Sony Vaio VGN-TX2P January 31, 2006
Posted by dorigo in computers, personal.1 comment so far
The vgn-tx2p is a ultraportable notebook designed for travelers. Weighting less than 3 pounds, and with a up to 6 hours battery life, it’s ideal for me. I walk from my home in Venice to the train every morning, and then from the railway station in Padova to my office. All in all, I walk an hour per day, which is very healthy if you don’t have a large weight on your shoulders…
Today I received my new Vaio. I have been looking with longing eyes at similar models for a while now, as my colleagues nonchalantly took them off their light bags and played with them during meetings or conference talks. I felt it was about time I got something like that myself.
My former notebook - which is probably going to end its career somewhere on a shelf at the Physics department, now that i am turning it in - is a Toshiba Satellite, and it weighs a ton - more than 8 pounds by itself. I got it two years ago, when it was already a couple of years old and had been used by a colleague who was then leaving our department. I worked with my Toshiba a lot, but recently the thing was giving me trouble with the hard disk, and the CD player did not work anymore.
Having apologized enough for burdening the university budget with another expensive laptop, I can freely express my joy… This thing is a prodige in miniaturization. The screen is 10.5″ across, extremely bright, and has the same resolution of most 14″-15″ heavyweights. It weighs like a book and its battery lasts two or three times as much as the one in the Toshiba. The keys are smaller than usual but they are a pleasure to touch.
Enough writing… I’m off to make love with it a little bit more now. Tomorrow I’ll inaugurate it in the Munich-Chicago flight.
Hospitals and clinical labs January 31, 2006
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My frequentation of hospitals and clinical laboratories has peaked recently, when - after taking x-rays in November for a broken rib, paying a few visits to my father who has been hospitalized until a few days ago, and taking a complete blood exam for the INFN recently,
I visited the Bologna hospital yesterday afternoon, to consult a specialist for my father.
The string of visits has not ended yet: in mid-February I have to take an optometric test, after which I will be finally ready to get a medical examination at the INFN laboratories in Legnaro.
Anyway, in Bologna I met doctor Michele Baccarani, an expert in blood diseases. Talking to him was illuminating. After carefully reviewing all the papers I had brought, he explained in clear terms the clinical situation, the available therapies, and their degree of effectiveness - very low, for the case at hand. I felt at school again as dr. Baccarani, having learned I was a
researcher myself (although admittedly not in a contiguous matter) took his time to describe in a scientific way the possible mechanisms known to medicine to intervene in the DNA’s ability to replicate and produce the blood constituents.
The more you know, the more you understand how little you know. That applies equally well to particle physics and medicine, I am afraid.
And I ache for both.
TeV4LHC Proceedings January 30, 2006
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You can download a copy of my contribution to the proceedings of the TeV4LHC workshop, titled “The Z->bb decay as a b-jet energy calibration tool” at the following link:
http://www.pd.infn.it/~dorigo/zbb_tev4lhc.ps
The proceedings are being put together (the deadline for contributions was today) and will soon appear as a yellow book style report.
Non-physicists are encouraged to visit some other entry in this blog at this point. Instead, for you lazy and bored particle hunters out there, I will describe the highlights of the above mentioned excerpt below.
The Z decay to pairs of b-quark jets is difficult to extract from the huge QCD background in hadronic collisions, but is worth the effort. A sizable signal of these decays is being collected during Run II at the Tevatron by the CDF experiment, with a dedicated trigger exploiting the impact parameter of tracks produced by the long-lived B hadrons. The signal can be used as a calibration line to determine the b-jet energy scale factor (JES), which measures the discrepancy between the effect of detector response and energy corrections in real and simulated hadronic jets from b-quark decay. The b-JES is a critical ingredient in all precision measurements of the top quark mass, the JES being the largest source of systematic uncertainty in the determination of that quantity.
A large statistics Z peak is also quite useful as a testing ground for algorithms that attempt an increase in the jet energy resolution, a factor on which the discovery reach of the
Tevatron experiments critically depend, both for all light Higgs boson searches and for the search of more exotic hadronic resonances. Several such algorithms are under development at the Tevatron. One of these, the Hyperball algorithm (my own creation), has been described in some detail in my 2005 Quantum Diaries blog. See for instance http://qd.typepad.com/6/2005/06/the_hyperballs_.html
Full many a Higgs… January 30, 2006
Posted by dorigo in personal, physics.2 comments
My love for English Literature has lived undampened to this day from my high school, when I was infected by my English professor, Alessandro Todesca. I am an ignorant, I must confess: too lazy to deepen my knowledge, I just enjoy the few poems I got to know and love as a student. But I know most of them by heart.
I remember getting on my friends’ nerves once, when I recited - better say shouted - the whole Rhyme of the Ancient Mariner (a ballad by Samuel Taylor Coleridge, in seven verses) during our ascent of Cima Scalieret, an easy but enduring 10000-feet peak in the Dolomites. Since then, I have become aware that reciting poems is not generally considered entertaining, and learned to keep them to myself, when - in vacant or in pensive mood - I have time to
silently spell them and enjoy their purity.
Today I was giving the finishing touches to my contribution to the TeV4LHC proceedings, when I happened to recall four lines from Richard Burns I put in the first page of my Ph.D. thesis. They are from “Elegy Written in a Country Churchyard”:
Full many a gem of purest ray serene
The dark unfathom’d caves of ocean bear;
Full many a flow’r is born to blush unseen
And waste its sweetness in the desert air.
Most certainly they came to my mind due to the combination of my receiving a Kunzite (see pic in an earlier post from today, below) and thinking about the Z boson decay to b quarks, which indeed was the subject of my Ph.D. thesis.
The relevance of these verses to the general melancholy of the Higgs hunter at the Tevatron is obvious… Suffices to say that the Tevatron is currently producing of the order of 20 Higgs bosons per day in CDF and D0, and yet they blush unseen, born by dark unfathomed caves of billion-event datasets, or waste their signal in the desert of a trigger veto.
A Kunzite for my collection January 30, 2006
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Julien arrived today from Fermilab, bringing back a small envelope I had been waiting for three months now… I had purchased a Kunzite on Ebay, but had not had a chance to pick it up from my FNAL mailbox.
Kunzite is a variety of Spodumene, a semi-precious stone of pink color. It is one of my favourite stones, and bought this specimen, a 15cts clear sample cut a’ la portuguese, back in September.
Below you can see how it looks like.
Anand and Topalov January 29, 2006
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The 2006 edition of the Corus chess tournament in Wijk aan Zee, in the Netherlands, finished today with two clear winners (see http://www.coruschess.com/). Corus has been one of the most prestigious chess events for many years now. This time, among the 14 participants figured the bulgarian Veselin Topalov (number 2 in the rating list of January 2006, and current World Champion), and Viswanathan Anand (#3), together with 12 more players among the very elite of the chess world. Veselin and Vishy took first place with 9 points out of 13 after a hot last round, when Topalov was forced to a draw by the ungarian prodige Peter Leko, and Anand won in perfect style a difficult endgame with the israeli Boris Gelfand.
Many years ago I used to follow these tournaments very closely, and a couple times I traveled to the Antwerp (1989) and Brussels (1988) to interview the players and take pictures. I could do this as a reporter thanks to Antonio Rosino, a Fide chess master and a great friend, who credited me as working for the now out of print magazine “Contromossa”, which he directed.
I did publish on “Scacco!”, another italian magazines, the pictures I took in those two occasions. Many made the cover, actually. And I wrote an interview with GM Ulf Andersson. I also interviewed the young Anand back in 1988, when he had just won the junior World Championship and had not yet blossomed. He was following the SWIFT tournament in Brussels as an observer.
Anand was -and as far as I know has remained- a very easygoing person. I remember talking to him on the lounge of a luxury hotel in Brussels (was it the Sheraton ? I forgot that), and offering him a chess puzzle he did not solve!
The problem was indeed a puzzle more than one of those ordinary 2- or 3-movers that grandmasters usually solve at a glance. It had to do with retrograde analysis: to determine the position of the white king, one had to understand how that position had been achieved.
Retrograde analysis is not chess in the pure sense. It is logic in one of its purest form, and the chain of deductions one has to make in order to find the solution of puzzles is at times mindboggling. In a future post I’ll show an example of my own concoction, but for the time being interested readers are addressed to the following excellent site:
Par Condicio January 28, 2006
Posted by dorigo in politics.add a comment
A latin expression, par condicio means “equal conditions”. In Italy par condicio is the catchword for a law that dictates that national broadcasters have to assign an equal share of air time to all political parties involved in an election, once the legislature is ended and elections are close. A democratic rule, you would think.
