Anomalous quartic electroweak gauge-boson interactions

Authors:

• O.J.P. Eboli (eboli AT fma.if.usp.br)

• M.C. Gonzalez-Garcia (concha AT max2.physics.sunysb.edu)

Description of the models:

We concentrate on anomalous quartic interaction among the electroweak gauge bosons that do not have a triple vertex associated to it. We describe these interactions using dimension eight effective operators assuming that the recently observed Higgs boson belongs to a SU(2)_L doublet; see the file quartic.pdf for further details. This model is an extension of the Standard Model (SM) implemented at http://feynrules.irmp.ucl.ac.be/wiki/StandardModel; for further details see this link.

The model labeled SM_LS0_LS1 contains the standard model interactions supplemented by the dimension eight operators L_S,0 and L_S,1 defined in the file quartic.pdf. These dimension eight effective operators modify the vertices WWWW, WWZZ, and WWZZ that can be a simple re-scaling of the SM quartic interaction for a suitable choice of couplings.

The model labeled SM_LT012 contains the standard model interactions supplemented by the dimension eight operators L_T,0 , L_T,1 and L_T,2 defined in the file quartic.pdf. These dimension eight effective operators give rise to anomalous WWWW, WWZZ, WWAZ, WWAA, AAAA, AAAZ, AAZZ, AZZZ, and ZZZZ vertices.

The model labeled SM_LM0123 contains the standard model interactions supplemented by the dimension eight operators L_M,0 , L_M,1 , L_M,2 and L_M,3 defined in the file quartic.pdf. These dimension eight effective operators give rise to anomalous WWWW, WWZZ, WWAZ, WWAA, AAZZ, AZZZ, and ZZZZ vertices.

The model labeled SM_LT8_LT9 contains the standard model interactions supplemented by the dimension eight operators L_T,8 and L_T,9 defined in the file quartic.pdf. These dimension eight effective operators give rise to anomalous AAAA, AAAZ, AAZZ, AZZZ, and ZZZZ vertices.

References

• Strongly interacting vector bosons at the CERN LHC: Quartic anomalous couplings , A.S. Belyaev et al, Phys.Rev. D59 (1999) 015022 ​(hep-ph/9805229)

• p p ---> j j e+- mu+- nu nu and j j e+- mu-+ nu nu at order ... for the study of the quartic electroweak gauge boson vertex at CERN LHC, O.J.P. Eboli, M.C. Gonzalez-Garcia , and J.K. Mizukoshi, Phys.Rev. D74 (2006) 073005 ​(hep-ph/0606118 the dimension eight operators are from this reference)

• Anomalous quartic gauge boson couplings at hadron colliders, Oscar J.P. Eboli, M.C. Gonzalez-Garcia, S.M. Lietti, and S.F. Novaes., Phys.Rev. D63 (2001) 075008 ​hep-ph/0009262)

• Bosonic quartic couplings at CERN LHC, O.J.P. Eboli, M.C. Gonzalez-Garcia, and S.M. Lietti, Phys.Rev. D69 (2004) 095005 ​(hep-ph/0310141)

Instructions

The model files include the quartic and SM vertices in the unitary gauge. To generate models with any of the other dimension eight operators use the notebooks quartic_ls01.nb or quartic_lt89.nb as examples and include the additional interactions that are already defined in the model file quartic.fr. The anomalous couplings are set to 1 GeV^-4 by default, thus they should be conveniently chosen before the event generation.

NEW VERSION: the user must specify the number of anomalous vertices in the scattering amplitude generated by MadGraph. For one vertex use NP=1.