Using $e^+ e^-$ collision data collected at the BESIII detector at center-of-mass energies between 4.128 and 4.226 GeV, corresponding to an integrated luminosity of $7.33~{\rm fb}^{-1}$, we determine the absolute branching fractions of fifteen hadronic $D_s^{+}$ decays with a double-tag technique. In particular, we make precise measurements of the branching fractions $\mathcal{B}(D_s^+ \to K^+ K^- \pi^+)=(5.49 \pm 0.04 \pm 0.07)\%$, $\mathcal{B}(D_s^+ \to K_S^0 K^+)=(1.50 \pm 0.01 \pm 0.01)\%$ and $\mathcal{B}(D_s^+ \to K^+ K^- \pi^+ \pi^0)=(5.50 \pm 0.05 \pm 0.11)\%$, where the first uncertainties are statistical and the second ones are systematic. The \emph{CP} asymmetries in these decays are also measured and all are found to be compatible with zero.

We present measurements of the Born cross sections for the processes e^{+}e^{-}→ωχ_{c1} and ωχ_{c2} at center-of-mass energies sqrt[s] from 4.308 to 4.951 GeV. The measurements are performed with data samples corresponding to an integrated luminosity of 11.0  fb^{-1} collected with the BESIII detector operating at the Beijing Electron Positron Collider storage ring. Assuming the e^{+}e^{-}→ωχ_{c2} signals come from a single resonance, the mass and width are determined to be M=(4413.6±9.0±0.8)  MeV/c^{2} and Γ=(110.5±15.0±2.9)  MeV, respectively, which is consistent with the parameters of the well-established resonance ψ(4415). In addition, we also use one single resonance to describe the e^{+}e^{-}→ωχ_{c1} line shape and determine the mass and width to be M=(4544.2±18.7±1.7)  MeV/c^{2} and Γ=(116.1±33.5±1.7)  MeV, respectively. The structure of this line shape, observed for the first time, requires further understanding.

Based on (2712.4±14.3)×106 e+e−→ψ(3686) events collected with the BESIII detector operating at the BEPCII Collider, we report the first evidence of χc0→ΛΛ¯ϕ decays and the first observation of χc1,2→ΛΛ¯ϕ decays, with significances of 4.1σ, 11.3σ and 13.0σ, respectively. The decay branching fractions of χc0,1,2→ΛΛ¯ϕ are measured to be (2.99±1.24±0.19)×10−5, (6.01±0.90±0.40)×10−5, and (7.13±0.81±0.36)×10−5, where the first uncertainties are statistical and the second systematic. No obvious enhancement near the ΛΛ¯ production threshold or excited Λ state is found in the Λϕ (or Λ¯ϕ) system. Published by the American Physical Society 2024

We present cross sections for the reaction e(+)e(-) -> (KSKL0)-K-0 at center-of-mass energies ranging from 3.51 to 4.95 GeV using data samples collected in the BESIII experiment, corresponding to a total integrated luminosity of 26.5 fb(-1). The ratio of neutral-to-charged kaon form factors at large momentum transfers (12 < Q(2) < 25 GeV2) is determined to be 0.21 +/- 0.01, which indicates a small but significant effect of flavor-SU(3) breaking in the kaon wave function, and, consequently, excludes the possibility that flavor-SU(3) breaking is the primary reason for the strong experimental violation of the pQCD prediction vertical bar F(pi(+/-))vertical bar/vertical bar F(K-+/-)vertical bar = f(pi)(2)/f(K)(2), where F(pi(+/-)) and F(K-+/-) are the form factors, and f(pi) and f(K) are the decay constants of charged pions and kaons, respectively. We also observe a significant signal for the charmless decay psi(3770)->(KSKL0)-K-0 for the first time. Within a 1 sigma contour of the likelihood value, the branching fraction for psi(3770)-> K K-0(S)L(0) is determined to be B=(2.63(-1.59)(+1.40)) x 10(-5), and the relative phase between the continuum and psi(3770) amplitudes is phi = (-0.39(-0.10)(+0.05))pi. The branching fraction is in good agreement with the S- and D-wave charmonia mixing scheme proposed in the interpretation of the "rho pi puzzle" between J/psi and psi(3686) decays.

