| 1. |
- Collaboration, The PANDA, et al.
(författare)
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Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR
- 2016
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Ingår i: European Physical Journal A. - : Springer Publishing Company. - 1434-6001 .- 1434-601X. ; 52:10
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Tidskriftsartikel (refereegranskat)abstract
- Simulation results for future measurements of electromagnetic proton form factors at P ¯ ANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel p¯ p→ e+e- is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e.p¯ p→ π+π-, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.
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| 2. |
- Singh, B., et al.
(författare)
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Feasibility study for the measurement of pi N transition distribution amplitudes at (P)over-barANDA in (P)over-barp -> J/psi pi(0)
- 2017
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 95:3
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Tidskriftsartikel (refereegranskat)abstract
- The exclusive charmonium production process in (P) over barp annihilation with an associated pi 0 meson (p) over barp -> J/psi pi(0) is studied in the framework of QCD collinear factorization. The feasibility of measuring this reaction through the J/psi -> e(+) e(-) decay channel with the AntiProton ANnihilation at DArmstadt ((P) over bar ANDA) experiment is investigated. Simulations on signal reconstruction efficiency as well as the background rejection from various sources including the (P) over barp -> pi(+)pi(-)pi(0) and (p) over barp -> J/psi pi(0)pi(0) reactions are performed with PANDAROOT, the simulation and analysis software framework of the (P) over bar ANDA experiment. It is shown that the measurement can be done at (P) over bar ANDA with significant constraining power under the assumption of an integrated luminosity attainable in four to five months of data taking at the maximum design luminosity.
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| 3. |
- Singh, B., et al.
(författare)
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Study of doubly strange systems using stored antiprotons
- 2016
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Ingår i: Nuclear Physics A. - : Elsevier. - 0375-9474 .- 1873-1554. ; 954, s. 323-340
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Tidskriftsartikel (refereegranskat)abstract
- Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the PANDA experiment at FAIR. For the first time, high resolution gamma-spectroscopy of doubly strange Lambda Lambda-hypernuclei will be performed, thus complementing measurements of ground state decays of Lambda Lambda-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Xi(-) -atoms will be feasible and even the production of Omega(-) -atoms will be within reach. The latter might open the door to the vertical bar S vertical bar = 3 world in strangeness nuclear physics, by the study of the hadronic Omega(-) -nucleus interaction. For the first time it will be possible to study the behavior of Xi(+) in nuclear systems under well controlled conditions.
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| 4. |
- Singh, B. P., et al.
(författare)
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Experimental access to Transition Distribution Amplitudes with the PANDA experiment at FAIR
- 2015
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Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 51:8
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Tidskriftsartikel (refereegranskat)abstract
- Baryon-to-meson Transition Distribution Amplitudes (TDAs) encoding valuable new information on hadron structure appear as building blocks in the collinear factorized description for several types of hard exclusive reactions. In this paper, we address the possibility of accessing nucleon-to-pion (pi N) TDAs from (p) over barp -> e(+)e(-)pi(0) reaction with the future PANDA detector at the FAIR facility. At high center-of-mass energy and high invariant mass squared of the lepton pair q(2), the amplitude of the signal channel (p) over barp -> e(+)e(-)pi(0) admits a QCD factorized description in terms of pi N TDAs and nucleon Distribution Amplitudes (DAs) in the forward aid backward kinematic regimes. Assuming the validity of this factorized description, we perform feasibility studies for measuring (p) over barp -> e(+)e(-)pi(0) with the PANDA detector. Detailed simulations on signal reconstruction efficiency as well as on rejection of the most severe background channel, i.e. (p) over barp -> pi(+)pi(-)pi(0) were performed for the center-of-mass energy squared s = 5 GeV2 and s = 10 GeV2, in the kinematic regions 3.0 < q(2) < 4.3 GeV2 and 5 < q(2) < 9 GeV2, respectively, with a neutral pion scattered in the forward or backward cone vertical bar cos theta(pi 0)vertical bar > 0.5 in the proton-antiproton center-of-mass frame. Results of the simulation show that the particle identification capabilities of the PANDA detector will allow to achieve a background rejection factor of 5 . 10(7) (1 . 10(7)) at low (high) q(2) for s = 5 GeV2, and of 1 . 10(8) (6 . 10(6)) at low (high) q(2) for s = 10 GeV2, while keeping the signal reconstruction efficiency at around 40%. At both energies, a clean lepton signal can be reconstructed with the expected statistics corresponding to 2 of integrated luminosity. The cross sections obtained from the simulations are used to show that a test of QCD collinear factorization can be done at the lowest order by measuring scaling laws and angular distributions. The future measurement of the signal channel cross section with PANDA will provide a new test of the perturbative QCD description of a novel class of hard exclusive reactions and will open the possibility of experimentally accessing pi N TDAs.
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| 5. |
- Akiba, K., et al.
(författare)
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LHC forward physics
- 2016
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Ingår i: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 43:11
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Tidskriftsartikel (refereegranskat)
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| 6. |
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| 7. |
- Bursill, D., et al.
(författare)
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Gout, Hyperuricaemia and Crystal-Associated Disease Network (G-CAN) consensus statement regarding labels and definitions of disease states of gout
- 2019
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 78:11, s. 1592-1600
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Tidskriftsartikel (refereegranskat)abstract
- Objective There is a lack of standardisation in the terminology used to describe gout. The aim of this project was to develop a consensus statement describing the recommended nomenclature for disease states of gout. Methods A content analysis of gout-related articles from rheumatology and general internal medicine journals published over a 5-year period identified potential disease states and the labels commonly assigned to them. Based on these findings, experts in gout were invited to participate in a Delphi exercise and face-to-face consensus meeting to reach agreement on disease state labels and definitions. Results The content analysis identified 13 unique disease states and a total of 63 unique labels. The Delphi exercise (n=76 respondents) and face-to-face meeting (n=35 attendees) established consensus agreement for eight disease state labels and definitions. The agreed labels were as follows: 'asymptomatic hyperuricaemia', 'asymptomatic monosodium urate crystal deposition', 'asymptomatic hyperuricaemia with monosodium urate crystal deposition', 'gout', 'tophaceous gout', 'erosive gout', 'first gout flare' and 'recurrent gout flares'. There was consensus agreement that the label 'gout' should be restricted to current or prior clinically evident disease caused by monosodium urate crystal deposition (gout flare, chronic gouty arthritis or subcutaneous tophus). Conclusion Consensus agreement has been established for the labels and definitions of eight gout disease states, including 'gout' itself. The Gout, Hyperuricaemia and Crystal-Associated Disease Network recommends the use of these labels when describing disease states of gout in research and clinical practice.
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| 8. |
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| 9. |
- Lammer, H., et al.
(författare)
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Geophysical and Atmospheric Evolution of Habitable Planets
- 2010
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Ingår i: Astrobiology. - : Mary Ann Liebert Inc. - 1531-1074 .- 1557-8070. ; 10:1, s. 45-68
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Tidskriftsartikel (refereegranskat)abstract
- The evolution of Earth-like habitable planets is a complex process that depends on the geodynamical and geophysical environments. In particular, it is necessary that plate tectonics remain active over billions of years. These geophysically active environments are strongly coupled to a planet's host star parameters, such as mass, luminosity and activity, orbit location of the habitable zone, and the planet's initial water inventory. Depending on the host star's radiation and particle flux evolution, the composition in the thermosphere, and the availability of an active magnetic dynamo, the atmospheres of Earth-like planets within their habitable zones are differently affected due to thermal and nonthermal escape processes. For some planets, strong atmospheric escape could even effect the stability of the atmosphere.
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| 10. |
- Marchesi, F, et al.
(författare)
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COVID-19 in adult acute myeloid leukemia patients: a long-term follow-up study from the European Hematology Association survey (EPICOVIDEHA)
- 2023
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Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 1592-8721 .- 0390-6078. ; 108:1, s. 22-33
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Tidskriftsartikel (refereegranskat)abstract
- Patients with acute myeloid leukemia (AML) are at high risk of dying from coronavirus disease 2019 (COVID-19). The optimal management of AML patients with COVID-19 has not been established. Our multicenter study included 388 adult AML patients diagnosed with COVID-19 between February 2020 and October 2021. The vast majority were receiving or had received AML treatment in the preceding 3 months. COVID-19 was severe in 41.2% and critical in 21.1% of cases. The chemotherapeutic schedule was modified in 174 patients (44.8%), delayed in 68 and permanently discontinued in 106. After a median follow-up of 325 days, 180 patients (46.4%) had died; death was attributed to COVID-19 (43.3%), AML (26.1%) or to a combination of both (26.7%), whereas in 3.9% of cases the reason was unknown. Active disease, older age, and treatment discontinuation were associated with death, whereas AML treatment delay was protective. Seventy-nine patients had a simultaneous AML and COVID-19 diagnosis, with better survival when AML treatment could be delayed (80%; P<0.001). Overall survival in patients with a diagnosis of COVID-19 between January 2020 and August 2020 was significantly lower than that in patients diagnosed between September 2020 and February 2021 and between March 2021 and September 2021 (39.8% vs. 60% vs. 61.9%, respectively; P=0.006). COVID-19 in AML patients was associated with a high mortality rate and modifications of therapeutic algorithms. The best approach to improve survival was to delay AML treatment, whenever possible.
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| 11. |
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| 12. |
- Cattaneo, C, et al.
(författare)
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Simultaneous Onset of Haematological Malignancy and COVID: An Epicovideha Survey
- 2022
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Ingår i: Cancers. - : MDPI AG. - 2072-6694. ; 14:22
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Tidskriftsartikel (refereegranskat)abstract
- Background: The outcome of patients with simultaneous diagnosis of haematological malignancies (HM) and COVID-19 is unknown and there are no specific treatment guidelines. Methods: We describe the clinical features and outcome of a cohort of 450 patients with simultaneous diagnosis of HM and COVID-19 registered in the EPICOVIDEHA registry between March 2020 to February 2022. Results: Acute leukaemia and lymphoma were the most frequent HM (35.8% and 35.1%, respectively). Overall, 343 (76.2%) patients received treatment for HM, which was delayed for longer than one month since diagnosis in 57 (16.6%). An overall response rate was observed in 140 (40.8%) patients after the first line of treatment. After a median follow-up of 35 days, overall mortality was 177/450 (39.3%); 30-day mortality was significantly higher in patients not receiving HM treatment (42.1%) than in those receiving treatment (27.4%, p = 0.004), either before and/or after COVID-19, or compared to patients receiving HM treatment at least after COVID-19 (15.2%, p < 0.001). Age, severe/critical COVID-19, ≥2 comorbidities, and lack of HM treatment were independent risk factors for mortality, whereas a lymphocyte count >500/mcl at COVID-19 onset was protective. Conclusions: HM treatment should be delivered as soon as possible for patients with simultaneous diagnosis of COVID-19 and HM requiring immediate therapy.
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| 13. |
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| 14. |
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| 15. |
- Olsson, MIT, et al.
(författare)
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Gender Gap in Parental Leave Intentions : Evidence from 37 Countries
- 2023
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Ingår i: Political Psychology. - : Wiley-Blackwell Publishing Ltd. - 0162-895X .- 1467-9221. ; 44:6, s. 1163-1192
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Tidskriftsartikel (refereegranskat)abstract
- Despite global commitments and efforts, a gender-based division of paid and unpaid work persists. To identify how psychological factors, national policies, and the broader sociocultural context contribute to this inequality, we assessed parental-leave intentions in young adults (18–30 years old) planning to have children (N = 13,942; 8,880 identified as women; 5,062 identified as men) across 37 countries that varied in parental-leave policies and societal gender equality. In all countries, women intended to take longer leave than men. National parental-leave policies and women's political representation partially explained cross-national variations in the gender gap. Gender gaps in leave intentions were paradoxically larger in countries with more gender-egalitarian parental-leave policies (i.e., longer leave available to both fathers and mothers). Interestingly, this cross-national variation in the gender gap was driven by cross-national variations in women's (rather than men's) leave intentions. Financially generous leave and gender-egalitarian policies (linked to men's higher uptake in prior research) were not associated with leave intentions in men. Rather, men's leave intentions were related to their individual gender attitudes. Leave intentions were inversely related to career ambitions. The potential for existing policies to foster gender equality in paid and unpaid work is discussed.
