17 research outputs found
Predicting the Sparticle Spectrum from GUTs via SUSY Threshold Corrections with SusyTC
Grand Unified Theories (GUTs) can feature predictions for the ratios of quark
and lepton Yukawa couplings at high energy, which can be tested with the
increasingly precise results for the fermion masses, given at low energies. To
perform such tests, the renormalization group (RG) running has to be performed
with sufficient accuracy. In supersymmetric (SUSY) theories, the one-loop
threshold corrections (TC) are of particular importance and, since they affect
the quark-lepton mass relations, link a given GUT flavour model to the
sparticle spectrum. To accurately study such predictions, we extend and
generalize various formulas in the literature which are needed for a precision
analysis of SUSY flavour GUT models. We introduce the new software tool SusyTC,
a major extension to the Mathematica package REAP, where these formulas are
implemented. SusyTC extends the functionality of REAP by a full inclusion of
the (complex) MSSM SUSY sector and a careful calculation of the one-loop SUSY
threshold corrections for the full down-type quark, up-type quark and charged
lepton Yukawa coupling matrices in the electroweak-unbroken phase. Among other
useful features, SusyTC calculates the one-loop corrected pole mass of the
charged (or the CP-odd) Higgs boson as well as provides output in SLHA
conventions, i.e. the necessary input for external software, e.g. for
performing a two-loop Higgs mass calculation. We apply SusyTC to study the
predictions for the parameters of the CMSSM (mSUGRA) SUSY scenario from the set
of GUT scale Yukawa relations , , and
, which has been proposed recently in the context of SUSY
GUT flavour models.Comment: 54 pages, 12 figures. SusyTC can be downloaded from
http://particlesandcosmology.unibas.ch/pages/SusyTC.ht
Predicting the flavour and SUSY flavour structure from grand unified theories
Grand Unified Theories (GUTs) offer an attractive framework for flavour models, since they feature relations between quarks and leptons. Combining them with Supersymmetry (SUSY) and flavour symmetries, we derive predictions for the flavour and SUSY flavour structure from various GUT models and discuss how the double missing partner mechanism (DMPM) solution to the doublet-triplet splitting problem can be combined with predictions for GUT scale quark-lepton Yukawa coupling relations.
We construct two predictive SUSY SU(5) GUT models with an A4 flavour symmetry, that feature realistic quark-lepton Yukawa coupling ratios and mixing angle relations. These GUT scale predictions arise after GUT symmetry breaking from a novel combination of group theoretical Clebsch-Gordan factors, and we carefully construct additional shaping symmetries and renormalisable messenger sectors to protect the models' predictions from dangerous corrections. The major difference between both models are their respective predictions of a normal and inverse neutrino mass ordering. We perform Markov Chain Monte Carlo analyses, fit to experimental data, and discuss how the models can be tested by present and future experiments.
To combine predictive GUT scale quark-lepton Yukawa coupling ratios with the DMPM in SUSY SU(5), we introduce a second GUT breaking Higgs field in the adjoint representation. Two explicit flavour models with different predictions for the GUT scale Yukawa sector are presented, including shaping symmetries and renormalisable messenger sectors, and combined with the DMPM. We calculate the effective masses of the colour triplets mediating proton decay and find that they can be made sufficiently heavy.
In SUSY theories, the one-loop SUSY threshold corrections are of particular importance in investigating GUT scale quark-lepton mass relations and thus link a given GUT flavour model to the sparticle spectrum. We calculate the one-loop SUSY threshold corrections of the full MSSM Yukawa coupling matrices in the electroweak-unbroken phase and introduce a new software tool SusyTC as a major extension to the Mathematica package REAP. Finally we find predictions for the CMSSM parameters and sparticle masses from the GUT scale Yukawa coupling ratios used in the flavour models of this thesis
\theta^PMNS_13 = \theta_C / \sqrt2 from GUTs
The recent observations of the leptonic mixing angle \theta^PMNS_13 are
consistent with \theta^PMNS_13 = \theta_C / \sqrt2 (with \theta_C being the
Cabibbo angle \theta^CKM_12). We discuss how this relation can emerge in Grand
Unified Theories (GUTs) via charged lepton corrections. The key ingredient is
that in GUTs the down-type quark Yukawa matrix and the charged lepton Yukawa
matrix are generated from the same set of GUT operators, which implies that the
resulting entries are linked and differ only by group theoretical Clebsch
factors. This allows a link \theta^e_12 = \theta_C to be established, which can
induce \theta^PMNS_13 = \theta_C / \sqrt2 provided that the 1-3 mixing in the
neutrino mass matrix is much smaller than \theta_C. We find simple conditions
under which \theta^PMNS_13 = \theta_C / \sqrt2 can arise via this link in SU(5)
GUTs and Pati-Salam models. We also discuss possible corrections to this
relation. Using lepton mixing sum rules different neutrino mixing patterns can
be distinguished by their predictions for the Dirac CP phase \delta^PMNS.Comment: v3: 18 pages, section on corrections to exact relation adde
Towards predictive flavour models in SUSY SU(5) GUTs with doublet-triplet splitting
We discuss how the double missing partner mechanism solution to the
doublet-triplet splitting problem in four-dimensional supersymmetric SU(5)
Grand Unified Theories (GUTs) can be combined with predictive models for the
quark-lepton Yukawa coupling ratios at the GUT scale. It is argued that towards
this goal a second SU(5) breaking Higgs field in the adjoint representation is
very useful and we discuss all possible renormalizable superpotentials with two
adjoint Higgs fields and calculate the constraints on the GUT scale and
effective triplet mass from a two-loop gauge coupling unification analysis. Two
explicit flavour models with different predictions for the GUT scale Yukawa
sector are presented, including shaping symmetries and a renormalizable
messenger sector. Towards calculating the rates for proton decay induced by the
exchange of colour triplets, the required Clebsch-Gordan coefficients for their
couplings are calculated for the possible dimension five and six operators.
