DOCSLIB.ORG

Shanghai Plays Host to GIM Celebration

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Shanghai Plays Host to GIM Celebration CERNCOURIER.COM FIELD NOTES 50 YEARS OF THE GLASHOW–ILIOPOULOS–M aiani MECHaniSM Shanghai plays host to GIM celebration J Liu In 1969 many weak amplitudes could ical model of wea k interact ions.” be accurately calculated with a model To s id e s t e p t h i s pr o bl e m, G l a s h o w, I l i- of just three quarks, and Fermi’s con- o p o u l o s a n d M a i a n i br o u g ht i n t h e fo u r t h stant and the Cabibbo angle to couple “charm” quark, already introduced by t h e m. O n e e x c e p t i o n w a s t h e r e m a r k a bl e Bjorken, Glashow and others, with its suppression of strangeness-changing typical coupling to the quark combi- n e ut r a l c u r r e nt s. Jo h n I l io p o u lo s, Sh e l- nation left alone in the Cabibbo theory: don Lee Glashow and Luciano Maiani c ↔ sC = – s i n θC d + c o s θC s. A m pl it u d e s for boldly solved the mystery using loop s → d w it h u or c o n t h e s a m e fe r m i o n l i n e d i a g r a m s fe a t u r i n g t h e r e c e nt l y h y p o t h- would cancel exactly for mc = m u, sug- esised charm quark, making its exist- gesting a more natural means to suppress e n c e a s ol i d pr e d i c t i o n i n t h e pr o c e s s. To strangeness-changing neutral-cur- celebrate the 50th anniversary of their Happy anniversary Hong-Jian He, John Ellis, John Iliopoulos, rent processes to measured levels. For insight, the trio were guests of honour Sheldon Lee Glashow, Verónica Riquer and Luciano Maiani at a mc >> m u, a residual neutral-current effect at an international symposium at the celebration of 50 years of the GIM mechanism in Shanghai. w o u l d r e m a i n, w h i c h, b y i n s p e c t i o n, a n d T. D. L e e I n s t it ut e a t S h a n g h a i Ji a o To n g for dimensional reasons, is of order G 2 Universit y on 29 October 2019. sinθC cos θC (Gm c ). This was a real sur- The Glashow–Iliopoulos–Maiani cos θ, – sin θ prise: the “small” UV cutoff needed in (GIM) mechanism was conceived in d s the simple three-quark theory became an 1969, submitted to Physical Review D on W e s t i m a t e o f t h e m a s s o f t h e fo u r t h q u a r k, 5 M a r c h 1970, a n d p u bl i s h e d o n 1 O c t o b e r u, c u, c which was indeed sufficiently large to of that year, after several developments W have escaped detection in the unsuccess- had defined a conceptual framework ful searches for charmed mesons that had – for electroweak unification. These –s d been conducted in the 1960s. i n c lu d e d Ya n g–M i l l s t h e or y, t h e u n i v e r- sal V–A weak interaction, Schwinger’s sin θ, cos θ Embarrassment averted suggestion of electroweak unification, With the two quark doublets included, G l a s h o w’s d e fi n it io n o f t h e e l e c t r o w eak a detailed study of strangeness chang- group SU(2)L × U ( 1 ) Y, Cabibbo’s theory of ing neutral current processes gave mc semileptonic hadron decays and the ≈ 1.5 GeV, a value consistent with more u, c formulation of the leptonic electroweak recent data on the masses of charmed gauge theory by Weinberg and Salam, d s mesons and baryons. Another aspect with spontaneous symmetry breaking of the GIM cancellation is that the weak induced by the vacuum expectation value WW charged currents make an SU(2) algebra of new scalar fields. together with a neutral component that The GIM mechanism then called for a has no strangeness-changing terms. – fourth quark, charm, in addition to the –s d Thus, there is no difficulty in including t h r e e i nt r o d u c e d b y G e l l-M a n n, s u c h t h a t u, c t h e t w o q u a r k d o u bl e t s i n t h e u n i fie d e l ec- the first two blocks of the electroweak troweak group SU(2)L × U ( 1 ) Y of Glashow, 0 –0 theory are made each by one lepton and In the loop One-loop quark diagrams for K – K mixing in the We i n b e r g a n d S a l a m. T h e 1970 GI M p a p e r one quark doublet, [(νe, e), (u, d)] and light of the GIM mechanism. The charm–quark amplitudes have the noted that “In contradistinction to the [(νµ, µ), (c, s)]. Quarks u and c are cou- same magnitude but opposite sign as for up-quark lines, leading to conventional (three-quark) model, the pled by the weak interaction to two a perfect cancellation, cos θ sin θ + (–sin θ) cos θ = 0, in the case couplings of the neutral intermediary – super positions of the quarks d and s: where mc = mu, suggesting an explanation for the suppression of now hy p erc h a rge c on s er v i ng – c aus e no u ↔ d C, w it h d C t he Cabibbo combi nat ion processes with strangeness-changing neutral currents. embarrassment.” dC = cos θC d + sin θC s, a n d c ↔ sC, w it h s C the The GIM mechanism has become a 2 orthogonal combination. In subsequent amplitudes of order G sinθC cosθC (GΛ ), cornerstone of the Standard Model, y e a r s, a t h i r d g e n e r a t i o n, [(ντ, τ), (t, b)] w a s where G is the Fermi constant, Λ is an and gives a precise description of the predicted to describe CP violation. No fur- ultraviolet cutoff and GΛ2 (dimension- observed flavour-changing neutral-cur- ther generations have been observed yet. less) is the first term in a perturbative r e nt pr o c e s s e s for s a n d b q u a r k s. For t h i s expansion that could be continued to take reason, flavour-changing neutral cur- Charming prediction higher order diagrams into account. To rents are still an important benchmark The GIM mechanism was the solu- c o m pl y w it h t h e s t r ic t l i m it s e x i s t i n g a t and give strong constraints on theories tion to a problem arising in the sim- t h e t i m e, o n e h a d t o r e q u i r e a s u r pr i s i n g l y that go beyond the Standard Model in plest weak interaction theory with one small value of the cutoff,Λ , of 2–3 GeV, to t he TeV reg ion. charged vector boson coupled to the b e c o m p a r e d w it h t h e n a t u r a l l y e x p e c t e d C a bi b b o c u r r e nt s. A s p oi nt e d o ut i n 1968, value: Λ = G –1/2 ≈ 300 GeV. This problem Hong-Jian He T. D. Lee Institute, strangeness-changing neutral-current w a s t a k e n s e r i o u s l y b y t h e GI M a ut h or s, Shanghai Jiao Tong University and + – 0 –0 processes, such as K L → µ µ and K – K who wrote that “It appears necessary to Luciano Maiani T. D. Lee Institute and mixing, are generated at one loop with d e p a r t f r o m t h e or i g i n a l p h e n o m e n ol o g- Università di Roma. CERN COURIER MARCH/APRIL 2020 3.
Load more

Recommended publications
  • SHELDON LEE GLASHOW Lyman Laboratory of Physics Harvard University Cambridge, Mass., USA
    TOWARDS A UNIFIED THEORY - THREADS IN A TAPESTRY Nobel Lecture, 8 December, 1979 by SHELDON LEE GLASHOW Lyman Laboratory of Physics Harvard University Cambridge, Mass., USA INTRODUCTION In 1956, when I began doing theoretical physics, the study of elementary particles was like a patchwork quilt. Electrodynamics, weak interactions, and strong interactions were clearly separate disciplines, separately taught and separately studied. There was no coherent theory that described them all. Developments such as the observation of parity violation, the successes of quantum electrodynamics, the discovery of hadron resonances and the appearance of strangeness were well-defined parts of the picture, but they could not be easily fitted together. Things have changed. Today we have what has been called a “standard theory” of elementary particle physics in which strong, weak, and electro- magnetic interactions all arise from a local symmetry principle. It is, in a sense, a complete and apparently correct theory, offering a qualitative description of all particle phenomena and precise quantitative predictions in many instances. There is no experimental data that contradicts the theory. In principle, if not yet in practice, all experimental data can be expressed in terms of a small number of “fundamental” masses and cou- pling constants. The theory we now have is an integral work of art: the patchwork quilt has become a tapestry. Tapestries are made by many artisans working together. The contribu- tions of separate workers cannot be discerned in the completed work, and the loose and false threads have been covered over. So it is in our picture of particle physics. Part of the picture is the unification of weak and electromagnetic interactions and the prediction of neutral currents, now being celebrated by the award of the Nobel Prize.
