Mon·Jun 17, 2024Monday·June 17, 2024

1. 01*

   Phenomenology of the doubly-charged vector bilepton

   Mario W. Barela🇧🇷

   The Standard Model stands as the first established, complete (gravity aside), fundamental theory of nature. In the other hand, it is unable to account for some universal observations -- besides possessing a number of undesirable characteristics. Thus, there is a pressing need for new physics, which, in the high energy realm, usually imply new particles. In this thesis, we delve into one such particle: the doubly-charged vector bilepton. This particle is a singular feature of Beyond the Standard Model theories and its phenomenology is still incipient. We focus, in particular, on its power as a mediator of Charged Lepton Flavour Mediation, a type of process which, in turn, may represent a smoking gun with respect to its discovery or constraining of its parameters. Such processes have not been skeptically explored, and the lepton mixing in their interaction with the $U^{\pm \pm }$ not been properly focused on. The first step we take is investigating what bounds an LHC trimuon process may impose on the parameter space of this particle. The results motivate us to look for alternative experimental sources of limits. The seven 3-body lepton decay channels delivered a great prospect, and we perform a detailed, model independent analysis of what they can imply for the $U^{\pm \pm }$ and other two exotic species. Special attention is paid to occurring interferences between new contributions. Finally, we proceed to construct a thorough analysis of the evolution of couplings in the Minimal 3-3-1 Model, the main theory incorporating a vector bilepton, examining how it is threatened by Landau poles in its abelian coupling. We explicitly obtain the 1-loop contributions of exotic particles to the runnings, finding that the perturbative regime of the model is in fact considerably larger than conventionally assumed.

   hep-phhep-ex0 citations
2. 02*

   Bridging Electromagnetic and Gravitational Form Factors: Insights from LFHQCD

   Xiaobin Wang🇨🇳 · Zanbin Xing🇨🇳 · Minghui Ding🇩🇪 · Khépani Raya🇪🇸 · Lei Chang🇨🇳

   We propose an efficacious approach to derive the generalized parton distributions for the pion and proton, based upon prior knowledge of their respective parton distribution functions (PDFs). Our method leverages on integral representations of the electromagnetic form factors derived from the light-front holographic QCD (LFHQCD) formalism, coupled with PDFs computed from continuum Schwinger functional methods at the hadronic scale. Using these techniques, we calculate gravitational form factors and associated mass distributions for each hadron. Remarkably, our calculations yield results that closely match recent lattice QCD simulations conducted near the physical pion mass. This work not only deepens our understanding of hadronic structure but also highlights the efficacy of the LFHQCD approach in modeling fundamental properties of hadrons.

   hep-phnucl-th8 citations
3. 03*

   Collective excitations in magnetic topological insulators and axion dark matter search

   Koji Ishiwata🇯🇵 · Kentaro Nomura🇯🇵

   We investigate collective excitations in magnetic topological insulators (TIs) and their impact on axion detection. In the three-dimensional TI model with the Hubbard term, the effective action of magnons and amplitude modes is formulated by dynamical susceptibility under the antiferromagnetic and ferromagnetic states. One of the amplitude modes is identified as ``axionic'' quasi-particle and its effective coupling to the electromagnetic fields turns out to be roughly unchanged, or suppressed by up to two orders of magnitude, compared to the previous estimate, which may drastically change the sensitivity of the axion search using``axion' in magnetic TIs.

   hep-phastro-ph.COcond-mat.str-elJHEP(2024)·2 citations
4. 04*

   Defect Induced Heavy Meson Dynamics in the QCD Conformal Window

   Vigilante Di Risi🇮🇹 · Davide Iacobacci🇮🇹 · Francesco Sannino🇮🇹

   Upon introducing an heavy quark in the perturbative regime of the QCD conformal window we precisely determine the associated heavy meson spectrum and wave functions in terms of the number of light flavours and mass. We then compute the conformal Isgur-Wise function which is a central quantity in heavy quark physics. We further determine the impact of the residual low energy confining dynamics on the heavy meson spectrum. As a working framework, we adapt the heavy quark effective theory to the perturbative conformal window dynamics. Our work lays the foundations to systematically go beyond the infinite mass defect approximation in conformal field theories.

