The Nimrod Era
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SLAC-FUB- 1260 Baryon-Antibaryon Bootstrap Model of the Meson Spectrum G. Schierholz +> II. Institut Fiir Theoretische Physik
SLAC-FUB-1260 Baryon-Antibaryon Bootstrap Model of the Meson Spectrum G. Schierholz +> II. Institut fiir Theoretische Physik der Universitzt, Hamburg, Germany +) Present address:SIAC, P.O. Box 4349, Stanford, California 94305, USA. Abstract: In this work we present a baryon-antibaryon bootstrap model which, for the meson spectrum, we understand to be an alternative of the quark model. Starting from the baryon octets, the forces are constructed from the t-channel singulari- ties of the nearest meson multiplets and transformed into an SU(3) symmetric potential. At this stage we assume that the baryon and meson multiplets are degenerate. Any contributions from the u-channel are neglected for it is exotic and only contains the deuteron. The dynamical equation governing the bootstrap system is the relativistic analog of the Lippmann-Schwinger equation which is an integral equation in the baryon c.m. momentum. The potential is chosen to take account of relativistic effects. Inelastic contributions such as two-meson intermediate states are neglected. Reasons why they must be small are discussed. We are looking for a self-consistent solution of the bootstrap system in which baryon-antibaryon bound state multiplets, to be interpreted as mesons, are forced to coincide with the input meson multiplets. Furthermore, the output coupling constants and F/D ratios have, to a certain extent, to agree with their input values. Practically, it is required that the bootstrap system consists of only a few multiplets, the remainder being decoupled approximately. A self-consistent solution is found comprising scalar, pseudoscalar and vector singlets and octets with masses being in good agreement with their average physical masses. -
Remembering Alvin Tollestrup: 1924-2020 – CERN Courier
3/26/2020 Remembering Alvin Tollestrup: 1924-2020 – CERN Courier PEOPLE | NEWS Remembering Alvin Tollestrup: 1924-2020 6 March 2020 Alvin Tollestrup, who passed away on 9 February at the age of 95, was a visionary. When I joined his group at Caltech in the summer of 1960, experiments in particle physics at universities were performed at accelerators located on campus. Alvin had helped build Caltech’s electron synchrotron, the highest energy photon-producing accelerator at the time. But he thought more exciting physics could be performed elsewhere, and managed to get approval to run an experiment at Berkeley Lab’s Bevatron to measure a rare decay mode of the K+ meson. This was the rst time an outsider was allowed to access Berkeley’s machine, much to the consternation of Luis Alvarez and other university faculty. When I joined Alvin’s group he asked a postdoc, Ricardo Gomez, and me to design, build and test https://cerncourier.com/a/remembering-alvin-tollestrup-1924-2020/ 1/5 3/26/2020 Remembering Alvin Tollestrup: 1924-2020 – CERN Courier Machine maestro – Alvin Tollestrup led the pioneering a new type of particle detector called a spark work of designing and testing the superconducting magnets for the Tevatron, the rst large-scale chamber. He gave us a paper by two Japanese application of superconductivity. Credit: Fermilab authors on “A new type of particle detector: the discharge chamber”, not what he wanted, but a place to start. In retrospect it was remarkable that Alvin was willing to risk the success of his experiment on the creation of new technology. -
ANTIMATTER a Review of Its Role in the Universe and Its Applications
