28 results on '"Gero von Gersdorff"'
Search Results
2. Factorization of covariant Feynman graphs for the effective action
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Gero von Gersdorff
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Effective Field Theories ,SMEFT ,Renormalization and Regularization ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract We prove a neat factorization property of Feynman graphs in covariant perturbation theory. The contribution of the graph to the effective action is written as an integral over Schwinger parameters whose integrand is a product of a massless scalar momentum integral that only depends on the basic graph topology, and a background-field dependent piece that contains all the information of spin, gauge representations, masses etc. We give a closed expression for the momentum integral in terms of four graph polynomials whose properties we derive in some detail. Our results can also be useful for standard (non-covariant) perturbation theory.
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- 2023
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3. New covariant Feynman rules for effective field theories
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Gero von Gersdorff and Kevin Santos
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Effective Field Theories ,SMEFT ,Renormalization and Regularization ,Vector-Like Fermions ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract We provide a new and completely general formalism to compute the effective field theory matching contributions from integrating out massive fields in a manifestly gauge covariant way, at any desired loop order. The formalism is based on old ideas such as the background field method and the heat kernel, however we add some crucial new ingredients that greatly improve the simplicity and general applicability of the approach. We formulate our method in terms of Feynman rules, the resulting effective action is expressed in terms of local heat kernel coefficients. We also provide as supplementary material a mathematica code that facilitates the computation of these coefficients.
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- 2023
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4. Searching for anomalous top quark interactions with proton tagging and timing detectors at the LHC
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Cristian Baldenegro, Andrea Bellora, Sylvain Fichet, Gero von Gersdorff, Michael Pitt, and Christophe Royon
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Axions and ALPs ,Other Weak Scale BSM Models ,Specific BSM Phenomenol- ogy ,Top Quark ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract We study the LHC sensitivity to new broad neutral resonances produced in two-photon fusion and decaying to a top quark pair, γγ → t t ¯ $$ t\overline{t} $$ . This is probed in central exclusive t t ¯ $$ t\overline{t} $$ production in proton-proton collisions, pp → pt t ¯ p $$ pt\overline{t}p $$ . We use the tagging of the intact protons by PPS (CMS) and AFP (ATLAS) and consider the semi-leptonic t t ¯ $$ t\overline{t} $$ channel. The sensitivity is also mapped onto a set of dimension-8 γγt t ¯ $$ \gamma \gamma t\overline{t} $$ operators in the large mass limit. Using the kinematical correlations between the intact protons and the reconstructed t t ¯ $$ t\overline{t} $$ system, we obtain a sensitivity to the couplings of the dimension-8 operators of 1.4 10 −11 GeV −4 at 95% CL. The sensitivity to the anomalous couplings is significantly improved down to about 7 10 −12 GeV −4 if the proton time-of-flight is known with a precision of 20 ps in future measurements. The 95% CL sensitivity to broad neutral resonances reaches masses of order 1500 GeV when using timing information.
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- 2022
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5. Duration of Protection From Pneumonia After Pneumococcal Vaccination in Hemodialysis Patients (DOPPIO): Protocol for a Prospective Multicenter Study
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Sibylle Mellinghoff, Gero von Gersdorff, Caroline Bruns, Kerstin Albus, Vassiliki Dimitriou, Angela Steinbach, Mathias Schaller, Jörg Janne Vehreschild, Oliver A Cornely, and Blasius Janusch Liss
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Medicine ,Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
BackgroundPneumonia is a leading cause of death in patients with end-stage chronic kidney disease treated with dialysis. Current vaccination schedules recommend pneumococcal vaccination. However, this schedule disregards findings of rapid titer decline in adult hemodialysis patients after 12 months. ObjectiveThe primary objective is to compare pneumonia rates between recently vaccinated patients and patients vaccinated more than 2 years ago. As an exploratory objective, antipneumococcal antibody titers in hemodialysis patients will be determined as a function. Factors influencing antibody kinetics will be identified. MethodsWithin this prospective multicenter study, we aim to compare 2 strata of vaccinated patients: those recently vaccinated and those vaccinated more than 2 years ago. A total of 792 patients will be enrolled. Twelve partner sites (within the German Centre for Infection Research [DZIF]) with allocated dialysis practices participate in this study. All dialysis patients who are vaccinated against pneumococcal infection in accordance with Robert Koch Institute guidelines prior to enrollment will be eligible. Data on baseline demographics, vaccination history, and underlying disease will be assessed. Pneumococcal antibody titers will be determined at baseline and every 3 months for 2 years. DZIF clinical trial units coordinate titer assessment schedules and actively follow-up on study patients for 2-5 years after enrollment, including validation of end points of hospitalization, pneumonia, and death. ResultsThe study has enrolled 792 patients and the last follow-up has been completed. Currently, the statistical and laboratory analyses are ongoing. ConclusionsResults will increase physician adherence to current recommendations. Establishing a framework for the efficient evaluation of guideline recommendations through a combination of routine and study data will inform the evidence base for future guidelines. Trial RegistrationClinicalTrials.gov NCT03350425; https://clinicaltrials.gov/ct2/show/NCT03350425 International Registered Report Identifier (IRRID)DERR1-10.2196/45712
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- 2023
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6. Realistic GUT Yukawa couplings from a random clockwork model
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Gero von Gersdorff
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Astrophysics ,QB460-466 ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract We present realistic models of flavor in SU(5) and SO(10) grand unified theories (GUTs). The models are renormalizable and do not require any exotic representations in order to accommodate the necessary GUT breaking effects in the Yukawa couplings. They are based on a simple clockwork Lagrangian whose structure is enforced with just two (one) vectorlike U(1) symmetries in the case of SU(5) and SO(10) respectively. The inter-generational hierarchies arise spontaneously from products of matrices with order one random entries.
