Tue·Jun 25, 2024Tuesday·June 25, 2024

1. 01*

   Constraining the pseudo-Dirac nature of neutrinos using astrophysical neutrino flavor data

   Chee Sheng Fong🇧🇷 · Yago Porto🇧🇷

   The three Standard Model neutrinos can have Majorana mass or strictly Dirac mass, but both scenarios are practically indistinguishable in neutrino oscillation experiments. If they are pseudo-Dirac, however, there will be new mass splittings among the pseudo-Dirac pairs, potentially leaving traces in neutrino oscillation phenomena. In this work, we use flavor ratios of astrophysical neutrinos to discriminate different possible mass spectra of pseudo-Dirac neutrinos. We show that it will be possible to impose robust bounds of order $\delta m_3^2\lesssim 10^{-12}$ ${\text{eV}}^2$ on the new mass squared splitting involving the third pseudo-Dirac mass eigenstates (those with the least electron flavor composition) with the future experiment IceCube-Gen2. The derived sensitivity is robust because it only assumes an extragalactic origin for the astrophysical neutrinos and hierarchical pseudo-Dirac mass spectrum. In case the neutrino sources are known in the future, such bounds can potentially improve by up to five orders of magnitude, reaching $\delta m_3^2\lesssim 10^{-17}$ ${\text{eV}}^2$.

   hep-phastro-ph.HEPRD(2025)·13 citations
2. 02*

   Electroweak corrections and EFT operators in $W^{+}{W}^{-}$ production at the LHC

   Shankha Banerjee🇮🇳 · Daniel Reichelt🇬🇧 · Michael Spannowsky🇬🇧

   We investigate the impact of electroweak corrections and effective field theory operators on $W^{+}{W}^{-}$ production at the Large Hadron Collider (LHC). Utilizing the Standard Model effective-field theory (SMEFT) framework, we extend the Standard Model by incorporating higher-dimensional operators to encapsulate potential new physics effects. These operators allow for a model-independent approach to data interpretation, essential for probing beyond the Standard Model physics. We generate pseudodata at the next-to-leading order in quantum chromodynamics and include approximate electroweak corrections. Our analysis focuses on the interplay between these corrections and SMEFT operators at leading order. The inclusion of electroweak corrections is crucial as they can counteract the effects predicted by SMEFT operators, necessitating precise theoretical and experimental handling. By examining $pp\to W^{+}{W}^{-}$ production, a process sensitive to the electroweak symmetry-breaking mechanism, we demonstrate the importance of these corrections in isolating and interpreting new physics signatures. Our results highlight the significant role of electroweak corrections in enhancing the interpretative power of LHC data and in obtaining reliable constraints on new physics interactions.

   hep-phhep-exPRD(2024)·10 citations
3. 03*

   Decay of CP-even Higgs $H\to h\gamma \gamma$ in Two Higgs Doublet Model: one-loop analytic results, ward identity checks

   Khiem Hong Phan (Duy Tan Univ.)🇩🇰 · Dzung Tri Tran (Duy Tan Univ.)🇩🇰 · Thanh Huy Nguyen (HCMUS)🇻🇳

   The first analytic expressions for loop-induced contributions for the decay of CP-even Higgs $H\to h\gamma \gamma$ with $h$ being Standard-Model-like Higgs boson within the framework of Two Higgs Doublet Model are presented in this paper. The one-loop form factors for the decay processes are written in terms of the scalar one-loop Passarino-Veltman functions following the notations of the packages~{\tt LoopTools} and {\tt Collier}. Subsequently, physical results for the decay processes can be generated numerically by using one of the above-mentioned packages. The analytic expressions shown in this paper are verified by several numerical checks, for examples, the ultraviolet and infrared finiteness of one-loop amplitude. Furthermore, the amplitude satisfies the Ward-Takahashi identity due to on-shell photons in final states. The identity is also verified numerically in this work. In phenomenological studies, the differential decay rates as functions of the invariant mass of two photons in final states of $H\to h\gamma \gamma$ are first studied in parameter space of the Two Higgs Doublet Models.

   hep-phPTEP(2025)·6 citations
4. 04*

   Theoretical predictions for $t\bar{t}W$ cross sections at approximate N${}^3$LO

   Nikolaos Kidonakis🇺🇸 · Chris Foster🇺🇸

   We present theoretical calculations of higher-order QCD and electroweak corrections for the associated production of a top-antitop quark pair and a $W$ boson ($t\bar{t}W$ production) at LHC energies. We show predictions for cross sections at approximate N${}^3$LO (aN${}^3$LO) which include second-order and third-order soft-gluon corrections added to the exact NLO QCD+electroweak result. We compare our results to recent measurements from the LHC, and we find that our predictions provide improved agreement with the data. We also calculate the top-quark transverse momentum and rapidity distributions in $t\bar{t}W$ production. We find significant enhancements from the higher-order corrections to the total and differential cross sections for this process.

   hep-phPoS(2025)·1 citation
5. 05*

   Investigating higgsino dark matter in the semi-constrained NMSSM

   Kun Wang🇨🇳 · Jingya Zhu🇨🇳

   In this study, we explore the characteristics of higgsino-dominated dark matter (DM) within the semi-constrained Next-to-Minimal Supersymmetric Standard Model (scNMSSM), covering a mass range from hundreds of GeV to several TeV. We carefully analyzed the parameter space under existing theoretical and experimental constraints to confirm the viability of higgsino-dominated lightest supersymmetric particles (LSPs) with masses between 100 GeV and 4 TeV. Our study examines various DM annihilation mechanisms, emphasizing the significant role of coannihilation with the next-to-lightest supersymmetric particle (NLSP), which includes other higgsino-dominated particles such as ${\tilde{\chi }}_2^0$ and ${\tilde{\chi }}_1^{\pm }$. We categorize the annihilation processes into three main classes: ${\tilde{\chi }}_1^{\pm }$ coannihilation, Higgs funnel annihilation, and ${\tilde{\tau }}_1$ coannihilation, each combines interactions with ${\tilde{\chi }}_1^{\pm }$. Our results indicate that achieving the correct relic density in heavier higgsino LSPs requires a combination of coannihilation and Higgs funnel mechanisms. We also assess the potential of future experiments, such as XENONnT, LUX-ZEPLIN (LZ), PandaX-xT, and the Cherenkov Telescope Array (CTA), to probe these DM scenarios through direct and indirect detection. In particular, future spin-independent DM detection can cover all samples with the correct DM relic density for $\mu \gtrsim 1300$ GeV. Furthermore, future colliders like the International Linear Collider (ILC) and the Compact Linear Collider (CLIC) are found to exceed the detection capabilities of current hadron colliders, especially for higher mass NLSPs. Notably, CLIC at 3000 GeV is anticipated to thoroughly investigate all samples with insufficient DM relic density for $\mu \lesssim 1300$ GeV.

