Tue·May 16, 2023Tuesday·May 16, 2023

1. 01*

   Electromagnetic Radiation in chiral matter: the Cherenkov case

   Eduardo Barredo-Alamilla🇲🇽 · Luis F. Urrutia🇲🇽 · Manoel M. Ferreira Jr🇧🇷

   Starting from the modified Maxwell equations in Carroll-Field-Jackiw electrodynamics we study the electromagnetic radiation in a chiral medium characterized by an axion coupling $\theta (x)=b_{\mu }{x}^{\mu }$, with $b_{\mu }=(0,\mathbf{b})$, which gives rise to the magnetoelectric effect. Employing the stationary phase approximation we construct the Green's matrix in the radiation zone which allows the calculation of the corresponding electromagnetic potentials and fields for arbitrary sources. We obtain a general expression for the angular distribution of the radiated energy per unit frequency. As an application we consider a charge moving at constant velocity parallel to $\mathbf{b}$ in the medium and discuss the resulting Cherenkov radiation. We recover the vacuum Cherenkov radiation. For the case of a material with refraction index $n>1$ we find that zero, one or two Cherenkov cones can appear. The spectral distribution of the radiation together with the comparison of the radiation output of each cone are presented, as well as some angular plots showing the appearance of the cones.

   hep-phcond-mat.mes-hallhep-thPRD(2023)·13 citations
2. 02*

   Charm content of the proton: An analytic calculation

   A. R. Olamaei🇮🇷 · S. Rostami🇮🇷 · K. Azizi🇮🇷

   According to general understanding, the proton as one of the main ingredients of the nucleus is composed of one down and two up quarks bound together by gluons, described by Quantum Chromodynamics (QCD). In this view, heavy quarks do not contribute to the primary wave function of the proton. Heavy quarks arise in the proton perturbatively by gluon splitting and the probability gradually increases as $Q^2$ increases (extrinsic heavy quarks). In addition, the existence of non-perturbative intrinsic charm quarks in the proton has also been predicted by QCD. In this picture, the heavy quarks also exist in the proton's wave function. In fact, the wave function has a five-quark structure $|uudc\bar{c}⟩$ in addition to the three-quark bound state $|uud⟩$. So far, many studies have been done to confirm or reject this additional component. One of the recent studies has been done by the NNPDF collaboration. They established the existence of an intrinsic charm component at the 3-standard-deviation level in the proton from the structure function measurements. Most of the studies performed to calculate the contribution of the intrinsic charm so far have been based on the global analyses of the experimental data. In this article, for the first time we directly calculate this contribution by an analytic method. We estimate a $x^{c\bar{c}}=(1.36\pm 0.67)\%$ contribution for the $|uudc\bar{c}⟩$ component of the proton.

   hep-phhep-exhep-latnucl-thPRD(2023)·2 citations
3. 03*

   On the non-factorizable corrections to Higgs boson production in weak boson fusion

   Konstantin Asteriadis🇺🇸 · Christian Brønnum-Hansen🇩🇪 · Kirill Melnikov🇩🇪

   We discuss the non-factorizable corrections to Higgs boson production in weak boson fusion at the Large Hadron Collider. Such corrections depend on the finite part of the two-loop virtual amplitude $qQ\to q^{\prime }{Q}^{\prime }+H$ which, up to now, has only been computed in the eikonal approximation. We combine this contribution with real-virtual and double-real non-factorizable QCD corrections and study their impact on the various observables in weak boson fusion. We find that the non-factorizable corrections are strongly dominated by the two-loop virtual contributions, while all other contributions play a very minor role. This striking imbalance between real and virtual contributions is caused by a process-specific kinematic suppression of the former and a particular enhancement of the virtual corrections related to a Glauber phase.

   hep-phPRD(2024)·11 citations
4. 04*

   The two Higgs doublet type-II seesaw model: Naturalness and $\bar{B}\to X_s\gamma$ versus heavy Higgs masses

   B. Ait Ouazghour🇲🇦 · M. Chabab🇲🇦

   We extend the work \cite{Ouazghour:2018mld} to a more general and detailed analysis through studying the naturalness problem and $B$ physics constraints within the context of two higgs doublets model augmented with a complex scalar triplet field ($2HDMcT$). We first derive the modified Vetman conditions and show that naturalness problem might be evaded at the electroweak scale. Then, we evaluate the branching ratio of $\bar{B}\to X_s\gamma$ radiative decay at the Next to leading order. Besides unitarity, boundedness from below constraints and the present collider data from Higgs signal rate measurements, the parameter space of $2HDMcT$ is then revisited to see how the modified Veltman conditions and $\bar{B}\to X_s\gamma$ experimental bounds induce significant delimitations. Our analysis shows that the naturalness affects drastically the masses of heavy Higgs $h_3$, $A_2$, $H_2^{\pm }$ and $H^{\pm \pm }$. More specifically, we considered three benchmak scenarios corresponding to ${\mu }_2>20,40,70$ GeV. For ${\mu }_2>40$, we find stringent upper limits on $m_{h_2}$, $m_{A_1}$ and $m_{H_1^{\pm }}$ at $880$, $920$ and $918$ GeV respectively. If, in addition, the measurements of $\bar{B}\to X_s\gamma$ decay rate are also considered, the lower masses limits of nonstandard Higgs bosons ($h_2$, $h_3$, $A_1$, $A_2$, $H_1^{\pm }$, $H_2^{\pm }$, $H^{\pm \pm }$) are pushed up to higher values located between $490$ and $750$ GeV. Besides, we also demonstrate that the $\bar{B}\to X_s\gamma$ experimental limits can only be accommodated within $2HDMcT$ if two conditions are fullfilled : ${\alpha }_1$ parameter positive and the Higgs mass hierarchy $m_{h_3}>m_{H_2^{\pm }}>m_{H^{\pm \pm }}$.

