# CERN Preprints

2019-01-16
11:27
 Model-independent observation of exotic contributions to $B^0\to J/\psi K^+\pi^-$ decays An angular analysis of $B^0\to J/\psi K^+\pi^-$ decays is performed, using proton-proton collision data corresponding to an integrated luminosity of 3 ${\rm fb}^{-1}$ collected with the LHCb detector. [...] CERN-EP-2018-330 ; LHCB-PAPER-2018-043. - 2019. Fulltext - Related data file(s)

2019-01-16
10:10
 nPDF studies with electroweak bosons in pPb collisions at $\sqrt{s_{NN}}$ = 8.16 TeV with the CMS experiment / Kim, Hyunchul (Chonnam Natl. U.) /CMS Collaboration Yields of electroweak gauge bosons can be used to probe the nuclear parton distribution functions of quarks and antiquarks. Final results on W boson production in pPb collisions at a nucleon-nucleon center-of-mass energy of 8.16 TeV using the CMS detector will be presented. [...] CMS-CR-2019-002.- Geneva : CERN, 2019 - 6 p. Fulltext: PDF; In : Hard Probes 2018: International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions, Aix-les-bains, France, 1 - 5 Oct 2018

2019-01-16
10:10
 Detailed studies of prompt J/$\psi$ and $\psi(2S)$ production in pp, pPb and PbPb collisions at $\sqrt s$~=~5.02 TeV with the CMS experiment / Diab, Batoul (Ecole Polytechnique) /CMS Collaboration The understanding of charmonium production in PbPb collisions requires the inclusion of many phenomena such as dissociation in the QGP, partonic energy loss, statistical recombination, on top of cold nuclear matter effects (modifications of nPDFs, initial-state energy loss, nuclear break-up). Final results on prompt J/$\psi$ and $\psi(\mathrm{2S})$ production, based on the pp and PbPb data collected at 5.02 TeV by CMS in 2015, are reported, showing a stronger suppression of the excited state as compared to the ground state in all measured bins of ${p_{\mathrm{T}}}$ and centrality, as well as a hint for a weaker J/$\psi$ suppression at low ${p_{\mathrm{T}}}$ (possibly due to regeneration) and at high ${p_{\mathrm{T}}}$ (possibly due to partonic energy loss). [...] CMS-CR-2018-420.- Geneva : CERN, 2018 - 6 p. Fulltext: PDF; In : Hard Probes 2018: International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions, Aix-les-bains, France, 1 - 5 Oct 2018

2019-01-16
10:10
 Development of Novel Pixel Sensors for the CMS Upgrade for HL-LHC / Steinbrueck, Georg (Hamburg U.) The LHC is planning an upgrade program which will bring the luminosity up to about 7.5$\times10^{34}\textrm{ cm}^{-2}\textrm{s}^{-1}$ in 2027, with the goal of an integrated luminosity of 3000 fb$^{-1}$ by the end of 2037. This High Luminosity scenario, HL-LHC, will present new challenges of higher data rates and unprecedented radiation levels for the CMS Inner Tracker (IT): $\Phi_{\textrm eq}=2\times 10^{16}$~cm$^{-2}$, and 10 MGy, are expected at the inner layer of the pixel detector for 3000 fb$^{-1}$ integrated luminosity. To maintain or even improve the performance of the present vertex detector, new technologies have to be fully exploited for the so-called Phase-2 upgrade. Among them is the future version of front-end chips in 65-nm CMOS by the CERN RD53 Collaboration which supports small pixel sizes of 50$\times$50 or 25$\times$100 $\mu$m$^2$} and lower charge thresholds ($\approx1000~\textrm{e}^-$).\\ Thin planar n-in-p type silicon sensors (of thickness 100-150 $\mu$m), segmented into pixel sizes of 25$\times$100 $\mu$m$^2$ or 50$\times$50 $\mu$m$^2$ are expected to allow for a good detector resolution that is expected to be more robust with respect to radiation damage compared to the Phase-1 detector. [...] CMS-CR-2018-415.- Geneva : CERN, 2018 - 6 p. Fulltext: PDF; In : 2018 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2018), Sydney, Australia, 10 - 17 Nov 2018