A review of its role in the ANTIMATTER universe and its applications THE DISCOVERY OF NATURE’S SYMMETRIES ntimatter plays an intrinsic role in our Aunderstanding of the subatomic world THE UNIVERSE THROUGH THE LOOKING-GLASS C.D. Anderson, Anderson, Emilio VisualSegrè Archives C.D. The beginning of the 20th century or vice versa, it absorbed or emitted saw a cascade of brilliant insights into quanta of electromagnetic radiation the nature of matter and energy. The of definite energy, giving rise to a first was Max Planck’s realisation that characteristic spectrum of bright or energy (in the form of electromagnetic dark lines at specific wavelengths. radiation i.e. light) had discrete values The Austrian physicist, Erwin – it was quantised. The second was Schrödinger laid down a more precise that energy and mass were equivalent, mathematical formulation of this as described by Einstein’s special behaviour based on wave theory and theory of relativity and his iconic probability – quantum mechanics. The first image of a positron track found in cosmic rays equation, E = mc2, where c is the The Schrödinger wave equation could speed of light in a vacuum; the theory predict the spectrum of the simplest or positron; when an electron also predicted that objects behave atom, hydrogen, which consists of met a positron, they would annihilate somewhat differently when moving a single electron orbiting a positive according to Einstein’s equation, proton. However, the spectrum generating two gamma rays in the featured additional lines that were not process. The concept of antimatter explained. In 1928, the British physicist was born. -
Accelerator Disaster Scenarios, the Unabomber, and Scientific Risks
Accelerator Disaster Scenarios, the Unabomber, and Scientific Risks Joseph I. Kapusta∗ Abstract The possibility that experiments at high-energy accelerators could create new forms of matter that would ultimately destroy the Earth has been considered several times in the past quarter century. One consequence of the earliest of these disaster scenarios was that the authors of a 1993 article in Physics Today who reviewed the experi- ments that had been carried out at the Bevalac at Lawrence Berkeley Laboratory were placed on the FBI's Unabomber watch list. Later, concerns that experiments at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory might create mini black holes or nuggets of stable strange quark matter resulted in a flurry of articles in the popular press. I discuss this history, as well as Richard A. Pos- ner's provocative analysis and recommendations on how to deal with such scientific risks. I conclude that better communication between scientists and nonscientists would serve to assuage unreasonable fears and focus attention on truly serious potential threats to humankind. Key words: Wladek Swiatecki; Subal Das Gupta; Gary D. Westfall; Theodore J. Kaczynski; Frank Wilczek; John Marburger III; Richard A. Posner; Be- valac; Relativistic Heavy Ion Collider (RHIC); Large Hadron Collider (LHC); Lawrence Berkeley National Laboratory; Brookhaven National Laboratory; CERN; Unabomber; Federal Bureau of Investigation; nuclear physics; accel- erators; abnormal nuclear matter; density isomer; black hole; strange quark matter; scientific risks. arXiv:0804.4806v1 [physics.hist-ph] 30 Apr 2008 ∗Joseph I. Kapusta received his Ph.D. degree at the University of California at Berkeley in 1978 and has been on the faculty of the School of Physics and Astronomy at the University of Minnesota since 1982. -
Tachyons: May They Have a Role in Elementary Particle Physics?
Ae*/2*i? TACHYONS:UAY THEY HAVE A ROLE IN ELEMENTARY PARTICLE PHYSICS? ERASMO RCCAMI rALDYRJA.RDRIGiUESJrl . RELATOR» INTERNO N? 31* UNICAMP - ÍHtCC - *%— "\4& „ UNIVERSIDADE ESTADUAL PE CAMPINAS INSTITUTO 06 MATEMÁTICA, ESTATÍSTICA E CIÊNCIA DA COMPUTAÇÃO A piMicação deste relatório foi financiado com recursos do Convênio FTNEP - WSCC CAMPINAS . fAO PAULO BRASIL TACTON* MAY 1W% MU M ILIIflMTAKY IMIBJ*F.A. RELATÚMD ferrOtW) N» 3M AKTRACT: ThanulMj tohof^pcrtfctoHicttiiiliiiUMji ptjdtpJqBteQadhiqwOinMrtiMict)» miewtd aai ttcawd, najajy be cxajofthf, the tqHdt eoMftqwaasof the neonate itielMalfc neachanJcs of Ttchyoas. Ptfticajar attenüon it fÊ&ài $ ID tschyooa w tht posfble caiiim of Irtenrtinin ("hrtcrael Ifam*1); c.».. totht Bpfabtwwn "vktwl fMtkteTawl %f iihwEnl objacMü) toti» poeábitty of 'Nacnara dacay»" atthedeaticaJleid;(iB)toa£ar«Mft^^ nwaUiy partkk»("ekiDrfitiy tachyoBQaadtapoetiMi mraMcfinn with the dtiicttti wan paitirii i Nota: cat publkacio em A. Faesder and D. Wflkiami (Ed*.). Prope» in Particle and NuckofcPhysict, trai. 