3,851 research outputs found
A Preliminary Look at the Physics Reach of a Solar Neutrino TPC: Time-Independent Two Neutrino Oscillations
This paper will discuss the physics reach of a solar neutrino TPC containing
many tons of He4 under high pressure. Particular attention is given to the LMA
and SMA solutions, which are allowed by current data, and which are
characterized by a lack of time-dependent phenomena (either summer-winter or
day-night asymmetries). In this case, the physics of neutrino masses and mixing
is all contained in the energy dependence of the electron neutrino survival
probability, (or in its reciprocal, the electron neutrino disappearance
probability).Comment: 19 pages, 12 figure
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Association of Systemic Inflammation With Retinal Vascular Caliber in Patients With AIDS.
PurposeTo evaluate relationships among retinal vascular caliber and biomarkers of systemic inflammation in patients with AIDS.MethodsA total of 454 participants with AIDS had retinal vascular caliber (central retinal artery equivalent and central retinal vein equivalent) determined from enrollment retinal photographs by reading center graders masked to clinical and biomarker information. Cryopreserved plasma specimens were assayed for inflammatory biomarkers, including C-reactive protein (CRP), IL-6, interferon-γ inducible protein (IP)-10, kynurenine/tryptophan (KT) ratio, and intestinal fatty acid binding protein (I-FABP).ResultsIn the simple linear regression of retinal vascular caliber on plasma biomarkers, elevated CRP, IL-6, and IP-10 were associated with retinal venular dilation, and elevated KT ratio with retinal arteriolar narrowing. In the multiple linear regression, including baseline characteristics and plasma biomarkers, AMD was associated with dilation of retinal arterioles (mean difference: 9.1 μm; 95% confidence interval [CI] 5.2, 12.9; P < 0.001) and venules (mean difference, 10.9 μm; 95% CI, 5.3, 16.6; P < 0.001), as was black race (P < 0.001). Hyperlipidemia was associated with retinal venular narrowing (mean difference, -7.5 μm; 95% CI, -13.7, -1.2; P = 0.02); cardiovascular disease with arteriolar narrowing (mean difference, -5.2 μm; 95% CI, -10.3, -0.1; P = 0.05); age with arteriolar narrowing (slope, -0.26 μm/year; 95% CI, -0.46, -0.06; P = 0.009); and IL-6 with venular dilation (slope, 5.3 μm/standard deviation log10[plasma IL-6 concentration]; 95% CI, 2.7, 8.0; P < 0.001).ConclusionsThese data suggest that retinal vascular caliber is associated with age, race, AMD, hyperlipidemia, cardiovascular disease, and selected biomarkers of systemic inflammation
Dynamic critical behavior of the worm algorithm for the Ising model
We study the dynamic critical behavior of the worm algorithm for the two- and three-dimensional Ising models, by Monte Carlo simulation. The autocorrelation functions exhibit an unusual three-time-scale behavior. As a practical matter, the worm algorithm is slightly more efficient than Swendsen-Wang for simulating the two-point function of the three-dimensional Ising model
Improved KL->pi e nu Form Factor and Phase Space Integral with Reduced Model Uncertainty
Using the published KTeV sample of 2 million KL-> pi e nu decays and a new
form factor expansion with a rigorous bound on higher order terms, we present a
new determination of the KL->pi e nu form factor and phase space integral.
Compared to the previous KTeV result, the uncertainty in the new form factor
expansion is negligible and results in an overall uncertainty in the phase
space integral (IKe) that is a factor of two smaller: IKe = 0.15392 +- 0.00048
\.Comment: 3 pages, 2 figures, submitted to PRD Rapid Communicatio
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Search for the Higgs boson decays H -> ee and H -> eμ in pp collisions at root s=13 TeV with the ATLAS detector
Searches for the Higgs boson decays H -> ee and H -> e mu are performed using data corresponding to an integrated luminosity of 139 fb(-1) collected with the ATLAS detector in pp collisions at root s = 13 TeV at the LHC. No significant signals are observed, in agreement with the Standard Model expectation. For a Higgs boson mass of 125 GeV, the observed (expected) upper limit at the 95% confidence level on the branching fraction B(H -> ee) is 3.6 x 10(-4) (3.5 x 10(-4)) and on B(H -> e mu) is 6.2 x 10(-5) (5.9 x 10(-5)). These results represent improvements by factors of about five and six on the previous best limits on B(H -> ee) and B(H -> e mu) respectively. (C) 2019 The Author. Published by Elsevier B.V.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Determination of the Parity of the Neutral Pion via the Four-Electron Decay
We present a new determination of the parity of the neutral pion via the
double Dalitz decay pi^0 -> e+ e- e+ e-. Our sample, which consists of 30511
candidate decays, was collected from K_L -> pi0 pi0 pi0 decays in flight at the
KTeV-E799 experiment at Fermi National Accelerator Laboratory. We confirm the
negative pi^0 parity, and place a limit on scalar contributions to the pi^0 ->
e+ e- e+ e- decay amplitude of less than 3.3% assuming CPT conservation. The
pi^0 gamma* gamma* form factor is well described by a momentum-dependent model
with a slope parameter fit to the final state phase space distribution.
Additionally, we have measured the branching ratio of this mode to be B(pi^0 ->
e+ e- e+ e-) = (3.26 +- 0.18) x 10^(-5).Comment: 5 pages, 4 figures. Typographical error in radiative branching ratio
(Eq. 6) correcte
Measurements of the Decay
The E799-II (KTeV) experiment at Fermilab has collected 83262 events above a background of 79 events. We measure a decay width,
normalized to the (\pi^0 \to \gamma\gamma, \pi^0 to
\gamma\gamma, \pi^0_D \to e^+e^-\gamma) decay width, of K_L \to
e^+e^-\gamma. We also measure parameters of two form factor models. In the Bergstrom, Masso, and Singer
(BMS) parametrization, we find \caks = -0.517 \pm 0.030_{stat} \pm
0.022_{syst}. We separately fit for the first parameter of the D'Ambrosio,
Isidori, and Portoles (DIP) model and find \adip = -1.729 \pm 0.043_{stat} \pm
0.028_{syst}.Comment: 5 pages, 3 figures, submitted to PR
Detailed Study of the KL -> 3pi0 Dalitz Plot
Using a sample of 68 million KL -> 3pi0 decays collected in 1996-1999 by the
KTeV (E832) experiment at Fermilab, we present a detailed study of the KL ->
3pi0 Dalitz plot density. We report the first observation of interference from
KL->pi+pi-pi0 decays in which pi+pi- rescatters to 2pi0 in a final-state
interaction. This rescattering effect is described by the Cabibbo-Isidori
model, and it depends on the difference in pion scattering lengths between the
isospin I=0 and I=2 states, a0-a2. Using the Cabibbo-Isidori model, we present
the first measurement of the KL-> 3pi0 quadratic slope parameter that accounts
for the rescattering effect.Comment: accepted by Phys. Rev
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