SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(He X. Q.) "

Sökning: WFRF:(He X. Q.)

  • Resultat 1-50 av 465
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Ablikim, M., et al. (författare)
  • Measurement of the absolute branching fraction of D*(s0) (2317)(+/-) -> pi D-0(s)+/-
  • 2018
  • Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 97:5
  • Tidskriftsartikel (refereegranskat)abstract
    • The process e(+)e(-) -> D*D-+(s)*(s0) (2317)(-) + c.c. is observed for the first time with the data sample of 567 pb(-1) collected with the BESIII detector operating at the BEPCII collider at a center-of-mass energy root s = 4.6 GeV. The statistical significance of the D*(s0) (2317)(+/-) signal is 5.8 sigma and the mass is measured to be (2318.3 +/- 1.2 +/- 1.2) MeV/c(2). The absolute branching fraction B(D*(s0) (2317)(+/-) -> pi D-0(s)+/-) is measured as 1.00(-0.14)(+0.00) (stat)(-0.14)(+0.00) (syst) for the first time. The uncertainties are statistical and systematic, respectively.
  •  
2.
  • Ablikim, M., et al. (författare)
  • Amplitude analysis of the KSKS system produced in radiative J /psi decays
  • 2018
  • Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 98:7
  • Tidskriftsartikel (refereegranskat)abstract
    • An amplitude analysis of the KSKS system produced in radiative J/psi decays is performed using the (1310.6 +/- 7.0) x 10(6) nip decays collected by the BESIII detector. Two approaches are presented. A mass-dependent analysis is performed by parametrizing the KSKS invariant mass spectrum as a sum of Breit-aligner line shapes. Additionally, a mass-independent analysis is performed to extract a piecewise function that describes the dynamics of the KSKS system while making minimal assumptions about the properties and number of poles in the amplitude. The dominant amplitudes in the mass-dependent analysis include the f(0)(1710), f(0)(2200), and f(2)'(1525). The mass-independent results, which are made available as input for further studies, are consistent with those of the mass-dependent analysis and are useful for a systematic study of hadronic interactions. The branching fraction of radiative J/psi decays to KSKS is measured to be (8.1 +/- 0.4) x 10(-4), where the uncertainty is systematic and the statistical uncertainty is negligible.
  •  
3.
  • Ablikim, M., et al. (författare)
  • Branching fraction measurement of J/ψ→KSKL and search for J/ψ→KSKS
  • 2017
  • Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:11
  • Tidskriftsartikel (refereegranskat)abstract
    • Using a sample of 1.31 x 10(9) J/Psi events collected with the BESIII detector at the BEPCII collider, we study the decays of J/Psi -> KSKL and KSKS. The branching fraction of J/Psi -> KSKL is determined to be B(J/Psi -> KSKL) = (1.93 +/- 0.01 (stat) +/- 0.05 (syst)) x 10(-4), which significantly improves on previous measurements. No clear signal is observed for the J/Psi -> KSKS process, and the upper limit at the 95% confidence level for its branching fraction is determined to be B(J/Psi -> KSKS) < 1.4 x 10(-8), which improves on the previous searches by 2 orders in magnitude and reaches the order of the Einstein-Podolsky-Rosen expectation.
  •  
4.
  • Ablikim, M., et al. (författare)
  • First measurement of e(+)e(-) -> pK(S)(0)(n)over-barK(-) + c.c. above open charm threshold
  • 2018
  • Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 98:3
  • Tidskriftsartikel (refereegranskat)abstract
    • The process e(+)e(-) -> pK(S)(0)(n) over barK(-) + c.c. and its intermediate processes are studied for the first time, using data samples collected with the BESIII detector at BEPCII at center-of-mass energies of 3.773, 4.008, 4.226, 4.258, 4.358, 4.416, and 4.600 GeV, with a total integrated luminosity of 7.4 fb(-1). The Born cross section of e(+)e(-) -> pK(S)(0)(n) over barK(-) + c.c. is measured at each center-of-mass energy, but no significant resonant structure in the measured cross-section line shape between 3.773 and 4.600 GeV is observed. No evident structure is detected in the pK(-), nK(S)(0), pK(S)(0), nK(+), p (n) over bar, or (KSK-)-K-0 invariant mass distributions except for Lambda(1520). The Born cross sections of e(+)e(-) -> Lambda(1520)(n) over barK(S)(0) + c.c. and e(+)e(-) -> Lambda(1520)(p) over barK(+) + c.c. are measured, and the 90% confidence level upper limits on the Born cross sections of e(+)e(-) -> Lambda(1520)(Lambda) over bar (1520) are determined at the seven center-of-mass energies. There is an evident difference in line shape and magnitude of the measured cross sections between e(+)e(-) -> Lambda(1520)(-> pK(-))(n) over barK(S)(0) and e(+)e(-) -> pK-(Lambda) over bar (1520)(-> (n) over barK(S)(0)).
  •  
5.
  • Ablikim, M., et al. (författare)
  • Measurement of e(+)e(-) -> D(D)over-bar cross sections at the psi(3770) resonance
  • 2018
  • Ingår i: Chinese Physics C. - : IOP PUBLISHING LTD. - 1674-1137 .- 2058-6132. ; 42:8
  • Tidskriftsartikel (refereegranskat)abstract
    • We report new measurements of the cross sections for the production of D (D) over bar final states at the psi(3770) resonance. Our data sample consists of an integrated luminosity of 2.93 fb(-1) of e(+)e(-) annihilation data produced by the BEPCII collider and collected and analyzed with the BESIII detector. We exclusively reconstruct three D-0 and six D+ hadronic decay modes and use the ratio of the yield of fully reconstructed D (D) over bar events ("double tags") to the yield of all reconstructed D or (D) over bar mesons ("single tags") to determine the number of D-0(D) over bar (0) and D+D- events, benefiting from the cancellation of many systematic uncertainties. Combining these yields with an independent determination of the integrated luminosity of the data sample, we find the cross sections to be sigma(e(+)e(-) -> D-0(D) over bar (0)(-) )=(3.615 +/- 0.010 +/- 0.038) nb and sigma(e(+)e(-) -> D+D-)=(2.830 +/- 0.011 +/- 0.026) nb, where the uncertainties are statistical and systematic, respectively.
