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At least 1,441 records · Page 80
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Measurements of Zγ +jets differential cross sections in $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector

Differential cross-section measurements of $Zγ$ production in association with hadronic jets are presented, using the full 139 fb -1 dataset of $\sqrt{s}$ = 13 TeV proton–proton collisions collected by the ATLAS detector during Run 2 of the LHC. Distributions are measured using events in which the $Z$ boson decays leptonically and the photon is usually radiated from an initial-state quark. Measurements are made in both one and two observables, including those sensitive to the hard scattering in the event and others which probe additional soft and collinear radiation. Different Standard Model predictions, from both parton-shower Monte Carlo simulation and fixed-order QCD calculations, are compared with the measurements. In general, good agreement is observed between data and predictions from MATRIX and MiNNLO PS , as well as next-to-leading-order predictions from MADGRAPH5_AMC@NLO and SHERPA.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2025

Differential cross-section measurements of D± and Ds± meson production in proton-proton collisions at s = 13 TeV with the ATLAS detector

The production of D± and Ds±$$ {D}_s^{\pm } $$ charmed mesons is measured using the D±/Ds±$$ {D}_s^{\pm } $$→ ϕ(μμ)π± decay channel with 137 fb−1 of s$$ \sqrt{s} $$ = 13 TeV proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider during the years 2016–2018. The charmed mesons are reconstructed in the range of transverse momentum 12 < pT < 100 GeV and pseudorapidity |η| < 2.5. The differential cross-sections are measured as a function of transverse momentum and pseudorapidity, respectively, and compared with next-to-leading- order QCD predictions. The predictions are found to be consistent with the measurements in the visible kinematic region within the large theoretical uncertainties.

Aad, G↗
DOE OSTI2026

Measurement of the Υ(1S), Υ(2S), and Υ(3S) differential cross sections in pp collisions at $\sqrt{s}=13.6$ TeV

The production cross sections of the Υ(1S), Υ(2S), and Υ(3S) mesons are measured in proton-proton collisions at $\sqrt{s}=13.6$ TeV, using a data sample collected in 2022 by the CMS experiment and corresponding to an integrated luminosity of 37.4 fb −1 . The measurement is performed in the μ + μ − decay channels, differentially as a function of transverse momentum in the 20–200 GeV range, in the |y| < 0.6 and 0.6 < |y| < 1.2 rapidity intervals.

Hadron-Hadron Scattering↗
DOE OSTI2017

Differential distributions for t-channel single top-quark production and decay at next-to-next-to-leading order in QCD

We present a detailed phenomenological study of the next-to-next-to-leading order (NNLO) QCD corrections for t-channel single top (anti-)quark production and its semi-leptonic decay at the CERN Large Hadron Collider (LHC). We find the NNLO corrections for the total inclusive rates at the LHC with different center of mass energies are generally smaller than the NLO corrections, indicative of improved convergence. However, they can be large for differential distributions, reaching a level of 10% or more in certain regions of the transverse momentum distributions of the top (anti-)quark and the pseudo-rapidity distributions of the leading jet in the event. In all cases the perturbative hard-scale uncertainties are greatly reduced after the NNLO corrections are included. We also show a comparison of the normalized parton-level distributions to recent data from the 8 TeV measurement of the ATLAS collaboration. The NNLO corrections tend to shift the theoretical predictions closer to the measured transverse momentum distribution of the top (anti)-quark. Importantly, for the LHC at 13 TeV, we present NNLO cross sections in a fiducial volume with decays of the top quark included.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2018

Measurements of the differential jet cross section as a function of the jet mass in dijet events from proton-proton collisions at $ \sqrt{s}=13$ TeV

Measurements of the differential jet cross section are presented as a function of the jet mass in dijet events, in bins of jet transverse momentum, with and without a jet grooming algorithm. The data have been recorded by the CMS Collaboration in proton-proton collisions at the LHC at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 2.3 fb$^{-1}$. The absolute cross sections show slightly different jet transverse momentum spectra in data and Monte Carlo event generators for the settings used. Removing this transverse momentum dependence, the normalized cross section for ungroomed jets is consistent with the prediction from Monte Carlo event generators for masses below 30% of the transverse momentum. The normalized cross section for groomed jets is measured with higher precision than the ungroomed cross section. Semi-analytical calculations of the jet mass beyond leading logarithmic accuracy are compared to data, as well as predictions at leading order and next-to-leading order, which include parton showering and hadronization. Overall, in the normalized cross section, the theoretical predictions agree with the measured cross sections within the uncertainties for masses from 10 to 30% of the jet transverse momentum.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Analysis of the Wtb vertex from the measurement of triple-differential angular decay rates of single top quarks produced in the t -channel at $ \sqrt{s}=8 $ TeV with the ATLAS detector

