BES Collaboration

Evidence for f0(980)f0(980) production in chi_c0 decays

BES Collaboration, M. Ablikim

Using a sample of 14 million $I ¨ (2 S)$ events accumulated with the BES II detector, evidence for $f_{0} (980) f_{0} (980)$ production in $I ¨ _{c 0}$ decays is obtained for the first time; th…

Direct Measurements of the Branching Fractions for the Semileptonic Decays $D^{0} \to K^{-} I^¼^{+} I^½_{I^} ¼$ and $D^{0} \to I ¨ ^{-} I^¼^{+} I^½_{I^} ¼$

BES Collaboration, M. Ablikim

Based on the data sample of 33 pb $^{- 1}$ collected at and around 3.773 GeV with the BES-II detector at the BEPC collider, the absolute branching fractions for the semileptonic deca…

Experimental study of $I ¨ (2 S)$ decays to $\K^+ K^- Ï^+ Ï^- Ï^0$ final states

M. Ablikim, BES Collaboration

$K^{+} K^{-} I ¨ ^{+} I ¨ ^{-} I ¨ ^{0}$ final states are studied using a sample of $14 \times 1 0^{6}$ $I ¨ (2 S)$ decays collected with the Beijing Spectrometer (BESII) at the Beijing Electron-Position Coll…

First Measurements of eta_c Decaying into K^+K^-2(pi^+pi^-) and 3(pi^+pi^-)

BES Collaboration, M. Ablikim

The decays of eta_c to K^+K^-2(pi^+pi^-) and 3(pi^+pi^-) are observed for the first time using a sample of 5.8X10^7 J/Ïevents collected by the BESII detector. The product branchin…

Direct Measurements of Absolute Branching Fractions for D0 and D+ Inclusive Semimuonic Decays

BES Collaboration, M. Ablikim

By analyzing about 33 $p b^{- 1}$ data sample collected at and around 3.773 GeV with the BES-II detector at the BEPC collider, we directly measure the branching fractions for the…

Search for K_S K_S in J/psi and psi(2S) decays

J. Z. Bai, BES Collaboration

The CP violating processes J/psi-->K_S K_S and psi(2S)-->K_S K_S are searched for using samples of 58 million J/psi and 14 million psi(2S) events collected with the Beijing Spectro…

A Study of J/psi-->gamma gamma V(rho,phi) Decays with the BESII Detector

BES Collaboration

Using a sample of $58 \times 1 0^{6}$ $J / I ¨ $ events collected with the BESII detector, radiative decays $J / I ¨ \to I^^{3} I^^{3} V$ , where $V = I ¨ $ or $I ¨ $ , are studied. A resonance around 1420 MeV/c…

First observation of $I ¨ (2 S) \to p n ˉ I ¨ ^{-} + c . c .$

M. Ablikim, BES Collaboration

Using 14 million $I ¨ (2 S)$ events collected with the Beijing Spectrometer (BESII) at the Beijing Electron-Positron Collider, the branching fractions of $I ¨ (2 S)$ decays to $p \bar{n}…

Observation of a near-threshold enhancement in the ÏÏmass spectrum from the doubly OZI suppressed decay J/Ï\to Î³ÏÏ

BES Collaboration

An enhancement near threshold is observed in the ÏÏinvariant mass spectrum from the doubly OZI suppressed decays of J/Ï\to Î³ÏÏ, based on a sample of 5.8 X 10^7 J/Ïevents col…

hep-ex2011

Observation of charged kappa in J/psi -> K(892)-+Kspi+-, K(892)-+ -> Kspi-+ at BESII

BES Collaboration, M. Ablikim

Using 58 million J/psi decays obtained by BESII, a charged kappa particle is observed in the analysis of the Kspi+- system recoiling against K*(892)-+ selected in J/psi -> KsKspi+p…

Observation of $\psp$ decays to $I ¨ (770) I ¨ $ and $I ¨ (2150) I ¨ $

BES Collaboration, M. Ablikim

\pspto ÏÏis observed for the fisrt time in a data sample of 14M \psp decays collected by the BESII detector at BEPC. The branching fraction is measured to be \BR(psptoÏÏ)=(5.1+…

Measurements of the observed cross sections for e+e -> exclusive light hadrons containing K^S_0 meson at \sqrt{s} = 3.773 and 3.650 GeV