  •  
6.
  • 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.
  •  
7.
  • Ablikim, M., et al. (författare)
  • Measurement of the Absolute Branching Fraction of the Inclusive Decay Lambda(+)(c) -> Lambda plus X
  • 2018
  • Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 121:6
  • Tidskriftsartikel (refereegranskat)abstract
    • Based on an e(+)e(-) collision data sample corresponding to an integrated luminosity of 567 pb(-1) taken at the center-of-mass energy of root s = 4.6 GeV with the BESIII detector, we measure the absolute branching fraction of the inclusive decay Lambda(+)(c) -> Lambda + X to be B(Lambda(+)(c) -> Lambda + X) = (38.2(-2.2)(+2.8) +/- 0.9)% using the double-tag method, where X refers to any possible final state particles. In addition, we search for direct CP violation in the charge asymmetry of this inclusive decay for the first time, and obtain A(CP) [B(Lambda(+)(c) -> Lambda + X) - B((Lambda) over bar (-)(c) -> (Lambda) over bar + X)]/[B(Lambda(+)(c) -> Lambda + X) + B((Lambda) over bar (-)(c) -> (Lambda) over bar + X)] = (2.1(-6.6)(+7.0) +/- 1.6)%, a statistically limited result with no evidence of CP violation.
  •  
8.
  • Ablikim, M., et al. (författare)
  • Measurement of the integrated Luminosities of cross-section scan data samples around the psi(3770) mass region
  • 2018
  • Ingår i: Chinese Physics C. - : SCIENCE PRESS. - 1674-1137 .- 2058-6132. ; 42:6
  • Tidskriftsartikel (refereegranskat)abstract
    • To investigate the nature of the psi(3770) resonance and to measure the cross section for e(+)e(-) -> D (D) over bar, a cross-section scan data sample, distributed among 41 center-of-mass energy points from 3.73 to 3.89 GeV, was taken with the BESIII detector operated at the BEPCII collider in the year 2010. By analyzing the large angle Bhabha scattering events, we measure the integrated luminosity of the data sample at each center-of-mass energy point. The total integrated luminosity of the data sample is 76.16 +/- 0.04 +/- 0.61 pb(-1), where the first uncertainty is statistical and the second systematic.
  •  
9.
  • Ablikim, M., et al. (författare)
  • Search for invisible decays of omega and phi with J/psi data at BESIII
  • 2018
  • Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 98:3
  • Tidskriftsartikel (refereegranskat)abstract
    • Using a data sample of (1310.6 +/- 7.0) x 10(6) J/psi events collected with the BESIII detector operating at the BEPCII collider, we perform the first experimental search for invisible decays of a light vector meson (V = omega, phi) via J/psi -> V-eta decays. The decay of eta -> pi(+)pi(-)pi(0) is utilized to tag the V meson decaying into the invisible final state. No evidence for a significant invisible signal is observed, and the upper limits on the ratio of branching fractions at the 90% confidence level are determined to be B(omega -> invisible)/B(omega -> pi(+)pi(-)pi(0)) < 8.1 x 10(-5) and B(phi -> invisible)/B(phi -> K+K-) < 3.4 x 10(-4). By using the world average values of B(omega -> pi(+)pi(-)pi(0) and B(phi -> K+K-,) the upper limits on the decay branching fractions at the 90% confidence level are set as B(omega -> invisible) < 7.3 x 10(-5) and B(phi -> invisible) < 1.7 x 10(-4), respectively.
  •  
10.
  • 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.
  •  
11.
  • Ablikim, M., et al. (författare)
  • Amplitude analysis of D0 → K -π+π+π-
  • 2017
  • Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 95:7
  • 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%.
  •  
12.
  • Ablikim, M., et al. (författare)
  • Improved measurements of two-photon widths of the chi(cJ) states and helicity analysis for chi(c2) -> gamma gamma
  • 2017
  • Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 96:9
  • Tidskriftsartikel (refereegranskat)abstract
    • Based on 448.1 x 10(6) Psi(3686) events collected with the BESIII detector, the decays Psi(3686) -> gamma chi(cJ), chi(cJ) -> gamma gamma(J = 0, 1, 2) are studied. The decay branching fractions of chi(c0,2) -> gamma gamma are measured to be B(chi(c0) -> gamma gamma) = (1.93 +/- 0.08 +/- 0.05 +/- 0.05) x 10(-4) and B(chi(c2) -> gamma gamma) = (3.10 +/- 0.09 +/- 0.07 +/- 0.11) x 10(-4) which correspond to two-photon decay widths of Gamma(gamma gamma)(chi(c0)) = 2.03 +/- 0.08 +/- 0.06 +/- 0.13 keV and Gamma(gamma gamma)(chi(c2)) = 0.60 +/- 0.02 +/- 0.01 +/- 0.04 keV with a ratio of R = Gamma(gamma gamma)(chi(c2))/Gamma(gamma gamma)(chi(c0)) = 0.295 +/- 0.014 +/- 0.007 +/- 0.027, where the uncertainties are statistical, systematic and associated with the uncertainties of B(Psi(3686) -> gamma chi(c0,2)) and the total widths Gamma(chi(c0,2)), respectively. For the forbidden decay of chi(c1) -> gamma gamma, no signal is observed, and an upper limit on the two-photon width is obtained to be Gamma(gamma gamma)(chi(c1)) < 5.3 eV at the 90% confidence level. The ratio of the two-photon widths between helicity-zero and helicity-two components in the decay chi(c2) -> gamma gamma is also measured to be f(0/2) = Gamma(lambda=0)(gamma gamma) (chi(c2))/Gamma(lambda=2)(gamma gamma) (chi(c2)) = (0.0 +/- 0.6 +/- 1.2) x 10(-2), where the uncertainties are statistical and systematic, respectively.