Using e^{+}e^{-} collision data corresponding to an integrated luminosity of 7.33  fb^{-1} recorded by the BESIII detector at center-of-mass energies between 4.128 and 4.226 GeV, we present an analysis of the decay D_{s}^{+}→π^{+}π^{-}e^{+}ν_{e}, where the D_{s}^{+} is produced via the process e^{+}e^{-}→D_{s}^{*±}D_{s}^{∓}. We observe the f_{0}(980) in the π^{+}π^{-} system and the branching fraction of the decay D_{s}^{+}→f_{0}(980)e^{+}ν_{e} with f_{0}(980)→π^{+}π^{-} measured to be (1.72±0.13_{stat}±0.10_{syst})×10^{-3}, where the uncertainties are statistical and systematic, respectively. The dynamics of the D_{s}^{+}→f_{0}(980)e^{+}ν_{e} decay are studied with the simple pole parametrization of the hadronic form factor and the Flatté formula describing the f_{0}(980) in the differential decay rate, and the product of the form factor f_{+}^{f_{0}}(0) and the c→s Cabibbo-Kobayashi-Maskawa matrix element |V_{cs}| is determined for the first time to be f_{+}^{f_{0}}(0)|V_{cs}|=0.504±0.017_{stat}±0.035_{syst}. Furthermore, the decay D_{s}^{+}→f_{0}(500)e^{+}ν_{e} is searched for the first time but no signal is found. The upper limit on the branching fraction of D_{s}^{+}→f_{0}(500)e^{+}ν_{e}, f_{0}(500)→π^{+}π^{-} decay is set to be 3.3×10^{-4} at 90% confidence level.

Abstract Using e + e − collision data collected by the BESIII detector at BEPCII corresponding to an integrated luminosity of 30 fb −1, we measure Born cross sections and effective form factors for the process e + e − → Ξ 0 Ξ ¯ 0 $$ {e}^{+}{e}^{-}\to {\Xi}^0{\overline{\Xi}}^0 $$ at forty-five center-of-mass energies between 3.51 and 4.95 GeV. The dressed cross section is fitted, assuming a power-law function plus a charmonium(-like) state, i.e., ψ(3770), ψ(4040), ψ(4160), ψ(4230), ψ(4360), ψ(4415) or ψ(4660). No significant charmonium(-like) state decaying into Ξ 0 Ξ ¯ 0 $$ {\Xi}^0{\overline{\Xi}}^0 $$ is observed. Upper limits at the 90% confidence level on the product of the branching fraction and the electronic partial width are provided for each decay. In addition, ratios of the Born cross sections and the effective form factors for e + e − → Ξ 0 Ξ ¯ 0 $$ {e}^{+}{e}^{-}\to {\Xi}^0{\overline{\Xi}}^0 $$ and e + e − → Ξ − Ξ ¯ + $$ {e}^{+}{e}^{-}\to {\Xi}^{-}{\overline{\Xi}}^{+} $$ are also presented to test isospin symmetry and the vector meson dominance model.

Using e+e− collision data corresponding to an integrated luminosity of 7.33 fb−1 recorded by the BESIII detector at center-of-mass energies between 4.128 and 4.226 GeV, we present an analysis of the decay Ds+→π+π−e+νe, where the Ds+ is produced via the process e+e−→Ds*±Ds∓. We observe the f0(980) in the π+π− system and the branching fraction of the decay Ds+→f0(980)e+νe with f0(980)→π+π− measured to be (1.72±0.13stat±0.10syst)×10−3, where the uncertainties are statistical and systematic, respectively. The dynamics of the Ds+→f0(980)e+νe decay are studied with the simple pole parametrization of the hadronic form factor and the Flatté formula describing the f0(980) in the differential decay rate, and the product of the form factor f+f0(0) and the c→s Cabibbo-Kobayashi-Maskawa matrix element |Vcs| is determined for the first time to be f+f0(0)|Vcs|=0.504±0.017stat±0.035syst. Furthermore, the decay Ds+→f0(500)e+νe is searched for the first time but no signal is found. The upper limit on the branching fraction of Ds+→f0(500)e+νe, f0(500)→π+π− decay is set to be 3.3×10−4 at 90% confidence level.Received 23 March 2023Revised 29 November 2023Accepted 28 February 2024DOI:https://doi.org/10.1103/PhysRevLett.132.141901Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasLeptonic, semileptonic & radiative decaysMultiquark bound statesQuantum chromodynamicsStrong interactionPhysical SystemsCharm quarkMesonsPropertiesForm factorsParticles & Fields

The number of psi' events accumulated by the BESIII experiment from March 3 through April 14, 2009, is determined by counting inclusive hadronic events. The result is 106.41x(1.00+/-0.81%)x10(6). The error is systematic dominant; the statistical error is negligible.

