A. Fantini
A5046529053- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Dark Matter and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Particle Accelerators and Free-Electron Lasers
- Nuclear Physics and Applications
- Advanced X-ray Imaging Techniques
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Nuclear physics research studies
- Medical Imaging Techniques and Applications
- Advanced X-ray and CT Imaging
- Cosmology and Gravitation Theories
- Gamma-ray bursts and supernovae
- X-ray Spectroscopy and Fluorescence Analysis
- Emotion and Mood Recognition
- Particle Detector Development and Performance
- Noncommutative and Quantum Gravity Theories
- Quantum, superfluid, helium dynamics
- Scientific Computing and Data Management
- Advanced NMR Techniques and Applications
- Black Holes and Theoretical Physics
- Radiation Detection and Scintillator Technologies
- Geophysics and Gravity Measurements
University of Rome Tor Vergata
2012-2024
National Research Council
2023-2024
University of Pisa
2023-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Roma I
2011-2023
Istituto Nazionale di Fisica Nucleare, Roma Tor Vergata
2010-2022
University of Catania
2020
Istituto Nazionale di Fisica Nucleare, Sezione di Catania
2018
Gran Sasso Science Institute
2018
University of Turin
2018
Istituto Nazionale di Fisica Nucleare, Sezione di Bari
2016
The existence of a new force beyond the Standard Model is compelling because it could explain several striking astrophysical observations which fail standard interpretations. We searched for light vector mediator this dark force, $\mathrm{U}$ boson, with KLOE detector at DA$\Phi$NE $\mathrm{e}^{+}\mathrm{e}^{-}$ collider. Using an integrated luminosity 1.54 fb$^{-1}$, we studied process $\mathrm{e}^{+}\mathrm{e}^{-} \to \mathrm{U}\gamma$, $\mathrm{U} \mathrm{e}^{+}\mathrm{e}^{-}$, using...
We have searched for a light vector boson U, the possible carrier of "dark force", with KLOE detector at DAΦNE e+e− collider, motivated by astrophysical evidence presence dark matter in Universe. Using collisions collected an integrated luminosity 239.3 pb−1, we look dimuon mass peak reaction e+e−→μ+μ−γ, corresponding to decay U→μ+μ−. find no U signal. set 90% CL upper limit mixing parameter squared between photon and 1.6×10−5 8.6×10−7 region 520<mU<980 MeV.
The recent interest in a light gauge boson the framework of an extra U(1) symmetry motivates searches mass range below 1 GeV. We present search for such particle, dark photon, e+e−→Uγ, U→π+π− based on 28 million e+e−→π+π−γ events collected at DAΦNE by KLOE experiment. π+ π− production initial-state radiation compensates loss sensitivity previous U→e+e−, μ+μ− due to small branching ratios ρ–ω resonance region. found no evidence signal and set limit 90% CL mixing strength between photon ε2, U...
Neutral kaon pairs produced in phi decays anti-symmetric entangled state can be exploited to search for violation of CPT symmetry and Lorentz invariance. We present an analysis the CP-violating process phi->K_S K_L->pi+pi-pi+pi- based on 1.7 fb-1 data collected by KLOE experiment at Frascati phi-factory DAFNE. The are used perform a measurement CPT-violating parameters Delta_amu neutral kaons contest Standard Model Extension framework. measured reference frame fixed stars are: Delta_ao =...
A bstract The three precision measurements of the cross section σ ( e + − → π γ(γ)) using initial state radiation by KLOE collaboration provide an important input for prediction hadronic contribution to anomalous magnetic moment muon. These are correlated both statistical and systematic uncertainties and, therefore, simultaneous use these requires covariance matrices that fully describe correlations. We present construction them determine a combined measurement γ(γ)). find, from this...
Abstract Particle identification techniques are fundamental tools in nuclear physics experiments. Discriminating particles or nuclei produced interactions allows to better understand the underlying mechanisms. The energy interval of these reactions is very broad, from sub-eV up TeV. For this reason, many different approaches have been developed, often combining two more observables. This paper reviews several with emphasis on expertise gained within current scientific program Italian...
The BGOOD photoproduction experiment accesses forward meson angles and low momentum exchange kinematics in the $uds$ sector, which may be sensitive to molecular-like hadron structure. Our results strangeness sector suggest a dominant role of meson-baryon dynamics. This includes structures $K^0\Sigma^0$, $K^+\Sigma^0$ $K^+\Sigma^0(1385)$ residing at $\Sigma^{(*)}K^{(*)}$ thresholds have an equivalence $P_C$ states $\Sigma_C^{(*)}\bar D^{(*)}$ thresholds. In non-strange baryon-baryon...
The double π0 photoproduction off the proton has been measured in beam energy range of 0.65–1.5 GeV. total and differential cross sections Σ asymmetry were extracted. section for first time third resonance region nucleon shows a prominent peak. interpretation these results by two independent theoretical models infers mostly selective excitation P11- D13-nucleon resonances.Received 17 January 2003DOI:https://doi.org/10.1103/PhysRevLett.90.222001©2003 American Physical Society
The possibility of anisotropies in the speed light relative to limiting electrons is considered. absence sidereal variations energy Compton-edge photons at European Synchrotron Radiation Facility's GRAAL facility constrains such representing first nonthreshold collision-kinematics study Lorentz violation. When interpreted within minimal standard-model extension, this result yields two-sided limit 1.6×10−14 95% confidence level on a combination parity-violating photon and electron...
