24 research outputs found
pQCD at the Kinematical Boundary of its Applicability
I examines the applicability and possible need for a re-formulation of pQCD,
as we know it, in the DIS limit of small and . Gluon saturation,
implied by s-channel unitarity, and its possible experimental signatures are
critically assessed.Comment: 6 pages, 4 figure (in ps) talk given at XXXI International Symposium
on Multiparticle Dynamics, Sep. 1-7, 2001, Datong China URL
http://ismd31.ccnu.edu.cn
Soft Scattering Re - Visited
An updated formulation of soft diffraction, compatible with and channel unitarity, is presented. Its consequent general soft scattering features at high energies are explored. The critical interplay between theory and data analysis and its consequent implications with regards to the theoretical foundations of soft scattering theory are discussed
Efficient Long-Text Understanding with Short-Text Models
Transformer-based pretrained language models (LMs) are ubiquitous across
natural language understanding, but cannot be applied to long sequences such as
stories, scientific articles and long documents, due to their quadratic
complexity. While a myriad of efficient transformer variants have been
proposed, they are typically based on custom implementations that require
expensive pretraining from scratch. In this work, we propose SLED:
SLiding-Encoder and Decoder, a simple approach for processing long sequences
that re-uses and leverages battle-tested short-text pretrained LMs.
Specifically, we partition the input into overlapping chunks, encode each with
a short-text LM encoder and use the pretrained decoder to fuse information
across chunks (fusion-in-decoder). We illustrate through controlled experiments
that SLED offers a viable strategy for long text understanding and evaluate our
approach on SCROLLS, a benchmark with seven datasets across a wide range of
language understanding tasks. We find that SLED is competitive with specialized
models that are up to 50x larger and require a dedicated and expensive
pretraining step.Comment: Accepted for publication in Transactions of the Association for
Computational Linguistics (TACL), 2023. Authors' final version (pre-MIT
ZeroSCROLLS: A Zero-Shot Benchmark for Long Text Understanding
We introduce ZeroSCROLLS, a zero-shot benchmark for natural language
understanding over long texts, which contains only test and small validation
sets, without training data. We adapt six tasks from the SCROLLS benchmark, and
add four new datasets, including two novel information fusing tasks, such as
aggregating the percentage of positive reviews. Using ZeroSCROLLS, we conduct a
comprehensive evaluation of both open-source and closed large language models,
finding that Claude outperforms ChatGPT, and that GPT-4 achieves the highest
average score. However, there is still room for improvement on multiple open
challenges in ZeroSCROLLS, such as aggregation tasks, where models struggle to
pass the naive baseline. As the state of the art is a moving target, we invite
researchers to evaluate their ideas on the live ZeroSCROLLS leaderboard.Comment: Findings of EMNLP 202
An Investigation of the Hard Contribution to phi Photoproduction
We investigate the possibility that the process of phi photoproduction may
have a significant hard perturbative QCD component. This suggestion is based on
a study of the energy dependence of the forward phi photoproduction cross
section followed by a calculation where we show that a coherent sum of the pQCD
and conventional soft Pomeron contributions provides an excellent reproduction
of the experimental data. Our results suggest that the transition from the
predominantly soft photoproduction of light rho and omega vector mesons to the
predominantly hard photoproduction of heavy J/psi and upsilon is smooth and
gradual, similar to the transition observed in deep inelastic scattering
studies of the proton structure function in the small x limit. Our predictions
for higher HERA energies are presented.Comment: 14 pages including 5 postscript figure
Inclusive production in a QCD and N=4 SYM motivated model for soft interactions
The results presented in this paper differ from our previous unsuccessful
attempt to predict the rapidity distribution at . The original
version of our model (GLMM) only summed a particular class of Pomeron diagrams
(enhanced diagrams). We believe that this was the reason for our failure to
describe the inclusive LHC data. We have developed a new approach
(GLM) that also includes the summation of the semi-enhanced diagrams.This
contribution is essential for a successful description of the inclusive
distributions, which is presented here.Comment: 4 pages, 3 figure