Tue·Sep 17, 2024Tuesday·September 17, 2024

1. 01*

   EW corrections and Heavy Boson Radiation at a high-energy muon collider

   Yang Ma🇮🇹 · Davide Pagani🇮🇹 · Marco Zaro🇮🇹

   In this work we investigate several phenomenological and technical aspects related to electroweak (EW) corrections at a high-energy muon collider, focusing on direct production processes (no VBF configurations). We study in detail the accuracy of the Sudakov approximation, in particular the Denner-Pozzorini algorithm, comparing it with exact calculations at NLO EW accuracy. We also assess the relevance of resumming EW Sudakov logarithms (EWSL) at 3 and 10 TeV collisions. Furthermore, we scrutinise the impact of additional Heavy Boson Radiation (HBR), namely the weak emission of $W,Z$, and Higgs bosons in inclusive and semi-inclusive configurations. All results are obtained via the fully automated and publicly available code MadGraph5_aMC@NLO.

   hep-phhep-exPRD(2025)·21 citations
2. 02*

   Towards a unified description of hadron scattering at all energies

   Dominik Stamen🇩🇪 · Daniel Winney🇩🇪 · Arkaitz Rodas🇺🇸 · Cesar Fernandez-Ramirez🇪🇸 · Vincent Mathieu🇪🇸 · Gloria Montana🇺🇸 · Alessandro Pilloni🇮🇹 · Adam P. Szczepaniak🇺🇸

   The construction of general amplitudes satisfying symmetries and $S$-matrix constraints has been the primary tool in studying the spectrum of hadrons for over half a century. In this work, we present a new parameterization, which can fulfill many expectations of $S$-matrix and Regge theory and connects the essential physics of hadron scattering in the resonance region and in asymptotic limits. In this construction, dynamical information is entirely contained in Regge trajectories that generalize resonance poles in the complex energy plane to moving poles in the angular momentum plane. We highlight the salient features of the model, compare with existing literature on dispersive and dual amplitudes, and benchmark the formalism with an initial numerical application to the $\rho$ and $\sigma /f_0(500)$ mesons in $\pi \pi$ scattering.

   hep-phhep-thPRD(2024)·5 citations
3. 03*

   N${}^3$LL + $\mathcal{O}({\alpha }_s^2)$ predictions of lepton-jet azimuthal angular distribution in deep-inelastic scattering

   Shen Fang🇨🇳 · Mei-Sen Gao🇨🇳 · Hai Tao Li🇨🇳 · Ding Yu Shao🇨🇳

   We present an analysis of lepton-jet azimuthal decorrelation in deep-inelastic scattering (DIS) at next-to-next-to-next-to-leading logarithmic (N${}^3$LL) accuracy, combined with fixed-order corrections at $\mathcal{O}({\alpha }_s^2)$. In this study, jets are defined in the lab frame using the anti-$k_T$ clustering algorithm and the winner-take-all recombination scheme. The N${}^3$LL resummation results are derived from the transverse-momentum dependent factorization formula within the soft-collinear effective theory, while the $\mathcal{O}({\alpha }_s^2)$ fixed-order matching distribution is calculated using the {\tt NLOJET++} event generator. The azimuthal decorrelation between the jet and electron serves as a critical probe of the three-dimensional structure of the nucleon. Our numerical predictions provide a robust framework for precision studies of QCD and the nucleon's internal structure through jet observables in DIS. These results are particularly significant for analyses involving jets in HERA data and the forthcoming electron-ion collider experiments.

   hep-phhep-exnucl-exnucl-thJHEP(2025)·11 citations
4. 04*

   Tachyonic effects on Kähler moduli stabilized inflaton potential in type-IIB/F theory

   Abhijit Let🇮🇳 · Buddhadeb Ghosh🇮🇳

   We investigate the effects of inclusion of charged tachyonic open-string scalars in the perturbative and the non-perturbative Kähler moduli stabilizations in a geometry of three intersecting magnetized D7-brane stacks in type-IIB/F theory and also study the overall influence of this process on the inflaton potential, in a hybrid inflation scenario. We find that a tachyon lowers the minimum of the inflaton potential and assists to end the inflation. For simplicity, we have included one tachyon at a time in the present work and observe that this procedure preserves the features of slow-roll plateau of the potential. An interesting observation here is that the tachyonic part of the potential can be fine-tuned to get an almost zero minimum of the potential, thereby conforming to the small experimental value of the cosmological constant

   hep-phEPJC(2024)·0 citations
5. 05*

   Study of quasi-two-body B^{0}\rightarrow T(\pi\pi, K\bar{K},\pi\eta) decays in perturbative QCD approach

   Lun-Lian Mu🇨🇳 · Xian-Qiao Yu🇨🇳

   In this study, we calculate the CP-averaged branching ratios and the direct CP-violating asymmetries of the three body decays B^{0}\rightarrow T(\pi\pi, K\bar{K},\pi\eta) in the perturbative QCD approach, where T denotes tensor mesons a_{2}(1320), K^{*}_{2}(1430), f_{2}(1270) and f^{'}_{2}(1525), and the daughter branching is f_{0}(980)\rightarrow \pi\pi, K\bar{K},f_{0}(500)\rightarrow \pi\pi, a_{0}(980)\rightarrow K\bar{K}, \pi\eta. We found the following (a) With \theta=135^{\circ}, we evaluate the branching fractions of B^{0} \rightarrow K^{*}_{2}(1430)f_{0}(980)[ \rightarrow \pi^ {+}\pi^{-}] to be 4.30\times10^{-6},then under the narrow-width approximation we extract the branching fraction of the decay B^{0} \rightarrow K^{*}_{2}(1430)f_{0}(980) to be 8.78\times10^{-6},which is consistent with the current experimental data well. (b) The decay rates for the considered decay modes are generally in the order of 10^{-8} to 10^{-5}. (c) The branching fractions are sensitive to the \theta, and the opposite is true for \phi. The \phi is really small, so the decay branching ratio has only little change, except for some decays involving f^{'}_{2}(1525). (d) The \theta and \phi can bring remarkable change to the direct CP asymmetries of pure penguin processes so that it is not 0. (e) We calculate the relative partial decay widths {\Gamma}(a_{0} \rightarrow K\overline{K})/{\Gamma}(a_{0} \rightarrow \pi\eta) and the ratio {\cal B}(f_{0} \rightarrow K^{+}K^{-})/{\cal B}(f_{0} \rightarrow \pi^{+}\pi^{-}), which are in agreement with the existing experimental values. Our results can help one to understand the internal structure of scalar mesons and the nature of tensor mesons and can be tested by future experiments.

   hep-phPRD(2025)·2 citations
6. 06*

   Heavy top quark mass in the minimal universal seesaw model

   Albertus Hariwangsa Panuluh🇯🇵 · Takuya Morozumi🇯🇵

   We study the hierarchy between $M_T,v_L$, and $v_R$, the relevant energy scales of the Minimal Universal Seesaw Model (MUSM), where the two lightest quark families remain massless at tree level. We also predict the heavy top quark mass, $m_{t^{\prime }}$. We do some numerical analysis using recent experimental data. Our numerical analysis demonstrates that $M_T$ is sensitive to the values of the Yukawa couplings. The heavy top quark mass $(m_{t^{\prime }})$ is predicted to be within the range from 1.4 TeV to 7.2 TeV.

