| 1. |
- Ablikim, M., et al.
(författare)
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Amplitude analysis of D0 → K -π+π+π-
- 2017
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Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 95:7
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Tidskriftsartikel (refereegranskat)abstract
- We present an amplitude analysis of the decay D0 → K -π+π+π- based on a data sample of 2.93 fb−1 acquired by the BESIII detector at the ψ(3770) resonance. With a nearly background free sample of about 16000 events, we investigate the substructure of the decay and determine the relative fractions and the phases among the different intermediate processes. Our amplitude model includes the two-body decays D0 → ¯K*0ρ0, D0 → K−a+1(1260) and D0 → K−1(1270)π+, the three-body decays D0 →¯K*0π+π− and D0 → K−π+ρ0, as well as the four-body nonresonant decay D0 → K−π+π+π−. The dominant intermediate process is D0 → K−a+1(1260), accounting for a fit fraction of 54.6%.
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| 2. |
- Ablikim, M., et al.
(författare)
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Amplitude analysis of the chi(c1) -> eta pi(+)pi(-) decays
- 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
- Using 448.0 x 10(6) psi(3686) events collected with the BESIII detector, an amplitude analysis is performed for psi(3686) -> gamma chi(c1), chi(c1) ->eta pi(+)pi(-) decays. The most dominant two- body structure observed is a(0)(980)(+/-) pi(-/+); a(0)(980)(+/-) -> eta pi(+/-.) line shape is modeled using a dispersion relation, and a significant nonzero a(0) (980) coupling to the eta'pi channel is measured. We observe chi(c1) -> a(2)(1700)pi production for the first time, with a significance larger than 17 sigma. The production of mesons with exotic quantum numbers, J(PC) = 1(-+), is investigated, and upper limits for the branching fractions chi(c1) -> pi(1)(1400)(+/-)pi(-/+) , chi(c1) -> pi(1)(1600)(+/-)pi(-/+) and chi(c1) -> pi 1(2015)(+/-)pi(-/+) with subsequent pi(1)(X)(+/-) -> eta pi(+/-) decay, are determined.
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| 3. |
- Ablikim, M., et al.
(författare)
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Measurement of integrated luminosity and center-of-mass energy of data taken by BESIII at √s=2.125 GeV
- 2017
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Ingår i: Chinese Physics C. - : IOP Publishing. - 1674-1137 .- 2058-6132. ; 41:11
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Tidskriftsartikel (refereegranskat)abstract
- To study the nature of the state Y (2175), a dedicated data set of e(+)e(-) collision data was collected at the center-of-mass energy of 2.125 GeV with the BESIII detector at the BEPCII collider. By analyzing large-angle Bhabha scattering events, the integrated luminosity of this data set is determined to be 108.49 +/- 0.02 +/- 0.85 pb(-1), where the first uncertainty is statistical and the second one is systematic. In addition, the center-of-mass energy of the data set is determined with radiative dimuon events to be 2126.55 +/- 0.03 +/- 0.85 MeV, where the first uncertainty is statistical and the second one is systematic.
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| 4. |
- Ablikim, M., et al.
(författare)
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Measurement of Singly Cabibbo Suppressed Decays Lambda(+)(c) -> p pi(+)pi(-) and Lambda(+)(c) -> pK(+)K(-)
- 2016
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 117:23
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Tidskriftsartikel (refereegranskat)abstract
- Using 567 pb(-1) of data collected with the BESIII detector at a center-of-mass energy of root s = 4.599 GeV, near the Lambda(+)(c)->(Lambda) over bar (-)(c) threshold, we study the singly Cabibbo-suppressed decays Lambda c(+) -> p pi(+) pi(-) and Lambda(+)(c) -> pK(+) K- By normalizing with respect to the Cabibbo-favored decay Lambda(+)(c)-> p pi(+)pi(-) we obtain ratios of branching fractions: [B(Lambda(+)(c) -> p pi(+)pi(-))/B(Lambda(+)(c) -> pK(-)pi(+))] = (6.70 +/- 0.48 +/- 0.25)% [B Lambda(+)(c) -> p phi)/B(Lambda(+)(c) -> pK(-)pi(+))] = (1.81 +/- 0.33 +/- 0.13)%,and [B(Lambda(+)(c) -> pK(+)K(non-phi)(-)/B(Lambda(+)(c) -> pK(-)pi(+))] (9.36 +/- 2.22 +/- 0.71)x10(-3), where the uncertainties are statistical and systematic, respectively. The absolute branching fractions are also presented. Among these measurements, the decay Lambda(+)(c) -> p pi(+)pi(-) is observed for the first time, and the precision of the branching fraction for Lambda(+)(c) -> pK(+)K(non-phi)(-) and Lambda(+)(c) -> p phi is significantly improved.
