Total Hadronic Cross Sections via the Holographic Pomeron Exchange

The analysis on the hadron-hadron scattering at high energies in the framework of holographic QCD is presented. Combining the Pomeron exchange kernel and the hadron-Pomeron couplings which are obtained from the bottom-up AdS/QCD models, we calculate the total cross sections. Our calculation for the nucleon-nucleon scattering is consistent with the experimental data including the recent ones measured by the TOTEM collaboration at the LHC. Within the framework, one can consider other processes involving other hadrons. As examples to show this feature of the model, the resulting total cross sections of the pion-nucleon and pion-pion scattering are also presented.Comment: 4 pages, 1 figure, prepared for the proceedings of the 8th International Conference on Quarks and Nuclear Physics (QNP2018), 13 - 17 November 2018, Tsukuba, Japa

Pomeron dynamics in the AdS space and structure functions of hadrons at small x

The Pomeron dynamics is investigated via deep inelastic scattering (DIS) at small x in the framework of holographic quantum chromodynamics. The small x DIS process is assumed to be described by the graviton exchange between external vector current and hadron in the AdS space. Our calculations for $F_2^p$, $F_2^\pi$, as well as the longitudinal counterpart $F_L^p$ are consistent with the experimental data. We discuss origins of a difference between $F_2$ and $F_L$ in our approach.Comment: 4 pages, 3 figures, contribution to the proceedings of QCD@Work 2012: International Workshop on QCD - Theory and Experiment, June 18-21, Lecce, Ital

Holographic description of total hadronic cross sections at high energies

We investigate the hadron-hadron total cross sections at high energies in the framework of holographic QCD. In our model setup, the involved strong interaction is described by the Brower-Polchinski-Strassler-Tan Pomeron exchange kernel, and the two form factors are obtained from the bottom-up AdS/QCD models. We show that the resulting nucleon-nucleon total cross section is consistent with the experimental data recently measured by the TOTEM collaboration at the LHC. As examples to see the general versatility of the model, we also present our analysis on the pion-nucleon and pion-pion cases, which can be predicted because all the adjustable parameters are fixed by the nucleon-nucleon data.Comment: 7 pages, 2 figures, prepared for the proceedings of QCD@Work 2018 - International Workshop on Quantum Chromodynamics, 25 - 28 June 2018, Matera, Ital

Hadronic structure of the photon at small x in holographic QCD

We present our analysis on the photon structure functions at small Bjorken variable x in the framework of the holographic QCD. In the kinematic region, a photon can fluctuate into vector mesons and behaves like a hadron rather than a pointlike particle. Assuming the Pomeron exchange dominance, the dominant hadronic contribution to the structure functions is computed by convoluting the probe and target photon density distributions obtained from the wave functions of the U(1) vector field in the five-dimensional AdS space and the Brower-Polchinski-Strassler-Tan Pomeron exchange kernel. Our calculations are in agreement with both the experimental data from OPAL collaboration at LEP and those calculated from the parton distribution functions of the photon proposed by Gl\"uck, Reya, and Schienbein. The predictions presented here will be tested at future linear colliders, such as the planned International Linear Collider.Comment: 6 pages, 3 figures, contribution to the proceedings of QCD@Work 2016 - International Workshop on QCD - Theory and Experiment, 27-30 June 2016, Martina Franca, Ital

Photon structure functions at small xx in holographic QCD

We investigate the photon structure functions at small Bjorken variable $x$ in the framework of the holographic QCD, assuming dominance of the Pomeron exchange. The quasi-real photon structure functions are expressed as convolution of the Brower-Polchinski-Strassler-Tan (BPST) Pomeron kernel and the known wave functions of the U(1) vector field in the five-dimensional AdS space, in which the involved parameters in the BPST kernel have been fixed in previous studies of the nucleon structure functions. The predicted photon structure functions, as confronted with data, provide a clean test of the BPST kernel. The agreement between theoretical predictions and data is demonstrated, which supports applications of holographic QCD to hadronic processes in the nonperturbative region. Our results are also consistent with those derived from the parton distribution functions of the photon proposed by Gl\"uck, Reya, and Schienbein, implying realization of the vector meson dominance in the present model setup.Comment: 6 pages, 5 figures; v2: version accepted for publication in Phys. Lett. B, Fig. 2 and clarifications added to Section