BES Collaboration

By analyzing the data sets of 17.3 pb $^{- 1}$ taken at $s = 3.773$ GeV and of 6.5 pb $^{- 1}$ taken at $s = 3.650$ GeV with the BES-II detector at the BEPC collider, we meas…

Determination of BR(chi_{cJ} --> p \bar{p}) in psi(2S) decays

J. Z. Bai, BES Collaboration

The processes psi(2S) --> gamma chi_{cJ}, chi_{cJ} --> p pbar (J=0,1,2) are studied using a sample of 14X10^6 psi(2S) decays collected with the Beijing Spectrometer at the Beijing…

First measurements of J/Psi decays into $I^£^{+} I^ˉ £^{-}$ and $I^^{0} I^ˉ ^{0}$

BES Collaboration

Based on 58 million J/Psi events collected with the BESII detector at the BEPC, the baryon pair processes J/Psi to $I^£^{+} I^ˉ £^{-}$ and J/Psi to $I^^{0} I^ˉ ^{0}$ are observed for the…

Measurement of branching fractions for the inclusive Cabibbo-favored ~K0(892) and Cabibbo-suppressed K0(892) decays of neutral and charged D mesons

M. Ablikim, BES Collaboration

The branching fractions for the inclusive Cabibbo-favored ~K*0 and Cabibbo-suppressed K*0 decays of D mesons are measured based on a data sample of 33 pb-1 collected at and around…

Study of J/psi decays to Lambda Lambdabar and Sigma0 Sigma0bar

BES Collaboration, M. Ablikim

The branching ratios and Angular distributions for J/psi decays to Lambda Lambdabar and Sigma0 Sigma0bar are measured using BESII 58 million J/psi.

Obervation of Ï_{cJ}--> omega omega decays

BES Collaboration, M. Ablikim

Decays of $Ï_{c0,2}\ar\ww$ are observed for the first time using a sample of $14.0 \times 1 0^{6}$ $I ¨ (2 S)$ events collected with the BESII detector. The branching ratios are determin…

Observation of a near-threshold enhancement in th p pbar mass spectrum from radiative J/psi-->gamma p pbar decays

BES Collaboration, J. Z. Bai, Y. Ban +1

We observe a narrow enhancement near 2mp in the invariant mass spectrum of ppbar pairs from radiative J/psi-->gamma ppbar decays. The enhancement can be fit with either an S- or P-…

Measurements of Cabibbo Suppressed Hadronic Decay Fractions of Charmed D0 and D+ Mesons

BES Collaboration

Using data collected with the BESII detector at $e^{+} e^{-}$ storage ring Beijing Electron Positron Collider, the measurements of relative branching fractions for seven Cabibbo sup…

Measurement of the branching fractions for $J / I ¨ \to I^^{3} I ¨ ^{0}$ , $I^^{3} I^\cdot$ and $I^^{3} I^\cdot^{'}$

M. Ablikim, J. Z. Bai, BES Collaboration

The decay modes $\jpsi\arÎ³Ï^0, Î³Î·$ and $Î³\etap$ are analyzed using a data sample of 58 million $\jpsi$ decays collected with the BESII detector at BEPC. The branching fraction…

Observation of a resonance X(1835) in J/Ï--> Î³Ï^+ Ï^- Î·^{\prime}

BES Collaboration, M. Ablikim

The decay channel J/Ï--> Î³Ï^+ Ï^- Î·^{\prime} is analyzed using a sample of 5.8\times 10^7 JÏevents collected with the BESII detector. A resonance, the X(1835), is observed in…

Measurements of the observed cross sections for $e^{+} e^{-} \to$ light hadrons at $s =$ 3.773 and 3.650 GeV

BES Collaboration

Using the data sets of 17.3 pb $^{- 1}$ collected at $s =$ 3.773 GeV and 6.5 pb $^{- 1}$ collected at $s =$ 3.650 GeV with the BESII detector at the BEPC collider, we have…

Improved measurement of $I ¨ (2 S)$ decays into $I ¨ ^{+} I ¨ ^{-}$

BES Collaboration, M. AblikimJ

Using 14M $I ¨ (2 S)$ events collected at BESII, the branching fraction of $I ¨ (2 S) \to I ¨ ^{+} I ¨ ^{-}$ is measured to be $B r_{I ¨ I ¨ } = (3.10 \pm 0.21 \pm 0.38) \times 1 0^{- 3}$ , where the first…

