Refine
Year of publication
Document Type
- Preprint (764)
- Article (625)
- Conference Proceeding (4)
- Doctoral Thesis (1)
- Working Paper (1)
Language
- English (1388)
- German (6)
- Multiple languages (1)
Has Fulltext
- yes (1395)
Is part of the Bibliography
- no (1395)
Keywords
- Heavy Ion Experiments (20)
- Hadron-Hadron Scattering (11)
- Hadron-Hadron scattering (experiments) (11)
- BESIII (9)
- LHC (9)
- Branching fraction (7)
- e +-e − Experiments (7)
- Heavy-ion collision (6)
- HIV (5)
- Particle and Resonance Production (5)
- ALICE experiment (4)
- Charm physics (4)
- Collective Flow (4)
- Electroweak interaction (4)
- Inverse kinematics (4)
- Jets (4)
- Lepton colliders (4)
- Quark-Gluon Plasma (4)
- Quasi-free scattering (4)
- ALICE (3)
- Biomarkers (3)
- COVID-19 (3)
- Charm Physics (3)
- Charmed mesons (3)
- Experimental nuclear physics (3)
- Experimental particle physics (3)
- Hadronic decays (3)
- Heavy Ions (3)
- Jets and Jet Substructure (3)
- Oncology (3)
- Osteoporosis (3)
- Particle and resonance production (3)
- QCD (3)
- Quarkonium (3)
- Spectroscopic factors (3)
- breast cancer (3)
- e+-e− Experiments (3)
- pp collisions (3)
- Antiretroviral therapy (2)
- Beauty production (2)
- Bone density (2)
- Branching fractions (2)
- CT (2)
- Cirrhosis (2)
- Diagnostic markers (2)
- Diagnostik (2)
- Electroweak Interaction (2)
- Epilepsy (2)
- Exotics (2)
- Früherkennung (2)
- Heart failure (2)
- Heavy Quark Production (2)
- Hypertension (2)
- Inflammation (2)
- Lepton-Nucleon Scattering (experiments) (2)
- Leptonic, semileptonic & radiative decays (2)
- Liver diseases (2)
- Mammakarzinom (2)
- Nachsorge (2)
- Nuclear reactions (2)
- Particle Correlations and Fluctuations (2)
- Particle correlations and fluctuations (2)
- Particle decays (2)
- Pb–Pb collisions (2)
- Relativistic heavy-ion collisions (2)
- Richtlinie (2)
- Seizure (2)
- Shell model (2)
- Single electrons (2)
- Single-particle states (2)
- Spectroscopy (2)
- Spine (2)
- biomarker (2)
- diagnosis (2)
- follow‑up (2)
- guideline (2)
- pelvic packing (2)
- reference values (2)
- screening (2)
- 900 GeV (1)
- ABC transporters (1)
- ALICE detector (1)
- ALK (1)
- APRI (1)
- ATPases (1)
- Accelerators & Beams (1)
- Accelerators & storage rings (1)
- Acute coronary syndrome (1)
- Alpha-synuclein (1)
- Angiography (1)
- Angiomyolipoma (1)
- Anti-nuclei (1)
- Anti-seizure medication (1)
- Anticonvulsant (1)
- Antiretrovirals (1)
- Antirheumatic agents (1)
- Antiviral therapy (1)
- Aortic valve (1)
- Apoptosis (1)
- Artesunate (1)
- Atherosclerosis (1)
- Atomic & molecular beams (1)
- Atomic, Molecular & Optical (1)
- Atrial fibrillation (1)
- B cell receptor (1)
- B cell subpopulations (1)
- BESIII detector (1)
- BRCA1 (1)
- BRCA2 (1)
- Bacterial genomics (1)
- Bayesian inference (1)
- Beam loss (1)
- Bhabha (1)
- Biomarker (1)
- Bipolar disorder (1)
- Bleeding (1)
- Blood plasma (1)
- Blood pressure (1)
- Body mass index (1)
- Bone diseases, Metabolic (1)
- Boosted Jets (1)
- Born cross section measurement (1)
- Breast cancer (1)
- C-clamp (1)
- C3M (1)
- C4M (1)
- CD16 (1)
- CD56 (1)
- COVID 19 (1)
- CP violation (1)
- CRPC (1)
- CT dual-energy computed tomography (1)
- CVID (1)
- Cancer (1)
- Cancer treatment (1)
- Cardiac implantable electronic devices (1)
- Cardiac rehabilitation (1)
- Cardiac resynchronization therapy (1)
- Cardiac troponin (1)
- Cardiology (1)
- Cardiovascular biology (1)
- Cardiovascular disease risk (1)
- Cardiovascular diseases (1)
- Cell-to-Cell Spread (1)
- Centrality Class (1)
- Centrality Selection (1)
