by Pietro Antonioli. Published: 22 June 2012


Physics at the LHC conference in Vancouver, Canada

From the 4th - 9th of June I attended the Physics at LHC conference (PLHC) reporting heavy flavours results in pp collisions on behalf of the ALICE Collaboration. At this conference we had nine ALICE speakers; three important overview talks were also assigned to ALICE collaboration members.

Concerning the results I personally reported, it was good to see the complementarity that the ALICE detector offers with respect to other LHC detectors at work. Besides ALICE specialisation on heavy-ions, as we know ,in pp collisions we have a good niche arising from PID capabilities of the detector and from low pt reach. Our plot showing the electron spectra coming from heavy flavours (see arxiv:1205.5423) together with ATLAS result is particularly suited for this! Our result on J/psi polarization (Phys. Rev. Lett. 108 (2012) 082001) was also highlighted in several theoretical and overview speeches.

On a more general note the Conference reported results recently presented or published by the different collaborations. As ALICE we presented a wealth of new results the week before at Hard Probes with various papers from ALICE reaching at the same time the Cornell archive: they have also been also shown and discussed with interest at PLHC. Topics covered by ALICE speakers included diffraction, strangeness, particle correlations, identified spectra, heavy flavours and flow, virtually covering all physics working groups active in ALICE. The conference gave indeed a significant space to heavy ion physics and Constantin Loizides (LBNL) provided a valuable summary of the results coming from LHC. As he concluded, “the LHC is ideal for studying the QGP”.

We had then had a full day dominated, not surprisingly, by searches for Higgs, SUSY and exotics. It seems that for new results on the Higgs hunt from ATLAS and CMS we will need to wait ICHEP. Interestingly at this conference LHCb, ATLAS and CMS presented a new joint analysis on strange B mesons decay to muon pairs, which further constraints the parameter space for SUSY. Someone called it a tombstone for SUSY even if, of course, we still have enough space to adjust things.

Altogether the speakers provided a valuable comprehensive picture of what is going on at LHC and I recommend for a quick scan the slides presented on the last day by ‘our’ John Harris (Yale University) on long term perspectives for heavy ion physics and by Karl Jacobs (Fribourg University), as experimental conference summary.

Alvaro De Rujula (CERN), in his usual provoking style, made an intriguing speech on the connection between LHC and what we are not understanding from the rest of the Universe, with emphasis on dark matter searches. I very much agree with him that we really need some radical different thinking and paradigm shift to match our beloved (and incomplete) Standard Model of particle physics with what is emerging from cosmic microwave background radiation, structure formation, galaxies rotation and much more. My humble opinion is that we are really missing something big, if we are currently oddly forced to conclude that we understand (and we know what is made of) just the 4% of the Universe - as Richard Panek put it in his popular book last year - with the other 96% suspiciously dark. I do hope that LHC will shed some lights on this too and will perhaps trigger a different understanding. Some good suggestions have been made to bring the relevant scientific communities working together even more closely.

The conference was well organized and the venue, as often happens when based in a large North American campus, particularly well suited. Vancouver looked interesting and I left with some envy of some colleagues who had the possibility to further explore the wonderful British Columbia….