Direct Measurement of the Branching Fraction for the Decay of $D^{+} \to K ˉ^{0} e^{+} I^½_{e}$ and Determination of $I^ (D^{0} \to K^{-} e^{+} I^½_{e}) / I^ (D^{+} \to K ˉ^{0} e^{+} I^½_{e})$

BES Collaboration

The absolute branching fraction for the decay $D^{+} \to K ˉ^{0} e^{+} I^½_{e}$ is determined using $5321 \pm 149 \pm 160$ singly tagged $D^{-}$ sample from the data collected around 3.773 G…

hep-ex1999

Direct Measurement of B(D0->phiX0) and B(D+->phiX+)

BES Collaboration, J. Z. Bai

The first measurement of B(0->phi X0) and an upper limit for B(D+->phi X+) are determined from 22.3 pb-1 of e+e- annihilation data at a C. M. energy of 4.03 GeV. The data were reco…

Search for the Pentaquark State in $I ¨ (2 S)$ and $J / I ¨ $ Decays to $K_{S}^{0} p K^{-} n ˉ$ and $K_{S}^{0} p ˉ K^{+} n$

BES Collaboration, J. Z. Bai

Results are presented on $I ¨ (2 S)$ and $J / I ¨ $ hadronic decays to $K_{S}^{0} p K^{-} n ˉ$ and $K_{S}^{0} p ˉ K^{+} n$ final states from data samples of 14 million $I ¨ (2 S)$ and 58 million $J / I ¨ $ …

Measurements of $I ¨ (2 S)$ decays into $I ¨ I ¨ ^{0}$ , $I ¨ I^\cdot$ , $I ¨ I^\cdot^{^{'}}$ , $I ¨ I^\cdot$ , and $I ¨ I^\cdot^{^{'}}$

BES Collaboration

Decays of the $I ¨ (2 S)$ into Vector plus Pseudoscalar meson final states have been studied with 14 million $I ¨ (2 S)$ events collected with the BESII detector. Branching fractions of…

The $I ¨ $ pole in $J / I ¨ \to I ¨ I ¨ ^{+} I ¨ ^{-}$

BES Collaboration

Using a sample of 58 million $J / I ¨ $ events recorded in the BESII detector, the decay $J / I ¨ \to I ¨ I ¨ ^{+} I ¨ ^{-}$ is studied. There are conspicuous $I ¨ f_{2} (1270)$ and $b_{1} (1235) I ¨ $ signals…

Evidence of psi(3770) non-DD-bar Decay to J/psi pi+pi-

BES Collaboration

Evidence of $I ¨ (3770)$ decays to a non- $D D ˉ$ final state is observed. A total of $11.8 \pm 4.8 \pm 1.3$ $Ï(3770) \to \PPJP$ events are obtained from a data sample of 27.7 $…

Evidence of $I ¨ $ particle in $J / I ¨ \to I ¨ I ¨ I ¨ $

BES Collaboration

Based on a sample of 7.8 million BESI $J / I ¨ $ events, the decay of $J / I ¨ \to I ¨ I ¨ ^{+} I ¨ ^{-}$ is studied. A low mass enhancement in the $I ¨ ^{+} I ¨ ^{-}$ invariant mass spectrum recoiling aga…

Observation of a threshold enhancement in the p \bar{Lambda} invariant mass spectrum

BES Collaboration, M. Ablikim

An enhancement near the m_p + M_Î mass threshold is observed in the combined p \barÎ and \bar{p}Îinvariant mass spectrum from J/Ï--> p K^- \bar{Lambda} + c.c. decays. It can be…

Measurements of J/Ïdecays into ÏK \bar{K} Ïand ÏK \bar{K} Ï

BES Collaboration

The decays of $J / I ¨ \to I ¨ K K ˉ I ¨ $ and $J / I ¨ \to I ¨ K K ˉ I ¨ $ are studied using $5.8 \times 1 0^{7}$ $J / I ¨ $ events collected with the Beijing Spectrometer (BESII) at the Beijing E…

Measurement of Cross Sections for $D^{0} D ˉ^{0}$ and $D^{+} D^{-}$ Production in $e^{+} e^{-}$ Annihilation at $s = 3.773$ GeV