The electroweak production and subsequent decay of single top quarks in the t-channel is determined by the properties of the Wtb vertex, which can be described by the complex parameters of an effective Lagrangian. We use an analysis of a triple-differential decay rate in t-channel production to simultaneously determine five generalised helicity fractions and phases, as well as the polarisation of the produced top quark. The complex parameters are then constrained. This analysis is based on 20.2 fb -1 of proton-proton collision data at a centre-of-mass energy of 8 TeV collected with the ATLAS detector at the LHC. The fraction of decays containing transversely polarised W bosons is measured to be f 1 = 0.30 ± 0.05. The phase between amplitudes for transversely and longitudinally polarised W bosons recoiling against left-handed b-quarks is measured to be δ - = 0.002π + 0.017π + 0.016π , giving no indication of CP violation. The fractions of longitudinal or transverse W bosons accompanied by right-handed b-quarks are also constrained. Based on these measurements, limits are placed at 95% CL on the ratio of the complex coupling parameters Re [g R /V L ϵ [-0.12, 0.17] and Im [g R /V L ϵ [-0.07, 0.06]. Constraints are also placed on the ratios |V R /V L | and |g L /V L |. Additionally, the polarisation of single top quarks in the t-channel is constrained to be P > 0.72 (95% CL). None of the above measurements make assumptions about the value of any of the other parameters or couplings and all of them are in agreement with the Standard Model.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Measurement of the Drell-Yan triple-differential cross section in $pp$ collisions at $\sqrt{s}=8$ TeV

This article presents a measurement of the triple-differential cross section for the Drell-Yan process Z/γ * → ℓ + ℓ - where ℓ is an electron or a muon. The measurement is performed for invariant masses of the lepton pairs, m ℓℓ , between 46 and 200 GeV using a sample of 20.2 fb -1 of pp collisions data at a centre-of-mass energy of $\sqrt{s}=8$ TeV collected by the ATLAS detector at the LHC in 2012. The data are presented in bins of invariant mass, absolute dilepton rapidity, |y ℓℓ |, and the angular variable cos θ * between the outgoing lepton and the incoming quark in the Collins-Soper frame. The measurements are performed in the range |y ℓℓ | < 2.4 in the muon channel, and extended to |y ℓℓ | < 3.6 in the electron channel. The cross sections are used to determine the Z boson forward-backward asymmetry as a function of |y ℓℓ | and m ℓℓ . The measurements achieve high-precision, below the percent level in the pole region, excluding the uncertainty in the integrated luminosity, and are in agreement with predictions. These precision data are sensitive to the parton distribution functions and the effective weak mixing angle.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Celestial dual superconformal symmetry, MHV amplitudes and differential equations

Celestial and momentum space amplitudes for massless particles are related to each other by a change of basis provided by the Mellin transform. Therefore properties of celestial amplitudes have counterparts in momentum space amplitudes and vice versa. In this paper, we study the celestial avatar of dual superconformal symmetry of $\mathcal{N}$ = 4 Yang-Mills theory. We also analyze various differential equations known to be satisfied by celestial n-point tree-level MHV amplitudes and identify their momentum space origins.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2021

Measurement of the inclusive and differential $t\overline{t}γ$ cross sections in the single-lepton channel and EFT interpretation at $\sqrt{s}$ = 13 TeV

The production cross section of a top quark pair in association with a photon is measured in proton-proton collisions at a center-of-mass energy of 13 TeV. The data set, corresponding to an integrated luminosity of 137 fb -1 , was recorded by the CMS experiment during the 2016–2018 data taking of the LHC. The measurements are performed in a fiducial volume defined at the particle level. Events with an isolated, highly energetic lepton, at least three jets from the hadronization of quarks, among which at least one is b tagged, and one isolated photon are selected. The inclusive fiducial $t\overline{t}γ$ cross section, for a photon with transverse momentum greater than 20 GeV and pseudorapidity |η| < 1.4442, is measured to be 798 ± 7(stat) ± 48(syst) fb, in good agreement with the prediction from the standard model at next-to-leading order in quantum chromodynamics. The differential cross sections are also measured as a function of several kinematic observables and interpreted in the framework of the standard model effective field theory (EFT), leading to the most stringent direct limits to date on anomalous electromagnetic dipole moment interactions of the top quark and the photon.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2019

Differential Many-Body Effects for Initial and Core Ionic States: Impact on XPS Spectra