   hep-phhep-lathep-thPRD(2024)·3 citations
5. 05*

   Analyzing leptonic decays of heavy quarkonia in covariant confined quark model

   Stanislav Dubnička🇸🇰 · Anna Zuzana Dubničková🇸🇰 · Mikhail A. Ivanov🇷🇺 · Andrej Liptaj🇸🇰 · Akmaral Tyulemissova🇷🇺 · Zhomart Tyulemissov🇷🇺

   The leptonic decay widths of heavy quarkonia are complementary observables to the semileptonic decays of heavy mesons and provide additional insight into the possible lepton flavor universality breaking. We analyze the former in the framework of the covariant confined quark model, introducing a novel approach for the description of the radially excited quarkonia states, which is based on constituent quark mass running and the orthogonality of the states. We are able to describe the experimental observations by our approach within the Standard model, which does not support new physics explanations.

   hep-phPRD(2024)·4 citations
6. 06*

   Antenna subtraction for processes with identified particles at hadron colliders

   Leonardo Bonino🇨🇭 · Thomas Gehrmann🇨🇭 · Matteo Marcoli🇬🇧 · Robin Schürmann🇨🇭 · Giovanni Stagnitto🇮🇹

   Collider processes with identified hadrons in the final state are widely studied in view of determining details of the proton structure and of understanding hadronization. Their theory description requires the introduction of fragmentation functions, which parametrise the transition of a produced parton into the identified hadron. To compute higher-order perturbative corrections to these processes requires a subtraction method for infrared singular configurations. We extend the antenna subtraction method to hadron fragmentation processes in hadronic collisions up to next-to-next-to-leading order (NNLO) in QCD by computing the required fragmentation antenna functions in initial-final kinematics. The integrated antenna functions retain their dependence on the momentum fractions of the incoming and fragmenting partons.

   hep-phJHEP(2024)·25 citations
7. 07*

   The gauge coupling evolutions of an $\mathrm{SU}(8)$ theory with the maximally symmetry breaking pattern

   Ning Chen🇨🇳 · Zhanpeng Hou🇨🇳 · Ying-nan Mao🇨🇳 · Zhaolong Teng🇨🇳

   We study the renormalizable group equations (RGEs) of the extended strong and weak gauge couplings in an $\mathrm{SU}(8)$ theory, where three-generational SM fermions are non-trivially embedded. This framework was previously found to generate the observed SM quark/lepton mass hierarchies and the Cabibbo-Kobayashi-Maskawa mixing pattern through its maximally breaking pattern. The field theoretical two-loop RGEs can not achieve the gauge coupling unification with the minimal setup, unless additional adjoint Higgs fields as well as the gravity-induced $d=5$ term to the $\mathrm{SU}(8)$ field strength term are included.

   hep-phhep-thJHEP(2024)·5 citations
8. 08*

   Steady state, displacement current and spin polarization for massless fermion in a shear flow

   Shu Lin🇨🇳 · Ziyue Wang🇨🇳

   We consider spin polarization of massless fermions in a shear flow, whose complete contributions contain magnetization current and side-jump current known from collisional chiral kinetic theory. We argue that the side-jump current adopts interpretation of displacement current. We explicitly determine the displacement current contribution in the steady state reached in shear flow for a QED plasma. We find the displacement contribution enhances the magnetization contribution at small and large momenta, but leads to a suppression effect at intermediate momenta. Major differences from previous studies on collisional effect are: (i) the fermions are in the same steady state as the medium rather than being probes; (ii) Compton scattering and pair annihilation are also included in addition to the Coulomb scattering considered before.

   hep-phnucl-exnucl-thPRD(2025)·18 citations
9. 09*

   HackAnalysis 2: A powerful and hackable recasting tool

   Mark D. Goodsell🇫🇷

   This is the manual for the version 2 of HackAnalysis, a powerful, lightweight, versatile and, most importantly, hackable, recasting tool. New features in this version include: compressed event format storage for ultra-fast development; integration of new physics and mathematics routines via RestFrames and Eigen; automatic computation of systematic uncertainties; an interface to ONNX for neural networks; easy implementation of new models via QNUMBERS blocks; a python package for interfacing to pyhf, spey and in-built statistics routines for fast computation of experimental limits; improved integration with BSMArt for fast scanning, and a new batch running/convergence check. Several new (electroweakino) analyses are included with this release.

