| 1. |
- Ablikim, M., et al.
(författare)
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Amplitude analysis of the π$^0$π$^0$ system produced in radiative J/ψ decays
- 2016
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Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 93:3
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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.
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| 2. |
- Ablikim, M., et al.
(författare)
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Measurement of azimuthal asymmetries in inclusive charged dipion production in $e^+e^-$ annihilations at $\sqrt{s}$ = 3.65 GeV
- 2016
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Ingår i: PHYSICAL REVIEW LETTERS. - 0031-9007 .- 1079-7114. ; 116:4
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Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the azimuthal asymmetries of two charged pions in the inclusive process $e^+e^-\rightarrow \pi\pi X$ based on a data set of 62 $\rm{pb}^{-1}$ at the center-of-mass energy $\sqrt{s}=3.65$ GeV collected with the BESIII detector. These asymmetries can be attributed to the Collins fragmentation function. We observe a nonzero asymmetry, which increases with increasing pion momentum. As our energy scale is close to that of the existing semi-inclusive deep inelastic scattering experimental data, the measured asymmetries are important inputs for the global analysis of extracting the quark transversity distribution inside the nucleon and are valuable to explore the energy evolution of the spin-dependent fragmentation function.
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| 3. |
- Ablikim, M., et al.
(författare)
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Measurement of the center-of-mass energies at BESIII via the di-muon process
- 2016
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Ingår i: Chinese Physics C. - : IOP Publishing. - 1674-1137 .- 2058-6132. ; 40:6
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Tidskriftsartikel (refereegranskat)abstract
- From 2011 to 2014, the BESIII experiment collected about 5 fb$^{-1}$ data at center-of-mass energies around 4 GeV for the studies of the charmonium-like and higher excited charmonium states. By analyzing the di-muon process $e^{+}e^{-}\rightarrow\gamma_{\rm ISR/FSR}\mu^{+}\mu^{-}$, the center-of-mass energies of the data samples are measured with a precision of 0.8 MeV. The center-of-mass energy is found to be stable for most of time during the data taking.
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| 4. |
- Ablikim, M., et al.
(författare)
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Measurement of the form factors in the decay D+ → ωe+νe and search for the decay D+ → ϕe+νe
- 2015
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Ingår i: Physical Review D. - : American Physical Society. - 1550-7998 .- 1550-2368. ; 92:7
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Tidskriftsartikel (refereegranskat)abstract
- Using 2.92 fb−1 of electron-positron annihilation data collected at a center-of-mass energy of √s=3.773 GeV with the BESIII detector, we present an improved measurement of the branching fraction B(D+ → ωe+νe)=(1.63±0.11±0.08)×10−3. The parameters defining the corresponding hadronic form factor ratios at zero momentum transfer are determined for the first time; we measure them to be rV=1.24±0.09±0.06 and r2=1.06±0.15±0.05. The first and second uncertainties are statistical and systematic, respectively. We also search for the decay D+ → ϕe+νe. An improved upper limit B(D+ → ϕe+νe)<1.3×10−5 is set at 90% confidence level.
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| 5. |
- Ablikim, M., et al.
(författare)
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Measurements of psi(3686) -> K-Lambda(Xi)over-bar(+) + c.c. and psi(3686) -> gamma K-Lambda(Xi)over-bar(+) + c.c.
- 2015
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:9
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Tidskriftsartikel (refereegranskat)abstract
- Using a sample of 1.06 x 10(8) psi(3686) events produced in e(+)e(-) collisions at root s = 3.686 GeV and collected with the BESIII detector at the BEPCII collider, we present studies of the decays psi(3686) -> K-Lambda(Xi) over bar (+) + c.c. and psi(3686) -> gamma K-Lambda(Xi) over bar (+) + c.c. We observe two hyperons, Xi(1690)(-) and Xi(1820)(-), in the K-Lambda invariant mass distribution in the decay psi(3686) -> K-Lambda(Xi) over bar (+) + c.c. with significances of 4.9 sigma and 6.2 sigma, respectively. The branching fractions of psi(3686) -> K-Lambda(Xi) over bar (+) + c.c., psi(3686) -> K-Sigma(0)(Xi) over bar (+) + c.c, psi(3686) -> gamma chi cJ -> gamma K-Lambda(Xi) over bar (+) + c.c (J = 0, 1, 2), and psi(3686) -> Xi(1690/1820)(-)(Xi) over bar (+) + c.c with sub-sequent decay Xi(1690/1820)(-) -> K-Lambda are measured for the first time.
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| 6. |
- Ablikim, M., et al.
