Nuclear Theory·nucl-th

Friday·June 15, 2018

6 papers—2 primary·4 cross-listed

03
Hollowness in $pp$ and $p p ˉ$ scattering in a Regge model
Wojciech Broniowski🇵🇱 · László Jenkovszky🇺🇦 · Enrique Ruiz Arriola🇪🇸 · István Szanyi🇺🇦
The proton-proton and proton-antiproton inelasticity profiles in the impact parameter display very interesting and sensitive features which cannot be deduced solely from the current large body of high-energy scattering data. In particular, phenomenological studies exhibit a link between the ratio of the real to imaginary parts of the elastic scattering amplitude at a finite momentum transfer, and the corresponding change of character of the inelastic processes from central to peripheral collisions. We describe how a theoretical model, accommodating the existing data, based on the Regge hypothesis including both the Pomeron and odderon as double poles, and $ω$ and $f$ mesons as single poles in the complex- $J$ plane, generates a hollow in the inelasticity at low impact parameters. The hollowness effect, which generally may be sensitive to model details, does unequivocally take place both for $pp$ and $p p ˉ$ collisions within the applied Regge framework, indicating inapplicability of inelasticity-folding geometric approaches.
↳ hep-phnucl-thPRD(2018)·47 citations
04
Charge-dependent Flow Induced by Magnetic and Electric Fields in Heavy Ion Collisions
Umut Gürsoy🇳🇱 · Dmitri Kharzeev🇺🇸 · Eric Marcus🇳🇱 · Krishna Rajagopal🇺🇸 · Chun Shen🇺🇸
We investigate the charge-dependent flow induced by magnetic and electric fields in heavy ion collisions. We simulate the evolution of the expanding cooling droplet of strongly coupled plasma hydrodynamically, using the iEBE-VISHNU framework, and add the magnetic and electric fields as well as the electric currents they generate in a perturbative fashion. We confirm the previously reported effect of the electromagnetically induced currents, that is a charge-odd directed flow $Δ v_{1}$ that is odd in rapidity, noting that it is induced by magnetic fields (à la Faraday and Lorentz) and by electric fields (the Coulomb field from the charged spectators). In addition, we find a charge-odd $Δ v_{3}$ that is also odd in rapidity and that has a similar physical origin. We furthermore show that the electric field produced by the net charge density of the plasma drives rapidity-even charge-dependent contributions to the radial flow $⟨ p_{T} ⟩$ and the elliptic flow $Δ v_{2}$ . Although their magnitudes are comparable to the charge-odd $Δ v_{1}$ and $Δ v_{3}$ , they have a different physical origin, namely the Coulomb forces within the plasma.
↳ hep-phhep-thnucl-exnucl-thPRC(2018)·127 citations
05
$Ξ$ (2030) and $Ξ$ (2120) as $K ˉ^{*} Σ$ molecular states
Yin Huang🇨🇳 · Rong Wang🇫🇷 · Jun He🇨🇳 · Ju-Jun Xie🇨🇳 · Lisheng Geng🇨🇳
In this work, the molecular states from the \bar{K}^{*}\Sigma interaction are studied in a quasipotential Bethe-Salpeter equation approach with the one-boson-exchange potentials. We consider the exchanges of vector (\rho,\omega and \phi) mesons and pseudoscalar (\pi and \eta) mesons to describe the \bar{K}^{*}\Sigma interaction with the coupling constants determined by the SU(3) symmetry, The poles of the scattering amplitude are searched for to find the molecular states dynamically generated from the \bar{K}^{*}\Sigma interaction. A bound state with quantum number I(J^{p})=1/2(5/2^{+}) is produced, which can be associated to the \Xi(2030) baryon. Other bound states with J\le{}5/2 are also searched for and it is found that there exist bound states with quantum numbers I(J^P)=1/2(1/2^-), 1/2(3/2^{-}), and 1/2(3/2^+). The \Xi(2120) may be a candidate for one of these three bound states. In addition, we also find two bound states with isospin 3/2 and spin parities 1/2^- and 1/2^+.
↳ hep-phnucl-th2 citations
06
Inverting the mass hierarchy of jet quenching effects with prompt $b$ -jet substructure
Ivan Vitev🇺🇸
In these proceedings, we discuss the role of heavy quark mass on the formation of parton showers. Mass effects are not well understood when parton branching occurs in nuclear matter, such as the quark-gluon plasma. Recently, a theoretically consistent picture of open heavy flavor production in ultra relativistic nuclear collisions has begun to emerge based on effective theories of QCD, such as soft collinear effective theory with Glauber gluons. We show that implementation of in-medium splitting processes containing heavy quarks into next-to-leading order calculations of heavy flavor production leads to larger cross section suppression when compared to traditional energy loss phenomenology. To better constrain the important mass dependence of in-medium splitting functions, we propose a new measurement in relativistic heavy ion collisions, based on a two-prong structure inside a reconstructed heavy flavor jet. In the region of jet transverse momenta where parton mass effects are leading, we predict a unique reversal of the mass hierarchy of jet quenching effects in heavy ion relative to proton collisions. We find that the momentum sharing distribution of prompt $b$ -tagged jets is more strongly modified in comparison to the one for light jets. The work summarized here opens new directions of research on the substructure of heavy flavor jets.
↳ hep-phnucl-thJ.Phys.Conf.Ser.(2018)·0 citations

Affiliations

first authorsco-authorsvia INSPIRE

Hollowness in pp and ppˉ​ scattering in a Regge model

Charge-dependent Flow Induced by Magnetic and Electric Fields in Heavy Ion Collisions

Ξ(2030) and Ξ(2120) as Kˉ∗Σ molecular states

Inverting the mass hierarchy of jet quenching effects with prompt b-jet substructure

Affiliations

Hollowness in $pp$ and $p p ˉ$ scattering in a Regge model

$Ξ$ (2030) and $Ξ$ (2120) as $K ˉ^{*} Σ$ molecular states

Inverting the mass hierarchy of jet quenching effects with prompt $b$ -jet substructure