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- 2020
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7. A random clockwork of flavor
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Fernando Abreu de Souza and Gero von Gersdorff
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Beyond Standard Model ,Quark Masses and SM Parameters ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract We propose a simple clockwork model of flavor which successfully generates the Standard Model flavor hierarchies from random order-one couplings. With very few parameters we achieve distributions of models in excellent agreement with observation. We explain in some detail the interpretation of our mechanism as random localization of zero modes in theory space. The scale of the vectorlike fermions is mostly constrained by lepton flavor violation with secondary constraints arising from rare meson decays.
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- 2020
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8. Validation of a United Kingdom Model to Predict Mortality in Incident Dialysis Patients in the Dialysis Outcomes and Practice Patterns Study Cohort: Introduction of a Clinical Risk Score
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Martin Wagner, MD, PhD, David M. Kent, MD, MSc, Ronald L. Pisoni, PhD, MS, Damian Fogarty, MD, Gero von Gersdorff, MD, Christoph Wanner, MD, and Navdeep Tangri, MD, PhD
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Diseases of the genitourinary system. Urology ,RC870-923 - Published
- 2022
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9. Universal approximations for flavor models
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Gero von Gersdorff
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Beyond Standard Model ,Quark Masses and SM Parameters ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract We develop a systematic analytical approximation scheme for the singular value decompositions of arbitrary complex three dimensional matrices Y with non-degenerate singular values. We derive exact expressions for the errors of this approximation and show that they are bounded from above by very simple ratios of the form (y i /y j )2n where y i < y j are singular values of Y and n is the order of the approximation. The applications we have in mind are the analytical and numerical treatments of arbitrary theories of flavor. We also compute upper bounds for the errors of the Cabbibo Kobayashi Maskawa (CKM) matrix that only depend on the ratios of the masses and the physical CKM angles.
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- 2019
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10. A clockwork solution to the doublet-triplet splitting problem
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Gero von Gersdorff
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Physics ,QC1-999 - Abstract
Maybe the biggest puzzle in grand unified theories (GUTs) is the apparent large splitting of the doublet and triplet Higgs masses. We suggest a novel mechanism to solve this puzzle, which relies on the clockwork mechanism to generate large hierarchies from order-one numbers. The tension between gauge coupling unification and proton lifetime from minimal SU(5) GUTs is also removed in this scenario, and the theory remains perturbative until the Planck scale. We comment on a possible extra dimensional implementation of the idea.
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- 2021
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11. Diminished Short- and Long-Term Antibody Response after SARS-CoV-2 Vaccination in Hemodialysis Patients
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Louise Füessl, Tobias Lau, Isaac Lean, Sandra Hasmann, Bernhard Riedl, Florian M. Arend, Johanna Sorodoc-Otto, Daniela Soreth-Rieke, Marcell Toepfer, Simon Rau, Haxhrije Salihi-Halimi, Michael Paal, Wilke Beuthien, Norbert Thaller, Yana Suttmann, Gero von Gersdorff, Ron Regenauer, Anke von Bergwelt-Baildon, Daniel Teupser, Mathias Bruegel, Michael Fischereder, and Ulf Schönermarck
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SARS-CoV-2 ,vaccination ,antibody response ,hemodialysis ,Medicine - Abstract
Short-term studies have shown an attenuated immune response in hemodialysis patients after COVID-19-vaccination. The present study examines how antibody response is maintained after vaccination against SARS-CoV-2 in a large population of hemodialysis patients from six outpatient dialysis centers. We retrospectively assessed serum antibody levels against SARS-CoV-2 spike protein and nucleocapsid protein (electrochemiluminescence immunoassays, Roche Diagnostics) after COVID-19-vaccination in 298 hemodialysis and 103 non-dialysis patients (controls), comparing early and late antibody response. Compared to a non-dialysis cohort hemodialysis patients showed a favorable but profoundly lower early antibody response, which decreased substantially during follow-up measurement (median 6 months after vaccination). Significantly more hemodialysis patients had anti-SARS-CoV-2-S antibody titers below 100 U/mL (p < 0.001), which increased during follow-up from 23% to 45% but remained low in the control group (3% vs. 7%). In multivariate analysis, previous COVID-19 infections (p < 0.001) and female gender (p < 0.05) were significantly associated with higher early as well as late antibody vaccine response in hemodialysis patients, while there was a significant inverse correlation between patient age and systemic immunosuppression (p < 0.001). The early and late antibody responses were significantly higher in patients receiving vaccination after a SARS-CoV-2 infection compared to uninfected patients in both groups (p < 0.05). We also note that a higher titer after complete immunization positively affected late antibody response. The observation, that hemodialysis patients showed a significantly stronger decline of SARS-CoV-2 vaccination antibody titers within 6 months, compared to controls, supports the need for booster vaccinations to foster a stronger and more persistent antibody response.
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- 2022
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12. Cluster Randomized Controlled Trial on the Effects of 12 Months of Combined Exercise Training during Hemodialysis in Patients with Chronic Kidney Disease—Study Protocol of the Dialysis Training Therapy (DiaTT) Trial
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Gero von Gersdorff, Pia von Korn, André Duvinage, Gabriele Ihorst, Anika Josef, Margit Kaufmann, Thomas Baer, Tim Fellerhoff, Iris Fuhrmann, Elisa Koesel, Sven Zeissler, Lars Bobka, Marion Heinrich, Anette Schindler, Rasmus Weber, Cornelia Breuer, Anna Maria Meyer, M. Cristina Polidori, Sophia M.T. Dinges, Julia Schoenfeld, Mathias Siebenbuerger, Stefan Degenhardt, Kirsten Anding-Rost, and Martin Halle
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exercise ,frailty ,quality of life ,health economics ,kidney failure ,end stage renal disease ,Biology (General) ,QH301-705.5 - Abstract
Patients with chronic kidney disease (CKD) on hemodialysis (HD) experience treatment-related immobility and physical deconditioning, which is responsible for an increased risk of frailty and a high burden of multi-morbidity. Exercise has been shown to counteract this vicious cycle; however, its effectiveness has only been investigated in small cohorts. Therefore, the objective of the Dialysis Training Therapy (DiaTT) trial will be to assess the effects of a 12-month intradialytic exercise program on physical functioning, frailty and health economics in a large cohort of HD patients in a real-world setting. DiaTT will be a prospective, cluster-randomized (1:1), controlled, multi-center, interventional clinical trial across 28 dialysis units, aiming at the recruitment of >1100 CKD patients on HD. The intervention group will receive 12 months’ intradialytic exercise (combined aerobic and resistance training), whereas the usual care group will not receive intervention. The primary endpoint will be a change on the sit-to-stand test (STS60) result between baseline and 12 months. Secondary endpoints will include physical functioning, frailty, quality of life, 3-point MACE, hospitalizations, survival, quality of HD, health literacy and health care costs. By including almost as many patients as previously investigated in smaller trials, DiaTT will be the largest randomized, controlled trial assessing frailty, quality of life and mortality in the field of nephrology.
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- 2021
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13. Natural fermion hierarchies from random Yukawa couplings
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Gero von Gersdorff
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Beyond Standard Model ,Quark Masses and SM Parameters ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract The Standard Model of particle physics requires Yukawa matrices with eigenvalues that differ by orders of magnitude. We propose a novel way to explain this fact without any small or large parameters. The mechanism is based on the observation that products of matrices of random order-one numbers have hierarchical spectra. The same mechanism can easily account for the hierarchical structure of the quark mixing matrix.
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- 2017
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14. Use of intravenous iron and risk of anaphylaxis
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Nicholas Moore, Patrick Blin, Jochen Dress, Antje Timmer, Jacques Benichou, Jonas Reinold, Ron M.C. Herings, Edeltraut Garbe, Ingvild Odsbu, Susana Perez-Gutthann, Nuria Saigi-Morgui, Gunnar Toft, Vera Ehrenstein, Cécile Droz-Perroteau, Andreas J. Bircher, D. S. Rampton, Michael Forstner, Carla Franzoni, Elisabeth Smits, Joan Fortuny, Régis Lassalle, Katherine Rascher, Gero von Gersdorff, Mathias Schaller, Kenneth J. Rothman, Jetty A. Overbeek, Tania Schink, Marie Linder, Bianca Kollhorst, Lawrence Rasouliyan, Lia Gutierrez, RTI Health Solutions, Research Triangle Institute International (RTI International), University of Cologne, CIC Bordeaux, Université Bordeaux Segalen - Bordeaux 2-Institut National de la Santé et de la Recherche Médicale (INSERM), Karolinska Institutet [Stockholm], PHARMO Institute for Drug Outcomes Research, Leibniz Institute for Prevention Research and Epidemiology - BIPS, Leibniz Association, Aarhus University [Aarhus], Carl Von Ossietzky Universität Oldenburg, Vrije Universiteit Amsterdam [Amsterdam] (VU), CHU Rouen, Normandie Université (NU), Université de Rouen Normandie (UNIROUEN), University Hospital Basel [Basel], Università della Svizzera italiana = University of Italian Switzerland (USI), Royal Free Hospital [London, UK], General practice, and Epidemiology and Data Science
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medicine.medical_specialty ,severe hypersensitivity reactions ,Epidemiology ,Iron ,Pharmacy ,01 natural sciences ,Cohort Studies ,010104 statistics & probability ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,anaphylaxis ,cohort study ,Humans ,Pharmacology (medical) ,Cumulative incidence ,030212 general & internal medicine ,0101 mathematics ,IV iron ,Anaphylaxis ,Dextran ,business.industry ,Original Articles ,medicine.disease ,Severe hypersensitivity reactions ,Confidence interval ,3. Good health ,Penicillin ,Europe ,dextran ,Ambulatory ,Observational study ,Administration, Intravenous ,Original Article ,[SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie ,business ,Cohort study ,multidatabase ,Multidatabase ,medicine.drug - Abstract
International audience; PURPOSE: This post-authorisation safety study estimated the risk of anaphylaxis in patients receiving intravenous (IV) iron in Europe, with interest in iron dextran and iron non-dextrans. Studies conducted in the United States have reported risk of anaphylaxis to IV iron ranging from 2.0 to 6.8 per 10 000 first treatments. METHODS: Cohort study of IV iron new users, captured mostly through pharmacy ambulatory dispensing, from populations covered by health and administrative data sources in five European countries from 1999 to 2017. Anaphylaxis events were identified through an algorithm that used parenteral penicillin as a positive control. RESULTS: A total of 304 210 patients with a first IV iron treatment (6367 iron dextran), among whom 13–16 anaphylaxis cases were identified and reported as a range to comply with data protection regulations. The pooled unadjusted incidence proportion (IP) ranged from 0.4 (95% confidence interval [CI], 0.2–0.9) to 0.5 (95% CI, 0.3–1.0) per 10 000 first treatments. No events were identified at first dextran treatments. There were 231 294 first penicillin treatments with 30 potential cases of anaphylaxis (IP = 1.2; 95% CI, 0.8–1.7 per 10 000 treatments). CONCLUSION: We found an IP of anaphylaxis from 0.4 to 0.5 per 10 000 first IV iron treatments. The study captured only a fraction of IV iron treatments administered in hospitals, where most first treatments are likely to happen. Due to this limitation, the study could not exclude a differential risk of anaphylaxis between iron dextran and iron non-dextrans. The IP of anaphylaxis in users of penicillin was consistent with incidences reported in the literature.
