Physics

James D. Bjorken, also known as "BJ" by colleagues and physicists around the world, has been awarded the prestigious 2015 Wolf prize in Physics together with cosmologist Robert Kirshner. Bjorken deserves a lot of credit for his contribution to subnuclear physics: the official motivation is 

"For predicting scaling in deep inelastic scattering, leading to identification of nucleon's pointlike constituents "

Today I collected in my mailbox the hefty "Review of Particle Physics", the publication of the Particle Data Group which contains a summary of everything we know about subatomic particles. For the first time, the publisher is a Chinese journal: Chinese Physics C. This might be considered a detail, but it is a sign of times: China has been increasing its involvement in fundamental physics research in the last decade, and it may well become the leading country in this business in the future.

In this post, I will provide the ultra orthodox fringe view (translation: just my view) on the problems that face physics when doing classical problems with gravity.  The difference between this blog and a more conventional presentation is that I will emphasize the problems instead of starting off with the leading proposals of the day.

ATLAS sent today to the Cornell arxiv and to the journal JHEP their latest measurement of the top-antitop production asymmetry, and having five free minutes this afternoon I gave a look at the paper, as the measurement is of some interest. The analysis is done generally quite well, but I found out there is one things I do not particularly like in it... It does not affect the result in this case, but the used procedure is error-prone. 

But let's go in order. First I owe you a quick-and-dirty explanation of what is the top asymmetry and why you might care about it.
Me

Me

Jan 30 2015 | 6 comment(s)

This blog - which, in different sites, has been online since 2005, hence for over 10 years now - enjoys a core of faithful readers, who over the years have learnt more detail on my personal life than they probably thought they'd need. But it also occasionally attracts larger crowds of web navigants with an interest in particle physics. They have all rights to not know who I am and whether I am a 20yo geek or a retired professor, male or female, etcetera. 

Time-dependent Maxwell's equations in media 

By Robyn Arianrhod, Monash University

It’s hard to imagine life without mobile phones, radio and television. Yet the discovery of the electromagnetic waves that underpin such technologies grew out of an abstract theory that’s 150 years old.

Can a penalty kick simultaneously score a goal and miss?

In the realm of quantum mechanics that is certainly be true, because microscopic objects can take different paths at the same time.  Almost 100 years ago physicists Werner Heisenberg, Max Born and Erwin Schrödinger created this new field of physics which would be called quantum mechanics. Objects of the quantum world, according to quantum theory, no longer move along a single well-defined path. Rather, they can simultaneously take different paths and end up at different places at once. Physicists speak of quantum superposition of different paths.  
The publishing giant Elsevier is about to launch a new journal, Reviews in Physics. This will be a fully open-access, peer-reviewed journal which aims at providing short reviews (15 pages maximum) on physics topics at the forefront of research. The web page of the journal is here, and a screenshot is shown below.

The CMS collaboration has released yesterday results of a search for Majorana neutrinos in dimuon data collected by the CMS detector in 8 TeV proton-proton collisions delivered by the LHC in 2012. If you are short of time and just need an executive summary, here it is: no such thing is seen, unfortunately, and limits are set on the production rate of heavy neutrinos N as a function of their mass. If you have five spare minutes, however, you might be interested in some more detail of the search and its results.

I live in Massachusetts, home of the National Football League team the New England Patriots.  I admit to being a fan, being raised as a Minnesota Viking by two enthusiastic parents.  The Vikings have been to two super bowl 5 times (and lost 5 times, ouch).  Since 1980, I have lived in Massachusetts where the Patriots know how to win the whole thing.  Does that method involve cheating?