   hep-ph13 citations
10. 10*

    New strategies for probing $B\to D^{\ast }\ell {\bar{\nu }}_{\ell }$ lattice and experimental data

    Marzia Bordone🇨🇭 · Andreas Juttner🇬🇧

    We present an analysis of the exclusive semileptonic decay $B\to D^{\ast }\ell {\bar{\nu }}_{\ell }$ based on the Belle and Belle II data made public in 2023, combined with recent lattice-QCD calculations of the hadronic transition form factors by FNAL/MILC, HPQCD and JLQCD. We also consider a new combination of the Belle and Belle II data sets by HFLAV. The analysis is based on the form-factor parameterisation by Boyd-Grinstein-Lebed (BGL), using Bayesian and frequentist statistics, for which we discuss novel strategies. We compare the results of an analysis where the BGL parameterisation is fit only to the lattice data with those from a simultaneous fit to lattice and experiment, and discuss the resulting predictions for the CKM-matrix element $V_{cb}$, as well as other phenomenological observables, such as $R^{\tau /\mu }(D^{\ast })$. We find tensions when comparing analyses based on different combinations of experimental or theoretical input, requiring the introduction of a systematic error for some of our results.

    hep-phhep-latEPJC(2025)·29 citations
11. 11*

    Calculation of the chiral Lagrangian coefficients with light vector mesons

    Zi-Kan Geng🇨🇳 · Qing Wang🇨🇳

    We calculate the coefficients in the effective chiral Lagrangian from QCD, which includes pseudo-scalar mesons and vector mesons (with hidden symmetry), up to O(p4). This encompasses both the normal and anomalous parts. Our work builds on a previous study that derived the chiral Lagrangian from first principles of QCD, where the low-energy coefficients are defined in terms of specific Green's functions in QCD. This research extends our earlier efforts that focused on calculating the low-energy coefficients of the chiral Lagrangian for pure pseudo-scalar mesons. This marks the first calculation of chiral Lagrangian coefficients for vector mesons from QCD, particularly for the important parameters a and g, which are typically considered inputs in existing literature. Notably, the regularization method used previously is inadequate for this broader scope. We find that cut-off regularization yields reasonable results for both pseudo-scalar mesons and vector mesons, though it has certain limitations. Finally, we demonstrate that our method aligns with the Weinberg sum rules.

    hep-phhep-th1 citation
12. 12*

    A search for leptonic photon Z_l at all three CLIC energy stages by using artificial neural networks (ANN)

    S. O. Kara🇹🇷 · S. Akkoyun🇬🇧

    In this work, the possible dynamics of the massive leptonic photon \(Z_{l}\) are reconsidered via the process \(e^{+}e^{-} \ rightarrow \mu^{+}\mu^{-}\) at Compact Linear Collider (CLIC) with updated center of mass energies (\(380\ GeV,\ 1500\ GeV\ and\ 3000\ GeV\)). We show that the new generation colliders as CLIC can observe massive leptophilic vector boson Z_l with mass up to the center of mass energy, provided that leptonic coupling constant is \(g_{l} \geq 10^{- 3}\). In this study, we also estimated the cross-sections by artificial neural networks using the theoretical results we obtained for CLIC. According to the results obtained, it was seen that these predictions could be made through machine learning.

    hep-phActa Phys.Polon.B(2024)·2 citations
13. 13*

    Systematic analysis of search strategies for $L_{\mu }-L_{\tau }$ gauge bosons at Belle II

    C. Brown🇬🇧 · J. Fiaschi🇬🇧 · O. Fischer🇬🇧 · T. Teubner🇬🇧

    Extensions of the Standard Model with masses at or below the GeV scale are motivated by searches for dark matter and precision measurements in the quark and lepton flavour sectors, including that of the muon anomalous magnetic moment. An excellent experimental environment to test such light new physics is given by the Belle II experiment, which foresees to take up to 50 ab${}^{-1}$ of data. Here we consider a model with an additional gauged $U(1{)}_{L_{\mu }-L_{\tau }}$ symmetry that introduces a neutral gauge boson, a Dark Photon, with possibly large couplings to muon- and tau-flavored leptons, including neutrinos. Dark Photon mixing with the Standard Model photon is loop induced, allowing it to couple to electrically charged fermions other than muons and taus. We systematically investigate the possible search strategies for Dark Photons with four fermions final states. We identified search channels with muons as the most promising ones, and we analyse the kinematic distributions to obtain cuts that optimise the sensitivity of Belle II searches for the Dark Photon. Summarising the sensitivities from the most promising search channels we provide a comprehensive overview of future searches at Belle II.