   hep-phhep-exEPJ Web Conf.(2024)·1 citation
7. 07*

   Insight into the nature of the $P_c(4457)$ and related pentaquarks

   U. Özdem🇹🇷

   We systematically study the electromagnetic properties of pentaquark states from different perspectives to better understand their nature, internal structure, and quantum numbers, determine their hadronization processes, and shed light on their true nature. The present study examines the magnetic moments of the $P_c(4457)$ and related hidden-charm pentaquark states with and without strangeness ($[dd][uc]\bar{c}$, $[uu][sc]\bar{c}$, $[dd][sc]\bar{c}$, $[ss][uc]\bar{c}$ and $[ss][dc]\bar{c}$), employing a comprehensive analysis that encompasses both the compact pentaquark configuration and $J^P={\frac{3}{2}}^{-}$ quantum numbers. The present study compares the results regarding the magnetic moment of the $P_c(4457)$ pentaquark state with those reported in the existing literature. The numerical results obtained in this study, when considered alongside existing literature, indicate that the magnetic moments of hidden-charm pentaquark states may offer insights into their underlying structures, which in turn can inform the distinction between their spin-parity quantum numbers. It seems that for the future experimental search of the family of hidden-charm pentaquark states, studying the electromagnetic properties of the hidden-charm pentaquark states can provide valuable information.

   hep-phhep-exhep-latEPJC(2025)·15 citations
8. 08*

   High-Energy and Ultra-High-Energy Neutrinos from Primordial Black Holes

   Quan-feng Wu🇨🇳 · Xun-Jie Xu🇨🇳

   Primordial Black Holes (PBHs) are capable of emitting extremely energetic particles independent of their interactions with the Standard Model. In this work, we investigate whether PBHs evaporating in the early universe could be responsible for some of the observed high-energy neutrinos above the TeV or PeV scale in the present universe. We compute the energy spectrum of neutrinos directly emitted by PBHs with a monochromatic mass function and estimate the wash-out point, which determines the maximum energy of the spectrum. We find that the spectrum generally extends to high energies following a power law of $E_{\nu }^{-3}$ until it reaches the wash-out point, which crucially depends on the PBH mass. For PBHs of $10^{13}$ grams, the spectrum can extend up to the PeV scale, though the flux is too low for detection. We also consider an indirect production mechanism involving dark particles that are emitted by PBHs and decay into neutrinos at a much later epoch. This mechanism allows lighter (such as those in the gram to kilogram range) PBHs to produce more energetic neutrino fluxes without being washed out by the thermal plasma in the early universe. In this scenario, we find that ultra-high-energy neutrinos around or above the EeV scale can be generated, with sufficiently high fluxes detectable by current and future high-energy neutrino observatories such as IceCube and GRAND.

   hep-phastro-ph.COastro-ph.HEJCAP(2025)·19 citations
9. 09*

   Light right-handed Smuons at the LHC: Natural dark matter and $g_{\mu }-2$ in an unexplored realm of the pMSSM

   Xiangwei Yin🇨🇳 · Tianjun Li🇨🇳 · James A. Maxin🇺🇸 · Dimitri V. Nanopoulos🇺🇸

   We introduce an in-depth study of an unprobed pMSSM region offering a natural solution to dark matter. Since the 1980s this region has been referred to as the "bulk", consisting of sub 200 GeV neutralinos and right-handed smuons. The bulk satisfies recent muon $g_{\mu }-2$ measurements and sustains consistency with $all$ presently operating SUSY experiments and LHC constraints. Initial ingress into the bulk will arrive soon via the LUX-ZEPLIN 1000-day experiment. The ATLAS Collaboration at the LHC has confirmed that observation of these light right-handed smuon events can occur at the ongoing LHC Run 3 and forthcoming High-Luminosity LHC. Moreover, the future FCC-ee and CEPC circular colliders should handily observe the events.

   hep-phPRD(2025)·1 citation
10. 10*

    $n-\overline{n}$ Oscillation in $S^1/Z_2\times Z_2^{\prime }$ Orbifold $SU(5)$ GUT

    Ankit Das🇮🇳 · Sarthak Duary🇮🇳 · Utpal Sarkar🇮🇳

    We explore the possibility of $B$ and $B-L$ violating processes, specifically proton decay and neutron-antineutron oscillation, using explicit realization of operators in the $SU(5)$ grand unified theory with an $S^1/Z_2\times Z_2^{\prime }$ orbifold space.

    hep-phhep-thNPB(2025)·0 citations
11. 11*

    Revisiting the Problem of Positronium Moving Across a Magnetic Field

    B. O. Kerbikov🇷🇺 · A. A. Simovonian🇷🇺

    Positronium spectrum and lifetimes are known with high precision. The situation is different for positronium moving across a magnetic field. The total momentum does not commute with the Hamiltonian and is replaced by the conserved pseudomomentum. The internal dynamics is not separated from the motion of the system as a whole. The Coulomb potential well is distorted and a wide outer potential well is created. We analytically determine the energy spectrum for a broad range of magnetic field and pseudomomentum values. The ground state energy is compared with the result obtained by solving the Bethe-Salpeter equation. The gauge independence of the pseudomomentum expectation value is established. On the pseudomomentum-magnetic field plane we locate the region in which the ground state resides in the outer well. The results may play a role in the suppression of pulsars' radio emission (polar cap problem).

    hep-phastro-ph.HEPRD(2025)·1 citation
12. 12*

    Neutral pion to two-photons transition form factor revisited

    M. Atif Sultan🇨🇳 · Jiayin Kang🇨🇳 · Adnan Bashir🇲🇽 · Lei Chang🇨🇳

    Based upon a combined formalism of Schwinger-Dyson and Bethe-Salpeter equations in quantum chromodynamics (QCD), we propose a QCD kindred algebraic model for the dressed quark propagator, for the Bethe-Salpeter amplitude of the pion and the electromagnetic quark-photon interaction vertex. We then compute the ${\gamma }^{\ast }{\pi }^0\gamma$ transition form factor $G^{{\gamma }^{\ast }{\pi }^0\gamma }(Q^2)$ for a wide range of photon momentum transfer squared $Q^2$. The quark propagator is expanded out in its perturbative functional form but with dynamically generated dressed quark mass. It has complex conjugate pole singularities in the complex-momentum plane which is motivated by the solution of the quark gap equation with rainbow-ladder truncation of the infinite set of Schwinger-Dyson equations. This complex pole singularity structure of the quark propagator can be associated with a signal of confinement which prevents quarks to become stable asymptotic states. The Bethe-Salpeter amplitude is expressed without a spectral density function, which encapsulate its low and large momentum behaviour. The QCD evolution of the distribution amplitude is also incorporated into our model through the direct implementation of Efremov-Radyushkin-Brodsky-Lepage evolution equations. We include the effects of the quark anomalous magnetic moment in the description of the quark-photon vertex whose infrared enhancement is known to dictate hadronic properties. Once the QCD kindred model is constructed, we calculate the form factor $G^{{\gamma }^{\ast }{\pi }^0\gamma }(Q^2)$ and find it consistent with direct QCD-based studies as well as most available experimental data. It slightly exceeds the conformal limit for large $Q^2$ which might be attributed to the scaling violations in QCD. The associated interaction radius and neutral pion decay width turn out to be compatible with experimental data.

