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

▶

Sep 13, 2023 27 likes •156 views

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

SLIDE 1

KARLSRUHE INSTITUTE OF TECHNOLOGY (KIT)

What is a particle?

KSETA Tutorial Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler | 21-23 July, 2014

KIT – University of the State of Baden-Wuerttemberg and National Laboratory of the Helmholtz Association

www.kit.edu

SLIDE 2

History of the Standard Model

Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle? 2/12

SLIDE 3

Introduction

The Standard Model of particle physics was developed throughout the latter half of the 20th century as an result of many discoveries in the same century

Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle? 3/12

SLIDE 4

Years of discovery

Discovery of many new particles . . .

1890 1897

e−

1905

1919

1936

1932

n, e+

1947

π, K (s), Λ0

2014 1956

νe

1962

νµ

1964

1969

u, d

1975

1977

1983

W, Z

1974

J/ψ

1979

1995

2000

ντ

2012

And many many more . . .

Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle? 4/12

SLIDE 5

In the early days

1897 J. J. Thomson discovers that cathode rays consist of unique particles and measures the charge mass ratio (independent

f the cathode material) ⇒ e− discovered

1911 Discovery of the atomic nucleus by E. Rutherford 1919 E. Rutherford discovers the proton

Future

Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle? 5/12

SLIDE 6

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

Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle? 6/12

SLIDE 7

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

Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle? 7/12

SLIDE 8

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 νe using the reaction ¯

νe + p → n + e+

(C. L. Cowan et al.) 1962 Discovery of νµ by L. Ledermann, M. Schwartz, and Jack Steinberger 2000 DONUT collaboration discovers ντ

Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle? 8/12

SLIDE 9

. . . 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

Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle? 9/12

SLIDE 10

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

July 4th 2012 The Status of the Higgs Search

J. Incandela for the CMS COLLABORATION

H è γγ candidate

Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle? 10/12

SLIDE 11

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

Manuel Kambeitz, Ivan Shvetsov, Michael Ziegler – What is a particle? 11/12

SLIDE 12

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