The Charm of Theoretical Physics (1958– 1993)?
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Searches for Electroweak Production of Supersymmetric Gauginos and Sleptons and R-Parity Violating and Long-Lived Signatures with the ATLAS Detector
Searches for electroweak production of supersymmetric gauginos and sleptons and R-parity violating and long-lived signatures with the ATLAS detector Ruo yu Shang University of Illinois at Urbana-Champaign (for the ATLAS collaboration) Supersymmetry (SUSY) • Standard model does not answer: What is dark matter? Why is the mass of Higgs not at Planck scale? • SUSY states the existence of the super partners whose spin differing by 1/2. • A solution to cancel the quantum corrections and restore the Higgs mass. • Also provides a potential candidate to dark matter with a stable WIMP! 2 Search for SUSY at LHC squark gluino 1. Gluino, stop, higgsino are the most important ones to the problem of Higgs mass. 2. Standard search for gluino/squark (top- right plots) usually includes • large jet multiplicity • missing energy ɆT carried away by lightest SUSY particle (LSP) • See next talk by Dr. Vakhtang TSISKARIDZE. 3. Dozens of analyses have extensively excluded gluino mass up to ~2 TeV. Still no sign of SUSY. 4. What are we missing? 3 This talk • Alternative searches to probe supersymmetry. 1. Search for electroweak SUSY 2. Search for R-parity violating SUSY. 3. Search for long-lived particles. 4 Search for electroweak SUSY Look for strong interaction 1. Perhaps gluino mass is beyond LHC energy scale. gluino ↓ 2. Let’s try to find gauginos! multi-jets 3. For electroweak productions we look for Look for electroweak interaction • leptons (e/μ/τ) from chargino/neutralino decay. EW gaugino • ɆT carried away by LSP. ↓ multi-leptons 5 https://cds.cern.ch/record/2267406 Neutralino/chargino via WZ decay 2� 3� 2� SR ɆT [GeV] • Models assume gauginos decay to W/Z + LSP. -
The Particle World
The Particle World ² What is our Universe made of? This talk: ² Where does it come from? ² particles as we understand them now ² Why does it behave the way it does? (the Standard Model) Particle physics tries to answer these ² prepare you for the exercise questions. Later: future of particle physics. JMF Southampton Masterclass 22–23 Mar 2004 1/26 Beginning of the 20th century: atoms have a nucleus and a surrounding cloud of electrons. The electrons are responsible for almost all behaviour of matter: ² emission of light ² electricity and magnetism ² electronics ² chemistry ² mechanical properties . technology. JMF Southampton Masterclass 22–23 Mar 2004 2/26 Nucleus at the centre of the atom: tiny Subsequently, particle physicists have yet contains almost all the mass of the discovered four more types of quark, two atom. Yet, it’s composite, made up of more pairs of heavier copies of the up protons and neutrons (or nucleons). and down: Open up a nucleon . it contains ² c or charm quark, charge +2=3 quarks. ² s or strange quark, charge ¡1=3 Normal matter can be understood with ² t or top quark, charge +2=3 just two types of quark. ² b or bottom quark, charge ¡1=3 ² + u or up quark, charge 2=3 Existed only in the early stages of the ² ¡ d or down quark, charge 1=3 universe and nowadays created in high energy physics experiments. JMF Southampton Masterclass 22–23 Mar 2004 3/26 But this is not all. The electron has a friend the electron-neutrino, ºe. Needed to ensure energy and momentum are conserved in ¯-decay: ¡ n ! p + e + º¯e Neutrino: no electric charge, (almost) no mass, hardly interacts at all. -
Setting Cold Fusion in Context: a Reply
Fifth International Conference on Cold Fusion 9-13 April, 1995 - Monte Carlo, Monaco ICCF5 ©1995 Setting Cold Fusion in context: a reply Giuliano Preparata Dipartimento di Fisica - Universitd di Milano INFN - Sezione di Milano Abstract This talk consists of three parts: the first on the "pathological" nature of Cold Fusion (CF) phenomena, the second on a wide theoretical effort based on the new ideas of QED coherence in matter, and the third replying to explicit criticisms to my work. The "pathological" Science of Cold Fusion Six years after the momentous announcement of March 23, 1989 the world of Science is still divided: a large majority that regards Cold Fusion (CF) an eminent example of "pathological" science, a small battered minority that still carries on with very limited means, both financial and, alas, intellectual, struggling for the survival of the grandiose dream that Fleischmann and Pons (FP) brought to mankind that now distant spring day of 1989. Why did it go this way? Why a phenomenologyl that has found so many diverse confirmations. by several different experimental groups, has failed to convince such a large number of scientists, that have turned their back on this fascinating field? I believe we must try to give an honest answer to these important ques tions, for if we fail to understand why so many of our colleagues perceive CF as a pathological form of science, we are doomed to remain marginal even if we will able, as in fact we are doing, to make substantial progress. It seems to me that the basic reason why CF is almost universally consid ered "pathological", is that it is so at odds with deeply rooted expectations based on the generally accepted picture of condensed matter and nuclear physics, that it requires the established scientist an almost heroic effort even IThroughout this talk I shall confine myself to the PdjD system pioneered by FP, i.e. -
Ninety Years of X-Ray Spectroscopy in Italy 1896-1986
Ninety years of X-ray spectroscopy in Italy 1896-1986 Vanda Bouché1,2, Antonio Bianconi1,3,4 1 Rome Int. Centre Materials Science Superstripes (RICMASS), Via dei Sabelli 119A, 00185Rome, Italy 2 Physics Dept., Sapienza University of Rome, P.le A. Moro 2, 00185 Rome, Italy 3 Institute of Crystallography of Consiglio Nazionale delle Ricerche, IC-CNR, Montero- tondo, Rome, Italy 4 National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoeshosse 31, 115409 Moscow, Russia Ninety years of X-ray spectroscopy research in Italy, from the X-rays dis- covery (1896), and the Fermi group theoretical research (1922-1938) to the Synchrotron Radiation research in Frascati from 1963 to 1986 are here summarized showing a coherent scientific evolution which has evolved into the actual multidisciplinary research on complex phases of condensed mat- ter with synchrotron radiation 1. The early years of X-ray research The physics community was very quick to develop an intense research in Italy on X rays, after the discovery on 5th January, 1896 by Röngten in Munich. Antonio Garbasso in Pisa [1], and then in Rome Alfonso Sella, with Quirino Majorana, Pietro Blaserna and Garbasso, published several papers on Nuovo Cimento [2], starting the Italian experimental school on X-rays research in XIX century [3]. The focus was on the mechanism of the emission by the X-ray tubes, the nature of X-rays (wave or particles), the propagation characteristics in the matter, the absorption and diffusion. Cambridge and Edinburgh at the beginning of the XX century became the world hot spots of X-ray spectroscopy with Charles Barkla who demonstrated the electromagnetic wave nature of X-ray propagation in the vacuum, similar with light and Henry Moseley, who studied the X-ray emission spectra, recorded the X-ray emission lines of most of the elements of the Mendeleev atomic table. -
Guido Altarelli (1941–2015)
Available online at www.sciencedirect.com ScienceDirect Nuclear Physics B 901 (2015) 249–251 www.elsevier.com/locate/nuclphysb Obituary Guido Altarelli (1941–2015) Guido Altarelli was one of a small group of physicists who shaped our current theory of the fundamental interactions: the so-called Standard Model. Guidos wa born in Rome in the midst of World War II, and in Rome he spent his early years. His hometown was very present in his words and memories, and he never lost contact with Rome during his scientific career: he never sold the apartment in which he grew up (he actually lived in it after the death of his parents), and after so many years spent abroad, he never lost his beautiful Roman accent — we always had the feeling that he did it on purpose. He graduated in 1964 at University of Roma La Sapienza, one out of an outstanding group of young