| 11. |
- Ablikim, M., et al.
(författare)
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First observations of h(c )-> hadrons
- 2019
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 99:7
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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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| 12. |
- Ablikim, M., et al.
(författare)
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Improved measurements of the absolute branching fractions of the inclusive decays D+(0) -> phi X
- 2019
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 100:7
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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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| 13. |
- Ablikim, M., et al.
(författare)
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Measurement of branching fractions for D meson decaying into phi meson and a pseudoscalar meson
- 2019
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Ingår i: Physics Letters B. - : ELSEVIER. - 0370-2693 .- 1873-2445. ; 798
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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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| 14. |
- Ablikim, M., et al.
(författare)
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Measurement of branching fractions of psi(3686) -> phi eta ', phi f(1) (1285) and phi eta(1405)
- 2019
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Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 100:9
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Tidskriftsartikel (refereegranskat)abstract
- Using a sample of 448.1 x 10(6) psi(3686) events collected with the BESIII detector, we perform a study of the decay psi(3686) -> phi pi(+)pi(-)eta. The branching fraction of psi(3686) -> phi eta' is determined to be (1.51 +/- 0.16 +/- 0.12) x 10(-5), which is consistent with the previous measurement but with significantly improved precision. The resonances f(1)(1285) and eta(1405) are clearly observed in the pi(+)pi(-)eta mass spectrum with statistical significances of 18s and 9.7 sigma, respectively. The corresponding product branching fractions are measured to be B(psi(3686) -> phi f(1)(1285), f(1)(1285) -> pi(+)pi(-)eta) = )1.03 +/- 0.10 +/- 0.09) x 10(-5) and B(psi(3686) -> phi eta(1405), eta(1405) -> pi(+)pi(-)eta) = (8.46 +/- 1.37 +/- 0.92) x 10(-6). These results are used to test the perturbative QCD "12% rule."
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| 15. |
- Ablikim, M., et al.
(författare)
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Measurement of the branching fraction of J/psi -> omega eta 'pi(+)pi(-) and search for J/psi -> omega X(1835), X(1835) -> eta 'pi(+)pi(-) decay
- 2019
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 99:7
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Tidskriftsartikel (refereegranskat)abstract
- Using a sample of 1.31 x 10(9) J/psi events collected by the BESIII detector at BEPCII during 2009 and 2012, we study the J/psi -> omega eta'pi(+)pi(-) thorn p-hadronic process. For the first time, we measure the branching ratio B(J/psi -> omega eta'pi(+)pi(-)) = (1.12 +/- 0.02 +/- 0.13) x 10(-3). We search for the X(1835) state in the eta'pi(+)pi(-) invariant mass spectra. No evidence is found and we estimate the upper limit on the branching fraction at 90% confidence level to be B(J/psi -> omega X(1835), X(1835) -> eta'pi(+)pi(-)) < 6.2 x 10(-5).
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| 16. |
- Ablikim, M., et al.
(författare)
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Measurements of weak decay asymmetries of Lambda(+)(c) -> pK(S)(0), Lambda pi(+), Sigma(+)pi(0), and Sigma(0)pi(+)
- 2019
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 100:7
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Tidskriftsartikel (refereegranskat)abstract
- Using e(+)e(-) -> Lambda(+)(c)(Lambda) over bar (-)(c). production from a 567 pb(-1) data sample collected by BESIII at 4.6 GeV, a full angular analysis is carried out simultaneously on the four decay modes of Lambda(+)(c) -> pK(S)(0), Lambda pi(+), Sigma(+)pi(0), and Sigma(0)pi(+). For the first time, the Lambda(+)(c) transverse polarization is studied in unpolarized e(+)e(-) collisions, where a nonzero effect is observed with a statistical significance of 2.1 sigma. The decay asymmetry parameters of the Lambda(+)(c) weak hadronic decays into pK(S)(0), Lambda pi(+), Sigma(+)pi(0), and Sigma(0)pi(+) are measured to be 0.18 +/- 0.43(stat) +/- 0.14(syst), -0.80 +/- 0.11(stat) +/- 0.02(syst), -0.57 +/- 0.10(stat) +/- 0.07(syst), and -0.73 +/- 0.17(stat) +/- 0.07(syst), respectively. In comparison with previous results, the measurements for the Lambda pi(+) and Sigma(+)pi(0) modes are consistent but with improved precision, while the parameters for the pK(S)(0) and Sigma(+)pi(0) modes are measured for the first time.