- Charge fluctuations (1)
- Charge-transfer collisions (1)
- Charmonium (1)
- Charmonium (-like) (1)
- Chemoradiotherapy (1)
- Child (1)
- Children (1)
- Chronic obstructive pulmonary disease (1)
- Circular accelerators (1)
- Clinical study (1)
- Clinical variation (1)
- Cohort studies (1)
- Collective Flow, (1)
- Comparative effectiveness research (1)
- Comparison with QCD (1)
- Complex II (1)
- Computed tomography, X-ray (1)
- Consensus (1)
- Consensus document (1)
- Contrast agent (1)
- Costs (1)
- Cross section (1)
- Cross sections (1)
- Culture positive (1)
- D meson (1)
- Dark photon (1)
- Dark sector (1)
- De-isolation (1)
- Death rates (1)
- Dermatomyositis (1)
- Diagnosis (1)
- Diagnostic differentiation (1)
- Digestive system procedures (1)
- Direct nuclear reactions (1)
- Direct reactions (1)
- Docetaxel (1)
- Drug screens (1)
- Dual-energy computed tomography (1)
- Economics (1)
- Eicosanoids (1)
- Ejection fraction (1)
- Elderly (1)
- Electromagnetic form factor (1)
- Electromagnetic form factors (1)
- Electron-pion identification (1)
- Electronic transitions (1)
- Elliptic flow (1)
- Endocrinology (1)
- Endoscopy (1)
- Ephrin-B2–EphB4 (1)
- Esophagectomy (1)
- Europe (1)
- European Society for Immunodeficiencies (ESID) (1)
- Everolimus (1)
- Exercise training (1)
- Exosomes (1)
- FAPI PET (1)
- FIB-4 (1)
- FOS: Physical sciences (1)
- Falciparum (1)
- Fatty acids (1)
- Fatty liver (1)
- Femtoscopy (1)
- Fibre/foam sandwich radiator (1)
- Fibrosis (1)
- Fibrotest (1)
- First-line combination antiretroviral therapy (1)
- Flavor changing neutral currents (1)
- Flavor symmetries (1)
- Flavour Physics (1)
- Form factors (1)
- Forschung (1)
- Frailty (1)
- Gadobutrol (1)
- Gadopentate dimeglumine (1)
- General practitioners (1)
- Genetics (1)
- German PID-NET registry (1)
- Gleason Grade Group (1)
- HBT (1)
- HBV (1)
- HCV (1)
- HER2-positive (1)
- HIV-1 (1)
- HNO (1)
- Hadron production (1)
- Hadron-Hadron Scattering Heavy (1)
- Hadron-hadron interactions (1)
- Hals-Nasen-Ohren-Heilkunde (1)
- Hard Scattering (1)
- Health economics (1)
- Heavy Ion Experiment (1)
- Heavy flavor production (1)
- Heavy flavour production (1)
- Heavy ion storage ring (1)
- Heavy ions (1)
- Heavy-flavour decay muons (1)
- Heavy-flavour production (1)
- Heavy-ion collisions (1)
- Hematology (1)
- Hepatitis B virus (1)
- Hepatitis C virus (1)
- Hepatocellular carcinoma (1)
- Hepatotoxicity (1)
- Hereditary breast and ovarian cancer (1)
- Herniated disk (1)
- High Energy Physics - Experiment (hep-ex) (1)
- High-energy neutron detection (1)
- Human behaviour (1)
- Hyperons (1)
- INR (1)
- IgG substitution therapy (1)
- Image processing (1)
- Implantable cardioverter-defibrillator (1)
- In-TIPS thrombosis (1)
- Inclusive spectra (1)
- Initial state radiation (1)
- Intensity interferometry (1)
- International normalized ratio (1)
- Intervertebral disc displacement (1)
- Invariant Mass Distribution (1)
- Invisible decays (1)
- Ionisation energy loss (1)
- Isoscalar giant resonances (1)
- Jet Physics (1)
- Jet Substructure (1)
- Kidney diseases (1)
- Lehre (1)
- Leukemias (1)
- Liver (1)
- Liver enzymes (1)
- Liver fibrosis (1)
- Liver transplantation (1)
- Long non-coding RNAs (1)
- Low & intermediate-energy accelerators (1)
- MHC (1)
- MRI (1)
- MTOR inhibitor (1)
- MYCN amplification (1)
- Malaria (1)
- Masquelet technique (1)
- Material budget (1)
- MicroRNAs (1)
- Mid-rapidity (1)
- Minimum Bias (1)
- Mitochondria (1)
- Molecular diagnostic testing (1)
- Molecular neuroscience (1)
- Monte Carlo (1)
- Multi-Parton Interactions (1)
