Quantum mechanics in the 21st century
Quantum mechanics has existed for more than 100 years but some long-standing debates are still alive and waiting for a solution. The field calls for creativity and exceptional skills, in both theory and experiment. Now, new experimental techniques and a new theoretical understanding hold the tantalizing promise of future breakthroughs, as was evident at a recent workshop at the European Centre for Theoretical Physics (ECT*) in Trento.
The international workshop "Speakable in quantum mechanics: atomic, nuclear and subnuclear physics tests", devoted to the hot topics of quantum mechanics, took place on 29 August – 2 September. Some 40 scientists participated, with a well balanced mix of theoreticians and experimentalists. Several young scientists gave interesting talks and contributed to the discussions – an extremely good sign for the future of research in quantum mechanics.
The workshop opened with a session that addressed possible probes of decoherence in quantum gravity and tests of quantum mechanics with facilities such as the DAΦNE collider at the Frascati National Laboratory, where pairs of neutral kaons are copiously produced in an entangled state. In particular, it is now possible to test the predictions of quantum mechanics in these massive kaon systems, where the effects of quantum gravity might became important and alter the predictions of nonrelativistic quantum mechanics. Bell-type inequalities can also be checked in such systems. Other sophisticated experiments that probe quantum entanglement with photons, neutrons and even complex molecules were also discussed.
The mystery that still shrouds the collapse of the wave function has been addressed in recent years by novel theories, such as the Ghirardi–Rimini–Weber model, which modifies the Schrödinger equation by adding a nonlinear term. No experimental tests have been performed to date and part of the discussion in the workshop was focused on this important topic, with many ideas for possible future experiments.
One session was entirely devoted to experimental tests of the spin-statistics connection, in particular to searches of small violations of the Pauli exclusion principle. Because the principle is tightly embedded in the very essence of modern field theory, it is quite difficult to build conceptual frameworks that allow for a violation, and thus it is difficult both to conceive experiments and to give a consistent interpretation of the experimental results. Nonetheless, experimentalists go boldly forward and test the principle to a high accuracy in atomic and nuclear systems. Experimental results from the VIP, DAMA and Borexino experiments in the Gran Sasso National Laboratory were presented and discussed, together with their theoretical implications and future perspectives.
In a special talk, Angelo Bassi of the University of Trieste presented the EU Cost Action "Fundamental Problems in Quantum Physics", which is dedicated to items that are closely related to those discussed during the workshop (CERN Courier June 2011 p32). This encounter may help to create a closer and long-standing collaboration between the scientists present at the meeting, including the possibility of using the Short Term Scientific Missions promoted by this Action.
The workshop was organized by Catalina Curceanu (LNF-INFN, Frascati), Johann Marton (SMI and TU Vienna) and Edoardo Milotti (University and INFN Trieste). Its ultimate success owed much to the session chairs, F de Martini, A di Domenico, B Hiesmayr, H Rauch and N Zanghí, as well as to all of the participants who contributed to the lively discussions.
Visits
Ryoji Chubachi, centre, executive member of the Council for Science and Technology Policy, cabinet office, government of Japan and vice-chair, representative corporate executive officer and member of the board of the Sony Corporation, was welcomed to CERN by Peter Jenni, former ATLAS spokesperson, left, and Taka Kondo, ATLAS collaboration member from KEK, on 31 August. They visited the ATLAS underground experimental area and the ATLAS visitor centre.
On 6 September José Lino Barañao, Argentinian minister of science, technology and innovation, left, visited the CERN Control Centre with Michael Benedikt, from CERN’s Beams Department. During his time at CERN the minister also toured the LHC superconducting magnet test hall, the ATLAS visitor centre and the Universe of Particles in the Globe of Science and Innovation.
Fernando Schmidt Ariztía, undersecretary for foreign affairs for Chile, visited CERN on 12 September. His tour of CERN included the ATLAS visitor centre, the LHC superconducting magnet test hall, the CERN Control Centre and the AMS control centre. He also met CERN’s director-general, Rolf Heuer.
On 13 September, Kofi Annan, president of the Kofi Annan Foundation and former secretary-general of the United Nations, centre, was welcomed to CERN by the director-general, Rolf Heuer, right, and Felicitas Pauss, CERN’s head of international relations. His tour of CERN included the LHC superconducting magnet test hall, the ATLAS visitor centre and the exhibition Universe of Particles.
Balkan Summer Institute 2011 convenes by the blue Danube
The 2011 Balkan Summer Institute for 2011 (BSI2011) – this year’s core meeting of the South-eastern European Network in Mathematical and Theoretical Physics (SEENET-MTP) – took place on 19 August – 1 September in Donji Milanovac, in the heart of the Djerdap National Park, with an introductory seminar in Niš, Serbia. A total of 178 participants attended the institute from 28 countries.