  •  
13.
  • Ablikim, M., et al. (författare)
  • Measurement of the absolute branching fraction for Lambda(+)(c) -> Lambda mu(+)nu(mu)
  • 2017
  • Ingår i: Physics Letters B. - : ELSEVIER SCIENCE BV. - 0370-2693 .- 1873-2445. ; 767, s. 42-47
  • Tidskriftsartikel (refereegranskat)abstract
    • We report the first measurement of the absolute branching fraction for Lambda(+)(c) -> Lambda mu(+)nu(mu).This measurement is based on a sample of e+e(-) annihilation data produced at a center-of-mass energy root s = 4.6 GeV, collected with the BESIII detector at the BEPCII storage rings. The sample corresponds to an integrated luminosity of 567 pb(-1). The branching fraction is determined to be B( Lambda(+)(c) -> Lambda mu(+)nu(mu)) = (3.49 +/- 0.46( stat) +/- 0.27( syst))%. In addition, we calculate the ratio B( Lambda(+)(c) -> Lambda mu(+)nu(mu))/B(Lambda(+)(c) -> Lambda e(+)nu(e) to be 0.96 +/- 0.16( stat) +/- 0.04( syst).
  •  
14.
  • Ablikim, M., et al. (författare)
  • Measurement of the matrix elements for the decays eta' -> eta pi(+) pi(-) and eta' -> eta pi(0)pi(0)
  • 2018
  • Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 97:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Based on a sample of 1.31 x 10(9) J/psi events collected with the BESIII detector, the matrix elements for the decays eta' -> eta pi(+) pi(-) and eta' -> eta pi(0)pi(0) are determined using 351,016 eta' -> (eta -> gamma gamma)pi' pi(-) and 56,249 eta' -> (eta -> gamma gamma)pi(0) pi(0) events with background levels less than 1%. Two commonly used representations are used to describe the Dalitz plot density. We find that an assumption of a linear amplitude does not describe the data well. A small deviation of the obtained matrix elements between eta' -> eta pi(+) pi(-) and eta' -> eta pi(0)pi(0) is probably caused by the mass difference between charged and neutral pions or radiative corrections. No cusp structure in eta' -> eta pi(0)pi(0) is observed.
  •  
15.
  • Ablikim, M., et al. (författare)
  • Measurements of the absolute branching fractions for D-s(+) -> eta e(+)nu(e) and D-s(+) -> eta ' e(+)nu(e)
  • 2016
  • Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 94:11
  • Tidskriftsartikel (refereegranskat)abstract
    • By analyzing 482 pb(-1) of e(+)e(-) collision data collected at root s = 4.009 GeV with the BESIII detector at the BEPCII collider, we measure the absolute branching fractions for the semileptonic decays D-s(+) -> eta e(+)nu(e) and D-s(+) -> eta ' e(+)nu(e) to be B(D-s(+) -> eta e(+)nu(e)) = (2.30 +/- 0.31 +/- 0.08)% and B(D-s(+) -> eta ' e(+)nu(e)) = (0.93 +/- 0.30 +/- 0.05)%, respectively, and their ratio B(D-s(+) -> eta ' e(+)nu(e)) / B(D-s(+) -> eta ' e(+)nu(e)) = 0.40 +/- 0.14 +/- 0.02, where the first uncertainties are statistical and the second ones are systematic. The results are in good agreement with previous measurements within uncertainties; they can be used to determine the eta-eta' mixing angle and improve upon the D-s(+) semileptonic branching ratio precision.
  •  
16.
  • Ablikim, M., et al. (författare)
  • Measurements of the branching fractions for the semileptonic decays D-s(+) -> phi e(+)v(e), phi mu(+)v(mu), eta mu(+)v(mu) and eta 'mu(+)v(mu)
  • 2018
  • Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 97:1
  • Tidskriftsartikel (refereegranskat)abstract
    • By analyzing 482 pb(-1) of e(+) e(-) collision data collected at the center-of-mass energy root s = 4.009 GeV with the BESIII detector, we measure the branching fractions for the semi-leptonic decays D-s(+) -> phi e(+)v(e), phi mu(+)v(mu), eta mu(+)v(mu) and eta'mu(+)v(mu) to be B(D-s(+) -> phi e(+)v(e)) = (2.26 +/- 0.45 +/- 0.09)%, B(D-s(+) -> phi mu+v(mu)) = (1.94 +/- 0.53 +/- 0.09)%, B(D-s(+) -> eta mu(+)v(mu)) = (2.42 +/- 0.46 +/- 011)% and B(D-s(+) -> eta'mu(+)v(mu)) = (1.06 +/- 0.54 +/- 0.07)%, where the first and second uncertainties are statistical and systematic, respectively. The branching fractions for the three semi-muonic decays D-s(+) -> phi mu(+)v(mu), eta mu(+)v(mu) and eta'mu(+)v(mu) are determined for the first time and that of D-s(+) -> phi e(+)v(e) is consistent with the world average value within uncertainties.
  •  
17.
  • Ablikim, M., et al. (författare)
  • Observation of Lambda(+)(c) -> nK(S)(0)pi(+)
  • 2017
  • Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 118:11
  • Tidskriftsartikel (refereegranskat)abstract
    • We report the first direct measurement of decays of the Lambda(+)(c) baryon involving the neutron. The analysis is performed using 567 pb(-1) of e(+)e(-) collision data collected at root s = 4.599 GeV with the BESIII detector at the BEPCII collider. We observe the decay Lambda(+)(c) -> nK(S)(0)pi(+) and measure the absolute branching fraction to be B(Lambda(+)(c) -> nK(S)(0)pi(+)) = [1.82 +/- 0.23(stat) +/- 0.11(syst)]%. A comparison to B[Lambda(+)(c) -> p( (K) over bar pi)(0)] provides an important test of isospin symmetry and final state interactions.
  •  
18.
  • Ablikim, M., et al. (författare)
  • Observation of psi(3686) -> eta ' e(+)e(-)
  • 2018
  • Ingår i: Physics Letters B. - : ELSEVIER SCIENCE BV. - 0370-2693 .- 1873-2445. ; 783, s. 452-458
  • 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.
  •  
19.
  • Ablikim, M., et al. (författare)
  • Observation of χc2→η′η′ and χc0,2→ηη′
  • 2017
  • Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:11
  • Tidskriftsartikel (refereegranskat)abstract
    • Using a sample of 448.1×106  ψ(3686) events collected with the BESIII detector in 2009 and 2012, we study the decays χc0,2→η′η′ and ηη′. The decays χc2→η′η′, χc0→ηη′ and χc2→ηη′ are observed for the first time with statistical significances of 9.6σ, 13.4σ and 7.5σ, respectively. The branching fractions are determined to be B(χc0→η′η′)=(2.19±0.03±0.14)×10−3, B(χc2→η′η′)=(4.76±0.56±0.38)×10−5, B(χc0→ηη′)=(8.92±0.84±0.65)×10−5 and B(χc2→ηη′)=(2.27±0.43±0.25)×10−5, where the first uncertainties are statistical and the second are systematic. The precision for the measurement of B(χc0→η′η′) is significantly improved compared to previous measurements. Based on the measured branching fractions, the role played by the doubly and singly Okubo-Zweig-Iizuka disconnected transition amplitudes for χc0,2 decays into pseudoscalar meson pairs can be clarified.
  •  
20.
  • Ablikim, M., et al. (författare)
  • 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
  • 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.
  •  
21.
  • Ablikim, M., et al. (författare)
  • Search for D-0 -> gamma gamma and improved measurement of the branching fraction for D-0 -> pi(0)pi(0)
  • 2015
  • Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:11
  • Tidskriftsartikel (refereegranskat)abstract
    • Using 2.92 fb(-1) of electron-positron annihilation data collected at root s = 3.773 GeV with the BESIII detector, we report the results of a search for the flavor-changing neutral current process D-0 -> gamma gamma using a double-tag technique. We find no signal and set an upper limit at 90% confidence level for the branching fraction of B(D-0 -> gamma gamma < 3.8 x 10(-6). We also investigate D-0-meson decay into two neutral pions, obtaining a branching fraction of B(D-0 -> pi(0)pi(0)) = (8.24 +/- 0.21(stat) +/- 0.30(syst)) x 10(-4), the most precise measurement to date and consistent with the current world average.
  •  
22.
  • Ablikim, M., et al. (författare)
  • Search for the rare decays D -> h(h((')))e(+) e(-)
  • 2018
  • Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 97:7
  • Tidskriftsartikel (refereegranskat)abstract
    • We search for rare decays of D mesons to hadrons accompanied by an electron-positron pair (h(h((')))e(+)e(- )),using an e(+)e(-) collision sample corresponding to an integrated luminosity of 2.93 fb(-1) collected with the BESIII detector at root s = 3.773 GeV. No significant signals are observed, and the corresponding upper limits on the branching fractions at the 90% confidence level are determined. The sensitivities of the results are at the level of 10(-5)-10(-6), providing a large improvement over previous searches.
  •  
23.
  • 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."
  •  
24.
  • Ablikim, M., et al. (författare)
  • Amplitude analysis of the pi(0)pi(0) system produced in radiative J/psi decays
  • 2015
  • Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 92:5
  • Tidskriftsartikel (refereegranskat)abstract
    • An amplitude analysis of the pi(0)pi(0) system produced in radiative J/psi decays is presented. In particular, a piecewise function that describes the dynamics of the pi(0)pi(0) system is determined as a function of M pi(0)pi(0) from an analysis of the (1.311 +/- 0.011) x 10(9) J/psi decays collected by the BESIII detector. The goal of this analysis is to provide a description of the scalar and tensor components of the pi(0)pi(0) system while making minimal assumptions about the properties or number of poles in the amplitude. Such a model-independent description allows one to integrate these results with other related results from complementary reactions in the development of phenomenological models, which can then be used to directly fit experimental data to obtain parameters of interest. The branching fraction of J/psi -> pi(0)pi(0) is determined to be (1.15 +/- 0.05) x 10(-3), where the uncertainty is systematic only and the statistical uncertainty is negligible.
  •  
25.
  • Ablikim, M., et al. (författare)
  • An improved limit for Gamma(ee) of X(3872) and Gamma(ee) measurement of psi(3686)
  • 2015
  • Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 749, s. 414-420
  • Tidskriftsartikel (refereegranskat)abstract
    • Using the data sets taken at center-of-mass energies above 4 GeV by the BESIII detector at the BEPCII storage ring, we search for the reaction e(+)e(-) -> gamma(ISR) X(3872) -> gamma(ISR)pi(+)pi(-) J/psi via the Initial State Radiation technique. The production of a resonance with quantum numbers J(PC) = 1(++) such as the X(3872) via single photon e(+)e(-) annihilation is forbidden, but is allowed by a next-to-leading order box diagram. We do not observe a significant signal of X(3872), and therefore give an upper limit for the electronic width times the branching fraction Gamma B-X(3872)(ee)(X(3872) -> pi(+)pi(-) J/psi) < 0.13 eVat the 90% confidence level. This measurement improves upon existing limits by a factor of 46. Using the same final state, we also measure the electronic width of the psi(3686) to be Gamma(psi)(ee)(3686) ee = 2213 +/- 18(stat) +/- 99(sys) eV.
  •  
26.
  • 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.
  •  
27.