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- 2021
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15. Multidimensional analysis of factors responsible for the low prevalence of ambulatory peritoneal dialysis in Germany (MAU-PD): a cross-sectional Mixed-Methods Study Protocol
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Ute Karbach, Stephanie Stock, Christina Samel, Tim Ohnhaeuser, Gero von Gersdorff, Nadine Scholten, Holger Pfaff, Katherine Rascher, Martin Hellmich, Thomas Mettang, and Isabell Schellartz
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Male ,medicine.medical_specialty ,Health Knowledge, Attitudes, Practice ,medicine.medical_treatment ,030232 urology & nephrology ,Psychological intervention ,Qualitative property ,Ambulatory Care Facilities ,Peritoneal dialysis ,03 medical and health sciences ,0302 clinical medicine ,Germany ,Surveys and Questionnaires ,Health care ,medicine ,Protocol ,Humans ,030212 general & internal medicine ,Dialysis ,Reimbursement ,business.industry ,Health services research ,claims data ,General Medicine ,Cross-Sectional Studies ,Family medicine ,dialysis ,Kidney Failure, Chronic ,Female ,Health Services Research ,business ,Peritoneal Dialysis ,qualitative research ,Qualitative research ,study protocol ,quantitative research - Abstract
IntroductionPatients with end-stage kidney failure can be treated either by transplant or by dialysis, which can be administered as haemodialysis (HD) or peritoneal dialysis (PD). Although they are equivalent therapeutic options in terms of mortality, the percentage of patients in Germany treated with PD is currently very low (∼6%) compared with other countries. The aim of our study is to analyse the factors behind this percentage and their relevance to the choice of dialysis treatment in Germany. This includes analyses of regional disparities in the provision of care for dialysis patients as well as the evaluations of costs and the influence of reimbursement structures. This approach should provide further insights to explain the variation in the usage of PD and HD and will help to define starting points for future interventions.Methods and analysisA mixed-methods approach will be applied to several data sources, including administrative data (ambulatory physicians’ claim data, statutory health insurance claim data), quality assurance data from one of the largest German dialysis providers Kuratorium für Dialyse (KfH) and qualitative and quantitative survey data (patients, nephrologists and dialysis nurses). Qualitative data will be analysed content-analytically. Based on the quantitative data, multivariable analyses will be performed and, where possible, hierarchical models will be tested. This multidimensional approach will enable us to account for the different factors influencing the penetration of PD in Germany.Ethics and disseminationEthics approval (17-299) has been obtained from the Ethics Committee of the Medical Faculty of the University of Cologne on 25 April 2018. National and international dissemination will be accomplished by informing healthcare practitioners, patients and professional organisations and other stakeholders via conferences, scientific and non-scientific publications and seminars.Trial registration numberDRKS00012555; Pre-Results.
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- 2019
16. Hemodialysis outcomes in a global sample of children and young adult hemodialysis patients: the PICCOLO MONDO cohort
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Brett Plattner, Xiaoqi Xu, Roberto Picoits-Filho, Katherine D. Westreich, Cristina Marelli, Jeroen P. Kooman, Maria E. Ferris, Michael Etter, Paola Carioni, Daniele Marcelli, Albert Power, Debbie S. Gipson, Len A. Usvyat, Gero von Gersdorff, Lucimary de Castro Sylvestre, Peter Kotanko, Qingqing Xiao, Keisha L. Gibson, Franciscus van der Sande, Interne Geneeskunde, MUMC+: MA Nefrologie (9), and RS: NUTRIM - R3 - Chronic inflammatory disease and wasting
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young adults ,Transplantation ,Pediatrics ,medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,030232 urology & nephrology ,Sample (statistics) ,03 medical and health sciences ,0302 clinical medicine ,Nephrology ,international ,Cohort ,medicine ,030212 general & internal medicine ,Hemodialysis ,adolescents ,Young adult ,business ,Dialysis - Abstract
Background The aim of this study was to describe the experience of pediatric and young adult hemodialysis (HD) patients from a global cohort. Methods The Pediatric Investigation and Close Collaborative Consortium for Ongoing Life Outcomes for MONitoring Dialysis Outcomes (PICCOLO MONDO) study provided de-identified electronic information of 3244 patients, ages 0–30 years from 2000 to 2012 in four regions: Asia, Europe, North America and South America. The study sample was categorized into pediatric (≤18 years old) and young adult (19–30 years old) groups based on the age at dialysis initiation. Results For those with known end-stage renal disease etiology, glomerular disease was the most common diagnosis in children and young adults. Using Europe as a reference group, North America [odds ratio (OR) 2.69; CI 1.29, 5.63] and South America (OR 4.21; CI 2.32, 7.63) had the greatest mortality among young adults. North America also had higher rates of overweight, obesity, hypertension, cardiovascular disease, hospitalizations and secondary diabetes compared with all other regions. Initial catheter use was greater for North American (86.4% in pediatric patients and 75.2% in young adults) and South America (80.6% in pediatric patients and 75.9% in young adults). Catheter use at 1-year follow-up was most common in North American children (77.3%) and young adults (62.9%). Asia had the lowest rate of catheter use. For both age groups, dialysis adequacy (equilibrated Kt/V) ranged between 1.4 and 1.5. In Asia, patients in both age groups had significantly longer treatment times than in any other region. Conclusions The PICCOLO MONDO study has provided unique baseline and 1-year follow-up information on children and young adults receiving HD around the globe. This cohort has brought to light aspects of care in these age groups that warrant further investigation.
