Comment on the Number of Flavors in Standard Model
A widely used definition (see e.g. Wikipedia for a summery) of the number of particle ‘flavors’ in the SM is 6: 3 particle mass copies (e. g. electron, muon, tau for charged leptons; u, c, t for up-quarks …) doubled by the two up- and down- states.
Flavor is still a mystery in the SM. Historical Rabi’s quip “Who ordered the muon?” is steel urgent now for the three flavor mass copies of elementary particles.
I believe that the recent discovery of gravitational waves has been described in enough detail by reporters and bloggers around, that my own contribution here would be pointless. Of course I am informed of the facts and reasonably knowledgeable about the topic, and my field of research is not too distant from the one that produced the discovery, so I could in principle offer something different from what you can find by just googling around. But I have a better idea.
What I think you cannot read elsewhere are the free thoughts I had as I listened to the announcement by the VIRGO collaboration. So maybe this may be a different kind of contribution, and of some interest to you.
In recent releases announcing the forthcoming publication of new results on the detection of gravitational waves, the collaborations LIGO
, as well as the Centre National de la Recherche Scientifique (CNRS
, France), explicitly (and wrongly) attribute to Albert Einstein the original prediction of th
LIGO the Laser Interferometer Gravitational-Wave Observatory may announce the detection of gravitational waves tomorrow at 10:30AM Eastern time. I will watch it and live tweet it. The question of the day for most normal people will be... What are gravitational waves? See below for the answer to this question, and below that a live stream of my tweets on the subject as it happens.
UPDATE: The Perimeter Institute a hub of theoretical physics research will have their own livestream following the LIGO press conference.
UPDATE2: Updated to display a collection of my tweets on gravitational waves during and near the time of the press conference.
The Large Hadron Collider is probably the world’s most famous science experiment. The 27 km-long ring-shaped particle accelerator beneath the edge of the Alps grabbed the world’s attention in 2013 when it proved the existence of the Higgs boson particle. This helped physicists confirm that one of their key theories about the way the universe worked was correct – a huge step for science.
But particle accelerators also have a big impact on our real lives. Even Christmas wouldn’t be the same without them.
After the ATLAS and CMS collaboration disclosed their first Run 2 results on diphoton searches, less than two months ago, the realization that it would be impossible to keep up-to-date with all the theoretical ideas that were being put forth was immediate. The flood of papers discussing the 750 GeV bump was - and still is - too much to handle if reading papers is not your primary occupation.This is unfortunate, as many of my colleagues believe that the new tentative signal is real.
(Click this link
for a step-by-step derivation of the "Hamilton-Jacobi Schrödinger" equation) (Let me know about link issues to PDF)
Sir Willian Rowan Hamilton realized the equivalence of the Hamilton-Jacobi equation and the eikonal in 1834. With a little bit of imaginary work theoreticians of his time could have derived a quantum mechanical Hamilton-Jacobi equation equivalent to the Schrödinger equation.
With a long delay, last week I was finally able to have a look at the book "From the Great Wall to the Great Collider - China and the Quest to Uncover the Inner Workings of the Universe", by Steve Nadis and Shing-Tung Yau. And I would like to report about my impressions here.
The following text, a short excerpt from the book "Anomaly!", recounts the time when the top quark was about to be discovered, in 1994-95. After the "evidence" paper that CDF had published in 1994, the CDF and DZERO experiments were both running for the first prize - a discovery of the last quark.
Being back in blogging mood, I decided I would make a poll among the most affectionate readers of this column - those who will come here to read "blog" pieces and not only "articles which are sponsored on the relevant spots in the main web page of the Science20 site.
The idea is that I have a few topics to offer for the next few posts, and I would offer you to choose which one you are interested to read about. Of course, you could also suggest that I write about something different from my proposed topics - but I do not guarantee that I will comply, as I might feel unfit to the requested tasks. We'll see, though.
Here is a short list of a few things I can spend my time talking about in a post here.
- recent CMS results
- recent ATLAS results