The energy-dependent cross section for e(+)e(-) -> eta psi(2S) is measured at 18 center of mass energies from 4.288 to 4.951 GeV using the BESIII detector. Using the same data samples, we also perform the first search for the reaction e(+)e(-) -> eta(X) over tilde(3872), but no evidence is found for the (X) over tilde(3872) in the pi(+)pi(-) J/psi. mass distribution. At each of the 18 center of mass energies, upper limits at the 90% confidence level on the cross section for e(+)e(-) -> eta psi(2S) and on the product of the e(+)e(-) -> eta(X) over tilde(3872) cross section with the branching fraction of (X) over tilde(3872) -> pi(+)pi(-)J/psi are reported.

Using a data sample corresponding to an integrated luminosity of 10.9 fb(-1) collected at center-of-mass energies from 4.16 to 4.34 GeV with the BESIII detector, we search for the decay chi(c1) (3872) -> pi(+)pi(-)chi(c1) in the radiative production e(+)e(-) -> gamma chi(c1) (3872). No significant signal is observed, and the ratio for the branching fraction of chi(c1) (3872) -> pi(+)pi(-)chi(c1) to chi(c1) (3872) -> pi(+)pi(-)J/psi is measured as R equivalent to B[chi(c1)(3872)->pi(+)pi(-)chi(c1)]/B[chi(c1)(3872)->pi(+)pi(-)J/psi] < 0.18 at 90% confidence level. An upper limit on the product of the cross section sigma[e(+)e(-) -> gamma chi(c1) (3872)] and the branching fraction B[chi(c1)(3872)->pi(+)pi(-)chi(c1)] at each center-of-mass energy is also given. These measurements favor the nonconventional charmonium nature of the chi(c1)(3872) state.

Based on 7.33 fb-1 of e thorn e- collision data collected at center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector, the experimental studies of the doubly Cabibbo-suppressed decays D thorn s -> K thorn K thorn pi- and D thorn s -> K thorn K thorn pi-pi 0 are reported. We determine the absolute branching fraction of D thorn s -> K thorn K thorn pi- to be (1.24 thorn 0.28 -0.26 ostat thorn 0.06osyst thorn thorn x 10-4. No significant signal of D thorn s -> K thorn K thorn pi-pi 0 is observed and the upper limit on its decay branching fraction at 90% confidence level is set to be 1.7 x 10-4.

A high-precision measurement of the branching fraction of the decay J/ψ→pp¯η is performed using (10 087±44)×106 J/ψ events recorded by the BESIII detector at the BEPCII storage ring. The branching fractions of the two decays J/ψ→pp¯η(η→γγ) and J/ψ→pp¯η(η→π+π−π0) are measured individually to be B(J/ψ→pp¯η(η→γγ))=(1.480±0.001±0.024)×10−3 and B(J/ψ→pp¯η(η→π+π−π0))=(1.557±0.003±0.038)×10−3, where the first uncertainties are statistical and the second systematic. Both results are compatible within their uncorrelated systematic uncertainties. The combined result is B(J/ψ→pp¯η)=(1.495±0.001±0.023)×10−3, where the first uncertainty is the combined statistical uncertainty and the second one the combined systematic uncertainty of both analyses, incorporating correlations between them. In addition, the pp¯ threshold region is investigated for a potential threshold enhancement, and no evidence for one is observed. Published by the American Physical Society 2024

Based on (2712.4 +/- 14.1) x 10(6) Psi (3686) events collected with the BESIII detector, we study the decays h(c)-> 3(pi(+) pi(-) )pi(0), h(c)->(pi(+) pi(-)) omega, h(c)-> 2(pi(+) pi(-))pi(0)eta, h(c)-> 2(pi(+) pi (-)) eta, and h(c)-> pp . The decay channel h(c)-> 2(pi(+) pi(-))pi(0)h(c)-> 2(pi(+) pi(-))pi(0) is observed for the first time, and its branching fraction is determined to be (9.28 +/- 1.14 +/- 0.77) x 10(-3), where the first uncertainty is statistical and the second is systematic. In addition, first evidence is found for the modes h(c)-> 2(pi(+) pi(-))pi(0)eta. and h(c)->(pi(+) pi(-)) omega. with significances of 4.8 sigma and 4.7 sigma, and their branching fractions are determined to be (7.55 +/- 1.51 +/- 0.77) x 10(- 3) and (4.00 +/- 0.86 +/- 0.35)x 10(-3), respectively. No significant signals of h(c)-> 2(pi(+) pi (-)) eta h(c)-> 2(pi(+) pi (-)) eta. and h(c)-> pp are observed, and the upper limits of the branching fractions of these decays are determined to be <6.19 x 10(- 4) and <4.40 x 10(- 5) at the 90% confidence level, respectively.

