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| 6. |
- Ablikim, M., et al.
(författare)
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Amplitude analysis of the D+ -> K-S(0)pi + (0)(pi) Dalitz plot
- 2014
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:5, s. 052001-
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Tidskriftsartikel (refereegranskat)abstract
- We perform an analysis of the D+ -> K-S(0)pi + (0)(pi) Dalitz plot using a data set of 2.92 fb(-1) of e(+) e(-) collisions at the (3770) mass accumulated by the BESIII experiment, in which 166694 candidate events are selected with a background of 15.1%. The Dalitz plot is found to be well represented by a combination of six quasitwo- body decay channels [k(SP)(0)(+) (1450)(+,) ] plus a small nonresonant component. Using the fit fractions from this analysis, partial branching ratios are updated with higher precision than previous measurements.
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| 7. |
- Ablikim, M., et al.
(författare)
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Measurement of chi(cJ) decaying into eta ' K+K-
- 2014
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:7, s. 074030-
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Tidskriftsartikel (refereegranskat)abstract
- Using (106.41 +/- 0.86) x 10(6) Psi(3686) events collected with the BESIII detector at BEPCII, we study for the first time the decay chi(cJ) -> eta'K+K- (J = 1, 2), where eta' -> gamma rho(0) and eta' -> eta pi(+)pi(-). A partial wave analysis in the covariant tensor amplitude formalism is performed for the decay chi(c1) -> eta'K+K-. Intermediate processes chi(c1) -> eta'f(2)'(1525) chi(c1) -> K-0*(1430)K-+/-(-/+) (K-0*(1430)(+/-) -> eta'K-+/-) are observed with statistical significances larger than 5 sigma, and their branching fractions are measured.
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| 8. |
- 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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| 9. |
- Ablikim, M., et al.
(författare)
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Observation of eta' -> pi(+) pi(-) pi(+) pi(-) and eta' -> pi(+) pi(-) pi(0) pi(0)
- 2014
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 112:25, s. 251801-
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Tidskriftsartikel (refereegranskat)abstract
- Using a sample of 1.3 x 10(9) J/psi events collected with the BESIII detector, we report the first observation of eta' -> pi(+) pi(-) pi(+) pi(-) and eta' -> pi(+) pi(-) pi(0) pi(0). The measured branching fractions are B(eta' -> pi(+) pi(-) pi(+) pi(-)) = [8.53 +/- 0.69(stat.) +/- 0.64(syst.)] x 10(-5) and B(eta' -> pi(+) pi(-) pi(0) pi(0)) = [1.82 +/- 0.35(stat.) +/- 0.18(syst.)] x 10(-4), which are consistent with theoretical predictions based on a combination of chiral perturbation theory and vector-meson dominance.
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| 10. |
- Ablikim, M., et al.
(författare)
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Precision measurement of the mass of the tau lepton
- 2014
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:1
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Tidskriftsartikel (refereegranskat)abstract
- An energy scan near the tau pair production threshold has been performed using the BESIII detector. About 24 pb(-1) of data, distributed over four scan points, were collected. This analysis is based on t pair decays to ee, e mu, eh, h, hh, e.,. and p. final states, where h denotes a charged p or K. The mass of the t lepton is measured from a maximum likelihood fit to the t pair production cross- section data to be m(tau) = 1776.91 +/- 0.12_0.10 - 0.13 _ MeV/c(2), which is currently the most precise value in a single measurement.
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| 11. |
- Ablikim, M., et al.
(författare)
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Search for the radiative transitions Psi(3770) -> gamma eta(c) and gamma eta(c) (2S)
- 2014
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:11, s. 112005-
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Tidskriftsartikel (refereegranskat)abstract
- By using a 2.92 fb-1 data sample taken at pffisffiffi 3.773 GeV with the BESIII detector operating at the BEPCII collider, we search for the radiative transitions.d3770c and cd2S through the hadronic decays cdcd2S. K0 SK p. No significant excess of signal events above background is observed. We set upper limits at a 90% confidence level for the product branching fractions to be Bdd3770cxBd.c. K0 SK k p < 1.6x10-5 and Bd.d3770cd2SxBd.cd2S. K0 SK p<5.6x10-6. Combining our result with world-average values of Bd.cd.cd2S. K0 SK p, we find the branching fractions Bd.d3770c< 6.8 x 10-4 and Bd.d3770cd2S< 2.0 x 10-3 at a 90% confidence level.