The analysis of the γp→ηπ0p reaction has been performed using data from GRAAL experiment. total and differential cross sections beam asymmetry have obtained threshold up to 1.5 GeV energy. two resonances S11(1535) Δ(1700) are expected be excited in intermediate states this reaction. results used test predictions based on assumption that both dynamically generated meson-baryon interaction provided by chiral Lagrangians. term involving excitation, followed decay into ηΔ(1232), is found...
Using 1.6 fb−1 of e + − → ϕ ηγ data collected with the KLOE detector at DAΦNE, Dalitz plot distribution for η π 0 decay is studied world's largest sample ∼ 4.7 · 106 events. The density parametrized as a polynomial expansion up to cubic terms in normalized dimensionless variables X and Y . experiment sensitive all charge conjugation conserving expansion, including gX 2 term. statistical uncertainty parameters improved by factor two respect earlier measurements.
We searched for the $μ^+μ^-$ decay of a light vector gauge boson, also known as dark photon, in $e^+ e^- \to μ^+ μ^- γ_{\rm ISR}$ process by means Initial State Radiation (ISR) method. used 1.93~fb$^{-1}$ data collected KLOE experiment at DA$Φ$NE $ϕ$-factory. No structures have been observed over irreducible $μ^+ μ^-$ background. A 90\% CL limit on ratio $\varepsilon^2=α^{\prime}/α$ between coupling constant and fine structure $ 3\times 10^{-6}-2\times 10^{-7}$ has set photon mass region 519...
A measurement of the vector to pseudoscalar conversion decay $\phi \to \pi^0 e^+e^-$ with KLOE experiment is presented. sample $\sim 9500$ signal events was selected from a data set 1.7 fb$^{-1}$ $e^+e^-$ collisions at $\sqrt{s} \sim m_{\phi}$ collected DA$\Phi$NE collider. These were used obtain first transition form factor $| F_{\phi \pi^0}(q^2) |$ and new branching ratio decay: $\rm{BR}\,(\phi e^+e^-) = (\,1.35 \pm 0.05^{\,\,+0.05}_{\,\,-0.10}\,) \times 10 ^{-5}$. The result improves...
We have studied the vector to pseudoscalar conversion decay ϕ→ηe+e−, with η→π0π0π0, KLOE detector at DAΦNE. The data set of 1.7 fb−1 e+e− collisions s∼Mϕ contains a clear signal ∼31,000 events from which we measured value BR(ϕ→ηe+e−)=(1.075±0.007±0.038)×10−4. same sample is used determine transition form factor by fit invariant mass spectrum, obtaining bϕη=(1.28±0.10−0.08+0.09) GeV−2, that improves five precision previous measurement and in good agreement VMD expectations.
We searched for evidence of a Higgsstrahlung process in secluded sector, leading to final state with dark photon U and Higgs boson h', the KLOE detector at DAFNE. investigated case h' lighter than U, decaying into muon pair producing missing energy signature. found no set upper limits its parameters range 2m_mu<m_U<1000 MeV, m_h'<m_U.
The absolute branching ratio of the K+→π+π−π+(γ) decay, inclusive final-state radiation, has been measured using ∼17 million tagged K+ mesons collected with KLOE detector at DAΦNE, Frascati ϕ-factory. result is:BR(K+→π+π−π+(γ))=0.05565±0.00031stat±0.00025syst a factor ≃ 5 more precise respect to previous result. This work completes program precision measurements dominant kaon ratios KLOE.
We have carried out a new direct search for the CP violating decay KS -> 3pi0 with 1.7 fb^-1 of e+e- collisions collected by KLOE detector at phi-factory DAFNE. searched this in sample about 5.9 x 10^8 KL events tagging means interaction calorimeter and requiring six prompt photons. With respect to our previous search, analysis has been improved increasing factor four tagged more effective background rejection fake tags spurious clusters. find no candidates data simulated samples, while...
We have measured the running of effective QED coupling constant $\alpha(s)$ in time-like region $0.6<\sqrt s< 0.975$ GeV with KLOE detector at DA$\Phi$NE using Initial State Radiation process $e^+e^-\to\mu^+ \mu^-\gamma$. It represents first measurement this energy region. Our results show a more than 5$\sigma$ significance hadronic contribution to $\alpha(s)$, which is strongest direct evidence both time- and space-like regions achieved single measurement. By $e^+e^-\to\pi^+\pi^-$ cross...
$K^+\Lambda(1405)$ photoproduction has been studied at the BGOOD experiment via all neutral decay, $\Lambda(1405)\rightarrow\Sigma^0\pi^0$. The unique experimental setup allows both cross section and $\Lambda(1405)$ invariant mass distribution (line shape) to be measured over a broad $K^+$ polar angle range, extending extreme forward angles unattainable previous experiments. Evidence is provided for role of triangle singularity driven by $N^*(2030)$ resonance, which appears contribute...