Heavy Hadrons under Extreme Conditions
Final Report Abstract
With this research project I have studied the properties of heavy hadrons under extreme conditions starting from effective theories that incorporate the most relevant scales and symmetries of Quantum Chromodynamics (QCD). On the one hand, the equation of state of matter with strangeness has been the focused of part of my research in connection with neutron stars. Neutron stars are a unique laboratory for determining the equation of state of visible matter under extreme conditions. Furthermore, neutron stars offer the chance of testing the possible effects of the elusive dark matter onto ordinary matter, while giving some hints on its properties. Regarding the equation of state of visible strange matter, cooling simulations for isolated neutron stars have been performed, finding that cooling observations are compatible with an equation of state that produces small neutron-star radii. Moreover, the compatibility of the equation of state with the tidal deformability measurements coming from the neutron-star merger GW170817 event has been analyzed, allowing for different types of phase transitions and the inclusion of Delta isobars. With respect to dark matter and the interaction with visible matter, the possible formation of compact stellar objects with dark matter have been considered by studying the effect of different dark matter masses and different self-interacting strengths. The mass of neutron stars turns out to be influenced by the presence of dark matter in the surrounding environment, as it decreases going towards the center of the Milky Way. Once future observations will provide the pulsar mass in a dark matter rich environment, close to the galactic center, the present result will be able to put constraints on the characteristics of our Galaxy halo dark matter profile, on the nature of dark matter, on its strength of self-interaction, and on the particle mass. On the other hand, a spectroscopic analysis of newly discovered charmed and beauty baryonic states has been carried out by considering a scheme consistent with heavy-quark spin symmetry, which is a QCD symmetry that appears as the quark masses become larger than the typical confinement scale. The dependence on the renormalization procedure of the unitarized coupled-channel approach has been addressed, thus, being able to show that at least three experimental Wc will have odd parity and J=1/2 or J=3/2. Moreover, the newly discovered Xc(2930) and Xc(2970) experimental states turn out to be heavy-quark partners, whereas the experimental Σc(2800), Xc(2930) and Ωc(3090)/Ωc(3119) belong to the same spin multiplet. Also, the existence of new states have been predicted in the beauty sector, such as Ωb(6360) that belongs to the multiplet of Xb(6227) and Σb(6097). This state is expected to be found in the near future within the experimental programs at LHCb/CERN or JPARC. Furthermore, I have performed first steps towards extracting information on the properties of the hot dense QCD phases by studying the properties of heavy hadrons in the low-density and high-temperature regime, such as the one expected at RHIC/BNL and LHCb/CERN. The model has been extended to the high-temperature regime in order to analyze charmed mesons in a light-meson environment. These results have been then used to compute the charmed Euclidean correlators and compare them with those obtained from lattice QCD. The inclusion of the in-medium properties of charmed mesons in the calculation of the Euclidean correlators leads to a similar behaviour as the one obtained in lattice QCD for temperatures well below the transition deconfinement temperature. Moreover, the study of the propagation of heavy hadrons with charm and beauty content in heavy-ion collisions have just started by means of determining the collision rates and the transport coefficients at finite temperature for the experimental conditions at the LHCb/CERN, ALICE/CERN upgrade and CBM/FAIR. Last but not least, this research program has been successfully disseminated in conferences and workshops as well as in the media, with several invited seminars and outreach talks, whereas a new generation of young scientists has been trained thanks to this project.
Publications
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Cooling of small and massive hyperonic stars. Astrophysical Journal, Vol. 863. 2018, Number 1, 104.
Rodrigo Negreiros, Laura Tolos, Mario Centelles, Angels Ramos, Veronica Dexheimer
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Ωc excited states within a SU(6)lsf×HQSS model. European Physical Journal C, Vol. 78. 2018, Article number: 114.
Juan Nieves, Rafael Pavao, Laura Tolos
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Dense matter with eXTP. Science China Physics, Mechanics & Astronomy, Vol. 62. 2019, Article number: 29503.
Anna Watts et al. (Laura Tolos)
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Interplay between ∆ particles and Hyperons in Neutron Stars.
Astrophysical Journal, Vol. 883. 2019, Number 2, 168.
Patricia Ribes, Angels Ramos, Laura Tolos, Claudia Gonzalez-Boquera, Mario Centelles
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Strangeness in Nuclei and Neutron Stars. Progress in Particle and Nuclear Physics, Vol. 112. 2020, 103770.
Laura Tolos, Laura Fabbietti
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Ξc and Ξb excited states with a SU(6)lsf× HQSS model. European Physical Journal C, Vol. 80. 2020, Article number: 22.
Juan Nieves, Rafael Pavao, Laura Tolos
