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Observation of $e^{+}e^{-} \to \phi\chi_{c1}$ and $\phi\chi_{c2}$ at $\sqrt{s}$=4.600 GeV
http://lt-jds.jinr.ru/record/72364
Using a data sample collected with the BESIII detector operating at the BEPCII storage ring at a center-of-mass energy of $\sqrt{s}=4.600$ GeV, we search for the production of $e^{+}e^{-} \to \phi\chi_{c0,1,2}$ and the charmonium-like state $Y(4140)$ in the radiative transition $e^{+}e^{-} \to \gamma Y(4140)$ with $Y(4140)$ subsequently decaying into $\phi J/\psi$. The processes $e^{+}e^{-} \to \phi\chi_{c1}$ and $\phi\chi_{c2}$ are observed for the first time, each with a statistical significance of more than 10\sigma, and the Born cross sections are measured to be $(4.2^{+1.7}_{-1.0}\pm 0.3)$ pb and $(6.7^{+3.4}_{-1.7}\pm 0.5)$ pb, respectively, where the first uncertainties are statistical and the second systematic. No significant signals are observed for $e^{+}e^{-} \to \phi\chi_{c0}$ and $e^{+}e^{-} \to \gamma Y(4140)$ and upper limits on the Born cross sections at $90\%$ confidence level are provided at $\sqrt{s}=4.600$ GeV.Ablikim, MedinaTue, 09 Jan 2018 10:37:16 GMThttp://lt-jds.jinr.ru/record/72364Measurement of branching fractions for $\psi(3686)\rightarrow\gamma\eta',\gamma\eta$ and $\gamma\pi^{0}$
http://lt-jds.jinr.ru/record/71935
Using a data sample of $448\times10^{6}$ $\psi(3686)$ events collected with the BESIII detector operating at the BEPCII storage ring, the decays $\psi(3686)\rightarrow\gamma\eta$ and $\psi(3686)\rightarrow\gamma\pi^{0}$ are observed with a statistical significance of $7.3\sigma$ and $ 6.7\sigma$, respectively. The branching fractions are measured to be $\mathcal{B}(\psi(3686)\rightarrow\gamma\eta)=(0.85\pm0.18\pm0.05)\times10^{-6}$ and $\mathcal{B}(\psi(3686)\rightarrow\gamma\pi^{0})=(0.95\pm0.16\pm0.05)\times10^{-6}$. In addition, we measure the branching fraction of $\psi(3686)\rightarrow\gamma\eta'$ to be $\mathcal{B}(\psi(3686)\rightarrow\gamma\eta')=(125.1\pm2.2\pm6.2)\times 10^{-6}$, with improved precision compared to previous results.Ablikim, MedinaFri, 01 Sep 2017 09:02:50 GMThttp://lt-jds.jinr.ru/record/71935Search for $\psi(3686)\to \gamma\eta_c(\eta(1405))\to \gamma \pi^{+}\pi^{-}\pi^{0}$
http://lt-jds.jinr.ru/record/71818
Using a sample of $4.48\times10^{8}$ $\psi(3686)$ events collected with the BESIII detector, a search for the isospin violating decay $\eta_{c}\to\pi^{+}\pi^{-}\pi^{0}$ via $\psi(3686)\to\gamma\eta_{c}$ is presented. No signal is observed, and the upper limit on $\mathcal{B}(\psi(3686)\to \gamma\eta_{c}\to \gamma\pi^{+}\pi^{-}\pi^{0} )$ is determined to be $1.6\times10^{-6}$ at the $90\%$ confidence level. In addition, a search for $\eta(1405)\to f_{0}(980)\pi^{0}$ in $\psi(3686)$ radiative decays is performed. No signal is observed, and the branching fraction $\mathcal{B}(\psi(3686)\to\gamma\eta(1405)\to \gamma f_{0}(980)\pi^{0}\to\gamma \pi^+\pi^-\pi^0 )$ is calculated to be less than $ 5.2\times10^{-7}$ at the $90\%$ confidence level.Ablikim, MedinaTue, 01 Aug 2017 08:10:34 GMThttp://lt-jds.jinr.ru/record/71818Determination of spin and parity of the $Z_c(3900)$
http://lt-jds.jinr.ru/record/71728
