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.
Performance of triple GEM prototypes in strong magnetic field has been evaluated bymeans of a muon beam at the H4 line of the SPS test area at CERN. Data have been reconstructedand analyzed offline ...with two reconstruction methods: the charge centroid and the micro-Time-Projection-Chamber exploiting the charge and the time measurement respectively. A combinationof the two reconstruction methods is capable to guarantee a spatial resolution better than 150{\mu}min magnetic field up to a 1 T.
Phys. Rev. Lett. 124, 152001 (2020) A study of the two body decays $B^\pm\rightarrow X_{c\bar c}K^\pm$, where
X$_{c\bar c}$ refers to one charmonium state, is reported by BaBar
collaboration using a ...data sample of 424 fb$^{-1}$. The absolute determination
of branching fractions for these decays are significantly improved compared to
previous BaBaR measurements. Evidence is found for the decay $B^+\rightarrow
X(3872)K^+$ at the $3\sigma$ level. The absolute branching fraction ${\cal
B}(B^+\rightarrow X(3872)K^+) = (2.1\pm0.6({\rm stat})\pm0.3({\rm syst}))\times
10^{-4}$ is measured for the first time. It follows that ${\cal
B}(X(3872)\rightarrow J/\psi\pi^+\pi^-)=(4.1\pm1.3)\%$, supporting the
hypothesis of a molecular component for this resonance.
Using the entire BaBar \(\Upsilon(4S)\) data set, the first two-dimensional unbinned angular analysis of the semileptonic decay \(\overline{B} \rightarrow D \ell^- \overline{\nu}_\ell\) is performed, ...employing hadronic reconstruction of the tag-side \(B\) meson from \(\Upsilon(4S)\to B\overline{B}\). Here, \(\ell\) denotes the light charged leptons \(e\) and \(\mu\). A novel data-driven signal-background separation procedure with minimal dependence on simulation is developed. This procedure preserves all multi-dimensional correlations present in the data. The expected \(\sin^2\theta_\ell\) dependence of the differential decay rate in the Standard Model is demonstrated, where \(\theta_\ell\) is the lepton helicity angle. Including input from the latest lattice QCD calculations and previously available experimental data, the underlying form factors are extracted using both model-independent (BGL) and dependent (CLN) methods. Comparisons with lattice calculations show flavor SU(3) symmetry to be a good approximation in the \(B_{(s)}\to D_{(s)}\) sector. Using the BGL results, the CKM matrix element \(|V_{cb}|=(41.09\pm 1.16)\times 10^{-3}\) and the Standard Model prediction of the lepton-flavor universality violation variable \(\mathcal{R}(D)=0.300\pm 0.004\), are extracted. The value of \(|V_{cb}|\) from \(\overline{B} \rightarrow D \ell^- \overline{\nu}_\ell\) tends to be higher than that extracted using \(\overline{B} \rightarrow D \ell^- \overline{\nu}_\ell\). The Standard Model \(\mathcal{R}(D)\) calculation is at a \(1.97\sigma\) tension with the latest HFLAV experimental average.
MPGD are the new frontier in gas trackers. Among this kind of devices, theGEM chambers are widely used. The experimental signals acquired with the detector mustobviously be reconstructed and ...analysed. In this contribution, a new offline software to performreconstruction, alignment and analysis on the data collected with APV-25 and TIGER ASICswill be presented. GRAAL (Gem Reconstruction And Analysis Library) is able to measurethe performance of a MPGD detector with a strip segmented anode (presently). The code isdivided in three parts: reconstruction, where the hits are digitized and clusterized; tracking,where a procedure fits the points from the tracking system and uses that information to align thechamber with rotations and shifts; analysis, where the performance is evaluated (e.g. efficiency,spatial resolution,etc.). The user must set the geometry of the setup and then the programreturns automatically the analysis results, taking care of different conditions of gas mixture,electric field, magnetic field, geometries, strip orientation, dead strip, misalignment and manyothers.
