String Phenomenology 1 Minimal Supersymmetric Standard Model
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Color Breaking in the Quantum Leaped Stop Decay
Color breaking in the quantum leaped stop decay Imre Czövek [email protected] Abstract. The superfield propagator contains a measurable quantum leap, which comes from the definition of SUSY. In the sfermion -> Goldstino + fermion vertex change: 1. the spin of sparticle with discrete 1/2, 2. the Grassman superspace with the Goldstino shift operator. 3. the spacetime as the result of extra dimensional leap. The leap nature of SUSY transformations appears in the squark decay, it is the analog definition of SUSY. The quantum leaped outgoing propagators are determined and break locally the energy and the charge. Like to the teleportation the entangled pairs are here the b quark and the Goldstino. The dominant stop production is from gluons. The stop-antistop pair decay to quantum leaped b (c or t) quark, and the decay break the color. I get for the (color breaking) quantum leap: 10^-18 m. 10^-11 m color breaking would be needed for a color breaking chain reaction. The open question is: Are the colliders producing supersymmetry charge? Because some charges in QGP can make long color breaking and a chain reaction. A long color broken QGP state in the re-Big Bang theory could explain the near infinite energy and the near infinite mass of the universe: - at first was random color QGP in the flat space-time, - at twice the color restoration in the curved space-time, which eats the Goldstinos, - and finally the baryon genesis. The re Big Bang make a supernova like collapse and a flat explosion of Universe. This explanation of SUSY hides the Goldstone fermion in the extra dimensions, the Goldstino propagate only in superspace and it is a not observable dark matter. -
String Phenomenology
Introduction Model Building Moduli Stabilisation Flavour Problem String Phenomenology Joseph Conlon (Oxford University) EPS HEP Conference, Krakow July 17, 2009 Joseph Conlon (Oxford University) String Phenomenology Introduction Model Building Moduli Stabilisation Flavour Problem Chalk and Cheese? Figure: String theory and phenomenology? Joseph Conlon (Oxford University) String Phenomenology Introduction Model Building Moduli Stabilisation Flavour Problem String Theory ◮ String theory is where one is led by studying quantised relativistic strings. ◮ It encompasses lots of areas ( black holes, quantum field theory, quantum gravity, mathematics, particle physics....) and is studied by lots of different people. ◮ This talk is on string phenomenology - the part of string theory that aims at connecting to the Standard Model and its extensions. ◮ It aims to provide a (brief) overview of this area. (cf Angel Uranga’s plenary talk) Joseph Conlon (Oxford University) String Phenomenology Introduction Model Building Moduli Stabilisation Flavour Problem String Theory ◮ For technical reasons string theory is consistent in ten dimensions. ◮ Six dimensions must be compactified. ◮ Ten = (Four) + (Six) ◮ Spacetime = (M4) + Calabi-Yau Space ◮ All scales, matter, particle spectra and couplings come from the geometry of the extra dimensions. ◮ All scales, matter, particle spectra and couplings come from the geometry of the extra dimensions. Joseph Conlon (Oxford University) String Phenomenology Introduction Model Building Moduli Stabilisation Flavour Problem Model Building Various approaches in string theory to realising Standard Model-like spectra: ◮ E8 E8 heterotic string with gauge bundles × ◮ Type I string with gauge bundles ◮ IIA/IIB D-brane constructions ◮ Heterotic M-Theory ◮ M-Theory on G2 manifolds Joseph Conlon (Oxford University) String Phenomenology Introduction Model Building Moduli Stabilisation Flavour Problem Heterotic String Start with an E8 vis E8 hid gauge group in ten dimensions. -
Color Screening in Quantum Chromodynamics Arxiv
Color Screening in Quantum Chromodynamics Alexei Bazavov, Johannes H. Weber Department of Computational Mathematics, Science and Engineering and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA October 6, 2020 Abstract We review lattice studies of the color screening in the quark-gluon plasma. We put the phenomena related to the color screening into the context of similar aspects of other physical systems (electromag- netic plasma or cold nuclear matter). We discuss the onset of the color screening and its signature and significance in the QCD transi- tion region, and elucidate at which temperature and to which extent the weak-coupling picture based on hard thermal loop expansion, po- tential nonrelativistic QCD, or dimensionally-reduced QCD quantita- tively captures the key properties of the color screening. We discuss the different regimes pertaining to the color screening and thermal arXiv:2010.01873v1 [hep-lat] 5 Oct 2020 dissociation of the static quarks in depth for various spatial correla- tion functions that are studied on the lattice, and clarify the status of their asymptotic screening masses. We finally discuss the screening correlation functions of dynamical mesons with a wide range of flavor and spin content, and how they conform with expectations for low- and high-temperature behavior. 1 Contents 1 Introduction3 2 Field theoretical foundations7 2.1 Partition function and Lagrangian . .7 2.2 Finite temperature field theory . 11 2.3 Lattice regularization . 14 2.4 Renormalization and weak coupling . 17 2.5 Light quarks . 19 2.6 Heavy quarks . 21 2.7 Implementation of QCD on the lattice . -
Arxiv:1711.04534V4 [Hep-Ph]
UCI-HEP-TR-2017-15 Millicharged Scalar Fields, Massive Photons and the Breaking of SU(3)C U(1)EM × Jennifer Rittenhouse West∗ Department of Physics and Astronomy, University of California, Irvine, CA 92697, USA and SLAC National Accelerator Laboratory, Stanford University, Stanford, California 94309, USA (Dated: April 10, 2019) Under the assumption that the current epoch of the Universe is not special, i.e. is not the final state of a long history of processes in particle physics, the cosmological fate of SU(3)C × U(1)EM is investigated. Spontaneous symmetry breaking of U(1)EM at the temperature of the Universe today is carried out. The charged scalar field φEM which breaks the symmetry is found to be ruled out for the charge of the electron, q = e. − Scalar fields with millicharges are viable and limits on their masses and charges are found to be q . 10 3e and −5 mφEM . 10 eV. Furthermore, it is possible that U(1)EM has already been broken at temperatures higher −18 than T = 2.7K given the nonzero limits on the mass of the photon. A photon mass of mγ = 10 eV, the ∼ −13 current upper limit, is found to require a spontaneous symmetry breaking scalar mass of mφEM 10 eV with charge q = 10−6e, well within the allowed parameter space of the model. Finally, the cosmological fate of the strong interaction is studied. SU(3)C is tested for complementarity in which the confinement phase of QCD + colored scalars is equivalent to a spontaneously broken SU(3) gauge theory. -
A Study of Mesons and Glueballs
A Study of Mesons and Glueballs Tapashi Das Department of Physics Gauhati University This thesis is submitted to Gauhati University as requirement for the degree of Doctor of Philosophy Faculty of Science July 2017 Scanned by CamScanner Scanned by CamScanner Scanned by CamScanner Scanned by CamScanner Abstract The main work of the thesis is devoted to the study of heavy flavored mesons using a QCD potential model. Chapter 1 deals with the brief introduction of the theory of Quantum Chro- modynamics (QCD), potential models and the use of perturbation theory. In Chapter 2, the improved potential model is introduced and the solution of the non-relativistic Schro¨dinger’s equation for a Coulomb-plus-linear potential, V(r) = 4αs + br + c, Cornell potential has − 3r been conducted. The first-order wave functions are obtained using Dalgarno’s method. We explicitly consider two quantum mechanical aspects in our improved model: (a) the scale factor ‘c’ in the potential should not affect the wave function of the system even while applying the perturbation theory and (b) the choice of perturbative piece of the Hamiltonian (confinement or linear) should determine the effective radial separation between the quarks and antiquarks. Therefore for the validation of the quantum mechanical idea, the constant factor ‘c’ is considered to be zero and a cut-off rP is obtained from the theory. The model is then tested to calculate the masses, form factors, charge radii, RMS radii of mesons. In Chapter 3, the Isgur-Wise function and its derivatives of semileptonic decays of heavy-light mesons in both HQET limit (m ∞) and finite mass limit are calculated. -