   hep-phCPC(2024)·5 citations
6. 06*

   Theoretical constraints on models with vector-like fermions

   Amit Adhikary🇫🇷 · Marek Olechowski🇵🇱 · Janusz Rosiek🇵🇱 · Michal Ryczkowski🇵🇱

   We provide a set of theoretical constraints on models in which the Standard Model field content is extended by vector-like fermions and in some cases also by a real scalar singlet. Our approach is based on the study of electroweak vacuum stability, perturbativity of model couplings and gauge couplings unification with the use of renormalization group equations. We show that careful analysis of these issues leads to strong constraints on the parameter space of the considered models. This, in turn, has important implications for phenomenology, as we show using examples of the double Higgs boson production, electroweak precision observables, and the electroweak phase transition.

   hep-phPRD(2024)·23 citations
7. 07*

   Update on technical aspects of $B$ meson mixing at NNLO

   Pascal Reeck🇩🇪

   This report summarises important technical challenges and their solutions in the calculation of the next-to-next-to-leading order QCD corrections to the width difference $\Delta {\Gamma }_s$ in the $B_s-{\overline{B}}_s$ system. We focus on the treatment of spinor structures with products of up to 22 $\gamma$ matrices by means of projection and tensor integrals. Moreover, we present an approach for the semi-numeric computation of master integrals.

   hep-phPoS(2024)·1 citation
8. 08*

   Exploring the mass spectrum and the electromagnetic properties of the possible ${\Xi }_{cc}{K}^{(\ast )}$ and ${\Xi }_{cc}{\bar{K}}^{(\ast )}$ molecules

   Li-Cheng Sheng🇨🇳 · Jin-Yu Huo🇨🇳 · Rui Chen🇨🇳 · Fu-Lai Wang🇨🇳 · Xiang Liu🇨🇳

   Using the one-boson-exchange model, we investigate the interactions between the doubly charmed baryon ${\Xi }_{cc}(3621)$ and the $S-$wave (anti-)kaon accounting for the $S-D$ wave mixing and coupled-channel effects. We find the coupled ${\Xi }_{cc}K/{\Xi }_{cc}{K}^{\ast }$ state with $I(J^P)=0(1/2^{-})$, the ${\Xi }_{cc}{K}^{\ast }$ state with $0(1/2^{-})$, the ${\Xi }_{cc}\bar{K}$ state with $0(1/2^{-})$, and the ${\Xi }_{cc}{\bar{K}}^{\ast }$ states with $0(1/2^{-},3/2^{-})$ can be recommended as good doubly charmed molecular candidates with strangeness $|S|=1$. We further examine their M1 radiative decay behaviors and magnetic moments within the constituent quark model framework. This information can enhance our understanding of their inner structures, including the distribution of electric charge and the orientation of the constituent quarks' spins.

   hep-phPRD(2024)·12 citations
9. 09*

   Determination of Strong Coupling Constant from Inclusive Semileptonic Decays of Charmed Mesons

   Jinfei Wu🇨🇳 · Xinchou Lou🇨🇳 · Yuzhi Che🇨🇳 · Gang Li🇨🇳 · Yanping Huang🇨🇳 · Manqi Ruan🇨🇳 · Jingbo Ye🇨🇳

   Employing the heavy quark expansion model with the kinetic scheme, we evaluate ${\alpha }_S(m_c^2)$, the strong coupling constant at the charm quark mass $m_c$ with data on inclusive semileptonic decays of charmed mesons. Using the experimental values of semileptonic decay widths of the $D^0$ and the $D^{+}$, the value of ${\alpha }_s(m_c^2)$ is determined to be $0.445\pm 0.009\pm 0.114$, where the first uncertainty is experimental and the second systematic. This reported ${\alpha }_s(m_c^2)$ is in good agreement with the value of ${\alpha }_s(m_c^2)$ calculated by running ${\alpha }_S(m_Z^2)$ at the $Z^0$ boson mass $m_Z$ with the renormalization group evolution equation. In addition, values of ${\alpha }_s(m_c^2)$ obtained individually from each of the $D^0$, $D^{+}$, and $D_s^{+}$ mesons are found to be consistent being of the same origin.

   hep-phhep-exCPC(2025)·4 citations
10. 10*

    A Benchmarking of QCD Evolution at Approximate $N^{3}LO$

    A. Cooper-Sarkar🇬🇧 · T. Cridge🇩🇪 · F. Giuli🇨🇭 · L.A. Harland-Lang🇬🇧 · F. Hekhorn🇫🇮 · J. Huston🇺🇸 · G. Magni🇳🇱 · S. Moch🇩🇪 · R.S. Thorne🇬🇧

    We present a detailed benchmarking of different treatments of the QCD evolution of unpolarized PDFs at approximate $N^{3}LO$ ($a{N}^{3}LO$) order in the QCD coupling. Namely, the implementations in the public $a{N}^{3}LO$ releases of the MSHT and NNPDF global PDF fitters, as well as that of the theoretical FHMRUVV collaboration are compared. This follows the same procedure as in previous benchmarking exercises at lower order, that is by considering the impact of this evolution on a set of simple toy PDFs.

    hep-ph23 citations
11. 11*

    Comments on the publication "Discrete symmetries tested at 10e-4 precision using linear polarization of photons from positronium annihilations" by P. Moskal et al

