Thu·Nov 30, 2017Thursday·November 30, 2017

1. 01*

   Measurement of Z${}^0$-boson production at large rapidities in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV

   ALICE Collaboration

   The production of Z${}^0$ bosons at large rapidities in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV is reported. Z${}^0$ candidates are reconstructed in the dimuon decay channel (${\mathrm{Z}}^0\to {\mu }^{+}{\mu }^{-}$), based on muons selected with pseudo-rapidity $-4.0<\eta <-2.5$ and $p_{\mathrm{T}}>20$ GeV/$c$. The invariant yield and the nuclear modification factor, $R_{\mathrm{AA}}$, are presented as a function of rapidity and collision centrality. The value of $R_{\mathrm{AA}}$ for the 0-20% central Pb-Pb collisions is $0.67\pm 0.11\text{mbox}(stat.)\pm 0.03\text{mbox}(syst.)\pm 0.06\text{mbox}(corr.syst.)$, exhibiting a deviation of $2.6\sigma$ from unity. The results are well-described by calculations that include nuclear modifications of the parton distribution functions, while the predictions using vacuum PDFs deviate from data by $2.3\sigma$ in the 0-90% centrality class and by $3\sigma$ in the 0-20% central collisions.

   nucl-exhep-exPLB(2018)·37 citations
2. 02*

   Astrophysical S-factor of the ${}^{14}\text{N(p,}\gamma {\text{)}}^{15}\text{O}$ reaction at 0.4 -- 1.3\,MeV

   L. Wagner🇸🇪 · S. Akhmadaliev🇸🇪 · M. Anders🇸🇪 · D. Bemmerer🇩🇪 · A. Caciolli🇸🇪 · St. Gohl🇸🇪 · M. Grieger🇸🇪 · A. Junghans🇩🇪 · M. Marta🇸🇪 · F. Munnik🇸🇪 · T. P. Reinhardt🇸🇪 · S. Reinicke🇸🇪 and 9 other authors

   The ${}^{14}\text{N(p,}\gamma {\text{)}}^{15}\text{O}$ reaction is the slowest reaction of the carbon-nitrogen cycle of hydrogen burning and thus determines its rate. The precise knowledge of its rate is required to correctly model hydrogen burning in asymptotic giant branch stars. In addition, it is a necessary ingredient for a possible solution of the solar abundance problem by using the solar ${}^{13}$N and ${}^{15}$O neutrino fluxes as probes of the carbon and nitrogen abundances in the solar core. After the downward revision of its cross section due to a much lower contribution by one particular transition, capture to the ground state in ${}^{15}$O, the evaluated total uncertainty is still 8\%, in part due to an unsatisfactory knowledge of the excitation function over a wide energy range. The present work reports precise S-factor data at twelve energies between 0.357-1.292~MeV for the strongest transition, capture to the 6.79~MeV excited state in ${}^{15}$O, and at ten energies between 0.479-1.202~MeV for the second strongest transition, capture to the ground state in ${}^{15}$O. An R-matrix fit is performed to estimate the impact of the new data on astrophysical energies. The recently suggested slight enhancement of the 6.79~MeV transition at low energy could not be confirmed. The present extrapolated zero-energy S-factors are $S_{6.79}(0)$~=~1.24$\pm$0.11~keV~barn and $S_{\mathrm{GS}}(0)$~=~0.19$\pm$0.05~keV~barn.

   nucl-exastro-ph.SRPRC(2018)·32 citations
3. 03*

   Initial state and hydrodynamic modeling of heavy-ion collisions at RHIC BES energies

   Chun Shen🇺🇸 · Björn Schenke🇺🇸

   We present a fully three-dimensional initial state model for relativistic heavy-ion collisions at RHIC Beam Energy Scan (BES) collision energies. The initial energy and net baryon density profiles are produced based on a classical string deceleration model. The baryon stopping and fluctuations during this early stage of the collision are investigated by studying the net baryon rapidity distribution and longitudinal decorrelation of the transverse geometry.

   ↳ nucl-thhep-phnucl-exPoS(2018)·19 citations
4. 04*

   Telescoping jet substructure

   Yang-Ting Chien🇺🇸 · Alex Emerman🇺🇸 · Shih-Chieh Hsu🇺🇸 · Samuel Meehan🇺🇸 · Zachery Montague🇺🇸

   We introduce a novel jet substructure method which exploits the variation of observables with respect to a sampling of phase-space boundaries quantified by the variability. We apply this technique to identify boosted W boson and top quark jets using telescoping subjets which utilizes information coming from subjet topology and that coming from subjet substructure. We find excellent performance of the variability, in particular its robustness against finite detector resolution. The extension to telescoping jet grooming and other telescoping jet substructure observables is also straightforward. This method provides a new direction in heavy particle tagging and suggests a systematic approach to the decomposition of jet substructure.

   ↳ hep-phhep-exnucl-exPRD(2020)·10 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.