    hep-phJHEP(2024)·2 citations
14. 14*

    Spectroscopic Shifts in Deuterated Methanol Induced by Variation of me/mp

    J. S. Vorotyntseva🇷🇺 · S. A. Levshakov🇷🇺 · M. G. Kozlov🇷🇺

    Numerical calculations of the sensitivity coefficients, Q_mu, of microwave molecular transitions in the ground torsion-rotation state of deuterated methanol (CH3OD, CD3OH, and CD3OD) to small variations in the fundamental physical constant mu = me/mp - the electron-to-proton mass ratio - are reported. Theoretical motivation for changes in mu comes from a variety of models beyond the Standard Model of particle physics which are invoked to explain the nature of dark matter and dark energy that dominate the Universe. The calculated values of Q_mu range from -300 to +73 and, thus, make deuterated methanol promising for searches for small space-time changes in mu. It is also shown that among the calculated sensitivity coefficients Q_mu using different Hamiltonians in the present and previous works, there are several pronounced outliers of unclear nature.

    hep-phastro-ph.COphysics.atom-phPRA(2024)·3 citations
15. 15*

    Getting More Out of Black Hole Superradiance: a Statistically Rigorous Approach to Ultralight Boson Constraints from Black Hole Spin Measurements

    Sebastian Hoof🇮🇹 · David J. E. Marsh🇬🇧 · Júlia Sisk-Reynés🇬🇧 · James H. Matthews🇬🇧 · Christopher Reynolds🇬🇧

    Black hole (BH) superradiance can provide strong constraints on the properties of ultralight bosons (ULBs). While most of the previous work has focused on the theoretical predictions, here we investigate the most suitable statistical framework to constrain ULB masses and self-interactions using BH spin measurements. We argue that a Bayesian approach based on a simple timescales analysis provides a clear statistical interpretation, deals with limitations regarding the reproducibility of existing BH analyses, incorporates the full information from BH data, and allows us to include additional nuisance parameters or to perform hierarchical modelling with BH populations in the future. We demonstrate the feasibility of our approach using mass and spin posterior samples for the X-ray binary BH M33 X-7 and, for the first time in this context, the supermassive BH IRAS 09149-6206. We explain the differences to existing ULB constraints in the literature and illustrate the effects of various assumptions about the superradiance process (equilibrium regime vs cloud collapse, higher occupation levels). As a result, our procedure yields the most statistically rigorous ULB constraints available in the literature, with important implications for the QCD axion and axion-like particles. We encourage all groups analysing BH data to publish likelihood functions or posterior samples as supplementary material to facilitate this type of analysis, and for theory developments to compress their findings to effective timescale modifications.

    hep-phastro-ph.HEgr-qcMNRAS(2026)·71 citations
16. 16*

    Cosmic Ray Muons in Laboratories Deep Underground

    William Woodley🇨🇦 · Anatoli Fedynitch🇹🇼 · Marie-Cécile Piro🇨🇦

    We provide comprehensive calculations of total muon fluxes, energy and angular spectra, and mean muon energies in deep underground laboratories - under flat overburdens and mountains and underwater - using our latest calculation code, MUTE v3. For precise modeling, we compiled rock densities and chemical compositions for various underground labs, as well as topographic map profiles of overburdens, and integrated them into our calculations. Our results show excellent agreement with available data for most underground sites when using the latest surface muon flux model, daemonflux. Moreover, since our calculations do not rely on underground measurements of muons or other secondaries, we can verify the consistency of measurements across different detectors at different sites. MUTE is an open-source, publicly available program, providing a solid framework for accurate muon flux predictions in various underground environments, essential for applications in cosmic ray physics and dark matter searches.

