Search results for "variance"
showing 10 items of 2030 documents
Validation of the Italian version of the abbreviated expanded prostate Cancer index composite (EPIC-26) in men with prostate Cancer
2019
Abstract Background This study aims to validate and evaluate the psychometric properties and reliability of the Italian version of the Expanded Prostate Cancer Index Composite – Short Form (EPIC-26), a measure of quality of life (QoL) for prostate cancer patients. Methods Two hundred and eighty-four prostate cancer patients completed the Italian version of the EPIC-26 questionnaire at 45 days (T1) and 3 months (T2) after robot-assisted radical prostatectomy (RARP). Psychometric properties were evaluated using structural equation modeling: the goodness of fit of the correlated five-factor model (CFFM) for the EPIC-26 was assessed using the confirmatory factor analysis (CFA), while longitudin…
Resilience as a predictor of Quality of Life in participants with borderline personality disorder before and after treatment.
2021
Abstract Background Studies have suggested that psychotherapy improves the Quality of Life (QoL) of participants with Borderline Personality Disorder (BPD). However, there are no studies on the differential efficacy of treatments on the QoL of participants with BPD. Moreover, the relationship between QoL and resilience has rarely been studied in participants with BPD. Objectives: a) to examine whether people with BPD have worse QoL than the non-clinical population; b) to examine whether there are statistically significant differences between Dialectical Behavioural Therapy (DBT), Systems Training for Emotional Predictability and Problem Solving (STEPPS), or Cognitive Behavioural Therapy-Tre…
Recovering Quantum Properties of Continuous-Variable States in the Presence of Measurement Errors.
2016
We present two results which combined enable one to reliably detect multimode, multipartite entanglement in the presence of measurement errors. The first result leads to a method to compute the best (approximated) physical covariance matrix given a measured non-physical one. The other result states that a widely used entanglement condition is a consequence of negativity of partial transposition. Our approach can quickly verify entanglement of experimentally obtained multipartite states, which is demonstrated on several realistic examples. Compared to existing detection schemes, ours is very simple and efficient. In particular, it does not require any complicated optimizations.
Pionic effects in deep inelastic scattering off nuclei
1992
The structure functions calculated in the Chiral bag model reproduce quite well, after appropriate perturbative evolution to large energy scales, the experimental data. We use these results to interpret the structure of the $EMC$ data as a quenching of the pion decay constant due to the in medium behavior of the nucleon. This explanation supports recent proposals of this phenomenon whose origin is the scale invariance of the $QCD$ lagrangian.
Non-Markovianity of Gaussian Channels
2015
We introduce a necessary and sufficient criterion for the non-Markovianity of Gaussian quantum dynamical maps based on the violation of divisibility. The criterion is derived by defining a general vectorial representation of the covariance matrix which is then exploited to determine the condition for the complete positivity of partial maps associated to arbitrary time intervals. Such construction does not rely on the Choi-Jamiolkowski representation and does not require optimization over states.
Electromagnetic lattice gauge invariance in two-dimensional discrete-time quantum walks
2018
International audience; Gauge invariance is one of the more important concepts in physics. We discuss this concept in connection with the unitary evolution of discrete-time quantum walks in one and two spatial dimensions, when they include the interaction with synthetic, external electromagnetic fields. One introduces this interaction as additional phases that play the role of gauge fields. Here, we present a way to incorporate those phases, which differs from previous works. Our proposal allows the discrete derivatives, that appear under a gauge transformation, to treat time and space on the same footing, in a way which is similar to standard lattice gauge theories. By considering two step…
Massive quarks in NLO dipole factorization for DIS : Longitudinal photon
2021
In this work, we will present the first complete calculation of the one-loop longitudinal photon-to-quark-antiquark light cone wave function, with massive quarks. The quark masses are renormalized in the pole mass scheme. The result is used to calculate the next-to-leading order correction to the high energy Deep Inelastic Scattering longitudinal structure function on a dense target in the dipole factorization framework. For massless quarks the next-to-leading order correction was already known to be sizeable, and our result makes it possible to evaluate it also for massive quarks.
On the Pauli-Villars regularisation scheme in the NJL model
1993
Abstract We consider the Nambu-Jona-Lasinio model with a Pauli-Villars cutoff. We point out that previous attempts to use this regularisation have not been consistent and it is shown that if used correctly this approach yields very reasonable values for the cutoff parameter and quark condensate when we demand that ƒπ is fixed to its experimental value. Finally it is argued that because of its covariance and smooth nature this regularisation scheme has significant advantages over other regulators on the market.
The soliton-soliton interaction in the Chiral Dilaton Model
2012
We study the interaction between two B = 1 states in the Chiral Dilaton Model where baryons are described as nontopological solitons arising from the interaction of chiral mesons and quarks. By using the hedgehog solution for B = 1 states we construct, via a product ansatz, three possible B = 2 configurations to analyse the role of the relative orientation of the hedgehog quills in the dynamics of the soliton-soliton interaction and investigate the behavior of these solutions in the range of long/intermediate distance. One of the solutions is quite binding due to the dynamics of the pi and sigma fields at intermediate distance and should be used for nuclear matter studies. Since the product…
Fitting strategies to extract the axial charge of the nucleon from lattice QCD
2014
We report on a comparison of several fit methods used for the extraction of the nucleon axial charge gA from lattice QCD with two dynamical flavours of O(a) improved Wilson quarks. We use plateau fits, summed operator insertions (the summation method) and a new “midpoint” method to investigate contributions from excited states that affect the determination of gA. We also present a method to perform correlated fits when the standard estimator for the inverse of the covariance matrix becomes unstable.