    [Show full text]
  • Curriculum Vitae Del Prof. LUCIANO MAIANI
    Curriculum vitae del Prof. LUCIANO MAIANI Nato a Roma, il 16 Luglio 1941. Professore ordinario di Fisica Teorica, Università di Roma “La Sapienza” Curriculum Vitae 1964 Laurea in Fisica (110 e lode) presso l'Università di Roma. 1964 Ricercatore presso l’Istituto Superiore di Sanità. Nello stesso anno inizia la sua attività di fisico teorico collaborando con il gruppo dell'Università di Firenze guidato dal Prof. R.Gatto. 1969 Post-doctor per un semestre presso il Lyman Laboratory of Physics dell'Università di Harvard (USA). 1976/84 Professore Ordinario di Istituzioni di Fisica Teorica presso l'Università di Roma “La Sapienza” 1977 Professore visitatore presso l'Ecole Normale Superieure di Parigi. 1979/80 Professore visitatore, per un semestre, al CERN di Ginevra. 1984 Professore di Fisica Teorica presso l'Università di Roma “La Sapienza”. 1985/86 Professore visitatore per un anno al CERN di Ginevra. 1993/98 Presidente dell'Istituto Nazionale di Fisica Nucleare 1993/96 Delegato italiano presso il Council del CERN 1995/97 Presidente del Comitato Tecnico Scientifico, Fondo Ricerca Applicata, MURST 1998 Presidente del Council del CERN 1999/2003 Direttore Generale del CERN 2005 Socio Nazionale dell’Accademia Nazionale dei Lincei, Roma 2005-2008 Coordinatore Progetto HELEN-EuropeAid 2008 Presidente del Consiglio Nazionale delle Ricerche Laurea honoris causa Université de la Méditerranée, Aix-Marseille Università di San Pietroburgo Università di Bratislava Università di Varsavia Affiliazioni Accademia Nazionale dei Lincei, Socio Nazionale Fellow, American Physical Society Socio dell’Accademia Nazionale delle Scienze detta “dei XL” Socio dell’Accademia delle Scienze Russe Membro, Academia Europaea di Scienze ed Arti Premi 1980 Medaglia Matteucci, conferita dall'Accademia Nazionale dei XL.
    [Show full text]
  • PDF) Submittals Are Preferred) and Information Particle and Astroparticle Physics As Well As Accelerator Physics
    CERNNovember/December 2019 cerncourier.com COURIERReporting on international high-energy physics WELCOME CERN Courier – digital edition Welcome to the digital edition of the November/December 2019 issue of CERN Courier. The Extremely Large Telescope, adorning the cover of this issue, is due to EXTREMELY record first light in 2025 and will outperform existing telescopes by orders of magnitude. It is one of several large instruments to look forward to in the decade ahead, which will also see the start of high-luminosity LHC operations. LARGE TELESCOPE As the 2020s gets under way, the Courier will be reviewing the LHC’s 10-year physics programme so far, as well as charting progress in other domains. In the meantime, enjoy news of KATRIN’s first limit on the neutrino mass (p7), a summary of the recently published European strategy briefing book (p8), the genesis of a hadron-therapy centre in Southeast Europe (p9), and dispatches from the most interesting recent conferences (pp19—23). CLIC’s status and future (p41), the abstract world of gauge–gravity duality (p44), France’s particle-physics origins (p37) and CERN’s open days (p32) are other highlights from this last issue of the decade. Enjoy! To sign up to the new-issue alert, please visit: http://comms.iop.org/k/iop/cerncourier To subscribe to the magazine, please visit: https://cerncourier.com/p/about-cern-courier KATRIN weighs in on neutrinos Maldacena on the gauge–gravity dual FPGAs that speak your language EDITOR: MATTHEW CHALMERS, CERN DIGITAL EDITION CREATED BY IOP PUBLISHING CCNovDec19_Cover_v1.indd 1 29/10/2019 15:41 CERNCOURIER www.
    [Show full text]
  • Introduction to Flavour Physics
    Introduction to flavour physics Y. Grossman Cornell University, Ithaca, NY 14853, USA Abstract In this set of lectures we cover the very basics of flavour physics. The lec- tures are aimed to be an entry point to the subject of flavour physics. A lot of problems are provided in the hope of making the manuscript a self-study guide. 1 Welcome statement My plan for these lectures is to introduce you to the very basics of flavour physics. After the lectures I hope you will have enough knowledge and, more importantly, enough curiosity, and you will go on and learn more about the subject. These are lecture notes and are not meant to be a review. In the lectures, I try to talk about the basic ideas, hoping to give a clear picture of the physics. Thus many details are omitted, implicit assumptions are made, and no references are given. Yet details are important: after you go over the current lecture notes once or twice, I hope you will feel the need for more. Then it will be the time to turn to the many reviews [1–10] and books [11, 12] on the subject. I try to include many homework problems for the reader to solve, much more than what I gave in the actual lectures. If you would like to learn the material, I think that the problems provided are the way to start. They force you to fully understand the issues and apply your knowledge to new situations. The problems are given at the end of each section.
    [Show full text]
  • The Charm of Theoretical Physics (1958– 1993)?
    Eur. Phys. J. H 42, 611{661 (2017) DOI: 10.1140/epjh/e2017-80040-9 THE EUROPEAN PHYSICAL JOURNAL H Oral history interview The Charm of Theoretical Physics (1958{ 1993)? Luciano Maiani1 and Luisa Bonolis2,a 1 Dipartimento di Fisica and INFN, Piazzale A. Moro 5, 00185 Rome, Italy 2 Max Planck Institute for the History of Science, Boltzmannstraße 22, 14195 Berlin, Germany Received 10 July 2017 / Received in final form 7 August 2017 Published online 4 December 2017 c The Author(s) 2017. This article is published with open access at Springerlink.com Abstract. Personal recollections on theoretical particle physics in the years when the Standard Theory was formed. In the background, the remarkable development of Italian theoretical physics in the second part of the last century, with great personalities like Bruno Touschek, Raoul Gatto, Nicola Cabibbo and their schools. 1 Apprenticeship L. B. How did your interest in physics arise? You enrolled in the late 1950s, when the period of post-war reconstruction of physics in Europe was coming to an end, and Italy was entering into a phase of great expansion. Those were very exciting years. It was the beginning of the space era. L. M. The beginning of the space era certainly had a strong influence on many people, absolutely. The landing on the moon in 1969 was for sure unforgettable, but at that time I was already working in Physics and about to get married. My interest in physics started well before. The real beginning was around 1955. Most important for me was astronomy. It is not surprising that astronomy marked for many people the beginning of their interest in science.
