Talk:W and Z bosons

Updated W boson mass

I updated the mass of the W boson with the Wired article "Physicists Pinpoint W Boson, Narrow Search for Higgs" to set the mass at 80.387 GeV ±0.019 GeV, however, its main reference is this Science 2.0 blog entry "An Exquisite New W Mass Measurement From CDF !", which has the world average mass for the W boson at 80.390 GeV ±0.016 GeV. The Wired article only talks about the preliminary CDF II results, not the world average. Unfortunately, if I remember correctly, the Wired article counts as a reliable source, while the blog entry doesn't. Am I wrong? If so, please update the mass to reflect the latter mass, instead of the former. Thanks. -- HiEv 06:27, 24 February 2012 (UTC)

I reverted the change to the mass. While Wired may be considered a reliable reference in Wikipedia in general, I think in this instance it's incorrect to update the mass based on an article in a nonscientific magazine. CDF has yet to publish a peer-reviewed article with their finding. Plus the result that should be listed on this page is not the CDF measurement but the world average updated to include the CDF result. This will be (as was preliminarily listed by CDF) 80.390 GeV/c^2 +- 16 MeV/c^2. --Certain (talk) 13:26, 24 February 2012 (UTC)

I don't have a high number of edit, so I don't now if I can comment for this question, but I think, like a physicist, that we cannot change the mass of W before the publication on the Particle Data Group. --Gianluigi (come to Mars) 01:01, 25 February 2012 (UTC)

As a particle physicist, I can say I wouldn't quote as fact something that hasn't yet been published in a journal. Certainly not in an encyclopedia. Plus there's a good chance the uncertainty can change before publication---a preliminary analysis is just that: preliminary. However, since this was on a blag, it seems everyone who read the story is going to come here and update the mass prematurely.--Certain (talk) 02:25, 25 February 2012 (UTC)

Another further update can be seen here, [1] with a mass of 80387 +- 17 MeV/c2 (0.02% precesion).--Almuhammedi (talk) 20:02, 2 March 2012 (UTC)

It should be obvious from everyone above listing slightly different values that this page should not be updated until a new world average incorporating the new D0 and CDF measurements (yes, D0 is now presenting a new measurement: http://arxiv.org/pdf/1203.0293.pdf) is published in a proper journal (not just the arXiv). Links to science blogs, conference presentations, or working group pages with preliminary results are not acceptable sources for the mass of a fundamental particle, in my opinion. --Certain (talk) 15:36, 5 March 2012 (UTC)

The Scientific Inquiry - Questions

The article should note that this phenomenon, from what I read, takes place in a bubble chamber and that there may very well be footage showing this as it happens.
That the description for the Z boson lacks completely, almost like implying a "magical" existence
You may want to improve on these points! No science can insist on "shamanism".

An update note.
one may consider to alter the description to this:
1. n0 → p+ + W−
2. W− → e− + ν(e), that is, for both of these, instability/decay splits these particles as matters of natural processes
So if this happens in a bubble chamber then it must be possible to film it. 2nd valid note is that W− has a different role in "Unified Physics", throwing out some word-dressing.
Thus, by this, the drawing absolutely has potential for improvement. This should be clear!
It should also be clear that the W bosons (2) have no controversy in being particles themselves, but that the explanation they enter into, may have it.
I may come across as shaky, but this is about a culture that has problems with presenting itself so I put the claim back to the community that the community can't accept a scant standard on some and where they (from USA) are in control, they flaunt NASA "miracles" and all other while of course sitting with closet-notions of Military Complex USA, financial radicalism and outrageous sinking of SS Kursk! Are you reading me, please??? 62.16.242.218 (talk) 18:41, 24 February 2013 (UTC)

The process you write above, where a neutron spits out a W- which then in turn becomes an electron and neutrino, happens all the time. This is ordinary beta decay of the free neutron (assuming the neutron is free-- otherwise it's beta decay of a neutron in some neutron-rich nuclide). It has no chance of being "filmed" in a bubble chamber, as the lifetime of the the W- is3 x 10^-25 seconds, which at the speed of light gives it a chance to go a distance of about 0.1 fm (far less than the radius of a neutron) before it decays. This is a track too short to see.

For this reason, W lifetimes are never measured directly, but usually via the width of the relativistic Breit–Wigner distribution of their decay energies. The shape of this distribution allows the decay energy (in this case the mass of the W- particle that decays) to be measured indirectly. The W happens to have about a 3.1 GeV decay energy width, which corresponds to a 80 GeV decay energy, which is then taken to be the mass of the original W particle. SBHarris 03:15, 13 October 2013 (UTC)

Something Missing

Correct me if I'm wrong but "The W+, W−, and Z0 bosons, together with the photon (γ), comprise the four gauge bosons of the electroweak interaction." is incomplete. I believe the gluons are also gauge bosons. --~hb2007 13:39, 25 February 2014 (UTC)

-- The gluon is a gauge boson, but not one of the "electroweak interaction" like the sentence indicates. — Preceding unsigned comment added by 169.231.17.205 (talk) 04:35, 2 March 2014 (UTC)

Z boson decay

There were a few comments regarding this section being a little confusing (collected below). I tried to improve it, but I guess it could still use some work. 157.82.231.50 (talk) 08:47, 10 March 2014 (UTC)

comment 1

In the formulae, for calculating the 'branching ratios', of Z-boson decays into fermions, the 'weak mixing angle' term x~1/4. The BRs listed in the table, do not correspond, to the formulae according to which they are supposedly calculated -- with the exception of "hadrons", interpreted as the relative sum, of both quark branches. 24.143.65.75 (talk) 07:38, 10 January 2012 (UTC)

comment 2

I think the following sentence from the article is wrong.