    hep-phnucl-thPRD(2024)·6 citations
13. 13*

    Two-loop QED/QCD corrections for polarized $\gamma \gamma \to \gamma \gamma$ process in SANCphot

    Serge Bondarenko🇷🇺 · Aidos Issadykov🇷🇺 · Lidia Kalinovskaya🇷🇺 · Andrey Sapronov🇷🇺 · Diana Seitova🇰🇿

    The new version of the SANCphot integrator has been prepared for fast and stable numerical calculations up to two loops for polarized light-by-light scattering. One-loop modules based on the helicity formalism with massive particles and two-loop modules with massless particles inside the loops are used. The presented study is driven by the potential of polarized photon beams to probe the high energy region. This study is a contribution to the research program of the CEPC project being under development in China.

    hep-phJETP Lett.(2024)·0 citations
14. 14*

    Evolution of unpolarized transverse momentum dependent parton distributions of twist-3

    Xue-Tao Liu🇨🇳 · Ping-An Liu🇨🇳 · Yu-Lu Liu🇨🇳 · An-Ping Chen🇨🇳

    We revisit the calculation of the evolution equations for four unpolarized twist-3 transverse momentum dependent (TMD) parton distribution functions (PDFs) at $\mathcal{O}({\alpha }_s)$. Unlike the existing calculations in the literature, which are based on the background field method, we derive the evolution equations directly through diagram expansion. Additionally, instead of using the $\delta$ regulator, we employ the exponential regulator to regularize the rapidity divergences. We find that the evolutions of the four twist-3 TMD PDFs are governed by eight homogeneous equations. Our evolution kernels agree with one set of results in the literature, but differ from another by a sign. Considering the advantages of the exponential regulator in high-order perturbative calculations, our results are crucial for computing the twist-3 TMD PDFs at $\mathcal{O}({\alpha }_s^2)$.

    hep-phPRD(2025)·1 citation
15. 15*

    Revealing the $q^2$ dependence in $b\to s{\mu }^{+}{\mu }^{-}$ baryonic decay modes

    Ajay Kumar Yadav🇮🇳 · Manas Kumar Mohapatra🇮🇳 · Suchismita Sahoo🇮🇳

    Measurements from the LHCb experiment and $B$ factories have revealed several discrepancies in angular observables of rare semileptonic $B$ decays involving the quark-level transition $b\to s{\ell }^{+}{\ell }^{-}$. In this work, we conduct a model-independent comparative analysis of the rare semileptonic decays of baryons ${\Lambda }_b$, ${\Sigma }_b$ and ${\Xi }_b$, exploring various new physics scenarios. Our analysis includes predictions for branching ratios and angular observables, including forward-backward asymmetry, longitudinal polarization fractions, and lepton flavor universality ratios, both within the Standard Model and across six distinct new physics scenarios. Notably, we find that certain new physics scenarios significantly affect the observables in the $({\Lambda }_b,{\Sigma }_b,{\Xi }_b)\to (\Lambda ,\Sigma ,\Xi ){\mu }^{+}{\mu }^{-}$ processes.

    hep-phNPB(2025)·2 citations
16. 16*

    More is Different: Multi-Axion Dynamics Changes Topological Defect Evolution

    Junseok Lee🇯🇵 · Kai Murai🇯🇵 · Fuminobu Takahashi🇯🇵 · Wen Yin🇯🇵

    We study topological defects in multi-axion models arising from multiple Peccei-Quinn (PQ) scalars. Using a simplified two-axion system, we reveal fundamental differences in the evolution of these defects compared to single-axion scenarios. This finding is particularly significant because, despite the fact that integrating out heavier axions reduces these models to an effective single PQ scalar theory at low energies, the actual physical behavior of topological defects differs markedly from single-axion predictions. Unlike single-axion models where conventional cosmic strings form, multi-axion scenarios with post-inflationary or mixed initial conditions generically produce networks of strings interconnected by high-tension domain walls. This results in a severe cosmological domain wall problem. We determine string-wall network instability conditions and discuss cosmological implications including the application to the QCD axion and gravitational wave generation. Our findings highlight that multi-axion dynamics can lead to qualitatively different outcomes for topological defects, challenging the conventional picture of cosmic evolution of topological defects based on single-axion models.

    hep-phastro-ph.COJCAP(2025)·22 citations
17. 17*

    Detecting meV-Scale Dark Matter via Coherent Scattering with an Asymmetric Torsion Balance

    Pengshun Luo🇨🇳 · Shigeki Matsumoto🇯🇵 · Jie Sheng🇨🇳 · Chuan-Yang Xing🇨🇳 · Lin Zhu🇨🇳 · Zhi-Jie Zhuge🇨🇳

    Dark matter with mass in the crossover range between wave dark matter and particle dark matter, around $(10^{-3},10^3)$eV, remains relatively unexplored by terrestrial experiments. In this mass regime, dark matter scatters coherently with macroscopic objects. The effect of the coherent scattering greatly enhances the accelerations of the targets that the dark matter collisions cause by a factor of $\sim 10^{23}$. We propose a novel torsion balance experiment with test bodies of different geometric sizes to detect such dark matter-induced acceleration. This method provides the strongest constraints on the scattering cross-section between the dark matter and a nucleon in the mass range $(10^{-3},1)$eV.

    hep-phPRD(2025)·8 citations
18. 18*

    Roles of the scalar $f_0(500)$ and $f_0(980)$ in the process $D^0\to {\pi }^0{\pi }^0{\bar{K}}^0$

    Xiao-Hui Zhang🇨🇳 · Han Zhang🇨🇳 · Bai-Cian Ke🇨🇳 · Li-Juan Liu🇨🇳 · De-Min Li🇨🇳 · En Wang🇨🇳

    Motivated by the near-threshold enhancement and the dip structure around 1~GeV in the ${\pi }^0{\pi }^0$ invariant mass distribution of the process $D^0\to {\pi }^0{\pi }^0{\bar{K}}^0$ observed by the CLEO Collaboration, we have investigated this process by taking into account the contribution from the $S$-wave pseudoscalar meson-pseudoscalar meson interactions within the chiral unitary approach, and also the one from the intermediate resonance $K^{\ast }(892)$. Our results are in good agreement with the CLEO measurements, which implies that, the near-threshold enhancement near the ${\pi }^0{\pi }^0$ threshold is mainly due to the contributions from the scalar meson $f_0(500)$ and the intermediate $K^{\ast }$, and the cusp structure around 1~GeV in the ${\pi }^0{\pi }^0$ invariant mass distribution should be associated with the scalar meson $f_0(980)$.