    [Show full text]
  • Doing Electroweak Physics with Roberto
    IL NUOVO CIMENTO 40 C (2017) 153 DOI 10.1393/ncc/i2017-17153-y Colloquia: PRZ Memorial Doing electroweak physics with Roberto ∗ Luciano Maiani(1)(2)(3)( ) (1) INFN, Sezione di Roma - Roma, Italy (2) Dipartimento di Fisica, Universit`adiRoma-Roma,Italy (3) CERN - Gen`eve, Switzerland received 27 November 2017 Summary. — Friendship and Collaboration with Roberto, while the Standard Theory was unfolding under our eyes. At the end of the sixties, dual models dominated the scene as the theory of strong interactions. However, the years 1971-1973 brought decisive discoveries [1]. • 1971, ’t Hooft and Veltman showed that the Weinberg-Salam theory is renormalisable; • 1972, Bouchiat, Iliopoulos and Meyer proved the cancellation of Adler anomalies in the electroweak theory with four quarks. In a letter from John, there must be charm, quarks have color and are fractionally charged; • 1973 the discovery of neutral currents by Gargamelle at CERN; • ... and in the same year came the discovery of asymptotic freedom of the Yang-Mills theory by Gross and Wilczeck and Politzer. Shortly after, the idea of color interaction of quarks was put forward by Fritzsch, Gell-Mann and Leutwyler. In three years, the paradigm of particle interactions shifted completely towards field theory, a shining example of what Thomas Kuhn in 1962 had called a scientific revolution. In 1974, the discovery of the J/Ψ opened another chapter: heavy fermions, initiated with charm and later continued with the heavy lepton, beauty and top. The Standard Theory was taking form, everybody became electroweak & free, at least asymptotically. ∗ ( ) E-mail: [email protected] Creative Commons Attribution 4.0 License (http://creativecommons.org/licenses/by/4.0) 1 2 LUCIANO MAIANI 1.
    [Show full text]
  • Frsoolm^ LAPP-IH-09 November 1979
    fRSOOlM^ LAPP-IH-09 November 1979 NEW QUARKS AND LEPTONS *5 Mary K. Gaillard LAPP, Annecy-le-Vieux, France Luciano Maiani Univ. of Rone, Italy CONTENTS 1. Introduction: a glimpse of quark and lcpton history 2. Elementary properties of quarks and leptons 3. Weak interactions of b and t quarks 4. Grand unified theories 5. Conclusions and outlook ' Lectures given at the Cargeae Institute, July 1979. I. A. P. r. (HtviN ur nmfwE Boiri. rosrAtr iv> ?ion ANNTCY IE.VICL'X crorx rnirnoNl TABLE OF CONTENTS P»ge 1. Introduction: a glimpse of quark and lepton history 1 2. Elementary properties of quarks and leptons 1 2.1 What do He really know ? 1 2.2 Renormalizable gauge theories 11 2.3 The fermion mass matrix and the structure of the veak currents 18 3. Weak interactions of fa and t quarks 21 3.1 The veak mixing angles 21 3.2 Zounds on the veak mixing angles 23 3.3 Weak decays of b and t 29 3.4 Multilepton configurations in b and t decays 34 4. Grand unified theories 4.1 The unification of veak, electromagnetic and strong interactions 37 4.2 The minimal model: SD(5) 42 4.3 Feraion masses and constraints on the number of generations 45 4.4 Proton decay 49 4.5 Sounds on the t-quark mass 54 5. Conclusions and outlook t. IHTKOWJCTIQW; A CL IMPS E OT QUAME àM XMTtQK HISTOit nowadays M era eeeustaeved to think of partiel* intereeeioas 1B »m of alaeaotary eouplinfs of quarks and leptona.