15. Pergamon PKM, Oxford, U JC. 0915). fJiiimiidaili Pifertwl i^f CitiTftrtf bKittitodcl^CMnitic«,E«Ut/«tkacCilticudjiCompiit»(to WECC-UNJCAMP CanaPoftal 61*6 13.100 - Campina», SP BRASIL O tontefrto do prcttiK* Relatório Interno Í it única ropcniabkidadt do aator. Junho-1915 - 379 - TACHTOBS: MM TIBET HAVE A ROLE IB BtEHESTAEY «ARTICLE KTSICS t * Brass» Recemi1»2 and Valdyr A. Rodrigues Jr.1 Depart. da Matem. Aplicada, üniv. Estadual de Campinas, Campinas, Sr, Brazil. Istituto di Física, üniversítã Statala di Catania, Catania, Italy. "should bt thoughts which ten tin* fastar glide than tha tun's beams Driving back shadows over low* ring hills" Shakespeare(1S97> ABSTRACT The possible role of space-like objects in eleacntary particle physics(and in quantum mechan ics) fs reviewed and discussed, vainly by exploiting the explicit consequences of the peculiar relativistic mechanics of Tachyons. -
Birth of the Hagedorn Temperature
CERN Courier December 2014 CERN Courier December 2014 Bookshelf Inside Story about CERN and its latest “biggest” appeal to anyone who has an interest discovery – the Higgs boson. According in understanding the broader world to the preface, this one sets out to tell the view of human endeavour that includes story from a different perspective, by religious faith and science. I hope that it putting at its centre the modern scientists inspires people to take a more open and who are exploring this terra incognita. wide-ranging view of human life. Faithful Birth of the Hagedorn temperature Interviews with a dozen scientists working to Science should be on the bookshelf of at CERN, ranging from the director-general, anyone who is interested to explore this Rolf Heuer, to physicists working on the more comprehensive human experience. experiments, form the main part of the ● Emmanuel Tsesmelis, CERN. The statistical bootstrap thermal physics – not unusual in the particle book. These interviews are interspersed and nuclear context in the early 1970s. He with explanatory texts, and there are also a Books received model and the discovery of remembered our discussions in Frankfurt number of factual chapters about the history a few years later, resuming my education at of physics and especially particle physics, What Makes a Champion! Over Fifty quark–gluon plasma. CERN as if we had never been interrupted. from Galileo to Einstein. Extraordinary Individuals Share Their Looking back to those long sessions in the Does the book achieve what it sets out to Insights winter of 1977/1978, I see a blackboard full do, namely to give basic research a human By Allan Snyder (ed.) of clean, exact equations – and his sign not to face? Yes and no. -
Sakata Model Precursor 2: Eightfold Way, Discovery of Ω- Quark Model: First Three Quarks A
Introduction to Elementary Particle Physics. Note 20 Page 1 of 17 THREE QUARKS: u, d, s Precursor 1: Sakata Model Precursor 2: Eightfold Way, Discovery of ΩΩΩ- Quark Model: first three quarks and three colors Search for free quarks Static evidence for quarks: baryon magnetic moments Early dynamic evidence: - πππN and pN cross sections - R= σσσee →→→ hadrons / σσσee →→→ µµµµµµ - Deep Inelastic Scattering (DIS) and partons - Jets Introduction to Elementary Particle Physics. Note 20 Page 2 of 17 Sakata Model 1956 Sakata extended the Fermi-Yang idea of treating pions as nucleon-antinucleon bound states, e.g. π+ = (p n) All mesons, baryons and their resonances are made of p, n, Λ and their antiparticles: Mesons (B=0): Note that there are three diagonal states, pp, nn, ΛΛ. p n Λ Therefore, there should be 3 independent states, three neutral mesons: π0 = ( pp - nn ) / √2 with isospin I=1 - - p ? π K X0 = ( pp + nn ) / √2 with isospin I=0 0 ΛΛ n π+ ? K0 Y = with isospin I=0 Or the last two can be mixed again… + 0 Λ K K ? (Actually, later discovered η and η' resonances could be interpreted as such mixtures.) Baryons (B=1): S=-1 Σ+ = ( Λ p n) Σ0 = ( Λ n n) mixed with ( Λ p p) what is the orthogonal mixture? Σ- = ( Λ n p) S=-2 Ξ- = ( Λ Λp) Ξ- = ( Λ Λn) S=-3 NOT possible Resonances (B=1): ∆++ = (p p n) ∆+ = (p n n) mixed with (p p p) what is the orthogonal mixture? ∆0 = (n n n) mixed with (n p p) what is the orthogonal mixture? ∆- = (n n p) Sakata Model was the first attempt to come up with some plausible internal structure that would allow systemizing the emerging zoo of hadrons. -
