Thu·May 18, 2023Thursday·May 18, 2023

1. 01*

   Axial anomaly effect to the chiral-partner structure of diquarks at high temperature

   Daiki Suenaga🇯🇵 · Makoto Oka🇯🇵

   Masses of positive-parity and negative-parity diquarks are investigated at finite temperature with a quark chemical potential. We employ the three-flavor Nambu-Jona-Lasinio model, in order to delineate chiral properties of the diquarks, in particular, the mass degeneracy of chiral partners under extreme conditions. We focus on the effects of $U(1{)}_A$ axial anomaly on manifestation of the chiral-partner structures. We find that, in the absence of anomaly effects to the diquarks, the mass degeneracies in all $[ud]$, $[su]$ and $[sd]$ diquark sectors take place prominently above the pseudocritical temperature of the chiral restoration. On the other hand, the anomaly effects are found to hinder the $[ud]$ diquark from exhibiting the mass degeneracy, accompanied by a slow reduction of the $\bar{s}s$ condensate, while the $[su]$ and $[sd]$ diquarks are not much affected. Our present investigation will provide useful information on the chiral-partner structure with the anomaly effects of diquarks for heavy-ion collision experiments of singly heavy baryons and doubly heavy tetraquarks, and for future lattice simulations of the diquarks.

   hep-phnucl-thPRD(2023)·11 citations
2. 02*

   $\Delta$-baryon axialvector and pseudoscalar form factors, and associated PCAC relations

   Pei-Lin Yin🇨🇳 · Chen Chen🇨🇳 · Christian S. Fischer🇩🇪 · Craig D. Roberts🇨🇳

   A quark+diquark Faddeev equation treatment of the baryon bound state problem in Poincaré-invariant quantum field theory is used to deliver parameter-free predictions for all six $\Delta$-baryon elastic weak form factors. Amongst the results, it is worth highlighting that there are two distinct classes of such $\Delta$-baryon form factors, $(g_1,g_3,G_{\pi \Delta \Delta })$, $(h_1,h_3,H_{\pi \Delta \Delta })$, the functions within each of which are separately linked via partial conservation of axial current (PCAC) and Goldberger-Treiman (GT) relations. Respectively within each class, the listed form factors possess qualitatively the same structural features as the nucleon axial, induced pseudoscalar, and pion-nucleon coupling form factors. For instance, the $\Delta$-baryon $g_1$ axial form factor can reliably be approximated by a dipole function, characterised by an axial charge $g_A^{{\Delta }^{+}}=0.71(9)$ and mass-scale $m_A^{\Delta }=0.95(2)m_{\Delta }$. Moreover, the two distinct $\Delta$-baryon PCAC form factor relations are satisfied to a high degree of accuracy on a large range of $Q^2$; the associated GT relations present good approximations only on $Q^2/m_{\Delta }^2\simeq 0$; and pion pole dominance approximations are reliable within both classes. There are two $\pi \Delta \Delta$ couplings: $g_{\pi \Delta \Delta }=10.46(1.88)$; $h_{\pi \Delta \Delta }=35.73(3.75)$; and the associated form factors are soft. Such couplings commonly arise in phenomenology, which may therefore benefit from our analyses. A flavour decomposition of the axial charges reveals that quarks carry $71$\% of the $\Delta$-baryon spin. The analogous result for the proton is $\approx 65$\%.

   hep-phhep-exhep-latnucl-ex+1EPJA(2023)·8 citations
3. 03*

   Chemical potential of a hadronic fireball in the freeze-out stage

   Yaroslav D. Krivenko-Emetov🇦🇹 · Andriy I. Smetana🇦🇹

   This article explores the van der Waals gas model proposed to describe the hadronic stages of nuclear fireball evolution during the cooling stage. Two different models were proposed for the early and late stages of hadronization. At the initial stage, a two-component meson model consisting of ${\pi }^0$ and ${\pi }^{+}$ mesons was suggested, and at the later stage, a two-component nucleon model consisting of protons and neutrons was proposed. The interaction potential for both models was represented by a rectangular well, and the statistical sum was calculated using the saddle-point method. The analytic expressions for pressure and chemical potentials obtained from the model were compared with the corresponding numerical results of other authors obtained earlier using quantum chromodynamics (QCD) methods. The possibility of applying and using the effective chemical potential is also analyzed.

   hep-phnucl-th0 citations
4. 04*

   Gravitational Positivity for Phenomenologists: Dark Gauge Boson in the Swampland

   Katsuki Aoki🇯🇵 · Toshifumi Noumi🇯🇵 · Ryo Saito🇯🇵 · Sota Sato🇯🇵 · Satoshi Shirai🇯🇵 · Junsei Tokuda🇰🇷 · Masahito Yamazaki🇯🇵

   The gravitational positivity bound gives quantitative "swampland'' constraints on low-energy effective theories inside theories of quantum gravity. We give a comprehensive discussion of this bound for those interested in applications to phenomenological model building. We present a practical recipe for deriving the bound, and discuss subtleties relevant for realistic models. As an illustration, we study the positivity bound on the scattering of the massive gauge bosons in the Higgs/Stückelberg mechanism. Under certain assumptions on gravitational amplitudes at high energy, we obtain a lower bound $m_V\gtrsim {\Lambda }_{\mathrm{UV}}^2/g{M}_{\mathrm{Pl}}$ on the gauge boson mass $m_V$, where $g$ is the coupling constant of the gauge field, $M_{\mathrm{Pl}}$ is the reduced Planck mass and ${\Lambda }_{\mathrm{UV}}$ is the ultraviolet cutoff of the effective field theory. This bound can strongly constrain new physics models involving a massive gauge boson.

   hep-phastro-ph.COgr-qchep-thPRD(2024)·22 citations
5. 05*

   Magnetic dipole moments of bottom-charm baryons in light-cone QCD

   U. Ozdem🇹🇷

   The magnetic dipole moments of the doubly-heavy baryons include significant data on their inner structure and geometric shape. Moreover, understanding the electromagnetic properties of doubly-heavy baryons is the key to confinement and heavy flavor effects. Inspired by this, we extract the magnetic dipole moments of the spin-$\frac{1}{2}$ bottom-charm baryons utilizing the QCD light-cone sum rule with considering the distribution amplitudes of the photon.The magnetic dipole moments are obtained as ${\mu }_{{\Xi }_{bc}^{+}}=-0.50_{-0.12}^{+0.14}{\mu }_N$, ${\mu }_{{\Xi }_{bc}^0}=0.39_{-0.05}^{+0.06}{\mu }_N$ and ${\mu }_{{\Omega }_{bc}^0}=0.38_{-0.04}^{+0.05}{\mu }_N$, ${\mu }_{{\Xi }_{bc}^{\prime +}}=0.57_{-0.12}^{+0.13}{\mu }_N$, ${\mu }_{{\Xi }_{bc}^{\prime 0}}=-0.29_{-0.06}^{+0.07}{\mu }_N$ and ${\mu }_{{\Omega }_{bc}^{\prime 0}}=-0.26_{-0.05}^{+0.06}{\mu }_N$. Comparing the results obtained on the magnetic dipole moments of the ${\Omega }_{bc}^{(\prime )0}$ baryon with those of the ${\Xi }_{bc}^{(\prime )0}$ baryon, the $U$-symmetry is minimally broken. We have compared our results with other theoretical predictions that could be a useful complementary tool for the interpretation of the doubly-heavy baryon sector, and we observe that they are not in mutual agreement with each other.

   hep-phhep-exhep-latEPJC(2023)·5 citations
6. 06*

   Effect of color reconnection and rope formation on strange particle production in p+p collisions at $\sqrt{s}=13$ TeV

   Hushnud Hushnud🇮🇳 · Kalyan Dey🇮🇳

   Strange particles are produced only during high-energy collisions and carry important information regarding collision dynamics. Recent results by the ALICE Collaboration on strangeness enhancement in high-multiplicity p+p collisions have highlighted the importance of the rope hadronization mechanism in high-energy nucleon-nucleon collisions. With the help of the \texttt{PYTHIA8} model, we made an attempt to study the strange particle production in high-energy p+p collisions at the LHC energy in the light of different color reconnection models and rope hadronization mechanism. The effect of color reconnection ranges on different observables is also discussed. The integrated yield of strange hadrons and bayon-to-meson ratios as a function of charged-particle multiplicity in p+p collisions at $\sqrt{s}$ = 13 TeV are well described by the hadronization mechanism of color ropes together with the QCD-based color reconnection scheme. The increasing trend of the average transverse momentum, $⟨p_{\mathrm{T}}⟩$, as a function of $⟨dN/d\eta {⟩}_{|\eta |<0.5}$ can be explained quantitatively by the MPI-based color reconnection mechanism with a reconnection range of RR = 3.6; on the other hand, it is underestimated by the rope hadronization model.

   hep-phNPA(2024)·3 citations
7. 07*

   Physics implication from higher weak isospin decomposition

   Phung Van Dong🇻🇳 · Duong Van Loi🇻🇳

   The $SU(3{)}_L\otimes U(1{)}_X$ symmetry actually studied is directly broken to the electroweak symmetry $SU(2{)}_L\otimes U(1{)}_Y$ by a Higgs triplet, predicting a relevant new physics at TeV scale. This work argues, by contrast, that the higher weak isospin $SU(3{)}_L$ might be broken at a high energy scale, much beyond $1$ TeV, by a Higgs octet to an intermediate symmetry $SU(2{)}_L\otimes U(1{)}_{T_8}$ at TeV, before the latter $U(1{)}_{T_8}$ recombined with $U(1{)}_X$ defines (i.e., broken to) $U(1{)}_Y$ by a Higgs singlet. The new physics coupled to $SU(3{)}_L$ breaking phase is decoupled, whereas what remains is a novel family-nonuniversal abelian model, $U(1{)}_{T_8}\otimes U(1{)}_X$, significantly overhauling the standard model as well as yielding consistent results for neutrino mass, dark matter, $W$-mass anomaly, and FCNC, differently from the usual 3-3-1 model.

   hep-phEPJC(2023)·3 citations
8. 08*

   Medium modifications to jet angularities using SCET with Glauber gluons

   Ankita Budhraja🇮🇳 · Rishi Sharma🇮🇳 · Balbeer Singh🇮🇳

   We perform a comprehensive analysis of medium modifications on ungroomed jet angularities, ${\tau }_a$, within the framework of Soft-Collinear Effective Theory with Glauber gluons (SCET${}_{\mathrm{G}}$). Angularities are a one-parameter family of jet substructure observables with angularity exponent $a<2$ for infrared safety. Variation of the angularity exponent allows one to modify the relative weighting of the collinear-to-soft radiations in the jet, thereby giving access to different moments of the jet transverse momentum spectrum. In this article, we focus on $a<1$ and provide detailed results for $a=-1,0$, and $0.5$. Within SCET${}_{\mathrm{G}}$, the interactions between jet and medium constituents are mediated by off-shell Glauber gluons generated from the color sources in the medium. While medium modifications are incorporated into the jet function via the use of medium-induced splitting functions, the soft function remains unmodified for $a<1$. For all values of $a$, we find that compared to jets in vacuum, the medium-modified distributions are shifted towards smaller values of jet angularity and have a steeper fall. This redistribution of the ungroomed angularity spectrum is more apparent for a jet with a larger cone size and for higher values of $a$. We also present results for the medium sensitivity towards $p_T$ of the jet and for a jet initiated in a less central event ($10-30\%$ centrality). Finally, we provide the ratios of nucleus-nucleus and proton-proton differential angularity distributions for different angularity exponents, and for two values of the jet radius parameter.

   hep-phPRD(2025)·12 citations
9. 09*

   Exploring dark matter models with global fits

   Tomás E. Gonzalo🇩🇪

   In this conference paper I present the results from a few global studies of Dark Matter (DM) models, in light of recent constraints from direct detection, indirect detection and collider experiments. I show the most recent analysis of models of singlet Higgs-portal DM, where the DM particle is a scalar, vector, Majorana or Dirac fermion. I also present the results from a global study of an effective field theory of DM, where we find that the model shows a strong preference for a low scale of new physics. For all models I show the prospects for detection or exclusions with future experiments.

   hep-phPoS(2024)·0 citations
10. 10*

    Mathematical Aspects of the Asymptotic Expansion in Contour Improved Perturbation Theory for Hadronic Tau Decays

    Néstor G. Gracia🇪🇸 · André H. Hoang🇦🇹 · Vicent Mateu🇪🇸

    Recently, it was demonstrated that the discrepancy between the fixed-order (FOPT) and contour-improved (CIPT) perturbative expansions for $\tau$-lepton decay hadronic spectral function moments, which had been affecting the precision of ${\alpha }_s$ determinations for many years, is related to the CIPT expansion being inconsistent with the standard formulation of the operator product expansion (OPE). Even though the problem can be alleviated phenomenologically for the most part by employing a renormalon-free scheme for the gluon-condensate matrix element, the principal inconsistency of CIPT remains. The CIPT expansion is special because it is not a power expansion, but represents an asymptotic expansion in a sequence of functions of the strong coupling. In this article we provide a closer look at the mathematical aspects of the asymptotic sequence of the functions the CIPT method is based on, and we expose the origin of the CIPT inconsistency as well as the reasons for its apparent good convergence at low orders. Our results are of general interest, and may in particular provide a useful tool to check for the consistency of expansion methods that are similar to CIPT.

    hep-phPRD(2023)·16 citations
11. 11*

    Effects of Kaluza-Klein Neutrinos on $R_D$ and $R_{D^{\ast }}$

    Janus Capellan Aban🇹🇼 · Chuan-Ren Chen🇹🇼 · Chrisna Setyo Nugroho🇹🇼

    Recent measurements of $R_D$ and $R_{D^{\ast }}$ by the LHCb collaboration show deviations from their respective Standard Model values. These semileptonic $B$ meson decays, associated with $b\to c\tau \bar{\nu }$ transition, are pointing toward new physics beyond the Standard Model via leptonic flavor universality violation. In this paper, we show that such anomaly can be resolved by the cummulative Kaluza-Klein (KK) modes of singlet right-handed neutrino which propagates in the large extra dimensional space. We found that the number of extra dimension should be 2 to explain $R_D$ and $R_{D^{\ast }}$. We show that both $R_D$ and $R_{D^{\ast }}$ constraint the energy scale $M_F$ of this extra dimension which are compatible with the limits from lepton flavor violating tau decays. In contrast, our findings are in tension with the limits coming from the neutrino experiments which set the most stringent lower bound on $M_F$. The future measurements of $R_{D^{(\ast )}}^{exp}$ with reduced uncertainties will exclude this extra dimensional model with right-handed neutrino propagating in the bulk, if the central values stay.

    hep-phPLB(2024)·2 citations
12. 12*

    Multimessenger Constraints on Radiatively Decaying Axions from GW170817

    Melissa Diamond🇨🇦 · Damiano F.G. Fiorillo🇩🇰 · Gustavo Marques-Tavares🇺🇸 · Irene Tamborra🇩🇰 · Edoardo Vitagliano🇮🇱

    The metastable hypermassive neutron star produced in the coalescence of two neutron stars can copiously produce axions that radiatively decay into $\mathcal{O}(100)$~MeV photons. These photons can form a fireball with characteristic temperature smaller than $1\mathrm{MeV}$. By relying on X-ray observations of GW170817/GRB 170817A with CALET CGBM, Konus-Wind, and Insight-HXMT/HE, we present new bounds on the axion-photon coupling for axion masses in the range $1$-$400\mathrm{MeV}$. We exclude couplings down to $5\times 10^{-11}\mathrm{Ge}{\mathrm{V}}^{-1}$, complementing and surpassing existing constraints. Our approach can be extended to any feebly-interacting particle decaying into photons.

    hep-phastro-ph.HEPRL(2024)·105 citations
13. 13*

    On the difference between Fixed-Order and Contour-Improved Perturbation Theory

    Maarten Golterman (SFSU)🇺🇸 · Kim Maltman (York U. & CSSM, Adelaide U.)🇦🇺 · Santiago Peris (UAB, IFAE & SFSU)🇪🇸

    Using standard mathematical methods for asymptotic series and the large-${\beta }_0$ approximation, we define a Minimum Distance between the Fixed-Order perturbative series and the Contour-Improved perturbative series in the strong coupling ${\alpha }_s$ for finite-energy sum rules as applied to hadronic $\tau$ decays. This distance is similar, but not identical, to the Asymptotic Separation of Hoang and Regner, which is defined in terms of the difference of the two series after Borel resummation. Our results confirm a nonzero nonperturbative result in ${\alpha }_s$ for this Minimum Distance as a measure of the intrinsic difference between the two series, as well as a conflict with the Operator Product Expansion for Contour-Improved Perturbation Theory.

    hep-phPRD(2023)·17 citations
14. 14*

    Looking forward to photon-coupled long-lived particles II: dark axion portal

    Krzysztof Jodłowski🇰🇷

    The dark axion portal is a dimension-5 coupling between an axion-like particle (ALP), a photon, and a dark photon, which is one of the targets of the intensity frontier searches looking for $\sim$sub-GeV long-lived particles (LLPs). In this work, we re-examine the limits set by existing detectors such as CHARM and NuCal, and by future experiments such as FASER2, MATHUSLA, and SHiP. We extend previous works by i) considering several mass regimes of the Dark Sector (DS) particles, leading to an extended lifetime regime of the unstable species, ii) including LLPs production occurring in previously neglected vector meson decays that actually dominate the LLP yield, and iii) by implementing secondary LLP production. It takes place by Primakoff-like upscattering of lighter DS species into LLP on tungsten layers of neutrino emulsion detector FASER$\nu$2. This process will allow FASER2 to cover a significant portion of the $\gamma c\tau \sim 1m$ region of the parameter space that is otherwise difficult to cover due to the large ($\sim O(100)m$) distance between the primary LLP production point and the decay vessel, where LLP decays take place, which is required in typical beam-dumb experiments for SM background suppression.

    hep-ph6 citations
15. 15*

    Atmospheric Neutrino Octant from Flavour Symmetry

    Claudio Corianò🇮🇹 · Paul H. Frampton🇮🇹 · Pietro Santorelli🇮🇹

    The binary tetrahedral group ($T^{{}^{\prime }}$) has provided the most successful flavour symmetry in understanding simultaneously the three mixing angles both for quarks in the CKM matrix and for neutrinos in the PMNS matrix. One prediction, invariant under leptonic CP violation, relates the atmospheric and reactor neutrino mixings ${\theta }_{23}$ and ${\theta }_{13}$ respectively. We study sedulously this relation using the latest neutrino data. It is natural to focus on the frustrating experimental octant ambiguity of ${\theta }_{23}$. We conclude that the flavour symmetry requires that ${\theta }_{23}$ is in the second octant $\theta >45^0$, not in the first one ${\theta }_{23}<45^0$, and eagerly await experimental confirmation of this prediction.

    hep-phMod.Phys.Lett.A(2024)·1 citation
16. 16*

    Jet Diffusion versus JetGPT -- Modern Networks for the LHC

    Anja Butter🇩🇪 · Nathan Huetsch🇩🇪 · Sofia Palacios Schweitzer🇩🇪 · Tilman Plehn🇩🇪 · Peter Sorrenson🇩🇪 · Jonas Spinner🇩🇪

    We introduce two diffusion models and an autoregressive transformer for LHC physics simulations. Bayesian versions allow us to control the networks and capture training uncertainties. After illustrating their different density estimation methods for simple toy models, we discuss their advantages for Z plus jets event generation. While diffusion networks excel through their precision, the transformer scales best with the phase space dimensionality. Given the different training and evaluation speed, we expect LHC physics to benefit from dedicated use cases for normalizing flows, diffusion models, and autoregressive transformers.

    hep-phSciPost Phys.Core(2025)·99 citations
17. 17*

    Quantum to classical parton dynamics in QCD media

    João Barata🇺🇸 · Jean-Paul Blaizot🇫🇷 · Yacine Mehtar-Tani🇺🇸

    We study the time evolution of the density matrix of a high energy quark propagating in a dense QCD medium where it undergoes elastic collisions (radiation is ignored in the present study). The medium is modeled as a stochastic color field with a Gaussian correlation function. This allows us to eliminate the medium degrees of freedom and obtain a simple master equation for the evolution of the reduced density matrix of the high energy quark, making use of approximations that are familiar in the description of open quantum systems. This master equation is solved analytically, and we demonstrate that its solution can be reconstructed from a simple Langevin equation. At late times, one finds that only the color singlet component of the density matrix survives the quark's propagation through the medium. The off-diagonal elements of the density matrix are suppressed successively in transverse position space and in momentum space, and become independent of the details of the initial condition. This behavior is reflected in the corresponding von Neumann entropy, whose growth at late time is related to the increase of the classical phase space explored by the high energy quark in its motion through the medium. The interpretation of the Wigner transform as a classical distribution is further supported by the fact that the associated classical entropy coincides at late time with the von Neumann entropy.

    hep-phquant-phPRD(2023)·12 citations
18. 18*

    Constraints on the spectral signatures of superconducting cosmic strings

    Bryce Cyr🇬🇧 · Jens Chluba🇬🇧 · Sandeep Kumar Acharya🇬🇧

    If they exist, networks of superconducting cosmic strings are capable of injecting copious amounts of electromagnetic energy into the background over a broad range of frequencies. We study this injection both analytically, as well as numerically using the thermalization code CosmoTherm. With our refined analytic formalism, we update constraints from CMB spectral distortions by following the injection of entropy, as well as energy, on the amplitude of the $\mu$-distortion, leading to a significant improvement in those limits. Furthermore, we utilize the full shape of the distorted spectrum from CosmoTherm to include constraints from non-$\mu$, non-$y$ type distortions. Additionally, we use the outputs for the ionization history and global 21cm signal to derive and update constraints on string model parameters using measurements from other datasets. Analysis of CMB anisotropies provides the most stringent constraints, though with a slightly modified shape and strength when compared to previous results. Modifications of the reionization history provide new bounds in the high current domain, and we also find that the observations of the low-frequency radio background probe a small region of parameter space not explored by other datasets. We also analyze global $21$-cm constraints, and find that the inclusion of soft photon heating plays a crucial role, essentially removing any constraints in the considered parameter domain. Spectral distortion measurements from COBE/FIRAS are covered by other constraints, but our conservative forecast shows that a PIXIE-type satellite would probe important unexplored regions of parameter space.

    ↳ astro-ph.COgr-qchep-phMNRAS(2023)·23 citations
19. 19*

    An optimized search for dark matter in the galactic halo with HAWC

    A. Albert🇺🇸 · R. Alfaro🇲🇽 · C. Alvarez🇲🇽 · J.C. Arteaga-Velazquez🇲🇽 · D. Avila Rojas🇲🇽 · H.A. Ayala Solares🇺🇸 · E. Belmont-Moreno🇲🇽 · K.S. Caballero-Mora🇲🇽 · T. Capistran🇲🇽 · A. Carraminana🇲🇽 · S. Casanova🇵🇱 · O. Chaparro-Amaro🇲🇽 and 54 other authors

    The Galactic Halo is a key target for indirect dark matter detection. The High Altitude Water Cherenkov (HAWC) observatory is a high-energy (~300 GeV to >100 TeV) gamma-ray detector located in central Mexico. HAWC operates via the water Cherenkov technique and has both a wide field of view of 2 sr and a >95% duty cycle, making it ideal for analyses of highly extended sources. We made use of these properties of HAWC and a new background-estimation technique optimized for extended sources to probe a large region of the Galactic Halo for dark matter signals. With this approach, we set improved constraints on dark matter annihilation and decay between masses of 10 and 100 TeV. Due to the large spatial extent of the HAWC field of view, these constraints are robust against uncertainties in the Galactic dark matter spatial profile.

    ↳ astro-ph.HEastro-ph.COastro-ph.IMhep-phJCAP(2023)·21 citations
20. 20*

    Machine learning study to identify collective flow in small and large colliding systems

    Shuang Guo🇨🇳 · Han-Sheng Wang🇨🇳 · Kai Zhou🇩🇪 · Guo-Liang Ma🇨🇳

    Collective flow has been found to be similar between small colliding systems ($p$ $+$ $p$ and $p$ $+$ A collisions) and large colliding systems (peripheral A $+$ A collisions) at the CERN Large Hadron Collider. In order to study the differences of collective flow between small and large colliding systems, we employ a point cloud network to identify $p$ $+$ Pb collisions and peripheral Pb $+$ Pb collisions at $\sqrt{s_{NN}}=$ 5.02 TeV generated from a multiphase transport model (AMPT). After removing the discrepancies in the pseudorapidity distribution and the $p_{\mathrm{T}}$ spectra, we capture the discrepancy in collective flow. Although the verification accuracy of our PCN is limited due to similar event-by-event distributions of elliptic and triangular flow, we demonstrate that collective flow between $p$ $+$ Pb collisions and peripheral Pb $+$ Pb collisions becomes more distinct with increasing final hadron multiplicity and parton scattering cross section. This study not only highlights the potential of PCN techniques in advancing the understanding of collective flow in varying colliding systems, but more importantly lays the groundwork for the future PCN-related research.

    ↳ nucl-thhep-phnucl-exPRC(2024)·10 citations
21. 21*

    Applicability of the Klein-Gordon equation for pair production in vacuum and plasma

    Haidar Al-Naseri🇸🇪 · Gert Brodin🇸🇪

    In this paper, a phase-space description of electron-positron pair-creation will be applied, based on a Wigner transformation of the Klein-Gordon equation. The resulting theory is similar in many respects to the equations from the Dirac-Heisenberg-Wigner formalism. However, in the former case, all physics related to particle spin is neglected. In the present paper we compare the pair-production rate in vacuum and plasmas, with and without spin effects, in order to evaluate the accuracy and applicability of the spinless approximation. It is found that for modest frequencies of the electromagnetic field, the pair production rate of the Klein-Gordon theory is a good approximation to the Dirac theory, provided the matter density is small enough for Pauli blocking to be neglected, and a factor of two related to the difference in the vacuum energy density is compensated for.

    ↳ physics.plasm-phhep-phPRE(2023)·4 citations
22. 22*

    Effect of the Coriolis force on the electrical conductivity of quark matter: A nonrelativistic description

    Ashutosh Dwibedi🇮🇳 · Cho Win Aung🇮🇳 · Jayanta Dey🇮🇳 · Sabyasachi Ghosh🇮🇳

    Rotating quarks and hadronic systems, produced in peripheral heavy ion collisions, can experience Coriolis force and other forces due to rotational motion. Considering only the effect of Coriolis force, we have calculated the electrical conductivity for non-relativistic rotating matter using the Relaxation Time Approximation based Boltzmann transport equation. A similarity in mathematical calculations of electrical conductivity at finite rotation and finite magnetic fields is exposed, where an equivalence role between Coriolis force on massive particle's motion and Lorentz force on charged particle's motion is noticed. As the beginning level step, we consider only the Coriolis force in the non-relativistic formalism, which will be extended in the future towards the relativistic case, and to adopt other forces for a more realistic description of the rotating quark and hadronic system.

    ↳ nucl-thcond-mat.stat-mechhep-phPRC(2024)·11 citations
23. 23*

    Baryon diffusion coefficient of the strongly interacting medium

    Tribhuban Parida🇮🇳 · Sandeep Chatterjee🇮🇳

    We propose that the transverse momentum ($p_T$) differential splitting of directed flow ($\Delta v_1$) between proton and anti-proton can serve as a sensitive observable to extract the baryon diffusion coefficient (${\kappa }_B$) of the hot and dense strongly interacting matter produced in relativistic heavy ion collisions. We use relativistic dissipative hydrodynamics framework with Glauber model based initial condition for the energy as well as baryon deposition that is calibrated to capture the rapidity dependence of charged particle multiplicity, net proton yield as well as the elusive $v_1$ splitting between proton and anti-proton. We employ the commonly used kinetic theory motivated ansatz: ${\kappa }_B=C_B\frac{n_B}{T}\left(\frac{1}{3}\text{coth}\left(\frac{{\mu }_B}{T}\right)-\frac{n_{B}T}{ϵ+P}\right)$ where $n_B$, $ϵ$, $P$, $T$ and ${\mu }_B$ are baryon number density, energy density, pressure, temperature and baryon chemical potential respectively while $C_B$ is an arbitrary constant which is largely unknown for the Quantum Chromodynamics (QCD) medium. We find that the variation of $\Delta v_1$ with $p_T$ is strongly influenced by the choice of $C_B$. Further, we find that the recent STAR measurement of the centrality dependence of the rapidity slope of $\Delta v_1$ prefers $0.5<C_B<1.5$.

    ↳ nucl-thhep-exhep-phnucl-ex8 citations
24. 24*

    On-shell Operator Construction in the Effective Field Theory of Gravity

    Hao-Lin Li🇧🇪 · Zhe Ren🇨🇳 · Ming-Lei Xiao🇺🇸 · Jiang-Hao Yu🇨🇳 · Yu-Hui Zheng🇨🇳

    We construct the on-shell amplitude basis and the corresponding effective operators for generic modified gravity theory, such as pure gravity with higher derivatives, scalar-tensor gravity, Einstein-Yang-Mills, etc. Taking the Weyl tensor as the building block, we utilize the Young tensor technique to obtain independent operators, without equation of motion and total derivative redundancies. We update our algorithm and vastly increase the speed for finding the monomial basis (m-basis) of effective operators expressed in terms of Weyl tensors with Lorentz indices, the familiar form for the General Relativity community. Finally, we obtain the complete and independent amplitude and operator basis for GRSMEFT and GRLEFT up to mass dimension 10.

    ↳ gr-qchep-phhep-thJHEP(2023)·19 citations
25. 25*

    Rescaling strange-cluster stars and its implications on gravitational-wave echoes

    Chen Zhang🇨🇳 · Yong Gao🇨🇳 · Cheng-Jun Xia🇨🇳 · Renxin Xu🇨🇳

    Solid states of strange-cluster matter called strangeon matter can form strangeon stars that are highly compact. We show that strangeon matter and strangeon stars can be recast into dimensionless forms by a simple reparametrization and rescaling, through which we manage to maximally reduce the number of degrees of freedom. With this dimensionless scheme, we find that strangeon stars are generally compact enough to feature a photon sphere that is essential to foster gravitational-wave (GW) echoes. Rescaling the dimension back, we illustrate its implications on the expanded dimensional parameter space, and calculate the GW echo frequencies associated with strangeon stars, showing that the minimum echo frequency is $\sim 8$ kHz for empirical parameter space that satisfies the GW170817 constraint, and can reduce to $\mathcal{O}(100)$ Hertz at the extended limit.

    ↳ astro-ph.HEgr-qchep-phnucl-thPRD(2023)·24 citations
26. 26*

    `Passion for Earth': A New Beginning

    Francesco Vissani🇮🇹

    In this essay, I discuss an interdisciplinary science that is just blossoming: that of geo-neutrinos. I begin with a couple of episodes from the history of thought, showing the deep roots of Earth science and its many connections with microphysics. I then recall the stage of full maturity reached in the knowledge of neutrinos, which allows one to argue the full reliability of recent measurements. I conclude with a discussion of the state of the field and its prospects for the near future, and with a dedication to the memory of a colleague and friend, Giovanni Fiorentini, a pioneer of these studies.

    ↳ physics.pop-phhep-phGiornale di Fisica Vol. LXIV, pp. 67-85, …·0 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.