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- 2016
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17. Monitoring Dialysis Outcomes across the World - The MONDO Global Database Consortium
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Jeroen P. Kooman, Len A. Usvyat, Frank M. van der Sande, Yosef S. Haviv, Yuedong Wang, Adam Tashman, Ted Toffelmire, Mathias Schaller, Adrian Guinsburg, Nathan W. Levin, Cristina Marelli, Inga Bayh, Michael Etter, Albert Power, Gero von Gersdorff, Claudia Barth, Aileen Grassmann, Stephan Thijssen, Laura Scatizzi, Charles D. Pusey, Daniele Marcelli, Peter Kotanko, Interne Geneeskunde, and RS: NUTRIM - R3 - Chronic inflammatory disease and wasting
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Local practice ,Databases, Factual ,Descriptive statistics ,Database ,business.industry ,Reproducibility of Results ,Hematology ,General Medicine ,Patient data ,Joint analysis ,Global Health ,Dialysis patients ,computer.software_genre ,Renal Dialysis ,Nephrology ,Outcome Assessment, Health Care ,Global health ,Humans ,Medicine ,Observational study ,Registries ,Dialysis (biochemistry) ,business ,computer - Abstract
Background/Aims: Dialysis providers frequently collect detailed longitudinal and standardized patient data, providing valuable registries of routine care. However, even large organizations are restricted to certain regions, limiting their ability to separate effects of local practice from the pathophysiology shared by most dialysis patients. To overcome this limitation, the MONDO (MONitoring Dialysis Outcomes) research consortium has created a platform for the joint analysis of data from almost 200,000 dialysis patients worldwide. Methods: We examined design and operation of MONDO as well as its methodology with respect to patient inclusion, descriptive data and other study parameters. Results: MONDO partners contribute primary databases of anonymized patient data and collaboratively analyze populations across national and regional boundaries. To that end, datasets from different electronic health record systems are converted into a uniform structure. Patients are enrolled without systematic exclusions into open cohorts representing the diversity of patients. A large number of patient level treatment and outcome data is recorded frequently and can be analyzed with little delay. Detailed variable definitions are used to determine if a parameter can be studied in a subset or all databases. Conclusion: MONDO has created a large repository of validated dialysis data, expanding the opportunities for outcome studies in dialysis patients. The density of longitudinal information facilitates in particular trend analysis. Limitations include the paucity of uniform definitions and standards regarding descriptive information (e.g. comorbidities), which limits the identification of patient subsets. Through its global outreach, depth, breadth and size, MONDO advances the observational study of dialysis patients and care.
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- 2013
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18. Effective theory for neutral resonances and a statistical dissection of the ATLAS diboson excess
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Gero von Gersdorff, Sylvain Fichet, and Universidade Estadual Paulista (Unesp)
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Physics ,Nuclear and High Energy Physics ,Particle physics ,Atlas (topology) ,Physics beyond the Standard Model ,Graviton ,FOS: Physical sciences ,Resonance ,Field Theories in Higher Dimensions ,Effective field theories ,Poisson distribution ,symbols.namesake ,High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,Beyond Standard Model ,symbols ,Effective field theory ,Brane ,Shape analysis (digital geometry) - Abstract
We classify the complete set of dimension-5 operators relevant for the resonant production of a singlet of spin 0 or 2 linearly coupled to the Standard Model (SM). We compute the decay width of such states as a function of the effective couplings, and provide the matching to various well-motivated New Physics scenarios. We then investigate the possibility that one of these neutral resonances be at the origin of the excess in diboson production recently reported by the ATLAS collaboration. We perform a shape analysis of the excess under full consideration of the systematic uncertainties to extract the width $\Gamma_{\rm tot}$ of the hypothetical resonance, finding it to be in the range 26 GeV $, Comment: 31 pages
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- 2015
19. A Bayesian view of the Higgs sector with higher dimensional operators
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Beranger Dumont, Sylvain Fichet, Gero von Gersdorff, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Centre de Physique Théorique [Palaiseau] (CPHT), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), INPG 53, Universidade Federal do Rio Grande do Norte (UFRN), École Polytechnique and CNRS, and Universidade Estadual Paulista (Unesp)
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Physics ,Nuclear and High Energy Physics ,Gauge boson ,Particle physics ,Top quark ,Large Hadron Collider ,Higgs Physics ,010308 nuclear & particles physics ,Physics beyond the Standard Model ,Electroweak interaction ,High Energy Physics::Phenomenology ,FOS: Physical sciences ,01 natural sciences ,Higgs sector ,Standard Model ,High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,[PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph] ,0103 physical sciences ,Beyond Standard Model ,Higgs boson ,High Energy Physics::Experiment ,010306 general physics - Abstract