   hep-phPLB(2023)·7 citations
5. 05*

   Neutrino forces and experimental probes

   Xun-Jie Xu🇨🇳

   Neutrinos as almost massless particles could mediate long-range forces, known as neutrino forces. In this talk, I will introduce some theoretical aspects of neutrino forces, including why the potential of a neutrino force has the $1/r^5$ form and how it may vary under different circumstances. Experimental probes and possible implications for cosmology are also briefly discussed.

   hep-phastro-ph.COhep-ex0 citations
6. 06*

   Revisiting ${\Xi }_Q-{\Xi }_Q^{\prime }$ mixing in QCD sum rules

   Xiao-Yu Sun🇨🇳 · Fu-Wei Zhang🇨🇳 · Yu-Ji Shi🇨🇳 · Zhen-Xing Zhao🇨🇳

   In this work, we perform a QCD sum rules analysis on the ${\Xi }_Q-{\Xi }_Q^{\prime }$ mixing. Contributions from up to dimension-6 four-quark operators are considered. However, it turns out that, only dimension-4 and dimension-5 operators contribute, which reveals the non-perturbative nature of mixing. Especially we notice that only the diagrams with the two light quarks participating in gluon exchange contribute to the mixing. Our results indicate that the mixing angle ${\theta }_c=(1.2\sim 2.8{)}^{\circ }$ for the $Q=c$ case and ${\theta }_b=(0.28\sim 0.34{)}^{\circ }$ for the $Q=b$ case. Our prediction of ${\theta }_c$ is consistent with the most recent Lattice QCD result within error. Such a small mixing angle seems unlikely to resolve the tension between the recent experimental measurement from Belle and Lattice QCD calculation for the semileptonic decay ${\Xi }_c^0\to {\Xi }^{-}{e}^{+}{\nu }_e$.

   hep-phEPJC(2023)·14 citations
7. 07*

   Pulsar timing residual induced by ultralight tensor dark matter

   Yu-Mei Wu🇨🇳 · Zu-Cheng Chen🇨🇳 · Qing-Guo Huang🇨🇳

   Ultralight boson fields, with a mass around $10^{-23}\text{eV}$, are promising candidates for the elusive cosmological dark matter. These fields induce a periodic oscillation of the spacetime metric in the nanohertz frequency band, which is detectable by pulsar timing arrays. In this paper, we investigate the gravitational effect of ultralight tensor dark matter on the arrival time of radio pulses from pulsars. We find that the pulsar timing signal caused by tensor dark matter exhibits a different angular dependence than that by scalar and vector dark matter, making it possible to distinguish the ultralight dark matter signal with different spins. Combining the gravitational effect and the coupling effect of ultralight tensor dark matter with standard model matter provides a complementary way to constrain the coupling parameter $\alpha$. We estimate $\alpha \lesssim 10^{-6}\sim 10^{-5}$ in the mass range $m<5\times 10^{-23}\mathrm{eV}$ with current pulsar timing array.

   hep-phastro-ph.COastro-ph.HEgr-qcJCAP(2023)·47 citations
8. 08*

   Exploring Ultralight Scalar Assistance in Sterile Neutrino Dark Matter: Cold Spectrum and Unusual X/Gamma-ray Signatures

   Yuxuan He🇨🇳 · Jia Liu🇨🇳 · Xiaolin Ma🇨🇳 · Xiao-Ping Wang🇨🇳

   We present a scalar-driven sterile neutrino production model where the interaction with the ultralight scalar field modifies the oscillation production of sterile neutrinos in the early universe. The model effectively suppresses the production of sterile neutrinos at low temperatures due to the heavy scalar mass, resulting in a colder matter power spectrum that avoids constraints from small-scale structure observations. In this model, the dominant dark matter relic is from sterile neutrinos, with only a small fraction originating from the ultralight scalar. Furthermore, the model predicts a detectable X/gamma-ray flux proportional to the cubic density of local sterile neutrinos for a light scalar mass due to the light scalar coupling to sterile neutrinos. This distinguishes our model from normal decaying dark matter, which has a linear dependence on the density. In addition, the model predicts a potential low-energy monochromatic neutrino signal that can be detectable by future neutrino telescopes.

   hep-phastro-ph.COJCAP(2023)·2 citations
9. 09*

   Physics with intact protons at the LHC: from the odderon discovery to the sensitivity to beyond standard model physics

   C. Royon🇺🇸

   We describe the discovery of the colorless $C$-odd gluonic compound, the odderon, by the D0 and TOTEM Collaborations by comparing elastic differential cross sections measured in $pp$ and $p\bar{p}$ interactions at high energies. We also discuss the reach on quartic anomalous couplings and the sensitivity to axion like particle production by using the LHC as a $\gamma \gamma$ collider and detecting the intact protons at high luminosity.

