Measurement of the Strong Interaction Induced Shift and Width of the 1$s$ State of Kaonic Deuterium at J-PARC

Abstract

101) 102 J. Zmeskal et al.The antikaon-nucleon (KN ) interaction close to threshold provides crucial information on the interplay between spontaneous and explicit chiral symmetry breaking in low-energy QCD. In this context, the importance of kaonic deuterium X-ray spectroscopy has been well recognized, but no experimental results have yet been obtained due to the difficulty of the measurement. We propose to measure the shift and width of the kaonic deuterium 1s state with an accuracy of 60 eV and 140 eV, respectively, at J-PARC. These results, together with the kaonic hydrogen data (KpX at KEK, DEAR and SIDDHARTA at DAΦNE), will then permit the determination of values of both the isospin I = 0 and I = 1 antikaon-nucleon scattering lengths and will provide the most stringent constraints on the antikaon-nucleon interaction, promising a breakthrough. Refined Monte Carlo studies were performed, including the investigation of background suppression factors for the described setup. These studies have demonstrated the feasibility of determining the shift and width of the kaonic deuterium atom 1s state with the desired accuracy of 60 eV and 140 eV.

Strangeness in nuclei and neutron stars

“…As mentioned in Sec. 2.1.1, it is expected that the future measurement of kaonic deuterium in J-PARC [48] and DAφNE [49] facilities will further constrain the subthreshold behaviour of theKN amplitude. Another interesting conclusion of all these works is that the dynamics of the Λ(1405) is described by the superposition of two poles of the scattering matrix, between theKN and πΣ thresholds [7][8][9].…”

Faddeev approach to the reaction K−d→πΣn at pK=1GeVMiyagawa1, Haidenbauer2, Kamada3 2018Phys. Rev. C101182View full textAdd to dashboardCite

“…Currently there are major experimental efforts to provide further constraints on theKN interaction. One of them concerns plans for measuring the level shift of K − d atoms in order to pin down the I = 1KN amplitude [18]. Access to the energy dependence of the amplitudes below theKN threshold and thus to quantitative information on the pole structure of the (1405) is possible in studies of the π system.…”

Kaonic Hydrogen and Deuterium in Hamiltonian Effective Field Theory

“…The energy distributions of X-rays emitted from the excited kaonic atom may be measured to obtain ∆E 1S in experiment [16][17][18][19][20][21]. The difference between the measured and QED-predicted nP − 1S transition energy is essentially the same as ∆E 1S , since the nP level is scarcely affected by the strong interaction.…”

“…The reduced mass of the anti-kaon and the deuteron is a little larger than that of KN and thus kaonic deuterium would be easier to form under the pure electromagnetic interaction. There has been a proposal to search for kaonic deuterium in SIDDHARTA-2 and the J-PARC E57 experiment [18][19][20][21].…”