We investigate the possibilities of New Physics affecting the Standard Model (SM) Higgs sector. An effective Lagrangian with dimension-six operators is used to capture the effect of New Physics. We carry out a global Bayesian inference analysis, considering the recent LHC data set including all available correlations, as well as results from Tevatron. Trilinear gauge boson couplings and electroweak precision observables are also taken into account. The case of weak bosons tensorial couplings is closely examined and NLO QCD corrections are taken into account in the deviations we predict. We consider two scenarios, one where the coefficients of all the dimension-six operators are essentially unconstrained, and one where a certain subset is loop suppressed. In both scenarios, we find that large deviations from some of the SM Higgs couplings can still be present, assuming New Physics arising at 3 TeV. In particular, we find that a significantly reduced coupling of the Higgs to the top quark is possible and slightly favored by searches on Higgs production in association with top quark pairs. The total width of the Higgs boson is only weakly constrained and can vary between 0.7 and 2.7 times the Standard Model value within 95% Bayesian credible interval (BCI). We also observe sizeable effects induced by New Physics contributions to tensorial couplings. In particular, the Higgs boson decay width into $Z\gamma$ can be enhanced by up to a factor 12 within 95% BCI., Comment: 37 pages, 10 figures, references added, published in JHEP
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- 2013
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20. Interdialytic weight gain, systolic blood pressure, serum albumin, and C-reactive protein levels change in chronic dialysis patients prior to death
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Michael Etter, Frank M. van der Sande, Adam Tashman, Ted Toffelmire, Len A. Usvyat, Cristina Marelli, Claudia Barth, Maggie Lam, Laura Scatizzi, Yuedong Wang, Gero von Gersdorff, Peter Kotanko, Stephan Thijssen, Daniele Marcelli, Mathias Schaller, Inga Bayh, Aileen Grassmann, Adrian Guinsburg, Nathan W. Levin, Jeroen P. Kooman, Interne Geneeskunde, RS: NUTRIM - R3 - Chronic inflammatory disease and wasting, and RS: CARIM School for Cardiovascular Diseases
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Male ,systolic blood pressure ,medicine.medical_specialty ,Asia ,Time Factors ,Databases, Factual ,Systole ,medicine.medical_treatment ,Serum albumin ,Argentina ,Blood Pressure ,Serum Albumin, Human ,outcomes ,Weight Gain ,Risk Assessment ,Weight loss ,Renal Dialysis ,Risk Factors ,Internal medicine ,medicine ,Humans ,Renal Insufficiency, Chronic ,Intensive care medicine ,Serum Albumin ,Aged ,Retrospective Studies ,biology ,business.industry ,C-reactive protein ,Retrospective cohort study ,Middle Aged ,United States ,Europe ,nutrition ,Blood pressure ,C-Reactive Protein ,Treatment Outcome ,inflammation ,Nephrology ,Cohort ,biology.protein ,Disease Progression ,Female ,Hemodialysis ,medicine.symptom ,business ,epidemiology and outcomes ,Weight gain ,Biomarkers - Abstract
Reports from a United States cohort of chronic hemodialysis patients suggested that weight loss, a decline in pre-dialysis systolic blood pressure, and decreased serum albumin may precede death. However, no comparative studies have been reported in such patients from other countries. Here we analyzed dynamic changes in these parameters in hemodialysis patients and included 3593 individuals from 5 Asian countries; 35,146 from 18 European countries; 8649 from Argentina; and 4742 from the United States. In surviving prevalent patients, these variables appeared to have notably different dynamics than in patients who died. While in all populations the interdialytic weight gain, systolic blood pressure, and serum albumin levels were stable in surviving patients, these indicators declined starting more than a year ahead in those who died with the dynamics similar irrespective of gender and geographic region. In European patients, C-reactive protein levels were available on a routine basis and indicated that levels of this acute-phase protein were low and stable in surviving patients but rose sharply before death. Thus, relevant fundamental biological processes start many months before death in the majority of chronic hemodialysis patients. Longitudinal monitoring of these dynamics may help to identify patients at risk and aid the development of an alert system to initiate timely interventions to improve outcomes.
- Published
- 2013
21. Neutrino Mixing from Wilson Lines in Warped Space
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Michael Wiechers, Mariano Quiros, and Gero von Gersdorff
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Physics ,Nuclear and High Energy Physics ,Particle physics ,Gauge boson ,High Energy Physics::Phenomenology ,FOS: Physical sciences ,Mass matrix ,Symmetry (physics) ,Massless particle ,MAJORANA ,High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,Gauge group ,High Energy Physics::Experiment ,Neutrino ,Lepton - Abstract
We consider the generation of the hierarchical charged lepton spectrum and anarchic neutrino masses and mixing angles in warped extra dimensional models with Randall-Sundrum metric. We have classified all possible cases giving rise to realistic spectra for both Dirac and Majorana neutrinos. An anarchic neutrino spectrum requires a convenient bulk symmetry broken by boundary conditions on both UV and IR branes. We have in particular considered the case of Majorana neutrinos with a continuous bulk symmetry. To avoid unwanted massless extra gauge bosons the 4D group should be empty. If the 4D coset is not vanishing it can provide a Wilson Line description of the neutrino Majorana mass matrix. We have studied an example based on the bulk gauge group U(3)_{L} \otimes U(3)_{N} \otimes_{i} U(1)_{E^i} with the Wilson Line in SO(3)_{N} satisfying all required conditions. A \chi^2-fit to experimental data exhibits the 95% CL region in the parameter space with no fine-tuning. As a consequence of the symmetries of the theory there is no tree-level induced lepton flavor violation and so one-loop processes are consistent with experimental data for KK-modes about a few TeV. The model is easily generalizable to models with IR deformed metrics with similar conclusions., Comment: 28 pages, 9 eps plots, uses axodraw; v2 Title changed, comments on phenomenology added, version to be published in JHEP
- Published
- 2012
22. From Soft Walls to Infrared Branes
- Author
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Gero von Gersdorff
- Subjects
Physics ,Nuclear and High Energy Physics ,Compactification (physics) ,Warp drive ,010308 nuclear & particles physics ,FOS: Physical sciences ,Singular point of a curve ,Space (mathematics) ,Curvature ,01 natural sciences ,High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,Classical mechanics ,Singularity ,0103 physical sciences ,Brane cosmology ,Brane ,010306 general physics ,Particle Physics - Phenomenology - Abstract
