Tue·Jul 30, 2024Tuesday·July 30, 2024

1. 01*

   Theoretical underpinnings of CP-Violation at the High-energy Frontier

   Shaouly Bar-Shalom🇮🇱 · Amarjit Soni🇺🇸 · Jose Wudka🇺🇸

   We present a general analysis for the discovery potential of CP-violation (CPV) searches in scattering processes at TeV-scale colliders in an effective field theory framework, using the SMEFT basis for higher dimensional operators. In particular, we systematically examine the CP-violating sector of the SMEFT framework in some well motivated limiting cases, based on flavour symmetries of the underlying heavy theory. We show that, under naturality arguments of the underlying new physics (NP) and in the absence of (or suppressed) flavour-changing interactions, there is only a single operator, $Q_{t\varphi }={\varphi }^{†}\varphi \left({\bar{q}}_{3}t\right)\tilde{\varphi }$ which alters the top-Yukawa coupling, that can generate a non-vanishing CP-violating effect from tree-level SM$\times$NP interference terms. We find, however, that CPV from $Q_{t\varphi }={\varphi }^{†}\varphi \left({\bar{q}}_{3}t\right)\tilde{\varphi }$ is expected to be at best of $O(1\%)$ and, therefore, very challenging if at all measurable at the LHC or other future high-energy colliders. We then conclude that a potentially measurable CP-violating effect of $O(10\%)$ can arise in high-energy scattering processes ONLY if flavour-changing interactions are present in the underlying NP; in this case a sizable CPV can be generated at the tree-level by pure NP$\times$NP effects and not from SM$\times$NP interference. We provide several examples of CPV at the LHC and at a future $e^{+}{e}^{-}$ collider to support these statements.

   hep-phhep-exhep-thPLB(2025)·4 citations
2. 02*

   Axion signals from neutron star populations

   U. Bhura🇬🇧 · R. A. Battye🇬🇧 · J. I. McDonald🇬🇧 · S. Srinivasan🇩🇪

   Neutron stars provide a powerful probe of axion dark matter, especially in higher frequency ranges where there remain fewer laboratory constraints. Populations of neutron stars near the Galactic Centre have been proposed as a means to place strong constraints on axion dark matter. One downside of this approach is that there are very few direct observations of neutron stars in this region, introducing uncertainties in the total number of neutron stars in this ``invisible" population at the Galactic Centre, whose size must be inferred through birth rate modelling. We suggest this number could also be reduced due to stellar dynamics carrying stars away from the Galactic Centre via large kick velocities at birth. We attempt to circumvent the uncertainty on the Galactic Centre population size by modelling the axion signal from better understood populations outside the Galactic Centre using {\tt PsrPopPy} which is normalised against pulsar observations. We consider lower-frequency, wider-angle searches for this signal via a range of instruments including MeerKAT and SKA-low but find that the sensitivity is not competitive with existing constraints. Finally, returning to the Galactic Centre, we compare populations to single objects as targets for axion detection. Using the latest modelling of axion-photon conversion in the Galactic Centre magnetar, we conclude that within astrophysical uncertainties, the Galactic Centre population and the magnetar could give comparable sensitivities to axion dark matter, suggesting one should continue to search for both signals in future surveys.

   hep-phastro-ph.COastro-ph.HEJCAP(2024)·8 citations
3. 03*

   Lepton flavor violation in exclusive $b\to d{\ell }_i{\ell }_j$ and $b\to s{\ell }_i{\ell }_j$ decay modes

   Damir Bečirević🇫🇷 · Florentin Jaffredo🇫🇷 · João Paulo Pinheiro🇪🇸 · Olcyr Sumensari🇫🇷

   We discuss the exclusive lepton flavor violating (LFV) decays modes based on $b\to d{\ell }_i{\ell }_j$ and $b\to s{\ell }_i{\ell }_j$ by considering the ground state mesons and baryons. After spelling out the expressions for such decay rates in a low energy effective theory which includes generic contributions arising from physics beyond the Standard Model (BSM), we show that the experimental bounds on meson decays can be used to bound the corresponding modes involving baryons. We find, for example, $\mathcal{B}({\Lambda }_b\to \Lambda \mu \tau )\lesssim 4\times 10^{-5}$. We also consider two specific models and constrain the relevant LFV couplings by using the low energy observables. In the first model we assume the Higgs mediated LFV and find the resulting decay rates to be too small to be experimentally detectable. We also emphasize that the regions favored by the bounds $\mathcal{B}(h\to \mu \tau {)}^{\mathrm{Atlas}}$ and $\mathcal{B}(h\to e\tau {)}^{\mathrm{Atlas}}$ are not compatible with $\mathcal{B}(\mu \to e\gamma {)}^{\mathrm{MEG}}$ to $1\sigma$. In the second model we assume LFV mediated by a heavy $Z^{\prime }$ boson and find that the corresponding $b$-hadron branching fractions can be $\mathcal{O}(10^{-6})$, thus possibly within experimental reach at LHCb and Belle~II.

   hep-phPRD(2024)·18 citations
4. 04*

   Test of Bell Locality Violation in Flavor Entangled Neutral Meson Pair

   Kaiwen Chen🇨🇳 · Zhi-Peng Xing🇨🇳 · Ruilin Zhu🇨🇳

   The quasi-spin entanglement of neutral mesons to test the Bell nonlocality is systematically studied. In the case of CP violation, the concrete expression of the Bell inequality for entangled neutral meson pairs is derived. The violation of Bell inequality in the oscillations of $B_d^0-{\bar{B}}_d^0$, $B_s^0-{\bar{B}}_s^0$, $D^0-{\bar{D}}^0$ and $K^0-{\bar{K}}^0$ meson pair systems are found at certain evolution time including the latest experimental data. Our study is helpful for studying CP-violating involved flavor entanglement and testing Bell inequality violation in the current and future high energy experiment facilities.

   hep-phNPA(2025)·8 citations
5. 05*

   Cold nuclear matter effects on azimuthal decorrelation in heavy-ion collisions

   Néstor Armesto🇪🇸 · Florian Cougoulic🇪🇸 · Bin Wu🇪🇸

   The assumption of factorization lies at the core of calculations of medium effects on observables computable in perturbative Quantum Chromodynamics. In this work we examine this assumption, for which we propose a setup to study hard processes and bulk nuclear matter in heavy-ion collisions on the same footing using the Glauber modelling of heavy nuclei. To exemplify this approach, we calculate the leading-order corrections to azimuthal decorrelation in Drell-Yan and boson-jet processes due to cold nuclear matter effects, not considering radiation. At leading order in both the hard momentum scale and the nuclear size, the impact-parameter dependent cross section is found to factorize for both processes. The factorization formula involves a convolution of the hard cross section with the medium-modified parton distributions, and, for boson-jet production, the medium-modified jet function.

