Nuclear Theory·nucl-th

Tuesday·September 29, 2015

17 papers—11 primary·6 cross-listed

12
Perturbative results for two and three particle threshold energies in finite volume
Maxwell T. Hansen🇩🇪 · Stephen R. Sharpe🇺🇸
We calculate the energy of the state closest to threshold for two and three identical, spinless particles confined to a cubic spatial volume with periodic boundary conditions and with zero total momentum in the finite-volume frame. The calculation is performed in relativistic quantum field theory with particles coupled via a $λ ϕ^{4}$ interaction, and we work through order $λ^{3}$ . The energy shifts begin at $O (1/ L^{3})$ , and we keep subleading terms proportional to $1/ L^{4}$ , $1/ L^{5}$ and $1/ L^{6}$ . These terms allow a non-trivial check of the results obtained from quantization conditions that hold for arbitrary interactions, namely that of Lüscher for two particles and our recently developed formalism for three particles. We also compare to previously obtained results based on non-relativistic quantum mechanics.
↳ hep-latnucl-thPRD(2016)·71 citations
13
Novel Collective Phenomena in High-Energy Proton-Proton and Proton-Nucleus Collisions
Kevin Dusling🇺🇸 · Wei Li🇺🇸 · Bjoern Schenke🇺🇸
The observation of long-range collective correlations for particles emitted in high-multiplicity pp and pPb collisions has opened up new opportunities of investigating novel high-density QCD phenomena in small colliding systems. We review experimental results related to the studies of collective phenomena in small systems from RHIC and the LHC over the past several years. Latest development in theoretical interpretations motivated by different frameworks are also reviewed, and confronted with the experimental data. Perspectives on possible future directions are discussed, with the aim of further exploring the rich emergent QCD phenomena.
↳ nucl-exhep-exhep-phnucl-thIJMPE(2016)·301 citations
14
Role of the $f_{1} (1285)$ state in the $J / ψ \to ϕ K ˉ K^{*}$ and $J / ψ \to ϕ f_{1} (1285)$ decays
Ju-Jun Xie🇨🇳 · E. Oset🇨🇳
We study the role of the $f_{1} (1285)$ resonance in the decays of $J / ψ \to ϕ K ˉ K^{*}$ and $J / ψ \to ϕ f_{1} (1285)$ . The theoretical approach is based on the results of chiral unitary theory where the $f_{1} (1285)$ resonance is dynamically generated from the $K^{*} K ˉ - c . c .$ interaction. In order to further test the dynamical nature of the $f_{1} (1285)$ state, we investigate the $J / ψ \to ϕ K ˉ K^{*}$ decay close to the $K ˉ K^{*}$ threshold and make predictions for the ratio of the invariant mass distributions of the $J / ψ \to ϕ K ˉ K^{*}$ decay and the $J / ψ \to ϕ f_{1} (1285)$ partial decay width with all the parameters of the mechanism fixed in previous studies. The results can be tested in future experiments and therefore offer new clues on the nature of the $f_{1} (1285)$ state.
↳ hep-phhep-exnucl-exnucl-thPLB(2016)·9 citations
15
Holographic entropy and real-time dynamics of quarkonium dissociation in non-Abelian plasma
Ioannis Iatrakis🇺🇸 · Dmitri E. Kharzeev🇺🇸
The peak of the heavy quark pair entropy at the deconfinement transition, observed in lattice QCD, suggests that the transition is effectively driven by the increase of the entropy of bound states. The growth of the entropy with the inter-quark distance leads to the emergent entropic force that induces dissociation of quarkonium states. Since the quark-gluon plasma around the transition point is a strongly coupled system, we use the gauge-gravity duality to study the entropy of heavy quarkonium and the real-time dynamics of its dissociation. In particular, we employ the Improved Holographic QCD model as a dual description of large $N_{c}$ Yang Mills theory. Studying the dynamics of the fundamental string between the quarks placed on the boundary, we find that the entropy peaks at the transition point. We also study the real-time dynamics of the system by considering the holographic string falling in the black hole horizon where it equilibrates. In the vicinity the deconfinement transition, the dissociation time is found to be less than a fermi, suggesting that the entropic destruction is the dominant dissociation mechanism in this temperature region.
↳ hep-phhep-thnucl-thPRD(2016)·32 citations
16
Self-similarity of strangeness production in pp collisions at RHIC
M. Tokarev (1) · I. Zborovsky (2) ((1) Veksler and Baldin Laboratory of High Energy Physics, Joint Institute for Nuclear Research, Dubna, Moscow region, Russia (2) Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Rez, Czech Republic)
New experimental data on transverse momentum spectra of strange particles (KS0, K-, K*, phi,...) produced in pp collisions at sqrt s = 200 GeV obtained by the STAR and PHENIX collaborations at RHIC are analysed in the framework of z-scaling approach. Scaling properties of the data z-presentation are illustrated. Self-similarity of strange particle production is discussed. A microscopic scenario of constituent interactions developed within the z-scaling approach is used to study constituent energy loss, proton momentum fraction and recoil mass in dependence on the transverse momentum, strangeness, and mass of the inclusive particle. The obtained results can be useful for understanding strangeness origin, for searching for new physics with strange probes and can serve as a benchmark for complex analyses of self-similar features of strange production in heavy ion collisions.
↳ hep-phnucl-exnucl-thJ.Phys.Conf.Ser.(2016)·4 citations
17
A covariant model for the negative parity resonances of the nucleon
G. Ramalho🇧🇷
We present a model for the $γ^{*} N \to N^{*}$ helicity amplitudes, where $N$ is the nucleon and $N^{*}$ is a negative parity nucleon excitation, member of the $S U (6)$ -multiplet $[70, 1^{-}]$ . The model combines the results from the single quark transition model for the helicity amplitudes with the results of the covariant spectator quark model for the $γ^{*} N \to N^{*} (1535)$ and $γ^{*} N \to N^{*} (1520)$ transitions. With the knowledge of the amplitudes $A_{1/2}$ and $A_{3/2}$ for those transitions we calculate three independent coefficients defined by the single quark transition model and make predictions for the helicity amplitudes associated with the $γ^{*} N \to N^{*} (1650)$ , $γ^{*} N \to N^{*} (1700)$ , $γ^{*} N \to Δ (1620)$ , and $γ^{*} N \to Δ (1700)$ transitions. In order to facilitate the comparison with future experimental data at high $Q^{2}$ , we provide also simple parametrizations for the amplitudes, compatible with the expected falloff at high $Q^{2}$ .
↳ hep-phhep-exhep-latnucl-ex+1J.Phys.Conf.Ser.(2016)·0 citations

Affiliations

first authorsco-authorsvia INSPIRE

Perturbative results for two and three particle threshold energies in finite volume

Novel Collective Phenomena in High-Energy Proton-Proton and Proton-Nucleus Collisions

Role of the f1​(1285) state in the J/ψ→ϕKˉK∗ and J/ψ→ϕf1​(1285) decays

Holographic entropy and real-time dynamics of quarkonium dissociation in non-Abelian plasma

Self-similarity of strangeness production in pp collisions at RHIC

A covariant model for the negative parity resonances of the nucleon

Affiliations

Role of the $f_{1} (1285)$ state in the $J / ψ \to ϕ K ˉ K^{*}$ and $J / ψ \to ϕ f_{1} (1285)$ decays