- Multi-neutron detection (1)
- Multi-strange baryons (1)
- Multi-wire proportional drift chamber (1)
- Multivariate analysis (1)
- Mycobacteria (1)
- Mycobacterium avium complex (1)
- Myocardial infarction (1)
- NK cells (1)
- NMR spectroscopy (1)
- Nanoscale biophysics (1)
- Neoadjuvant radiochemotherapy (1)
- Neoadjuvant therapy (1)
- Neural network (1)
- Neutrinos (1)
- Non-small cell lung cancer (1)
- Noninferiority (1)
- Nontuberculous mycobacteria (1)
- Nuclear astrophysics (1)
- Nuclear modification factor (1)
- Nuclear physics of explosive environments (1)
- Nuclear structure & decays (1)
- Nucleon induced nuclear reactions (1)
- ORL (1)
- Oesophagogastric cancer oxaliplatin (1)
- Oldest-old (1)
- One-nucleon removal (1)
- Open pulmonary tuberculosis (1)
- Opportunistic infections (1)
- Optical tweezers (1)
- Orbital electron capture (1)
- Osteoporotic fractures (1)
- Otorhinolaryngology (1)
- Oxidative phosphorylation (1)
- PDE‐5‐inhibitor (1)
- PID prevalence (1)
- PYTHIA (1)
- Pacemaker (1)
- Parkinson’s disease (1)
- Particle phenomena (1)
- Pathological complete response (1)
- Pb–Pb (1)
- Percutaneous (1)
- Personalized medicine (1)
- Phantoms (imaging) (1)
- Phospholipids (1)
- Photon counting (1)
- Physical activity (1)
- Plasmodium (1)
- Plastic scintillator array (1)
- Point-of-care testing (1)
- Polarization (1)
- Pre-treatment drug resistance mutations (1)
- Predictive markers (1)
- Prevention (1)
- Production Cross Section (1)
- Prognosis (1)
- Properties of Hadrons (1)
- Protease inhibitor therapy (1)
- Proton (1)
- Proton–proton (1)
- Psychiatric disorders (1)
- QGP (1)
- Quantitative Imaging (1)
- Quantum chromodynamics (1)
- Quark Deconfinement (1)
- Quark Gluon Plasma (1)
- Quark Production (1)
- Quark gluon plasma (1)
- Quinine (1)
- RAS pathway (1)
- Radiative capture (1)
- Radiative decay (1)
- Rapidity Range (1)
- Rare decays (1)
- Reactions with relativistic radioactive beams (1)
- Registries (1)
- Regulatory networks (1)
- Relativistic heavy ion physics (1)
- Renal lesions (1)
- Research (1)
- Residency (1)
- Resolution Parameter (1)
- Respiratory infections (1)
- Retinal diseases (1)
- Rhabdomyoma (1)
- SARS CoV 2 (1)
- SARS-CoV-2 (1)
- SARS-CoV‑2 pandemic (1)
- SARS-CoV‑2-Pandemie (1)
- SR-BI (1)
- SVR (1)
- Semi-leptonic decays (1)
- Severe malaria (1)
- Single muons (1)
- Single particle decay spectroscopy (1)
- Sociodemographic characteristics (1)
- Specialist training (1)
- Spectroscopic factors & electromagnetic moments (1)
- Sphingolipids (1)
- Sputum smear-negative (1)
- Stentoplasty (1)
- Storage ring (1)
- Subependymal giant cell astrocytoma (1)
- Super-resolution microscopy (1)
- Surgical oncology (1)
- Systematic Uncertainty (1)
- TB-therapy (1)
- TIPS (1)
- TR (1)
- TSC (1)
- Teaching (1)
- Techniques Electromagnetic calorimeters (1)
- Time Projection Chamber (1)
- Tomography (1)
- Tomography (x-ray computed) (1)
- Tracking (1)
- Transferases (1)
- Transient elastography (1)
- Transition radiation detector (1)
- Transjugular Intrahepatic Portosystemic Shunt (1)
- Transverse momentum (1)
- Trigger (1)
- Triple negative (1)
- Triple-negative breast cancer (1)
- Two body weak decay (1)
- Type 2 diabetes (1)
- University hospitals (1)
- Universitätskliniken (1)
- Vector Boson Production (1)
- Vertebral augmentation (1)
- Vertebral body stenting (1)
- Vertebral fracture (1)
- Viral load (1)
- Virological failure (1)
- Virtual noncalcium reconstructions (1)
- Weiterbildung (1)
- X-ray computed (1)
- X-ray crystallography (1)
- Xenon-based gas mixture (1)
- Y states (1)
- accessory proteins (1)