   hep-phhep-exRev.Mex.Fis.Suppl.(2023)·0 citations
10. 10*

    Plasma harmonic generation for highly efficient Breit-Wheeler pair creation

    Suo Tang🇨🇳

    Observation of efficient Breit-Wheeler electron-positron pair creation is one of the main goals for modern-day strong laser-particle experiments. We propose exploring this process by colliding plasma-generated harmonics, from currently available laser pulses, with a beam of GeV photons. We show that the creation yield is enhanced for more than one order of magnitude, compared with the yield obtained without high-harmonic generation. The robustness of the yield enhancement is demonstrated by considering multiple interaction parameters and the potential photon source for the upcoming experiments. Moreover, we show that due to the evident field asymmetry in the plasma-generated harmonics, the spin-polarization of the created pairs could be as high as $60\%$.

    hep-phPLB(2023)·3 citations
11. 11*

    Thermal effects in $\nu$ DM production

    Salvador Rosauro-Alcaraz🇫🇷

    We study the possibility to produce a keV neutrino dark matter candidate through the two-body decays of heavy neutrinos present in TeV scale neutrino mass generation mechanism. Given that the dark matter production happens at the heavy neutrino scale, namely around the electroweak scale, we address thermal effects and study how these modify the dark matter production rates through freeze-in.

    hep-ph0 citations
12. 12*

    Novel model for particle emission in small collision systems

    Dimitar Mihaylov🇩🇪 · Jaime González González🇩🇪

    Collider experiments provide an opportunity to produce particles at close distances and momenta. The measured correlation functions between particles can provide information on both the effective emission source and the interaction potential. In recent years, experiments at the LHC have shown that precision studies of the strong interaction are possible using correlation techniques, provided a good handle on the source function. The current work presents a new numerical framework called Common Emission in CATS (CECA), capable of simulating the effective emission source of an N-body system based on the properties of the single particles. The framework differentiates between primordial particle emission and particle production through resonances, allowing to verify the hypothesis proposed by the ALICE collaboration that a common baryon-baryon emission source is present in small collision systems. The new framework is used to analyze ALICE data on pp and p$\Lambda$ correlations and compare the results to previous studies based on the common emission source scenario. It is demonstrated that the best fit to the p$\Lambda$ correlation data is obtained using a scattering length of $1.15\pm 0.07$ fm in the S=1 channel.

    hep-phEPJC(2023)·29 citations
13. 13*

    QCD mesonic screening masses using Gribov quantization

    Sumit🇮🇳 · Najmul Haque🇮🇳 · Binoy Krishna Patra🇮🇳

    The screening masses of mesons provide a gauge invariant and definite order parameter of chiral symmetry restoration. Different mesonic correlation lengths for flavor non-singlets, at least up to NLO, are well-defined gauge invariant physical quantities calculated earlier using the perturbative resummation techniques. The NLO perturbative results match the available non-perturbative lattice QCD results at the high-temperature regime. We have studied the spatial correlation lengths of various mesonic observables using the non-perturbative Gribov resummation, both for quenched QCD and (2 + 1) flavor QCD. The study follows the analogies with the NRQCD effective theory, a well-known theory for studying heavy quarkonia at zero temperature.

    hep-phPLB(2023)·14 citations
14. 14*

    Geometrical causality: casting Feynman integrals into quantum algorithms

    German F. R. Sborlini🇪🇸

    The calculation of higher-order corrections in Quantum Field Theories is a challenging task. In particular, dealing with multiloop and multileg Feynman amplitudes leads to severe bottlenecks and a very fast scaling of the computational resources required to perform the calculation. With the purpose of overcoming these limitations, we discuss efficient strategies based on the Loop-Tree Duality, its manifestly causal representation and the underlying geometrical interpretation. In concrete, we exploit the geometrical causal selection rules to define a Hamiltonian whose ground-state is directly related to the terms contributing to the causal representation. In this way, the problem can be translated into a minimization one and implemented in a quantum computer to search for a potential speed-up.

    hep-phhep-thquant-phRev.Mex.Fis.Suppl.(2023)·3 citations
15. 15*

    Testing Bell inequalities and entanglement with di-boson final states

    Luca Marzola🇪🇪

    We explore the phenomenology of quantum entanglement at collider experiments by computing the polarization density matrix of processes yielding two massive gauge bosons. After reviewing the formalism, we detail observables suitable to test the presence of entanglement and quantum correlations in the di-boson system. The implied violation of Bell inequalities can be observed with future data at the LHC in the decays of the Higgs boson to $Z$ boson pairs.

    hep-ph1 citation
16. 16*

    Exploring Models with Modular Symmetry in Neutrino Oscillation Experiments

    Priya Mishra🇮🇳 · Mitesh Kumar Behera🇹🇭 · Papia Panda🇮🇳 · Monojit Ghosh🇭🇷 · Rukmani Mohanta🇮🇳

