In this letter, we evaluate the potential of linear e+e− colliders to measure the top quark mass in radiative events and in a suitable short-distance scheme. We present a calculation of the ...differential cross section for production of a top quark pair in association with an energetic photon from initial state radiation, as a function of the invariant mass of the tt¯ system. This matched calculation includes the QCD enhancement of the cross section around the tt¯ production threshold and remains valid in the continuum well above the threshold. The uncertainty in the top mass determination is evaluated in realistic operating scenarios for the Compact Linear Collider (CLIC) and the International Linear Collider (ILC), including the statistical uncertainty and the theoretical and experimental systematic uncertainties. With this method, the top quark mass can be determined with a precision of 110 MeV in the initial stage of CLIC, with 1 ab−1 at s=380 GeV, and with a precision of approximately 150 MeV at the ILC, with L=4 ab−1 at s=500 GeV. Radiative events allow measurements of the top quark mass at different renormalization scales, and we demonstrate that such a measurement can yield a statistically significant test of the evolution of the MSR mass mtMSR(R) for scales R<mt.
Jet cross sections have been measured in proton-proton collisions at a centre-of-mass energy of 7 TeV using the ATLAS detector. The measurement uses an integrated luminosity of 17 nb
−1 recorded at ...the Large Hadron Collider. The anti-
k
t
algorithm is used to identify jets with a jet resolution parameter
R
=
0.6
. The dominant uncertainty comes from the jet energy scale, which is determined to within 7% for central jets above 60 GeV transverse momentum. Inclusive single-jet differential cross sections are presented as functions of jet transverse momentum and rapidity. The results are compared to expectations based on next-to-leading-order QCD, which agree with the data, providing a validation of the theory in a new kinematic regime.
A
bstract
The Compact Linear Collider (CLIC) is a proposed future high-luminosity linear electron-positron collider operating at three energy stages, with nominal centre-of-mass energies
s
= 380 GeV, ...1
.
5 TeV, and 3 TeV. Its aim is to explore the energy frontier, providing sensitivity to physics beyond the Standard Model (BSM) and precision measurements of Standard Model processes with an emphasis on Higgs boson and top-quark physics. The opportunities for top-quark physics at CLIC are discussed in this paper. The initial stage of operation focuses on top-quark pair production measurements, as well as the search for rare flavour-changing neutral current (FCNC) top-quark decays. It also includes a top-quark pair production threshold scan around 350 GeV which provides a precise measurement of the top-quark mass in a well-defined theoretical framework. At the higher-energy stages, studies are made of top-quark pairs produced in association with other particles. A study of t
̄
tH production including the extraction of the top Yukawa coupling is presented as well as a study of vector boson fusion (VBF) production, which gives direct access to high-energy electroweak interactions. Operation above 1 TeV leads to more highly collimated jet environments where dedicated methods are used to analyse the jet constituents. These techniques enable studies of the top-quark pair production, and hence the sensitivity to BSM physics, to be extended to higher energies. This paper also includes phenomenological interpretations that may be performed using the results from the extensive top-quark physics programme at CLIC.
We present an Optimal Filtering (OF) algorithm to reconstruct the energy, time and pedestal of a photomultiplier signal from its digital samples. The OF algorithm was first developed for liquid ...ionization calorimeters, its implementation in scintillator calorimeters, specifically in the ATLAS hadronic Tile calorimeter (TileCal), is the aim of this study. The objective is to implement the algorithm on the DSPs of the Read Out Driver cards in order to reconstruct online the energy of the calorimeter and provide it to the second level trigger. The algorithm is tested and compared with a plain filtering algorithm using both calibration and real data from the TileCal detector. The results are promising specially in the regions where the electronic noise contributes significantly to the resolution
Abstract
Study question
Can non-invasive preimplantation genetic testing of aneuploidies (niPGT-A) improve the clinical outcome in IVF patients after proper validation?
Summary answer
We demonstrate ...the usefulness of the embryonic cell-free DNA (cfDNA) in the blastocyst culture medium to select more objectively the blastocysts with higher implantation potential.
What is known already
One of the greatest challenges in IVF is accurately selecting viable embryos that are more likely to achieve healthy livebirths following embryo transfer. Trophectoderm (TE) biopsy and PGT-A provide a direct assessment of chromosome status and improve implantation and clinical pregnancy rates per transfer. A non-invasive alternative is to analyse embryonic cfDNA in the blastocyst culture medium. Previous studies have shown that cfDNA testing in culture medium of blastocysts on day 6 of development allows aneuploidy detection with high concordance rates compared to TE biopsy and inner cell mass (Rubio et al., 2020).
Study design, size, duration
Observational study of the clinical application of niPGT-A (July 2020-December 2020). The clinical application consisted in a first validation phase, comparing TE biopsies with cfDNA in the media of 28 blastocysts. And, in a second phase, niPGT-A was applied and the outcome of 13 single embryo transfers (SETs) compared to 13 PGT-A SETs and 130 IVF/ICSI SETs performed in a period of six months. In the three groups, women and donors age was ≤38 years.