    hep-phPRD(2024)·25 citations
17. 17*

    Fundamental constants from photon-photon scattering in three-beam collisions

    Alexander J. Macleod🇨🇿 · Ben King🇬🇧

    Direct measurement of the elastic scattering of real photons on an electromagnetic field would allow the fundamental low-energy constants of quantum electrodynamics (QED) to be experimentally determined. We show that scenarios involving the collision of three laser beams have several advantages over conventional two-beam scenarios. The kinematics of a three-beam collision allows for a higher signal-to-noise ratio in the detection region, without the need for polarimetry and separates out contributions from different orders of photon scattering. A planar configuration of colliding a photon beam from an x-ray free electron laser with two optical beams is studied in detail. We show that measurements of elastic photon scattering and vacuum birefringence are possible with currently available technology.

    hep-phphysics.opticsphysics.plasm-phPRA(2024)·12 citations
18. 18*

    Smooth reheating and dark matter via non-Abelian gauge theory

    Simone Biondini🇨🇭 · Helena Kolesova🇳🇴 · Simona Procacci🇨🇭

    We demonstrate how a dark sector can provide a crucial link between a vacuum-dominated early universe and the later radiation-dominated epoch. As an example, we consider a feeble axion-like coupling of dark non-Abelian gauge fields with a single inflaton. In this scenario, a dark heat bath emerges at the end of inflation. As the dark sector cools down, its gauge fields confine into composite glueball states. The reheating of the visible sector is realized through portal interactions. After confinement, discrete symmetries protect part of the glueball states that form relic dark matter, while the others keep decaying into Standard Model degrees of freedom. The dark relic abundance depends mostly on the departure from equilibrium dynamics after the phase transition, constraining the confinement scale of the dark sector. Moreover, indirect detection and Big-Bang nucleosynthesis set bounds on the scale of portal interactions. We show that in a narrow but non-vanishing region of the parameter space, the correct dark matter abundance and sufficient reheating temperature are simultaneously reached.

    hep-phastro-ph.COgr-qcPLB(2024)·9 citations
19. 19*

    Interpolating gauge-fixing for Yang-Mills-Chern-Simons theory in D=3

    Daniel O. R. Azevedo🇧🇷 · Oswaldo M. Del Cima🇧🇷 · Thadeu S. Dias🇧🇷 · Emílio D. Pereira🇧🇷

    The Yang-Mills-Chern-Simons theory in three-dimensional Minkowski space-time is studied in a gauge-fixing scheme which interpolates between the covariant gauge and light-cone gauge, the interpolating gauge-fixing. The ultraviolet finiteness of the theory is proved via the Becchi-Rouet-Stora (BRS) algebraic renormalization procedure, which allows us to demonstrate the vanishing of all $\beta$-functions and all anomalous dimensions to all orders in perturbation theory.

    ↳ hep-thhep-phmath-phmath.MP+1EPJC(2024)·3 citations
20. 20*

    Quantum Gravity Effects on the Tachyon Inflation from Thermodynamic Perspective

    M. Bitaj🇮🇷 · N. Rashidi🇮🇷 · K. Nozari🇮🇷 · M. Roushan🇮🇷

    By considering the Friedmann equations emerging from the entropy-area law of black hole thermodynamics in the context of the generalized uncertainty principle, we study tachyon inflation in the early universe. The presence of a minimal length modifies the Friedmann equations and hence the slow-roll and perturbation parameters in the tachyon model. These modifications, though small, affect the viability of the tachyon inflation in confrontation with observational data. We compare the numerical results of the model with Planck2018 TT, TE, EE +lowE+lensing+BAO+BK14(18) data and Planck2018 TT, TE,EE +lowE+lensing+BK14(18) +BAO+LIGO $\&$ Virgo2016 data at $68\%$ and $95\%$ CL. We show that while the tachyon inflation with power-law, inverse power-law and inverse exponential potentials is not observationally viable in comparison with the $1\sigma$ and $2\sigma$ confidence levels of the new joint data, in the presence of the minimal length the model becomes observationally viable.

