NaNet:a low-latency NIC enabling GPU-based, real-time low level trigger systems

We implemented the NaNet FPGA-based PCI2 Gen2 GbE/APElink NIC, featuring GPUDirect RDMA capabilities and UDP protocol management offloading. NaNet is able to receive a UDP input data stream from its GbE interface and redirect it, without any intermediate buffering or CPU intervention, to the memory of a Fermi/Kepler GPU hosted on the same PCIe bus, provided that the two devices share the same upstream root complex. Synthetic benchmarks for latency and bandwidth are presented. We describe how NaNet can be employed in the prototype of the GPU-based RICH low-level trigger processor of the NA62 CERN experiment, to implement the data link between the TEL62 readout boards and the low level trigger processor. Results for the throughput and latency of the integrated system are presented and discussed.Comment: Proceedings for the 20th International Conference on Computing in High Energy and Nuclear Physics (CHEP

A high-resolution TDC-based board for a fully digital trigger and data acquisition system in the NA62 experiment at CERN

A Time to Digital Converter (TDC) based system, to be used for most sub-detectors in the high-flux rare-decay experiment NA62 at CERN SPS, was built as part of the NA62 fully digital Trigger and Data AcQuisition system (TDAQ), in which the TDC Board (TDCB) and a general-purpose motherboard (TEL62) will play a fundamental role. While TDCBs, housing four High Performance Time to Digital Converters (HPTDC), measure hit times from sub-detectors, the motherboard processes and stores them in a buffer, produces trigger primitives from different detectors and extracts only data related to the lowest trigger level decision, once this is taken on the basis of the trigger primitives themselves. The features of the TDCB board developed by the Pisa NA62 group are extensively discussed and performance data is presented in order to show its compliance with the experiment requirements.Comment: 6 pages, 7 figures, presented to IEEE RT 2014 Conference and I want to publish in TN

A Probe into the Reform of Public Calligraphy Course in Chinese Colleges and Universities

中国书法是中国传统文化中的瑰宝，它既是一门艺术，又有着深厚的文化内涵。我国普通高校开设公共书法教学是与目前倡导的素质教育，培养创新型人才，提倡人的全面和谐发展的高等教育理念相一致的。加强高校公共书法教育，是全面推进素质教育的有效途径之一，也是提高当代大学生人文素质的重要手段。它对促进大学生人格完善、创造力培养以及民族文化的传承等有着不可低估的作用。本文主要针对我国普通高等院校公共书法教学现状进行分析，并由此比较借鉴日本高校中实施书法教学的成功经验提出对我国高校公共书法教学改革的具体建议和措施，设计并实践一种具备学科视野的、以学生为主体的公共书法教学的新模式。论文共分为五部分。引言扼要介绍论文写...Chinese calligraphy is a treasure of Chinese traditional culture. It not only is an art, but also has profound culture contents. Opening the public calligraphy course to the university students is in accordance with the concept that advocated by the current quality- oriented education, which aims to cultivate the students’ creative talent and comprehensive development. This paper concentrates on a...学位：文学硕士院系专业：艺术教育学院美术系_美术学学号：20042201

Measurement of the very rare K+→π+ννˉK^+ \to \pi^+ \nu \bar\nu decay

The decay K+→π+νν¯ , with a very precisely predicted branching ratio of less than 10−10 , is among the best processes to reveal indirect effects of new physics. The NA62 experiment at CERN SPS is designed to study the K+→π+νν¯ decay and to measure its branching ratio using a decay-in-flight technique. NA62 took data in 2016, 2017 and 2018, reaching the sensitivity of the Standard Model for the K+→π+νν¯ decay by the analysis of the 2016 and 2017 data, and providing the most precise measurement of the branching ratio to date by the analysis of the 2018 data. This measurement is also used to set limits on BR(K+→π+X ), where X is a scalar or pseudo-scalar particle. The final result of the BR(K+→π+νν¯ ) measurement and its interpretation in terms of the K+→π+X decay from the analysis of the full 2016-2018 data set is presented, and future plans and prospects are reviewed