physicists who later played an essential role in the foundation and development of modern fundamental physics. Right after graduation he followed Raoul Gatto in Florence, where this promising group of scientists grew up and became mature researchers. In the following years (1968–1970) he was in the United States, were the quantum field theory of the fundamental interactions was being developed at the time; at the Rockefeller University in 1969 he overlapped with another young physicist he had already met at La Sapienza, Giorgio Parisi. In 1970 he obtained a position at his Alma Mater, where he became a full professor in 1980. In that period he visited Ecole Normale Supérieure in Paris (1976–1977, when Giorgio Parisi was in Paris too, and again in 1981), and Boston University (1985–1986). -
Qcd in Heavy Quark Production and Decay
QCD IN HEAVY QUARK PRODUCTION AND DECAY Jim Wiss* University of Illinois Urbana, IL 61801 ABSTRACT I discuss how QCD is used to understand the physics of heavy quark production and decay dynamics. My discussion of production dynam- ics primarily concentrates on charm photoproduction data which is compared to perturbative QCD calculations which incorporate frag- mentation effects. We begin our discussion of heavy quark decay by reviewing data on charm and beauty lifetimes. Present data on fully leptonic and semileptonic charm decay is then reviewed. Mea- surements of the hadronic weak current form factors are compared to the nonperturbative QCD-based predictions of Lattice Gauge The- ories. We next discuss polarization phenomena present in charmed baryon decay. Heavy Quark Effective Theory predicts that the daugh- ter baryon will recoil from the charmed parent with nearly 100% left- handed polarization, which is in excellent agreement with present data. We conclude by discussing nonleptonic charm decay which are tradi- tionally analyzed in a factorization framework applicable to two-body and quasi-two-body nonleptonic decays. This discussion emphasizes the important role of final state interactions in influencing both the observed decay width of various two-body final states as well as mod- ifying the interference between Interfering resonance channels which contribute to specific multibody decays. "Supported by DOE Contract DE-FG0201ER40677. © 1996 by Jim Wiss. -251- 1 Introduction the direction of fixed-target experiments. Perhaps they serve as a sort of swan song since the future of fixed-target charm experiments in the United States is A vast amount of important data on heavy quark production and decay exists for very short. -
The Nobel Prize in Physics 1999
The Nobel Prize in Physics 1999 The last Nobel Prize of the Millenium in Physics has been awarded jointly to Professor Gerardus ’t Hooft of the University of Utrecht in Holland and his thesis advisor Professor Emeritus Martinus J.G. Veltman of Holland. According to the Academy’s citation, the Nobel Prize has been awarded for ’elucidating the quantum structure of electroweak interaction in Physics’. It further goes on to say that they have placed particle physics theory on a firmer mathematical foundation. In this short note, we will try to understand both these aspects of the award. The work for which they have been awarded the Nobel Prize was done in 1971. However, the precise predictions of properties of particles that were made possible as a result of their work, were tested to a very high degree of accuracy only in this last decade. To understand the full significance of this Nobel Prize, we will have to summarise briefly the developement of our current theoretical framework about the basic constituents of matter and the forces which hold them together. In fact the path can be partially traced in a chain of Nobel prizes starting from one in 1965 to S. Tomonaga, J. Schwinger and R. Feynman, to the one to S.L. Glashow, A. Salam and S. Weinberg in 1979, and then to C. Rubia and Simon van der Meer in 1984 ending with the current one. In the article on ‘Search for a final theory of matter’ in this issue, Prof. Ashoke Sen has described the ‘Standard Model (SM)’ of particle physics, wherein he has listed all the elementary particles according to the SM. -
