169 research outputs found
The ATLAS discovery potential for MSSM neutral Higgs bosons decaying to a mu+mu- pair in the mass range up to 130 GeV
Results are presented on the discovery potential for MSSM neutral Higgs
bosons in the Mh-{max}scenario. The region of large tan beta, between 15 and
50, and mass between ~ 95 and 130 GeV is considered in the framework of the
ATLAS experiment at the Large Hadron Collider (LHC), for a centre-of-mass
energy = 14 TeV. This parameter region is not fully covered by the present data
either from LEP or from Tevatron. The h/A bosons, supposed to be very close in
mass in that region, are studied in the channel h/A -> mu+mu- accompanied by
two b-jets. The study includes a method to control the most copious background,
Zo -> mu+mu- accompanied by two b-jets. A possible contribution of the H boson
to the signal is also considered
Higgs-boson production associated with a bottom quark at hadron colliders with SUSY-QCD corrections
The Higgs boson production p p (p\bar p) -> b h +X via b g -> b h at the LHC,
which may be an important channel for testing the bottom quark Yukawa coupling,
is subject to large supersymmetric quantum corrections. In this work the
one-loop SUSY-QCD corrections to this process are evaluated and are found to be
quite sizable in some parameter space. We also study the behavior of the
corrections in the limit of heavy SUSY masses and find the remnant effects of
SUSY-QCD. These remnant effects, which are left over in the Higgs sector by the
heavy sparticles, are found to be so sizable (for a light CP-odd Higgs and
large \tan\beta) that they might be observable in the future LHC experiment.
The exploration of such remnant effects is important for probing SUSY,
especially in case that the sparticles are too heavy (above TeV) to be directly
discovered at the LHC.Comment: Results for the Tevatron adde
Sterols sense swelling in lipid bilayers
In the mimetic membrane system of phosphatidylcholine bilayers, thickening
(pre-critical behavior, anomalous swelling) of the bilayers is observed, in the
vicinity of the main transition, which is non-linear with temperature. The
sterols cholesterol and androsten are used as sensors in a time-resolved
simultaneous small- and wide angle x-ray diffraction study to investigate the
cause of the thickening. We observe precritical behavior in the pure lipid
system, as well as with sterol concentrations less than 15%. To describe the
precritical behavior we introduce a theory of precritical phenomena.The good
temperature resolution of the data shows that a theory of the influence of
fluctuations needs modification. The main cause of the critical behavior
appears to be a changing hydration of the bilayer.Comment: 11 pages, 7 ps figures included, to appear in Phys.Rev.
Charged Higgs production from SUSY particle cascade decays at the LHC
We analyze the cascade decays of the scalar quarks and gluinos of the Minimal
Supersymmetric extension of the Standard Model, which are abundantly produced
at the Large Hadron Collider, into heavier charginos and neutralinos which then
decay into the lighter ones and charged Higgs particles, and show that they can
have substantial branching fractions. The production rates of these Higgs
bosons can be much larger than those from the direct production mechanisms, in
particular for intermediate values of the parameter , and could
therefore allow for the detection of these particles. We also discuss charged
Higgs boson production from direct two-body top and bottom squark decays as
well as from two- and three-body gluino decays.Comment: 30 pages with 10 figures, latex. Uses axodraw.sty and epsfig.st
Higgs Boson Theory and Phenomenology
Precision electroweak data presently favors a weakly-coupled Higgs sector as
the mechanism responsible for electroweak symmetry breaking. Low-energy
supersymmetry provides a natural framework for weakly-coupled elementary
scalars. In this review, we summarize the theoretical properties of the
Standard Model (SM) Higgs boson and the Higgs sector of the minimal
supersymmetric extension of the Standard Model (MSSM). We then survey the
phenomenology of the SM and MSSM Higgs bosons at the Tevatron, LHC and a future
e+e- linear collider. We focus on the Higgs discovery potential of present and
future colliders and stress the importance of precision measurements of Higgs
boson properties.Comment: 90 pages, 31 figures. Revised version. To be published in Progress in
Particle and Nuclear Physics. This paper with higher resolution figures can
be found at http://scipp.ucsc.edu/~haber/higgsreview/higgsrev.p
Outcome of COVID-19 in hospitalised immunocompromised patients: an analysis of the WHO ISARIC CCP-UK prospective cohort study
Background
Immunocompromised patients may be at higher risk of mortality if hospitalised with Coronavirus Disease 2019 (COVID-19) compared with immunocompetent patients. However, previous studies have been contradictory. We aimed to determine whether immunocompromised patients were at greater risk of in-hospital death and how this risk changed over the pandemic.
Methods and findings
We included patients > = 19 years with symptomatic community-acquired COVID-19 recruited to the ISARIC WHO Clinical Characterisation Protocol UK prospective cohort study. We defined immunocompromise as immunosuppressant medication preadmission, cancer treatment, organ transplant, HIV, or congenital immunodeficiency. We used logistic regression to compare the risk of death in both groups, adjusting for age, sex, deprivation, ethnicity, vaccination, and comorbidities. We used Bayesian logistic regression to explore mortality over time. Between 17 January 2020 and 28 February 2022, we recruited 156,552 eligible patients, of whom 21,954 (14%) were immunocompromised. In total, 29% (n = 6,499) of immunocompromised and 21% (n = 28,608) of immunocompetent patients died in hospital. The odds of in-hospital mortality were elevated for immunocompromised patients (adjusted OR 1.44, 95% CI [1.39, 1.50], p 80 years was 99% for men and 98% for women. The study is limited by a lack of detailed drug data prior to admission, including steroid doses, meaning that we may have incorrectly categorised some immunocompromised patients as immunocompetent.
Conclusions
Immunocompromised patients remain at elevated risk of death from COVID-19. Targeted measures such as additional vaccine doses, monoclonal antibodies, and nonpharmaceutical preventive interventions should be continually encouraged for this patient group
Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.
BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362
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