C. Touramanis
A5040833853- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Astrophysics and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Particle Accelerators and Free-Electron Lasers
- Medical Imaging Techniques and Applications
- Radiation Detection and Scintillator Technologies
- Computational Physics and Python Applications
- Black Holes and Theoretical Physics
- Superconducting Materials and Applications
- Nuclear physics research studies
- Muon and positron interactions and applications
- Particle accelerators and beam dynamics
- Nuclear Physics and Applications
- Cosmology and Gravitation Theories
- Stochastic processes and statistical mechanics
- Advanced Data Storage Technologies
- Distributed and Parallel Computing Systems
- Planetary Science and Exploration
- Cold Atom Physics and Bose-Einstein Condensates
- Radioactive Decay and Measurement Techniques
University of Liverpool
2016-2025
University of California, Irvine
2013-2023
Universidad Autónoma de Madrid
2023
University of Bern
2023
Albert Einstein College of Medicine
2023
Colorado State University
2021-2023
Boston University
1997-2023
Duke University
2021-2023
Istituto Nazionale di Fisica Nucleare, Sezione di Bologna
2020-2023
Budker Institute of Nuclear Physics
2014-2020
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...
A new experiment is described to detect a permanent electric dipole moment of the proton with sensitivity $10^{-29}e\cdot$cm by using polarized "magic" momentum $0.7$~GeV/c protons in an all-electric storage ring. Systematic errors relevant are discussed and techniques address them presented. The measurement sensitive physics beyond Standard Model at scale 3000~TeV.
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...
The T2K experiment studies oscillations of an off-axis muon neutrino beam between the J-PARC accelerator complex and Super-Kamiokande detector. Special emphasis is placed on measuring mixing angle theta_13 by observing electron appearance via sub-dominant to oscillation, searching for CP violation in lepton sector. includes a sophisticated, off-axis, near detector, ND280, situated 280 m downstream production target order measure properties understand better interactions at energy scale below...
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 use fits to recent published CPLEAR data on neutral kaon decays $π^+π^-$ and $πeν$ constrain the CPT--violation parameters appearing in a formulation of system as an open quantum-mechanical system. The obtained upper limits are approaching range suggested by certain ideas concerning quantum gravity.
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 $\pi^+\pi^-\eta$,...
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...
The ARIADNE project is developing innovative optical readout technologies for two-phase liquid Argon time projection chambers (LArTPCs). Optical presents an exciting alternative to the current paradigm of charge readout. simple, scalable and cost effective. This paper first demonstration 3D TPC, using CF4 gas as a proof principle. Both cosmic rays Americium-241 alpha source have been imaged in 100 mbar CF4. A single-photon sensitive camera was developed by combining Timepix3 (TPX3) based...
A dedicated measurement of additional radiation in e+e−→μ+μ−γ and e+e−→π+π−γ initial-state-radiation events is presented using the full BABAR data sample. For first time results are at next-to- next-to-next-to-leading order, with one two photons, respectively, for from initial final states. Comparison predictions phokhara afkqed Monte Carlo generators performed, revealing discrepancies one-photon rates angular distributions former. This disagreement has a negligible effect on e+e−→π+π−(γ)...
The Argon Dark Matter (ArDM-1t) experiment is a ton-scale liquid argon (LAr) double-phase time projection chamber designed for direct searches. Such device allows to explore the low energy frontier in LAr with charge imaging detector. ionization extracted from into gas phase and there amplified by use of Large Electron Multiplier order reduce detection threshold. Direct fine spatial granularity, combined measurement amplitude evolution associated primary scintillation light, provide powerful...
The process $e^+e^- \to \pi^+\pi^-2\pi^0\gamma$ is investigated by means of the initial-state radiation technique, where a photon emitted from incoming electron or positron. Using $454.3 \rm{fb}^{-1}$ data collected around center-of-mass energy $\sqrt{s} = 10.58 \rm{GeV}$ BaBar experiment at SLAC, approximately 150000 signal events are obtained. corresponding non-radiative cross section measured with relative uncertainty $3.6\%$ in region $1.5 \rm{GeV}$, surpassing all existing measurements...
The decay ${\ensuremath{\tau}}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{K}_{S}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ has been studied using $430\ifmmode\times\else\texttimes\fi{}{10}^{6}$ ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\tau}}^{+}{\ensuremath{\tau}}^{\ensuremath{-}}$ events produced at a center-of-mass energy around 10.6 GeV the PEP-II collider and with BABAR detector. mass spectrum of ${K}^{\ensuremath{-}}{K}_{S}$ system measured...
We study the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}}{\ensuremath{\eta}}^{\ensuremath{'}}$ in double-tag mode and measure for first time ${\ensuremath{\gamma}}^{\ensuremath{\star}}{\ensuremath{\gamma}}^{\ensuremath{\star}}\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}$ transition form factor ${F}_{{\ensuremath{\eta}}^{\ensuremath{'}}}({Q}_{1}^{2},{Q}_{2}^{2})$ momentum-transfer range $2<{Q}_{1}^{2}$, ${Q}_{2}^{2}<60\text{ }\text{...
We study the processes $e^+ e^-\to K^0_S K^0_L\pi^0\gamma$, $K^0_S K^0_L\eta\gamma$, and K^0_L\pi^0\pi^0\gamma$, where photon is radiated from initial state, providing cross section measurements for hadronic final states over a continuum of center-of-mass energies. The results are based on 469~$fb^{-1}$ data collected at or near $\Upsilon(4S)$~ resonance with BaBar detector SLAC. present first K^0_L\pi^0$, K^0_L\eta$, K^0_L\pi^0\pi^0$ sections up to energy 4~GeV, their intermediate...
We study the processes e+e−→π+π−π0π0π0γ and π+π−π0π0ηγ in which an energetic photon is radiated from initial state. The data are collected with BABAR detector at SLAC. About 14 000 4700 events, respectively, selected a sample corresponding to integrated luminosity of 469 fb−1. invariant mass hadronic final state defines effective e+e− center-of-mass energy. From spectra, first precise measurement e+e−→π+π−π0π0π0 cross section ever e+e−→π+π−π0π0η performed. energies range threshold 4.35 GeV....
Many scenarios of physics beyond the Standard Model predict existence new gauge singlets, which might be substantially lighter than weak scale. The experimental constraints on additional scalars with masses in MeV to GeV range could significantly weakened if they interact predominantly leptons rather quarks. At an $e^+e^-$ collider, such a leptophilic scalar ($\phi_L$) would produced through radiation from $\tau$ lepton. We report herein search for $e^+e^- \to \tau^+\tau^- \phi_L$, $\phi_L...
Axionlike particles (ALPs) are predicted in many extensions of the standard model, and their masses can naturally be well below electroweak scale. In presence couplings to bosons, these could emitted flavor-changing B meson decays. We report herein a search for an ALP, a, reaction B^{±}→K^{±}a, a→γγ using data collected by BABAR experiment at SLAC. No significant signal is observed, 90% confidence level upper limits on ALP coupling bosons derived as function mass, improving current...