SwePub - sökning: WFRF:(Zhou Wen)

Numrering	Referens	Omslagsbild	Hitta
51.	Ablikim, M., et al. (författare) Observation of the hindered electromagnetic Dalitz decay psi(3686) -> e(+) e(-)eta(c) 2022 Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 106:11 Tidskriftsartikel (refereegranskat)abstract Using a data sample of (448.1 +/- 2.9) x 10(6) psi(3686) decays collected at an e(+)e(& minus;) center-of-mass energy of 3.686 GeV by the BESIII detector at Beijing Electron Positron Collider II, we report an observation of the hindered electromagnetic Dalitz decay psi(3686) -> e(+)e(& minus;)eta(c) with a significance of 7.9 sigma. The branching fraction is determined to be B(psi(3686) -> e(+)e(& minus;)eta(c)) = (3.77 +/- 0.40(stat) +/- 0.18(syst)) x 10(& minus;5), agreeing well with the prediction of the vector meson dominance model. This is the first measurement of the electromagnetic Dalitz transition between the psi(3686) and the eta(c), which provides new insight into the electromagnetic properties of this decay, and offers new opportunities to measure the absolute branching fractions of eta(c) decays.
52.	Ablikim, M., et al. (författare) Observation of the J/ψ and ψ(3686) decays into ηΣ+¯Σ− 2022 Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 106:11 Tidskriftsartikel (refereegranskat)abstract The decays J/ψ → ηΣ+¯Σ− and ψ(3686) → ηΣ+¯Σ− are observed for the first time, using (10087±44) × 106 J/ψ and (448.1±2.9) × 106 ψ(3686) events collected with the BESIII detector at the BEPCII collider. We determine the branching fractions of these two decays to be B(J/ψ → ηΣ+¯Σ−) = (6.34±0.21±0.37) × 10−5 and B(ψ(3686) → ηΣ+¯Σ−) = (9.59±2.37±0.61) × 10−6, where the first uncertainties are statistical and the second are systematic. The ratio of these two branching fractions is determined to be B(ψ(3686) → ηΣ+¯Σ−) / B(J/ψ → ηΣ+¯Σ−) = (15.1±3.8)%, which is in agreement with the "12% rule".
53.	Ablikim, M., et al. (författare) Observation of Three Charmoniumlike States with JPC=1--in e+ e- → D0D-π 2023 Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 130:12 Tidskriftsartikel (refereegranskat)abstract The Born cross sections of the process e+e- -> D0D-x+ at center-of-mass energies from 4.189 to 4.951 GeV are measured for the first time. The data samples used correspond to an integrated luminosity of 17.9 fb-1 and were collected by the BESIII detector operating at the BEPCII storage ring. Three enhancements around 4.20, 4.47, and 4.67 GeV are visible. The resonances have masses of 4209.6 +/- 4.7 +/- 5.9 MeV=c2, 4469.1 +/- 26.2 +/- 3.6 MeV=c2, and 4675.3 +/- 29.5 +/- 3.5 MeV=c2 and widths of 81.6 +/- 17.8 +/- 9.0 MeV, 246.3 +/- 36.7 +/- 9.4 MeV, and 218.3 +/- 72.9 +/- 9.3 MeV, respectively, where the first uncertainties are statistical and the second systematic. The first and third resonances are consistent with the psi(4230) and psi(4660) states, respectively, while the second one is compatible with the psi(4500) observed in the e+e- -> K+K-J=psi process. These three charmoniumlike psi states are observed in the e+e- -> D0D-x+ process for the first time.
54.	Ablikim, M., et al. (författare) Observation of Z(c)(3900)(0) in e(+)e(-) -> pi(0)pi(0) J/Psi 2015 Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 115:11 Tidskriftsartikel (refereegranskat)abstract Using a data sample collected with the BESIII detector operating at the BEPCII storage ring, we observe a new neutral state Z(c)(3900)(0) with a significance of 10.4 sigma. The mass and width are measured to be 3894.8 +/- 2.3 +/- 3.2 MeV/c(2) and 29.6 +/- 8.2 +/- 8.2 MeV, respectively, where the first error is statistical and the second systematic. The Born cross section for e(+)e(-) -> pi(0)pi(0) J/Psi and the fraction of it attributable to pi(0)Z(c)(3900)(0) -> pi(0)pi(0) J/Psi in the range E-c.m. = 4.19-4.42 GeV are also determined. We interpret this state as the neutral partner of the four-quark candidate Z(c)(3900)(+/-).
55.	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.
56.	Ablikim, M., et al. (författare) Precise Measurements of Decay Parameters and CP Asymmetry with Entangled Lambda-(Lambda)over-bar Pairs 2022 Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 129:13 Tidskriftsartikel (refereegranskat)abstract Based on 10 billion J/psi events collected at the BESIII experiment, a search for CP violation in Lambda decay is performed in the difference between CP-odd decay parameters alpha_ for Lambda -> p pi(-) and alpha(+) for (Lambda) over bar -> (p) over bar pi(+) by using the process e(+)e(-) -> J/psi -> Lambda(Lambda) over bar. With a five-dimensional fit to the full angular distributions of the daughter baryon, the most precise values for the decay parameters arc determined to be a_ = 0.7519 +/- 0.0036 +/- 0.0024 and alpha(+) = -0.7559 +/- 0.0036 +/- 0.0030, respectively. The Lambda and (Lambda) over bar averaged value of the decay parameter is extracted to be a(avg) = 0.7542 +/- 0.0010 +/- 0.0024 with unprecedented accuracy. The CP asymmetry A(CP) = (alpha_ + alpha(+))/(a_-alpha(+)) is determined to be -0.0025 +/- 0.0046 +/- 0.0012, which is one of the most precise measurements in the baryon sector. The reported results for the decay parameter will play an important role in the studies of the polarizations and CP violations for the strange, charmed and beauty baryons.
