Nuclear Theory·nucl-th

Monday·August 28, 2017

7 papers—3 primary·4 cross-listed

01
[Submitted on 25 Aug 2017]
$η$ -nucleus interaction from the $d + d$ reaction around the $η$ production threshold
N. Ikeno🇯🇵 · H. Nagahiro🇯🇵 · D. Jido🇯🇵 · S. Hirenzaki🇯🇵
The $η$ mesic nucleus is considered to be one of the interesting exotic many body systems and has been studied since 1980's theoretically and experimentally. Recently, the formation of the $η$ mesic nucleus in the fusion reactions of the light nuclei such as $d + d \to (η + α) \to X$ has been proposed and the experiments have been performed by WASA-at-COSY. We develop a theoretical model to evaluate the formation rate of the $η$ mesic nucleus in the fusion reactions and show the calculated results. We find that the $η$ bound states could be observed in the reactions in cases with the strong attractive and small absorptive $η$ -nucleus interactions. We compare our results with existing data of the $d + d \to η + α$ and the $d + d \to^{3} He + N + π$ reactions. We find that the analyses by our theoretical model with the existing data can provide new information on the $η$ -nucleus interaction.
Comments:
14 pages, 31 figures, 1 table, submitted to EPJA
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1708.07692 [pdf]
EPJA(2017)·23 citations
02
[Submitted on 24 Aug 2017]
Power series expansion method in tensor-optimized antisymmetrized molecular dynamics beyond the Jastrow correlation method
Takayuki Myo · Hiroshi Toki · Kiyomi Ikeda · Hisashi Horiuchi · Tadahiro Suhara
We developed a new variational method for tensor-optimized antisymmetrized molecular dynamics (TOAMD) for nuclei. In TOAMD, the correlation functions for the tensor force and the short-range repulsion are introduced and used in the power series form of the wave function, which is different from the Jastrow method. Here, nucleon pairs are correlated in multi-steps with different forms, while they are correlated only once including all pairs in the Jastrow correlation method. Each correlation function in every term is independently optimized in the variation of total energy in TOAMD. For $s$ -shell nuclei using the nucleon-nucleon interaction, the energies in TOAMD are better than those in the variational Monte Carlo method with the Jastrow correlation function. This means that the power series expansion using the correlation functions in TOAMD describes the nuclei better than the Jastrow correlation method.
Comments:
7 pages, 4 figures. arXiv admin note: text overlap with arXiv:1706.09560, update references
Subjects:
Nuclear Theory (nucl-th); Strongly Correlated Electrons (cond-mat.str-el)
arXiv:
1708.07748 [pdf]
PRC(2017)·19 citations
03
[Submitted on 24 Aug 2017]
Examining the model dependence of the determination of kinetic freeze-out temperature and transverse flow velocity in small collision system
Hai-Ling Lao🇨🇳 · Fu-Hu Liu🇨🇳 · Bao-Chun Li🇨🇳 · Mai-Ying Duan🇨🇳 · Roy A. Lacey🇺🇸
The transverse momentum distributions of the identified particles produced in small collision systems at the Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) have been analyzed by four models. The first two models utilize the blast-wave model with different statistics. The last two models employ certain linear correspondences based on different distributions. The four models describe the experimental data measured by the Pioneering High Energy Nuclear Interaction eXperiment (PHENIX), Solenoidal Tracker at RHIC (STAR), and A Large Ion Collider Experiment (ALICE) cCollaborations equally well. It is found that both the kinetic freeze-out temperature and transverse flow velocity in the central collisions are comparable with those in the peripheral collisions. With the increase of collision energy from that of the RHIC to that of the LHC, the considered quantities typically do not decrease. Comparing with the central collisions, the proton-proton collisions are closer to the peripheral collisions.
Comments:
17 pages, 9 figures. Nuclear Science and Techniques, Accepted. arXiv admin note: text overlap with arXiv:1703.04944
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1708.07749 [pdf]
Nucl.Sci.Tech.(2018)·33 citations
04
[Submitted on 24 Aug 2017] (cross-list from hep-ph)
Double, triple, and $n$ -parton scatterings in high-energy proton and nuclear collisions
David d'Enterria🇨🇭 · Alexander Snigirev🇷🇺
The framework to compute the cross sections for the production of particles with high mass and/or large transverse momentum in double- (DPS), triple- (TPS), and in general $n$ -parton scatterings, from the corresponding single-parton ( $σ_{SPS}$ ) values in high-energy proton-proton, proton-nucleus, and nucleus-nucleus is reviewed. The basic parameter of the factorized $n$ -parton scattering ansatz is an effective cross section $σ_{eff}$ encoding all unknowns about the underlying generalized $n$ -parton distribution in the proton (nucleon). In its simplest and most economical form, the $σ_{eff}$ parameter can be derived from the transverse parton profile of the colliding protons and/or nucleus, using a Glauber approach. Numerical examples for the cross sections and yields expected for the concurrent DPS or TPS production of heavy-quarks, quarkonia, and/or gauge bosons in proton and nuclear collisions at LHC and Future Circular Collider (FCC) energies are provided. The obtained cross sections are based on perturbative QCD predictions for $σ_{SPS}$ at next-to-leading-order (NLO) or next-to-NLO (NNLO) accuracy including, when needed, nuclear modifications of the corresponding parton densities.
Comments:
33 pages, 9 figures. Review chapter in "Multiple parton interactions at the LHC", Bartalini & Gaunt eds., World Scientific
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1708.07519 [pdf]
Adv.Ser.Direct.High Energy Phys.(2018)·54 citations
05
[Submitted on 24 Aug 2017] (cross-list from hep-ph)
Elastic scattering of a quark from a color field: longitudinal momentum exchange
Jamal Jalilian-Marian🇺🇸
Perturbative QCD in the small Bjorken $x$ limit can be formulated as an effective theory known as the Color Glass Condensate (CGC) formalism. The CGC formalism takes into account the dynamics of large gluon densities at small $x$ and has been successfully applied to Deep Inelastic Scattering (DIS) and particle production in high energy hadronic and nuclear collisions in the small $x$ kinematic region. The effective degrees of of freedom in CGC are Wilson lines which enter in the effective quark (and gluon) propagators and re-sum multiple soft scatterings from the small $x$ gluon field of the target. It is however known that the CGC effective theory breaks down when one probes the moderately large $x$ (high $p_{t}$ ) kinematics where collinear factorization and DGLAP evolution of parton distribution functions should be the right framework. Here we propose a general framework which may allow one to eventually unify the two approaches and to calculate pQCD cross sections in both small and large Bjorken $x$ regions. We take the first step towards this goal by deriving an expression for the quark propagator in a background field which includes scatterings from both small and large $x$ modes of the gluon field of the target. We describe how this quark propagator can be used to calculate QCD structure functions $F_{2}$ and $F_{L}$ at all $x$ and thus generalize the dipole model of DIS. We outline this approach can also be used to extend the so-called hybrid approach to particle production in the forward rapidity region of high energy hadronic and nuclear collisions to all $x$ and $p_{t}$ regions and speculate on how one may apply the same techniques to extend the McLerran-Venugopalan effective action used in high energy heavy ion collisions to include high $p_{t}$ physics.
Comments:
22 pages, 14 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1708.07533 [pdf]
PRD(2017)·47 citations
06
[Submitted on 22 Aug 2017] (cross-list from quant-ph)
Monotonic properties of the shift and penetration factors
Carl R. Brune · Gerald M. Hale · Mark W. Paris
We study derivatives of the shift and penetration factors of collision theory with respect to energy, angular momentum, and charge. Definitive results for the signs of these derivatives are found for the repulsive Coulomb case. In particular, we find that the derivative of the shift factor with respect to energy is positive for the repulsive Coulomb case, a long anticipated but heretofore unproven result. These results are closely connected to the properties of the sum of squares of the regular and irregular Coulomb functions; we also present investigations of this quantity.
Comments:
13 pages, 1 figure
Subjects:
Quantum Physics (quant-ph); Mathematical Physics (math-ph); math.CA (math.CA); math.MP (math.MP); Nuclear Theory (nucl-th)
arXiv:
1708.07554 [pdf]
PRC(2018)·2 citations
07
[Submitted on 25 Aug 2017] (cross-list from hep-ph)
Single- and double-scattering production of four muons in ultraperipheral PbPb collisions at the Large Hadron Collider
Andreas van Hameren🇵🇱 · Mariola Klusek-Gawenda🇵🇱 · Antoni Szczurek🇵🇱
We discuss production of two $μ^{+} μ^{-}$ pairs in ultraperipheral ultrarelativistic heavy ion collisions at the LHC. We take into account electromagnetic (two-photon) double-scattering production and for a first time direct $γ γ$ production of four muons in one scattering. We study the unexplored process $γ γ \to μ^{+} μ^{-} μ^{+} μ^{-}$ . We present predictions for total and differential cross sections. Measurable nuclear cross sections are obtained and corresponding differential distributions and counting rates are presented.
Comments:
13 pages, 11 figures, 1 table
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1708.07742 [pdf]
PLB(2018)·22 citations

Affiliations

first authorsco-authorsvia INSPIRE

η-nucleus interaction from the d+d reaction around the η production threshold

Power series expansion method in tensor-optimized antisymmetrized molecular dynamics beyond the Jastrow correlation method

Examining the model dependence of the determination of kinetic freeze-out temperature and transverse flow velocity in small collision system

Double, triple, and n-parton scatterings in high-energy proton and nuclear collisions

Elastic scattering of a quark from a color field: longitudinal momentum exchange

Monotonic properties of the shift and penetration factors

Single- and double-scattering production of four muons in ultraperipheral PbPb collisions at the Large Hadron Collider

Affiliations

$η$ -nucleus interaction from the $d + d$ reaction around the $η$ production threshold

Double, triple, and $n$ -parton scatterings in high-energy proton and nuclear collisions