    Our study aims to investigate the viability of neutrino mass models that arise from discrete non-Abelian modular symmetry groups, i.e., ${\Gamma }_N$ with ($N=1,2,3,\dots$) in the future neutrino experiments T2HK, DUNE, and JUNO. Modular symmetry reduces the usage of flavon fields compared to the conventional discrete flavor symmetry models. Theories based on modular symmetries predict the values of leptonic mixing parameters, and therefore, these models can be tested in future neutrino experiments. In this study, we consider three models based on the $A_4$ modular symmetry, i.e., Model-A, B, and C such a way that they predict different values of the oscillation parameters but still allowed with respect to the current data. In the future, it is expected that T2HK, DUNE, and JUNO will measure the neutrino oscillation parameters very precisely, and therefore, some of these models can be excluded in the future by these experiments. We have estimated the prediction of these models numerically and then used them as input to scrutinize these models in the neutrino experiments. Assuming the future best-fit values of ${\theta }_{23}$ and ${\delta }_{\mathrm{CP}}$ remain the same as the current one, our results show that at $5\sigma$ C.L, Model-A can be excluded by T2HK whereas Model-B can be excluded by both T2HK and DUNE. Model-C cannot be excluded by T2HK and DUNE at $5\sigma$ C.L. Further; our results show that JUNO alone can exclude Model-B at an extremely high confidence level if the future best-fit of ${\theta }_{12}$ remains at the current-one. We have also identified the region in the ${\theta }_{23}$ - ${\delta }_{\mathrm{CP}}$ parameter space, for which Model-A cannot be separated from Model-B in T2HK and DUNE.

    hep-phJHEP(2023)·15 citations
17. 17*

    Two-Real-Singlet Model Benchmark Planes -- A Moriond Update

    Tania Robens🇭🇷

    I present an update on the the Benchmark Planes in the Two-Real-Singlet Model (TRSM), a model that enhances the Standard Model (SM) scalar sector by two real singlets, where an additional Z2 x Z2' symmetry is imposed. I discuss the case where all fields acquire a vacuum expectation value, such that the model contains in total 3 CP-even neutral scalars that can interact with each other. I remind the readers of the previously proposed benchmark planes, current constraints, and possible signatures at current and future colliders. This is an update for Moriond 2023 of results presented in arXiv:2209.10996.

    hep-ph9 citations
18. 18*

    Short Baseline Oscillations and the Gallium Mystery

    Vedran Brdar🇨🇭

    Data from several neutrino experiments suggest an anomalous neutrino flavor transition across relatively short baselines which is in conflict with the three-flavor neutrino oscillation paradigm. In particular, MiniBooNE and BEST collaborations have reported anomalous findings at $\sim 5\sigma$. In this contribution, such measurements and their possible explanations within and beyond the Standard Model are discussed.

    hep-phhep-ex0 citations
19. 19*

    Next-to-leading-logarithmic PanScales showers for Deep Inelastic Scattering and Vector Boson Fusion

    Melissa van Beekveld🇬🇧 · Silvia Ferrario Ravasio🇨🇭

    We introduce the first family of parton showers that achieve next-to-leading logarithmic (NLL) accuracy for processes involving a $t$-channel exchange of a colour-singlet, and embed them in the PanScales framework. These showers are applicable to processes such as deep inelastic scattering (DIS), vector boson fusion (VBF), and vector boson scattering (VBS). We extensively test and verify the NLL accuracy of the new showers at both fixed order and all orders across a wide range of observables. We also introduce a generalisation of the Cambridge-Aachen jet algorithm and formulate new DIS observables that exhibit a simple resummation structure. The NLL showers are compared to a standard transverse-momentum ordered dipole shower, serving as a proxy for the current state-of-the-art leading-logarithmic showers available in public codes. Depending on the observable, we find discrepancies at NLL of the order of $15\%$. We also present some exploratory phenomenological results for Higgs production in VBF. This work enables, for the first time, to resum simultaneously global and non-global observables for the VBF process at NLL accuracy.

    hep-phJHEP(2024)·49 citations
20. 20*

    Precision prediction of a democratic up-family philic KSVZ axion model at the LHC

    Anupam Ghosh🇮🇳 · Partha Konar🇮🇳

    In this work, we study the $SU(2{)}_L$ singlet complex scalar extended KSVZ model that, in addition to providing a natural solution to the strong-CP problem, furnishes two components of dark matter that satisfy observer relic density without fine-tuning the model's parameters. A colored vector-like quark (VLQ) is naturally present in the KSVZ axion model, providing a rich dark matter and collider phenomenology. In this extended model, scalar dark matter interacts with the Standard Model up-type quarks (up, charm, top) through VLQ. We explore the possibility of democratic Yukawa interaction of the VLQ with all up-type quarks and scalar dark matter candidate. We also employ next-to-leading order NLO-QCD correction on dominant production channels for VLQ pair production to study a unique search at the LHC, generating a pair of boosted tops with sizeable missing transverse momentum. Such corrections are significant and reduce factorization and renormalization scale uncertainties substantially. The NLO fixed order results are matched with the Pythia8 parton shower. After being pair-produced, each VLQ decays into a dark matter and a top quark. We conducted a multivariate analysis using jet substructure variables of boosted top fatjets with a significant missing transverse momentum signal. This analysis allows us to explore a substantial parameter space of this model at the 14 TeV LHC.

    hep-phPhys.Dark Univ.(2025)·25 citations
21. 21*

    NeatIBP 1.0, A package generating small-size integration-by-parts relations for Feynman integrals