(författare)
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Search for a light CP-odd Higgs boson in radiative decays of J/psi
- 2016
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Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 93:5
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Tidskriftsartikel (refereegranskat)abstract
- We search for a light Higgs boson A(0) in the fully reconstructed decay chain of J/psi -> gamma A(0), A(0)-> mu(+)mu(-) using (225.0 +/- 2.8) x 10(6) J/psi events collected by the BESIII experiment. The A(0) is a hypothetical CP-odd light Higgs boson predicted by many extensions of the Standard Model including two spin-0 doublets plus an extra singlet. We find no evidence for A(0) production and set 90% confidence-level upper limits on the product branching fraction B(J/psi -> gamma A(0)) x B(A(0)-> mu(+)mu(-)) in the range of (2.8-495.3) x 10(-8) for 0.212 <= mA(0) <= 3.0 GeV/c(2). The new limits are five times below our previous results, and the nature of the A(0) is constrained to be mostly singlet.
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| 7. |
- Ablikim, M., et al.
(författare)
-
Search for D-0 -> gamma gamma and improved measurement of the branching fraction for D-0 -> pi(0)pi(0)
- 2015
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:11
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Tidskriftsartikel (refereegranskat)abstract
- Using 2.92 fb(-1) of electron-positron annihilation data collected at root s = 3.773 GeV with the BESIII detector, we report the results of a search for the flavor-changing neutral current process D-0 -> gamma gamma using a double-tag technique. We find no signal and set an upper limit at 90% confidence level for the branching fraction of B(D-0 -> gamma gamma < 3.8 x 10(-6). We also investigate D-0-meson decay into two neutral pions, obtaining a branching fraction of B(D-0 -> pi(0)pi(0)) = (8.24 +/- 0.21(stat) +/- 0.30(syst)) x 10(-4), the most precise measurement to date and consistent with the current world average.
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| 8. |
- Ablikim, M., et al.
(författare)
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Study of J/Psi -> p(p)over-bar phi at BESIII
- 2016
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Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 93:5
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Tidskriftsartikel (refereegranskat)abstract
- Using a data sample of 1.31×109 J/ψ events accumulated with the BESIII detector, the decay J/ψ→pp¯ϕ is studied via two decay modes, ϕ→KS0KL0 and ϕ→K+K-. The branching fraction of J/ψ→pp¯ϕ is measured to be B(J/ψ→pp¯ϕ)=[5.23±0.06(stat)±0.33(syst)]×10-5, which agrees well with a previously published measurement, but with a significantly improved precision. No evident enhancement near the pp¯ mass threshold, denoted as X(pp¯), is observed, and the upper limit on the branching fraction of J/ψ→X(pp¯)ϕ→pp¯ϕ is determined to be B(J/ψ→X(pp¯)ϕ→pp¯ϕ)<2.1×10-7 at the 90% confidence level.
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| 9. |
- Ablikim, M., et al.
(författare)
-
Study of psi decays to the Xi(-)(Xi)over-bar(+) and Sigma(1385)(-/+)(Sigma)over-bar(1385)(+/-) final states
- 2016
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Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 93:7
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Tidskriftsartikel (refereegranskat)abstract
- We study the decays of the charmonium resonances J/psi and psi(3686) to the final states Xi(-)(Xi) over bar (+), S(1385)(-/+)(Sigma) over bar (1385)(+/-) based on a single baryon tag method using data samples of (223.7 +/- 1.4) x 10(6) J/psi and (106.4 +/- 0.9) x 10(6) psi(3686) events collected with the BESIII detector at the BEPCII collider. The decay psi(3686) -> Sigma(1385)(-/+)(Sigma) over bar (1385)(+/-) is observed for the first time, and the measurements of the other processes, including the branching fractions and angular distributions, are in good agreement with, and much more precise than, the previously published results. Additionally, the ratios B(psi(3686)->Xi(-)(Xi) over bar (+))/B(J/psi ->Xi(-)(Xi) over bar (+)), B(psi(3686)->Sigma(1385)(-)(Sigma) over bar (1385)(+))/B(J/psi ->Sigma(1385)(-)(Sigma) over bar (1385)(+)) and B(psi(3686)->Sigma(1385)(+)(Sigma) over bar (1385)(-))/B(J/psi ->Sigma(1385)(+)(Sigma) over bar (1385)(-)) are detetmind
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| 10. |
- Ablikim, M., et al.
(författare)
-
Amplitude analysis of the pi(0)pi(0) system produced in radiative J/psi decays
- 2015
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 92:5
-
Tidskriftsartikel (refereegranskat)abstract
- An amplitude analysis of the pi(0)pi(0) system produced in radiative J/psi decays is presented. In particular, a piecewise function that describes the dynamics of the pi(0)pi(0) system is determined as a function of M pi(0)pi(0) from an analysis of the (1.311 +/- 0.011) x 10(9) J/psi decays collected by the BESIII detector. The goal of this analysis is to provide a description of the scalar and tensor components of the pi(0)pi(0) system while making minimal assumptions about the properties or number of poles in the amplitude. Such a model-independent description allows one to integrate these results with other related results from complementary reactions in the development of phenomenological models, which can then be used to directly fit experimental data to obtain parameters of interest. The branching fraction of J/psi -> pi(0)pi(0) is determined to be (1.15 +/- 0.05) x 10(-3), where the uncertainty is systematic only and the statistical uncertainty is negligible.
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