  • Ablikim, M., et al. (författare)
  • Determination of the Spin and Parity of the Z(c)(3900)
  • 2017
  • Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 119:7
  • Tidskriftsartikel (refereegranskat)abstract
    • The spin and parity of the Z(c)(3900)(+/-) state are determined to be J(P) = 1(+) with a statistical significance larger than 7 sigma over other quantum numbers in a partial wave analysis of the process e(+)e(-) -> pi(+)pi(-) J/psi We use a data sample of 1.92 fb(-1) accumulated at root s = 4.23 and 4.26 GeV with the BESIII experiment. When parametrizing the Z(c)(3900)(+/-) with a Flatte-like formula, we determine its pole mass M-pole = (3881.2 +/- 4.2(stat) +/- 52.7(syst)) MeV/c(2) and pole width Gamma(pole) = (51.8 +/- 4.6(stat) +/- 36.0(syst)) MeV. We also measure cross sections for the process e(+)e(-) -> Z(c)(3900)(+)pi(-) + c.c. -> J/psi pi(+)pi(-) and determine an upper limit at the 90% confidence level for the process e(+)e(-) -> Z(c)(4020)(+)pi(-) + c.c. -> J/psi pi(+)pi(-).
  •  
28.
  • Ablikim, M., et al. (författare)
  • Evidence for the singly Cabibbo suppressed decay Lambda(+)(c) -> p eta and search for Lambda(+)(c) -> p pi(0)
  • 2017
  • Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 95:11
  • Tidskriftsartikel (refereegranskat)abstract
    • We study the singly Cabibbo suppressed decays Lambda(+)(c) -> p eta and Lambda(+)(c) -> p pi(0) using Lambda(+)(c)(Lambda) over bar (-)(c) pairs produced by e(+)e(-) collisions at a center-of-mass energy of root s = 4.6 GeV. The data sample was collected by the BESIII detector at the BEPCII collider and corresponds to an integrated luminosity of 567 pb(-1). We find the first evidence for the decay Lambda(+)(c) -> p eta with a statistical significance of 4.2 sigma and measure its branching fraction to be B(Lambda(+)(c) -> p eta) = (1.24 +/- 0.28(stat) +/- 0.10(sys)) x 10(-3). No significant Lambda(+)(c) -> p pi(0) signal is observed. We set an upper limit on its branching fraction B(Lambda(+)(c) -> p pi(0)) < 2.7 x 10(-4) at the 90% confidence level.
  •  
29.
  • Ablikim, M., et al. (författare)
  • Evidence for e+e−→γηc(1S) at center-of-mass energies between 4.01 and 4.60 GeV
  • 2017
  • Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:5
  • Tidskriftsartikel (refereegranskat)abstract
    • We present first evidence for the process e(+)e(-) -> gamma eta(c)(1S) at six center-of-mass energies between 4.01 and 4.60 GeV using data collected by the BESIII experiment operating at BEPCII. We measure the Born cross section at each energy using a combination of twelve eta(c)(1S) decay channels. We also combine all six energies under various assumptions for the energy-dependence of the cross section. If the process is assumed to proceed via the Y(4260), we measure a peak Born cross section sigma(peak)(e(+)e(-) -> gamma eta(c)(1S)) = 2.11 +/- 0.49 (stat.) +/- 0.36 (syst.) pb with a statistical significance of 4.2 sigma.
  •  
30.
  • Ablikim, M., et al. (författare)
  • Improved measurements of X-cJ -> Sigma(+) (Sigma)over-bar(-) and Sigma(0)(Sigma)over-bar(0) decays
  • 2018
  • Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 97:5
  • Tidskriftsartikel (refereegranskat)abstract
    • Using a data sample of (448.1 +/- 2.9) x 10(6) psi (3686) events collected with the BESIII detector at the BEPCII collider, we present measurements of branching fractions for the decays X-cJ -> Sigma(+) (Sigma) over bar (-) and Sigma(0) (Sigma) over bar (0) The decays X-c1.2 -> Sigma(+) (Sigma) over bar (-) and Sigma (Sigma) over bar (0) are observed for the first time, and the branching fractions for X-c0 -> Sigma(+) (Sigma) over bar (-) and Sigma(0) (Sigma) over bar (0) decays are measured with improved precision. The branching fraction ratios between the charged and neutral modes are consistent with the prediction of isospin symmetry.
  •  
31.
  • Ablikim, M., et al. (författare)
  • Measurement of B(psi(3770) -> gamma chi(c1)) and search for psi(3770) -> gamma chi(c2)
  • 2015
  • Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:9
  • Tidskriftsartikel (refereegranskat)abstract
    • We report a measurement of the branching fraction for psi(3770) -> gamma chi(c1) and search for the transition psi(3770) -> gamma chi(c2) based on 2.92 fb(-1) of e(+)e(-) data accumulated at root s = 3.773 GeV with the BESIII detector at the BEPCII collider. We measure B(psi(3770) -> gamma chi(c1)) = (2.48 +/- 0.15 +/- 0.23) x 10(-3), which is the most precise measurement to date. The upper limit on the branching fraction of psi(3770) -> gamma chi(c2) at a 90% confidence level is B(psi(3770) -> gamma chi(c2)) < 0.64 x 10(-3). The corresponding partial widths are Gamma(psi(3770) -> gamma chi(c1)) = (67.5 +/- 4.1 +/- 6.7)keV and Gamma(psi(3770) -> gamma chi(c2)) < 17.4 keV.
  •  
32.
  • 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.
  •  
33.
  • Ablikim, M., et al. (författare)
  • Measurement of higher-order multipole amplitudes in psi(3686) -> gamma chi(c1,2) with chi(c1,2) -> gamma J/psi and search for the transition eta(c)(2S) -> gamma J/psi
  • 2017
  • Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 95:7
  • Tidskriftsartikel (refereegranskat)abstract
    • Using 106 x 10(6) psi(3686) events collected with the BESIII detector, we measure multipole amplitudes for the decay psi(3686) ->; gamma chi(c1,2) -> gamma gamma J/psi beyond the dominant electric-dipole amplitudes. The normalized magnetic-quadrupole (M2) amplitude for psi(3686) -> gamma chi(c1,2) -> gamma gamma J/psi and the normalized electric-dipole amplitudes for psi(3686) -> gamma chi(c2) -> gamma J/psi and determined. The M2 amplitudes for psi(3686) -> gamma chi(c1) and ; chi(c1,2) -> gamma J/psi are found to differ significantly from zero and are consistent with theoretical predictions. We also obtain the ratios of M2 contributions of psi(3686) and J/psi decays to;2,chi(c1,2,) b(2)(1/)b(2)(2) = 1.35 +/- 0.72 and a(2)(1/)a(2)(2) = 0.617 +/- 0.083,,which agree well with theoretical expectations. By considering the multipole contributions of chi(c1,2), we measure the product branching fractions for the cascade decays psi(3686) -> gamma chi(c 0,1,2) -> gamma gamma J/psi and search for the process eta(c)(2s) -> gamma J/psi through psi(3686) -> gamma eta(c)(2s).The product branching fraction for psi(3686) -> gamma chi(c0) -> gamma gamma J/psi is 3 sigma larger than published measurements, while those of psi(3686) -> gamma chi(c1,2) -> gamma gamma J/psi are consistent. No significant signal for the decay psi(3686) -> gamma eta(c) (2s) -> gamma gamma J/psi is observed, and the upper limit of the product branching fraction at the 90% confidence level is determined.
