A5078220101- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Computational Physics and Python Applications
- Particle Accelerators and Free-Electron Lasers
- Medical Imaging Techniques and Applications
- Superconducting Materials and Applications
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Cosmology and Gravitation Theories
- Stochastic processes and statistical mechanics
- Astrophysics and Cosmic Phenomena
- International Science and Diplomacy
- Distributed and Parallel Computing Systems
- Radiation Detection and Scintillator Technologies
- Advanced NMR Techniques and Applications
- Markov Chains and Monte Carlo Methods
- Particle accelerators and beam dynamics
- Geophysics and Gravity Measurements
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Data Storage Technologies
Heidelberg University
2014-2025
University of Zurich
2016-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Bologna
2023-2024
Délégation Paris 7
2021-2023
Sorbonne Paris Cité
2021-2023
Laboratoire de Physique Nucléaire et de Hautes Énergies
2021-2023
Université Paris Cité
2021-2023
Sorbonne Université
2021-2023
Centre National de la Recherche Scientifique
2021-2023
University of Bologna
2023
The Belle detector at the KEKB electron-positron collider has collected almost 1 billion Y(4S) events in its decade of operation. Super-KEKB, an upgrade is under construction, to increase luminosity by two orders magnitude during a three-year shutdown, with ultimate goal 8E35 /cm^2 /s luminosity. To exploit increased luminosity, been proposed. A new international collaboration Belle-II, being formed. Technical Design Report presents physics motivation, basic methods accelerator upgrade, as...
We measure the branching fraction of B−→τ−¯ντ using full Υ(4S) data sample containing 772×106 B¯¯¯B pairs collected with Belle detector at KEKB asymmetric-energy e+e− collider. Events are tagged by reconstructing one B mesons decaying into hadronic final states, and candidates detected in recoil. find evidence for a significance 3.0 standard deviations including systematic errors B(B−→τ−¯ντ)=[0.72+0.27−0.25(stat)±0.11(syst)]×10−4.Received 16 November...
We report the first observations of spin-singlet bottomonium states hb(1P) and hb(2P). The are produced in reaction e+e−→hb(nP)π+π− using a 121.4 fb−1 data sample collected at energies near Υ(5S) resonance with Belle detector KEKB asymmetric-energy e+e− collider. determine M[hb(1P)]=(9898.2+1.1+1.0−1.0−1.1) MeV/c2 M[hb(2P)]=(10 259.8±0.6+1.4−1.0) MeV/c2, which correspond to P-wave hyperfine splittings ΔMHF=(+1.7±1.5) (+0.5+1.6−1.2) respectively. significances hb(2P) 5.5σ 11.2σ, find that...
We report on a search for heavy neutrinos in B-meson decays. The results are obtained using data sample that contains 772x10^6 BB-bar pairs collected at the Upsilon(4S) resonance with Belle detector KEKB asymmetric-energy e+e- collider. No signal is observed and upper limits set mixing of left-handed Standard Model mass range 0.5 - 5.0 GeV/c^2.
We present a measurement of angular observables, $P_4'$, $P_5'$, $P_6'$, $P_8'$, in the decay $B^0 \to K^\ast(892)^0 \ell^+ \ell^-$, where $\ell^+\ell^-$ is either $e^+e^-$ or $\mu^+\mu^-$. The analysis performed on data sample corresponding to an integrated luminosity $711~\mathrm{fb}^{-1}$ containing $772\times 10^{6}$ $B\bar B$ pairs, collected at $\Upsilon(4S)$ resonance with Belle detector asymmetric-energy collider KEKB. Four $P_{4,5,6,8}'$ are extracted five bins invariant mass...
The cross section for e^+e^- \to \eta J/\psi between \sqrt{s}=3.8 GeV/c^2 and 5.3 is measured via initial state radiation using 980 fb^{-1} of data on around the \Upsilon(nS)(n=1,2,3,4,5) resonances collected with Belle detector at KEKB. Two resonant structures \psi(4040) \psi(4160) are observed in invariant mass distribution. Fitting spectrum coherent sum two Breit-Wigner functions, one obtains BR(\psi(4040)\to\eta J/\psi)\cdot\Gamma_{ee}^{\psi(4040)} = (4.8\pm0.9\pm1.4) eV...
