CEPC will use 650 MHz cavities for the collider. Each collider cryomodule contains six 650 MHz 2-cell cavities, which is totally new. Therefore, new helium vessel and tuner are designed for the 650 MHz 2-cell cavity. Also, a test cryomodule, which consists of two 650 MHz 2-cell cavities, has begun as the first step to the full scale cryomodule. This paper mainly focuses on the structure design of Helium vessel and tuner for the 2-cell cavity.

Z. H. Mi Z. Q. Li P. Sha J. Y. Zhai F. S. He Q. Ma B. Q. Liu X. Y. Zhang R. X. Han F. B. Meng H. J. Zheng

We study the evolution of star-forming galaxies with $10^{10} M_\odot<M_*<10^{11.6} M_\odot$ over the redshift range of 0.7<z<1.2 using the emission line galaxies (ELGs) in the extended Baryon Oscillation Spectroscopic Survey (eBOSS). By applying the incomplete conditional stellar mass function (ICSMF) model proposed in Guo et al., we simultaneously constrain the sample completeness, the stellar--halo mass relation (SHMR) and the quenched galaxy fraction. We obtain the intrinsic stellar mass functions for star-forming galaxies in the redshift bins of 0.7<z<0.8, 0.8<z<0.9, 0.9<z<1.0 and 1.0<z<1.2, as well as the stellar mass function for all galaxies in the redshift bin of 0.7<z<0.8. We find that the eBOSS ELG sample only selects about 1%-10% of the star-forming galaxy population at the different redshifts, with the lower redshift samples to be more complete. There is only weak evolution in the SHMR of the ELGs from z=1.2 to z=0.7, as well as the intrinsic galaxy stellar mass functions for lower-mass galaxies of $M_*<10^{11} M_\odot$. There is significant decrease of the stellar mass function for star-forming galaxies with redshift at the massive end. Our best-fitting models show that the central ELGs at these redshifts live in halos of mass $M\sim10^{12} M_\odot$ while the satellite ELGs occupy slightly more massive halos of $M\sim10^{12.6} M_\odot$. The average satellite fraction of the observed ELGs varies from 13% to 17%, with the galaxy bias increasing from 1.1 to 1.4 from z=0.7 to 1.2.

Hong Guo Xiaohu Yang Anand Raichoor Zheng Zheng Johan Comparat V. Gonzalez-Perez Jean-Paul Kneib Donald P. Schneider Dmitry Bizyaev Daniel Oravetz Audrey Oravetz Kaike Pan

We report the discovery of five quasars with redshifts of 4.67 - 5.27 and z'-band magnitudes of 19.5-20.7 M_B ~ -27. All were originally selected as distant quasar candidates in optical/near-infrared photometry from the Sloan Digital Sky Survey (SDSS), and most were confirmed as probable high-redshift quasars by supplementing the SDSS data with J and K measurements. The quasars possess strong, broad Lyman-alpha emission lines, with the characteristic sharp cutoff on the blue side produced by Lyman-alpha forest absorption. Three quasars contain strong, broad absorption features, and one of them exhibits very strong N V emission. The amount of absorption produced by the Lyman-alpha forest increases toward higher redshift, and that in the z=5.27 object (D_A ~ 0.7) is consistent with a smooth extrapolation of the absorption seen in lower redshift quasars. The high luminosity of these objects relative to most other known objects at z >~ 5 makes them potentially valuable as probes of early quasar properties and of the intervening intergalactic medium.

W. Zheng Z. I. Tsvetanov D. P. Schneider X. Fan R. H. Becker M. Davis R. L. White M. A. Strauss J. Annis N. A. Bahcall A. J. Connolly I. Csabai A. F. Davidsen M. Fukugita J. E. Gunn T. M. Heckman G. S. Hennessy Z. Ivezic G. R. Knapp E. Peng A. S. Szalay A. R. Thakar B. Yanny D. G. York

We stack Spitzer 24 micron images for ~7000 galaxies with 0.1<z<1 in the Chandra Deep Field South to probe the thermal dust emission in low-luminosity galaxies over this redshift range. Through stacking, we can detect mean 24 micron fluxes that are more than an order of magnitude below the individual detection limit. We find that the correlations for low and moderate luminosity galaxies between the average L_IR/L_UV and rest-frame B-band luminosity, and between the star formation rate (SFR) and L_IR/L_UV, are similar to those in the local Universe. This verifies that oft-used assumption in deep UV/optical surveys that the dust obscuration-SFR relation for galaxies with SFR < 20 solar mass per year varies little with epoch. We have used this relation to derive the cosmic IR luminosity density from z=1 to z=0.1. The results also demonstrate directly that little of the bolometric luminosity of the galaxy population arises from the faint end of the luminosity function, indicating a relatively flat faint-end slope of the IR luminosity function with a power law index of 1.2+-0.3.

