2,798 research outputs found
Constraining the Hadronic Contributions to the Muon Anomalous Magnetic Moment
The mini-proceedings of the Workshop on "Constraining the hadronic
contributions to the muon anomalous magnetic moment" which included the "13th
meeting of the Radio MonteCarLow WG" and the "Satellite meeting R-Measurements
at BES-III" held in Trento from April 10th to 12th, 2013, are presented. This
collaboration meeting aims to bring together the experimental e+e- collider
communities from BaBar, Belle, BESIII, CMD2, KLOE, and SND, with theorists
working in the fields of meson transitions form factors, hadronic contributions
to (g-2)_\mu and effective fine structure constant, and development of Monte
Carlo generator and Radiative Corrections for precision e+e- and tau physics.Comment: 45 pages, 17 contributions. Editors: P. Masjuan and G. Venanzon
Search for the Hypothetical pi -> mu x Decay
The KARMEN collaboration has reported the possible observation of a hitherto
unknown neutral and weakly interacting particle x, which is produced in the
decay pi -> mu + x with a mass m(x) = 33.9 MeV. We have searched for this
hypothetical decay branch by studying muons from pion decay in flight with the
LEPS spectrometer at the piE3 channel at PSI and find branching ratios BR(pi-
to mu- anti-x) < 4e-7 and BR(pi+ to mu+ x) < 7e-8 (95\% C.L.). Together with
the limit BR > 2e-8 derived in a recent theoretical paper our result would
leave only a narrow region for the existence of x if it is a heavy neutrino.Comment: 10 pages, TeX (uses epsf), 3 Postscript figures uu-encode
Evidence for the tongue of ionization under northward interplanetary magnetic field conditions
[1] The activities of the International Ionospheric Tomography Community open up new possibilities of simultaneously imaging the large-scale spatial structure of the ionosphere in different longitude sectors. In the study, tomography receiver chains in Scandinavia and Greenland were used to provide a wide view of the plasma density structure in the winter, magnetic postnoon sector under conditions of stable, positive interplanetary magnetic field B z component. The spatial distributions of the plasma are discussed in light of a high-latitude plasma convection pattern pertinent to the conditions, which is supported by DMSP flow measurements. The observations are consistent with a tongue of dayside photoionization being drawn antisunward by the convection pattern to form an arc of enhanced plasma density around the periphery of the polar cap
Population-based screen-detected type 2 diabetes mellitus is associated with less need for insulin therapy after 10 years
INTRODUCTION: With increased duration of type 2 diabetes, most people have a growing need of glucose-lowering medication and eventually might require insulin. Presumptive evidence is reported that early detection (eg, by population-based screening) and treatment of hyperglycemia will postpone the indication for insulin treatment. A treatment legacy effect of population-based screening for type 2 diabetes of about 3 years is estimated. Therefore, we aim to compare insulin prescription and glycemic control in people with screen-detected type 2 diabetes after 10 years with data from people diagnosed with type 2 diabetes seven (treatment legacy effect) and 10 years before during care-as-usual. RESEARCH DESIGN AND METHODS: Three cohorts were compared: one screen-detected cohort with 10 years diabetes duration (Anglo-Danish-Dutch study of Intensive Treatment in People with Screen-Detected Diabetes in Primary care (ADDITION-NL): n=391) and two care-as-usual cohorts, one with 7-year diabetes duration (Groningen Initiative to Analyze Type 2 Diabetes Treatment (GIANTT) and Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC): n=4473) and one with 10-year diabetes duration (GIANTT and ZODIAC: n=2660). Insulin prescription (primary outcome) and hemoglobin A1c (HbA1c) of people with a known diabetes duration of 7 years or 10 years at the index year 