Search

The European Physical Society - High Energy Physics Conference 2019, EPS-HEP 2019, Ghent, Belgium, Belgium, 10 Jul 2019 - 17 Jul 2019; Proceedings of Science / International School for Advanced Studies (EPS-HEP2019), 596 (2020). doi:10.22323/1.364.0596, The requirement of electroweak naturalness in simple supersymmetric models motivates the existence of a cluster of four light higgsinos with mass $100 - 300$ GeV, the lighter the better. While such light compressed spectra may be challenging to observe at the LHC, future $e^+e^-$ colliders with $\sqrt{s} > 2$m(higgsino) would serve as both a SUSY discovery machine and a precision microscope. We study signatures of higgsino pair production at the ILC based on full, Geant4-based simulation of the ILD detector concept. We examine several benchmark scenarios that may or may not be accessible to HL-LHC searches, with mass differences between the higgsino states between 4 and 20 GeV. Assuming $\sqrt{s}\geq$ 500 GeV and $1000$ fb$^{-1}$ of integrated luminosity, the individual higgsino masses can be measured to $1 - 2\%$ precision in case of the larger mass differences, and at the level of 5$\%$ for the smallest mass difference case. The higgsino mass splittings are sensitive to the electroweak gaugino masses and can allow extraction of gaugino masses to $3 - 20\%$ (depending on the model).Extrapolation of gaugino masses via renormalization group running can test the hypothesis of gaugino mass unification. We also examine a case with natural generalized mirage mediation where the unification of gaugino masses at an intermediate scale apparently gives rise to a natural SUSY spectrum somewhat beyond the reach of the HL-LHC., Published by SISSA, Trieste

Physical review / D D 101(9), 095026 (2020). doi:10.1103/PhysRevD.101.095026, The requirement of electroweak naturalness in simple supersymmetric models implies the existence of a cluster of four light Higgsinos with a mass ∼100–300 GeV, the lighter the better. While such light compressed spectra may be challenging to observe at the LHC, the International Linear e+e- Collider (ILC) with s>2mHiggsino would serve as both a SUSY discovery machine and a precision microscope. We study Higgsino pair production signatures at the ILC based on a full, geant4-based simulation of the ILD detector concept. We examine several benchmark scenarios that may be challenging for discovery at the HL-LHC due to mass differences between the Higgsino states between 20 and 4 GeV. Assuming s=500 GeV and 1000 fb-1 of integrated luminosity, the individual Higgsino masses can be measured to 1%–2% precision in the case of the larger mass differences, and at the level of 5% for the smallest mass difference case. The Higgsino mass splittings are sensitive to the electroweak gaugino masses and allow extraction of gaugino masses to ∼3%–20% (depending on the model). Extrapolation of gaugino masses via renormalization group running can test the hypothesis of gaugino mass unification. We also examine a case with natural generalized mirage mediation, where the unification of gaugino masses at an intermediate scale apparently gives rise to a natural SUSY spectrum somewhat beyond the reach of HL-LHC., Published by Inst.302363, Melville, NY

Background: Paediatric musculoskeletal matters (PMM-www.pmmonline.org) is a free, evidence-based and peer reviewed open e-resource for paediatric musculoskeletal (MSK) medicine targeting non-MSK specialists. Since launch (Nov-2014) PMM has reached 190 countries with >78,000 users, >244,500 hits. Users who have declared their training background on the website are mainly non-MSK specialists. Feedback from users has requested further content to reflect international healthcare systems. PMM India was developed in collaboration with the Indian Academy of Paediatrics (IAP; Sept-2015, >3,700 users, 16,000 hits to date) and showcases successful partnership with local clinicians in developing PMM with local context. Further ‘internationalisation’ is now ongoing with additional global partners to develop PMM International. Here, we describe the process for international development. Methods: Paediatric rheumatologists in 11 countries around the world were approached to peer-review and identify additional PMM content to reflect paediatric MSK medicine in their health care systems (e.g., case mix, clinical presentations, care pathways), with a focus on knowledge relevant for non-MSK specialists. New content was developed by local teams identified by the paediatric rheumatologist(s) who then collated and provided expert overview before submission for editorial review. All contributions were provided in English. Additional cases and images were included with appropriate consent. Results: PMM International additions to the original website brings new content predominately focused on infections/infection-related disease with MSK features or as differential diagnoses for rheumatic disease. Most content is in English with requests for translation of some content (e.g., pGALS which is available in 11 languages to date). PMM International will be further peer reviewed with open access to all. A PMM app is planned to facilitate access where internet capacity is limited. Conclusion: Rapid globalisation necessitates appropriate e-resources with content that reflect international health care contexts. PMM International targets non-MSK specialist audiences to raise awareness and early recognition of MSK pathology. Our work reflects strong collaborative global partnerships within the paediatric rheumatology community. PMM has been endorsed by the Paediatric Rheumatology European Association (PReS) as an educational resource. Implementation of PMM International has yet to be formally evaluated (i.e., change in knowledge, practice), but data thus far supports wide reach and positive uptake from the target audience user groups.