    E.A. George🇺🇸 · T.E. Haugen🇺🇸 · O. Naviliat-Cuncic🇫🇷 · P.A. Voytas🇺🇸

    The authors of Ref.[1] (referred to here as "Moskal et al.") claim to have performed the most precise test of P, T and CP invariance in the decay of ortho-Positronium. In this note: 1) we demonstrate, assuming standard properties for Compton scattering, that the average value of the correlation measured by Moskal et al. must necessarily be zero, independently of any physics occurring in o-Ps decay; 2) we point out that there is no formal justification to equate the normal vector to the Compton scattering plane with the incident photon polarization, as done by Moskal et al.; 3) we observe the absence of characterization of the device as a Compton polarimeter, which is paramount in photon polarimetry; 4) we review previous measurements of the polarization of photons from o-Ps decay, properly implementing the Compton polarimetry technique, and make the connection with tests of discrete symmetries; and 5) we stress that the correlation proposed by Moskal et al. cannot be generated solely by the physics of o-Ps decay, including possible violations of discrete symmetries.

    hep-phhep-exnucl-ex1 citation
12. 12*

    Displaced Heavy Neutral Lepton from New Higgs Doublet

    Fa-Xin Yang🇨🇳 · Feng-Lan Shao🇨🇳 · Zhi-Long Han🇨🇳 · Yi Jin🇨🇳 · Honglei Li🇨🇳

    Heavy neutral leptons $N$ are introduced to explain the tiny neutrino masses via the seesaw mechanism. For proper small mixing parameter $V_{\ell N}$, the heavy neutral leptons $N$ become long-lived, which leads to the displaced vertex signature at colliders. In this paper, we consider the displaced heavy neutral lepton from the neutrinophilic Higgs doublet ${\Phi }_{\nu }$ decay. The new Higgs doublet with MeV scale VEV can naturally explain the tiny neutrino masses with TeV scale $N$. Different from current experimental searches via the $W^{\pm }\to {\ell }^{\pm }N$ decay, the new decays as $H^{\pm }\to {\ell }^{\pm }N$ are not suppressed by the small mixing parameter $V_{\ell N}$. Therefore, a larger parameter space is expected to be detected at colliders. We then investigate the promising region at the 14 TeV HL-LHC and the 3 TeV CLIC. According to our simulation, the DV signature could probe $|V_{\ell N}{|}^2\gtrsim 10^{-19}$ with $m_N<m_{H^{+}}$, which covers the seesaw predicted value $|V_{\ell N}{|}^2\sim m_{\nu }/m_N$. We could probe $m_{H^{+}}\lesssim 1200$ GeV at the 14 TeV HL-LHC and $m_{H^{+}}\lesssim 1490$ GeV at the 3 TeV CLIC.

    hep-phhep-exEPJC(2025)·3 citations
13. 13*

    Constraining long-lived particles from Higgs boson decays at the LHC with displaced vertices and jets

    Zeren Simon Wang🇹🇼

    Long-lived particles (LLPs) originating from decays of the Standard-Model or Beyond-the-Standard-Model Higgs bosons are often featured with signatures of displaced vertices (DVs) and jets at colliders. In this work, we show that a recent ATLAS search for DVs plus jets, with its recast implementation, can efficiently place bounds on such hadronically or semi-leptonically decaying LLPs. In particular, we find the search is uniquely sensitive to LLP proper decay lengths of about 1-100 mm, probing complementary regions in the parameter space of the relevant models compared to other prompt and LLP searches.

    hep-phhep-exPRD(2024)·9 citations
14. 14*

    Pursue of CP violation in hyperon decay

    German Valencia🇦🇺

    I review the status of CP violation in hyperon decay in light of recent progress by BESIII and the anticipated improvements at the super tau-charm facility. I emphasize the complementarity between kaons and hyperons for studying CP violation in $|\Delta S|=1,2$ processes.

    hep-phInt.J.Mod.Phys.A(2024)·0 citations
15. 15*

    Bell nonlocality and entanglement in $e^{+}{e}^{-}\to Y\bar{Y}$ at BESIII

    Sihao Wu🇨🇳 · Chen Qian🇨🇳 · Qun Wang🇨🇳 · Xiao-Rong Zhou🇨🇳

    The Bell nonlocality and entanglement are two kinds of quantum correlations in quantum systems. Due to the recent upgrade in Beijing Spectrometer III (BESIII) experiment, it is possible to explore the nonlocality and entanglement in hyperon-antihyperon systems produced in electron-positron annihilation with high precision data. We provide a systematic method for studying quantum correlations in spin-1/2 hyperon-antihyperon systems through the measures for the nonlocality and entanglement. We find that with nonvanishing polarizations of the hyperon and its antihyperon, the kinematic region of nonlocality in the hyperon-antihyperon system is more restricted than the ${\tau }^{+}{\tau }^{-}$ system in which polarizations of $\tau$ leptons are vanishing. We also present an experimental proposal to probe the nonlocality and entanglement in hyperon-antihyperon systems at BSEIII.

    hep-phquant-phPRD(2024)·50 citations
16. 16*

    Large CP Violation from the Minimum Seesaw Model

    Yu-Cheng Qiu🇨🇳 · Jin-Wei Wang🇨🇳 · Tsutomu T. Yanagida🇯🇵

    The minimum seesaw model with two right-handed neutrinos is considered, where the lightest neutrino is naturally massless. Instead of adopting texture zeros in the lepton Yukawa matrices, which cause both theoretical and experimental troubles, here we propose two-$\mathbf{ϵ}$ textures, where $\mathbf{ϵ}$ is a small number. Combined with neutrino oscillation experimental data, we find that a large CP angle is preferred for the normal neutrino mass order. In contrast, the CP angle almost vanishes for the inverted order. This can be well-tested in near-future experiments, such as Hyper-Kamiokande. Besides, the predicted effective Majorana neutrino mass $m_{ee}$ and the total neutrino mass $\sum m_i^{\nu }$ are also within reach of ongoing or future experiments.

    hep-phPRD(2024)·0 citations
17. 17*

    Constraining dark matter from strong phase transitions in a $U(1{)}_{L_{\mu }-L_{\tau }}$ model: Implications for neutrino masses and muon $g-2$