2014 were compared using regression analyses. RESULTS: Insulin was prescribed in 10.5% (10-year screen detection), 14.7% (7-year care-as-usual) and 19.0% (10-year care-as-usual). People in the 7-year and 10-year care-as-usual groups had a 1.5 (95% CI 1.0 to 2.1) and 1.8 (95% CI 1.3 to 2.7) higher adjusted odds for getting insulin prescribed than those after screen detection. Lower HbA1c values were found 10 years after screen detection (mean 50.1 mmol/mol (6.7%) vs 51.8 mmol/mol (6.9%) and 52.8 mmol/mol (7.0%)), compared with 7 years and 10 years after care-as-usual (MDadjusted: 1.6 mmol/mol (95% CI 0.6 to 2.6); 0.1% (95% CI 0.1 to 0.2) and 1.8 mmol/mol (95% CI 0.7 to 2.9); and 0.2% (95% CI 0.1 to 0.3)). CONCLUSION: Population-based screen-detected type 2 diabetes is associated with less need for insulin after 10 years compared with people diagnosed during care-as-usual. Glycemic control was better after screen detection but on average good in all groups
Search for Light Gauge Bosons of the Dark Sector at the Mainz Microtron
A new exclusion limit for the electromagnetic production of a light U(1)
gauge boson {\gamma}' decaying to e^+e^- was determined by the A1 Collaboration
at the Mainz Microtron. Such light gauge bosons appear in several extensions of
the standard model and are also discussed as candidates for the interaction of
dark matter with standard model matter. In electron scattering from a heavy
nucleus, the existing limits for a narrow state coupling to e^+e^- were reduced
by nearly an order of magnitude in the range of the lepton pair mass of 210
MeV/c^2 < m_e^+e^- < 300 MeV/c^2. This experiment demonstrates the potential of
high current and high resolution fixed target experiments for the search for
physics beyond the standard model.Comment: 4 pages, 7 figure
Measuring the hadronic cross section via radiative return
Recently it has been demonstrated that particle factories, such as DAPHNE and
PEP-II, operating at fixed center-of-mass energies, are able to measure
hadronic cross sections as a function of the hadronic system energy using the
raditive return. This paper is an experimental overview of the progress in this
aera. Preliminary results from KLOE for the process e+e- -> \rho \gamma ->
\pi+\pi-\gamma and a fit to the pion form factor are presented. Some first
results from the BABAR collaboration are also shown.Comment: Invited talk presented at RADCOR/Loops and Legs 2002, Kloster
Banz/Germany, September 8-13 2002, 6 pages, 2 Figures; v1: references added,
typos correcte
Study of the decay phi--> f0(980)g --> pi+pi-g with the KLOE detector
We measured, with the KLOE detector, the spectrum of pi+pi- invariant mass in
a sample of 6.7 x 10^5 e+e- --> pi+pi-g events with the photon at large polar
angle (theta_g>45^o) at a centre of mass energy sqrt(s) around the phi mass. We
observe a clear contribution from the intermediate process phi --> f0(980)g. A
sizeable effect is also observed in the distribution of the forward-backeard
asymmetry. We use different theoretical models to fit the spectrum and we
determine the f_0 mass and coupling constants to the phi, to pi+pi- and to KK.Comment: 15 pages, 6 figures, submitted to Phys.Lett.
Study of the a_0(980) meson via the radiative decay phi->eta pi^0 gamma with the KLOE detector
We have studied the phi->a_0(980) gamma process with the KLOE detector at the
Frascati phi-factory DAPhNE by detecting the phi->eta pi^0 gamma decays in the
final states with eta->gamma gamma and eta->pi^+ pi^- pi^0. We have measured
the branching ratios for both final states: Br(phi->eta pi^0 gamma)=(7.01 +/-
0.10 +/- 0.20)x10^-5 and (7.12 +/- 0.13 +/- 0.22)x10^-5 respectively. We have
also extracted the a_0(980) mass and its couplings to eta pi^0, K^+ K^-, and to
the phi meson from the fit of the eta pi^0 invariant mass distributions using
different phenomenological models.Comment: 17 pages, 6 figures, submitted to Physics Letters B. Corrected typos
in eq.
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