Entries - S


Think before you use this word. Can you be more specific? What kind of scientist are they? A physicist? A theorist?

Avoid empty phrases such as: Scientists have learned in recent years that... Such a construction doesn't convey any useful information.

See forbidden words



Is preferable to colloquiumWe're writing in English, not Latin.



No hyphen. 

In 2013, the Large Hadron Collider (LHC) will start its first long shutdown for maintenance.

Do not confuse the noun will the phrasal verb:

The research project was shut down due to lack of funding.



The SI unit of dose equivalent (the biological effect of ionizing radiation), equal to an effective dose of a joule of energy per kilogram of recipient mass.

symbol: Sv



Number, no hyphen (except as a compound adjective), lower case "s"

Particle physicists describe the certainty of a result on a scale that goes up to 5 sigma. One sigma could be a random statistical fluctuation in the data, 3 sigma counts as evidence, but only a full 5-sigma result is a discovery. By definition, the probability that a 5-sigma result is wrong is less than one in a million.

1 sigma

3 sigma

5 sigma etc. 

The certainty of the result was given as 3 sigma.

physics, style

sign in

And sign out

Never "Log in, log out".

Note for web developers: This functionality should be handled by the CERN toolbar.



Never use a "smiley" icon in any CERN communication



CERN follows the “British English” rules for spelling, set out in the Oxford English Dictionary.

Check this style guide first for exceptions and points of grammar, then consult the OED.

For guidelines on writing in French – for CERN websites and print documents alike – refer to the translation department's "Guide de Typographie".

spelling, style


Not spokesman or spokeswoman


Standard Model

Caps when referring to the theory of particle physics.

The Standard Model is a theory that describes particle physics. The MacBook is a standard model of computer.

Add a hyphen when using the term as a compound adjective: 

The results of the experiment were consistent with Standard-Model predictions.

Avoid abbreviating Standard Model to SM. It’s irritating to the reader to have to check back on unnecessary abbreviations.

physics, style

strapline ("strap")

Straps are a maximum of 150 characters, including spaces. 

The strap gives added “teaser” information not included in the headline, providing a succinct summary of the most important points of the article. It tells the reader what to expect, and invites them to find out more. 

Remember the strap will always appear with the headline, never on its own, and usually in lists.

Such a list might appear on the site like this (headlines in bold, straps below): 



No hyphen



No hyphen when added as a prefix.

superconductivity, supercomputer, superfluid, etc

The one exception is "super-duper" (informal English meaning "fantastic, wonderful") which should only be used in quotes.



A neutrino detector in Japan. 

Capital S, capital K, hyphen. 

See their website



Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic fields occurring in certain materials when cooled below a characteristic critical temperature. 

Superconducting is preferable to "superconductive" as an adjective (though both are technically correct). 

The superconducting wires on the Large Hadron Collider are maintained at 1.9 K (-271.3°C) – colder than outer space – by a closed liquid-helium circuit.


physics, style


Capital "S" when referring to CERN's first particle accelerator. Otherwise, lower case. 

A synchrocyclotron is a type of cyclotron in which the frequency of the driving radiofrequency-electric-field is varied to compensate for relativistic effects as particle velocity approaches the speed of light. This is in contrast to the classical cyclotron, where this frequency is constant.

CERN's first accelerator, the Synchrocyclotron, first started up on 11 May 1957. It was one of the few synchrocyclotrons in the world at the time. 

physics, spelling, style


Not synchro-cyclotron, synchrocyclotron, or other such historical derivations.

A synchrotron is a cyclotron in which the magnetic field strength increases with the energy of the particles to keep their orbital radius constant.

physics, spelling, style

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