704 research outputs found
Interpretations of the ATLAS Diboson Anomaly
Recently, the ATLAS Collaboration recorded an interesting anomaly in diboson
production with excesses at the diboson invariant mass around 2 TeV in boosted
jets of all the , , and channels. We offer a theoretical
interpretation of the anomaly using a phenomenological right-handed model with
extra and bosons. Constraints from narrow total decay widths, dijet
cross sections, and production are taken into account. We also
comment on a few other possibilities.Comment: v4: match the published version; v3: 18 pages, 6 figures, change to
leptophobic Z' model to take into account the EW constraints, and some
updates to the analysis and text; v2: 17 pages, 7 figures; a new section and
a new figure are added; correct the statement about the WH; references are
also adde
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Asking ‘what it does’ rather than ‘what it is’: the invisibility and opportunity of Taiwan’s role on the global health stage
In 2017, some twenty Taiwanese students from diverse disciplinary backgrounds formed a study group: medicine, epidemiology, law, sociology, politics, and geography. Its overall objective is to understand better what has been referred to as ‘global health’. For that, we have been thinking of a difficult yet crucial question: what is global health, and why should we, as Taiwanese citizens, need to study it? In this article, we reflect on our motivations and discussions. We began by reading the text ‘Governing Global Health: Who Runs the World and Why?’, which compares the activities of different global health actors – intergovernmental and nongovernmental – and their relationships with nations states. Building on this approach, in this article we will draw on the limitations and opportunities for Taiwan to take part in the contemporary global health system
The Top Window for dark matter
We investigate a scenario that the top quark is the only window to the dark
matter particle. We use the effective Lagrangian approach to write down the
interaction between the top quark and the dark matter particle. Requiring the
dark matter satisfying the relic density we obtain the size of the effective
interaction. We show that the scenario can be made consistent with the direct
and indirect detection experiments by adjusting the size of the effective
coupling. Finally, we calculate the production cross section for at the Large Hadron Collider (LHC), which will give rise to an
interesting signature of a top-pair plus large missing energy.Comment: 17 pages including 8 figures; added references and a footnot
Gamma-ray Constraints on Effective Interactions of the Dark Matter
Using an effective interaction approach to describe the interactions between
the dark matter particle and the light degrees of freedom of the standard
model, we calculate the gamma-ray flux due to the annihilation of the dark
matter into quarks, followed by fragmentation into neutral pions which
subsequently decay into photons. By comparison to the mid-latitude data
released from the Fermi-LAT experiment, we obtain useful constraints on the
size of the effective interactions and they are found to be comparable to those
deduced from collider, gamma-ray line and anti-matter search experiments.
However, the two operators induced by scalar and vector exchange among
fermionic dark matter and light quarks that contribute to spin-independent
cross sections are constrained more stringently by the recent XENON100 data.Comment: 22 pages, 4 figures; title fixed and a couple of references adde
AV-SUPERB: A Multi-Task Evaluation Benchmark for Audio-Visual Representation Models
Audio-visual representation learning aims to develop systems with human-like
perception by utilizing correlation between auditory and visual information.
However, current models often focus on a limited set of tasks, and
generalization abilities of learned representations are unclear. To this end,
we propose the AV-SUPERB benchmark that enables general-purpose evaluation of
unimodal audio/visual and bimodal fusion representations on 7 datasets covering
5 audio-visual tasks in speech and audio processing. We evaluate 5 recent
self-supervised models and show that none of these models generalize to all
tasks, emphasizing the need for future study on improving universal model
performance. In addition, we show that representations may be improved with
intermediate-task fine-tuning and audio event classification with AudioSet
serves as a strong intermediate task. We release our benchmark with evaluation
code and a model submission platform to encourage further research in
audio-visual learning.Comment: Submitted to ICASSP 2024; Evaluation Code:
https://github.com/roger-tseng/av-superb Submission Platform:
https://av.superbbenchmark.or
Global Study of the Simplest Scalar Phantom Dark Matter Model
We present a global study of the simplest scalar phantom dark matter model.
The best fit parameters of the model are determined by simultaneously imposing
(i) relic density constraint from WMAP, (ii) 225 live days data from direct
experiment XENON100, (iii) upper limit of gamma-ray flux from Fermi-LAT
indirect detection based on dwarf spheroidal satellite galaxies, and (iv) the
Higgs boson candidate with a mass about 125 GeV and its invisible branching
ratio no larger than 40% if the decay of the Higgs boson into a pair of dark
matter is kinematically allowed. The allowed parameter space is then used to
predict annihilation cross sections for gamma-ray lines, event rates for three
processes mono-b jet, single charged lepton and two charged leptons plus
missing energies at the Large Hadron Collider, as well as to evaluate the muon
anomalous magnetic dipole moment for the model.Comment: Matches JCAP accepted version. 25 pages, 7 figure
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