Proceedings of The 39th International Conference on High Energy Physics — PoS(ICHEP2018) - Sissa Medialab Trieste, Italy, 2019. - ISBN - doi:10.22323/1.340.0631 The 39th International Conference on High Energy Physics, ICHEP2018, Seoul, Korea, 4 Jul 2018 - 11 Jul 2018; Sissa Medialab Trieste, Italy 631 pp. (2019). doi:10.22323/1.340.0631, Data from the LHC at 7, 8, and 13 TeV, have, so far, yielded no evidence for new particles beyondthe Standard Model Higgs boson. However, the complementary nature of physics with e+e−collisions still offers many interesting scenarios in which new particles can be discovered at theILC. These scenarios take advantage of the capability of experiments at e+e−colliders to observeparticles yielding final states with missing energy and small mass differences, to observe mono-photon events with precisely controlled backgrounds, and to observe the full range of exotic decaymodes of the Higgs boson. The searches that an e+e−collider makes possible are particularlyimportant for models of dark matter involving a dark sector with particles of 10–100 GeV mass.In this talk, we will review the opportunities that the ILC offers for new particle discovery., Published by Sissa Medialab Trieste, Italy

EPS-HEP2017, Venice, Italy, 5 Jul 2017 - 12 Jul 2017; Proceedings of Science (EPS-HEP2017), 306 (2017)., Radiatively-driven natural supersymmetry, a theoretically and experimentally well-motivated framework, centers around the predicted existence of four light, nearly mass-degenerate Higgsinos with mass $\sim 100-200$ GeV (not too far above $m_Z$). The small mass splittings amongst the higgsinos, typically 4-20 GeV, results in very little visible energy arising from decays of the heavier higgsinos. Given that other SUSY particles are considerably heavy, this makes detection challenging at hadron colliders. On the other hand, the clean environment of an electron-positron collider with $\sqrt{s}>2m_{higgsino}$ would enable a decisive search of these required higgsinos, and thus either the discovery or exclusion of natural SUSY. We present a detailed simulation study of precision measurements of higgsino masses and production cross sections at $\sqrt{s}$ = 500 GeV of the proposed International Linear Collider currently under consideration for construction in Japan. The study is based on a Geant4 simulation of the International Large Detector concept. We examine several benchmark points just beyond the HL-LHC reach, with four light higgsinos directly accessible by the ILC, and the mass differences between the lightest SUSY particle and the heavier states ranging from about 4 to 20 GeV. It can be shown that their masses and production cross sections can be precisely measured to approximately 1\% precision or better. These precise measurements allow for extracting the underlying weak scale SUSY parameters, giving predictions for the masses of heavier SUSY states. These provide motivation for future high-energy colliders. Additionally, dark matter properties may be derived. Evolution of the measured gaugino masses to high energies should allow testing the hypothesis of gaugino mass unification., Published by SISSA, Trieste

The Shintake Monitor is an essential beam tuning device installed at the interaction point (IP) of ATF2 [1] , the final focus test beam line of the Accelerator Test Facility (ATF) to measure its nanometer order vertical e − beam sizes ( σ y ⁎ ). The e − beam collides with a target of laser interference fringes, and σ y ⁎ is derived from the modulation depth of the resulting Compton signal photons measured by a downstream photon detector. By switching between several laser crossing angle modes, it is designed to accommodate a wide range of σ y ⁎ from 20 nm to a few micrometers with better than 10% accuracy. Owing to this ingenious technique, Shintake Monitor 1 [2] , [3] is the only existing device capable of measuring σ y ⁎ σ y ⁎ down to the design value of 37 nm. Shintake Monitor has demonstrated stable σ y ⁎ measurement with 5–10% stability. Major improvements in hardware and measurement schemes contributed to the suppression of error sources. This paper describes the design concepts and beam time performance of Shintake Monitor, as well as an extensive study of systematic errors with the aim of precisely extracting σ y ⁎ from the measured modulation.

