The decay width of stringy hadrons

by Prof. Cobi Sonnenschein (Tel Aviv U)

Tuesday 3 Oct 2017, 14:00 → 15:00 Europe/Zurich

4/2-037 - TH meeting room (CERN)

I will start with briefly describing the HISH ( Holography Inspired Hadronic String) model and reviewing the fits of the spectra of mesons, baryons, glueballs and exotic hadrons.

I will present the determination of the hadron strong decay widths. The main decay mechanism is that of a string splitting into two strings. The corresponding total decay width behaves as Γ = πATL where T and L are the tension and length of the string and A is a dimensionless universal constant. The partial width of a given decay mode is given by Γi/Γ = Φi exp(−2πCm2sep/T) where Φi is a phase space factor, msep is the mass of the ”quark” and ”antiquark” created at the splitting point, and C is a dimensionless coefficient close to unity.

I will show the fits of the theoretical results to experimental data for mesons and baryons. I will examine both the linearity in L and the expo- nential suppression factor. The linearity was found to agree with the data well for mesons but less for baryons. The extracted coefficient for mesons A = 0.095 ± 0.015 is indeed quite universal. The exponential suppression was applied to both strong and radiative decays. I will discuss the relation with string fragmentation and jet formation. I will extract the quark-diquark structure of baryons from their decays. A stringy mechanism for Zweig sup- pressed decays of quarkonia will be proposed and will be shown to reproduce the decay width of Υ states. The dependence of the width on spin and flavor symmetry will be discussed. We further apply this model to the decays of glueballs and exotic hadrons.