Nuclear Theory·nucl-th

Thursday·July 13, 2023

19 papers—7 primary·12 cross-listed

08
Spectroscopy and femtoscopic correlation function of the $B D ˉ$ , $B = (N, Δ)$ system in quark delocalization color screening model
Xuejie Liu · Dianyong Chen · Hongxia Huang · Jialun Ping
In this work, we systematically investigate the pentaquark systems with quark contents $q q q q c ˉ$ with the analyzed total spin and parity quantum numbers of $J^{P} = \frac{1}{2}^{-}$ , $J^{P} = \frac{3}{2}^{-}$ and $J^{P} = \frac{5}{2}^{-}$ , in the I=0, I=1 and I=2 isospin channels. The effective potentials between baryon and meson clusters are given, and the possible bound states are also investigated. Also, the study of the scattering process of the open channels is performed to identify possible resonance states. Our estimations indicate that several possible bound states and narrow baryon-meson resonances are found from corresponding the calculation processes. Furthermore, to bridge the gap between theoretical predictions and experimental measurement, we also extract the low-energy scattering parameters and compute the femtoscopic correlation functions for the $N D ˉ$ system using the CATS framework. The results demonstrate that the predicted $I = 0$ bound state manifests as a significant enhancement at low momentum accompanied by a characteristic suppression. In contrast, the $I = 1$ correlations remain relatively flat as the predicted resonances are kinematically distant from the threshold. The $I = 2$ sector exhibits strong spin dependence, where the bound state signal in the $J = 1/ 2^{-}$ channel is largely masked by repulsive components in spin-averaged observables. This cancellation effect suggests that future experimental searches at ALICE and LHCb may require spin-selective measurements to identify such states. These predictions provide crucial theoretical guidance for future experiments.
↳ hep-phnucl-th2 citations
09
Quantum Simulation of Lattice QCD with Improved Hamiltonians
Anthony N. Ciavarella🇺🇸
Quantum simulations of lattice gauge theories are anticipated to directly probe the real time dynamics of QCD, but scale unfavorably with the required truncation of the gauge fields. Improved Hamiltonians are derived to correct for the effects of gauge field truncations on the SU(3) Kogut-Susskind Hamiltonian. It is shown in $1 + 1 D$ that this enables low chromo-electric field truncations to quantitatively reproduce features of the untruncated theory over a range of couplings and quark masses. In $3 + 1 D$ , an improved Hamiltonian is derived for lattice QCD with staggered massless fermions. It is shown in the strong coupling limit that the spectrum qualitatively reproduces aspects of two flavor QCD and simulations of a small system are performed on IBM's {\tt Perth} quantum processor.
↳ hep-latnucl-thquant-phPRD(2023)·82 citations
10
Practical Dirac Majorana confusion theorem: Issues and Applicability
C. S. Kim🇰🇷
We inspect the model-independent study of practical Dirac Majorana confusion theorem (pDMCT) -- a wide spread belief that the difference between Dirac and Majorana neutrinos via any kinematical observable would be practically impossible to determine because of the difference only being proportional to the square of neutrino mass -- in context of processes that have at least a neutrino antineutrino pair in their final state. We scrutinize the domain of applicability of pDMCT and also highlight those aspects that are often misunderstood. We try to clarify some of the frequently used concepts that are used to assert pDMCT as a generic feature irrespective of the process, or observable, such as the existence of any analytic continuity between Dirac and Majorana neutrinos in the limit mass(neutrino) -> 0. In summary, we illustrate that pDMCT is not any fundamental property of neutrinos, instead, it is a phenomenological feature of neutrino non-observation, depending on models and processes.
↳ hep-phhep-exhep-thnucl-thEPJC(2023)·8 citations
11
Exponential Resummation of QCD at finite chemical potential
Sabarnya Mitra🇮🇳
A comprehensive study of the QCD phase diagram is one of the challenging and open problems in high energy physics. Having significant astrophysical implications, this is also important in constructing the chronological evolution of the universe. With this aim, this thesis describes the behaviour of thermodynamic observables like pressure and number density with changing chemical potential $μ$ , through the method of an unbiased exponential resummation of lower order Taylor series of these observables at a finite $μ$ . We address the problem of biased estimates, which manifest uncontrollably in exponential resummation and which become severe in the domain of large values, higher orders of $μ$ and also in observables which are higher $μ$ derivatives of the thermodynamic potential. We show that our new formalism of unbiased exponential resummation can eliminate these biased estimates exactly upto a given order of $μ$ , and can capture important contributions of higher order Taylor series for all our working temperatures starting from hadronic phase to the plasma phase, including the crossover region. We also demonstrate that this new formalism is highly efficient in saving appreciable computational time and storage space for computations.
↳ hep-phhep-latnucl-exnucl-th2 citations
12
QCD on Rotating Lattice with Staggered Fermions
Ji-Chong Yang🇨🇳 · Xu-Guang Huang🇨🇳
We investigate the finite-temperature quantum chromodynamics (QCD) on a rotating lattice with $N_{f} = 2 + 1$ staggered fermions and the projective plane boundary condition. We observe a negative rotational rigidity (defined in the main text) and a negative quark spin susceptibility associated with the chiral vortical effect. In contrast to most of the effective model predictions, we find that the chiral condensate decreases and the Polyakov loop increases with imaginary rotation, implying a rotational catalysis of chiral symmetry breaking and confinement by real rotation. We determine the phase boundaries for both chiral and confinement-deconfinement phase transitions on the $Ω_{I}$ - $T$ plane, where $Ω_{I}$ is the imaginary angular velocity.
↳ hep-lathep-phhep-thnucl-th49 citations
13
Chemical freeze-out parametrization with mean field repulsive hadron resonance gas model
Sunny Kumar Singh🇮🇳 · Nachiketa Sarkar🇮🇳 · Deeptak Biswas🇮🇳
We have examined the chemical freeze-out surface of the heavy-ion collision experiments within an interacting hadron resonance gas model. By considering repulsive interaction among hadrons in the mean-field level, we have suitably parameterized the freeze-out surface by fitting the yield data of mid-rapidity for the most central collision, for the collision energy available in AGS, RHIC (BES), and LHC programs. To suitably account for the repulsive interaction among mesons and (anti-) baryons, we have introduced phenomenological parameters $K_{M}$ and $K_{B}$ in the freeze-out parametrization. Although a finite value of these two parameters seem to be necessary to have an improved normalized \emph{chi-square}, the effect on the rest of the parameters like temperature and relevant chemical potentials seem to be within the standard variance.
↳ hep-phnucl-th0 citations
14
Dispersion relations alone cannot guarantee causality
Lorenzo Gavassino🇺🇸 · Marcelo M. Disconzi🇺🇸 · Jorge Noronha🇺🇸
We show that linear superpositions of plane waves involving a single-valued, covariantly stable dispersion relation $ω (k)$ always propagate outside the lightcone, unless $ω (k) = a + bk$ . This implies that there is no notion of causality for individual dispersion relations, since no mathematical condition on the function $ω (k)$ (such as the front velocity or the asymptotic group velocity conditions) can serve as a sufficient condition for subluminal propagation in dispersive media. Instead, causality can only emerge from a careful cancellation that occurs when one superimposes all the excitation branches of a physical model. This is shown to happen automatically in local theories of matter that are covariantly stable. Hence, we find that the need for nonhydrodynamic modes in relativistic fluid mechanics is analogous to the need for antiparticles in relativistic quantum mechanics.
↳ hep-thgr-qcmath-phmath.MP+1PRL(2024)·45 citations
15
Searching for universality of dineutron correlation at the surface of Borromean nuclei
A.Corsi🇫🇷 · Y.Kubota🇯🇵 · J. Casal🇪🇸 · M.Gomez-Ramos🇪🇸 · A. M. Moro🇪🇸 · G. Authelet🇫🇷 · H. Baba🇯🇵 · C. Caesar🇩🇪 · D. Calvet🇫🇷 · A. Delbart🇫🇷 · M. Dozono🇯🇵 · J. Feng🇨🇳 and 56 other authors
The dineutron correlation is systematically studied in three different Borromean nuclei near the neutron dripline, 11Li, 14Be and 17B, via the (p, pn) knockout reaction measured at the RIBF facility in RIKEN. For the three nuclei, the correlation angle between the valence neutrons is found to be largest in the same range of intrinsic momenta, which can be associated to the nuclear surface. This result reinforces the prediction that the formation of the dineutron is universal in environments with low neutron density, such as the surface of neutron-rich Borromean nuclei.
↳ nucl-exnucl-thPLB(2023)·14 citations
16
A comparative study of different approaches for heavy quark energy loss, based on the latest experimental data
Marjan Rahimi Nezhad🇮🇷 · Fatemeh Taghavi Shahri🇮🇷 · Sharareh Mehrabi Pari🇮🇷 · Kurosh Javidan🇮🇷
This paper presents a comparative analysis of three distinct methods used to calculate the collisional energy loss of heavy quarks in Quark-Gluon Plasma. The study focuses on the calculation of the nuclear suppression factor of charm quarks in Pb-Pb collisions at $S_{N N} = 5.02$ TeV. All three models are examined using the same numerical evolution based on the well-known Fokker-Planck equation by considering critical phenomena like a non-equilibrium state at the onset of heavy ion collision. The outcomes of each approach are compared with the latest data from ALICE and ATLAS experiments spanning from 2018 to 2022. This study aims to compare the degree of agreement between each approach and recently obtained experimental data, in the intermediate and high $P_{T}$ regions.
↳ hep-phnucl-thEur.Phys.J.Plus(2024)·3 citations
17
State dependence of tunneling processes and thermonuclear fusion
Roberto Onofrio · Carlo Presilla
We discuss the sensitivity of tunneling processes to the initial preparation of the quantum state. We compare the case of Gaussian wave packets of different positional variances using a generalised Woods-Saxon potential for which analytical expressions of the tunneling coefficients are available. Using realistic parameters for barrier potentials we find that the usual plane wave approximation underestimates fusion reactivities by an order of magnitude in a range of temperatures of practical relevance for controlled energy production.
↳ quant-phnucl-exnucl-thNPA(2024)·1 citation
18
In-medium gluon radiation spectrum with all-order resummation of multiple scatterings in longitudinally evolving media
Carlota Andres🇫🇷 · Liliana Apolinário🇵🇹 · Fabio Dominguez🇪🇸 · Marcos Gonzalez Martinez🇪🇸
Over the past years, there has been a sustained effort to systematically enhance our understanding of medium-induced emissions occurring in the quark-gluon plasma, driven by the ultimate goal of advancing our comprehension of jet quenching phenomena. To ensure meaningful comparisons between these new calculations and experimental data, it becomes crucial to model the interplay between the radiation process and the evolution of the medium parameters, typically described by a hydrodynamical simulation. This step presents particular challenges when dealing with calculations involving the resummation of multiple scatterings, which have been shown to be necessary for achieving an accurate description of the in-medium emission process. In this paper, we extend our numerical calculations of the fully-resummed gluon spectrum to account for longitudinally expanding media. This new implementation allows us to quantitatively assess the accuracy of previously proposed scaling laws that establish a correspondence between an expanding medium and a ``static equivalent''. Additionally, we show that such scaling laws yield significantly improved results when the static reference case is replaced by an expanding medium with the temperature following a simple power-law decay. Such correspondence will enable the application of numerical calculations of medium-induced energy loss in realistic evolving media for a broader range of phenomenological studies.
↳ hep-phnucl-thJHEP(2024)·19 citations
19
Diffractive Deep Inelastic Scattering in the Dipole Picture at Next-to-Leading Order
G. Beuf🇵🇱 · H. Hänninen🇫🇮 · T. Lappi🇫🇮 · H. Mäntysaari🇫🇮 · Y. Mulian🇪🇸
We calculate the contribution from the $q q ˉ g$ state production to the diffractive cross sections in deep inelastic scattering at high energy. The obtained cross section is finite by itself, and consists a part of the full next-to-leading order result for the diffractive structure functions. Our calculation for the diffractive structure functions is performed using exact kinematics, under the shockwave approximation of the scattering process. Once the calculation is completed, we show that the previously known behaviour at the high- $Q^{2}$ and large- $M_{X}^{2}$ regime can be extracted from our results by taking the appropriate limits. Furthermore, we discuss the steps required to obtain the complete next-to-leading order results for the structure functions in the color glass condensate (CGC) formalism, and the application of these results to phenomenology.
↳ hep-phnucl-th0 citations

Affiliations

first authorsco-authorsvia INSPIRE