   hep-phnucl-thJHEP(2024)·2 citations
6. 06*

   Experiments and phenomenology of electric dipole moments

   Joan Ruiz-Vidal🇪🇸

   The Standard Model (SM) is the best description of fundamental particles and their interactions we have to date. From this theory, all phenomena in the macroscopic world (except for gravity) can be explained, and it has successfully predicted all outcomes of particle experiments on Earth. However, cosmological observations of the early Universe yield a large imbalance between its content of matter and antimatter, which is several orders of magnitude above the SM prediction. To explain these observations, new interactions that do not respect the charge-parity symmetry must exist beyond the SM. Such interactions would induce electric dipole moments (EDMs) in known particles. In Part I of this thesis, we propose to extend the active experimental program of EDM searches to charm and bottom baryons, $\tau$ leptons, and $\Lambda$ hyperons; also allowing the measurement of their corresponding magnetic dipole moments (MDMs). The EDM and MDM of short-lived particles can be accessed with a bent-crystal experiment to be installed in the Large Hadron Collider (LHC), while longer-lived $\Lambda$ particles can be measured at the LHCb experiment with no additional instrumentation. In Part II, an analysis of LHCb data to measure the $\Lambda$ polarization in ${\Lambda }_c^{+}\to \Lambda {\pi }^{+}{\pi }^{+}{\pi }^{-}$ decays, essential ingredient for the proposed measurement, is presented. In the last part of the thesis, we derive new indirect bounds on heavy quark EDMs with already available data and explore the phenomenological implications of these and other EDM limits on New Physics models, with special emphasis on extensions of the SM with colour-octet scalars.

   hep-phhep-ex1 citation
7. 07*

   Determination of the multipole moments of the $J^P=3^{-}$ mesons via QCD sum rules

   T.M.Aliev🇹🇷 · S.Bilmis🇹🇷 · M.Savci🇹🇷

   The multipole moments of the $J^P=3^{-}$ tensor mesons are obtained using light-cone sum rules. Our results are compared with the predictions of the light-cone helicity formalism within the framework of SU(3) flavor symmetry. We observe a good agreement between the two approaches. The obtained multipole moments of tensor mesons provide deeper insights into their properties and better understanding of the strong and electromagnetic decay channels of these mesons.

   hep-phPRD(2024)·0 citations
8. 08*

   Hunting for the prospective $T_{cc}$ family based on the diquark-antidiquark configuration

   Wen-Chao Dong🇨🇳 · Zhi-Gang Wang🇨🇳

   Inspired by the first $T_{cc}$ observation at the LHCb Collaboration, the spectroscopic properties of the entire isoscalar and isovector $T_{cc}$ family are systematically investigated by means of multiple sorts of relativized and nonrelativistic diquark formalisms, which include the Godfrey-Isgur relativized diquark model, the modified Godfrey-Isgur relativized diquark model incorporating the color screening effects, the nonrelativistic diquark model with the Gaussian type hyperfine potential, and the nonrelativistic diquark model with the Yukawa type hyperfine potential. In terms of the $1S$-wave double-charm tetraquark state with $I(J^P)=0(1^{+})$, the predicted masses of most diquark-antidiquark scenarios are somewhat higher than the observed value of the $T_{cc}(3875{)}^{+}$ structure. In light of the diquark-antidiquark configuration, this work unveils the mixing angles of the orbitally excited isovector $T_{cc}$ states and the magic mixing angles of the ideal heavy-light tetraquarks for the first time. As the advancement of the experimental detection capability, these phenomenological predictions will effectively boost the hunting for the prospective low-lying $T_{cc}$ states in the future.

   hep-phNPB(2025)·9 citations
9. 09*

   Studies of $Z$ boson decay into double ${\rm Y}$ mesons at the NLO QCD accuracy

   Cong Li🇨🇳 · Ying-Zhao Jiang🇨🇳 · Zhan Sun🇨🇳

   In this paper, we employ the nonrelativistic QCD factorization to conduct a comprehensive examination of the $Z$ boson decay into a pair of ${\rm Y}$ mesons, achieving accuracy at the next-to-leading-order (NLO) in ${\alpha }_s$. Our calculations demonstrate that the QED diagrams are indispensable in comparison to the pure QCD diagrams, and the implementation of QCD corrections markedly enhance the QCD results, whereas it substantially diminish the QED results. To ensure consistency with the experimental methodology, we have taken into account the feed-down transitions originating from higher excited states, which exhibit significant relevance. Combining all the contributions, we arrive at the NLO prediction of ${\mathcal{B}}_{Z\to {\rm Y}(nS)+{\rm Y}(mS)}\sim 10^{-11}$, which is notably lower than the upper limits set by CMS.

   hep-phPRD(2024)·2 citations
10. 10*

    The electromagnetic form factors and spin polarization of ${\Lambda }_c^{+}$ in the process $e^{+}{e}^{-}\to {\Lambda }_c^{+}{\bar{\Lambda }}_c^{-}$

    Cheng Chen🇨🇳 · Bing Yan🇨🇳 · Ju-Jun Xie🇨🇳

    The total cross sections of the process $e^{+}{e}^{-}\to {\Lambda }_c^{+}{\bar{\Lambda }}_c^{-}$ close to the threshold are calculated within the vector meson dominance model. It is found that the theoretical results can describe the current experimental measurements. In particular, the results for the angular distribution parameters about the differential cross section are consistent with the experiments from BESIII Collaboration. In addition, the relative phase $\Delta \Phi$ of the electromagnetic form factors was given, and the spin polarization of ${\Lambda }_c^{+}$ is predicted at center-mass energy $4.7\mathrm{GeV}$. It is hopeful to provide a new perspective on the characteristics of the charmed baryon ${\Lambda }_c^{+}$.

    hep-phCPC(2025)·9 citations
11. 11*

    Hidden and double charm-strange tetraquarks and their decays in a potential quark model