    Zihao Wu🇨🇳 · Janko Boehm🇩🇪 · Rourou Ma🇨🇳 · Hefeng Xu🇨🇳 · Yang Zhang🇨🇳

    In this work, we present the package {\sc NeatIBP}, which automatically generates small-size integration-by-parts (IBP) identities for Feynman integrals. Based on the syzygy and module intersection techniques, the generated IBP identities' propagator degree is controlled and thus the size of the system of IBP identities is shorter than that generated by the standard Laporta algorithm. This package is powered by the computer algebra systems {\sc Mathematica} and {\sc Singular}, and the library {\sc SpaSM}. It is parallelized on the level of Feynman integral sectors. The generated small-size IBP identities can subsequently be used for either finite field reduction or analytic reduction. We demonstrate the capabilities of this package on several multi-loop IBP examples.

    hep-phhep-thComput.Phys.Commun.(2024)·122 citations
22. 22*

    The QED of Bernabéu-Tarrach sumrule for electric polarizability and its implication for the Lamb shift

    Volodymyr Biloshytskyi🇩🇪 · Iulian Ciobotaru-Hriscu🇩🇪 · Franziska Hagelstein🇩🇪 · Vadim Lensky🇩🇪 · Vladimir Pascalutsa🇩🇪

    We attempt to rehabilitate a sum rule (proposed long ago by Bernabéu and Tarrach) which relates the electric polarizability of a particle to the total photoabsorption of quasi-real longitudinally polarized photons by that particle. We discuss its perturbative verification in QED, which is largely responsible for the scepticism about its validity. The failure of the QED test can be understood via the Sugawara-Kanazawa theorem and is due to the non-vanishing contour contribution in the pertinent dispersion relation. We show another example where this contribution is absent and the perturbative test works exactly. On the empirical side, we show that the sum rule gives a reasonable estimate of the $\pi N$-channel contribution to the proton electric polarizability. If this sum rule is valid indeed, there should be a sum rule for the so-called ``subtraction function'' entering the data-driven calculations of the polarizability effects in the Lamb shift. We have written down a possible sum rule for the subtraction function and verified it in a perturbative calculation.

    hep-phnucl-thphysics.atom-phPRD(2024)·4 citations
23. 23*

    Leading directions in the SMEFT

    Admir Greljo🇨🇭 · Ajdin Palavrić🇨🇭

    Short-distance new physics at (or slightly) above the TeV scale should not excessively violate the approximate flavor symmetries of the SM in order to comply with stringent constraints from flavor-changing neutral currents. In this respect, flavor symmetries provide an effective organizing principle for the vast parameter space of the SMEFT. In this work, we classify all possible irreducible representations under $U(3{)}^5$ flavor symmetry of new heavy spin-0, 1/2, and 1 fields which integrate out to dimension-6 operators at the tree level. For a general perturbative UV model, the resulting flavor-symmetric interactions are very restrictive and, in most cases, predict a single Hermitian operator with a definite sign. These leading directions in the SMEFT space deserve particular attention. We derive an extensive set of present experimental constraints by utilizing the existing global SMEFT fits, which incorporate data from top quark, Higgs boson, and electroweak measurements, along with constraints on dilepton and 4-lepton contact interactions. The derived set of bounds comprehensively summarises the present knowledge from indirect searches of flavor-blind new physics mediators.

    hep-phhep-exJHEP(2023)·41 citations
24. 24*

    Modular invariance and the QCD angle

    Ferruccio Feruglio🇮🇹 · Alessandro Strumia🇮🇹 · Arsenii Titov🇮🇹

    String compactifications on an orbi-folded torus with complex structure give rise to chiral fermions, spontaneously broken CP, modular invariance. We show that this allows simple effective theories of flavour and CP where: i) the QCD angle vanishes; ii) the CKM phase is large; iii) quark and lepton masses and mixings can be reproduced up to order one coefficients. We implement such general paradigm in supersymmetry or supergravity, with modular forms or functions, with or without heavy colored states.

    hep-phhep-thJHEP(2023)·62 citations
25. 25*

    Black Holes in Massive Dynamical Chern-Simons gravity: scalar hair and quasibound states at decoupling

    Chloe Richards🇺🇸 · Alexandru Dima🇺🇸 · Helvi Witek🇺🇸

    Black holes have a unique sensitivity to the presence of ultralight matter fields or modifications of the underlying theory of gravity. In the present paper we combine both features by studying an ultralight, dynamical scalar field that is nonminimally coupled to the gravitational Chern-Simons term. In particular, we numerically simulate the evolution of such a scalar field around a rotating black hole in the decoupling approximation and find a new kind of massive scalar hair anchored around the black hole. In the proximity of the black hole, the scalar exhibits the typical dipolar structure of hairy solutions in (massless) dynamical Chern-Simons gravity. At larger distances, the field transitions to an oscillating scalar cloud that is induced by the mass term. Finally, we complement the time-domain results with a spectral analysis of the scalar field characteristic frequencies.