X. Z. Zheng E. F. Bell H. -W. Rix C. Papovich E. Le Floc'h G. H. Rieke P. G. Pérez-González

Reply to Ikeda (arXiv:0712.3341).

D. F. Agterberg Z. Zheng S. Mukherjee

Using an $e^+e^-$ annihilation data sample corresponding to an integrated luminosity of $2.93\,\rm fb^{-1}$ collected at the center-of-mass energy of 3.773\,GeV with the BESIII detector, we measure the absolute branching fractions of $D^+\to\eta\eta\pi^+$, $D^+\to\eta\pi^+\pi^0$, and $D^0\to\eta\pi^+\pi^-$ to be $(2.96 \pm 0.24 \pm 0.13)\times 10^{-3}$, $(2.23 \pm 0.15 \pm 0.11)\times 10^{-3}$, and $(1.20 \pm 0.07 \pm 0.04)\times 10^{-3}$, respectively, where the first uncertainties are statistical and the second ones systematic. The $D^+\to\eta\eta\pi^+$ decay is observed for the first time and the branching fractions of $D^{+(0)}\to\eta\pi^+\pi^{0(-)}$ are measured with much improved precision. In addition we test for $CP$ asymmetries in the separated charge-conjugate branching fractions; no evidence of $CP$ violation is found.

BESIII Collaboration

Using $2.93 \rm fb^{-1}$ of $e^+e^-$ collision data collected at a center-of-mass energy of 3.773 GeV with the BESIII detector, the first observation of the doubly Cabibbo-suppressed decay $D^+\to K^+\pi^+\pi^-\pi^0$ is reported. After removing decays that contain narrow intermediate resonances, including $D^+\to K^+\eta$, $D^+\to K^+\omega$, and $D^+\to K^+\phi$, the branching fraction of the decay $D^+\to K^+\pi^+\pi^-\pi^0$ is measured to be $(1.13 \pm 0.08_{\rm stat} \pm 0.03_{\rm syst})\times 10^{-3}$. The ratio of branching fractions of $D^+\to K^+\pi^+\pi^-\pi^0$ over $D^+\to K^-\pi^+\pi^+\pi^0$ is found to be $(1.81\pm0.15)$\%, which corresponds to $(6.28\pm0.52)\tan^4\theta_C$, where $\theta_C$ is the Cabibbo mixing angle. This ratio is significantly larger than the corresponding ratios for other doubly Cabibbo-suppressed decays. The asymmetry of the branching fractions of charge-conjugated decays $D^\pm\to K^\pm\pi^\pm\pi^\mp\pi^0$ is also determined, and no evidence of $CP$ violation is found. In addition, the first evidence of the $D^+\to K^+\omega$ decay, with a statistical significance of 3.3$\sigma$, is presented and its decay branching fraction is determined to be $({5.7^{+2.5}_{-2.1}}_{\rm stat}\pm0.2_{\rm syst})\times10^{-5}$.

BESIII Collaboration

Using $2.93\,\rm fb^{-1}$ of $e^+e^-$ collision data taken at a center-of-mass energy of 3.773\,GeV with the BESIII detector, we report the first measurements of the absolute branching fractions of fourteen hadronic $D^{0(+)}$ decays to exclusive final states with an $\eta$, e.g., $D^0\to K^-\pi^+\eta$, $K^0_S\pi^0\eta$, $K^+K^-\eta$, $K^0_SK^0_S\eta$, $K^-\pi^+\pi^0\eta$, $K^0_S\pi^+\pi^-\eta$, $K^0_S\pi^0\pi^0\eta$, and $\pi^+\pi^-\pi^0\eta$; $D^+\to K^0_S\pi^+\eta$, $K^0_SK^+\eta$, $K^-\pi^+\pi^+\eta$, $K^0_S\pi^+\pi^0\eta$, $\pi^+\pi^+\pi^-\eta$, and $\pi^+\pi^0\pi^0\eta$. Among these decays, the $D^0\to K^-\pi^+\eta$ and $D^+\to K^0_S\pi^+\eta$ decays have the largest branching fractions, which are $\mathcal{B} (D^0\to K^-\pi^+\eta )=(1.853\pm0.025_{\rm stat}\pm0.031_{\rm syst})\%$ and $\mathcal{B}(D^+\to K^0_S\pi^+\eta)=(1.309\pm0.037_{\rm stat}\pm0.031_{\rm syst})\%$, respectively. We also determine the $CP$ asymmetries for the six decays with highest event yields. No evidence of $CP$ violation is found.