    Feng-Xiao Liu🇨🇳 · Ru-Hui Ni🇨🇳 · Xian-Hui Zhong🇨🇳 · Qiang Zhao🇨🇳

    We carry out a systematic study of the $1S$-wave hidden and double charm-strange tetraquarks $cs\bar{c}\bar{s}$ and $cc\bar{s}\bar{s}$ in a nonrelativistic potential quark model framework with the explicitly correlated Gaussian method, and the mass spectra, color-spin configurations and possible decay modes are obtained. We find that although these states are all above their open flavor thresholds, their rearrangement decay widths are rather narrow which can be understood by the mismatching of the wave functions between the initial and final states. It implies that the tetraquarks of $cs\bar{c}\bar{s}$ and $cc\bar{s}\bar{s}$ may have a good chance to exist as genuine tetraquark states. It also shows that the color-spin configurations of the $cs\bar{c}\bar{s}$ and $cc\bar{s}\bar{s}$ systems are quite different. We find that for a physical state of $cs\bar{c}\bar{s}$ its color configurations can be dominated by either the $|11{⟩}_c$ or $|88{⟩}_c$ ones. It suggests that some hidden charm-strange tetraquark states may strongly couple to two color-singlet hadrons if the kinematics and dynamics allow. In contrast, we find that the color configurations $|11{⟩}_c$ and $|88{⟩}_c$ in a double charm-strange $cc\bar{s}\bar{s}$ state are rather compatible. It may suggest that an overall color-singlet tetraquark (i.e. a genuine color-singlet) should always play a role in the $T_{cc\bar{s}\bar{s}}$ states. Discussions taking into account some experimental candidates are presented, and suggestions on further experimental searches are also made.

    hep-phEPJC(2025)·10 citations
12. 12*

    Disentangling left-handed and right-handed neutrino effects in $B_c\to \tau {\bar{\nu }}_{\tau }$ decay

    Quan-Yi Hu🇨🇳

    Inspired by the anomalies in $B\to D^{(\ast )}\tau {\bar{\nu }}_{\tau }$ decay, in this work, we carefully study the influence of the most general dimension-six effective operators involving right-handed neutrinos on the four cascade decays $B_c\to \tau (\to {\nu }_{\tau }h){\bar{\nu }}_{\tau }$ ($h=\pi ,\rho$) and $B_c\to \tau (\to {\nu }_{\tau }\ell {\bar{\nu }}_{\ell }){\bar{\nu }}_{\tau }$ ($\ell =\mu ,e$). We calculate for the first time the analytical results of the distributions of the differential decay rates of these cascade decays with respect to the energy of the charged particles in the final state. We select a total of 13 new physics benchmark points, among which 9 are derived from the effect of purely left-handed neutrinos, and the other 4 are from the effect of purely right-handed neutrinos. We find that the benchmark points BP4, BP6, BP11, and BP13 can significantly increase the values of these distributions while the BP3 causes a sharp decrease in these distributions. The end-point behavior of the differential distribution $d\Gamma /d{E}_{\pi }$ can be used to disentangle the effects of left-handed and right-handed neutrinos. Finally, in order to eliminate the uncertainties brought by the CKM matrix element $V_{cb}$ and the decay constant $f_{B_c}$, we introduce the normalized distributions $d\Gamma /(\Gamma d{E}_a)$ ($a=\pi ,\rho ,\mu ,e$), which are only sensitive to the right-handed neutrinos. We find that in each normalized distribution there exists a fixed point that is not related to any dimension-six effective operators considered in this work.

    hep-phJHEP(2024)·1 citation
13. 13*

    Revisiting gauge invariance and Reggeization of pion exchange

    Gloria Montana🇺🇸 · Daniel Winney🇩🇪 · Lukasz Bibrzycki🇵🇱 · Cesar Fernandez-Ramirez🇪🇸 · Giorgio Foti🇮🇹 · Nadine Hammoud🇪🇸 · Vincent Mathieu🇪🇸 · Robert J. Perry🇪🇸 · Alessandro Pilloni🇮🇹 · Arkaitz Rodas🇺🇸 · Vanamali Shastry🇺🇸 · Wyatt A. Smith🇺🇸 · Adam P. Szczepaniak🇺🇸

    The Reggeized pion is expected to provide the main contribution to the forward cross section in light meson photoproduction reactions with charge exchange at high energies. We discuss the Reggeization of pion exchange in charged pion photoproduction with an emphasis on consistency with current conservation. We show that the gauge-invariant amplitude for the exchange of a particle with generic even spin $J\ge 2$ in the $t$-channel is analytic at $J=0$, and that it can be interpreted in terms of the nucleon electric current. This enables us to reconcile the dynamics in the $s$- and $u$-channel, which involves also nucleon exchanges, with the amplitude expressed in terms of $t$-channel partial waves, as required by Regge theory.

    hep-phnucl-thPRD(2024)·9 citations
14. 14*

    Common Origin of Dark Matter and Leptogenesis in $U(1{)}_{B-L}$

    Ang Liu🇨🇳 · Feng-Lan Shao🇨🇳 · Zhi-Long Han🇨🇳 · Yi Jin🇨🇳 · Honglei Li🇨🇳

    In this paper, we investigate the common parameter space of dark matter and leptogenesis in the $U(1{)}_{B-L}$ symmetry. This model involves a complex scalar $\varphi$, sterile neutrinos $N$, and Majorana dark matter $\chi$, where only dark matter $\chi$ is charged under the $Z_2$ symmetry. Masses of $N$ and $\chi$ are generated via the Yukawa interactions to $\varphi$ after breaking of the $U(1{)}_{B-L}$ symmetry. TeV scale sterile neutrinos $N$ are responsible for the generation of baryon asymmetry through the resonance leptogenesis mechanism. The new particles in the $U(1{)}_{B-L}$ have a significant impact on the dilution of $N$, thus on leptogenesis. Meanwhile, the annihilation processes of dark matter $\chi$ are almost identical to that of $N$, which indicates that both leptogenesis and dark matter are closely related to satisfying the observed results simultaneously. Under various theoretical and experimental constraints, the viable common parameter space of dark matter and leptogenesis is obtained for both global and local $U(1{)}_{B-L}$ symmetry.

    hep-phJHEP(2024)·6 citations
15. 15*

    Charged lepton flavour violation from inverse seesaw with flavour and CP symmetries

    F. P. Di Meglio🇪🇸 · C. Hagedorn🇪🇸

    We study charged lepton flavour violation in a scenario in which light neutrino masses are generated via the inverse seesaw mechanism with 3+3 gauge singlet fermions, Ni and Sj, i,j=1,2,3. Lepton mixing is predicted with the help of the flavour symmetries Delta (3 n^2) and Delta (6 n^2) combined with CP. In the neutral lepton sector, the non-trivial flavour structure is only encoded in the Dirac neutrino Yukawa matrix (the coupling relating left-handed lepton doublets and gauge singlets Ni). Current experimental bounds on the processes mu -> e gamma, mu -> 3 e, mu-e conversion in nuclei and the tau lepton decays tau -> l gamma and tau -> 3 l, l=e, mu, do not constrain the considered parameter space of this scenario. Prospective limits on the decay mu -> 3 e and mu-e conversion in aluminium instead can markedly reduce the available parameter space. We also comment on the effects of the heavy sterile states on light neutrino masses and lepton mixing.