After Dinner Speech by Dr
1 After Dinner Speech by Dr. Josef Rembser CERN, Geneva 14 September 2009 Celebration in honour of Professor Herwig Schopper’s 85 th Birthday I. Dear Friends, honourable, dear Professor Schopper! On 28 February of this year, you celebrated your 85th Birthday. This evening we are looking back on this memorable date, wishing you many happy returns of the day. You have been blessed with a life full of harmony and accomplishments, always keeping young physically and intellectually. This is a special blessing granted to a person: Love and family, friendships and encounters, giving and receiving, working and achieving acknowledgements and honours in a fulfilling profession and in challenging missions. Tomorrow, a scientific Colloquium will honour you as researcher and scientific teacher . Today, on the eve of the colloquium, I would like to speak about Herwig Schopper as a research politician and a research manager . My personal remarks and remembrances will focus, dear Herwig Schopper, on the guiding contributions you made in shaping, promoting and advancing science and research and their relevant policies in Germany and in Europe. 2 Professor Heuer, I am grateful for your invitation. It is a pleasure for me to give today's After-Dinner speech in honour of our jubilee. For many years during my service in the German Ministry of Research and Technology (BMFT) in Bonn I had close personal and professional connections with you, dear Professor Schopper, regarding German science and research policy including CERN. II. In 1945, with the end of the 2 nd World War, Germany as guilty party and loser plunged the world and its own country into destruction and suffering, thus experiencing a historical catastrophe. -
The Making of the Standard Theory
August 11, 2016 9:28 The Standard Theory of Particle Physics - 9.61in x 6.69in b2471-ch02 page 29 Chapter 2 The Making of the Standard Theory John Iliopoulos Laboratoire de Physique Th´eorique, Ecole´ Normale Sup´erieure, 24 rue Lhomond, 75005 Paris, France 1. Introduction The construction of the Standard Model, which became gradually the Standard Theory of elementary particle physics, is, probably, the most remarkable achieve- ment of modern theoretical physics. In this Chapter we shall deal mostly with the weak interactions. It may sound strange that a revolution in particle physics was initiated by the study of the weakest among them (the effects of the gravitational interactions are not measurable in high energy physics), but we shall see that the weak interactions triggered many such revolutions and we shall have the occasion to meditate on the fundamental significance of “tiny” effects. We shall outline the various steps, from the early days of the Fermi theory to the recent experimental discoveries, which confirmed all the fundamental predictions of the Theory. We shall follow a phenomenological approach, in which the introduction of every new concept is motivated by the search of a consistent theory which agrees with experiment. As we shall explain, this is only part of the story, the other part being the requirement of mathematical consistency. Both went in parallel and the real history requires the understanding of both. In fact, as we intend to show, the initial motivation was not really phenomenological. It is one of these rare cases in which a revolution in physics came from theorists trying to go beyond a simple phenomenological model, The Standard Theory of Particle Physics Downloaded from www.worldscientific.com not from an experimental result which forced them to do so. -
Lisbon Conference