    ↳ gr-qchep-phPRD(2023)·16 citations
26. 26*

    Two-body problem in theories with kinetic screening

    Mateja Bošković🇮🇹 · Enrico Barausse🇮🇹

    New light scalar degrees of freedom may alleviate the dark matter and dark energy problems, but if coupled to matter, they generally mediate a fifth force. In order for this fifth force to be consistent with existing constraints, it must be suppressed close to matter sources, e.g. through a non-linear screening mechanism. In this work, we investigate the non-relativistic two-body problem in shift-symmetric scalar-tensor theories that exhibit kinetic screening ($k$-mouflage), both numerically and analytically. We develop an approximate scheme, based on a Hodge-Helmholtz decomposition of the Noether current associated to the shift symmetry, allowing for a qualitative insight into the dynamics and yielding results in good agreement with the numerical ones in most of the parameter space. We apply the formalism to polynomial $k$-essence and to Dirac-Born-Infeld (DBI) type theories, as well as to theories that develop ``anti-screening''. In the deep nonlinear regime, we find that the fifth force is screened slightly more efficiently in equal-mass systems than in extreme mass-ratio ones. However, we find that systems with comparable masses also exhibit regions where the screening is ineffective. These descreened spheroidal regions (bubbles) could in principle be probed in the solar system with sufficiently precise space accelerometers.

    ↳ gr-qcastro-ph.COhep-phPRD(2023)·8 citations
27. 27*

    How to strengthen constraints on non-Newtonian gravity from measuring the lateral Casimir force

    G. L. Klimchitskaya🇷🇺 · V. M. Mostepanenko🇷🇺

    It has been known that in the nanometer interaction range the available experimental data do not exclude the Yukawa-type corrections to Newton's gravitational law which exceed the Newtonian gravitational force by many orders of magnitude. The strongest constraints on the parameters of Yukawa-type interaction in this interaction range follow from the experiments on neutron scattering and from measurements of the lateral and normal Casimir forces between corrugated surfaces. In this work, we demonstrate that by optimizing the experimental configuration at the expense of the higher corrugation amplitudes and smaller periods of corrugations it is possible to considerably strengthen the currently available constraints within the wide interaction range from 4.5 to 37nm. We show that the maximum strengthening by more than a factor of 40 is reachable for the interaction range of 19nm.

    ↳ quant-phhep-phUniverse·5 citations
28. 28*

    The Weak Gravity Conjecture, Overcharged Shells and Gravitational Traps

    Alex Kehagias🇬🇷 · Kostas D.Kokkotas🇩🇪 · Antonio Riotto🇨🇭 · John Taskas🇬🇷 · George Tringas🇫🇷

    The Weak Gravity Conjecture predicts that in quantum gravity there should exist overcharged states, that is states with charge larger than their mass. Extending this to large masses and charges, we are expecting similar overcharged classical solutions. This has been demonstrated in higher-derivative extensions of General Relativity. In this paper we investigate the existence of overcharged solutions in General Relativity. We study the dynamics of a thin shell of mass $m$ and charge $Q$ under the action of its own gravitational and $U(1)$ fields. We show that shells with surface energy $\sigma$ and pressure $P$ obeying $P=w\sigma$ with $0\le w\le 1$ are necessarily undercharged $m\ge |Q|$ and always collapse to form Reissner-Nordström black holes. Nevertheless, if $-1\le w<0$, we find that overcharged $m\le |Q|$ shells exist, which however, are inevitably stabilized at finite radial distance.

    ↳ hep-thgr-qchep-phClass.Quant.Grav.(2024)·3 citations
29. 29*

    Is Cosmic Birefringence model-dependent?

    Lu Yin🇰🇷 · Joby Kochappan🇰🇷 · Tuhin Ghosh🇰🇷 · Bum-Hoon Lee🇰🇷

    Exciting clues to isotropic cosmic birefringence have recently been detected in the $EB$ cross-power spectra of the polarization data of the cosmic microwave background (CMB). Early Dark Energy (EDE) models with a pseudoscalar field coupled to photons via a Chern-Simons term can be used to explain this phenomenon, and can also potentially be used to simultaneously resolve the $H_0$ tension. In this work we incorporate an early dark energy scalar field, including a Chern-Simons coupling, into an existing Boltzmann solver and numerically recover the $EB$ cross-power spectrum for two models in the literature; the $\alpha$-attractor, and the Rock `n' Roll field. We find that both the models fit the $EB$ spectra, and the $EB$ spectra alone do not possess sufficient constraining power to distinguish the two models based on current data.

    ↳ astro-ph.COhep-phJCAP(2023)·29 citations
30. 30*

    Decay of Nambu-Goto Cosmic String Loops via Coupling to a Massive Kalb-Ramond Field

    I. Yu. Rybak🇵🇹

    We study the dynamics of Nambu-Goto cosmic string loops coupled to a massive Kalb-Ramond field. This coupling provides a framework for describing the interaction between the cosmic string and the gauge field. Within this setup, we compute the energy flux associated with the radiation of massive Kalb-Ramond modes from oscillating string loops. For loops featuring kinks, we find that the decay time scales with the square of the loop length. In contrast, loops with cusps exhibit a decay time proportional to 3/2 times the loop length. The results are in good agreement with field-theoretic simulations of Nambu-Goto-like loops in the Abelian-Higgs model, supporting the validity of the calculation.

