Fri·Feb 24, 2017Friday·February 24, 2017

1. 01*

   12 GeV CEBAF - The Physics and Experiments

   Volker D. Burkert🇺🇸

   In this talk the role of spin and polarization is discussed in experimental search for new excited baryon states and in the study of the internal quark-gluon structure of the proton and neutron. Also the perspective of spin physics at the 12 GeV CEBAF electron accelerator is discussed and what we hope to learn about fundamental properties of hadrons such as their multi-dimensional structure through the momentum and spatial imaging, and about the forces on the quarks in the proton and how quark confinement may be realized through the spatial distribution of such forces.

   nucl-exhep-phnucl-th1 citation
2. 02*

   Isoscalar Single-Pion Production in the Region of Roper and $d^{\ast }(2380)$ Resonances

   WASA-at-COSY Collaboration: P. Adlarson · W. Augustyniak · W. Bardan · M. Bashkanov · F. S. Bergmann · M. Berłowski · H. Bhatt · A. Bondar · M. Büscher · H. Calen · I. Ciepał · H. Clement and 80 other authors

   Exclusive measurements of the quasi-free $pn\to pp{\pi }^{-}$ and $pp\to pp{\pi }^0$ reactions have been performed by means of $pd$ collisions at $T_p$ = 1.2 GeV using the WASA detector setup at COSY. Total and differential cross sections have been obtained covering the energy region $T_p=0.95-1.3$ GeV ($\sqrt{s}$ = 2.3 - 2.46 GeV), which includes the regions of $\Delta (1232)$, $N^{\ast }(1440)$ and $d^{\ast }(2380)$ resonance excitations. From these measurements the isoscalar single-pion production has been extracted, for which data existed so far only below $T_p$ = 1 GeV. We observe a substantial increase of this cross section above 1 GeV, which can be related to the Roper resonance $N^{\ast }(1440)$, the strength of which shows up isolated from the $\Delta$ resonance in the isoscalar $(N\pi {)}_{I=0}$ invariant-mass spectrum. No evidence for a decay of the dibaryon resonance $d^{\ast }(2380)$ into the isoscalar $(NN\pi {)}_{I=0}$ channel is found. An upper limit of 90 $\mu$b (90 $\%$ C.L.) corresponding to a branching ratio of 5 $\%$ has been deduced.

   nucl-exhep-exPLB(2017)·40 citations
3. 03*

   More efficient formulas for efficiency correction of cumulants and effect of using averaged efficiency

   Toshihiro Nonaka🇯🇵 · Masakiyo Kitazawa🇯🇵 · ShinIchi Esumi🇯🇵

   We derive formulas for the efficiency correction of cumulants with many efficiency bins. The derivation of the formulas is simpler than the previously suggested method, but the numerical cost is drastically reduced from the naive method. From analytical and numerical analyses in simple toy models, we show that the use of the averaged efficiency in the efficiency correction can lead to wrong corrected values, which have larger deviation for higher order cumulants. These analyses show the importance of carrying out the efficiency correction without taking the average.

   ↳ physics.data-anhep-phnucl-exnucl-thPRC(2017)·82 citations
4. 04*

   An overview of experimental results from ultra-relativistic heavy-ion collisions at the CERN LHC: hard probes

   Panagiota Foka🇩🇪 · Malgorzata Anna Janik🇵🇱

   The first collisions of lead nuclei, delivered by the CERN Large Hadron Collider (LHC) at the end of 2010, at a centre-of-mass energy per nucleon pair $\sqrt{s_{NN}}$ = 2.76 TeV, marked the beginning of a new era in ultra-relativistic heavy-ion physics. The study of the properties of the produced hot and dense strongly-interacting matter at these unprecedented energies is currently experimentally pursued by all four big LHC experiments, ALICE, ATLAS, CMS, and LHCb. The more than a factor 10 increase of collision energy at LHC, relative to the previously achieved maximal energy at other collider facilities, results in an increase of production rates of hard probes. This review presents selected experimental results focusing on observables probing hard processes in heavy-ion collisions delivered during the first three years of the LHC operation. It also presents the first results from Run 2 heavy-ion data at the highest energy, as well as from the studies of the reference pp and pPb systems, which are an integral part of the heavy-ion programme.

   ↳ hep-exhep-phnucl-exnucl-thRev.Phys.(2016)·59 citations
5. 05*

   An overview of experimental results from ultra-relativistic heavy-ion collisions at the CERN LHC: bulk properties and dynamical evolution

   Panagiota Foka🇩🇪 · Malgorzata Anna Janik🇵🇱

   The first collisions of lead nuclei, delivered by the CERN Large Hadron Collider (LHC) at the end of 2010, at a centre-of-mass energy per nucleon pair $\sqrt{s_{NN}}$ = 2.76 TeV, marked the beginning of a new era in ultra-relativistic heavy-ion physics. Following the Run 1 period, LHC also successfully delivered PbPb collisions at the collision energy $\sqrt{s_{NN}}$ = 5.02 TeV at the end of 2015. The study of the properties of the produced hot and dense strongly-interacting matter at these unprecedented energies is experimentally pursued by all four big LHC experiments, ALICE, ATLAS, CMS, and LHCb. This review presents selected experimental results from heavy-ion collisions delivered during the first three years of the LHC operation focusing on the bulk matter properties and the dynamical evolution of the created system. It also presents the first results from Run 2 heavy-ion data at the highest energy, as well as from the studies of the reference pp and pPb systems, which are an integral part of the heavy-ion programme.

   ↳ hep-exhep-phnucl-exnucl-thRev.Phys.(2016)·88 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.