The photon spectrum in the inclusive electromagnetic radiative decays of the B meson, B → X(s)γ plus B → X(d)γ, is studied using a data sample of (382.8 ± 4.2) × 10(6)Υ(4S) → BB decays collected by ...the BABAR experiment at SLAC. The spectrum is used to extract the branching fraction B(B → X(s)γ) = (3.21 ± 0.33) × 10(-4) for E(γ) >1.8 GeV and the direct CP asymmetry A(CP) (B → X(s+d)γ) = 0.057 ± 0.063. The effects of detector resolution and Doppler smearing are unfolded to measure the photon energy spectrum in the B meson rest frame.
The Beijing Spectrometer (BESIII) collaboration uses \(e^+e^-\) collisions in the tau-charm energy region to study a broad spectrum of topics. These include studies of light mesons and light baryons, ...studies of charmonium, including exotic mesons and baryons containing charmonium, studies of charmed mesons and baryons, studies of QCD and tau physics, as well as searches for new physics. The following is a Snowmass white paper that outlines the BESIII accomplishments and potential in each of these areas.
In the next years, the energy and intensity frontiers of the experimental Particle Physics will be pushed forward with the upgrade of existing accelerators (LHC at CERN) and the envisaged ...construction of new machines at energy scales up to hundreds TeV or with unprecedented intensity (FCC-hh, FCC-ee, ILC, Muon Collider). Large size, cost-effective, high-efficiency detection systems in high background environments are required in order to accomplish the physics program. MPGDs offer a diversity of technologies that allow them to meet the required performance challenges at future facilities thanks to the specific advantages that each technology provides. MPGDs allow stable operation, with environmentally friendly gas mixtures, at very high background particle flux with high detection efficiency and excellent spatial resolution. These features make MPGD one of the primary choices as precise muon tracking and trigger system in general-purpose detectors at future HEP colliders. In addition, the low material budget and the flexibility of the base material make MPGDs suitable for the development of very light, full cylindrical fine tracking inner trackers at lepton colliders. On-going R&Ds aim at pushing the detector performance at the limits of each technology. We are working in continuing to consolidate the construction and stable operation of large-size detectors, able to cope with large particle fluxes. In this white paper, we describe some of the most prominent MPGD technologies, their performance measurements, the challenges faced in the most recent applications, and the areas of improvement towards efficient tracking and Muon detection at future high energy physics colliders.
The CGEM-IT readout chain Amoroso, A; R Baldini Ferroli; Balossino, I ...
arXiv.org,
08/2021
Paper, Journal Article
Odprti dostop
An innovative Cylindrical Gas Electron Multiplier (CGEM) detector is under construction for the upgrade of the inner tracker of the BESIII experiment. A novel system has been worked out for the ...readout of the CGEM detector, including a new ASIC, dubbed TIGER -Torino Integrated GEM Electronics for Readout, designed for the amplification and digitization of the CGEM output signals. The data output by TIGER are collected and processed by a first FPGA-based module, GEM Read Out Card, in charge of configuration and control of the front-end ASICs. A second FPGA-based module, named GEM Data Concentrator, builds the trigger selected event packets containing the data and stores them via the main BESIII data acquisition system. The design of the electronics chain, including the power and signal distribution, will be presented together with its performance.
In the framework of the ATTRACT-uRANIA project, funded by the European Community, we are developing an innovative neutron imaging detector based on micro-Resistive WELL (\(\mu\) -RWELL) technology. ...The \(\mu\) -RWELL, based on the resistive detector concept, ensuring an efficient spark quenching mechanism, is a highly reliable device. It is composed by two main elements: a readout-PCB and a cathode. The amplification stage for this device is embedded in the readout board through a resistive layer realized by means of an industrial process with DLC (Diamond-Like Carbon). A thin layer of B\(_4\)C on the copper surface of the cathode allows the thermal neutrons detection through the release of \(^7\)Li and \(\alpha\) particles in the active volume. This technology has been developed to be an efficient and convenient alternative to the \(^3\)He shortage. The goal of the project is to prove the feasibility of such a novel neutron detector by developing and testing small planar prototypes with readout boards suitably segmented with strip or pad read out, equipped with existing electronics or readout in current mode. Preliminary results from the test with different prototypes, showing a good agreement with the simulation, will be presented together with construction details of the prototypes and the future steps of the project.
Gaseous detectors are used in high energy physics as trackers or, more generally, as devices for the measurement of the particle position. For this reason, they must provide high spatial resolution ...and they have to be able to operate in regions of intense radiation, i.e. around the interaction point of collider machines. Among these, Micro Pattern Gaseous Detectors (MPGD) are the latest frontier and allow to overcome many limitations of the pre-existing detectors, such as the radiation tolerance and the rate capability. The gas Electron Multiplier (GEM) is a MPGD that exploits an intense electric field in a reduced amplification region in order to prevent discharges. Several amplification stages, like in a triple-GEM, allow to increase the detector gain and to reduce the discharge probability. Reconstruction techniques such as charge centroid (CC) and micro-Time Projection Chamber (\(\upmu\)TPC) are used to perform the position measurement. From literature triple-GEMs show a stable behaviour up to \(10^8\,\)Hz/cm\(^2\). A testbeam with four planar triple-GEMs has been performed at the Mainz Microtron (MAMI) facility and their performance was evaluated in different beam conditions. In this article a focus on the time performance for the \(\upmu\)TPC clusterization is given and a new measurement of the triple-GEM limits at high rate will be presented.
BESIII data show a particular angular distribution for the decay of the
$J/\psi$ and $\psi(2S)$ mesons into the hyperons $\Lambda\overline{\Lambda}$
and $\Sigma^0\overline{\Sigma}^0$. More in details ...the angular distribution of
the decay $\psi(2S) \to \Sigma^0\overline{\Sigma}^0$ exhibits an opposite trend
with respect to that of the other three channels: $J/\psi \to
\Lambda\overline{\Lambda}$, $J/\psi \to \Sigma^0\overline{\Sigma}^0$ and
$\psi(2S) \to \Lambda\overline{\Lambda}$. We define a model to explain the
origin of this phenomenon.
Thermal mud is a therapeutic agent widely used in the treatment of painful arthritic processes. The mechanism by which mud therapy works is still not well known. Its effect continues for months after ...completion of treatment. In order to verify whether thermal mud treatment brings about changes in the production of hormone peptides from proopiomelanocortin, the levels of plasma beta-endorphin and some hormones of the pituitary-adrenal glands (ACTH and cortisol) were determined in patients affected by osteoarthritis undergoing thermal mud therapy.
The levels of plasma beta-endorphin and some hormones of the pituitary-adrenal glands (ACTH and cortisol) were assessed by radiometric methods in seventeen males affected by osteoarthritis. The patients underwent a cycle of twelve sessions of thermal mud therapy. The tests were carried out immediately before thermal treatment, immediately after the first session, twelve days after the start of treatment, and again one month after completion of the treatment.
beta-endorphin levels decreased significantly twelve days after the start of treatment. The level was still lower, although not significantly, even thirty days after completion of the treatment. Plasma ACTH also decreased during treatment. The decrease of this hormone was progressive and persisted after completion of treatment. Significant variations compared to baseline were found only thirty days after completion of treatment. Plasma cortisol decreased significantly after only one session of mud therapy. This hormone did not decrease any further during treatment, however, after twelve days it was still significantly lower than baseline. After completion of treatment, cortisol slightly increased, but thirty days later it was still lower, although not significantly, than baseline.
It may be suggested that thermal treatment, by reducing inflammation, reduced pain and therefore diminished the cause of stress.
We report on a precision measurement of the ratio \({\cal R}_{\tau\mu}^{\Upsilon(3S)} = {\cal B}(\Upsilon(3S)\to\tau^+\tau^-)/{\cal B}(\Upsilon(3S)\to\mu^+\mu^-)\) using data collected with the BaBar ...detector at the SLAC PEP-II \(e^+e^-\) collider. The measurement is based on a 28 fb\(^{-1}\) data sample collected at a center-of-mass energy of 10.355 GeV corresponding to a sample of 122 million \(\Upsilon(3S)\) mesons. The ratio is measured to be \({\cal R}_{\tau\mu}^{\Upsilon(3S)} = 0.966 \pm 0.008_\mathrm{stat} \pm 0.014_\mathrm{syst}\) and is in agreement with the Standard Model prediction of 0.9948 within 2 standard deviations. The uncertainty in \({\cal R}_{\tau\mu}^{\Upsilon(3S)}\) is almost an order of magnitude smaller than the only previous measurement.
Phys. Rev. D 101, 112003 (2020) We present a search for seven lepton-flavor-violating neutral charm decays of
the type $D^{0}\rightarrow X^{0} e^{\pm} \mu^{\mp}$, where $X^{0}$ represents a
...$\pi^{0}$, $K^{0}_{\rm S}$, $\bar{K^{*0}}$, $\rho^{0}$, $\phi$, $\omega$, or
$\eta$ meson. The analysis is based on $468$ fb$^{-1}$ of $e^+e^-$ annihilation
data collected at or close to the $\Upsilon(4S)$ resonance with the BaBar
detector at the SLAC National Accelerator Laboratory. No significant signals
are observed, and we establish 90\% confidence level upper limits on the
branching fractions in the range $(5.0 - 22.5)\times 10^{-7}$. The limits are
between one and two orders of magnitude more stringent than previous
measurements.
