Thu·Mar 7, 2019Thursday·March 7, 2019

1. 01*

   Measurement of prompt photon production in $\sqrt{s_{\mathrm{NN}}}=8.16$ TeV $p$+Pb collisions with ATLAS

   ATLAS Collaboration

   The inclusive production rates of isolated, prompt photons in $p$+Pb collisions at $\sqrt{s_{\mathrm{NN}}}=8.16$ TeV are studied with the ATLAS detector at the Large Hadron Collider using a dataset with an integrated luminosity of 165 nb${}^{-1}$ recorded in 2016. The cross-section and nuclear modification factor $R_{p\mathrm{Pb}}$ are measured as a function of photon transverse energy from 20 GeV to 550 GeV and in three nucleon-nucleon centre-of-mass pseudorapidity regions, (-2.83,-2.02), (-1.84,0.91), and (1.09,1.90). The cross-section and $R_{p\mathrm{Pb}}$ values are compared with the results of a next-to-leading-order perturbative QCD calculation, with and without nuclear parton distribution function modifications, and with expectations based on a model of the energy loss of partons prior to the hard scattering. The data disfavour a large amount of energy loss and provide new constraints on the parton densities in nuclei.

   nucl-exhep-exPLB(2019)·54 citations
2. 02*

   Odd-mass nuclei in the cluster shell model

   R. Bijker🇲🇽 · A.H. Santana-Valdés

   In this contribution, we present the cluster shell model which is analogous to the Nilsson model, but for cluster potentials. Special attention is paid to the consequences of the discrete symmetries of three alpha-particles in an equilateral triangle configuration. This configuration is characterized by a special structure of the rotational bands which can be used as a fingerprint of the underlying geometric configuration. The cluster shell model is applied to the nucleus 13C.

   ↳ nucl-thnucl-exJ.Phys.Conf.Ser.(2019)·2 citations
3. 03*

   Electromagnetic couplings of pentaquarks

   E. Ortiz-Pacheco🇲🇽 · R. Bijker🇲🇽

   In this contribution, we discuss the electromagnetic couplings of pentaquark states with hidden charm. This work is motivated by recent experiments at CERN by the LHCb Collaboraton and current experiments at JLab to confirm the existence of hidden-charm pentaquarks in photoproduction experiments.

   ↳ nucl-thhep-exhep-phnucl-exJ.Phys.Conf.Ser.(2019)·0 citations
4. 04*

   New exotic beams from the SPIRAL 1 upgrade

   P. Delahaye · M. Dubois · L. Maunoury · J. Angot · O. Bajeat · B. Blank · J. C. Cam · P. Chauveau · R. Frigot · B. Jacquot · P. Jardin · P. Lecomte and 12 other authors

   Since 2001, the SPIRAL 1 facility has been one of the pioneering facilities in ISOL techniques for reaccelerating radioactive ion beams: the fragmentation of the heavy ion beams of GANIL on graphite targets and subsequent ionization in the Nanogan ECR ion source has permitted to deliver beams of gaseous elements (He, N, O, F, Ne, Ar, Kr) to numerous experiments. Thanks to the CIME cyclotron, energies up to 20 AMeV could be obtained. In 2014, the facility was stopped to undertake a major upgrade, with the aim to extend the production capabilities of SPIRAL 1 to a number of new elements. This upgrade, which is presently under commissioning, consists in the integration of an ECR booster in the SPIRAL 1 beam line to charge breed the beam of different 1+ sources. A FEBIAD source (the so-called VADIS from ISOLDE) was chosen to be the future workhorse for producing many metallic ion beams. The charge breeder is an upgraded version of the Phoenix booster which was previously tested in ISOLDE. The performances of the aforementioned ingredients of the upgrade (targets, 1+ source and charge breeder) have been and are still being optimized in the frame of different European projects (EMILIE, ENSAR and ENSAR2). The upgraded SPIRAL 1 facility will provide soon its first new beams for physics and further beam development are undertaken to prepare for the next AGATA campaign. The results obtained during the on-line commissioning period permit to evaluate intensities for new beams from the upgraded facility.

   ↳ physics.acc-phnucl-exNucl.Instrum.Meth.B(2020)·13 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.