S. Passaggio
A5050287044- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Computational Physics and Python Applications
- Cosmology and Gravitation Theories
- Medical Imaging Techniques and Applications
- Particle Accelerators and Free-Electron Lasers
- Atomic and Subatomic Physics Research
- Black Holes and Theoretical Physics
- Superconducting Materials and Applications
- Nuclear physics research studies
- Radiation Detection and Scintillator Technologies
- Distributed and Parallel Computing Systems
- Astrophysics and Cosmic Phenomena
- Advanced Data Storage Technologies
- Stochastic processes and statistical mechanics
- Muon and positron interactions and applications
- Particle accelerators and beam dynamics
- Quantum chaos and dynamical systems
- Lanthanide and Transition Metal Complexes
- Stochastic processes and financial applications
- Radiation Therapy and Dosimetry
Istituto Nazionale di Fisica Nucleare, Sezione di Genova
2016-2025
University of Manchester
2023-2024
Institute for High Energy Physics
2023-2024
Institute of Science and Technology
2023-2024
University of Geneva
2023-2024
Atlas Scientific (United States)
2024
A. Alikhanyan National Laboratory
2024
The University of Adelaide
2018-2023
European Organization for Nuclear Research
2023
Brandeis University
2023
Based on the full BaBar data sample, we report improved measurements of ratios R(D(*)) = B(B -> D(*) Tau Nu)/B(B l Nu), where is either e or mu. These are sensitive to new physics contributions in form a charged Higgs boson. We measure R(D) 0.440 +- 0.058 0.042 and R(D*) 0.332 0.024 0.018, which exceed Standard Model expectations by 2.0 sigma 2.7 sigma, respectively. Taken together, our results disagree with these at 3.4 level. This excess cannot be explained boson type II two-Higgs-doublet...
Dark sectors charged under a new Abelian interaction have recently received much attention in the context of dark matter models. These models introduce light mediator, so-called photon (A′), connecting sector to standard model. We present search for reaction e+e−→γA′, A′→e+e−, μ+μ− using 514 fb−1 data collected with BABAR detector. observe no statistically significant deviations from model predictions, and we set 90% confidence level upper limits on mixing strength between at 10−4−10−3...
We search for single-photon events in 53 fb−1 of e+e− collision data collected with the BABAR detector at PEP-II B-Factory. look a single high-energy photon and large missing momentum energy, consistent production spin-1 particle A′ through process e+e−→γA′; A′→invisible. Such particles, referred to as "dark photons," are motivated by theories applying U(1) gauge symmetry dark matter. find no evidence such processes set 90% confidence level upper limits on coupling strength mass range mA′≤8...
Many models of physics beyond the Standard Model predict existence new Abelian forces with gauge bosons mediating interactions between "dark sectors" and Model. We report a search for dark boson Z' coupling only to second third generations leptons in reaction e+e- -> mu+mu- Z', using 514 fb-1 data collected by BABAR experiment. No significant signal is observed masses range 0.212 - 10 GeV. Limits on parameter g' as low 7x10^-4 are derived, leading improvements bounds compared those...
We search for the flavor-changing neutral-current decays $B\ensuremath{\rightarrow}{K}^{(*)}\ensuremath{\nu}\overline{\ensuremath{\nu}}$, and invisible $J/\ensuremath{\psi}\ensuremath{\rightarrow}\ensuremath{\nu}\overline{\ensuremath{\nu}}$ $\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\nu}\overline{\ensuremath{\nu}}$ via $B\ensuremath{\rightarrow}{K}^{(*)}J/\ensuremath{\psi}$ $B\ensuremath{\rightarrow}{K}^{(*)}\ensuremath{\psi}(2S)$, respectively, using a data sample of...
The process e+e- --> p anti-p gamma is studied using 469 fb-1 of integrated luminosity collected with the BABAR detector at PEP-II collider, an center-of-mass energy 10.6 GeV. From analysis invariant mass spectrum, dependence cross section for measured from threshold to 4.5 ratio electric and magnetic form factors, |G_E/G_M|, asymmetry in proton angular distribution are masses below 3 We also measure branching fractions decays J/psi psi(2S) anti p.