In this paper, the contribution of many-body effects to the X-ray photoelectron spectroscopy, XPS, of an NO molecule is studied using wavefunction theory where the specific consequences of different many-body terms are examined and contrasted. It is shown that there is a differential importance of the many-body effects for the different configurations involved in the XPS. These are the ground, initial state configuration and final, N(1s) and O(1s) core hole ionic configurations. The consequences of the many-body effects are examined for the binding energies, BEs, to the two final state multiplets, triplet, and singlet, for each of the core ions and for the relative intensities of the XPS transitions to these multiplets. The many-body effects examined are those described as static effects that arise for individual terms that are important. The objective is to understand the chemical and physical origins that determine the importance of the correlation effects for the XPS, rather than to obtain very accurate predictions of the BEs. An important theoretical construct that is tested and justified is the equivalent core approximation where the core-ionized atom is replaced by the next higher element in the periodic table. This construct allows us to establish a correlation for the relative importance of the many-body effects in terms of effective charges of the different atoms. This is a correlation that has not been considered before and that we expect may have general relevance. The potential of the effects that we have identified for the XPS of NO to be relevant for the XPS of more complex, condensed phase systems is considered.

XPS, Static Correlation, Equivalent core model↗
DOE OSTI2019

Differentiation of pancreatic neuroendocrine tumors from pancreas renal cell carcinoma metastases on CT using qualitative and quantitative features

Purpose: To assess qualitative and quantitative imaging features on enhanced CT that may differentiate pancreatic neuroendocrine tumors (PNETs) from pancreatic renal cell carcinoma (RCC) metastases. Methods: This IRB-approved multi-center retrospective case–control study compared 43 resected PNETs and 28 resected RCC metastases with pre-operative enhanced CT identified consecutively between 2003 and 2017. Two blinded radiologists (R1/R2) independently assessed tumor location, attenuation (relative to pancreas), composition (solid/cystic/mixed), homogeneity (homogeneous/heterogeneous), calcification, multiplicity, and for main pancreatic duct (MPD) dilation. Tumors were segmented for quantitative texture analysis. Data were analyzed with Chi square, logistic regression, and receiver operating characteristic (ROC). Inter-observer agreement was assessed (Cohen’s kappa). Results: There was no difference in age, gender, location, attenuation, or composition (P > 0.05) between groups. PNETs were larger than RCC metastases (37 ± 23 mm vs. 26 ± 21 mm, P = 0.038), more frequently solitary (P < 0.001), subjectively more heterogeneous (P = 0.033/0.144, R1/R2), and associated with calcification (P = 0.002/0.004) and MPD dilation (P = 0.025/0.006). Agreement for subjective features was moderate-to-almost perfect (K = 0.4879–0.9481). Quantitative texture analysis showed higher entropy in PNETs (6.32 ± 0.49 versus 5.96 ± 0.53; P = 0.004) with no difference in other features studied (P > 0.05). Entropy had ROC area under the curve for diagnosis of PNET of 0.77 ± 0.06, with optimal sensitivity/specificity of 71.4/79.1%. Conclusions: Compared to pancreatic RCC metastases, PNETs are larger, more frequently solitary, contain calcification, show MPD dilation, and are subjectively and quantitatively more heterogeneous tumors.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Computed tomography-based texture analysis of bladder cancer: differentiating urothelial carcinoma from micropapillary carcinoma

Purpose: The purpose of the study is to determine the feasibility of using computed tomography-based texture analysis (CTTA) in differentiating between urothelial carcinomas (UC) of the bladder from micropapillary carcinomas (MPC) of the bladder. Methods: Regions of interests (ROIs) of computerized tomography (CT) images of 33 MPCs and 33 UCs were manually segmented and saved. Custom MATLAB code was used to extract voxel information corresponding to the ROI. The segmented tumors were input to a pre-existing radiomics platform with a CTTA panel. A total of 58 texture metrics were extracted using four different texture extraction techniques and statistically analyzed using a Wilcoxon rank-sum test to determine the differences between UCs and MPCs. Results: Of the 58 texture metrics extracted using the gray level co-occurrence matrix (GLCM) and gray level difference matrix (GLDM), 28 texture metrics were statistically significant (p < 0.05) for differences in tumor textures and 27 texture metrics were statistically significant (p < 0.05) for peritumoral fat textures. The remaining nine metrics extracted using histogram and fast Fourier transform analyses did not show significant differences between the textures of the tumors and their peritumoral fat. Conclusions: CTTA shows that MPC have a more heterogeneous texture compared to UC. As visual discrimination of MPC from UC from clinical CT scans are difficult, results from this study suggest that tumor heterogeneity extracted using GLCM and GLDM may be a good imaging aid in segregating MPC from UC. This tool can aid clinicians in further sub-classifying bladder cancers on routine imaging, a process which has potential to alter treatment and patient care.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Efficacy of perfusion CT in differentiating of pancreatic ductal adenocarcinoma from mass-forming chronic pancreatitis and characterization of isoattenuating pancreatic lesions

