First Measurement of a Long-Lived pi(+) pi(-) Atom Lifetime
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F19%3A00503671" target="_blank" >RIV/61389005:_____/19:00503671 - isvavai.cz</a>
Alternative codes found
RIV/68378271:_____/19:00503671 RIV/68407700:21340/19:00331805
Result on the web
<a href="https://doi.org/10.1103/PhysRevLett.122.082003" target="_blank" >https://doi.org/10.1103/PhysRevLett.122.082003</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1103/PhysRevLett.122.082003" target="_blank" >10.1103/PhysRevLett.122.082003</a>
Alternative languages
Result language
angličtina
Original language name
First Measurement of a Long-Lived pi(+) pi(-) Atom Lifetime
Original language description
The adapted DIRAC experiment at the CERN PS accelerator observed for the first time long-lived hydrogenlike pi(+)pi(-) atoms, produced by protons hitting a beryllium target. A part of these atoms crossed the gap of 96 mm between the target and a 2.1 pm thick platinum foil, in which most of them dissociated. Analyzing the observed number of atomic pairs, n(A)(L) = 436(-61)(+157)vertical bar(tot) the lifetime of the 2p state is found to be QED tau(2p) = (0.45(-0.30)(+1.08) vertical bar(tot)) x 10(-11) s, not contradicting the corresponding QED 2p state lifetime r., -P 1.17 x 10(-11) s. This lifetime value is three orders of magnitude larger than our previously measured value of the pi(+) pi(-) atom ground state lifetime r = (3.15(-0.26)(+0.28)vertical bar(tot)) x 10(-15) s. Further studies of long-lived n-+ atoms will allow us to measure energy differences between p and s atomic states and so to discriminate between the isoscalar and isotensor Kin scattering lengths with the aim to check QCD predictions.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10304 - Nuclear physics
Result continuities
Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2019
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Physical Review Letters
ISSN
0031-9007
e-ISSN
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Volume of the periodical
122
Issue of the periodical within the volume
8
Country of publishing house
US - UNITED STATES
Number of pages
7
Pages from-to
082003
UT code for WoS article
000460667600006
EID of the result in the Scopus database
2-s2.0-85062291704