics has not experienced the sort of revolutions that took place during the first quarter of the twentieth century, the seeds planted at that time are still bearing fruit and continue to engender new developments.
    [Show full text]
  • On the Higgs Boson (PDF)
    The Higgs Boson C.Jeynes, Guildford 30 th August 2012 There is today great excitement about the "observation" of the long-sought Higgs Boson re- ported (unofficially) on 4 th July 2012. In this essay I will try to describe first what a Higgs Boson is, with an Introduction to the events, then a very simple description of the appropriate physics that should be accessible to everybody ("Glossary"); then I will show why I think that Christians should be interested in it. I list references at the end. Introduction to the events A Higgs boson is a massive scalar excitation remaining after the excitations of the argument of the conden- sate wave function of the symmetry-breaking scalar multiplet have combined with some of the gauge fields to provide the longitudinal components of massive vector bosons. Peter Higgs, Comptes Rendus Physique , 2007 (op.cit .) The "Higgs boson" was predicted by Peter Higgs in 1964, but his was only one (important) contribution to the vigorous theoretical developments at the time. François Englert and Robert Brout actually had precedence over Higgs since they discussed the ‘Higgs mechanism’ in much greater generality than Higgs had done; their paper appeared in the same issue of Physics Re- view Letters but was received earlier and was based on earlier work, namely the tree approxi- mation to the vector field propagator in spontaneously broken gauge theories by Feynman dia- gram methods, whereas Higgs started from classical Lagrangian field theory. The same year Gerald Guralnik, Carl Hagen, and Tom Kibble also showed how a massive boson could be con- sistently expected from the field equations, in a paper which cited the other two.
    [Show full text]
  • Here, at Last! and and Peter W.Peter Higgs Speed of Light, Without to Ofspeed Light, Get Any Possibility Caught Atoms in Or Molecules
    THE NOBEL PRIZE IN PHYSICS 2013 POPULAR SCIENCE BACKGROUND Here, at last! François Englert and Peter W. Higgs are jointly awarded the Nobel Prize in Physics 2013 for the theory of how particles acquire mass. In 1964, they proposed the theory independently of each other (Englert together with his now deceased colleague Robert Brout). In 2012, their ideas were confrmed by the discovery of a so called Higgs particle at the CERN laboratory outside Geneva in Switzerland. The awarded mechanism is a central part of the Standard Model of particle physics that describes how the world is constructed. According to the Standard Model, everything, from fowers and people to stars and planets, consists of just a few building blocks: matter particles. These particles are governed by forces medi- ated by force particles that make sure everything works as it should. The entire Standard Model also rests on the existence of a special kind of particle: the Higgs particle. It is connected to an invisible feld that flls up all space. Even when our universe seems empty, this feld is there. Had it not been there, electrons and quarks would be mass- less just like photons, the light particles. And like photons they would, just as Einstein’s theory predicts, rush through space at the speed of light, without any possibility to get caught in atoms or molecules. Nothing of what we know, not even we, would exist. The Higgs particle, H, completes the Standard Model of particle physics that describes building blocks of the universe. Both François Englert and Peter Higgs were young scientists when they, in 1964, independently of each other put forward a theory that rescued the Stand- ard Model from collapse.
    [Show full text]
  • What Is a Higgs Boson?
    Fermi National Accelerator Laboratory August 2015 What is a Higgs boson? In 2012 at the Large Hadron Collider, scientists discovered the long-sought Higgs boson. Now the question is: Are there more types of Higgs bosons? The Higgs field provides mass to quarks and other elementary particles that are the building blocks of matter. The photon and the gluon do not interact with the Higgs field, and hence they have no mass. Whether the Higgs field is the origin of the mass of dark matter or the tiny mass of the three known types of neutrinos is not yet known. What is a Higgs field? What is a Higgs boson? When did scientists discover the Higgs boson? The Higgs field is a force field that acts like a giant vat of molasses Scientists searched for the Higgs boson for more than two decades, spread throughout the universe. Most of the known types of particles starting with the LEP experiments at CERN in the 1990s and the that travel through it stick to the molasses, which slows them down Tevatron experiments at Fermilab in the 2000s. Years’ worth of LEP and makes them heavier. The Higgs boson is a particle that helps and Tevatron data narrowed the search for the Higgs particle. Then, transmit the mass-giving Higgs field, similar to the way a particle of in 2012 at CERN’s Large Hadron Collider (LHC), two experiments, light, the photon, transmits the electromagnetic field. ATLAS and CMS, reported the observation of a Higgs-like particle. With further analysis the new particle was confirmed as the Higgs boson in 2013.
    [Show full text]
  • Ilc Newsline Special Issue: the Higgs
    ABOUT | ARCHIVE | SUBSCRIBE | CONTACT | LINEARCOLLIDER.ORG 5 JULY 2012 ILC NEWSLINE SPECIAL ISSUE: THE HIGGS The news was impossible to miss: LHC experiments ATLAS and CMS found a new particle in their data that could be the Higgs boson. Auditoriums were packed, excitement was high. The theorists who predicted the boson's existence received standing ovations. There was #Higgsteria on twitter – 4 July 2012 was Higgs day. Read CERN's press release or view the pictures and videos to relive the moment. But what does all this mean for the ILC? It's definitely good news. Find out how the ILC can help in the search and study in this special Higgs issue of ILC NewsLine. FEATURE The Higgs is Different Theoretical physicist and ILCSC chair Jonathan Bagger explains how by Jonathan Bagger The Higgs is Different, says Jonathan Bagger, a theoretical physicist and chair of the International Linear Collider Steering Committee ILCSC. It has no spin, it fills the vacuum, but most importantly, it opens the door to a new range of questions. Questions which a linear collider with its clean and controlled collisions could help answer. RESEARCH DIRECTOR'S REPORT DIRECTOR'S CORNER Encouraging news from The Higgs and the ILC CERN by Barry Barish by Sakue Yamada The announcements of the most recent results from the We in the ILC Research search for the Higgs boson Directorate are thrilled at the LHC bring into sharper with the announcement focus the new physics at the from CERN this week energy frontier and the that a Higgs-like particle potential role of the ILC.
    [Show full text]
  • In 1964, Peter Higgs Suggested the Existence of a New Field (Now Called the Higgs Field) to Explain Why Particles Have Mass
    Durham University THE HIGGS BOSON In 1964, Peter Higgs suggested the existence of a new field (now called the Higgs field) to explain why particles have mass. The Higgs mechanism explains mass by saying that the Universe is filled with the Higgs field. Interacting with the Higgs field gives the particles mass. The Higgs boson would be experimental evidence of the Higgs mechanism. The Higgs field doesn©t just interact with particles ± it also interacts with itself. This self-interaction is the Higgs boson. The analogy most often used is to think of the Higgs field as a room full of physicists. Suddenly, Einstein walks into the room and everyone gathers around him. This makes it very difficult for Einstein to walk through the room ± he (the particle) has acquired mass by interacting with the physicists (the Higgs field). least Although we haven©t yet directly detected a Higgs boson, there is a vast amount of likely indirect evidence that its mass is within the kinematic range to be seen at the LHC and ILC. In order to understand the origin of mass we need to measure its mass and couplings with high precision. The ILC will be able to make these precision measurements and to establish uniquely the Higgs mechanism. It will even be possible to verify whether it behaves like a Standard Model Higgs boson or whether it points to most new physics beyond the Standard Model, such as Supersymmetry. likely At the ILC, we will be able to make a decay-mode- independent observation of the properties of the Higgs boson to incredible precision.
    [Show full text]