Tue·Aug 20, 2019Tuesday·August 20, 2019

1. 01*

   Measurement of neutron and proton analyzing powers on $C$, $CH$, $C{H}_2$ and $Cu$ targets in the momentum region 3-4.2 GeV/c

   S.N. Basilev🇷🇺 · Yu.P. Bushuev🇷🇺 · O.P. Gavrishchuk🇷🇺 · V.V. Glagolev🇷🇺 · D.A. Kirillov🇷🇺 · N.V. Kostayeva🇷🇺 · A.D. Kovalenko🇷🇺 · K.S. Legostaeva🇷🇺 · A.N. Livanov🇷🇺 · I.A. Philippov🇷🇺 · N.M. Piskunov🇷🇺 · A.A. Povtoreiko🇷🇺 and 19 other authors

   The analyzing powers for proton elastic scattering ($\vec{p}A\to pX$) and neutron charge exchange ($\vec{n}A\to pX$) reactions on nuclei have been measured on $C$, $CH$, $C{H}_2$ and $Cu$ targets at incident neutron momenta 3.0 - 4.2 GeV/c by detecting one charged particle in forward direction. The polarized neutron measurements are the first of their kind. The experiment was performed using the Nuclotron accelerator in JINR Dubna, where polarized neutrons and protons were obtained from breakup of a polarized deuteron beam which has a maximum momentum of 13 GeV/c. The polarimeter ALPOM2 was used to obtain the analyzing power dependence on the transverse momentum of the final-state nucleon. These data have been used to estimate the figure of merit of a proposed experiment at Jefferson Laboratory to measure the recoiling neutron polarization in the quasi-elastic ${}^{2}H(\vec{e},e^{\prime }\vec{n})$ reaction, which yields information on the charge and magnetic elastic form factors of the neutron.

   nucl-exhep-exEPJA(2020)·13 citations
2. 02*

   Comment on N. Rijal et al. "Measurement of d + 7Be Cross Sections for Big-Bang Nucleosynthesis"

   Moshe Gai🇺🇸

   Rijal, et al. in their recent publication [Phys. Rev. Lett {\bf 122}, 182701 (2019), arXiv:1808.07893], on "Measurement of d + ${}^7$Be Cross Sections for Big-Bang Nucleosynthesis (BBN)", misrepresent their result, they misrepresent previous work of Parker (72) and of Caughlan and Fowler (88), and quite possibly, contradicts the very BBN theory that has been established over the last few decades. This comment is intended to correct these misrepresentations and critically review their claims on BBN.

   nucl-exastro-ph.COnucl-th3 citations
3. 03*

   Hybrid Color Glass Condensate and hydrodynamic description of the Relativistic Heavy Ion Collider small system scan

   Bjoern Schenke🇺🇸 · Chun Shen🇺🇸 · Prithwish Tribedy🇺🇸

   Multi-particle correlation observables in the Relativistic Heavy Ion Collider small system scan are computed in a framework that contains both initial state momentum anisotropies from the Color Glass Condensate effective theory and final state hydrodynamic evolution. The initial state is computed using the IP-Glasma model and coupled to viscous relativistic hydrodynamic simulations, which are followed by microscopic hadronic transport. All parameters of the calculation were previously constrained using experimental data on Au+Au collisions at the same center of mass energy. We find that the qualitative features of the experimental data, such as the system and centrality dependence of the charged hadron momentum anisotropy, can only be reproduced when final state interactions are present. On the other hand, we also demonstrate that the details of the initial state are crucially important for the quantitative description of observables in the studied small systems, as neglecting the initial transverse flow profile or the initial shear stress tensor, which contain information on the momentum anisotropy from the Color Glass Condensate, has dramatic effects on the produced final state anisotropy. We further show that the initial state momentum anisotropy is correlated with the observed elliptic flow in all small systems, with the effect increasing with decreasing multiplicity. We identify the precise measurement of $v_2$ in d+Au and Au+Au collisions at RHIC energy at the same multiplicity as a means to reveal effects of the initial state momentum anisotropy.

