Tomorrow I will be packing up and leaving CERN to fly back home, after a quite eventful, productive, extenuating, exhilarating week. The reason for my coming to Geneva was the CMS week, an event that takes place four times a year, and where a good fraction of the members of our 2400-strong collaboration gather to listen to updates of the experiment, the detector, the analyses, and to discuss rules, appointments, organizational issues.
Ok, now it is public, so I can also broadcast it: LHC last night got the two proton beams to collide at 2.36 TeV total center of mass energy. You can see a few event displays here:http://atlas.web.cern.ch/Atlas/public/EVTDISPLAY/events.html
I am still waiting for some public info from CMS... Stay posted for more colorful event displays!
Well, as you know I cannot say anything about internal matters of the CMS experiment at the LHC, but I know that other sites will have information pretty soon on the matter. So my advice for tonight is to browse the web, and possibly the site of less discreet bloggers than myself. The CERN twitter feed might also be a good idea... All I can say is that LHC is working like a charm these days!
One of the cool things I have learned to do, through years of experience in data analysis at particle colliders, is to visualize the complex kinematics of a signal process in a multi-dimensional space, and imagine ways to separate it from backgrounds by selecting in the hyperspace the signal-rich region. I came across a very simple example of the above rather abstract statement yesterday, and I wish to share it with you.
To help you visualize what I am going to discuss, here is the example: an avocado in a square tumbler. The avocado is top pair production, and the glass is Z plus b-antib production.
... Confused ? Let me explain.
The verdict is out: Amanda Knox and Raffaele Sollecito killed Meredith Kercher.
The murder of the young British student in Perugia two years ago was a highly disputed case, and the proof of guilt of the two young lovers -a US citizen studying in Perugia and her boyfriend- appears largely based on indicia, and not on the more solid ground one usually expects for a conviction in similar instances.
I do not know about you, but top quarks fascinate me. Since my early years as a student in particle physics I participated in the top search, and then the top discovery, with the CDF experiment at the Tevatron collider; and I then worked for many more years with top quark samples. And that particle is fascinating for many different reasons: its phenomenology, the richness of its decays, its mass close to the scale of electroweak symmetry breaking.
I feel honored by having had a chance to study the first few tens of top quark events that physicists have been able to produce, and yet I regret that during the last few years I have been unable to put my hands on the much larger datasets collected by the CDF experiment.
The Carnival of Physics
is an event organized by Gravità Zero
and Gravedad Cero
, two sites of scientific outreach in Italy and Spain. I participate with three recent articles which are published on their site. Most other contributions are in Italian and Spanish, but you might still find it interesting to visit the two sites (which feature different contributions). Among the sponsors of this enterprise are WIRED, El Pais, Publico, and La Stampa.
Last night the Large Hadron Collider at CERN has circulated the highest-energy beams of particles ever produced. The beam energy has been brought up from the injection energy of 450 GeV to 1.18 TeV, thus outperforming by 20% the flattop beam energy of the Tevatron collider, Fermilab's proton-antiproton collider, which operates at a beam energy of 980 GeV.
I had an idea that the theories of the earliest stages of the universe were speculative. I just never really knew how speculative until I really looked at them. The CMB is as far back as we have actual data. From that we have to divine everything.
Can a subject be too remote from the domain of traditional physics for physicists to dare applying their methods of research to it? Unlikely. If the objects under investigation in some remote area of research can be subjected to clean and unambiguous experiments, you will likely find physicists dabbling into the area.