Mon·Sep 25, 2023Monday·September 25, 2023

1. 01*

   The dynamic hadronization of charm quarks in heavy-ion collisions

   Christian Bierlich🇸🇪 · Gösta Gustafson🇸🇪 · Leif Lönnblad🇸🇪 · Harsh Shah🇸🇪

   The PYTHIA8/ANGANTYR model for heavy ion collisions was recently updated with a mechanism for \textit{global colour reconnection}. The colour reconnection model used is QCD colour algebra inspired and enhances baryon production due to the formation of string junctions. In this paper, we present updates to the junction formation and string fragmentation mechanisms, connected to heavy quark fragmentation. This allows for the simulation of heavy quark fragmentation, using junction formation, in heavy ion collisions. The framework is validated for proton collisions, and we show results for charm baryon production in proton-lead collisions.

   hep-phhep-exnucl-exEPJC(2024)·17 citations
2. 02*

   Revealing the Origin of Mass through Studies of Hadron Spectra and Structure

   Craig D. Roberts🇨🇳

   The Higgs boson is responsible for roughly 1% of the visible mass in the Universe. Obviously, therefore, Nature has another, very effective way of generating mass. In working toward identifying the mechanism, contemporary strong interaction theory has arrived at a body of basic predictions, viz. the emergence of a nonzero gluon mass-scale, a process-independent effective charge, and dressed-quarks with constituent-like masses. These three phenomena - the pillars of emergent hadron mass (EHM) - explain the origin of the vast bulk of visible mass in the Universe. Their expressions in hadron observables are manifold. This contribution highlights a few; namely, some of the roles of EHM in building the meson spectrum, producing the leading-twist pion distribution amplitude, and moulding hadron charge and mass distributions.

   hep-phhep-exhep-latnucl-ex+1EPJ Web Conf.(2024)·0 citations
3. 03*

   Study on the sensitivity of the Higgs boson couplings in photon-photon collision at CLIC and muon collider

   S. Spor🇹🇷

   In a model-independent way, we explore the potential of photon-induced interactions with the process ${\gamma }^{\ast }{\gamma }^{\ast }\to ZZ$ to investigate CP-conserving and CP-violating dimension-six operators of Higgs-gauge boson couplings using the Standard Model Effective Field Theory (SMEFT). The existence of anomalous $H\gamma \gamma$ and $HZZ$ couplings is discussed at 3 TeV Compact Linear Collider (CLIC) and 10 TeV Muon Collider (MuC) with integrated luminosities of 5 and 10 ab${}^{-1}$, respectively. All signal and relevant background events are generated in MadGraph and passed through PYTHIA for parton showering and hadronization. The detector effects are evaluated using CLIC and MuC detector cards tuned in Delphes. We report the 95% confidence level limits on the Wilson coefficients ${\overline{c}}_{\gamma }$, ${\overline{c}}_{HB}$, ${\overline{c}}_{HW}$, ${\tilde{c}}_{\gamma }$, ${\tilde{c}}_{HB}$, and ${\tilde{c}}_{HW}$ and compare them with the experimental and phenomenological limits.

   hep-phJ.Phys.G(2024)·6 citations
4. 04*

   Prospects for establishing limits on the SMEFT operators from the production processes of three and four top quarks in hadron collisions

   A. Aleshko🇷🇺 · E. Boos🇷🇺 · V. Bunichev🇷🇺 · L. Dudko🇷🇺

   Numerical simulations of processes of three and four top quark hadroproduction are carried out in the SMEFT model framework. The simulated data are used to derive expected theoretical constraints on Wilson coefficients of relevant SMEFT operators of dimension six. Obtained limits for both cases are discussed and compared in terms of processes' sensitivity to possible BSM contribution. Results show that operator $O_{tt}^1$ is better constrained by the process of four top quark production, whereas other four operators $O_{QQ}^1$, $O_{Qt}^1$, $O_{Qt}^8$ and $O_{QQ}^8$, are similarly constrained in three and four top quark production processes. In all cases, the expected limits taken from the simultaneous analysis of the production of three and four top quarks are strengthened. Analytical expressions for the partial amplitudes of the processes $tt\to tt$ and $t\bar{t}\to t\bar{t}$ caused by the operators $O_{tt}^1$, $O_{QQ}^1$, $O_{Qt}^1$, $O_{Qt}^8$, $O_{QQ}^8$ were obtained for the first time. Based on the expressions of the obtained partial amplitudes, graphs of the perturbative unitarity boundary for the listed operators were drawn. The question of how kinematic cuts motivated by partial unitarity affect the resulting constraints on the Willson coefficients is addressed. It is shown that in all cases the limits are getting somewhat worse if such cuts are applied.