This paper presents a full simulation study of the measurement of the production cross section (${\ensuremath{\sigma}}_{ZH}$) of the Higgsstrahlung process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}ZH$ and the Higgs boson mass (${M}_{\mathrm{H}}$) at the International Linear Collider (ILC), using events in which a Higgs boson recoils against a $Z$ boson decaying into a pair of muons or electrons. The analysis is carried out for three center-of-mass energies $\sqrt{s}=250$, 350, and 500 GeV, and two beam polarizations ${e}_{\mathrm{L}}^{\ensuremath{-}}{e}_{\mathrm{R}}^{+}$ and ${e}_{\mathrm{R}}^{\ensuremath{-}}{e}_{\mathrm{L}}^{+}$, for which the polarizations of ${e}^{\ensuremath{-}}$ and ${e}^{+}$ are $(P{e}^{\ensuremath{-}},P{e}^{+})=\phantom{\rule{0ex}{0ex}}(\ensuremath{-}80%,+30%)$ and ($+80%$, $\ensuremath{-}30%$), respectively. Assuming an integrated luminosity of $250\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ for each beam polarization at $\sqrt{s}=250\text{ }\text{ }\mathrm{GeV}$, where the best lepton momentum resolution is obtainable, ${\ensuremath{\sigma}}_{ZH}$ and ${M}_{\mathrm{H}}$ can be determined with a precision of 2.5% and 37 MeV for ${e}_{\mathrm{L}}^{\ensuremath{-}}{e}_{\mathrm{R}}^{+}$ and 2.9% and 41 MeV for ${e}_{\mathrm{R}}^{\ensuremath{-}}{e}_{\mathrm{L}}^{+}$, respectively. Regarding a 20 year ILC physics program, the expected precisions for the HZZ coupling and ${M}_{\mathrm{H}}$ are estimated to be 0.4% and 14 MeV, respectively. The event selection is designed to optimize the precisions of ${\ensuremath{\sigma}}_{ZH}$ and ${M}_{\mathrm{H}}$ while minimizing the bias on the measured ${\ensuremath{\sigma}}_{ZH}$ due to discrepancy in signal efficiencies among Higgs decay modes. For the first time, model independence has been demonstrated to a sub-percent level for the ${\ensuremath{\sigma}}_{ZH}$ measurement at each of the three center-of-mass energies. The results presented show the impact of center-of-mass energy and beam polarization on the evaluated precisions and serve as a benchmark for the planning of the ILC run scenario.

A core prediction of natural Supersymmetry is the existence of four light higgsinos not too far above the mass of the $Z$ boson. The small mass splittings amongst the higgsinos -- typically 5-20\,GeV -- imply very little visible energy release from decays of heavier higgsinos. In particular, if other SUSY particles are quite heavy, as can be the case in SUSY with radiatively-driven naturalness, the higgsinos are extremely hard to detect at hadron colliders. The clean environment of electron-positron colliders with $\sqrt{s} > 2m_{\mathrm{higgsino}}$, however, would allow for a decisive search for the required light higgsinos. Thus, $e^+e^-$ colliders should either discover or exclude natural SUSY. We present a detailed study of higgsino pair production at the proposed International Linear $e^+e^-$ Collider which is under consideration for construction in Japan. A variety of precision measurements should allow for extraction of underlying parameters and provide a window onto physics at the grand unified scale.

A novel final focus system design featuring the Local Chromaticity Correction scheme has beenproposed for ILC. This is to be verified at ATF2, a test facility for ILC, through focusing an e-beam down to the design vertical beam size (“σy”) of 37 nm. Shintake Beam Size Monitor (“IPBSM”),installed at the virtual interaction point of ATF2, is the only existing device capable of measuring σy below 100 nm, making it indispensable for achieving the goals of ATF2 and a strong candidate for R&D at future linear colliders. This is attributed to its ingenious technique of scanning the phase oflaser interference fringes relative to the e-beam. Beam sizes are derived from the resulting Compton signal modulation measured by a downstream detector. Having been upgraded in a variety of ways since its first debut at FFTB, Shintake Monitor is capable of measuring a wide range of σy from 25 nm to 6 μm with better than 10% resolution. This paper describes the system's design, role in beam tuning, and various hardware upgrades to further improve its performance.

