Physics Letters B (Dec 2015)
First observation of long-lived π+π− atoms
- B. Adeva,
- L. Afanasyev,
- A. Anania,
- S. Aogaki,
- A. Benelli,
- V. Brekhovskikh,
- T. Cechak,
- M. Chiba,
- P. Chliapnikov,
- P. Doskarova,
- D. Drijard,
- A. Dudarev,
- M. Duma,
- D. Dumitriu,
- D. Fluerasu,
- A. Gorin,
- O. Gorchakov,
- K. Gritsay,
- C. Guaraldo,
- M. Gugiu,
- M. Hansroul,
- Z. Hons,
- S. Horikawa,
- Y. Iwashita,
- V. Karpukhin,
- J. Kluson,
- M. Kobayashi,
- V. Kruglov,
- L. Kruglova,
- A. Kulikov,
- E. Kulish,
- A. Kuptsov,
- A. Lamberto,
- A. Lanaro,
- R. Lednicky,
- C. Mariñas,
- J. Martincik,
- L. Nemenov,
- M. Nikitin,
- K. Okada,
- V. Olchevskii,
- V. Ovsiannikov,
- M. Pentia,
- A. Penzo,
- M. Plo,
- P. Prusa,
- G. Rappazzo,
- A. Romero Vidal,
- A. Ryazantsev,
- V. Rykalin,
- J. Saborido,
- J. Schacher,
- A. Sidorov,
- J. Smolik,
- F. Takeutchi,
- L. Tauscher,
- T. Trojek,
- S. Trusov,
- T. Urban,
- T. Vrba,
- V. Yazkov,
- Y. Yoshimura,
- M. Zhabitsky,
- P. Zrelov
Affiliations
- B. Adeva
- Santiago de Compostela University, Spain
- L. Afanasyev
- JINR, Dubna, Russia
- A. Anania
- INFN, Sezione di Trieste and Messina University, Messina, Italy
- S. Aogaki
- IFIN-HH, National Institute for Physics and Nuclear Engineering, Bucharest, Romania
- A. Benelli
- Czech Technical University in Prague, Czech Republic
- V. Brekhovskikh
- IHEP, Protvino, Russia
- T. Cechak
- Czech Technical University in Prague, Czech Republic
- M. Chiba
- Tokyo Metropolitan University, Japan
- P. Chliapnikov
- IHEP, Protvino, Russia
- P. Doskarova
- Czech Technical University in Prague, Czech Republic
- D. Drijard
- CERN, Geneva, Switzerland
- A. Dudarev
- JINR, Dubna, Russia
- M. Duma
- IFIN-HH, National Institute for Physics and Nuclear Engineering, Bucharest, Romania
- D. Dumitriu
- IFIN-HH, National Institute for Physics and Nuclear Engineering, Bucharest, Romania
- D. Fluerasu
- IFIN-HH, National Institute for Physics and Nuclear Engineering, Bucharest, Romania
- A. Gorin
- IHEP, Protvino, Russia
- O. Gorchakov
- JINR, Dubna, Russia
- K. Gritsay
- JINR, Dubna, Russia
- C. Guaraldo
- INFN, Laboratori Nazionali di Frascati, Frascati, Italy
- M. Gugiu
- IFIN-HH, National Institute for Physics and Nuclear Engineering, Bucharest, Romania
- M. Hansroul
- CERN, Geneva, Switzerland
- Z. Hons
- Nuclear Physics Institute ASCR, Rez, Czech Republic
- S. Horikawa
- Zurich University, Switzerland
- Y. Iwashita
- Kyoto University, Kyoto, Japan
- V. Karpukhin
- JINR, Dubna, Russia
- J. Kluson
- Czech Technical University in Prague, Czech Republic
- M. Kobayashi
- KEK, Tsukuba, Japan
- V. Kruglov
- JINR, Dubna, Russia
- L. Kruglova
- JINR, Dubna, Russia
- A. Kulikov
- JINR, Dubna, Russia
- E. Kulish
- JINR, Dubna, Russia
- A. Kuptsov
- JINR, Dubna, Russia
- A. Lamberto
- INFN, Sezione di Trieste and Messina University, Messina, Italy
- A. Lanaro
- University of Wisconsin, Madison, USA
- R. Lednicky
- Institute of Physics ASCR, Prague, Czech Republic
- C. Mariñas
- Santiago de Compostela University, Spain
- J. Martincik
- Czech Technical University in Prague, Czech Republic
- L. Nemenov
- JINR, Dubna, Russia
- M. Nikitin
- JINR, Dubna, Russia
- K. Okada
- Kyoto Sangyo University, Kyoto, Japan
- V. Olchevskii
- JINR, Dubna, Russia
- V. Ovsiannikov
- Voronezh State University, Russia
- M. Pentia
- IFIN-HH, National Institute for Physics and Nuclear Engineering, Bucharest, Romania
- A. Penzo
- INFN, Sezione di Trieste, Trieste, Italy
- M. Plo
- Santiago de Compostela University, Spain
- P. Prusa
- Czech Technical University in Prague, Czech Republic
- G. Rappazzo
- INFN, Sezione di Trieste and Messina University, Messina, Italy
- A. Romero Vidal
- Santiago de Compostela University, Spain
- A. Ryazantsev
- IHEP, Protvino, Russia
- V. Rykalin
- IHEP, Protvino, Russia
- J. Saborido
- Santiago de Compostela University, Spain
- J. Schacher
- Albert Einstein Center for Fundamental Physics, Laboratory of High Energy Physics, Bern, Switzerland
- A. Sidorov
- IHEP, Protvino, Russia
- J. Smolik
- Czech Technical University in Prague, Czech Republic
- F. Takeutchi
- Kyoto Sangyo University, Kyoto, Japan
- L. Tauscher
- Basel University, Switzerland
- T. Trojek
- Czech Technical University in Prague, Czech Republic
- S. Trusov
- Skobeltsin Institute for Nuclear Physics of Moscow State University, Moscow, Russia
- T. Urban
- Czech Technical University in Prague, Czech Republic
- T. Vrba
- Czech Technical University in Prague, Czech Republic
- V. Yazkov
- Skobeltsin Institute for Nuclear Physics of Moscow State University, Moscow, Russia
- Y. Yoshimura
- KEK, Tsukuba, Japan
- M. Zhabitsky
- JINR, Dubna, Russia
- P. Zrelov
- JINR, Dubna, Russia
- DOI
- https://doi.org/10.1016/j.physletb.2015.09.060
- Journal volume & issue
-
Vol. 751,
no. C
pp. 12 – 18
Abstract
After observing and investigating the double-exotic (a double-exotic atom is a bound system, in which both oppositely charged components are unstable particles like μ,π,K,…) π+π− atom with the ground state lifetime τ of about 3×10−15 s, the upgraded DIRAC experiment at the CERN PS accelerator observes for the first time long-lived states of the same atom with lifetimes of about 10−11 s and more. The number of characteristic pion pairs resulting from the breakup (ionisation) of long-lived π+π− atoms amounts to 436±61, corresponding to a signal-to-error ratio of better than 7 standard deviations. This observation opens a new possibility to measure energy differences between p and s atomic states and so to determine ππ scattering lengths.