   hep-phInt.J.Mod.Phys.A(2024)·6 citations
5. 05*

   Evaluation of Bjorken polarised sum rule with a renormalon-motivated approach

   Cesar Ayala🇨🇱 · Camilo Castro-Arriaza🇨🇱 · Gorazd Cvetič🇨🇱

   We use the known renormalon structure of Bjorken polarised sum rule (BSR) ${\overline{\Gamma }}_1^{p-n}(Q^2)$ to evaluate the leading-twist part of that quantity. In addition, we include $D=2$ and $D=4$ Operator Product Expansion (OPE) terms and fit this expression to available experimental data for inelastic BSR. Since we use perturbative QCD (pQCD) coupling, which fails at low squared spacelike momenta $Q^2\lesssim 1{\mathrm{GeV}}^2$ due to Landau singularities, the fit is performed for $Q^2\ge Q_{\min }^2$ where $Q_{\min }^2\approx (1.7\pm 0.3){\mathrm{GeV}}^2$. Due to large BSR experimental uncertainties, the extracted value of the pQCD coupling has very large uncertainties, especially when $Q_{\min }^2$ is varied. However, when we fix the pQCD coupling to the known world average values, the $D=2$ and $D=4$ residue parameters can be determined within large but reasonable uncertainties.

   hep-phPLB(2024)·12 citations
6. 06*

   Earth Tomography with ICAL at INO

   Deepak Raikwal🇮🇳 · Sandhya Choubey🇸🇪

   Observing matter effects in atmospheric neutrinos travelling through the entire mantle and core of the Earth is a promising way of enhancing our understanding of Earth's density structure. In that context we study the prospects of Earth tomography with the ICAL detector at the India-based Neutrino Observatory. While this experiment is smaller in size in comparison to some of the other bigger detectors being proposed, it is the only neutrino experiment with charge-identification sensitivity. In particular, ICAL can see matter effects separately in neutrinos and antineutrinos. This has been seen to enhance ICAL's sensitivity to earth matter effects and hence the mass ordering sensitivity for both normal and inverted mass orderings. It is therefore, pertinent to see if the ICAL sensitivity to earth tomography is competitive or better with respect to other experiments, especially for the inverted mass ordering, where other experiments suffer reduced sensitivity. We present the sensitivity of ICAL to earth tomography by taking into consideration both the Earth's mass constraint as well as the hydrostatic equilibrium constraints.

   hep-phPRD(2024)·10 citations
7. 07*

   Analytical Quantum Field methods in Particle Physics

   Alexandre Salas-Bernárdez🇪🇸

   In this thesis we deal with different aspects of quantum field theory, particularly in non-perturbative but also perturbative regimes, applied to the intellectual construction that is the Standard Model for Particle Physics (SM), but also its extension via effective theories. We have developed the following practical contributions in different subfields of Particle Physics: qualitatively assessing why the SM has those specific symmetries, explaining the ${}^3{P}_0$ mechanism of meson decay from fundamental Quantum Chromodynamics (QCD) calculations, experimentally distinguishing Effective Theories of the Electroweak sector beyond the SM in accelerators, extrapolating LHC data (low energies) to possible resonant regions of new physics (high energies) with controlled uncertainties and studying precision calculations of QCD (high energies) in coordinate space.

   hep-ph1 citation
8. 08*

   Revisiting models that enhance $B^{+}\to K^{+}\nu \bar{\nu }$ in light of the new Belle II measurement

