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Combined limit on the production of a light gauge boson decaying into mu(+) mu(-) and pi(+) pi(-)
- Source :
- Physics Letters B, Vol 784, Iss, Pp 336-341 (2018), Physics Letters
- Publication Year :
- 2018
- Publisher :
- Uppsala universitet, Kärnfysik, 2018.
-
Abstract
- We searched for the $\mu^+\mu^-$ decay of a light vector gauge boson, also known as dark photon, in the $e^+ e^- \to \mu^+ \mu^- \gamma_{\rm ISR}$ process by means of the Initial State Radiation (ISR) method. We used 1.93~fb$^{-1}$ of data collected by the KLOE experiment at the DA$\Phi$NE $\phi$-factory. No structures have been observed over the irreducible $\mu^+ \mu^-$ background. A 90\% CL limit on the ratio $\varepsilon^2=\alpha^{\prime}/\alpha$ between the dark coupling constant and the fine structure constant of $ 3\times 10^{-6}-2\times 10^{-7}$ has been set in the dark photon mass region between 519 MeV and 973 MeV. This new limit has been combined with the published result obtained investigating the hypothesis of the dark photon decaying into hadrons in $e^+ e^- \to \pi^+ \pi^- \gamma_{\rm ISR}$ events. The combined 90\% CL limit increases the sensitivity especially in the $\rho-\omega$ interference region and excludes $\varepsilon^2$ greater than $(13-2)\times 10^{-7}$. For dark photon masses greater than 600 MeV the combined limit is lower than 8~$\times\, 10^{-7}$ resulting more stringent than present constraints from other experiments.<br />Comment: 7 pages, 9 figures, 1 table, accepted for publication in Physics Letters B
- Subjects :
- Nuclear and High Energy Physics
Dark forces
e(+) e(-) Collisions
High Energy Physics::Lattice
Electron–positron annihilation
Hadron
Radiation
01 natural sciences
e+e− Collision
Dark photon
High Energy Physics - Experiment
Subatomär fysik
High Energy Physics::Theory
e+e- Collisions, Dark forces. Gauge vector boson, Upper limits
Astronomi, astrofysik och kosmologi
0103 physical sciences
Subatomic Physics
Astronomy, Astrophysics and Cosmology
Limit (mathematics)
e + e − Collisions
Gauge vector boson
Upper limits
010306 general physics
Condensed Matter::Quantum Gases
Coupling constant
Physics
Gauge boson
010308 nuclear & particles physics
High Energy Physics::Phenomenology
Settore FIS/01 - Fisica Sperimentale
Upper limit
Fine-structure constant
lcsh:QC1-999
Dark force
High Energy Physics::Experiment
Atomic physics
lcsh:Physics
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- Physics Letters B, Vol 784, Iss, Pp 336-341 (2018), Physics Letters
- Accession number :
- edsair.doi.dedup.....40496836767cdacab2b6839aa4e4510a