Wed·Dec 24, 2014Wednesday·December 24, 2014

1. 01*

   Measurement of the neutron lifetime with ultra-cold neutrons stored in a magneto-gravitational trap

   V.F. Ezhov🇷🇺 · A.Z. Andreev🇷🇺 · G. Ban🇫🇷 · B.A. Bazarov🇷🇺 · P. Geltenbort🇫🇷 · A.G. Glushkov🇷🇺 · V.A. Knyazkov🇷🇺 · N.A. Kovrizhnykh · G.B. Krygin🇷🇺 · O. Naviliat-Cuncic🇫🇷 · V.L. Ryabov🇷🇺

   We report a new measurement of the neutron lifetime using ultra-cold neutrons stored in a magneto-gravitational trap made of permanent magnets. Neutrons surviving in the trap after fixed storage times have been counted and the trap losses have continuously been monitored during storage by detecting neutrons leaking from the trap. The value of the neutron lifetime resulting from this measurement is ${\tau }_n=(878.3\pm 1.9)$s. It is the most precise measurement of the neutron lifetime obtained with magnetically stored neutrons.

   nucl-exphysics.ins-detJETP Lett.(2018)·134 citations
2. 02*

   Diffraction physics with ALICE at the LHC

   Sergey Evdokimov (for the ALICE collaboration)🇷🇺

   The ALICE experiment is equipped with a wide range of detectors providing excellent tracking and particle identification in the central region, as well as forward detectors with extended pseudorapidity coverage, which are well suited for studying diffractive processes. Cross section measurements of single and double diffractive processes performed by ALICE in pp collisions at $\sqrt{s}=0.9,2.76,7$~TeV will be reported. Currently, ALICE is studying double-gap events in pp collisions at $\sqrt{s}=7$~TeV, which give an insight into the central diffraction processes: current status and future perspectives will be discussed. The upgrade plans for diffraction studies, further extending the pseudorapidity acceptance of the ALICE setup for the forthcoming Run 2 of the LHC, will be outlined.

   ↳ hep-exnucl-ex3 citations
3. 03*

   J/$\psi$ and $\psi (2S)$ measurement in $p$+$p$ collisions at $\sqrt{s}=$ 200 and 500 GeV in the STAR experiment

   Barbara Trzeciak (for the STAR Collaboration)🇨🇿

   In this paper, results on the J/$\psi$ cross section and polarization measured via the dielectron decay channel at mid-rapidity in $p+p$ collisions at $\sqrt{s}$ = 200 and 500 GeV in the STAR experiment are discussed. The first measurement of $\psi (2S)$ to J/$\psi$ ratio at $\sqrt{s}$ = 500 GeV is also reported.

   ↳ hep-exnucl-exJ.Phys.Conf.Ser.(2015)·8 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.