The spin and parity of the $Z_c(3900)^\pm$ state are determined to be $J^P=1^+$ with a statistical significance larger than $7\sigma$ over other quantum numbers in a partial wave analysis of the process $e^+e^-\to \pi^+\pi^-J/\psi$. We use a data sample of 1.92 fb$^{-1}$ accumulated at $\sqrt{s}=4.23$ and 4.26 GeV with the BESIII experiment. When parameterizing the $Z_c(3900)^\pm$ with a Flatte-like formula, we determine its pole mass $M_\textrm{pole}=(3881.2\pm4.2_\textrm{stat}\pm52.7_\textrm{syst})\textrm{MeV}/c^2$ and pole width $\Gamma_\textrm{pole}=(51.8\pm4.6_\textrm{stat}\pm36.0_\textrm{syst})\textrm{MeV}$. We also measure cross sections for the process $e^+e^-\to Z_c(3900)^+\pi^-+c.c.\to J/\psi\pi^+\pi^-$ and determine an upper limit at the 90\% confidence level for the process $e^+e^-\to Z_c(4020)^+\pi^-+c.c.\to J/\psi\pi^+\pi^-$.Ablikim, MedinaTue, 04 Jul 2017 09:11:30 GMThttp://lt-jds.jinr.ru/record/71728Measurement of cross sections of the interactions $e^+e^-\rightarrow \phi\phi\omega$ and $e^+e^-\rightarrow \phi\phi\phi$ at center-of-mass energies from 4.008 to 4.600 GeV
http://lt-jds.jinr.ru/record/71699
Using data samples collected with the BESIII detector at the BEPCII collider at six center-of-mass energies between 4.008 and 4.600 GeV, we observe the processes $e^+e^-\rightarrow \phi\phi\omega$ and $e^+e^-\rightarrow \phi\phi\phi$. The Born cross sections are measured and the ratio of the cross sections $\sigma(e^+e^-\rightarrow \phi\phi\omega)/\sigma(e^+e^-\rightarrow \phi\phi\phi)$ is estimated to be $1.75\pm0.22\pm0.19$ averaged over six energy points, where the first uncertainty is statistical and the second is systematic. The results represent first measurements of these interactions.Ablikim, MedinaTue, 04 Jul 2017 09:10:49 GMThttp://lt-jds.jinr.ru/record/71699Evidence for $e^{+}e^{-} \to \gamma\eta_c(1S)$ at center-of-mass energies between 4.01 and 4.60 GeV
http://lt-jds.jinr.ru/record/71538
We present first evidence for the process $e^+e^-\to \gamma\eta_c(1S)$ at six center-of-mass energies between 4.01 and 4.60~GeV using data collected by the BESIII experiment operating at BEPCII. These data sets correspond to a total integrated luminosity of 4.6~fb$^{-1}$. We measure the Born cross section at each energy using a combination of twelve $\eta_c(1S)$ decay channels. Because the significance of the signal is marginal at each energy ($\le3.0\sigma$), we also combine all six energies under various assumptions for the energy-dependence of the cross section. If the process is assumed to proceed via the $Y(4260)$, we measure a peak Born cross section $\sigma_{\mathrm{ peak}}(e^+e^-\to\gamma\eta_c(1S)) = 2.11 \pm 0.49 (\mathrm{stat.}) \pm 0.36 (\mathrm{syst.})$~pb with a statistical significance of 4.2$\sigma$.Ablikim, MedinaThu, 01 Jun 2017 07:22:32 GMThttp://lt-jds.jinr.ru/record/71538Observation of $e^{+}e^{-} \to \eta h_{c}$ at center-of-mass energies from 4.085 to 4.600 GeV
http://lt-jds.jinr.ru/record/71424
