The Quantum Chromodynamics Theory of Tetraquarks and Mesomesonic Particles Unfinished Draft Version
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Quantum Field Theory*
Quantum Field Theory y Frank Wilczek Institute for Advanced Study, School of Natural Science, Olden Lane, Princeton, NJ 08540 I discuss the general principles underlying quantum eld theory, and attempt to identify its most profound consequences. The deep est of these consequences result from the in nite number of degrees of freedom invoked to implement lo cality.Imention a few of its most striking successes, b oth achieved and prosp ective. Possible limitation s of quantum eld theory are viewed in the light of its history. I. SURVEY Quantum eld theory is the framework in which the regnant theories of the electroweak and strong interactions, which together form the Standard Mo del, are formulated. Quantum electro dynamics (QED), b esides providing a com- plete foundation for atomic physics and chemistry, has supp orted calculations of physical quantities with unparalleled precision. The exp erimentally measured value of the magnetic dip ole moment of the muon, 11 (g 2) = 233 184 600 (1680) 10 ; (1) exp: for example, should b e compared with the theoretical prediction 11 (g 2) = 233 183 478 (308) 10 : (2) theor: In quantum chromo dynamics (QCD) we cannot, for the forseeable future, aspire to to comparable accuracy.Yet QCD provides di erent, and at least equally impressive, evidence for the validity of the basic principles of quantum eld theory. Indeed, b ecause in QCD the interactions are stronger, QCD manifests a wider variety of phenomena characteristic of quantum eld theory. These include esp ecially running of the e ective coupling with distance or energy scale and the phenomenon of con nement. -
Book of Abstracts Ii Contents
2014 CAP Congress / Congrès de l’ACP 2014 Sunday, 15 June 2014 - Friday, 20 June 2014 Laurentian University / Université Laurentienne Book of Abstracts ii Contents An Analytic Mathematical Model to Explain the Spiral Structure and Rotation Curve of NGC 3198. .......................................... 1 Belle-II: searching for new physics in the heavy flavor sector ................ 1 The high cost of science disengagement of Canadian Youth: Reimagining Physics Teacher Education for 21st Century ................................. 1 What your advisor never told you: Education for the ’Real World’ ............. 2 Back to the Ionosphere 50 Years Later: the CASSIOPE Enhanced Polar Outflow Probe (e- POP) ............................................. 2 Changing students’ approach to learning physics in undergraduate gateway courses . 3 Possible Astrophysical Observables of Quantum Gravity Effects near Black Holes . 3 Supersymmetry after the LHC data .............................. 4 The unintentional irradiation of a live human fetus: assessing the likelihood of a radiation- induced abortion ...................................... 4 Using Conceptual Multiple Choice Questions ........................ 5 Search for Supersymmetry at ATLAS ............................. 5 **WITHDRAWN** Monte Carlo Field-Theoretic Simulations for Melts of Diblock Copoly- mer .............................................. 6 Surface tension effects in soft composites ........................... 6 Correlated electron physics in quantum materials ...................... 6 The -
Zero-Point Energy in Bag Models
Ooa/ea/oHsnif- ^*7 ( 4*0 0 1 5 4 3 - m . Zero-Point Energy in Bag Models by Kimball A. Milton* Department of Physics The Ohio State University Columbus, Ohio 43210 A b s t r a c t The zero-point (Casimir) energy of free vector (gluon) fields confined to a spherical cavity (bag) is computed. With a suitable renormalization the result for eight gluons is This result is substantially larger than that for a spher ical shell (where both interior and exterior modes are pre sent), and so affects Johnson's model of the QCD vacuum. It is also smaller than, and of opposite sign to the value used in bag model phenomenology, so it will have important implications there. * On leave ifrom Department of Physics, University of California, Los Angeles, CA 90024. I. Introduction Quantum chromodynamics (QCD) may we 1.1 be the appropriate theory of hadronic matter. However, the theory is not at all well understood. It may turn out that color confinement is roughly approximated by the phenomenologically suc cessful bag model [1,2]. In this model, the normal vacuum is a perfect color magnetic conductor, that iis, the color magnetic permeability n is infinite, while the vacuum.in the interior of the bag is characterized by n=l. This implies that the color electric and magnetic fields are confined to the interior of the bag, and that they satisfy the following boundary conditions on its surface S: n.&jg= 0, nxBlg= 0, (1) where n is normal to S. Now, even in an "empty" bag (i.e., one containing no quarks) there will be non-zero fields present because of quantum fluctua tions. -
18. Lattice Quantum Chromodynamics
18. Lattice QCD 1 18. Lattice Quantum Chromodynamics Updated September 2017 by S. Hashimoto (KEK), J. Laiho (Syracuse University) and S.R. Sharpe (University of Washington). Many physical processes considered in the Review of Particle Properties (RPP) involve hadrons. The properties of hadrons—which are composed of quarks and gluons—are governed primarily by Quantum Chromodynamics (QCD) (with small corrections from Quantum Electrodynamics [QED]). Theoretical calculations of these properties require non-perturbative methods, and Lattice Quantum Chromodynamics (LQCD) is a tool to carry out such calculations. It has been successfully applied to many properties of hadrons. Most important for the RPP are the calculation of electroweak form factors, which are needed to extract Cabbibo-Kobayashi-Maskawa (CKM) matrix elements when combined with the corresponding experimental measurements. LQCD has also been used to determine other fundamental parameters of the standard model, in particular the strong coupling constant and quark masses, as well as to predict hadronic contributions to the anomalous magnetic moment of the muon, gµ 2. − This review describes the theoretical foundations of LQCD and sketches the methods used to calculate the quantities relevant for the RPP. It also describes the various sources of error that must be controlled in a LQCD calculation. Results for hadronic quantities are given in the corresponding dedicated reviews. 18.1. Lattice regularization of QCD Gauge theories form the building blocks of the Standard Model. While the SU(2) and U(1) parts have weak couplings and can be studied accurately with perturbative methods, the SU(3) component—QCD—is only amenable to a perturbative treatment at high energies. -
Particle Physics Dr Victoria Martin, Spring Semester 2012 Lecture 12: Hadron Decays
Particle Physics Dr Victoria Martin, Spring Semester 2012 Lecture 12: Hadron Decays !Resonances !Heavy Meson and Baryons !Decays and Quantum numbers !CKM matrix 1 Announcements •No lecture on Friday. •Remaining lectures: •Tuesday 13 March •Friday 16 March •Tuesday 20 March •Friday 23 March •Tuesday 27 March •Friday 30 March •Tuesday 3 April •Remaining Tutorials: •Monday 26 March •Monday 2 April 2 From Friday: Mesons and Baryons Summary • Quarks are confined to colourless bound states, collectively known as hadrons: " mesons: quark and anti-quark. Bosons (s=0, 1) with a symmetric colour wavefunction. " baryons: three quarks. Fermions (s=1/2, 3/2) with antisymmetric colour wavefunction. " anti-baryons: three anti-quarks. • Lightest mesons & baryons described by isospin (I, I3), strangeness (S) and hypercharge Y " isospin I=! for u and d quarks; (isospin combined as for spin) " I3=+! (isospin up) for up quarks; I3="! (isospin down) for down quarks " S=+1 for strange quarks (additive quantum number) " hypercharge Y = S + B • Hadrons display SU(3) flavour symmetry between u d and s quarks. Used to predict the allowed meson and baryon states. • As baryons are fermions, the overall wavefunction must be anti-symmetric. The wavefunction is product of colour, flavour, spin and spatial parts: ! = "c "f "S "L an odd number of these must be anti-symmetric. • consequences: no uuu, ddd or sss baryons with total spin J=# (S=#, L=0) • Residual strong force interactions between colourless hadrons propagated by mesons. 3 Resonances • Hadrons which decay due to the strong force have very short lifetime # ~ 10"24 s • Evidence for the existence of these states are resonances in the experimental data Γ2/4 σ = σ • Shape is Breit-Wigner distribution: max (E M)2 + Γ2/4 14 41. -
Fully Strange Tetraquark Sss¯S¯ Spectrum and Possible Experimental Evidence
PHYSICAL REVIEW D 103, 016016 (2021) Fully strange tetraquark sss¯s¯ spectrum and possible experimental evidence † Feng-Xiao Liu ,1,2 Ming-Sheng Liu,1,2 Xian-Hui Zhong,1,2,* and Qiang Zhao3,4,2, 1Department of Physics, Hunan Normal University, and Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Changsha 410081, China 2Synergetic Innovation Center for Quantum Effects and Applications (SICQEA), Hunan Normal University, Changsha 410081, China 3Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China 4University of Chinese Academy of Sciences, Beijing 100049, China (Received 21 August 2020; accepted 5 January 2021; published 26 January 2021) In this work, we construct 36 tetraquark configurations for the 1S-, 1P-, and 2S-wave states, and make a prediction of the mass spectrum for the tetraquark sss¯s¯ system in the framework of a nonrelativistic potential quark model without the diquark-antidiquark approximation. The model parameters are well determined by our previous study of the strangeonium spectrum. We find that the resonances f0ð2200Þ and 2340 2218 2378 f2ð Þ may favor the assignments of ground states Tðsss¯s¯Þ0þþ ð Þ and Tðsss¯s¯Þ2þþ ð Þ, respectively, and the newly observed Xð2500Þ at BESIII may be a candidate of the lowest mass 1P-wave 0−þ state − 2481 0þþ 2440 Tðsss¯s¯Þ0 þ ð Þ. Signals for the other ground state Tðsss¯s¯Þ0þþ ð Þ may also have been observed in PC −− the ϕϕ invariant mass spectrum in J=ψ → γϕϕ at BESIII. The masses of the J ¼ 1 Tsss¯s¯ states are predicted to be in the range of ∼2.44–2.99 GeV, which indicates that the ϕð2170Þ resonance may not be a good candidate of the Tsss¯s¯ state. -
Pos(LATTICE2014)106 ∗ [email protected] Speaker
Flavored tetraquark spectroscopy PoS(LATTICE2014)106 Andrea L. Guerrieri∗ Dipartimento di Fisica and INFN, Università di Roma ’Tor Vergata’ Via della Ricerca Scientifica 1, I-00133 Roma, Italy E-mail: [email protected] Mauro Papinutto, Alessandro Pilloni, Antonio D. Polosa Dipartimento di Fisica and INFN, ’Sapienza’ Università di Roma P.le Aldo Moro 5, I-00185 Roma, Italy Nazario Tantalo CERN, PH-TH, Geneva, Switzerland and Dipartimento di Fisica and INFN, Università di Roma ’Tor Vergata’ Via della Ricerca Scientifica 1, I-00133 Roma, Italy The recent confirmation of the charged charmonium like resonance Z(4430) by the LHCb ex- periment strongly suggests the existence of QCD multi quark bound states. Some preliminary results about hypothetical flavored tetraquark mesons are reported. Such states are particularly amenable to Lattice QCD studies as their interpolating operators do not overlap with those of ordinary hidden-charm mesons. The 32nd International Symposium on Lattice Field Theory, 23-28 June, 2014 Columbia University New York, NY ∗Speaker. c Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. http://pos.sissa.it/ Flavored tetraquark spectroscopy Andrea L. Guerrieri 1. Introduction The recent confirmation of the charged resonant state Z(4430) by LHCb [1] strongly suggests the existence of genuine compact tetraquark mesons in the QCD spectrum. Among the many phenomenological models, it seems that only the diquark-antidiquark model in its type-II version can accomodate in a unified description the puzzling spectrum of the exotics [2]. Although diquark- antidiquark model has success in describing the observed exotic spectrum, it also predicts a number of unobserved exotic partners. -
Physics Letters B 816 (2021) 136227