    hep-phPRD(2024)·8 citations
19. 19*

    Neutrino theory: open questions and future opportunities

    Raymond R. Volkas🇦🇺

    The subtitle of my talk is ``The quest for understanding the origin of neutrino masses''. After reviewing why the discovery of neutrino masses is also the discovery of New Physics, the substance of the talk details mechanisms for generating Majorana neutrino masses and implications for experimental searches and/or cosmology. I review high-scale seesaw, low-scale seesaw and radiative mechanisms, asking at every turn how testable the scenario is. While it is clear that determining the origin of neutrino masses -- knowing what Lagrangian to put into textbooks -- is a distant and ambitious goal, I end with experimental advances that we can reasonably hope for that would constitute progress.

    hep-phPoS(2025)·2 citations
20. 20*

    Reinforcement learning-based statistical search strategy for an axion model from flavor

    Satsuki Nishimura🇯🇵 · Coh Miyao🇯🇵 · Hajime Otsuka🇯🇵

    We propose a reinforcement learning-based search strategy to explore new physics beyond the Standard Model. The reinforcement learning, which is one of machine learning methods, is a powerful approach to find model parameters with phenomenological constraints. As a concrete example, we focus on a minimal axion model with a global $U(1)$ flavor symmetry. Agents of the learning succeed in finding $U(1)$ charge assignments of quarks and leptons solving the flavor and cosmological puzzles in the Standard Model, and find more than 150 realistic solutions for the quark sector taking renormalization effects into account. For the solutions found by the reinforcement learning-based analysis, we discuss the sensitivity of future experiments for the detection of an axion which is a Nambu-Goldstone boson of the spontaneously broken $U(1)$. We also examine how fast the reinforcement learning-based searching method finds the best discrete parameters in comparison with conventional optimization methods. In conclusion, the efficient parameter search based on the reinforcement learning-based strategy enables us to perform a statistical analysis of the vast parameter space associated with the axion model from flavor.

    hep-phcs.LGhep-thJHEP(2025)·14 citations
21. 21*

    Neutrino Model in Left-Right Symmetric Linear Seesaw Augmented with $A_4$ Modular Group

    Raktima Kalita🇮🇳 · Mahadev Patgiri🇮🇳

    In this work, we have implemented $A_4$ modular symmetry in the left-right symmetric linear seesaw model. Interestingly, such modular symmetry restricts the proliferation of flavon fields, and as a result, the predictibility of the model is enhanced. The fermion sector of the model comprises of quarks, leptons and a sterile fermion in each generation, while the scalar sector consists of Higgs doublets and bidoublets. We investigate numerically various Yukawa coupling co-efficients, the neutrino masses and mixing parameters in our intended model and predictions become consistent with $3\sigma$ range of current neutrino oscillation data. We also studied the non-unitarity, effects on lepton flavor violation in our model and evolution of lepton asymmetry to explain the current baryon asymmetry of the universe.

    hep-phEPJC(2025)·1 citation
22. 22*

    Leading Twist-Two Gauge-Variant Counterterms

    Thomas Gehrmann🇨🇭 · Andreas von Manteuffel🇩🇪 · Tong-Zhi Yang🇨🇭

    Anomalous dimensions of twist-two operators govern the scale evolution of parton distribution functions. For off-shell external states, the physical twist-two operators mix with unknown gauge-variant operators under renormalization. In this talk, we apply the method proposed by us in~\cite{Gehrmann:2023ksf} to compute all gauge-variant one-loop counterterm Feynman rules with five legs, which enter the determination of the four-loop splitting functions in QCD.

    hep-phhep-thPoS(2024)·5 citations
23. 23*

    Probing dimension-8 SMEFT operators through neutral meson mixing

    Yi Liao (South China Normal U.)🇨🇳 · Xiao-Dong Ma (South China Normal U.)🇨🇳 · Hao-Lin Wang (South China Normal U.)🇨🇳

    We investigate the impact of effective interactions of dimension-8 (dim-8) operators in the standard model effective field theory (SMEFT) on neutral meson mixing, focusing on the $K^0-{\bar{K}}^0$, $B_{d,s}-{\bar{B}}_{d,s}$, and $D^0-{\bar{D}}^0$ systems. Within the framework of the low energy effective field theory (LEFT), each system is governed by eight dim-6 operators, with four originating at tree level from dim-6 SMEFT operators and the other four from dim-8 SMEFT operators. Notably, in certain UV complete models those dim-8 operators instead of the dim-6 ones are generated at the leading order. Our analysis focuses on those dim-8 operators and includes their one-loop QCD renormalization group running effects. By leveraging the LEFT master formula we impose stringent constraints on the effective scales associated with these dim-8 operators. We find that neutral meson mixing can probe an effective scale up to 80 TeV for some operators, surpassing the constraints imposed on other dim-8 operators by other observables. Lastly, we present a UV complete model capable of generating dim-8 operators at the leading order, thus offering a unique perspective on the interplay between different operator dimensions in probing new physics phenomena.

    hep-phJHEP(2025)·15 citations
24. 24*

    $J/\psi$ photoproduction near threshold and signals for the hidden charm pentaquarks

    Ming-Xiao Duan🇨🇳 · Chang Gong🇨🇳 · Lin Qiu🇨🇳 · Qiang Zhao🇨🇳

    We study the $J/\psi$ photoproduction $\gamma p\to J/\psi p$ near threshold to investigate the role played by the open charm channels and possible signals from the hidden charm $P_c$ pentaquark states. With the diffractive mechanism described by a Pomeron exchange model extrapolated from high energies to the lower energy region, it shows that the differential cross sections compared with the recent results from the GlueX Collaboration have apparent deficits in the large scattering angles. The inclusion of the open charm channels and intermediate $P_c$ states can significantly improve the descriptions of the differential cross section data, in particular, at the energy regions of the ${\Lambda }_c{\bar{D}}^{(\ast )}$ thresholds. This can explain the structures observed by the GlueX Collaboration at the ${\Lambda }_c{\bar{D}}^{(\ast )}$ thresholds as the open charm CUSP effects. Given that these $P_c$ pentaquark states are hadronic molecules dynamically generated by the ${\Sigma }_c{\bar{D}}^{(\ast )}$, we find that the production of these $P_c$ states should be suppressed at leading order since their couplings to both $\gamma p$ and $J/\psi p$ are through loop transitions. This can explain why no obvious signals for the $P_c$ states are observed by the present datasets. In order to further disentangling the role played by $s$-channel mechanisms, we also investigate the polarized beam asymmetry which shows sensitivities to the open charm threshold effects and interferences from the $P_c$ productions. Experimental measurement of this observable at the Jefferson Laboratory is strongly encouraged.

    hep-ph5 citations
25. 25*

    Multidimensional Deconvolution with Profiling

    Huanbiao Zhu🇺🇸 · Krish Desai🇺🇸 · Mikael Kuusela🇺🇸 · Vinicius Mikuni🇺🇸 · Benjamin Nachman🇺🇸 · Larry Wasserman🇺🇸

