Thursday, 30 May 2013


I'd just like to offer my congratulations to Vincent Audin and Bruno Boileau for becoming the first same-sex couple to wed in France.  Another useful reminder that sometimes, things can get better.  May many other French couples be able to follow and gain the happiness of a full legal union.

Monday, 27 May 2013

Never Miss a Trick

Ah, Labour.  Just when I was warming up to you again after the Blair/Brown years, you show excellent timing.
Labour and the Conservatives could unite to push through the controversial communications bill despite Lib Dem objections, a former Tory leader says.
The bill, allowing the monitoring of all UK citizens' internet use, was dropped after a split in the coalition.
But Lord Howard said David Cameron had "to act in the national interest" following the Woolwich murder.
Labour leader Ed Miliband has said that "if he [the PM] wants a communications bill, we'll help him get it through".
Never let it be said that the Americans are the only ones to respond to a terrorist incident with a broad suppression of civil liberties.
The Communications Data Bill would have given police and security services access, without a warrant, to details of all online communication in the UK - such as the time, duration, originator and recipient, and the location of the device from which it was made.
But it's okay!  Only the guilty have anything to fear from the police.  There is, of course, no reason to want privacy apart from the desire to conceal your criminal actions.  If you're not willing to do something in public, it must be wrong.  And sarcasm will be a capital offence.

Saturday, 25 May 2013

Planck 2013 Summary Talk

There's one talk left at Planck this year, the summary/outlook talk.  But I've decided I don't feel like live blogging this one.  Sorry!

Friday, 24 May 2013

Planck 2013 Day Five Live Blog 3

Lunch ran long, so I missed the first  two talks.

Planck 2013 Day Five Live Blog 2

Okay, some much-needed coffee and it's time for the second session of the morning.

Planck 2013 Day Five Live Blog

Final day of the conference, and we're back to purely plenary (including review) talks.  As I have every day I pass on the first review talk.  There doesn't seem to be an obvious theme of the day.

Thursday, 23 May 2013

Planck 2013 Day Four Live Blog 2

Last parallel session of the conference, and I'm staying with the Higgs talks.  Even if this session will run till 6pm.

Planck 2013 Day Four Live Blog 1

So, last night was the conference banquet and this morning we had string theory talks.  A combination of events that gave me little motivation to attend and less to pay any attention, hence no blogging from me.  After lunch, we have the last set of parallel talks, and I think I'll be attending the Higgs talks.  My own talk here was on a similar subject, albeit off in one of the BSM sessions, and it is an obviously exciting area right now.

Wednesday, 22 May 2013

Planck 2013 Day Three Live Blog 4

Last parallel session of the day, and I'm going to the Dark Matter session.  Conference Website.

Planck 2013 Day Three Live Blog 3

We kick off the afternoon talks with a parallel session on BSM physics.  Conference Website.

Planck 2013 Day Three Live Blog 2

Second morning session, after a much-needed coffee break.  We continue the study of flavour physics.  Conference website.

Planck 2013 Day Three Live Blog

Once again, I've come into the first review talk halfway through, so I won't comment on it.  Well, other than to note that despite having an hour, he still managed to run ten minutes over.  The theme of the morning is flavour, a topic I never find as interesting as I should.  Conference website.

A Small Thought

It seems to be currently popular to compare UK Prime Minister David Cameron to John Major.  For example, this was raised directly to him in a recent Today programme interview, see here.  This is unfair.

Not only did Major win an outright majority in parliament, more people voted for his Conservatives in 1992 than have voted for any political party in UK history.

Tuesday, 21 May 2013


Unfortunately, I'm going to have to stop my live blog as my laptop is running out of power.  The lack of power outlets in the lecture halls strikes again!  Tomorrow, I'll be sure to charge up fully in the morning.

Planck 2013 Day Two Live Blog 3

After lunch, for the first parallel session of the conference.  I've chosen to go to the LHC session before the coffee break.

Planck 2013 Day Two Live Blog 2

Second Plenary session, first after the crucial coffee break.  Conference website.

