Strength of theEp=1.842MeV resonance in the40Ca(p,γ

Abstract

The strength of the Ep = 1.842 MeV resonance in the 40 Ca(p,γ) 41 Sc reaction is determined with two different methods: First, by an absolute strength measurement using calcium hydroxide targets, and second, relative to the well-determined strength of the resonance triplet at Eα = 4.5 MeV in the 40 Ca(α,γ) 44 Ti reaction. The present new value of ωγ = (0.192 ± 0.017) eV is 37% (equivalent to 3.5σ) higher than the evaluated literature value. In addition, the ratio of the strengths of the 1.842 MeV 40 Ca(p,γ) 41 Sc and 4.5 MeV 40 Ca(α,γ) 44 Ti resonances has been determined to be 0.0229 ± 0.0018. The newly corrected strength of the 1.842-MeV resonance can be used in the future as a normalization point for experiments with calcium targets.

Updating and optimizing error parton distribution function sets in the Hessian approach. II.

“…This conclusion is further supported by examining the magnitude of the two measuresd 0 and d 0 , introduced in Ref. [1], which give the distance between the original and updated PDFs in the parameter space, relative to the updated and original errors, respectively. For the ATLAS 7 TeV W and Z data the value ofd 0 = 1.49 indicates that the original best-fit PDF was far outside the error band for the updated PDFs, so that the new best fit obtained by ePump is more likely to be affected by nonlinearities in the dependence of the observables and the PDFs on the fitting parameters.…”

“…As extensively discussed in Ref. [1], a technique for estimating the impact of new data on the PDFs, without performing a full global analysis, is extremely useful. (See also Refs.…”

“…In Ref. [1] some examples were given comparing the results of ePump with a full global analysis, as well as several phenomenological analyses using ePump. In addition, an exercise using ePump was performed in Ref.…”

“…In Ref. [1] results were shown for this exercise where the jet data was included by ePump. In this paper we present more details of this check with jet data, and also present additional checks with Deeply-Inelastic Scattering (DIS) and Drell-Yan data.…”

Felsenkeller 5 MV underground accelerator: Towards the Holy Grail of Nuclear Astrophysics 12C(α, γ)16O

“…The Felsenkeller scientific program draws on many years of experience in nuclear astrophysics experiments at the overground HZDR 3 MV Tandetron accelerator [19][20][21][22][23][24] and on a long-standing involvement in the LUNA collaboration [10,11]. Complementary experiments studying the γ-widths of relevant levels [25,26] have been performed at the local bremsstrahlung facility [27] and are underway at the local neutron time-of-flight facility [28].…”