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| 5. |
- Ablikim, M., et al.
(författare)
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Measurements of cross section of e(+)e(-) -> p(p)over-bar pi(0) at center-of-mass energies between 4.008 and 4.600 GeV
- 2017
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Ingår i: Physics Letters B. - : ELSEVIER SCIENCE BV. - 0370-2693 .- 1873-2445. ; 771, s. 45-51
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Tidskriftsartikel (refereegranskat)abstract
- Based on e(+)e(-) annihilation data samples collected with the BESIII detector at the BEPCII collider at 13 center-of-mass energies from 4.008 to 4.600 GeV, measurements of the Born cross section of e(+)e(-) -> p (p) over bar pi(0) are performed. No significant resonant structure is observed in the measured energy dependence of the cross section. The upper limit on the Born cross section of e(+)e(-) -> Y (4260) -> p (p) over bar pi(0) at the 90% C. L. is determined to be 0.01 pb. The upper limit on the ratio of the branching fractions B(Y(4260) -> p (p) over bar pi(0))/B(Y(4260) -> pi(+)pi(-) j/Psi) at the 90% C. L. is determined to be 0.02%.
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| 6. |
- Ablikim, M., et al.
(författare)
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Measurements of the branching fractions for D+ -> (KSKSK+)-K-0-K-0+, (KSKS0)-K-0 pi + and D-0 -> (KSKS0)-K-0, (KSKSKS0)-K-0-K-0
- 2017
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 765, s. 231-237
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Tidskriftsartikel (refereegranskat)abstract
- By analyzing 2.93 fb(-1) of data taken at the psi(3770) resonance peak with the BESIII detector, we measure the branching fractions for the hadronic decays D+ -> (KSKSK+)-K-0-K-0, D+ -> (KSKS0)-K-0 pi(+), D-0 -> (KSKS0)-K-0 and D-0 -> (KSKSKS0)-K-0-K-0.They are determined to be B(D+ -> (KSKSK+)-K-0-K-0) = (2.54 +/- 0.05(stat.) +/- 0.12(sys.))x 10(-3), B(D+ -> (KSKS0)-K-0 pi(+)) = (2.70 +/- 0.05(stat,) +/- 0.12(sys.)) x 10(-3), B(D+ -> (KSKS0)-K-0) = (1.67 +/- 0.11(stat.) +/- 0.11(sys.)) x 10(-4) and B(D+ -> (KSKSKS0)-K-0-K-0) = (7.21 +/- 0.33(stat.) +/- 0.44(sys,)) x 10(-4), where the second one is measured for the first time and the others are measured with significantly improved precision over the previous measurements.
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| 7. |
- Ablikim, M., et al.
(författare)
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Observation of an Anomalous Line Shape of the eta 'pi(+)pi(-) Mass Spectrum near the p(p)over-bar Mass Threshold in J/psi -> gamma eta 'pi(+)pi(-)
- 2016
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 117:4
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Tidskriftsartikel (refereegranskat)abstract
- Using 1.09 x 10(9) J/psi events collected by the BESIII experiment in 2012, we study the J / psi -> gamma eta'pi(+)pi(-) process and observe a significant abrupt change in the slope of the eta'pi(+)pi(-) invariant mass distribution at the proton-antiproton (p (p) over bar) mass threshold. We use two models to characterize the eta'pi(+)pi(-) line shape around 1.85 GeV/c(2): one that explicitly incorporates the opening of a decay threshold in the mass spectrum (Flatte formula), and another that is the coherent sum of two resonant amplitudes. Both fits show almost equally good agreement with data, and suggest the existence of either a broad state around 1.85 GeV/c(2) with strong couplings to the c final states or a narrow state just below the p (p) over bar mass threshold. Although we cannot distinguish between the fits, either one supports the existence of a p (p) over bar moleculelike state or bound state with greater than 7 sigma significance.