    In many experimental contexts, it is necessary to statistically remove the impact of instrumental effects in order to physically interpret measurements. This task has been extensively studied in particle physics, where the deconvolution task is called unfolding. A number of recent methods have shown how to perform high-dimensional, unbinned unfolding using machine learning. However, one of the assumptions in all of these methods is that the detector response is correctly modeled in the Monte Carlo simulation. In practice, the detector response depends on a number of nuisance parameters that can be constrained with data. We propose a new algorithm called Profile OmniFold, which works in a similar iterative manner as the OmniFold algorithm while being able to simultaneously profile the nuisance parameters. We illustrate the method with a Gaussian example as a proof of concept highlighting its promising capabilities.

    hep-phphysics.data-anstat.APstat.ML8 citations
26. 26*

    A study of pure multi-strange hadrons production in Pb+Pb collisions at LHC energies using HYDJET++ model

    Gauri Devi (Banaras Hindu University, Varanasi, India)🇮🇳 · B. K. Singh (Banaras Hindu University, Varanasi, India, & Discipline of Natural Sciences, PDPM Indian Institute of Information Technology Design & Manufacturing, Jabalpur, India)🇮🇳

    For the present work, we have used the HYDJET++ model to explore the production of pure multi$-$strange hadrons in Pb+Pb collisions at $\sqrt{s_{NN}}$= 2.76 TeV and $\sqrt{s_{NN}}$= 5.02 TeV collision energies, respectively. \textcolor{red}{We have performed simulation to investigate transverse momentum ($p_T$) spectra and elliptic flow ($v_2$) for $\varphi -$meson and $\Omega -$baryons, and compared the results with ALICE experimental data as well as predictions from various phenomenological models across different centrality classes. Furthermore, we have calculated the nuclear modification factors ($R_{AA}$ and $R_{CP}$), which provide a perception of jet quenching phenomena. Hence, our findings enable the study of the energy and system dependence of $\varphi$ and $\Omega$ hadrons production over a wide range of ultra-relativistic collision energies. We also present the particle ratios ( $\Omega /\varphi$, ${\overline{\Omega }}^{+}/{\Omega }^{-}$, $\Omega /\pi$, and $\varphi /\pi$ ), offering insights into the strangeness enhancement and chemical properties of the medium at both LHC collision energies. Additionally, we explored the predictions for $\Omega$-baryon in Pb+Pb collisions at$\sqrt{s_{NN}}$= 5.02 TeV, focusing on $R_{AA}$, $R_{CP}$, and particle ratios within the HYDJET++ framework, offering insights into future measurements and particle dynamics in high-energy heavy-ion collisions.

    hep-phPRC(2025)·3 citations
27. 27*

    What we can learn from the angular differential rates (only) in semileptonic $B\to D^{\ast }\ell {\nu }_{\ell }$ decays

    G. Martinelli🇮🇹 · S. Simula🇮🇹 · L. Vittorio🇫🇷

    We present a simple approach to the study of semileptonic $B\to D^{\ast }\ell {\nu }_{\ell }$ decays based on the angular distributions of the final state particles only. Our approach is model independent and never requires the knowledge of $|V_{cb}|$. By studying such distributions in the case of light leptons, a comparison between results from different data sets from the Belle and BelleII Collaborations and between data and Standard Model calculations is also given for several interesting quantities. A good consistency is observed between some of the experimental results and the theoretical predictions.

    hep-phhep-exhep-latPRD(2025)·7 citations
28. 28*

    Improved ${\pi }^0,\eta ,{\eta }^{\prime }$ transition form factors in resonance chiral theory and their $a_{\mu }^{\mathrm{HLbL}}$ contribution

    Emilio J. Estrada🇲🇽 · Sergi Gonzàlez-Solís🇪🇸 · Adolfo Guevara🇲🇽 · Pablo Roig🇲🇽

    Working with Resonance Chiral Theory, within the two resonance multiplets saturation scheme, we satisfy leading (and some subleading) chiral and asymptotic QCD constraints and accurately fit simultaneously the ${\pi }^0,\eta ,{\eta }^{\prime }$ transition form factors, for single and double virtuality. In the latter case, we supplement the few available measurements with lattice data to ensure a faithful description. Mainly due to the new results for the doubly virtual case, we improve over existing descriptions for the $\eta$ and ${\eta }^{\prime }$. Our evaluation of the corresponding pole contributions to the hadronic light-by-light piece of the muon $g-2$ read: $a_{\mu }^{{\pi }^0\text{-}\mathrm{pole}}=\left(61.9\pm 0.6_{-1.5}^{+2.4}\right)\times 10^{-11}$, $a_{\mu }^{\eta \text{-}\mathrm{pole}}=\left(15.2\pm 0.5_{-0.8}^{+1.1}\right)\times 10^{-11}$ and $a_{\mu }^{{\eta }^{\prime }\text{-}\mathrm{pole}}=\left(14.2\pm 0.7_{-0.9}^{+1.4}\right)\times 10^{-11}$, for a total of $a_{\mu }^{{\pi }^0+\eta +{\eta }^{\prime }\text{-}\mathrm{pole}}=\left(91.3\pm 1.0_{-1.9}^{+3.0}\right)\times 10^{-11}$, where the first and second errors are the statistical and systematic uncertainties, respectively.

    hep-phhep-exhep-latJHEP(2024)·59 citations
29. 29*

    Nuclear-level effective theory of $\mu \to e$ conversion: Inelastic process

    W. C. Haxton🇺🇸 · Evan Rule🇺🇸

    Mu2e and COMET will search for electrons produced via the neutrinoless conversion of stopped muons bound in 1s atomic orbits of ${}^{27}$Al, improving existing limits on charged lepton flavor violation (CLFV) by roughly four orders of magnitude. Conventionally, $\mu \to e$ conversion experiments are optimized to detect electrons originating from transitions where the nucleus remains in the ground state, thereby maximizing the energy of the outgoing electron. Clearly, detection of a positive signal in forthcoming experiments would stimulate additional work $-$ including subsequent conversion experiments using complementary nuclear targets $-$ to further constrain the new physics responsible for CLFV. Here we argue that additional information can be extracted without the need for additional experiments, by considering inelastic conversion in ${}^{27}$Al. Transitions to low-lying nuclear excited states can modify the near-endpoint spectrum of conversion electrons, with the ratio of the elastic and inelastic responses being sensitive to the underlying CLFV operator. We extend the nuclear effective theory of $\mu \to e$ conversion to the inelastic case, which adds five new response functions to the six that arise for the elastic process. We evaluate these nuclear response functions in ${}^{27}$Al and calculate the resulting conversion-electron signal, taking into account the resolution anticipated in Mu2e/COMET. We find that ${}^{27}$Al is an excellent target choice from the perspective of the new information that can be obtained from inelastic $\mu \to e$ conversion.

    hep-phhep-exnucl-thPRC(2025)·3 citations
30. 30*

    Status of tension between NO$\nu$A and T2K after Neutrino 2024 and possible role of non-standard neutrino interactions

    Sabya Sachi Chatterjee🇩🇪 · Antonio Palazzo🇮🇹

    In a previous work we have shown that the data presented by the two long-baseline accelerator experiments NO$\nu$A and T2K at the Neutrino 2020 conference displayed a tension, and that it could be alleviated by non-standard neutrino interactions (NSI) of the flavor changing type involving the $e-\mu$ or the $e-\tau$ sectors with couplings $|{\epsilon }_{e\mu }|\sim |{\epsilon }_{e\tau }|\sim 0.1$. As a consequence a hint in favor of NSI emerged. In the present paper we reassess the issue in light of the new data released by the two experiments at the Neutrino 2024 conference. We find that the tension in the determination of the standard CP-phase ${\delta }_{\mathrm{CP}}$ extracted by the two experiments in the normal neutrino mass ordering persists and has a statistical significance of $\sim 2\sigma$. Concerning the NSI, we find that including their effects in the fit, the two values of ${\delta }_{\mathrm{CP}}$ preferred by NO$\nu$A and T2K return in very good agreement. The current statistical significance of the hint of non zero NSI is $\sim 1.8\sigma$. Further experimental data are needed in order to settle the issue.

    hep-phhep-exPRD(2024)·20 citations
31. 31*

    Is the real two-Higgs-doublet model consistent?