    ↳ hep-thastro-ph.COhep-phEPJC(2025)·1 citation
31. 31*

    Effect of extinction on quasar luminosity distances determined from UV and X-ray flux measurements

    Michal Zajaček🇨🇿 · Bożena Czerny🇵🇱 · Narayan Khadka🇺🇸 · Mary Loli Martínez-Aldama🇨🇱 · Raj Prince🇵🇱 · Swayamtrupta Panda🇧🇷 · Bharat Ratra🇺🇸

    In Khadka et al. (2023), a sample of X-ray-detected reverberation-mapped quasars was presented and applied for the comparison of cosmological constraints inferred using two well-established relations in AGN -- the X-ray/UV luminosity ($L_X-L_{UV}$) relation and the broad-line region radius-luminosity ($R-L$) relation. $L_X-L_{UV}$ and $R-L$ luminosity distances to the same quasars exhibit a distribution of their differences that is generally asymmetric and positively shifted for the six cosmological models we consider. We demonstrate that this behaviour can be interpreted qualitatively to arise as a result of the dust extinction of UV/X-ray quasar emission. We show that the extinction always contributes to the non-zero difference between $L_X-L_{UV}$-based and $R-L$-based luminosity distances and we derive a linear relationship between the X-ray/UV colour index $E_{X-UV}$ and the luminosity-distance difference, which also depends on the value of the $L_X-L_{UV}$ relation slope. Taking into account the median and the peak values of the luminosity-distance difference distributions, the average X-ray/UV colour index falls in the range of ${\overline{E}}_{X-UV}=0.03-0.28$ mag for the current sample of 58 sources. This amount of extinction is typical for the majority of quasars and it can be attributed to the circumnuclear and interstellar media of host galaxies. After applying the standard hard X-ray and far-UV extinction cuts, heavily extincted sources are removed but overall the shift towards positive values persists. The effect of extinction on luminosity distances is more pronounced for the $L_X-L_{UV}$ relation since the extinction of UV and X-ray emissions both contribute.

    ↳ astro-ph.GAastro-ph.COgr-qchep-ph+1ApJ(2024)·28 citations
32. 32*

    Neural Network predictions of inclusive electron-nucleus cross sections

    O. Al Hammal🇫🇷 · M. Martini🇫🇷 · J. Frontera-Pons🇫🇷 · T. H. Nguyen🇻🇳 · R. Perez-Ramos🇫🇷

    We investigate whether a neural network approach can reproduce and predict the electron-nucleus cross sections in the kinematical domain of present and future accelerator-based neutrino oscillation experiments. For this purpose, we consider the large amount of data available to the community via the web-page ``Quasielastic Electron Nucleus scattering archive'', and use a residual, fully connected feedforward neural network. We illustrate the training performances of the neural network by comparing its results with experimental data for the electron double-differential cross section on carbon. The agreement between predictions and data is remarkable from quasielastic to deep-inelastic scattering. To test the predicting power of the neural network we consider the numerous kinematical conditions for which experimental cross sections on calcium are available. Furthermore, we show the predictions of the electron scattering cross sections on oxygen, argon, and titanium: nuclei of particular interest in the context of present and future accelerator-based neutrino oscillation program. The agreement between these predictions and the data is comparable to the one of other theoretical models commonly used to calculate electron and neutrino cross sections, such as SuSAv2 and GiBUU. Results obtained with GENIE, a Monte Carlo event generator, are also discussed for comparison. The good performances obtained with our neural network suggest that neural networks could be exploited for theoretical and experimental investigations of electron- and neutrino-nucleus scattering.

    ↳ nucl-thhep-exhep-phnucl-exPRC(2023)·8 citations
33. 33*

    Resolving phase transition properties of dense matter through tidal-excited g-mode from inspiralling neutron stars

    Zhiqiang Miao🇨🇳 · Enping Zhou🇨🇳 · Ang Li🇨🇳

    The investigation of the phase state of dense matter is hindered by complications of first-principle nonperturbative quantum chromodynamics. By performing the first consistent general-relativistic calculations of tidal-excited g-mode of neutron stars with a first-order strong interaction phase transition in the high-density core, we demonstrate that gravitational wave signal during binary neutron star inspiral probes their innermost hadron-quark transition and provides potent constraints from present and future gravitational-wave detectors.

    ↳ nucl-thastro-ph.HEgr-qchep-phApJ(2024)·24 citations
34. 34*

    Dark sectors and {\tau} physics at Belle II

    Laura Zani (on behalf of the Belle II collaboration)🇮🇹

    The possibility of a dark sector weakly coupling to Standard Model (SM) particles through new light mediators is explored at the Belle II experiment. We present here results from three different searches, for a long-lived (pseudo)scalar particle in rare $B$ decays; for a di-tau resonance in four-muon final states, and the update on the search for a \zprime\ boson decaying invisibly. We also look for lepton flavor violation by searching for $\tau \to \ell \alpha$ decays, with $\alpha$ a new invisible boson, and we report the first untagged reconstruction of $\tau$ pairs events searching for the neutrinoless decays $\tau \to \ell \varphi$. Finally, we present the world's most precise measurement of the $\tau$ lepton mass. These studies are performed on samples from the data collected by the Belle II detector during 2019-2021 data taking.