57.	Ablikim, M., et al. (författare) Precision measurement of the D(0) decay branching fractions 2015 Ingår i:* Physical Review D. - 1550-7998 .- 1550-2368 .- 2470-0010. ; 91:3 Tidskriftsartikel (refereegranskat)abstract Using 482 pb(-1) of data taken at root s = 4.009 GeV, we measure the branching fractions of the decays of D(0) into D-0 pi(0) and D-0 gamma to be B(D(0) -> D-0 pi(0)) = (65.5 +/- 0.8 +/- 0.5)% and B(D(0) -> D0 gamma) = (34.5 +/- 0.8 +/- 0.5)%, respectively, by assuming that the D(0) decays only into these two modes. The ratio of the two branching fractions is B(D(0) -> D-0 pi(0))/B(D(0) -> D-0 gamma) = 1.90 +/- 0.07 +/- 0.05, which is independent of the assumption made above. The first uncertainties are statistical and the second ones systematic. The precision is improved by a factor of 3 compared to the present world average values.
58.	Ablikim, M., et al. (författare) Precision Measurement of the Decay Sigma(+) -> p gamma in the Process J/psi -> Sigma(+)(Sigma)over-bar(-) 2023 Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 130:21 Tidskriftsartikel (refereegranskat)abstract Using (10 087 +/- 44) x 10(6) J/psi events collected with the BESIII detector, the radiative hyperon decay Sigma(+) -> p gamma is studied at an electron-positron collider experiment for the first time. The absolute branching fraction is measured to be (0.996 +/- 0.021(stat) +/- 0.018(syst)) x 10(-3), which is lower than its world average value by 4.2 standard deviations. Its decay asymmetry parameter is determined to be -0.652 +/- 0.056(stat) +/- 0.020(syst). The branching fraction and decay asymmetry parameter are the most precise to date, and the accuracies are improved by 78% and 34%, respectively.
59.	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.
60.	Ablikim, M., et al. (författare) Search for baryon and lepton number violation in J/ψ → Λc+e- + c.c. 2019 Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 99:7 Tidskriftsartikel (refereegranskat)abstract Using 1.31 x 109 J/ψ events collected by the BESIII detector at the Beijing Electron Positron Collider, we search for the process J/ψ → Λc+e- + c.c. for the first time. In this process, both baryon and lepton number conservation is violated. No signal is found and the upper limit on the branching fraction Β(J/ψ → Λc+e- + c.c.) is set to be 6.9 x 10-8 at the 90% confidence level.
61.	Ablikim, M., et al. (författare) Search for C-parity violation in J/psi -> gamma gamma and gamma phi 2014 Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:9, s. 092002- Tidskriftsartikel (refereegranskat)abstract Using 1.06 x 10(8) psi(3686) events recorded in e(+)e(-) collisions at root s = 3.686 GeV with the BESIII at the BEPCII collider, we present searches for C-parity violation in J/psi -> gamma gamma and gamma phi decays via psi(3686) -> J/psi pi(+)pi(-). No significant signals are observed in either channel. Upper limits on the branching fractions are set to be B(J/psi -> gamma gamma) < 2.7 x 10(-7) and B(J/psi -> gamma phi) < 1.4 x 10(-6) at the 90% confidence level. The former is one order of magnitude more stringent than the previous upper limit, and the latter represents the first limit on this decay channel.
62.	Ablikim, M., et al. (författare) Search for the decay J/ψ → γ+ invisible 2020 Ingår i: Physical Review D. - : American Physical Society. - 1550-7998 .- 1550-2368. ; 101:11 Tidskriftsartikel (refereegranskat)abstract We search for J/ψ radiative decays into a weakly interacting neutral particle, namely an invisible particle, using the J/ψ produced through the process ψ(3686)→π+π−J/ψ in a data sample of (448.1±2.9)×106 ψ(3686) decays collected by the BESIII detector at BEPCII. No significant signal is observed. Using a modified frequentist method, upper limits on the branching fractions are set under different assumptions of invisible particle masses up to 1.2 GeV/c2. The upper limit corresponding to an invisible particle with zero mass is 7.0×10−7 at the 90% confidence level.