   Xiao-Gang He🇨🇳 · Xiao-Dong Ma🇨🇳 · German Valencia🇦🇺

   Belle II has recently reported the new measurement $\mathcal{B}(B^{+}\to K^{+}\nu \bar{\nu })=(2.3\pm 0.7)\times 10^{-5}$ \cite{Belle-II:2023esi} which is two times larger than their previous result (although consistent within errors) and about $2.7\sigma$ higher than the SM prediction. We re-examine new physics scenarios we have discussed previously which can enhance this rate to determine if they can accommodate the higher value reported in the new measurement. We use consistency with existing bounds on $B\to K^{\ast }\nu \bar{\nu }$, $b\to s{\ell }^{+}{\ell }^{-}$, $B\to D^{(\ast )}\ell \bar{\nu }$ and $B_s$ mixing to limit possible explanations for the excess. For the case of LFV neutrino couplings, we find that only two leptoquarks remain viable requiring a large $C_{9^{\prime }}^{\tau \tau }=-C_{10^{\prime }}^{\tau \tau }$. For models with different types of light dark matter particle pairs (scalar, fermion, or vector), the preliminary $q^2$ distribution from Belle II, which shows that the excess appears mostly for bins with $3\le q^2\le 7$ GeV${}^2$ \cite{Belle-II:2023esi}, implies only the vector current operators with scalar or vector dark matter particles with masses in the hundreds of MeV can match the anomaly.

   hep-phPRD(2024)·79 citations
9. 09*

   Low Scale Leptogenesis in Singlet-Triplet Scotogenic Model

   Labh Singh🇮🇳 · Devabrat Mahanta🇮🇳 · Surender Verma🇮🇳

   The scotogenic model presents an elegant and succinct framework for elucidating the origin of tiny neutrino masses within the framework of the Standard Model, employing radiative corrections within the domain of the dark sector. We investigate the possibility of achieving low-scale leptogenesis in the singlet-triplet scotogenic model (STSM), where dark matter mediates neutrino mass generation. We initially considered a scenario involving two moderately hierarchical heavy fermions, N and $\Sigma$, wherein the lepton asymmetry is generated by the out-of-equilibrium decay of both particles. Our analysis indicates that the scale of leptogenesis in this scenario is similar to that of standard thermal leptogenesis and is approximately $M_{N,\Sigma }\sim 10^9$ GeV, which is comparable to the Type-I seesaw case. Further, we consider the case with three heavy fermions ($N_1$, $N_2$, and $\Sigma$) with the hierarchy $M_{N_1}<M_{\Sigma }\ll M_{N_2}$, which yields the lower bound on heavy fermions up to 3.1 TeV, therefore significantly reduce the scale of the leptogenesis up to TeV scale. The only prerequisite is suppression in the $N_1$ and $\Sigma$ Yukawa couplings, which causes suppressed washout effects and a small active neutrino mass of about $10^{-5}$ eV. This brings about the fascinating insight that experiments aiming to measure the absolute neutrino mass scale can test low-scale leptogenesis in the scotogenic model. Further, the hyperchargeless scalar triplet $\Omega$ provides an additional contribution to mass of the $W$-boson explaining CDF-II result.

   hep-phJCAP(2024)·12 citations
10. 10*

    Predictions for Neutrinos and New Physics from Forward Heavy Hadron Production at the LHC

    Luca Buonocore🇨🇭 · Felix Kling🇩🇪 · Luca Rottoli🇨🇭 · Jonas Sominka🇩🇪

    Scenarios with new physics particles feebly interacting with the Standard Model sector provide compelling candidates for dark matter searches. Geared with a set of new experiments for the detection of neutrinos and long-lived particles the Large Hadron Collider (LHC) has joined the hunt for these elusive states. On the theoretical side, this emerging physics program requires reliable estimates of the associated particle fluxes, in particular those arising from heavy hadron decays. In this work, we provide state-of-the-art QCD predictions for heavy hadron production including radiative corrections at next-to-leading order and using parton distribution functions including small-$x$ resummation at next-to-leading logarithmic accuracy. We match our predictions to parton showers to provide a realistic description of hadronisation effects. We demonstrate the utility of our predictions by presenting the energy spectrum of neutrinos from charm hadron decays. Furthermore, we employ our predictions to estimate, for the first time, FASER's sensitivity to electrophilic ALPs, which are predominantly generated in beauty hadron decays.

