M. Fritsch
A5043618974- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Particle Detector Development and Performance
- Medical Imaging Techniques and Applications
- Computational Physics and Python Applications
- Atomic and Subatomic Physics Research
- Particle Accelerators and Free-Electron Lasers
- Nuclear physics research studies
- Superconducting Materials and Applications
- Cosmology and Gravitation Theories
- Radiation Detection and Scintillator Technologies
- Advanced Data Storage Technologies
- Stochastic processes and statistical mechanics
- Radiation Therapy and Dosimetry
- Atomic and Molecular Physics
- Particle accelerators and beam dynamics
- Advanced NMR Techniques and Applications
- Nuclear Physics and Applications
- CCD and CMOS Imaging Sensors
- Distributed and Parallel Computing Systems
- Scientific Research and Discoveries
Ruhr University Bochum
2007-2024
Institute of High Energy Physics
2015-2024
China Center of Advanced Science and Technology
2015-2024
Joint Institute for Nuclear Research
2024
Moscow Institute of Physics and Technology
2024
Hospital Universitário Pedro Ernesto
2024
Universidade do Estado do Rio de Janeiro
2024
Central South University
2024
Beihang University
2024
COMSATS University Islamabad
2015-2024
We study initial-state radiation events, ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\gamma}}_{\mathrm{ISR}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi}$, with data collected the BABAR detector. observe an accumulation of events near $4.26\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ in invariant-mass spectrum ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi}$. Fits to mass indicate that a broad resonance about is...
We study the decay ${B}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ using $117\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ events collected at $Y(4S)$ resonance with BABAR detector PEP-II ${e}^{+}{e}^{\ensuremath{-}}$ asymmetric-energy storage ring. measure branching fractions $\mathcal{B}$...
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...
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) =...
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...
The e+e−→pp¯ cross section is determined over a range of pp¯ masses, from threshold to 4.5 GeV/c2, by studying the e+e−→pp¯γ process. data set corresponds an integrated luminosity 232 fb−1, collected with BABAR detector at PEP-II storage ring, e+e− center-of-mass energy 10.6 GeV. mass dependence ratio electric and magnetic form factors, |GE/GM|, measured for masses below 3 GeV/c2; its value found be significantly larger than 1 up 2.2 GeV/c2. We also measure J/ψ→pp¯ ψ(2S)→pp¯ branching...
We study e+e−→J/ψ cc¯ by measuring the invariant mass distribution recoiling against fully reconstructed J/ψ decays, using 124 fb−1 of data collected at a center-of-mass energy 10.6 GeV with BABAR detector. observe signals for ηc(1S), χc0, and ηc(2S) in recoil distribution, thus confirming previous measurements. measure σ(e+e−→J/ψ+cc¯)B(cc¯→>2 charged) to be 17.6±2.8(stat)−2.1+1.5(syst) fb, 10.3±2.5(stat)−1.8+1.4(syst) 16.4±3.7(stat)−3.0+2.4(syst) fb cc¯=ηc(1S), ηc(2S), respectively.Received...
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.
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{...
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...
There has recently been a dramatic renewal of interest in the subjects hadron spectroscopy and charm physics. This renaissance driven part by discovery plethora charmonium-like $XYZ$ states at BESIII $B$ factories, observation an intriguing proton-antiproton threshold enhancement possibly related $X(1835)$ meson state BESIII, as well measurements mesons baryons. We present detailed survey important topics tau-charm physics that can be further explored over remaining lifetime BEPCII...
We study the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\psi}(3686)$ using $5.1\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of data collected at 16 center-of-mass energy ($\sqrt{s}$) points from 4.008 to 4.600 GeV by BESIII detector operating BEPCII collider. The measured Born cross sections for are consistent with previous results, but much improved precision. A fit section shows contributions two...