63.	Ablikim, M., et al. (författare) Search for the light hadron decay Ï‡c1(3872) â†’ Ï€+Ï€-Î· 2024 Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 109:1 Tidskriftsartikel (refereegranskat)abstract With a data sample corresponding to an integrated luminosity of 11.5 fb(-1) collected with the BESIII detector operating at the BEPCII storage ring, for the first time the light hadron decay chi(c1()3872)->pi(+)pi(-)eta is searched for. While no significant signal is observed, the upper limits at the 90% confidence level for sigma[e(+)e(-)->gamma chi(c1)(3872)]B[chi(c1)(3872)->pi(+)pi(-)eta] at center of mass energies from 4.13 GeV to 4.34 GeV are determined. By normalizing to the chi(c1)(3872)->pi(+)pi(-)J/psi decay channel, a 90% confidence level upper limit for the branching fraction ratio R=B[chi(c1)(3872)->pi(+)pi(-)eta]/B[chi(c1)(3872)->pi(+)pi(-)J/psi]<0.12 is given. These measurements provide important inputs for understanding the internal structure of the chi(c1)(3872) resonance
64.	Ablikim, M., et al. (författare) Search for the rare decay of ψ(3686)→Λ+c¯pe+e−+c.c. at BESIII 2018 Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 97:9 Tidskriftsartikel (refereegranskat)abstract Based on a data sample of (448.1 +/- 2.9) x 10(6)Psi(3686) decays collected with the BESIII experiment, a search for the flavor changing neutral current transition Psi(3686) -> Lambda(+)(c) pe(+) e(-) + c.c. is performed for the first time. No signal candidates are observed and the upper limit on the branching fraction of Psi(3686) -> Lambda(+)(c) pe(+) e(-) is determined to be 1.7 x 10(-6) at the 90% confidence level. The result is consistent with expectations from the standard model, and no evidence for new physics is found.
65.	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.
66.	Ablikim, M., et al. (författare) Search for the weak decay eta ' -> K-+/-pi(-/+) and precise measurement of the branching fraction B(J/psi -> phi eta ') 2016 Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 93:7 Tidskriftsartikel (refereegranskat)abstract We present the first search for the rare decay of eta' into K-+/- pi(-/+) in J/psi -> phi eta', using a sample of 1.3 x 10(9) J/psi events collected with the BESIII detector. No significant signal is observed, and the upper limit at the 90% confidence level for the ratio B(eta' -> K-+/- pi(-/+))/B(eta' -> gamma pi(+/-) pi(-/+)) is determined to be 1.3 x 10(-4). In addition, we report the measurement of the branching fraction of J/psi -> phi eta' to be [5.10 +/- 0.03(stat) +/- 0.32(syst)] x 10(-4), which agrees with previous results from BESII.
67.	Ablikim, M., et al. (författare) Search for the weak radiative decay ?c plus ? : ? plus ? at BESIII 2023 Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 107:5 Tidskriftsartikel (refereegranskat)abstract The Cabibbo-allowed weak radiative decay A+c -> E+gamma has been searched for in a sample of A+c over bar A- c pairs produced in e+e- annihilations, corresponding to an integrated luminosity of 4.5 fb-1 collected with the BESIII detector at center-of-mass energies between 4.60 and 4.70 GeV. No excess of signal above background is observed, and we set an upper limit on the branching fraction of this decay to be B(A+c -> E+gamma) < 4.4 x 10-4 at a confidence level of 90%, which is in agreement with Standard Model expectations.
68.	Ablikim, M., et al. (författare) Search for the Y(4140) via e(+)e(-) -> gamma phi J/psi at root s=4.23, 4.26 and 4.36 GeV 2015 Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:3 Tidskriftsartikel (refereegranskat)abstract Using data samples collected at center-of-mass energies root s = 4.23, 4.26, and 4.36 GeV with the BESIII detector operating at the BEPCII storage ring, we search for the production of the charmoniumlike state Y(4140) through a radiative transition followed by its decay to phi J/psi. No significant signal is observed and upper limits on sigma[e(+)e(-) -> gamma Y(4140)] . B(Y(4140) -> phi J/psi at the 90% confidence level are estimated as 0.35, 0.28, and 0.33 pb at root s = 4.23, 4.26, and 4.36 GeV, respectively.
69.	Ablikim, M., et al. (författare) Search for X(3872) -> pi(0)chi(c0) and X(3872) -> pi pi chi(c0) at BESIII 2022 Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 105:7 Tidskriftsartikel (refereegranskat)abstract Using 9.9 fb(-1) of e(+)e(-) collision data collected by the BESIII detector at center-of-mass energies between 4.15 and 4.30 GeV, we search for the processes e(+)e(-) -> gamma(X)(3872) with X(3872) -> pi(0)chi(c0) and X(3872) -> pi pi chi(c0). We set upper limits (at 90% C.L.) of B(X(3872)->pi(0)chi(c0))/B(X(3872) -> pi(+)pi(-) J/psi) < 3.6, B(X(3872) -> pi(+)pi(-)chi(c0))/B(X(3872) -> pi(+)pi(-) J/psi) < 0.56, and B(X(3872) -> pi(+)pi(-)chi(c0))/B(X(3872) -> pi(+)pi(-) J/psi) < 1.7. Combined with the BESIII measurement of X(3872) -> pi(0)chi(c1), we also set an upper limit of B(X(3872)->pi(0)chi(c0))/B(X(3872) -> pi(0)chi(c1) < 4.5.
70.	Ablikim, M., et al. (författare) Search for Z(c)(3900)(+/-) -> omega pi(+/-) 2015 Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 92:3 Tidskriftsartikel (refereegranskat)abstract The decay Z(c)(3900)(+/-) -> omega pi(+/-) is searched for using data samples collected with the BESIII detector operating at the BEPCII storage ring at center-of-mass energies root s = 4.23 and 4.26 GeV. No significant signal for the Z(c)(3900)(+/-) is found, and upper limits at the 90% confidence level on the Born cross section for the process e(+)e(-) -> Z(c)(3900)(+/-) pi(-/+) -> omega pi(+)pi(-) are determined to be 0.26 and 0.18 pb at root s = 4.23 and 4.26 GeV, respectively.
