Exceptional Seminar Sonnenschein Jacob (Tel Aviv)
I will show that the non-stringy holographic description of hadrons, namely the one based on fields that reside on the bulk and flavor branes, fails to reproduce the hadronic spectra. I will briefly review the stringy duals of Wilson loops and determine the sufficient conditions of confining backgrounds. I will show that the latter are also the requirements for holographic stringy mesons to admit a Regge-like spectrum. I will determine a map between holographic stringy mesons and strings with massive endpoints in 4d flat space-time. Models of classical rotating strings with massive endpoints will be written down. I will discuss the (still unsolved) quantization of such systems. Fits of the models to mesonic data will be presented. A universal model that describes mesons of u,d,s,c quarks will be developed. Mesons with b quarks will also be fitted. I will describe the construction of stringy baryons in holography. I will show that the best description of baryons is in terms of a single string with a quark and a di-quark on its ends. I will present fits of such a model to the baryonic data. Finally I will describe the stringy decays of holographic hadrons.