BES Collaboration

The cross sections for $D^{0} D ˉ^{0}$ and $D^{+} D^{-}$ production at 3.773 GeV have been measured with BES-II detector at BEPC. These measurements are made by analyzing a data sample…

Measurements of the absolute branching fractions for D->Kbar pi e+ nu_e, D-> Kbar e+nu_e and determination of Gamma(D+ -> K0bar e+ nu_e)/Gamma(D+ -> K0bar e+nu_e)

BES Collaboration, M. Ablikim

Using the data of about 33 pb $^{- 1}$ collected at and around 3.773 GeV with the BES-II detector at the BEPC collider, we have studied the exclusive semileptonic decays $D^+ \to K^-…

hep-ph2002

A Measurement of Psi(2S) Resonance Parameters

BES Collaboration, J. Z. Bai

Cross sections for e+e- to hadons, pi+pi- J/Psi, and mu+mu- have been measured in the vicinity of the Psi(2S) resonance using the BESII detector operated at the BEPC. The Psi(2S) t…

Direct Measurements of the Branching Fractions for $D^{0} \to K^{-} e^{+} I^½_{e}$ and $D^{0} \to I ¨ ^{-} e^{+} I^½_{e}$ and Determinations of the Form Factors $f_{+}^{K} (0)$ and $f^{I ¨} _{+} (0)$

BES Collaboration

The absolute branching fractions for the decays $D^{0} \to K^{-} e^{+} I^½_{e}$ and $D^{0} \to I ¨ ^{-} e^{+} I^½_{e}$ are determined using $7584 \pm 198 \pm 341$ singly tagged $D ˉ^{0}$ sample from the…

Anomalous Line-Shape of Cross Sections for $e^{+} e^{-} \to Hadrons$ in the Center-of-Mass Energy Region between 3.650 and 3.872 GeV

BES Collaboration

We observe an obvious anomalous line-shape of the $e^{+} e^{-} \to hadrons$ total cross sections in the energy region between 3.700 and 3.872 GeV from the data samples taken with…

hep-ex1999

Measurement of the Inclusive Charm Cross Section at 4.03 GeV and 4.14 GeV

BES Collaboration

The cross section for charmed meson production at $s = 4.03$ and 4.14 GeV has been measured with the Beijing Spectrometer. The measurement was made using 22.3 $p b^{- 1}$ of…

Observation of a broad 1^-- resonant structure around 1.5 GeV/ $c^{2}$ in the K^+K^- mass spectrum in J/psi --> K^+K^-pi^0

BES Collaboration, M. Ablikim

A broad peak is observed at low K^+K^- invariant mass in J/psi --> K^+K^-pi^0 decays found in a sample of 5.8\times 10^7 J/psi events collected with the BESII detector. A partial w…

Partial Wave Analysis of $I ¨ _{c 0} \to I ¨ ^{+} I ¨ ^{-} K^{+} K^{-}$

M. Ablikim, BES Collaboration

A partial wave analysis of $I ¨ _{c 0} \to I ¨ ^{+} I ¨ ^{-} K^{+} K^{-}$ in $I ¨ (2 S) \to I^^{3} I ¨ _{c 0}$ decay is presented using a sample of 14 million $I ¨ (2 S)$ events accumulated by the BES II detector. Th…

Measurement of Inclusive Monmentum Spectra and Multiplicity Distributions of Charged Particles at $s \sim 2 - 5$ GeV

BES Collaboration, J. Z. Bai

Inclusive momentum spectra and multiplicity distributions of charged particles measured with BESII detector at center of mass energies of 2.2,2.6,3.0,3.2,4.6 and 4.8 GeV are presen…

psi(2S) Radiative Decay Measurements

BES Collaboration, M. Ablikim

Using a sample of 14 million $\psip$ events collected with the BESII detector, branching fractions or upper limits on the branching fractions of $\psip$ decays into $Î³\ppb$, $Î³2(…

Search for the decays $J / I ¨ \to I^^{3} I ¨ I ¨ $ and $J / I ¨ \to I^^{3} I ¨ I ¨ $