    ↳ astro-ph.COgr-qchep-phhep-thPhys.Dark Univ.(2024)·2 citations
21. 21*

    Charmoniumlike Channels $1^{+}$ with Isospin $1$ from Lattice and Effective Field Theory

    Mitja Sadl🇸🇮 · Sara Collins🇩🇪 · Zhi-Hui Guo🇨🇳 · M. Padmanath🇮🇳 · Sasa Prelovsek🇸🇮 · Lin-Wan Yan🇨🇳

    Many exotic charmoniumlike mesons have already been discovered experimentally, of which the $Z_c$ mesons with $I=1$ are prominent examples. We investigate $J^{PC}=1^{+\pm }$ states with flavor $\bar{c}c\bar{q}q$ ($q=u,d$) in $I=1$ using lattice QCD. This is the first study of these mesons employing more than one volume and involving frames with nonzero total momentum. We utilize two $N_f=2+1$ CLS ensembles with $m_{\pi }\simeq 280$MeV. The simulations are performed with unphysical light quark masses at a single lattice spacing of $a\simeq 0.086$fm and omit $\psi (2S)\pi$, $\psi (3770)\pi$ and three-particle decay channels, so our results provide only qualitative insights. Resulting eigenenergies are compatible or just slightly shifted down with respect to noninteracting energies, where the most significant shifts occur for certain $D{\bar{D}}^{\ast }$ states. Both channels $1^{+\pm }$ have a virtual pole slightly below the threshold if $D{\bar{D}}^{\ast }$ is assumed to be decoupled from other channels. In addition, we perform a coupled channel analysis of $J/\psi \pi$ and $D{\bar{D}}^{\ast }$ scattering with $J^{PC}=1^{+-}$ within an effective field theory framework. The $J/\psi \pi$ and $D{\bar{D}}^{\ast }$ line shapes from BESIII and finite-volume energies from several lattice QCD simulations, including this work, are fitted simultaneously. All fits yield two poles relatively close to the $D{\bar{D}}^{\ast }$ threshold and reasonably reproduce the experimental $Z_c$ peaks. They also reproduce lattice energies up to slightly above the $D{\bar{D}}^{\ast }$ threshold, while reproduction at even higher energies is better for fits that put more weight on the lattice data. Our findings suggest that the employed EFT can reasonably reconcile the peaks in the experimental line shapes and the lattice energies, although those lie close to noninteracting energies. We also study $J/\psi \pi$ scattering in s wave and place upper bounds on the phase shift.

    ↳ hep-lathep-phPRD(2025)·17 citations
22. 22*

    Fitting the DESI BAO Data with Dark Energy Driven by the Cohen-Kaplan-Nelson Bound

    Patrick Adolf · Martin Hirsch · Sara Krieg · Heinrich Päs · Mustafa Tabet

    Gravity constrains the range of validity of quantum field theory. As has been pointed out by Cohen, Kaplan, and Nelson (CKN), such effects lead to interdependent ultraviolet (UV) and infrared (IR) cutoffs that may stabilize the dark energy of the universe against quantum corrections, if the IR cutoff is set by the Hubble horizon. As a consequence of the cosmic expansion, this argument implies a time-dependent dark energy density. In this paper we confront this idea with recent data from DESI BAO, Hubble and supernova measurements. We find that the CKN model provides a better fit to the data than the $\Lambda$CDM model and can compete with other models of time-dependent dark energy that have been studied so far.

    ↳ astro-ph.COgr-qchep-phhep-th
23. 23*

    Quasinormal modes of slowly-spinning horizonless compact objects

    M. V. S. Saketh🇺🇸 · Elisa Maggio🇩🇪

    One of the main predictions of general relativity is the existence of black holes featuring a horizon beyond which nothing can escape. Gravitational waves from the remnants of compact binary coalescences have the potential to probe new physics close to the black hole horizons. This prospect is of particular interest given several quantum-gravity models that predict the presence of horizonless and singularity-free compact objects. The membrane paradigm is a generic framework that allows one to parametrise the interior of compact objects in terms of the properties of a fictitious fluid located at the object's radius. It has been used to derive the quasinormal mode spectrum of static horizonless compact objects. Extending the membrane paradigm to rotating objects is crucial to constrain the properties of the spinning merger remnants. In this work, we extend the membrane paradigm to linear order in spin and use it to analyse the relationships between the quasi-normal modes, the object's reflectivity, and the membrane parameters. We find a breaking of isospectrality between axial and polar modes when the object is partially reflecting or the compactness differs from the black hole case. We also find that in reflective ultracompact objects some of the modes tend towards instability as the spin increases. Finally, we show that the spin enhances the deviations from the black-hole quasinormal mode spectrum as the compactness decreases. This implies that spinning horizonless compact objects may be more easily differentiated than nonspinning ones in the prompt ringdown.