71.	Ablikim, M., et al. (författare) Studies of the decay D+s →†’ K+K-µ+vµ 2023 Ingår i: Journal of High Energy Physics (JHEP). - : Springer. - 1126-6708 .- 1029-8479. ; :12 Tidskriftsartikel (refereegranskat)abstract The D+s → K+K−μ+νμ decay is studied based on 7.33 fb−1 of e+e− collision data collected with the BESIII detector at center-of-mass energies in the range from 4.128 to 4.226 GeV. The absolute branching fraction is measured as B(D+s → ϕμ+νμ) = (2.25 ± 0.09 ± 0.07) × 10−2, the most precise measurement to date. Combining with the world average of B(D+s → ϕe+νe), the ratio of the branching fractions obtained is B(D+s → ϕμ+νμ) / B(D+s → ϕe+νe) = 0.94 ± 0.08, in agreement with lepton universality. By performing a partial wave analysis, the hadronic form factor ratios at q2 = 0 are extracted, finding rV = V (0) / A1(0) = 1.58 ± 0.17 ± 0.02 and r2 = A2(0) / A1(0) = 0.71 ± 0.14 ± 0.02, where the first uncertainties are statistical and the second are systematic. No significant S-wave contribution from f0(980) → K+K− is found. The upper limit B(D+s → f0(980)μ+νμ) · B(f0(980) → K+K−) < 5.45 × 10−4 is set at 90% credibility level.
72.	Ablikim, M., et al. (författare) Study of e(+)e(-) -> D+D-pi(+)pi(-) at center-of-mass energies from 4.36 to 4.60 GeV 2020 Ingår i: Physics Letters B. - : ELSEVIER. - 0370-2693 .- 1873-2445. ; 804 Tidskriftsartikel (refereegranskat)abstract We report a study of the e(+)e(-) -> D+D-pi(+)pi(-) process using e(+)e(-) collision data samples with an integrated luminosity of 2.5 fb(-1) at center-of-mass energies from 4.36 to 4.60 GeV, collected with the BESIII detector at the BEPCII storage ring. The D1(2420)+ is observed in the D+pi(+)pi(-) mass spectrum. The mass and width of the D-1(2420)+ are measured to be (2427.2 +/- 1.0(stat).+/- 1.2(syst).) MeV/c(2) and (23.2 +/- 2.3(stat). +/- 2.3(syst).) MeV, respectively. In addition, the Born cross sections of the e(+)e(-) -> D-1(2420)D-+(-) + c.c. -> D+D-pi(+)pi(-) and e(+)e(-) -> psi(3770)pi(+)pi(-) -> D+D-pi(+)pi(-) processes are measured as a function of the center-of-mass energy. (c) 2020 The Author. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
73.	Ablikim, M., et al. (författare) Study of e(+)e(-) -> gamma omega J/psi and Observation of X(3872) -> omega J/psi 2019 Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 122:23 Tidskriftsartikel (refereegranskat)abstract We study the e(+)e(-) -> gamma omega J/psi process using 11.6 fb(-1) e(+)e(-) annihilation data taken at center-of-mass energies from root s = 4.008 GeV to 4.600 GeV with the BESIII detector at the BEPCII storage ring. The X(3872) resonance is observed for the first time in the omega J/psi system with a significance of more than 5 sigma. The relative decay ratio of X(3872) -> omega J/psi and pi(+)pi(-)J/psi is measured to be R = 1.6(-0.3)(+0.4) +/- 0.2, where the first uncertainty is statistical and the second systematic (the same hereafter). The root s-dependent cross section of e(+)e(-) -> gamma X(3872) is also measured and investigated, and it can be described by a single Breit- Wigner resonance, referred to as the Y(4200), with a mass of 4200.6(-13.3)(+7.9) +/- 3.0 MeV/c(2) and a width of 115(-26)(+38) +/- 12 MeV. In addition, to describe the omega J/psi mass distribution above 3.9 GeV/c(2), we need at least one additional Breit-Wigner resonance, labeled as X(3915), in the fit. The mass and width of the X(3915) are determined. The resonant parameters of the X(3915) agree with those of the Y(3940) in B -> K omega J/psi and of the X(3915) in gamma gamma -> omega J/psi observed by the Belle and BABAR experiments within errors.
74.	Ablikim, M., et al. (författare) Study of e(+)e(-) -> omega chi(cJ) at Center of Mass Energies from 4.21 to 4.42 GeV 2015 Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 114:9 Tidskriftsartikel (refereegranskat)abstract Based on data samples collected with the BESIII detector at the BEPCII collider at nine center of mass energies from 4.21 to 4.42 GeV, we search for the production of e(+)e(-) -> omega chi(cJ) (J = 0, 1, 2). The process e(+)e(-) -> omega chi(c0) is observed for the first time, and the Born cross sections at root s = 4.23 and 4.26 GeV are measured to be (55.4 +/- 6.0 +/- 5.9) and (23.7 +/- 5.3 +/- 3.5) pb, respectively, where the first uncertainties are statistical and the second are systematic. The omega chi(c0) signals at the other seven energies and the e(+)e(-) -> omega chi(c1) and omega chi(c2) signals are not significant, and the upper limits on the cross sections are determined. By examining the omega chi(c0) cross section as a function of center of mass energy, we find that it is inconsistent with the line shape of the Y(4260) observed in e(+)e(-) -> pi(+)pi(-) J/psi Assuming the omega chi(c0) signals come from a single resonance, we extract the mass and width of the resonance to be (4230 +/- 8 +/- 6) MeV/c(2) and (38 +/- 12 +/- 2) MeV, respectively, and the statistical significance is more than 9 sigma.