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| 12. |
- Ablikim, M., et al.
(författare)
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Search for the rare decays J/y -> D-s(-) rho(+) and J/psi -> <(D)over bar(0)<(K)over bar*(0)
- 2014
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:7, s. 071101-
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Tidskriftsartikel (refereegranskat)abstract
- A search for the rare decays of J/psi -> D-S(-) rho(+) + c.c. and J/psi -> <(D)over bar(0)<(K)over bar*(0) + c.c. is performed with a data sample of 225.3-million J/psi events collected with the Beijing Spectrometer III detector. No evident signal is observed. Upper limits on the branching fractions are determined to be beta(J/psi -> D-S(-)rho(+) + c.c.) < 1.3 x 10(-5) and beta(J/psi -> <(D)over bar(0)<(K)over bar*(0) + c.c.) < 2.5 x 10(-6) at the 90% confidence level.
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| 13. |
- Ablikim, M., et al.
(författare)
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Study of e(+)e(-) -> p(p)over-bar in the vicinity of psi(3770)
- 2014
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 735, s. 101-107
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Tidskriftsartikel (refereegranskat)abstract
- Using 2917 pb(-1) of data accumulated at 3.773 GeV, 44.5 pb(-1) of data accumulated at 3.65 GeV and data accumulated during a psi(3770) line-shape scan with the BESIII detector, the reaction e(+)e(-) -> p (p) over bar is studied considering a possible interference between resonant and continuum amplitudes. The cross section of e(+)e(-) -> psi(3770) -> p (p) over bar, sigma(e(+)e(-)-> psi(3770) -> p (p) over bar), is found to have two solutions, determined to be (0.059(-0.020)(+0.070) +/- 0.012) pb with the phase angle phi = (255.8(-26.6)(+39.0) +/- 4.8). (< 0.166 pb at the 90% confidence level), or sigma(e(+)e(-) -> psi(3770) -> p<(p)over bar>) = (2.57(-0.13)(+0.12) +/- 0.12) pb with phi = (266.9(-6.3)(+6.1) +/- 0.9)degrees both of which agree with a destructive interference. Using the obtained cross section of psi(3770) -> p (p) over bar, the cross section of p (p) over bar -> psi(3770), which is useful information for the future PANDA experiment, is estimated to be either (9.8(-3.9)(+11.8)) nb (< 27.5 nb at 90% C.L.) or (425.6(-43.7)(+42.9)) nb. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license.
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| 14. |
- Ablikim, M., et al.
(författare)
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Study of e(+)e(-) -> p(p)over-bar pi(0) in the vicinity of the psi(3770)
- 2014
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:3, s. 032007-
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Tidskriftsartikel (refereegranskat)abstract
- The process e(+)e(-) -> p (p) over bar pi(0) has been studied by analyzing data collected at root s = 3.773 GeV, root s = 3.650 GeV, and during a psi(3770) line shape scan with the BESIII detector at the BEPCII collider. The Born cross section of p (p) over bar pi(0) in the vicinity of the psi(3770) is measured, and the Born cross section of psi(3770) -> p (p) over bar pi(0) is extracted considering interference between resonant and continuum production amplitudes. Two solutions with the same probability and a significance of 1.5 sigma are found. The solutions for the Born cross section of psi(3770) -> p (p) over bar pi(0) are 33.8 +/- 1.8 +/- 2.1 pb and 0.06(-0.04-0.01)(+0.10+0.01) pb (< 0.22 pb at a 90% confidence level). Using the estimated cross section and a constant decay amplitude approximation, the cross section sigma(p<(p)over bar> -> psi(3770)pi(0)) is calculated for the kinematic situation of the planned (p) over bar ANDA experiment. The maximum cross section corresponding to the two solutions is expected to be less than 0.79 nb at 90% confidence level and 122 +/- 10 nb at a center-of-mass energy of 5.26 GeV.
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| 15. |
- 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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| 16. |
- 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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| 17. |
- 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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| 18. |
- Ablikim, M., et al.