They are provided in detailed tables in the appendix, together with additional
helpful material for GUT flavour model building.Comment: 47 pages, 9 figures; version published in JHE
A flavour GUT model with theta_13^PMNS = theta_C / sqrt(2)
We propose a supersymmetric SU(5) GUT model with an A_4 family symmetry -
including a full flavon- and messenger sector - which realises the relation
theta_13^PMNS \simeq theta_C / sqrt(2). The neutrino sector features
tri-bimaximal mixing, and theta_13^PMNS \simeq theta_C / sqrt(2) emerges from
the charged lepton contribution to the PMNS matrix, which in turn is linked to
quark mixing via specific GUT relations. These GUT relations arise after GUT
symmetry breaking from a novel combination of group theoretical Clebsch-Gordan
factors, which in addition to large theta_13^PMNS lead to promising quark
lepton mass ratios for all generations of quarks and leptons and to m_s / m_d =
18.95_(-0.24)^(+0.33), in excellent agreement with experimental results. The
model also features spontaneous CP violation, with all quark and lepton CP
phases determined from family symmetry breaking. We perform a full Markov Chain
Monte Carlo fit to the available quark and lepton data, and discuss how the
model can be tested by present and future experiments.Comment: 21 pages, version accepted for publication in Nuclear Physics
Prediction of RECRUITment In randomized clinical Trials (RECRUIT-IT)— : —rationale and design for an international collaborative study
Funding: BK has received a project specific grant from the University of Basel to realize this project. In addition, this study is supported by the Swiss National Science Foundation (grant 320030_149496/1) and the Gottfried and Julia Bangerter-Rhyner Foundation. The provided work by BG, JHL, CW, and JY has been supported by the National Cancer Institute Cancer Centre Support Grant P30 CA168524 and used BISR core. The Health Services Research Unit, University of Aberdeen, receives core funding from the Chief Scientist Office of the Scottish Government Health Directorates. DC is supported by a Research Chair from the Canadian Institute for Health Research. The mentioned funding sources have no role in the design and conduct of the study; the collection, management, analysis, and interpretation of the data; the preparation, review, or approval of the manuscript; or the decision to submit the manuscript for publication.Peer reviewedPublisher PD
Glucocorticoid withdrawal and glucocorticoid-induced adrenal insufficiency: Study protocol of the randomized controlled «TOASST" (Taper Or Abrupt Steroid STop) multicenter trial
BACKGROUND
Despite the widespread use of glucocorticoids in inflammatory and autoimmune disorders, there is uncertainty about the safe cessation of long-term systemic treatment, as data from prospective trials are largely missing. Due to potential disease relapse or glucocorticoid-induced hypocortisolism, the drug is often tapered to sub-physiological doses rather than stopped when the underlying disease is clinically stable, increasing the cumulative drug exposure. Conversely, the duration of exposure to glucocorticoids should be minimized to lower the risk of side effects.
METHODS
We designed a multicenter, randomized, triple-blinded, placebo-controlled trial to test the clinical noninferiority of abrupt glucocorticoid stop compared to tapering after ≥28 treatment days with ≥420 mg cumulative and ≥7.5 mg mean daily prednisone-equivalent dose. 573 adult patients treated systemically for various disorders will be included after their underlying disease has been stabilized. Prednisone in tapering doses or matching placebo is administered over 4 weeks. A 250 mg ACTH-test, the result of which will be revealed a posteriori, is performed at study inclusion; all patients are instructed on glucocorticoid stress cover dosing. Follow-up is for 6 months. The composite primary outcome measure is time to hospitalization, death, initiation of unplanned systemic glucocorticoid therapy, or adrenal crisis. Secondary outcomes include the individual components of the primary outcome, cumulative glucocorticoid doses, signs and symptoms of hypocortisolism, and the performance of the ACTH test in predicting the clinical outcome. Cox proportional hazard, linear, and logistic regression models will be used for statistical analysis.
CONCLUSION
This trial aims to demonstrate the clinical noninferiority and safety of abrupt treatment cessation after ≥28 days of systemic glucocorticoid therapy in patients with stabilized underlying disease.
TRIAL REGISTRATION
ClinicalTrials.gov Identifier: NCT03153527; EUDRA-CT: 2020-005601-48 https://clinicaltrials.gov/ct2/show/NCT03153527?term=NCT03153527&draw=2&rank=1