Investigation of K + K - pairs in the effective mass region near 2 m K

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21340%2F22%3A00359160" target="_blank" >RIV/68407700:21340/22:00359160 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1103/PhysRevD.106.032006" target="_blank" >https://doi.org/10.1103/PhysRevD.106.032006</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevD.106.032006" target="_blank" >10.1103/PhysRevD.106.032006</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Investigation of K + K - pairs in the effective mass region near 2 m K

Popis výsledku v původním jazyce

The DIRAC experiment at CERN investigated in the reaction pð24 GeV=cÞ þ Ni the particle pairs KþK-; πþπ-, and pp with relative momentum Q in the pair system less than 100 MeV=c. Because of background influence studies, DIRAC explored three subsamples of KþK- pairs, obtained by subtractingusing the time-of-flight (TOF) technique-the background from initial Q distributions with KþK- sample fractions more than 70%, 50%, and 30%. The corresponding pair distributions in Q and in its longitudinal projection QL were analyzed first in a Coulomb model, which takes into account only the Coulomb finalstate interaction (FSI) and assuming pointlike pair production. This Coulomb model analysis leads to a KþK- yield increase of about four at QL 1/4 0.5 MeV=c compared to 100 MeV=c. In order to study contributions from strong interaction, a second more sophisticated model was applied, considering also strong FSI via the resonances f0ð980Þ and a0ð980Þ and a variable distance r between the produced K mesons besides Coulomb FSI. This analysis was based on three different parameter sets for the pair production. For the 70% subsample and with the best parameters, 3680 370 KþK- pairs were found to be compared to 3900 410 KþK- extracted by means of the Coulomb model. Knowing the efficiency of the TOF cut for background suppression, the total number of detected KþK- pairs was evaluated to be around 40000 10%, which agrees with the result from the 30% subsample. The KþK- pair number in the 50% subsample differs from the two other values by about three standard deviations, confirming—as discussed in the paper—that experimental data in this subsample is less reliable. In summary, the upgraded DIRAC experiment observed increased KþK- production at small relative momentum Q. The pair distribution in Q is well described by Coulomb FSI, whereas a potential influence from strong interaction in this Q region is insignificant within experimental errors.

Název v anglickém jazyce

Investigation of K + K - pairs in the effective mass region near 2 m K

Popis výsledku anglicky

The DIRAC experiment at CERN investigated in the reaction pð24 GeV=cÞ þ Ni the particle pairs KþK-; πþπ-, and pp with relative momentum Q in the pair system less than 100 MeV=c. Because of background influence studies, DIRAC explored three subsamples of KþK- pairs, obtained by subtractingusing the time-of-flight (TOF) technique-the background from initial Q distributions with KþK- sample fractions more than 70%, 50%, and 30%. The corresponding pair distributions in Q and in its longitudinal projection QL were analyzed first in a Coulomb model, which takes into account only the Coulomb finalstate interaction (FSI) and assuming pointlike pair production. This Coulomb model analysis leads to a KþK- yield increase of about four at QL 1/4 0.5 MeV=c compared to 100 MeV=c. In order to study contributions from strong interaction, a second more sophisticated model was applied, considering also strong FSI via the resonances f0ð980Þ and a0ð980Þ and a variable distance r between the produced K mesons besides Coulomb FSI. This analysis was based on three different parameter sets for the pair production. For the 70% subsample and with the best parameters, 3680 370 KþK- pairs were found to be compared to 3900 410 KþK- extracted by means of the Coulomb model. Knowing the efficiency of the TOF cut for background suppression, the total number of detected KþK- pairs was evaluated to be around 40000 10%, which agrees with the result from the 30% subsample. The KþK- pair number in the 50% subsample differs from the two other values by about three standard deviations, confirming—as discussed in the paper—that experimental data in this subsample is less reliable. In summary, the upgraded DIRAC experiment observed increased KþK- production at small relative momentum Q. The pair distribution in Q is well described by Coulomb FSI, whereas a potential influence from strong interaction in this Q region is insignificant within experimental errors.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10303 - Particles and field physics

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

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

1079-7114

Svazek periodika

106

Číslo periodika v rámci svazku

3

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

13

Strana od-do

"032006-1"-"032006-13"

Kód UT WoS článku

000860413600003

EID výsledku v databázi Scopus

2-s2.0-85136242016