- acoustic radiation force impulse imaging (1)
- acute myeloid leukemia (1)
- adaptive immunity (1)
- adult and elderly patients (1)
- allogeneic transplantation (1)
- angiography (1)
- angiopoietin-like 3 (ANGPTL3) (1)
- annual bleeding rate (1)
- anterior chamber depth changes (1)
- antigen presentation (1)
- auditory system (1)
- autoimmunity (1)
- biopsy cores (1)
- bone marrow derived mononuclear cells (1)
- cART (1)
- cancer therapy (1)
- cardiac magnetic resonance (1)
- castration resistance (1)
- cataract surgery (1)
- cell-free protein synthesis (1)
- center-of-mass energy (1)
- charmonium-like states (1)
- children (1)
- chronic kidney disease (1)
- clinical stage (1)
- co-infection (1)
- cohlear implant (1)
- cohort study (1)
- collagen degradation marker (1)
- component study (1)
- computer-assisted (1)
- critical size defect (1)
- cryo-EM (1)
- cyanines (1)
- cytarabine dose (1)
- dE/dx (1)
- decision aids (1)
- detector (1)
- dimuon (1)
- dislocation (1)
- e+e − annihilation (1)
- e+e⁻ − Experiments (1)
- e+e− Experiments (1)
- e-scooter (1)
- effective lens position (1)
- effectiveness (1)
- elderly (1)
- electric and acustic stymulation (1)
- electric scooter (1)
- electron-positron collision (1)
- embolization (1)
- erectile dysfunction (1)
- experimental results (1)
- exponential model (1)
- external fixation (1)
- fibrosis imaging (1)
- fibrotest (1)
- flow cytometry (1)
- fracture (1)
- hadron spectroscopy (1)
- hadronic events (1)
- haemophilia A (1)
- head-and-neck cancer (1)
- heavy ion experiments (1)
- heavy-ion storage rings (1)
- helicity amplitude analysis (1)
- hemodynamic instability (1)
- hemorrhage (1)
- hepatitis C (1)
- high-risk neuroblastoma (1)
- immune reconstitution (1)
- inclusive J/ψ decays (1)
- induced membrane (1)
- interoperability (1)
- intrinsically disordered region (1)
- inverse kinematics (1)
- lactate (1)
- lapatinib (1)
- learning loss (1)
- lung cancer (1)
- mTOR inhibitor (1)
- management (1)
- membrane proteins (1)
- metastasis (1)
- metastatic prostate cancer (1)
- mindfulness (1)
- molecular machines (1)
- molecular tug-of-war (1)
- mortality (1)
- myocardial fibrosis (1)
- neoadjuvant therapy (1)
- neutron-induced reactions (1)
- non-ST-segment elevation acute coronary syndrome (1)
- non-invasive fibrosis assessment (1)
- nonstructural proteins (1)
- non‐selective beta‐blocker (1)
- nuclear cardiology (1)
- number of J/ψ events (1)
- oxLDL (1)
- p53 pathway (1)
- pelvic injury (1)
- pelvic ring fracture (1)
- peptide editing (1)
- peptide-loading complex (1)
- photoacid (1)
- phylogeny (1)
- plasma-derived factor VIII concentrate, prophylaxis (1)
- point shear wave elastography (1)
- portal hypertension (1)
- primary active transporters (1)
- primary immunodeficiency (PID) (1)
- proteomics (1)
- proton transfer (1)
- pseudoexfoliative syndrome (1)
- psychotherapy process (1)
- quality control (1)
- quark gluon plasma (1)
- randomized controlled trial (RCT) (1)
- registry for primary immunodeficiency (1)
- resectability (1)
- risk group (1)
- scaffold size (1)
- scar (1)
- school closure (1)
- seed and soil (1)
- sequence alignment (1)
- smart home (1)
- smart living (1)
- spectra (1)
- sphingolipid (1)
- spinal bone metastasis (1)
- spine (1)
- spiro compounds (1)
- stage migration (1)
- structural biology (1)
- structural proteins (1)
- student achievement (1)
- surrogate reactions (1)
- survival (1)
- systematic review (1)
- tapasin (1)
- tetraquark (1)
- therapeutic alliance (1)
- traffic accident (1)
- transient elastography (1)
- transportation (1)