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| 16. |
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| 17. |
- Bursill, D., et al.
(författare)
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Gout, Hyperuricemia, and Crystal-Associated Disease Network Consensus Statement Regarding Labels and Definitions for Disease Elements in Gout
- 2019
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Ingår i: Arthritis Care & Research. - : Wiley. - 2151-464X. ; 71:3, s. 427-434
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Tidskriftsartikel (refereegranskat)abstract
- Objective The language currently used to describe gout lacks standardization. The aim of this project was to develop a consensus statement on the labels and definitions used to describe the basic disease elements of gout. Methods Experts in gout (n = 130) were invited to participate in a Delphi exercise and face-to-face consensus meeting to reach consensus on the labeling and definitions for the basic disease elements of gout. Disease elements and labels in current use were derived from a content analysis of the contemporary medical literature, and the results of this analysis were used for item selection in the Delphi exercise and face-to-face consensus meeting. Results There were 51 respondents to the Delphi exercise and 30 attendees at the face-to-face meeting. Consensus agreement (>= 80%) was achieved for the labels of 8 disease elements through the Delphi exercise; the remaining 3 labels reached consensus agreement through the face-to-face consensus meeting. The agreed labels were monosodium urate crystals, urate, hyperuric(a)emia, tophus, subcutaneous tophus, gout flare, intercritical gout, chronic gouty arthritis, imaging evidence of monosodium urate crystal deposition, gouty bone erosion, and podagra. Participants at the face-to-face meeting achieved consensus agreement for the definitions of all 11 elements and a recommendation that the label "chronic gout" should not be used. Conclusion Consensus agreement was achieved for the labels and definitions of 11 elements representing the fundamental components of gout etiology, pathophysiology, and clinical presentation. The Gout, Hyperuricemia, and Crystal-Associated Disease Network recommends the use of these labels when describing the basic disease elements of gout.
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| 18. |
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| 19. |
- Varela, AR, et al.
(författare)
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Status and Trends of Physical Activity Surveillance, Policy, and Research in 164 Countries: Findings From the Global Observatory for Physical Activity-GoPA! 2015 and 2020 Surveys
- 2023
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Ingår i: Journal of physical activity & health. - : Human Kinetics. - 1543-5474 .- 1543-3080. ; 20:2, s. 112-128
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Tidskriftsartikel (refereegranskat)abstract
- Background: Physical activity (PA) surveillance, policy, and research efforts need to be periodically appraised to gain insight into national and global capacities for PA promotion. The aim of this paper was to assess the status and trends in PA surveillance, policy, and research in 164 countries. Methods: We used data from the Global Observatory for Physical Activity (GoPA!) 2015 and 2020 surveys. Comprehensive searches were performed for each country to determine the level of development of their PA surveillance, policy, and research, and the findings were verified by the GoPA! Country Contacts. Trends were analyzed based on the data available for both survey years. Results: The global 5-year progress in all 3 indicators was modest, with most countries either improving or staying at the same level. PA surveillance, policy, and research improved or remained at a high level in 48.1%, 40.6%, and 42.1% of the countries, respectively. PA surveillance, policy, and research scores decreased or remained at a low level in 8.3%, 15.8%, and 28.6% of the countries, respectively. The highest capacity for PA promotion was found in Europe, the lowest in Africa and low- and lower-middle-income countries. Although a large percentage of the world’s population benefit from at least some PA policy, surveillance, and research efforts in their countries, 49.6 million people are without PA surveillance, 629.4 million people are without PA policy, and 108.7 million live in countries without any PA research output. A total of 6.3 billion people or 88.2% of the world’s population live in countries where PA promotion capacity should be significantly improved. Conclusion: Despite PA is essential for health, there are large inequalities between countries and world regions in their capacity to promote PA. Coordinated efforts are needed to reduce the inequalities and improve the global capacity for PA promotion.
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| 20. |
- Ablikim, M., et al.
(författare)
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Determination of Strong-Phase Parameters in D -> K-S,L(0)pi(+)pi(-)
- 2020
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Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 124:24
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Tidskriftsartikel (refereegranskat)abstract
- We report the most precise measurements to date of the strong-phase parameters between D-0 and (D) over bar (0) decays to K-S,L(0)pi(+)pi(-) using a sample of 2.93 fb(-1) of e(+) e(-) annihilation data collected at a center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider. Our results provide the key inputs for a binned model-independent determination of the Cabibbo-Kobayashi-Maskawa angle gamma/phi(3) with B decays. Using our results, the decay model sensitivity to the gamma/phi(3 )measurement is expected to be between 0.7 degrees and 1.2 degrees, approximately a factor of three smaller than that achievable with previous measurements, based on the studies of the simulated data. The improved precision of this work ensures that measurements of gamma/phi(3) will not be limited by knowledge of strong phases for the next decade. Furthermore, our results provide critical input for other flavor-physics investigations, including charm mixing, other measurements of CP violation, and the measurement of strong-phase parameters for other D-decay modes.
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| 21. |
- Ablikim, M., et al.
(författare)
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Measurement of cross section for e(+)e(-) -> Xi(-)(Xi)over-bar(+) near threshold at BESIII
- 2021
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Ingår i: Physical Review D. - COLLEGE PK, MD USA : American Physical Society. - 2470-0010 .- 2470-0029. ; 103:1
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Tidskriftsartikel (refereegranskat)abstract
- The Born cross sections and effective form factors for process e(+)e(-) -> Xi(-)(Xi) over bar (+) are measured at eight center-of-mass energies between 2.644 and 3.080 GeV, using a total integrated luminosity of 363.9 pb(-1 )e(+) e(-) collision data collected with the BESIII detector at BEPCII. After performing a fit to the Born cross section of e(+)e(-) -> Xi(-)(Xi) over bar (+), no significant threshold effect is observed.
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| 22. |
- Ablikim, M., et al.
