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Register a new userConfirmation of a charged charmoniumlike state $Z_c(3885)^{mp}$ in $e^+e^-topi^{pm}(Dbar{D}^*)^mp$ with double $D$ tag
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We present a study of the process $e^+e^-topi^{pm}(Dbar{D}^*)^{mp}$ using data samples of 1092~pb$^{-1}$ at $sqrt{s}=4.23$~GeV and 826~pb$^{-1}$ at $sqrt{s}=4.26$~GeV collected with the BESIII detector at the BEPCII storage ring. With full reconstruction of the $D$ meson pair and the bachelor $pi^{pm}$ in the final state, we confirm the existence of the charged structure $Z_c(3885)^{mp}$ in the $(Dbar{D}^*)^{mp}$ system in the two isospin processes $e^+e^-topi^+D^0D^{*-}$ and $e^+e^-topi^+D^-D^{*0}$. By performing a simultaneous fit, the statistical significance of $Zc(3885)^{mp}$ signal is determined to be greater than 10$sigma$, and its pole mass and width are measured to be $M_{rm{pole}}$=(3881.7$pm$1.6(stat.)$pm$1.6(syst.))~MeV/$c^2$ and $Gamma_{rm{pole}}$=(26.6$pm$2.0(stat.)$pm$2.1(syst.))~MeV, respectively. The Born cross section times the $(Dbar{D}^*)^{mp}$ branching fraction ($sigma(e^+e^-topi^{pm}Z_{c}(3885)^{mp}) times Br(Z_{c}(3885)^{mp}to(Dbar{D}^*)^{mp})$) is measured to be $(141.6pm7.9(text{stat.})pm12.3(text{syst.}))~text{pb}$ at $sqrt{s}=4.23$~GeV and $(108.4pm6.9(text{stat.})pm8.8(text{syst.}))~text{pb}$ at $sqrt{s}=4.26$~GeV. The polar angular distribution of the $pi^{pm}$-$Z_c(3885)^{mp}$ system is consistent with the expectation of a quantum number assignment of $J^P=1^+$ for $Z_c(3885)^{mp}$.
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We study the process $e^+e^- to (D^{*} bar{D}^{*})^{pm} pi^mp$ at a center-of-mass energy of 4.26GeV using a 827pb$^{-1}$ data sample obtained with the BESIII detector at the Beijing Electron Positron Collider. Based on a partial reconstruction technique, the Born cross section is measured to be $(137pm9pm15)$pb. We observe a structure near the $(D^{*} bar{D}^{*})^{pm}$ threshold in the $pi^mp$ recoil mass spectrum, which we denote as the $Z^{pm}_c(4025)$. The measured mass and width of the structure are $(4026.3pm2.6pm3.7)$MeV/c$^2$ and $(24.8pm5.6pm7.7)$MeV, respectively. Its production ratio $frac{sigma(e^+e^-to Z^{pm}_c(4025)pi^mp to (D^{*} bar{D}^{*})^{pm} pi^mp)}{sigma(e^+e^-to (D^{*} bar{D}^{*})^{pm} pi^mp)}$ is determined to be $0.65pm0.09pm0.06$. The first uncertainties are statistical and the second are systematic.
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We report a study of the process $e^{+} e^{-} to (D^{*} bar{D}^{*})^{0} pi^0$ using $e^+e^-$ collision data samples with integrated luminosities of $1092 rm{pb}^{-1}$ at $sqrt{s}=4.23 rm{GeV}$ and $826 rm{pb}^{-1}$ at $sqrt{s}=4.26 rm{GeV}$ collected with the BESIII detector at the BEPCII storage ring. We observe a new neutral structure near the $(D^{*} bar{D}^{*})^{0}$ mass threshold in the $pi^0$ recoil mass spectrum, which we denote as $Z_{c}(4025)^{0}$. Assuming a Breit-Wigner line shape, its pole mass and pole width are determined to be $(4025.5^{+2.0}_{-4.7}pm3.1) rm{MeV}/c^2$ and $(23.0pm 6.0pm 1.0) rm{MeV}$, respectively. The Born cross sections of $e^{+}e^{-}to Z_{c}(4025)^{0} pi^0to (D^{*} bar{D}^{*})^{0}pi^0$ are measured to be $(61.6pm8.2pm9.0) rm{pb}$ at $sqrt{s}=4.23 rm{GeV}$ and $(43.4pm8.0pm5.4) rm{pb}$ at $sqrt{s}=4.26 rm{GeV}$. The first uncertainties are statistical and the second are systematic.
We report a new measurement of the exclusive $e^+ e^- to D^{(*) pm} D^{*mp}$ cross sections as a function of the center-of-mass energy from the $D^{(*) pm} D^{* mp}$ threshold through $sqrt{s}=6.0$ GeV with initial-state radiation. The analysis is based on a data sample collected with the Belle detector with an integrated luminosity of $951$ fb$^{-1}$. The accuracy of the cross section measurement is increased by a factor of two over the first Belle study. We perform the first angular analysis of the $e^+ e^- to D^{* pm} D^{* mp}$ process and decompose this exclusive cross section into three components corresponding to the $D^*$ helicities.
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