| 31. |
- Ablikim, M., et al.
(författare)
-
Study of the decays D+-> eta(('))e(+)nu(e)
- 2018
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 97:9
-
Tidskriftsartikel (refereegranskat)abstract
- The charm semileptonic decays D+ -> eta e(+)nu(e) and D+ -> eta'e(+)nu(e) are studied with a sample of e(+)e(-) collision data corresponding to an integrated luminosity of 2.93 fb(-1) collected at root s = 3.773 GeV with the BESIII detector. We measure the branching fractions for D+ -> eta e(+)upsilon(e) to be (10.74 +/- 0.81 +/- 0.51)x10(-4), and for D+ -> eta'e(+)nu(e) to be (1.91 +/- 0.51 +/- 0.13) x 10(-4), where the uncertainties are statistical and systematic, respectively. In addition, we perform a measurement of the form factor in the decay D+ -> eta e(+)nu(e) . All the results are consistent with those obtained by the CLEO-c experiment.
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| 32. |
- Ablikim, M., et al.
(författare)
-
Study of two-photon decays of pseudoscalar mesons via J/Psi radiative decays
- 2018
-
Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 97:7
-
Tidskriftsartikel (refereegranskat)abstract
- Using a sample of 4.48 x 10(8) Psi(3686) events collected with the BESIII detector at the BEPCII collider, we study the two-photon decays of the pseudoscalar mesons pi(0,) eta , eta' , eta(1405), eta(1475), eta(1760), and X(1835) in J/Psi radiative decays using Psi(3686) -> pi(+) pi(-) J/Psi events. The pi(0), eta, and eta' mesons are clearly observed in the two-photon mass spectra, and the branching fractions are determined to be B(J/Psi -> gamma pi(0) -> 3 gamma) = (3.57 +/- 0.12 +/- 0.16) x 10(-5), B(J/Psi -> gamma eta -> 3 gamma) = (4.42 +/- 0.04 +/- 0.18) x 10(-4), and B(J/Psi -> gamma eta' -> 2 gamma) = (1.26 +/- 0.02 +/- 0.05) x 10(-4), where the first error is statistical and the second is systematic. No clear signal for eta(1405), eta(1475), eta(1760) or X(1835) is observed in the two- photon mass spectra, and upper limits at the 90% confidence level on the product branching fractions are obtained.
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| 33. |
- Ablikim, M., et al.
(författare)
-
Study of J/ψ and ψ(3686) decay to Λ¯Λ and Σ0¯Σ0 final states
- 2017
-
Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 95:5
-
Tidskriftsartikel (refereegranskat)abstract
- Using 1310.6 x 10(6) J/psi and 447.9 x 10(6) psi (3686) events collected with the BESIII detector at the BEPCII e(+)e(-) collider, the branching fractions and the angular distributions of J/psi and psi (3686) decays to Lambda(Lambda) over bar and Sigma(0)(Sigma) over tilde (0) final states are measured. The branching fractions are determined, with much improved precision, to be 19.43 +/- 0.03 +/- 0.33, 11.64 +/- 0.04 +/- 0.23, 3.97 +/- 0.02 +/- 0.12 and 2.44 +/- 0.03 +/- 0.11 for J/psi -> Lambda(Lambda) over bar -> Sigma(0)(Sigma) over tilde (0) , psi (3686) -> Lambda(Lambda) over bar and psi (3686) -> Sigma(0)(Sigma) over tilde (0), respectively. The polar angular distributions of psi (3686) decays are measured for the first time, while those of J/psi decays are measured with much improved precision. In addition, the ratios of branching fractions B(psi(3686)->Lambda(Lambda) over bar)/B(J/psi -> Lambda(Lambda) over bar) and B(psi(3686)->Sigma(0)(Sigma) over tilde (0))/B(J/psi ->Sigma(0)(Sigma) over tilde (0)) are determined to test the "12% rule."
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| 34. |
-
- 2019
-
Tidskriftsartikel (refereegranskat)
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| 35. |
- Ablikim, M., et al.
(författare)
-
Branching fraction measurements of psi (3686) -> gamma chi(cJ)
- 2017
-
Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:3
-
Tidskriftsartikel (refereegranskat)abstract
- Using a sample of 106 million psi(3686) decays, the branching fractions of psi(3686) -> gamma chi(c0), psi(3686) -> gamma chi(c1), and psi(3686) -> gamma chi(c2) are measured with improved precision to be (9.389 +/- 0.014 +/- 0.332) %, (9.905 +/- 0.011 +/- 0.353) %, and (9.621 +/- 0.013 +/- 0.272) %, respectively, where the first uncertainties are statistical and the second ones are systematic. The product branching fractions of (psi 3686) -> gamma chi(c1), chi(c1) -> gamma J/psi (3686) -> gamma chi(c2), chi(c2) -> gamma J/psi and the branching fractions of chi(c1) -> gamma J/psi and chi(c2) -> gamma J/psi are also presented.
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| 36. |
- Ablikim, M., et al.