We report the observation of B(s)⁰→J/ψf₀(980) and evidence for B(s)⁰→J/ψf₀(1370), which are CP eigenstate decay modes. These results obtained from 121.4 fb⁻¹ data collected at Υ(5S) resonance with Belle detector KEKB e(+)e⁻ collider. measure branching fractions B(B(s)⁰→J/ψf₀(980); f₀(980)→π(+)π⁻)=(1.16(-0.19)(+0.31)(stat)(-0.17)(+0.15)(syst)(-0.18)(+0.26)(N(B(s)((*))B(s)((*)))))×10⁻⁴ a significance 8.4σ, B(B(s)⁰→J/ψf₀(1370);...
We report the results of a high-statistics search for H dibaryon production in inclusive Υ(1S) and Υ(2S) decays. No indication an with mass near M(H)=2m(Λ) threshold is seen either H→Λpπ(-) or ΛΛ decay channels 90% confidence level branching-fraction upper limits are set that between one two orders magnitude below measured branching fractions decays to antideuterons. Since Υ(1S,2S) produce flavor-SU(3)-symmetric final states, these put stringent constraints on properties. The based analyses...
The LHCb collaboration has redesigned its trigger to enable the full offline detector reconstruction be performed in real time. Together with real-time alignment and calibration of detector, a software infrastructure make persistent high-level physics objects produced during processing, this redesign enabled widespread deployment analysis Run 2. We describe design 2 reconstruction, present data-driven performance measurements for representative sample LHCb's programme.
We have made a precise measurement of the absolute branching fractions Bs->Ds(*)+ Ds(*)- decays using 121.4 fb-1 data recorded by Belle experiment running on Upsilon(5S) resonance. The results are B(Bs0->Ds+ Ds-) = (0.58 +0.11 -0.09 +-0.13)%, B(Bs0->Ds*+- Ds-+) (1.8 +-0.2 +-0.4)%, and B(Bs0->Ds*+ Ds*-) (2.0 +-0.3 +-0.5)%; sum is B(Bs0->Ds(*)+ (4.3 +-0.4 +-1.0)%. Assuming saturates to CP-even final states, fraction constrains ratio Delta(Gamma_s)/cos(phi_s), where Delta(Gamma_s) difference in...
We report the first measurement of $τ$ lepton polarization in decay ${\bar B} \rightarrow D^* τ^- {\barν_τ}$ as well a new ratio branching fractions $R(D^{*}) = \mathcal{B}({\bar {\barν_τ}) / \ell^- {\barν_{\ell}})$, where $\ell^-$ denotes an electron or muon, with decays $τ^- π^- ν_τ$ and ρ^- ν_τ$. use full data sample $772 \times 10^6$ $B{\bar B}$ pairs accumulated Belle detector at KEKB electron-positron collider. Our preliminary results, $R(D^*) 0.276 \pm 0.034{\rm (stat.)} ^{+0.029}...
We report preliminary results on the analysis of three-body Y(10860)=> B barB pi, Y(10860) => (B barB* + c.c.) pi and B* decays including an observation Zb(10610)+- pi-+ [B barB*+c.c]+- Zb(10650)+- [B* barB*]+- as intermediate channels. measure branching fractions to be Br(Y(10860)=> barB*+c.c.]+- pi-+)=(28.3+-2.9+-4.6)x10^{-3} pi-+)=(14.1+-1.9+-2.4)x10^{-3} set 90% C.L. upper limit barB]+- pi-+)<4.0x10^{-3}. also amplitude Y(10860)=>Y(nS)pi+pi-, n=1,2,3 internal structure...
We report first observations of $B_s^0\to J/\psi\eta$ and J/\psi\eta'$. The results are obtained from 121.4 fb^{-1} data collected at the $\Upsilon(5S)$ resonance with Belle detector KEKB $e^+e^-$ collider. obtain branching fractions Br(B_s^0\to J/\psi\eta)= [5.10\pm 0.50(stat.)\pm 0.25(syst.)^{+1.14}_{-0.79}(N_{B_s^(*)\bar B_s^(*))] \times 10^{-4}, J/\psi\eta')=[3.71\pm 0.61(stat.)\pm 0.18(syst.)^{+0.83}_{-0.57}(N_{B_s^(*)\bar 10^{-4}. ratio two is measured to be $\frac{Br(B_s\to...