Five dimensional warped spaces with soft walls are generalizations of the standard Randall-Sundrum compactifications, where instead of an infrared brane one has a curvature singularity (with vanishing warp factor) at finite proper distance in the bulk. We project the physics near the singularity onto a hypersurface located a small distance away from it in the bulk. This results in a completely equivalent description of the soft wall in terms of an effective infrared brane, hiding any singular point. We perform explicitly this calculation for two classes of soft wall backgrounds used in the literature. The procedure has several advantages. It separates in a clean way the physics of the soft wall from the physics of the five dimensional bulk, facilitating a more direct comparison with standard two-brane warped compactifications. Moreover, consistent soft walls show a sort of universal behavior near the singularity which is reflected in the effective brane Lagrangian. Thirdly, for many purposes, a good approximation is obtained by assuming the bulk background away from the singularity to be the usual Randall-Sundrum metric, thus making the soft wall backgrounds better analytically tractable. We check the validity of this procedure by calculating the spectrum of bulk fields and comparing it to the exact result, finding very good agreement., 14 pages, 2 figures, v2: subsection on IR brane potentials and appendix on fermions added, version to appear in PRD
- Published
- 2010
23. One-Loop Effective Action in Orbifold Compactifications
- Author
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Gero von Gersdorff
- Subjects
High Energy Physics - Theory ,Physics ,Nuclear and High Energy Physics ,Supergravity ,FOS: Physical sciences ,Moduli ,Renormalization ,High Energy Physics - Phenomenology ,Theoretical physics ,High Energy Physics - Phenomenology (hep-ph) ,High Energy Physics - Theory (hep-th) ,Covariant transformation ,Gauge theory ,Effective action ,Mathematics::Symplectic Geometry ,Heat kernel ,Orbifold ,Particle Physics - Theory - Abstract
We employ the covariant background formalism to derive generic expressions for the one-loop effective action in field theoretic orbifold compactifications. The contribution of each orbifold sector is given by the effective action of its fixed torus with a shifted mass matrix. We thus study in detail the computation of the heat kernel on tori. Our formalism manifestly separates UV sensitive (local) from UV-insensitive (nonlocal) renormalization. To exemplify our methods, we study the effective potential of 6d gauge theory as well as kinetic terms for gravitational moduli in 11d supergravity., Comment: 30 pages, 1 figure, 3 tables, v2: appendix on zeta function regularization added, discussion of 6d example expanded, version to appear in JHEP
- Published
- 2008
24. Radiative Scherk-Schwarz supersymmetry breaking
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Antonio Riotto, Mariano Quiros, and Gero von Gersdorff
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Physics ,High Energy Physics - Theory ,Nuclear and High Energy Physics ,Group (mathematics) ,Supergravity ,High Energy Physics::Phenomenology ,FOS: Physical sciences ,Supersymmetry breaking ,Hidden sector ,High Energy Physics::Theory ,High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,High Energy Physics - Theory (hep-th) ,Radiative transfer ,Brane ,Orbifold ,Vacuum expectation value ,Mathematical physics - Abstract
We analyze the Scherk-Schwarz (SS) supersymmetry breaking in brane-world five dimensional theories compactified on the orbifold $S^1/\mathbb{Z}_2$. The SS breaking parameter is undetermined at the tree-level (no-scale supergravity) and can be interpreted as the Hosotani vacuum expectation value corresponding to the $U(1)_R$ group in five dimensional N=2 (ungauged) supergravity. We show that the SS breaking parameter is fixed at the loop level to either 0 or 1/2 depending on the matter content propagating in the bulk but in a rather model-independent way. Supersymmetry breaking is therefore fixed through a radiative Scherk-Schwarz mechanism. We also show that the two discrete values of the SS parameter, as well as the supersymmetry breaking shift in the spectrum of the bulk fields, are altered in the presence of a brane-localized supersymmetry breaking arising from some hidden sector dynamics. The interplay between the SS and the brane localized breaking is studied in detail., 16 pages, 2 figures, uses axodraw. References added
- Published
- 2002
25. One-loop Higgs mass finiteness in supersymmetric Kaluza–Klein theories
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P. John, Mariano Quiros, Gero von Gersdorff, and Antonio Delgado
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle physics ,Kaluza–Klein theory ,Superpotential ,High Energy Physics::Phenomenology ,FOS: Physical sciences ,Supersymmetry ,Lambda ,Coupling (probability) ,High Energy Physics - Phenomenology ,High Energy Physics::Theory ,High Energy Physics - Phenomenology (hep-ph) ,Higgs boson ,Phenomenology ,High Energy Physics ,Brane ,Orbifold - Abstract
This is Version nr. 2 (28 Aug 2001) of the original paper (11 Apr 2001). Includes corrected typos., We analyze the one-loop ultraviolet sensitivity of the Higgs mass in a five-dimensional supersymmetric theory compactified on the orbifold S^1/Z_2, with superpotential localized on a fixed-point brane. Four-dimensional supersymmetry is broken by Scherk-Schwarz boundary conditions. Kaluza-Klein interactions are regularized by means of a brane Gaussian distribution along the extra dimension with length l_s\simeq\Lambda^{-1}_s, where \Lambda_s is the cutoff of the five-dimensional theory. The coupling of the n-mode, with mass M^{(n)}, acquires the n-dependent factor exp{-(M^{(n)}/\Lambda_s)^2/2}, which makes it to decouple for M^{(n)}\gg \Lambda_s. The sensitivity of the Higgs mass on \Lambda_s is strongly suppressed and quadratic divergences cancel by supersymmetry. The one-loop correction to the Higgs mass is finite and equals, for large values of \Lambda_s, the value obtained by the so-called KK-regularization., Work supported in part by CICYT, Spain, under contract AEN98-0816, and by EU under contracts HPRN-CT-2000-00152 and HPRN-CT-2000-00148.
