1. |
- Ablikim, M., et al.
(författare)
-
Absolute measurements of branching fractions of Cabibbo-suppressed hadronic D0(+) decays involving multiple pions
- 2022
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 106:9
-
Tidskriftsartikel (refereegranskat)abstract
- By analyzing e(+)e(-) annihilation data with an integrated luminosity of 2.93 fb(-1) collected at the center-of-mass energy root s = 3.773 GeV with the BESIII detector, we present the first absolute measurements of the branching fractions of twenty Cabibbo-suppressed hadronic D0(+) decays involving multiple pions. The highest four branching fractions obtained are B(D-0 -> pi(+)pi(-)pi(0)) = (1.343 +/- 0.013(stat) +/- 0.016(syst))%, B(D-0 -> pi(+)pi(-)2 pi(0)) = (1.002 +/- 0.019(stat )+/- 0.024(syst))%, B(D-0 -> 2 pi(+)pi(-)pi(0))=(1.165 +/- 0.021(stat) +/- 0.021(sy)(st))%, and B(D+ -> 2 pi(+)pi(-)pi(0)). (1.074 +/- 0.040(stat) 0.030(syst))%. The CP asymmetries for the six decays with highest signal yields are also determined and found to be compatible with zero.
|
|
2. |
- Ablikim, M., et al.
(författare)
-
Amplitude analysis and branching fraction measurement of D-s(+)-> K- K+ pi(+) pi(0)
- 2021
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:3
-
Tidskriftsartikel (refereegranskat)abstract
- The first amplitude analysis of the decay D-s(+)-> K- K+ pi(+) pi(0) is presented using the data samples, corresponding to an integrated luminosity of 6.32 fb(-1), collected with the BESIII detector at e(+)e(-) center-of-mass energies between 4.178 and 4.226 GeV. More than 3000 events selected with a purity of 97.5% are used to perform the amplitude analysis, and nine components are found necessary to describe the data.
|
|
3. |
- Ablikim, M., et al.
(författare)
-
Amplitude analysis and branching-fraction measurement of D-s(+) -> K-S(0)pi(+)pi(0)
- 2021
-
Ingår i: Journal of High Energy Physics (JHEP). - : Springer Nature. - 1126-6708 .- 1029-8479. ; :6
-
Tidskriftsartikel (refereegranskat)abstract
- By using 6.32 fb(-1) of data collected with the BESIII detector at center-of-mass energies between 4.178 and 4.226 GeV, we perform an amplitude analysis of the decay D-s(+) -> K-S(0) pi(+)pi(0) and determine the relative fractions and phase differences of different intermediate processes, which include K-S(0) rho(770)(+), K-S(0)rho(1450)(+), K*(892)(0) pi(+), K* (892)(+) pi(0), and K* (1410)(0) pi(+). With the detection efficiency based on the amplitude analysis results, the absolute branching fraction is measured to be B(D-s(+) -> K-S(0) pi(+) pi(0)) = (5.43 +/- 0.30(stat) +/- 0.15(syst)) x 10(-3).
|
|
4. |
- Ablikim, M., et al.
(författare)
-
Amplitude analysis and branching-fraction measurement of D+s → K0SK−π+π
- 2021
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 103:9
-
Tidskriftsartikel (refereegranskat)abstract
- Using 6.32 fb−1 of e+e− collision data collected by the BESIII detector at the center-of-mass energies between 4.178 and 4.226 GeV, an amplitude analysis of the D+s → K0SK−π+π+ decays is performed for the first time to determine the intermediate-resonant contributions. The dominant component is the D+s → K∗(892)+¯K∗(892)0 decay with a fraction of (40.6±2.9stat±4.9sys)%. Our results of the amplitude analysis are used to obtain a more precise measurement of the branching fraction of the D+s → K0SK−π+π+ decay, which is determined to be (1.46±0.05stat±0.05sys)%.
|
|
5. |
- Ablikim, M., et al.
(författare)
-
Amplitude analysis and branching fraction measurement of D+s → K−K+π+π+π−
- 2022
-
Ingår i: Journal of High Energy Physics (JHEP). - : Springer Nature. - 1126-6708 .- 1029-8479. ; :7
-
Tidskriftsartikel (refereegranskat)abstract
- Using e(+)e(-) annihilation data corresponding to a total integrated luminosity of 6.32 fb(-1) collected at the center-of-mass energies between 4.178 and 4.226 GeV with the BE- SIII detector, we perform an amplitude analysis of the decay D-s(+) -> K-K+pi(+)pi(+)pi(-) and de-termine the relative fractions and phases of different intermediate processes. Absolute branch- ing fraction of D-s(+) -> K-K+pi(+)pi(+)pi(-) decay is measured to be (6.60 +/- 0.47(stat). +/- 0.38(syst).) x 10(-3). The dominant intermediate process is D-s(+) -> a(1) (1260)(+)phi,phi -> K- K+, a(1)(1260)(+) -> rho pi(+), rho -> pi(+)pi(-), with a branching fraction of (5.15 +/- 0.41(stat.) +/- 0.32(syst.)) x 10(-3).
|
|
6. |
- Ablikim, M., et al.
(författare)
-
Amplitude analysis and branching-fraction measurement of D+s → π+π0η′
- 2022
-
Ingår i: Journal of High Energy Physics (JHEP). - : Springer Nature. - 1126-6708 .- 1029-8479. ; :4
-
Tidskriftsartikel (refereegranskat)abstract
- Using data collected with the BESIII detector in e(+)e(-) collisions at center-of-mass energies between 4.178 and 4.226 GeV and corresponding to 6.32 fb(-1) of integrated luminosity, we report the amplitude analysis and branching-fraction measurement of the D-s(+) -> pi(+)pi(0)eta' decay. We find that the dominant intermediate process is D-s(+) -> rho(+)eta' and the significances of other resonant and nonresonant processes are all less than 3 sigma. The upper limits on the branching fractions of S-wave and P-wave nonresonant components are set to 0.10% and 0.74% at the 90% confidence level, respectively. In addition, the branching fraction of the D-s(+) -> pi(+)pi(0)eta' decay is measured to be (6.15 +/- 0.25(stat.) +/- 0.18(syst.))%, which receives significant contribution only from D-s(+) -> rho(+)eta' according to the amplitude analysis.
|
|
7. |
- Ablikim, M., et al.
