Nuclear Theory·nucl-th

Wednesday·March 27, 2019

6 papers—3 primary·3 cross-listed

01
Elastic scattering, inelastic excitation, and 1n pick-up transfer cross sections for $^{10}$ B+ $^{120}$ Sn at energies near the Coulomb barrier
M. A. G. Alvarez · M. Rodríguez-Gallardo · L. R. Gasques · L. C. Chamon · J. R. B. Oliveira · V. Scarduelli · A. S. Freitas · E. S. Rossi Jr. · V. A. B. Zagatto · J. Rangel · J. Lubian · I. Padron
The $^{10}$ B+ $^{120}$ Sn reaction has been systematically studied at laboratory energies around the Coulomb barrier: E $_{LAB} =$ 31.5, 33.5, 35.0, and 37.5 MeV. Cross sections for the elastic scattering and some reaction processes have been measured: excitation to the $1^{+}$ state of $^{10}$ B; excitation to the $2^{+}$ and $3^{-}$ states of $^{120}$ Sn; and the one-neutron pick-up transfer $^{120}$ Sn( $^{10}$ B, $^{11}$ B) $^{119}$ Sn. Coupled reaction channel (CRC) calculations have been performed in the context of the double-folding São Paulo potential. The theoretical calculations result in a good overall description of the experimental angular distributions. The effect on the theoretical elastic-scattering angular distributions of couplings to the inelastic and transfer states (through the CRC calculations) and to the continuum states (through continuum-discretized coupled-channels calculations) has been investigated.
nucl-thPRC(2018)·20 citations
02
Kaonic Nuclear Clusters --- a New Paradigm of Particle and Nuclear Physics ---
Y. Akaishi🇯🇵 · T. Yamazaki🇯🇵
Lambda*=Lambda(1405) plays an essential role in forming kaonic nuclear clusters (KNC). The simplest KNC, K-pp, has the structure Lambda*p=(K-p){I=0}p, where a real kaon migrates between two nucleons, mediating super-strong Lambda*-p$ attraction. Production data of K-pp have been accumulated by DISTO, J-PARC E27 and J-PARC E15 experiments. In the case of K-K-pp, the attractive covalent bond of Lambda*Lambda* is doubly enhanced compared to the Lambda*-p one. As a consequence, a m-th Lambda* multiplet, (Lambda*)m, with m(m-1)/2 bonds becomes more stable than its corresponding neutron aggregate, (n)m, with m=8 ~ 12. This may suggest the possible existence of stable Lambda* matter. The production of K-K-pp by high-energy pp or heavy-ion collisions is awaited as a doorway to so-far unknown Lambda* matter.
nucl-th5 citations
03
Further Theoretical Analysis on the $K^{-}^{3} He \to Λ p n$ Reaction for the $K ˉ N N$ Bound-State Search in the J-PARC E15 Experiment
Takayasu Sekihara (JAEA, Ibaraki)🇯🇵 · Eulogio Oset (Valencia U. & Valencia U., IFIC)🇪🇸 · Angels Ramos (Barcelona U., ECM & ICC, Barcelona U.)🇪🇸
Based on the scenario that a $K ˉ N N$ bound state is generated and it eventually decays into $Λ p$ , we calculate the cross section of the $K^{-}^{3} He \to Λ p n$ reaction, which was recently measured in the J-PARC E15 experiment. We find that the behavior of the calculated differential cross section $d^{2} σ / d M_{Λ p} d q_{Λ p}$ , where $M_{Λ p}$ and $q_{Λ p}$ are the $Λ p$ invariant mass and momentum transfer in the $(K^{-}, n)$ reaction in the laboratory frame, respectively, is consistent with the experiment. Furthermore, we can reproduce almost quantitatively the experimental data of the $Λ p$ invariant mass spectrum in the momentum transfer window $350 MeV / c < q_{Λ p} < 650 MeV / c$ . These facts strongly suggest that the $K ˉ N N$ bound state was indeed generated in the J-PARC E15 experiment.
nucl-thhep-phnucl-exJPS Conf.Proc.(2019)·5 citations
04
Impact of the chromo-electromagnetic field fluctuations on transport coefficients of heavy quarks and shear viscosity to entropy density ratio of quark-gluon plasma
Ashik Ikbal Sheikh🇮🇳 · Zubayer Ahammed🇮🇳
The chromo-electromagnetic field fluctuations in the quark-gluon plasma (QGP) play an important role as these field fluctuations result energy gain of heavy quarks. We consider these fluctuations and evaluate the transport coefficients, e.g., drag and diffusion coefficients of charm quarks and shear viscosity to entropy density ratio ( $η / s$ ) of the QGP. We find a significant effect of such fluctuations on the transport coefficients. These fluctuations cause a reduction of the drag and diffusion coefficients. We also observe that the shear viscosity to entropy density ratio of the QGP is closer to the value obtained in Lattice QCD (LQCD) and functional renormalization group calculations when the effects of such fluctuations are included.
↳ hep-phnucl-thNPA(2019)·2 citations
05
Structure Functions of the Nucleon in a Soliton Model
I. Takyi🇿🇦 · H. Weigel🇿🇦
We study nucleon structure functions in the soliton picture of the bosonized Nambu-Jona-Lasinio model. We focus on their vacuum contributions and examine whether they are outweighed by their valence quark counterparts.
↳ hep-phnucl-thJPS Conf.Proc.(2019)·1 citation
06
Strong LHCb evidence supporting the existence of the hidden-charm molecular pentaquarks
Rui Chen🇨🇳 · Zhi-Feng Sun🇨🇳 · Xiang Liu🇨🇳 · Shi-Lin Zhu🇨🇳
On March 26th, 2019, at the Rencontres de Moriond QCD conference, the LHCb Collaboration reported the observation of three new pentaquarks, namely $P_{c} (4312)$ , $P_{c} (4440)$ and $P_{c} (4457)$ , which are consistent with the loosely bound molecular hidden-charm pentaquark states composed of an S-wave charmed baryon $Σ_{c}$ and an S-wave anti-charmed meson ( $D ˉ, D ˉ^{*}$ ). In this work, we present a direct calculation by the one-boson-exchange (OBE) model and demonstrate explicitly that the $P_{c} (4312)$ , $P_{c} (4440)$ and $P_{c} (4457)$ do correspond to the loosely bound $Σ_{c} D ˉ$ with $(I = 1/2, J^{P} = 1/ 2^{-})$ , $Σ_{c} D ˉ^{*}$ with $(I = 1/2, J^{P} = 1/ 2^{-})$ and $Σ_{c} D ˉ^{*}$ with $(I = 1/2, J^{P} = 3/ 2^{-})$ , respectively.
↳ hep-phhep-exhep-latnucl-thPRD(2019)·261 citations

Affiliations

first authorsco-authorsvia INSPIRE

Elastic scattering, inelastic excitation, and 1n pick-up transfer cross sections for 10B+120Sn at energies near the Coulomb barrier

Kaonic Nuclear Clusters --- a New Paradigm of Particle and Nuclear Physics ---

Further Theoretical Analysis on the K−3He→Λpn Reaction for the KˉNN Bound-State Search in the J-PARC E15 Experiment

Impact of the chromo-electromagnetic field fluctuations on transport coefficients of heavy quarks and shear viscosity to entropy density ratio of quark-gluon plasma

Structure Functions of the Nucleon in a Soliton Model

Strong LHCb evidence supporting the existence of the hidden-charm molecular pentaquarks

Affiliations

Elastic scattering, inelastic excitation, and 1n pick-up transfer cross sections for $^{10}$ B+ $^{120}$ Sn at energies near the Coulomb barrier

Further Theoretical Analysis on the $K^{-}^{3} He \to Λ p n$ Reaction for the $K ˉ N N$ Bound-State Search in the J-PARC E15 Experiment