A Portable Wireless DAQ System for Gaseous Detectors

A real-time wireless analog/digital electronic system for the data acquisition of a proportional counter detector is presented. Gaseous detectors working principle is based on the ionization of a gas due to a particle. The ions are then accelerated towards two electrodes and the read out signal is amplified, shaped and discriminated. It is then sent to the DAQ （data acquisition） electronics. The power supply system can be either the common 220 V source or a battery, whose autonomy is about 72 h during data acquisition. The analog electronics are made up of a high voltage generator for the detector＇s electrodes, an amplifier system, a shaper and a discriminator. The digital environment is based on an Arduino Mega-2560 board. A wireless modular shield is plugged on the board, in order to access the Arduino board via the 802.11b/g wireless protocol. Four temperature sensors and two pressure sensors are placed in the surroundings of the detector and they are connected to the system in order to read out environmental conditions. The software application, if required by the user, periodically acquires the data produced by the detector, formats them together with the sensor readings into a frame and sends the frame via UDP to an external server. The server plots the data on a webpage. During the data acquisition, the microcontroller continuously monitors the battery status, in order to safely stop the system in case of low battery. The DAQ system is controlled via a web page hosted inside Arduino, which acts like a server. Such page allows to set the detector working parameters （high voltage, discriminator threshold）, to start the data acquisition, to test the system via a debug panel and to read temperature and pressure sensors. Experimental results are presented.

Measurements of the center-of-mass energies at BESⅢ via the di-muon process

From 2011 to 2014, the BESIII experiment collected about 5 fb^-1 data at center-of-mass energies around 4 GeV for the studies of the charmonium-like and higher excited charmonium states. By analyzing the di-muon process e＋e- →yma/Fsμ^＋μ^-, the center-of-mass energies of the data samples are measured with a precision of 0.8 MeV. The center-of-mass energy is found to be stable for most of the time during data taking.

A model to explain the angular distribution of J/Ψ and Ψ(2S) decay into ■ and ■

BESⅢ data show a particular angular distribution for the decay of J/Ψ and Ψ(2 S) mesons into ■ and Σ~0Σ~0 hyperons: the angular distribution of the decay Ψ(2 S) →Σ~0Σ~0 exhibits an opposite trend with respect to the other three channels: J/Ψ→■, J/Ψ→Σ~0Σ~0 and Ψ(2 S) →■. We define a model to explain the origin of this phenomenon.

Innovative single-shot 2D pulse front tilt diagnostic

The presence of pulse front tilt(PFT),caused by angular dispersion(AD)in femtosecond laser pulses,could degrade the performance of the laser system and/or impact the experimental yields.We present a single-shot diagnostic capable of measuring the AD in the x–y plane by adopting an intensity mask.It can be applied to stretched pulses,making it ideal for diagnosing the AD along the amplification chain of a high-power laser system,and to ultrashort pulses exiting from an optical compressor.In this way,it can help in properly characterizing a laser pulse before it is delivered to the target area.In this Letter,we present experimental evidence of AD retrieval for different compression configurations,supported by theoretical analysis.

BABAR measurement of baryon time-like form factors via initial state radiation

BABAR has measured with unprecedented accuracy the e^＋e^- → pp and e^＋e^- →∧∧ cross sections by means of the initial state radiation technique, which has the advantages of good efficiency, good energy resolution and full angular acceptance, even exactly at threshold. A peculiar feature of these cross sections is their non-vanishing values at threshold. In the case of charged baryons, this phenomenon is expected according to the Coulomb interaction between the outgoing baryon and antibaryon. Once this Coulomb enhancement factor is taken into account, the striking result is achieved that the proton form factor at threshold is ｜GP（4Mp^2）｜ = 1, that is what is expected for pointlike fermion pairs, in spite of the proton structure. However a Coulomb enhancement factor is not expected for neutral fermions, likely in contradiction with the BABAR data. Qualitatively this behaviour is consistent with Coulomb interactions at the valence quark level.

Research and development of the back-end electronics for the two-dimensional improved resistive plate chambers in CMS upgrade

Purpose To complement and ensure redundancy in the endcap muon system of the Compact Muon Solenoid(CMS)detector and to extend the Resistive Plate Chamber(RPC)system coverage,improved RPCs(iRPCs)with either orthogonal layer strips with one-end electronics or single layer strips with two-end electronics providing more precise time measurement will be installed in the very forward pseudorapidity region of|η|<2.4.The iRPC readout system needs to support twodimensional(2D)or two-end readout.In addition,it must combine detector data with Timing,Trigger and fast Control(TTC)and Slow Control(SC)into one data stream over a bi-directional optical link with a line rate of 4.8 Gb/s between the Front-End Electronics(FEE)and the Back-End Electronics(BEE).To fulfill these requirements,a prototype BEE for the iRPC 2D chamber has been researched and designed.Methods A Micro-Telecommunication and Computing Architecture(μTCA)-based processing card was designed in this study to establish a prototype system together with aμTCA crate.The Giga-Bit Transceiver(GBT)protocol is integrated to provide bi-directional communication between the FEE and BEE.A server is connected with the BEE by a Gigabit Ethernet(GbE)link for SC and a 10-GbE link for Data AcQuisition(DAQ).Results The Bit Error Rate(BER)test of the back-end board and a joint test with the iRPC 2D prototype chamber were performed.ABERof less than 1.331×10−16 was obtained.The timemeasurement with a resolution of 3.05 nswas successfully realized,and detector efficiencies of 97.7%for longitudinal strips and 96.0%for orthogonal strips were measured.Test results demonstrate the correctness and reliability of the prototype BEE.Conclusion The BEE prototype satisfies the requirements for the iRPC 2D chamber,and it worked stably and reliably during a long-term joint test run.