Luminosity Determination and Searches for Supersymmetric Sleptons and Gauginos at the ATLAS Experiment Anders Floderus
Luminosity determination and searches for supersymmetric sleptons and gauginos at the ATLAS experiment Thesis submitted for the degree of Doctor of Philosophy by Anders Floderus CERN-THESIS-2014-241 30/01/2015 DEPARTMENT OF PHYSICS LUND, 2014 Abstract This thesis documents my work in the luminosity and supersymmetry groups of the ATLAS experiment at the Large Hadron Collider. The theory of supersymmetry and the concept of luminosity are introduced. The ATLAS experiment is described with special focus on a luminosity monitor called LUCID. A data- driven luminosity calibration method is presented and evaluated using the LUCID detector. This method allows the luminosity measurement to be calibrated for arbitrary inputs. A study of particle counting using LUCID is then presented. The charge deposited by particles passing through the detector is shown to be directly proportional to the luminosity. Finally, a search for sleptons and gauginos in final states −1 with exactly two oppositely charged leptons is presented. The search is based onp 20.3 fb of pp collision data recorded with the ATLAS detector in 2012 at a center-of-mass energy of s = 8 TeV. No significant excess over the Standard Model expectation is observed. Instead, limits are set on the slepton and gaugino masses. ii Populärvetenskaplig sammanfattning Partikelfysiken är studien av naturens minsta beståndsdelar — De så kallade elementarpartiklarna. All materia i universum består av elementarpartiklar. Den teori som beskriver vilka partiklar som finns och hur de uppför sig heter Standardmodellen. Teorin har historiskt sett varit mycket framgångsrik. Den har gång på gång förutspått existensen av nya partiklar innan de kunnat påvisas experimentellt, och klarar av att beskriva många experimentella resultat med imponerande precision. -
Aspects of String Phenomenology
Aspects of string phenomenology I. Antoniadis CERN New Perspectives in String Theory: opening conference Galileo Galilei Institute, Florence, 6-8 April 2009 1 main questions and list of possibilities 2 phenomenology of low string scale 3 general issues of high string scale 4 string GUTs 5 framework of magnetized branes I. Antoniadis (CERN) 1 / 27 Are there low energy string predictions testable at LHC ? What can we hope from LHC on string phenomenology ? I. Antoniadis (CERN) 2 / 27 Very different answers depending mainly on the value of the string scale Ms - arbitrary parameter : Planck mass MP TeV −→ - physical motivations => favored energy regions: ∗ 18 MP 10 GeV Heterotic scale High : ≃ 16 ( MGUT 10 GeV Unification scale ≃ 11 2 Intermediate : around 10 GeV (M /MP TeV) s ∼ SUSY breaking, strong CP axion, see-saw scale Low : TeV (hierarchy problem) I. Antoniadis (CERN) 3 / 27 Low string scale =>experimentally testable framework - spectacular model independent predictions perturbative type I string setup - radical change of high energy physics at the TeV scale explicit model building is not necessary at this moment but unification has to be probably dropped particle accelerators - TeV extra dimensions => KK resonances of SM gauge bosons - Extra large submm dimensions => missing energy: gravity radiation - string physics and possible strong gravity effects : string Regge excitations · production of micro-black holes ? [9] · microgravity experiments - change of Newton’s law, new forces at short distances I. Antoniadis (CERN) 4 / 27 Universal -
Lecture Course: Introduction to String Phenomenology