75.	Ablikim, M., et al. (författare) Study of e plus e- ? : ?-?? plus at center-of-mass energies from 3.49 to 3.67 GeV 2023 Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 107:5 Tidskriftsartikel (refereegranskat)abstract Using data samples of e+e- collisions collected with the BESIII detector at eight center-of-mass energy points between 3.49 and 3.67 GeV, corresponding to an integrated luminosity of 670 pb-1, we present the upper limits of Born cross sections and the effective form factor for the process e+e- -> omega- over bar omega+. A fit to the cross sections using a perturbative QCD-derived energy-dependent function shows no significant threshold effect. The upper limit on the measured effective form factor is consistent with a theoretical prediction within the uncertainty of 1 sigma. These results provide new experimental information on the production mechanism of omega.
76.	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.
77.	Ablikim, M., et al. (författare) Study of J/psi -> eta phi pi(+)pi(-) at BESIII 2015 Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:5 Tidskriftsartikel (refereegranskat)abstract invariant mass spectrum of phi f(0)(980) with a statistical significance of greater than 10 sigma. The corresponding mass and width are determined to be M = 2200 +/- 6(stat) +/- 5(syst) MeV/c(2) and Gamma = 104 +/- 15(stat) +/- 15(syst) MeV, respectively, and the product branching fraction is measured to be B(J/psi ->eta Y(2175), Y(2175)->phi f(0)(980), f(0)(980)->pi(+)pi(-)) = (1.20 +/- 0.14(stat)+/- 0.37(syst))x10(-4). The results are consistent within errors with those of previous experiments. We also measure the branching fraction of J/psi ->phi f(1)(1285) with f(1)(1285)->eta pi(+)pi(-) and set upper limits on the branching fractions for J/psi ->phi eta(1405)/phi X(1835)/phi X(1870) with eta(1405)/X(1835)/X(1870)->eta pi(+)pi(-) at the 90% confidence level.
78.	Ablikim, M., et al. (författare) Study of the decay D+s→π+π+π−η and observation of the W-annihilation decay D+s→a0(980)+ρ0 2021 Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:7 Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract The decay D-s(+) -> pi(+) pi(+) pi(-)eta is observed for the first time, using e(+)e(-) collision data corresponding to an integrated luminosity of 6.32 fb(-1), collected by the BESIII detector at center-of-mass energies between 4.178 and 4.226 GeV. The absolute branching fraction for this decay is measured to be B(D-s(+) -> pi(+) pi(+) pi(-)eta) = (3.12 +/- 0.13(stat) +/- 0.09(syst))% The first amplitude analysis of this decay reveals the substructures in D-s(+) -> pi(+) pi(+) pi(-)eta and determines the relative fractions and the phases among these substructures. The dominant intermediate process is D-s(+) -> a(1)(1260)(+)eta, a(1)(1260)(+) -> rho(770)(0)pi(+) with a branching fraction of (1.73 +/- 0.14(stat) +/- 0.08(syst))%. We also observe the W-annihilation process D-s(+) -> a(0)(980)(+) rho(770)(0), a(0)(980)(+) -> pi(+)eta. with a branching fraction of (0.21 +/- 0.08(stat) +/- 0.05(syst))%, which is larger than the branching fractions of other measured pure W-annihilation decays by 1 order of magnitude.
79.	Ablikim, M., et al. (författare) Study of the resonance structures in the process e(+) e(-) -> pi(+) pi(-) J/psi 2022 Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 106:7 Tidskriftsartikel (refereegranskat)abstract Using about 23 fb(-1) of data collected with the BESIII detector operating at the BEPCII storage ring, a precise measurement of the e(+) e(-) -> pi(+) pi(-) J/psi Born cross section is performed at center-of-mass energies from 3.7730 to 4.7008 GeV. Two structures, identified as the Y(4220) and the Y(4320) states, are observed in the energy-dependent cross section with a significance larger than 10 sigma. The masses and widths of the two structures are determined to be (M,(sic)) = (4221.4 +/- 1.5 +/- 2.0 MeV=c(2); 41.8 +/- 2.9 +/- 2.7 MeV) and (M,(sic)) = (4298 +/- 12 +/- 26 MeV=c(2); 127 +/- 17 +/- 10 MeV)respectively. A small enhancement around 4.5 GeV with a significance about 3s, compatible with the psi(4415), might also indicate the presence of an additional resonance in the spectrum. The inclusion of this additional contribution in the fit to the cross section affects the resonance parameters of the Y(4320) state.
