Colloquia

Spintronics : from fundamental spin physics to daily applied leading-edge technology.

0:00:00 Slide 1
0:03:39 Slide 2
0:07:18 Slide 3
0:14:35 Slide 4
0:21:52 Slide 5
0:29:09 Slide 6
0:36:26 Slide 7
0:43:43 Slide 8
0:51:00 Slide 9
0:58:17 Slide 10
1:05:34 Slide 11

The Institut Laue-Langevin (ILL) is an international research institute which operates the currently most powerful source of neutrons in the world, a 58 MW reactor. The neutron beams provided by the reactor feed a broad range of instruments which are dedicated to a wide variety of research activities. The majority of instruments are dedicated to the study of solid-state physics, materials science, chemistry, the biosciences, and earth sciences. However, nuclear and low energy particle physics studies are also vigorously pursued with the aid of neutrons. The talk will mainly concentrate on this latter aspect. We make use of hot, thermal, cold, and ultra-cold neutrons with velocities of between a few kilometers and a few meters per second, corresponding to kinetic energies in the electronvolt-to-nanoelectronvolt range. It will be briefly discussed how thermal neutrons can be used to investigate the structure and behavior of nuclei by generating excited nuclear states. The main part of the talk will be dedicated to experiments with cold and ultra-cold neutrons which are a suitable tool for investigating subtle aspects of the four known fundamental forces of Nature - electromagnetism, the weak and the strong forces, and gravity.

Organiser(s): Daniel Treille / PH-EP Unit

Note: Tea & coffee will be served at 16:00 hrs..

0:00:00 Slide 1
0:04:06 Slide 2
0:08:12 Slide 3
0:16:23 Slide 4
0:24:35 Slide 5
0:32:46 Slide 6
0:40:58 Slide 7
0:49:09 Slide 8
0:57:20 Slide 9
1:05:32 Slide 10
1:13:43 Slide 11

On Wednesday 16 June at 4.00 p.m. a symposium will be held in the CERN Main Auditorium in memory of three great figures in the history of CERN and its Research Programmes, namely Charles Peyrou, Lucien Montanet and Rafael Armenteros, all of whom recently passed away. Each of them, notably led CERN's bubble-chamber programmes. Tributes appeared in the Weekly Bulletin issues 17/2003, 28/2003 and 14/2004.
Since the symposium will take place on the day between the Scientific Policy Committee (SPC) meeting and the Council session, it will be possible for many colleagues and friends to attend alongside family members. All CERN staff members who wish to attend are also invited.
Eight speakers who were close to each of the men at various times will share their vivid recollections, recalling the major scientific contributions they made and underlining the important role they played both at CERN and in the international scientific community.
At the end of the symposium, drinks will be served at the invitation of the Director-General.
Speakers : Manuel Aguilar-Benitez, Paul Baillon, Patrick Fleury, Leonid Nemenov, Henri Piatier, Emanuele Quercigh, Juan-Antonio Rubio, Ryszard Sosnowski

Organiser(s): Daniel Treille PH-EP.

0:00:00 Slide 1
0:08:19 Slide 2
0:16:37 Slide 3
0:33:14 Slide 4
0:49:51 Slide 5
1:06:27 Slide 6
1:23:04 Slide 7
1:39:41 Slide 8
1:56:17 Slide 9
2:12:54 Slide 10
2:29:31 Slide 11

I will discuss the experimental signatures at the LHC of a novel paradigm-shift away from naturalness, suggested by the cosmological constant problem and the multitude of vacua in string theory. In the new paradigm supersymmetry can be broken near the unification scale, and the only light superparticles are the gauginos and higgsinos, which account for the successful unification of gauge couplings. This framework removes all the phenomenological difficulties of standard SUSY. The mass of the Higgs is in the range 120-160 GeV. Measuring the couplings of the Higgs to the gauginos and higgsinos precicely tests for high-scale SUSY. The gluino is strikingly long lived, and a measurement of its lifetime can determine the SUSY breaking scale. Signatures at the LHC detectors include out-of-time energy depositions, displaced vertices, and intermittent tracks..

0:00:00 Slide 1
0:03:26 Slide 2
0:06:51 Slide 3
0:13:42 Slide 4
0:20:32 Slide 5
0:27:23 Slide 6
0:34:14 Slide 7
0:41:04 Slide 8
0:47:55 Slide 9
0:54:45 Slide 10
1:01:36 Slide 11

In the 1980s many people were excited by the concept that cosmic strings, as relics of the Grand Unified Era, could be responsible for the formation of cosmic structure. In the 1990s the cosmic string concept steadily lost ground to the Inflationary model both as a result of the difficulty of calculations and more definitively through observations of the CMB. About the time many expected the new WMAP data to deliver the coup de grace, the concepts of cosmic strings as major physical phenomena (not so important in structure formation) has begun a renaissance. This new interest is motivated by one of the original ideas that topological defects are inevitable in symmetry breaking by the Kibble (1976) mechanism and the introduction of new ideas such as brane-cosmology/inflation and the realization that cosmic strings may be the only acceptable such defect. We find ourselves back in the business of trying to detect or limit and understand cosmic strings once again for the insight and constraints they put on particle physics and cosmology. This talk reviews current limits and observations about cosmic strings.

Organiser(s): Daniel Treille / PH-EP and Luis Alvarez-Gaume / PH-TH
*Please note unusual day!
**Tea and coffee will be served at 16:00.

