Kiwi Particle Physicist

September 19, 2007


This little animation has been doing the rounds since last year. I finally got around to tracking it down on YouTube and posting it. Very moving.

September 07, 2007

Rugby World Cup Odds

The first game of the 2007 Rugby World Cup - France versus Argentina - kicks off in a few hours, and I thought it would be interesting to have a look at the odds on some of the teams before the tournament starts. All odds are taken from the best odds listed on odds aggregator BestBetting.

As of this morning (Japan time) the odds and winning percentages for the traditional top five and Japan are as follows:

New Zealand (1.63, 61.3%)
France (7.60, 13.2%)
South Africa (8.80, 11.4%)
Australia (13.00, 7.7%)
England (36.00, 2.8%)
Japan (5001, 0.02%)

The site also allows you to make graphs showing the change over the last few hours, days, or weeks. See some of the graphs below.

1) Graph showing the change since 2007/07/04 of the decimal odds for various teams to win the Rugby World Cup. Colours represent New Zealand (Black); France (Blue); South Africa (Green); Australia (Canary Yellow); and England (Red) respectively. Japan is not shown.

2) Graph showing the movement of the implied winning percentages of six teams since 2007/07/04. Colours represent New Zealand (Black); France (Blue); South Africa (Green); Australia (Canary Yellow); England (Red); and Japan (Magenta.)

3) Identical to graph 2) above, except with the frontrunners NZ removed and vertical axis scaled so it's easier to see the movement amongst the minnows. Note France, whose winning chances have risen from about 7% two months ago to over 13% this morning.

So there you have it. According to everybody who is willing to put their money where their mouth is, New Zealand have a 61.3% chance of hoisting the trophy, the remainder of the top five are given 35.1% combined, and the other 15 teams a miserly total of about 5% combined (note that the total sums to greater than 100%.) The ABs have dropped a few percent from the start of the tri-nations, but not too much of a shift. The big surprise is the winning chances for the French which have shot up over the last couple of months. Is this based on their performance in the Six Nations, or perhaps everyone is overestimating home ground advantage?

On a personal note, this is my third World Cup in Japan, and as far as I can remember the ABs were overwhelming favourites going into the last two as well. Neither of those ended very nicely. 60% sounds like pretty certain odds - I just hope they don't choke it for the third time in a row.

Typhoon 9

I'm back up at the lab in Tsukuba again, for the first time in a couple of months. We have the annual summer shutdown at the moment, so the accelerator and detector aren't moving. Instead everybody is busy organizing and participating in a variety of summer schools.

Firstly we had Belle Plus, a four day summer school for high school students. This was the second time we held this event, the first being around this time last year. Overall I think it went pretty well. All the students seemed to have a fairly good time and I think we managed to fix a few of the minor problems we had last year. Belle Plus was from Thursday to Sunday last week (8/30 ~ 9/2).

Secondly we have "Belle Sofware Festa" from Wednesday to Friday this week (9/5 ~ 9/7). This is basically an interactive tutorial aimed at students trying to learn how to use the Belle Software, although there are a handful of senior staff who are sitting in as well. I'm not sure if it's a good thing that the people in charge of running the experiment are sitting here asking questions about how to log onto the computers, but at least they're trying. Up until now we haven't really had a common complete set of documentation for the analysis procedure, which has made it hard for new students to get involved with analysis. This event is long overdue, and I'm sure the slides will come in handy for future students as well.

So, that's what I've been up to for the last week or so. There was a bit of excitement last night though as the first major typhoon for the year came through Tsukuba. The animation below, which I took from the IMOC Weather Page site shows the hourly rainfall in central Japan from 10AM yesterday (9/6) until 10AM today (you have to click to view on some browsers.) The peak rainfall were I am was about 30~40mm per hour at just before midnight last night, but it's still pouring down now. Hopefully it will have passed by the time I go home tomorrow.

March 14, 2007

Pi Day

Today, March 14 (3.14) is Pi Day, where we honour what is arguably the most important mathematical constant we know of. Pi was originally defined as the ratio of the circumference of a circle to it’s diameter, but it has a habit of popping up in a variety of unrelated places, for example when calculating particle lifetimes or interaction cross sections. To celebrate today I thought I’d post the number here, up to the end of the Feynman Point, along with a nice animation from Wikipedia that illustrates where the number comes from by unrolling a circle's circumference. Enjoy.

7477130996051870721134999999 and so on

February 08, 2007

ILC Cost Estimate

The Reference Design Report for the ILC has just been released this afternoon in Beijing, China. For the first time the design committee released a "preliminary value estimate" of the cost for the ILC in its present design.

- 1.8 Billion ILC Value Units for site-related costs, such as the costs for tunnelling in a specific region,
- 4.9 Billion ILC Value Units for the value of the high technology and conventional components;
- Approximately 2,000 persons per year or 13,000 person-years for the required supporting manpower (= 22 million person-hours)

Here one ILC Value Unit is equal to $USD1 or about JPY117, so that will come in at about $7b to $8b for the whole project. At one stage some people in the loop were guestimating about $11b, so this estimate sounds a little bit on the cheap side. I hope they can pull it off.

