arXiv subjects

Roger Decker

Publications and source records attributed to Roger Decker.

5 recordsLinked to original sources

arXiv1994

Radiative Corrections to the Decay $τ\toπν_τ$

We have calculated the radiative corrections to the decay $τ\to π(K) ν_τ$, taking to account internal bremsstrahlung and structure dependent radiation in the radiative decay and point meson, hadronic structure dependent and short distance contributions in the virtual corrections. We display the spectra of the photon energy and of the pion-photon invariant mass in the decay $τ\toπν_τγ$ and compare with the PHOTOS Monte-Carlo. Our result for the radiative correction to the ratio $Γ(τ\toπν_τ(γ))/ Γ(π\toμν_μ(γ))$ is $δR_{τ/π} = \left(0.16 \pm 0.14 \right) \%$ and for the ratio $Γ(τ\to Kν_τ(γ))/ Γ(K\toμν_μ(γ))$, we obtain $δR_{τ/K } = \left(0.90 \pm 0.22 \right) \%$.

hep-ph↗

arXiv1994

Short and Long Distance Effects in the Decay $τ\to πν_τ(γ)$

We calculate the radiative corrections to the decays $τ\to M ν_τ$ and $π\to l ν_ł$, where the meson $M$ is $M=π$ or $K$ and the lepton $l$ is $l = e$ or $μ$. We perform a complete calculation, which includes internal bremsstrahlung and structure dependent radiation in the radiative decays and point meson, hadronic structure dependent and short distance contributions in the virtual corrections. Our result for the radiative correction to the ratio $Γ(τ\toπν_τ(γ))/ Γ(π\toμν_μ(γ))$ is $δR_{τ/π} = \left(0.16_{\T - 0.14}^{\T+0.09}\right) \%$. For the ratio $Γ(τ\to Kν_τ(γ)) / Γ(K\to μν_μ(γ))$, we obtain $δR_{τ/K } = \left(0.90_{\T - 0.26}^{\T + 0.17}\right) \%$. For completeness we have also calculated the ratio of the electronic and muonic decay modes of the pion.

hep-ph↗

arXiv1994

Addendum To Our Paper: "Radiative Tau Decays With One Pseudoscalar Meson"

In a previous paper we have calculated the decay $τ\toπν_τγ$. We used a given relative sign between the internal bremsstrahlung and the structure dependent radiation, which has been used by several other authors before. However, we believe that there are good arguments why the opposite sign is the physical one. We briefly discuss these arguments and then investigate how the predictions for the decay $τ\toπν_τγ$ are affected by this sign.

hep-ph↗

arXiv1993

Pseudoscalar Mass Effects in Decays of Taus with Three Pseudoscalar Mesons

We study the effects of non-vanishing pseudoscalar masses in $τ$ decays into three mesons. The hadronic matrix elements are obtained by using the generalized structure of the chiral currents with nonvanishing pseudoscalar masses and implementing the low-lying resonances in the different channels. We demonstrate that suitable angular distributions are sensitive to the mass effects in the chiral Langrangian. Numerical results for the rele\-% vant structure functions are given for the decay modes $τ\rightarrow νπ^-π^-π^+$, $νK^-π^-π^+$ and $νK^-π^-K^+$.

hep-ph↗

arXiv1993

Radiative Corrections to the decay tau -> pi (K) nu_tau

We have calculated the O(alpha) radiative corrections to the tau decay tau -> pi (K) nu, taking into account both the point meson contribution and the structure dependent radiation. We find for the ratio Gamma(tau -> pi nu (gamma)) / Gamma(pi -> mu nu (gamma)) a radiative correction of + 1.2% and for Gamma(tau -> K nu (gamma)) / Gamma(K -> mu nu (gamma)) one of + 2.0%. We compare our results with an earlier estimation and with experimental data.

hep-ph↗