Particle physics question for Kelsey or anyone else that can answer....

I am finishing up the book I am reading on Dark matter, and Mr. Krauss mentions "spontaneous symmetry breaking" (not a hard concept) creating or producing  spin-0 particles or scaler particles  (Higgs Boson?).   My question is, have any of these particles, as yet, been observed?  The book I am reading is slighty dated, and so I am not even sure it is up to date on the vacuum energy  postion towards dark matter and a flat universe.

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kelseymh6 years ago
Yes and no. The Higgs boson (spin-0, hence "scalar" as opposed to "vector", not to be confused with "scaler") has not been observed, though the mass range where we expect to find it has been narrowed recently by Fermilab results.

Spontaneous symmetry breaking, and the particles which result from it, have certainly been observed -- the massless photon and the massive weak vector bosons (W+, W-, Z0). In the Standard Model, the unified electroweak interaction is described by an SU(2)×U(1) symmetry, in which four massless vector bosons interact, a triplet of W's (0, -, and +) from the SU(2) weak isospin group, and a neutral B from the U(1) hypercharge group.

Spontaneous symmetry breaking, in a manner similar to the Zeeman splitting of atomic energy levels, forces the degenerate (both massless) pair W0 and B to split, one staying massless (the photon) and the other acquiring a large (and predicted!) mass around 90 GeV (the Z0). The same symmetry breaking gives mass to the charged W's, around 83 GeV.

All of this was predicted by Weinberg, Salam, and Glashow in the late 1960s, nearly two decades before the Z0 and W's were experimentally observed (by the UA1 and UA2 collaborations at CERN).
Goodhart (author)  kelseymh6 years ago
Thank you Kelseymh for that, although I will need to look up a few terms, as the book had not dealt with them, I grasp the overall concept and appreciate your taking time to explain it to me. Helping me bring the book a little more up to date.

Fantastic....
The Wikipedia articles on physics are a good place to start. Use any of the keywords from my post and that should get you started.
Goodhart (author)  kelseymh6 years ago
Well, I finally knuckled under and finished Krauss' book Quintessence: The mystery of the missing mass of the universe.

I must say, either Krauss has a hidden talent for making the weird, and unconventional seem normal and understandable, or I have a penchent for this subject  LOL

Anyways, had I waited to finish the book before asking the questions, I would have gotten my answer, albeit in a bit less technical explanation ;-)   Not that I am faulting yours,  because his was much more wordy (took up the last 3 chapters and the epilog and the appendix  (yeah, it interested me that much that I read them too).  

I can understand one's wanting to get into said field of particle physics....it is indeed fascinating all around. 

Thank you for your patience with my former ignorance on the subject (not that I am now any kind of expert, but I am discussing the subject on a science forum in FB with a fellow that can not understand the difference between weight and mass *sigh*  (I do believe my "example" of weight being dependant on the gravitational field one is in (say on the moon, the earth or on Jupiter)  helped him sort it out however. 

Thanks again for all your help.
:-D I'm glad you both enjoyed the book and got something out of it. Krauss is an excellent physics writer (and by "excellent" I mean "I agree with his approach" :-), unlike the "ooh aren't we mysterious" Weinbergs and Hawkings...
Goodhart (author)  kelseymh6 years ago
Indeed, he seems like someone you could have tea with and he'd discuss the subject on what ever level the other person was capable of. Another physicist I'd like to meet ;-)
Goodhart (author)  Goodhart6 years ago
BTW: I enjoyed reading the book, the other fellow I was chatting with, hasn't a clue, and was just making things up as he went......
Goodhart (author)  kelseymh6 years ago
Yes, I will have to take this a little more slowly as it a lot more detailed then Krauss gets for the general public. I do have a few more questions for later, if the last part of his book doesn't answer of hint at an answer to them, to fill in or at least point me in the right direction towards my search for, the answers. Thanks again.
Goodhart (author)  kelseymh6 years ago
Fascinating....the book, near the end deals with symmetries, and left/right handedness problem (and pct) etc. this is all really cool stuff...
For the lay person, is there a cookie analogy to explain this? i.e. if we bombard an oreo cookie with sufficient force to split it, we can observe how the cookie crumbles and the resultant particulates?
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