The absolute branching fraction of the decay Lambda(c)(2625)(+) -> Lambda(+)(c)pi(+)pi(-) is measured for the first time to be (50.2 +/- 5.7(stat) +/- 3.5(syst))% with 368.48 pb(-1) of e(+)e(-) collision data collected by the BESIII detector at the center-of-mass energies of root s = 4.918 and 4.950 GeV. Although the central value of the result is lower than the theoretical prediction of 67%, obtained from isospin symmetry, they are consistent taking the uncertainties into account. This is the first absolute branching fraction measurement for Lambda(c)(2625)(+) since it was found. This measurement is necessary to obtain the coupling constants for the transitions between s-wave and p-wave charmed baryons in heavy hadron chiral perturbation theory. In addition, we search for the decay Lambda(c)(2595)(+) -> Lambda(+)(c)pi(+)pi(-). No significant signal is observed, and the upper limit on its branching fraction is determined to be 85.0% at the 90% confidence level.

The absolute branching fraction of the decay Λc(2625)+→Λc+π+π− is measured for the first time to be (50.2±5.7stat±3.5syst)% with 368.48 pb−1 of e+e− collision data collected by the BESIII detector at the center-of-mass energies of s=4.918 and 4.950 GeV. Although the central value of the result is lower than the theoretical prediction of 67%, obtained from isospin symmetry, they are consistent taking the uncertainties into account. This is the first absolute branching fraction measurement for Λc(2625)+ since it was found. This measurement is necessary to obtain the coupling constants for the transitions between s-wave and p-wave charmed baryons in heavy hadron chiral perturbation theory. In addition, we search for the decay Λc(2595)+→Λc+π+π−. No significant signal is observed, and the upper limit on its branching fraction is determined to be 85.0% at the 90% confidence level. Published by the American Physical Society 2024

The energy-dependent cross section for e+e−→ηψ(2S) is measured at 18 center of mass energies from 4.288 to 4.951 GeV using the BESIII detector. Using the same data samples, we also perform the first search for the reaction e+e−→ηX˜(3872), but no evidence is found for the X˜(3872) in the π+π−J/ψ mass distribution. At each of the 18 center of mass energies, upper limits at the 90% confidence level on the cross section for e+e−→ηψ(2S) and on the product of the e+e−→ηX˜(3872) cross section with the branching fraction of X˜(3872)→π+π−J/ψ are reported. Published by the American Physical Society 2024

Abstract The branching fraction of D + → K S 0 π 0 e + ν e $$ {D}^{+}\to {K}_S^0{\pi}^0{e}^{+}{\nu}_e $$ is measured for the first time using 7.93 fb −1 of e + e − annihilation data collected at the center-of-mass energy s $$ \sqrt{s} $$ = 3.773 GeV with the BESIII detector operating at the BEPCII collider, and is determined to be B D + → K S 0 π 0 e + ν e = 0.881 ± 0.017 stat . ± 0.016 syst . % $$ \mathcal{B}\left({D}^{+}\to {K}_S^0{\pi}^0{e}^{+}{\nu}_e\right)=\left(0.881\pm {0.017}_{\textrm{stat}.}\pm {0.016}_{\textrm{syst}.}\right)\% $$ . Based on an analysis of the D + → K S 0 π 0 e + ν e $$ {D}^{+}\to {K}_S^0{\pi}^0{e}^{+}{\nu}_e $$ decay dynamics, we observe the S-wave and P-wave components with fractions of f S-wave = (6.13 ± 0.27stat. ± 0.30syst. )% and f K ¯ ∗ 892 0 = 93.88 ± 0.27 stat . ± 0.29 syst . % $$ {f}_{{\overline{K}}^{\ast }{(892)}^0}=\left(93.88\pm {0.27}_{\textrm{stat}.}\pm {0.29}_{\textrm{syst}.}\right)\% $$ , respectively. From these results, we obtain the branching fractions B D + → K S 0 π 0 S − wave e + ν e = 5.41 ± 0.35 stat . ± 0.37 syst . × 10 − 4 $$ \mathcal{B}\left({D}^{+}\to {\left({K}_S^0{\pi}^0\right)}_{S-\textrm{wave}}{e}^{+}{\nu}_e\right)=\left(5.41\pm {0.35}_{\textrm{stat}.}\pm {0.37}_{\textrm{syst}.}\right)\times {10}^{-4} $$ and B D + → K ¯ ∗ 892 0 e + ν e = 4.97 ± 0.11 stat . ± 0.12 syst . % $$ \mathcal{B}\left({D}^{+}\to {\overline{K}}^{\ast }{(892)}^0{e}^{+}{\nu}_e\right)=\left(4.97\pm {0.11}_{\textrm{stat}.}\pm {0.12}_{\textrm{syst}.}\right)\% $$ . In addition, the hadronic form-factor ratios of D + → K ¯ ∗ 892 0 e + ν e $$ {D}^{+}\to {\overline{K}}^{\ast }{(892)}^0{e}^{+}{\nu}_e $$ at q 2 = 0, assuming a single-pole dominance parameterization, are determined to be r V = V 0 A 1 0 = 1.43 ± 0.07 stat . ± 0.03 syst . $$ {r}_V=\frac{V(0)}{A_1(0)}=1.43\pm {0.07}_{\textrm{stat}.}\pm {0.03}_{\textrm{syst}.} $$ and r 2 = A 2 0 A 1 0 = 0.72 ± 0.06 stat . ± 0.02 syst . $$ {r}_2=\frac{A_2(0)}{A_1(0)}=0.72\pm {0.06}_{\textrm{stat}.}\pm {0.02}_{\textrm{syst}.} $$ .