BES Collaboration

Using 58 million $J / I ¨ $ events collected with the Beijing Spectrometer (BESII) at the Beijing Electron-Positron Collider, the decays $J / I ¨ \to I^^{3} I ¨ I ¨ $ and $J / I ¨ \to I^^{3} I ¨ I ¨ $ are searc…

physics.ins-det2005

BESII Detector Simulation

BES Collaboration

A Monte Carlo program based on Geant3 has been developed for BESII detector simulation. The organization of the program is outlined, and the digitization procedure for simulating t…

Observation of Two New N* Peaks in J/psi -> $pp i^{-} n ˉ$ and $p ˉ I ¨ ^{+} n$ Decays

BES Collaboration

The $I ¨ N$ system in decays of $J / I ¨ \to N ˉ N I ¨ $ is limited to be isospin 1/2 by isospin conservation. This provides a big advantage in studying $N^{*} \to I ¨ N$ compared with $I ¨ N$ an…

Observation of the decay $\psip\rar\kstark$

BES Collaboration, M. Ablikim

Using 14 million $I ¨ (2 S)$ events collected with the BESII detector, branching fractions of $\psip\rar\kstarkpm$ and $\kstarknn$ are determined to be: $\calB(\psip\rar\kstarkpm)=(2.…

First Measurement of the Branching Ratio of $J / I ¨ \to I^^{3} f_{2} (1270) f_{2} (1270)$

BES Collaboration, M. Ablikim

Using 58 million $J / I ¨ $ events taken with the BES II detector at the Beijing Electron Positron Collider, a new decay mode $J / I ¨ \to I^^{3} f_{2} (1270) f_{2} (1270) \to I^^{3} I ¨ ^{+} I ¨ ^{-} I ¨ ^{+} I ¨ ^{-}$ …

Study of JÏdecaying into Ïp \bar p

BES Collaboration

The decay $J / I ¨ \to I ¨ p p ˉ$ is studied using a $5.8 \times 1 0^{7}$ $J / I ¨ $ event sample accumulated with the BES II detector at the Beijing electron-positron collider. The decay br…

Partial wave analysis of J/Ï\to Î³ÏÏ

BES Collaboration

Using $5.8 \times 1 0^{7} J / I ¨ $ events collected in the BESII detector, the radiative decay $J / I ¨ \to I^^{3} I ¨ I ¨ \to I^^{3} K^{+} K^{-} K_{S}^{0} K_{L}^{0}$ is studied. The $I ¨ I ¨ $ invariant mass distributio…

Direct Measurement of the Pseudoscalar Decay Constant fD+

BES Collaboration

The absolute branching fraction of $D^{+} \to I^¼^{+} I^½$ has been directly measured by an analysis of a data sample of about 33 $p b^{- 1}$ collected around $s = 3.773$ GeV wi…

Observation of $K^{} (892)^{0} K ˉ^{} (892)^{0}$ in $I ¨ _{c J}$ Decays

BES Collaboration, M. Ablikim

$K^{*} (892)^{0} K ˉ^{*} (892)^{0}$ signals from $I ¨ _{c J} (J = 0, 1, 2)$ decays are observed for the first time using a data sample of 14 million $I ¨ (2 S)$ events accumulated at the BES II dete…

hep-ex2009

Partial wave analysis of J/psi to p pbar pi0

BES Collaboration

Using a sample of 58 million $J / I ¨ $ events collected with the BESII detector at the BEPC, more than 100,000 $J / I ¨ \to p p ˉ I ¨ ^{0}$ events are selected, and a detailed partial wave…

Psi(2S) two- and three-body hadronic decays

BES Collaboration, J. Z. Bai

We report measurements of branching fractions for psi(2S) decays into omega pi pi, b1 pi,omega f2(1270),omega KK, omega p pbar, phi pi pi, phi f0(980),phi KK, and an upper limit fo…

Study of psi(2S) decays to X J/psi

BES Collaboration, M. Ablikim

Using J/psi -> mu^+ mu^- decays from a sample of approximately 4 million psi(2S) events collected with the BESI detector, the branching fractions of psi(2S) -> eta J/psi, pi^0 pi^0…

Search for the Rare Decays J/Psi --> Ds- e+ nu_e, J/Psi --> D- e+ nu_e, and J/Psi --> D0bar e+ e-