- trastuzumab (1)
- traumatic brain injury (1)
- trigger efficiency (1)
- ultrafast spectroscopy (1)
- vertebroplasty (1)
- web of things (1)
- x-ray techniques (1)
- Λ+c baryon (1)
- Σ hyperon (1)
- √sN N = 2.76 TeV (1)
Institute
- Physik (1262)
- Frankfurt Institute for Advanced Studies (FIAS) (956)
- Informatik (921)
- Medizin (103)
- ELEMENTS (18)
- Geowissenschaften (10)
- Biochemie und Chemie (5)
- Exzellenzcluster Herz-Lungen-System (3)
- Informatik und Mathematik (3)
- Biochemie, Chemie und Pharmazie (2)
Based on 4.5 fb−1 of e+e− collision data accumulated at center-of-mass energies between 4599.53 MeV and 4698.82 MeV with the BESIII detector, the decay Λ+c→nK0Sπ+π0 is observed for the first time with a significance of 9.2σ. The branching fraction is measured to be (0.85±0.13±0.03)%, where the first uncertainty is statistical and the second systematic, which differs from the theoretical prediction based on isospin by 4.4σ. This indicates that there may be resonant contributions or some unknown dynamics in this decay.
The Born cross sections for the process e+e−→ωη′ are measured at 22 center-of-mass energies from 2.000 to 3.080 GeV using data collected with the BESIII detector at the BEPCII collider. A resonant structure is observed with a statistical significance of 9.6σ. A Breit-Wigner fit determines its mass to be MR=(2153±30±31) MeV/c2 and its width to be ΓR=(167±77±7) MeV, where the first uncertainties are statistical and the second are systematic.
Evidence for the singly Cabibbo suppressed decay Λ+c→pπ0 is reported for the first time with a statistical significance of 3.7σ based on 6.0 fb−1 of e+e− collision data collected at center-of-mass energies between 4.600 and 4.843 GeV with the BESIII detector at the BEPCII collider. The absolute branching fraction of Λ+c→pπ0 is measured to be (1.56+0.72−0.58±0.20)×10−4. Combining with the branching fraction of Λ+c→nπ+, (6.6±1.3)×10−4, the ratio of the branching fractions of Λ+c→nπ+ and Λ+c→pπ0 is calculated to be 3.2+2.2−1.2. As an important input for the theoretical models describing the decay mechanisms of charmed baryons, our result indicates that the non-factorizable contributions play an essential role and their interference with the factorizable contributions should not be significant. In addition, the absolute branching fraction of Λ+c→pη is measured to be (1.63±0.31stat±0.11syst)×10−3.
We search for an axion-like particle (ALP) a through the process ψ(3686)→π+π−J/ψ, J/ψ→γa, a→γγ in a data sample of (2.71±0.01)×109 ψ(3686) events collected by the BESIII detector. No significant ALP signal is observed over the expected background, and the upper limits on the branching fraction of the decay J/ψ→γa and the ALP-photon coupling constant gaγγ are set at 95% confidence level in the mass range of 0.165≤ma≤2.84GeV/c2. The limits on B(J/ψ→γa) range from 8.3×10−8 to 1.8×10−6 over the search region, and the constraints on the ALP-photon coupling are the most stringent to date for 0.165≤ma≤1.468GeV/c2.
A light scalar X0 or vector X1 particles have been introduced as a possible explanation for the (g−2)μ anomaly and dark matter phenomena.
Using (8.998±0.039)×109 $\jpsi$ events collected by the BESIII detector, we search for a light muon philic scalar X0 or vector X1 in the processes J/ψ→μ+μ−X0,1 with X0,1 invisible decays. No obvious signal is found, and the upper limits on the coupling g′0,1 between the muon and the X0,1 particles are set to be between 1.1×10−3 and 1.0×10−2 for the X0,1 mass in the range of 1<M(X0,1)<1000~MeV/c2 at 90% confidence level.