Lisbon Conference Braganca Gil, President of the Portuguese Physical Society, addresses the Lisbon conference. (Photo A. Amor) Although no major physics discover of experiments is emerging to test erators and storage rings. ies were announced, the European the predictions of these broader the Another pointer to the future ca me Physical Society's International ories. Some experimentalists are on the first day of the conference, Conference on High Energy Physics, turning away from their traditional when CERN Director General Her- held in Lisbon from 9-15 July, was haunts at high energy accelerators wig Schopper, in a talk on the future significant in that it showed the to mount new 'passive' experiments development of European particle emerging pattern of physics for the deep underground to search for new physics, indicated the initial success 1980s. phenomena. Theoreticians are striv of tests with antiprotons in the SPS With the electroweak theory ade ing to use the new insights on the (see page 2&9). He proudly empha quately explaining almost all of lep- structure of matter to aid cosmolo- sized that this remarkable achieve tonic physics and with quantum gists in their bid to reconstruct the ment had been accomplished just chromodynamics (QCD) emerging early history of the universe. Gravity three years, almost to the day, since as the theory of inter-quark forces, too is being fed into the new unifica the antiproton project had been for physicists are confidently looking to tion schemes. mally approved at CERN. broaden their horizons. -
Structure of Matter
STRUCTURE OF MATTER Discoveries and Mysteries Part 2 Rolf Landua CERN Particles Fields Electromagnetic Weak Strong 1895 - e Brownian Radio- 190 Photon motion activity 1 1905 0 Atom 191 Special relativity 0 Nucleus Quantum mechanics 192 p+ Wave / particle 0 Fermions / Bosons 193 Spin + n Fermi Beta- e Yukawa Antimatter Decay 0 π 194 μ - exchange 0 π 195 P, C, CP τ- QED violation p- 0 Particle zoo 196 νe W bosons Higgs 2 0 u d s EW unification νμ 197 GUT QCD c Colour 1975 0 τ- STANDARD MODEL SUSY 198 b ντ Superstrings g 0 W Z 199 3 generations 0 t 2000 ν mass 201 0 WEAK INTERACTION p n Electron (“Beta”) Z Z+1 Henri Becquerel (1900): Beta-radiation = electrons Two-body reaction? But electron energy/momentum is continuous: two-body two-body momentum energy W. Pauli (1930) postulate: - there is a third particle involved + + - neutral - very small or zero mass p n e 휈 - “Neutrino” (Fermi) FERMI THEORY (1934) p n Point-like interaction e 휈 Enrico Fermi W = Overlap of the four wave functions x Universal constant G -5 2 G ~ 10 / M p = “Fermi constant” FERMI: PREDICTION ABOUT NEUTRINO INTERACTIONS p n E = 1 MeV: σ = 10-43 cm2 휈 e (Range: 1020 cm ~ 100 l.yr) time Reines, Cowan (1956): Neutrino ‘beam’ from reactor Reactions prove existence of neutrinos and then ….. THE PREDICTION FAILED !! σ ‘Unitarity limit’ > 100 % probability E2 ~ 300 GeV GLASGOW REFORMULATES FERMI THEORY (1958) p n S. Glashow W(eak) boson Very short range interaction e 휈 If mass of W boson ~ 100 GeV : theory o.k. -
Asia Pacific Physics Newsletter
Asia Pacific Physics Newsletter March 2016 Volume 5 • Number 1 worldscinet.com/appn Takaaki Kajita 2015 Physics Nobel Laureate published by Institute of Advanced Studies, Nanyang Technological University (IAS@NTU) and South East Asia Theoretical Physics Association (SEATPA) South East Asia Theoretical Physics Association Asia Pacific Physics Newsletter March 2016 • Volume 5 • Number 1 A publication of the IAS@NTU Singapore and SEATPA Asia Pacific Physics Newsletter publishes articles reporting frontier discoveries in EDITORIAL physics, research highlights, and news to facilitate interaction, collaboration and 3 cooperation among physicists in Asia Pacific physics community. PEOPLE Editor-in-Chief 4 “Observing the Distant Supernova” — Interview with Kok Khoo Phua Nobel Laureate Prof Brian Schmidt Associate Editor-in-Chief “Discovering the W and Z Bosons” — Interview with Swee Cheng Lim Nobel Laureate Prof Carlo Rubbia SEATPA Committee Christopher C Bernido Phil Chan Leong Chuan Kwek Choy Heng Lai Swee Cheng Lim Ren Bao Liu Hwee Boon Low Anh Ký Nguyên Choo Hiap Oh OPINION AND COMMENTARY Kok Khoo Phua 10 China’s Great Scientific Leap Forward: Completion of a Roh Suan Tung Preecha Yupapin planned ‘Great Collider’ would transform particle physics Hishamuddin Zainuddin Freddy Zen Editorial Team NEWS Sen Mu 12 CityU’s Institute for Advanced Study will Champion Bold New Han Sun Chi Xiong Research Initiatives Case made for 'Ninth Planet' Graphic Designers Chuan Ming Loo Erin Ong Cover Photo: "Takaaki Kajita 5171- 2015" by Bengt Nyman - Own work.