    Carlos Henrique de Lima🇨🇦 · Heather E. Logan🇨🇦

    We provide strong evidence that the widely-studied real two-Higgs-doublet model is inconsistent under renormalization due to quark-induced divergent CP violation (CPV). We identify the necessary ingredients for the CPV to enter the renormalization-group equations based on symmetry proprieties of the divergent diagrams. We demonstrate that while these ingredients are present starting at six loops, the divergent CPV is zero at that order due to approximate symmetries. We show that these symmetries are broken at seven loops and determine the parameter dependence of the resulting divergent CPV.

    hep-phhep-thPRL(2024)·8 citations
32. 32*

    Gravitational charge production

    Martin A. Mojahed🇩🇪 · Kai Schmitz🇩🇪 · Xun-Jie Xu🇨🇳

    Wash-in leptogenesis is an attractive mechanism to produce the baryon asymmetry of the Universe. It treats right-handed-neutrino interactions as spectator processes, on the same footing as electroweak sphalerons, that reprocess primordial charge asymmetries in the thermal plasma into a baryon-minus-lepton asymmetry. The origin of these primordial charges must be accounted for by new $CP$-violating dynamics at very high energies. In this paper, we propose such a scenario of chargegenesis that, unlike earlier proposals, primarily relies on new interactions in the gravitational sector. We point out that a coupling of a conserved current to the divergence of the Ricci scalar during reheating can lead to nonzero effective chemical potentials in the plasma that, together with a suitable charge-violating interaction, can result in the production of a primordial charge asymmetry. Gravitational chargegenesis represents a substantial generalization of the idea of gravitational baryogenesis. We provide a detailed analysis of a generic and minimal realization that is consistent with inflation and show that it can successfully explain the baryon asymmetry of the Universe.

    hep-phgr-qchep-thPRD(2025)·11 citations
33. 33*

    Neutron Tagging Can Greatly Reduce Spallation Backgrounds in Super-Kamiokande

    Obada Nairat🇺🇸 · John F. Beacom🇺🇸 · Shirley Weishi Li🇺🇸

    Super-Kamiokande's spallation backgrounds - the delayed beta decays of nuclides following cosmic-ray muons - are nearly all produced by the small fraction of muons with hadronic showers. We show that these hadronic showers also produce neutrons; their captures can be detected with high efficiency due to the recent addition of dissolved gadolinium to Super-Kamiokande. We show that new cuts based on the neutron tagging of showers could reduce spallation backgrounds by a factor of at least four beyond present cuts. With further work, this could lead to a near-elimination of detector backgrounds above about 6 MeV, which would significantly improve the sensitivity of Super-Kamiokande. These findings heighten the importance of adding gadolinium to Hyper-Kamiokande, which is at a shallower depth. Further, a similar approach could be used in other detectors, for example, the JUNO liquid-scintillator detector, which is also at a shallower depth.

    hep-phastro-ph.HEhep-exnucl-ex+1PRD(2025)·13 citations
34. 34*

    The Juno Mission as a Probe of Long-Range New Physics

    Praniti Singh🇺🇸 · Shi Yan🇺🇸 · Itamar J. Allali🇺🇸 · JiJi Fan🇺🇸 · Lingfeng Li🇺🇸

    Orbits of celestial objects, especially the geocentric and heliocentric ones, have been well explored to constrain new long-range forces beyond the Standard Model (SM), often referred to as fifth forces. In this paper, for the first time, we apply the motion of a spacecraft around Jupiter to probe fifth forces that don't violate the equivalence principle. The spacecraft is the Juno orbiter, and ten of its early orbits already allow a precise determination of the Jovian gravitational field. We use the shift in the precession angle as a proxy to test non-gravitational interactions between Juno and Jupiter. Requiring that the contribution from the fifth force does not exceed the uncertainty of the precession shift inferred from data, we find that a new parameter space with the mass of the fifth-force mediator around $10^{-14}$ eV is excluded at 95% C.L.

    hep-phastro-ph.EPastro-ph.IMphysics.space-phJHEP(2025)·2 citations
35. 35*

    Cambridge Lectures on The Standard Model

    Fernando Quevedo🇬🇧 · Andreas Schachner🇩🇪

    These lecture notes cover the Standard Model (SM) course for Part III of the Cambridge Mathematical Tripos, taught during the years 2020-2023. The course comprised 25 lectures and 4 example classes. Following a brief historical introduction, the SM is constructed from first principles. We begin by demonstrating that essentially only particles with spin/helicity $0,\frac{1}{2},1,\frac{3}{2},2$ can describe matter and interactions, using spacetime symmetries, soft theorems, gauge redundancies, Ward identities, and perturbative unitarity. The remaining freedom lies in the choice of the Yang-Mills gauge group and matter representations. Effective field theories (EFTs) are a central theme throughout the course, with the 4-Fermi interactions and chiral perturbation theory serving as key examples. Both gravity and the SM itself are treated as EFTs, specifically as the SMEFT (Standard Model Effective Field Theory). Key phenomenological aspects of the SM are covered, including the Higgs mechanism, Yukawa couplings, the CKM matrix, the GIM mechanism, neutrino oscillations, running couplings, and asymptotic freedom. The discussion of anomalies and their non-trivial cancellations in the SM is detailed. Simple examples of calculations, such as scattering amplitudes and decay rates, are provided. The course concludes with a brief overview of the limitations of the SM and an introduction to the leading proposals for physics beyond the Standard Model.