The Accelerator Test Facility 2 (ATF2) is an extension of the ATF beamline extraction featuring an ILC-type final focus system. Among the project's major purposes are establishment of hardware and beam handling technologies aimed at transverse focusing of ATF's electron beam to below 40 nm in the vertical. A laser-interferometer type high resolution beam size monitor named the “Shintake Monitor” is installed at ATF2's virtual interaction point, and plays a crucial role in achieving this aim. A laser interference fringe is formed by crossing two coherent laser rays. This functions as an interaction target for probing the electron beam. Beam size sensitivity of the monitor depends on the pitch of the interference fringe, and maximizes at about one fifth of the pitch. The Shintake Monitor at ATF2 is designed to be capable of measuring beam sizes ranging from 6 μm down to 20 nm in the vertical. A vertical beam size of approximately 300 nm has been measured during the run of May 2010. For this running period, ATF2 operated under a special optics configuration with ten times the nominal IP beta function. For the most recent run, due to switching beam optics back to nominal, BG levels rose about 10 times from May. Shintake Monitor had been proven in May to fulfill expectations provided BG is low. However with high BG, its accuracy decreased, which makes low S/N a major concern. In this paper, we describe the design and current status of the Shintake Monitor.

A tailor-made serogroup B outer membrane vesicle vaccine was evaluated in the context of a serogroup B meningococcal epidemic dominated by Neisseria meningitidis strain B:4:P1.7b,4.To determine the safety, reactogenicity and immunogenicity in infants aged 6-8 months of a meningococcal B vaccine developed against the New Zealand epidemic strain.Observer-blind, randomised, controlled trial conducted in 296 healthy infants in Auckland, New Zealand.Infants were randomised 4:1 to receive three doses of New Zealand candidate vaccine (epidemic strain NZ98/254, B:4:P1.7b,4) or meningococcal C conjugate vaccine at 6-weekly intervals.Immune response was determined by human complement mediated serum bactericidal assay. Sero-response was a fourfold or greater rise in titre compared to baseline, with baseline titres4 required to increase toor=8. Blood samples were taken before vaccination, 6 weeks after dose two, and 4 weeks after dose three. Local and systemic reactions were recorded for 7 days following vaccination.Sero-response to the candidate vaccine strain, NZ98/254, was demonstrated in 74% of vaccinees (95% CI: 68% to 80% intention-to-treat; 67% to 79% per protocol) after three doses of New Zealand candidate vaccine. No meningococcal C conjugate vaccine recipients were sero-responders to NZ98/254 after three doses. Both vaccines were well tolerated with no vaccine related serious adverse events.Our data indicate that the New Zealand candidate vaccine administered in three doses to this group of 6-8-month-old infants was safe and immunogenic against the candidate vaccine strain NZ98/254 (Neisseria meningitidis B:4:P1.7b,4).

学位の種別: 課程博士, 審査委員会委員 : (主査)東京大学教授 徳宿 克夫, 東京大学教授 牧島 一夫, 東京大学教授 坂本 宏, 東京大学准教授 川本 辰男, 東京大学准教授 山下 了

Background A New Zealand serogroup B meningococcal epidemic prompted trials of a strain-specific (B:4:P1.7-2,4) outer membrane vesicle vaccine (MeNZB). Methods Adults, school children, and infants provided serum after three MeNZB doses to evaluate antibody persistence via serum bactericidal assay. Toddler (16–24 months) non-responders and responders received a fourth MeNZB dose 11 and 17 months after dose three respectively. Response was a ≥4-fold rise in bactericidal titre to a titre of ≥8. Results Geometric mean bactericidal titres (GMTs), with 95% CI, after dose 3: adults: 27 (14–52), 5 (3–11), and 7 (3–15) at 1, 10, and 22 months; school children: 18 (13–25) and 4 (3–6) at 1 and 4 months; infants: 27 (19–39) and 2 (2–3) at 1 and 7 months. The titre achieved after priming significantly influenced persistence.Toddler non-responder GMTs were 4 (3–5) and 1 (1–1) at 1 and 11 months after dose 3 and 69 (46–106) 1 month after dose 4. Responder GMTs were 24 (19–30) and 3 (2–4) at 1 and 17 months after dose 3 and 259 (184–363) 1 month after dose 4. Dose 4 had no safety concerns. Conclusions Immune response to MeNZB was most sustained in adults. In infants, bactericidal titres decayed almost to baseline by 7 months after dose 3. Toddlers showed marked immune response following a fourth dose suggesting memory. Persisting antibody is likely to be necessary for ongoing protection, as seen with serogroup C meningococci.