0:00:00 Slide 1
0:09:01 Slide 2
0:18:01 Slide 3
0:36:01 Slide 4
0:54:01 Slide 5
1:12:01 Slide 6
1:30:01 Slide 7
1:48:01 Slide 8
2:06:01 Slide 9
2:24:01 Slide 10
2:42:01 Slide 11

The NA48/2 experiment at the CERN SPS has collected more than 100 million fully reconstructed K^±-->π±π⁰π⁰ decays.

The preliminary analysis of a third of the data shows a sudden change of slope of the π⁰π⁰ invariant mass distribution in the region around 2m, where m is the mass of the charged pion. This anomaly, which was never observed before, is interpreted as a cusp-like effect resulting mainly from the contribution of the K^±-->π±π⁰π⁰ decay amplitude through π⁺π^- -->π⁰π⁰ charge exchange.

The study of this phenomenon is a new and potentially more accurate method to measure a⁰-a², the difference of the I = 0 and I = 2 S-wave scattering lengths.



The colloquium will consist of two parts: the experiment, given by Italo Mannelli, and the theory by Nicola Cabibbo.



Organiser(s): Luis Alvarez-Gaume / PH-TH

Note: * Tea & coffee will be served at 16.00 hrs..

0:00:00 Slide 1
0:06:44 Slide 2
0:13:27 Slide 3
0:20:10 Slide 4
0:26:53 Slide 5
0:33:36 Slide 6
0:40:19 Slide 7
0:47:02 Slide 8
0:53:45 Slide 9
1:00:28 Slide 10

Evolution of nonvolatile semiconductor memory : from floating gate to nanocrystal.

0:00:00 Slide 1
0:02:39 Slide 2
0:05:18 Slide 3
0:10:36 Slide 4
0:15:54 Slide 5
0:21:11 Slide 6
0:26:29 Slide 7
0:31:47 Slide 8
0:37:04 Slide 9
0:42:22 Slide 10
0:47:40 Slide 11

From Special Relativity to Cosmic Inflation.

0:00:00 Slide 1
0:03:57 Slide 2
0:07:54 Slide 3
0:15:47 Slide 4
0:23:40 Slide 5
0:31:33 Slide 6
0:39:26 Slide 7
0:47:19 Slide 8
0:55:12 Slide 9
1:03:05 Slide 10
1:10:58 Slide 11

For may years harnessing fusion energy was considered the final solution to the world's energy crisis. ITER is the last step in the elusive quest. This presentation will provide in its various acientific, technological and political aspects..

0:00:00 Slide 1
0:04:48 Slide 2
0:09:36 Slide 3
0:19:11 Slide 4
0:28:46 Slide 5
0:38:21 Slide 6
0:47:56 Slide 7
0:57:31 Slide 8
1:07:06 Slide 9
1:16:41 Slide 10
1:26:16 Slide 11

Experimental high energy physics is poised to break out of the prison of the Standard Model. When the field turns to the exploration of exciting new phenomena beyond the Standard Model, will there still be a role for the study of old-fashioned heavy quarks and leptons?.

0:00:00 Slide 1
0:03:57 Slide 2
0:07:54 Slide 3
0:15:48 Slide 4
0:23:41 Slide 5
0:31:35 Slide 6
0:39:28 Slide 7
0:47:22 Slide 8
0:55:15 Slide 9
1:03:09 Slide 10
1:11:02 Slide 11

Understanding turbulence is vital in astrophysics, geophysics and many engineering applications, with thermal convection playing a central role. I shall describe progress that has recently been made in understanding this ubiquitous phenomenon by making controlled experiments using low-temperature helium, and a brief account of the frontier topic of superfluid turbulence will also be given. CERN might be able to play a unique role in experiments to probe these two problems..

0:00:00 Slide 1
0:02:54 Slide 2
0:05:47 Slide 3
0:11:34 Slide 4
0:17:21 Slide 5
0:23:08 Slide 6
0:28:55 Slide 7
0:34:42 Slide 8
0:40:29 Slide 9
0:46:16 Slide 10
0:52:03 Slide 11

Nature has sprinkled black holes of various sizes throughout the universe, from stellar mass black holes in X-ray sources to supermassive black holes of billions of solar masses in quasars. Astronomers today are probing the spacetime near black holes using X-rays, and gravitational waves will open a different view in the near future. These tools give us an unprecedented opportunity to test ultra-strong-field general relativity, including the fundamental theorem of the uniqueness of the Kerr metric and Roger Penrose's cosmic censorship conjecture. Already, fascinating studies of spectral lines are showing the extreme gravitational lensing effects near black holes and allowing crude measurements of black hole spin. When the ESA-NASA gravitational wave detector LISA begins its observations in about 10 years, it will make measurements of dynamical spacetimes near black holes with an accuracy greater even than that which theoreticians can reach with their computations today. Most importantly, when gravitational waves from colliding black holes are detected we will have the first direct observations of black holes themselves..

0:00:00 Slide 1
0:03:49 Slide 2
0:07:38 Slide 3
0:15:15 Slide 4
0:22:52 Slide 5
0:30:29 Slide 6
0:38:07 Slide 7
0:45:44 Slide 8
0:53:21 Slide 9
1:00:58 Slide 10
1:08:35 Slide 11