Abstract
After decades-long attempts to measure the mass shift and understand the origin of hadron mass, it became clear that one has to analyze hadrons with small vacuum width. Also, to identify the effect of chiral symmetry breaking, one has to start by looking at chiral partners. In this talk, I will review why such consideration inevitably led us to consider $K^*$ and $K_1$ in nuclear matter [T. Song, T. Hatsuda, S H Lee, PLB792 (2019) 160-169]. With the kaon beam at JPARC, one could observe the mass shift of both particles in a nuclear target experiment. Once the masses and mass difference of $K^*$ and $K_1$ mesons are measured, we will be closer to understanding the origin of the hadron masses and the effects of chiral symmetry breaking in them.
Highlights
The mass of a hadron can not be understood from the traditional picture of a composite particle, the mass of which can be expressed in terms of the masses of its constituents and a small binding energy
In the original in-medium QCD sum rules [4], the changes of the vector meson masses were dominantly due to the change of the four-quark condensate for the light quark system and the strange quark condensate for the strange quark system
Evidence of mass shift by 3.4 % at normal nuclear density was reported by the KEK-PS E325 collaboration [8]
Summary
The mass of a hadron can not be understood from the traditional picture of a composite particle, the mass of which can be expressed in terms of the masses of its constituents and a small binding energy. The problem with final state interaction was found to be solvable by combining the measurement of excitation functions and the transparency ratios Motivated by such recent experimental progresses, the author has recently estimated the spectral shift of the f1 meson, which is a chiral partner of ω in the limit where the disconnected diagrams are neglected, in the QCD sum rule approach [15]. One can show that the difference between the vector and axial-vector correlation functions in the open strange channel is an order parameter of chiral symmetry [17]. As can be seen above, the combination of propagators appear, which will be proportional to the density of zero modes Using these methods, one can construct chiral order parameters of different types of correlation functions.
Sign-in/Register to view highlights & summary 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.