(författare)
-
Amplitude analysis and branching fraction measurement of Ds+ → K+K-π
- 2021
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:1
-
Tidskriftsartikel (refereegranskat)abstract
- We report an amplitude analysis and branching fraction measurement of D-s(+) -> K+K-pi(+) decay using a data sample of 3.19 fb(-1) recorded with BESIII detector at a center-of-mass energy of 4.178 GeV. We perform a model-independent partial wave analysis in the low K+K- mass region to determine the K+K- S-wave line shape, followed by an amplitude analysis of our very pure high-statistics sample. With the detection efficiency based on the amplitude analysis results, the absolute branching fraction is measured to be B(D-s(+) -> K+K-pi(+)) = (5.47 +/- 0.08(stat) +/- 0.13(sys))%.
|
|
8. |
- Ablikim, M., et al.
(författare)
-
Amplitude analysis and branching fraction measurement of the decay D+ K0S → π+π0π0
- 2023
-
Ingår i: Journal of High Energy Physics (JHEP). - : Springer. - 1126-6708 .- 1029-8479. ; :9
-
Tidskriftsartikel (refereegranskat)abstract
- Using 2.93 fb−1 of e+e− collision data collected with the BESIII detector at the center-of-mass energy 3.773 GeV, we perform the first amplitude analysis of the decay D+ → π+π0π0 and determine the relative magnitudes and phases of different intermediate processes. The absolute branching fraction of D+ → π+π0π0 is measured to be (2.888 ± 0.058stat. ± 0.069syst.)%. The dominant intermediate processes are D+ → a1(1260)+(→ ρ+π0) and D+ → *0ρ+, with branching fractions of (8.66 ± 1.04stat. ± 1.39syst.) × 10−3 and (9.70 ± 0.81stat. ± 0.53syst.) × 10−3, respectively.
|
|
9. |
- Ablikim, M., et al.
(författare)
-
Amplitude analysis and branching fraction measurement of the decay D+s → K+π+π−
- 2022
-
Ingår i: Journal of High Energy Physics (JHEP). - : Springer. - 1126-6708 .- 1029-8479. ; :8
-
Tidskriftsartikel (refereegranskat)abstract
- Using 6.32 fb−1 of e+e− collision data collected at the center-of-mass energies between 4.178 and 4.226 GeV with the BESIII detector, we perform an amplitude analysis of the decay D+s → K+π+π− and determine the amplitudes of the various intermediate states. The absolute branching fraction of D+s → K+π+π− is measured to be (6.11 ± 0.18stat. ± 0.11syst.) × 10−3. The branching fractions of the dominant intermediate processes D+s → K+ρ0, ρ0 → π+π− and D+s → K*(892)0π+, K*(892)0 → K+π− are determined to be (1.96 ± 0.19stat. ± 0.23syst.) × 10−3 and (1.85 ± 0.12stat. ± 0.13syst.) × 10−3, respectively. The intermediate resonances f0(500), f0(980), and f0(1370) are observed for the first time in this channel.
|
|
10. |
- Ablikim, M., et al.
(författare)
-
Amplitude analysis and branching fraction measurement of the decay D+s → K+π+π−π0
- 2022
-
Ingår i: Journal of High Energy Physics (JHEP). - : Springer. - 1126-6708 .- 1029-8479. ; :9
-
Tidskriftsartikel (refereegranskat)abstract
- The singly Cabibbo-suppressed decay D+s → K+π+π−π0 is observed by using a data set corresponding to an integrated luminosity of 6.32 fb−1 recorded by the BESIII detector at the centre-of-mass energies between 4.178 and 4.226 GeV. The first amplitude analysis of D+s → K+π+π−π0 reveals the sub-structures in this decay and determines the fractions and relative phases of different intermediate processes. The dominant intermediate process is D+s → K*0ρ+, with a fit fraction of (40.5 ± 2.8stat. ± 1.5syst.)%. With the detection efficiency based on our amplitude analysis, the absolute branching fraction for D+s → K+π+π−π0 is measured to be (9.75 ± 0.54stat. ± 0.17syst.) × 10−3.
|
|
11. |
- Ablikim, M., et al.
(författare)
-
Amplitude analysis and branching fraction measurement of the decay D-s(+) -> pi(+)pi(0)pi(0)
- 2022
-
Ingår i: Journal of High Energy Physics (JHEP). - : Springer. - 1126-6708 .- 1029-8479. ; :1
-
Tidskriftsartikel (refereegranskat)abstract
- Using a data set corresponding to an integrated luminosity of 6.32fb(-1) recorded by the BESIII detector at center-of-mass energies between 4.178 and 4.226 GeV, an amplitude analysis of the decay D-s(+) -> pi(+)pi(0)pi(0 ) is performed, and the relative fractions and phases of different intermediate processes are determined. The absolute branching fraction of the decay D-s(+) -> pi(+)pi(0)pi(0)is measured to be (0.50 +/- 0.04(stat) 0.02(syst) )%. The absolute branching fraction of the intermediate process D-s(+) -> f(0)(980)pi(+), f(0)(980) ->pi(0)pi(0 ), is determined to be (0.28 +/- 0.04(stat) +/- 0.04(syst))%.
|
|
12. |
- Ablikim, M., et al.
(författare)
-
Amplitude analysis of D+-> K-S(0)pi(+)pi(+)pi(-)
- 2019
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 100:7
-
Tidskriftsartikel (refereegranskat)abstract
- The decay D+-> K-S(0)pi(+)pi(+)pi(-) is studied with an amplitude analysis using a data set of 2.93 fb(-1) of e(+)e(-) collisions at the psi(3770) peak accumulated by the BESIII detector. Intermediate states and nonresonant components, and their relative fractions and phases, have been determined. The significant amplitudes, which contribute to the model that best fits the data, are composed of five quasitwo-body decays K(S)(0)a(1)(1260)(+), (K) over bar (1)(1270)(0)pi(+) (K) over bar (1)(1400)(0)pi(+), (K) over bar (1)(1650)(0)pi(+), and (K) over bar (1460)(0)pi(+), a three-body decay K-S(0)pi(+)rho(0), as well as a nonresonant component K-S(0)pi(+)pi(+)pi(-). The dominant amplitude is K(S)(0)a(1)(1260)(+), with a fit fraction of (40.3 +/- 2.1 +/- 2.9)%, where the first and second uncertainties are statistical and systematic, respectively.
|
|
13. |
- 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.
|
|
14. |
- Ablikim, M., et al.
