Nuclear Theory·nucl-th

Monday·December 30, 2024

19 papers—10 primary·9 cross-listed

11
Analysis of NOvA and MicroBooNE charged-current inclusive neutrino measurements within the SuSAv2 framework
J. Gonzalez-Rosa🇪🇸 · G. D. Megias🇪🇸 · J. A. Caballero🇪🇸 · M. B. Barbaro🇮🇹
In this work we compare the SuSAv2 model, based on the superscaling phenomenon and the relativistic mean field theory, with charged-current inclusive neutrino cross sections from the NOvA and MicroBooNE experiments, whose targets are composed primarily by 12 C and 40 Ar, respectively. The neutrino energy in these experiments covers a kinematic range from tens of MeV to roughly 20 GeV. Thus, we consider the different reaction mechanisms that contribute significantly to these kinematics, namely quasielastic, two-particle two-hole meson exchange currents, resonances and deep inelastic scattering contributions.
↳ hep-phnucl-thPRD(2025)·6 citations
12
Excitation of the isoscalar giant monopole resonance using 6Li inelastic scattering
J. Arroyo · U. Garg · H. Akimune · G. P. A. Berg · D. C. Cuong · M. Fujiwara · M. N. Harakeh · M. Itoh · T. Kawabata · K. Kawase · J.T. Matta · D. Patel · M. Uchida · M. Yosoi
The incompressibility of infinite nuclear matter (K_\infty) is a parameter in the description of the nuclear equation of state that governs the energy cost associated with density oscillations near the saturation density. The most direct experimental method for studying this property of infinite nuclear matter is to probe the isoscalar giant monopole resonance (ISGMR) in finite nuclei. This work explores the use of 6Li as a probe to study the ISGMR in several stable nuclei: 58Ni, 90Zr, 116Sn, and 208Pb, as complementary to using inelastic scattering of {\alpha}-particles, which has been used to great effect over the last several decades. Elastic and inelastic scattering data for these targets were collected with 343-MeV 6Li beams. In all nuclei studied in this work, the ISGMR strength distributions extracted from multipole decomposition analyses of the inelastic scattering spectra agree very well with the previously measured ISGMR responses from {\alpha}-particle scattering, establishing the feasibility of employing 6Li inelastic scattering in investigations of the ISGMR.
↳ nucl-exnucl-thPRC(2025)·4 citations
13
Phase and equation of state of finite density QC $_{2}$ D at lower temperature
Etsuko Itou · Kei Iida🇯🇵 · Kotaro Murakami🇯🇵 · Daiki Suenaga
We investigate the phase structure and the equation of state (EoS) for dense two-color QCD at low temperatures, $T = 40$ MeV ( $3 2^{4}$ lattice) and $T = 80$ MeV ( $1 6^{4}$ lattice). A rich phase structure below the pseudo-critical temperature $T_{c}$ as a function of quark chemical potential $μ$ has been revealed. By performing $T = 40$ MeV simulations, essentially similar results to the previous ones at $T = 80$ MeV are obtained, but several finer understandings are achieved. Breaking of the conformal bound is also confirmed thanks to smaller statistical errors. This talk is mainly based on Refs.~\cite{Iida:2022hyy, Iida:2024irv}. It also includes related studies and subsequent developments that were not mentioned in the original papers.
↳ hep-lathep-phnucl-thPoS(2025)·0 citations
14
Towards factorization with emergent scales for jets in dense media
Balbeer Singh🇺🇸 · Varun Vaidya🇺🇸
Employing the recently developed open quantum system Effective Field Theory framework, we investigate jet production and evolution in a dense nuclear medium in electron-ion/heavy-ion collisions. We confirm that the frequent monitoring of the jet by the medium leads to the emergence of a perturbative transverse momentum scale, often referred to as the saturation scale that necessitates further factorization to completely isolate the non-perturbative physics of the medium. A part of this goal is achieved in this paper by providing an operator definition for the broadening probability of a gluon in the medium within the Markovian approximations. We show that this distribution is (semi)universal; it depends on the angular measurement on the jet and probes both the large and small $x$ dynamics of the medium. We further elucidate all other contributions to non-perturbative physics suggesting that the parameterization of non-perturbative physics is more complex than previously assumed and outline steps required for a complete factorization of the jet production cross section.
↳ hep-phhep-thnucl-th4 citations
15
Spin alignment of vector mesons in local equilibrium by Zubarev's approach
Shi-Zheng Yang🇨🇳 · Xin-Qing Xie🇨🇳 · Shi Pu🇨🇳 · Jian-Hua Gao🇨🇳 · Qun Wang🇨🇳
We compute the $00$ element of the spin density matrix, denoted as $ρ_{00}$ and called the spin alignment, up to the second order of the gradient expansion in local equilibrium by Zubarev's approach. In the first order, we obtain $ρ_{00} = 1/3$ , meaning that the contributions from thermal vorticity and shear stress tensor are vanishing. The non-vanishing contributions to $ρ_{00} - 1/3$ appear in the second order of gradients in the Belinfante and canonical cases. We also discuss the properties of the spin density matrix under the time reversal transformation. The effective transport coefficient for the spin alignment induced by the thermal shear stress tensor is T-odd in the first order, implying that the first order effect is dissipative.
↳ hep-phnucl-thPRD(2025)·11 citations
16
Vector and Tensor Spin Polarization for Vector Bosons at Local Equilibrium
Zhong-Hua Zhang🇨🇳 · Xu-Guang Huang🇨🇳 · Francesco Becattini🇮🇹 · Xin-Li Sheng🇮🇹
We derive expressions for the vector and tensor components of the spin polarization of massive vector bosons at local thermodynamic equilibrium up to second order in the space-time gradients of the thermodynamic fields pertaining to the canonical stress-energy tensor and spin tensor of the free Proca field. A set of Feynman rules is devised to calculate the Wigner function and the matrix-valued spin-dependent distribution (MVSD) functions order by order in space-time gradients. Due to constraints imposed by time-reversal symmetry, the leading contribution to spin alignment - defined as the 00-component of the tensor polarization - arises from second-order terms in MVSD, for which we provide an analytic formula. We discuss the physical meaning of different contributions to vector and tensor polarization. These formulae provide a prediction of a contribution to the spin alignment which can be compared with the observations in relativistic heavy-ion collisions.
↳ hep-phnucl-thJHEP(2025)·16 citations
17
Bolstering up the existence of $P_{s} (2080)$
Breno Agatão🇧🇷 · A. Vertel Nieto🇧🇷 · K. P. Khemchandani🇧🇷 · A. Martinez Torres🇧🇷 · Seung-il Nam🇰🇷
We present a detailed study of the partial decay widths of a spin-parity resonance $J^{P} = 3/ 2^{-}$ $N^{*}$ with a mass of $≃$ 2070 MeV obtained from the coupled channel s wave vector-baryon $ρN$ , $ω N$ , $ϕN$ , $K^{*} Λ$ and $K^{*} Σ$ dynamics. This state, which couples strongly to the $K^{*} Σ$ channel, corresponds to a nucleon with a hidden strange quark content, in analogy to the $P_{c}$ states discovered by the LHCb collaboration, and we denote it as $P_{s} (2080)$ . A state with such a nature can decay to vector-baryon, pseudoscalar-baryon, and pseudoscalar-baryon resonance channels, involving triangular loops in the latter two cases. As we will show, the partial decay widths to pseudoscalar-baryon resonance channels, like $π N^{*} (1535)$ , $π N^{*} (1650)$ , $K Λ (1405)$ , are comparable to those related to ground state baryons in the final state, like $π N$ , $η N$ , $K Λ$ . In this way, reactions involving such lighter baryon resonances in the final state can be used as an alternative source of information on the properties of a $N^{*}$ with hidden strangeness.
↳ hep-phnucl-thPRD(2025)·0 citations
18
Composite nature of the $T_{cc}$ state
Xian-Wei Kang🇨🇳 · Wen-Shuo Ding🇨🇳
In 2021, LHCb collaboration reported a very narrow state in the $D^{0} D^{0} π^{+}$ mass spectrum just below the $D^{*+} D^{0}$ mass threshold. We consider the influence of the Castillejo-Dalitz-Dyson (CDD) pole in the scattering amplitude to derive a general treatment for the two-body final state interaction near its threshold. The line shape (or the energy dependent event distribution) are then obtained, where the parameters can be fixed by fitting to the experimental data on the $D^{0} D^{0} π^{+}$ mass spectrum. Within our method the data are quite well reproduced. The pole structure in the complex energy plane indicates that the $T_{cc}$ state has a large portion of elementary degree of freedom (e.g., the compact tetraquark component) inside its hadron wave function. The compositeness as a measure of molecule component in its wave function is predicted to be $0.2 3_{- 0.09}^{+ 0.40}$ . Clearly, the non-molecular component takes a non-negligible or even dominant portion.
↳ hep-phhep-exnucl-thCommun.Theor.Phys.(2025)·1 citation
19
Hard Photon Triggered Jets in $p$ - $p$ and $A$ - $A$ Collisions
C. Sirimanna🇺🇸 · Y. Tachibana🇯🇵 · A. Majumder🇺🇸 · A. Angerami🇺🇸 · R. Arora🇺🇸 · S. A. Bass🇺🇸 · Y. Chen🇺🇸 · R. Datta🇺🇸 · L. Du🇨🇦 · R. Ehlers🇺🇸 · H. Elfner🇩🇪 · R. J. Fries🇺🇸 and 40 other authors
An investigation of high transverse momentum (high- $p_{T}$ ) photon triggered jets in proton-proton ( $p$ - $p$ ) and ion-ion ( $A$ - $A$ ) collisions at $s_{N N} = 0.2$ and $5.02 TeV$ is carried out, using the multistage description of in-medium jet evolution. Monte Carlo simulations of hard scattering and energy loss in heavy-ion collisions are performed using parameters tuned in a previous study of the nuclear modification factor ( $R_{AA}$ ) for inclusive jets and high- $p_{T}$ hadrons. We obtain a good reproduction of the experimental data for photon triggered jet $R_{AA}$ , as measured by the ATLAS detector, the distribution of the ratio of jet to photon $p_{T}$ ( $X_{J γ}$ ), measured by both CMS and ATLAS, and the photon-jet azimuthal correlation as measured by CMS. We obtain a moderate description of the photon triggered jet $I_{AA}$ , as measured by STAR. A noticeable improvement in the comparison is observed when one goes beyond prompt photons and includes bremsstrahlung and decay photons, revealing their significance in certain kinematic regions, particularly at $X_{J γ} > 1$ . Moreover, azimuthal angle correlations demonstrate a notable impact of non-prompt photons on the distribution, emphasizing their role in accurately describing experimental results. This work highlights the success of the multistage model of jet modification to straightforwardly predict (this set of) photon triggered jet observables. This comparison, along with the role played by non-prompt photons, has important consequences on the inclusion of such observables in a future Bayesian analysis.
↳ hep-phnucl-exnucl-thPRC(2025)·8 citations

Affiliations

first authorsco-authorsvia INSPIRE