| 1. |
- Jakobsson, Gerd, et al.
(författare)
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Heroin-Related Compounds and Metabolic Ratios in Postmortem Samples Using LC-MS-MS
- 2021
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Ingår i: Journal of Analytical Toxicology. - : Oxford University Press. - 0146-4760 .- 1945-2403. ; 45:3, s. 215-225
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Tidskriftsartikel (refereegranskat)abstract
- Analysis of postmortem samples with the presence of morphine can sometimes be challenging to interpret. Tolerance complicates interpretation of intoxications and causes of death due to overlap in therapeutic and fatal concentrations. Determination of metabolites and metabolic ratios can potentially differentiate between abstinence, continuous administration, and perhaps time of administration. The purpose of this study was to (a) develop and validate a method for quantitation of morphine-3 beta-D-glucuronide, morphine-6 beta-D-glucuronide, normorphine, codeine-6 beta-D-glucuronide, norcodeine, codeine, 6-acetylmorphine, and ethylmorphine in urine using liquid chromatography-tandem mass spectrometry; (b) apply the method to opiate related deaths; (c) compare metabolic ratios in urine in different causes of death (CoD) and after different drug intakes and (d) compare heroin intoxications in rapid and delayed deaths. Validation parameters such as precision, bias, matrix effects, stability, process efficiency, and dilution integrity were assessed and deemed acceptable. Lower limits of quantitation ranged from 0.01-0.2 mu g/mL for all analytes. Autopsy cases (n=135) with paired blood and urine samples were analyzed. Cases were divided into three groups based on CoD; opiate intoxication, intoxication with other drugs than opiates, and other CoD. The cases were classified by intake: codeine (n=42), heroin (n=36), morphine (n=49), and ethylmorphine (n=3). Five cases were classified as mixed intakes and excluded. Heroin intoxications (n=35) were divided into rapid (n=15) or delayed (n=20) deaths. Parent drug groups were compared using metabolic ratio morphine-3 beta-D-glucuronide/morphine and significant differences were observed between codeine vs morphine (p=0.005) and codeine vs heroin (p <= 0.0001). Urine and blood concentrations, and metabolic ratios in rapid and delayed heroin intoxications were compared and determined a significant difference for morphine (p=0.001), codeine (p=0.009), 6-acetylmorphine (p=0.02) in urine, and morphine (p=0.02) in blood, but there was no significant difference (p=0.9) between metabolic ratios. Morphine-3 beta-D-glucuronide results suggested a period of abstinence prior to death in 25% of the heroin intoxications.
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| 2. |
- Ablikim, M., et al.
(författare)
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Measurement of the Absolute Branching Fraction and Decay Asymmetry of Lambda -> n gamma
- 2022
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Ingår i: Physical Review Letters. - : American Physical Society (APS). - 0031-9007 .- 1079-7114. ; 129:21
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Tidskriftsartikel (refereegranskat)abstract
- The radiative hyperon decay Lambda -> n gamma is studied using (10087 +/- 44) x 10(6) J/psi. events collected with the BESIII detector operating at BEPCII. The absolute branching fraction of the decay Lambda -> n gamma is determined to be (0.832 +/- 0.038(stat) +/- 0.054(syst)) x 10(-3), which is a factor of 2.1 lower and 5.6 standard deviations different than the previous measurement. By analyzing the joint angular distribution of the decay products, the first determination of the decay asymmetry a. is reported with a value of -0.16 +/- 0.10(stat) +/- 0.05(syst).
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| 3. |
- Ablikim, M., et al.
(författare)
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Observation of J/ψ decays to e+e−e+e− and e+e−μ+μ−
- 2024
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Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 109:5
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 4. |
- Ablikim, M., et al.
(författare)
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Observation of the decay J/Ψ → e+e-η(1405) with η(1405) →†’ π0f0(980)
- 2024
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Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 109:1
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Tidskriftsartikel (refereegranskat)abstract
- Using a data sample of (10087 ± 44) x 106 J/ψ events collected by the BESIII detector in 2009, 2012, 2018 and 2019, the electromagnetic Dalitz process J/ψ → e+e-η(1405) is observed via the decay η(1405) → π0f0(980), f0(980) → π+π-, with a significance of about 9.8σ. The branching fraction of this decay is measured to be B(J/ψ → e+e−η(1405) → e+e−π0f0(980) → J/ψ→ e+e-η(1405) → e+e-π0f0(980) → e+e-π0π+ π-) = (2.04 ± 0.20(stat) ± 0.08(syst)) x 10-7. The branching fraction ratio B(J/ψ → e+e- η(1405))/B(J/ψ → γη(1405)) is determined to be (1.36 ± 0.17(stat) ± 0.06(syst)) x 10-2. Furthermore, an e+e- invariant mass dependent transition form factor of J/ψ → e+e-η(1405) is presented for the first time. The obtained result provides input for different theoretical models and is valuable for the improved understanding the intrinsic structure of the η(1405) meson.
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| 5. |
- Ablikim, M., et al.
(författare)
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Amplitude Analysis of D-s(+) -> pi(+)pi(0)eta and First Observation of the W-Annihilation Dominant Decays D-s(+) -> a(0)(980)(+)pi(0) and D-s(+) -> a(0)(980)(0)pi(+)
- 2019
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Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 123:11
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Tidskriftsartikel (refereegranskat)abstract
- We present the first amplitude analysis of the decay D-s(+) -> pi(+)pi(0)eta. We use an e(+)e(-) collision data sample corresponding to an integrated luminosity of 3.19 fb(-1) collected with the BESIII detector at a center-of-mass energy of 4.178 GeV. We observe for the first time the W-annihilation dominant decays D-s(+) -> a(0)(980)(+)pi(0) and D-s(+) -> a(0)(980)(0)pi(+). We measure the absolute branching fraction B(D-s(+) -> a(0)(980)(+(0))pi(0(+)), a(0)(980)(+(0)) -> pi(+(0)())eta = (1.46 +/- 0.15(stat )+/- 0.23 sys)%, which is larger than the branching fractions of other measured pure W-annihilation decays by at least one order of magnitude. In addition, we measure the branching fraction of D-s(+) -> pi(+)pi(0)eta with significantly improved precision.