    hep-phhep-exEPJC(2024)·53 citations
11. 11*

    Non-perturbative Suppression of Chiral Vortical Effect in Hot (s)QGP for Hyperons Spin Polarization in Heavy Ion Collisions

    Ruslan Abramchuk🇮🇱 · Maik Selch🇮🇱

    With the Field Correlator Method (FCM) for QCD, we show that the Chiral Vortical Effect (CVE) in hot (strongly-interacting) Quark-Gluon Plasma ((s)QGP) is modified by non-perturbative interactions: by Color-Magnetic confinement, and by remnant Color-Electric interaction, which is encoded in the Polyakov line. The obtained result demonstrates numerical suppression of CVE comparable to the phenomenological suppression used for numerical simulations of RHIC-STAR data on hyperons spin polarization in non-central heavy ion collision (HIC). The parameters range in the temperature - quark chemical potential plane is expected to cover ALICE and RHIC data. The chiral current is calculated for the rigidly rotating model of (s)QGP in the linear order in angular velocity at the rotation axis with account of non-perturbative interactions.

    hep-phEPJC(2024)·5 citations
12. 12*

    Flavor anomalies in leptoquark model with gauged $U(1{)}_{L_{\mu }-L_{\tau }}$

    Chuan-Hung Chen🇹🇼 · Cheng-Wei Chiang🇹🇼

    Leptoquarks (LQs) have been extensively studied in the context of $B$ anomalies. When $U(1{)}_{L_{\mu }-L_{\tau }}$ is introduced to a scalar LQ model with the LQ $S_1$ charged under the new symmetry, $S_1$ primarily couples to the third-generation leptons while its couplings to first and second-generation leptons are naturally suppressed. Furthermore, only $S_1$ in the scalar LQ models has the feature that down-type quarks merely couple to neutrinos but not the charged leptons, avoiding strict restrictions from $b\to s{\mu }^{+}{\mu }^{-}$. With this distinctive characteristic of $S_1$, we investigate its impact on rare processes involving the $d_i\to d_j\nu \bar{\nu }$ transitions. Under the dominant constraints from $\Delta F=2$ processes, we find that the $S_1$ contributions to the branching ratios (BRs) of $B\to K(K^{\ast })\nu \bar{\nu }$ and $K_L\to {\pi }^0\nu \bar{\nu }$ can be factorized into the same multiplicative factor multiplying the standard model predictions. Enhancement in the BRs can possibly exceed a factor of 2. In particular, $\mathcal{B}(K^{+}\to {\pi }^{+}\nu \bar{\nu })$ can reach the upper $1\sigma$ error of the experimental value, i.e., $\simeq 15.4\times 10^{-11}$. We also show that the model can fit the new world averages of $R(D)$ and $R(D^{\ast })$.

    hep-phhep-exPRD(2024)·29 citations
13. 13*

    Combining Resonant and Tail-based Anomaly Detection

    Gerrit Bickendorf🇩🇪 · Manuel Drees🇩🇪 · Gregor Kasieczka🇩🇪 · Claudius Krause🇩🇪 · David Shih🇺🇸

    In many well-motivated models of the electroweak scale, cascade decays of new particles can result in highly boosted hadronic resonances (e.g. $Z/W/h$). This can make these models rich and promising targets for recently developed resonant anomaly detection methods powered by modern machine learning. We demonstrate this using the state-of-the-art CATHODE method applied to supersymmetry scenarios with gluino pair production. We show that CATHODE, despite being model-agnostic, is nevertheless competitive with dedicated cut-based searches, while simultaneously covering a much wider region of parameter space. The gluino events also populate the tails of the missing energy and $H_T$ distributions, making this a novel combination of resonant and tail-based anomaly detection.

    hep-phhep-exPRD(2024)·22 citations
14. 14*

    Precision unification and the scale of supersymmetry

    Prudhvi N. Bhattiprolu🇺🇸 · James D. Wells🇺🇸

    In this letter, we study the implications of precise gauge coupling unification on supersymmetric particle masses. We argue that precise unification favors the superpartner masses that are in the range of several TeV and well beyond. We demonstrate this in the minimal supersymmetric theory with a common sparticle mass threshold, and two simple high-scale scenarios: minimal supergravity and minimal anomaly-mediated supersymmetry. We also identify candidate models with a Higgsino or a wino dark matter candidate. Finally, the analysis shows unambiguously that unless one takes foggy naturalness notions too seriously, the lack of direct superpartner discoveries at the LHC has not diminished the viability of supersymmetric unified theories in general nor even precision unification in particular.

    hep-phPRD(2024)·8 citations
15. 15*

    Local infrared safety in time-ordered perturbation theory

    George Sterman🇺🇸 · Aniruddha Venkata🇺🇸

    We develop a general expression for weighted cross sections in leptonic annihilation to hadrons based on time-ordered perturbation theory (TOPT). The analytic behavior of the resulting integrals over spatial momenta can be analyzed in the language of Landau equations and infrared (IR) power counting. For any infrared-safe weight, the cancellation of infrared divergences is implemented locally at the integrand level, and in principle can be evaluated numerically in four dimensions. We go on to show that it is possible to eliminate unphysical singularities that appear in time-ordered perturbation theory for arbitrary amplitudes. This is done by reorganizing TOPT into an equivalent form that combines classes of time orderings into a ``partially time-ordered perturbation theory". Applying the formalism to leptonic annihilation, we show how to derive diagrammatic expressions with only physical unitarity cuts.

    hep-phJHEP(2024)·16 citations
16. 16*

    Nonabelian Kinetic Mixing in a Confining Phase

    Gonzalo Alonso-Álvarez🇨🇦 · Ruike Cao🇨🇳 · James M. Cline🇨🇦 · Karishma Moorthy🇨🇦 · Tianzhuo Xiao🇨🇦

    Dark matter from a hidden sector with SU($N$) gauge symmetry can have a nonabelian kinetic mixing portal with the standard model. The dark photon becomes massive in the confining phase without the need for spontaneous symmetry breaking. Depending on the particle content of the dark sector, there can be two or more composite vectors that get kinetic mixing through a heavy mediator particle $X$. This provides a model of composite dark photons giving a portal for direct detection of dark baryons. Avoiding exotic charged relics requires additional couplings allowing $X$ to decay to dark quarks and standard model fields, leading to further portals between the dark matter and the standard model. We comprehensively study the constraints on such models from colliders, rare decays, direct detection, and big bang nucleosynthesis.

    hep-phastro-ph.COJHEP(2024)·7 citations
17. 17*

    Constraints on fifth forces and ultralight dark matter from OSIRIS-REx target asteroid Bennu

    Yu-Dai Tsai🇺🇸 · Davide Farnocchia🇺🇸 · Marco Micheli🇮🇹 · Sunny Vagnozzi🇮🇹 · Luca Visinelli🇨🇳

    Using the OSIRIS-REx mission and ground-based tracking data for the asteroid Bennu, we derive new constraints on fifth forces and ultralight dark matter. The bounds we obtain are strongest for mediator masses $m\sim 10^{-18}-10^{-17}\mathrm{eV}$, where we currently achieve the tightest bounds. Our limits can be translated to a wide class of models leading to Yukawa-type fifth forces, and we demonstrate how they apply to $U(1{)}_B$ dark photons and baryon-coupled scalars. Our results demonstrate the potential of asteroid tracking in probing well-motivated extensions of the Standard Model and ultralight dark matter satisfying the fuzzy dark matter constraints.

    hep-phastro-ph.COgr-qchep-ex+1Commun.Phys.(2024)·29 citations
18. 18*

    Back To The Roots: Tree-Based Algorithms for Weakly Supervised Anomaly Detection

    Thorben Finke🇩🇪 · Marie Hein🇩🇪 · Gregor Kasieczka🇩🇪 · Michael Krämer🇩🇪 · Alexander Mück🇩🇪 · Parada Prangchaikul🇩🇪 · Tobias Quadfasel🇩🇪 · David Shih🇺🇸 · Manuel Sommerhalder🇩🇪