We observe for the first time the process $e^{+}e^{-} \rightarrow \eta h_c$ with data collected by the BESIII experiment. Significant signals are observed at the center-of-mass energy $\sqrt{s}=4.226$ GeV, and the Born cross section is measured to be $(9.5^{+2.2}_{-2.0} \pm 2.7)$ pb. Evidence for $\eta h_c$ is observed at $\sqrt{s}=4.358$ GeV with a Born cross section of $(10.0^{+3.1}_{-2.7} \pm 2.6)$ pb, and upper limits on the production cross section at other center-of-mass energies between 4.085 and 4.600 GeV are determined.Ablikim, MedinaTue, 02 May 2017 07:53:33 GMThttp://lt-jds.jinr.ru/record/71424Improved measurements of branching fractions for $\eta_c\to\phi\phi$ and $\omega\phi$
http://lt-jds.jinr.ru/record/70878
Using $(223.7\pm1.4)\times10^6$ $J/\psi$ events accumulated with the BESIII detector, we study $\eta_c$ decays to $\phi\phi$ and $\omega\phi$ final states. The branching fraction of $\eta_c\to\phi\phi$ is measured to be $Br(\eta_c\to\phi\phi)=(2.1\pm0.1\pm0.3\pm0.5)\times10^{-3}$, where the first uncertainty is statistical, the second is systematic, and the third is from the uncertainty of $Br(J/\psi\to\gamma\eta_c)$. No significant signal for the double OZI-suppressed decay of $\eta_c\to\omega\phi$ is observed, and the upper limit on the branching fraction is determined to be $Br(\eta_c\to\omega\phi)<2.5\times 10^{-4}$ at the 90\% confidence level.Ablikim, MedinaMon, 09 Jan 2017 09:27:04 GMThttp://lt-jds.jinr.ru/record/70878Precise measurement of the $e^+e^-\to \pi^+\pi^-J/\psi$ cross section at center-of-mass energies from 3.77 to 4.60 GeV
http://lt-jds.jinr.ru/record/70760
The cross section for the process $e^+e^-\to \pi^+\pi^-J/\psi$ is measured precisely at center-of-mass energies from 3.77 to 4.60 GeV using 9 fb$^{-1}$ of data collected with the BESIII detector operating at the BEPCII storage ring. Two resonant structures are observed in a fit to the cross section. The first resonance has a mass of $(4222.0\pm 3.1\pm 1.4)$~MeV/$c^2$ and a width of $(44.1\pm 4.3\pm 2.0)$~MeV, while the second one has a mass of $(4320.0\pm 10.4 \pm 7.0)$~MeV/$c^2$ and a width of $(101.4^{+25.3}_{-19.7}\pm 10.2)$~MeV, where the first errors are statistical and second ones systematic. The first resonance is near $4.22$~GeV/$c^2$, corresponding to the so-called $Y(4260)$ resonance reported by previous experiments. However, our measured mass is lower and the width is narrower than previous measurements. The second structure is observed in $e^+e^-\to \pi^+\pi^-J/\psi$ for the first time. The statistical significance is estimated to be larger than $7.6\sigma$.Ablikim, MedinaFri, 02 Dec 2016 06:42:34 GMThttp://lt-jds.jinr.ru/record/70760Observation of $\Lambda^+_{c}\to nK^0_S\pi^+$
http://lt-jds.jinr.ru/record/70719
We report the first direct measurement of decays of the $\Lambda^+_c$ baryon involving the neutron. The analysis is performed using 567 pb$^{-1}$ of $e^+e^-$ collision data collected at $\sqrt{s}=4.599$ GeV with the BESIII detector at the BEPCII collider. We observe the decay $\Lambda^+_{c}\rightarrow n K^0_S\pi^+$ and measure the absolute branching fraction to be $\mathcal{B}({\Lambda^+_{c}\rightarrow n K^0_S\pi^+})=(1.82\pm0.23({\rm stat})\pm0.11({\rm syst}))\%$. A comparison to $\mathcal{B}({\Lambda^+_{c}\rightarrow p(\bar{K}\pi)^0})$ provides an important test of isospin symmetry and final state interactions.Ablikim, MedinaFri, 02 Dec 2016 06:41:46 GMThttp://lt-jds.jinr.ru/record/70719Measurements of the branching fractions for $D^+\to K^0_SK^0_SK^+$, $K^0_SK^0_S\pi^+$ and $D^0\to K^0_SK^0_S$, $K^0_SK^0_SK^0_S$