Planck 2013 Day Two Live Blog 1

The first talk of the day was a cosmology/dark matter review.  I arrived late, halfway through the talk, and it was explicitly a review so I left this talk alone.  We follow this with the first plenary talk of the day.

Planck 2013 Day One, Live Blog 2

A fourth parallel session of the day.  Conference website.

Planck 2013 Live Blog: Day One

Okay, this post technically isn't a live blog.  I unfortunately missed the morning sessions, due to a combination of jet lag, lack of sleep and not being able to find the conference.  I did manage to attend the first session after lunch (the third plenary session), but I did not have internet access at that time as I hadn't registered.  But I did take notes, with the intention of putting them up later.  Conference website.

We had three talks: a good if slightly unclear advert for a linear collider; an inflationary talk that I found a bit hard to follow; and a talk that was half software-advert, half the-CMSSM-isn't-ruled-out-yet-honest.

Tuesday, 14 May 2013

Good News Round Up, Marriage Edition

Minnesota legalizes gay marriage:
With deafening cheers and overwhelming emotion, the Minnesota Senate voted 37-30 to legalize same-sex marriage.
“Today, love wins,” said Sen. Tony Lourey, DFL-Kerrick.
Technically it still needs to be signed by the Governer, but he has long stated his willingness to do so.

Hong Kong woman wins right to marry:
The Court of Final Appeal ruled that Hong Kong's current law, which barred the transsexual woman from marrying her male partner, is unconstitutional.
It's nice to remember that things can get better.

Monday, 13 May 2013

Yet Another Shooting

Oh look, its another shooting incident in the USA.
As many as 12 people have been shot during a Mother's Day parade in the US city of New Orleans, police say.
Police Supt Ronal Serpas told reporters that three or four people required surgery but no deaths are reported.
The victims included a 10-year-old girl who suffered a minor wound, he added.
It is unclear what sparked the shooting, which happened in the city's 7th Ward on Sunday afternoon. Police say two or three suspects were seen fleeing the area.
As usual, I have mixed feelings.  On the one hand, the US has made it clear that they value guns over innocent lives many, many times, and it won't be my children who are sacrificed to the Great God Second Amendment.  On the other hand, I'm not as lacking in basic humanity as the previous sentence suggests; plus I have American friends, who I'd like not to get randomly shot one day.

Brookhaven and Pheno Review

With these two conferences behind me, and my trusty laptop back in my hands, I'd like to briefly reflect on them as a whole.  Both conferences were, unsurprisingly, quite similar; same general area, same length, same structure, even a few of the same talks, most notably from Marc Kamionkowski on cosmology.  The biggest difference between the two was size, Pheno having at least twice as many participants.

What, then, can we take away?

Monday, 6 May 2013

Pheno 2013 Live Blog

I am abanding this live blog, as it is impossible on this total piece of shit tablet.  I leave what is below for posterity.
I'm unfortunately on a tablet right now, which will be a problem.

Talk 1: Cristina Blino: SM Results from LHC

We start with a review of theSM results from the LHC.

Actually, we start with some bad feedback, but that's been fixed now.

Usual stuff, namely illustrating the challenge that the experimentalists must face with pile up, for example.  It convinces me; I think the whole thing is black magic.

Standard Model  background to the interesting stuff, but it describes the data so qell over so many orders of magnitude that it is really a bit too good.

Writng on this tablet is awful.

Despite the LHC being a hadronic machine, and thus not clean, the high luminosity has already let to some impressive precision, especially for the gauge bosons (leptonic modes).

Forward-Backward asymmetry in lepton pair production.  Any asymmetry at LHC is tricky, due to symmetric initial state.  Measured, agrees with lepton machines; relevant for future studies of ttbar asymmetry.

W-photon production slightly in excess of theory; look into this later.

Triple gauge couplings are a common result; I don't actually know what models would show up there.  Limits improve, of course.

One problem with some of these plots for diboson production, is that it's not clear if theoretical errors are shown.  Some of jh the measurements are slightly off the theory lines, but I expect there's still one-sigma agreement.

Top Quark:
  • One top pair per second.
  • Cross Section already systematics-dominated.
  • Ah theory errors shown here.  Even the small difference from 7 to 8 TeV cross section can be resolved.
  • Single top; errors here still relatively large.
First talk runs long.  Not an auspicious opening.