Lecture Course: Introduction to String Phenomenology WS 2014/15 • Lecturer: Prof. Jan Louis II. Institut f¨ur Theoretische Physik der Universit¨at Hamburg Luruper Chaussee 149, 22761 Hamburg Office: Campus Bahrenfeld, Bldg. 2a, Rm 601 Phone: 8998-2261 E-mail: [email protected] home page: www.desy.de/∼jlouis/ • Date and Place: Fr, 11:00 – 12:30, SR 2/2a, Bldg. 2a, Campus Bahrenfeld supplementary classes are offered biweekly: Mon, 11:00 – 12:30, SR 2/2a, Bldg. 2a, Campus Bahrenfeld • Credit Points: Please contact me at the beginning if you need Credit Points for this course. • Recomended Textbooks [1 ] K. Becker, M. Becker and J. Schwarz, String Theory and M-Theory, Cam- bridge University Press, 2007. [2 ] R. Blumenhagen, D. L¨ust, S. Theisen, Basic Concepts of String Theory, Springer, 2013 [3 ] M. Dine, Supersymmetry and String Theory, Cambridge University Press, 2007. [4 ] D. Freedman and A. Van Proeyen, Supergravity, Cambridge University Press, 2012. [5 ] M. Green, J. Schwarz and E. Witten, Superstring Theory, Vol I& II, Cam- bridge University Press, 1987. [6 ] L. Ibanez and A. Uranga, String Theory and Particle Physics, Cambridge University Press, 2012. [7 ] J. Polchinski, String Theory, Vol I& II, Cambridge University Press, 1998. • Course syllabus (Fr, 11:00 – 12:30): 16.10: Introduction to string theory 24.10: The low energy effective action of string theory 31.10: Calabi-Yau compactifications 07.11: Calabi-Yau compactifications of the heterotic string 14.11: Supersymmtry breaking and gaugino condensation 21.11: D-branes in type II Calabi-Yau -
Standard Model (SM)
International School on Theory & Analysis in Particle Physics The Standard Model (SM) Main textbook: Modern Elementary Particle Physics, Kane Additional reading: SM: An Introduction, Novaes, arXiv:hep-ph/0001283 Symmetries of SM, Willenbrock, arXiv:hep-ph/0410370 Other advanced undergraduate / beginning graduate level textbooks: Quantum Field Theory, Ryder Introduction to Elementary Particles, Griffiths Quarks & Leptons, Halzen & Martin An Introduction to the SM of P.P., Cottingham & Greenwood Gauge Theories in Particle Physics, Aitchison & Hey Nefer Şenoğuz / Doğuş University Outline Lecture 1 Review: groups, spinors, gauge invariance The Standard Model: introduction and particle content Lecture 2 QCD: Quarks, confinement, mesons and baryons Electroweak Theory: Neutral and charged currents Lecture 3 Spontaneous symmetry breaking and Higgs mechanism Cross sections and decay widths: W and Z Lecture 4 Higgs Boson Quark mixing and CP violation Open questions, grand unification 2 What is the Standard Model (SM) of Particle Physics? • SM is the theory describing electromagnetic, weak & strong interactions • ~40 years old, spectacularly confirmed (except Higgs) • beyond the SM: neutrino masses, theoretical puzzles • whatever LHC finds, SM is valid as an effective theory for E < TeV • SM is a gauge theory based on review: groups, gauge invariance • matter content: quarks and leptons review: Dirac spinors 3 review: groups Rotation group O(n): [Orthogonal], n(n-1)/2 parameters SO(n): [Special] determinant = 1 Generators of rotation: SO(3): 3 parameter -
String Phenomenology and Model Building Gary Shiu
String Phenomenology and Model Building \New Trends in High Energy Physics and QCD" School and Workshop Natal, Brazil, October 2014 Gary Shiu Department of Physics, University of Wisconsin, Madison, WI 53706, USA 1 Abstract This is a set of 3 lectures (50 minutes each) prepared for the Natal School 2014. The aim of these lectures is to introduce the basic ideas of string theory and their applications to particle physics. These lectures hopefully serve to complement the lectures by Eduardo Ponton (BSM and Extra Dimensions), Marc Besanon (Phenomenology and experimental aspects of SUSY and searches for extra dimensions at the LHC), Dmitry Melnikov (Holography and Hadron Physics), and Jorge Noronha (AdS/CFT and applications to particle physics). These lectures are an update of my lectures at the TASI 2008 Summer School and the Trieste 2010 Spring School { both serve as useful references for this course. 