BESIII Collaboration

By analyzing a data sample corresponding to an integrated luminosity of $2.93~\mathrm{fb}^{-1}$ collected at a center-of-mass energy of 3.773 GeV with the BESIII detector, we measure for the first time the absolute branching fraction of the $D^+\to \eta \mu^+\nu_\mu$ decay to be ${\mathcal B}_{D^+\to \eta \mu^+\nu_\mu}=(10.4\pm1.0_{\rm stat}\pm0.5_{\rm syst})\times 10^{-4}$. Using the world averaged value of ${\mathcal B}_{D^+\to \eta e^+\nu_e}$, the ratio of the two branching fractions is determined to be ${\mathcal B}_{D^+\to \eta \mu^+\nu_\mu}/{\mathcal B}_{D^+\to \eta e^+\nu_e}=0.91\pm0.13$, which agrees with the theoretical expectation of lepton flavor universality within uncertainty. Here, the uncertainty is the sum in quadrature of the statistical and systematic uncertainties. By studying the differential decay rates in five four-momentum transfer intervals, we obtain the product of the hadronic form factor $f^{\eta}_{+}(0)$ and the $c\to d$ Cabibbo-Kobayashi-Maskawa matrix element $|V_{cd}|$ to be $f_{+}^\eta (0)|V_{cd}|=0.087\pm0.008_{\rm stat}\pm0.002_{\rm syst}$. Taking the input of $|V_{cd}|$ from the global fit in the standard model, we determine $f_{+}^\eta (0)=0.39\pm0.04_{\rm stat}\pm0.01_{\rm syst}$. On the other hand, using the value of $f_+^{\eta}(0)$ calculated in theory, we find $|V_{cd}|=0.242\pm0.022_{\rm stat}\pm0.006_{\rm syst}\pm0.033_{\rm theory}$.

BESIII Collaboration

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.

