Nuclear Theory·nucl-th

Wednesday·December 25, 2019

10 papers—5 primary·5 cross-listed

06
Three Point Energy Correlators in the Collinear Limit: Symmetries, Dualities and Analytic Results
Hao Chen🇨🇳 · Ming-Xing Luo🇨🇳 · Ian Moult🇺🇸 · Tong-Zhi Yang🇨🇳 · Xiaoyuan Zhang🇨🇳 · Hua Xing Zhu🇨🇳
Energy Correlators measure the energy deposited in multiple detectors as a function of the angles between the detectors. In this paper, we analytically compute the three particle correlator in the collinear limit in QCD for quark and gluon jets, and also in $N = 4$ super Yang-Mills theory. We find an intriguing duality between the integrals for the energy correlators and infrared finite Feynman parameter integrals, which maps the angles of the correlators to dual momentum variables. In $N = 4$ , we use this duality to express our result as a rational sum of simple Feynman integrals (triangles and boxes). In QCD our result is expressed as a sum of the same transcendental functions, but with more complicated rational functions of cross ratio variables as coefficients. Our results represent the first analytic calculation of a three-prong jet substructure observable of phenomenological relevance for the LHC, revealing unexplored simplicity in the energy flow of QCD jets. They also provide valuable data for improving the understanding of the light-ray operator product expansion.
↳ hep-phhep-thnucl-thJHEP(2020)·116 citations
07
Reanalysis of the most strange dibaryon within constituent quark models
Hongxia Huang🇨🇳 · Xinmei Zhu🇨🇳 · Jialun Ping🇨🇳
The most strange dibaryon $ΩΩ$ with quantum numbers $S = - 6$ , $I = 0$ , and $J^{P} = 0^{+}, 1^{-}, 2^{+}, 3^{-}$ is reanalyzed in the framework of quark delocalization color screening model (QDCSM) and chiral quark model (ChQM). The $ΩΩ$ dibaryon with $J^{P} = 0^{+}$ is bound, and the one with other quantum numbers $J^{P} = 1^{-}, 2^{+}, 3^{-}$ are all unbound in our calculation. The low-energy scattering phase shifts, the scattering length, and the effective range of the $ΩΩ$ dibaryon with $J^{P} = 0^{+}$ also support the existence of such strange dibaryon. This dibaryon is showed to be a shallow bound state in QDCSM, while the binding energy becomes much larger in the ChQM by including the effect of the hidden-color channel coupling. And the scalar nonet meson-exchange in the ChQM also provides more attraction for the $ΩΩ$ system. Experimental search for such most strange dibaryon will provide much information for understanding the hadron-hadron interactions in different quark models.
↳ hep-phnucl-thPRC(2020)·10 citations
08
Magneto-vortical effect in strongly coupled plasma
Yanyan Bu🇨🇳 · Shu Lin🇨🇳
Based on a holographic model incorporating both chiral anomaly and gravitational anomaly, we study the effect of magneto-vortical coupling on transport properties of a strongly coupled plasma. The focus of present work is on the generation of a vector charge density and an axial current, as response to vorticity in a magnetized plasma. The transport coefficients parameterising the vector charge density and axial current are calculated both analytically (in the weak magnetic field limit) and also numerically (for general values of the magnetic field). We find the generation of vector charge receives both non-anomalous and anomalous contributions, with the non-anomalous contribution dominating in the limit of strong magnetic field and the anomalous contribution sensitive to both chiral anomaly and gravitational anomaly. On the contrary, we find the axial current is induced entirely due to the gravitational anomaly, thus we interpret the axial current generation as chiral vortical effect. The corresponding chiral vortical conductivity is found to be suppressed by the magnetic field. By Onsager relation, these transport coefficients are responsible for the generation of a thermal current due to a transverse electric field or a transverse axial magnetic field, which we call thermal Hall effect and thermal axial magnetic effect, respectively.
↳ hep-thhep-phnucl-thEPJC(2020)·10 citations
09
Diffractive Dissociation of Alpha Particles as a Test of Isophobic Short-Range Correlations inside Nuclei
Jennifer Rittenhouse West🇺🇸 · Stanley J. Brodsky🇺🇸 · Guy F. de Téramond🇨🇷 · Iván Schmidt🇨🇱
The CLAS collaboration at Jefferson Laboratory has compared nuclear parton distributions for a range of nuclear targets and found that the EMC effect measured in deep inelastic lepton-nucleus scattering has a strongly "isophobic" nature. This surprising observation suggests short-range correlations between neighboring $n$ and $p$ nucleons in nuclear wavefunctions that are much stronger compared to $p - p$ or $n - n$ correlations. In this paper we propose a definitive experimental test of the nucleon-nucleon explanation of the isophobic nature of the EMC effect: the diffractive dissociation on a nuclear target $A$ of high energy $^{4} He$ nuclei to pairs of nucleons $n$ and $p$ with high relative transverse momentum, $α + A \to n + p + A^{'} + X$ . The comparison of $n - p$ events with $p - p$ and $n - n$ events directly tests the postulated breaking of isospin symmetry. The experiment also tests alternative QCD-level explanations for the isophobic EMC effect. In particular it will test a proposal for hidden-color degrees of freedom in nuclear wavefunctions based on isospin-zero $[u d]$ diquarks.
↳ hep-phnucl-exnucl-thPLB(2020)·8 citations
10
N $^{*}$ Experiments and what they tell us about Strong QCD Physics
Volker D. Burkert🇺🇸
I give an overview on experimental studies of the spectrum and the structure of the excited states of the nucleon and what we can learn about their internal structure. One focus is on the efforts to obtain a more complete picture of the light-quark baryon excitation spectrum employing electromagnetic beams that will allow us to draw some conclusions on the symmetries underlying the spectrum. For the higher mass excitations, the full employment of coupled channel approaches is essential when searching for new excited states in the large amounts of data already accumulated in different channels involving a variety of polarization observables. The other focus is on the study of transition form factors and helicity amplitudes and their dependences on $Q^{2}$ , especially on some of the more prominent resonances, especially $Δ (1232) \frac{3}{2}^{+}$ , $N (1440) \frac{1}{2}^{+}$ , and negative parity states $N (1535) \frac{1}{2}^{-}$ , and $N (1675) \frac{5}{2}^{-}$ . These were obtained in pion and eta electroproduction experiments off proton targets and have already led to further insights in the active degrees-of-freedom as a function of the distance scale involved.
↳ nucl-exhep-lathep-phnucl-thEPJ Web Conf.(2020)·21 citations

Affiliations

first authorsco-authorsvia INSPIRE

Three Point Energy Correlators in the Collinear Limit: Symmetries, Dualities and Analytic Results

Reanalysis of the most strange dibaryon within constituent quark models

Magneto-vortical effect in strongly coupled plasma

Diffractive Dissociation of Alpha Particles as a Test of Isophobic Short-Range Correlations inside Nuclei

N∗ Experiments and what they tell us about Strong QCD Physics

Affiliations

N $^{*}$ Experiments and what they tell us about Strong QCD Physics