Tue·Jan 27, 2015Tuesday·January 27, 2015

1. 01*

   An Upgrade Proposal from the PHENIX Collaboration

   A. Adare · S. Afanasiev · C. Aidala · N.N. Ajitanand · Y. Akiba · R. Akimoto · J. Alexander · K. Aoki · N. Apadula · H. Asano · E.T. Atomssa · T.C. Awes and 465 other authors

   In this document the PHENIX collaboration proposes a major upgrade to the PHENIX detector at the Relativistic Heavy Ion Collider. This upgrade, sPHENIX, enables an extremely rich jet and beauty quarkonia physics program addressing fundamental questions about the nature of the strongly coupled quark-gluon plasma (QGP), discovered experimentally at RHIC to be a perfect fluid. The startling dynamics of the QGP on fluid-like length scales is an emergent property of quantum chromodynamics (QCD), seemingly implicit in the Lagrangian but stubbornly hidden from view. QCD is an asymptotically free theory, but how QCD manifests as a strongly coupled fluid with specific shear viscosity near $T_C$, as low as allowed by the uncertainty principle, is as fundamental an issue as that of how confinement itself arises.

   nucl-ex138 citations
2. 02*

   Measurement of heavy-flavour production as a function of multiplicity in pp and p-Pb collisions with ALICE

   Riccardo Russo (for the ALICE Collaboration)🇮🇹

   In these proceedings results are presented from the measurement of open heavy-flavour production as a function of charged-particle multiplicity in pp collisions at $\sqrt{s}$ = 7 TeV and p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$=5.02 TeV recorded with the ALICE detector in 2010 and 2013, respectively. ${\mathrm{D}}^0$, ${\mathrm{D}}^{+}$ and ${\mathrm{D}}^{\ast +}$ mesons are reconstructed from their hadronic decay channels in the central rapidity region, and their production yields are measured in various multiplicity and $p_{\mathrm{T}}$ intervals. The per-event yields of $\mathrm{D}$ mesons in the various multiplicity intervals, normalized to their multiplicity-integrated value, and their evolution with $p_{\mathrm{T}}$ are measured for pp and p-Pb collisions to study the contribution of Multi-Parton Interactions (MPIs) to open charm production in the two systems. The nuclear modification factor of $\mathrm{D}$ mesons in p-Pb collisions, defined as the ratio of the $\mathrm{D}$-meson yields in p-Pb and pp collisions scaled by the average number of binary collisions $<N_{\mathrm{coll}}>$, is discussed in terms of its dependence on the event activity. Several experimental estimators of the event activity are used in order to assess the role of kinematic biases.

   nucl-exNPA(2014)·6 citations
3. 03*

   Theoretical reaction rates of the ${}^{12}$C($\alpha$,$\gamma$)${}^{16}$O reaction from the potential model

   M. Katsuma

   The radiative capture cross sections of ${}^{12}$C($\alpha$,$\gamma$)${}^{16}$O and derived reaction rates are calculated from the direct capture potential model. The resulting $S$-factor at low energies is found to be dominated by $E$2 transition to the ${}^{16}$O ground state. The $E$1 and $E$2 $S$-factors at $E_{c.m.}=0.3$ MeV are $S_{E1}\approx 3$ keV~b and $S_{E2}=150_{-17}^{+41}$ keV~b, respectively. The sum of the cascade transition through the excited state of ${}^{16}$O is $S_{\mathrm{casc}}=18\pm 4.5$ keV~b. The derived reaction rates at low temperatures seem to be concordant with those from the previous evaluation. For astrophysical applications, our reaction rates below $T_9=3$ are provided in an analytic expression.

   ↳ nucl-thastro-ph.SRnucl-exPoS(2015)·0 citations
4. 04*

   Feasibility Studies of Exclusive Diffractive Bremsstrahlung Measurement at RHIC Energies

   J. Chwastowski🇵🇱 · A. Cyz🇵🇱 · L. Fulek🇵🇱 · R. Kycia🇵🇱 · B. Pawlik🇵🇱 · R. Sikora🇵🇱 · J. Turnau🇵🇱

   Feasibility studies of an observation of the exclusive diffractive bremsstrahlung at RHIC at $\sqrt{s}=200$~GeV and at $\sqrt{s}=500$~GeV are reported. A simplified approach to the photon and the scattered proton energy reconstruction is used. Influence of possible backgrounds is discussed.

   ↳ hep-exnucl-exActa Phys.Polon.B(2015)·5 citations
5. 05*

   Probing the braneworld hypothesis with a neutron-shining-through-a-wall experiment

   Michael Sarrazin🇧🇪 · Guillaume Pignol🇫🇷 · Jacob Lamblin🇫🇷 · Fabrice Petit🇧🇪 · Guy Terwagne🇧🇪 · Valery V. Nesvizhevsky🇫🇷

   The possibility for our visible world to be a 3-brane embedded in a multidimensional bulk is at the heart of many theoretical edifices in high-energy physics. Probing the braneworld hypothesis is thus a major experimental challenge. Following recent theoretical works showing that matter swapping between braneworlds can occur, we propose a neutron-shining-through-a-wall experiment. We first show that an intense neutron source such as a nuclear reactor core can induce a hidden neutron flux in an adjacent hidden braneworld. We then describe how a low-background detector can detect neutrons arising from the hidden world and quantify the expected sensitivity to the swapping probability. As a proof of concept, a constraint is derived from previous experiments.

   ↳ hep-phhep-exnucl-exPRD(2015)·22 citations
6. 06*

   Exploring the properties of the phases of QCD matter - research opportunities and priorities for the next decade

   U. Heinz (Ohio State)🇺🇸 · P. Sorensen (BNL)🇺🇸 · A. Deshpande (Stony Brook)🇺🇸 · C. Gagliardi (Texas A&M)🇺🇸 · F. Karsch (BNL & Bielefeld)🇩🇪 · T. Lappi (Jyvaskyla)🇫🇮 · Z.-E. Meziani (Temple U)🇺🇸 · R. Milner (MIT)🇺🇸 · B. Muller (BNL & Duke)🇺🇸 · J. Nagle (Colorado)🇺🇸 · J.-W. Qiu (BNL)🇺🇸 · K. Rajagopal (MIT)🇺🇸 · G. Roland (MIT)🇺🇸 · R. Venugopalan (BNL)🇺🇸

   This document provides a summary of the discussions during the recent joint QCD Town Meeting at Temple University of the status of and future plans for the research program of the relativistic heavy-ion community. A list of compelling questions is formulated, and a number of recommendations outlining the greatest research opportunities and detailing the research priorities of the heavy-ion community, voted on and unanimously approved at the Town Meeting, are presented. They are supported by a broad discussion of the underlying physics and its relation to other subfields. Areas of overlapping interests with the "QCD and Hadron Structure" ("cold QCD") subcommunity, in particular the recommendation for the future construction of an Electron-Ion Collider, are emphasized. The agenda of activities of the "hot QCD" subcommunity at the Town Meeting is attached.

   ↳ nucl-thhep-exhep-phnucl-ex37 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.