80.	Ablikim, M., et al. (författare) Study of η(1405)/η(1475) in J/ψ→γK0SK0Sπ0 decay 2023 Ingår i: Journal of High Energy Physics (JHEP). - : Springer Nature. - 1126-6708 .- 1029-8479. ; :3 Tidskriftsartikel (refereegranskat)abstract Using a sample of (10.09 +/- 0.04) x 109 J/psi decays collected with the BESIII detector, partial wave analyses of the decay J/psi -> gamma(KSKS0)-K-0 pi(0) are performed within the (KSKS0)-K-0 pi(0) invariant mass region below 1.6 GeV/c(2). The covariant tensor amplitude method is used in both mass independent and mass dependent approaches. Both analysis approaches exhibit dominant pseudoscalar and axial vector components, and show good consistency for the other individual components. Furthermore, the mass dependent analysis reveals that the (KSKS0)-K-0 pi(0) invariant mass spectrum for the pseudoscalar component can be well described with two isoscalar resonant states using relativistic Breit-Wigner model, i.e., the eta(1405) with a mass of 1391.7 +/- 0.7(-0.3)(+11.3) MeV/c(2) and a width of 60.8 +/- 1.2(-12.0)(+5.5) MeV, and the eta(1475) with a mass of 1507.6 +/- 1.6(-32.2)(+15.5) MeV/c(2) and a width of 115.8 +/- 2.4(-10.9)(+14.8) MeV. The first and second uncertainties are statistical and systematic, respectively. Alternate models for the pseudoscalar component are also tested, but the description of the -10.9 invariant mass spectrum deteriorates significantly.
81.	Ablikim, M., et al. (författare) Amplitude Analysis of D-s(+) -> pi(+)pi(0)eta and First Observation of the W-Annihilation Dominant Decays D-s(+) -> a(0)(980)(+)pi(0) and D-s(+) -> a(0)(980)(0)pi(+) 2019 Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 123:11 Tidskriftsartikel (refereegranskat)abstract We present the first amplitude analysis of the decay D-s(+) -> pi(+)pi(0)eta. We use an e(+)e(-) collision data sample corresponding to an integrated luminosity of 3.19 fb(-1) collected with the BESIII detector at a center-of-mass energy of 4.178 GeV. We observe for the first time the W-annihilation dominant decays D-s(+) -> a(0)(980)(+)pi(0) and D-s(+) -> a(0)(980)(0)pi(+). We measure the absolute branching fraction B(D-s(+) -> a(0)(980)(+(0))pi(0(+)), a(0)(980)(+(0)) -> pi(+(0)())eta = (1.46 +/- 0.15(stat )+/- 0.23 sys)%, which is larger than the branching fractions of other measured pure W-annihilation decays by at least one order of magnitude. In addition, we measure the branching fraction of D-s(+) -> pi(+)pi(0)eta with significantly improved precision.
82.	Ablikim, M., et al. (författare) Amplitude analysis of D-s(+) -> pi(+) pi(-) pi(+) 2022 Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 106:11 Tidskriftsartikel (refereegranskat)abstract Utilizing the data set corresponding to an integrated luminosity of 3.19 fb(-1) collected by the BESIII detector at a center-of-mass energy of 4.178 GeV, we perform an amplitude analysis of the D-s(+) -> pi(+) pi(-) pi(+) decay. The sample contains 13,797 candidates with a signal purity of similar to 80%. The amplitude and phase of the contributing pi pi S wave are measured based on a quasi-model-independent approach, along with the amplitudes and phases of the P and D waves parametrized by Breit-Wigner models. The fit fractions of different intermediate decay channels are also reported.
83.	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.
84.	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.
85.	Ablikim, M., et al. (författare) Amplitude analysis of the π$^0$π$^0$ system produced in radiative J/ψ decays 2016 Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 93:3 Tidskriftsartikel (refereegranskat)abstract An amplitude analysis of the π0π0 system produced in radiative J/ψ decays is presented. In particular, a piecewise function that describes the dynamics of the π0π0 system is determined as a function of Mπ0π0 from an analysis of the (1.311±0.011)×109 J/ψ decays collected by the BESIII detector. The goal of this analysis is to provide a description of the scalar and tensor components of the π0π0 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/ψ→γπ0π0 is determined to be (1.15±0.05)×10-3, where the uncertainty is systematic only and the statistical uncertainty is negligible.
86.	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.
87.	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.
88.	Ablikim, M., et al. (författare) Determination of the absolute branching fractions of D0 → K-e+νe and D+ → K0e+νe 2021 Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:5 Tidskriftsartikel (refereegranskat)abstract Using 2.93 fb(-1) of e(+)e(-) collision data collected with the BESIII detector at a center-of-mass energy of 3.773 GeV, we measure the absolute branching fractions of the decays D-0 -> K(-)e(+)nu(e) and D+ -> (K) over bar (0)e(+)nu(e) to be (3.567 +/- 0.031(stat) +/- 0.025(syst))% and (8.68 +/- 0.14(stat) +/- 0.16(syst))%, respectively. Starting with the process e(+)e(- ) -> D (D) over bar, a new reconstruction method is employed to select events that contain candidates for both D -> (K) over bare(+)nu(e) and (D) over bar -> Ke(-)(nu) over bar (e) decays. The branching fractions reported in this work are consistent within uncertainties with previous BESIII measurements that selected events containing D -> (K) over bare(+)nu(e) and hadronic (D) over bar decays. Combining our results with the lifetimes of the D degrees and D+ mesons and the previous BESIII measurements leads to a ratio of the two decay partial widths of (Gamma) over bar (D0 -> K-e+)(nu e)/(Gamma) over bar (D+ -> (K) over bar 0e+)(nu e) = 1.039 +/- 0.021. This ratio supports isospin symmetry in the D-0 -> K(-)e(+)nu(e) and D+ -> (K) over bar (0)e(+)nu(e) decays within 1.9 sigma.