We report the measurement of the cross sections for e+e−→hadrons at center-of-mass (c.m.) energies from 3.645 to 3.871 GeV. We observe a new resonance R(3810) in the cross sections for the first time, and observe the R(3760) resonance with high significance in the cross sections. The R(3810) has a mass of (3804.5±0.9±0.9) ~MeV/c2, a total width of (5.4±3.5±3.2)~MeV, and an electronic partial width of (19.4±7.4±12.1)~eV. Its significance is 7.7σ. The R(3810) could be interpreted as a hadro-charmonium resonance predicted by Quantum Chromodynamics (QCD). In addition, we measure the mass (3751.9±3.8±2.8) ~MeV/c2, the total width (32.8±5.8±8.7)~MeV, and the electronic partial width (184±75±86)~eV with improved precision for the R(3760). Furthermore, for the R(3780) we measure the mass (3778.7±0.5±0.3) ~MeV/c2 and total width (20.3±0.8±1.7)~MeV with improved precision, and the electronic partial width (265±69±83)~eV. The R(3780) can be interpreted as the 13D1 state of charmonium. Its mass and total width differ significantly from the corresponding fitted values given by the Particle Data Group in 2022 by 7.1 and 3.2 times the uncertainties for ψ(3770), respectively. ψ(3770) has been interpreted as the 13D1 state for 45 years.
We search for an axion-like particle (ALP) a through the process ψ(3686)→π+π−J/ψ, J/ψ→γa, a→γγ in a data sample of (2.71±0.01)×109 ψ(3686) events collected by the BESIII detector. No significant ALP signal is observed over the expected background, and the upper limits on the branching fraction of the decay J/ψ→γa and the ALP-photon coupling constant gaγγ are set at 95% confidence level in the mass range of 0.165≤ma≤2.84GeV/c2. The limits on B(J/ψ→γa) range from 8.3×10−8 to 1.8×10−6 over the search region, and the constraints on the ALP-photon coupling are the most stringent to date for 0.165≤ma≤1.468GeV/c2.
The Cabbibo-favored decay Λ+c→Ξ0K+π0 is studied for the first time using 6.1 fb−1 of e+e− collision data at center-of-mass energies between 4.600 and 4.840 GeV, collected with the BESIII detector at the BEPCII collider. With a double-tag method, the branching fraction of the three-body decay Λ+c→Ξ0K+π0 is measured to be (7.79±1.46±0.71)×10−3, where the first and second uncertainties are statistical and systematic, respectively. The branching fraction of the two-body decay Λ+c→Ξ(1530)0K+ is (5.99±1.04±0.29)×10−3, which is consistent with the previous result of (5.02±0.99±0.31)×10−3. In addition, the upper limit on the branching fraction of the doubly Cabbibo-suppressed decay Λ+c→nK+π0 is 7.1×10−4 at the 90% confidence level. The upper limits on the branching fractions of Λ+c→Σ0K+π0 and ΛK+π0 are also determined to be 1.8×10−3 and 2.0×10−3, respectively.
Relative fractions and phases of the intermediate decays are determined. With the detection efficiency estimated by the results of the amplitude analysis, the branching fraction of Dþ s → K−Kþπþπ0 decay is measured to be ð5.42 0.10stat 0.17systÞ%.
A light scalar X0 or vector X1 particles have been introduced as a possible explanation for the (g−2)μ anomaly and dark matter phenomena.
Using (8.998±0.039)×109 $\jpsi$ events collected by the BESIII detector, we search for a light muon philic scalar X0 or vector X1 in the processes J/ψ→μ+μ−X0,1 with X0,1 invisible decays. No obvious signal is found, and the upper limits on the coupling g′0,1 between the muon and the X0,1 particles are set to be between 1.1×10−3 and 1.0×10−2 for the X0,1 mass in the range of 1<M(X0,1)<1000 MeV/c2 at 90% confidence level.