BSI2011 was composed of four complementary events: "Trends in Modern Physics" (BSS2011), a seminar for physics teachers; the "Summer School on Cosmology and Particle Physics" (BS2011), for MSc and PhD students; and two workshops entitled "Scientific and Human Legacy of Julius Wess" (JW2011) and "Particle Physics from TeV to Planck Scale" (BW2011). A number of social activities were also organized during the institute.
The main goal of the BSS2011 seminar was to improve the quality of teaching, the promotion of science and new approaches in education. Lectures were followed by computer sessions, a CERN video link, laboratories and hands-on exercises. Sofoklis Sotiriou demonstrated the ideas and experience of the European teachers’ programmes "Pathway" and "Discover the Cosmos", which provided the opportunity to interact with working scientists and receive data from sources, such as CERN.
The BS2011 school gathered six renowned experts as lecturers (Fred Adams (Michigan), Ignatios Antoniadis (CERN), Tao Han (Wisconsin), Neil Lambert (CERN), Viatcheslav Mukhanov (Munich) and Goran Senjanović (ICTP)), two tutors (Miha Nemevšek (ICTP) and Alexander Vikman (CERN)) and around 50 students, mostly from Europe. An introduction and a summary were given by Goran Djordjević (Niš).
The JW2011 workshop was dedicated to the scientific and human legacy of Julius Wess. One of the founders of SEENET–MTP in 2003, he contributed much to facilitate research and return physicists and scientists from the former Yugoslavia to international science. His associates, students and admirers met at the lower course of his favourite river Danube to discuss the state of art in the scientific fields to which he had made important contributions, in particular noncommutative physics.
At the by-now traditional workshop BW2011, 25 invited lecturers presented their latest results on dark matter and its role in cosmology, astrophysics, particle physics and related fields. Luis Álvarez-Gaumé opened the workshop with a talk on "minimal inflation", which is based on the general properties of supersymmetry-breaking in supergravity models.
Among the highlights that followed, Dejan Stojković reviewed the "vanishing dimensions" paradigm. It appears that experimental evidence of lower-dimensionality at higher energies may already exist – a statistically significant planar alignment of events with energies higher than a tera-electron-volt has been observed in some cosmic-ray experiments. The LHC should be able to see effects associated with the dimensional crossover. Glenn Starkman gave a talk on large-scale anomalies in the cosmic-microwave background (CMB), which suggest that either something is wrong with the understanding of the large-scale properties of the universe or that the low multipoles of the CMB data are not of cosmic origin.
Sezen Sekmen (CMS) and Takanori Kono (ATLAS) presented the latest results and ongoing experimental and technical constraints of their detectors at the LHC. Both lectures were great opportunities for a number of researchers and advanced students to get a good insight into the current research of both collaborations. In his talk, Goran Senjanović pointed out that neutrino mass is the only established physics beyond the Standard Model and as such provides a great window into new physics. This is especially true if the neutrino is a Majorana particle, which is automatic in the case of the seesaw mechanism.
A round table "Balkan Forum" focused on (inter)regional co-operation through SEENET–MTP in science and education. The network will soon consist of 19 nodes from 10 Balkan countries, with around 250 individual members and numerous partners from Europe and the world. The publication of a number of scientific issues originating from BSI2011 is planned for the beginning of 2012.
The directors of BSI2011 were: E Dudas (Palaiseau), G Dvali (Munich/CERN), D Lüst (Munich), G Senjanović (Trieste), D Stojković (Buffalo) and G Djordjević (Niš). The institute was organized by the Faculty of Science and Mathematics (FSM) and SEENET–MTP office in Niš, in co-operation with ICTP Trieste, LMU and MPI Munich, CPHT Palaiseau, the Faculty of Physics Craiova and the Physical Society Niš as a local co-organizer.
The main support for BSI2011, as a whole or for some of its events, came from ICTP and its partner CEI, DAAD and the Serbian Ministry for Education and Science. Co-sponsors of BSI2011 were UNESCO Venice Office as a permanent supporter of the SEENET–MTP, EPS, ESF, EU and CERN (UNILHC Network and MassTeV grant), the French Embassy in Belgrade, the Perimeter Institute, Project BELISSIMA and FSM Niš.
• For more details, see the SEENET–MTP site at www.seenet-mtp.info and the BSI2011 site at http://bsi2011.seenet-mtp.info.
• G Djordjević and I Antoniades.