1,513 research outputs found
Supersymmetric type-III seesaw: lepton flavour violating decays and dark matter
We study a supersymmetric version of the seesaw mechanism type-III. The model
consists of the MSSM particle content plus three copies of 24 superfields. The
fermionic part of the SU(2) triplet contained in the 24 is responsible for the
type-III seesaw, which is used to explain the observed neutrino masses and
mixings. Complete copies of 24 are introduced to maintain gauge coupling
unification. These additional states change the beta functions of the gauge
couplings above the seesaw scale. Using mSUGRA boundary conditions we calculate
the resulting supersymmetric mass spectra at the electro-weak scale using full
2-loop renormalization group equations. We show that the resulting spectrum can
be quite different compared to the usual mSUGRA spectrum. We discuss how this
might be used to obtain information on the seesaw scale from mass measurements.
Constraints on the model space due to limits on lepton flavour violating decays
are discussed. The main constraints come from the bounds on the decay mu to e
and gamma but there are also regions where the decay tau to mu and gamma gives
stronger constraints. We also calculate the regions allowed by the dark matter
constraint. For the sake of completeness, we compare our results with those for
the supersymmetric seesaw type-II and, to some extent, with type-I.Comment: 32 pages, 16 eps figures. One ref. added; small changes in tex
Lepton flavor violation in low-scale seesaw models: SUSY and non-SUSY contributions
Taking the supersymmetric inverse seesaw mechanism as the explanation for
neutrino oscillation data, we investigate charged lepton flavor violation in
radiative and 3-body lepton decays as well as in neutrinoless
conversion in muonic atoms. In contrast to former studies, we take into account
all possible contributions: supersymmetric as well as non-supersymmetric. We
take CMSSM-like boundary conditions for the soft supersymmetry breaking
parameters. We find several regions where cancellations between various
contributions exist, reducing the lepton flavor violating rates by an order of
magnitude compared to the case where only the dominant contribution is taken
into account. This is in particular important for the correct interpretation of
existing data as well as for estimating the reach of near future experiments
where the sensitivity will be improved by one to two orders of magnitude.
Moreover, we demonstrate that ratios like BR()/BR() can be used to determine whether the supersymmetric contributions
dominate over the and contributions or vice versa.Comment: 75 pages, 7 figures. v3: references and comments added. Matches
published versio
The generalised NMSSM at one loop: fine tuning and phenomenology
We determine the degree of fine tuning needed in a generalised version of the
NMSSM that follows from an underlying Z4 or Z8 R symmetry. We find that it is
significantly less than is found in the MSSM or NMSSM and extends the range of
Higgs mass that have acceptable fine tuning up to Higgs masses of mh ~ 130 GeV.
For universal boundary conditions analogous to the CMSSM the phenomenology is
rather MSSM like with the singlet states typically rather heavy. For more
general boundary conditions the singlet states can be light, leading to
interesting signatures at the LHC and direct detection experiments.Comment: 20 pages, 9 figures, matches published versio
Enhancing lepton flavour violation in the supersymmetric inverse seesaw beyond the dipole contribution
In minimal supersymmetric models the -penguin usually provides
sub-dominant contributions to charged lepton flavour violating observables. In
this study, we consider the supersymmetric inverse seesaw in which the
non-minimal particle content allows for dominant contributions of the
-penguin to several lepton flavour violating observables. In particular, and
due to the low-scale (TeV) seesaw, the penguin contribution to, for instance,
\Br(\mu \to 3e) and conversion in nuclei, allows to render some of
these observables within future sensitivity reach. Moreover, we show that in
this framework, the -penguin exhibits the same non-decoupling behaviour
which had previously been identified in flavour violating Higgs decays in the
Minimal Supersymmetric Standard Model.Comment: 29 pages, 9 figures, 4 tables; v2: minor corrections, version to
appear in JHE
Two loop electroweak corrections to and in the B-LSSM
The rare decays and are important to research new physics beyond standard model. In
this work, we investigate two loop electroweak corrections to and in the minimal
supersymmetric extension of the SM with local gauge symmetry (B-LSSM),
under a minimal flavor violating assumption for the soft breaking terms. In
this framework, new particles and new definition of squarks can affect the
theoretical predictions of these two processes, with respect to the MSSM.
