A. Calcaterra
A5012673180- 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
- Particle Accelerators and Free-Electron Lasers
- Black Holes and Theoretical Physics
- Computational Physics and Python Applications
- Atomic and Subatomic Physics Research
- Medical Imaging Techniques and Applications
- Nuclear physics research studies
- Superconducting Materials and Applications
- Radiation Detection and Scintillator Technologies
- Cosmology and Gravitation Theories
- Particle accelerators and beam dynamics
- Astrophysics and Cosmic Phenomena
- Muon and positron interactions and applications
- Advanced NMR Techniques and Applications
- Nuclear Physics and Applications
- Stochastic processes and statistical mechanics
- Advanced Data Storage Technologies
- Antenna Design and Analysis
- advanced mathematical theories
- Microwave Engineering and Waveguides
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2016-2025
Institute of High Energy Physics
2014-2024
University of Groningen
2023
Istituto Nazionale di Fisica Nucleare, Sezione di Perugia
2020-2022
University of Perugia
2002-2022
Boğaziçi University
2016-2022
Hunan University
2022
Moscow Institute of Physics and Technology
2021
Shanghai Jiao Tong University
2021
Sapienza University of Rome
2021
We study the process ee+ e- → π+ π- J/ψ at a center-of-mass energy of 4.260 GeV using 525 pb(-1) data sample collected with BESIII detector operating Beijing Electron Positron Collider. The Born cross section is measured to be (62.9±1.9±3.7) pb, consistent production Y(4260). observe structure around 3.9 GeV/c2 in π(±)J/ψ mass spectrum, which we refer as Z(c)(3900). If interpreted new particle, it unusual that carries an electric charge and couples charmonium. A fit invariant neglecting...
Based on the full BABAR data sample, we report improved measurements of ratios R(D(*))=B(B[over ¯]→D(*)τ(-)ν[over ¯](τ))/B(B[over ¯]→D(*)ℓ(ℓ)(-)ν[over ¯](ℓ)), where ℓ is either e or μ. 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 2.0σ 2.7σ, respectively. Taken together, our results disagree with these at 3.4σ level. This excess cannot be explained...
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 study e+e-→π+π-hc at center-of-mass energies from 3.90 to 4.42 GeV by using data samples collected with the BESIII detector operating Beijing Electron Positron Collider. The Born cross sections are measured 13 and found be of same order magnitude as those e+e-→π+π-J/ψ but a different line shape. In π±hc mass spectrum, distinct structure, referred Zc(4020), is observed 4.02 GeV/c2. Zc(4020) carries an electric charge couples charmonium. A fit invariant neglecting possible interferences,...
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...
We study the process e+e−→(D∗¯D∗)±π∓ at a center-of-mass energy of 4.26 GeV using 827 pb−1 data sample obtained with BESIII detector Beijing Electron Positron Collider. Based on partial reconstruction technique, Born cross section is measured to be (137±9±15) pb. observe structure near (D∗¯D∗)± threshold in π∓ recoil mass spectrum, which we denote as Z±c(4025). The and width are (4026.3±2.6±3.7) MeV/c2 (24.8±5.6±7.7) MeV, respectively. Its production ratio...
We report on a study of the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}{(D{\overline{D}}^{*})}^{\ensuremath{\mp}}$ at $\sqrt{s}=4.26\text{ }\text{ }\mathrm{GeV}$ using $525\text{ }\mathrm{pb}{}^{\ensuremath{-}1}$ data sample collected with BESIII detector BEPCII storage ring. A distinct charged structure is observed in ${(D{\overline{D}}^{*})}^{\ensuremath{\mp}}$ invariant mass distribution. When fitted to mass-dependent-width...
The cross section for the process $e^+e^-\to \pi^+\pi^-J/\psi$ is measured precisely at center-of-mass energies from 3.77 to 4.60~GeV using 9~fb$^{-1}$ of data collected with BESIII detector operating BEPCII storage ring. Two resonant structures are observed in a fit section. first resonance has mass $(4222.0\pm 3.1\pm 1.4)$~MeV/$c^2$ and width $(44.1\pm 4.3\pm 2.0)$~MeV, while second one $(4320.0\pm 10.4 \pm 7.0)$~MeV/$c^2$ $(101.4^{+25.3}_{-19.7}\pm 10.2)$~MeV, where errors statistical...
We extract the $e^+e^-\rightarrow \pi^+\pi^-$ cross section in energy range between 600 and 900 MeV, exploiting method of initial state radiation. A data set with an integrated luminosity 2.93 fb$^{-1}$ taken at a center-of-mass 3.773 GeV BESIII detector BEPCII collider is used. The measured systematic uncertainty 0.9%. pion form factor $|F_\pi|^2$ as well contribution to leading order hadronic vacuum polarization $(g-2)_\mu$. find this value be $a_\mu^{\pi\pi,\rm LO}(600-900\;\rm MeV) =...
