Nuclear Theory·nucl-th

Friday·July 30, 2021

12 papers—1 primary·11 cross-listed

01
Nucleon-nucleon scattering with perturbative pions: The uncoupled $P$ -wave channels
J. B. Habashi🇺🇸
The uncoupled $P$ -wave channels of nucleon-nucleon scattering are studied in an effective field theory (EFT) including a perturbative dibaryon field and perturbative pions. Good agreement between EFT results and the Nijmegen partial wave analysis is observed up to a center-of-mass momentum $k \approx 400$ MeV. Using a method that combines renormalization and fitting together, the long-standing convergence problem of EFTs in these channels with perturbative pions, for momenta above the pion mass is addressed from a new perspective.
nucl-thhep-lathep-phPRC(2022)·3 citations
02
First-Generation New Physics in Simplified Models: From Low-Energy Parity Violation to the LHC
Andreas Crivellin🇨🇭 · Martin Hoferichter🇨🇭 · Matthew Kirk🇮🇹 · Claudio Andrea Manzari🇨🇭 · Luc Schnell🇫🇷
New-physics (NP) constraints on first-generation quark-lepton interactions are particularly interesting given the large number of complementary processes and observables that have been measured. Recently, first hints for such NP effects have been observed as an apparent deficit in first-row CKM unitarity, known as the Cabibbo angle anomaly, and the CMS excess in $q q ˉ \to e^{+} e^{-}$ . Since the same NP would inevitably enter in searches for low-energy parity violation, such as atomic parity violation, parity-violating electron scattering, and coherent neutrino-nucleus scattering, as well as electroweak precision observables, a combined analysis is required to assess the viability of potential NP interpretations. In this article we investigate the interplay between LHC searches, the Cabibbo angle anomaly, electroweak precision observables, and low-energy parity violation by studying all simplified models that give rise to tree-level effects related to interactions between first-generation quarks and leptons. Matching these models onto Standard Model effective field theory, we derive master formulae in terms of the respective Wilson coefficients, perform a complete phenomenological analysis of all available constraints, point out how parity violation can in the future be used to disentangle different NP scenarios, and project the constraints achievable with forthcoming experiments.
↳ hep-phhep-exnucl-exnucl-thJHEP(2021)·75 citations
03
The photon content of the proton in the CT18 global analysis
Keping Xie🇺🇸 · T. J. Hobbs🇺🇸 · Tie-Jiun Hou🇨🇳 · Carl Schmidt🇺🇸 · Mengshi Yan🇨🇳 · C.-P. Yuan🇺🇸
Recently, two photon PDF sets based on implementations of the LUX ansatz into the CT18 global analysis were released. In CT18lux, the photon PDF is calculated directly using the LUX master formula for all scales, $μ$ . In an alternative realization, CT18qed, the photon PDF is initialized at the starting scale, $μ_{0}$ , using the LUX formulation and evolved to higher scales $μ (> μ_{0})$ with a combined QED+QCD kernel at $O (α), O (α α_{s})$ and $O (α^{2})$ . In the small- $x$ region, the photon PDF uncertainty is mainly induced by the quark and gluon PDFs, through the perturbative DIS structure functions. In comparison, the large- $x$ photon uncertainty comes from various low-energy, nonperturbative contributions, including variations of the inelastic structure functions in the resonance and continuum regions, higher-twist and target-mass corrections, and elastic electromagnetic form factors of the proton. We take the production of doubly-charged Higgs pairs, $(H^{++} H^{--})$ , as an example of scenarios beyond the Standard Model to illustrate the phenomenological implications of these photon PDFs at the LHC.
↳ hep-phhep-exnucl-thSciPost Phys.Proc.(2022)·8 citations
04
Spin and Pseudo-Spin Symmetries in Radial Dirac Equation and Exceptional Hermite Polynomials
Özlem Yeşiltaş · Aynur Özcan
We have generalized the solutions of the radial Dirac equation with a tensor potential under spin and pseudospin symmetry limits to exceptional orthogonal Hermite polynomials family. We have obtained new general rational potential models which are the generalization of the nonlinear isotonic potential families and also energy dependent.
↳ math-phmath.MPnucl-thEur.Phys.J.Plus(2021)·0 citations
05
Possible studies of gluon transversity in the spin-1 deuteron at hadron-accelerator facilities
S. Kumano (KEK/J-PARC)🇯🇵 · Qin-Tao Song (Zhengzhou University)🇨🇳