89.	Ablikim, M., et al. (författare) Determination of the CP-even fraction of D0? : K0Sp+p-p0 2023 Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 108:3 Tidskriftsartikel (refereegranskat)abstract Quantum-correlated D D over bar pairs collected by the BESIII experiment at the & psi;(3770) resonance corresponding to an integrated luminosity of 2.93 fb-1 are used to study the D0 & RARR; K0S & pi;+& pi;- & pi;0 decay mode. The CP-even fraction of D0 & RARR; K0S & pi;+& pi;- & pi;0 decays is determined to be 0.235 & PLUSMN; 0.010 & PLUSMN; 0.002, where the first uncertainty is statistical and the second is systematic.
90.	Ablikim, M., et al. (författare) Determination of the number of ψ(3686) events at BESIII 2018 Ingår i: Chinese Physics C. - : IOP Publishing. - 1674-1137 .- 2058-6132. ; 42:2 Tidskriftsartikel (refereegranskat)abstract The numbers of psi(3686) events accumulated by the BESIII detector for the data taken during 2009 and 2012 are determined to be (107.0 +/- 0.8)x10(6) and (341.1 +/- 2.1)x10(6), respectively, by counting inclusive hadronic events, where the uncertainties are systematic and the statistical uncertainties are negligible. The number of events for the sample taken in 2009 is consistent with that of the previous measurement. The total number of psi(3686) events for the two data taking periods is (448.1 +/- 2.9) x 10(6).
91.	Ablikim, M., et al. (författare) Evidence for the decays of Lambda(+)(C) -> Sigma(+) eta and Sigma(+) eta ' 2019 Ingår i: Chinese Physics C. - : IOP PUBLISHING LTD. - 1674-1137 .- 2058-6132. ; 43:8 Tidskriftsartikel (refereegranskat)abstract We study the hadronic decays of Lambda(+)(C) to the final states Sigma(+) eta and Sigma(+) eta', using an e(+) e(-) annihilation data sample of 567 pb(-1) taken at a center-of-mass energy of 4.6 GeV with the BESIII detector at the BEPCII collider. We find evidence for the decays Lambda(+)(C) -> Sigma(+) eta and Sigma(+) eta' with statistical significance of and, respectively. Normalizing to the reference decays Lambda(+)(C) -> Sigma(+) pi(0) and Sigma(+) omega, we obtain the ratios of the branching fractions B(Lambda(+)(C) -> Sigma(+) eta)/B(Lambda(+)(C) -> Sigma(+) pi(0)) and B(Lambda(+)(C) -> Sigma(+) eta')/B(Lambda(+)(C) -> Sigma(+) omega) to be 0.35 +/- 0.16 +/- 0.02 and 0.86 +/- 0.34 +/- 0.04, respectively. The upper limits at the 90% confidence level are set to be B(Lambda(+)(C) -> Sigma(+) eta)/B(Lambda(+)(C) -> Sigma(+) pi(0)) < 0.58 and B(Lambda(+)(C) -> Sigma(+) eta')/B(Lambda(+)(C) -> Sigma(+) omega) < 1.2. Using BESIII measurements of the branching fractions of the reference decays, we determine B(Lambda(+)(C) -> Sigma(+) eta) = (0.41 +/- 0.19 +/- 0.05)% (<0.68%) and B(Lambda(+)(C) -> Sigma(+) eta') = (1.34 +/- 0.53 +/- 0.19)% (<1.9%). Here, the first uncertainties are statistical and the second systematic. The obtained branching fraction of Lambda(+)(C) -> Sigma(+) eta is consistent with the previous measurement, and the branching fraction of Lambda(+)(C) -> Sigma(+) eta' is measured for the first time.
92.	Ablikim, M., et al. (författare) Evidence for the eta(c)(2S) -> pi(+)pi(-)eta decay 2023 Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 107:5 Tidskriftsartikel (refereegranskat)abstract The decay eta(c)(2S) -> pi(+)pi(-)eta is searched for through the radiative transition psi(3686) -> gamma eta(c)(2S) using 448 million psi(3686) events accumulated at the BESIII detector. The first evidence of eta(c)(2S) -> pi(+)pi(-)eta is found with a statistical significance of 3.5 sigma. The product of the branching fractions of psi(3686) -> gamma eta(c)(2S) and eta(c)(2S) -> pi(+)pi(-)eta is measured to be Br(psi(3686) -> gamma eta(c)(2S)) x Br(eta(c)(2S) -> pi(+)pi(-)eta) = (2.97 +/- 0.81 +/- 0.26) x 10(-6), where the first uncertainty is statistical and the second one is systematic. The branching fraction of the decay eta(c)(2S) -> pi(+)pi(-)eta is determined to be Br(eta(c)(2S) -> pi(+)pi(-)eta) = (42.4 +/- 11.6 +/- 3.8 +/- 30.3) x 10(-4), where the third uncertainty is transferred from the uncertainty of the branching fraction of psi(3686) -> gamma eta(c)(2S).
93.	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.
94.	Ablikim, M., et al. (författare) Future Physics Programme of BESIII * 2020 Ingår i: Chinese Physics C. - : IOP Publishing. - 1674-1137 .- 2058-6132. ; 44:4 Tidskriftsartikel (refereegranskat)abstract There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESIII and B factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related X(1835) meson state at BESIII, as well as the threshold measurements of charm mesons and charm baryons. We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESIII during the remaining operation period of BEPCII. This survey will help in the optimization of the data-taking plan over the coming years, and provides physics motivation for the possible upgrade of BEPCII to higher luminosity.