Our beloved premier does not agree. He considers it “illiberal”. He of course would not mind using his huge mediatic power - his own three private networks, Canale 5, Italia 1, and Retequattro, plus his control of the three national networks Rai 1, Rai 2, and Rai 3 - to brainwash everybody. He tried to abolish the par condicio just before the end of the legislature, but so far has not managed to do so: his lightweight allies object, in the fear of being obscured. Berlusconi did manage, though, to change the rules of political elections, returning to a proportional system of assigning seats based on the percentages obtained by the parties. This is estimated to have gained him 20 to 30 seats in the future parliament, in case of his predicted defeat, making it much harder for a center-left government to legiferate.
Today, the president of the italian republic, Carlo Azeglio Ciampi, for the second time in two weeks asked that the par condicio be enforced with all means, even if the legislature is going to last 13 more days. The legislature had been agreed to end yesterday, but Silvio Berlusconi moved that date two weeks away, to allow himself total use of televisions without the hindrance of the unwanted law.
My son Filippo was expecting to see a movie tonight on Canale 5. Every Saturday, on that network a kids movie is shown at 9PM. Not today. Silvio Berlusconi is on air instead, interviewed by Claudio Martelli, once a politician himself, and now an anchorman for Berlusconi’s networks. Two hours of prime time for Silvio tonight, to be added to the twenty or so he got so far since the beginning of the year.
Are we still a democracy ? Yes, if you look at appearances. No, if you look at the substance of things.
CMS January 27, 2006
Posted by dorigo in physics.4 comments
CMS is a particle physics experiment in construction at the CERN LHC - the Large Hadron Collider, an accelerator for protons that is designed to provide the highest energy proton-proton collisions ever achieved, seven times more than the present record set by Fermilab’s Tevatron collider.
The acronym CMS stands for “Compact Muon Solenoid” (not “Central” as I had mistyped this morning): the focus of the name is on the detection of muons, which are particles very infrequently produced in proton collisions. Their detection provides a clean handle to identify the production of new particles that physicists are trying to discover: the main example is the long-sought Higgs boson, which might be detected when it decays to pairs of Z bosons, each in turn producing a high-energy muon.
Muons are penetrating particles: they can traverse several meters of dense matter without interacting with it other than leaving a ionization trail. All other produced particles in the collision - hundreds of them - can be screened with a meter of steel, so one could just place a ionization detector outside a thick slab of steel to see just muons coming out.
However, physicists are greedy, and they want to know everything about the collisions, not just measuring a muon here and another there. So CMS is actually an enormously complex device, endowed with millions of electronic channels reading tens of different detecting devices. More than 2000 physicists have been working for more than 10 years to put together this incredibly complex device. Another such detector is being built just a few kilometers away: it is the ATLAS detector, a competitor of CMS. Both will benefit from the protons accelerated by the LHC.
CMS is built like an onion: around the interaction point, where protons are smashed together by the intersection of two opposing beams, there are several layers of microstrips detectors - where all electrically charged particles (not just muons) can be tracked thanks to the ionization they leave in 300 microns-thick silicon. As particles escape these inner layers, they enter crystals of lead tungstate - a material that produces light when traversed. Outside of these crystals, thick layers of heavy absorber sandwiching slabs of plastic scintillators provide a further measurement of both charged and neutral particles. Finally, four layers of muon detectors encircle the whole detector.
All in all, CMS weighs more than a battleship. It is an impressive, huge construction, which will be installed deep underground, where the 27-km long tunnel of the collider rests, screening with tens of meters of rock the happy citizens of Geneva from the harmful radiation.
The experiment is expected to start data taking in 2008. If the Higgs boson exists, it will be discovered in not more than one or two years. But things will not end there: many theoretical physicists are convinced that a whole host of yet undiscovered new particles are within CMS and ATLAS reach. These “supersymmetric” particles (there should exist one supersymmetric particle for all ordinary particles already known), if discovered, will change wholly the way we describe the world at the subatomic scales.
What would be the benefit of discovering these new objects to our lives ? We do not know. The idea of finding out more about the physical world is just to deepen our knowledge. Roentgen did not know whether he was doing anything good when he played with vacuum tubes, but as soon as he saw his newly-discovered x rays were able to provide an image of the structure of thick objects, an application was instantly found: a arm bone was fixed after x-raying it just months after the discovery. With supersymmetric particles it might be harder to find an easy application, but science cannot stop…