    ↳ hep-exhep-ph0 citations
35. 35*

    Weak equivalence principle violation for mixed scalar particles

    Massimo Blasone🇮🇹 · Petr Jizba🇨🇿 · Gaetano Lambiase🇮🇹 · Luciano Petruzziello🇮🇹

    We investigate the non-relativistic limit of the Klein--Gordon equation for mixed scalar particles and show that, in this regime, one unavoidably arrives at redefining the particle's inertial mass. This happens because, in contrast to the case when mixing is absent, the antiparticle sector contribution cannot be neglected for particles with definite flavor. To clearly demonstrate this feature, we adopt the Feshbach--Villars formalism for Klein--Gordon particles. Furthermore, within the same framework, we also demonstrate that, in the presence of a weak gravitational field, the mass parameter that couples to gravity (gravitational mass) does not match the effective inertial mass. This, in turn, implies a violation of the weak equivalence principle. Finally, we prove that the Bargmann's superselection rule, which prohibits oscillating particles on the basis of the Galilean transformation, is incompatible with the non-relativistic limit of the Lorentz transformation and hence does not collide with the results obtained.

    ↳ hep-thhep-phEPJC(2023)·3 citations
36. 36*

    Baryon inhomogeneities driven charge dependent directed flow in heavy ion collisions

    Tribhuban Parida🇮🇳 · Sandeep Chatterjee🇮🇳

    Electromagnetic field in heavy ion collisions are expected to cause charge dependent directed flow splitting ($\Delta v_1$). Such charge dependent $\Delta v_1$ has been observed by the STAR collaboration. We demonstrate that relativistic dissipative fluid dynamic simulations with baryon diffusion that include realistic model of baryon stopping in the initial condition and no contribution from electromagnetic field describe the measured $\Delta v_1$ for observables involving baryons and anti-baryons. This suggests strong background contribution from baryon current as a response to initial state baryon inhomogeneities to such charge dependent $\Delta v_1$ involving baryons and anti-baryons. Our current model calculations that only account for the evolution of the baryon charge and not electric charge and strangeness miss the observed $\Delta v_1$ of mesons leaving their interpretation open.

    ↳ nucl-thhep-phnucl-ex13 citations
37. 37*

    Halos of dark energy

    P. P. Avelino🇵🇹

    We investigate the properties of dark energy halos in models with a nonminimal coupling in the dark sector. We show, using a quasistatic approximation, that a coupling of the mass of dark matter particles to a standard quintessence scalar field $\varphi$ generally leads to the formation of dark energy concentrations in and around compact dark matter objects. These are associated with regions where scalar field gradients are large and the dark energy equation of state parameter is close to $-1/3$. We find that the energy and radius of a dark energy halo are approximately given by $E_{\mathrm{halo}}\sim {\mathbf{\beta }}^2\phi m$ and $r_{\mathrm{halo}}\sim \sqrt{\mathbf{\beta }\phi (R/H)}$, where $\phi =Gm/(R{c}^2)$, $m$ and $R$ are, respectively, the mass and radius of the associated dark matter object, $\mathbf{\beta }=-(8\pi G{)}^{-1/2}d\ln m/d\varphi$ is the nonminimal coupling strength parameter, $H$ is the Hubble parameter, $G$ is the gravitational constant, and $c$ is the speed of light in vacuum. We further show that current observational limits on $\mathbf{\beta }$ over a wide redshift range lead to stringent constraints on $E_{\mathrm{halo}}/m$ and, therefore, on the impact of dark energy halos on the value of the dark energy equation of state parameter. We also briefly comment on potential backreaction effects that may be associated with the breakdown of the quasistatic approximation and determine the regions of parameter space where such a breakdown might be expected to occur.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2023)·0 citations
38. 38*

    Cold New Early Dark Energy pulls the trigger on the $H_0$ and $S_8$ tensions: a simultaneous solution to both tensions without new ingredients

    Juan S. Cruz🇩🇰 · Florian Niedermann🇸🇪 · Martin S. Sloth🇩🇰

    In this work, we show that the Cold New Early Dark Energy (Cold NEDE) model in its original form can solve both the Hubble tension and the $S_8$ tension without adding any new ingredients at the fundamental level. So far, it was assumed that the trigger field in the Cold NEDE model is completely subdominant. However, relaxing this assumption and letting the trigger field contribute a mere $0.5\%$ of the total energy density leads to a resolution of the $S_8$ tension while simultaneously improving it as a solution to the $H_0$ tension. Fitting this model to baryonic acoustic oscillations, large-scale-structure, supernovae (including a SH0ES prior), and cosmic microwave background data, we report a preferred NEDE fraction of $f_{\mathrm{NEDE}}=0.134_{-0.025}^{+0.032}$ ($68\%$ C.L.), lifting its Gaussian evidence for the first time above $5\sigma$ (up from $4\sigma$ when the trigger contribution to dark matter is negligible). At the same time, we find the new concordance values $H_0=71.71\pm 0.88\mathrm{km}{\sec }^{-1}{\mathrm{Mpc}}^{-1}$ and $S_8=0.793\pm 0.018$. Excluding large-scale structure data and the SH${}_0$ES prior, both Gaussian tensions are reduced below the $2\sigma$ level.

    ↳ astro-ph.COhep-phhep-thJCAP(2023)·56 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.