    hep-phhep-exNPB(2025)·5 citations
16. 16*

    Search for QCD axion dark matter with transmon qubits and quantum circuit

    Shion Chen🇯🇵 · Hajime Fukuda🇯🇵 · Toshiaki Inada🇯🇵 · Takeo Moroi🇯🇵 · Tatsumi Nitta🇯🇵 · Thanaporn Sichanugrist🇯🇵

    We propose a direct axion dark matter (DM) search using superconducting transmon qubits as quantum sensors. With an external magnetic field applied, axion DM generates an oscillating electric field which causes the excitation of the qubit; such an excitation can be regarded as a signal of the axion DM. We provide a theoretical consideration of the excitation process of the qubits taking into account the effects of the shielding cavity surrounding the qubits and estimate the signal rate for the axion DM detection. We also discuss the enhancement of the DM signal by using cavity resonance and entangled quantum sensors realized by a quantum circuit. Combining these two effects, we can reach the parameter region suggested by QCD axion models.

    hep-phastro-ph.COhep-exquant-phPRD(2024)·29 citations
17. 17*

    Axion halo around a binary system of dwarf stars

    András Patkós🇭🇺

    The gravitational field of a clump of ultralight axion like particles (ALPs) in its core with a rotating binary system of dwarf stars is computed. It is established that the induced quadrupole mass moment of the clump is controlled parametrically by the $M_a/M$ mass ratio of the axion clump and the the binary core.

    hep-phastro-ph.SRUkr.J.Phys.(2024)·0 citations
18. 18*

    Probing Charm Yukawa Coupling through $ch$ Associated Production at the Hadron Colliders

    Nuoyu Dong · Hongsheng Hou · Zhuoni Qian · Bowen Wang · Qingjun Xu

    At present, the study of the charm-quark Yukawa coupling at the Large Hadron Collider mainly focuses on the Higgs decay processes. Such signal suffers from overwhelming QCD background and derives its sensitivity primarily from the $Vh$ associated production channel. In addition, sensitivity to a possible CP phase in charm-quark Yukawa at the hadron collider is not discussed. We investigate the charm-Higgs associated production signal, that contains a potentially detectable interference term between $cch$ Yukawa coupling mediated diagrams and $ggh$ coupling mediated diagram. Such interference term is sensitive to the relative CP phase between contributing diagrams. High dimensional kinematic information are exploited by machine learning techniques to separate the different contribution, and sensitivity on the coupling is derived. Assuming a real ${\kappa }_c$ modification framework, 1$\sigma$ bound of $-5.6<{\kappa }_c<5.6$ (HL-LHC) and $-1.51<{\kappa }_c<1.62$ (FCC) are achieved. When allowing for CP-phase in the charm Yukawa, a combined 1$\sigma$ bound of $0.32<|{\kappa }_c|<1.69$, $-77^{\circ }<\alpha <77^{\circ }$ (HL-LHC) and $0.70<|{\kappa }_c|<1.29$, $-55^{\circ }<\alpha <55^{\circ }$ (FCC) can be achieved on the magnitude and CP phase of the coupling respectively.

    hep-phPRD(2025)·2 citations
19. 19*

    Accelerating template generation in resonant anomaly detection searches with optimal transport

    Matthew Leigh🇨🇭 · Debajyoti Sengupta🇨🇭 · Benjamin Nachman🇺🇸 · Tobias Golling🇨🇭

    We introduce Resonant Anomaly Detection with Optimal Transport (RAD-OT), a method for generating signal templates in resonant anomaly detection searches. RAD-OT leverages the fact that the conditional probability density of the target features vary approximately linearly along the optimal transport path connecting the resonant feature. This does not assume that the conditional density itself is linear with the resonant feature, allowing RAD-OT to efficiently capture multimodal relationships, changes in resolution, etc. By solving the optimal transport problem, RAD-OT can quickly build a template by interpolating between the background distributions in two sideband regions. We demonstrate the performance of RAD-OT using the LHC Olympics R\&D dataset, where we find comparable sensitivity and improved stability with respect to deep learning-based approaches.

    hep-phhep-exJHEP(2025)·9 citations
20. 20*

    Large pseudoscalar Yukawa couplings in the complex 3HDM

    Rafael Boto🇵🇹 · Luis Lourenco🇵🇹 · Jorge C. Romão🇵🇹 · João P. Silva🇵🇹

    As LHC's Run3 unfolds, we peer deeper into the couplings of the 125GeV Higgs ($h_{125}$) and also test for extra scalars. Even before such extra scalars are found, one can probe them by using the fact that theories with multiple Higgs doublets allow for substantial deviations of the couplings of $h_{125}$ from their SM values. Indeed, the observed couplings already place stringent limits on such theories. We investigate the curious possibility that $h_{125}$ couples to the top quark mostly as a scalar, while it couples to the bottom quark mostly as a pseudoscalar. This possibility was allowed by 2017 data for the so-called C2HDM; a two Higgs doublet model with a single source of explicit CP violation. It was shown recently that this possibility disappears when using the full experimental data of 2024. Here we discuss a three Higgs doublet with explicit CP violation (C3HDM), and show that the curious CP-even/CP-odd $t$/$b$ possibility is partly resuscitated, prompting further experimental exploration of this prospect.

    hep-phJHEP(2024)·9 citations
21. 21*

    QCD jets in a hot and dense medium: a study of shower formation time and collision kernels

    Rouzbeh Modarresi-Yazdi🇨🇦 · Shuzhe Shi🇨🇳 · Charles Gale🇨🇦 · Sangyong Jeon🇨🇦

    With the use of MARTINI, a model which considers evolving QCD jets against a fluid dynamical background, it is shown that the introduction of formation time to the parton shower after the initial hard scattering is essential for a simultaneous description of charged hadron and jet $R_{AA}$. This inclusion also improves jet shape ratio at small angle and jet fragmentation function ratios of leading charged hadrons. The MARTINI framework is then aimed at a study of the leading order, next-to-leading-order, and non perturbative collision kernels. Sizable differences in the modification of jet substructure observables, i.e., jet shape and fragmentation functions are observed. Such differences are caused by the difference in the radiation rates of relatively soft gluons that survive in the evolution in medium.