(författare)
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Amplitude analysis of the pi(0)pi(0) system produced in radiative J/psi decays
- 2015
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 92:5
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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.
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| 19. |
- Ablikim, M., et al.
(författare)
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An improved limit for Gamma(ee) of X(3872) and Gamma(ee) measurement of psi(3686)
- 2015
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 749, s. 414-420
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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.
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| 20. |
- Ablikim, M., et al.
(författare)
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Branching fraction measurement of J/ψ→KSKL and search for J/ψ→KSKS
- 2017
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Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:11
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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.
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| 21. |
- Ablikim, M., et al.
(författare)
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Dark photon search in the mass range between 1.5 and 3.4 GeV/c
- 2017
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 774, s. 252-257
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Tidskriftsartikel (refereegranskat)abstract
- Using a data set of 2.93 fb taken at a center-of-mass energy root s = 3.773 GeV with the BESIII detector at the BEPCII collider, we perform a search for an extra U(1) gauge boson, also denoted as a dark photon. We examine the initial state radiation reactions e(+)e(-) -> e(+)e(-) gamma(ISR) and e(+)e(-) -> mu(+)mu(-) gamma(ISR) for this search, where the dark photon would appear as an enhancement in the invariant mass distribution of the leptonic pairs. We observe no obvious enhancement in the mass range between 1.5 and 3.4 GeV/c(2) and set a 90% confidence level upper limit on the mixing strength of the dark photon and the Standard Model photon. We obtain a competitive limit in the tested mass range.
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| 22. |
- Ablikim, M., et al.
(författare)
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Determination of the Spin and Parity of the Z(c)(3900)
- 2017
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Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 119:7
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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(-).
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| 23. |
- Ablikim, M., et al.
(författare)
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Evidence for e+e−→γηc(1S) at center-of-mass energies between 4.01 and 4.60 GeV
- 2017
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Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:5
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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.
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| 24. |
- Ablikim, M., et al.
(författare)
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Improved measurement of the absolute branching fraction of D+ -> (K)over-bar(0)mu(+)nu(mu)
- 2016
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Ingår i: European Physical Journal C. - : SPRINGER. - 1434-6044 .- 1434-6052. ; 76:7
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Tidskriftsartikel (refereegranskat)abstract
- By analyzing 2.93 fb(-1) of data collected at root s = 3.773 GeV with the BESIII detector, we measure the absolute branching fraction B(D+ -> (K) over bar (0) (+)(mu)nu(mu)) = (8.72 +/- 0.07(stat). +/- 0.18(sys).) %, which is consistent with previous measurements within uncertainties but with significantly improved precision. Combining the Particle Data Group values of B(D-0 -> K- mu(+)nu(mu)), B(D+-> (K) over bar (0)e(+)nu(e)), and the lifetimes of the D-0 and D+ mesons with the value of B(D+ -> (K) over bar (0)mu(+)nu(mu)) measured in this work, we determine the following ratios of partial widths: Gamma (D-0 -> (K) over bar (-)mu(+)nu(mu))/Gamma (D+ -> (K) over bar (0)mu+nu(mu)) = 0.963 +/- 0.044 and Gamma (D+ -> (K) over bar (0) mu+nu(mu))/Gamma(D+ -> (K) over bar (0)e+nu(e)) = 0.988 +/- 0.033.
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| 25. |
- Ablikim, M., et al.
(författare)
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Improved measurements of branching fractions for eta(c) -> phi phi and omega phi
- 2017
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 95:9
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Tidskriftsartikel (refereegranskat)abstract
- Using (223.7 +/- 1.4) x 10(6) J / Psi events accumulated with the BESIII detector, we study eta(c) decays to phi phi and omega phi final states. The branching fraction of n(c) -> phi phi is measured to be Br(eta(c) -> phi phi) = (2.5 +/- 0(-0.7)(+0.3) +/- 0.6) X 10(-3,) where the first uncertainty is statistical, the second is systematic, and the third is from the uncertainty of Br(J / Psi -> gamma eta(C)). No significant signal for the double Okubo-Zweig-Iizuka suppressed decay of eta(c) -> omega phi is observed, and the upper limit on the branching fraction is determined to be Br(eta(c) -> omega phi) < 2.5 x 10(-4) at the 90% confidence level.
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