Quark Confinement and the Hadron Spectrum XI

Session

Parallel II: B9 Light Quarks

2

12 Sept 2014, 14:00

St. Petersburg

Conveners

Parallel II: B9 Light Quarks

• Hagop Sazdjian (University Paris-Sud)

89. Corrections Beyond the Leading Order in Processes $\pi^0\to e^+e^-$ and $\pi^0\to e^+e^-\gamma$

Mr Tomas Husek (Charles University (CZ))

12/09/2014, 14:00

Section B: Light Quarks

In this talk we will discuss two important processes of the low energy hadron physics: the Dalitz decay of $\pi^0$ and $\pi^0\to e^+e^-$. We briefly summarize experimental and theoretical results on the rare decay $\pi^0\to e^+e^-$. The analytical two-loop QED corrections together with the bremsstrahlung contribution beyond the soft-photon approximation are reviewed. Using the leading...

127. Influence of quark-gluon vertex corrections on the spectrum of Hadrons

Dr Richard Williams (University of Giessen)

12/09/2014, 14:20

Section B: Light Quarks

We present a calculation of the Hadron spectrum in the Dyson-Schwinger/Bethe-Salpeter approach to continuum QCD. A sophisticated truncation featuring all covariant structures of the quark-gluon vertex, with its inherent flavour dependence, is employed in a framework that preserves the dynamics of chiral symmetry breaking. The study is suggestive as to the relevance of additional resonant...

150. Tetraquarks as four-body bound states in a Bethe-Salpeter approach

Mr Walter Heupel (Justus-Liebeig University Giessen)

12/09/2014, 14:40

Section B: Light Quarks

In the framework of Dyson-Schwinger equations, we present the first calculation of a four-body Bethe-Salpeter equation as required for the covariant description of tetraquarks. In a first approach we focus on the lightest tetraquark candidate, the $f_0(500)$, with an aim to determine the complete scalar nonet. Further investigations in this approach will focus on tetraquarks in the vector...

148. Regge trajectories of ordinary and non-ordinary mesons from their poles

Jenifer Nebreda Manjon (YITP, Kyoto University)

12/09/2014, 15:00

Section B: Light Quarks

Our results on obtaining the Regge trajectory of a resonance from its pole in a scattering process and from analytic constraints in the complex angular momentum plane will be presented. The method, suited for resonances that dominate an elastic scattering amplitude, has been applied to the rho(770), f_2(1275), f_2´(1525) and the f0(500) resonances. Whereas for the first three we obtain...

107. Potential of a combined analysis of the $\tau^{-}\rightarrow (K\pi)^{-}\nu_{\tau}$ and $\tau^{-}\rightarrow K^{-}\eta\nu_{\tau}$ decays

Mr Sergi Gonzàlez-Solís (IFAE-U.A.Barcelona)

12/09/2014, 15:20

Section B: Light Quarks

We illustrate how the $K^\star(1410)$ resonance parameters can be extracted with improved precision by exploiting the synergy of a combined study of the $\tau^-\to (K\pi)^-\nu_\tau$ and $\tau^-\to K^-\eta\nu_\tau$ decays for the first time. On the one hand we take advantage of the much larger statistics accumulated for the former decay in the $K_S\pi^-$ channel, while on the other we also...

227. Alpha_s determination from the C-parameter distribution

Vicent Mateu (University of Vienna)

12/09/2014, 15:40

Section B: Light Quarks

For the e+e- C-parameter we use soft-collinear effective theory to derive a factorization theorem, and then compute the cross section at N3LL + O(alphas^3). Differences with Thrust are highlighted. Our result holds for C in the peak, tail, and far tail regions, and we treat hadronization effects using a universal nonperturbative soft function defined in field theory. We analyze all available...