2 1 Introduction This is the first of 3 lectures on \String Phenomenology and Model Building". My plan for these lectures is roughly as follows: Lecture I: String Phenomenology, with Branes • Lecture II: D-brane Model Building • Lecture III: Randall-Sundrum Scenario in String Theory: Warped Throats & their Field Theory • Duals Basic Theme: The basic theme of these lectures is to introduce some modern string theory tools useful for building models and scenarios of particle physics beyond the Standard Model. Of course, particle physics is not all what string phenomenology is about. String theory, being a quantum theory of gravity, is also a natural arena to address questions about early universe cosmology. However, string cosmology is a topic that warrants a set of lectures on its own. -
Arxiv:2010.07320V3 [Hep-Ph] 15 Jun 2021 Yecag Portal
Preprint typeset in JHEP style - HYPER VERSION UWThPh 2020-15 CCTP-2020-7 ITCP-IPP-2020/7 String (gravi)photons, “dark brane photons”, holography and the hypercharge portal P. Anastasopoulos1,∗ M. Bianchi2,† D. Consoli1,‡ E. Kiritsis3 1 Mathematical Physics Group, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria 2 Dipartimento di Fisica, Universit`adi Roma “Tor Vergata” & I.N.F.N. Sezione di Roma “Tor Vergata”, Via della Ricerca Scientifica, 00133 Roma, Italy 3 Crete Center for Theoretical Physics, Institute for Theoretical and Computational Physics, Department of Physics, University of Crete, 70013, Heraklion, Greece and Universite de Paris, CNRS, Astroparticule et Cosmologie, F-75006 Paris, France Abstract: The mixing of graviphotons and dark brane photons to the Standard Model hypercharge is analyzed in full generality, in weakly-coupled string theory. Both the direct mixing as well as effective terms that provide mixing after inclusion of arXiv:2010.07320v3 [hep-ph] 15 Jun 2021 SM corrections are estimated to lowest order. The results are compared with Effective Field Theory (EFT) couplings, originating in a hidden large-N theory coupled to the SM where the dark photons are composite. The string theory mixing terms are typically subleading compared with the generic EFT couplings. The case where the hidden theory is a holographic theory is also analyzed, providing also suppressed mixing terms to the SM hypercharge. Keywords: Emergent photon, dark photon, graviphoton, holography, mixing, hypercharge portal. ∗[email protected] †[email protected] ‡[email protected] Contents 1. Introduction 2 1.1 The field theory setup 5 1.2 Results and outlook 7 2. -
113. Supersymmetry, Part II (Experiment) 1 113
113. Supersymmetry, part II (experiment) 1 113. Supersymmetry, Part II (Experiment) Updated September 2017 by O. Buchmueller (Imperial College London) and P. de Jong (Nikhef and University of Amsterdam). 113.1 Introduction 113.2 Experimental search program 113.3 Interpretation of results 113.4 Exclusion limits on gluino and squark masses 113.4.1 Exclusion limits on the gluino mass 113.4.2 Exclusion limits on squark mass 113.4.3 Summary of exclusion limits on squarks and gluinos assuming R-Parity conservation 113.5 Exclusion limits on masses of charginos and neutralinos 113.5.1 Exclusion limits on chargino masses 113.5.2 Exclusion limits on neutralino masses 113.6 Exclusion limits on slepton masses 113.6.1 Exclusion limits on the masses of charged sleptons 113.6.2 Exclusion limits on sneutrino masses 113.7 Exclusion limits on long-lived sparticles 113.8 Global interpretations 113.9 Summary and Outlook 113.1. Introduction Supersymmetry (SUSY), a transformation relating fermions to bosons and vice versa [1–9], is one of the most compelling possible extensions of the Standard Model of particle physics (SM). On theoretical grounds SUSY is motivated as a generalization of space-time symmetries. A low-energy realization of SUSY, i.e., SUSY at the TeV scale, is, however, not a necessary consequence. Instead, low-energy SUSY is motivated by the possible cancellation of quadratic divergences in radiative corrections to the Higgs boson mass [10–15]. Furthermore, it is intriguing that a weakly interacting, (meta)stable supersymmetric particle might make up some or all of the dark matter in the universe [16–18].