Fri·Apr 29, 2016Friday·April 29, 2016

1. 01*

   New Limits on Double Electron Capture of ${}^{40}$Ca and ${}^{180}$W

   G. Angloher🇩🇪 · M. Bauer🇩🇪 · P. Bauer🇩🇪 · I. Bavykina🇩🇪 · A. Bento🇵🇹 · C. Bucci🇮🇹 · L. Canonica🇮🇹 · C. Ciemniak🇩🇪 · X. Defay🇩🇪 · G. Deuter🇩🇪 · A. Erb🇩🇪 · F. v. Feilitzsch🇩🇪 and 44 other authors

   We analyzed low-background data from the CRESST-II experiment with a total net exposure of 730 kg days to extract limits on double electron capture processes. We established new limits for ${}^{40}$Ca with $T_{1/2}^{2v2K}>9.9\times 10^{21}$ y and $T_{1/2}^{0v2EC}>1.4\times 10^{22}$ y and for ${}^{180}$W with T${}_{1/2}^{2v2K}>3.1\times 10^{19}$ y and $T_{1/2}^{0v2EC}>9.4\times 10^{18}$ y at 90% CL. Depending on the process, these values improve the currently best limits by a factor of $\sim$1.4-30.

   nucl-exphysics.ins-detJ.Phys.G(2016)·15 citations
2. 02*

   Relation between (e,e') sum rules in 6,7Li and 4He nuclei.Experiment and cluster model

   V. D. Efros · I. S. Timchenko · A. Yu. Buki

   The sums over (e,e') spectra of 6Li and 7Li nuclei which correspond to the longitudinal sum rule are studied. It is suggested that due to the cluster structure of the lithium isotopes these sums may approximately be expressed in terms of such a sum pertaining to the alpha-particle. Calculation of these sums is performed in the framework of cluster models with antisymmetrization done with respect to all the nucleons. At momentum transfers higher than 0.8 fm^{-1} the relations expressing the A=6 or 7 sum in terms of the A=4 sum prove to be valid with rather high accuracy. In the region of momentum transfers around 1 fm^{-1} the longitudinal correlation functions of 6Li and 7Li nuclei are found to be close to that of the alpha-particle. The experimental longitudinal sums in the range between 0.450 and 1.625 fm^{-1} are employed to perform comparison with those calculated in the framework of cluster models. Out of the mentioned experimental sums, those in the range between 0.750 and 1.000 fm^{-1} in the 6Li case and between 0.750 and 1.125 fm^{-1} in the 7Li case are obtained in the present work. In the 6Li case a complete agreement is found while in the 7Li case an agreement only at a qualitative level is observed.

   ↳ nucl-thnucl-exEPJA(2016)·0 citations
3. 03*

   Critical endpoint in the presence of a chiral chemical potential

   Zhu-Fang Cui🇨🇳 · Ian C. Cloet🇺🇸 · Ya Lu🇨🇳 · Craig D. Roberts🇺🇸 · Sebastian M. Schmidt🇩🇪 · Shu-Sheng Xu🇨🇳 · Hong-Shi Zong🇨🇳

   A class of Polyakov-loop-modified Nambu--Jona-Lasinio (PNJL) models have been used to support a conjecture that numerical simulations of lattice-regularized quantum chromodynamics (QCD) defined with a chiral chemical potential can provide information about the existence and location of a critical endpoint in the QCD phase diagram drawn in the plane spanned by baryon chemical potential and temperature. That conjecture is challenged by conflicts between the model results and analyses of the same problem using simulations of lattice-regularized QCD (lQCD) and well-constrained Dyson-Schwinger equation (DSE) studies. We find the conflict is resolved in favor of the lQCD and DSE predictions when both a physically-motivated regularization is employed to suppress the contribution of high-momentum quark modes in the definition of the effective potential connected with the PNJL models and the four-fermion coupling in those models does not react strongly to changes in the mean-field that is assumed to mock-up Polyakov loop dynamics. With the lQCD and DSE predictions thus confirmed, it seems unlikely that simulations of lQCD with ${\mu }_5>0$ can shed any light on a critical endpoint in the regular QCD phase diagram.

   ↳ nucl-thhep-lathep-phnucl-exPRD(2016)·53 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.