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26. Anomalous gauge couplings from composite Higgs and warped extra dimensions
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Gero von Gersdorff, Sylvain Fichet, Universidade Federal do Rio Grande do Norte (UFRN), and Universidade Estadual Paulista (Unesp)
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Physics ,Particle physics ,Nuclear and High Energy Physics ,Electroweak interaction ,Electromagnetic Processes and Properties ,High Energy Physics::Phenomenology ,Graviton ,FOS: Physical sciences ,Observable ,Field Theories in Higher Dimensions ,Technicolor and Composite Models ,Parameter space ,Extra dimensions ,High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,Composite Higgs models ,Beyond Standard Model ,Higgs boson ,High Energy Physics::Experiment ,Brane - Abstract
We examine trilinear and quartic anomalous gauge couplings (AGCs) generated in composite Higgs models and models with warped extra dimensions. We first revisit the SU(2)_L x U(1)_Y effective Lagrangian and derive the charged and two-photon neutral AGCs. We derive the general perturbative contributions to the pure field-strength operators from spin 0, 1/2, 1 resonances by means of the heat kernel method. In the composite Higgs framework, we derive the pattern of expected deviations from typical SO(N) embeddings of the light composite top partner. We then study a generic warped extra dimension framework with AdS_5 background, recasting in few parameters the features of models relevant for AGCs. We also present a detailed study of the latest bounds from electroweak and Higgs precision observables, with and without brane kinetic terms. For vanishing brane kinetic terms, we find that the S and T parameters exclude KK gauge modes of the RS custodial [non-custodial] scenario below 7.7 [14.7] TeV, for a brane Higgs and below 6.6 [8.1] TeV for a Pseudo Nambu-Goldstone Higgs, at 95% CL. These constraints can be relaxed in presence of brane kinetic terms. The leading AGCs are probing the KK gravitons and the KK modes of bulk gauge fields in parts of the parameter space. In these scenarios, the future CMS and ATLAS forward proton detectors could be sensitive to the effect of KK gravitons in the multi-TeV mass range., Comment: 37 pages, 2 figures, 3 tables. Minor typos fixed, some comments and references added. Matches JHEP version
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27. The excitation of the global symmetry-breaking vacuum in composite Higgs models
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Gero von Gersdorff, Eduardo Pontón, Rogerio Rosenfeld, Sylvain Fichet, Universidade Estadual Paulista (Unesp), and Pontificia Univ Catolica Rio de Janeiro
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Global Symmetries ,Physics ,Gauge boson ,Particle physics ,Nuclear and High Energy Physics ,Large Hadron Collider ,010308 nuclear & particles physics ,High Energy Physics::Lattice ,High Energy Physics::Phenomenology ,FOS: Physical sciences ,Technicolor and Composite Models ,Global symmetry ,Renormalization group ,01 natural sciences ,Gluon ,High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,Composite Higgs models ,0103 physical sciences ,Goldstone boson ,Higgs boson ,High Energy Physics::Experiment ,010306 general physics - Abstract
We consider scenarios of Higgs compositeness where the Higgs doublet arises as a pseudo-Nambu Goldstone boson. Our focus is the physical scalar ("radial") excitation associated with the global symmetry breaking vacuum, which we call the "global Higgs". For the minimal case of a $SO(5)/SO(4)$ coset, the couplings of the global Higgs to Standard Model (SM) particles are fully determined by group theoretical factors and two decay constants. The global Higgs also couples to the composite resonances of the theory, inducing an interaction with the SM gauge bosons at one-loop. We thoroughly analyze representative fermionic sectors, considering a global Higgs both in the $\bf 5$ and $\bf 14$ representations of $SO(5)$ and taking into account the renormalization group evolution of couplings in the composite sector. We derive the one-loop effective couplings and all decays of the global Higgs, showing that its decay width over mass can range from $ O (10^{-3})$ to $ O(1)$. Because of the multiplicity of the resonances, the coupling of the global Higgs to gluons is sizeable, potentially opening a new window into composite models at the LHC., 27 pages, 2 figures. v3: References and comments added. Matches JHEP version
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28. Measurement of interaction-dressed Berry curvature and quantum metric in solids by optical absorption
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Wei Chen, Gero von Gersdorff
- Subjects
Physics ,QC1-999 - Abstract
The quantum geometric properties of a Bloch state in momentum space are usually described by the Berry curvature and quantum metric. In realistic gapped materials where interactions and disorder render the Bloch state not a viable starting point, we generalize these concepts by introducing dressed Berry curvature and quantum metric at finite temperature, in which the effect of many-body interactions can be included perturbatively. These quantities are extracted from the charge polarization susceptibility caused by linearly or circularly polarized electric fields, whose spectral functions can be measured from momentum-resolved exciton or infrared absorption rate. As a concrete example, we investigate Chern insulators in the presence of impurity scattering, whose results suggest that the quantum geometric properties are protected by the energy gap against many-body interactions.
- Published
- 2022
- Full Text
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