(författare)
-
Complete Measurement of the Λ Electromagnetic Form Factors
- 2019
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 123:12
-
Tidskriftsartikel (refereegranskat)abstract
- The exclusive process e(+)e(-) -> Lambda(Lambda) over bar, with Lambda -> p pi(-) and (Lambda) over bar -> (p) over bar pi(+), has been studied at root s = 2.396 GeV for measurement of the timelike Lambda electric and magnetic form factors, G(E) and G(M). A data sample, corresponding to an integrated luminosity of 66.9 pb(-1), was collected with the BESIII detector for this purpose. A multidimensional analysis with a complete decomposition of the spin structure of the reaction enables a determination of the modulus of the ratio R = vertical bar G(E)/G(M)vertical bar and, for the first time for any baryon, the relative phase Delta Phi = Phi(E) - Phi(M). The resulting values are R = 0.96 +/- 0.14(stat) +/- 0.02(syst) and Phi(F) = 37 degrees +/- 12 degrees (stat) +/- 6 degrees (syst), respectively. These are obtained using the recently established and most precise value of the asymmetry parameter alpha(Lambda) = 0.750 +/- 0.010 measured by BESIII. In addition, the cross section is measured with unprecedented precision to be sigma = 118.7 +/- 5.3(stat) +/- 5.1(syst) pb, which corresponds to an effective form factor of vertical bar G vertical bar = 0.123 +/- 0.003(stat) +/- 0.003(syst). The contribution from two-photon exchange is found to be negligible. Our result enables the first complete determination of baryon timelike electromagnetic form factors.
|
|
15. |
- Ablikim, M., et al.
(författare)
-
Cross section measurement of e(+) e(-) -> eta ' J/psi from root S=4.178 to 4.600 GeV
- 2020
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 101:1
-
Tidskriftsartikel (refereegranskat)abstract
- The cross section of the process e(+) e(-) -> eta ' J/ psi is measured at center-of-mass (c.m.) energies from root S = 4.178 to 4.600 GeV using data samples corresponding to a total integrated luminosity of 11 fb(-1) collected with the BESIII detector operating at the BEPCII storage ring. The dependence of the cross section on root S shows an enhancement around 4.2 GeV. While the shape of the cross section cannot be fully explained with a single psi(4160) or psi(4260) state, a coherent sum of the two states does provide a reasonable description of the data.
|
|
16. |
- Ablikim, M., et al.
(författare)
-
Cross section measurement of e(+)e(-) -> (KSKL0)-K-0 at root s=2.00-3.08 GeV
- 2021
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:9
-
Tidskriftsartikel (refereegranskat)abstract
- The cross sections of the process e(+)e(-) -> (KSKL0)-K-0 are measured at fifteen center-of-mass energies root s from 2.00 to 3.08 GeV with a total integrated luminosity of 582 pb(-1) and using the BESIII detector at the Beijing Electron Positron Collider. The results are found to be consistent with those obtained by BABAR. A resonant structure around 2.2 GeV is observed, with a mass and width of 2273.7 +/- 5.7 +/- 19.3 MeV/c(2) and 86 +/- 44 +/- 51 MeV, respectively, where the first uncertainties are statistical and the second ones are systematic. The product of its radiative width (Gamma(e+e-)) with its branching fraction to (KSKL0)-K-0 (Br-KS0KL0) is 0.9 +/- 0.6 +/- 0.7 eV.
|
|
17. |
- Ablikim, M., et al.
(författare)
-
Cross section measurement of e(+)e(-) -> p(p)over-bar eta and e(+)e(-) -> p(p)over-bar omega at center-of-mass energies between 3.773 GeV and 4.6 GeV
- 2021
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:9
-
Tidskriftsartikel (refereegranskat)abstract
- Based on 14.7 fb(-1) of e(+)e(-) annihilation data collected with the BESIII detector at the BEPCII collider at 17 different center-of-mass energies between 3.7730 GeV and 4.5995 GeV, Born cross sections of the two processes e(+)e(-) -> p (p) over bar eta and e(+)e(-) -> p (p) over bar omega are measured for the first time. No indication of resonant production through a vector state V is observed, and upper limits on the Born cross sections of e(+)e(-) -> p (p) over bar eta and e(+)e(-) -> p (p) over bar omega at the 90% confidence level are calculated for a large parameter space in resonance masses and widths. For the current world average parameters of the psi(4230) of m = 4.2187 GeV=c(2) and Gamma = 44 MeV, we find upper limits on resonant production of the p (p) over bar eta and p (p) over bar omega final states of 7.5 pb and 10.4 pb at the 90% CL, respectively.
|
|
18. |
- Ablikim, M., et al.
(författare)
-
Cross section measurement of e+e- → ηψ(2S) and search for e+e- → η(X) over tilde (3872)
- 2024
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 109:11
-
Tidskriftsartikel (refereegranskat)abstract
- 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- → η(X) over tilde(3872), but no evidence is found for the (X) over tilde(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- → eta(X) over tilde(3872) cross section with the branching fraction of (X) over tilde(3872) → π+π-J/ψ are reported.
|
|
19. |
- Ablikim, M., et al.
(författare)
-
Cross section measurement of e+e- → π+π-ψ(3686) from √s = 4.0076 GeV to 4.6984 GeV
- 2021
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:5
-
Tidskriftsartikel (refereegranskat)abstract
- Using data samples with a total integrated luminosity of 20.1 fb(-1) collected by the BESIII detector operating at the BEPCII collider, the cross section of the process e(+) e(-) -> pi(+) pi(-) psi(3686) is measured at center-of-mass energies between 4.0076 and 4.6984 GeV. The measured cross section is consistent with previous results, and with much improved precision. A fit to the measured energy-dependent cross section, which includes three Breit-Wigner functions and a nonresonant contribution, confirms the existence of the charmonium-like states Y(4220), Y(4390), and Y(4660). This is the first observation of the Y(4660) at the BESIII experiment.
|
|
20. |
- Ablikim, M., et al.
(författare)
-
Cross section measurements of e+e- -> K+ K- K+ K- and ΦK+ K- at center-of-mass energies from 2.10 to 3.08 GeV
- 2019
-
Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 100:3
-
Tidskriftsartikel (refereegranskat)abstract
- We measure the Born cross sections of the process e(+)e(-) -> K+ K- K+ K- at center-of-mass (c.m.) energies, root s, between 2.100 and 3.080 GeV. The data were collected using the BESIII detector at the BEPCII collider. An enhancement at root s = 2.232 GeV is observed, very close to the e(+)e(-) -> Lambda(Lambda) over bar production threshold. A similar enhancement at the same c.m. energy is observed in the e(+)e(-) -> phi K+ K- cross section. The energy dependence of the K+ K- K+ K- and phi K+ K- cross sections differs significantly from that of e(+)e(-) -> phi pi(+)pi(-).
|
|
21. |
- Ablikim, M., et al.