http://lt-jds.jinr.ru/record/70716
By analyzing $2.93\ \rm fb^{-1}$ of data taken at the $\psi(3770)$ resonance peak with the BESIII detector, we measure the branching fractions for the hadronic decays $D^+\to K^0_SK^0_S K^+$, $D^+\to K^0_SK^0_S \pi^+$, $D^0\to K^0_S K^0_S$ and $D^0\to K^0_SK^0_SK^0_S$. They are determined to be ${\mathcal B}(D^+\to K^0_SK^0_SK^+)=(2.54 \pm 0.05_{\rm stat.} \pm 0.12_{\rm sys.})\times 10^{-3}$, ${\mathcal B}(D^+\to K^0_SK^0_S\pi^+)=(2.70 \pm 0.05_{\rm stat.} \pm 0.12_{\rm sys.})\times 10^{-3}$, ${\mathcal B}(D^0\to K^0_SK^0_S)=(1.67 \pm 0.11_{\rm stat.} \pm 0.11_{\rm sys.})\times 10^{-4}$ and ${\mathcal B}(D^0\to K^0_SK^0_SK^0_S)=(7.21 \pm 0.33_{\rm stat.} \pm 0.44_{\rm sys.})\times 10^{-4}$, where the second one is measured for the first time and the others are measured with significantly improved precision over the previous measurements.Ablikim, MedinaFri, 02 Dec 2016 06:41:40 GMThttp://lt-jds.jinr.ru/record/70716Measurement of the Absolute Branching Fraction for $\Lambda_c^+\rightarrow \Lambda \mu^+\nu_{\mu}$
http://lt-jds.jinr.ru/record/70714
We report the first measurement of the absolute branching fraction for $\Lambda^+_{c}\rightarrow \Lambda \mu^+\nu_{\mu}$. This measurement is based on a sample of $e^+e^-$ annihilation data at a center-of-mass energy of $\sqrt{s}=4.6$ GeV collected with the BESIII detector at the BEPCII storage rings. The sample corresponds to an integrated luminosity of 567 pb$^{-1}$. The branching fraction is determined to be $\mathcal B({\Lambda^+_c\rightarrow \Lambda \mu^+\nu_{\mu}})=(3.49\pm0.46({\rm stat})\pm0.27({\rm syst}))\%$. In addition, we calculate the ratio $\mathcal{B}(\Lambda^+_c\rightarrow \Lambda \mu^+\nu_{\mu})/\mathcal{B}(\Lambda^+_c\rightarrow \Lambda e^+\nu_{e})$ to be $0.96\pm0.16({\rm stat})\pm0.04({\rm syst})$.Ablikim, MedinaFri, 02 Dec 2016 06:41:38 GMThttp://lt-jds.jinr.ru/record/70714Amplitude analysis of the $\chi_{c1} \to \eta\pi^+\pi^-$ decays
http://lt-jds.jinr.ru/record/70635
Using $448.0 \times 10^6$~$\psi(3686)$ events collected with the BESIII detector, an amplitude analysis is performed for $\psi(3686)\to\gamma\chi_{c1}$, $\chi_{c1}\to\eta\pi^+\pi^-$ decays. The most dominant two-body structure observed is $a_0(980)^{\pm}\pi^{\mp}$; $a_0(980)^{\pm}\to\eta\pi^{\pm}$. The $a_0(980)$ line shape is modeled using a dispersion relation, and a significant non-zero $a_0(980)$ coupling to the $\eta^{\prime}\pi$ channel is measured. We observe $\chi_{c1}\to a_2(1700)\pi$ production for the first time, with a significance larger than 17$\sigma$. The production of mesons with exotic quantum numbers, $J^{PC}=1^{-+}$, is investigated, and upper limits for the branching fractions $\chi_{c1}\to \pi_1(1400)^{\pm}\pi^{\mp}$, $\chi_{c1}\to \pi_1(1600)^{\pm}\pi^{\mp}$, and $\chi_{c1}\to\pi_1(2015)^{\pm}\pi^{\mp}$, with subsequent $\pi_1(X)^{\pm} \to \eta\pi^{\pm}$ decay, are determined.Ablikim, MedinaWed, 09 Nov 2016 07:57:32 GMThttp://lt-jds.jinr.ru/record/70635Measurement of Singly Cabibbo-Suppressed Decays $\Lambda_c^{+}\to p\pi^{+}\pi^{-}$ and $\Lambda_c^{+}\to pK^{+}K^{-}$
http://lt-jds.jinr.ru/record/70310
