Exotic hadrons and hybrid KT-factorization (Alessandro Giachino, Departamento de Física Teórica and IFIC, Centro Mixto Universidad de Valencia-CSIC Institutos de Investigación de Paterna))

Aprile 24, 2024@2:00 pm–3:00 pm
Aula 501

Seminario di Fenomenologia delle particelle

Exotic hadron spectroscopy is a hot field since it has experienced a very productive period in the past 20 years, especially in the last years, in which new discoveries and/or new evidences of exotic states are published every three-four months. The outlook for the coming decades is that it will continuously grow thanks to the increasing interest from both the theoretical and the experimental sides of the scientific community, as witnessed by the large amount of literature on this field.

In the first part of the talk, some of the main experimental findings and theoretical predictions given before the experimental discoveries, regarding fully charm tetraquarks and pentaquarks, will be presented and discussed.
In the sector of fully charm pentaquark states, I will provide an outline of both the compact pentaquark description [1] and the description based on the coupling between the meson-baryon channels and the 5-quark core channels for the nonstrange [2,3] and the strange sector [4], and I will compare the predictions of these models with the experimental data.
In the sector of fully charm and fully bottom tetraquarks, I will present the calculation of $0^++$ and $2^++$ fully heavy tetraquark decay widths and branching ratios within the vector meson dominance model in the fully bottom [5] and fully charm sector [6] and compare the results with the recent experimental data.

In the second part of the talk, I will show a new method to compute the virtual contributions in KT-factorization [7,8]. As I will explain, this new formalism is a fundamental step to bridge the gap between the lowest order calculations and the NLO corrections in hybrid kT-factorization, thus being relevant for a more precise description of the experimental data in the rich field of forward physics.

[1] E. Santopinto and A. Giachino, Phys. Rev. D 96, 014014 (2017).
[2] Y. Yamaguchi, A. Giachino, A. Hosaka, E. Santopinto, S. Takeuchi and M. Takizawa, Phys. Rev. D 96, 114031 (2017)
[3] Y. Yamaguchi, H. Garcìa-Tecocoatzi, A. Giachino, A. Hosaka, E. Santopinto, S. Takeuchi and M. Takizawa, Phys. Rev. D 101, 091502 (2020).
[4] A. Giachino, A. Hosaka, E. Santopinto, S. Takeuchi, M. Takizawa, Y. Yamaguchi, Phys. Rev. D 108, 074012 (2023).
[5] C. Becchi, A. Giachino, L. Maiani and E. Santopinto, Phys. Lett. B 806, 135495 (2020)
[6] C. Becchi, J. Ferretti, A. Giachino, L. Maiani and E. Santopinto, Phys. Lett. B 811, 135952 (2020).
[7] E. Blanco, A. Giachino, A. van Hameren, P. Kotko, Nucl. Phys. B 995 (2023).
[8] A new subtraction scheme at NLO exploiting the privilege of kT-factorization, A. Giachino, A. van Hameren and G. Ziarko, e-Print: 2312.02808, submitted to JHEP.

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