Resonances in QCD
We report on the EMMI Rapid Reaction Task Force meeting 'Resonances in QCD', which took place at GSI October 12-14, 2015. A group of 26 people met to discuss the physics of resonances in QCD. The aim of the meeting was defined by the following three key questions: What is needed to understand the physics of resonances in QCD? Where does QCD lead us to expect resonances with exotic quantum numbers? What experimental efforts are required to arrive at a coherent picture? For light mesons and baryons only those with ${\it up}$, ${\it down}$ and ${\it strange}$ quark content were considered. For heavy-light and heavy-heavy meson systems, those with ${\it charm}$ quarks were the focus. This docum…
Measurement of the e+e−→ωπ0π0 cross section at center-of-mass energies from 2.0 to 3.08 GeV
First Measurement of Polarizations in the Decay D0→ωφ
Observation of theψ(1 D23)State ine+e−→π+π−γχc1at BESIII
Alignment for the first precision measurements at Belle II
On March 25th 2019, the Belle II detector recorded the first collisions delivered by the SuperKEKB accelerator. This marked the beginning of the physics run with vertex detector. The vertex detector was aligned initially with cosmic ray tracks without magnetic field simultaneously with the drift chamber. The alignment method is based on Millepede II and the General Broken Lines track model and includes also the muon system or primary vertex position alignment. To control weak modes, we employ sensitive validation tools and various track samples can be used as alignment input, from straight cosmic tracks to mass-constrained decays. With increasing luminosity and experience, the alignment is …
Measurement of the branching fraction for ψ(3686)→ωKS0KS0
Partial wave analysis of J/ψ→γη′η′
Search for X(3872)→π0χc0 and X(3872)→ππχc0 at BESIII
Observation of the doubly radiative decay η′→γγπ0
Based on a sample of 1.31 billion J/psi events collected with the BESIII detector, we report the study of the doubly radiative decay eta' -> gamma gamma pi(0) for the first time, where the eta' meson is produced via the J/psi -> gamma eta' decay. The branching fraction of eta' -> gamma gamma pi(0) inclusive decay is measured to be B(eta' -> gamma gamma pi(0))(Incl) = (3.20 +/- 0.07(stat) +/- 0.23(sys)) x 10(-3), while the branching fractions of the dominant process eta' -> gamma omega and the non-resonant component are determined to be B(eta' -> gamma omega) x B(omega -> gamma pi(0)) = (23.7 +/- 1.4(stat) +/- 1.8(sys)) x 10(-4) and B(eta' -> gamma gamma pi(0))(NR) = (6.16 +/- 0.64(stat) +/-…
Study of light scalar mesons through Ds+→π0π0e+νe and KS0KS0e+νe decays
Data quality monitors of vertex detectors at the start of the Belle II experiment
The Belle II experiment features a substantial upgrade of the Belle detector and will operate at the SuperKEKB energy-asymmetric e+e− collider at KEK in Tsukuba, Japan. The accelerator completed its first phase of commissioning in 2016, and the Belle II detector saw its first electron-positron collisions in April 2018. Belle II features a newly designed silicon vertex detector based on double-sided strip layers and DEPFET pixel layers. A subset of the vertex detector was operated in 2018 to determine background conditions (Phase 2 operation). The collaboration completed full detector installation in January 2019, and the experiment started full data taking. This paper will report on the fin…
Search for baryon- and lepton-number violating decays D0→p¯e+ and D0→pe−
Measurement of the branching fraction of the doubly Cabibbo-suppressed decay D0→K+π−π0 and search for D0→K+π−π0π0
Amplitude analysis and branching-fraction measurement of Ds+→KS0K−π+π+
Using 6.32 fb−1 of e+e− collision data collected by the BESIII detector at the center-of-mass energies between 4.178 and 4.226 GeV, an amplitude analysis of the D+s → K0SK−π+π+ decays is performed ...