In summary, we have a terrifying array of data, with precision and agreement with theory that is both impressive and intimidating.  The most interesting result I saw was the W-gamma measurement, which probably isn't significant but right now we can't be too picky.

Talk 2: K.K. Gan: BSM searches at LHC

The obvious folow-up to the previous talk.

I really fucking hate trying to write on this tablet.  I'm spending far tpo much time fighting the fucking interface.  And forget correcting typos, that would imply being able to move the fucking cursor, and clearly that's an unreasonable functionality to expect.

SUSY: standard motivations.
  • Stop searches; leptons plus MET.
  • The degenerate slices still exist.
  • Coverage away from that is pretty good.  Exclusion up to order 400 GeV.
It's notable how the results immediately fpocus on stops.  No time wasted on traditional searches.  That's  the time we live in.
  • Heavy stop pairs, decaying to stop plus Z.  Gah, missed the limits there.
  • Gluino pair production, decaying to stops.
  • The usual TeV exclusion.
  • Two things occur to me.  How much wiggle room remains in the degenerate regimes, and can such a specyrum even arise in a top-down manner?
  • The pMSSM papers can probably answer that first question.
  • Squark and sbottom searches slightly underperformed expectations.  Interesting.
  • Electroweak production; chargino-neutralino production.  Three leptons, clean to compensate low cross section.
  • Limits on LSP up to 200 GeV for appropriate spectrum.  Chargino to 600 GeV for same assumptions.
  • Just lost a minute trying to make this thing work.  Fuck.
In summary: SUSY continues to look dead.  Lecture says don't worry; we can never exclude SUSY,so we have plenty of job security!

  • Exotica: Z primes?  Really, not very exotoc.  Of course, eady for experimentalists thanks to leptons.

Saturday, 4 May 2013

Brookhaven Forum Day 3 Blog II

Final session of the conference.  Conference Website.

Talk 3: 10:50am: Lloyd Knox, "The Universe According to Planck"

With Planck having recently presented results, it is natural to have a review from a member of that collaboration.

The better experiments always have the funkiest animations.

Did he just say the released data is only 40% of what they took?  I thought almost all results were out.

Detection of gravitational lensing at the absurd 25 sigma.

The usual argument for the origin of the density fluctuations, seen in the CMB and seeding structure formation, but the slides are quite nice.

LambdaCDM fits the data with ridiculous non-trivial precision.  Things that are needed and have no free parameters:
  • Neutrinos
  • Neutrino cooling
  • Helium (for BBM consistency)
  • Non-equilibrium recombination
  • Gravitational lensing

Sound horizon at surface of last scattering:
  • Directly measured from CMB
  • Imprints itself in large scale structure, c.f. BOSS experiment.

Constraints on Non-Gaussianity.
  • Inflation, of course, predicts small non-gaussianity in almost all models.
  • Some non-Gaussianity inevitable from gravitational interactions, so measurements all relative to that.
Interesting statement; there is a small tension in the value of H0 measured at Planck and at other experiments, but this can be ameliorated with additional light (relativistic) degrees of freedom.  I must look into this in more detail.

So in summary, everything works.

Talk 4: 11:30 am: Juan Maldacena, "Recent Advances in Formal Theory"

So to end the conference we have the traditional big name to keep people's attention.  I've never heard Juan speak, so I don't know what to expect.  I do worry that this subject might be a bit too much for me after a late night drinking yesterday, though; we'll see.

  • QFT works; we haven't seen any violations at the LHC etc.
  • There nonetheless remain some theoretical problems, gaps in our understanding.
  • Computational techniques; we've seen some of that here already.
  • Strong couplings; strings?
  • Fixed points and renormalisation flows; I recall the recent kerfluffle over the a theorem.
  • No surprise that AdS/CFT is brought up!
The topology of this talk is multiply-connected.

