What is a particle? KSETA Tutorial Manuel Kambeitz, Ivan Shvetsov, - PowerPoint PPT Presentation

What is a particle? KSETA Tutorial Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler | 21-23 July, 2014 K ARLSRUHE I NSTITUTE OF T ECHNOLOGY (KIT) www.kit.edu KIT – University of the State of Baden-Wuerttemberg and National Laboratory of the Helmholtz Association

History of the Standard Model 2/12 Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle?

Introduction The Standard Model of particle physics was developed throughout the latter half of the 20 th century as an result of many discoveries in the same century 3/12 Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle?

Years of discovery Discovery of many new particles . . . 1919 1936 1890 p µ 1897 1905 1932 1947 γ n , e + π, K ( s ), Λ 0 e − 1964 1969 1995 1956 1975 1979 2014 ν e Ξ u, d τ g t 1962 1974 1983 2000 2012 ν µ ν τ W, Z H J/ψ 1977 Υ And many many more . . . 4/12 Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle?

In the early days 1897 J. J. Thomson discovers that cathode rays consist of unique particles and measures the charge mass ratio (independent of the cathode material) ⇒ e − discovered 1911 Discovery of the atomic nucleus by E. Rutherford 1919 E. Rutherford discovers the proton Future 5/12 Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle?

The Particle Zoo 1936 C. D. Anderson and S. Neddermeyer discover a new particle in cosmic rays ⇒ µ 1947 Discovery of the Pion ( π ) and the Kaon ( K ) in cosmic rays . . . Meson octet : Is there a pattern behind all particles? 1964 Gell-Mann and Zweig postulate the existent of quarks, which the hadrons consist of 6/12 Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle?

Discovery of Quarks Deep inelastic scattering 1968 At Stanford Linear Accelerator Center (SLAC): Electrons were fired on protons and neutrons in atomic nuclei ⇒ Internal structure of p and n discoverd 7/12 Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle?

Where are the other Leptons . . . Tau 1975 Detection of the τ by M. L. Perl and his colleagues at the SLAC-LBL group 1930 W. Pauli postulates the neutrino 1956 Discovery of ν e using the ν e + p → n + e + reaction ¯ (C. L. Cowan et al.) 1962 Discovery of ν µ by L. Ledermann, M. Schwartz, and Jack Steinberger 2000 DONUT collaboration discovers ν τ 8/12 Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle?

. . . and the Bosons? Photon 1905 A. Einstein proposes the photon to describe the photoelectric effect (Nobel prize 1921) W and Z 1983 Discovery of W and Z at CERN Gluon 1979 Discovery of g at the DESY in 3-Jet events 9/12 Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle?

Last but not least, the Higgs 2012 Discovery of H by CMS and ATLAS collaboration H decays into many different particles Choose decays with clear signature H è γγ candidate J. Incandela for the CMS COLLABORATION July 4 th 2012 The Status of the Higgs Search 10/12 Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle?

Summary Over 100 years of discoveries Particle zoo structured with the Standard Model A lot of effort was needed to detect all these particles Some latest particle discoveries can not be explained by the Standard Model 11/12 Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle?

12/12 Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle?