847 research outputs found
Search for Zc(3900) ± → ωπ ±
No full textÇetin, Serkant Ali (Dogus Author)The decay Zc(3900)±→ωπ± is searched for using data samples collected with the BESIII detector operating at the BEPCII storage ring at center-of-mass energies s=4.23 and 4.26 GeV. No significant signal for the Zc(3900)± is found, and upper limits at the 90% confidence level on the Born cross section for the process e+e-→Zc(3900)±π →ωπ+π- are determined to be 0.26 and 0.18 pb at s=4.23 and 4.26 GeV, respectively
Search for Zc (3900)± →ωπ± SEARCH for Zc (3900)± →ωπ± M. ABLIKIM et al
No full textThe decay Zc(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 sqrt(s)=4.23 and 4.26 GeV. No significant signal for the Zc(3900)± is found, and upper limits at the 90% confidence level on the Born cross section for the process e+e- -->Zc(3900)±pi-+ -->omega pi+pi- are determined to be 0.26 and 0.18 pb at sqrt(s)=4.23 and 4.26 GeV, respectively
Observation of Zc (3900)0 in e+e- →π0π0J/ψ
No full textÇetin, Serkant Ali (Dogus Author)Using a data sample collected with the BESIII detector operating at the BEPCII storage ring, we observe a new neutral state Zc(3900)0 with a significance of 10.4σ. The mass and width are measured to be 3894.8±2.3±3.2MeV/c2 and 29.6±8.2±8.2MeV, respectively, where the first error is statistical and the second systematic. The Born cross section for e+e-→π0π0J/ψ and the fraction of it attributable to π0Zc(3900)0→π0π0J/ψ in the range Ec.m.=4.19-4.42GeV are also determined. We interpret this state as the neutral partner of the four-quark candidate Zc(3900)±
Confirmation of a charged charmoniumlike state Zc (3885)∓ in e+e- →π± (D D ¯ ∗)∓ with double D tag
No full textÇetin, Serkant Ali (Dogus Author)We present a study of the process e+e-→π±(DD¯∗)∓ using data samples of 1092 pb-1 at s=4.23 GeV and 826 pb-1 at s=4.26 GeV collected with the BESIII detector at the BEPCII storage ring. With full reconstruction of the D meson pair and the bachelor π± in the final state, we confirm the existence of the charged structure Zc(3885)∓ in the (DD¯∗)∓ system in the two isospin processes e+e-→π+D0D∗- and e+e-→π+D-D∗0. By performing a simultaneous fit, the statistical significance of Zc(3885)∓ signal is determined to be greater than 10σ, and its pole mass and width are measured to be Mpole=(3881.7±1.6(stat)±1.6(syst)) MeV/c2 and Γpole=(26.6±2.0(stat)±2.1(syst)) MeV, respectively. The Born cross section times the (DD¯∗)∓ branching fraction (σ(e+e-→π±Zc(3885)∓)×Br(Zc(3885)∓→(DD¯∗)∓)) is measured to be (141.6±7.9(stat)±12.3(syst)) pb at s=4.23 GeV and (108.4±6.9(stat)±8.8(syst)) pb at s=4.26 GeV. The polar angular distribution of the π±-Zc(3885)∓ system is consistent with the expectation of a quantum number assignment of JP=1+ for Zc(3885)∓
Observation of a neutral charmoniumlike state Zc (4025)0 in e+e- → (D∗ D ¯ ∗)0π0
No full textÇetin, Serkant Ali (Dogus Author)We report a study of the process e+e-→(D∗D¯∗)0π0 using e+e- collision data samples with integrated luminosities of 1092 pb-1 at s=4.23 GeV and 826 pb-1 at s=4.26 GeV collected with the BESIII detector at the BEPCII storage ring. We observe a new neutral structure near the (D∗D¯∗)0 mass threshold in the π0 recoil mass spectrum, which we denote as Zc(4025)0. Assuming a Breit-Wigner line shape, its pole mass and pole width are determined to be (4025.5-4.7+2.0±3.1) MeV/c2 and (23.0±6.0±1.0) MeV, respectively. The Born cross sections of e+e-→Zc(4025)0π0→(D∗D¯∗)0π0 are measured to be (61.6±8.2±9.0) pb at s=4.23 GeV and (43.4±8.0±5.4) pb at s=4.26 GeV. The first uncertainties are statistical and the second are systematic
Observation of e+e−→π0π0hc and a Neutral Charmoniumlike Structure Zc(4020)0
No full textUsing data collected with the BESIII detector operating at the Beijing Electron Positron Collider at center-of-mass energies of sqrt(s)=4.23, 4.26, and 4.36 GeV, we observe e+e-→π0π0hc for the first time. The Born cross sections are measured and found to be about half of those of e+e-→π+π-hc within less than 2σ. In the π0hc mass spectrum, a structure at 4.02 GeV/c2 is found. It is most likely to be the neutral isospin partner of the Zc(4020)± observed in the process of e+e-→π+π-hc being found. A fit to the π0hc invariant mass spectrum, with the width of the Zc(4020)0 fixed to that of its charged isospin partner and possible interferences with non-Zc(4020)0 amplitudes neglected, gives a mass of (4023.9±2.2±3.8) MeV/c2 for the Zc(4020)0, where the first error is statistical and the second systematic
Observation of Zc(39000)0 in e+e− → π0π0J/ψ
No full textUsing a data sample collected with the BESIII detector operating at the BEPCII storage ring, we observe a new neutral state Zc(39000)0 with a significance of 10.4σ. The mass and width are measured to be 3894.8 ± 2.3 ± 3.2 MeV=c2 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− → π0π0J=ψ and the fraction of it attributable to ψ0Zc(39000)0 → π0π0J=ψ in the range Ec.m. 4.19−4.42 GeV are also determined. We interpret this state as the neutral partner of the four-quark candidate Zc(3900)±
Study of e+e- →π+π-π0ηc and evidence for Zc (3900)± decaying into ρ±ηc STUDY of e+e- →π+π-π0ηc ... M. ABLIKIM et al
No full textWe study the reaction e+e-→π+π-π0ηc for the first time using data samples collected with the BESIII detector at center-of-mass energies s=4.226, 4.258, 4.358, 4.416, and 4.600 GeV. Evidence of this process is found and the Born cross section σB(e+e-→π+π-π0ηc), excluding e+e-→ωηc and ηηc, is measured to be (46-11+12±10) pb at s=4.226 GeV. Evidence for the decay Zc(3900)±→ρ±ηc is reported at s=4.226 GeV with a significance of 3.9σ, including systematic uncertainties, and the Born cross section times branching fraction σB(e+e-→π Zc(3900)±)×B(Zc(3900)±→ρ±ηc) is measured to be (48±11±11) pb, which indicates that e+e-→π Zc(3900)±→πρ±ηc dominates the e+e-→π+π-π0ηc process. The Zc(3900)±→ρ±ηc signal is not significant at the other center-of-mass energies and the corresponding upper limits are determined. In addition, no significant signal is observed in a search for Zc(4020)±→ρ±ηc with the same data samples. The ratios RZc(3900)=B(Zc(3900)±→ρ±ηc)/B(Zc(3900)±→π±J/ψ) and RZc(4020)=B(Zc(4020)±→ρ±ηc)/B(Zc(4020)±→π±hc) are obtained and compared with different theoretical interpretations of the Zc(3900)± and Zc(4020)±
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Confirmation of a charged charmoniumlike state Zc(3885)∓ in e+e-→π±(DD¯*)∓ with double D tag
No full textWe present a study of the process e+e-→π±(DD¯∗)∓ using data samples of 1092 pb-1 at s=4.23 GeV and 826 pb-1 at s=4.26 GeV collected with the BESIII detector at the BEPCII storage ring. With full reconstruction of the D meson pair and the bachelor π± in the final state, we confirm the existence of the charged structure Zc(3885)∓ in the (DD¯∗)∓ system in the two isospin processes e+e-→π+D0D∗- and e+e-→π+D-D∗0. By performing a simultaneous fit, the statistical significance of Zc(3885)∓ signal is determined to be greater than 10σ, and its pole mass and width are measured to be Mpole=(3881.7±1.6(stat)±1.6(syst)) MeV/c2 and Γpole=(26.6±2.0(stat)±2.1(syst)) MeV, respectively. The Born cross section times the (DD¯∗)∓ branching fraction (σ(e+e-→π±Zc(3885)∓)×Br(Zc(3885)∓→(DD¯∗)∓)) is measured to be (141.6±7.9(stat)±12.3(syst)) pb at s=4.23 GeV and (108.4±6.9(stat)±8.8(syst)) pb at s=4.26 GeV. The polar angular distribution of the π±-Zc(3885)∓ system is consistent with the expectation of a quantum number assignment of JP=1+ for Zc(3885)∓
Study of e+e−→π0X(3872)γ and search for Zc(4020)0→X(3872)γ
No full textUsing data samples collected with the BESIII detector operating at the BEPCII storage ring at center-of-mass energies from 4.178 to 4.600 GeV, we study the process e+e-→π0X(3872)γ and search for Zc(4020)0→X(3872)γ. We find no significant signal and set upper limits on σ(e+e-→π0X(3872)γ)·B(X(3872)→π+π-J/ψ) and σ(e+e-→π0Zc(4020)0)·B(Zc(4020)0→X(3872)γ)·B(X(3872)→π+π-J/ψ) for each energy point at 90% confidence level, which is of the order of several tenths p
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