   ↳ nucl-thhep-phnucl-exPLB(2020)·103 citations
4. 04*

   Quantum Brownian motion of a heavy quark pair in the quark-gluon plasma

   Takahiro Miura🇯🇵 · Yukinao Akamatsu🇯🇵 · Masayuki Asakawa🇯🇵 · Alexander Rothkopf🇳🇴

   In this paper we study the real-time evolution of heavy quarkonium in the quark-gluon plasma (QGP) on the basis of the open quantum systems approach. In particular, we shed light on how quantum dissipation affects the dynamics of the relative motion of the quarkonium state over time. To this end we present a novel non-equilibrium master equation for the relative motion of quarkonium in a medium, starting from Lindblad operators derived systematically from quantum field theory. In order to implement the corresponding dynamics, we deploy the well established quantum state diffusion method. In turn we reveal how the full quantum evolution can be cast in the form of a stochastic non-linear Schrödinger equation. This for the first time provides a direct link from quantum chromodynamics (QCD) to phenomenological models based on non-linear Schrödinger equations. Proof of principle simulations in one-dimension show that dissipative effects indeed allow the relative motion of the constituent quarks in a quarkonium at rest to thermalize. Dissipation turns out to be relevant already at early times well within the QGP lifetime in relativistic heavy ion collisions.

   ↳ nucl-thhep-phnucl-exquant-phPRD(2020)·71 citations
5. 05*

   Reply to Comment on "Is a Trineutron Resonance Lower in Energy than a Tetraneutron Resonance?"

   S. Gandolfi🇺🇸 · H.-W. Hammer🇩🇪 · P. Klos🇩🇪 · J. E. Lynn🇩🇪 · A. Schwenk🇩🇪

   We reply to a Comment on our Letter [Phys. Rev. Lett. 118, 232501 (2017), arXiv:1612.01502] by A. Deltuva and R. Lazauskas [Phys. Rev. Lett 123, 069201 (2019), arXiv:1904.00925].

   ↳ nucl-thnucl-exPRL(2019)·12 citations
6. 06*

   Towards a theory of baryon resonances

   Ulf-G. Meißner🇩🇪

   In this talk, I discuss methods that allow for a systematic and model-independent calculation of the hadron spectrum. These are lattice QCD and/or its corresponding Effective Field Theories. Assorted results are shown and I take the opportunity to discuss some misconceptions often found in the literature.

   ↳ nucl-thhep-exhep-lathep-ph+1EPJ Web Conf.(2020)·5 citations
7. 07*

   Charged particle spectra from ${\mu }^{-}$ capture on Al

   A. Gaponenko🇺🇸 · A. Grossheim🇨🇦 · A. Hillairet🇨🇦 · G. M. Marshall🇨🇦 · R. E. Mischke🇨🇦 · A. Olin🇨🇦

   Published data on the emission of charged particles following nuclear muon capture are extremely limited. In addition to its interest as a probe of the nuclear response, these data are important for the design of some current searches for lepton flavor violation. This work presents momentum spectra of protons and deuterons following ${\mu }^{-}$ capture in aluminum. It is the first measurement of a muon capture process performed with a tracking spectrometer. A precision of better than 10% over the momentum range of 100--190 MeV/c for protons is obtained; for deuterons of 145--250 MeV/c the precision is better than 20%. The observed partial yield of protons with emission momenta above 80 MeV/c (kinetic energy 3.4 MeV) is $0.0322\pm 0.0007(\text{stat})\pm 0.0022(\text{syst})$ per capture, and for deuterons above 130 MeV/c (4.5 MeV) it is $0.0122\pm 0.0009(\text{stat})\pm 0.0006(\text{syst})$. Extrapolating to total yields gives $0.045\pm 0.001(\text{stat})\pm 0.003(\text{syst})\pm 0.001(\text{extrapolation})$ per capture for protons and $0.018\pm 0.001(\text{stat})\pm 0.001(\text{syst})\pm 0.002(\text{extrapolation})$ for deuterons, which are the most precise measurements of these quantities to date.

   ↳ hep-exnucl-exPRC(2020)·9 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.