Optimal transport for a novel event description at hadron colliders

We propose a novel strategy for disentangling proton collisions at hadron colliders such as the LHC that considerably improves over the current state of the art. Employing a metric inspired by optimal transport problems as the cost function of a graph neural network, our algorithm is able to compare two particle collections with different noise levels and learns to flag particles originating from the main interaction amidst products from up to 200 simultaneous pileup collisions. We thereby sidestep the critical task of obtaining a ground truth by labeling particles and avoid arduous human annotation in favor of labels derived in situ through a self-supervised process. We demonstrate how our approach—which, unlike competing algorithms, is trivial to implement—improves the resolution in key objects used in precision measurements and searches alike and present large sensitivity gains in searching for exotic Higgs boson decays at the High-Luminosity LHC

‘I never realised everybody felt as happy as I do when I am around autistic people’: A thematic analysis of autistic adults’ relationships with autistic and neurotypical friends and family

AbstractMany autistic people are motivated to have friends, relationships and close family bonds, despite the clinical characterisation of autism as a condition negatively affecting social interaction. Many first-hand accounts of autistic people describe feelings of comfort and ease specifically with other autistic people. This qualitative research explored and contrasted autistic experiences of spending social time with neurotypical and autistic friends and family. In total, 12 autistic adults (10 females, aged 21–51) completed semi-structured interviews focused on time spent with friends and family; positive and negative aspects of time spent with neurotypical and autistic friends and family; and feelings during and after spending time together. Three themes were identified: cross-neurotype understanding, minority status and belonging. Investigation of these themes reveals the benefits of autistic people creating and maintaining social relationships with other autistic people, in a more systematic way than previous individual reports. They highlight the need for autistic-led social opportunities and indicate benefits of informal peer support for autistic adults.Lay abstractAlthough autistic people may struggle to interact with others, many autistic people have said they find interacting with other autistic people more comfortable. To find out whether this was a common experience, we did hour-long interviews with 12 autistic adults. We asked them questions about how it feels when spending time with their friends and family, and whether it felt different depending on whether the friends and family were autistic or neurotypical. We analysed the interviews and found three common themes in what our participants said. First, they found spending with other autistic people easier and more comfortable than spending time with neurotypical people, and felt they were better understood by other autistic people. Second, autistic people often felt they were in a social minority, and in order to spend time with neurotypical friends and family, they had to conform with what the neurotypical people wanted and were used to. Third, autistic people felt like they belonged with other autistic people and that they could be themselves around them. These findings show that having time with autistic friends and family can be very beneficial for autistic people and played an important role in a happy social life

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum