1,306 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
Displaying 3D images: algorithms for single-image random-dot
No full textA new, simple, and symmetric algorithm can be implemented that results in higher levels of detail in solid objects than previously possible with autostereograms. In a stereoscope, an optical instrument similar to binoculars, each eye views a different picture and thereby receives the specific image that would have arisen naturally. An early suggestion for a color stereo computer display involved a rotating filter wheel held in front of the eyes. In contrast, this article describes a method for viewing on paper or on an ordinary computer screen without special equipment, although it is limited to the display of 3D monochromatic objects. (The image can be colored, say, for artistic reasons, but the method we describe does not allow colors to be allocated in a way that corresponds to an arbitrary coloring of the solid object depicted.) The image can easily be constructed by computer from any 3D scene or solid object description
Zc(3900)/Zc(3885) as a virtual state from πJ/ψ-D¯∗D interaction
No full textAbstract In this work, we study the πJ/ψ and D¯∗D invariant mass spectra of the Y(4260) decay to find out the origin of the Zc(3900) and Zc(3885) structures. The πJ/ψ-D¯∗D interaction is studied in a coupled-channel quasipotential Bethe–Saltpeter equation approach, and embedded to the Y(4260) decay process to reproduce both π-J/ψ and D∗-D0 invariant mass spectra observed at BESIII simultaneously. It is found out that a virtual state at energy about 3870 MeV is produced from the interaction when both invariant mass spectra are comparable with the experiment. The results support that both Zc(3900) and Zc(3885) have the same origin, that is, a virtual state from πJ/ψ-D¯∗D interaction, in which the D¯∗D interaction is more important and the coupling between D¯∗D and πJ/ψ channels plays a minor role
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 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)±
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
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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