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| 8. |
- Ablikim, M., et al.
(författare)
-
Observation of psi(3686) -> eta ' e(+)e(-)
- 2018
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Ingår i: Physics Letters B. - : ELSEVIER SCIENCE BV. - 0370-2693 .- 1873-2445. ; 783, s. 452-458
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Tidskriftsartikel (refereegranskat)abstract
- Using a data sample of 448.1 x 10(6) psi(3686) events collected with the BESIII detector at the BEPCII collider, we report the first observation of the electromagnetic Dalitz decay psi(3686) -> eta'e(+)e(-), with significances of 7.0 sigma and 6.3 sigma when reconstructing the eta' meson via its decay modes eta' -> gamma pi(+)pi(-) and eta' -> pi(+)pi(-) eta (eta -> gamma gamma), respectively. The weighted average branching fraction is determined to be B(psi(3686) -> eta'e(+)e(-)) = (1.90 +/- 0.25 +/- 0.11) x 10(-6), where the first uncertainty is statistical and the second systematic.
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| 9. |
- Ablikim, M., et al.
(författare)
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Precision Measurement of the e(+)e(-) -> Lambda(+)(c)(Lambda)over-bar(c)(-) Cross Section Near Threshold
- 2018
-
Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 120:13
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Tidskriftsartikel (refereegranskat)abstract
- The cross section of the e(+)e(-) -> Lambda(+)(c)(Lambda) over bar (-)(c) process is measured with unprecedented precision using data collected with the BESIII detector at root s = 4574.5, 4580.0, 4590.0 and 4599.5 MeV. The nonzero cross section near the Lambda(+)(c)(Lambda) over bar (-)(c) production threshold is cleared. At center-of-mass energies root s = 4574.5 and 4599.5 MeV, the higher statistics data enable us to measure the Lambda(c) polar angle distributions. From these, the.c electric over magnetic form-factor ratios (vertical bar G(E)/G(M)vertical bar) are measured for the first time. They are found to be 1.14 +/- 0.14 +/- 0.07 and 1.23 +/- 0.05 +/- 0.03, respectively, where the first uncertainties are statistical and the second are systematic.
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| 10. |
- Ablikim, M., et al.
(författare)
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Amplitude Analysis of the Decays eta ' -> pi(+)pi(-)pi(0) and eta' -> pi(0)pi(0)pi(0)
- 2017
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 118:1
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Tidskriftsartikel (refereegranskat)abstract
- Based on a sample of 1.31 x 10(9) J/Psi events collected with the BESIII detector, an amplitude analysis of the isospin-violating decays eta' -> pi(+)pi(-)pi(0) and eta' -> pi(0)pi(0)pi(0) is performed. A significant P-wave contribution from eta' -> rho(+/-)eta(-/+) is observed for the first time in eta' -> pi(+)pi(-)pi(0). The branching fraction is determined to be B(eta' -> rho(+/-)pi(-/+)) = (7.44 +/- 0.60 +/- 1.26 +/- 1.84) x 10(-4), where the first uncertainty is statistical, the second systematic, and the third model dependent. In addition to the nonresonant S-wave component, there is a significant sigma meson component. The branching fractions of the combined S-wave components are determined to be B(eta' -> pi(+)pi(-)pi(0))(S) = (37.63 +/- 0.77 +/- 2.22 +/- 4.48) x 10(-4) and B(eta' -> pi(0)pi(0)pi(0)) = (35.22 +/- 0.82 +/- 2.54) x 10(-4), respectively. The latter one is consistent with previous BESIII measurements.
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