Wed·Jan 24, 2018Wednesday·January 24, 2018

1. 01*

   Evidence for high excitation energy resonances in the 7 alpha disassembly of ${}^{28}$Si

   X. G. Cao · E. J. Kim · K. Schmidt · K. Hagel · M. Barbui · J. Gauthier · S. Wuenschel · G. Giuliani · M. R. D. Rodriguez · S. Kowalski · H. Zheng · M. Huang and 10 other authors

   The excitation function for the 7 alpha de-excitation of ${}^{28}$Si nuclei excited to high excitation energies in the collisions of 35 MeV/nucleon ${}^{28}$Si with ${}^{12}$C reveals resonance structures that may indicate the population of high spin toroidal isomers such as those predicted by a number of recent theoretical calculations. This interpretation is supported by extended theoretical analyses.

   nucl-exPRC(2019)·46 citations
2. 02*

   Phenomenology of single-inclusive jet production with jet radius and threshold resummation

   Xiaohui Liu🇨🇳 · Sven-Olaf Moch🇩🇪 · Felix Ringer🇺🇸

   We perform a detailed study of inclusive jet production cross sections at the LHC and compare the QCD theory predictions based on the recently developed formalism for threshold and jet radius joint resummation at next-to-leading logarithmic accuracy to inclusive jet data collected by the CMS collaboration at $\sqrt{S}=7$ and $13$TeV. We compute the cross sections at next-to-leading order in QCD with and without the joint resummation for different choices of jet radii $R$ and observe that the joint resummation leads to crucial improvements in the description of the data. Comprehensive studies with different parton distribution functions demonstrate the necessity of considering the joint resummation in fits of those functions based on the LHC jet data.

   ↳ hep-phhep-exnucl-exPRD(2018)·47 citations
3. 03*

   Uncertainties in radiative neutron-capture rates relevant to the $A\sim 80$ $r$-process peak

   I. K. B. Kullmann · E. W. Hafli · A.C. Larsen🇳🇴 · E. Lima

   The rapid neutron-capture process ($r$-process) has for the first time been confirmed to take place in a neutron-star merger event. A detailed understanding of the rapid neutron-capture process is one of the holy grails in nuclear astrophysics. In this work we investigate one aspect of the $r$-process modelling: uncertainties in radiative neutron-capture cross sections and astrophysical reaction rates for isotopes of the elements Fe, Co, Ni, Cu, Zn, Ga, Ge, As, and Se. In particular, we study deviations from standard libraries used for astrophysics, and the influence of a very-low $\gamma$-energy enhancement in the average, reduced $\gamma$-decay probability on the ($n,\gamma$) rates. We find that the intrinsic uncertainties are in some cases extremely large, and that the low-energy enhancement, if present in neutron-rich nuclei, may increase the neutron-capture reaction rate significantly.

   ↳ nucl-thastro-ph.HEnucl-ex1 citation
4. 04*

   Spin-1 particles and perturbative QCD

   J. P. B. C. de Melo (LFTC - Cruzeiro do Sul)🇧🇷 · T. Frederico (Instituto Tecnológico de Aeronáutica - ITA)🇧🇷 · Chueng -R. Ji (Departament of Physics, North Carolina State University, NCSU)🇺🇸

   Due to the angular condition in the light-front dynamics (LFD), the extraction of the electromagnetic form factors for spin-1 particles can be uniquely determined taking into account implicitly non-valence and/or the zero-mode contributions to the matrix elements of the electromagnetic current. No matter which matrix elements of the electromagnetic current is used to extract the electromagnetic form factors, the same unique result is obtained. As physical observables, the electromagnetic form factors obtained from matrix elements of the current in LFD must be equal to those obtained in the instant form calculations. Recently, the Babar collaboration \cite{Aubert2008} has analyzed the reaction $e^{+}{e}^{-}\to {\rho }^{+}+{\rho }^{-}$ at $\sqrt{s}=10.58GeV$ to measure the cross section as well as the ratios of the helicity amplitudes $F_{{\lambda }^{\prime }\lambda }$. We present our recent analysis of the Babar data for the rho meson considering the angular condition in LFD to put a stringent test on the onset of asymptotic perturbative QCD and predict the energy regime where the subleading contributions are still considerable.

   ↳ hep-phhep-exhep-thnucl-ex+1Few Body Syst.(2018)·1 citation

* 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.