Physics
"It turns out that any optimal classical decision rule is also some Bayesian rule. In other words, even if the decision maker is not a Bayesian, he will behave as if he were!"
Frederick James, Statistical Methods in Experimental Physics
Carl Brannen is well known to the regulars of this blog. He is an independent researcher and my favourite non-professional theorist, because he gives me the hope that brilliant minds, who were diverted from the natural path of doing basic research, may return to it for good. And Carl provides us with another important proof: that institutionalized science does sometimes listen to the voice of those who have something to say regardless of who signs their monthly paycheck. It may give them a hard time getting their papers published, though.Carl has recently won a honorable mention for a paper…
Do you remember the "e-e-gamma-gamma-met" event ? I am sure you do not. It is an incredibly striking event that appeared toward the end of the Tevatron Run I in the CDF data. One event that was so incredibly striking, so impossible to produce through standard model processes, that many in my experiment felt sure that it was going to be the portal through which we would enter the realm of Supersymmetry, or other fancy new physics scenarios.
I am talking about the CDF experiment at the Tevatron, one of the two such endeavours to which I devote my research time. CDF collects 2-Tera-…
"An illustration of the confusion about the tau is provided by two editions of a popular book on particle physics by Nigel calder entitled The Key to the Universe. In the first edition Calder wrote:
Martin Perl and his colleagues detected peculiar events occurring in SPEAR. From the scene of collision an electron and a heavy electron (the well-known muon) carrying opposite electric charges were ejected at the same moment without any other detectable particles coming out. No conventional process, involving conventional particles, could account for such events.The particle called U was…
As a first act in the new committee, I have decided to publish a small article on the recent issue with the Omega_b discovery. The Omega_b is a particle which has been seen for the first time by the D0 collaboration last year, and then also observed by CDF this year. The controversy with this particle is due to the fact that the two observations are in stark disagreement with each other, to the point that one might well claim they constitute the observation of two distinct new states! I discussed the matter in some detail in this blog, and for that sake I even did some studies with…
Everyday use of a mathematical concept
The concept of probability is not alien to even the least mathematically versed among us: even those who do not remember the basic math they had in primary schools use it currently in their daily reasoning. I find the liberal use of the word "probability" (and derivates) in common language interesting, for two reasons. One, because the word has in fact a very definite mathematical connotation. And two, because the word is often used to discuss the knowledge of a system's evolution in time without a clear notion of which, among either of two strikingly…
Well, it is now official, so I thought I would let my blog know about it too: I am honored to announce that I was chosen to serve in the CMS Statistics Committee. Along with eight highly distinguished colleagues, I will work for at least the next two years in a group that will take care of ensuring the accuracy of all results that our 2500-strong collaboration will produce.
CMS is one of the two high-energy physics experiments designed to study the proton-proton collisions delivered by the LHC, the Large Hadron Collider at CERN in Geneva, Switzerland. The machine is expected to start data-…
Mathematical functions are all around us. We may not realize it but they are there! Check it out on the pictures below.A blade of light, selected by the venetian blinds of my living room window, draws a curved, complicated, multiple-valued function on the semi-transparent orange curtains. Maybe the curve below is even more fascinating:And this is only what we observe macroscopically... By examining the boundary of the illuminated regions, we would detect the diffraction pattern of the blind, which would be described by an even more fascinating function. But that is matter for a separate post…
Most of us like to be in control: of what happens around us, of our own feelings, of our actions, of the actions and well-being of our beloved ones. Being in control means feeling secure, unthreatened. It is the prevalence of order on chaos. And chaos, I have grown to realize, is one of the things that scares me most. Yes, I am a true control freak.
This week I am spending my evenings in the CDF control room, as a Scientific Coordinator. That literally means being in control of what happens to the detector and its subsystems, and ensuring that data is collected with the maximum efficiency. Of…
"17.35 Shot setup begins.18.07 Loading final protons.18.20 Loading pbars.18.48 Preparing to ramp.18.50 Ramping.18.52 Jacking.18.53 Squeezing.18.56 Initiating collisions.18.57 Ramping."
(From Fermilab's Main Control Room logbook today)