  • The extra symmetry often makes the theories simpler; no surprise to see N=4 SYM brought up.
  • Work in N=2, N=1 and even N=0 :)
N = 4 SYM:
  • Maximally supersymetric U(Nc) QCD with coupling g
  • All fields lie in the adjoint representation
  • Planar limit: Nc to infinity, g^2 Nc fixed
Connection to strings: chain of gluons behaves like a string; closed strings are glueballs.  The string coupling goes like 1/Nc, hence the planar limit is the very weak coupling limit.

Discussion on loops in RGE flows; will we get enough details?  No, just a quote of the proof.

Some discussion on entanglement that seems to be related to the black hole entropy, and the way in which surfaces seem to describe the volumes they contain.  My head is dropping, though, and I didn't manage to follow the details.

Friday, 3 May 2013

Brookhaven Forum Day 3

Unfortunately, I missed the first talk this morning on direct detection of dark matter.  I'm really not much of a morning person in general, and the last day of a conference is always a bit tricky because you start to flag.

Still, ready for the second talk of the day.

Talk 2: 9:40 am: Tracy Slater, "Dark Matter Phenomenology and Indirect Detection"

Brookhaven Forum 2013 Day 2, Live Blog IV

Final session of the day, the "New Ideas/BSM" session.  Conference Website.

Brookhaven Forum 2013 Live Blog: Day 2, Blog III

After that slightly disappointing (from my point of view) plenary session, its time for the parallel sessions.  The ability to select which session to attend should ensure I'm listening to relevant talks, I hope!  In particular, I've decided to hit the Higgs/BSM talks for the first session this afternoon.  Conference Website.

Brookhaven Forum 2013 Day 2 Blog II

This session is more on strongly interacting stuff, so I'm less optimistic, this being somewhat away from my primary interests.  We'll see.

Thursday, 2 May 2013

Brookhaven Forum 2013 Day 2

So, yesterday was a pretty good day that reminded me just how much I enjoy conferences.  Hopefully today can continue to deliver.  Conference Website

Brookhaven Forum Live Blog IV

First Parallel session.  Conference website

Abhishek Kumar, Searching for Very Light Stops
  • Stops relevant for naturalness, take the case m_stop < m_top.
  • Non-standard stop decays: b-W-neutralino with W on/off shell, c-neutralino.
  • Use MFV to handle the flavour-violating decays.
  • Flavour-violating decay can dominate over four-body decay, even when both are allowed.  Depends on left/right handed nature of lightest stop.
  • ISR needed to account for MET properly.
  • Limits up to ~250 GeV.
Sujeet Akula, Gluino-driven Radiative Breaking in Grand Unified Supergravity
  • Pointed towards Higgs to two photons, among other things, as evidence for light sleptons
  • Of course, also lots of things that push SUSY scale up.
  • Good talk, but too long on the background.  Get to what's new before you run out of time!
  • Basic structure: gluino mass at GUT scale is much larger than the other soft masses.
  • Heavy gluino drives squarks heavy and radiatively breaks EWSB.
  • Higgsino mass mu also driven large.
  • Large seems to mean a factor of 10.
  • Non-universal gaugino masses need non-trivial GUT-scale Higgses.
This is claiming a lot for only tweaking the CMSSM by one number.

Eva Popenda, Squark Pair Production at NLO matched with Parton Showers
  • NLO standard is Prospino, which assumes that all squarks degenerate.
  • Go beyond that for the first time in an event generator.
  • This is all a bit technical for me.
  • Even when squarks degenerate, subchannel cross sections disagree: Prospino assumption (all subchannels identical) not exact.
  • NLO corrections can give ~20% corrections to shapes of distributions.

Brookhaven Forum 2013 Part III

First session after lunch, and we have a cosmology talk from Marc Kamionkowski.

Brookhaven Forum 2013 Live Blog II

New session, new blog.

Wednesday, 1 May 2013

Brookhaven Forum 2013 Live Blog

For the next two-and-a-half days, I'm attending the Brookhaven Forum 2013.  I was here three years ago, and enjoyed it then.  Sadly I had to miss the last meeting, but I'm glad to be back.  I'm not expecting anything dramatic here, but I'm going to live blog the conference in lieu of taking notes.  This way, I might actually go back and look at what I've written before!