    Weakly supervised methods have emerged as a powerful tool for model-agnostic anomaly detection at the Large Hadron Collider (LHC). While these methods have shown remarkable performance on specific signatures such as di-jet resonances, their application in a more model-agnostic manner requires dealing with a larger number of potentially noisy input features. In this paper, we show that using boosted decision trees as classifiers in weakly supervised anomaly detection gives superior performance compared to deep neural networks. Boosted decision trees are well known for their effectiveness in tabular data analysis. Our results show that they not only offer significantly faster training and evaluation times, but they are also robust to a large number of noisy input features. By using advanced gradient boosted decision trees in combination with ensembling techniques and an extended set of features, we significantly improve the performance of weakly supervised methods for anomaly detection at the LHC. This advance is a crucial step towards a more model-agnostic search for new physics.

    hep-phhep-exphysics.data-anPRD(2024)·51 citations
19. 19*

    Anharmonic Effects on the Squeezing of Axion Perturbations

    Valentina Danieli🇮🇹 · Takeshi Kobayashi🇮🇹 · Nicola Bartolo🇮🇹 · Sabino Matarrese🇮🇹 · Matteo Viel🇮🇹

    It is assumed in standard cosmology that the Universe underwent a period of inflation in its earliest phase, providing the seeds for structure formation through vacuum fluctuations of the inflaton scalar field. These fluctuations get stretched by the quasi-exponential expansion of the Universe and become squeezed. The aim of this paper is to deepen the understanding of the squeezing process, considering the effect of self-interactions. Axion-like particles can provide a useful setup to study this effect. Specifically we focus on the consequences that a non-trivial evolution of the background axion field has on the squeezing of the perturbations. We follow the evolution of the axion's fluctuation modes from the horizon exit during inflation to the radiation-dominated epoch. We compute Bogoliubov coefficients and squeezing parameters, which are linked to the axion particle number and isocurvature perturbation. We find that the quantum mechanical particle production and the squeezing of the perturbations are enhanced, if one accounts for anharmonic effects, i.e., the effect of higher order terms in the potential. This effect becomes particularly strong towards the hilltop of the potential.

    hep-phastro-ph.COgr-qchep-th+1JCAP(2024)·2 citations
20. 20*

    Bootstrapping gauge theories

    Yifei He🇫🇷 · Martin Kruczenski🇺🇸

    We consider asymptotically free gauge theories with gauge group $SU(N_c)$ and $N_f$ quarks with mass $m_q\ll {\Lambda }_{\text{QCD}}$ that undergo chiral symmetry breaking and confinement. We propose a bootstrap method to compute the S-matrix of the pseudo-Goldstone bosons (pions) that dominate the low energy physics. For the important case of $N_c=3$, $N_f=2$, a numerical implementation of the method gives the phase shifts of the $S0$, $P1$ and $S2$ waves in good agreement with experimental results. The method incorporates gauge theory information ($N_c$, $N_f$, $m_q$, ${\Lambda }_{\text{QCD}}$) by using the form-factor bootstrap recently proposed by Karateev, Kuhn and Penedones together with a finite energy version of the SVZ sum rules. At low energy we impose constraints from chiral symmetry breaking. The only low energy numerical inputs are the pion mass $m_{\pi }$ and the quark and gluon condensates.

