7,723 research outputs found
Perturbative estimates of the eigenfunctions of the non-forward BFKL kernel
No full textWe discuss, within the context of first order perturbation theory, the correction to the NLO BFKL wavefunction for scattering processes with non-zero momentum transfer, arising from the fact that in NLO the kernel is not covariant under conformal transformations
The Role of Evidence in Establishing Trust in Repositories
No full textThis article arises from work by the Digital Curation Centre (DCC) Working Group examining mechanisms to roll out audit and certification services for digital repositories in the United Kingdom. Our attempt to develop a program for applying audit and certification processes and tools took as its starting point the RLG-NARA Audit Checklist for Certifying Digital Repositories. Our intention was to appraise critically the checklist and conceive a means of applying its mechanics within a diverse range of repository environments. We were struck by the realization that while a great deal of effort has been invested in determining the characteristics of a 'trusted digital repository', far less effort has concentrated on the ways in which the presence of the attributes can be demonstrated and their qualities measured. With this in mind we sought to explore the role of evidence within the certification process, and to identify examples of the types of evidence (e.g., documentary, observational, and testimonial) that might be desirable during the course of a repository audit.
On the top-antitop invariant mass spectrum at the LHC from a Higgs boson signal perspective
No full textMSSM effects in top-antitop production at the LHC
No full textWe report on a calculation of the effects of supersymmetry on the cross-section for top-antitop production at LHC. A numerical study is carried out for the ten benchmarks of the Snowmass accord. It is found that the higher order effects involving supersymmetric particles in internal loops can be as high as 6%, both for the cross-section and the (parity even) helicity asymmetry, for one particular benchmark. For other benchmarks smaller but nonetheless observable corrections are found
A light Higgs boson would invite supersymmetry
No full textIf the Higgs boson weighs about 115 GeV, the effective potential of the Standard Model becomes unstable above a scale ofabout 106 GeV. This instability may be rectified only by new bosonic particles such as stop squarks. However, avoiding theinstability requires fine-tuning of the model couplings, in particular if the theory is not to become non-perturbative before the Planck scale. Such fine-tuning is automatic in a supersymmetric model, but is lost if there are no higgsinos. A light Higgs bosonwould be prima facie evidence for supersymmetry in the top-quark and Higgs sectors
, Ross Laird
No full textRoss Laird, PhD RCC is a clinical consultant focused on trauma, addictions, and social vulnerability. He is also a best-selling author, award-winning scholar and educator, and clinical supervisor for BC’s largest licensed non-profit program in addictions, trauma, and mental health. Dr. Laird focuses particularly on traumatized and marginalized client populations — those navigating homelessness, mental illness, and complex trauma — and provides professional development training for organizations that serve them: social service agencies, first responders, cultural groups, nonprofits, and educational institutions. He also works extensively with organizations in arts and culture and Indigenous communities to develop trauma-informed practices for cultural programming, museum exhibitions, and community initiatives
Erratum to: “Weak corrections to gluon-induced top–antitop hadro-production” [Phys. Lett. B 639 (2006) 513]
No full textAbstractThis is an Erratum to a Letter of ours [S. Moretti, M.R. Nolten, D.A. Ross, Phys. Lett. B 639 (2006) 513]. After its publication, we have discovered a mistake in a numerical program that affects the results presented therein. We provide here the corrected version
Weak effects in proton beam asymmetries at polarised RHIC and beyond
No full textWe report on a calculation of the full one-loop weak corrections through the order to parton–parton scattering in all possible channels at the Relativistic Heavy Ion Collider (RHIC) running with polarised pp beams (RHIC-Spin). This study extends the analysis previously carried out for the case of 2?2 subprocesses with two external gluons, by including all possible four-quark modes with and without an external gluon. The additional contributions due to the new four-quarks processes are extremely large, of order 50 to 100% (of either sign), not only in the case of parity-violating beam asymmetries but also for the parity-conserving ones and (although to a more limited extent) the total cross section. Such effects on the CP-violating observables would be an astounding 5 times larger for the case of the LHC with polarised beams—which has been discussed as one of the possible upgrades of the CERN machine—whereas they would be much reduced for the case of the CP-conserving ones as well as the cross section
One-loop weak corrections to three-jet observables at the Z pole
No full textWe briefly illustrate the impact of the genuinely weak one-loop virtual terms of the O (αS αEW3) factorisable corrections to the three-jet cross section at √s = MZ. Their importance for the measurement of αS at GigaZ luminosities is emphasised
Weak corrections to gluon-induced top-antitop hadro-production
No full textWe calculate purely weak virtual one-loop corrections to the production cross section of top–antitop pairs at the Large Hadron Collider via the gluon–gluon fusion subprocess. We find very small negative corrections to the total cross section, of order ?0.6%, but significantly larger effects to the differential one, particularly in the transverse momentum distribution, of order ?5% to ?10% (in observable regions). In case of parity-conserving spin-asymmetries of the final state, corrections are typically of a few negative percent, with the exception of positive and negative peaks at +12% and ?5%, respectively (near where the tree-level predictions change sign), while those arising in parity-violating asymmetries (which are identically zero in QCD) are typically at a level of a few permille
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