The recent PSI Lamb shift experiment and the controversy about proton size revived the interest in measuring the hyperfine splitting in muonic hydrogen as an alternative possibility for comparing ordinary and muonic hydrogen spectroscopy data on proton electromagnetic structure. This measurement critically depends on the energy dependence of the muon transfer rate to heavier gases in the epithermal range. The available data provide only qualitative information, and the theoretical predictions have not been verified. We propose a new method by measurements of the transfer rate in thermalized target at different temperatures, estimate its accuracy and investigate the optimal experimental conditions.
The results of calculations of the muon transfer rate from the 1S state of muonic hydrogen to the nucleus of a free oxygen atom are presented in the interval of collision energies from 10^(-4) to 10 eV. The calculations were performed within a version of the perturbed stationary states method proposed earlier. The electron screening in the entrance channel of the transfer reaction was taken into account. A p-wave resonance in the transfer rate is predicted at collision energies of about 0.1 eV. This result is of interest in the context of the planned laser experiment on precise measurements of…
We report the first experimental determination of the collision-energy dependence of the muon transfer rate from the ground state of muonic hydrogen to oxygen at near-thermal energies. A sharp increase by nearly an order of magnitude in the energy range 0 - 70 meV was found that is not observed in other gases. The results set a reliable reference for quantum-mechanical calculations of low-energy processes with exotic atoms, and provide firm ground for the measurement of the hyperfine splitting in muonic hydrogen and the determination of the Zemach radius of the proton by the FAMU collaboration…
The "proton radius puzzle" was recently solved by reducing the four-standard deviation discrepancy between the results for electronic hydrogen ($H$) and muonic hydrogen ($μH$) atoms to $3.3$ value. The value of the root-mean-square radius of the proton ($r_p$), extracted from experiments on measuring the one-photon $2s-4p$ transition and the Lamb shift in hydrogen, is now $0.8335(95)$ fm, that is in good agreement with the muonic hydrogen experiments, $0.84087(39)$ fm. Even so, these values deviate significantly from the CODATA value, which is determined as the average using the results for va…
Comment on "Sixth-Order Vacuum-Polarization Contribution to the Lamb Shift of Muonic Hydrogen" by T. Kinoshita and M. Nio, Phys. Rev. Lett. 82, 3240 (1999)
在评论中,我们讨论了兰姆位移的$α^3$校正的附加项,这在Kinoshita和Nio的计算中被遗漏(Phys. Rev. Lett. 82,3240(1999))。
Toward the measurement of the hyperfine structure of muonic hydrogen in the FAMU experiment. Multi-pass cavity optimization for experiments with pulsed sources
The first measurement of the temperature dependence of the muon transfer rate from muonic hydrogen to oxygen was performed by the FAMU collaboration in 2016. The results provide evidence that the transfer rate rises with the temperature in the range 104-300 K. This paper presents the results of the experiment done in 2018 to extend the measurements towards lower (70 K) and higher (336 K) temperatures. The 2018 results confirm the temperature dependence of the muon transfer rate observed in 2016 and sets firm ground for comparison with the theoretical predictions.
Laser Excitation of Muonic 1S Hydrogen Hyperfine Transition: Effects of Multi-pass Cell Interference
NOVA School of Science and Technology, NOVA University Lisbon(新大学科学技术学院,新里斯本大学);PSI Center for Neutron and Muon Sciences(瑞士保罗谢勒研究所中子与μ子科学中心);LIBPhys-UC, Department of Physics, University of Coimbra(科英布拉大学物理系LIBPhys-UC);Institute for Particle Physics and Astrophysics, ETH Zurich(苏黎世联邦理工学院粒子物理与天体物理研究所)
We present a high-precision calculation of the recoil--finite-size correction to the hyperfine splitting (HFS) in muonic and electronic hydrogen based on nucleon electromagnetic form factors obtained from dispersion theory. This will help guide the upcoming searches of the HFS transition in muonic hydrogen, and will allow a precise determination of the polarizability and Zemach radius contributions when this transition is found.
Nonperturbative numerical calculation of the fine and hyperfine structure of muonic hydrogen by Breit potential including the effects from the proton size
Low-energy direct muon transfer from H to Ne$^{10+}$, S$^{16+}$ and Ar$^{18+}$ using two-state close-coupling approximation to Faddeev-Hahn-type equation