    hep-phnucl-thPRC(2025)·14 citations
22. 22*

    Irreducible cosmological backgrounds of a real scalar with a broken symmetry

    Francesco D'Eramo🇮🇹 · Andrea Tesi🇮🇹 · Ville Vaskonen🇪🇪

    We explore the irreducible cosmological implications of a singlet real scalar field. Our focus is on theories with an approximate and spontaneously broken ${\mathbb{Z}}_2$ symmetry where quasi-stable domain walls can form at early times. This seemingly simple framework bears a wealth of phenomenological implications that can be tackled by means of different cosmological and astrophysical probes. We elucidate the connection between domain wall dynamics and the production of dark matter and gravitational waves. In particular, we identify three main benchmark scenarios. The gravitational wave signal observed by pulsar timing arrays can be generated by the domain walls if the mass of the singlet is $m_s\sim$PeV. For lower masses, but with $m_s\gtrsim 10$GeV, scalars produced in the annihilation of the domain walls can be dark matter with a distinctive feature in their power spectrum. Finally, the thermal bath provides an unavoidable source of unstable scalars via the freeze-in mechanism whose subsequent decays can be tested by their imprints on cosmological and terrestrial observables.

    hep-phastro-ph.COPRD(2024)·13 citations
23. 23*

    Likely existence of bound states and the Efimov effect in the triple-$J/\psi$ system

    Ya-Wen Pan🇨🇳 · Zhi-Wei Liu🇨🇳 · Li-Sheng Geng🇨🇳 · Atsushi Hosaka🇯🇵 · Xiang Liu🇨🇳

    The ground-breaking discovery of the first fully charmed tetraquark state $X(6900)$ in the $J/\psi J/\psi$ invariant mass distribution by the LHCb collaboration has inspired intensive theoretical studies. Various interpretations, such as molecular states, compact tetraquark states, and coupled-channel effects, have been proposed for these states. Of particular interest is the ongoing search for the triple-$J/\psi$ state--a fully-charmed hexaquark state. To deepen our understanding of the triple-$J/\psi$ state and to guide future experimental searches, we study the triple-$J/\psi$ system in this work employing the Gaussian expansion method and the $J/\psi J/\psi$ potential parameterized to yield a shallow bound state, as suggested in several theoretical works. Our results support a triple-$J/\psi$ bound state, even in cases where the attractive interaction between the two $J/\psi$ mesons is very weak. Moreover, our analysis implies the Efimov effect in the triple-$J/\psi$ system. In addition, we extend our investigation to the triple-${\rm Y}(1S)$ system and obtain results similar to those for the triple-$J/\psi$ system.

    hep-phhep-exnucl-exnucl-thPRD(2024)·3 citations
24. 24*

    Constraints for scalars and pseudoscalars from ${\left(g-2\right)}_l$ and existing $e^{+}{e}^{-}$ colliders

    Aleksandr Pustyntsev🇩🇪 · Marc Vanderhaeghen🇩🇪

    Scalars and pseudoscalars with masses in the MeV to GeV range are of interest in different extensions of the Standard Model. Such particles are often associated with dark matter, the strong CP problem and the ${\left(g-2\right)}_{\mu }$ anomaly. In this work we investigate limits for masses of such particles and their couplings to photons and leptons which can be derived from present and currently operating $e^{+}{e}^{-}$ collider experiments and recent ${\left(g-2\right)}_l$ measurements. Our work expands upon previous studies in several ways, demonstrating that the interplay of both couplings is a decisive factor in this type of analyses.

    hep-phPRD(2024)·7 citations
25. 25*

    Universal New Physics Latent Space

    Anna Hallin🇩🇪 · Gregor Kasieczka🇩🇪 · Sabine Kraml🇫🇷 · André Lessa🇧🇷 · Louis Moureaux🇩🇪 · Tore von Schwartz🇩🇪 · David Shih🇺🇸

    We develop a machine learning method for mapping data originating from both Standard Model processes and various theories beyond the Standard Model into a unified representation (latent) space while conserving information about the relationship between the underlying theories. We apply our method to three examples of new physics at the LHC of increasing complexity, showing that models can be clustered according to their LHC phenomenology: different models are mapped to distinct regions in latent space, while indistinguishable models are mapped to the same region. This opens interesting new avenues on several fronts, such as model discrimination, selection of representative benchmark scenarios, and identifying gaps in the coverage of model space.

    hep-phcs.LGhep-exphysics.data-anPRD(2025)·5 citations
26. 26*

    Finding excesses in model parameter space

    Kierthika Chathirathas🇩🇪 · Torben Ferber🇩🇪 · Felix Kahlhoefer🇩🇪 · Alessandro Morandini🇩🇪

    Simulation-based inference (SBI) makes it possible to infer the parameters of a model from high-dimensional low-level features of the observed events. In this work we show how this method can be used to establish the presence of a weak signal on top of an unknown background, to discard background events and to determine the signal properties. The key idea is to use SBI methods to identify events that are similar to each other in the sense that they agree on the inferred model parameters. We illustrate this method for the case of axion-like particles decaying to photons at beam-dump experiments. For poor detector resolution the diphoton mass cannot be reliably reconstructed, so there is no simple high-level observable that can be used to perform a bump hunt. Since the SBI methods do not require explicit high-level observables, they offer a promising alternative to increase the sensitivity to new physics.

    hep-phhep-exEPJC(2025)·2 citations
27. 27*

    Toponium Hunter's Guide

    J. A. Aguilar-Saavedra🇪🇸

    We address the discovery and characterisation of toponium production at the Large Hadron Collider. In the dilepton decay mode, multivariate analyses of spin and colour observables could provide evidence that an excess of events present near the $t\bar{t}$ threshold corresponds to a spin-zero colour singlet. The semileptonic decay mode may also exhibit an excess near threshold, but is not expected to play any role in the toponium characterisation.

    hep-phhep-exPRD(2024)·40 citations
28. 28*

    Exploring the Quantum Universe: Pathways to Innovation and Discovery in Particle Physics

    Shoji Asai🇯🇵 · Amalia Ballarino🇨🇭 · Tulika Bose🇺🇸 · Kyle Cranmer🇺🇸 · Francis-Yan Cyr-Racine🇺🇸 · Sarah Demers🇺🇸 · Cameron Geddes🇺🇸 · Yuri Gershtein🇺🇸 · Karsten Heeger🇺🇸 · Beate Heinemann🇩🇪 · JoAnne Hewett🇺🇸 · Patrick Huber🇺🇸 and 20 other authors

    This is the report from the 2023 Particle Physics Project Prioritization Panel (P5) approved by High Energy Physics Advisory Panel (HEPAP) on December 8, 2023. The final version was made public on May 8, 2024 and submitted to DOE SC and NSF MPS.

    ↳ hep-exastro-ph.COhep-phhep-th84 citations
29. 29*

    On Formulating the Non-Geometric Scalar Potentials

    George K. Leontaris🇬🇷 · Pramod Shukla🇮🇳

    In the context of four-dimensional type II supergravities, the successive application of various S/T-dualities leads to a generalized notion of fluxes, which includes certain (non-)geometric fluxes along with the standard RR and NS-NS p-form fluxes. These fluxes induce a diverse set of superpotential couplings leading to scalar potentials with a very rich structure, which may possibly result in a vast landscape of physical vacua. However such scalar potentials typically consist of a huge number of terms and in order to make any attempt for phenomenological model building with some analytic understanding/control it is necessary to formulate them in some compact and concise form. Along these lines we review various equivalent methods of deriving the same scalar potential through a set of master formulae, which may open up a new avenue for model building using non-geometric fluxes.

