Physics

The "new" section of experimental physics papers in the arxiv today features a preprint by the CDF collaboration, titled "First Observation of Vector Boson Pairs in a Hadronic Final State at the Tevatron Collider". This is another instance of a difficult analysis where the CDF and DZERO experiments have competed in the past, and one which is relevant for Higgs boson searches. And CDF got there first once again.

I will describe in detail the analysis and the results later today, because this particular study is dear to me for at least three different reasons:
This afternoon Lisa Randall, one of the most famous theoretical physicists of our time, received from the hands of Flavio Zanonato, mayor of Padova, the keys of the city.
Planck 2009

Planck 2009

May 25 2009 | 1 comment(s)

This morning the Planck 09 conference started at the Auditorium Altinate (see picture, right) in Padova. For a week, theorists and experimentalists will discuss hot topics in a variety of fields, from particle physics to cosmology, to string theory. A PDF file with the program is online.

When Albert Einstein constructed his general theory of relativity he decided to resort to some reverse engineering and introduced a 'pressure' term in his equations. The value of this pressure was chosen such that it kept the general relativistic description of the universe stable against the gravitational attraction of the matter filling the universe.

A new paper in the Arxiv attracted my attention this morning. It is titled "Perturbative QCD effects and the search for a signal at the Tevatron", and is authored by a set of quite distinguished theorists: C.Anastasiou, G.Dissertori, M.Grazzini, F.Stockli, and B.Webber.
Last Tuesday CDF announced their own discovery of the Omega_b baryon, a measurement which creates a controversy with the competing experiment at the Tevatron collider, DZERO. That is because DZERO had already claimed discovery for that particle, almost one year ago, and because the two measurements disagree wildly with each other. Just browse through my past few posts in this column and you will find all the information you need (how lazy can one be with links?).
In thirty minutes (4 PM Chicago time) a live streaming of the Omega_b discovery by CDF will be broadcast at this link: http://vms-db-srv.fnal.gov/fmi/xsl/VMS_Site_2/000Return/video/r_live.xsl

Please follow it if you are interested in particle physics - Pat Lukens, the main author of the analysis, and a very experienced and skilled physicist who has spent the better part of his life for the good of the CDF experiment, will be discussing this fantastic new analysis for all of us.

In the last few days I indulged in a rather technical description of the checks I made on DZERO's evaluation of the significance of their observation of Omega_b particles. In those occasions I did not discuss either what the Omega_b is, nor what is its relevance, nor the details of how DZERO collected a small but significant sample of events characterized by the production of that ephemeral particle.
Good news today. Yesterday afternoon Werner Faymann, the Austrian Federal Chancellor, announced that Austria will not leave CERN, as previously suggested. An official confirmation of this decision will be received this afternoon by letter by the President of the CERN Council.

The decision of Austria does not surprise me - it would have been both crazy and self-destructive for Austrians to decide to leave the rich program of particle physics that they have contributed heavily to make a reality.
In a previous article here I considered from a statistical standpoint the signal of Omega_b candidate decays extracted by the DZERO collaboration in a large dataset of proton-antiproton collisions -the ones produced by today's most powerful hadron collider, the Tevatron at the Fermi National Accelerator Laboratory.