Using e+e− annihilation data sets collected with the BESIII detector, we measure the cross sections of the processes e+e−→e+e− and e+e−→μ+μ− at fifteen center-of-mass energy points in the vicinity of the J/ψ resonance. By a simultaneous fit to the measured, center-of-mass energy dependent cross sections of the two processes, the combined quantities ΓeeΓee/Γtot and ΓeeΓμμ/Γtot are determined to be (0.346±0.009) and (0.335±0.006) keV, respectively, where Γee, Γμμ, and Γtot are the electronic, muonic, and total decay widths of the J/ψ resonance, respectively. Using the resultant ΓeeΓμμ/Γtot and ΓeeΓee/Γtot, the ratio Γee/Γμμ is calculated to be 1.031±0.015, which is consistent with the expectation of lepton universality within about two standard deviations. Assuming lepton universality and using the branching fraction of the J/ψ leptonic decay measured by BESIII in 2013, Γtot and Γll are determined to be (93.0±2.1) and (5.56±0.11) keV, respectively, where Γll is the average leptonic decay width of the J/ψ resonance.
Observation of 𝜒𝑐𝐽→Λ¯Λ𝜂
(2022)
By analyzing (448.1±2.9)×106 𝜓(3686) events collected with the BESIII detector operating at the BEPCII collider, the decays of 𝜒𝑐𝐽→Λ
¯Λ𝜂 (𝐽=0, 1, and 2) are observed for the first time with statistical significances of 13.9𝜎, 6.7𝜎, and 8.2𝜎, respectively. The product branching fractions of 𝜓(3686)→𝛾𝜒𝑐𝐽 and 𝜒𝑐𝐽→Λ¯Λ𝜂 are measured. Dividing by the world averages of the branching fractions of 𝜓(3686)→𝛾𝜒𝑐𝐽, the branching fractions of 𝜒𝑐𝐽→Λ¯Λ𝜂 decays are determined to be (2.31±0.30±0.21)×10−4, (5.86±1.38±0.68)×10−5, and (1.05±0.21±0.15)×10−4 for 𝐽=0, 1 and 2, respectively, where the first uncertainties are statistical and the second systematic.
The radiative hyperon decay Λ→nγ is studied using (10087±44)×106 J/ψ events collected with the BESIII detector operating at BEPCII. The absolute branching fraction of the decay Λ→nγ is determined with a significance of 5.6σ to be [0.832±0.038(stat.)±0.054(syst.)]×10−3, which lies significantly below the current PDG value. By analyzing the joint angular distribution of the decay products, the first determination of the decay asymmetry αγ is reported with a value of −0.16±0.10(stat.)±0.05(syst.).
We report a search for a heavier partner of the recently observed Zcs(3985)− state, denoted as Z′−cs, in the process e+e−→K+D∗−sD∗0+c.c., based on e+e− collision data collected at the center-of-mass energies of s√=4.661, 4.682 and 4.699 GeV with the BESIII detector. The Z′−cs is of interest as it is expected to be a candidate for a hidden-charm and open-strange tetraquark. A partial-reconstruction technique is used to isolate K+ recoil-mass spectra, which are probed for a potential contribution from Z′−cs→D∗−sD∗0 (c.c.). We find an excess of Z′−cs→D∗−sD∗0 (c.c.) candidates with a significance of 2.1σ, after considering systematic uncertainties, at a mass of (4123.5±0.7stat.±4.7syst.) MeV/c2. As the data set is limited in size, the upper limits are evaluated at the 90\% confidence level on the product of the Born cross sections (σBorn) and the branching fraction (B) of Z′−cs→D∗−sD∗0, under different assumptions of the Z′−cs mass from 4.120 to 4.140 MeV and of the width from 10 to 50 MeV at the three center-of-mass energies. The upper limits of σBorn⋅B are found to be at the level of O(1) pb at each energy. Larger data samples are needed to confirm the Z′−cs state and clarify its nature in the coming years.
We report a search for a heavier partner of the recently observed Zcs(3985)− state, denoted as Z′−cs, in the process e+e−→K+D∗−sD∗0+c.c., based on e+e− collision data collected at the center-of-mass energies of s√=4.661, 4.682 and 4.699 GeV with the BESIII detector. The Z′−cs is of interest as it is expected to be a candidate for a hidden-charm and open-strange tetraquark. A partial-reconstruction technique is used to isolate K+ recoil-mass spectra, which are probed for a potential contribution from Z′−cs→D∗−sD∗0 (c.c.). We find an excess of Z′−cs→D∗−sD∗0 (c.c.) candidates with a significance of 2.1σ, after considering systematic uncertainties, at a mass of (4123.5±0.7stat.±4.7syst.) MeV/c2. As the data set is limited in size, the upper limits are evaluated at the 90\% confidence level on the product of the Born cross sections (σBorn) and the branching fraction (B) of Z′−cs→D∗−sD∗0, under different assumptions of the Z′−cs mass from 4.120 to 4.140 MeV and of the width from 10 to 50 MeV at the three center-of-mass energies. The upper limits of σBorn⋅B are found to be at the level of O(1) pb at each energy. Larger data samples are needed to confirm the Z′−cs state and clarify its nature in the coming years.
