@article{49b175026c3240c38b1a1152ad45309b,
title = "Measurements of Strong-Interaction Effects in Kaonic-Helium Isotopes at Sub-eV Precision with X-Ray Microcalorimeters",
abstract = "We have measured the 3d→2p transition x rays of kaonic He3 and He4 atoms using superconducting transition-edge-sensor microcalorimeters with an energy resolution better than 6 eV (FWHM). We determined the energies to be 6224.5±0.4(stat)±0.2(syst) eV and 6463.7±0.3(stat)±0.1(syst) eV, and widths to be 2.5±1.0(stat)±0.4(syst) eV and 1.0±0.6(stat)±0.3(stat) eV, for kaonic He3 and He4, respectively. These values are nearly 10 times more precise than in previous measurements. Our results exclude the large strong-interaction shifts and widths that are suggested by a coupled-channel approach and agree with calculations based on optical-potential models.",
author = "{(J-PARC E62 Collaboration)} and T. Hashimoto and S. Aikawa and T. Akaishi and H. Asano and M. Bazzi and Bennett, {D. A.} and M. Berger and D. Bosnar and Butt, {A. D.} and C. Curceanu and Doriese, {W. B.} and Durkin, {M. S.} and Y. Ezoe and Fowler, {J. W.} and H. Fujioka and Gard, {J. D.} and C. Guaraldo and Gustafsson, {F. P.} and C. Han and R. Hayakawa and Hayano, {R. S.} and T. Hayashi and Hays-Wehle, {J. P.} and Hilton, {G. C.} and T. Hiraiwa and M. Hiromoto and Y. Ichinohe and M. Iio and Y. Iizawa and M. Iliescu and S. Ishimoto and Y. Ishisaki and K. Itahashi and M. Iwasaki and Y. Ma and T. Murakami and R. Nagatomi and T. Nishi and H. Noda and H. Noumi and K. Nunomura and O'Neil, {G. C.} and T. Ohashi and H. Ohnishi and S. Okada and H. Outa and K. Piscicchia and Reintsema, {C. D.} and Y. Sada and F. Sakuma",
note = "Funding Information: We would like to thank the staff members of J-PARC/KEK for their extensive efforts especially on the stable operation of the facility. We are grateful to the fruitful theoretical calculations and discussions with Dr. J. Yamagata-Sekihara, Dr. S. Hirenzaki, Dr. E. Hiyama, and Dr. E. Friedman. We acknowledge Dr. T. Koike who performed an electromagnetic calculation of the atomic states of kaonic-helium isotopes. This work was supported by Grains-in-Aid for Scientific Research from MEXT and JSPS (Grants No. JP24105003, No. JP25105514, No. JP26220703, No. JP26707014, No. JP15H05438, No. JP15H00785, No. JP16H02190, No. JP16K17718, No. JP17J07791, No. JP17J07948, No. JP18H01237, No. JP18H05402, No. JP18H05458, No. JP20K14524, and No. JP20K20527), Incentive Research Projects from RIKEN, the Mitsubishi Foundation (Grant No. 26145), EU STRONG-2020 Project (European Union{\textquoteright}s Horizon 2020 research and innovation programme under grant agreement No. 824093), and HRZZ Project No. 8570. T. H. was supported by the MEXT Leading Initiative for Excellent Young Researchers Grant. Publisher Copyright: {\textcopyright} 2022 American Physical Society.",
year = "2022",
month = mar,
day = "18",
doi = "10.1103/PhysRevLett.128.112503",
language = "English",
volume = "128",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "11",
}