Review of Kaon Physics at CERN and in Europe

The Kaon physics program at CERN and in Europe will be presented. I will first give a short review of recent results form the NA48/2 and NA62 experiments, with special emphasis to the measurement of RK , the ratio of Kaon leptonic decays rates, K → eν and K → μν, using the full minimum bias data sample collected in 2007-2008. The main subject of the talk will be the study of the highly suppressed decay K → πνν. While its rate can be predicted with minimal theoretical uncertainty in the Standard Model (BR ∼ 8 × 10−11), the smallness of BR and the challenging experimental signature make it very difficult to measure. The branching ratio for this decay is thus a sensitive probe of the flavour sector of the SM. The aim of NA62 is the measurement of the K → πνν BR with ∼ 10% precision in two years of data taking. This will require the observation of 10K decays in the experiment's fiducial volume, as well as the use of high-performance systems for precision tracking, particle identification, and photon vetoing. These aspects of the experiment will also allow NA62 to carry out a rich program of searches for lepton flavour and/or number violating K decays. Data taking will start in October 2014. The physics prospects and the status of the construction and commissioning of the NA62 experiment will be presented. In the last part of the talk I will report on Kaon physics results and prospects from other experiments at CERN (e.g. LHCb) and in Europe (e.g. KLOE and KLOE-2) and briefly mention the status in US

Recent NA48/2 results on QCD and ChPT

The NA48/2 experiment at CERN collected a very large sample of charged kaon decays into multiple final states.This data allow measurements related to QCD and Chiral Perturbation Theory (ChPT). In particular, we collected about 1500 events of the very rare decay $K^{\pm} \rightarrow \mu^{\pm} \nu e^+ e^-$ over almost negligible background in the region with m(e$^+$e$^-$) above 140 MeV, which is of great interest in Chiral Perturbation Theory, thanks to the $m_{ee}$ spectrum and a model-independent measurement of the decay rate for this region. Also we performed the first observation of the rare decay $K^+ \rightarrow \pi^+ \pi^0 e^+ e^-$, with about 5000 candidates and 5% background contamination, and the preliminary branching ratio in the full kinematic region has been measured, in perfect agreement with theoretical predictions based on Chiral Perturbation Theory. Finally, we obtained our final measurement of the charged kaon semileptonic decays form factors based on 4.28 million $K^{\pm} e3$ and 2.91 million $K^{\pm} \mu3$ selected decays, with the smallest uncertainty for $K^{\pm} e3$ and a competitive result for $K^{\pm} \mu3$ and leading to the most precise combined $K^{\pm} l3$ result that reduces the form factor uncertainty of $\lvert V_{us} \rvert$

ChPT test at NA48 and NA62 experiment at CERN

The new published measurements of th

Search for the dark photon in π0\pi^0 decays

A sample of 1.69 x 10^7 fully reconstructed pi^0 -> gammae^+e^- in the kinematic range m_ee > 10MeV/c^2 with a negligible background contamination collected by the NA48/2 experiment at CERN in 2003-04 is analysed to search for the dark photon (A') via the decay chain pi;^0 -> gammaA', A' -> e^+e. No signal is observed, and preliminary exclusion limits on space of dark photon mass m_A' and mixing parameter ϵ^2 are reported.A sample of 1.69 × 107 fully reconstructed π0 → γe+e− in the kinematic range mee > 10MeV/c2 with a negligible background contamination collected by the NA48/2 experiment at CERN in 2003-04 is analysed to search for the dark photon (A′) via the decay chain π;0 → γA′, A′ → e+e. No signal is observed, and preliminary exclusion limits on space of dark photon mass mA′ and mixing parameter ϵ2 are reported

Precision measurement of the form factors of the semileptonic decay K±→π0ℓ±νK^ \pm \to \pi^0 \ell^\pm \nu (Kl3)

The NA48/2 experiment at CERN collected a very large sample of charged kaon decays into multiple final states. This data allow measurements related to QCD. We obtained our final measurement of the charged kaon semileptonic decays form factors based on 4.28 million Ke3 and 2.91 million Kmu3 selected decays, with the smallest uncertainty for Ke3 and a competitive result for Kmu3 and leading to the most precise combined Kl3 result coming from the Kaon sector that reduces the form factor uncertainty of $|V_{us} |$