Mon·Dec 29, 2025Monday·December 29, 2025

1. 01*

   Regge theory in hadron physics

   Daniel Winney🇩🇪 · Adam P. Szczepaniak🇺🇸

   We provide a pedagogical introduction to Regge theory as it pertains to the study of hadrons and their interactions. We clarify the fundamental concepts of analyticity in the complex angular momentum plane and their implications for scattering amplitudes. We highlight historical developments that significantly shaped our understanding of scattering theory and the strong interaction, both before and following the discovery of QCD. We end with a review of more recent applications of Regge theory in QCD phenomenology, including describing exchange processes, constraining low-energy amplitudes, and analyzing resonances in the complex angular momentum plane.

   hep-ph5 citations
2. 02*

   Mass Spectra of ${\Lambda }_Q{\bar{\Sigma }}_Q$ Hexaquark States in QCD Sum Rules

   Xuan-Heng Zhang🇨🇳 · Cong-Feng Qiao🇨🇳

   Recently, the BESIII Collaboration indicate that no ${\Lambda }_c{\bar{\Sigma }}_c$ bound-state with a mass near threshold in the range $4715$--$4735\mathrm{MeV}$ was observed. In order to determine the plausible mass region of the states in this structure, we calculate the mass spectrum of the ${\Lambda }_c{\bar{\Sigma }}_c$ configuration with the method of QCD sum rules. Two linearly independent interpolating currents are constructed, and contributions from nonperturbative condensates up to dimension 12 are included in the numerical results. Consequently, we obtain the masses of the candidate states with quantum numbers $J^P=0^{-},0^{+},1^{-},1^{+}$. Our results show that the central values of the ${\Lambda }_c{\bar{\Sigma }}_c$ ground-state masses lie around the $5.8\mathrm{GeV}$ region, which do not support them as bound states and consistent with the findings reported by the BESIII Collaboration. Furthermore, we compute the mass spectrum of the ${\Lambda }_b{\bar{\Sigma }}_b$ states with quantum numbers $J^P=0^{-},0^{+},1^{-},1^{+}$, which could be served as hidden-bottom candidates in the experimental detecting.

   hep-phhep-exnucl-thJHEP(2026)·2 citations
3. 03*

   Neutrino Textures from Modular $A_4$ Left--Right Symmetry: Experimental Signatures at DUNE and T2HK in the Post-JUNO Era

   Bhabana Kumar🇮🇳 · Debajyoti Dutta🇮🇳 · Mrinal Kumar Das🇮🇳

   We have realized different two-zero textures within the framework of the left right symmetric model using the ${\Gamma }_3\cong A_4$ modular group. The matter multiplets of the model are assigned as three singlet representations of the $A_4$ group, and their charge assignments together with the modular weights of the Yukawa couplings are chosen in such a way that different two-zero textures of the neutrino mass matrix are obtained. In total, we have successfully realized seven different two-zero textures. Furthermore, we have studied neutrinoless double beta decay and lepton flavor violating (LFV) processes, and have calculated the effective Majorana mass and the branching ratios for LFV processes for each of the textures. We further probe these two-zero textures at the long-baseline neutrino experiments DUNE and T2HK. We find that DUNE, especially when combined with T2HK, can significantly restrict the ${\theta }_{23}-{\delta }_{\mathrm{CP}}$ parameter space predicted by these textures. Moreover, the inclusion of high-precision determinations of ${\theta }_{12}$ (from JUNO) and ${\theta }_{13}$ leads to a substantial, further reduction of the allowed parameter space. For assumed inverted mass ordering, the synergy of DUNE and T2HK leads to a highly predictive scenario for the $B_2$ and $B_4$ textures, as the allowed regions collapse into tiny islands near the CP-conserving points in the lower and higher octant of ${\theta }_{23}$, respectively.