Purpose: Multidetector computed tomography (MDCT) is routinely used in the diagnosis of pancreatic ductal adenocarcinoma (PDAC), but it may be inadequate in some cases, especially mass-forming chronic pancreatitis (MFCP) and isoattenuating pancreatic lesions. Perfusion CT (pCT) may help resolve this problem. The aim of this study was to evaluate whether pCT could help differentiating PDAC from MFCP and in characterization of isoattenuating pancreatic lesions. Materials and methods: This prospective study included 89 cases of pancreatic lesions detected by MDCT and further analyzed with pCT. Sixty-one cases with final pathological diagnosis PDAC and 12 cases with MFCP were included from the study. Blood volume (BV), blood flow (BF), mean transit time (MTT), and permeability surface area product (PS) maps were obtained. Perfusion values obtained from the lesions and normal parenchyma were compared. Results: Compared with normal parenchyma, BV, BF, PS were lower and MTT was longer in PDAC and MFCP (p < 0.05). Compared with MFCP, BV, BF, PS were lower and MTT was longer in PDAC (p < 0.001). Compared with normal parenchyma, BV, BF, PS were lower and MTT was longer in isoattenuating lesions, (p < 0.001). Cutoff values of 7.60 mL/100 mL, 64.43 mL/100 mL/min, 28.08 mL/100 mL/min for BV, BF, PS, respectively, provided 100% sensitivity and specificity and 7.47 s for MTT provided 98.3% sensitivity, 80% specificity for distinguishing PDAC from MFCP. Conclusion: pCT is a useful technology that can be helpful in overcoming the limitations of routine MDCT in diagnosing PDAC and characterization of isoattenuating lesions.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Differentiation of aggressive from non-aggressive pancreatic solid pseudopapillary neoplasms using computed tomography

Purposes: Microscopic aggressive behaviors may be related with the prognosis of solid pseudopapillary neoplasms (SPNs). In this study, we investigate computed tomography (CT) features and differential diagnosis of aggressive and non-aggressive SPNs in pancreas. Materials and methods: 122 patients with pathologically proven SPNs in pancreas were included. Patients’ age, tumor site, texture, shape, margins, exophytic growth, capsule, calcification, hemorrhage, pancreatic duct dilatation or pancreatic parenchyma atrophy, peripancreatic infiltration or metastases, vascular encasement, and enhancement pattern were assessed. The diagnostic accuracy was analyzed by using the receiver operating characteristic curve (ROC). Results: There were 30 aggressive SPNs and 92 non-aggressive SPNs. Aggressive SPNs showed significantly higher frequencies of an ill-defined margin, patient age > 40.5 years, and tumor size < 42.1 mm, but lower frequencies of complete capsule, hemorrhage compared with non-aggressive SPNs (p < 0.05). Lack of complete capsule and age > 40.5 years were independent risk factors of aggressive SPNs (odd ratio 7.08 and 3.1, respectively). When we applied the two predictors in the logistic regression model, the area under the curve (AUC) was 0.77 with sensitivity of 86.7% and specificity of 55.4%. Conclusion: Size less than 42.1 mm, lack of complete capsule, ill-defined, and absent bleeding are useful CT imaging features for predicating aggressive SPNs. Patient age > 40.5 years and lack of complete capsule showed acceptable diagnostic performance for discriminating aggressive from non-aggressive SPNs.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Differentiation of pancreatic head ductal adenocarcinoma from inflammatory pancreatic pseudomass by MR cholangio-pancreatography: utility of the duct-interrupted, corona, and attraction signs