  •  
34.
  •  
35.
  • Ablikim, M., et al. (författare)
  • Measurement of the leptonic decay width of J/psi using initial state radiation
  • 2016
  • Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 761, s. 98-103
  • Tidskriftsartikel (refereegranskat)abstract
    • Using a data set of 2.93 fb(-1) taken at a center-of-mass energy of root s = 3.773 GeV with the BESIII detector at the BEPCII collider, we measure the process e(+) e(-) -> J/psi gamma -> mu(+)mu(-)gamma and determine the product of the branching fraction and the electronic width B-mu mu . Gamma(ee) = (333.4 +/- 2.5(stat) +/- 4.4(sys)) eV. Using the earlier-published BESIII result for B-mu mu = (5.973 +/- 0.007(stat) +/- 0.037(sys))%, we derive the J/psi electronic width Gamma(ee) = (5.58 +/- 0.05(stat) +/- 0.08(sys)) keV. (C) 2016 The Author(s). Published by Elsevier B.V.
  •  
36.
  • Ablikim, M., et al. (författare)
  • Measurement of the proton form factor by studying e(+)e(-) -> p(p)over-tilde
  • 2015
  • Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:11
  • Tidskriftsartikel (refereegranskat)abstract
    • Using data samples collected with the BESIII detector at the BEPCII collider, we measure the Born cross section of e(+)e(-) -> p (p) over tilde at 12 center-of-mass energies from 2232.4 to 3671.0 MeV. The corresponding effective electromagnetic form factor of the proton is deduced under the assumption that the electric and magnetic form factors are equal (vertical bar G(E)vertical bar = vertical bar G(M)vertical bar). In addition, the ratio of electric to magnetic form factors, vertical bar G(E)/G(M)vertical bar, and vertical bar G(M)vertical bar are extracted by fitting the polar angle distribution of the proton for the data samples with larger statistics, namely at root s = 2232.4 and 2400.0 MeV and a combined sample at root s = 3050.0, 3060.0 and 3080.0 MeV, respectively. The measured cross sections are in agreement with recent results from BABAR, improving the overall uncertainty by about 30%. The vertical bar G(E)/G(M)vertical bar ratios are close to unity and consistent with BABAR results in the same q(2) region, which indicates the data are consistent with the assumption that vertical bar G(E)vertical bar = vertical bar G(M)vertical bar within uncertainties.
  •  
37.
  • Ablikim, M., et al. (författare)
  • Measurements of psi(3686) -> K-Lambda(Xi)over-bar(+) + c.c. and psi(3686) -> gamma K-Lambda(Xi)over-bar(+) + c.c.
  • 2015
  • Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:9
  • Tidskriftsartikel (refereegranskat)abstract
    • Using a sample of 1.06 x 10(8) psi(3686) events produced in e(+)e(-) collisions at root s = 3.686 GeV and collected with the BESIII detector at the BEPCII collider, we present studies of the decays psi(3686) -> K-Lambda(Xi) over bar (+) + c.c. and psi(3686) -> gamma K-Lambda(Xi) over bar (+) + c.c. We observe two hyperons, Xi(1690)(-) and Xi(1820)(-), in the K-Lambda invariant mass distribution in the decay psi(3686) -> K-Lambda(Xi) over bar (+) + c.c. with significances of 4.9 sigma and 6.2 sigma, respectively. The branching fractions of psi(3686) -> K-Lambda(Xi) over bar (+) + c.c., psi(3686) -> K-Sigma(0)(Xi) over bar (+) + c.c, psi(3686) -> gamma chi cJ -> gamma K-Lambda(Xi) over bar (+) + c.c (J = 0, 1, 2), and psi(3686) -> Xi(1690/1820)(-)(Xi) over bar (+) + c.c with sub-sequent decay Xi(1690/1820)(-) -> K-Lambda are measured for the first time.
  •  
38.
  • Ablikim, M., et al. (författare)
  • Observation of a(0)(0)(980)-f(0)(980) Mixing
  • 2018
  • Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 121:2
  • Tidskriftsartikel (refereegranskat)abstract
    • We report the first observation of a(0)(0)(980)-f(0)(980) mixing in the decays of J/psi -> phi f(0)(980) -> phi a(0)(0)(980) -> phi eta pi(0) and chi(c1) -> a(0)(0)(980)pi(0) -> f(0)(980)pi(0)->pi(+)pi(-)pi(0), using data samples of 1.31 x 10(9) J/psi events and 4.48 x 10(8) psi (3686) events accumulated with the BESIII detector. The signals of f(0)(980) -> a(0)(0)(980) and a(0)(0)(980) -> f(0)(980) mixing are observed at levels of statistical significance of 7.4 sigma and 5.5 sigma, respectively. The corresponding branching fractions and mixing intensities are measured and the constraint regions on the coupling constants, g(a0K+K-) and g(f0K+K-), are estimated. The results improve the understanding of the nature of a(0)(0)(980) and f(0)(980).
  •  
39.
  • Ablikim, M., et al. (författare)
  • 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
  • Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 117:4
  • 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.
