Strong-Phase Measurement in Charmed-Hadron Decays in Belle II Experiment and $${c{-}}{\tau}$$ Factory

2020 ◽  
Vol 83 (6) ◽  
pp. 980-983
Author(s):  
V. Popov
Keyword(s):  
Phase Measurement ◽  
Strong Phase ◽  
Charmed Hadron ◽  
Belle Ii

scholarly journals Measurement of the D → K−π+π+π− and D → K−π+π0 coherence factors and average strong-phase differences in quantum-correlated $$ D\overline{D} $$ decays

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
M. Ablikim ◽  
◽  
M. N. Achasov ◽  
P. Adlarson ◽  
S. Ahmed ◽  
...  
Keyword(s):  
The Other ◽  
Unitarity Triangle ◽  
Quantum Superposition ◽  
Final State ◽  
Data Set ◽  
Strong Phase ◽  
Signal Decay ◽  
Belle Ii ◽  
Coherence Factors ◽  
Phase Differences

Abstract The decays D → K−π+π+π− and D → K−π+π0 are studied in a sample of quantum-correlated $$ D\overline{D} $$ D D ¯ pairs produced through the process e+e− → ψ(3770) → $$ D\overline{D} $$ D D ¯ , exploiting a data set collected by the BESIII experiment that corresponds to an integrated luminosity of 2.93 fb−1. Here D indicates a quantum superposition of a D0 and a $$ {\overline{D}}^0 $$ D ¯ 0 meson. By reconstructing one neutral charm meson in a signal decay, and the other in the same or a different final state, observables are measured that contain information on the coherence factors and average strong-phase differences of each of the signal modes. These parameters are critical inputs in the measurement of the angle γ of the Unitarity Triangle in B− → DK− decays at the LHCb and Belle II experiments. The coherence factors are determined to be RK3π = $$ {0.52}_{-0.10}^{+0.12} $$ 0.52 − 0.10 + 0.12 and $$ {R}_{K{\pi \pi}^0} $$ R K ππ 0 = 0.78 ± 0.04, with values for the average strong-phase differences that are $$ {\delta}_D^{K3\pi }=\left({167}_{-19}^{+31}\right){}^{\circ} $$ δ D K 3 π = 167 − 19 + 31 ° and $$ {\delta}_D^{K{\pi \pi}^0}=\left({196}_{-15}^{+14}\right){}^{\circ} $$ δ D K ππ 0 = 196 − 15 + 14 ° , where the uncertainties include both statistical and systematic contributions. The analysis is re-performed in four bins of the phase-space of the D → K−π+π+π− to yield results that will allow for a more sensitive measurement of γ with this mode, to which the BESIII inputs will contribute an uncertainty of around 6°.

scholarly journals Charm Meson Physics at BESIII

2018 ◽  
Vol 46 ◽  
pp. 1860063
Author(s):  
Lei Li
Keyword(s):  
Decay Constant ◽  
Phase Measurement ◽  
Center Of Mass ◽  
Form Factors ◽  
Mass Energy ◽  
Text Data ◽  
Strong Phase ◽  
Center Of Mass Energy ◽  
Plot Analysis ◽  
Mixing Parameter

Based on 2.93 fb[Formula: see text] data taken at the center-of-mass energy of [Formula: see text] GeV with the BESIII detector at the BEPCII collider, we report the precise measurements of the decay constant [Formula: see text], the form factors of [Formula: see text] semileptonic decays [Formula: see text] and [Formula: see text], the Dalitz plot analysis of [Formula: see text], the strong phase measurement in [Formula: see text] and the [Formula: see text] mixing parameter [Formula: see text].

Performance and applications of the holography electron microscope

1993 ◽  
Vol 51 ◽  
pp. 1078-1079
Author(s):  
Akira Tonomura
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Phase Measurement ◽  
Electron Holography ◽  
Imaging Method ◽  
High Contrast ◽  
Magnetic Lens ◽  
High Brightness ◽  
Holographic Imaging ◽  
Dynamic Observation

Electron holography is a two-step imaging method. However, the ultimate performance of holographic imaging is mainly determined by the brightness of the electron beam used in the hologram-formation process. In our 350kV holography electron microscope (see Fig. 1), the decrease in the inherently high brightness of field-emitted electrons is minimized by superposing a magnetic lens in the gun, for a resulting value of 2 × 109 A/cm2 sr. This high brightness has lead to the following distinguished features. The minimum spacing (d) of carrier fringes is d = 0.09 Å, thus allowing a reconstructed image with a resolution, at least in principle, as high as 3d=0.3 Å. The precision in phase measurement can be as high as 2π/100, since the position of fringes can be known precisely from a high-contrast hologram formed under highly collimated illumination. Dynamic observation becomes possible because the current density is high.