2019-01-16
10:08
 CMS ECAL monitoring and calibration in LHC Run 2 / Monti, Fabio (INFN, Milan Bicocca ; Milan Bicocca U.) /CMS Collaboration Precise calibration and monitoring of the CMS electromagnetic calorimeter (ECAL) are key ingredients in achieving the excellent ECAL performance required by many physics analyses employing electrons and photons. This poster describes the methods used to monitor and inter-calibrate the ECAL response, using physics channels such as W/Z boson decays to electrons and pi0/eta decays to photon pairs, and also exploiting the azimuthal symmetry of the minimum bias events. [...] CMS-CR-2018-171.- Geneva : CERN, 2018 - 6 p. Fulltext: PDF; In : Sixth Annual Conference on Large Hadron Collider Physics, Bologna, Italy, 4 - 9 Jun 2018

2019-01-16
04:51
 T2K ND280 Upgrade - Technical Design Report / Abe, K. ; Aihara, H. ; Ajmi, A. ; Andreopoulos, C. ; Antonova, M. ; Aoki, S. ; Asada, Y. ; Ashida, Y. ; Atherton, A. ; Atkin, E. et al. In this document, we present the Technical Design Report of the Upgrade of the T2K Near Detector ND280. [...] arXiv:1901.03750 ; CERN-SPSC-2019-001 (SPSC-TDR-006). - 196 p. Fulltext

2019-01-16
04:51
 Deep observations of the globular cluster M15 with the MAGIC telescopes / MAGIC Collaboration A population of globular clusters (GCs) has been recently established by the Fermi-LAT telescope as a new class of GeV $\gamma$-ray sources. [...] arXiv:1901.04367. - 11 p. Fulltext

2019-01-16
04:51
 Research and Development for Near Detector Systems Towards Long Term Evolution of Ultra-precise Long-baseline Neutrino Experiments / Alvarez Ruso, Luis (Valencia U., IFIC) ; Asaadi, Jonathan (Texas U., Arlington) ; Bolognesi, Sara (Paris, CEA) ; Bordoni, Stefania (CERN) ; de Roeck, Albert (CERN) ; Diwan, Milind Vaman (Brookhaven) ; Lux, Thorsten (Barcelona, IFAE) ; Meloni, Davide (Rome III U.) ; Nessi, Marzio (CERN) ; Popov, Boris (Dubna, JINR ; Paris U., VI-VII) et al. With the discovery of non-zero value of $\theta_{13}$ mixing angle, the next generation of long-baseline neutrino (LBN) experiments offers the possibility of obtaining statistically significant samples of muon and electron neutrinos and anti-neutrinos with large oscillation effects. [...] arXiv:1901.04346. - Fulltext

2019-01-16
04:51
 First measurement of tW production cross-section at $\sqrt s$~= 13 TeV with CMS / Priyanka ; Ranjan, Kirti ; Bhardwaj, Ashutosh The inclusive cross-section for tW production in proton-proton collisions at $\sqrt{s} = 13$ TeV is measured for an integrated luminosity of 35.9 fb$^{-1}$ collected by the CMS experiment. [...] arXiv:1901.04179. - 5 p. Fulltext

2019-01-16
04:51
 MATHUSLA: A Detector Proposal to Explore the Lifetime Frontier at the HL-LHC / MATHUSLA Collaboration The observation of long-lived particles at the LHC would reveal physics beyond the Standard Model, could account for the many open issues in our understanding of our universe, and conceivably point to a more complete theory of the fundamental interactions. [...] arXiv:1901.04040 ; FERMILAB-PUB-19-016-CMS. - 8 p. MATHUSLA website - Fulltext