(författare)
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Model-independent determination of the relative strong-phase difference between D-0 and (D)over-bar(0) -> K-S,L(0)pi(+)pi(-) and its impact on the measurement of the CKM angle gamma/phi(3)
- 2020
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 1550-7998 .- 1550-2368. ; 101:11
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Tidskriftsartikel (refereegranskat)abstract
- Crucial inputs for a variety of CP-violation studies can be determined through the analysis of pairs of quantum-entangled neutral D mesons, which are produced in the decay of the psi(3770) resonance. The relative strong-phase parameters between D-0 and (D) over bar (0) in the decays D-0 -> K-S,L(0)pi(+)pi(-) are studied using 2.93 fb(-1) of e(+)e(-) annihilation data delivered by the BEPCII collider and collected by the BESIII detector at a center-of-mass energy of 3.773 GeV. Results are presented in regions of the phase space of the decay. These are the most precise measurements to date of the strong-phase parameters in D-0 -> K-S,L(0)pi(+)pi(-) decays. Using these parameters, the associated uncertainty on the Cabibbo-Kobayashi-Maskawa angle gamma/phi(3) is expected to be between 0.7 degrees and 1.2 degrees for an analysis using the decay B-+/- -> DK +/-, D -> K-S(0)pi(+)pi(-), where D represents a superposition of D-0 and (D) over bar (0) states. This is a factor of 3 smaller than that achievable with previous measurements. Furthermore, these results provide valuable input for charm-mixing studies, other measurements of CP violation, and the measurement of strong-phase parameters for other D-decay modes.
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| 23. |
- Ablikim, M., et al.
(författare)
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Observation of a resonant structure in e(+)e(-)-> omega eta and another in e(+)e(-)-> omega pi(0) at center-of-mass energies between 2.00 and 3.08 GeV
- 2021
-
Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 813
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Tidskriftsartikel (refereegranskat)abstract
- Born cross sections for the processes e(+)e(-) -> omega eta and e(+)e(-) -> omega pi(0) have been determined for centerof-mass energies between 2.00 and 3.08GeVwith the BESIII detector at the BEPCII collider. The results obtained in this work are consistent with previous measurements but with improved precision. Two resonant structures are observed. In the e(+)e(-) -> omega eta cross sections, a resonance with a mass of (2176 +/- 24 +/- 3) MeV/c(2) and a width of (89 +/- 50 +/- 5) MeV is observed with a significance of 6.2 sigma. Its properties are consistent with the phi(2170). In the e(+)e(-) -> omega pi(0) cross sections, a resonance denoted Y (2040) is observed with a significance of more than 10 sigma. Its mass and width are determined to be (2034 +/- 13 +/- 9) MeV/c(2) and (234 +/- 30 +/- 25) MeV, respectively, where the first uncertainties are statistical and the second ones are systematic. (C) 2020 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license.
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| 24. |
- Ablikim, M., et al.
(författare)
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Observation of the double Dalitz decay eta' -> e(+)e(-)e(+)e(-)
- 2022
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Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 105:11
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Tidskriftsartikel (refereegranskat)abstract
- Based on (0087 +/- 44) x 10(6) J/psi events collected with the BESIII detector at BEPCII, the double Dalitz decay eta' -> e(+)e(-)e(+)e(-) is observed for the first time via the J/psi -> gamma eta' decay process. The significance is found to be 5.7s with systematic uncertainties taken into consideration. Its branching fraction is determined to be B(eta' -> e(+)e(-)e(+)e(-)) = (4.5 +/- 1.0(stat) +/- 0.5(sys)) x 10(-6).
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| 25. |
- Ablikim, M., et al.
(författare)
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Observation of the Leptonic Decay D+ -> T+ Yr
- 2019
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Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 123:21
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Tidskriftsartikel (refereegranskat)abstract
- We report the first observation of D+ -> tau(+) nu(tau), with a significance of 5.1 sigma. We measure beta(D+ tau+nu(tau)) = (1.20 0.12S)t) x 10-3. Taking the world average B(D- /./ v) = (3.74 0.17) x 10-4, we obtain R=ire=1-4(0 rlyr)/F(T) y p = 3.21 0.64,tat 0.43,9,,., which is consistent with the standard model expectation of lepton flavor universality. Using external inputs, our results give values for the Tr decay constant fn. and the Cabibbo-Kobayashi-Maskawa matrix element V,r that are consistent with, but less precise than, other determinations.
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| 26. |
- Ablikim, M., et al.
(författare)
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Search for the X (2370) and observation of eta(c) -> eta eta eta ' in J/psi -> gamma eta eta eta '
- 2021
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Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 103:1
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Tidskriftsartikel (refereegranskat)abstract
- Using a sample of 1.31 x 10(9) J/psi events collected with the BESIII detector, we perform a study of J/psi -> gamma eta eta eta' to search for the X(2370) and eta(c) in the eta eta eta' invariant mass distribution. No significant signal for the X(2370) is observed, and we set an upper limit for the product branching fraction of B(J/psi -> gamma X(2370) . B(X(2370) -> eta eta eta') < 9.2 x 10(-6) at the 90% confidence level. A clear eta(c) signal is observed for the first time, yielding a product branching fraction of B(J/psi -> gamma eta(c)).B(eta c -> eta eta eta') = (4.86 +/- 0.62(stat) +/- 0.45(sys)) x 10(-5).
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| 27. |
- Ablikim, M., et al.
(författare)
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Study of e(+)e(-) -> D+D-pi(+)pi(-) at center-of-mass energies from 4.36 to 4.60 GeV
- 2020
-
Ingår i: Physics Letters B. - : ELSEVIER. - 0370-2693 .- 1873-2445. ; 804
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Tidskriftsartikel (refereegranskat)abstract
- We report a study of the e(+)e(-) -> D+D-pi(+)pi(-) process using e(+)e(-) collision data samples with an integrated luminosity of 2.5 fb(-1) at center-of-mass energies from 4.36 to 4.60 GeV, collected with the BESIII detector at the BEPCII storage ring. The D1(2420)+ is observed in the D+pi(+)pi(-) mass spectrum. The mass and width of the D-1(2420)+ are measured to be (2427.2 +/- 1.0(stat).+/- 1.2(syst).) MeV/c(2) and (23.2 +/- 2.3(stat). +/- 2.3(syst).) MeV, respectively. In addition, the Born cross sections of the e(+)e(-) -> D-1(2420)D-+(-) + c.c. -> D+D-pi(+)pi(-) and e(+)e(-) -> psi(3770)pi(+)pi(-) -> D+D-pi(+)pi(-) processes are measured as a function of the center-of-mass energy. (c) 2020 The Author. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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| 28. |
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| 29. |
- Ablikim, M., et al.