    Sandhya Choubey🇸🇪 · Sarif Khan🇩🇪 · Marco Merchand🇸🇪 · Sampsa Vihonen🇸🇪

    In this paper, we study a non-minimal gauged $U(1{)}_{L_{\mu }-L_{\tau }}$ model, where we add two complex singlet scalars, three right-handed Majorana neutrinos (RHN), and a vector-like dark fermion to the Standard Model (SM), all non-trivially charged under the extra gauge symmetry. The model offers an easy resolution to the muon $(g-2)$ anomaly, which fixes the scale of spontaneous symmetry breaking. Furthermore, the two-zero minor structure in the RHN mass matrix provides successful predictions for neutrino oscillation parameters, including the Dirac phase. The extended scalar sector can easily induce first-order phase transitions. We identify all possible phase transition patterns in the three-dimensional field space. We quantify the associated gravitational waves from the sound wave source and demonstrate that the signatures can be observed in future space-based experiments. We find that strong first-order phase transitions require large values of scalar quartic couplings which constrain the scalar dark matter (DM) relic density to a maximum of $10^{-2}$ and $10^{-5}$ when we consider the DM direct detection bound. Nonetheless, the model successfully explains the DM relic density via contribution from the vector-like dark fermion. We show the allowed range of the model parameters that can address all the beyond SM issues targeted in this study.

    hep-phJHEP(2024)·4 citations
18. 18*

    Probing the Neutrino Seesaw Scale with Gravitational Waves

    Bartosz Fornal🇺🇸 · Dyori Polynice🇺🇸 · Luka Thompson🇺🇸

    Neutrinos are the most elusive particles of the Standard Model. The physics behind their masses remains unknown and requires introducing new particles and interactions. An elegant solution to this problem is provided by the seesaw mechanism. Typically considered at a high scale, it is potentially testable in gravitational wave experiments by searching for a spectrum from cosmic strings, which offers a rather generic signature across many high-scale seesaw models. Here we consider the possibility of a low-scale seesaw mechanism at the PeV scale, generating neutrino masses within the framework of a model with gauged U(1) lepton number. In this case, the gravitational wave signal at high frequencies arises from a first order phase transition in the early Universe, whereas at low frequencies it is generated by domain wall annihilation, leading to a double-peaked structure in the gravitational wave spectrum. The signals discussed here can be searched for in upcoming experiments, including gravitational wave interferometers, pulsar timing arrays, and astrometry observations.

    hep-phgr-qcPRD(2024)·4 citations
19. 19*

    Production of pentaquarks with hidden charm and double strangeness in ${\Xi }_b$ and ${\Omega }_b$ decays

    E. Oset🇪🇸 · L. Roca🇪🇸 · M. Whitehead🇬🇧

    Recently, several pentaquark states $P_{css}$, with global flavor $\bar{c}cssn$, have been predicted within a theoretical framework based on unitary coupled channels. We study theoretically the feasibility to observe the $P_{css}$ with $I(J^P)=\frac{1}{2}({\frac{1}{2}}^{-})$ in the decays ${\Xi }_b^0\to \eta {\eta }_c{\Xi }^0$ and ${\Omega }_b^{-}\to K^{-}{\eta }_c{\Xi }^0$. Indeed, within the model, the ${\eta }_c{\Xi }^0$ channel is the lowest mass pseudoscalar-baryon channel to which this pentaquark state couples, thus we can expect to observe its signal in the ${\eta }_c{\Xi }^0$ invariant mass distribution of the mentioned decays. We identify the dominant weak decay processes and then implement the hadronization into the different meson-baryon channels in the final state, linked by flavor symmetry. The dominant meson-baryon final state interaction is then implemented to generate the full amplitude, implicitly accounting for the dynamical emergence of the pentaquark states. We obtain a clear Breit-Wigner-like resonant signal in the spectrum of the ${\Omega }_b^{-}$ decay, exceeding that in the ${\Xi }_b^0$ decay by two to three orders of magnitude. In the case of the latter decay, the resonant state would manifest as a significant dip in the spectrum. We study the feasibility of searching for these $b$-hadron decay modes and analysing their resonant components using the current and future data samples from the LHCb experiment.

    hep-phPRD(2024)·10 citations
20. 20*

    A Scotogenic model with U(1) symmetry and a scalar dark matter

    Anjan Kumar Barik🇮🇳 · Najimuddin Khan🇮🇳 · Santosh Kumar Rai🇮🇳

    We study a scotogenic model augmented with an additional U(1) gauge and a discrete Z2 symmetry. The lightest Z2-odd particle in our model becomes the dark matter (DM) candidate while tiny neutrino masses are realized at one loop. We explore the parameter space of the model for which the DM relic density is satisfied, and the correct low-energy neutrino observables are reproduced. The extended gauge symmetry includes beyond Standard Model (SM) particle spectrum consisting of vector-like fermions and scalars. We also highlight possible collider signatures of these particles at the LHC.

    hep-phPRD(2025)·2 citations
21. 21*

    Radiative QED corrections to the lepton anomaly from four-loop vacuum polarization insertions with three identical leptons

    O.P. Solovtsova🇷🇺 · V.I. Lashkevich🇧🇾 · L.P. Kaptari🇷🇺

    Analytical expressions for the tenth order electromagnetic corrections to the lepton ($L=e,\mu$ and $\tau$) anomaly $a_L$ are derived explicitly for a class of Feynman diagrams with insertions of the vacuum polarization operator consisting of four closed lepton loops. We consider a particular case when one loop is formed by the lepton $L$ of the same kind as the one under consideration, the other three loops being formed by leptons $\ell \ne L$. The method is based on the consecutive application of dispersion relations for the polarization operator and the Mellin--Barnes transform for the propagators of massive particles. The result is expressed in terms of the mass ratio $r=m_{\ell }/m_L$. We investigate the behaviour of the exact analytical expressions as $r\to 0$ and $r\to \infty$ and compare them with the corresponding asymptotic expansions known in the literature.

    hep-phhep-th0 citations
22. 22*

    Theory Driven Evolution of the Weak Mixing Angle

    Jens Erler🇩🇪 · Rodolfo Ferro-Hernandez🇩🇪 · Simon Kuberski🇨🇭

    We present the first purely theoretical calculation of the weak mixing angle in the MS scheme at low energies by combining results from lattice QCD with perturbation theory. We discuss its correlation with the hadronic contribution to the anomalous magnetic moment of the muon and to the energy dependence of the electromagnetic coupling. We also compare the results with calculations using cross-section data as input. Implications for the Standard Model prediction of the mass of the W boson are also discussed.

    hep-phhep-latPRL(2024)·8 citations
23. 23*

    Phenomenological Aspects of Lee-Wick QED

    Fayez Abu-Ajamieh🇮🇳 · Pratik Chattopadhyay🇨🇳 · Marco Frasca🇮🇹

    We study some phenomenological aspects of Lee-Wick (LW) QED. In particular, we show that LW QED implies charge dequantization and a flavor-dependent LW scale. We study the implications of the Weak Gravity Conjecture (WGC) in LW QED and calculate the modified electric force and potential and use the former to reformulate the WGC in LW QED. We also calculate the photon self-energy and the Uehling potential in LW QED. We show that bounds on milli-charged particles from matter neutrality experiments and from Cavendish-type experiments set stringent limits on the LW scale of fermions and of the photon.

    hep-phNPB(2025)·8 citations
24. 24*

    Modeling of axion and electromagnetic fields coupling in a particle-in-cell code

    Xiangyan An🇨🇳 · Min Chen🇨🇳 · Jianglai Liu🇨🇳 · Zhengming Sheng🇨🇳 · Jie Zhang🇨🇳

    Axions have aroused widespread research interest because they can solve the strong CP problem and serve as a possible candidate for dark matter. Currently, people have explored a lot of axion detection experiments, including passively detecting the existing axions in the universe, and actively generating axions in the laboratory. Recently, axion-coupled laser-plasma interactions have been discussed as a novel method to detect axions. Petawatt (PW) lasers are considered as a powerful tool to study not only the vacuum polarization but also the axion coupling, due to their extreme fields. However, particle-in-cell (PIC) simulation is still missed in current studies, which limits the understanding of axion-coupled laser-plasma interactions. In this paper, we proposed the method to include the axion field and the coupling with electromagnetic (EM) fields in PIC codes. The axion wave equation and modified Maxwell's equations are numerically solved, while the EM field modulation from axions is considered as a first-order perturbation. Meanwhile, different axion field boundary conditions are considered to satisfy different simulation scenarios. The processes of conversions between axions and photons, and weak laser pulse propagation with axion effects are checked as benchmarks of the code. Such an extended PIC code may help researchers develop novel axion detection schemes based on laser-plasma interactions and provide a better understanding of axion-coupled astrophysical processes.

    hep-phphysics.plasm-phMatter Radiat.Extremes(2024)·5 citations
25. 25*

    Discovering neutrino tridents at the Large Hadron Collider

    Wolfgang Altmannshofer🇺🇸 · Toni Mäkelä🇵🇱 · Subir Sarkar🇬🇧 · Sebastian Trojanowski🇵🇱 · Keping Xie🇺🇸 · Bei Zhou🇺🇸

    Neutrino trident production of di-lepton pairs is well recognized as a sensitive probe of both electroweak physics and physics beyond the Standard Model. Although a rare process, it could be significantly boosted by such new physics, and it also allows the electroweak theory to be tested in a new regime. We demonstrate that the forward neutrino physics program at the Large Hadron Collider offers a promising opportunity to measure for the first time, dimuon neutrino tridents with a statistical significance exceeding $5\sigma$. We present predictions for various proposed experiments and outline a specific experimental strategy to identify the signal and mitigate backgrounds, based on "reverse tracking" dimuon pairs in the FASER$\nu$2 detector. We also discuss prospects for constraining beyond Standard Model contributions to neutrino trident rates at high energies.

    hep-phhep-exPRD(2024)·28 citations
26. 26*

    Study of Heavy Quarkonia in the presence of magnetic field by Nikiforov Uvarov method

    Rishabh Sharma🇮🇳 · Siddhartha Solanki🇮🇳 · Manohar Lal🇮🇳 · Vineet Kumar Agotiya🇮🇳

    The N-dimensional radial Schrodinger equation has been solved using the Nikiforov Uvarov (NU) method, in which we used the medium modified form of Cornell potential and quasi-particle Debye mass with strong magnetic field background. The binding energies and the mass spectra of heavy quarkonium have been studied in the N-dimensional space for different values of magnetic field, the binding energy decreases with increasing magnetic field, which shows early dissociation of heavy quarkonium system. The influence of dimensionality number has also been discussed on binding energies of J/{\psi} and {\Upsilon} for fixed value of magnetic field. It is found that with an increase in dimensionality, the binding energy starts decreasing from a higher initial value. The results obtained are quite consistent with recent studies.

    hep-phnucl-thInt.J.Mod.Phys.A(2024)·3 citations
27. 27*

    Spurious gauge-invariance and ${\gamma }_5$ in Dimensional Regularization

    Pablo Olgoso Ruiz🇮🇹 · Luca Vecchi🇮🇹

    Dimensional regularization is arguably the most popular and efficient scheme for multi-loop calculations. Yet, when applied to chiral (gauge) theories like the Standard Model and its extensions, one is forced to deal with the infamous "${\gamma }_5$ problem". The only formulation that has been demonstrated to be consistent at all orders in perturbation theory, known as Breiteinlhoner-Maison-'t Hooft-Veltman scheme, is rather cumbersome because of the lack of manifest chiral gauge-invariance. In this paper we point out that this drawback can be alleviated by the introduction of auxiliary fields that restore a spurious version of gauge-invariance. If combined with the background field method, all 1PI amplitudes and the associated counterterms are formally covariant and thus severely constrained by the symmetries. As an illustration we evaluate the symmetry-restoring counterterms at 1-loop in the most general renormalizable gauge theory with Dirac fermions and scalar fields, the Standard Model representing a particular example.

