Search for a vector gauge boson in ϕ meson decays with the KLOE detector (original) (raw)
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Limit on the production of a light vector gauge boson in ϕ meson decays with the KLOE detector
Physics Letters B, 2013
We present a new limit on the production of a light dark-force mediator with the KLOE detector at DAΦNE. This boson, called U , has been searched for in the decay φ → η U , U → e + e − , analyzing the decay η → π 0 π 0 π 0 in a data sample of 1.7 fb −1 . No structures are observed in the e + e − invariant mass distribution over the background. This search is combined with a previous result obtained from the decay η → π + π − π 0 , increasing the sensitivity. We set an upper limit at 90% C.L. on the ratio between the U boson coupling constant and the fine structure constant of α ′ /α < 1.7 × 10 −5 for 30 < M U < 400 MeV and α ′ /α ≤ 8 × 10 −6 for the subregion 50 < M U < 210 MeV. This result assumes the Vector Meson Dominance expectations for the φηγ * transition form factor. The dependence of this limit on the transition form factor has also been studied.
Search for light vector boson production in e+e−→μ+μ−γ interactions with the KLOE experiment
Physics Letters B
We have searched for a light vector boson U, the possible carrier of a “dark force”, with the KLOE detector at the DAFNE e+e−collider, motivated by astrophysical evidence for the presence of dark matter in the Universe. Using e+e−collisions collected with an integrated luminosity of 239.3pb−1, we look for a dimuon mass peak in the reaction e+e−→μ+μ−γ, corresponding to the decay U→μ+μ−. We find no evidence for a U vector boson signal. We set a 90% CL upper limit for the mixing parameter squared between the photon and the Uboson of 1.6 ×10^{−5} to 8.6 ×10^{−7} for the mass region 520 <m_U<980MeV.
KLOE Results on Light Meson Properties
Arxiv preprint arXiv:0904.4669, 2009
The KLOE experiment operating at the φ-factory DAΦNE has collected an integrated luminosity of about 2.5 fb −1 and 250 pb −1 , on and off the φ meson peak respectively. Recent results achieved from studying properties of pseudoscalar and scalar mesons are presented.
Limit on light gauge boson production in e+e−→μ+μ−γ interactions with the KLOE experiment
We have searched for a light vector boson U, the possible carrier of a “dark force”, with the KLOE detector at the DAΦNE e+e− collider, motivated by the astrophysi- cal evidence for the presence of “dark matter” in the universe. Using e+e− collisions collected for an integrated luminosity of 239. 3 pb−1, we look for a dimuon mass peak in the reaction e+e−→μ+μ−γ, corresponding to the decay U →μ+μ−. We find no evidence for a U vector boson signal. We set a 90% CL upper limit for the kinetic mixing parameter epsilon^2 of 1.6×10^−5 to 8.5×10^−7 for the mass region 520 < m U < 980 MeV.Limit on light gauge boson production in e + e − → µ + µ − γ interactions with the KLOE experiment .
Limit on the production of a new vector boson in e + e − → Uγ, U → π + π − with the KLOE experiment
Physics Letters B, 2016
The recent interest in a light gauge boson in the framework of an extra U(1) symmetry motivates searches in the mass range below 1 GeV. We present a search for such a particle, the dark photon, in e + e − → Uγ, U → π + π − based on 28 million e + e − → π + π − γ events collected at DAΦNE by the KLOE experiment. The π + π − production by initial-state radiation compensates for a loss of sensitivity of previous KLOE U → e + e − , µ + µ − searches due to the small branching ratios in the ρ − ω resonance region. We found no evidence for a signal and set a limit at 90% CL on the mixing strength between the photon and the dark photon, ε 2 , in the U mass range between 527 and 987 MeV. Above 700 MeV this new limit is more stringent than previous ones.
We have searched for a light vector boson U , the possible carrier of a "dark force", with the KLOE detector at the DAΦNE e + e − collider, motivated by the astrophysical evidence for the presence of "dark matter" in the universe. Using e + e − collisions collected for an integrated luminosity of 239.3 pb −1 , we look for a dimuon mass peak in the reaction e + e − →µ + µ − γ, corresponding to the decay U → µ + µ − . We find no evidence for a U vector boson signal. We set a 90% CL upper limit for the kinetic mixing parameter ǫ 2 of 1.6×10 −5 to 8.5×10 −7 for the mass region 520 < m U < 980 MeV.
Search for the decay ϕ→K0K¯0γ with the KLOE experiment
Physics Letters B, 2009
We have searched for the decay φ → K 0 K 0 γ , by detecting K S pairs plus a photon and with the K S-mesons decaying to π + π − , in a sample of about 1.5×10 9 φ-decays collected by the KLOE experiment at DAΦNE. The reaction proceeds through the intermediate states f 0 (980)γ, a 0 (980)γ. We find five events with 3.2 events expected from background processes. We obtain the upper limit: BR(φ → K 0 K 0 γ) < 1.9 × 10 −8 at 90% C.L. .