(författare)
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Search for the decay eta ' -> gamma gamma eta (Search for the decay η′→γγη)
- 2019
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 100:5
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Tidskriftsartikel (refereegranskat)abstract
- Using a data sample of 1.31 x 10(9) J/psi events collected with the BESIII detector, a search for eta' -> gamma gamma eta via J/psi ->gamma eta' is performed for the first time. No significant eta' signal is observed in the gamma gamma eta invariant mass spectrum, and the branching fraction of eta' -> gamma gamma eta is determined to be less than 1.33 x 10(-4) at the 90% confidence level.
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| 30. |
- Ablikim, M., et al.
(författare)
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Amplitude analysis and branching fraction measurement of Ds+ → K+K-π
- 2021
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Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:1
-
Tidskriftsartikel (refereegranskat)abstract
- We report an amplitude analysis and branching fraction measurement of D-s(+) -> K+K-pi(+) decay using a data sample of 3.19 fb(-1) recorded with BESIII detector at a center-of-mass energy of 4.178 GeV. We perform a model-independent partial wave analysis in the low K+K- mass region to determine the K+K- S-wave line shape, followed by an amplitude analysis of our very pure high-statistics sample. With the detection efficiency based on the amplitude analysis results, the absolute branching fraction is measured to be B(D-s(+) -> K+K-pi(+)) = (5.47 +/- 0.08(stat) +/- 0.13(sys))%.
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| 31. |
- Ablikim, M., et al.
(författare)
-
Amplitude analysis of D+-> K-S(0)pi(+)pi(+)pi(-)
- 2019
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 100:7
-
Tidskriftsartikel (refereegranskat)abstract
- The decay D+-> K-S(0)pi(+)pi(+)pi(-) is studied with an amplitude analysis using a data set of 2.93 fb(-1) of e(+)e(-) collisions at the psi(3770) peak accumulated by the BESIII detector. Intermediate states and nonresonant components, and their relative fractions and phases, have been determined. The significant amplitudes, which contribute to the model that best fits the data, are composed of five quasitwo-body decays K(S)(0)a(1)(1260)(+), (K) over bar (1)(1270)(0)pi(+) (K) over bar (1)(1400)(0)pi(+), (K) over bar (1)(1650)(0)pi(+), and (K) over bar (1460)(0)pi(+), a three-body decay K-S(0)pi(+)rho(0), as well as a nonresonant component K-S(0)pi(+)pi(+)pi(-). The dominant amplitude is K(S)(0)a(1)(1260)(+), with a fit fraction of (40.3 +/- 2.1 +/- 2.9)%, where the first and second uncertainties are statistical and systematic, respectively.
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| 32. |
- Ablikim, M., et al.
(författare)
-
Complete Measurement of the Λ Electromagnetic Form Factors
- 2019
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 123:12
-
Tidskriftsartikel (refereegranskat)abstract
- The exclusive process e(+)e(-) -> Lambda(Lambda) over bar, with Lambda -> p pi(-) and (Lambda) over bar -> (p) over bar pi(+), has been studied at root s = 2.396 GeV for measurement of the timelike Lambda electric and magnetic form factors, G(E) and G(M). A data sample, corresponding to an integrated luminosity of 66.9 pb(-1), was collected with the BESIII detector for this purpose. A multidimensional analysis with a complete decomposition of the spin structure of the reaction enables a determination of the modulus of the ratio R = vertical bar G(E)/G(M)vertical bar and, for the first time for any baryon, the relative phase Delta Phi = Phi(E) - Phi(M). The resulting values are R = 0.96 +/- 0.14(stat) +/- 0.02(syst) and Phi(F) = 37 degrees +/- 12 degrees (stat) +/- 6 degrees (syst), respectively. These are obtained using the recently established and most precise value of the asymmetry parameter alpha(Lambda) = 0.750 +/- 0.010 measured by BESIII. In addition, the cross section is measured with unprecedented precision to be sigma = 118.7 +/- 5.3(stat) +/- 5.1(syst) pb, which corresponds to an effective form factor of vertical bar G vertical bar = 0.123 +/- 0.003(stat) +/- 0.003(syst). The contribution from two-photon exchange is found to be negligible. Our result enables the first complete determination of baryon timelike electromagnetic form factors.
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| 33. |
- Ablikim, M., et al.
(författare)
-
Cross section measurement of e(+) e(-) -> eta ' J/psi from root S=4.178 to 4.600 GeV
- 2020
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 101:1
-
Tidskriftsartikel (refereegranskat)abstract
- The cross section of the process e(+) e(-) -> eta ' J/ psi is measured at center-of-mass (c.m.) energies from root S = 4.178 to 4.600 GeV using data samples corresponding to a total integrated luminosity of 11 fb(-1) collected with the BESIII detector operating at the BEPCII storage ring. The dependence of the cross section on root S shows an enhancement around 4.2 GeV. While the shape of the cross section cannot be fully explained with a single psi(4160) or psi(4260) state, a coherent sum of the two states does provide a reasonable description of the data.
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| 34. |
- Ablikim, M., et al.