Considering the constraints from updated experimental data, the numerical
results show that the B-LSSM can fit the experimental data for the branching
ratios of and . The
results of the rare decays also further constrain the parameter space of the
B-LSSM.Comment: 33 pages, 9 figures, Published in EPJ
Determination of the Oswestry Disability Index score equivalent to a "satisfactory symptom state" in patients undergoing surgery for degenerative disorders of the lumbar spine-a Spine Tango registry-based study.
BACKGROUND CONTEXT
The achievement of a given change score on a valid outcome instrument is commonly used to indicate whether a clinically relevant change has occurred after spine surgery. However, the achievement of such a change score can be dependent on baseline values and does not necessarily indicate whether the patient is satisfied with the current state. The achievement of an absolute score equivalent to a patient acceptable symptom state (PASS) may be a more stringent measure to indicate treatment success.
PURPOSE
This study aimed to estimate the score on the Oswestry Disability Index (ODI, version 2.1a; 0-100) corresponding to a PASS in patients who had undergone surgery for degenerative disorders of the lumbar spine.
STUDY DESIGN/SETTING
This is a cross-sectional study of diagnostic accuracy using follow-up data from an international spine surgery registry.
PATIENT SAMPLE
The sample includes 1,288 patients with degenerative lumbar spine disorders who had undergone elective spine surgery, registered in the EUROSPINE Spine Tango Spine Surgery Registry.
OUTCOME MEASURES
The main outcome measure was the ODI (version 2.1a).
METHODS
Surgical data and data from the ODI and Core Outcome Measures Index (COMI) were included to determine the ODI threshold equivalent to PASS at 1 year (±1.5 months; n=780) and 2 years (±2 months; n=508) postoperatively. The symptom-specific well-being item of the COMI was used as the external criterion in the receiver operating characteristic (ROC) analysis to determine the ODI threshold equivalent to PASS. Separate sensitivity analyses were performed based on the different definitions of an "acceptable state" and for subgroups of patients. JF is a copyright holder of the ODI.
RESULTS
The ODI threshold for PASS was 22, irrespective of the time of follow-up (area under the curve [AUC]: 0.89 [sensitivity {Se}: 78.3%, specificity {Sp}: 82.1%] and AUC: 0.91 [Se: 80.7%, Sp: 85.6] for the 1- and 2-year follow-ups, respectively). Sensitivity analyses showed that the absolute ODI-22 threshold for the two follow-up time-points were robust. A stricter definition of PASS resulted in lower ODI thresholds, varying from 16 (AUC=0.89; Se: 80.2%, Sp: 82.0%) to 18 (AUC=0.90; Se: 82.4%, Sp: 80.4%) depending on the time of follow-up.
CONCLUSIONS
An ODI score ≤22 indicates the achievement of an acceptable symptom state and can hence be used as a criterion of treatment success alongside the commonly used change score measures. At the individual level, the threshold could be used to indicate whether or not a patient with a lumbar spine disorder is a "responder" after elective surgery
Automated DBS Extraction Prior to Hilic/RP LC-MS/MS Target Screening of Drugs
This article describes a rapid LC-MS/MS target screening method based on an automated extraction of 5 mu L dried blood spots (DBS), two 5 min chromatographic runs on orthogonal phase columns (RP and Hilic) and a data dependent acquisition (DDA) of product ions spectra for the reliable identification of the detected compounds. The extraction step was performed in 2 min by using the LC autosampler itself in 96-well plates. This procedure was evaluated using 22 model compounds frequently encountered in forensic investigations, i.e., cocaine, benzodiazepines, amphetamines, opioids, antidepressants and antipsychotics. These investigations showed that even if the extraction step was reduced to a minimum, the extraction recoveries were satisfactory (median value of 40 %) and allowed for the detection of the model compounds in their therapeutic ranges, with the exception of morphine. Moreover, the use of two different chromatographic columns broadened the number of screening targets to those that behaved poorly under RP conditions, such as amphetamines or glucuronides, while keeping chromatographic gradients very short. This procedure was applied to 34 authentic post-mortem cases. It allowed the detection of 89 % of the compounds that were quantified in the routine procedures and the formal identification of 77 % of the compounds using their product ions spectra. These results were considered more than satisfactory compared to routine screening alone (GC-MS and LC-DAD, 55 % compound identification). The method described in this article is therefore a powerful approach for a fast, reliable and efficient target screening of drugs in forensic and clinical investigations
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