    ↳ hep-thhep-phPoS(2024)·0 citations
30. 30*

    On the determination of the $D$ meson width in the nuclear medium with the transparency ratio

    Victor Montesinos🇪🇸 · Natsumi Ikeno🇯🇵 · Eulogio Oset🇪🇸 · Miguel Albaladejo🇪🇸 · Juan Nieves🇪🇸 · Laura Tolos🇪🇸

    We have studied the feasibility of the experimental determination of the width of a $D$ meson in a nuclear medium by using the method of the nuclear transparency. The cross section for inclusive production of a $D^{+}$ in different nuclei is evaluated, taking care of the $D^{+}$ absorption in the nucleus, or equivalently, the survival probability of the $D^{+}$ in its way out of the nucleus from the point of production. We use present values of the in medium width of $D$ mesons and calculate ratios of the cross sections for different nuclei to the ${}^{12}\text{C}$ nucleus as reference. We find ratios of the order of $0.6$ for heavy nuclei, a large deviation from unity, which indicates that the method proposed is adequate to measure this relevant magnitude, so far only known theoretically.

    ↳ nucl-thhep-phPLB(2025)·5 citations
31. 31*

    Fermion Masses and Mixings in String Theory with Dirac Neutrinos

    Mudassar Sabir🇨🇳 · Adeel Mansha🇨🇳 · Tianjun Li🇨🇳 · Zhi-Wei Wang🇨🇳

    Analyzing the supersymmetric Pati-Salam landscape on a ${\mathbb{T}}^6/({\mathbb{Z}}_2\times {\mathbb{Z}}_2)$ orientifold in IIA string theory, we have found only two models that accurately account for all standard model fermion masses and mixings. The models are dual to each other under the exchange of two SU(2) sectors and feature 12 adjoint scalars, the maximum number allowed in the landscape, whose linear combination yields the two light Higgs eigenstates. Dirac neutrino-masses in normal ordering $(50.6,10.6,6.2)\pm 0.1$~meV satisfying both the experimental as well as swampland constraints.

    ↳ hep-thhep-exhep-phPRD(2025)·6 citations
32. 32*

    Ultra-light dark matter with non-canonical kinetics reopening the mass window

    Shiyun Lu🇨🇳 · Amara Ilyas🇨🇳 · Xiao-Han Ma🇨🇳 · Bo Wang🇨🇳 · Dongdong Zhang🇨🇳 · Yi-Fu Cai🇨🇳

    Fuzzy dark matter (FDM) with mass around $10^{-22}$ eV is viewed as a promising paradigm in understanding the structure formation of the local universe at small scales. Recent observations, however, begin to challenge FDM in return. We focus on the arguments between the solution to CDM small-scale curiosities and recent observations on matter power spectrum, and find its implication on an earlier formation of small-scale structure. In this article, we propose a scheme of k-ULDM scalar field with a differently-evolving sound speed, thanks to the non-canonical kinetics. With the help of the Dirac-Born-Infeld (DBI) theory, we illustrate to change the behavior of the quantum pressure term countering collapse, therefore change the history of structure growth. We find that it can truly reopen the ULDM mass window closed by the Lyman-$\alpha$ problem. We will discuss such examples in this paper, while more possibilities remain to be explored.

    ↳ astro-ph.COgr-qchep-phJCAP(2025)·7 citations
33. 33*

    Constraints on the fuzzy dark matter mass window from high-redshift observables

    Hovav Lazare🇮🇱 · Jordan Flitter🇮🇱 · Ely D. Kovetz🇮🇱

    We use a combination of high-redshift observables to extract the strongest constraints to date on the fraction of axion fuzzy dark matter (FDM) in the mass window $10^{-26}\mathrm{eV}\lesssim m_{\mathrm{FDM}}\lesssim 10^{-23}\mathrm{eV}$. These observables include ultraviolet luminosity functions (UVLFs) at redshifts $4-10$ measured by the Hubble Space Telescope, a constraint on the neutral hydrogen fraction from high-redshift quasar spectroscopy, the cosmic microwave background optical depth to reionization measurement from Planck and upper bounds on the 21cm power spectrum from HERA. In order to calculate these signals for FDM cosmology, we use the 21cmFirstCLASS code to interface between AxiCLASS and 21cmFAST and consistently account for the full cosmic history from recombination to reionization. To facilitate a full Bayesian likelihood analysis, we developed a machine-learning based pipeline, which is both accurate, and enables a swift statistical inference, orders of magnitude faster than a brute force approach. We find that FDM of mass $m_{\mathrm{FDM}}=10^{-23}\mathrm{eV}$ is bound to less than $16\%$ of the total dark matter, where the constrains strengthen towards smaller masses, reaching down to $1\%$ for $m_{\mathrm{FDM}}=10^{-26}\mathrm{eV}$, both at $95\%$ confidence level. In addition, we forecast that a future detection of the 21cm power spectrum with HERA will lower the upper bound at $m_{\mathrm{FDM}}=10^{-23}\mathrm{eV}$ to $\lesssim 1\%$.

    ↳ astro-ph.COhep-phPRD(2024)·22 citations
34. 34*

    Proving the absence of large one-loop corrections to the power spectrum of curvature perturbations in transient ultra-slow-roll inflation within the path-integral approach

    Ryodai Kawaguchi🇯🇵 · Shinji Tsujikawa🇯🇵 · Yusuke Yamada🇯🇵

    We revisit one-loop corrections to the power spectrum of curvature perturbations $\zeta$ in an inflationary scenario containing a transient ultra-slow-roll (USR) period. In Ref.[1], it was argued that one-loop corrections to the power spectrum of $\zeta$ can be larger than the tree-level one within the parameter region generating the seeds of primordial black holes during the USR epoch, which implies the breakdown of perturbation theory. We prove that this is not the case by using a master formula for one-loop corrections to the power spectrum obtained in Ref.[2]. We derive the same formula within the path-integral formalism, which is simpler than the original derivation in [2]. To show the smallness of one-loop corrections, the consistency relations and the effective constancy of tree-level mode functions of $\zeta$ for super-Hubble modes play essential roles, with which the master formula gives a simple expression for one-loop corrections. For concreteness, we provide a reduced set of interactions including the leading-order one, while establishing the consistency relations in a self-consistent manner. We also show how the consistency relations of various operators hold explicitly, which plays a key role in proving the absence of large one-loop corrections.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2024)·39 citations
35. 35*