  •  
40.
  • Ablikim, M., et al. (författare)
  • Observation of J/psi -> gamma eta pi(0)
  • 2016
  • Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 94:7
  • Tidskriftsartikel (refereegranskat)abstract
    • We present the first study of the process J/psi -> gamma eta pi(0) using (223.7 +/- 1.4) x 10(6) J/psi events accumulated with the BESIII detector at the BEPCII facility. The branching fraction for J/psi -> gamma eta pi(0) is measured to be B(J/psi -> gamma eta pi(0)) = (2.14 +/- 0.18(stat) +/- 0.25(syst)) x 10(-5). With a Bayesian approach, the upper limits of the branching fractions B(J/psi -> gamma a(0)(980), a(0)(980) -> eta pi(0)) and B(J/psi -> gamma a(2)(1320), a(2)(1320) -> eta pi(0)) are determined to be 2.5 x 10(-6) and 6.6 x 10(-6) at the 95% confidence level, respectively. All of these measurements are given for the first time.
  •  
41.
  • Ablikim, M., et al. (författare)
  • Observation of the Dalitz decay eta ' -> gamma e(+)e(-)
  • 2015
  • Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 92:1
  • Tidskriftsartikel (refereegranskat)abstract
    • We report the first observation of the Dalitz decay eta' -> gamma e(+)e(-), based on a data sample of 1.31 billion J/psi events collected with the BESIII detector. The eta' mesons are produced via the J/psi -> gamma eta' decay process. The ratio (eta' -> gamma e(+)e(-))/Gamma (eta' -> gamma gamma) is measured to be (2.13 +/- 0.09(stat) +/- 0.07(sys)) x 10(-2). This corresponds to a branching fraction B(eta' -> gamma e(+)e(-)) = (4.69 +/- 0.20(stat) +/- 0.23(sys)) x 10(-4). The transition form factor is extracted and different expressions are compared to the measured dependence on the e(+)e(-) invariant mass. The results are consistent with the prediction of the vector meson dominance model.
  •  
42.
  • 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.))%.
  •  
43.
  • Ablikim, M., et al. (författare)
  • Observation of the electromagnetic doubly OZI-suppressed decay J/psi -> phi pi(0)
  • 2015
  • Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:11
  • Tidskriftsartikel (refereegranskat)abstract
    • Using a sample of 1.31 billion J/psi events accumulated with the BESIII detector at the BEPCII collider, we report the observation of the decay J/psi -> phi pi(0), which is the first evidence for a doubly Okubo-Zweig-Iizuka suppressed electromagnetic J/psi decay. A clear structure is observed in the K+K- mass spectrum around 1.02 GeV/c(2), which can be attributed to interference between J/psi -> phi pi(0) and J/psi -> K+K- pi(0) decays. Due to this interference, two possible solutions are found. The corresponding measured values of the branching fraction of J/psi -> phi pi(0) are [2.94 +/- 0.16(stat) +/- 0.16(syst)] x 10(-6) and [1.24 +/- 0.33(stat) +/- 0.30(syst)] x 10(-7).
  •  
44.
  • Ablikim, M., et al. (författare)
  • Observation of the isospin-violating decay J/psi -> phi pi(0)f(0) (980)
  • 2015
  • Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 92:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Using a sample of 1.31 x 10(9) J/psi events collected with the BESIII detector at the BEPCII collider, the decays J/psi -> phi pi(+)pi(-)pi(0) and J/psi -> phi pi(0)pi(0)pi(0) are investigated. The isospin- violating decay J/psi -> phi pi(0)f(0)(980) with f(0)(980)-> pi pi is observed for the first time. The width of the f(0)(980) obtained from the dipion mass spectrum is found to be much smaller than the world average value. In the pi(0)f(0)(980) mass spectrum, there is evidence of f(1)(1285) production. By studying the decay J/psi ->eta', the branching fractions of eta' -> pi(+)pi(-)pi(0) and eta' -> pi(0)pi(0)pi(0), as well as their ratio, are also measured.
  •  
45.
  • Ablikim, M., et al. (författare)
  • Search for the isospin violating decay Y(4260)-> J/psi eta pi(0)
  • 2015
  • Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 92:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Using data samples collected at center-of-mass energies of root s = 4.009, 4.226, 4.257, 4.358, 4.416, and 4.599 GeV with the BESIII detector operating at the BEPCII storage ring, we search for the isospin violating decay Y(4260)-> J/psi eta pi(0). No signal is observed, and upper limits on the cross section sigma(e(+)e(-) -> J/psi eta pi(0)) at the 90% confidence level are determined to be 3.6, 1.7, 2.4, 1.4, 0.9, and 1.9 pb, respectively.
  •  
46.
  • Ablikim, M., et al. (författare)
  • Search for the rare decays J/ψ→D0e+e−+c.c. and ψ(3686)→D0e+e−+c.c.
  • 2017
  • Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:11
  • Tidskriftsartikel (refereegranskat)abstract
    • Using the data samples of (1310.6 +/- 7.2) x 10(6) J/psi events and (448.1 +/- 2.9) x 10(6) psi(3686) events collected with the BESIII detector, we search for the rare decays J/psi -> D(0)e(+) e(-) + c.c. and psi(3686) -> D(0)e(+) e(-) + c.c. No significant signals are observed and the corresponding upper limits on the branching fractions at the 90% confidence level are determined to be B(J/psi -> D(0)e(+) e(-) + c.c.) < 8.5 x 10(-8) and B(psi(3686) -> D(0)e(+) e(-) + c.c.) < 1.4 x 10(-7), respectively. Our limit on B(J/psi -> D(0)e(+) e(-) + c.c.) is more stringent by 2 orders of magnitude than the previous results, and B(psi(3686) -> D(0)e(+) e(-) + c.c.) is measured for the first time.
  •  
47.