(författare)
-
Cross section measurements of e(+) e(-) -> omega chi(c0) from root s=4.178 to 4.278 GeV
- 2019
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 99:9
-
Tidskriftsartikel (refereegranskat)abstract
- The cross section of the process e(+)e(-) -> omega chi(C0) is measured at center -of -mass energies from root s = 4.178 to 4.278 GeV using a data sample of 7 fb(-1) collected with the BESIII detector operating at the BEPCII storage ring. The dependence of the cross section on root s shows a resonant structure with mass of (4218.5 +/- 1.6(stat) +/- 4.0(syst)) MeV/c(2) and width of (28.2 +/- 3.9(stat) +/- 1.6(syst)) MeV, respectively. This observation confirms and improves upon the result of a previous study. The angular distribution of the e(+) e(-) ->omega chi(C0) process is extracted for the first time.
|
|
22. |
- Ablikim, M., et al.
(författare)
-
Cross-section measurements of e plus e- ? ?K plus K - and e plus e- ??K0SK0S at center-of-mass energies between 3.7730 GeV and 4.7008 GeV
- 2023
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 108:3
-
Tidskriftsartikel (refereegranskat)abstract
- Based on 22.7 fb-1 of e+e- annihilation data collected at 33 different center-of-mass energies between 3.7730 and 4.7008 GeV with the BESIII detector at the BEPCII collider, Born cross sections of the two processes e+e- & RARR; & phi;K+K- and e+e- & RARR; & phi;K0SK0S are measured for the first time. No indication of resonant production through an intermediate vector state V is observed, and the upper limits on the product of the electronic width & UGamma;e+e- and the branching fraction Br(V & RARR; & phi;K over bar K) of the processes e+e- & RARR; V & RARR; & phi;K+K- and e+e- & RARR; V & RARR; & phi;K0SK0S at the 90% confidence level are obtained for a large parameter space in resonance masses and widths. For the current world average mass and width of the & psi;(4230) of m = 4.2187 GeV=c2 and & UGamma; = 44 MeV, we set upper limits on the & phi;K+K- and & phi;K0SK0S final states of 1.75 and 0.47 eV at the 90% confidence level, respectively.
|
|
23. |
- Ablikim, M., et al.
(författare)
-
Cross section measurements of the e(+)e(-) -> D*D+*(-) and e(+)e(-) -> D*D-+(-) processes at center-of-mass energies from 4.085 to 4.600 GeV
- 2022
-
Ingår i: Journal of High Energy Physics (JHEP). - : Springer Nature. - 1126-6708 .- 1029-8479. ; :5
-
Tidskriftsartikel (refereegranskat)abstract
- The Born cross sections of the e(+)e(-) -> D*D+*(-) and e(+)e(-) -> D*D-+(-) processes are measured using e(+)e(-) collision data collected with the BESIII experiment at center-of-mass energies from 4.085 to 4.600 GeV, corresponding to an integrated luminosity of 15.7 fb(-1). The results are consistent with and more precise than the previous measurements by the Belle, Babar and CLEO collaborations. The measurements are essential for understanding the nature of vector charmonium and charmonium-like states.
|
|
24. |
- Ablikim, M., et al.
(författare)
-
Cross section measurements of the processes e+e− → ωπ0 and ωη at center-of-mass energies between 3.773 and 4.701 GeV
- 2022
-
Ingår i: Journal of High Energy Physics (JHEP). - : Springer Nature. - 1126-6708 .- 1029-8479. ; :7
-
Tidskriftsartikel (refereegranskat)abstract
- The Born cross sections of the processes e(+)e(-) -> omega pi(0) and e(+)e(-) -> omega eta are measured at center-of-mass energies between 3.773 and 4.701 GeV using a total integrated luminosity of 22.7 fb(-1) collected with the BESIII detector operating at the BEPCII collider. A simple s(-n) dependence for the continuum process can describe the measured Born cross sections. No significant contributions from the psi(4160), Y(4230), Y(4360), psi(4415), Y(4660) resonances are found, which indicates relative small branching fractions for these resonances into the omega pi(0) and omega eta final states.
|
|
25. |
- Ablikim, M., et al.
(författare)
-
Cross sections for the reactions e+e−→K+K−π+π−(π0), K+K−K+K−(π0), π+π−π+π−(π0), p¯pπ+π−(π0) in the energy region between 3.773 and 4.600 GeV
- 2021
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:11
-
Tidskriftsartikel (refereegranskat)abstract
- Using the data samples collected in the energy range from 3.773 to 4.600 GeV with the BESIII detector at the BEPCII collider, we measure the dressed cross sections as a function of center-of-mass energy for e(+)e(-) -> K+K- pi(+)pi(-) (pi(0)), K+K-K+K- (pi(0)), pi(+)pi(-) pi(+)pi(-) (pi(0)), and p (p) over bar pi(+)pi(-)(pi(0)). The cross sections for e(+)e(-) -> K+K-K+K- pi(0), p (p) over bar pi(+)pi(-)(pi(0)) are the first measurements. Cross sections for the other five channels are much more precise than previous results in this energy region. We also search for charmonium and charmonium-like resonances, such as the Y(4230), decaying into the same final states. We find evidence of the psi(4040) decaying to pi(+)pi(-) pi(+)pi(-) pi(0) with a statistical significance of 3.6 sigma. Upper limits are provided for other decays since no clear signals are observed.
|
|
26. |
- Ablikim, M., et al.
(författare)
-
Determination of Spin-Parity Quantum Numbers for the Narrow Structure near the p¯Λ Threshold in e+e−→pK−¯Λ+c.c.
- 2023
-
Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 131:15
-
Tidskriftsartikel (refereegranskat)abstract
- A narrow structure in the p¯Λ system near the mass threshold, named as X(2085), is observed in the process e+e−→pK−¯Λ with a statistical significance greater than 20σ. Its spin and parity are determined for the first time to be JP=1+ in an amplitude analysis, with a statistical significance greater than 5σ over other quantum numbers (0−,1− and 2+). The pole positions of X(2085) are measured to be Mpole=(2084+4−2±9) MeV and Γpole=(58+4−3±25) MeV, where the first uncertainties are statistical and the second ones are systematic. The analysis is based on the study of the process e+e−→pK−¯Λ and uses the data samples collected with the BESIII detector at the center-of-mass energies √s=4.008, 4.178, 4.226, 4.258, 4.416, and 4.682 GeV with a total integrated luminosity of 8.35 fb−1.
|
|
27. |
- Ablikim, M., et al.
(författare)
-
Determination of Strong-Phase Parameters in D -> K-S,L(0)pi(+)pi(-)
- 2020
-
Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 124:24
-
Tidskriftsartikel (refereegranskat)abstract
- We report the most precise measurements to date of the strong-phase parameters between D-0 and (D) over bar (0) decays to K-S,L(0)pi(+)pi(-) using a sample of 2.93 fb(-1) of e(+) e(-) annihilation data collected at a center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider. Our results provide the key inputs for a binned model-independent determination of the Cabibbo-Kobayashi-Maskawa angle gamma/phi(3) with B decays. Using our results, the decay model sensitivity to the gamma/phi(3 )measurement is expected to be between 0.7 degrees and 1.2 degrees, approximately a factor of three smaller than that achievable with previous measurements, based on the studies of the simulated data. The improved precision of this work ensures that measurements of gamma/phi(3) will not be limited by knowledge of strong phases for the next decade. Furthermore, our results provide critical input for other flavor-physics investigations, including charm mixing, other measurements of CP violation, and the measurement of strong-phase parameters for other D-decay modes.
|
|
28. |
- 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.
|
|
29. |
- 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.
|
|
30. |
- Ablikim, M., et al.
(författare)
-
Determination of the ∑+ Timelike Electromagnetic Form Factors
- 2024
-
Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 132:8
-
Tidskriftsartikel (refereegranskat)abstract
- Based on data samples collected with the BESIII detector at the BEPCII collider, the process e+e- → Σ+Σ− (over bar) is studied at center -of -mass energies √s = 2.3960, 2.6454, and 2.9000 GeV. Using a fully differential angular description of the final state particles, both the relative magnitude and phase information of the Σ+ electromagnetic form factors in the timelike region are extracted. The relative phase between the electric and magnetic form factors is determined to be sin ΔΦ = -0.67 ± 0.29(stat) ± 0.18(syst) at √s = 2.3960 GeV, AO = 55° ± 19°(stat) ± 14°(syst) at √s = 2.6454 GeV, and 78° ± 22°(stat) ± 9°(syst) at √s = 2.9000 GeV. For the first time, the phase of the hyperon electromagnetic form factors is explored in a wide range of four -momentum transfer. The evolution of the phase along with fourmomentum transfer is an important input for understanding its asymptotic behavior and the dynamics of baryons.
|
|
31. |
- Ablikim, M., et al.
(författare)
-
Determination of the Λ+c spin via the reaction e+e− → Λc¯Λc
- 2021
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 103:9
-
Tidskriftsartikel (refereegranskat)abstract
- We report on a comparison of two possible Λ+c spin hypotheses, J=½ and 3/2, via the process e+e− → Λ+c¯Λ−c, using the angular distributions of Λ+c decays into pK0S, Λπ+, Σ0π+, and Σ+π0. The data were recorded at √s=4.6 GeV with the BESIII detector and correspond to an integrated luminosity of 587 pb−1. The Λ+c spin is determined to be J=½, with this value favored over the 3/2 hypothesis with a significance corresponding to more than 6 Gaussian standard deviations.
|
|
32. |
- Ablikim, M., et al.
(författare)
-
Direct Measurement of the Branching Fractions B(psi(3686) -> J/psi X) and B(psi(3770) -> J/psi X), and Observation of the State R(3760) in e(+)e(-) -> J/psi X
- 2021
-
Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 127:8
-
Tidskriftsartikel (refereegranskat)abstract
- We report a measurement of the observed cross sections of e(+)e(-) -> J/psi X based on 3.21 fb(-1) of data accumulated at energies from 3.645 to 3.891 GeV with the BESIII detector operated at the BEPCII collider. In analysis of the cross sections, we measured the decay branching fractions of B(psi(3686 -> J/psi X) = (64.4 +/- 0.6 +/- 1.6)% and B(psi(3770) -> J/psi X) = (0.5 +/- 0.2 +/- 0.1)% for the first time. The energy-dependent line shape of these cross sections cannot be well described by two Breit-Wigner (BW) amplitudes of the expected decays psi(3686) -> J/psi X and psi(3770) -> J/psi X. Instead, it can be better described with one more BW amplitude of the decay R(3760) -> J/psi X. Under this assumption, we extracted the R(3760) mass M-R(3760) = 3766.2 +/- 3.8 +/- 0.4 MeV/c(2), total width Gamma(tot)(R(3760)) = 22.2 +/- 5.9 +/- 1.4 MeV, and product of leptonic width and decay branching fraction Gamma(ee)(R(3760)) B[R(3760) -> J/psi X] = (79.4 +/- 85.5 +/- 11.7) eV. The significance of the R(3760) is 5.3 sigma. The first uncertainties of these measured quantities are from fits to the cross sections and second systematic.
|
|
33. |
- Ablikim, M., et al.
(författare)
-
Evidence for a Neutral Near-Threshold Structure in the K0S Recoil-Mass Spectra in e+e− → K0SD+sD*− and e+e− → K0SD*s+D−
- 2022
-
Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 129:11
-
Tidskriftsartikel (refereegranskat)abstract
- We study the processes e+e− → K0SD+sD*− and e+e− → K0SD*s+D−, as well as their charge conjugated processes, at five center-of-mass energies between 4.628 and 4.699 GeV, using data samples corresponding to an integrated luminosity of 3.8 fb−1 collected by the BESIII detector at the BEPCII storage ring. Based on a partial reconstruction technique, we find evidence of a structure near the thresholds for D+sD*− and D*s+D− production in the K0S recoil-mass spectrum, which we refer to as the Zcs(3985)0. Fitting with a Breit-Wigner line shape, we find the mass of the structure to be (3992.2±1.7±1.6) MeV/c2 and the width to be (7.7+4.1−3.8±4.3) MeV, where the first uncertainties are statistical and the second are systematic. The significance of the Zcs(3985)0 signal is found to be 4.6σ including both the statistical and systematic uncertainty. We report the Born cross section multiplied by the branching fraction at different energy points. The mass of the Zcs(3985)0 is close to that of the Zcs(3985)+. Assuming SU(3) symmetry, the cross section of the neutral channel is consistent with that of the charged one. Hence, we conclude that the Zcs(3985)0 is the isospin partner of the Zcs(3985)+.
|
|
34. |
- Ablikim, M., et al.
(författare)
-
Evidence for the Cusp Effect in η' Decays into ηπ0π0
- 2023
-
Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 130:8
-
Tidskriftsartikel (refereegranskat)abstract
- Using a sample of 4.3 x 105 eta' -> eta pi 0 pi 0 events selected from the ten billion J=psi event dataset collected with the BESIII detector, we study the decay eta' -> eta pi 0 pi 0 within the framework of nonrelativistic effective field theory. Evidence for a structure at pi+pi- mass threshold is observed in the invariant mass spectrum of pi 0 pi 0 with a statistical significance of around 3.5 sigma, which is consistent with the cusp effect as predicted by the nonrelativistic effective field theory. After introducing the amplitude for describing the cusp effect, the pi pi scattering length combination a0 - a2 is determined to be 0.226 10.060stat 10.013syst, which is in good agreement with theoretical calculation of 0.2644 10.0051.
|
|
35. |
- 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).
|
|
36. |
- Ablikim, M., et al.
(författare)
-
First direct measurement of the absolute branching fraction of Sigma(+) -> Lambda e(+)upsilon(e)
- 2023
-
Ingår i: Physical Review D. - : American Physical Society (APS). - 2470-0010 .- 2470-0029. ; 107:7
-
Tidskriftsartikel (refereegranskat)abstract
- The first direct measurement of the absolute branching fraction of Sigma(+) -> Lambda e(+)nu(e) is reported based on an e(+) e(-) annihilation sample of (10087 +/- 44) x 10(6) J/psi events collected with the BESIII detector at root s = 3.097 GeV. The branching fraction is determined to be B(Sigma(+)-> Lambda e(+)nu(e))=2.93 +/- 0.74 (stat) +/- 0.13(syst)] x 10(-5), which is the most precise measurement obtained in a single experiment to date and also the first result obtained at a collider experiment. Combining this result with the world average of B(Sigma(-)-> Lambda e(-) (nu) over bar (e). and the lifetimes of Sigma(+/-), the ratio, Gamma (Sigma(-) ->Lambda e(-) (nu) over bar (e) /Sigma(+) -> Lambda e(+) (nu) over bar (e), is determined to be 1.06 +/- 0.28, which is within 1.8 standard deviations of the value expected in the absence of second-class currents.
|
|
37. |
- Ablikim, M., et al.
(författare)
-
First Experimental Study of the Purely Leptonic Decay Ds*+→ e+ve
- 2023
-
Ingår i: Physical Review Letters. - : American Physical Society (APS). - 0031-9007 .- 1079-7114. ; 131:14
-
Tidskriftsartikel (refereegranskat)abstract
- Using 7.33 fb(-1) of e(+)e(-) collision data taken with the BESIII detector at the BEPCII collider, we report the first experimental study of the purely leptonic decay D-s*(+) -> e(+)v(e). Our data contain a signal of this decay with a statistical significance of 2.9s. The branching fraction of D-s*(+) -> e(+)v(e) is measured to be (2.1(-0.9stat)(+1.2) +/- 0.2(syst)+ x 10(-5), corresponding to an upper limit of 4.0 x 10(-5) at the 90% confidence level. Taking the total width of the D-s*(+) [(0.070 +/- 0.028+ keV] predicted with the radiative D-s*(+) decay from the lattice QCD calculation as input, the decay constant of the D-s*(+) is determined to be f(Ds*+) = (214-(+61)(46stat) +/- 44(syst)) MeV, corresponding to an upper limit of 354 MeVat the 90% confidence level.
|
|
38. |
- Ablikim, M., et al.
(författare)
-
First Measurement of Polarizations in the Decay D-0 -> omega phi
- 2022
-
Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 128:1
-
Tidskriftsartikel (refereegranskat)abstract
- Using a data sample corresponding to an integrated luminosity of 2.93 fb(-1) collected at a center-of-mass energy root s = 3.773 GeV by the BESIII detector, the decay D-0 -> omega phi is observed for the first time. The branching fraction is measured to be (6.48 +/- 10.9 +/- 1 0.40) x 10(-4) with a significance of 6.3 sigma, where the first and second uncertainties are statistical and systematic, respectively. An angular analysis reveals that the phi and omega mesons from the D-0 -> omega phi decay are transversely polarized. The 95% confidence level upper limit on longitudinal polarization fraction is set to be less than 0.24, which is inconsistent with current theoretical expectations and challenges our understanding of the underlying dynamics in charm meson decays.
|
|
39. |
- Ablikim, M., et al.
(författare)
-
First Measurement of the Absolute Branching Fraction of Λ→pμ−¯νμ
- 2021
-
Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 127:12
-
Tidskriftsartikel (refereegranskat)abstract
- The absolute branching fraction of Lambda -> p mu(-)(upsilon) over bar (mu) is reported for the fast time based on an e(+)e(-) annihilation sample of 10 x 10(9) J/psi events collected with the BESIII detector at N rs = 3.097 GeV. The branching fraction is determined to be B(Lambda -> p mu(-)(upsilon) over bar (mu)). [1.48 +/- 0.21(stat) +/- 0.08(syst)] x 10(-4), which is improved by about 30% in precision over the previous indirect measurements. Combining this result with the world average of B(Lambda -> pe(-)(upsilon) over bar (e)), we obtain the ratio {[Gamma(Lambda -> p mu(-)(upsilon) over bar (mu))]/[Gamma(Lambda -> pe(-)(upsilon) over bar (e))]} to be 0.178 +/- 0.028, which agrees with the standard model prediction assuming lepton flavor universality. The asymmetry of the branching fractions of Lambda -> p mu(-)(upsilon) over bar (mu) and (Lambda) over bar -> (p) over bar mu(+)upsilon(mu) is also determined, and no evidence for CP violation is found.
|
|
40. |
- Ablikim, M., et al.
(författare)
-
First Measurement of the Decay Asymmetry in the Pure W-Boson-Exchange Decay Λc+ → Ξ0K
- 2024
-
Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 132:3
-
Tidskriftsartikel (refereegranskat)abstract
- Based on 4.4 fb-1 of e+e- annihilation data collected at the center-of-mass energies between 4.60 and 4.70 GeV with the BESIII detector at the BEPCII collider, the pure W-boson-exchange decay Λc+ → Ξ0K+ is studied with a full angular analysis. The corresponding decay asymmetry is measured for the first time to be αΞ0K+ = 0.01 ± 0.16(stat) ± 0.03(syst). This result reflects the noninterference effect between the S- and P-wave amplitudes. The phase shift between S- and P-wave amplitudes has two solutions, which are δp - δs = -1.55 ± 0.25(stat) ± 0.05(syst) rad or 1.59 ± 0.25(stat) ± 0.05(syst) rad.
|
|
41. |
- Ablikim, M., et al.