M. Ablikim M. N. Achasov X. C. Ai O. Albayrak M. Albrecht D. J. Ambrose A. Amoroso F. F. An Q. An J. Z. Bai R. Baldini Ferroli Y. Ban D. W. Bennett J. V. Bennett M. Bertani D. Bettoni J. M. Bian F. Bianchi E. Boger I. Boyko R. A. Briere H. Cai X. Cai O. Cakir A. Calcaterra G. F. Cao S. A. Cetin J. F. Chang G. Chelkov G. Chen H. S. Chen H. Y. Chen J. C. Chen M. L. Chen S. J. Chen X. Chen X. R. Chen Y. B. Chen H. P. Cheng X. K. Chu G. Cibinetto H. L. Dai J. P. Dai A. Dbeyssi D. Dedovich Z. Y. Deng A. Denig I. Denysenko M. Destefanis F. De Mori Y. Ding C. Dong J. Dong L. Y. Dong M. Y. Dong Z. L. Dou S. X. Du P. F. Duan J. Z. Fan J. Fang S. S. Fang X. Fang Y. Fang R. Farinelli L. Fava O. Fedorov F. Feldbauer G. Felici C. Q. Feng E. Fioravanti M. Fritsch C. D. Fu Q. Gao X. L. Gao X. Y. Gao Y. Gao Z. Gao I. Garzia K. Goetzen L. Gong W. X. Gong W. Gradl M. Greco M. H. Gu Y. T. Gu Y. H. Guan A. Q. Guo L. B. Guo Y. Guo Y. P. Guo Z. Haddadi A. Hafner S. Han X. Q. Hao F. A. Harris K. L. He T. Held Y. K. Heng Z. L. Hou C. Hu H. M. Hu J. F. Hu T. Hu Y. Hu G. S. Huang J. S. Huang X. T. Huang Y. Huang T. Hussain Q. Ji Q. P. Ji X. B. Ji X. L. Ji L. W. Jiang X. S. Jiang X. Y. Jiang J. B. Jiao Z. Jiao D. P. Jin S. Jin T. Johansson A. Julin N. Kalantar-Nayestanaki X. L. Kang X. S. Kang M. Kavatsyuk B. C. Ke P. Kiese R. Kliemt B. Kloss O. B. Kolcu B. Kopf M. Kornicer A. Kupsc W. Kühn J. S. Lange M. Lara P. Larin C. Leng C. Li Cheng Li D. M. Li F. Li F. Y. Li G. Li H. B. Li J. C. Li Jin Li K. Li K. Li Lei Li P. R. Li Q. Y. Li T. Li W. D. Li W. G. Li X. L. Li X. N. Li X. Q. Li Z. B. Li H. Liang Y. F. Liang Y. T. Liang G. R. Liao D. X. Lin B. J. Liu C. X. Liu D. Liu F. H. Liu Fang Liu Feng Liu H. B. Liu H. H. Liu H. H. Liu H. M. Liu J. Liu J. B. Liu J. P. Liu J. Y. Liu K. Liu K. Y. Liu L. D. Liu P. L. Liu Q. Liu S. B. Liu X. Liu Y. B. Liu Z. A. Liu Zhiqing Liu H. Loehner X. C. Lou H. J. Lu J. G. Lu Y. Lu Y. P. Lu C. L. Luo M. X. Luo T. Luo X. L. Luo X. R. Lyu F. C. Ma H. L. Ma L. L. Ma Q. M. Ma T. Ma X. N. Ma X. Y. Ma Y. M. Ma F. E. Maas M. Maggiora Y. J. Mao Z. P. Mao S. Marcello J. G. Messchendorp J. Min T. J. Min R. E. Mitchell X. H. Mo Y. J. Mo C. Morales Morales N. Yu. Muchnoi H. Muramatsu Y. Nefedov F. Nerling I. B. Nikolaev Z. Ning S. Nisar S. L. Niu X. Y. Niu S. L. Olsen Q. Ouyang S. Pacetti Y. Pan P. Patteri M. Pelizaeus H. P. Peng K. Peters J. Pettersson J. L. Ping R. G. Ping R. Poling V. Prasad H. R. Qi M. Qi S. Qian C. F. Qiao L. Q. Qin N. Qin X. S. Qin Z. H. Qin J. F. Qiu K. H. Rashid C. F. Redmer M. Ripka G. Rong Ch. Rosner X. D. Ruan V. Santoro A. Sarantsev M. Savrié K. Schoenning S. Schumann W. Shan M. Shao C. P. Shen P. X. Shen X. Y. Shen H. Y. Sheng W. M. Song X. Y. Song S. Sosio S. Spataro G. X. Sun J. F. Sun S. S. Sun Y. J. Sun Y. Z. Sun Z. J. Sun Z. T. Sun C. J. Tang X. Tang I. Tapan E. H. Thorndike M. Tiemens M. Ullrich I. Uman G. S. Varner B. Wang B. L. Wang D. Wang D. Y. Wang K. Wang L. L. Wang L. S. Wang M. Wang P. Wang P. L. Wang W. Wang W. P. Wang X. F. Wang Y. D. Wang Y. F. Wang Y. Q. Wang Z. Wang Z. G. Wang Z. H. Wang Z. Y. Wang T. Weber D. H. Wei P. Weidenkaff S. P. Wen U. Wiedner M. Wolke L. H. Wu Z. Wu L. Xia L. G. Xia Y. Xia D. Xiao H. Xiao Z. J. Xiao Y. G. Xie Q. L. Xiu G. F. Xu L. Xu Q. J. Xu Q. N. Xu X. P. Xu L. Yan W. B. Yan W. C. Yan Y. H. Yan H. J. Yang H. X. Yang L. Yang Y. X. Yang M. Ye M. H. Ye J. H. Yin B. X. Yu C. X. Yu J. S. Yu C. Z. Yuan W. L. Yuan Y. Yuan A. Yuncu A. A. Zafar A. Zallo Y. Zeng Z. Zeng B. X. Zhang B. Y. Zhang C. Zhang C. C. Zhang D. H. Zhang H. H. Zhang H. Y. Zhang J. J. Zhang J. L. Zhang J. Q. Zhang J. W. Zhang J. Y. Zhang J. Z. Zhang K. Zhang L. Zhang X. Y. Zhang Y. Zhang Y. H. Zhang Y. N. Zhang Y. T. Zhang Yu Zhang Z. H. Zhang Z. P. Zhang Z. Y. Zhang G. Zhao J. W. Zhao J. Y. Zhao J. Z. Zhao Lei Zhao Ling Zhao M. G. Zhao Q. Zhao Q. W. Zhao S. J. Zhao T. C. Zhao Y. B. Zhao Z. G. Zhao A. Zhemchugov B. Zheng J. P. Zheng W. J. Zheng Y. H. Zheng B. Zhong L. Zhou X. Zhou X. K. Zhou X. R. Zhou X. Y. Zhou K. Zhu K. J. Zhu S. Zhu S. H. Zhu X. L. Zhu Y. C. Zhu Y. S. Zhu Z. A. Zhu J. Zhuang L. Zotti B. S. Zou J. H. Zou