236 research outputs found
Z boson pair production at LHC in a stabilized Randall-Sundrum scenario
We study the Z boson pair production at LHC in the Randall-Sundrum scenario
with the Goldberger-Wise stabilization mechanism. It is shown that
comprehensive account of the Kaluza-Klein graviton and radion effects is
crucial to probe the model: The KK graviton effects enhance the cross section
of on the whole so that the resonance peak of the radion becomes
easy to detect, whereas the RS effects on the process are
rather insignificant. The and invariant-mass distributions are presented
to study the dependence of the RS model parameters. The production of
longitudinally polarized Z bosons, to which the SM contributions are
suppressed, is mainly due to KK gravitons and the radion, providing one of the
most robust methods to signal the RS effects. The sensitivity bounds
on with are also obtained such that
the effective weak scale of order 5 TeV can be experimentally
probed.Comment: 28 pages, LaTex file, 18 eps figure
The interplay of type I and type II interferons in murine autoimmune cholangitis as a basis for sex-biased autoimmunity
We have reported on a murine model of autoimmune cholangitis, generated by altering the AU-rich element (ARE) by deletion of the interferon gamma (IFN-γ) 3\u27 untranslated region (coined ARE-Del−/−), that has striking similarities to human primary biliary cholangitis (PBC) with female predominance. Previously, we suggested that the sex bias of autoimmune cholangitis was secondary to intense and sustained type I and II IFN signaling. Based on this thesis, and to define the mechanisms that lead to portal inflammation, we specifically addressed the hypothesis that type I IFNs are the driver of this disease. To accomplish these goals, we crossed ARE-Del−/− mice with IFN type I receptor alpha chain (Ifnar1) knockout mice. We report herein that loss of type I IFN receptor signaling in the double construct of ARE-Del−/− Ifnar1−/− mice dramatically reduces liver pathology and abrogated sex bias. More importantly, female ARE-Del−/− mice have an increased number of germinal center (GC) B cells as well as abnormal follicular formation, sites which have been implicated in loss of tolerance. Deletion of type I IFN signaling in ARE-Del−/− Ifnar1−/− mice corrects these GC abnormalities, including abnormal follicular structure. Conclusion: Our data implicate type I IFN signaling as a necessary component of the sex bias of this murine model of autoimmune cholangitis. Importantly these data suggest that drugs that target the type I IFN signaling pathway would have potential benefit in the earlier stages of PBC. (Hepatology 2018;67:1408-1419)
The Leptonic Higgs as a Messenger of Dark Matter
We propose that the leptonic cosmic ray signals seen by PAMELA and ATIC
result from the annihilation or decay of dark matter particles via states of a
leptonic Higgs doublet to leptons, linking cosmic ray signals of dark
matter to LHC signals of the Higgs sector. The states of the leptonic Higgs
doublet are lighter than about 200 GeV, yielding large and
event rates at the LHC. Simple models are
given for the dark matter particle and its interactions with the leptonic
Higgs, for cosmic ray signals arising from both annihilations and decays in the
galactic halo. For the case of annihilations, cosmic photon and neutrino
signals are on the verge of discovery.Comment: 34 pages, 9 figures, minor typos corrected, references adde
Experimental Probes of Localized Gravity: On and Off the Wall
The phenomenology of the Randall-Sundrum model of localized gravity is
analyzed in detail for the two scenarios where the Standard Model (SM) gauge
and matter fields are either confined to a TeV scale 3-brane or may propagate
in a slice of five dimensional anti-deSitter space. In the latter instance, we
derive the interactions of the graviton, gauge, and fermion Kaluza-Klein (KK)
states. The resulting phenomenological signatures are shown to be highly
dependent on the value of the 5-dimensional fermion mass and differ
substantially from the case where the SM fields lie on the TeV-brane. In both
scenarios, we examine the collider signatures for direct production of the
graviton and gauge KK towers as well as their induced contributions to
precision electroweak observables. These direct and indirect signatures are
found to play a complementary role in the exploration of the model parameter
space. In the case where the SM field content resides on the TeV-brane, we show
that the LHC can probe the full parameter space and hence will either discover
or exclude this model if the scale of electroweak physics on the 3-brane is
less than 10 TeV. We also show that spontaneous electroweak symmetry breaking
of the SM must take place on the TeV-brane.Comment: 62 pages, Latex, 22 figure
Prevalence and predictors for sustained remission in rheumatoid arthritis
Objective
Remission is a key goal in managing rheumatoid arthritis (RA), with sustained remission as
the preferred sequelae of short-term remission. However little is known about the predictors
of sustained remission for patients reaching remission. Using two independent cohorts, we
aimed to evaluate the prevalence and predictors for sustained remission.
Methods
The study cohort consisted of subjects with RA from the Brigham and Women’s Hospital
Rheumatoid Arthritis Sequential Study (BRASS) and the Korean Observational Study Network for Arthritis (KORONA). We analyzed subjects who reached remission in 2009 with follow up data for two consecutive years. Remission was defined by the Disease Activity Score
28- (DAS28-CRP) of less than 2.6. Sustained remission was defined as three consecutive
annual visits in remission. Predictors for sustained remission were identified by multivariate
logistic regression analysis.
Results
A total of 465 subjects were in remission in 2009. Sustained remission was achieved by 53
of 92 (57.5%) in BRASS and by 198 of 373 (53.1%) in KORONA. In multivariate analyses,
baseline predictors of sustained remission were: disease duration less than 5 years [odds
ratio (OR) 1.96, 95% confidence interval (95% CI) 1.08–3.58], Modified Health Assessment
Questionnaire (MHAQ) score of 0 (OR 1.80, 95% CI 1.18–2.74), and non-use of oral glucocorticoid (OR 1.58, 95% CI 1.01–2.47). Conclusion
More than half of RA subjects in remission in 2009 remained in remission through 2011.
Short disease duration, no disability, and non-use of oral glucocorticoid at baseline were
associated with sustained remission
Filgotinib versus placebo or adalimumab in patients with rheumatoid arthritis and inadequate response to methotrexate: a phase III randomised clinical trial
Objective To evaluate the efficacy and safety of the Janus kinase-1-preferential inhibitor filgotinib versus placebo or tumour necrosis factor-alpha inhibitor therapy in patients with active rheumatoid arthritis (RA) despite ongoing treatment with methotrexate (MTX).Methods This 52-week, multicentre, double-blind, placebo-controlled and active-controlled phase III trial evaluated once-daily oral filgotinib in patients with RA randomised 3:3:2:3 to filgotinib 200 mg (FIL200) or filgotinib 100 mg (FIL100), subcutaneous adalimumab 40 mg biweekly, or placebo (through week 24), all with stable weekly background MTX. The primary endpoint was the proportion of patients achieving 20% improvement in American College of Rheumatology criteria (ACR20) at week 12. Additional efficacy outcomes were assessed sequentially. Safety was assessed from adverse events and laboratory abnormalities.Results The proportion of patients (n=1755 randomised and treated) achieving ACR20 at week 12 was significantly higher for FIL200 (76.6%) and FIL100 (69.8%) versus placebo (49.9%; treatment difference (95% CI), 26.7% (20.6% to 32.8%) and 19.9% (13.6% to 26.2%), respectively; both p<0.001). Filgotinib was superior to placebo in key secondary endpoints assessing RA signs and symptoms, physical function and structural damage. FIL200 was non-inferior to adalimumab in terms of Disease Activity Score in 28 joints with C reactive protein <= 3.2 at week 12 (p<0.001); FIL100 did not achieve non-inferiority. Adverse events and laboratory abnormalities were comparable among active treatment arms.Conclusions Filgotinib improved RA signs and symptoms, improved physical function, inhibited radiographic progression and was well tolerated in patients with RA with inadequate response to MTX. FIL200 was non-inferior to adalimumab.Pathophysiology and treatment of rheumatic disease
Narrowband Searches for Continuous and Long-duration Transient Gravitational Waves from Known Pulsars in the LIGO-Virgo Third Observing Run
Isolated neutron stars that are asymmetric with respect to their spin axis are possible sources of detectable continuous gravitational waves. This paper presents a fully coherent search for such signals from eighteen pulsars in data from LIGO and Virgo's third observing run (O3). For known pulsars, efficient and sensitive matched-filter searches can be carried out if one assumes the gravitational radiation is phase-locked to the electromagnetic emission. In the search presented here, we relax this assumption and allow both the frequency and the time derivative of the frequency of the gravitational waves to vary in a small range around those inferred from electromagnetic observations. We find no evidence for continuous gravitational waves, and set upper limits on the strain amplitude for each target. These limits are more constraining for seven of the targets than the spin-down limit defined by ascribing all rotational energy loss to gravitational radiation. In an additional search, we look in O3 data for long-duration (hours-months) transient gravitational waves in the aftermath of pulsar glitches for six targets with a total of nine glitches. We report two marginal outliers from this search, but find no clear evidence for such emission either. The resulting duration-dependent strain upper limits do not surpass indirect energy constraints for any of these targets. © 2022. The Author(s). Published by the American Astronomical Society
Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model
We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society
Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background
The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω0T<5.58×10-8, Ω0V<6.35×10-8, and Ω0S<1.08×10-7 at a reference frequency f0=25 Hz. © 2018 American Physical Society
Erratum: "A Gravitational-wave Measurement of the Hubble Constant Following the Second Observing Run of Advanced LIGO and Virgo" (2021, ApJ, 909, 218)
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