Physics Letters B 816 (2021) 136227 Contents lists available at ScienceDirect Physics Letters B www.elsevier.com/locate/physletb Scalar isoscalar mesons and the scalar glueball from radiative J/ψ decays ∗ A.V. Sarantsev a,b, I. Denisenko c, U. Thoma a, E. Klempt a, a Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Germany b NRC “Kurchatov Institute”, PNPI, Gatchina 188300, Russia c Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow region, Russia a r t i c l e i n f o a b s t r a c t ¯ Article history: A coupled-channel analysis of BESIII data on radiative J/ψ decays into ππ, K K , ηη and ωφ has been Received 12 January 2021 performed. The partial-wave amplitude is constrained by a large number of further data. The analysis Received in revised form 16 March 2021 finds ten isoscalar scalar mesons. Their masses, widths and decay modes are determined. The scalar Accepted 16 March 2021 mesons are interpreted as mainly SU(3)-singlet and mainly octet states. Octet isoscalar scalar states Available online xxxx are observed with significant yields only in the 1500-2100 MeV mass region. Singlet scalar mesons are Editor: M. Doser produced over a wide mass range but their yield peaks in the same mass region. The peak is interpreted = ± +10 = ± +30 as scalar glueball. Its mass and width are determined to M 1865 25−30 MeV and 370 50−20 MeV, − its yield in radiative J/ψ decays to (5.8 ± 1.0) 10 3. © 2021 The Author(s). -
Quantum Mechanics Quantum Chromodynamics (QCD)
Quantum Mechanics_quantum chromodynamics (QCD) In theoretical physics, quantum chromodynamics (QCD) is a theory ofstrong interactions, a fundamental forcedescribing the interactions between quarksand gluons which make up hadrons such as the proton, neutron and pion. QCD is a type of Quantum field theory called a non- abelian gauge theory with symmetry group SU(3). The QCD analog of electric charge is a property called 'color'. Gluons are the force carrier of the theory, like photons are for the electromagnetic force in quantum electrodynamics. The theory is an important part of the Standard Model of Particle physics. A huge body of experimental evidence for QCD has been gathered over the years. QCD enjoys two peculiar properties: Confinement, which means that the force between quarks does not diminish as they are separated. Because of this, when you do split the quark the energy is enough to create another quark thus creating another quark pair; they are forever bound into hadrons such as theproton and the neutron or the pion and kaon. Although analytically unproven, confinement is widely believed to be true because it explains the consistent failure of free quark searches, and it is easy to demonstrate in lattice QCD. Asymptotic freedom, which means that in very high-energy reactions, quarks and gluons interact very weakly creating a quark–gluon plasma. This prediction of QCD was first discovered in the early 1970s by David Politzer and by Frank Wilczek and David Gross. For this work they were awarded the 2004 Nobel Prize in Physics. There is no known phase-transition line separating these two properties; confinement is dominant in low-energy scales but, as energy increases, asymptotic freedom becomes dominant. -
10 Progressing Beyond the Standard Models
i i “proc16” — 2016/12/12 — 10:17 — page 177 — #193 i i BLED WORKSHOPS Proceedings to the 19th Workshop IN PHYSICS What Comes Beyond ::: (p. 177) VOL. 17, NO. 2 Bled, Slovenia, July 11–19, 2016 10 Progressing Beyond the Standard Models B.A. Robson ? The Australian National University, Canberra, ACT 2601, Australia Abstract. The Standard Model of particle physics (SMPP) has enjoyed considerable success in describing a whole range of phenomena in particle physics. However, the model is con- sidered incomplete because it provides little understanding of other empirical observations such as the existence of three generations of leptons and quarks, which apart from mass have similar properties. This paper examines the basic assumptions upon which the SMPP is built and compares these with the assumptions of an alternative model, the Generation Model (GM). The GM provides agreement with the SMPP for those phenomena which the SMPP is able to describe, but it is shown that the assumptions inherent in the GM allow