First Measurement of a Long-Lived pi(+) pi(-) Atom Lifetime

Kód výsledku v 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>

Nalezeny alternativní kódy

RIV/68378271:_____/19:00503671 RIV/68407700:21340/19:00331805

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

First Measurement of a Long-Lived pi(+) pi(-) Atom Lifetime

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

First Measurement of a Long-Lived pi(+) pi(-) Atom Lifetime

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10304 - Nuclear physics

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Review Letters

ISSN

0031-9007

e-ISSN

—

Svazek periodika

122

Číslo periodika v rámci svazku

8

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

7

Strana od-do

082003

Kód UT WoS článku

000460667600006

EID výsledku v databázi Scopus

2-s2.0-85062291704