Towards an effective-lagrangian approach to fermion-loop corrections
نویسندگان
چکیده
We present a study of the non-local lagrangian approach to incorporate higher-order effects in e+e− → n fermions. In its minimal version, the nonlocal lagrangian approach is found to exhibit problems with unitarity and high-energy behaviour. We identify the origin of these problems and obtain some first clues about possible solutions by investigating the zero-mode solutions of the Ward Identities. A numerical analysis of the importance of the zero-mode solutions is presented for four-fermion production processes. Work supported by the European Union under contract HPRN-CT-2000-00149 Financially supported by MIUR under contract 2001023713-006 1
منابع مشابه
Electroweak Theory and the 1996/97 Precision Electroweak Data * †
We review the empirical evidence for the validity of the Standard Electroweak Theory in Nature. The experimental data are interpreted in terms of an effective Lagrangian for Z physics, allowing for potential sources of SU(2) violation and containing the predictions of the Standard Electroweak Theory as a special case. Particular emphasis is put on discriminating loop corrections due to fermion-...
متن کاملSpectator Effects in Heavy Quark Effective Theory at O(1/mQ)
We complete the one loop renormalization of the HQET lagrangian at O(1/mQ) including four fermion operators with two heavy and two light quark fields in the operator basis. It is shown that as a consequence the short distance coefficients of the operators bilinear in the heavy quark field receive nontrivial corrections. ¶email: [email protected]
متن کاملSpectator Effects in Heavy Quark Effective Theory at O(1/m3Q)
We complete the one loop renormalization of the HQET lagrangian at O(1/m3Q) including four fermion operators with two heavy and two light quark fields in the operator basis. It is shown that as a consequence the short distance coefficients of the operators bilinear in the heavy quark field receive nontrivial corrections. email: [email protected]
متن کاملHidden Local Symmetry at One Loop
We show that one-loop corrections with the hidden gauge boson loop preserve in the low energy limit all the successful tree level predictions of the hidden local symmetry in the SU(2)L×SU(2)R/SU(2)V chiral Lagrangian. Most amazingly, the ρ meson dominance of the pion electromagnetic form factor survives the one-loop corrections at any momentum, if and only if we take the parameter choice a = 2....
متن کاملTowards an effective-action approach to fermion-loop corrections
We present a study of the effective action approach to incorporate higher-order effects in e+e− → n fermions. In its minimal version, the effective action approach is found to exhibit problems with unitarity and high-energy behaviour. We identify the origin of these problems by investigating the zero-mode solutions of the Ward Identities. A numerical analysis of the importance of the zero-mode ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2003