(författare)
-
First measurement of ΛN inelastic scattering with Λ from e+ e- → J/Ψ → ΛΛ(over bar)
- 2024
-
Ingår i: Physical Review C. - : American Physical Society. - 2469-9985 .- 2469-9993. ; 109:5
-
Tidskriftsartikel (refereegranskat)abstract
- Using an e+e- collision data sample of (10087 ± 44)x106 J/Ψ. events taken at the center-of-mass energy of 3.097 GeV by the BESIII detector at the BEPCII collider, the process Λ + N → Σ+ + X is studied for the first time employing a novel method. The Σ+ hyperons are produced by the collisions of Λ hyperons from J/Ψ decays with nuclei in the material of the BESIII detector. The total cross section of Λ + 9Be → Σ+ + X is measured to be σ = (37.3 ± 4.7 ± 3.5) mb with Λ momenta within [1.057, 1.091] GeV/c, where the uncertainties are statistical and systematic, respectively. This analysis is the first study of Λ-nucleon interactions at an e+e- collider, providing information and constraints relevant for the strong-interaction potential, the origin of color confinement, the unified model for baryon-baryon interactions, and the internal structure of neutron stars.
|
|
42. |
- Ablikim, M., et al.
(författare)
-
First measurements of χcJ→Σ−¯Σ+(J=0,1,2) decays
- 2020
-
Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 101:9
-
Tidskriftsartikel (refereegranskat)abstract
- We measured the branching fractions of the decays chi(cJ) -> Sigma(-)(Sigma) over bar (+) for the first time using the final states n (n) over bar pi(+)pi(-). The data sample exploited here is 448.1 x 10(6) psi(3686) events collected with BESIII. We find B(chi(cJ) -> Sigma(-)(Sigma) over bar (+)) = (51.3 +/- 2.4 +/- 4.1) x 10(-5), (5.7 +/- 1.4 +/- 0.6) x 10(-5), and (4.4 +/- 1.7 +/- 0.5) x 10(-5), for J = 0, 1, 2, respectively, where the first uncertainties are statistical and the second systematic.
|
|
43. |
- Ablikim, M., et al.
(författare)
-
First Observation of D+ -> eta mu(+)nu(mu) and Measurement of Its Decay Dynamics
- 2020
-
Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 124:23
-
Tidskriftsartikel (refereegranskat)abstract
- By analyzing a data sample corresponding to an integrated luminosity of 2.93 fb(-1) collected at a center-of-mass energy of 3.773 GeV with the BESIII detector, we measure for the first time the absolute branching fraction of the D+ -> eta mu(+) nu(mu) decay to be BD+ ->eta mu+nu mu = (10.4 +/- 1.0(stat) +/- 0.5(syst)) x 10(-4). Using the world averaged value of BD+ ->eta e+nu e, the ratio of the two branching fractions is determined to be = BD+ ->eta mu+nu mu/BD+ ->eta e+nu e =0.91 +/- 0.13((stat+syst)), which agrees with the theoretical expectation of lepton flavor universality within uncertainty. By studying the differential decay rates in five four-momentum transfer intervals, we obtain the product of the hadronic form factor f(+)(eta)(0) and the c -> d Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-cd vertical bar to be f(+)(eta)(0)vertical bar V-cd vertical bar = 0.087 +/- 0.008(stat) +/- 0.002(syst). Taking the input of vertical bar V-cd vertical bar from the global fit in the standard model, we determine f(+)(eta)(0) = 0.39 +/- 0.04(stat) +/- 0.01(syst). On the other hand, using the value of f(+)(eta)(0) calculated in theory, we find vertical bar V-cd vertical bar= 0.242 +/- 0.022(stat )+/- 0.006(syst) +/- 0.033(theory).
|
|
44. |
- Ablikim, M., et al.
(författare)
-
First observation of Î+ c â ÎK+ Ï0 and evidence of Î+ c â ÎK+ Ï + Ï -
- 2024
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 109:3
-
Tidskriftsartikel (refereegranskat)abstract
- We present the first observation of the singly Cabibbo-suppressed decay Lambda thorn c ->Lambda K thorn pi 0with asignificance of5.7 sigma and the first evidence of Lambda thorn c ->Lambda K thorn pi thorn pi-decay with a significance of3.1 sigma,basedone thorn e-annihilation data recorded by the BESIII detector at the BEPCII collider. The data correspond to anintegrated luminosity of6.4fb-1, in the center-of-mass energy range from 4.600 to 4.950 GeV. Wedetermine the branching fractions of Lambda thorn c ->Lambda K thorn pi 0and Lambda thorn c ->Lambda K thorn pi thorn pi-relative to their Cabibbo-favored counterparts to beBo Lambda thorn c ->Lambda K thorn pi 0 thorn Bo Lambda thorn c ->Lambda pi thorn pi 0 thorn 1/4o2.090.39stat0.07syst thorn x10-2andBo Lambda thorn c ->Lambda K thorn pi thorn pi- thorn Bo Lambda thorn c ->Lambda pi thorn pi thorn pi- thorn 1/4o1.130.41stat0.06syst thorn x10-2, respectively. Moreover, by combining our measured result with theworld average ofBo Lambda thorn c ->Lambda pi thorn pi 0 thorn , we obtain the branching fractionBo Lambda thorn c ->Lambda K thorn pi 0 thorn 1/4o1.490.27stat0.05syst0.08ref thorn x10-3. This result significantly departs from theoretical predictionsbased on quarkSUo3 thorn flavor symmetry, which is underpinned by the presumption of meson pairS-waveamplitude dominance
|
|
45. |
- Ablikim, M., et al.
(författare)
-
First observation of the decay chi(cJ) -> Sigma(+)(p)over-barK(S)(0)+ c.c. (J=0,1,2)
- 2019
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 100:9
-
Tidskriftsartikel (refereegranskat)abstract
- Using E1 radiative transitions psi(3686) -> gamma chi(cJ) from a sample of (448.1 +/- 2.9) x 10(6) psi(3686) events collected with the BESIII detector, the decays chi(cJ) -> Sigma(+)(p) over barK(S)(0) + c.c.(J = 0,1,2) are studied. The decay branching fractions are measured to be B(chi(c0) -> Sigma(+)(p) over barK(S)(0) + c.c.) = (3.52 +/- 0.19 +/- 0.21) x 10(-4), B(chi(c1) -> Sigma(+)(p) over barK(S)(0) + c.c.) = (1.53 +/- 0.10 +/- 0.08) x 10(-4), and B(chi(c2) -> Sigma(+)(p) over barK(S)(0) + c.c.) = (8.25 +/- 0.83 +/- 0.49) x 10(-5), where the first and second uncertainties are the statistical and systematic ones, respectively. No evident intermediate resonances arc observed in the studied processes.
|
|
46. |
- Ablikim, M., et al.