Using 567 $pb^{-1}$ of data collected with the BESIII detector at a center-of-mass energy of $\sqrt{s}=$ 4.599 $GeV$, near the $\Lambda_{c}^{+}\Lambda_{c}^{-}$ threshold, we study the singly Cabibbo-suppressed decays $\Lambda_c^{+}\to p\pi^{+}\pi^{-}$ and $\Lambda_c^{+}\to pK^{+}K^{-}$. By normalizing with respect to the Cabibbo-favored decay $\Lambda_c^{+}\to pK^{-}\pi^{+}$, we obtain ratios of branching fractions: $\frac{\mathcal{B}(\Lambda_c^{+}\to p\pi^{+}\pi^{-})}{\mathcal{B}(\Lambda_c^{+}\to pK^{-}\pi^{+})}$ = $(6.70 \pm 0.48 \pm 0.25)\%$, $\frac{\mathcal{B}(\Lambda_c^{+}\to p\phi)}{\mathcal{B}(\Lambda_c^{+}\to pK^{-}\pi^{+})}$ = $(1.81 \pm 0.33 \pm 0.13)\%$, and $\frac{\mathcal{B}(\Lambda_c^{+}\to pK^{+}K^{-}_{\text{non-}\phi})}{\mathcal{B}(\Lambda_c^{+}\to pK^{-}\pi^{+})}$ = $(9.36 \pm 2.22 \pm 0.71)\times10^{-3}$, where the uncertainties are statistical and systematic, respectively. The absolute branching fractions are also presented. Among these measurements, the decay $\Lambda_c^{+}\to p\pi^{+}\pi^{-}$ is observed for the first time, and the precision of the branching fraction for $\Lambda_c^{+}\to pK^{+}K^{-}_{\text{non-}\phi}$ and $\Lambda_c^{+}\to p\phi$ is significantly improved.Ablikim, MedinaFri, 02 Sep 2016 11:24:01 GMThttp://lt-jds.jinr.ru/record/70310Determination of the number of $J/\psi$ events with inclusive $J/\psi$ decays
http://lt-jds.jinr.ru/record/70201
A measurement of the number of $J/\psi$ events collected with the BESIII detector in 2009 and 2012 is performed using inclusive decays of the $J/\psi$ . The number of $J/\psi$ events taken in 2009 is recalculated to be $(223.7\pm1.4)\times 10^6$, which is in good agreement with the previous measurement, but with significantly improved precision due to improvements in the BESIII software. The number of $J/\psi$ events taken in 2012 is determined to be $(1086.9\pm 6.0)\times 10^6$. In total, the number of $J/\psi$ events collected with the BESIII detector is measured to be $(1310.6\pm 7.0)\times 10^6$, where the uncertainty is dominated by systematic effects and the statistical uncertainty is negligible.Ablikim, MedinaThu, 04 Aug 2016 07:47:13 GMThttp://lt-jds.jinr.ru/record/70201Amplitude analysis of the decays $\eta^\prime\rightarrow\pi^+\pi^-\pi^0$ and $\eta^\prime\rightarrow\pi^0\pi^0\pi^0$
http://lt-jds.jinr.ru/record/69970
Based on a sample of $1.31\times10^9$ $J/\psi$ events collected with the BESIII detector, an amplitude analysis of the isospin violating decays $\eta^\prime\rightarrow\pi^+\pi^-\pi^0$ and $\eta^\prime\rightarrow\pi^0\pi^0\pi^0$ is performed. Significant $P$-wave contribution from $\eta^\prime\rightarrow\rho^{\pm}\pi^{\mp}$ is observed for the first time in $\eta^\prime\rightarrow\pi^+\pi^-\pi^0$. The branching fraction is determined to be ${\mathcal B}(\eta^\prime\rightarrow\rho^{\pm}\pi^{\mp})=(7.44\pm0.60\pm1.26\pm1.84)\times 10^{-4}$, where the first uncertainty is statistical, the second systematic and the third model dependent. In addition to the non-resonant $S$-wave component, a contribution from the $\sigma$ meson is also essential. The branching fractions of the $S$-wave components are determined as ${\mathcal B}(\eta^\prime\rightarrow\pi^+\pi^-\pi^0)_S=(37.63\pm0.77\pm2.22\pm4.48)\times 10^{-4}$ and ${\mathcal B}(\eta^\prime\rightarrow\pi^0\pi^0\pi^0)=(35.22\pm0.82\pm2.60)\times 10^{-4}$, respectively. The latter one is consistent with previous BESIII measurements.Ablikim, MedinaMon, 04 Jul 2016 11:04:10 GMThttp://lt-jds.jinr.ru/record/69970Observation of an anomalous line shape of the $\eta^{\prime}\pi^{+}\pi^{-}$ mass spectrum near the $p\bar{p}$ mass threshold in $J/\psi\rightarrow\gamma\eta^{\prime}\pi^{+}\pi^{-}$
