The Bosonic Sector of the Electroweak Interactions, Status a(4)

Higgs boson couplings with gauge bosons are given by the covariant derivative of the scalar kinetic terms.

LΦ=(DµΦ+)(DµΦ)=

v2

2v2(Φ+Φ?

v2

2µ2=?

M2H

λ

(8)

Our notations are the following ones:

W aµν=?µW aν??νW aµ?g?abc W bµW cµ(9)

Wµ=?→Wµ·?→τ

2

,(10)

Φ= φ+

1

2

(v+H+iφ0) ,(11)

Dµ=(?µ+i g1Y Bµ+i g2Wµ),

U=v2U=( Φ,Φ),(12)

where Φ=iτ2Φ?and A ≡T rA.

Standard radiative corrections

The status of the Standard Model (SM) is reviewed. We emphazize the fact that in spite of the success of the SM for the descrition of the fermionic sector, the status of the bosonic sector (gauge and scalar) suffers from many theoretical deficiencies and f

General Lorentz and U(1)invariant forms for ZW +W ?and γW +W ?couplings

M 2

W V νλ W ?λµ W

+µ

ν(15)4)ez V

M 2W ?Z νλ W

+λµ

W ?µ

ν(18)7)eg SM V K V (?µZ ν+?νZ µ)W +µW ?

ν(19)where the abelian W a µν=?µW a ν??νW a µis used as well as the dual

?Z µν=1

The status of the Standard Model (SM) is reviewed. We emphazize the fact that in spite of the success of the SM for the descrition of the fermionic sector, the status of the bosonic sector (gauge and scalar) suffers from many theoretical deficiencies and f

As summarized in Table1the three?rst terms are C-and P-conserving(charge, magnetic moment and quadrupole moment),the fourth one is C-and P-violating but

CP-conserving(anapole term)and the last three ones are CP-violating.The speci?c helicity properties[20],[21]of the W+W?state for each type of coupling are also given in the last three lines of Table1.The identi?cation of these properties is particularly useful

for experimental analysis as it gives a way to disentangle the various forms.

Table1:Space-time properties of the seven3-boson coupling forms

P P P

C C

CP CP

TT

LL

LT LT LT

NP can contribute to such new couplings and form factors.This may happen in

various ways.The basic W,Z structure may di?er from the SM one if one uses an alternative description,for ex.if W,Z are massive vector bosons not directly generated by the gauge principle(composite states like hadronicρ,ω,...vector mesons)[27],[29]. In these cases tree level modi?cations of the self-boson couplings(?niteδκ,λ,...)may exist.In less drastic pictures in which the SU(2)×U(1)system is kept but extended or coupled to a new additional sector,tree level modi?cations may still appear through mixing of W,Z with higher vector bosons(especially if these ones pertain to a strongly interacting sector like SU(2)V)[5],[6].In any case at1-loop,NP e?ects will always appear through contributions of virtual states.They can even be enhanced by non-perturbative e?ects(hypercolour factors,resonant e?ects,...).The peculiarities of the terms generated in this way[37](for example the speci?c sectors that they a?ect,charged versus neutral states,transverse versus longitudinal ones,Higgs versus no-Higgs?nal states,...)and the symmetries that they respect should re?ect their origin and help to identify the nature of NP through detailed analyses of the processes.

We shall discuss these questions in a precise manner through the e?ective lagrangian method.If the characteristic scaleΛof NP is su?ciently larger than M W,e?ective lagrangians among usual particles are obtained by integrating out all heavy degrees of freedom.They can be written in the form

L=Σi ¯f i

The status of the Standard Model (SM) is reviewed. We emphazize the fact that in spite of the success of the SM for the descrition of the fermionic sector, the status of the bosonic sector (gauge and scalar) suffers from many theoretical deficiencies and f

dimensionless.A priori such a series can be in?nite and one needs restrictions in order to have in practice a useful description.These restrictions must be done on a physical basis because often an apparently”harmless”mathematical property can have very important physical consequences.As already said and motivated by LEP1results we restrict O i to not involve lepton and quark?elds.The next restriction comes from the dimension. IfΛ>>M W it is natural to expect observable e?ects only from the lowest dimensions d=4,6,perhaps8.

Global symmetries

xγ(26)

c

No quadrupole coupling is generated at this level.This set of free parameters can be further reduced if one considers the high energy behaviour of boson-boson scattering amplitudes.Because of these non-standard terms,they grow like s2.Demanding that these terms cancel,one obtains certain relations among the four free parameters which ?nally reduce to only one[28].

s

x Z=?

m2t

π

The status of the Standard Model (SM) is reviewed. We emphazize the fact that in spite of the success of the SM for the descrition of the fermionic sector, the status of the bosonic sector (gauge and scalar) suffers from many theoretical deficiencies and f

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