This cost estimate will now have a big effect on the site selection process over the next couple of years, and also on the decision on whether or not to upgrade the Belle experiment and build a Super B factory here at KEK. It will be interesting to get everyone elses reactions here at Belle, although I have a fairly good idea what some of them will be saying already.

Update : The reports are now available for download on the web at the ILC site. The full report [PDF] and a two page outline of the cost estimation [PDF] can be found on the site.

It turns out the above estimate does not include the tunnels for the 1000 GeV Stage Two Upgrade, or the funding to construct the detectors, "which are assumed to be funded by a seperate agreement." This will probably bump the cost up to $8b to $9b for the 500 GeV Stage 1 project, excluding the costs for land aquisition.

December 18, 2006

Great Weather

Brilliant high resolution photo of the most recent spacewalk from NASA

It was taken at December 12 during the first EVA of the mission, and shows the astronauts installing a new truss segment. You can see the lovely weather in New Zealand in the background. Country looks great. Can't wait to get home in a week from now.

November 17, 2006

BGM/Luminosity Party!

During the meeting two days ago we heard that the KEKB accelerator team had reached a new world record luminosity of 17/nb/s. It’s been over a year since we hit 16/nb/s, so it’s well overdue. Oide san, who is in charge of the accelerator, promised us we would have 30/nb/s by this time next year though. We were originally planning on having a party last night anyway, like we do for every BGM, but it took on a new meaning with this result.

Unfortunate Timing...

More photos are here, here, and here, although some of them might only work from inside KEK.

Afterwards a few students headed back to the dorm for round two. This used to be a standard procedure whenever there was a meeting here, but recently we never seem to be able to get enough people together. A lot of students left the experiment last year after finishing their masters degrees. On top of that, quite a few of those who are left have moved up to Tsukuba permanently, so there aren’t normally very many of the old crowd together in the dorm anymore. Last night though there were about ten of us, so we bought a few drinks and snacks beforehand and sat in the lounge yapping until about 3-ish. Good evening. Missed the start of the meeting today, but it was worth it.

November 16, 2006


Spent most of yesterday afternoon trying to recover the data I wiped. Luckily I had a backup from just four days ago on the computers in Osaka, and I hadn’t made too many new changes since then. I basically just copied all the old data files and scripts from the corresponding directory back to the Belle computers, tweaked a few of the scripts, and then ran them again to recover the changes since the last backup.

Things could have been a lot worse. Ever since the hard disk on my Mac PowerBook G4 kicked the bucket last December -- taking my masters thesis and two years worth of presentations and notes with it -- I’ve been very careful about taking backups. I usually back up data on the uni and Belle computers every couple of days, important files on the PowerBook every week or so, and the rest of my files about once a month. Strongly recommend it (mum!).

While I’m at it I think I’ll use this chance to plug the Mac’s. The service I got when the disk packed it last year was awesome. It’s not unusual for hard disks to bury themselves, especially on laptops, but the Mac guys here in Osaka came and picked it up, replaced the disk, and had it back to me in three days over the Xmas holidays. They even replaced it with a new 60GB disk free of charge because they had run out of 40GB version! Highly recommend them.

I’m up at the lab since Tuesday evening for a three day BGM (Belle General Meeting). We have a party tonight and then the last day of the meeting is tomorrow. Will probably head back to Kyoto on Sunday. Off for a run before I start on the beers.

November 15, 2006


I was just using the Belle computers this morning trying to get some work done on my analysis. I wanted to wipe all my old files that start with "fp", so I tried to type
rm fp*

Except instead I ended up with
rm fp *

I'm awesome! At the time I was in the directory with all of my data files and the scripts which I use to run the analysis on them. I have an old backup from a few days ago in Osaka, but it's going to take a while to get everything back to where it was. I think I'll go for a commiseration beer.

October 25, 2006

Bottom Baryon Discovery

Congratulations to CDF on the discovery of the Sigma_b plus and the Sigma_b minus, the first baryons to contain a bottom (b)-quark.

In addition to the stable up (u) and down (d) quarks, which make up ordinary matter, there exist heavier unstable quarks named strange (s), charm (c), bottom (b) and top (t), which can be combined to make exotic particles that don’t occur naturally in the world around us. The Sigma_b plus (uub) is an exotic relative of the proton (uud), where the bottom quark has replaced the usual down quark. The Sigma_b minus contains a b-quark and two d-quarks, and is a relative of the less well-known Delta minus.

Tomasso has a good post on the discovery, where he shows the graph below of the mass distribution of the Sigma_b candidates they found, and there is also a good explanation of the discovery on the Physorg page, from where I borrowed the above diagram.