Chiral-odd gluon transversity distribution could shed light on a new aspect of hadron physics. Although we had much progress recently on quark transversity distributions, there is no experimental measurement on the gluon transversity. The gluon trasversity does not exist in the spin-1/2 nucleons and it exists in the spin-1 deuteron. Therefore, it could probe new hadron physics in the deuteron beyond the basic bound system of a proton and a neutron because the nucleons cannot contribute directly. Here, we explain that the gluon transversity can be measured at hadron accelerator facilities, such as Fermilab and NICA, in addition to charged-lepton scattering measurements at lepton accelerator facilities by showing cross sections of the proton-deuteron Drell-Yan process as an example.
↳ hep-phhep-exhep-latnucl-thSciPost Phys.Proc.(2022)·0 citations
06
New results on proton-induced reactions on Vanadium for $^{47}$ Sc production and the impact of level densities on theoretical cross sections
F. Barbaro🇮🇹 · L. Canton🇮🇹 · M.P. Carante🇮🇹 · A. Colombi🇮🇹 · L. De Dominicis🇮🇹 · A. Fontana🇮🇹 · F. Haddad🇫🇷 · L. Mou🇮🇹 · G. Pupillo🇮🇹
New data for the $^{\mbox} na t$ V(p,x) reactions have been measured in the range 26-70 MeV, with production of the nuclides $^{47}$ Sc, $^{43}$ Sc, $^{44 m}$ Sc, $^{44 g}$ Sc, $^{46}$ Sc, $^{48}$ Sc, $^{42}$ K, $^{43}$ K, $^{48}$ V, $^{48}$ Cr, $^{49}$ Cr, and $^{51}$ Cr. The focus is on the production of $^{47}$ Sc, a $β^{-}$ -emitter suitable for innovative radiotheranostic applications in nuclear medicine. The measured cross sections for this radionuclide and its contaminants are compared with the theoretical excitation functions calculated with the TALYS code. In view of novel radiopharmaceutical applications, it is essential to accurately describe these cross-sections for the evaluation of yields, purities, and dose releases. Hence, we optimize the level-density parameters of the microscopic models in the TALYS code to obtain the best possible descriptions of the new data. We consider different irradiation conditions to estimate the production yields from the cross sections determined in this work.
↳ nucl-exnucl-thphysics.med-phPRC(2021)·8 citations
07
Critical properties of various sizes of cluster in the Ising percolation transition
Lizhu Chen🇨🇳 · Yeyin Zhao🇨🇳 · Xiaobing Li🇨🇳 · Zhiming Li🇨🇳 · Yuanfang Wu🇨🇳
It is proposed that the $O (n)$ spin and geometrical percolation models can help to study the QCD phase diagram due to the universality properties of the phase transition. In this paper, correlations and fluctuations of various sizes of cluster in the Ising model are systematically studied. With a finite size system, we demonstrate how to use the finite size scaling and fixed point behavior to search for critical point. At critical point, the independency of system size is found from skewness and kurtosis of the maximum, second and third largest cluster and their correlations. It is similar to the Binder-ratio, which has provided a remarkable identification of the critical point. Through an explanation of the universal characteristic of skewness and kurtosis of the order parameter, a possible application to the relativistic heavy-ion collisions is also discussed.
↳ hep-phnucl-thIJMPE(2021)·3 citations
08
Triply-heavy tetraquarks in an extended relativized quark model
Qi-Fang Lü🇨🇳 · Dian-Yong Chen🇨🇳 · Yu-Bing Dong🇨🇳 · Elena Santopinto🇮🇹
In this paper, we adopt an extended relativized quark model to investigate the triply-heavy tetrquarks systematically. The mass spectra are obtained by solving the four-body relativized Hamiltonian including the Coulomb potential, confining potential, spin-spin interactions, and relativistic corrections. We find that all of the triply-heavy tetraquarks lie above the corresponding meson-meson thresholds, and thus no stable one exists. In particular, besides the spin-spin interactions, the Coulomb and confining potentials also contribute to the mass splittings in the $c b c ˉ q ˉ$ and $c b b ˉ q ˉ$ systems. Moreover, the whole mass spectra for triply heavy tetraquarks show quite similar patterns, which preserve the light flavor SU(3) symmetry and heavy quark symmetry well. Through the fall-apart mechanism, the triply-heavy tetraquarks may easily decay into the heavy quarkonium plus heavy-light mesons, which are good candidates for investigation in future experiments.
↳ hep-phhep-exnucl-thPRD(2021)·24 citations
09
Time reversal-odd effects in QCD and beyond
Dylan Manna🇺🇸 · Andrea Signori🇮🇹 · Christine Aidala🇺🇸
In this paper we will describe a parallel between phenomenological and symmetry-based descriptions of the process dependence of the time-reversal-odd phenomena in QCD, such as the Sivers effect, with the goal of defining the essential elements that lead to such process dependence in QCD. This will then serve as a starting point to explore possible generalizations in a different gauge theory.
↳ hep-phhep-exnucl-thSciPost Phys.Proc.(2022)·2 citations
10
Bayesian inference of strange star equation of state using the GW170817 and GW190425 data
Zhiqiang Miao🇨🇳 · Jin-Liang Jiang🇨🇳 · Ang Li🇨🇳 · Lie-Wen Chen🇨🇳
The observations of compact star inspirals from LIGO/Virgo provide a valuable tool to study the highly uncertain equation of state (EOS) of dense matter at the densities in which the compact stars reside. It is not clear whether the merging stars are neutron stars or quark stars containing self-bound quark matter. In this work, we explore the allowed bag-model-like EOSs by assuming the merging stars are strange quark stars (SQSs) from a Bayesian analysis employing the tidal deformability observational data of the GW170817 and GW190425 binary mergers. We consider two extreme states of strange quark matter, either in nonsuperfluid or color-flavor locked (CFL) and find the results in these two cases essentially reconcile. In particular, our results indicate that the sound speed in the SQS matter is approximately a constant close to the conformal limit of $c / 3$ . The universal relations between the mass, the tidal deformability and the compactness are provided for the SQSs. The most probable values of the maximum mass are found to be $M_{TOV} = 2.1 0_{- 0.12}^{+ 0.12} (2.1 5_{- 0.14}^{+ 0.16}) M_{⊙}$ for normal (CFL) SQSs at a $90%$ confidence level. The corresponding radius and tidal deformability for a $1.4 M_{⊙}$ star are $R_{1.4} = 11.5 0_{- 0.55}^{+ 0.52} (11.42_{- 0.44}^{+ 0.52}) km$ and $Λ_{1.4} = 650_{- 190}^{+ 230} (630_{- 150}^{+ 220})$ , respectively. We also investigate the possibility of GW190814's secondary component $m_{2}$ of mass $2.5 9_{- 0.09}^{+ 0.08} M_{⊙}$ being an SQS, and find that it could be a CFL SQS with the pairing gap $Δ$ larger than $244 MeV$ and the effective bag parameter $B_{eff}^{1/4}$ in the range of $170$ to $192$ MeV, at a $90%$ confidence level.
↳ astro-ph.HEhep-phnucl-thApJL(2021)·56 citations
11
Correlations between azimuthal asymmetries and multiplicity and mean transverse momentum in small collisions systems in the CGC
Tolga Altinoluk🇵🇱 · Néstor Armesto🇪🇸 · Alex Kovner🇺🇸 · Michael Lublinsky🇮🇱 · Vladimir V. Skokov🇺🇸
Considering a dilute-dense situation suitable for pA collisions, we compute in the Color Glass Condensate the correlation between azimuthal asymmetries, specifically the squared second Fourier coefficient $v_{2}^{2}$ , and the total multiplicity in the event. We also analyse the correlation between $v_{2}^{2}$ and the mean squared transverse momentum of particles in the event. In both cases, we find that the correlations are generally very small, consistent with the observations. We also note an interesting sharp change in the value of $v_{2}^{2}$ and its correlations as a function of the width of the transverse momentum bin, related with a change of the dominance of Bose and HBT quantum correlations.
↳ hep-phnucl-thSciPost Phys.Proc.(2022)·1 citation
12
Relativistic spin hydrodynamics with torsion and linear response theory for spin relaxation
Masaru Hongo🇺🇸 · Xu-Guang Huang🇨🇳 · Matthias Kaminski🇺🇸 · Mikhail Stephanov🇺🇸 · Ho-Ung Yee🇺🇸
Using the second law of local thermodynamics and the first-order Palatini formalism, we formulate relativistic spin hydrodynamics for quantum field theories with Dirac fermions, such as QED and QCD, in a torsionful curved background. We work in a regime where spin density, which is assumed to relax much slower than other non-hydrodynamic modes, is treated as an independent degree of freedom in an extended hydrodynamic description. Spin hydrodynamics in our approach contains only three non-hydrodynamic modes corresponding to a spin vector, whose relaxation time is controlled by a new transport coefficient: the rotational viscosity. We study linear response theory and observe an interesting mode mixing phenomenon between the transverse shear and the spin density modes. We propose several field-theoretical ways to compute the spin relaxation time and the rotational viscosity, via the Green-Kubo formula based on retarded correlation functions.
↳ hep-thcond-mat.mes-hallcond-mat.stat-mechhep-ph+1JHEP(2021)·162 citations

Affiliations

first authorsco-authorsvia INSPIRE