http://lt-jds.jinr.ru/record/69754
Using $1.09\times10^{9}$ $J/\psi$ events collected by the BESIII experiment in 2012, we study the $J/\psi\rightarrow\gamma\eta^{\prime}\pi^{+}\pi^{-}$ process and observe a significant abrupt change in the slope of the $\eta^{\prime}\pi^{+}\pi^{-}$ invariant mass distribution at the proton-antiproton ($p\bar{p}$) mass threshold. We use two models to characterize the $\eta^{\prime}\pi^{+}\pi^{-}$ line shape around $1.85~\text{GeV}/c^{2}$: one which explicitly incorporates the opening of a decay threshold in the mass spectrum (Flatt\'{e} formula), and another which is the coherent sum of two resonant amplitudes. Both fits show almost equally good agreement with data, and suggest the existence of either a broad state around $1.85~\text{GeV}/c^{2}$ with strong couplings to $p\bar{p}$ final states or a narrow state just below the $p\bar{p}$ mass threshold. Although we cannot distinguish between the fits, either one supports the existence of a $p\bar{p}$ molecule-like state or bound state with greater than $7\sigma$ significance.Ablikim, MedinaWed, 04 May 2016 07:33:13 GMThttp://lt-jds.jinr.ru/record/69754Measurement of the leptonic decay width of $J/\psi$ using initial state radiation
http://lt-jds.jinr.ru/record/69742
Using a data set of 2.93 fb$^{-1}$ taken at a center-of-mass energy of $\sqrt{s}$ = 3.773 GeV with the BESIII detector at the BEPCII collider, we measure the process $e^+e^-\rightarrow J/\psi\gamma\rightarrow \mu^+\mu^-\gamma$ and determine the product of the branching fraction and the electronic width $\mathcal B_{\mu\mu}\cdot \Gamma_{ee} = (333.4 \pm 2.5_{\rm stat} \pm 4.4_{\rm sys})$~eV. Using the earlier-published BESIII result for $\mathcal B_{\mu\mu}$ = (5.973 $\pm$ 0.007$_{\rm stat}$ $\pm$ 0.037$_{\rm sys}$)\%, we derive the $J/\psi$ electronic width $\Gamma_{ee}$~= (5.58 $\pm$ 0.05$_{\rm stat}$ $\pm$ 0.08$_{\rm sys}$) keV.Ablikim, MedinaWed, 04 May 2016 07:33:05 GMThttp://lt-jds.jinr.ru/record/69742Study of $\psi$ decays to the $\Xi^{-}\bar\Xi^{+}$ and $\Sigma(1385)^{\mp}\bar\Sigma(1385)^{\pm}$ final states
http://lt-jds.jinr.ru/record/69442
We study the decays of the charmonium resonances $J/\psi$ and $\psi(3686)$ to the final states $\Xi^{-}\bar\Xi^{+}$, $\Sigma(1385)^{\mp}\bar\Sigma(1385)^{\pm}$ based on a single baryon tag method using data samples of $(223.7 \pm 1.4) \times 10^{6}$ $J/\psi$ and $(106.4 \pm 0.9) \times 10^{6}$ $\psi(3686)$ events collected with the BESIII detector at the BEPCII collider. The decay $\psi(3686)\rightarrow\Sigma(1385)^{\mp}\bar\Sigma(1385)^{\pm}$ is observed for the first time, and the measurements of the other processes, including the branching fractions and angular distributions, are in good agreement with and much more precise than the previously published