Refine
Document Type
- Preprint (63)
- Article (39)
- Working Paper (2)
Language
- English (104)
Has Fulltext
- yes (104)
Is part of the Bibliography
- no (104)
Keywords
- e +-e − Experiments (7)
- Particle and Resonance Production (5)
- BESIII (4)
- Branching fraction (3)
- Charm Physics (3)
- Spectroscopy (3)
- Electroweak Interaction (2)
- Exotics (2)
- Quarkonium (2)
- law and finance (2)
Institute
- Physik (102)
- Center for Financial Studies (CFS) (2)
Using an 𝑒+𝑒− collision data sample with a total integrated luminosity of 3.19 fb−1 collected with the BESIII detector at a center-of-mass energy of 4.178 GeV, the branching fraction of the inclusive decay of the 𝐷+𝑠 meson to final states including at least three charged pions is measured for the first time to be ℬ(𝐷+𝑠→𝜋+𝜋+𝜋−𝑋)=(32.81±0.35stat±0.63syst)%. In this measurement the charged pions from 𝐾0𝑆 meson decays are excluded. The partial branching fractions of 𝐷+𝑠→𝜋+𝜋+𝜋−𝑋 are also measured as a function of the 𝜋+𝜋+𝜋− invariant mass.
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.
We show that the presence of high frequency trading (HFT) has significantly mitigated the frequency and severity of end-of-day price dislocation, counter to recent concerns expressed in the media. The effect of HFT is more pronounced on days when end of day price dislocation is more likely to be the result of market manipulation on days of option expiry dates and end of month. Moreover, the effect of HFT is more pronounced than the role of trading rules, surveillance, enforcement and legal conditions in curtailing the frequency and severity of end-of-day price dislocation. We show our findings are robust to different proxies of the start of HFT by trade size, cancellation of orders, and co-location.
We examine the impact of stock exchange trading rules and surveillance on the frequency and severity of suspected insider trading cases in 22 stock exchanges around the world over the period January 2003 through June 2011. Using new indices for market manipulation, insider trading, and broker-agency conflict based on the specific provisions of the trading rules of each stock exchange, along with surveillance to detect non-compliance with such rules, we show that more detailed exchange trading rules and surveillance over time and across markets significantly reduce the number of cases, but increase the profits per case.