(författare)
-
Measurement of e(+)e(-) -> K(K)over-barJ/psi cross sections at center-of-mass energies from 4.189 to 4.600 GeV
- 2018
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 97:7
-
Tidskriftsartikel (refereegranskat)abstract
- We investigate the process e(+)e(-) -> K (K) over barJ/psi at center-of-mass energies from 4.189 to 4.600 GeV using 4.7 fb(-1) of data collected by the BESIII detector at the BEPCII collider. The Born cross sections for the reactions e(+)e(-) -> K(+)K(-)J/psi and K(S)(0)K(S)(0)J/psi are measured as a function of center-of-mass energy. The energy dependence of the cross section for e(+)e(-) -> K(+)K(-)J/psi is shown to differ from that for pi(+)pi(-)J/psi in the region around the Y(4260). In addition, there is evidence for a structure around 4.5 GeV in the e(+)e(-) -> K(+)K(-)J/psi cross section that is not present in pi(+)pi(-)J/psi.
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| 37. |
- Ablikim, M., et al.
(författare)
-
Measurement of e+e−→π0π0ψ(3686) at √s from 4.009 to 4.600 GeV and observation of a neutral charmoniumlike structure
- 2018
-
Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 97:5
-
Tidskriftsartikel (refereegranskat)abstract
- Using ethorne-collision data collected with the BESIII detector at the BEPCII collider corresponding to an integrated luminosity of 5.2 fb(-1) at center-of-mass energies (root s) from 4.009 to 4.600 GeV, the process e(+)e(-) -> pi(0)pi(0)psi(3686) is studied for the first time. The corresponding Born cross sections are measured and found to be half of those of the reaction e(+)e(-) -> pi(0)pi(0)psi(3686). This is consistent with the expectation from isospin symmetry. Furthermore, the Dalitz plots for pi(0)pi(0)psi(3686) are accordant with those of pi(0)pi(0)psi(3686) at all energy points, and a neutral analog to the structure in pi(+/-)psi(3686) around 4040 MeV/c(2) first observed at root s = 4.416 GeV is observed in the isospin neutral mode at the same energy.
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| 38. |
- Ablikim, M., et al.
(författare)
-
Measurements of the branching fractions of the singly Cabibbo-suppressed decays D0→ωη, η(')π0 and η(')η
- 2018
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 97:5
-
Tidskriftsartikel (refereegranskat)abstract
- By analyzing a data sample of 2.93 fb(-1) collected at root s = 3.773 GeV with the BESIII detector operated at the BEPCII storage rings, we measure the branching fractions B(D-0 -> omega eta) = (2.15 +/- 0.17(stat) +/- 0.15(sys)) x 10(-3), B(D-0 ->eta pi(0)) = (0.58 +/- 0.05(stat) +/- 0.05(sys)) x 10(-3), B(D-0 ->eta'pi(0)) = (0.93 +/- 0.11(stat) +/- 0.09(sys)) x 10(-3), B(D-0 -> eta eta) = (2.20 +/- 0.07(stat) +/- 0.06(sys)) x 10(-3) and B(D-0 -> eta'eta) = (0.94 degrees +/- 0.25(stat) +/- 0.11(sys)) x 10(-3). We note that B(D-0 -> omega eta) is measured for the first time and that B(D-0 -> eta eta) is measured with much improved precision.
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| 39. |
- Ablikim, M., et al.
(författare)
-
Observation of the decay Lambda(+)(c) -> Sigma(-)pi(+)pi(+)pi(0)
- 2017
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 772, s. 388-393
-
Tidskriftsartikel (refereegranskat)abstract
- We report the first observation of the decay Lambda(+)(c) -> Sigma(-)pi(+)pi(+)pi(0), based on data obtained in e(+)e(-) annihilations with an integrated luminosity of 567 pb(-1) at vs = 4.6 GeV. The data were collected with the BESIII detector at the BEPCII storage rings. The absolute branching fraction B(Lambda(+)(c) -> Sigma(-)pi(+)pi(+)pi(0)) is determined to be (2.11 +/- 0.33(stat.) +/- 0.14(syst.))%. In addition, an improved measurement of B(Lambda(+)(c) -> Sigma(-)pi(+)pi(+)pi(0)) is determined as (1.81 +/- 0.17(stat.) +/- 0.09(syst.))%.
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| 40. |
- Ablikim, M., et al.
(författare)
-
Observation of ψ(3686)→n¯n and improved measurement of ψ(3686)→p¯p
- 2018
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 98:3
-
Tidskriftsartikel (refereegranskat)abstract
- We observe the decay psi (3686) -> n (n) over bar for the first time and measure psi (3686) -> p (p) over bar with improved accuracy by using 1.07 x 10(8) psi (3686) events collected with the BESIII detector. The measured branching fractions are B(psi(3686) -> n (n) over bar) = (3.06 +/- 0.06 +/- 0.14) x 10(-4) and B(psi(3686) -> p (p) over bar) = (3.05 +/- 0.02 +/- 0.12) x 10(-4). Here, the first uncertainties are statistical, and the second ones are systematic. With the hypothesis that the polar angular distributions of the neutron and proton in the center-of-mass system obey 1 + alpha cos(2) theta, we determine the a parameters to be alpha(n (n) over bar) = 0.68 +/- 0.12 +/- 0.11 and alpha(p (p) over bar) = 1.03 +/- 0.06 +/- 0.03 for psi(3686) -> n (n) over bar and psi(3686) -> p (p) over bar, respectively.
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