Purpose: To determine sensitivity and specificity of the “duct-interrupted,” “corona,” and “attraction” signs on MR cholangio-pancreatography (MRCP) in distinguishing pancreatic head ductal adenocarcinoma (PDAC) from inflammatory pancreatic pseudomass (IPP). Materials and methods: This study included 53 adults (33 men and 20 women, mean age, 55 years; range, 17–87 years) with a pancreatic head mass who underwent MRCP. Three blinded radiologists independently reviewed each MRCP exam and three signs were assessed: (1) the “duct-interrupted” sign, deemed positive for PDAC if the duct within the mass demonstrated complete interruption with upstream dilation; (2) the “corona” sign, considered positive for PDAC if dilated side-branches were located exclusively outside the mass; and (3) the “attraction” sign, deemed positive for IPP if the dilated common bile duct showed attraction and angulation towards the mass. Sensitivity, specificity, and positive and negative predictive values of the signs were calculated, as well as interobserver agreement. Results: Out of 53 masses, 17 (32%) were PDAC and 36 (68%) were IPP. Sensitivity, specificity, and positive and negative predictive values of the “duct-interrupted” sign to differentiate between PDAC from IPP for the three readers were 29–53%, 89–95%, 56–82% and 73–81%, respectively (κ = 0.41); for the “corona” sign, they were 29–53%, 81–100%, 56–100%, and 75–78%, respectively (κ = 0.4), and for the “attraction” sign, they were 20–25%, 71–82%, 64–75%, and 31–34%, respectively (κ = 0.54). Conclusion: The “duct-interrupted” and “corona” MRCP signs have high specificity for diagnosing PDAC, while the “attraction” sign has good specificity for identifying IPP.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2022

An adaptive stochastic sequential quadratic programming with differentiable exact augmented lagrangians

In this study, we consider solving nonlinear optimization problems with a stochastic objective and deterministic equality constraints. We assume for the objective that its evaluation, gradient, and Hessian are inaccessible, while one can compute their stochastic estimates by, for example, subsampling. We propose a stochastic algorithm based on sequential quadratic programming (SQP) that uses a differentiable exact augmented Lagrangian as the merit function. To motivate our algorithm design, we first revisit and simplify an old SQP method Lucidi developed for solving deterministic problems, which serves as the skeleton of our stochastic algorithm. Based on the simplified deterministic algorithm, we then propose a non-adaptive SQP for dealing with stochastic objective, where the gradient and Hessian are replaced by stochastic estimates but the stepsizes are deterministic and prespecified. Finally, we incorporate a recent stochastic line search procedure Paquette and Scheinberg into the non-adaptive stochastic SQP to adaptively select the random stepsizes, which leads to an adaptive stochastic SQP. The global "almost sure" convergence for both non-adaptive and adaptive SQP methods is established. Numerical experiments on nonlinear problems in CUTEst test set demonstrate the superiority of the adaptive algorithm.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2018

Development of a Computer-Aided Differential Diagnosis System to Distinguish Between Usual Interstitial Pneumonia and Non-specific Interstitial Pneumonia Using Texture- and Shape-Based Hierarchical Classifiers on HRCT Images

A computer-aided differential diagnosis (CADD) system that distinguishes between usual interstitial pneumonia (UIP) and non-specific interstitial pneumonia (NSIP) using high-resolution computed tomography (HRCT) images was developed, and its results compared against the decision of a radiologist. Six local interstitial lung disease patterns in the images were determined, and 900 typical regions of interest were marked by an experienced radiologist. A support vector machine classifier was used to train and label the regions of interest of the lung parenchyma based on the texture and shape characteristics. Based on the regional classifications of the entire lung using HRCT, the distributions and extents of the six regional patterns were characterized through their CADD features. The disease division index of every area fraction combination and the asymmetric index between the left and right lungs were also evaluated. A second SVM classifier was employed to classify the UIP and NSIP, and features were selected through sequential-forward floating feature selection. For the evaluation, 54 HRCT images of UIP (n = 26) and NSIP (n = 28) patients clinically diagnosed by a pulmonologist were included and evaluated. The classification accuracy was measured based on a fivefold cross-validation with 20 repetitions using random shuffling. For comparison, thoracic radiologists assessed each case using HRCT images without clinical information or diagnosis. The accuracies of the radiologists’ decisions were 75 and 87%. The accuracies of the CADD system using different features ranged from 70 to 81%. Finally, the accuracy of the proposed CADD system after sequential-forward feature selection was 91%.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Combination of Mesenchymal Stromal Cells and Cardiac Stem Cells in a Multilayer Cell Construct Promotes Activation of Notch Signaling and Initiation of Endothelial Differentiation

We showed the possibility of generating combined tissue-engineered cell consisting of layers of rat cardiac stem cells and mesenchymal stromal cells from the adipose tissue. Cell—cell interaction within the cell sheet promoted proliferation of cardiac stem cells, expression of endothelial differentiation marker ETS1, and Notch signaling activation. The obtained results provide new insights into possible mechanisms of stimulation of endogenous regeneration processes after myocardial damage and demonstrate potential of cell-based cardiomyoplasty with the use of these combined cell sheets.

60 APPLIED LIFE SCIENCES↗