Wed·Oct 8, 2014Wednesday·October 8, 2014

1. 01*

   Measurement of prompt psi(2S) to J/psi yield ratios in PbPb and pp collisions at sqrt(s[NN]) = 2.76 TeV

   CMS Collaboration

   The ratio between the prompt psi(2S) and J/psi yields, reconstructed via their decays into muon pairs, is measured in PbPb and pp collisions at sqrt(s[NN]) = 2.76 TeV. The analysis is based on PbPb and pp data samples collected by CMS at the LHC, corresponding to integrated luminosities of 150 inverse microbarns and 5.4 inverse picobarns, respectively. The double ratio of measured yields, (N[psi(2S)]/N[J/psi])[PbPb] / (N[psi(2S)]/ N[J/psi])[pp], is computed in three PbPb collision centrality bins and two kinematic ranges: one at midrapidity, abs(y) < 1.6, covering the transverse momentum range 6.5 < pt < 30 GeV/c, and the other at forward rapidity, 1.6 < abs(y) < 2.4, extending to lower pt values, 3 < pt < 30 GeV/c. The centrality-integrated double ratio changes from 0.45 +/- 0.13 (stat) +/- 0.07 (syst) in the first range to 1.67 +/- 0.34 (stat) +/- 0.27 (syst) in the second. This difference is most pronounced in the most central collisions.

   nucl-exhep-exPRL(2014)·86 citations
2. 02*

   The Coldest Cubic Meter in the Known Universe

   Jonathan Ouellet🇺🇸

   CUORE is a 741 kg array of TeO2 bolometers that will search for the neutrinoless double beta decay of 130Te. The detector is being constructed at the Laboratori Nazionali del Gran Sasso in Italy, where it will begin taking data in 2015. The CUORE cryostat will cool several metric tonnes of material to below 1 K and the CUORE detector itself will operate at a typical temperature of 10 mK. At this temperature, the CUORE detector will be the coldest contiguous cubic meter in the known Universe.

   ↳ physics.ins-dethep-exnucl-ex7 citations
3. 03*

   Densities mixture unfolding for data obtained from detectors with finite resolution and limited acceptance

   Nikolai Gagunashvili🇮🇸

   A procedure based on a Mixture Density Model for correcting experimental data for distortions due to finite resolution and limited detector acceptance is presented. Addressing the case that the solution is known to be non-negative, in the approach presented here, the true distribution is estimated by a weighted sum of probability density functions with positive weights and with the width of the densities acting as a regularisation parameter responsible for the smoothness of the result. To obtain better smoothing in less populated regions, the width parameter is chosen inversely proportional to the square root of the estimated density. Furthermore, the non-negative garrotte method is used to find the most economic representation of the solution. Cross-validation is employed to determine the optimal values of the resolution and garrotte parameters. The proposed approach is directly applicable to multidimensional problems. Numerical examples in one and two dimensions are presented to illustrate the procedure.

   ↳ physics.data-anastro-ph.IMhep-exnucl-ex+1Nucl.Instrum.Meth.A(2015)·1 citation
4. 04*

   J/$\psi$ and $\psi$(2S) production in p-Pb collisions with ALICE at the LHC

   Marco Leoncino (for the ALICE collaboration)🇮🇹

   The ALICE collaboration has studied the inclusive J/$\psi$ and $\psi (2S)$ production in p-Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV at the CERN LHC. The J/$\psi$ measurement is performed in the ${\mu }^{+}{\mu }^{-}$ ( - 4.46 < $y_{cms}$ < - 2.96 and 2.03 < $y_{cms}$ < 3.53 ) and in the $e^{+}{e}^{-}$ ( - 1.37 < $y_{cms}$ < 0.46 ) decay channels, down to zero transverse momentum. The results are in fair agreement with theoretical predictions based on nuclear shadowing, as well as with models including, in addition, a contribution from partonic energy loss. Finally, the $\psi (2S)$ measurement in the ${\mu }^{+}{\mu }^{-}$ decay channel has been performed. In particular, a significantly smaller $\psi (2S)$ nuclear modification factor, with respect to the J$/\psi$ one, has been observed.

   ↳ hep-exnucl-exPoS(2014)·3 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.