Participants/materials, setting, methods
Embryos were cultured in a Geri incubator (Merck) up to day 4, and then individually cultured in 10µl drops of CCSS (Fujifilm) until day 6 in a bench-top K-system. At day 6, blastocysts were vitrified, and media collected in sterile PCR tubes after at least 40 hours in culture. After collection, media were immediately frozen and analyzed by NGS analysis in our reference laboratory (Igenomix, Spain). Deferred transfer was performed according to media results.
Main results and the role of chance
Before the first clinical cases, a validation of the protocol comparing the results of cfDNA with the TE biopsies of the same day–6 blastocyst was performed, and ploidy concordance rates were 87.5%.
Similar results were found for niPGT-A and PGT-A in terms of aneuploidy results and in clinical outcomes. The percentages of informative results were 95% and 97% and the aneuploidy rates were 44% and 46%, for niPGT-A and PGT-A, respectively. Clinical pregnancy rates were in both groups of aneuploidy testing, 69.2%, with 8 ongoing pregnancies (61.5%) and 4 tested by prenatal screaning NACE. For untested embryos clinical pregnancy (57.7%) and ongoing pregnancy rates (48.5%) were lower than in the two groups of tested embryos (niPGT-A and PGT-A).
In the niPGT-A cycles embryo transfer was performed according to media results and morphology. We did a secondary analysis of which blastocyst we would transfer, if only morphology is considered. We observed that if we only select the embryos by morphology, in 61.5% of the cases we would choose the same embryo than with niPGT-A, and in 30.4% of the cases we would transfer a blastocyst with an aneuploid medium.
Limitations, reasons for caution
Our results are encouraging but should be interpreted with caution due to the small sample size. Larger and randomized controlled trials are needed to verify and extend our findings in each group.
Wider implications of the findings: We observed consistent results for niPGT-A compared to TE biopsies in our internal validation. These results endorse the clinical application of niPGT-A in the routine of the laboratory and can avoid the embryo manipulation also reducing the subjectivity when embryos are selected only by morphology.
Trial registration number
Sa–16552/19-EC:428
TileCal is the hadronic tile calorimeter of the ATLAS experiment at LHC/CERN. The central element of the back-end system of the TileCal detector is the read-out driver (ROD).The main components of ...the TileCal ROD are the Digital Signal Processors (DSPs) placed on the processing unit (PU) daughterboards. This paper presents a detailed description of the code developed for the DSPs. The code is divided into two different parts: the first part contains the core functionalities and the second part the reconstruction algorithms. The core acts as an operating system and controls configuration, data reception and transmission and synchronization between front-end data and the timing, trigger and control (TTC) information. The reconstruction algorithms implemented on the DSP are the optimal filtering (OF), muon tagging (MTag) and missing calculation. The OF algorithm reconstructs the deposited energy and the phase of the signal for every calorimeter channel within a front-end module. This reconstructed energy is used by the MTag algorithm to tag low transverse momentum muons that may escape the ATLAS muon spectrometer Level 1 trigger whereas the Missing algorithm computes the total transverse energy and the projection on and axis for the entire module that will be used by the Level 2 trigger system.
The ATLAS hadronic Tile Calorimeter detector (TileCal) is an iron-scintillating tiles sampling calorimeter designed to operate at the Large Hadron Collider accelerator at CERN. The central element of ...the back-end system of the TileCal detector is a 9U VME read-out driver (ROD) board. The operation of the TileCal calorimeter requires a total of 32 ROD boards. This paper summarizes the tests performed during the ROD production and the results obtained. Data processing is performed in the ROD by digital signal processors, whose operation is based on the use of online algorithms such as the optimal filtering algorithm for the signal amplitude, pedestal and time reconstruction and the online Muon tagging algorithm which identifies low transverse momentum muons. The initial performance of both algorithms run during commissioning is also presented in this paper.
This paper describes the development of the optical multiplexer board (OMB), also known as PreROD board, for the TileCal readout system in the ATLAS experiment. The aim of this board is to overcome ...the problems that may arise in the integrity of data due to radiation effects. The solution adopted has been to add redundancy to data transmission and so two optical fibers with the same data come out from the detector front end boards. The OMB has to decide in real time which fiber, eventually, carries data with no errors switching it to the output link connected to the read out driver (ROD) motherboard where data processing takes place. Besides, the board may be also used as a data injector for testing purposes of the ROD motherboard. The paper describes the design and tests of the first prototype, implemented as a 6U VME64x slave module, including both hardware aspects, focusing on signal integrity problems, and firmware aspects, dealing with the cyclic redundancy code algorithms used to check data consistency used to make the decision
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