    hep-phhep-thJHEP(2024)·19 citations
28. 28*

    Explaining PTA Results by Metastable Cosmic Strings from SO(10) GUT

    Stefan Antusch🇨🇭 · Kevin Hinze🇨🇭 · Shaikh Saad🇨🇭

    In a recent paper (see https://doi.org/10.1103/PhysRevD.108.095053), we have demonstrated that the 2023 PTA results, which hint at a stochastic gravitational wave (GW) background at nanohertz frequencies, point towards a promising model-building route for realizing $SO(10)$ Grand Unification with embedded inflation. The proposed supersymmetric scenario solves the doublet-triplet splitting without fine-tuning, accounts for charged fermion and neutrino masses, avoids conflicts with current proton decay bounds, and includes only representations no larger than the adjoint. It features multi-step breaking of $SO(10)$ to the Standard Model gauge symmetry, with inflation embedded such that metastable cosmic strings are produced at the end of inflation. This cosmic string network generates a stochastic GW background that can explain the PTA results. In this paper, we provide a detailed analysis of the singled out GUT model class, focusing on how the gauge coupling unification condition affects the scales of multi-step $SO(10)$ breaking and the preferred GW spectra. The lowest breaking scale, linked to inflation, the generation of right-handed neutrino masses for the seesaw mechanism, and metastable cosmic string production, coincides with the range suggested by the PTA results.

    hep-phastro-ph.COJCAP(2024)·23 citations
29. 29*

    The neutrino roof: Single-scatter ceilings in dark matter direct detection

    Nirmal Raj🇮🇳 · Biprajit Mondal🇮🇳

    We identify the maximum cross sections probed by single-scatter ``WIMP" searches in dark matter direct detection. Due to Poisson fluctuations in scatter multiplicity, these ceilings scale logarithmically with mass for heavy dark matter and often lie in regions probed by multiscatter searches. Using a generalized formula for single-scatter event rates we recast WIMP searches by the quintal-to-tonne scale detectors XENON1T, XENONnT, LZ, PANDAX-II, PANDAX-4T, DarkSide-50 and DEAP-3600 to obtain ceilings and floors up to a few $10^{17}$ GeV mass and $10^{-22}$ cm${}^2$ per-nucleus cross section. We do this for coherent, geometric, isospin-violating xenophobic and argophobic spin-independent scattering, and neutron-only and proton-only spin-dependent scattering. Future large-exposure detectors would register an almost irreducible background of atmospheric neutrinos that would determine a dark matter sensitivity ceiling that we call the ``neutrino roof", in analogy with the well-studied ``neutrino floor". Accounting for this background, we estimate the reaches of the 10$-$100 tonne scale DarkSide-20k, DARWIN/XLZD, PANDAX-xT, and Argo, which would probe many decades of unconstrained parameter space up to the Planck mass, as well as of $10^3-10^4$ tonne scale noble liquid detectors that have been proposed in synergy with neutrino experiments.

    hep-phastro-ph.HEhep-exPRD(2024)·6 citations
30. 30*

    Phenomenology of ultralight bosons around compact objects: in-medium suppression

    Enrico Cannizzaro🇵🇹 · Thomas F.M. Spieksma🇩🇰

    Mixing between ultralight bosons and the Standard Model photon may allow access to the hitherto invisible Universe. In the presence of plasma, photons are dressed with an effective mass which will influence the conversion between the two. We study this phenomenon, known as in-medium suppression, in the context of black hole physics. We consider both axion-photon mixing around charged black holes and dark photon-photon mixing around neutral black holes. We find that the presence of plasma indeed influences the conversion rate, possibly quenching it altogether for large plasma densities, and discuss implications for superradiance and observational signatures.

    hep-phastro-ph.HEgr-qcPRD(2024)·7 citations
31. 31*

    Cosmic Stability of Dark Matter from Pauli Blocking

    Brian Batell🇺🇸 · Wen Yin🇯🇵

    Why does dark matter (DM) live longer than the age of the Universe? Here we study a novel sub-eV scalar DM candidate whose stability is due to the Pauli exclusion of its fermionic decay products. We analyze the stability of the DM condensate against decays, scatterings (i.e., evaporation), and parametric resonance, delineating the viable parameter regions in which DM is cosmologically stable. In a minimal scenario in which the scalar DM decays to a pair of new exotic fermions, we find that scattering can populate an interacting thermal dark sector component to energies far above the DM mass. This self-interacting dark radiation may potentially alleviate the Hubble tensions. Furthermore, our scenario can be probed through precise measurements of the halo mass function or the masses of dwarf spheroidal galaxies since scattering prevents the DM from becoming too dense. On the other hand, if the lightest neutrino stabilizes the DM, the cosmic neutrino background (C$\nu$B) can be significantly altered from the $\Lambda$CDM prediction and thus be probed in the future by C$\nu$B detection experiments.

    hep-phPRD(2024)·8 citations
32. 32*

    Thermal Dark Matter with Low-Temperature Reheating

    Nicolás Bernal🇦🇪 · Kuldeep Deka🇦🇪 · Marta Losada🇦🇪

    We explore the production of thermal dark matter (DM) candidates (WIMPs, SIMPs, ELDERs and Cannibals) during cosmic reheating. Assuming a general parametrization for the scaling of the inflaton energy density and the standard model (SM) temperature, we study the requirements for kinetic and chemical DM freeze-out in a model-independent way. For each of the mechanisms, up to two solutions that fit the entire observed DM relic density exist, for a given reheating scenario and DM mass. As an example, we assume a simple particle physics model in which DM interacts with itself and with SM through contact interactions. We find that low-temperature reheating can accommodate a wider range of couplings and larger masses than those permitted in the usual instantaneous high-temperature reheating. This results in DM solutions for WIMPs reaching masses as high as $10^{14}$~GeV, whereas for SIMPs and ELDERs, we can reach masses of $10^{13}$~GeV. Interestingly, current experimental data already constrain the enlarged parameter space of these models with low-reheating temperatures. Next-generation experiments could further probe these scenarios.

    hep-phastro-ph.COhep-thJCAP(2024)·34 citations
33. 33*

    Meso-inflationary Peccei-Quinn symmetry breaking with non-minimal coupling

    Yermek Aldabergenov🇨🇳 · Ding Ding🇨🇳 · Wei Lin🇨🇳 · Yidun Wan🇨🇳

    We study a realization of the inflationary scenario where the Peccei-Quinn (PQ) symmetry is spontaneously broken during inflation, facilitated by its non-minimal coupling to gravity. This results in effectively two-field inflation: the early stage is driven by an inflaton field with the PQ symmetry intact, and the later stage is driven by the PQ scalar after its effective mass becomes tachyonic, causing destabilization from the origin. The non-minimal coupling serves the dual purpose of restoring the PQ symmetry during early inflation and flattening the PQ potential post-tachyonic shift, allowing for continued slow roll. We analyze the inflationary background solutions and scalar perturbations, which are amplified at small scales via significant isocurvature perturbations generated near the symmetry-breaking epoch. These perturbations lead to second-order gravitational waves, detectable by next-generation space-based experiments.