    Meson-nucleus bound states in quark meson coupling model

    Arpita Mondal🇮🇳 · Amruta Mishra🇮🇳

    The formations of the $K(\bar{K})$, $D(\bar{D})$, and $B(\bar{B})$ meson-nucleus bound states in ${}^{16}\mathrm{O}$, ${}^{40}\mathrm{Ca}$, ${}^{90}\mathrm{Zr}$, ${}^{197}\mathrm{Au}$, and ${}^{208}\mathrm{Pb}$ nucleus are investigated using the quark meson coupling model. The model relies on a mean field description of non-overlapping nucleon bags bound by the self-consistent interactions of scalar ($\sigma$, $\delta$) and vector ($\omega$, $\rho$) mesons with the (anti)quarks inside the bags, which is further extended to explore the properties of nuclei. We estimate the meson-nucleus bound state energies by solving the Klein-Gordon equations with the real potentials calculated self-consistently within the model, using a coordinate space approach. The calculations are carried out for different nuclear interactions. The effects of Coulomb interaction are considered in the present study for the charged mesons. Our study indicates the formation of rather deeply bound $B$-mesic states at the very central region of the nuclei, compared to the $D$ and $K$ mesons, offering a more promising probe to explore subtle nuclear medium effects. The investigations of such bound states are of particular interest for the upcoming $\bar{\mathrm{P}}\mathrm{ANDA}$ at FAIR, J-PARC-E29, and JLab experiments.

    ↳ nucl-thhep-phPRC(2024)·10 citations
36. 36*

    Vacuum Energy of Non-Supersymmetric $\tilde{\mathbf{S}}$ Heterotic String Models

    Luke A. Detraux🇬🇧 · Alonzo R. Diaz Avalos🇬🇧 · Alon E. Faraggi🇬🇧 · Benjamin Percival🇬🇧

    We use the free fermionic formulation of the heterotic-string in four dimensions to study the vacuum structure and energy of non-supersymmetric tachyon free models that correspond to compactifications of tachyonic vacua of the ten dimensional heterotic-string. We explore the class of heterotic $SO(10)$ non-supersymmetric models constructed from the $\tilde{S}$-model in the Free Fermionic Formalism, and investigate the dependence of the potential on the geometric moduli. This paper will explore a sample of $10^9$ string vacua to find the frequency of viable models, classifying these vacua by the following fertility criteria: tachyon presence; number of spinorial $16/\overline{16}$ representations; vectorial $10$ states; Top Quark Mass Coupling compatibility. Of these we find those that mimic supersymmetric models with equal number of bosons and fermions at the massless level - $a_{00}=0$. Tachyon free models occur with a frequency of $5.309\times 10^{-3}$. Furthermore, models that fulfil the rest of the phenomenological fertility conditions and the additional condition on $a_{00}$ occur with probability $4.0\times 10^{-9}$ We analyse the partition functions and study the moduli dependence of such models, finding that almost all fertile models have finite, positive potential at the Free Fermionic Point, with $2$ out of $84$ of the fertile cores having negative, finite potential. We demonstratate that the Free Fermionic Point is not necessarily a minimum in the potential. This work provides further evidence that supersymmetry may not be a necessary ingredient of phenomenological models, recreating many of the desirable features of such models without employing supersymmetry.

    ↳ hep-thhep-phPRD(2024)·11 citations
37. 37*

    Investigation of kaonic atom optical potential by the high precision data of kaonic ${}^3$He and ${}^4$He atoms

    J. Yamagata-Sekihara (Kyoto Sangyo U.)🇯🇵 · Y. Iizawa (Tokyo Inst. Tech.)🇯🇵 · D. Jido (Tokyo Inst. Tech.)🇯🇵 · N. Ikeno (Tottori U.)🇯🇵 · T. Hashimoto (Nishina Car., RIKEN and RIKEN)🇯🇵 · S. Okada (Chubu U. and RIKEN)🇯🇵 · S. Hirenzaki (Nara Women's U.)🇯🇵

    We theoretically investigate kaonic atom states based on the latest high precision data of the $2p$ states of the kaonic atoms in ${}^3$He and ${}^4$He (J-PARC E62). We consider the phenomenological form for the optical potential proportional to the nuclear density distributions and determine the potential parameters by the latest data. We find two sets of potential parameters for each of $K^{-}{-}^3$He and $K^{-}{-}^4$He that reproduce the data. We then extract the potential parameters consistent with the data of ${}^3$He and ${}^4$He atoms simultaneously. Using the potential, we investigate the structure of the kaonic atoms and kaonic nuclei for various nuclei up to Sn. We also report the optical potential parameters suited for the global description of the atomic data, the possible strong isospin dependence of the potential, and the different strength of the data of $K^{-}{-}^3$He and $K^{-}{-}^4$He in the restrictions on the potential parameters. In addition, we find that the study of the $1s$ states of the kaonic helium atom is very interesting as a next step, and the determination of the orbital angular momenta of the kaonic nuclear states is helpful for the unified understandings of the atomic and nuclear bound states of kaon because of the mutual influence between the atomic and the nuclear states of kaon with the same orbital angular momentum.

    ↳ nucl-thhep-exhep-phnucl-exPTEP(2025)·5 citations
38. 38*

    Impact of Parameters in the Blazar Jet Magnetic Field Model on Axion-Like Particle Constraints

    Lin-Qing Gao🇨🇳 · Xiao-Jun Bi🇨🇳 · Jun Li🇨🇳 · Peng-Fei Yin🇨🇳

    The interaction between axion-like particles (ALPs) and photons induces ALP-photon oscillations in astrophysical magnetic fields, leading to spectral distortions in the $\gamma$-ray spectrum of blazars. The primary uncertainty of this phenomenon may originate from the magnetic field within the jet of the blazar. While many studies have explored the effects of ALP-photon oscillations using typical values for jet magnetic field parameters, it is important to recognize that these parameters can be constrained by multi-wavelength observations. In this study, we utilize the high energy $\gamma$-ray spectrum of Mrk 421 obtained from MAGIC and Fermi-LAT observations. By employing multi-wavelength fitting with a one-zone synchrotron self-Compton model, we derive the parameters characterizing the magnetic field model within the jet, and investigate their impacts on the ALP constraints.

