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Daniel Hayden

Publications and source records attributed to Daniel Hayden.

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Further Reduction of the PDF Uncertainty in the High-Mass Drell-Yan Spectrum Utilizing Neutral and Charged Current Inputs

Uncertainties in the parametrization of Parton Distribution Functions are a serious limiting systematic uncertainty in Large Hadron Collider searches for Beyond the Standard Model physics. This is especially true for measurements at high scales induced by quark and anti-quark collisions, where Drell-Yan continuum backgrounds are dominant. In Phys. Rev. D99, 054004 (2019) we presented a unique strategy for improving uncertainties using neutral current Drell-Yan backgrounds and here we update that strategy and include charged current Drell-Yan final states in the program and demonstrate significant improvements. Through a judicious selection of measurable kinematical quantities can reduce the assigned systematic PDF uncertainties by significant factors in limit-setting or discovery for neutral and charged, high mass Intermediate Vector Bosons. This approach will be take advantage of the huge statistical precision of future High Luminosity, Large Hadron Collider Standard Model datasets and could also improve uncertainties in the high statistics results from LHC Run 3.

hep-ph

Probing Parton distribution functions at large x via Drell-Yan Forward-Backward Asymmetry

The forward-backward asymmetry of the Drell-Yan process in dilepton decays at high invariant masses can be used to probe the parton distribution functions at large x. The behavior of three modern PDF sets (CT18NNLO, MSHT20, and NNPDF4.0) are compared, and updated under various scenarios via ePump using proton-proton collision pseudo-data generated at sqrt(s) = 13 TeV with 3000 fb^{-1} of integrated luminosity.

hep-ph

Summarizing experimental sensitivities of collider experiments to dark matter models and comparison to other experiments

Comparisons of the coverage of current and proposed dark matter searches can help us to understand the context in which a discovery of particle dark matter would be made. In some scenarios, a discovery could be reinforced by information from multiple, complementary types of experiments; in others, only one experiment would see a signal, giving only a partial, more ambiguous picture; in still others, no experiment would be sensitive and new approaches would be needed. In this whitepaper, we present an update to a similar study performed for the European Strategy Briefing Book performed within the dark matter at the Energy Frontier (EF10) Snowmass Topical Group We take as a starting point a set of projections for future collider facilities and a method of graphical comparisons routinely performed for LHC DM searches using simplified models recommended by the LHC Dark Matter Working Group and also used for the BSM and dark matter chapters of the European Strategy Briefing Book. These comparisons can also serve as launching point for cross-frontier discussions about dark matter complementarity.

hep-ph

A New Method for Reducing PDF Uncertainties in the High-Mass Drell-Yan Spectrum

Uncertainties in the parametrization of Parton Distribution Functions (PDFs) are becoming a serious limiting systematic uncertainty in Large Hadron Collider (LHC) searches for Beyond the Standard Model physics. This is especially true for measurements at high scales induced by quark and anti-quark collisions, where Drell-Yan continuum backgrounds are dominant. Tools are recently available which enable exploration of PDF fitting strategies and emulate the effects of new data in a future global fit. ePump is such a tool and it is shown that judicious selection of measurable kinematical quantities can reduce the assigned systematic PDF uncertainties by significant factors. This will be made possible by the huge statistical precision of future LHC Standard Model datasets.

hep-ex

Z Prime: A Story

This is an imaginary story that could come to pass involving a detector, a Boson, and good resolution. It was written for Snowmass 2013, as a white paper for the New Physics group. The story describes a scenario in which nature has designated the existence of a Left-Right Symmetric Model Z' at a pole mass of 3 TeV, which is observed by analysers through the dilepton decay channel. Signal and Background samples were generated for a proton-proton collider at $\sqrt{s}$ = 14 TeV and $\sqrt{s}$ = 33 TeV, with enough events to represent a dataset of up to 3000 fb$^{-1}$ for each centre of mass energy. These samples were passed through the Delphes fast simulation framework to produce detector reconstructed events. The story is played out from first hints to a well established new discovery with plentiful data, and attempts to capture the journey and excitement that this entails.

hep-ex

A Search for Heavy Resonances in the Dilepton Channel

There are many extensions to the Standard Model of particle physics which predict the addition of a U(1) symmetry, and/or extra spatial dimensions, which give rise to new high mass resonances such as the Z' and Randall-Sundrum graviton. The LHC provides a unique opportunity to explore the TeV scale where these phenomena may become apparent, and can be searched for using the precision tracking and high energy resolution calorimetry of the ATLAS detector. This poster presents the search for high mass resonances in the dilepton channel, and was conducted with an integrated luminosity of 1.08/1.21 fb-1 in the dielectron/dimuon channel respectively, at a centre of mass energy \surd s = 7 TeV.

hep-ex