Using a data sample of 4.481×108 𝜓(3686) events collected with the BESIII detector, we report the first observation of the four-lepton-decays 𝐽/𝜓→𝑒+𝑒−𝑒+𝑒− and 𝐽/𝜓→𝑒+𝑒−𝜇+𝜇− utilizing the process 𝜓(3686)→𝜋+𝜋−𝐽/𝜓. The branching fractions are determined to be [5.48±0.31(stat)±0.45(syst)]×10−5 and [3.53±0.22(stat)±0.13(syst)]×10−5, respectively. The results are consistent with theoretical predictions. No significant signal is observed for 𝐽/𝜓→𝜇+𝜇−𝜇+𝜇−, and an upper limit on the branching fraction is set at 1.6×10−6 at the 90% confidence level. A 𝐶𝑃 asymmetry observable is constructed for the first two channels, which is measured to be (−0.012±0.054±0.010) and (0.062±0.059±0.006), respectively. No evidence for 𝐶𝑃 violation is observed in this process.
Using inclusive decays of the J/ψ, a precise determination of the number of J/ψ events collected with the BESIII detector is performed. For the two data sets taken in 2009 and 2012, the numbers of J/ψ events are recalculated to be (224.0±1.3)×106 and (1088.5±4.4)×106 respectively, which are in good agreement with the previous measurements. For the J/ψ sample taken in 2017--2019, the number of events is determined to be (8774.0±39.4)×106. The total number of J/ψ events collected with the BESIII detector is determined to be (10087±44)×106, where the uncertainty is dominated by systematic effects and the statistical uncertainty is negligible.
Using inclusive decays of the J/ψ, a precise determination of the number of J/ψ events collected with the BESIII detector is performed. For the two data sets taken in 2009 and 2012, the numbers of J/ψ events are recalculated to be (224.0±1.3)×106 and (1088.5±4.4)×106 respectively, which are in good agreement with the previous measurements. For the J/ψ sample taken in 2017--2019, the number of events is determined to be (8774.0±39.4)×106. The total number of J/ψ events collected with the BESIII detector is determined to be (10087±44)×106, where the uncertainty is dominated by systematic effects and the statistical uncertainty is negligible.
Using about 23 fb−1 of data collected with the BESIII detector operating at the BEPCII storage ring, a precise measurement of the e+e−→π+π−J/ψ Born cross section is performed at center-of-mass energies from 3.7730 to 4.7008 GeV. Two structures, identified as the Y(4220) and the Y(4320) states, are observed in the energy-dependent cross section with a significance larger than 10σ. The masses and widths of the two structures are determined to be (M,Γ) = (4221.4±1.5±2.0 MeV/c2, 41.8±2.9±2.7 MeV) and (M,Γ) = (4298±12±26 MeV/c2, 127±17±10 MeV), respectively. A small enhancement around 4.5 GeV with a significance about 3σ, compatible with the ψ(4415), might also indicate the presence of an additional resonance in the spectrum. The inclusion of this additional contribution in the fit to the cross section affects the resonance parameters of the Y(4320) state.
Using about 23 fb−1 of data collected with the BESIII detector operating at the BEPCII storage ring, a precise measurement of the e+e−→π+π−J/ψ Born cross section is performed at center-of-mass energies from 3.7730 to 4.7008 GeV. Two structures, identified as the Y(4220) and the Y(4320) states, are observed in the energy-dependent cross section with a significance larger than 10σ. The masses and widths of the two structures are determined to be (M,Γ) = (4221.4±1.5±2.0 MeV/c2, 41.8±2.9±2.7 MeV) and (M,Γ) = (4298±12±26 MeV/c2, 127±17±10 MeV), respectively. A small enhancement around 4.5 GeV with a significance about 3σ, compatible with the ψ(4415), might also indicate the presence of an additional resonance in the spectrum. The inclusion of this additional contribution in the fit to the cross section affects the resonance parameters of the Y(4320) state.