(författare)
-
First Observation of the Direct Production of the χc1 in e+e− Annihilation
- 2022
-
Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 129:12
-
Tidskriftsartikel (refereegranskat)abstract
- We study the direct production of the JPC=1++ charmonium state χc1(1P) in electron-positron annihilation by carrying out an energy scan around the mass of the χc1(1P). The data were collected with the BESIII detector at the BEPCII collider. An interference pattern between the signal process e+e−→χc1(1P)→γJ/ψ→γμ+μ− and the background processes e+e−→γISRJ/ψ→γISRμ+μ− and e+e−→γISRμ+μ− is observed by combining all the data samples. The χc1(1P) signal is observed with a significance of 5.1σ. This is the first observation of a C-even state directly produced in e+e− annihilation. The electronic width of the χc1(1P) resonance is determined to be Γee=(0.12+0.13−0.08) eV, which is of the same order of magnitude as theoretical calculations.
|
|
47. |
- Ablikim, M., et al.
(författare)
-
First observation of the semileptonic decay Λ+c → pK−e+νe
- 2022
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 106:11
-
Tidskriftsartikel (refereegranskat)abstract
- Using 4.5 fb−1 of e+e− annihilation data samples collected at the center-of-mass energies ranging from 4.600 GeV to 4.699 GeV with the BESIII detector at the BEPCII collider, a first study of the semileptonic decays Λ+c→pK−e+νe, Λ+c→Λ(1520)e+νe and Λ+c→Λ(1405)e+νe is performed. The Λ+c→pK−e+νe decay is observed with a significance of 8.2σ and the branching fraction is measured to be B(Λ+c→pK−e+νe)=(0.88±0.17stat±0.07syst)×10−3. We also report evidence of Λ+c→Λ(1520)e+νe and Λ+c→Λ(1405)e+νe with significances of 3.3σ and 3.2σ, respectively, and measure B(Λ+c→Λ(1520)e+νe)=(1.02±0.52stat±0.11syst)×10−3 and B(Λ+c→Λ(1405)[→pK−]e+νe)=(0.42±0.19stat±0.04syst)×10−3. Combining these with the inclusive semileptonic Λ+c branching fraction measured by BESIII, the relative fraction is determined to be [B(Λ+c→pK−e+νe)/B(Λ+c→Xe+νe)]=(2.1±0.4stat±0.2syst)%, which provides a clear confirmation that semileptonic Λ+c decays are not saturated by the Λℓ+νℓ final state.
|
|
48. |
- Ablikim, M., et al.
(författare)
-
First observations of h(c )-> hadrons
- 2019
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 99:7
-
Tidskriftsartikel (refereegranskat)abstract
- Based on (4.48 +/- 0.03) x 10(8) Psi(3686) events, collected with the BESIII detector at the BEPCII storage ring, five h(c) hadronic decays are searched for via the process Psi(3686) -> pi(0)h(c). Three of them, h(c) -> p (p) over bar pi(+)pi(-) , pi(+)pi(-)pi(0 )and 2(pi(+)pi(-))pi(0) are observed for the first time with significances of 7.4 sigma, 4.6 sigma, and 9.1 sigma, and their branching fractions are determined to be (2.89 +/- 0.32 +/- 0.55) x 10(-3), (1.60 +/- 0.40 +/- 0.32) x 10(-3), and (7.44 +/- 0.94 +/- 1.52) x 10(-3), respectively, where the first uncertainties are statistical and the second systematic. No significant signal is observed for the other two decay modes, and the corresponding upper limits of the branching fractions are determined to be B(h(c) -> 3(pi(+)pi(-))pi(0)) < 8.7 x 10(-3) and B(h(c) -> K+K-pi(+)pi(-) ) < 5.8 x 10(-4) at the 90% confidence level.
|
|
49. |
- Ablikim, M., et al.
(författare)
-
First simultaneous measurement of Î0 and (Î)over-bar0 asymmetry parameters in Ï(3686) decay
- 2023
-
Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 108:1
-
Tidskriftsartikel (refereegranskat)abstract
- The Xi(0) asymmetry parameters are measured using entangled quantum Xi(0) - (Xi) over bar (0) pairs from a sample of (448.1 +/- 2.9) x 10(6) psi(3686) events collected with the BESIII detector at BEPCII. The relative phase between the transition amplitudes of the Xi(0)(Xi) over bar helicity states is measured to be Delta Phi = -0.050 +/- 0.150 +/- 0.020 rad, which implies that there is no obvious polarization at the current level of statistics. The decay parameters of the Xi(0) hyperon (alpha(Xi 0), alpha((Xi) over bar0), phi(Xi 0), phi((Xi) over bar0)) and the angular distribution parameter [alpha(psi(3686))] and Delta Phi are measured simultaneously for the first time. In addition, the CP asymmetry observables are determined to be A(CP)(Xi 0) = (alpha(Xi 0) + alpha((Xi) over bar0))/(alpha(Xi 0) - alpha((Xi) over bar0)) = -0.007 +/- 0.082 +/- 0.025 and Delta phi(Xi 0)(CP) = (phi(Xi 0) + phi((Xi) over bar0))/2 = -0.079 +/- 0.082 +/- 0.010 rad, which are consistent with CP conservation.
|
|
50. |
- Ablikim, M., et al.
(författare)
-
First Study of Reaction Ξ0n → Ξ-p Using Ξ0-Nucleus Scattering at an Electron-Positron Collider
- 2023
-
Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 130:25
-
Tidskriftsartikel (refereegranskat)abstract
- Using (1.0087 & PLUSMN; 0.0044) x 1010 J=iy events collected with the BESIII detector at the BEPCII storage ring, the process E0n & RARR; E-p is studied, where the E0 baryon is produced in the process J=iy & RARR; E0E over bar 0 and the neutron is a component of the 9Be, 12C, and 197Au nuclei in the beam pipe. A clear signal is observed with a statistical significance of 7.1u. The cross section of the reaction E0 + 9Be & RARR; E- + p + 8Be is determined to be u(E0 + 9Be & RARR; E- + p + 8Be) = (22.1 & PLUSMN; 5.3stat & PLUSMN; 4.5sys) mb at the E0 momentum of 0.818 GeV=c, where the first uncertainty is statistical and the second is systematic. No significant H-dibaryon signal is observed in the E-p final state. This is the first study of hyperon-nucleon interactions in electron-positron collisions and opens up a new direction for such research.
|
|