We report the observation of two narrow structures at 10610MeV/c^2 and 10650MeV/c^2 in pi^{\pm}Upsilon(nS) (n=1,2,3) pi^{\pm}h_b(mP) (m=1,2) mass spectra that are produced association with a single charged pion Upsilon(5S) decays. The measured masses widths averaged over five final states M_1=10608.4\pm2.0MeV/c^2, Gamma_1=15.6\pm2.5MeV M_2=10653.2\pm1.5MeV/c^2, Gamma_2=14.4\pm3.2MeV. Analysis favors quantum numbers I^G(J^P)=1^+(1^+) for both states. results obtained 121.4fb^{-1} data sample...
We present a measurement of the branching fractions and charge-parity-($CP$-)violating parameters in $B\ensuremath{\rightarrow}\ensuremath{\omega}K$ decays. The results are obtained from final data sample containing $772\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected at $\mathrm{\ensuremath{\Upsilon}}(4S)$ resonance with Belle detector KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. obtain...
Using $535\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B$-meson pairs collected by the Belle detector at KEKB ${e}^{+}{e}^{\ensuremath{-}}$ collider, we measure branching fractions of $(7.16\ifmmode\pm\else\textpm\fi{}0.10(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.60(\mathrm{syst})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ for ${B}^{+}\ensuremath{\rightarrow}J/\ensuremath{\psi}{K}^{+}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ and...
The LHCb experiment at CERN is undergoing an upgrade in preparation for the Run 3 data taking period of LHC. As part this trigger moving to a fully software implementation operating LHC bunch crossing rate. We present evaluation CPU-based and GPU-based first stage High Level Trigger. After detailed comparison both options are found be viable. This document summarizes performance details these options, outcome which has led choice as baseline.
A bstract We search for CP violation in the decay ${D^{+}}\to K_S^0{K^{+}}$ using a data sample with an integrated luminosity of 977 fb −1 collected Belle detector at KEKB e + − asymmetric-energy collider. No has been observed and asymmetry is measured to be (−0.25 ± 0.28 0.14)%, which most sensitive measurement date. After subtracting due ${K^0}-{{\overline{K}}^0}$ mixing, {{\overline{K}}^0}{K^{+}}$ found (+0.08 0.14)%.
We report an observation of the |$B^{\pm } \to J/\psi \eta K^{\pm }$| and |$B^0 K^0_S$| decays using |$772\times 10^{6}B\overline {B}$| pairs collected at |$\Upsilon (4S)$| resonance with Belle detector KEKB asymmetric-energy |$e^+e^-$| collider. obtain branching fractions |${\mathcal B}(B^{\pm }\rightarrow })=(1.27\pm 0.11(\hbox {stat.})\pm {syst.}))\times 10^{-4}$| B}(B^0\to K^0_S)=(5.22 \pm 0.78 (\hbox {stat.}) 0.49 10^{-5}$|. search for a new narrow charmonium(-like) state |$X$| in...
We report a measurement of the time-integrated $CP$ asymmetry in neutral charm meson decay $D^0 \to K^0_S K^0_S$ using 921~fb$^{-1}$ data collected at $Υ(4S)$ and $Υ(5S)$ resonances with Belle detector KEKB asymmetric-energy $e^+e^-$ collider. The observed is $$ A_{CP}(D^0 K^0_S) = (-0.02 \pm 1.53 0.17) \%, where first uncertainty statistical second systematic. This latter dominated by error normalisation channel. result consistent Standard Model expectations improves respect to previous...
We have made the first observation of B(s)(0)→D(s)(*)+ D(s)(*)- decays using 23.6 fb(-1) data recorded by Belle experiment running on Υ(5S) resonance. The branching fractions are measured to be B(B(s)(0)→D(s)+ D(s)-)=(1.03(-0.32-0.25)(+0.39+0.26))%, B(B(s)(0)→D(s)(*±) D(s)(∓))=(2.75(-0.71)(+0.83)±0.69)%, and B(B(s)(0)→D(s)*+ D(s)*-)=(3.08(-1.04-0.86)(+1.22+0.85))%; sum is B[B(s)(0)→D(s)(*)+ D(s)(*)-]=(6.85(-1.30-1.80)(+1.53+1.79))%. Assuming saturates CP-even final states, fraction...
We report a search for B0 decays into invisible final states using data sample of 657×106 B¯¯¯B pairs collected at the Υ(4S) resonance with Belle detector KEKB e+e− collider. The signal is identified by fully reconstructing hadronic decay accompanying B meson and requiring no other particles in event. No significant observed, we obtain an upper limit 1.3×10−4 90% confidence level branching fraction decay.Received 26 June 2012DOI:https://doi.org/10.1103/PhysRevD.86.032002© 2012 American...