We present measurements of Collins asymmetries in the inclusive process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\pi}\ensuremath{\pi}X$, where $\ensuremath{\pi}$ stands for charged pions, at a center-of-mass energy 10.6 GeV. use data sample $468\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected by BABAR experiment PEP-II $B$ factory SLAC, and consider pairs pions produced opposite hemispheres hadronic events. observe clear distributions azimuthal angles two...
A precise measurement of the cross section for process e+e−→K+K−(γ) from threshold to an energy 5 GeV is obtained with initial-state radiation (ISR) method using 232 fb−1 data collected BABAR detector at e+e− center-of-mass energies near 10.6 GeV. The uses effective ISR luminosity determined e+e−→μ+μ−(γ)γISR same set. corresponding lowest-order contribution hadronic vacuum polarization term in muon magnetic anomaly found be aμKK,LO=(22.93±0.18stat±0.22syst)×10−10. charged kaon form factor...
The ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}p\overline{p}$ cross section and the proton magnetic form factor have been measured in center-of-mass energy range from 3.0 to 6.5 GeV using initial-state radiation technique with an undetected photon. This is first measurement of at energies higher than 4.5 GeV. analysis based on $469\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ integrated luminosity collected BABAR detector PEP-II collider ${e}^{+}{e}^{\ensuremath{-}}$ near 10.6...
Inclusive production cross sections of $\pi^\pm$, $K^\pm$ and $p\bar{p}$ per hadronic $e^+e^-$ annihilation event in are measured at a center-of-mass energy 10.54 GeV, using relatively small sample very high quality data from the BaBar experiment PEP-II $B$-factory SLAC National Accelerator Laboratory. The drift chamber Cherenkov detector provide clean samples identified over wide range momenta. Since is below threshold to produce $B\bar{B}$ pair, with $B$ bottom-quark meson, these represent...
We search for the rare flavor-changing neutral current process $B^{+}\rightarrow K^{+}τ^{+}τ^{-}$ using data from BABAR experiment. The sample, collected at center-of-mass energy of $Υ{(4S)}$ resonance, corresponds to a total integrated luminosity 424 fb$^{-1}$ and 471 million $B\overline{B}$ pairs. reconstruct one $B$ meson, produced in $Υ{(4S)}\rightarrow B^{+} B^{-}$ decay, many hadronic decay modes activity compatible with K^{+} τ^{+}τ^{-}$ rest event. Each $τ$ lepton is required...
We study the lepton forward-backward asymmetry ${\mathcal{A}}_{FB}$ and longitudinal ${K}^{*}$ polarization ${F}_{L}$, as well an observable ${P}_{2}$ derived from them, in rare decays $B\ensuremath{\rightarrow}{K}^{*}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$, where ${\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$ is either ${e}^{+}{e}^{\ensuremath{-}}$ or ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$, using full sample of 471 million...
We study the processes $e^+ e^-\to K_S^0 K_L^0 \gamma$, $K_S^0 \pi^+\pi^-\gamma$, and K^+K^-\gamma$, where photon is radiated from initial state, providing cross section measurements for hadronic states over a continuum of center-of-mass energies. The results are based on 469 fb$^{-1}$ data collected with BaBar detector at SLAC. observe $\phi(1020)$ resonance in K_L^0$ final state measure product its electronic width branching fraction about 3% uncertainty. present measurement $ energy range...
We report the determination of Cabibbo-Kobayashi-Maskawa $CP$-violating angle $\ensuremath{\gamma}$ through combination various measurements involving ${B}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}D{K}^{\ifmmode\pm\else\textpm\fi{}}$, ${B}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{D}^{*}{K}^{\ifmmode\pm\else\textpm\fi{}}$, and ${B}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}D{K}^{*\ifmmode\pm\else\textpm\fi{}}$ decays performed by BABAR experiment at...
An angular analysis of the decay ${\overline{B} \rightarrow D^\ast \ell^- \overline{\nu}_\ell}$, $\ell\in\{e,\mu\}$, is reported using full $e^+e^-$ collision data set collected by \babar experiment at $\Upsilon(4S)$ resonance. One $B$ meson from ${\Upsilon(4S)\to B\overline{B}}$ fully reconstructed in a hadronic mode, which constrains kinematics and provides determination neutrino momentum vector. The semileptonic described di-lepton mass squared, $q^2$, three angles. first unbinned fit to...
