just to make it clear what I mean:

I do not mind anonymous comments here. However, anonymity comes at a price. As a non-disclosed person, you do not have all the rights of persons with a name and an email – you may be anyone, so you are effectively nobody. Of course, I still respect everybody’s (and nobody’s) opinions here…

Cheers,
T.

Tommaso I do not need you to defend me. I will humbly suggest that professor reread the very same books he listed.

Cheers,
T.

PS: please do not put anonymous commenters like quantoken (or yourself for that matter) at the same level as esteemed scientists like Jeff, who may have forgotten group theory but give a daily contribution to the advancement of Physics. The books you advise are good but Jeff has read scores of those.

T.

Embarasment is in the eyes of the beholder.
cheers

thank you for your explanation, which I had failed to give, on why the Higgs has to be a scalar. It is a useful didactical contribution to this discussion.

Cheers,
T.

So, any Higgs or Higgs-like particle has to have spin=0. If you don’t agree, first you have to invent a mechanism for particle masses which doesn’t involve any symmetry breaking.

the question posed by quantoken is not totally silly. Indeed, while for the conjugate pairs linear momentum-position and energy-time the uncertainty principle applies strictly and there are no grey areas, for angular momentum and angular position things are more complicated – basically due to the quantization of L.

My short answer to how is it possible that a particle has intrinsic angular momentum equal to zero is that the uncertainty principle applies to quantities for which the pairs of conjugate variables are defined, which is not the case for the spin of spin zero particles. In other words, there is no direction around which to define a angular coordinate.

I understand Quantoken’s confusion, though: by thinking at the quantum harmonic oscillator, where the zero-point energy has a nonzero value (hbar/2 times the natural frequency), one may be led to believe the same applies to a quantized quantity as intrinsic spin. That is not the case.

By the way, by digging in the internet I found a paper where the uncertainty relation of angular momentum and angular position is indeed measured, with photon beams. It is http://www.iop.org/EJ/article/1367-2630/6/1/103/njp4_1_103.html , (New J. Phys. 6 (2004) 103).

In it, I read that indeed, the product DL*Dphi can assume values smaller than h/(2*pi). It is an interesting reading…

Cheers,
T.

The first part is a warning. Modern science is based on the ethic that fame, prestige and sheer numbers alone do not garantee truth. Simply because schools of famous people say somehting doesn’t make it right. But this doesn’t mean that we should turn the ethic around. When some brave person stands up to say something unsual, challanging the famous, the powerful and the masses, then what he says is NOT more likely to be true simply because he is “original”. Originality is not a sufficient condition to jump to any conclusion, in particular that the masses are wrong. The ethics of modern science is based on the quality of argument, not in the numbers of people or the fame, power, money, looks, race, religion, sex, age, politcal party, of who is arguing.

The argument that uses Heisenberg’s uncertainty principle must be used and interpreted with some caution. There is a significant difference between angular momentum and linear momentum. As you know, the conjugate variable of linear momentum is linear position, whereas the conjugate variable of angular momentum is angular position. But while linear position is defined over the whole axies of real numbers, angular position is PERIODIC. You too pointed out that for bosons the angle is restricted between 0 and 2PI. You are right in saying that Heisenberg’s relation forces us to conclude that IF spin (intrinsic angular momentum) is precisely known then the angle is completely uncertain. But that simply means that all angles between 0 and 2PI are equally probable. I don’t see any infinities!

ciao for now

Pion is not an elementary particle. Pion is a combinary of two quarks. Each quark has a none zero spin. The spin of two quarks happen to cancel each other resulting in a zero spin. But it’s OK for a composite, i.e., none-elementary particle like pion.

Higgs boson, as far as I know, if it exists, is NOT a composite particle and is truely a fundamental particle, so it can not have zero spin. If it has zero spin, you break the quantum uncertainty principle right here. The spin must be one. But then, if Higgs particle does not exist, then there is no point arguing whether its spin is zero or one. So let’s stop the argument right here and wait until you show me that Higgs boson is discovered, then we can discuss.

Quantoken, doing outreach is not easy, it is time consuming, and it requires a significant effort in trying to simplify matters to make them readable. Mistakes are common. But… John is a quite accurate person and he seldom makes any. And in fact, he did not.

The Higgs -if it exists- is a scalar particle. It has zero spin. It still belongs to the category of “bosons”, because bosons have integer spins, and 0 is an integer.

Please explain what you remember about quantum mechanics preventing zero spin particles – which do occur, as Jeff points out, even in well-known particles. And leave taxpayers money alone, it’s a trembling little sum anyway.

Cheers,
T.