    ↳ hep-thhep-ph15 citations
36. 36*

    Gravitational Wave Birefringence in Symmetron Cosmology

    Ze-Xuan Xiong🇨🇳 · Da Huang🇨🇳

    The symmetron is a light scalar which provides a screening mechanism so as to evade the strong constraints from local gravity tests. In order to achieve this goal, a $Z_2$ symmetry is imposed on the symmetron model. In this paper, we introduce a new symmetron Chern-Simons-like gravitational interaction which is $Z_2$ invariant but breaks the parity symmetry explicitly. As a result, it is found that this coupling can generate gravitational wave (GW) amplitude birefringence when GWs propagate over the symmetron backgrounds. Due to the matter density difference, the symmetron profile changes significantly when entering the galaxy, so that we need to discuss the extra-galactic and galactic situations separately. On the one hand, the cosmological symmetron field follows the adiabatic solution, which induces a parity-violating GW amplitude correction with its exponent proportional to the GW frequency and the traveling distance. On the other hand, the symmetron takes the screening solution within the Milky Way, and the generated GW birefringence is only a function of the GW frequency. By further comparing these two contributions, we find that the extra-galactic symmetron field produces the dominant birefringence effects. Finally, with the latest GW data from LIGO-Virgo-Kagra, we place a reasonable constraint on the parity-violating coupling parameter in this symmetron model.

    ↳ gr-qcastro-ph.COhep-phPRD(2025)·8 citations
37. 37*

    Pion-nucleon scattering with decuplet contribution in heavy baryon SU(3) chiral perturbation theory

    Jing Ou-Yang🇨🇳 · Bo-Lin Huang🇨🇳

    We calculate the complete $T$ matrices with decuplet contributions for pion-nucleon scattering to order $\mathcal{O}({ϵ}^3)$ in heavy baryon SU(3) chiral perturbation theory. The baryon mass in the chiral limit $M_0$ and the low-energy constants are determined by fitting to phase shifts of $\pi N$, the experimental octet-baryon masses, and the value of ${\sigma }_{\pi N}$ simultaneously. By using these constants, we obtain the $KN$ $\sigma$ terms, ${\sigma }_{KN}^{(1)}=(375.07\pm 33.02)$ MeV and ${\sigma }_{KN}^{(2)}=(275.32\pm 32.24)$ MeV, with the errors being only statistical. An excellent description of the phase shifts is obtained for all partial waves. We also present results for scattering lengths and scattering volumes. In addition, the convergence of the approach is also discussed.

    ↳ nucl-thhep-lathep-phnucl-exPRD(2024)·4 citations
38. 38*

    Effect of Magnetic Fields on Urca Rates in Neutron Star Mergers

    Pranjal Tambe🇮🇳 · Debarati Chatterjee🇮🇳 · Mark Alford🇺🇸 · Alexander Haber🇺🇸

    Isospin-equilibrating weak processes, called ``Urca" processes, are of fundamental importance in astrophysical environments like (proto-)neutron stars, neutron star mergers, and supernovae. In these environments, matter can reach high temperatures of tens of MeVs and be subject to large magnetic fields. We thus investigate Urca rates at different temperatures and field strengths by performing the full temperature and magnetic-field dependent rate integrals for different equations of state. We find that the magnetic fields play an important role at temperatures of a few MeV, especially close to or below the direct Urca threshold, which is softened by the magnetic field. At higher temperatures, the effect of the magnetic fields can be overshadowed by the thermal effects. We observe that the magnetic field more strongly influences the neutron decay rates than the electron capture rates, leading to a shift in the flavor equilibrium.

    ↳ nucl-thastro-ph.HEhep-phPRC(2025)·13 citations
39. 39*

    Nonplanar Four-Loop Anomalous Dimensions of Twist-Two Operators in N=4 Super Yang-Mills Theory: Higher Moment, General Result, and Cusp Anomalous Dimension

    B.A. Kniehl🇺🇸 · V.N. Velizhanin🇩🇪

    We consider the nonplanar universal anomalous dimension of twist-two operators at four loops in N=4 supersymmetric Yang-Mills theory and push its direct diagrammatic calculation through Lorentz spin j=20, one unit beyond the state of the art, so as to confirm the correctness of the general, all-j result conjectured previously by us [1] imposing certain constraints on its analytic form. Thanks to our new result, such constraints can be eliminated altogether. By the same token, this allows us to re-derive, in a completely independent way, the nonplanar four-loop cusp anomalous dimension by taking the large-j limit of the general result.

    ↳ hep-thhep-phPRD(2025)·3 citations
40. 40*

    New Soft Theorems for Two-Scalar Sigma Models

    Karol Kampf🇨🇿 · Jiri Novotny🇨🇿 · Mikhail Shifman🇺🇸 · Jaroslav Trnka🇨🇿

    In this paper, we study the scattering amplitudes and soft theorems for the sigma models with two scalars. We show that if the particles are Goldstone bosons, then you necessarily get Adler zero with no possibility for non-trivial soft theorems. For non-Goldstone bosons, the soft behavior is generically captured by the geometric soft theorem studied by Cheung et al., and the right-hand side contains derivatives of lower-point amplitudes. Inspired by the recent work on the 2D sigma models, we study one special two-scalar sigma model, where the presence of symmetries in the target space translates into a special but non-trivial soft theorem without derivatives. We further generalize the construction to two larger classes of such models and derive certain soft theorem sum rules, again avoiding the derivatives of amplitudes. Our analysis provides an interesting hierarchy of two-scalar sigma models and soft theorems, ranging from Goldstone boson case to a generic target space, and showing that there are interesting theories in between.

    ↳ hep-thhep-phJHEP(2025)·3 citations
41. 41*

    Photon Ring Dimming as a Signature of Photon-Axion Conversion in Janis-Newman-Winicour Naked Singularity

    Ayush Hazarika🇮🇳 · Premachand Mahapatra🇮🇳 · Subhadip Sau🇮🇳

    The possible existence of axions in the universe introduces the intriguing possibility of photon-axion conversion in strong magnetic fields, particularly near compact objects like supermassive black holes or even naked singularity. In this study, we investigate the conversion of photons into axions in the vicinity of a Janis-Newman-Winicour (JNW) spacetime, a well-known naked singularity solution. Our analysis reveals that photons can efficiently convert into axions with masses less than $100\mathrm{neV}$. We calculate the conversion probability and find that it is significantly influenced by the characteristic parameter of the JNW spacetime. The potential observational signatures of this conversion, would be the dimming of photon ring in the X-ray and gamma-ray spectrum. Our findings suggest that compact objects like M87* could be prime candidates for detecting photon-axion conversion effects, provided future advances in high-resolution observations.

    ↳ gr-qcastro-ph.GAhep-phPRD(2025)·2 citations
42. 42*

    Fuzzy logic for reconstructing arbitrary moments of multiplicity distributions

    Anar Rustamov🇩🇪

    The Identity Method is a statistical technique developed to reconstruct moments of multiplicity distributions of particles produced in high-energy nuclear collisions. The method leverages principles from fuzzy logic, allowing for a more nuanced representation of particle identification by assigning degrees of membership to different particle types based on detector signals. In this contribution, a new framework, based on a multivariate moment generation function, is developed that allows the derivation of the formulas used in the Identity Method in a more robust way. Moreover, within the introduced framework, the Identity Method is easily extended to cope with arbitrarily higher-order moments. The techniques developed here offer significant potential for improving the accuracy of multiplicity distribution analyses in high-energy nuclear collisions. While the primary focus of the work presented is on applications in high-energy particle and nuclear physics, it can also be applied in other areas where signal identification is probabilistic and data are noisy, such as in medical imaging, remote sensing, and various other fields of experimental science.