We present a search for neutral, long-lived particle L that is produced in e+ e- collisions and decays at significant distance from the interaction point into various flavor combinations of two oppositely charged tracks. The analysis uses an data sample with luminosity 489.1 fb(-1) collected by BABAR detector ϒ(4S), ϒ(3S), ϒ(2S) resonances just below ϒ(4S). Fitting two-track mass distribution signal peak, we do not observe signal, set 90% confidence level upper limits on product production...
We study the process $e^+e^- \to \pi^+\pi^-\eta \gamma$, where photon is radiated from initial state. About 8000 fully reconstructed events of this are selected BaBar data sample with an integrated luminosity 469~fb$^{-1}$. Using $\pi^+\pi^-\eta$ invariant mass spectrum we measure \pi^+\pi^-\eta$ cross section in $e^+e^-$ center-of-mass energy range 1.15 to 3.5 GeV. The well described by Vector-Meson Dominance model four $\rho$-like states. observe $49\pm9$ $J/\psi$ decay $\pi^+\pi^-\eta$,...
Based on a sample of 500 million ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}c\overline{c}$ events recorded by the BABAR detector at c.m. energies close to 10.6 GeV, we report study decay ${D}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e}$. We measure ratio branching fractions,...
A study of the two-body decays B^{±}→X_{cc[over ¯]}K^{±}, where X_{cc[over ¯]} refers to one charmonium state, is reported by BABAR Collaboration using a data sample 424 fb^{-1}. The absolute determination branching fractions for these are significantly improved compared previous measurements. Evidence found decay B^{+}→X(3872)K^{+} at 3σ level. fraction B[B^{+}→X(3872)K^{+}]=[2.1±0.6(stat)±0.3(syst)]×10^{-4} measured first time. It follows that B[X(3872)→J/ψπ^{+}π^{-}]=(4.1±1.3)%,...
We study the processes $\gamma \gamma \to \eta_c \eta' K^+ K^-$, $\eta' \pi^+ \pi^-$, and $\eta \pi^-$ using a data sample of 519 $fb^{-1}$ recorded with BaBar detector operating at SLAC PEP-II asymmetric-energy $e^+e^-$ collider center-of-mass energies near $\Upsilon(nS)$ ($n = 2,3,4$) resonances. This is first observation decay $\eta_c K^-$ we measure branching fraction $\Gamma(\eta_c K^-)/(\Gamma(\eta_c \pi^-)=0.644\pm 0.039_{\rm stat}\pm 0.032_{\rm sys}$. Significant interference...
We present Dalitz plot analyses for the decays of $B$ mesons to ${D}^{\ensuremath{-}}{D}^{0}{K}^{+}$ and ${\overline{D}}^{0}{D}^{0}{K}^{+}$. report observation ${D}_{s1}^{*}(2700{)}^{+}$ resonance in these two channels obtain measurements mass $M({D}_{s1}^{*}(2700{)}^{+})={2699}_{\ensuremath{-}7}^{+14}\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ width $\mathrm{\ensuremath{\Gamma}}({D}_{s1}^{*}(2700{)}^{+})={127}_{\ensuremath{-}19}^{+24}\text{ }\mathrm{MeV}$, including statistical systematic...
We report on a search for eleven lepton-number violating processes B+→X−ℓ+ℓ'+ with X−=K−, π−, ρ−, K*−, or D− and ℓ+/ℓ'+=e+ μ+, using sample of 471±3 million B¯B events collected the BABAR detector at PEP-II e+e− collider SLAC National Accelerator Laboratory. find no evidence any these modes place 90% confidence level upper limits their branching fractions in range (1.5–26)×10−7.Received 5 November 2013DOI:https://doi.org/10.1103/PhysRevD.89.011102© 2014 American Physical Society
We measure the mass difference, \Delta m_0, between D*(2010)+ and D0 natural line width, \Gamma, of transition -> pi+. The data were recorded with BABAR detector at center-of-mass energies near Upsilon(4S) resonance, correspond to an integrated luminosity approximately 477 1/fb. is reconstructed in decay modes K- pi+ pi- For mode we obtain Gamma = (83.4 +- 1.7 1.5) keV m_0 (145 425.6 0.6 1.8) keV, where quoted errors are statistical systematic, respectively. \Gamma (83.2 1.5 2.6) 426.6 0.5...