New LEP Paper

Twelve years ago, LEP -- the Large Electron-Positron collider -- finished taking data.  That's so long ago I was still an undergraduate, YouTube and Facebook didn't exist and even Google was relatively unknown.  So I was quite surprised to see a new paper on the arXiv from the LEP collaborations.

Not So Great

I've been living outside of the UK for over a decade now.  In the last couple of years, I've started to notice ads as part of the 'Great Britain' campaign, aiming to raise the profile of the UK for tourism, industry, investment and so on.  I don't remember ever seeing anything similar before this, so at the least it's a more aggressive promotion than recently.  The government obviously realises that in a global market you have to compete with other countries for these things.

Sometimes, you've got to laugh.

Please don't come to Britain – it rains and the jobs are scarce and low-paid. Ministers are considering launching a negative advertising campaign in Bulgaria and Romania to persuade potential immigrants to stay away from the UK.

The plan, which would focus on the downsides of British life, is one of a range of potential measures to stem immigration to Britain next year when curbs imposed on both country's citizens living and working in the UK will expire.

Quote of the Day

Physicists are only human (honest).  We like to crack the odd joke, even if our sense of humour can be a bit odd.  I have a friend whose advisor once put Harold Ramis in the acknowledgements of a paper on removing ghosts. There seems to be a competition going on in astro-ph for the most absurd paper title.  And then there's what I came across today, reading an old paper from the CTEQ collaboration.  Buried on page 6 was this little gem:

The two-part structure of χ2 loosely resembles a bicameral legislature such as the US Congress, where votes in the House are proportional to population—data points in our case—while votes in the Senate represent specific entities—experiments or data sets in our case.

At least it's not the House of Lords.

Physics at Different Scales

Back in November I wrote two posts about the problem of infinities in quantum field theories.  In the first of those, I introduced the two types of infinities that arise: infrared infinities, that happen when a kinematic variable goes to zero; and ultraviolet infinities, that come from the need to integrate (sum) amplitudes over an infinite volume.  In the second post, I explained how infrared divergences are resolved: the infinity occurs in something that is unmeasurable.  For example, it is impossible to distinguish between the production of an electron-positron pair, and the production of the same two particles plus a photon, if the energy of the photon is very small.  When making predictions, we need to include not only the things we do observe, but also the things we cannot; only then can we get well-defined answers.

Today, I want to return to this mini-series and discuss ultraviolet infinities.  I hope to outline the solution to this problem, which is a bit trickier.  This will lead on to the point I really wanted to get to from the beginning, which I'll have to leave for a final post by the end of the month.

Tasmania

So, after commenting on how I hoped to stay more current with this blog at the start of the year, I went silent for a week and a half.  I do have an excuse; I was travelling around Tasmania on a fairly impromptu vacation. A good chance to get out of town for a few days and see something different, but my net access was limited.  Now I'm back, somewhat refreshed and feeling better for it.  I would have posted explaining things before I left, but my connection here went down the night before.

I hope to make a more substantive post over the weekend, but not about my trip.  I don't plan to turn this blog into What I Did On My Holidays -- no plans to start a revolution.  Although, after living in Australia for several months, I have finally seen a kangaroo!

Age of Wonders

Sometimes, you have to stop and remember just how amazing the modern world is.  For example, this recent story about the first UK hand transplant:

A former pub landlord from West Yorkshire has become the first person in the UK to have a hand transplant.  Mark Cahill, who is 51, had been unable to use his right hand after it was affected by gout.  Doctors say he is making good progress after an eight-hour operation at Leeds General Infirmary.  It is still very early to assess how much control of the hand will be gained - so far he can wiggle his fingers, but has no sense of touch.

Transplants have become commonplace, almost boring.  But really: we're talking about replacing someone's hand.  There's a lot of stuff going through the wrist; blood vessels, nerves, muscles; and we (as a species) can connect that?  And make it work?

Hell, I didn't even realise till reading the article that this is not that new; the first hand transplant was almost fifteen years ago.  Just as long as we can avoid the world of Gil `the ARM' Hamilton.

Child Benefits

One inevitable consequence of living in another country is that you don't always stay on top of politics at home.  For example, yesterday I saw an article on the BBC about UK child benefits:

Some 200,000 people - of 1.2 million - have opted out of receiving child benefit, ahead of changes on Monday.  Treasury Minister David Gauke said that was "slightly above" what was expected.  Families with one parent earning more than £50,000 will lose part of the benefit. It will be fully withdrawn where one parent earns above £60,000.  But unless parents opt out of receiving it by the end of Sunday, higher earners will still get the benefit and will have to pay it back later.

The point of this news article is about how the changes to child benefits are working.  In particular, the system where benefits are by default paid but then must be repaid is not exactly efficient, and will probably be unpopular.  The fact that only one in six of the families affected by the new rules have acted suggests that the policy has not penetrated popular consciousness.

But as someone who hadn't seen the changes, I respond to them instead.