Interactions News Wire
#61-03
9/4/03
********************************************************************************
Source:
CERN
Content: CERN celebrates discoveries and looks to the future
Date
Issued:
9/2/03
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PR12.03
02.09.2003
CERN
celebrates discoveries and looks to the futureNobel laureates
will be among the distinguished guests at a symposium at CERN on 16 September.
The symposium will celebrate the double anniversary of major discoveries at CERN
that underlie the modern theory of particles and forces. It will also look
forward to future challenges and opportunities as the laboratory moves into a
new arena for discovery with the construction of the Large Hadron Collider. The
symposium will end with a panel discussion(*) on the future of particle physics,
chaired by Carlo
Rubbia.
Twenty
years ago, in 1983, CERN announced the discovery of particles known as W and Z,
a discovery that brought the laboratory its first Nobel Prize in 1984. Ten years
previously, physicists at CERN had already found indirect evidence for the
existence of the Z particle in the so-called "neutral currents". The charged W and neutral Z
particles
carry one of Nature's
fundamental forces, the weak force, which causes one form of radioactivity and
enables stars to shine. These discoveries provided convincing evidence for the
so-called electroweak theory, which unifies the weak force with the
electromagnetic force, and which is a cornerstone of the modern Standard Model of particles and
forces.
This
brought modern physics closer to one of its main goals: to understand Nature's
particles and forces in a single theoretical framework. James Clerk Maxwell took
the first steps along this path in the 1860s, when he realised that electricity
and magnetism were manifestations of the same phenomenon. It would be another
hundred years before theorists succeeded in taking the next step, unifying
Maxwell's electromagnetism with the weak force in a new electroweak
theory.
An important step towards
confirming electroweak unification came in 1973, when the late André Lagarrigue
and colleagues working with the Gargamelle bubble chamber at CERN observed
neutral currents - the neutral manifestation of the weak force that had been
predicted by electroweak theory but never previously observed. Later that
decade, Carlo Rubbia of CERN proposed turning the laboratory's most powerful
particle accelerator into a particle collider, an idea that received the support of the then Directors General, John Adams and Léon Van Hove.
By
colliding counter-rotating proton and antiproton beams head
on, enough energy would be concentrated to produce W and Z particles. This was
made possible, in particular, through Simon van der Meer's invention of
"stochastic cooling" to produce sufficiently dense antiproton beams. By
1981 the search for the W and Z particles was on. The observation of W particles
by the UA1 and UA2 experiments was announced at CERN on 20 and 21 January 1983.
The first observation of Z particles by UA1 followed soon after, with the announcement on 27 May.
In
1979, three of the theorists responsible for the electroweak theory, Sheldon
Glashow, Abdus Salam and Steven Weinberg, were awarded the Nobel Prize. In 1984,
Carlo Rubbia and Simon van der Meer shared the Prize for their part in the
discovery of the W and Z particles. The discovery also owes much to the
development of detector techniques, in particular by Georges Charpak at
CERN, who was rewarded with the Nobel Prize in 1992.
The
results ushered in more than a decade of precision measurements at the Large
Electron Positron collider, which tested the predictions of the Standard Model
that could be calculated due to the work of theorists Gerard 't Hooft and
Martinus Veltman, who shared the Nobel Prize in 1999.
In addition to reflecting on past
findings, speakers at the September symposium will also talk about the future of
CERN, including the Large Hadron Collider, set to switch on in 2007. By
colliding particles at extremely high energies, the LHC should shed light on
such questions as:
Why do particles have mass? What is
the nature of the dark matter in the Universe? Why did matter triumph over
antimatter in the first moments of the universe, making our existence possible?
What was the state of matter a few microsceconds after the Big
Bang?
(*) The members of the a panel
will be : CERN's Director General Luciano Maiani, together with Robert Aymar
(Director General of CERN from 1 January 2004), Georges Charpak, Pierre
Darriulat, Simon van der Meer, Lev Okun, Donald Perkins, Carlo Rubbia, Martinus
Veltman, and Steven Weinberg.
The symposium will be open to the public, and will run from
9 a.m. to approximately 6 p.m.
The full programme (also below this page) and further
information, photos, on the symposium are available
at:
http://www.cern.ch/cerndiscoveries/
see also:
Neutral currents:
http://www.cerncourier.com/main/article/43/5/22http://public.web.cern.ch/public/about/achievements/currents/neut-curr.htmlThe
W and Z discoveries:
http://www.nobel.se/physics/laureates/1984/press.htmlhttp://cerncourier.com/main/article/43/4/13/1Standard
Model:
http://public.web.cern.ch/public/about/why/SM/sm.html
http://public.web.cern.ch/public/about/why/forces/forces.htmlThe
future and the Large Hadron Collider:
http://public.web.cern.ch/public/about/future/future.html!!
PROGRAMME !!
1973: Neutral Currents 1983: W± & Z0
Bosons
----------------------------------------------------------
The
anniversary of CERN’s discoveries and a look into the
future
------------------------------------------------------------------------------
Tuesday
16th of September 2003 at CERN in the Main Auditorium :
9:00
Welcome L. Maiani (10mn)
9:10 The making of the Standard
Model S. Weinberg (45mn)
9:55 CERN’s contribution to accelerators
and beams G. Brianti (30mn)
10:25 The discovery of neutral currents D.
Haidt (30mn)
10:55 Coffee break
11:30 The discovery of the W & Z, a personal
recollection P. Darriulat (40mn)
12:10 W & Z
Physics at LEP P. Zerwas (30mn)
12:40 Lunch
14:00
Physics at the LHC J. Ellis (30mn)
14:30 Challenges of the
LHC:
The accelerator challenge of the LHC L. Evans (20mn)
The detector challenge of the LHC J. Engelen (20mn)
The computing
challenge of the LHC P. Messina (20mn)
15:30 Particle detectors and
Society G. Charpak (30mn)
16:00 Coffee break
16:30 Closing of the
symposium: The future for CERN L. Maiani (30mn)
17:00 Panel discussion:
Future of Particle Physics (45mn)
With
the participation of: Robert Aymar, Georges Charpak, Pierre Darriulat, Luciano
Maiani, Simon van der Meer, Lev Okun, Donald Perkins, Carlo Rubbia (Chair), Martinus Veltman and
Steven Weinberg
**********************
--
Renilde
Vanden Broeck
CERN - Press Office
CH-1211 Geneva 23,
Switzerland
Tel:+41 22 767 2141 Fax: + 41 22 785 0247
http://www.cern.ch/Press