    [Show full text]
  • Hydrogen Bond of QCD in Doubly Heavy Baryons and Tetraquarks
    PHYSICAL REVIEW D 100, 074002 (2019) Hydrogen bond of QCD in doubly heavy baryons and tetraquarks † ‡ Luciano Maiani ,1,2,* Antonio D. Polosa,2, and Veronica Riquer1,2, 1T. D. Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China 2Dipartimento di Fisica and INFN, Sapienza Universit`a di Roma, Piazzale Aldo Moro 2, I-00185 Roma, Italy (Received 8 August 2019; published 4 October 2019) In this paper we present in greater detail previous work on the Born-Oppenheimer approximation to treat the hydrogen bond of QCD, and add a similar treatment of doubly heavy baryons. Doubly heavy exotic resonances X and Z can be described as color molecules of two-quark lumps, the þ analogue of the H2 molecule, and doubly heavy baryons as the analog of the H2 ion, except that the two heavy quarks attract each other. We compare our results with constituent quark model and lattice QCD calculations and find further evidence in support of this upgraded picture of compact tetraquarks and baryons. DOI: 10.1103/PhysRevD.100.074002 I. INTRODUCTION Section II describes the Born-Oppenheimer approxima- Systems with heavy and light particles allow for an tion applied to a QCD double heavy hadron and gives the approximate treatment where the light and heavy degrees of two-body color couplings derived from the restriction that freedom are studied separately and solved one after the other. the hadron is an overall color singlet. Section III recalls the This is the Born-Oppenheimer approximation (BO), intro- salient features of the constituent quark model and gives duced in nonrelativistic quantum mechanics for molecules quark masses and hyperfine couplings derived from the S and crystals, where electrons coexist with the much heavier mass spectra of the -wave mesons and baryons.
    [Show full text]
  • Guido Altarelli and the Evolution of QCD
    IL NUOVO CIMENTO 39 C (2016) 355 DOI 10.1393/ncc/i2016-16355-1 Colloquia: La Thuile 2016 Guido Altarelli and the evolution of QCD R. Keith Ellis Institute for Particle Physics Phenomenology, Department of Physics, Durham University Durham DH1 3LE, UK received 26 July 2016 Summary. — I describe the contributions of Guido Altarelli to the development of Quantum Chromodynamics from the discovery of asymptotic freedom until the end of the Spp¯S collider era, 1973–1985. 1. – Introduction I have been asked to write an appreciation of Guido Altarelli’s role in the evolution of QCD. By evolution, I mean not only the evolution of the parton distributions, for which Guido is justly famous, but also the evolution in our ability to calculate with the QCD Lagrangian. In the Autumn of 1972 I arrived in Rome as a second-year graduate student, having been granted leave of absence from the University of Oxford where I was enrolled in the Theoretical Physics Department. My motivations for leaving Oxford were not entirely scientific, (see [1]), but Rome La Sapienza turned out to be a wonderful department, with an astonishing array of talent. As well as Guido Altarelli, there were Franco Buccella, Nicola Cabibbo, Raoul Gatto, Giorgio Parisi, Giuliano Preparata, and Massimo Testa and fellow students Roberto Petronzio and later Guido Martinelli. The nearby institutions hosted Sergio Ferrara, Etim Etim, Mario Greco, Luciano Maiani, Giulia Panchieri and Bruno Touschek. As always in Italy, the organisational details were a little fuzzy and real progress was only to be made by exploiting personal relationships.
    [Show full text]
  • The Puzzle of the Exotic Hadrons (XYZ) Luciano Maiani Roma Sapienza & INFN, Roma, Italy CERN, Geneva, Switzerland 1
    The puzzle of the Exotic Hadrons (XYZ) Luciano Maiani Roma Sapienza & INFN, Roma, Italy CERN, Geneva, Switzerland 1. New States • For long, we lived with the simplest paradigm: M. Gell-Mann, A Schematic Model of mesons = qq,¯ baryons = qqq Baryons and Mesons, PL 8, 214, 1964 • Paradigm rested on the absence of I=2, ππ resonances and of S>0 baryons. • The case had to be revisited, because the lowest lying, octet of scalar mesons- f0(980), a0(980), kappa(800) and sigma(600)- does not fit in the picture. • The X(3872), narrow width, with decays into J/Psi+ 2π/3π, discovered by Belle in 2003, does not fit into the “charmonium” states, • since then, Belle, BaBar, BES and LHcB have reported many other states that do not fit the charmonium picture, called X (1++) and Y(1--) states: molecules? hybrids? tetraquarks? • In 2007, Belle observed a charged “charmonium”, Z+(4430) → ψ(2S)+ π, that could not be interpreted as molecule, but later Babar suggested it was simply a reflection of K* states • LHCb has confirmed the Z+(4430) while other similar states, Z+(3900) and Z+(4020), have been discovered by BES III and confirmed by BELLE and by CLEOc. • Pentaquark discovered (P-> Ψ p) by LHCb in 2015 • New structures in Ψ φ spectrum in 2016…. more to follow? A new spectroscopy of mesons and baryons revealed Mainz, June 28, 2017 L. Maiani. Tetra&Pentaquarks 2 terminology of unanticipated charmonia • X, e.g. X(3872): neutral, typically seen in J/Psi+pions, positive parity, JPC=0++,1++, 2++ • Y, e.g.
    [Show full text]
  • Cerncourier Www
    CERN Courier June 2014 A Member of Viewpoint The Linde Group Latin America comes to CERN Luciano Maiani on forging with the arrival at CERN of the fi rst HELEN grant-holders from Latin America. Several new links between Europe and events were organized by HELEN in Argentina and in Mexico to transfer CERN the New World. technologies in accelerator physics and computing. For example, members of the CMS collaboration travelled to Brazil to help International collaboration in set up an LHC Computing Grid Tier-2 centre physics was born in Europe, for CMS at the Rio de Janeiro State University Our world is cool. after the Second World War, and in Sao Paulo. to explore subnuclear particle Prompted by the success of HELEN, in physics. An entirely new world, unveiled 2009 we proposed a new project that started in Linde Kryotechnik. by the interactions of cosmic rays in the February 2011 – the European Particle physics Earth’s atmosphere, could be studied only Latin-American NETwork (EPLANET), with particle accelerators so big that no Luciano Maiani. (Image credit: CNR.) funded by the EU in the Marie Curie Actions country in Europe could afford to build of the 7th Framework Programme. Supported them. The vision of distinguished European Brazil, which produced important physicists by EPLANET, professors and graduate scientists and statespersons led to CERN’s such as Roberto Salmeron, Alberto Santoro students can participate in the exciting Creating places colder than deep space, we are extending creation in 1954. and many others. On the theory side, Marcos research that began at the LHC in 2010, when the boundaries of knowledge to reveal a new generation In the 1980s a mutation took place as CERN Moshinski made signifi cant contributions the fi rst physics run started.
    [Show full text]
  • Tom Blake ! Warwick Week 2018
    An introduction to 3WCTMFlavour Physics @ ! Part 1 ! Tom Blake! ! Warwick Week 2018 1 An introduction to Flavour Physics • What’s covered in these lectures: 1. An introduction to flavour in the SM. ! ➡ A few concepts and a brief history of flavour physics. ! 2. CP violation (part 1) 3. CP violation (part 2). 4. Flavour changing neutral current processes. T. Blake 2 Questions for the LHC era? • What is the mechanism for EW symmetry breaking? ✓ We now know that this is the Higgs mechanism. • What “new physics” lies between the EW and Planck scale? x No idea! There is no evidence for new particles being directly produced at the TeV scale. • What is dark matter? x No idea! Dark matter could be heavy or it could be light. There is no evidence for large missing energy in BSM searches at CMS and ATLAS, which constrains EW scale dark matter, or in direct detection experiments. • Can we explain the matter antimatter asymmetry of the Universe? x No! The SM cannot explain the baryon asymmetry of the Universe. T. Blake 3 SM particle content { x3 colours T. Blake 4 Flavour in the SM • Particle physics can be described to excellent precision by a very simple theory: ! = (A , )+ (φ,A , ) LSM LGauge a i LHiggs a i with: ➡ Gauge terms that deals with the free fields and their interactions by the strong and electroweak interactions. ➡ Higgs terms that gives mass to the SM particles. T. Blake 5 Flavour in the SM • The Gauge part of the Lagrangian is experimentally very well verified, 1 = i ¯ ⇢⇢D F a F µ⌫,a .
    [Show full text]