results. Additionally, the ratios $\frac{{\cal{B}}(\psi(3686)\rightarrow\Xi^{-}\bar\Xi^{+})}{{\cal{B}}(J/\psi\rightarrow\Xi^{-}\bar\Xi^{+})}$, $\frac{{\cal{B}}(\psi(3686)\rightarrow\Sigma(1385)^{-}\bar\Sigma(1385)^{+})}{{\cal{B}}(J/\psi\rightarrow\Sigma(1385)^{-}\bar\Sigma(1385)^{+})}$ and $\frac{{\cal{B}}(\psi(3686)\rightarrow\Sigma(1385)^{+}\bar\Sigma(1385)^{-})}{{\cal{B}}(J/\psi\rightarrow\Sigma(1385)^{+}\bar\Sigma(1385)^{-})}$ are determined.Ablikim, MedinaFri, 11 Mar 2016 08:28:19 GMThttp://lt-jds.jinr.ru/record/69442Observation of pseudoscalar and tensor resonances in $J/\psi\rightarrow \gamma \phi \phi$
http://lt-jds.jinr.ru/record/69415
Based on a sample of $(1310.6 \pm 10.5) \times 10^{6}$ $J/\psi$ events collected with the BESIII detector operating at the BEPCII storage ring, a partial wave analysis of the decay $J/\psi\rightarrow \gamma \phi \phi$ is performed in order to study the intermediate states. Results of the partial wave analysis show that the structures are predominantly $0^{-+}$ states. The existence of the $\eta(2225)$ is confirmed, and its resonance parameters are measured. Two additional pseudoscalar states, the $\eta(2100)$ with a mass of $2050_{-24}^{+30}{}_{-26}^{+75}$ MeV/$c^{2}$ and a width of $250_{-30}^{+36}{}_{-164}^{+181}$ MeV/$c^{2}$ and the $X(2500)$ with a mass of $2470_{-19}^{+15}{}_{-23}^{+101}$ MeV/$c^{2}$ and a width of $230_{-35}^{+64}{}_{-33}^{+56}$ MeV/$c^{2}$, are observed. In addition to these three pseudoscalar states, the scalar state $f_0(2100)$, and three tensor states, the $f_2(2010)$, $f_2(2300)$ and $f_2(2340)$, are observed in the process $J/\psi\rightarrow \gamma \phi\phi$. The product branching fractions $\cal B$($J/\psi\rightarrow \gamma X\rightarrow \gamma \phi \phi$) are reported.Ablikim, MedinaFri, 11 Mar 2016 08:28:06 GMThttp://lt-jds.jinr.ru/record/69415Study of $J/\psi\to p\bar{p}\phi$ at BESIII
http://lt-jds.jinr.ru/record/69055
Using a data sample of $1.31 \times 10^{9}$ $J/\psi$ events accumulated with the BESIII detector, the decay $J/\psi\to p\bar{p}\phi$ is studied via two decay modes, $\phi\to K^{0}_{S}K^{0}_{L}$ and $\phi\to K^{+}K^{-}$. The branching fraction of $J/\psi\to p\bar{p}\phi$ is measured to be $\mathcal{B}(J/\psi\to p\bar{p}\phi)=[5.23\pm0.06(\mbox{stat})\pm0.33(\mbox{syst})]\times10^{-5}$, which agrees well with a previously published measurement, but with a significantly improved precision. No evident enhancement near the $p\bar{p}$ mass threshold, denoted as $X(p\bar{p})$, is observed, and the upper limit on the branching fraction of $J/\psi\to X(p\bar{p})\phi\to p\bar{p}\phi$ is determined to be $\mathcal{B}(J/\psi\to X(p\bar{p})\phi\to p\bar{p}\phi)<2.1\times10^{-7}$ at the 90\% confidence level.Ablikim, MedinaMon, 11 Jan 2016 08:19:39 GMThttp://lt-jds.jinr.ru/record/69055Search for pair production of a new quark that decays to a Z boson and a bottom quark with the ATLAS detector
http://lt-jds.jinr.ru/record/58449