BES Collaboration

We report on a search for the decays J/Psi --> Ds- e+ nu_e + c.c., J/Psi --> D- e+ nu_e + c.c., and J/Psi --> D0bar e+ e- + c.c. in a sample of 5.8 * 10^7 J/Psi events collected wi…

Measurements of the observed cross sections for $e^{+} e^{-} \to$ exclusive light hadrons containing $I ¨ ^{0} I ¨ ^{0}$ at $s = 3.773$ , 3.650 and 3.6648 GeV

BES Collaboration

By analyzing the data sets of 17.3, 6.5 and 1.0 pb $^{- 1}$ taken, respectively, at $s = 3.773$ , 3.650 and 3.6648 GeV with the BES-II detector at the BEPC collider, we measure t…

hep-ex1999

Charmonium Decays to Axialvector plus Pseudoscalar Mesons

BES Collaboration, J. Z. Bai

A sample of 3.79 million psi(2S) decays observed in the BES detector is used to study the decays of charmonium to axialvector plus pseudoscalar mesons. The branching fraction for p…

Direct Measurements of the Branching Fractions for Inclusive $K^{\pm}$ and Inclusive Semileptonic Decays of $D^{+}$ and $D^{0}$ Mesons

BES Collaboration

With singly-tagged $D ˉ$ samples selected from the data collected at and around 3.773 GeV with the BESII detector at the BEPC collider, we have measured the branching fractions…

hep-ex2001

Radiative Decay of the Ï(2S) into Two Pseudoscalar Mesons

BES Collaboration

Radiative decays of the radially excited charmonium resonance, Ï(2S), into ÏÏ, K Kbar and Î·Î·final states have been measured in a sample of 3.96 * 10^6 Ï(2S) events collected…

Search for Invisible Decays of $I^\cdot$ and $I^\cdot^{'}$ in $J / I ¨ \to I ¨ I^\cdot$ and $I ¨ I^\cdot^{'}$

BES Collaboration

Using a data sample of $58 \times 1 0^{6}$ $J / I ¨ $ decays collected with the BES II detector at the BEPC, searches for invisible decays of $I^\cdot$ and $I^\cdot^{'}$ in $J / I ¨ $ to $I ¨ I^\cdot$ and $…

First observation of J/Ïand Ï(2S) decaying to n K^0_S\barÎ+c.c

BES Collaboration

The decays of $\jpsi$ and $\psip$ to $n K_{S}^{0} I^ˉ + c . c .$ are observed and measured for the first time, and the perturbative QCD ``12%'' rule is tested, based on $5.8 \times 10^…

Observation of Y(2175) in $J / I ¨ \to I^\cdot I ¨ f_{0} (980)$

BES Collaboration, M. Ablikim

The decays of $J / I ¨ \to I^\cdot I ¨ f_{0} (980) (I^\cdot \to I^^{3} I^^{3}, I ¨ \to K^{+} K^{-}, f_{0} (980) \to I ¨ ^{+} I ¨ ^{-})$ are analyzed using a sample of $5.8 \times 1 0^{7}$ $J / I ¨ $ events collected with the BESII detec…

Production of $I ¨ $ in $I ¨ (2 S) \to I ¨ ^{+} I ¨ ^{-} J / I ¨ $

BES Collaboration, M. Ablikim

Using 14M $I ¨ (2 S)$ events accumulated by BESII at the BEPC, a Covariant Helicity Amplitude Analysis is performed for $I ¨ (2 S) \to I ¨ ^{+} I ¨ ^{-} J / I ¨ , J / I ¨ \to I^¼^{+} I^¼^{-}$ . The $I ¨ ^{+} I ¨ ^{-}$ mass…

Measurements of $J / I ¨ $ and $I ¨ (2 S)$ decays into $I^ I^ˉ I ¨ ^{0}$ and $I^ I^ˉ I^\cdot$

BES Collaboration, M. Ablikim

Using 58 million $J / I ¨ $ and 14 million $I ¨ (2 S)$ events collected by the BESII detector at the BEPC, branching fractions or upper limits for the decays $J / I ¨ $ and $Ï(2S) \to Î\bar…

First Evidence of Lambda Lambda-bar in Ï_cJ Decays

BES Collaboration, J. Z. Bai

The first observation of Ï_cJ (J=0,1,2) decays to Lambda Lambda-bar is reported using Ï(2S) data collected with the BESII detector at the BEPC. The branching ratios are determine…