So long, Stanisław Lem

March 27, 2006

Stanisław Lem, great Polish author of literatury fantastyczny, has died in Krakow at age 84. His science fiction, written while living under communism, was wonderfully different from the general mode in the West, focusing on humanistic aspects of technology and our concepts of the future. He also had an amazing sense of humor. Unfortunately his obits seem to focus on his writing a book filmed by Stephen Soderbergh.

In his honor, here is where I suggest starting if you want to discover Lem:

  • Nobody can go wrong with The Cyberiad, tales of robot colleagues plying their trade across the galaxy and discovering that “from strawberries under torture, one may extract all sorts of things.”
  • If you are a mathematician (or, better, if you know a couple but aren’t one yourself), you can try His Master’s Voice.
  • If you frequently worry about the end of the world, why not read The Futurological Congress?
  • What about the self-destructive yet irresistable logic of militarization? Fiasco is for you.
  • If you are in a more Borgesian mood, A Perfect Vacuum reviews books that don’t exist, that generally couldn’t be written, and that you’d probably not want to read anyway.

You can, of course, read Solaris, although contrary to what filmmakers would have you believe, it is not about the redeeming power of love; if anything, it is about the impossibility of communication, a slightly different topic.

Dziękuje, i do widzenia.

Hit-and-run

March 22, 2006

hep-ex/0603035 reports on the CDF Run I limits on large extra dimensions, in searches for high-energy diphoton and dielectron events. The production channel is via a virtual graviton. These analyses were, as far as I can tell, the Ph.D. theses of Simona Murgia and John Carlson. I have no idea why this paper is being posted now, and why it doesn’t have a full CDF author list on it. I don’t know if the analyses were ever made final (certainly, unlike DØ’s version, it doesn’t seem that the analyses were published before).

hep-ex/0603041 is a new measurement of the branching fraction of KL → π+ π- from the KLOE experiment. This is the famous decay that established CP violation in the kaon system, since a pure CP-odd scalar is forbidden from decaying to two pions. The KTeV experiment fairly recently redetermined the branching fractions of the major KL decays, and their B(KL → π+ π-) disagreed strongly with the PDG fit central value. The new KLOE result agrees with KTeV.

An aside: I find KLOE rather neat because it has similarities to CLEO, and not just from similar-sounding names. KLOE uses φ mesons produced in electron-positron collisions from the DAΦNE accelerator, which decays to pairs of kaons in a way very analogous to how we at CLEO use ψ” decays to pairs of charmed mesons. Neutral kaons are always produced as a KS KL pair, which allows tagging techniques to be used on the KL. Because the φ basically just falls apart, there is a good chance the KL will decay within the detector, with a displaced vertex. This event display shows a candidate CP-violating event.

Tevatron top mass

March 21, 2006

Tommaso Dorigo points us at a new Tevatron top mass combination (hep-ex/0603039), using Run I and II data from CDF and DØ — get your copy while it’s hot! The headliner is a combined 2.3 GeV uncertainty — or, more exciting, a 1.3% relative uncertainty on the top mass. Sure to slightly-more-tightly constrain the mtop-mW plane for a while to come.

Some features of note:

  • It uses Run II preliminary results for mtop. Since preliminary propagates, the combination is preliminary also.
  • The breakthrough in reducing the systematic uncertainties has been the new technique of calibrating the absolute jet energy scale using the dijet W decays from the top sample (Cornellians may remember the talk given by Pekka Sinervo a while back). This cleans up the QCD background enough so the no-go theorem prohibiting W→jj reconstruction at a hadron collider is violated. This procedure in a sense makes the jet energy scale a measurement, and so the energy scale is actually uncorrelated between statistically independent samples. Quite neat. It’s not absolutely perfect; they still need relative calibration from dijet and gamma-jet balancing, and b-jets have a somewhat different response from light quark jets, but it’s still pretty amazing, and the key to pushing the uncertainties down so far.
  • The combination is dominated by the Run II lepton+jets values which have had this magic in situ calibration, with some slight help from the Run I DØ lepton+jets and Run II CDF dilepton results. Through a miracle of statistics, the CDF Run I lepton+jets result contributes with a negative weight, which we are assured is good for us. Unfortunately Cornell doesn’t have NIM electronically before 1995, and it’s a bit late for a trudge to the library to find out what negative weights might mean.
  • The note number TEVEWWG/top 2006/01 shows that the Tevatron slash-and-abbrev brigade is as powerful as always.

In summary, they threaten us with better than 1% uncertainties on the top mass from the full Run II dataset. Here’s hoping.

The New Doctor Who

March 19, 2006

The new (ok, new to us) Doctor Who series has come to our side of the pond! Well, it came last Friday to the Sci-Fi Channel; I just got around to watching the two episodes of the U.S. premiere, “Rose” and “The End of the World.” “Rose” features an attempted takeover of Earth by plastic objects, and is worth watching if only for the scene involving a murderous trash bin.

Certain things have changed. For some reason, although in the old series the Tardis ventured to alien planets, the dark ages, and the far future, a police box seems much more out of place in contemporary England than it did in anywhere else. The Tardis itself seems to have gotten a significant interior upgrade – it even seems to have a flat screen display now, and the Doctor’s latest regeneration seems to have induced a severe lapse of taste in decor. However it does still sound the same.

As always, Britain is a must-visit for would-be world-destroying aliens. Since the “classic series,” though, the UK has changed quite a bit, and is now a much more multicultural, working-class place, with all those little blue-and-white stickers reminding you to close the fire doors. I’m not sure what the Pertwee doctor would make of the Eccleston doctor, but sure, why not.

The new series seems influenced by more recent British sci-fi (the likes of Douglas Adams and Red Dwarf), and its drama/humor is much more similar to them than to, say, Blake’s 7. I suspect the new format of hour-long episodes make it harder to build the story arcs in the way that five thirty-minute shows did. The new series also spends a lot more time on the Doctor-Companion (Billie Piper) relationship than one is used to; at the end of the first episode, he’s practically begging her to join him…

The special effects bear as much resemblance to those of old as the Airbus A380 does to the Montgolfiers’ balloon, but that’s to be expected.

All in all, very nice. Maybe next year we can look forward to the David Tennant doctor, who I hear prefers geek chic.

“Earth death is scheduled for 1539, followed by drinks in the Manchester suite.” — “The End of the World”

Ge sceal her geclic

March 19, 2006

So M.R. finds the greatest things. Please direct your attention to Geoffrey Chaucer Hath A Blog.

WMAP Three Year Results

March 19, 2006

Starting off:

So we had the privilege of having Cornell’s own Rachel Bean, of the WMAP science team, give a special physics colloquium an hour and a half after the release of the WMAP three year results on Thursday. The results, with exquisite precision, agree with the boring old cold dark matter + dark energy model of the universe’s evolution, with a dark energy equation of state that still looks depressingly like a cosmological constant. Sean Carroll discusses the results further.

I am a physicist.  A particle experimentalist.  I study the charm quark with data from the CLEO-c experiment at the Cornell Laboratory for Elementary Particle Physics.

Why is this blog here?  While theorists and cosmologists slag each other off elsewhere, I thought it would be fun to talk about particle experiment.  And maybe other things.

Thus endeth the mission statement.