progress beyond the SMPP. In particular the GM leads to new paradigms for both mass and gravity. The new theory for gravity provides an understanding of both dark matter and dark energy, representing progress beyond the Standard Model of Cosmology (SMC). Povzetek. Standardni Model elektrosibkeˇ in barvne interakcije zelo uspesnoˇ opiseˇ veliko pojavov v fiziki osnovnih delcev. Model imajo kljub temu za nepopoln, ker ne pojasni vrste empiricnihˇ dejstev, kot je obstoj treh generacij leptonov in kvarkov, ki imajo, razen razlicnihˇ mas, zelo podobne lastnosti. V prispevku obravnavamo osnovne predpostavke, na katerih so zgradili ta model in jih primerjamo s predpostavkami alternativnega modela, generacijskega modela. -
New Physics of Strong Interaction and Dark Universe
universe Review New Physics of Strong Interaction and Dark Universe Vitaly Beylin 1 , Maxim Khlopov 1,2,3,* , Vladimir Kuksa 1 and Nikolay Volchanskiy 1,4 1 Institute of Physics, Southern Federal University, Stachki 194, 344090 Rostov on Don, Russia; [email protected] (V.B.); [email protected] (V.K.); [email protected] (N.V.) 2 CNRS, Astroparticule et Cosmologie, Université de Paris, F-75013 Paris, France 3 National Research Nuclear University “MEPHI” (Moscow State Engineering Physics Institute), 31 Kashirskoe Chaussee, 115409 Moscow, Russia 4 Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Russia * Correspondence: [email protected]; Tel.:+33-676380567 Received: 18 September 2020; Accepted: 21 October 2020; Published: 26 October 2020 Abstract: The history of dark universe physics can be traced from processes in the very early universe to the modern dominance of dark matter and energy. Here, we review the possible nontrivial role of strong interactions in cosmological effects of new physics. In the case of ordinary QCD interaction, the existence of new stable colored particles such as new stable quarks leads to new exotic forms of matter, some of which can be candidates for dark matter. New QCD-like strong interactions lead to new stable composite candidates bound by QCD-like confinement. We put special emphasis on the effects of interaction between new stable hadrons and ordinary matter, formation of anomalous forms of cosmic rays and exotic forms of matter, like stable fractionally charged particles. The possible correlation of these effects with high energy neutrino and cosmic ray signatures opens the way to study new physics of strong interactions by its indirect multi-messenger astrophysical probes. -
The Flavour Puzzle, Discreet Family Symmetries
The flavour puzzle, discreet family symmetries 27. 10. 2017 Marek Zrałek Particle Physics and Field Theory Department University of Silesia Outline 1. Some remarks about the history of the flavour problem. 2. Flavour in the Standard Model. 3. Current meaning of the flavour problem? 4. Discrete family symmetries for lepton. 4.1. Abelian symmetries, texture zeros. 4.2. Non-abelian symmetries in the Standard Model and beyond 5. Summary. 1. Some remarks about the history of the flavour problem The flavour problem (History began with the leptons) I.I. Rabi Who ordered that? Discovered by Anderson and Neddermayer, 1936 - Why there is such a duplication in nature? - Is the muon an excited state of the electron? - Great saga of the µ → e γ decay, (Hincks and Pontecorvo, 1948) − − - Muon decay µ → e ν ν , (Tiomno ,Wheeler (1949) and others) - Looking for muon – electron conversion process (Paris, Lagarrigue, Payrou, 1952) Neutrinos and charged leptons Electron neutrino e− 1956r ν e 1897r n p Muon neutrinos 1962r Tau neutrinos − 1936r ν µ µ 2000r n − ντ τ 1977r p n p (Later the same things happen for quark sector) Eightfold Way Murray Gell-Mann and Yuval Ne’eman (1964) Quark Model Murray Gell-Mann and George Zweig (1964) „Young man, if I could remember the names of these particles, I „Had I foreseen that, I would would have been a botanist”, have gone into botany”, Enrico Fermi to advise his student Leon Wofgang Pauli Lederman Flavour - property (quantum numbers) that distinguishes Six flavours of different members in the two groups, quarks and