Extracted and typed by T.D. Gutierrez from a series of appendices in Diagrammatica by Nobel Laureate Martinus Veltman.

Download the plain version of the
Standard Model Lagrangian Density:
[ps][pdf][tex][txt]

Or download a "fun yet soul-crushing exam question" based on it:
[ps][pdf][tex][txt]

As far as I'm concerned, do what thou wilt with the equation as I've
presented it: reformat it using your own favorite LaTeX methods, have fun
inventing your own exam questions, or use it as is in your talks, web
pages, and
presentations. And, of course, there's the ever popular parlor game
Find the Sign Error. But first, a few things you should know...

The version you see here is a "post-electroweak symmetry breaking" form of
the Lagrangian and, although not inaccurate, it may not be its most
elegant or transparent form.

By this I mean it includes some specific form for the
Higgs fields and Fadeev-Popov ghosts, making things quite messy
(and model-dependent; although it's probably more "honest", depending on
your point of view).

A cleaner version and description (written sans Higgs,
and sans ghosts) can be found here.
An organized Veltman-like presentation can be found here.

**Lagra HUH?**
If you don't already know what a Lagrangian is, I probably won't be of much
help here. In short, if you know The Lagrangian, in principle you know everything there is to know about a
system -- even if you might have to work hard to get it. It is essentially an
ultra-compressed way to write A LOT of information.

**Where did I get it?**
It was compiled from the appendices of Veltman's book Diagramatica (thus the quasi-standard notions).
However, aside from somewhat irritating non-standard notion, the book is quite readable and pedagogically
useful. Also, kudos to Veltman for having the complete SML at all, even if it is spread out over many pages
in an appendix.

**How long did it take to type?**
In it's current form, the actual equation took me about four hours (spread over almost a week)
to write into a file using LaTeX. Sadly, I do think there is a sign error somewhere, but I
just don't have the energy to hunt it down... :(

**Why bother?**
Admittedly, it isn't particularly *useful* in its current form (especially since I haven't mentioned
what the notation means!). It is meant to be a kind of "visual treat", if
you will, seeing all the
different sectors written together. If you stare at it long enough (squinting helps) you can start to
induce nearly hypnotic hallucinations. What do YOU see in the Standard Model Lagrangian? (oddly, "a bunny"
seems to be the most common response)...And who says our
current best Theory can't fit on a T-Shirt (I've just ordered the first batch!)...

**I am familiar with quantum field theory and the Standard Model, but many parts of the Lagrangian look
unfamiliar; what the hell are all the terms?**
I'll be putting a legend up soon. Again, Veltman uses somewhat non-standard notation and compression
(e.g "u" means "up-like quarks"). If you are already familiar with the Standard Model then
you will probably recognize many parts of the Lagrangian already. The Higgs ghost fields (in the
electroweak sector) were particularly unfamiliar to me and seem
to take up quite a bit of the bulk of the equation.

Posted Circa 1999

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