    ↳ hep-thastro-ph.COgr-qchep-phAstrophys.J.Suppl.(2024)·6 citations
34. 34*

    Search for charmed baryons in the ${\Lambda }_c^{+}\eta$ system and measurement of the branching fractions of ${\Lambda }_c(2880{)}^{+}$ and ${\Lambda }_c(2940{)}^{+}$ decaying to ${\Lambda }_c^{+}\eta$ and $p{D}^0$ relative to ${\Sigma }_c(2455)\pi$

    Belle Collaboration: S. X. Li🇨🇳 · C. P. Shen🇨🇳 · I. Adachi🇯🇵 · J. K. Ahn🇰🇷 · H. Aihara🇯🇵 · D. M. Asner🇺🇸 · H. Atmacan🇺🇸 · T. Aushev🇷🇺 · R. Ayad🇸🇦 · Sw. Banerjee🇺🇸 · K. Belous🇷🇺 · J. Bennett🇺🇸 and 115 other authors

    We search for excited charmed baryons in the ${\Lambda }_c^{+}\eta$ system using a data sample corresponding to an integrated luminosity of 980 $\mathrm{f}{\mathrm{b}}^{-1}$. The data were collected by the Belle detector at the KEKB $e^{+}$$e^{-}$ asymmetric-energy collider. No significant signals are found in the ${\Lambda }_c^{+}\eta$ mass spectrum, including the known ${\Lambda }_c(2880{)}^{+}$ and ${\Lambda }_c(2940{)}^{+}$. Clear ${\Lambda }_c(2880{)}^{+}$ and ${\Lambda }_c(2940{)}^{+}$ signals are observed in the $p{D}^0$ mass spectrum. We set upper limits at 90\% credibility level on ratios of branching fractions of ${\Lambda }_c(2880{)}^{+}$ and ${\Lambda }_c(2940{)}^{+}$ decaying to ${\Lambda }_c^{+}\eta$ relative to ${\Sigma }_c(2455)\pi$ of $<0.13$ for the ${\Lambda }_c(2880{)}^{+}$ and $<1.11$ for the ${\Lambda }_c(2940{)}^{+}$. We measure ratios of branching fractions of ${\Lambda }_c(2880{)}^{+}$ and ${\Lambda }_c(2940{)}^{+}$ decaying to $p{D}^0$ relative to ${\Sigma }_c(2455)\pi$ of $0.75\pm 0.03(\text{stat.})\pm 0.07(\text{syst.})$ for the ${\Lambda }_c(2880{)}^{+}$ and $3.59\pm 0.21(\text{stat.})\pm 0.56(\text{syst.})$ for the ${\Lambda }_c(2940{)}^{+}$.

    ↳ hep-exhep-phPRD(2024)·6 citations
35. 35*

    Impact of reactor neutrino uncertainties on coherent scattering's discovery potential

    Leendert Hayen🇫🇷

    Nuclear power reactors are the most intense man-made source of antineutrino's and have long been recognized as promising sources for coherent elastic neutrino-nucleus scattering (CE$\nu$NS) studies. Its observation and the spectral shape of the associated recoil spectrum is sensitive to a variety of exotic new physics scenarios and many experimental efforts are underway. Within the context of the reactor antineutrino anomaly, which initially indicated eV-scale sterile neutrino's, the modeling of the reactor antineutrino spectrum has seen a significant evolution in the last decade. Even so, uncertainties remain due to a variety of nuclear structure effects, incomplete information in nuclear databases and fission dynamics complexities. Here, we investigate the effects of these uncertainties on one's ability to accurately distinguish new physics signals. For the scenarios discussed here, we find that reactor spectral uncertainties are similar in magnitude to the projected sensitivities pointing towards a need for $\beta$ spectroscopy measurements below the inverse $\beta$ decay threshold.

    ↳ nucl-thhep-phnucl-exJ.Phys.G(2025)·3 citations
36. 36*

    Integrated Study of X-ray Spectrum and Time Lags for HBL Mrk 421 within the Framework of the Multiple-Zone Leptonic Model

    Wen Hu🇨🇳 · Jia-Lai Kang🇨🇳 · Zhen-Yi Cai🇨🇳 · Jun-Xian Wang🇨🇳 · Zhen-Bo Su🇨🇳 · Guang-Cheng Xiao🇨🇳

    We present the timing analysis of 10 archived \XMM observations with an exposure of $>40$ ks of Markarian 421. Mrk 421 is the brightest high-frequency-peaked BL Lac object (HBL) emitting in X-rays produced by electrons accelerated in the innermost regions of a relativistic jet pointing toward us. For each observation, we construct averaged X-ray spectra in 0.5--10 keV band, as well as 100 s binned light curves (LCs) in various subbands. During these observations, the source exhibited various intensity states differing by close to an order of magnitude in flux, with the fractional variability amplitude increasing with energy through the X-ray band. Bayesian power spectral density analysis reveals that the X-ray variability can be characterized by a colored noise, with an index ranging from $\sim -1.9$ to $-3.0$. Moreover, both the standard cross-correlation function and cross-spectral methods indicate that the amount of time lags increases with the energy difference between two compared LCs. A time-dependent two-zone jet model is developed to extract physical information from the X-ray emission of Mrk 421. In the model, we assume that the jet emission mostly comprises a quasi-stationary component and a highly variable one. Our results show that the two-zone model can simultaneously provide a satisfactory description for both the X-ray spectra and time lags observed in different epochs, with the model parameters constrained in a fully acceptable interval. We suggest that shocks within the jets may be the primary energy dissipation process responsible for triggering the rapid variability, although magnetic reconnection cannot be excluded.