  • Ablikim, M., et al. (författare)
  • Search for ψ(3686)→γηc(η(1405))→γπ+π−π0
  • 2017
  • Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:11
  • Tidskriftsartikel (refereegranskat)abstract
    • Using a sample of 448.1×106  ψ(3686) events collected with the BESIII detector, a search for the isospin violating decay ηc→π+π−π0 via ψ(3686)→γηc is presented. No signal is observed, and the upper limit on B(ψ(3686)→γηc)×B(ηc→π+π−π0) is determined to be 1.6×10−6 at the 90% confidence level. In addition, a search for η(1405)→f0(980)π0 in ψ(3686) radiative decays is performed. No signal is observed, and the branching fraction B(ψ(3686)→γη(1405))×B(η(1405)→f0(980)π0)×B(f0(980)→π+π−) is calculated to be less than 5.0×10−7 at the 90% confidence level.
  •  
48.
  • Ablikim, M., et al. (författare)
  • Study of eta(1475) and X(1835) in radiative J/psi decays to gamma phi
  • 2018
  • Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 97:5
  • Tidskriftsartikel (refereegranskat)abstract
    • The decay J/psi -> gamma gamma phi is studied using a sample of 1.31 x 10(9) J/psi events collected with the BESIII detector. Two structures around 1475 MeV/c(2) and 1835 MeV/c(2) are observed in the gamma phi invariant mass spectrum for the first time. With a fit on the gamma phi invariant mass, which takes into account the interference between the two structures, and a simple analysis of the angular distribution, the structure around 1475 MeV/c(2) is found to favor an assignment as the eta(1475) and the mass and width for the structure around 1835 MeV/c(2) are consistent with the X(1835). The statistical significances of the two structures are 13.5 sigma and 6.3 sigma, respectively. The results indicate that both eta(1475) and X(1835) contain a sizeable s (s) over bar component.
  •  
49.
  • Ablikim, M., et al. (författare)
  • Study of J/ψ and ψ(3686) decays to π+π−η′
  • 2017
  • Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:11
  • Tidskriftsartikel (refereegranskat)abstract
    • Using the data samples of 1.31×109  J/ψ events and 4.48×108  ψ(3686) events collected with the BESIII detector, partial wave analyses on the decays J/ψ and ψ(3686)→π+π−η′ are performed with a relativistic covariant tensor amplitude approach. The dominant contribution is found to be J/ψ and ψ(3686) decays to ρη′. In the J/ψ decay, the branching fraction B(J/ψ→ρη′) is determined to be (7.90±0.19(stat)±0.49(sys))×10−5. Two solutions are found in the ψ(3686) decay, and the corresponding branching fraction B(ψ(3686)→ρη′) is (1.02±0.11(stat)±0.24(sys))×10−5 for the case of destructive interference, and (5.69±1.28(stat)±2.36(sys))×10−6 for constructive interference. As a consequence, the ratios of branching fractions between ψ(3686) and J/ψ decays to ρη′ are calculated to be (12.9±1.4(stat)±3.1(sys))% and (7.2±1.6(stat)±3.0(sys))%, respectively. We also determine the inclusive branching fractions of J/ψ and ψ(3686) decays to π+π−η′ to be (1.36±0.02(stat)±0.08(sys))×10−4 and (1.51±0.14(stat)±0.23(sys))×10−5, respectively
  •  
50.
  • Ablikim, M., et al. (författare)
  • Amplitude analysis of the chi(c1) -> eta pi(+)pi(-) decays
  • 2017
  • Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 95:3
  • 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.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-50 av 465
Typ av publikation
tidskriftsartikel (332)
konferensbidrag (6)
forskningsöversikt (2)
Typ av innehåll
refereegranskat (450)
övrigt vetenskapligt/konstnärligt (6)
Författare/redaktör
Jin, S. (329)
Cetin, S. A. (323)
Cakir, O. (320)
Chen, X. (292)
Berger, N. (243)
Chen, S. (225)
visa fler...
Bai, Y. (214)
Chen, H. (185)
Carvalho, J. (184)
Ferrer, A. (184)
Francis, D. (184)
Antonelli, M. (183)
Barillari, T. (183)
Barklow, T. (183)
Bella, G. (183)
Benekos, N. (183)
Bentvelsen, S. (183)
Besson, N. (183)
Bethke, S. (183)
Blumenschein, U. (183)
Boonekamp, M. (183)
Bruneliere, R. (183)
Calderini, G. (183)
Campana, S. (183)
Chudoba, J. (183)
Cranmer, K. (183)
Dallapiccola, C. (183)
Dubbert, J. (183)
Duckeck, G. (183)
Duflot, L. (183)
Eigen, G. (183)
Etzion, E. (183)
Fassouliotis, D. (183)
Ferrari, P. (183)
Fleck, I. (183)
Fuster, J. (183)
Garcia, C. (183)
Giagu, S. (183)
Goy, C. (183)
Graziani, E. (183)
Gross, E. (183)
Guicheney, C. (183)
Hamacher, K. (183)
Hauschild, M. (183)
Herten, G. (183)
Hughes, G. (183)
Kado, M. (183)
Kanaya, N. (183)
Kanzaki, J. (183)
Kawagoe, K. (183)
visa färre...
Lärosäte
Uppsala universitet (219)
Lunds universitet (82)
Karolinska Institutet (77)
Kungliga Tekniska Högskolan (70)
Stockholms universitet (47)
Göteborgs universitet (38)
visa fler...
Umeå universitet (17)
Högskolan i Skövde (8)
Högskolan Dalarna (8)
Linköpings universitet (4)
Chalmers tekniska högskola (4)
Linnéuniversitetet (4)
Mälardalens universitet (2)
Sveriges Lantbruksuniversitet (2)
Luleå tekniska universitet (1)
Högskolan i Halmstad (1)
Örebro universitet (1)
Jönköping University (1)
Mittuniversitetet (1)
Södertörns högskola (1)
visa färre...
Språk
Engelska (464)
Odefinierat språk (1)
Forskningsämne (UKÄ/SCB)
Naturvetenskap (225)
Medicin och hälsovetenskap (48)
Teknik (12)
Samhällsvetenskap (4)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy