arXiv subjects

Yen-Chu Chen

Publications and source records attributed to Yen-Chu Chen.

3 recordsLinked to original sources

arXiv2015

FPGA-based trigger system for the Fermilab SeaQuest experiment

The SeaQuest experiment (Fermilab E906) detects pairs of energetic μ+ and μ- produced in 120 GeV/c proton-nucleon interactions in a high rate environment. The trigger system consists of several arrays of scintillator hodoscopes and a set of field-programmable gate array (FPGA) based VMEbus modules. Signals from up to 96 channels of hodoscope are digitized by each FPGA with a 1-ns resolution using the time-to-digital convertor (TDC) firmware. The delay of the TDC output can be adjusted channel-by-channel in 1-ns steps and then re-aligned with the beam RF clock. The hit pattern on the hodoscope planes is then examined against pre-determined trigger matrices to identify candidate muon tracks. Information on the candidate tracks is sent to the 2nd-level FPGA-based track correlator to find candidate di-muon events. The design and implementation of the FPGA-based trigger system for SeaQuest experiment are presented.

physics.ins-det↗

arXiv2011

The Top Quark Forward Backward Asymmetry at CDF

It has been more than 15 years since the discovery of the top quark. Great strides have been made in the measurement of the top quark mass and the properties of it. Most results show consistency with the standard model. However, using 5 fb$^{-1}$ data, recent measurements of the asymmetry in the production of top and anti-top quark pair have demonstrated surprisingly large values at CDF. Using 4 fb$^{-1}$ data, D0 also has similar effect.

hep-ex↗

arXiv2008

Top Mass and Properties

The top quark was discovered in 1995. The top quark mass is now well measured at the Tevatron, with uncertainty getting below 1% of the top mass. The world average from last year was 170.9 $\pm$ 1.8 GeV/$c^2$. The new CDF measurement is 172 $\pm$ 1.2 (stat) $\pm$ 1.5 (sys) GeV/$c^2$, and D0 will soon present a new measurement. The top quark mass is an important parameter in the Standard Model, and should be measured as precisely as possible. To learn more about the top quark observed and study possible new physics, other properties also should be measured. At the Tevatron, the charge of the top quark can be measured directly. Examples of other properties studied and reported in this presentation are W helicity, top decay branching ratio to b ($R_b$), searches for $t \to H b$ and for flavor changing neutral current (FCNC). The results are all consistent with the Standard Model within current statistics. With significantly more data being collected at the Tevatron, precision measurements of the top properties are just starting.

hep-ex↗