    ↳ hep-thhep-lathep-phPRL(2024)·39 citations
21. 21*

    Balance Laws as Test of Gravitational Waveforms

    Lavinia Heisenberg🇩🇪

    Gravitational waveforms play a crucial role in comparing observed signals to theoretical predictions. However, obtaining accurate analytical waveforms directly from general relativity remains challenging. Existing methods involve a complex blend of post-Newtonian theory, effective-one-body formalism, numerical relativity, and interpolation, introducing systematic errors. As gravitational wave astronomy advances with new detectors, these errors gain significance, particularly when testing general relativity in the non-linear regime. A recent development proposes a novel approach to address this issue. By deriving precise constraints - or balance laws - directly from full non-linear GR, this method offers a means to evaluate waveform quality, detect template weaknesses, and ensure internal consistency. Before delving into the intricacies of balance laws in full non-linear general relativity, we illustrate the concept using a detailed mechanical analogy. We'll examine a dissipative mechanical system as an example, demonstrating how mechanical balance laws can gauge the accuracy of approximate solutions in capturing the complete physical scenario. While mechanical balance laws are straightforward, deriving balance laws in electromagnetism and general relativity demands a rigorous foundation rooted in mathematically precise concepts of radiation. Following the analogy with electromagnetism, we derive balance laws in general relativity. As a proof of concept, we employ an analytical approximate waveform model, showcasing how these balance laws serve as a litmus test for the model's validity.

    ↳ gr-qcastro-ph.COastro-ph.HEhep-ph+1Phil.Trans.Roy.Soc.Lond.A(2023)·7 citations
22. 22*

    Synchrotron radiation from cosmic string wakes

    Dilip Kumar🇮🇳 · Soumen Nayak🇮🇳 · Soma Sanyal🇮🇳

    Magnetic fields can be generated in cosmic string wakes due to the Biermann mechanism in the presence of neutrino inhomogeneities. As the cosmic string moves through the plasma the small magnetic field is amplified by the turbulence in the plasma. Relativistic charged particles which cross the magnetized wake of a cosmic string will therefore emit synchrotron radiation. The opening angle of the cosmic string is very small and so the wake appears like a relativistic jet. Assuming a homogeneous magnetic field in the wake of the string, we obtain the synchrotron emission from non thermal relativistic electrons in the wake of the string. The emitted radiation has a broad peak and is over a wide range of frequency. We show that the spectrum can be mapped to some of the unknown sources in different ranges of the current available catalogues.

    ↳ astro-ph.COhep-phInt.J.Mod.Phys.D(2025)·1 citation
23. 23*

    Center-symmetric Landau gauge: Further signatures of confinement

    Duifje Maria van Egmond🇫🇷 · Urko Reinosa🇫🇷

    In a recent article [1], we have identified new signatures for the Yang-Mills deconfinement transition, based on the finite-temperature longitudinal or (chromo-)electric gluon propagator as computed in the center-symmetric Landau gauge. Here, we generalize these considerations into a systematic study of the center symmetry identities obeyed by the correlation functions in this gauge. Any violation of these constraints signals the breaking of center symmetry and can thus serve as a probe for the deconfinement transition.

    ↳ hep-thhep-phPRD(2024)·7 citations
24. 24*

    Tackling Feynman integrals with quantum minimization algorithms

    German F. R. Sborlini🇪🇸

    One of the most severe bottlenecks to reach high-precision predictions in QFT is the calculation of multiloop multileg Feynman integrals. Several new strategies have been proposed in the last years, allowing impressive results with deep implications in particle physics. Still, the efficiency of such techniques starts to drastically decrease when including many loops and legs. In this talk, we explore the implementation of quantum algorithms to optimize the integrands of scattering amplitudes. We rely on the manifestly causal loop-tree duality, which translates the loop into phase-space integrals and avoids the spurious singularities due to non-causal effects. Then, we built a Hamiltonian codifying causal-compatible contributions and minimize it using a Variational Quantum Eigensolver. Our very promising results point towards a potential speed-up for achieving a more numerically-stable representation of Feynman integrals by using quantum computers.

    ↳ hep-thhep-phPoS(2024)·2 citations
25. 25*

    Pionic Final State Interactions and the Hypertriton Lifetime

    Fabian Hildenbrand🇩🇪 · Hans-Werner Hammer🇩🇪

    We analyze the contribution of pionic final state interactions (FSI) in the weak decay of the hypertriton. Focusing on the ${}^3$He channel, we find a contribution of the pionic FSI of the order of $18\%$. Assuming a fixed value for the branching ratio $R_3$ for the decay width into ${}^3$He over the decay width into ${}^3$He and $pd$ final states, we find values for the hypertriton lifetime that are consistent with the world average as well as recent measurements by the ALICE Collaboration.

    ↳ nucl-thhep-phEPJA(2023)·5 citations
26. 26*

    A precise determination of the strong-coupling constant from the recoil of $Z$ bosons with the ATLAS experiment at $\sqrt{s}=8$ TeV

    ATLAS Collaboration

    The coupling constant of the strong force is determined from the transverse-momentum distribution of $Z$ bosons produced in 8 TeV proton-proton collisions at the LHC and recorded by the ATLAS experiment. The $Z$-boson cross sections are measured in the full phase space of the decay leptons using 15.3 million electron and muon pairs, in a dataset collected in 2012 and corresponding to an integrated luminosity of 20.2 fb${}^{-1}$. The analysis is based on predictions evaluated at third order in perturbative QCD, supplemented by the resummation of logarithmically enhanced contributions in the low transverse-momentum region of the lepton pairs. The determined value of the strong coupling at the reference scale corresponding to the $Z$-boson mass is ${\alpha }_{\text{s}}(m_Z)=0.1183\pm 0.0009$. This is the most precise experimental determination of ${\alpha }_{\text{s}}(m_Z)$ achieved so far.

    ↳ hep-exhep-ph66 citations
27. 27*

    Study of neutron density fluctuation and neutron-proton correlation in Au+Au collisions using PYTHIA8/Angantyr

    Zhang Zuman🇨🇳 · Li Sha🇨🇳 · Yu Ning🇨🇳 · Lin Jianping🇨🇳 · Li Shuang🇨🇳 · Tang Siyu🇨🇳 · Zhou Daicui🇨🇳

    Utilizing the PYTHIA8 Angantyr model, which incorporates the multiple-parton interactions (MPI) based color reconnection (CR) mechanism, we study the relative neutron density fluctuation and neutron-proton correlation in Au+Au collisions at $\sqrt{s_{\text{NN}}}$ = 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV. In this study, we have not only delved into the dependence of these two remarkable observations on rapidity, centrality, and energy, but also presented an analysis of their interplay with the MPI and CR. Our results have shown that the light nuclei yield ratio of proton, deuteron, and triton, expressed by the elegant expression $N_t{N}_p/N_d^2$, remains unchanged even as the rapidity coverage and collision centrality increase. Interestingly, we have also revealed that the effect of CR is entirely dependent on the presence of MPI; CR has no impact on the yield ratio if MPI is off. Our findings further demonstrate that the light nuclei yield ratio experiences a slight increase with increasing collision energy as predicted by the PYTHIA8 Angantyr model, but it cannot describe the non-monotonic trend observed by the STAR experiment. Based on the Angantyr model simulation results, it is essential not to overlook the correlation between neutron and proton fluctuations. The Angantyr model is a good baseline for studying collisions in the absence of a Quark-Gluon Plasma (QGP) system, given its lack of flow and jet quenching.

    ↳ nucl-thhep-phCPC(2023)·1 citation
28. 28*

    Why is ${\mathrm{Pb}}^{208}$ the heaviest stable nuclide?

    B. P. Kosyakov🇷🇺 · E. Yu. Popov🇷🇺 · M. A. Vronsky🇷🇺

    In an effort to understand nuclei in terms of quarks we develop an effective theory to low-energy quantum chromodynamics in which a single quark contained in a nucleus is driven by a mean field due to other constituents of the nucleus. We analyze the reason why the number of $d$ quarks in light stable nuclei is much the same as that of $u$ quarks, while for heavier nuclei beginning with ${\mathrm{Ca}}^{40}$, the number of $d$ quarks is greater than the number of $u$ quarks. To account for the finiteness of the periodic table, we invoke a version of gauge/gravity duality between the dynamical affair in stable nuclei and that in extremal black holes. With the assumption that the end of stability for heavy nuclei is dual to the occurrence of a naked singularity, we find that the maximal number of protons in stable nuclei is $Z_{\max }^{\mathrm{H}}\approx 82$.

    ↳ nucl-thhep-phEPJC(2024)·3 citations

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