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| 17. |
- Ablikim, M., et al.
(författare)
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Observation of e(+)e(-) -> pi(+) pi(-)psi(3770) and D-1(2420)(0)(D)over-bar(0) + c.c
- 2019
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 100:3
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Tidskriftsartikel (refereegranskat)abstract
- Several intermediate states of the reaction channels e(+)e(-) -> pi(+)pi(-) D-0(D) over bar (0) and e(+)e(-) -> pi(+)pi-D+D- are studied using the data samples collected with the BESIII detector at center-of-mass energies above 4.08 GeV. For the first time in this final state, a psi(3770) signal is seen in the DD invariant mass spectrum, with a statistical significance of 5.2 sigma at root s = 4.42 GeV. There is also evidence for this resonance at root s = 4.26 and 4.36 GeV with statistical significance of 3.2 sigma and 3.3 sigma, respectively. In addition, the Born cross section of e(+)e(-) ->pi(+)pi(-)psi(3770) is measured. The proposed heavy-quark-spin-symmetry partner of the X(3872), the state X-2(4013), is also searched for in the D (D) over bar invariant mass spectra. No obvious signal is found. The upper limit of the Born cross section of the process e(+)e(-) -> rho X-0(2)(4013) combined with the branching fraction is measured. Also, the processes e(+)e(-) -> D-1(2420)(D) over bar c.c. are investigated. The neutral mode with D-1(2420)(0) -> D-0 pi(+)pi(-) is reported with statistical significance of 7.4 sigma at root s = 4.42 GeV for the first time, and evidence with statistical significance of 3.2 sigma and 3.3 sigma at root s = 4.36 and 4.60 GeV is seen, respectively. No evident signal for the process e(+)e(-) -> D-1(2420)(0)(D) over bar (0) + c.c., D-1(2420)(0) -> D*(+)pi(-) is reported. Evidence for e(+)e(-) -> D-1(2420)+D- + c.c., D-1(2420)(+) -> D+pi(+)pi(-) is reported with statistical significance of 3.1 sigma and 3.0 sigma at root s. = 4.36 and 4.42 GeV, respectively.
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| 18. |
- Ablikim, M., et al.
(författare)
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Observation of psi(3686) -> p(p)over-bar phi
- 2019
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 99:11
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Tidskriftsartikel (refereegranskat)abstract
- Using a data sample of 4.48 x 10(8) psi(3686) events collected with the BESIII detector, we present a first observation of psi(3686) -> p (p) over bar phi, and we measure its branching fraction to be [6.06 +/- 0.38(stat)+/- 0.48(syst)] x 10(-6). In contrast to the earlier discovery of a threshold enhancement in the p (p) over bar -mass spectrum of the channel j/psi -> gamma p (p) over bar, denoted as X(p (p) over bar), we do not find a similar enhancement in psi(3686) -> p (p) over bar phi. An upper limit of 1.82 x 10(-7) at the 90% confidence level on the branching fraction of psi(3686) -> X(p (p) over bar)phi -> p (p) over bar phi is obtained.
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| 19. |
- Ablikim, M., et al.
(författare)
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Observation of psi(3886) -> Xi(1530)(-)(Xi)over-bar(1530)(+) and Xi(1530)(-)(Xi)over-bar(+)
- 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 448.1 x 10(6) psi(3686) events collected with the BESIII detector at BEPCII, we employ a single-baryon tagging technique to make the first observation of psi(3686) -> Xi(1530)(-)(Xi) over bar (1530)(+) and Xi(1530)(-)(Xi) over bar (+) decays with a statistical significance of more than 10 sigma and 5.0 sigma, respectively. The branching fractions are measured to be B(psi(3686) -> Xi(1530)(-)(Xi) over bar (1530)(+)) = (11.45 +/- 0.40 +/- 0.59) x 10(-5) and B(psi(3686) -> Xi(1530)(-)(Xi) over bar (+)) = (0.70 +/- 0.11 +/- 0.04) x 10(-5). The angular distribution parameter for psi(3686) -> Xi(1530)(-)(Xi) over bar (1530)(+) is determined to be alpha = 0.40 +/- 0.24 +/- 0.06, which agrees with the theoretical predictions within 1 sigma. The first uncertainties are statistical, and the second systematic.
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| 20. |
- 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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