With data samples collected with the BESIII detector operating at BEPCII storage ring center-of-mass energies from 4.009 to 4.420 GeV, process e+e-→ γX(3872) is observed for first time a statistical significance of 6.3σ. The measured mass X(3872) (3871.9 ± 0.7s tat 0.2 syst) MeV/c(2), in agreement previous measurements. Measurements product cross section σ[e+e- → γX(3872)] and branching fraction B[X(3872)→π+π-J/ψ] 4.009, 4.229, 4.260, 4.360 GeV are reported. Our measurements consistent...
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...
The cross sections of ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{h}_{c}$ at center-of-mass energies from 3.896 to 4.600 GeV are measured using data samples collected with the BESIII detector operating Beijing Electron Positron Collider. found be same order magnitude as those ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi}$ and...
We report a study of the processes e+e−→K+D−sD*0 and K+D*−sD0 based on e+e− annihilation samples collected with BESIII detector operating at BEPCII five center-of-mass energies ranging from 4.628 to 4.698 GeV total integrated luminosity 3.7 fb−1. An excess events over known contributions conventional charmed mesons is observed near D−sD*0 D*−sD0 mass thresholds in K+ recoil-mass spectrum for √s=4.681 GeV. The structure matches mass-dependent-width Breit-Wigner line shape, whose pole width...
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...
Hadronic transitions of ${\ensuremath{\chi}}_{cJ}\ensuremath{\rightarrow}{\ensuremath{\eta}}_{c}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ ($J=0$, 1, 2) are searched for using a sample $1.06\ifmmode\times\else\texttimes\fi{}{10}^{8}$ $\ensuremath{\psi}(3686)$ events collected with the BESIII detector at BEPCII storage ring. The ${\ensuremath{\eta}}_{c}$ is reconstructed ${K}_{S}^{0}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ensuremath{\mp}}$ and...
From December 2011 to May 2014, about 5 fb−1 of data were taken with the BESIII detector at center-of-mass energies between 3.810 GeV and 4.600 study charmonium-like states higher excited charmonium states. The time-integrated luminosity collected sample is measured a precision 1% by analyzing events produced large-angle Bhabha scattering process.
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.
Although CP violation in the B meson system has been well established by factories, there no direct observation of time-reversal violation. The decays entangled neutral mesons into definite flavor states (B(0) or B(0)), and J/ψK(L)(0) ccK(S)(0) final (referred to as B(+) B(-)), allow comparisons between probabilities four pairs T-conjugated transitions, for example, B(0) → B(-) B(0), a function time difference two decays. Using 468 × 10(6) BB produced Υ(4S) collected BABAR detector at SLAC,...
We report the first measurement of absolute hadronic branching fractions ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}$ baryon at ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}{\overline{\mathrm{\ensuremath{\Lambda}}}}_{c}^{\ensuremath{-}}$ production threshold, in 30 years since discovery. In total, 12 Cabibbo-favored decay modes are analyzed with a double-tag technique, based on sample $567\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ ${e}^{+}{e}^{\ensuremath{-}}$ collisions $\sqrt{s}=4.599\text{...
Data sets were collected with the BESIII detector at BEPCII collider center-of-mass energy of √s = 3.650 GeV during May 2009 and 3.773 from January 2010 to 2011. By analyzing large angle Bhabha scattering events, integrated luminosities two data are measured be (44.49±0.02±0.44) pb−1 (2916.94±0.18±29.17) pb−1, respectively, where first error is statistical second systematic.
Based on data samples collected with the BESIII detector at BEPCII collider nine center of mass energies from 4.21 to 4.42 GeV, we search for production e^{+}e^{-}→ωχ_{cJ} (J=0, 1, 2). The process e^{+}e^{-}→ωχ_{c0} is observed first time, and Born cross sections sqrt[s]=4.23 4.26 GeV are measured be (55.4±6.0±5.9) (23.7±5.3±3.5) pb, respectively, where uncertainties statistical second systematic. ωχ_{c0} signals other seven e^{+}e^{-}→ωχ_{c1} ωχ_{c2} not significant, upper limits...
Using a data sample collected with the BESIII detector operating at BEPCII storage ring, we observe new neutral state Z_{c}(3900)^{0} significance of 10.4σ. The mass and width are measured to be 3894.8±2.3±3.2 MeV/c^{2} 29.6±8.2±8.2 MeV, respectively, where first error is statistical second systematic. Born cross section for e^{+}e^{-}→π^{0}π^{0}J/ψ fraction it attributable π^{0}Z_{c}(3900)^{0}→π^{0}π^{0}J/ψ in range E_{c.m.}=4.19-4.42 GeV also determined. We interpret this as partner...
Using data collected with the BESIII detector operating at Beijing Electron Positron Collider center-of-mass energies of sqrt[s]=4.23, 4.26, and 4.36 GeV, we observe e(+)e(-)→π(0)π(0)hc for first time. The Born cross sections are measured found to be about half those e(+)e(-)→π(+)π(-)hc within less than 2σ. In π(0)hc mass spectrum, a structure 4.02 GeV/c(2) is found. It most likely neutral isospin partner Zc(4020)(±) observed in process being A fit invariant width Zc(4020)(0) fixed that its...