    ↳ astro-ph.HEhep-phJCAP(2025)·9 citations
39. 39*

    Analytic Evaluation of Multiple Mellin-Barnes Integrals

    Sumit Banik🇨🇭 · Samuel Friot🇫🇷

    We summarize two geometrical approaches to analytically evaluate higher-fold Mellin-Barnes (MB) integrals in terms of hypergeometric functions. The first method is based on intersections of conic hulls, while the second one, which is more recent, relies on triangulations of a set of points. We demonstrate that, once automatized, the triangulation approach is computationally more efficient than the conic hull approach. As an application of this triangulation approach, we describe how one can derive simpler hypergeometric solutions of the conformal off-shell massless two-loop double box and one-loop hexagon Feynman integrals than those previously obtained from the conic hull approach. Lastly, by applying the above techniques on the MB representation of multiple polylogarithms, we show how to obtain new convergent series representations for these functions. These new analytic expressions were numerically cross-checked with GINAC.

    ↳ hep-thhep-phPoS(2024)·6 citations
40. 40*

    On the EFT of Dyon-Monopole Catalysis

    S. Bogojevic🇨🇦 · C.P. Burgess🇨🇦

    Monopole-fermion (and dyon-fermion) interactions provide a famous example where scattering from a compact object gives a cross section much larger than the object's geometrical size. This underlies the phenomenon of monopole catalysis of baryon-number violation because the reaction rate is much larger in the presence of a monopole than in its absence. It is sometimes claimed to violate the otherwise generic requirement that short distance physics decouples from long-distance observables -- a property that underpins the general utility of effective field theory (EFT) methods. Decoupling in this context is most simply expressed using point-particle effective field theories (PPEFTs) designed to capture systematically how small but massive objects influence their surroundings when probed only on length scales large compared to their size. These have been tested in precision calculations of how nuclear properties affect atomic energy levels for both ordinary and pionic atoms. We adapt the PPEFT formalism to describe low-energy $S$-wave dyon-fermion scattering with a view to understanding whether large catalysis cross sections violate decoupling (and show why they do not). We also explore the related but separate issue of the long-distance complications associated with polarizing the fermion vacuum exterior to a dyon and show in some circumstances how PPEFT methods can simplify calculations of low-energy fermion-dyon scattering in their presence. We propose an effective Hamiltonian governing how dyon excitations respond to fermion scattering in terms of a time-dependent vacuum angle and outline open questions remaining in its microscopic derivation.

    ↳ hep-thhep-phnucl-thJHEP(2024)·6 citations
41. 41*

    Universal corrections to the superfluid gap in a cold Fermi gas

    Silas R. Beane🇨🇭 · Zeno Capatti🇨🇭 · Roland C. Farrell🇺🇸

    A framework for computing the superfluid gap in an effective field theory (EFT) of fermions interacting via momentum-independent contact forces is developed. The leading universal corrections in the EFT are one-loop in-medium effects at the Fermi surface, and reproduce the well-known Gor'kov-Melik-Barkhudarov result. The complete subleading universal corrections are presented here, and include one-loop effects away from the Fermi surface, two-loop in-medium effects, as well as modifications to the fermion propagator. Together, these effects are found to reduce the gap at low densities. Applications to neutron superfluidity in neutron stars are also discussed.

    ↳ nucl-thcond-mat.quant-gascond-mat.supr-conhep-phPRA(2025)·5 citations
42. 42*

    Comment on "Final CONUS results on coherent elastic neutrino nucleus scattering at the Brokdorf reactor"

    J.I. Collar🇺🇸 · C.M. Lewis🇺🇸

    We describe several omissions and deficiencies in the arguments presented by Ackermann et al. (arXiv:2401.07684), pointing at missing information necessary to back up its conclusions.

    ↳ hep-exhep-phnucl-exphysics.ins-det1 citation
43. 43*

    Horndeski speed tests with scalar-photon couplings

    Eugeny Babichev🇫🇷 · Christos Charmousis🇫🇷 · Benjamin Muntz🇬🇧 · Antonio Padilla🇬🇧 · Ippocratis D. Saltas🇨🇿

    We revisit multi-messenger constraints from neutron star mergers on the speed of propagation of gravitational and electromagnetic waves in Horndeski and beyond Horndeski theories. By considering non-trivial couplings between the dark energy field and the electromagnetic sector, the electromagnetic wave can propagate through the cosmological background at non-unit speed, altering the phenomenological constraints on its gravitational counterpart. In particular, we show that recent models derived from a Kaluza-Klein compactification of higher dimensional Horndeski models fall into a broader class of theories disformally related to those whose gravitational waves propagate with unit speed. This disformal equivalence can, however, be broken by the gravitational couplings to other sectors with interesting phenomenological consequences. We also consider higher order couplings between the scalar and the photon with second order field equations, and show that they are not compatible with constraints coming from multi-messenger speed tests and the decay of the gravitational wave.

    ↳ gr-qcastro-ph.COhep-phhep-thJCAP(2025)·11 citations
44. 44*

    WZW terms without anomalies: generalised symmetries in chiral Lagrangians

    Joe Davighi🇨🇭 · Nakarin Lohitsiri🇬🇧

    We consider a 4d non-linear sigma model on the coset $(\mathrm{SU}(N{)}_L\times \mathrm{SU}(N{)}_R\times \mathrm{SU}(2))/(\mathrm{SU}(N{)}_{L+R}\times \mathrm{U}(1))\cong \mathrm{SU}(N)\times S^2$, that features a topological Wess-Zumino-Witten (WZW) term whose curvature is $\frac{n}{24{\pi }^2}\mathrm{Tr}(g^{-1}dg{)}^3\wedge {\mathrm{Vol}}_{S^2}$ where $g$ is the $\mathrm{SU}(N)$ pion field. This WZW term, unlike its familiar cousin in QCD, does not match any chiral anomaly, so its microscopic origin is not obviously QCD-like. We find that generalised symmetries provide a key to unlocking a UV completion. The $S^2$ winding number bestows the theory with a 1-form symmetry, and the WZW term intertwines this with the $\mathrm{SU}(N{)}^2$ flavour symmetry into a 2-group global symmetry. Like a 't Hooft anomaly, the 2-group symmetry should match between UV and IR, precluding QCD-like completions that otherwise give the right pion manifold. We instead construct a weakly-coupled UV completion that matches the 2-group symmetry, in which an abelian gauge field connects the QCD baryon number current to the winding number current of a $\mathbb{C}{P}^1$ model, and explicitly show how the mixed WZW term arises upon flowing to the IR. The coefficient is fixed to be the number of QCD colours and, strikingly, this matching must be 'tree-level exact' to satisfy a quantization condition. We discuss generalisations, and elucidate the more intricate generalised symmetry structure that arises upon gauging an anomaly-free subgroup of $\mathrm{SU}(N{)}_{L+R}$. This WZW term may even play a phenomenological role as a portal to a dark sector, that determines the relic abundance of dark matter.

    ↳ hep-thhep-phSciPost Phys.(2024)·14 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.