   hep-ph4 citations
4. 04*

   Fermionic domain-wall Skyrmions of QCD in a magnetic field

   Patrick Copinger🇯🇵 · Minoru Eto🇯🇵 · Muneto Nitta🇯🇵 · Zebin Qiu🇯🇵

   The ground state of low-energy QCD matter in strong magnetic fields is either a chiral soliton lattice (CSL), a periodic array of neutral pion domain walls (chiral solitons) perpendicular to the magnetic field, or domain-wall Skyrmion phase, in which Skyrmions are induced on top of the CSL. Previously found domain-wall Skyrmions are bosons with the baryon number two. In this paper, we show that the minimum domain-wall Skyrmions are fermions with baryon number one; a bosonic domain-wall Skyrmion can be separated without energy cost into two fermionic domain-wall Skyrmions attached on the opposite sides of a chiral soliton. The phase boundary between the CSL and domain-wall Skyrmion phases is unchanged. In the chiral limit, the CSL reduces to a linearly dependent neutral pion on the direction of the magnetic field, while fermionic domain-wall Skyrmions sit in an equal distance of half a period.

   hep-phhep-thnucl-thJHEP(2026)·5 citations
5. 05*

   Signature for charged Higgs pair production in 2HDM+a model at CLIC

   Shuo Yang🇨🇳 · Ziyang Yu🇨🇳 · Yiqi Wang🇨🇳 · Lei Wang🇨🇳

   In this work, we study the search for charged Higgs bosons in the Two-Higgs-Doublet Model plus an additional pseudo-scalar (2HDM+a) at the Compact Linear Collider (CLIC). Focusing on the pair production of charged Higgs bosons, followed by the decays $H^{\pm }\to aW$ and $H^{\mp }\to tb$, we analyze the signal channel of $4j+2b+E_T^{miss}$. Given the center-of-mass energy of CLIC as $\sqrt{s}=1500$ GeV, charged Higgs bosons with masses $m_{H^{\pm }}<\sqrt{s}/2$ are explored. Simulation results indicate that the signal significance of 400 GeV and 600 GeV charged Higgs bosons can reach $5\sigma$ in specific parameter spaces, and the $2\sigma$ exclusion limits in the $m_{H^{\pm }}-m_a$ plane are presented for $m_{H^{\pm }}$ in the range of [400, 650] GeV.

   hep-ph0 citations
6. 06*

   Next-to-leading order QCD corrections to electromagnetic production and decay of fully charm tetraquarks

   Xinran Liu🇨🇳 · Yefan Wang🇨🇳 · Ruilin Zhu🇨🇳

   We investigate the electromagnetic properties of the fully charm tetraquark states, particularly incorporating contributions from internal gluon radiation. The paper first presents analytical expressions for the next-to-leading-order (NLO) QCD corrections to the decay amplitudes of fully charm tetraquarks into two photons. It is found that the QCD corrections are significant for the $J^{PC}=0^{++}$ and $J^{PC}=2^{++}$ fully charm tetraquark decay process. Subsequently, by considering photon-photon fusion in ultra-peripheral high-energy collisions of protons and nuclei and in electron-positron collision, we provide theoretical predictions for the production cross sections of fully charm tetraquark states. The results presented in this work regarding the electromagnetic production and decay of fully charm tetraquarks shall be tested in current and future experiments.

   hep-phhep-exhep-latPRD(2026)·7 citations
7. 07*

   Towards precise baryogenesis in the 2HDM$+a$

   T. Gent🇬🇧 · S. Huber🇬🇧 · K. Mimasu🇬🇧 · J. M. No🇪🇸

   We perform a detailed investigation of the viable baryogenesis parameter space of a non-minimal Higgs sector consisting of two Higgs doublets and a singlet pseudoscalar (2HDM$+a$). In such a model, an early Universe period of transient CP violation may occur, driven by a nonvanishing vacuum expectation value of the CP-odd scalar $a$. This naturally avoids the stringent electric dipole moment experimental constraints on beyond-the-Standard-Model sources of CP violation. We provide a state-of-art computation of the baryon asymmetry, providing several important improvements over existing baryogenesis computations for this model. We show that the required thermal history and successful baryogenesis lead to a predictive scenario, testable in the near future by a combination of LHC searches and low-energy flavour measurements. Our improved predictions for the baryon asymmetry find that it is rather suppressed compared to earlier predictions, requiring larger mixing between the singlet and 2HDM pseudoscalars and hence leading to a more easily testable model at colliders.