The spin and parity of the $Z_c(3900)^\pm$ state are determined to be $J^P=1^+$ with a statistical significance larger than $7\sigma$ over other quantum numbers in partial wave analysis process $e^+e^-\to \pi^+\pi^-J/\psi$. We use data sample 1.92 fb$^{-1}$ accumulated at $\sqrt{s}=4.23$ 4.26 GeV BESIII experiment. When parameterizing Flatte-like formula, we determine its pole mass $M_\textrm{pole}=(3881.2\pm4.2_\textrm{stat}\pm52.7_\textrm{syst})\textrm{MeV}/c^2$ width...
The Born cross section of the $e^{+}e^{-}~\rightarrow~\Lambda_{c}^{+} \bar{\Lambda}_{c}^{-}$ process is measured with unprecedented precision using data collected BESIII detector at $\sqrt{s}=4574.5$, $45580.0$, $4590.0$ and $4599.5$ $\mathrm{MeV}$. non-zero near $\Lambda_{c}^{+} production threshold discerned. At center-of-mass energies $\sqrt{s}=4574.5$ $4599.5 $ $\mathrm{MeV}$, higher statistics enable us to measure $\Lambda_{c}$ polar angle distributions. From these, ratio between...
The process of $e^+e^- \rightarrow p\bar{p}$ is studied at 22 center-of-mass energy points ($\sqrt{s}$) from 2.00 to 3.08 GeV, exploiting 688.5~pb$^{-1}$ data collected with the BESIII detector operating BEPCII collider. Born cross section~($\sigma_{p\bar{p}}$) measured energy-scan technique and it found be consistent previously published data, but much improved accuracy. In addition, electromagnetic form-factor ratio ($|G_{E}/G_{M}|$) value effective ($|G_{\rm{eff}}|$), electric ($|G_E|$)...
The cross section of the process $e^{+} e^{-} \rightarrow K^{+} K^{-}$ is measured at a number center-of-mass energies $\sqrt{s}$ from 2.00 to 3.08 GeV with BESIII detector Beijing Electron Positron Collider (BEPCII). results provide best precision achieved so far. A resonant structure around 2.2 observed in line shape. Breit-Wigner fit yields mass $M=2239.2 \pm 7.1 11.3$~and width $\Gamma=139.8\pm12.3\pm20.6$ MeV, where first uncertainties are statistical and second ones systematic. In...
Abstract Using inclusive decays of , a precise determination the number events collected with BESIII detector was performed. For two data sets taken in 2009 and 2012, numbers were recalculated to be respectively; these are good agreement previous measurements. sample 2017–2019, determined . The total where uncertainty is dominated by systematic effects, statistical negligible.
Abstract From December 2019 to June 2021, the BESIII experiment collected approximately 5.85 fb −1 of data at center-of-mass energies between 4.61 and 4.95 GeV. This is highest collision energy BEPCII has reached date. The accumulated annihilation samples are useful for studying charmonium(-like) states charmed-hadron decays. By adopting a novel method analyzing production pairs in annihilation, measured with precision 0.6 MeV. Integrated luminosities better than 1% by events large-angle...
Abstract The integrated luminosities of data samples collected in the BESIII experiment 2016–2017 at center-of-mass energies between 4.19 and 4.28 GeV are measured with a precision better than 1% by analyzing large-angle Bhabha scattering events. old datasets 2010–2014 updated considering corrections related to detector performance, offsetting effect newly discovered readout errors electromagnetic calorimeter, which can haphazardly occur.
Using a sample of (10.09±0.04)×10^{9} J/ψ events collected with the BESIII detector operating at BEPCII storage ring, partial wave analysis decay J/ψ→γηη^{'} is performed. The first observation an isoscalar state exotic quantum numbers J^{PC}=1^{-+}, denoted as η_{1}(1855), reported in process J/ψ→γη_{1}(1855) η_{1}(1855)→ηη^{'}. Its mass and width are measured to be (1855±9_{-1}^{+6}) MeV/c^{2} (188±18_{-8}^{+3}) MeV, respectively, where uncertainties statistical second systematic, its...