4 research outputs found
Difficulties in the description of Drell-Yan processes at moderate invariant mass and high transverse momentum
We study the Drell-Yan cross section differential with respect to the
transverse momentum of the produced lepton pair. We consider data with moderate
invariant mass Q of the lepton pair, between 4.5 GeV and 13.5 GeV, and similar
(although slightly smaller) values of the transverse momentum q_T. We approach
the problem by deriving predictions based on standard collinear factorization,
which are expected to be valid toward the high-q_T end of the spectrum and to
which any description of the spectrum at lower q_T using transverse-momentum
dependent parton distributions ultimately needs to be matched. We find that the
collinear framework predicts cross sections that in most cases are
significantly below available data at high q_T. We discuss additional
perturbative and possible non-perturbative effects that increase the predicted
cross section, but not by a sufficient amount
Pretraining is All You Need: A Multi-Atlas Enhanced Transformer Framework for Autism Spectrum Disorder Classification
Autism spectrum disorder (ASD) is a prevalent psychiatric condition
characterized by atypical cognitive, emotional, and social patterns. Timely and
accurate diagnosis is crucial for effective interventions and improved outcomes
in individuals with ASD. In this study, we propose a novel Multi-Atlas Enhanced
Transformer framework, METAFormer, ASD classification. Our framework utilizes
resting-state functional magnetic resonance imaging data from the ABIDE I
dataset, comprising 406 ASD and 476 typical control (TC) subjects. METAFormer
employs a multi-atlas approach, where flattened connectivity matrices from the
AAL, CC200, and DOS160 atlases serve as input to the transformer encoder.
Notably, we demonstrate that self-supervised pretraining, involving the
reconstruction of masked values from the input, significantly enhances
classification performance without the need for additional or separate training
data. Through stratified cross-validation, we evaluate the proposed framework
and show that it surpasses state-of-the-art performance on the ABIDE I dataset,
with an average accuracy of 83.7% and an AUC-score of 0.832. The code for our
framework is available at https://github.com/Lugges991/METAForme
Difficulties in the description of Drell-Yan processes at moderate invariant mass and high transverse momentum
Difficulties in the description of Drell-Yan processes at low invariant mass and high transverse momentum
We study the Drell-Yan cross section differential with respect to the transverse momentum of the produced lepton pair. We consider data with moderate invariant mass Q of the lepton pair, between 4.5 GeV and 13.5 GeV, and similar (although slightly smaller) values of the transverse momentum qT . We approach the problem by deriving predictions based on standard collinear factorization, which are expected to be valid toward the high-qT end of the spectrum and to which any description of the spectrum at lower qT based on transverse-momentum dependent parton distributions ultimately needs to be matched. We find that the collinear framework predicts cross sections that in most cases are significantly below available data at high qT . We discuss additional perturbative and possible non-perturbative effects that increase the predicted cross section, but not by a sufficient amount