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity of e^(+)e^(-)collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm=3.773 GeV.The integrated luminosities of the datasets taken from December 2021 to June 2022,from November 2022 to June 2023,and from October 2023 to February 2024 were determined to be 4.995±0.019 fb^(-1),8.157±0.031 fb^(-1),and 4.191±0.016 fb^(-1),respectively,by analyzing large angle Bhabha scattering events.The uncertainties are dominated by systematic effects,and the statistical uncertainties are negligible.Our results provide essential input for future analyses and precision measurements.

Amplitude analysis of the decays D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)

Using e^(+)e^(−)annihilation data corresponding to an integrated luminosity of 2.93 fb^(−1)taken at the center-of-mass energy√s=3.773 GeV with the BESIII detector,a joint amplitude analysis is performed on the decays D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η).The fit fractions of individual components are obtained,and large interferences among the dominant components of the decays D^(0)→a_(1)(1260)π,D^(0)→π(1300)π,D^(0)→ρ(770)ρ(770),and D^(0)→2(ππ)_(S)are observed in both channels.With the obtained amplitude model,the CP-even fractions of D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η)are determined to be(75.2±1.1_(stat).±1.5_(syst.))%and(68.9±1.5_(stat).±2.4_(syst.))%,respectively.The branching fractions of D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η)are measured to be(0.688±0.010_(stat.)±0.010_(syst.))%and(0.951±0.025_(stat.)±0.021_(syst.))%,respectively.The amplitude analysis provides an important model for the binning strategy in measuring the strong phase parameters of D^(0)→4πwhen used to determine the CKM angleγ(ϕ_(3))via the B^(−)→DK^(−)decay.

Determination of the number ofψ(3686)events taken at BESⅢ

The number ofψ(3686)events collected by the BESⅢdetector during the 2021 run period is determined to be(2259.3±11.1)×10~6 by counting inclusiveψ(3686)hadronic events.The uncertainty is systematic and the statistical uncertainty is negligible.Meanwhile,the numbers ofψ(3686)events collected during the 2009 and 2012run periods are updated to be(107.7±0.6)×10~6 and(345.4±2.6)×10~6,respectively.Both numbers are consistent with the previous measurements within one standard deviation.The total number ofψ(3686)events in the three data samples is(2712.4±14.3)×10~6.

Measurements of the center-of-mass energies of e^(+)e^(-)collisions at BESIII

During the 2016-17 and 2018-19 running periods,the BESIII experiment collected 7.5 fb of e^(+)e^(-)collision data at center-of-mass energies ranging from 4.13 to 4.44 GeV.These data samples are primarily used for the study of excited charmonium and charmoniumlike states.By analyzing the di-muon process e^(+)e^(-)→(γISR=FSR)μ^(+)μ^(-),we measure the center-of-mass energies of the data samples with a precision of 0.6 MeV.Through a run-by-run study,we find that the center-of-mass energies were stable throughout most of the data-collection period.

Precision measurement of the integrated luminosity of the data taken by BESIII at center-of-mass energies between 3.810 GeV and 4.600 GeV

From December 2011 to May 2014, about 5 fb^-1 of data were taken with the BESIII detector at center-of- mass energies between 3.810 GeV and 4.600 GeV to study the charmonium-like states and higher excited charmonium states. The time-integrated luminosity of the collected data sample is measured to a precision of 1% by analyzing events produced by the large-angle Bhabha scattering process.

Determination of the number of ψ' events at BES Ⅲ

The number of φ＇ events accumulated by the BESIII experiment from March 3 through April 14, 2009, is determined by counting inclusive hadronic events. The result is 106.41×（1.00±0.81%）×10^6. The error is systematic dominant; the statistical error is negligible.

Measurement of the absolute branching fraction of D^+→K^0e^+v_e via K^0→π~0π~0

By analyzing 2.93 fb-1 data collected at the center-of-mass energy v/S = 3.773 GeV with the BESIII detector, we measure the absolute branching fraction of the semileptonic decay D＋- k0e＋ ve via k0-π0π0 - （8.59 ± 0.14 ± 0.21）% using k0- k0-π0π0, where the first uncertainty is statistical and the second systematic. Our result is consistent with previous measurements within uncertainties..