By analyzing 7.33  fb^{-1} of e^{+}e^{-} annihilation data collected at center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector, we report the observation of the semileptonic decay D_{s}^{+}→η^{'}μ^{+}ν_{μ}, with a statistical significance larger than 10σ, and the measurements of the D_{s}^{+}→ημ^{+}ν_{μ} and D_{s}^{+}→η^{'}μ^{+}ν_{μ} decay dynamics for the first time. The branching fractions of D_{s}^{+}→ημ^{+}ν_{μ} and D_{s}^{+}→η^{'}μ^{+}ν_{μ} are determined to be (2.235±0.051_{stat}±0.052_{syst})% and (0.801±0.055_{stat}±0.028_{syst})%, respectively, with precision improved by factors of 6.0 and 6.6 compared to the previous best measurements. Combined with the results for the decays D_{s}^{+}→ηe^{+}ν_{e} and D_{s}^{+}→η^{'}e^{+}ν_{e}, the ratios of the decay widths are examined both inclusively and in several ℓ^{+}ν_{ℓ} four-momentum transfer ranges. No evidence for lepton flavor universality violation is found within the current statistics. The products of the hadronic form factors f_{+,0}^{η^{(')}}(0) and the c→s Cabibbo-Kobayashi-Maskawa matrix element |V_{cs}| are determined. The results based on the two-parameter series expansion are f_{+,0}^{η}(0)|V_{cs}|=0.452±0.010_{stat}±0.007_{syst} and f_{+,0}^{η^{'}}(0)|V_{cs}|=0.504±0.037_{stat}±0.012_{syst}, which help to constrain present models on f_{+,0}^{η^{(')}}(0). The forward-backward asymmetries are determined to be ⟨A_{FB}^{η}⟩=-0.059±0.031_{stat}±0.005_{syst} and ⟨A_{FB}^{η^{'}}⟩=-0.064±0.079_{stat}±0.006_{syst} for the first time, which are consistent with the theoretical calculation.

Abstract Using 7.33 fb −1 of e + e − collision data samples collected with the BESIII detector at center-of-mass energies between 4.128 and 4.226 GeV, we search for the radiative decay D s + → γρ 770 + $$ {D}_s^{+}\to \gamma \rho {(770)}^{+} $$ for the first time. A hint of D s + → γρ 770 + $$ {D}_s^{+}\to \gamma \rho {(770)}^{+} $$ is observed with a statistical significance of 2.5σ. The branching fraction of D s + → γρ 770 + $$ {D}_s^{+}\to \gamma \rho {(770)}^{+} $$ is measured to be (2.2 ± 0.9stat. ± 0.2syst. ) × 10 −4, corresponding to an upper limit of 6.1 × 10 −4 at the 90% confidence level.

Analyzing e(+)e(-) collision data corresponding to an integrated luminosity of 7.33 fb(-1) collected at center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector, we measure the branching fraction of the semileptonic decay D-s(+) -> K(0)e(+) nu(e) to be (2.98 +/- 0.23(stat) +/- 0.12(syst)) x 10(-3). Based on fit to the partial decay rates in various q(2) intervals, the product value of D-s(+) -> K-0 hadronic form factor and Cabibbo-Kobayashi-Maskawa element is measured to be f(+)(K0)(0)vertical bar V-cd vertical bar = 0.143 +/- 0.011(stat) +/- 0.003(syst). With vertical bar V-cd vertical bar = 0.22486 +/- 0.00067 as an input, the hadronic form factor is evaluated to be f(+)(K0) = 0.636 +/- 0.049(stat) +/- 0.013(syst). The branching fraction and form factor measurements are factors of 1.6 and 1.7 more precise than the previous world averages, respectively.