arXiv subjects

P. Tuvike

Publications and source records attributed to P. Tuvike.

3 recordsLinked to original sources

arXiv2014

The decays of on-shell and off-shell polarized gauge bosons into massive quark pairs at NLO QCD

We discuss the polar angle decay distribution in the decay of on-shell and off-shell polarized (W,Z) gauge bosons into massive quark pairs. In particular for the off-shell decays in $H \to (W,Z) + (W^\ast,Z^\ast) (\to q_1\bar q_2)$ it is important to keep the masses of the charm and bottom quarks at their finite values since the scale of the problem is not set by $m_{W,Z}^2$ but by the off-shellness of the gauge boson which varies in the range $(m_1+m_2)^2 \le q^2 \le (m_H-m_{W,Z})^2$.

hep-ph↗

arXiv2013

Fully analytical O(α_s) results for on-shell and off-shell polarized W-boson decays into massive quark pairs

We provide analytical $O(α_s)$ results for the three polarized decay structure functions $H_{++},\,H_{00}$ and $H_{--}$ that describe the decay of a polarized $W$ boson into massive quark--antiquark pairs. As an application we consider the decay $t\to b+W^+$ involving the helicity fractions $ρ_{mm}$ of the $W^+$ boson followed by the polarized decay $\hbox{$W^+(\uparrow)$}\to q_1\bar{q}_2$ described by the polarized decay structure functions $H_{mm}$. We thereby determine the $O(α_s)$ polar angle decay distribution of the cascade decay process $t\to b+W^+(\to q_1\bar{q}_2)$. As a second example we analyze quark mass and off-shell effects in the cascade decays $H\to W^{-}+W^{\ast +}(\to q_1\bar{q}_2)$ and $H\to Z+Z^{\ast}(\to q\bar{q})$. For the decays $H\to W^{-}+W^{\ast +}(\to c\bar b)$ and $H\to Z+Z^{\ast}(\to b\bar{b})$ we find substantial deviations from the mass-zero approximation in particular in the vicinity of the threshold region.

hep-ph↗

arXiv2012

O(α_s) corrections to the decays of polarized W^+- and Z bosons into massive quark pairs

We present O(α_s) results on the decays of polarized W^+- and Z bosons into massive quark pairs. The NLO QCD corrections to the polarized decay functions are given up to the second order in the quark mass expansion. We find a surprisingly strong dependence of the NLO polarized decay functions on finite quark mass effects even at the relatively large mass scale of the W^+- and Z bosons. As a main application we consider the decay t -> b + W^+ involving the helicity fractions ρ_{mm} of the W^+ boson followed by the polarized decay W^+(\uparrow) -> q_1 qbar_2 for which we determine the O(α_s) polar angle decay distribution. We also discuss NLO polarization effects in the production/decay process e^+e^- -> Z(\uparrow) -> q qbar.

hep-ph↗