A search is reported for the pair production of a new quark, b', with at least one b' decaying to a Z boson and a bottom quark. The data, corresponding to 2.0 fb^-1 of integrated luminosity, were collected from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector at the CERN Large Hadron Collider. Using events with a b-tagged jet and a Z boson reconstructed from opposite-charge electrons, the mass distribution of large transverse momentum b' candidates is tested for an enhancement. No evidence for a b' signal is detected in the observed mass distribution, resulting in the exclusion at 95% confidence level of b' quarks with masses m_{b'} < 400 GeV that decay entirely via b' to Z+b. In the case of a vector-like singlet b' mixing solely with the third Standard Model generation, masses m_{b'} < 358 GeV are excluded.Abbott, BradMon, 21 May 2012 20:14:32 GMThttp://lt-jds.jinr.ru/record/58449Search for resonant WZ production in the WZ to l nu l' l' channel in sqrt(s) = 7 TeV pp collisions with the ATLAS detector
http://lt-jds.jinr.ru/record/58436
A generic search is presented for a heavy particle decaying to WZ to l nu l'l' (l, l' = e, mu) final states. The data were recorded by the ATLAS detector in sqrt(s) = 7 TeV pp collisions at the Large Hadron Collider and correspond to an integrated luminosity of 1.02 fb-1. The transverse mass distribution of the selected WZ candidates is found to be consistent with the Standard Model expectation. Upper limits on the production cross section times branching ratio are derived using two benchmark models predicting a heavy particle decaying to a WZ pair.Aad, GeorgesMon, 21 May 2012 20:13:36 GMThttp://lt-jds.jinr.ru/record/58436Search for supersymmetry with jets, missing transverse momentum and at least one hadronically decaying tau lepton in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS detector
http://lt-jds.jinr.ru/record/58420
A search for production of supersymmetric particles in final states containing jets, missing transverse momentum, and at least one hadronically decaying tau lepton is presented. The data were recorded by the ATLAS experiment in sqrt(s) = 7 TeV proton-proton collisions at the Large Hadron Collider. No excess above the Standard Model background expectation was observed in 2.05 fb-1 of data. The results are interpreted in the context of gauge mediated supersymmetry breaking models with Mmess = 250 TeV, N5 = 3, mu > 0, and Cgrav = 1. The production of supersymmetric particles is excluded at 95% C.L. up to a supersymmetry breaking scale Lambda = 30 Tev, independent of tan(beta), and up to Lambda = 43 TeV for large tan(beta).Abbott, BradMon, 21 May 2012 20:12:35 GMThttp://lt-jds.jinr.ru/record/58420Search for TeV-scale gravity signatures in final states with leptons and jets with the ATLAS detector at sqrt(s) = 7 TeV
http://lt-jds.jinr.ru/record/58396
The production of events with multiple high transverse momentum particles including charged leptons and jets is measured, using 1.04 fb-1 of proton-proton collision data recorded by the ATLAS detector during the first half of 2011 at sqrt(s) = 7 TeV. No excess beyond Standard Model expectations is observed, and upper limits on the fiducial cross sections for non-Standard Model production of these final states are set. Using models for string ball and black hole production and decay, exclusion contours are determined as a function of mass threshold and the fundamental gravity scale.Abbott, BradMon, 21 May 2012 20:11:49 GMThttp://lt-jds.jinr.ru/record/58396