    ↳ astro-ph.HEastro-ph.GAhep-phApJ(2024)·4 citations
37. 37*

    Brane Profiles of Non-Supersymmetric Strings

    J. Mourad (APC, U. Paris Cité)🇫🇷 · S. Raucci🇮🇹 · A. Sagnotti (Scuola Normale Superiore and INFN, Pisa)🇮🇹

    We connect the indications of 2D CFT for branes in non-supersymmetric strings to actual spacetime profiles, taking the bulk tadpole potentials into account. We find exact solutions for the uncharged branes that spread in the internal intervals of Dudas-Mourad vacua for non-tachyonic orientifolds and heterotic strings. These solutions involve suitable dressings of the uncharged branes of the nine-dimensional tadpole-free theory. Similar exact results for uncharged branes that are transverse to the internal space, or for charged branes, appear more challenging. Nevertheless, we identify their large-distance behavior, which is determined by linearized equations, and show that it is compatible with the CFT analysis in all expected cases. We also provide some hints on the leading back-reaction of the form-fields.

    ↳ hep-thgr-qchep-phmath-ph+1JHEP(2024)·16 citations
38. 38*

    Scale setting and hadronic properties in light quark sector with $(2+1)$-flavor Wilson fermions at the physical point

    Tatsumi Aoyama (Tokyo U., ISSP)🇯🇵 · Takahiro M. Doi (Kyoto U. and Wako, RIKEN)🇯🇵 · Takumi Doi (Wako, RIKEN)🇯🇵 · Etsuko Itou (Kyoto U., Yukawa Inst., Kyoto and Wako, RIKEN)🇯🇵 · Yan Lyu (Wako, RIKEN)🇯🇵 · Kotaro Murakami (Tokyo Inst. Tech. and Wako, RIKEN)🇯🇵 · Takuya Sugiura (Rissho U. and Wako, RIKEN) (HAL QCD Collaboration)🇯🇵

    We report scale setting and hadronic properties for our new lattice QCD gauge configuration set (HAL-conf-2023). We employ $(2+1)$-flavor nonperturbatively improved Wilson fermions with stout smearing and the Iwasaki gauge action on a $96^4$ lattice, and generate configurations of 8,000 trajectories at the physical point. We show the basic properties of the configurations such as the plaquette value, topological charge distribution and their auto-correlation times. The scale setting is performed by detailed analyses of the $\Omega$ baryon mass. We calculate the physical results of quark masses, decay constants of pseudoscalar mesons and single hadron spectra in light quark sector. The masses of the stable hadrons are found to agree with the experimental values within a sub-percent level.

    ↳ hep-lathep-phnucl-thPRD(2024)·25 citations
39. 39*

    Continuous-Spin Particles, On Shell

    Brando Bellazzini🇫🇷 · Stefano De Angelis🇫🇷 · Marcello Romano🇫🇷

    We study on-shell scattering amplitudes for continuous-spin particles (CSPs). Poincaré invariance, little-group $ISO(2)$ covariance, analyticity, and on-shell factorisation (unitarity) impose stringent conditions on these amplitudes. We solve them by realizing a non-trivial representation for all little-group generators on the space of functions of bi-spinors. The three-point amplitudes are uniquely determined by matching their high-energy limit to that of definite-helicity (ordinary) massless particles. Four-point amplitudes are then bootstrapped using consistency conditions, allowing us to analyze the theory in a very transparent way, without relying on any off-shell Lagrangian formulation. We present several examples that highlight the main features of the resulting scattering amplitudes. We discuss CSP's amplitudes as a new infrared deformation of ordinary massless amplitudes, which is controlled by the scale of the Pauli-Lubanski vector squared, as opposed to the familiar mass deformation. Finally, we explore under which conditions it is possible to relax some assumptions, such as strict on-shell factorisation, analyticity, or others. In particular, we also investigate how continuous-spin particles may couple to gravity and electromagnetism, in a loose version of $S$-matrix principles.

    ↳ hep-thhep-phJHEP(2025)·11 citations
40. 40*

    General-relativistic instability in rapidly accreting supermassive stars in the presence of dark matter

    Lionel Haemmerlé🇨🇭

    The collapse of supermassive stars (SMSs) via the general-relativistic (GR) instability would provide a natural explanation to the existence of the most extreme quasars. The presence of dark matter in SMSs is thought to potentially impact their properties, in particular their mass at collapse. Dark matter might be made of weakly interacting massive particles (WIMPs) that can be captured by the gravitational potential well of SMSs due to interaction with the baryonic gas. The annihilation of WIMPs can provide fuel to support the star before H-burning ignition, favouring low densities of baryonic gas, long stellar lifetimes and high final masses. Here, we estimate the impact of dark matter on the GR dynamical stability of rapidly accreting SMSs. We add a dark matter term to the relativistic equation of adiabatic pulsations and apply it to hylotropic structures in order to determine the onset point of the GR instability. We find that, in principle, the dark matter gravitational field can remove completely the GR instability. However, for SMSs fuelled by H-burning, the dark matter densities required to stabilise the star against GR are orders of magnitude above the values that are expected for the dark matter background. On the other hand, for SMSs fuelled by WIMP annihilation, we find that the low densities of baryonic gas inhibit the destabilising GR corrections, which shifts the stability limit by typically an order of magnitude towards higher masses. As long as central temperatures $\lesssim 10^7$ K are maintained by WIMP annihilation, the GR instability is reached only for stellar masses $>10^6$ M${}_{\odot }$. Dark matter can impact the GR dynamical stability of SMSs only in the case of energetically significant WIMP annihilation. The detection of a SMS with mass $>10^6$ M${}_{\odot }$ in an atomically cooled halo can be interpreted as an evidence of WIMP annihilation in the star's core.

    ↳ astro-ph.HEastro-ph.COastro-ph.GAastro-ph.SR+2Astron.Astrophys.(2024)·5 citations
41. 41*

    The Born rule for quantum probabilities from Newton's third law

    S.S. Afonin🇷🇺

    According to the Born rule, the probability density in quantum theory is determined by the square of the wave function. A generally accepted derivation of this rule has not yet been proposed. In the given work, a simple physical picture is constructed within which the Born rule arises in a natural way. In the proposed scheme, the interaction of a particle with a measuring apparatus is equivalent to creation of a "mirror image" of particle wave function in the space region of interaction. The observable quantity is the product of the particle wave function and its "image". The phase of the latter is reversed due to Newton's third law, thus leading to the Born rule.

    ↳ quant-phhep-phhep-th0 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.