Hadron dynamics with vector mesons: matching theory and experiment to identify new resonances and their nature

• Eulogio Oset

In this talk I shall address chiral dynamics and its extension to the vector sector with the local hidden gauge approach. I shall show how some resonances are dynamically generated in the approach from meson meson and meson baryon interactions. Then will address two very recent reactions, gamma p -> K^0 Sigma^+ , with its peculiar energy dependence close to the K^* Lambda threshold, from where we deduce evidence of one of the baryon resonances predicited before, around 2030 MeV. Then I shall address the J/psi - > eta K^* K^*bar from where we find evidence of a h_1 resonance around 1830 MeV, also predicted from the vector vector interaction. Some short review of the status of the molecular states in the charm and beauty sectors will follow.

Low vs high-lying modes for hadron mass generation

• Leonid Glozman (Graz U)

We study the effect of the chiral symmetry breaking low-lying modes of the Dirac operator and of the higher-lying modes on the hadron mass generation and on symmetries of hadrons in lattice QCD simulations.

The PANDA experiment at FAIR

• Tobias Stockmanns (Forschungszentrum Jülich GmbH)

The PANDA experiment is one of the key components of the future "Facility for Antiproton and Ion Research" at Darmstadt. Its goal is to study the features of the strong force in the transition region between perturbative and non-perturbative QCD. Therefore it utilizes the phase space cooled antiproton beam with a beam momentum between 1.5 GeV/c and 15 GeV/c to do precision measurements in the charmonium mass range. The physics program of PANDA covers a wide field of different topics: charmonium and charmed/multi-strange baryon spectroscopy, the search for hybrids and glueballs as well as the study of electromagnetic processes, single and double hypernuclei and hadrons in nuclear matter. To do these demanding measurements a complex experimental setup is needed using state-of-the-art detector technologies. During this presentation an overview of the physics program as well as the experimental setup will be given.

Dynamic Holographic QCD

• Nick Evans (U)

I present a simple AdS/QCD model in which the formation of the chiral condensate is dynamically determined. The gauge dynamics is input through the running of the quark bilinear's anomalous dimension, gamma. The condensate provides a dynamically generated infra-red wall in the computation of mesonic bound state masses and decay constants. As an example, I use the model, with perturbative computations of the running of gamma, to study SU(3) gauge theory with a continuous number of quark flavours, Nf. We follow the behaviour of the spectrum as we approach the conformal window through a walking gauge theory regime. The phase diagram of the theory is also computable in this model.

N =4 super Yang-Mills plasma

• Stanislaw Mrowczynski (National Center of Nuclear Reserach, Warsaw, Poland)

Motivated by the AdS/CFT duality, we study the N=4 super Yang-Mills plasma in the regime of weak coupling and compare it to the QCD plasma. Collective excitations and collisional processes are discussed. Since the Keldysh-Schwinger approach is used, the collective excitations in both equilibrium and non-equilibrium plasma are under consideration. The dispersion relations of gluon, fermion, and scalar fields are found in the Hard Loop Approximation and the corresponding effective action is given. The binary collisional processes, which occur at the lowest nontrivial order of the coupling constant, are reviewed and then the transport properties of the plasma are discussed. For more see: A. Czajka and St. Mrowczynski, Phys. Rev. D 86, 025017 (2012).

Magnetic Phenomena in holographic QCD

• Gilad Lifschytz (University of Haifa at Oranim)

I will review various effects connected to magnetic fields in the context of holographic QCD. These will include magnetic catalysis, new phases of matter and new phase transitions.

Regge trajectory of the f0(500) resonance from a dispersive connection to its pole

• Jose R. Pelaez (Universidad COmplutense)

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) and the f0(500) resonances. Whereas for the former we obtain a linear Regge trajectory, characteristic of ordinary quark-antiquark states, for the latter we find a non-linear trajectory with a much smaller slope at the resonance mass. We also show that if a linear trajectory with a slope of typical size is imposed for the f0(500), the corresponding amplitude is at odds with the data.

Hot SU(2) Glue around Deconfinement

• Tereza Mendes (University of Sao Paulo)

We investigate on the lattice the properties of electric and magnetic gluon propagators for finite-temperature SU(2) theory around the deconfinement transition. Special care is taken to handle the very strong systematic effects that arise in the critical region.

Effects of divergent ghost loops on the Green's functions of QCD

• Daniele Binosi (ECT* Fondazione Bruno Kessler)

I discuss certain characteristic features encoded in some of the fundamental QCD Green's functions, whose origin can be traced back to the (Landau gauge) nonperturbative masslessness of the ghost field. Specifically, the ghost loops that contribute to these Green's functions display infrared divergences, akin to those encountered in the perturbative treatment, in contradistinction to the gluonic loops, whose perturbative divergences are tamed by the dynamical generation of an effective gluon mass. In d=4, the aforementioned divergences are logarithmic, thus causing a relatively mild impact, whereas in d=3 they are linear, giving rise to enhanced effects. In the case of the gluon propagator, these effects do not interfere with its finiteness, but make its first derivative diverge at the origin, and introduce a maximum in the region of infrared momenta. The three-gluon vertex is also affected, and the induced divergent behavior is clearly exposed in certain special kinematic configurations, usually considered in lattice simulations; the sign of the corresponding divergence is unambiguously determined. The picture that emerges is finally compared to the available lattice data.