Luminosity measurements for the R scan experiment at BESIII

By analyzing the large-angle Bhabha scattering events e^＋e^- → （γ）e^＋e^- and diphoton events e^＋^e- → （γ）γγ for the data sets collected at center-of-mass （c.m.） energies between 2.2324 and 4.5900 GeV （131 energy points in total） with the upgraded Beijing Spectrometer （BESIII） at the Beijing Electron-Positron Collider （BEPCII）, the integrated luminosities have been measured at the different c.m. energies, individually. The results are important inputs for the R value and J/ψ resonance parameter measurements.

Nucleon form factors:the space-time connection

Analyticity of nucleon form factors allows to derive sum rules which, using space-like and time-like data as input, can give unique information about behaviors in energy regions not experimentally accessible. Taking advantage from new time-like data on proton-antiproton differential cross section and hence the possibility to separate electric and magnetic form factors also in the time-like region, we verify the consistency of the asymptotic behavior predicted by the perturbative QCD for the proton magnetic form factor.

Metal-organic framework-derived Ni2P/nitrogendoped carbon porous spheres for enhanced lithium storage

Transition metal phosphides(TMPs)/carbonaceous matrices have gradually attracted attention in the field of energy storage.In this study,we presented nickel phosphide(Ni2P)nanoparticles anchored to nitrogen-doped carbon porous spheres(Ni2P/NC)by using metal-organic framework-Ni as the template.The comprehensive encapsulation architecture provides closer contact among the Ni2P nanoparticles and greatly improves the structural integrity as well as the electronic conductivity,resulting in excellent lithium storage performance.The reversible specific capacity of 286.4 mA hg^-1 has been obtained even at a high current density of 3.0 Ag^-1 and 450.4 mA hg^-1 is obtained after 800 cycles at 0.5 Ag^-1.Furthermore,full batteries based on LiNi1/3Co1/3Mn1/3O2||Ni2P/NC exhibit both good rate capability and cycling life.This study provides a powerful and indepth insight on new advanced electrodes in high-performance energy storage devices.

Number of J/ψ events at BESIII

Using inclusive decays of J/ψ aprecise determination of the number of J/ψ events collected with the BESIII detector was performed.For the two data sets taken in 2009 and 2012,the numbers of J/ψ events were recalculated to be(224.0±1.3)×10^(6) and(1088.5±4.4)×10^(6),respectively;these numbers are in good agreement with the previous measurements. For the J/ψ sample taken in 2017-2019,the number of events was determined to be(8774.0±39.4)×10^(6).The total number of J/ψ events collected with the BESIII detector was determined to be(10087±44)×10^(6),where the uncertainty is dominated by systematic effects,and the statistical uncertainty is negligible.

Search for hidden-charm tetraquark with strangeness in e^(+)e^(−)→K^(+)D_(s)^(∗−) D^(∗0 )+ c.c.

We report a search for a heavier partner of the recently observed Z_(cs)(3985)^(-) state,denoted as Z_(cs)^('-),in the process e^(+)e^(−)→K^(+)D_(s)^(∗−) D^(∗0 )+ c.c.,based on e^(*)e^(-)collision data collected at the center-of-mass energies of √s=4.661,4.682 and 4.699 GeV with the BESIII detector.The Z_(cs)^('-) is of interest as it is expected to be a candidate for a hidden-charm and open-strange tetraquark.A partial-reconstruction technique is used to isolate K^(+)recoil-mass spectra,which are probed for a potential contribution from Z_(cs)^('-)→D_(s)^(∗−) D^(∗0 )+ c.c.We find an excess of Z_(cs)^('-)→D_(s)^(*-)-D^(*0)(c.c.)candidates with a significance of 2.1o,after considering systematic uncertainties,at a mass of(4123.5±0.7_(sat)±4.7_(syst.))MeV/c^(2).As the data set is limited in size,the upper limits are evaluated at the 90%confidence level on the product of the Born cross sections(σ^(Borm))and the branching fraction(B)of Z_(cs)^('-)→D_(s)^(*-)-D^(*0),under different assumptions of the Z_(cs)^('-) mass from 4.120 to 4.140 MeV and of the width from 10 to 50 MeV at the three center-of-mass energies.The upper limits of σ^(Born).B are found to be at the level of O(1)pb at each energy.Larger data samples are needed to confirm the Z_(cs)^('-) state and clarify its nature in the coming years.

Luminosities and energies of e^(+)e^(−) collision data taken between √s=4.61 GeV and 4.95 GeV at BESⅢ

From December 2019 to June 2021,the BESⅢ experiment collected approximately 5.85 fb^(−1) of data at center-of-mass energies between 4.61 and 4.95 GeV.This is the highest collision energy BEPCⅡ has reached to date.The accumulated e^(+)e^(−) annihilation data samples are useful for studying charmonium(-like)states and charmed-hadron decays.By adopting a novel method of analyzing the production of A_(c)^(+)A_(c)^(-) pairs in e^(+)e^(−) annihilation,the center-of-mass energies are measured with a precision of 0.6 MeV.Integrated luminosities are measured with a precision of better than 1% by analyzing the events of large-angle Bhabha scattering.These measurements provide important inputs to analyses based on these data samples.