Phenomenological Review on Quark–Gluon Plasma: Concepts Vs
Review Phenomenological Review on Quark–Gluon Plasma: Concepts vs. Observations Roman Pasechnik 1,* and Michal Šumbera 2 1 Department of Astronomy and Theoretical Physics, Lund University, SE-223 62 Lund, Sweden 2 Nuclear Physics Institute ASCR 250 68 Rez/Prague,ˇ Czech Republic; [email protected] * Correspondence: [email protected] Abstract: In this review, we present an up-to-date phenomenological summary of research developments in the physics of the Quark–Gluon Plasma (QGP). A short historical perspective and theoretical motivation for this rapidly developing field of contemporary particle physics is provided. In addition, we introduce and discuss the role of the quantum chromodynamics (QCD) ground state, non-perturbative and lattice QCD results on the QGP properties, as well as the transport models used to make a connection between theory and experiment. The experimental part presents the selected results on bulk observables, hard and penetrating probes obtained in the ultra-relativistic heavy-ion experiments carried out at the Brookhaven National Laboratory Relativistic Heavy Ion Collider (BNL RHIC) and CERN Super Proton Synchrotron (SPS) and Large Hadron Collider (LHC) accelerators. We also give a brief overview of new developments related to the ongoing searches of the QCD critical point and to the collectivity in small (p + p and p + A) systems. Keywords: extreme states of matter; heavy ion collisions; QCD critical point; quark–gluon plasma; saturation phenomena; QCD vacuum PACS: 25.75.-q, 12.38.Mh, 25.75.Nq, 21.65.Qr 1. Introduction Quark–gluon plasma (QGP) is a new state of nuclear matter existing at extremely high temperatures and densities when composite states called hadrons (protons, neutrons, pions, etc.) lose their identity and dissolve into a soup of their constituents—quarks and gluons. -
10.8 News 612 Mh
NEWS NATURE|Vol 442|10 August 2006 Views collide over fate of accelerator Its parts have been dismembered, its roof is leaking, and a wall is missing. Now activists and scientists are squabbling over whether to com- pletely raze the Bevatron — one of the most important particle accelerators ever built. The remains of the Bevatron, which was decommissioned more than a decade ago, take up prime real estate on the Lawrence Berkeley LAB. NATL BERKELEY LAWRENCE National Laboratory’s campus in Berkeley, Cali- fornia. Scientists at the lab want to tear it down to make way for fresh projects. But locals, many of whom oppose the demolition because of con- cerns about the possible release of contaminants, say they want to see it made into a museum. On 3 August, the city council’s Landmarks and Preservation Commission dealt a blow to those wanting landmark status for the accelera- tor by voting to recognize the Bevatron’s legacy without protecting the building. Nevertheless, landmark advocates have vowed to continue fighting. “It’s truly a landmark, a very unique building,” says Mark Divided: physicists up. Community members have expressed fears McDonald, who sits on the hope to reclaim the that razing the Bevatron would involve moving City of Berkeley’s Peace and space but local groups large amounts of loose asbestos through the city Justice Commission. “Some- want landmark status of Berkeley. Environmentalists also fear that body called it the world’s for the Bevatron. lead and other contaminants from the build- largest yurt.” The Bevatron, ing site could escape into the water table. -
Spinorial Regge Trajectories and Hagedorn-Like Temperatures
