Abstract
We study the thermal properties of the lowest multiplet of the QCD light-flavor scalar resonances, including the $f_0(500)/\sigma$, $K_{0}^{*}(700)/\kappa$, $f_0(980)$ and $a_0(980)$, in the framework of unitarized $U(3)$ chiral perturbation theory. After the successful fits to the meson-meson scattering inputs, such as the phase shifts and inelasticities, we obtain the unknown parameters and further calculate the resonance poles and their residues at zero temperature. By including the finite-temperature effects in the unitarized meson-meson scattering amplitudes, the thermal behaviors of the scalar resonance poles in the complex energy plane are studied. The masses of $\sigma$ and $\kappa$ are found to considerably decrease when increasing the temperatures, while their widths turn out to be still large when the temperatures reach around $200$ MeV. In contrast, both the masses and widths of the $f_0(980)$ and $a_0(980)$ are only slightly changed.
Highlights
Identifying the pattern of the chiral symmetry restoration, which plays the key role in understanding the complex phenomena from the relativistic heavy ion collisions, is one of the most important subjects in the study of QCD phase diagram
We study the thermal properties of the lowest multiplet of the QCD light-flavor scalar resonances, including the f0ð500Þ=σ, KÃ0ð700Þ=κ, f0ð980Þ and a0ð980Þ, in the framework of unitarized Uð3Þ chiral perturbation theory
The restoration of the chiral symmetry will definitely modify the hadronic spectrum at finite temperatures, which in turn will affect the hadron yields measured in the heavy-ion-collision experiments; e.g., it is found that the inclusion of the broad scalar resonance f0ð500Þ in the hadron-resonance-gas model clearly improves the description of the experimental data [1]
Summary
Identifying the pattern of the chiral symmetry restoration, which plays the key role in understanding the complex phenomena from the relativistic heavy ion collisions, is one of the most important subjects in the study of QCD phase diagram. Instead of including further the higher order corrections in the chiral amplitudes, we proceed in the discussions by simultaneously studying all the members of the possible lowest multiplet of the light scalar resonances σ, f0ð980Þ, κ, and a0ð980Þ within unitarized chiral perturbation theory ( χPT). Through this exploratory study, we obtain the thermal behaviors of all the aforementioned resonance poles, which can provide useful guides for the hadronresonance-gas models and gain insights into the mechanism of the chiral symmetry restoration.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
