Talk:Hierarchy problem

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[edit] Difference of problems

Are the two problems mentioned in the particle physics section the same problem or different problems? The first being the difference in scale between the weak force and gravity and the second being the stability of the Higgs mass to radiative corrections. For example, can I imagine solutions that solve one problem and not the other? I know it is fashionable in these days of extra dimensions to consider the two as being solved by the same mechanism, but what, for example, does supersymmetry have to say about the relative weakness of gravity? --Eujin16 (talk) 06:16, 7 December 2007 (UTC)

[edit] Diagrams

The diagrams in the figures are incorrect and should be removed because the second diagram does not exist (count the number of doublets at each vertex)! The correct set of diagrams for the cancellation of the quadratic divergence from the Higgs quartic coupling involvings the gauginos and gauge bosons (as the quartic coupling arises from the D-terms). The diagram could in principle be related to the top quark quadratic divegence, but would require relabelling (and then technically it would require both the left handed and right handed top squarks in seperate diagrams, but that is splitting hairs). -- jay 00:48, 1 February 2006 (UTC)

I think you're right. How about this as a replacement?

Cancellation of the Higgs boson quadratic mass renormalization between fermionic top quark loop and scalar stop squark tadpole Feynman diagrams in a supersymmetric extension of the Standard Model

-- Xerxes 18:08, 1 February 2006 (UTC)

I think that the first diagram should be tops (rather than stops). The original figure is used in several different places, so it would be great if it could be updated globally.

I mean to indicate that these are the diagrams that cancel the equivalent top diagrams. -- Xerxes 21:22, 1 February 2006 (UTC)

I don't believe that the first diagram cancels any diagram in the fermionic sector. It arises from a trilinear scalar coupling (ie a dimensionful coupling) that only gives rise to a log divergence and contributes to the top yukawa's renormalisation of the mu term (this diagram in the susy limit arises from the cross term in the Higgs' F-term potential). Although I could be being myopic... -- jay 02:56, 2 February 2006 (UTC)

I don't really know that much about this subject. I just tried to pick up enough from some papers to put together a better diagram. How's this one? -- Xerxes 17:48, 2 February 2006 (UTC)

Perfect! -- jay 21:04, 2 February 2006 (UTC)

Diagram as SVG

I made a vector version of the diagram. Please ensure that it is an accurate copy. VermillionBird (talk) 23:02, 20 January 2008 (UTC)

[edit] Relative strength of the weak force

"the weak force is 10³² times stronger than gravity."

Fundamental interaction shows the relative strength of the weak force (compared to gravity) as 10²⁵. Although it also mentions that the strengths are approximate, 10⁷ is quite a difference. How can these numbers be reconciled?

The strength relative of forces is not well defined and depends on the distance and how the force is being measured. The 10³² is the ratio of G_N to G_F. I don't know where 10²⁵ arises from, but it could be the strength of gravity at the weak scale relative to the strength of the weak force at the weak scale. I personally don't like these quantifiers, they give a rather misleading impression and can vary largely (because the functional forms of the forces are different) jay 02:37, 15 June 2007 (UTC)