EPJ Web of Conferences will be set by the publisher DOI: will be set by the publisher c Owned by the authors, published by EDP Sciences, 2016 Spinorial Regge trajectories and Hagedorn-like temperatures Spinorial space-time and preons as an alternative to strings Luis Gonzalez-Mestres1;a 1Megatrend Cosmology Laboratory, John Naisbitt University, Belgrade and Paris Goce Delceva 8, 11070 Novi Beograd, Serbia Abstract. The development of the statistical bootstrap model for hadrons, quarks and nuclear matter occurred during the 1960s and the 1970s in a period of exceptional theo- retical creativity. And if the transition from hadrons to quarks and gluons as fundamental particles was then operated, a transition from standard particles to preons and from the standard space-time to a spinorial one may now be necessary, including related pre-Big Bang scenarios. We present here a brief historical analysis of the scientific problematic of the 1960s in Particle Physics and of its evolution until the end of the 1970s, including cos- mological issues. Particular attention is devoted to the exceptional role of Rolf Hagedorn and to the progress of the statisticak boostrap model until the experimental search for the quark-gluon plasma started being considered. In parallel, we simultaneously expose recent results and ideas concerning Particle Physics and in Cosmology, an discuss current open questions. Assuming preons to be constituents of the physical vacuum and the stan- dard particles excitations of this vacuum (the superbradyon hypothesis we introduced in 1995), together with a spinorial space-time (SST), a new kind of Regge trajectories is expected to arise where the angular momentum spacing will be of 1/2 instead of 1. -
1 LAWRENCE RADIATION LABORATORY UNIVERSITY of CALIFORNIA BERKELEY
- UCRL-19821 To be published in Physics Today Prep r i nt UWRERE øiAftN tasouioiy UG 28 1973 1IflAfly AND 1 DOtJMENT5 QUARK OR BOOTSTRAP: TRIUMPH OR FRUSTRATION SECTION FOR HADRON PHYSICS? Geoffrey F. Chew May 18, 1970 AEC Contract No. W7405.eng.-48 TWO-WEEK LOAN COPY This is a Library Circulating Copy which may be borrowed for two weeks. For a personal retention copy, call Tech. Info. DIvIsion, Ext. 5545 LAWRENCE RADIATION LABORATORY '-0 00 UNIVERSITY of CALIFORNIA BERKELEY DISCLAIMER This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor the Regents of the University of California, nor any of their employees, makes any warranty, express or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or the Regents of the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof or the Regents of the University of California. UCRL-19821 -
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EPJ Web of Conferences 204, 06009 (2019) https://doi.org/10.1051/epjconf /201920406009 Baldin ISHEPP XXIV A look at hadronization via high multiplicity Elena Kokoulina1;2;∗, Andrey Kutov3;∗∗, Vladimir Nikitin1;∗∗∗, Vasilii Riadovikov4;∗∗∗∗, and Alexander Vorobiev4;y 1JINR, Joliot-Curie 6, Dubna, Moscow region, 141980, Russian Federation 2Sukhoi State Technical University of Gomel Prospect Octiabria, 48, 246746, Gomel, Republic of Belarus 3Institute of Physics and Mathematics Komi SC UrD RAS, Kommunisticheskaja st., 24, Syktyvkar, 167000, Russian Federation 4IHEP, Science sq. 1, Protvino, Moscow region, 142281, Russian Federation Abstract. Multiparticle production is studied experimentally and theoretically in QCD that describes interactions in the language of quarks and gluons. In the experiment the real hadrons are registered. Various phenomenological models are used for transfer from quarks and gluons to observed hadrons. In order to describe the high multiplicity region, we have developed a gluon dominance model (GDM). It represents a convolution of two stages. The first stage is de- scribed as a part of QCD. For the second one (hadronization), the phenomeno- logical model is used. To describe hadronization, a scheme has been proposed, consistent with the experimental data in the region of its dominance. Compar- ison of this model with data on e+e- annihilation over a wide energy interval (up to 200 GeV) has confirmed the fragmentation mechanism of hadronization, the development of the quark-gluon cascade with energy increase and domina- tion of bremsstrahlung gluons. The description of topological cross sections in pp collisions within GDM testifies that in hadron collisions the mechanism of hadronization is being replaced by the recombination one.