Report from EPS HEP 2011
Impressive results, so early on, and so much more yet to come! This was the prevalent feeling among the 800+ attendees of the EPS-HEP bi-annual meeting, held at the end of July, in Grenoble.
The spectacular performance of the Large Hadron Collider [LHC], which within a year has delivered the integrated luminosity milestone of one inverse femtobarn, along with the very fast analysis of the data by the experiments, was a leading actor at the conference. In parallel, with the Tevatron approaching the finalization of its physics program, and hot news coming from neutrino experiments and dark matter searches, conference attendees had a large number of exciting results to discuss during the breaks.
At the energy frontier the standard model still reigns supreme. The Tevatron and LHC experiments showed a wealth of new results on vector boson production and top physics, along with several searches for new physics. The latter now exclude large fractions of the relevant parameter spaces, challenging minimal models for supersymmetry and calling for more complex scenarios.
The LHC experiments have also joined the hunt for the Higgs boson. The LHC data have already resulted in new mass limits, which surpass the previous limits set at the Tevatron. Both the CMS and ATLAS experiments also reported a tantalizing observation of an excess of events in the low mass region. The reports provided an exciting topic for conversations throughout the conference, with everyone agreeing that the statistical significance is very small and a significant increase in the data samples is necessary.
On the Quantum chromodynamics front, updates on parton distribution functions from the HERA experiments, as well as several results from the LHC experiments, are now challenging the precision of theoretical predictions, while also contributing to further refinements of Monte Carlo simulations. In parallel, heavy ion physics is now firmly in a new era with the first lead-lead collisions of the LHC in 2010. ALICE, along with ATLAS and CMS, has produced a wealth of new results deeply probing the dynamics of the nuclear medium and challenging theoretical models.
A number of exciting strides were presented in flavor physics. New results from the Tevatron, the LHC experiments and particularly LHCb, as well as close-to-final results from experiments at the intensity frontier (BaBar, Belle) provide very significant tests of the standard model. Meanwhile, searches for charged lepton-flavor violation, electric dipole moments, and the updated dilepton charge asymmetries at the Tevatron continue to probe possible new effects.
The reviews on neutrino physics were dominated by the first indications for a sizeable mixing angle between the first and third family from the T2K and MINOS experiments. The implications for the measurement of CP violation in the neutrino sector mixing and the design of future neutrino factories were also analyzed.
One of the usual conference highlights is the ceremony for the award of the EPS High Energy and Particle Physics Prize. This year, the HEPP prize was awarded to Sheldon Lee Glashow, John Iliopoulos and Luciano Maiani for their crucial contribution to the theory of flavour, presently embedded in the standard theory of strong and electroweak interactions.
In line with the spirit of the Grenoble conference, marking the beginning of a new era, the closing session was devoted to an outlook for experimental and theoretical particle physics as a whole. Pier Oddone, Rolf Heuer and Atsuko Suzuki presented their visions for the future of particle physics from the perspective of the United States, Europe and Asia.
It was particularly moving to see how our Japanese colleagues are recovering after the tragic events caused by the tsunami and Suzuki, head of the KEK lab, thanked the community for its extended support.
Nobel laureate David Gross ended the conference with a summary from the theory point of view. Noting that the hunger for more statistics and confirmation of the tantalizing hints for new physics had gone beyond limits, he concluded the conference with the message: “Be patient! The fun is just starting!”