1. Combined limit on the production of a light gauge boson decaying into mu(+) mu(-) and pi(+) pi(-)
- Author
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P.A. Lukin, E. P. Solodov, E. Perez del Rio, A. D'Uffizi, D. Kisielewska-Kamińska, Michał Silarski, Filippo Ceradini, Paolo Ciambrone, G. Venanzoni, P. Fermani, V. L. Ivanov, P. De Simone, Paweł Moskal, A. De Santis, R. Messi, T. Johansson, G. Fantini, Eryk Czerwiński, E. Dané, Francesca Curciarello, D. Domenici, S. Giovannella, F. Bossi, Antonio Budano, C. Bloise, A. Anastasi, L. Tortora, A. Selce, Marco Schioppa, A. Di Domenico, Giuseppe Mandaglio, Magnus Wolke, P. Gauzzi, S. Miscetti, X. Kang, D. Babusci, N. Raha, A. Fantini, V. De Leo, Florin Sirghi, Vincenzo Patera, Andrzej Kupsc, Wojciech Krzemien, P. Branchini, E. De Lucia, M. Martini, Paolo Santangelo, D. Moricciani, G. D'Agostini, E.A. Kozyrev, A. Di Cicco, A. Passeri, S. Fiore, E. Graziani, Wojciech Wiślicki, M. Berlowski, B. Cao, Aleksander Gajos, Anastasi, A., Babusci, D., Berlowski, M., Bloise, C., Bossi, F., Branchini, P., Budano, A., Cao, B., Ceradini, F., Ciambrone, P., Curciarello, F., Czerwiński, E., D'Agostini, G., Danè, E., De Leo, V., De Lucia, E., De Santis, A., De Simone, P., Di Cicco, A., Di Domenico, A., Domenici, D., D'Uffizi, A., Fantini, A., Fantini, G., Fermani, P., Fiore, S., Gajos, A., Gauzzi, P., Giovannella, S., Graziani, E., Ivanov, V. L., Johansson, T., Kang, X., Kisielewska-Kamińska, D., Kozyrev, E. A., Krzemien, W., Kupsc, A., Lukin, P. A., Mandaglio, G., Martini, M., Messi, R., Miscetti, S., Moricciani, D., Moskal, P., Passeri, A., Patera, V., Perez del Rio, E., Raha, N., Santangelo, P., Schioppa, M., Selce, Andrea, Silarski, M., Sirghi, F., Solodov, E. P., Tortora, L., Venanzoni, G., Wiślicki, W., and Wolke, M.
- 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 - 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., Comment: 7 pages, 9 figures, 1 table, accepted for publication in Physics Letters B
- Published
- 2018