   hep-ph4 citations
8. 08*

   Gauge Coupling Unification in Gauge-Higgs GUT: Theory and Phenomenology

   Andrei Angelescu🇩🇪 · Andreas Bally🇩🇪 · Florian Goertz🇩🇪 · Sascha Weber🇩🇪

   We present a concise survey of the running of gauge couplings in realistic models of gauge-Higgs grand unification in a slice of AdS${}_5$ space and investigate their potential unification. Besides unifying the gauge groups of the Standard Model, these models can address various unresolved puzzles, such as the lightness of the Higgs boson and the strong hierarchies within fermion masses and mixings, as well as provide a common origin of the gauge symmetries and the sector that spontaneously breaks them. At the same time, they furnish interesting LHC signatures in the form of TeV-scale resonances of the $X,Y$-like bosons, providing a trace of the grand-unified group, accessible at low energies. Using the method of Planck-brane correlators allows us to evolve the couplings consistently from the electroweak scale up to the Planck scale, avoiding shortcomings of other frequently-used approaches and including the effects of bulk scalars, fermions, and gauge-bosons within a common framework. We thereby revisit, contrast, and supplement results in the literature, the latter for example by including brane masses and the gauge-Higgs vacuum expectation value. Moreover, in a phenomenology section, we apply our results to the concrete case of Georgi-Glashow-like unification with a SU(6) $\supset$ SU(5) symmetry in the 5D bulk, presenting a quantitative survey of the quality of unification. We find that grand unification is possible in such models in the presence of moderately large brane kinetic terms.

   hep-phJHEP(2026)·0 citations
9. 09*

   The Lepton-Gluon Portal Beyond Lepto-Gluons

   Linda M. Carpenter🇺🇸 · Katherine Schwind🇺🇸

   We explore models where single new exotic states interact with the Standard Model through an asymmetric Standard Model portal with couplings to at least one gluon and one lepton. We consider the complete set of effective operators up to dimension 6, and examine a few additional dimension 7 operators that contain interesting field content or potential collider signals. The lepton-gluon portal allows access to exotic states with an interesting range of SU(3) and SU(2) quantum numbers. Finally, we explore potential single-production modes and their phenomenological signatures at colliders.

   hep-ph0 citations
10. 10*

    Gravitational waves from seesaw assisted collapsing domain walls

    Debasish Borah🇮🇳 · Indrajit Saha🇮🇳

    Spontaneous breaking of discrete symmetries like $Z_2$ leads to the formation of stable topological defects such as domain walls which, if allowed to dominate, can potentially be in conflict with cosmological observations. Incorporating explicit $Z_2$-breaking bias terms can lead to annihilation of such walls while also emitting stochastic gravitational waves (GW). We study the role of heavy right-handed neutrinos present in the type-I seesaw framework to generate such a bias term via quantum corrections. This offers interesting correlations among the seesaw scale, GW peak amplitude and peak frequency which can be probed at present and future experiments related to GW as well as precision measurements of the cosmic microwave background (CMB). In flavor symmetric UV complete scenarios with degenerate RHNs at leading order, such tiny coupling of RHNs to a $Z_2$-odd scalar can also lead to small mass splittings suitable for explaining the observed baryon asymmetry of the universe via resonant leptogenesis.

    hep-phastro-ph.COPLB(2026)·13 citations
11. 11*

    Minimal A4 Type-II Seesaw Realization of Testable Neutrino Mass Sum Rules

    Salvador Centelles Chuliá🇪🇸 · Ranjeet Kumar🇮🇳

    We propose a flavour model based on an $A_4$ symmetry combined with a type-II seesaw mechanism for neutrino mass generation. The resulting neutrino mass matrix obeys a sum rule that, together with the measured mass-squared differences, fully determines the absolute neutrino mass spectrum. The constrained flavour structure yields correlated predictions for lepton mixing parameters, leads to inverted ordering after imposing mixing constraints, restricts the Majorana phases and implies a neutrinoless double beta decay rate close to its maximal value for inverted ordering. In the charged lepton sector an approximate triality symmetry arises in the seesaw limit, suppressing muon flavour-violating processes and allowing only specific $\tau$ decay channels. The model provides a tightly constrained and experimentally testable framework linking neutrino masses, lepton mixing and lepton-number-violating observables.