(författare)
-
Cross section measurement of e(+)e(-) -> (KSKL0)-K-0 at root s=2.00-3.08 GeV
- 2021
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:9
-
Tidskriftsartikel (refereegranskat)abstract
- The cross sections of the process e(+)e(-) -> (KSKL0)-K-0 are measured at fifteen center-of-mass energies root s from 2.00 to 3.08 GeV with a total integrated luminosity of 582 pb(-1) and using the BESIII detector at the Beijing Electron Positron Collider. The results are found to be consistent with those obtained by BABAR. A resonant structure around 2.2 GeV is observed, with a mass and width of 2273.7 +/- 5.7 +/- 19.3 MeV/c(2) and 86 +/- 44 +/- 51 MeV, respectively, where the first uncertainties are statistical and the second ones are systematic. The product of its radiative width (Gamma(e+e-)) with its branching fraction to (KSKL0)-K-0 (Br-KS0KL0) is 0.9 +/- 0.6 +/- 0.7 eV.
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| 35. |
- Ablikim, M., et al.
(författare)
-
Cross section measurement of e(+)e(-) -> p(p)over-bar eta and e(+)e(-) -> p(p)over-bar omega at center-of-mass energies between 3.773 GeV and 4.6 GeV
- 2021
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:9
-
Tidskriftsartikel (refereegranskat)abstract
- Based on 14.7 fb(-1) of e(+)e(-) annihilation data collected with the BESIII detector at the BEPCII collider at 17 different center-of-mass energies between 3.7730 GeV and 4.5995 GeV, Born cross sections of the two processes e(+)e(-) -> p (p) over bar eta and e(+)e(-) -> p (p) over bar omega are measured for the first time. No indication of resonant production through a vector state V is observed, and upper limits on the Born cross sections of e(+)e(-) -> p (p) over bar eta and e(+)e(-) -> p (p) over bar omega at the 90% confidence level are calculated for a large parameter space in resonance masses and widths. For the current world average parameters of the psi(4230) of m = 4.2187 GeV=c(2) and Gamma = 44 MeV, we find upper limits on resonant production of the p (p) over bar eta and p (p) over bar omega final states of 7.5 pb and 10.4 pb at the 90% CL, respectively.
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| 36. |
- Ablikim, M., et al.
(författare)
-
Cross section measurements of e+e- -> K+ K- K+ K- and ΦK+ K- at center-of-mass energies from 2.10 to 3.08 GeV
- 2019
-
Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 100:3
-
Tidskriftsartikel (refereegranskat)abstract
- We measure the Born cross sections of the process e(+)e(-) -> K+ K- K+ K- at center-of-mass (c.m.) energies, root s, between 2.100 and 3.080 GeV. The data were collected using the BESIII detector at the BEPCII collider. An enhancement at root s = 2.232 GeV is observed, very close to the e(+)e(-) -> Lambda(Lambda) over bar production threshold. A similar enhancement at the same c.m. energy is observed in the e(+)e(-) -> phi K+ K- cross section. The energy dependence of the K+ K- K+ K- and phi K+ K- cross sections differs significantly from that of e(+)e(-) -> phi pi(+)pi(-).
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| 37. |
- Ablikim, M., et al.
(författare)
-
Cross section measurements of e(+) e(-) -> omega chi(c0) from root s=4.178 to 4.278 GeV
- 2019
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 99:9
-
Tidskriftsartikel (refereegranskat)abstract
- The cross section of the process e(+)e(-) -> omega chi(C0) is measured at center -of -mass energies from root s = 4.178 to 4.278 GeV using a data sample of 7 fb(-1) collected with the BESIII detector operating at the BEPCII storage ring. The dependence of the cross section on root s shows a resonant structure with mass of (4218.5 +/- 1.6(stat) +/- 4.0(syst)) MeV/c(2) and width of (28.2 +/- 3.9(stat) +/- 1.6(syst)) MeV, respectively. This observation confirms and improves upon the result of a previous study. The angular distribution of the e(+) e(-) ->omega chi(C0) process is extracted for the first time.
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| 38. |
- Ablikim, M., et al.
(författare)
-
Direct Measurement of the Branching Fractions B(psi(3686) -> J/psi X) and B(psi(3770) -> J/psi X), and Observation of the State R(3760) in e(+)e(-) -> J/psi X
- 2021
-
Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 127:8
-
Tidskriftsartikel (refereegranskat)abstract
- We report a measurement of the observed cross sections of e(+)e(-) -> J/psi X based on 3.21 fb(-1) of data accumulated at energies from 3.645 to 3.891 GeV with the BESIII detector operated at the BEPCII collider. In analysis of the cross sections, we measured the decay branching fractions of B(psi(3686 -> J/psi X) = (64.4 +/- 0.6 +/- 1.6)% and B(psi(3770) -> J/psi X) = (0.5 +/- 0.2 +/- 0.1)% for the first time. The energy-dependent line shape of these cross sections cannot be well described by two Breit-Wigner (BW) amplitudes of the expected decays psi(3686) -> J/psi X and psi(3770) -> J/psi X. Instead, it can be better described with one more BW amplitude of the decay R(3760) -> J/psi X. Under this assumption, we extracted the R(3760) mass M-R(3760) = 3766.2 +/- 3.8 +/- 0.4 MeV/c(2), total width Gamma(tot)(R(3760)) = 22.2 +/- 5.9 +/- 1.4 MeV, and product of leptonic width and decay branching fraction Gamma(ee)(R(3760)) B[R(3760) -> J/psi X] = (79.4 +/- 85.5 +/- 11.7) eV. The significance of the R(3760) is 5.3 sigma. The first uncertainties of these measured quantities are from fits to the cross sections and second systematic.
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| 39. |
- Ablikim, M., et al.
(författare)
-
First measurements of χcJ→Σ−¯Σ+(J=0,1,2) decays
- 2020
-
Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 101:9
-
Tidskriftsartikel (refereegranskat)abstract
- We measured the branching fractions of the decays chi(cJ) -> Sigma(-)(Sigma) over bar (+) for the first time using the final states n (n) over bar pi(+)pi(-). The data sample exploited here is 448.1 x 10(6) psi(3686) events collected with BESIII. We find B(chi(cJ) -> Sigma(-)(Sigma) over bar (+)) = (51.3 +/- 2.4 +/- 4.1) x 10(-5), (5.7 +/- 1.4 +/- 0.6) x 10(-5), and (4.4 +/- 1.7 +/- 0.5) x 10(-5), for J = 0, 1, 2, respectively, where the first uncertainties are statistical and the second systematic.
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| 40. |
- Ablikim, M., et al.
