Finite-Width Effects in the Model of Unstable Particles With a Smeared Mass

Abstract

A phenomenological model of unstable particles based on uncertainty principle is discussed in quantum field approach. We show that the simplest quantum field description of mass uncertainty makes it possible to account finite width effects for particles with large decay widths.PACS number(s): 11.10St, 13.20Jf, 13.38Dg.

Factorization effect and near-threshold boson production at linear colliders.

“…However, there is another way of consideration. The model of UP with smeared mass [5] provides the possibility to describe Z and W in the final…”

“…Born cross-section was calculated with help of the program FeynCalc and integration over variable masses are fulfilled numerically. To escape the singularities, which arise in Higgs-resonance region as a result of integration over phase space of boson pairs, we introduce the q-dependent width of Higgs: The function ρ(m 2 ) is given in a traditional Lorentzian form [2,5]. This approach has a close analogy with the convolution method (CM) [7] (and references therein) and the semi-analytical approximation (SAA) [8], which usually are applied in the frame of standard descriptions.…”

“…This approach has a close analogy with the convolution method (CM) [7] (and references therein) and the semi-analytical approximation (SAA) [8], which usually are applied in the frame of standard descriptions. However, the status of these approaches are different (see [2,5,6]). In the framework of the model, the expression (2.2) directly follows from the smearing-mass conception for UP and the model function ρ(m 2 ) describes the distribution of the mass parameter [5].…”

“…However, the status of these approaches are different (see [2,5,6]). In the framework of the model, the expression (2.2) directly follows from the smearing-mass conception for UP and the model function ρ(m 2 ) describes the distribution of the mass parameter [5]. Moreover, the model definition of the unstable field function determines a strategy of corrections account [2,6].…”

Factorization in the model of unstable particles with continuous masses

“…For instance, double-pole approximation (DPA) [25][26][27]53], pinch-technique method [28,29], complex-mass scheme (CMS) [30,31], semi-analytical approximation [24], narrow-width approximation (NWA) [24,32], convolution method (CM) [33][34][35][36][37][38], etc. At the same time, alternative ways to deal with UPs were developed, such as effective theories of UP's [39,40], modified perturbation theory [10,21] and models with continuous mass spectrum [41,[55][56][57][58][59][60].…”