    hep-phPRD(2026)·5 citations
12. 12*

    Implications of Cosmic Birefringence for Multi-Field ALP Dark Matter

    Jialiang Shao🇨🇳 · Ippei Obata🇯🇵 · Dongdong Zhang🇨🇳

    Cosmic birefringence, characterized by the observed rotation of the polarization plane of the cosmic microwave background (CMB) radiation, serves as a critical probe for testing theories beyond the standard cosmological scenario. As a major component of the universe, dark matter plays a pivotal role in cosmic evolution, particularly in the formation of large-scale structures. However, its fundamental nature remains elusive. Axion-like particles (ALPs), as promising dark matter candidates, possess unique advantages in naturally explaining such phenomena. Previous studies on the implications of cosmic birefringence for these ultralight ALP fields have focused on single-field models with conventional potentials. These models face exclusion due to the washout effect - a suppression of the CMB polarization power spectrum induced by oscillatory dynamics of the scalar field within the mass range of less than $10^{-23}$ eV. To address this limitation, we develop a more general theoretical framework incorporating two ALP fields, providing analytical approximations and numerical calculations. Our findings reveal that the superposition of two ALP fields with distinct masses can relax the constraints imposed by the washout effect and reconcile with observations.

    ↳ astro-ph.COhep-ph1 citation
13. 13*

    A Rare Millisecond Pulsar with Cross-Pole Emission: Single-Pulse Insights from PSR J1857+0943

    Shi-jun Dang · Ji-guang Lu · Peng Jiang · Yu-lan Liu🇨🇳 · Jin-tao Xie · Habtamu Menberu Tedila · Fei-fei Kou · Jian-ping Yuan · Zhi-gang Wen · Shuang-qiang Wang🇨🇳 · Lun-hua Shang · Zu-rong Zhou🇨🇳 and 3 other authors

    Studies of subpulse variability in millisecond pulsars (MSPs) offer important constraints on their emission physics. Using the high sensitivity of FAST, we present the first identification of distinct single pulse fluctuation behaviour in PSR J1857+0943. We find that the third component(MP\_C3) of the main pulse may originate from a different region than the other two main-pulse components and may instead share a common origin with the interpulse. This conclusion is supported by four observational evidence as follows: First, the LRCCF shows a clear anticorrelation between MP\_C3 and the interpulse. Second, the single-pulse polarization at the main-pulse longitude reveals obvious component mixing. Third, the modulation period of the interpulse components is roughly twice that of MP\_C3. Fourth, the reduced modulation index in MP\_C3 suggests possible mixing of emission from different regions. The interpretation in this letter contrasts with the usual assumption that the main pulse and interpulse originate from opposite magnetic poles. Hence, PSR J1857+0943 provides a rare laboratory for probing component-dependent plasma behaviour in an MSP magnetosphere. Our results offer direct evidence that the main pulse can include emission associated with more than one magnetic pole and highlight the importance of single-pulse diagnostics for understanding the geometry and dynamics of pulsars with interpulse emission. In addition, we analyse the jitter properties of this pulsar and measure a one-hour jitter of ${\sigma }_{J,1\mathrm{h}}=78\pm 3\mathrm{ns}$ at 1.25 GHz, consistent with previous studies.

