EPS HEP 2015 in Vienna
Physicists from all over the world gathered in Vienna in July 2015 for the biennial European Physical Society Conference on High Energy Physics, organized for the first time in the Austrian city of music, and chaired by Prof. Jochen Schieck from the Institute of High Energy Physics of the Austrian Academy of Sciences. About 750 physicists joined from the 22nd to the 29th of July to profit from 425 parallel talks, 194 posters, and 41 plenary talks covering the latest experimental and theoretical work in physics of particle colliders, neutrinos, heavy ions, astroparticles, and cosmology, as well as detector and machine developments. This was completed by a strong physics outreach program, and a rich social program including an exceptional concert.
This prestigious series of EPS conferences is an occasion for the experiments to present their very latest results to the world. In Vienna, we were privileged to see the very first set of public results from the ATLAS and CMS large experiments using the new data taken at the LHC Collider in 2015, at a record proton-proton centre-of-mass energy of √s = 13 TeV. After an intense phase of re-commissioning of the detectors, following the first long shut down of the LHC, both experiments were able to exploit a total luminosity delivered of about 100 pb-1 to produce performances and first physics studies. This confirmed the remarkable preparation of the experiments that are about to explore new physics territories in the aftermath of the Higgs boson discovery. Possible connections between particle physics and cosmology were reviewed at the joined ECFA/EPS session hosted as usual on the Saturday of EPS HEP Conferences.
Exciting news also came from various other areas of particle and astroparticle physics. While Brout-Englert-Higgs mechanism allows us to introduce masses in a gauge-invariant way, the fermion masses and mixing depend on arbitrary matrices in flavour space. Indirect measurements could provide sensitivity to sources of flavour symmetry breaking beyond the standard model. A new result from the LHCb experiment at CERN confirms the flavour anomaly previously seen in BABAR at SLAC and then by BELLE at KEK in the B-meson decays 
. All together, the ratios of decay rates deviate from the standard model expectation, by about 4 σ. Meanwhile, the LHCb experiment also reported the observation of exotic resonances in the decay products of the neutral bottom baryon Λb that might be interpreted as charmonium-pentaquarks, possibly a new bound state allowed by quantum chromodynamics. In neutrino physics, the T2K experiment, which had been the first to observe oscillations of into , presented an update of their earlier disappearance results and three candidates for the appearance of 
into 
, presented an update of their earlier 
disappearance results and three candidates for the appearance of 
. This might eventually provide clues to distinguish between the different scenarios for the neutrino-mass hierarchy. Among the other highlights were recent results from the Dark Energy Survey collaboration who came with an impressive map of both luminous and dark matter, built using weak gravitational lensing, exhibiting potential candidates for superclusters and (super-) voids that correlated nicely with optically detected galaxy clusters in the foreground.
Physicists will now eagerly await the follow-up at the next EPS HEP Conference scheduled in Venice, Italy, in July 2017.
