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Anders Ryd

Publications and source records attributed to Anders Ryd.

7 recordsLinked to original sources
arXiv2022

Strange quark as a probe for new physics in the Higgs sector

This paper describes a novel algorithm for tagging jets originating from the hadronisation of strange quarks (strange-tagging) with the future International Large Detector (ILD) at the International Linear Collider (ILC). It also presents the first application of such a strange-tagger to a Higgs to strange ($h \rightarrow s\bar{s}$) analysis with the $P(e^-,e^+) = (-80\%,+30\%)$ polarisation scenario, corresponding to 900 fb$^{-1}$ of the initial proposed 2000 fb$^{-1}$ of data which will be collected by ILD during its first 10 years of data taking at $\sqrt{s} = 250$ GeV. Upper limits on the Standard Model Higgs-strange coupling strength modifier, $κ_s$, are derived at the 95% confidence level to be 7.14. The paper includes as well a preliminary study of a Ring Imaging Cherenkov (RICH) system capable of discriminating between kaons and pions at high momenta (up to 25 GeV), and thus enhancing strange-tagging performance at future Higgs factory detectors.

hep-ex↗
arXiv2020

Tracking Triggers for the HL-LHC

Hardware-based track reconstruction in the CMS and ATLAS trigger systems for the High-Luminosity LHC upgrade will provide unique capabilities. An overview is presented of earlier track trigger systems at hadron colliders, in particular for the Tevatron CDF and D0 experiments. We discuss the plans of the CMS and ATLAS experiments to implement hardware-based track reconstruction for the High-Luminosity LHC. Particular focus is placed on the track trigger capability of the upgraded CMS experiment. We discuss the challenges and opportunities of this novel handle, and review the alternatives that were considered for its implementation as well as discuss the expected performance. The planned track trigger systems for CMS and ATLAS have different goals, and we compare and contrast the two approaches.

physics.ins-det↗
arXiv2017

FPGA-Based Tracklet Approach to Level-1 Track Finding at CMS for the HL-LHC

During the High Luminosity LHC, the CMS detector will need charged particle tracking at the hardware trigger level to maintain a manageable trigger rate and achieve its physics goals. The tracklet approach is a track-finding algorithm based on a road-search algorithm that has been implemented on commercially available FPGA technology. The tracklet algorithm has achieved high performance in track-finding and completes tracking within 3.4 $μ$s on a Xilinx Virtex-7 FPGA. An overview of the algorithm and its implementation on an FPGA is given, results are shown from a demonstrator test stand and system performance studies are presented.

physics.ins-det↗
arXiv2009

Hadronic D and D_s Meson Decays

We provide a comprehensive review of hadronic decays of D and D_s mesons. We discuss current theoretical and experimental challenges and successes in understanding of hadronic transitions of those mesons. A brief overview of the theoretical and experimental tools are given before discussing the absolute branching fractions for D and D_s mesons. Cabibbo suppressed and rare hadronic decays are discussed and compared with theory before discussing our understanding of hadronic multibody decays.

hep-ph↗
arXiv2001

Measuring the Photon Helicity in Radiative B Decays

We propose a way of measuring the photon polarization in radiative B decays into K resonance states decaying to Kππ, which can test the Standard Model and probe new physics. The photon polarization is shown to be measured by the up-down asymmetry of the photon direction relative to the Kππdecay plane in the K resonance rest frame. The integrated asymmetry in K_1(1400)\to Kππ, calculated to be 0.34\pm 0.05 in the Standard Model, is measurable at currently operating B factories.

hep-ph↗
arXiv2001

A study of time-dependent CP-violating asymmetries in B0 --> J/psi K0S and B0 --> psi(2S) K0S decays

BABAR has studied the time dependent asymmetries in the the decays B0 -> J/psi K0S and B0 -> psi(2S) K0S in a data set of 9.0 fb^-1 taken at the Y(4S)resonance. In these channels we reconstruct 168 events of which 120 are flavor tagged and used in a likelihood fit where we determine sin2beta. The flavor of the other neutral $B$ mesons is tagged using information primarily from identified leptons and Kaons. A neural network is used to recover events without any clear Kaon or lepton signature. A preliminary result of sin2beta=0.12+/-0.37+/-0.09 is obtained.

hep-ex↗