(författare)
-
First Observation of D+ -> eta mu(+)nu(mu) and Measurement of Its Decay Dynamics
- 2020
-
Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 124:23
-
Tidskriftsartikel (refereegranskat)abstract
- By analyzing a data sample corresponding to an integrated luminosity of 2.93 fb(-1) collected at a center-of-mass energy of 3.773 GeV with the BESIII detector, we measure for the first time the absolute branching fraction of the D+ -> eta mu(+) nu(mu) decay to be BD+ ->eta mu+nu mu = (10.4 +/- 1.0(stat) +/- 0.5(syst)) x 10(-4). Using the world averaged value of BD+ ->eta e+nu e, the ratio of the two branching fractions is determined to be = BD+ ->eta mu+nu mu/BD+ ->eta e+nu e =0.91 +/- 0.13((stat+syst)), which agrees with the theoretical expectation of lepton flavor universality within uncertainty. By studying the differential decay rates in five four-momentum transfer intervals, we obtain the product of the hadronic form factor f(+)(eta)(0) and the c -> d Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-cd vertical bar to be f(+)(eta)(0)vertical bar V-cd vertical bar = 0.087 +/- 0.008(stat) +/- 0.002(syst). Taking the input of vertical bar V-cd vertical bar from the global fit in the standard model, we determine f(+)(eta)(0) = 0.39 +/- 0.04(stat) +/- 0.01(syst). On the other hand, using the value of f(+)(eta)(0) calculated in theory, we find vertical bar V-cd vertical bar= 0.242 +/- 0.022(stat )+/- 0.006(syst) +/- 0.033(theory).
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| 41. |
- Ablikim, M., et al.
(författare)
-
First observation of the decay chi(cJ) -> Sigma(+)(p)over-barK(S)(0)+ c.c. (J=0,1,2)
- 2019
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 100:9
-
Tidskriftsartikel (refereegranskat)abstract
- Using E1 radiative transitions psi(3686) -> gamma chi(cJ) from a sample of (448.1 +/- 2.9) x 10(6) psi(3686) events collected with the BESIII detector, the decays chi(cJ) -> Sigma(+)(p) over barK(S)(0) + c.c.(J = 0,1,2) are studied. The decay branching fractions are measured to be B(chi(c0) -> Sigma(+)(p) over barK(S)(0) + c.c.) = (3.52 +/- 0.19 +/- 0.21) x 10(-4), B(chi(c1) -> Sigma(+)(p) over barK(S)(0) + c.c.) = (1.53 +/- 0.10 +/- 0.08) x 10(-4), and B(chi(c2) -> Sigma(+)(p) over barK(S)(0) + c.c.) = (8.25 +/- 0.83 +/- 0.49) x 10(-5), where the first and second uncertainties are the statistical and systematic ones, respectively. No evident intermediate resonances arc observed in the studied processes.
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| 42. |
- Ablikim, M., et al.
(författare)
-
First Observation of the Direct Production of the χc1 in e+e− Annihilation
- 2022
-
Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 129:12
-
Tidskriftsartikel (refereegranskat)abstract
- We study the direct production of the JPC=1++ charmonium state χc1(1P) in electron-positron annihilation by carrying out an energy scan around the mass of the χc1(1P). The data were collected with the BESIII detector at the BEPCII collider. An interference pattern between the signal process e+e−→χc1(1P)→γJ/ψ→γμ+μ− and the background processes e+e−→γISRJ/ψ→γISRμ+μ− and e+e−→γISRμ+μ− is observed by combining all the data samples. The χc1(1P) signal is observed with a significance of 5.1σ. This is the first observation of a C-even state directly produced in e+e− annihilation. The electronic width of the χc1(1P) resonance is determined to be Γee=(0.12+0.13−0.08) eV, which is of the same order of magnitude as theoretical calculations.
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| 43. |
- Ablikim, M., et al.
(författare)
-
First observations of h(c )-> hadrons
- 2019
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 99:7
-
Tidskriftsartikel (refereegranskat)abstract
- Based on (4.48 +/- 0.03) x 10(8) Psi(3686) events, collected with the BESIII detector at the BEPCII storage ring, five h(c) hadronic decays are searched for via the process Psi(3686) -> pi(0)h(c). Three of them, h(c) -> p (p) over bar pi(+)pi(-) , pi(+)pi(-)pi(0 )and 2(pi(+)pi(-))pi(0) are observed for the first time with significances of 7.4 sigma, 4.6 sigma, and 9.1 sigma, and their branching fractions are determined to be (2.89 +/- 0.32 +/- 0.55) x 10(-3), (1.60 +/- 0.40 +/- 0.32) x 10(-3), and (7.44 +/- 0.94 +/- 1.52) x 10(-3), respectively, where the first uncertainties are statistical and the second systematic. No significant signal is observed for the other two decay modes, and the corresponding upper limits of the branching fractions are determined to be B(h(c) -> 3(pi(+)pi(-))pi(0)) < 8.7 x 10(-3) and B(h(c) -> K+K-pi(+)pi(-) ) < 5.8 x 10(-4) at the 90% confidence level.
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| 44. |
- Ablikim, M., et al.
(författare)
-
Future Physics Programme of BESIII *
- 2020
-
Ingår i: Chinese Physics C. - : IOP Publishing. - 1674-1137 .- 2058-6132. ; 44:4
-
Tidskriftsartikel (refereegranskat)abstract
- There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESIII and B factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related X(1835) meson state at BESIII, as well as the threshold measurements of charm mesons and charm baryons. We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESIII during the remaining operation period of BEPCII. This survey will help in the optimization of the data-taking plan over the coming years, and provides physics motivation for the possible upgrade of BEPCII to higher luminosity.
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| 45. |
- Ablikim, M., et al.
(författare)
-
Improved measurements of the absolute branching fractions of the inclusive decays D+(0) -> phi X
- 2019
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 100:7
-
Tidskriftsartikel (refereegranskat)abstract
- By analyzing 2.93 fb(-1) of e(+)e(-) annihilation data taken at the center-of-mass energy root s = 3.773 GeV with the BESIII detector, we determine the branching fractions of the inclusive decays D+-> phi X and D-0 -> phi X to be (1.135 +/- 0.034 +/- 0.031)% and (1.091 +/- 0.027 +/- 0.035)%, respectively, where X denotes any possible particle combination. The first uncertainties are statistical, and the second are systematic. We also determine the branching fractions of the decays D -> phi X and their charge conjugate modes (D) over bar -> phi(X) over bar separately for the first time, and no significant CP asymmetry is observed.
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| 46. |
- Ablikim, M., et al.
(författare)
-
Improved model-independent determination of the strong-phase difference between D0 and ¯D0→K0S,LK+K− decays
- 2020
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 1550-7998 .- 1550-2368. ; 102:5
-
Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the strong-phase difference between D-0 and (D) over bar (0) -> (KS,LK+K-)-K-0 decays, performed through a study of quantum-entangled pairs of charm mesons. The measurement exploits a data sample equivalent to an integrated luminosity of 2.93 fb(-1), collected by the BESIII detector in e(+)e(-) collisions corresponding to the mass of the psi(3770) resonance. The strong-phase difference is an essential input to the determination of the Cabibbo-Kobayashi-Maskawa (CKM) angle gamma/phi(3) through the decay B- -> DK-, where D can be either a D-0 or a (D) over bar (0) decaying to (KS,LK+K-)-K-0. This is the most precise measurement to date of the strong-phase difference in these decays.
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| 47. |
- Ablikim, M., et al.
(författare)
-
Inclusive charged and neutral particle multiplicity distributions in chi(cJ) and J/psi decays
- 2020
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 1550-7998 .- 1550-2368. ; 102:5
-
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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| 48. |
- Ablikim, M., et al.
(författare)
-
Measurement of branching fractions for D meson decaying into phi meson and a pseudoscalar meson
- 2019
-
Ingår i: Physics Letters B. - : ELSEVIER. - 0370-2693 .- 1873-2445. ; 798
-
Tidskriftsartikel (refereegranskat)abstract
- The four decay modes D-0 -> phi pi(0), D-0 -> phi eta, D+ -> phi pi(+), and D+ up arrow phi K+ are studied by using a data sample taken at the centre-of-mass energy root s = 3.773 GeVwith the BESIII detector, corresponding to an integrated luminosity of 2.93 fb(-1). The branching fractions of the first three decay modes are measured to be B(D-0 -> phi pi(0)) = (1.168 +/- 0.028 +/- 0.028) x 10(-3), B(D-0 -> phi eta) = (1.81 +/- 0.46 +/- 0.06) x 10(-4), and B(D+ -> phi pi(+)) = (5.70 +/- 0.05 +/- 0.13) x 10(-3), respectively, where the first uncertainties are statistical and the second are systematic. In addition, the upper limit of the branching fraction for D+ -> phi K+ is given to be 2.1 x 10(-5) at the 90% confidence level. The ratio of B(D-0 -> phi pi(0)) to B(D+ -> phi pi(+)) is calculated to be (20.49 +/- 0.50 +/- 0.45)%, which is consistent with the theoretical prediction based on isospin symmetry between these two decay modes.
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| 49. |
- Ablikim, M., et al.
(författare)
-
Measurement of cross sections for e(+) e(-) -> mu(+) mu(-) at center-of-mass energies from 3.80 to 4.60 GeV
- 2020
-
Ingår i: Physical Review D. - : American Physical Society (APS). - 2470-0010 .- 2470-0029. ; 102:11
-
Tidskriftsartikel (refereegranskat)abstract
- The observed cross sections for e(+)e(-) -> mu(+) mu(-) at energies from 3.8 to 4.6 GeVare measured using data samples taken with the BESIII detector operated at the BEPCII collider. We measure the muonic widths and determine the branching fractions of the charmonium states psi(4040), psi(4160), and psi(4415) decaying to mu(+)mu(-), as well as making a first determination of the phase of the amplitudes. In addition, we observe evidence for a structure in the dimuon cross section near 4.220 GeV/(c)2, which we denote as So4220+. Analyzing a coherent sum of amplitudes yields eight solutions, one of which gives a mass of M-S(4220) = 4216.7 +/- 8.9 +/- 4.1 MeV/c(2), a total width of Gamma(tot+)(S(4220)) = 47.2 +/- 22.8 +/- 10.5 MeV, and a muonic width of Gamma(mu mu)(S(4220))+ = 1.53 +/- 1.26 +/- 0.54 keV, where the first uncertainties are statistical and the second systematic. The eight solutions give the central values of the mass, total width, muonic width to be, respectively, in the range from 4212.8 to 4219.4 MeV/c(2), from 36.4 to 49.6 MeV, and from 1.09 to 1.53 keV. The statistical significance of the S(4220) signal is 3.9 sigma. Correcting the total dimuon cross section for radiative effects yields a statistical significance for this structure of 8.1 sigma.
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| 50. |
- Ablikim, M., et al.
(författare)
-
Measurement of J/psi -> Xi(1530+)(-) (Xi)over-bar(+) and evidence for the radiative decay Xi(153)(-) -> gamma Xi(-)
- 2020
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 101:1
-
Tidskriftsartikel (refereegranskat)abstract
- The SU(3)-flavor violating decay J/psi -> Xi(1530)(-) (Xi) over bar (+) + c.c. is studied using (1310.6 +/- 7.0) x 10(6) J/psi events collected with the BESIII detector at BEPCII, and the branching fraction is measured to be B(J/psi -> Xi(1530)(-) (Xi) over bar (+) + c.c.) = (3.17 +/- 0.02(stat) +/- 0.08(syst)) x 10(-4). This result is consistent with previous measurements with an order of magnitude improved precision. The angular parameter for this decay is measured for the first time and is found to be alpha = -0.21 +/- 0.04(stat) +/- 0.06(syst). In addition, we report evidence for the radiative decay Xi(1530)(-) -> gamma Xi(-) with a significance of 3.9 sigma, including the systematic uncertainties. The 90% confidence level upper limit on the branching fraction is determined to be B(Xi(1530)(-) -> gamma Xi(-)) <= 3.7%.
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