scholarly journals Long-lived light neutralinos at Belle II

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Sourav Dey ◽  
Claudio O. Dib ◽  
Juan Carlos Helo ◽  
Minakshi Nayak ◽  
Nicolás A. Neill ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Parameter Space ◽  
Rare Decays ◽  
Final States ◽  
Charged Pions ◽  
Belle Ii ◽  
Background Events ◽  
Displaced Vertex

Abstract We consider light neutralinos of mass about 1 GeV, produced from τ lepton rare decays at Belle II, in the context of R-parity-violating (RPV) supersymmetry. With large and clean samples of τ leptons produced at the Belle II experiment, excellent sensitivity to such light neutralinos with the exotic signatures of displaced vertices is expected. We focus on two benchmark scenarios of single RPV operators, $$ {\lambda}_{311}^{\prime }{L}_3{Q}_1{\overline{D}}_1 $$ λ 311 ′ L 3 Q 1 D ¯ 1 and $$ {\lambda}_{312}^{\prime }{L}_3{Q}_1{\overline{D}}_2 $$ λ 312 ′ L 3 Q 1 D ¯ 2 , which induce both the production and decay of the lightest neutralino. For the reconstruction of a displaced vertex, we require at least two charged pions in the final states. We perform Monte-Carlo simulations for both signal and background events, and find that Belle II can explore regions in the parameter space competitive with other probes. In particular, for the $$ {\lambda}_{311}^{\prime } $$ λ 311 ′ scenario, it can put limits up to two orders of magnitude stronger than the current bounds.

scholarly journals Erratum to: Revised constraints and Belle II sensitivity for visible and invisible axion-like particles

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Matthew J. Dolan ◽  
Torben Ferber ◽  
Christopher Hearty ◽  
Felix Kahlhoefer ◽  
Kai Schmidt-Hoberg
Keyword(s):  
Proton Beam ◽  
Numerical Code ◽  
Beam Dump ◽  
Belle Ii ◽  
Invisible Axion

A mistake has been found in the numerical code used to reproduce the bounds from proton beam dump experiments from ref. [1] in figures 2 and 7 of ref. [2]. Correcting this mistake leads to slightly stronger bounds as shown below. We note that this correction does not include recent improvements in the analysis of proton beam dump experiments [3]. Additional recent bounds on GeV-scale ALPs can be found in refs. [4–8].

scholarly journals Effect of mesoscale phase contrast on fatigue-delaying behavior of self-healing hydrogels

2021 ◽  
Vol 7 (16) ◽  
pp. eabe8210
Author(s):  
Xueyu Li ◽  
Kunpeng Cui ◽  
Takayuki Kurokawa ◽  
Ya Nan Ye ◽  
Tao Lin Sun ◽  
...  
Keyword(s):  
Crack Growth ◽  
Fatigue Resistance ◽  
Phase Contrast ◽  
Stress Singularity ◽  
Soft Materials ◽  
Self Healing ◽  
Strong Phase ◽  
Mesoscale Structure ◽  
High Fatigue ◽  
Affine Deformation

We investigate the fatigue resistance of chemically cross-linked polyampholyte hydrogels with a hierarchical structure due to phase separation and find that the details of the structure, as characterized by SAXS, control the mechanisms of crack propagation. When gels exhibit a strong phase contrast and a low cross-linking level, the stress singularity around the crack tip is gradually eliminated with increasing fatigue cycles and this suppresses crack growth, beneficial for high fatigue resistance. On the contrary, the stress concentration persists in weakly phase-separated gels, resulting in low fatigue resistance. A material parameter, λtran, is identified, correlated to the onset of non-affine deformation of the mesophase structure in a hydrogel without crack, which governs the slow-to-fast transition in fatigue crack growth. The detailed role played by the mesoscale structure on fatigue resistance provides design principles for developing self-healing, tough, and fatigue-resistant soft materials.

Comments on "An accurate digital phase measurement scheme"

1985 ◽  
Vol 73 (3) ◽  
pp. 490-491
Author(s):  
J.M. Carr ◽  
T.S. Rathore
Keyword(s):  
Phase Measurement ◽  
Measurement Scheme ◽  
Digital Phase
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