6,503 research outputs found
Searches for TeV-scale particles at the LHC using jet shapes
New particles at the TeV scale can decay hadronically with strongly
collimated jets, thus the standard reconstruction methods based on
invariant-masses of well-separated jets can fail. We discuss how to identify
such particles in pp collisions at the LHC using jet shapes which help to
reduce the contribution of QCD-induced events. We focus on a rather generic
example X to ttbar to hadrons, with X being a heavy particle, but the approach
is well suited for reconstruction of other decay channels characterized by a
cascade decay of known states.Comment: 14 pages, 6 figure
Precision searches in dijets at the HL-LHC and HE-LHC
This paper explores the physics reach of the High-Luminosity Large Hadron
Collider (HL-LHC) for searches of new particles decaying to two jets. We
discuss inclusive searches in dijets and b-jets, as well as searches in
semi-inclusive events by requiring an additional lepton that increases
sensitivity to different aspects of the underlying processes. We discuss the
expected exclusion limits for generic models predicting new massive particles
that result in resonant structures in the dijet mass. Prospects of the
Higher-Energy LHC (HE-LHC) collider are also discussed. The study is based on
the Pythia8 Monte Carlo generator using representative event statistics for the
HL-LHC and HE-LHC running conditions. The event samples were created using
supercomputers at NERSC.Comment: 27 pages, 19 figure
The hypertoric intersection cohomology ring
We present a functorial computation of the equivariant intersection
cohomology of a hypertoric variety, and endow it with a natural ring structure.
When the hyperplane arrangement associated with the hypertoric variety is
unimodular, we show that this ring structure is induced by a ring structure on
the equivariant intersection cohomology sheaf in the equivariant derived
category. The computation is given in terms of a localization functor which
takes equivariant sheaves on a sufficiently nice stratified space to sheaves on
a poset.Comment: Significant revisions in Section 5, with several corrected proof
Poisson-de Rham homology of hypertoric varieties and nilpotent cones
We prove a conjecture of Etingof and the second author for hypertoric
varieties, that the Poisson-de Rham homology of a unimodular hypertoric cone is
isomorphic to the de Rham cohomology of its hypertoric resolution. More
generally, we prove that this conjecture holds for an arbitrary conical variety
admitting a symplectic resolution if and only if it holds in degree zero for
all normal slices to symplectic leaves.
The Poisson-de Rham homology of a Poisson cone inherits a second grading. In
the hypertoric case, we compute the resulting 2-variable Poisson-de
Rham-Poincare polynomial, and prove that it is equal to a specialization of an
enrichment of the Tutte polynomial of a matroid that was introduced by Denham.
We also compute this polynomial for S3-varieties of type A in terms of Kostka
polynomials, modulo a previous conjecture of the first author, and we give a
conjectural answer for nilpotent cones in arbitrary type, which we prove in
rank less than or equal to 2.Comment: 25 page
Studies on the hyperplasia ('regeneration') of the rat liver following partial hepatectomy. Changes in lipid peroxidation and general biochemical aspects
Using the experimental model of partial hepatectomy in the rat, we have examined the relationship between cell division and lipid peroxidation activity. In rats entrained to a regime of 12 h light/12 h dark and with a fixed 8 h feeding period in the dark phase, partial hepatectomy is followed by a rapid regeneration of liver mass with cycles of synchronized cell division at 24 h intervals. The latter phenomenon is indicated in this study by pulses of thymidine kinase activity having maxima at 24 h, 48 h and 72 h after partial hepatectomy. Microsomes prepared from regenerating livers show changes in lipid peroxidation activity (induced by NADPH/ADP/iron or by ascorbate/iron), which is significantly decreased relative to that in microsomes from sham-operated controls, again at 24 h, 48 h and 72 h after the operation. This phenomenon has been investigated with regard to possible underlying changes in the content of microsomal fatty acids, the microsomal enzymes NADPH:cytochrome c reductase and cytochrome P-450, and the physiological microsomal antioxidant alpha-tocopherol. The cycles of decreased lipid peroxidation activity are apparently due, at least in part, to changes in microsomal alpha-tocopherol content that are closely associated in time with thymidine kinase activity
The design and relevance of a computerised therapy program for indigenous MÄori adolescents.
Background: Depression is a major health issue among MÄori indigenous adolescents, yet there has been little investigation into the relevance or effectiveness of psychological treatments for them. Further, consumer views are critical for engagement and adherence to therapy. However, there is little research regarding indigenous communitiesā opinions about psychological interventions for depression.
Objective: The objective of this study was to conduct semistructured interviews with MÄori (indigenous New Zealand) young people (taitamariki) and their families to find out their opinions of a prototype computerized cognitive behavioral therapy (cCBT) program called Smart, Positive, Active, Realistic, X-factor thoughts (SPARX), a free online computer game intended to help young persons with mild to moderate depression, feeling down, stress or anxiety. The program will teach them how to resolve their issues on their own using Cognitive Behavioural Therapy as psychotherapeutic approach.
Methods: There were seven focus groups on the subject of the design and cultural relevance of SPARX that were held, with a total of 26 participants (19 taitamarki, 7 parents/caregivers, all MÄori). There were five of the groups that were with whÄnau (family groups) (n=14), one group was with MÄori teenage mothers (n=4), and one group was with taitamariki (n=8). The general inductive approach was used to analyze focus group data.
Results: SPARX computerized therapy has good face validity and is seen as potentially effective and appealing for MÄori people. Cultural relevance was viewed as being important for the engagement of MÄori young people with SPARX. WhÄnau are important for young peoplesā well-being. Participants generated ideas for improving SPARX for MÄori and for the inclusion of whÄnau in its delivery.
Conclusions: SPARX computerized therapy had good face validity for indigenous young people and families. In general, MÄori participants were positive about the SPARX prototype and considered it both appealing and applicable to them. The results of this study were used to refine SPARX prior to it being delivered to taitamariki and non-MÄori young people
Measuring Hacking Ability Using a Conceptual Expertise Task
Hackers pose a continuous and unrelenting threat to organizations. Industry and academic researchers alike can benefit from a greater understanding of how hackers engage in criminal behavior. A limiting factor of hacker research is the inability to verify that self-proclaimed hackers participating in research actually possess their purported knowledge and skills. This paper presents current work in developing and validating a conceptual-expertise based tool that can be used to discriminate between novice and expert hackers. The implications of this work are promising since behavioral information systems researchers operating in the information security space will directly benefit from the validation of this tool.
Keywords: hacker ability, conceptual expertise, skill measuremen
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