716 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
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)±
4. The Assimilation and Dissimilation of Fu and Shi Poetry up to the Tang Dynasty
No full textThe intimate relationship between fu and shi poetry, whose mutual influence has been so important throughout the history of the genres, cannot be neglected. The two genres started out with distinct definitions, motivations, and contexts, but they frequently assimilated to one another; and yet a countervailing trend of dissimilation also led each genre to assert its independence after all. This chapter aims to shed light on this dynamic by tracing its development through different historical periods in early medieval China, and thus, to reveal the mutual influence and distinction between the fu and shi genres
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
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)±
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
Study of the process e+e- →π0π0J /ψ and neutral charmoniumlike state Zc (3900)0
No full textCross sections of the process e+e-→π0π0J/ψ at center-of-mass energies between 3.808 and 4.600 GeV are measured with high precision by using 12.4 fb-1 of data samples collected with the BESIII detector operating at the BEPCII collider facility. A fit to the measured energy-dependent cross sections confirms the existence of the charmoniumlike state Y(4220). The mass and width of the Y(4220) are determined to be (4220.4±2.4±2.3) MeV/c2 and (46.2±4.7±2.1) MeV, respectively, where the first uncertainties are statistical and the second systematic. The mass and width are consistent with those measured in the process e+e-→π+π-J/ψ. The neutral charmonium-like state Zc(3900)0 is observed prominently in the π0J/ψ invariant-mass spectrum, and, for the first time, an amplitude analysis is performed to study its properties. The spin-parity of Zc(3900)0 is determined to be JP=1+, and the pole position is (3893.1±2.2±3.0)-i(22.2±2.6±7.0) MeV/c2, which is consistent with previous studies of electrically charged Zc(3900)±. In addition, cross sections of e+e-→π0Zc(3900)0→π0π0J/ψ are extracted, and the corresponding line shape is found to agree with that of the Y(4220)
Incomplete spondylolysis of the first sacrum: a case report
No full textSpondylolysis is generally attributed to stress fracture, due to movement of the affected vertebrae relative to the vertebra below and is most common in lower lumbar vertebrae[1-8]. Since S1 and S2 are fused, spondylolysis of S1 due to stress fracture would unlikely to occur. Although there has been some reports of S1 spondylolysis in ancient Alaskan and Canadian Inuit skeletons, no clinical S1 spondylolysis case due to stress fracture has been reported until now. A 17 years old female gymnast with incomplete spondylolysis of S1 is presented by the authors.He SS, Zhao YC, Freeman BJ, Shi ZC, Li M, Zhang Y, Yu L
Polybaric partial melting in the continental mantle: Evidence from mantle xenoliths from Qilin, Guangdong Province
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