95.	Ablikim, M., et al. (författare) Improved measurement of the decays ?′ → ?+⁢?−⁢?+(0)⁢?−(0) and search for the rare decay ?′ → 4⁢?0 2024 Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 109:3 Tidskriftsartikel (refereegranskat)abstract Using a sample of 10 billion ?/? events collected with the BESIII detector, the decays ?′ → ?+⁢?−⁢?+⁢?−, ?′ → ?+⁢?−⁢?0⁢?0 and ?′ → 4⁢?0 are studied via the process ?/? → ?⁢?′. The branching fractions of ?′ → ?+⁢?−⁢?+⁢?− and ?′ → ?+⁢?−⁢?0 ?0 are measured to be (8.56±0.25⁢(stat)±0.23⁢(syst))×10−5 and (2.12±0.12⁢(stat)±0.10⁢(syst))×10−4, respectively, which are consistent with previous measurements but with improved precision. No significant ?′ → 4⁢?0 signal is observed, and the upper limit on the branching fraction of this decay is determined to be less than 1.24×10−5 at the 90% confidence level. In addition, an amplitude analysis of ?′ → ?+⁢?−⁢?+⁢?− is performed to extract the doubly virtual isovector form factor ? for the first time. The measured value of ?=1.22±0.33⁢(stat)±0.04⁢(syst), is in agreement with the prediction of the vector meson dominance model.
96.	Ablikim, M., et al. (författare) Improved measurements of the absolute branching fractions of the inclusive decays D+(0) -> phi X 2019 Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 100:7 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.
97.	Ablikim, M., et al. (författare) Inclusive charged and neutral particle multiplicity distributions in chi(cJ) and J/psi decays 2020 Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 1550-7998 .- 1550-2368. ; 102:5 Tidskriftsartikel (refereegranskat)abstract Using a sample of 106 million psi(3686) decays, psi(3686) -> gamma chi(cJ) (J = 0, 1, 2) and psi(3686) -> gamma chi(cJ), chi(cJ) -> gamma J/psi (J = 1, 2) events are utilized to study inclusive chi(cJ )-> anything, chi(cJ )-> hadrons, and J/psi( )-> anything distributions, including distributions of the number of charged tracks, electromagnetic calorimeter showers, and pi(0)s, and to compare them with distributions obtained from the BESIII Monte Carlo simulation. Information from each Monte Carlo simulated decay event is used to construct matrices connecting the detected distributions to the input predetection "produced" distributions. Assuming these matrices also apply to data, they are used to predict the analogous produced distributions of the decay events. Using these, the charged particle multiplicities are compared with results from MARK I. Further, comparison of the distributions of the number of photons in data with those in Monte Carlo simulation indicates that G-parity conservation should be taken into consideration in the simulation.
98.	Ablikim, M., et al. (författare) Luminosities and energies of e+e− collision data taken between √s=4.61 GeV and 4.95 GeV at BESIII 2022 Ingår i: Chinese Physics C. - : Institute of Physics (IOP). - 1674-1137 .- 2058-6132. ; 46:11 Tidskriftsartikel (refereegranskat)abstract From December 2019 to June 2021, the BESIII experiment collected approximately 5.85 fb−1 of data at center-of-mass energies between 4.61 and 4.95 GeV. This is the highest collision energy BEPCII has reached to date. The accumulated annihilation data samples are useful for studying charmonium(-like) states and charmed-hadron decays. By adopting a novel method of analyzing the production of pairs in annihilation, the center-of-mass energies are measured with a precision of 0.6 MeV. Integrated luminosities are measured with a precision of better than 1% by analyzing the events of large-angle Bhabha scattering. These measurements provide important inputs to analyses based on these data samples.
99.	Ablikim, M., et al. (författare) Measurement of branching fraction of D-s+ -> D-s(+)pi(0) relative to D-s+ -> D-s(+)gamma 2023 Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 107:3 Tidskriftsartikel (refereegranskat)abstract Based on 7.33 fb(-1) of e(+)e(-) collision data taken at center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector, we measure the branching fraction of D-s(+)-> D-s(+)pi(0) relative to that of D-s(+) -> D-s(+)gamma to be (6.16 +/- 10.43 +/- 10.18)%. The first uncertainty is statistical and the second one is systematic. By using the world average value of the branching fraction of D-s(+) -> D-s(+) e(+)e(-), we determine the branching fractions of D-s(+) -> D-s(+)gamma and D-s(*+) -> D-s(+)pi(0) to be (93.57 +/- 10.38 +/- 10.22)% and (5.76 +/- 10.38 +/- 10.16)%, respectively.
100.	Ablikim, M., et al. (författare) Measurement of cross section for e+e- -> Ξ0 Ξover-bar0 near threshold 2021 Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 820 Tidskriftsartikel (refereegranskat)abstract Using e(+)e(-) collision data at ten center-of-mass energies between 2.644 and 3.080 GeV collected with the BESIII detector at BEPCII and corresponding to an integrated luminosity of about 500 pb(-1), we measure the cross sections and effective form factors for the process e(+)e(-) -> Xi(0)(Xi) over bar (0) utilizing a single-tag method. A fit to the cross section of e(+)e(-) -> Xi(0)(Xi) over bar (0) with a pQCD-driven power function is performed, from which no significant resonance or threshold enhancement is observed. In addition, the ratio of cross sections for the processes e(+)e(-) -> Xi(0)(Xi) over bar (0) and Xi(0)(Xi) over bar (0) is calculated using recent BESIII measurement and is found to be compatible with expectation from isospin symmetry.

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