    ↳ gr-qcastro-ph.HEhep-phhep-thPRD(2024)·16 citations
24. 24*

    Investigating the Role of Quantum Entanglement in Heavy Ion Collisions through Elliptic Flow

    Mira Varma🇺🇸 · Oliver Baker🇺🇸

    This paper investigates the relationship between initial spatial anisotropy and final state momentum anisotropy in heavy ion collisions through the analysis of elliptic flow ($v_2$) as a function of transverse momentum ($p_T$). Building upon previous studies on thermalization in heavy ion collisions using transverse momentum distributions, we extend the analysis to the $p_T$ dependence of $v_2$ in Pb-Pb and Xe-Xe collisions. By employing a two-component model to extract the thermal and hard scattering contributions to the elliptic flow, we aim to gain further insights into the role of quantum entanglement in the rapid thermalization and collective behavior of the quark-gluon plasma (QGP).

    ↳ nucl-thhep-phquant-ph1 citation
25. 25*

    Quantumness of relic gravitons

    Massimo Giovannini🇨🇭

    Since the relic gravitons are produced in entangled states of opposite (comoving) three-momenta, their distributions and their averaged multiplicities must determine the maximal frequency of the spectrum above which the created pairs are exponentially suppressed. The absolute upper bound on the maximal frequency derived in this manner coincides with the THz domain and does not rely on the details of the cosmological scenario. The THz limit also translates into a constraint of the order of $10^{-33}$ on the minimal chirp amplitudes that should be effectively reached by all classes of hypothetical detectors aiming at the direct scrutiny of a signal in the frequency domain that encompasses the MHz and the GHz bands. The obtained high-frequency limit is deeply rooted in the quantumness of the produced gravitons whose multiparticle final sates are macroscopic but always non-classical. Since the unitary evolution preserves their coherence, the quantumness of the gravitons can be associated with an entanglement entropy that is associated with the loss of the complete information on the underlying quantum field. It turns out that the reduction of the density matrix in different bases leads to the same Von Neumann entropy whose integral over all the modes of the spectrum is dominated by the maximal frequency. Thanks to the THz bound the total integrated entropy of the gravitons can be comparable with the cosmic microwave background entropy but not larger. Besides the well known cosmological implications, we then suggest that a potential detection of gravitons between the MHz and the THz may therefore represent a direct evidence of macroscopic quantum states associated with the gravitational field.

    ↳ hep-thastro-ph.COgr-qchep-ph+1PRD(2024)·6 citations
26. 26*

    Cosmological scaling of precursor domain walls

    Mainak Mukhopadhyay🇺🇸 · Oriol Pujolas🇪🇸 · George Zahariade🇵🇱

    Domain wall (DW) networks have a large impact on cosmology and present interesting dynamics that can be controlled by various scaling regimes. In the first stage after spontaneous breaking of the discrete symmetry, the network is seeded with `DW precursors', the zeros of a tachyonic field. At sufficiently weak coupling, this stage can be quite long. The network is then driven to a non-relativistic scaling regime: in flat spacetime the correlation length grows like $L\sim t^{\kappa }$ with $\kappa =1/2$. We focus on the precursor regime in cosmology, assuming a power-law scale factor $a\propto t^{\alpha }$. We obtain the scaling exponent as a function of the external parameter, $\kappa (\alpha )$, by explicit computation in $1+1$ and $2+1$ dimensions, and find a smooth transition from nonrelativistic scaling with $\kappa \simeq 1/2$ for $\alpha \lesssim 1/2$ to DW gas regime $\kappa \simeq \alpha$ for $\alpha \gtrsim 1/2$, confirming previous arguments. The precise form of the transition $\kappa (\alpha )$ is surprisingly independent of dimension, suggesting that similar results should also be valid in $3+1$ dimensions.

    ↳ hep-thastro-ph.COhep-phPRD(2024)·4 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.