The decay width of a Z boson to a fermion–antifermion pair is proportional to the square of the weak charge T₃ − Qx, where T₃ is the third component of the weak isospin of the fermion, Q is the electric charge of the fermion (in units of the elementary charge), and x = sin²θ_W, where θ_W is the weak mixing angle.

This approach misses contributions in the order x². The calculation giving right numbers, starting from the Z-fermion vertex, might be beyond the scope of this article. — Preceding unsigned comment added by 141.20.47.46 (talk) 18:21, 28 January 2014 (UTC)

comment 3

The branching ratios of the Z boson into leptons and neutrinos is shown in a confusing way: For leptons the ~3% apply to each family separately, but for neutrinos the 20% apply to all three kinds of neutrinos. That should either be made clear, or the lepton contributions should be summed up so it's consistent with the other table rows and the numbers are comparable. --89.247.147.46 (talk) 17:51, 19 May 2010 (UTC)

W1, W2, W3

I don't see any discussion here of the W1, W2, and W3, which I assume to be underlying fields that constitute W and Z bosons. Since other articles mention these fields, I believe a discussion in this article would be warranted. — Preceding unsigned comment added by 70.247.166.192 (talk) 22:00, 29 August 2015 (UTC)

Assessment comment

The comment(s) below were originally left at Talk:W and Z bosons/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

Lacks references Snailwalker | talk 00:57, 21 October 2006 (UTC)

Last edited at 00:57, 21 October 2006 (UTC). Substituted at 10:05, 30 April 2016 (UTC)

SI units

I guess the Higgs vacuum formula must be in SI: $M_{W}={\tfrac {1}{2}}vg{\frac {1}{c^{2}q_{P}\pi {\sqrt {\alpha _{W}}}}}={\frac {v}{2\pi c^{2}}}{\tfrac {\sqrt {\alpha /\alpha _{W}}}{s_{W}}}$ using $\alpha _{W}\approx 1/128$??? At least this fits dimensions and quantities closely. If so, should not the α factor be in the formula anyway? Ra-raisch (talk) 08:25, 7 August 2017 (UTC)

Electron properties

"Since such an electron is not created from a nucleon,..." I was under the impression that a down quark could transform into an up quark and an electron. — Preceding unsigned comment added by 174.97.8.110 (talk) 01:31, 1 November 2017 (UTC)

The whole paragraph is a write-off in my opinion. It is too detailed for a lede and contains numerous errors. It should be a general introduction to the Z boson, but instead it talks only in the context of neutral-current electron–neutrino scattering. The one above it isn't any better. I suggest just deleting both. — dukwon (talk) (contribs) 08:53, 1 November 2017 (UTC)

W- Boson in beta decay

Forgive me if I'm misunderstanding, but in the article it states that a w- is ~80x more massive than a neutron, then later states that during beta decay the neutron emits a w-, which then further decays into an electron (~1/2,000 the mass of the neutron) and a neutrino (~1/500,000 the mass of an electron, or one billionth the mass of the neutron). Where did this extra mass come from, and then go? — Preceding unsigned comment added by Plattitudes (talk • contribs) 19:40, 11 January 2019 (UTC)

Yes, I came here with exactly the same question.78.33.185.122 (talk) 23:45, 25 August 2019 (UTC)

Plattitudes and IP: the force carrier article—linked from the second phrase in the introduction—must, in principle, explain this thing. It currently does not, because it is Wikipedia. Incnis Mrsi (talk) 05:20, 26 August 2019 (UTC)

… can decay to a lepton and neutrino

Do user watching (and editing) the article know that a neutrino is a lepton? Perhaps “can decay to a charged lepton and neutrino”? Incnis Mrsi (talk) 10:00, 19 August 2019 (UTC)

Fixed a bunch of clueless writing myself. Incnis Mrsi (talk) 05:20, 26 August 2019 (UTC)

Sans-serif abomination

Can anybody realize what “l⁺ν_l” means with the (Wikipedia default) sans-serif font and without looking at the source code? I cannot, and my first guess was |·| misplaced due to a typo or a wrecker script (or bot). Incnis Mrsi (talk) 05:20, 26 August 2019 (UTC)

Add Decays Into Info. It's Missing.

Some pages of quantum particles like the Higgs boson include what particles they decay into. This is very valuable information. Please add it to this page and others. 172.58.43.239 (talk) 06:54, 6 September 2019 (UTC)

The pages that have Decays Into info already put it in the "Infobox particle" section. 172.58.43.239 (talk) 07:00, 6 September 2019 (UTC) 172.58.43.239 (talk) 07:02, 6 September 2019 (UTC)

Mass of the boson significantly higher than SM prediction (7 sigmas)

• "'Extraordinary' W boson particle finding contradicts understanding of how universe works | Science | The Guardian".
• CDF Collaboration†‡; Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A. (2022-04-08). "High-precision measurement of the W boson mass with the CDF II detector". Science. 376 (6589): 170–176. doi:10.1126/science.abk1781. ISSN 0036-8075.

Alexcalamaro (talk) 06:50, 8 April 2022 (UTC)

Don't worry: Do we have finally found new physics with the latest W boson mass measurement?  :-) Alexcalamaro (talk) 14:56, 8 April 2022 (UTC)