117409239
$J / \psi$ electromagnetic production associated with light hadrons at $B$ factories
The electromagnetic productions of $J \psi$ associated with light hadrons(LH) and leptonic pairs($\mu^+\mu^-$, $\tau^+\tau^-$) at $B$ factories are studied. We find that the direct electromagnetic production cross sections of $J / \psi$($\psi(2S)$) associated with light hadrons is about $0.10(0.04)$ pb. The direct production cross sections of $J / \psi$($\psi(2S)$) associated with $\mu^+\mu^-$ is about $0.056(0.020)$ pb. If we include the contributions from $\psi(2S)$ decay, we can get the prompt cross section $\sigma[e^+e^- \to J/\psi +\mu^+\mu^-]=(0.068 \pm 0.002)$ pb, about $(16 \pm 5) %$ of the Belle data $\sigma[e^+e^- \to J/\psi +X_{non-c\bar c}]=(0.43\pm 0.09\pm 0.09)$ pb, meanwhile the $e^+e^- \to J/\psi +\tau^+\tau^-$ process only contributes $2 %$. The prompt cross section $\sigma[e^+e^- \to J/\psi +Light Hadrons]=(0.121 \pm 0.005)$ pb is about $(28 \pm 8) %$ of the Belle data.
119479887
S-D mixing and ψ (3770) production in e + e − annihilation and B decay and its radiative transitions
The large decay rate observed by Belle for ${B}^{+}\ensuremath{\rightarrow}\ensuremath{\psi}(3770){K}^{+}$, which is comparable to ${B}^{+}\ensuremath{\rightarrow}\ensuremath{\psi}(3686){K}^{+}$, might indicate either an unexpectedly large S-D mixing angle $|\ensuremath{\theta}|\ensuremath{\approx}{40}^{\ifmmode^\circ\else\textdegree\fi{}}$ or the leading role of the color-octet mechanism in D-wave charmonium production in $B$ decay. By calculating the production rate of $\ensuremath{\psi}(3770)$ in the continuum ${e}^{+}{e}^{\ensuremath{-}}$ annihilation at $\sqrt{s}=10.6\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$ with these two possible approaches (i.e., the large S-D mixing and the color-octet mechanism), we show that the measurement for this process at Belle and BABAR may provide a clear cut clarification for the two approaches. In addition, the radiative E1 transition ratio $\ensuremath{\Gamma}[\ensuremath{\psi}(3770)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{c2}]/\ensuremath{\Gamma}[\ensuremath{\psi}(3770)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{c1}]$ may dramatically change from $\ensuremath{\sim}$ 0.04 (for $\ensuremath{\theta}\ensuremath{\approx}{0}^{\ifmmode^\circ\else\textdegree\fi{}}$) to $\ensuremath{\sim}200$ (for $\ensuremath{\theta}\ensuremath{\approx}\ensuremath{-}{40}^{\ifmmode^\circ\else\textdegree\fi{}}$) due to the large S-D interference effect, thus the E1 transition measurement of $\ensuremath{\psi}(3770)$ at Beijing Spectrometer and CLEO-c will also be very useful in clarifying this issue.
124097178
Neutrino Oscillation and CP Violation in Low Energy Phenomenology of an SUSY Model
Neutrino oscillation and CP violation effects are discussed in an SUSY model proposed in Ref. [1]. The oscillation probabilities expected by this model in short baseline and long baseline neutrino oscillation experiments are calculated. The small conversion probability is predicted for all or oscillations. However, large long baseline oscillation probability is predicted, which could be observed in future long baseline experiments.
118620211
Relativistic Correction to Color Octet J/psi Production at Hadron Colliders
The relativistic corrections to the color-octet $J/\psi$ hadroproduction at the Tevatron and LHC are calculated up to $\mathcal{O}(v^2)$ in nonrelativistic QCD factorization frame. The short distance coefficients are obtained by matching full QCD with NRQCD results for the partonic subprocess $g+g\to J/\psi ({}^1S_0^{[8]},{}^3S_1^{[8]}, {}^3P_J^{[8]})+g$, $q+\bar{q}\to J/\psi ({}^1S_0^{[8]},{}^3S_1^{[8]}, {}^3P_J^{[8]})+g$ and $g+q({\bar{q}})\to J/\psi ({}^1S_0^{[8]},{}^3S_1^{[8]}, {}^3P_J^{[8]})+q({\bar{q}})$. The short distance coefficient ratios of relativistic correction to leading order for color-octet states ${^1}S_{0}^{[8]}$, ${^3}S_{1}^{[8]}$, and ${^3}P_{J}^{[8]}$ at large $p_T$ are approximately -5/6, -11/6, and -31/30, respectively, for each subprocess, and it is 1/6 for color-singlet state ${^3}S_{1}^{[1]}$. If the higher order long distance matrix elements are estimated through velocity scaling rule with adopting $v^2=0.23$ and the lower order long distance matrix elements are fixed, the leading order cross sections of color-octet states are reduced by about a factor of $20\sim40%$ at large $p_T$ at both the Tevatron and the LHC. Comparing with QCD radiative corrections to color-octet states, relativistic correction is ignored along with $p_T$ increasing. Using long distance matrix elements extracted from the fit to $J/\psi$ production at the Tevatron, we can find the unpolarization cross sections of $J/\psi$ production at the LHC taking into account both QCD and relativistic corrections are changed by about $20\sim50%$ of that considering only QCD corrections. These results indicate that relativistic corrections may play an important role in $J/\psi$ production at the Tevatron and the LHC.
55114796
IMPROVEMENT ON THE SINGLE BUNCH OPERATION OF THE TLS INJECTOR
The improvement on single bunch operation of the TLS (Taiwan Light Source) injector is presented in this study. Limited by the existing design of the TLS injector, the single bunch operation was not optimized in terms of bunch purity for specific users of TLS. A high voltage pulser was implemented to improve the situation. This pulser has been integrated into the high-voltage-deck (HV-deck) electronics of electron gun for single bunch generation. Both high-voltage pulses and the associated electron bunches are monitored with a wideband digital oscilloscope. The result shows that the bunch purity can be greatly improved by using the newly installed pulser. It also greatly eliminates the beam losses while injected into the booster ring.
45531082
PIEZOELECTRIC TRANSFORMER BASED CONTINUOUS- CONDUCTION-MODE VOLTAGE SOURCE CHARGE-PUMP POWER FACTOR CORRECTION ELECTRONIC BALLAST *
This paper presents the piezoelectric transformer (PT) based continuous-conduction-mode (CCM) voltage source (VS) charge-pump (CP) power factor correction (PFC) electronic ballast. By replacing L-C resonant tank and transformer in the conventional CCM VS CP-PFC electronic ballast with PT, the cost and volume can be reduced. The experimental results show that the electronic ballast using PT achieve high power factor and the switches can be operated under zero-voltageswitching condition.
91176234
DESIGN AND FABRICATION OF A 5-CELL HIGH CURRENT SUPERCONDUCTING CAVITY
Superconducting Energy Recovery Linacs have various applications, such as hard X-ray, electron-ion colliders and electron cooler of ions. The key component for accelerating such high current beams is the superconducting radio frequency cavity. The design of a 1.3 GHz 5-cell high current superconducting cavity has been carried out under the cooperation between Peking University and Argonne National Laboratory. Radio frequency property and damping of the higher order modes of this cavity have been discussed and the final design is presented. Room temperature RF measurements are also described in the paper.
56399920
THE UPGRADING OF THE TLS INJECTOR BUMPER AND SEPTUM POWER SUPPLIES FOR TOP-UP OPERATION
Due to the inevitable requirement of routine top-up mode operation at TLS (Taiwan Light Source), the reliability of all components in TLS injector has been reevaluated in the past several months. Among all possible subsystems to be reinforced, the bumper and septum power supplies revealed urgent need to be upgraded while being operated continuously in the user shifts. In this report, the modification of the charging mechanism of the pulsed power supplies is described. The modular feature of the newly-built units provides fast replacement capability in case of components failure. The unified specifications for all components have greatly reduced the effort in preparing spare parts. The test results of these units are presented in this report.
54875662
Power factor simulation of focus quadrupole DC power supply of white circuit system with MATLAB simulink
The focus quadrupole DC power supply used at white circuit system of booster ring of Synchrotron Radiation Research Center (SRRC) is a 19.2kW unit, but an AC power source to measure the power factor of such a power supply with built-in power factor measuring function is very expensive. Power factor simulation of this power supply with MATLAB Simulink software is economic and the simulated results may be used to find some efficient ways to correct this parameter if necessary. The results from the simulation model will be compared with the results of power factor monitored from direct measurement on AC mains. The model of quadrupole DC power supply is constructed and provided for better understanding for further modification.