    ↳ astro-ph.HEhep-ph0 citations
14. 14*

    Searching for Cosmological Collider in the Planck CMB Data II: collider templates and Modal analysis

    Petar Suman🇬🇧 · Dong-Gang Wang🇬🇧 · Wuhyun Sohn🇫🇷 · James R. Fergusson🇬🇧 · E.P.S. Shellard🇬🇧

    Signatures of massive particles during inflation are highly informative targets for cosmological experiments. With recent progress on both theoretical and observational frontiers, we have reached the point where these novel signals of primordial non-Gaussianities (PNG) can be systematically tested with increasingly precise data. In this paper, we present the results of improved CMB data analysis for cosmological collider signals using Planck CMB data. To set the stage, we first construct a set of simplified but characteristic collider templates which are accurate over a broad range of particle masses, spins and sound speeds. In order to break degeneracies with single-field PNG, we propose an orthogonalization scheme such that the collider templates are uncorrelated with the highly constrained equilateral and orthogonal shapes. On this basis, we deploy the Modal bispectrum estimator for the Planck analysis and perform a systematic scan of parameters to search for the most significant collider signal. The maximum signal-to-noise ratio is found to be $2.35\sigma$ for massive spin-0 exchange after taking into account the look-elsewhere effect. In addition, we cross-validate the Modal analysis with the CMB-BEST pipeline, which demonstrates the consistency of results across the benchmark examples of collider templates. Given the low signal-to-noise ratio regime we find at the current stage of PNG observations, we believe the orthogonalization procedure provides an optimized strategy for future tests of the cosmological collider with the ability to rule out single field inflation.

    ↳ astro-ph.COgr-qchep-phhep-th18 citations
15. 15*

    Non-abelian soft radiation data for a celestial theory

    Lorenzo Magnea🇮🇹 · Enrico Zunino🇬🇧

    Celestial holography posits that the long-distance behavior of gauge and gravity theories is dictated by two-dimensional conformal field theories defined on the celestial sphere. For non-abelian gauge theories, this proposal is verified, to all perturbative orders, by dipole color correlations in the infrared factor of non-abelian scattering amplitudes, which are given by a correlator of matrix-valued vertex operators in a free-boson theory on the sphere. Decades of high-order gauge-theory calculations have provided a number of further results that can be used to test and constrain a possible celestial theory: they include explicit expressions for soft emission currents up to three particles, and up to three loops for single soft emission. In this paper, we analyze this trove of data, appropriately translated in the celestial language, and we use them to extract information on the celestial theory. In particular, we show that all logarithms arising in the loop expansion of the single soft current can be reabsorbed in the scale choices for the $d$-dimensional coupling, casting some doubt on the need for a logarithmic celestial theory. We then note that the celestial OPEs suggested by the structure of multiple emission currents in collinear limits are never ambiguous, but involve coefficients depending on gluon energy fractions, which break holomorphic factorization, as well as associativity when double limits are taken. Strongly-ordered soft limits recover associativity, but suffer from ambiguities already discussed in earlier literature.

    ↳ hep-thhep-phClass.Quant.Grav.(2026)·7 citations
16. 16*

    High-energy Neutrino Predictions for T Coronae Borealis: Probing Particle Acceleration in Novae

    Prantik Sarmah🇨🇳 · Sovan Chakraborty🇮🇳 · Xilu Wang🇨🇳

    The MAGIC detection of near-TeV gamma rays from the 2021 RS Oph ($2.45$ kpc) outburst has established recurrent novae as TeV particle accelerators. However, the origin of this emission (hadronic vs leptonic) remains unclear due to the lack of coincident neutrinos detected by IceCube. The upcoming outburst of the much closer T Coronae Borealis (T CrB, $\sim 0.887$ kpc) offers a unique opportunity to detect these rare nova neutrinos. Here we present the first comparative analysis of the hadronic secondary fluxes expected from the upcoming T CrB outburst and evaluate their detectability across major observatories, considering two proton-acceleration mechanisms: (i) an external shock (ES) at $\sim 10^{13}$ cm, and (ii) magnetic reconnection (MR), near the white dwarf surface at $\sim 10^9$ cm. While the benchmark ES model predicts a gamma-ray flux detectable by current facilities, its corresponding neutrino flux largely remains undetectable. In contrast, the MR scenario generates a robust neutrino flux within the reach of IceCube and KM3NeT. Importantly, as the MR-produced gamma-rays are absorbed, the escaping MR neutrinos will arrive hours before any ES-origin signals. This distinct temporal separation can create a powerful phenomenological signature to disentangle the nova acceleration physics.

    ↳ astro-ph.HEastro-ph.GAhep-phApJL(2026)·3 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.