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| 6. |
- Ablikim, M., et al.
(författare)
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Amplitude analysis of D-s(+) -> pi(+) pi(-) pi(+)
- 2022
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Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 106:11
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Tidskriftsartikel (refereegranskat)abstract
- Utilizing the data set corresponding to an integrated luminosity of 3.19 fb(-1) collected by the BESIII detector at a center-of-mass energy of 4.178 GeV, we perform an amplitude analysis of the D-s(+) -> pi(+) pi(-) pi(+) decay. The sample contains 13,797 candidates with a signal purity of similar to 80%. The amplitude and phase of the contributing pi pi S wave are measured based on a quasi-model-independent approach, along with the amplitudes and phases of the P and D waves parametrized by Breit-Wigner models. The fit fractions of different intermediate decay channels are also reported.
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| 7. |
- Ablikim, M., et al.
(författare)
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Amplitude analysis of the π$^0$π$^0$ system produced in radiative J/ψ decays
- 2016
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Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 93:3
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Tidskriftsartikel (refereegranskat)abstract
- An amplitude analysis of the π0π0 system produced in radiative J/ψ decays is presented. In particular, a piecewise function that describes the dynamics of the π0π0 system is determined as a function of Mπ0π0 from an analysis of the (1.311±0.011)×109 J/ψ decays collected by the BESIII detector. The goal of this analysis is to provide a description of the scalar and tensor components of the π0π0 system while making minimal assumptions about the properties or number of poles in the amplitude. Such a model-independent description allows one to integrate these results with other related results from complementary reactions in the development of phenomenological models, which can then be used to directly fit experimental data to obtain parameters of interest. The branching fraction of J/ψ→γπ0π0 is determined to be (1.15±0.05)×10-3, where the uncertainty is systematic only and the statistical uncertainty is negligible.
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| 8. |
- Ablikim, M., et al.
(författare)
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An improved limit for Gamma(ee) of X(3872) and Gamma(ee) measurement of psi(3686)
- 2015
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 749, s. 414-420
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Tidskriftsartikel (refereegranskat)abstract
- Using the data sets taken at center-of-mass energies above 4 GeV by the BESIII detector at the BEPCII storage ring, we search for the reaction e(+)e(-) -> gamma(ISR) X(3872) -> gamma(ISR)pi(+)pi(-) J/psi via the Initial State Radiation technique. The production of a resonance with quantum numbers J(PC) = 1(++) such as the X(3872) via single photon e(+)e(-) annihilation is forbidden, but is allowed by a next-to-leading order box diagram. We do not observe a significant signal of X(3872), and therefore give an upper limit for the electronic width times the branching fraction Gamma B-X(3872)(ee)(X(3872) -> pi(+)pi(-) J/psi) < 0.13 eVat the 90% confidence level. This measurement improves upon existing limits by a factor of 46. Using the same final state, we also measure the electronic width of the psi(3686) to be Gamma(psi)(ee)(3686) ee = 2213 +/- 18(stat) +/- 99(sys) eV.
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| 9. |
- Ablikim, M., et al.
(författare)
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Evidence for e+e−→γηc(1S) at center-of-mass energies between 4.01 and 4.60 GeV
- 2017
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Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:5
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Tidskriftsartikel (refereegranskat)abstract
- We present first evidence for the process e(+)e(-) -> gamma eta(c)(1S) at six center-of-mass energies between 4.01 and 4.60 GeV using data collected by the BESIII experiment operating at BEPCII. We measure the Born cross section at each energy using a combination of twelve eta(c)(1S) decay channels. We also combine all six energies under various assumptions for the energy-dependence of the cross section. If the process is assumed to proceed via the Y(4260), we measure a peak Born cross section sigma(peak)(e(+)e(-) -> gamma eta(c)(1S)) = 2.11 +/- 0.49 (stat.) +/- 0.36 (syst.) pb with a statistical significance of 4.2 sigma.
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| 10. |
- Ablikim, M., et al.
(författare)
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Inclusive charged and neutral particle multiplicity distributions in chi(cJ) and J/psi decays
- 2020
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 1550-7998 .- 1550-2368. ; 102:5
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Tidskriftsartikel (refereegranskat)abstract
- Using a sample of 106 million psi(3686) decays, psi(3686) -> gamma chi(cJ) (J = 0, 1, 2) and psi(3686) -> gamma chi(cJ), chi(cJ) -> gamma J/psi (J = 1, 2) events are utilized to study inclusive chi(cJ )-> anything, chi(cJ )-> hadrons, and J/psi( )-> anything distributions, including distributions of the number of charged tracks, electromagnetic calorimeter showers, and pi(0)s, and to compare them with distributions obtained from the BESIII Monte Carlo simulation. Information from each Monte Carlo simulated decay event is used to construct matrices connecting the detected distributions to the input predetection "produced" distributions. Assuming these matrices also apply to data, they are used to predict the analogous produced distributions of the decay events. Using these, the charged particle multiplicities are compared with results from MARK I. Further, comparison of the distributions of the number of photons in data with those in Monte Carlo simulation indicates that G-parity conservation should be taken into consideration in the simulation.
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