    ↳ nucl-thhep-exhep-phnucl-exPRC(2024)·5 citations
43. 43*

    Probing Primordial Black Hole Formation from Domain Wall Isocurvature Perturbations: Constraints and Implications

    Bo-Qiang Lu🇨🇳 · Cheng-Wei Chiang🇹🇼 · Tianjun Li🇨🇳

    Domain walls are topological defects produced by the spontaneous symmetry-breaking of discrete symmetry during cosmological phase transitions. Domain walls can significantly contribute to the energy density in the late-evolution stage. We propose that the density perturbations from the fluctuations in the number density of the domain walls could collapse to form primordial black holes. This mechanism becomes effective when the domain wall energy density ratio to that of the radiation reaches about 0.1 in the radiation-dominated Universe. We find that models with $Z_2$ symmetry are excluded for interpreting pulsar timing array observations on the nano-Hz gravitational wave background since this model's domain wall number density fluctuations could lead to an overabundance of the primordial black holes. Moreover, the models, which generate approximately $N\sim 10$ domain walls from the spontaneous breaking of a discrete $Z_N$ symmetry, are also subject to stringent constraints due to the overproduction of primordial black holes.

    ↳ astro-ph.COhep-phJCAP(2026)·14 citations
44. 44*

    Exploring Single-Flavor Dibaryons: A lattice perspective

    Navdeep Singh Dhindsa🇮🇳 · Nilmani Mathur🇮🇳 · M. Padmanath🇮🇳

    We present a lattice calculation of dibaryons composed of single-flavor quarks with either charm or strange quark mass. We utilize a set of lattice QCD ensembles with $N_f=2+1+1$ dynamical HISQ fields, two spatial volumes, and four different lattice spacings generated by the MILC collaboration. By using an overlap action for the valence quark propagators, we calculate the ground state energies of dibaryons in $S=0$ and $S=2$ spin channels. By analyzing the energy difference of the ground state of the dibaryon with respect to the relevant threshold, we provide insights into the interactions involved in different spin channels at the charm and the strange quark masses.

    ↳ hep-lathep-phPoS(2025)·1 citation
45. 45*

    Primordial Black Holes from Domain Wall Density Fluctuations: Bridging Gravitational Wave Observations Across Two Frequency Bands

    Bo-Qiang Lu🇨🇳 · Cheng-Wei Chiang🇹🇼 · Tianjun Li🇨🇳

    We propose a novel mechanism for the formation of primordial black holes by demonstrating that the delayed production of isocurvature perturbations resulting from Poisson fluctuations within the domain wall network can lead to collapse and the formation of primordial black holes during the horizon crossing of domain walls. Our findings establish a statistical relationship between the number of domains and the power spectrum of the perturbations. This relationship can be employed to constrain the symmetry of the model in light of the potential overabundance of primordial black holes. Furthermore, by incorporating the effects of accretion, we demonstrate that the annihilation of the domain wall network at the QCD scale may provide a plausible common origin for gravitational wave observations across two distinct frequency bands.

    ↳ astro-ph.COhep-ph8 citations
46. 46*

    Multiple rescattering effects in the hard knockout reaction ${}^2\text{mbox}\mathbf{H}(\mathbf{p},2p)\mathbf{n}$

    A.B. Larionov🇷🇺

    The interaction of a proton with a deuteron is the simplest nuclear reaction. However, it allows the study of precursors of nuclear medium effects such as initial-state/final-state interactions (ISI/FSI). In case of hard proton knockout, the deviation of ISI/FSI from the 'standard' values may carry a signal of color transparency. In this regard, it is important to define the 'standard' as precisely as possible. This work continues previous studies within the framework of the Generalized Eikonal Approximation (GEA). The focus is on processes where the participating protons experience multiple soft rescattering on the spectator neutron. It is shown that correct treatment of deviations of the trajectories of outgoing protons from the longitudinal direction leads to a significant modification of partial amplitudes with soft rescattering of two outgoing protons and non-vanishing amplitudes with rescattering of incoming and outgoing protons. The new treatment of multiple rescattering is important in kinematics with a forward spectator neutron.

    ↳ nucl-thhep-exhep-phnucl-exEPJA(2025)·1 citation
47. 47*

    Lévy walk of pions in heavy-ion collisions

    Dániel Kincses🇭🇺 · Márton Nagy🇭🇺 · Máté Csanád🇭🇺

    The process of Lévy walk, i.e., movement patterns described by heavy-tailed random walks, plays a role in various phenomena, from chemical and microbiological systems through marine predators to climate change. Recent experiments have suggested that this phenomenon also appears in heavy-ion collisions. However, the theoretical interpretation supporting such findings is still debated. In high-energy collisions of heavy nuclei, the strongly interacting Quark Gluon Plasma is created, which, similarly to the early Universe, undergoes a rapid expansion and transition back to hadronic matter. In the subsequent expanding hadron gas, particles interact until kinetic freeze-out, when their momenta stop changing, and they freely transition toward the detectors. Measuring spatial freeze-out distributions is a crucial tool in understanding the dynamics of the created matter and the interactions among its constituents. In this paper, we introduce a three-dimensional analysis of the spatial freeze-out distribution of pions (the most abundant particles in such collisions). Utilising Monte-Carlo simulations of high-energy collisions, we show that the chain of processes ending in a final state pion has a step length distribution leading to Lévy-stable distributions. Subsequently, we show that simulated pion freeze-out distributions indeed exhibit heavy tails and can be described by a three-dimensional elliptically contoured symmetric Lévy-stable distribution.

    ↳ nucl-thhep-phCommun.Phys.(2025)·17 citations
48. 48*

    Minimally coupled $\beta$-exponential inflation with an $R^2$ term in the Palatini formulation

    Nilay Bostan🇺🇸 · Rafid H. Dejrah🇹🇷

    We focus on the inflationary predictions of $\beta$-exponential potential models, in which the inflaton is a representation of the field delineating the size of extra-dimension. Since it offers a well-motivated starting point for the study of physics at very high energies, we incorporate an $R^2$ term in the Palatini gravity. In addition, afterward the inflation, the inflaton oscillates about the minimum of the inflation potential, and reheats the universe. This occurs during the reheating phase, at which the inflaton decays into the standard model particles, which fill the universe. We extend our examination by considering the reheating effects on inflationary observables by employing the different scenarios of the reheat temperature. Supposing the standard thermal history after inflation, we display the inflationary predictions, $n_s,r,\mathrm{d}{n}_s/\mathrm{d}\ln k$ of $\beta$-exponential potential with minimal coupling in Palatini $R^2$ gravity. Also, different kinds of constraints from a variety of observations, such as BICEP/Keck, Planck 2018, as well as future possible detectable sensitivities that might be reached by CMB experiments: CMB-S4 and LiteBIRD are taken into account in this work. We indicate that our results are consistent with both the latest data and the future sensitivity forecasts of LiteBIRD/Planck and CMB-S4. Finally, the results in this study highlight the viability of our model even in the case of the existence of more stringent constraints expected from future achievable confidence level limits.

    ↳ astro-ph.COgr-qchep-ph4 citations
49. 49*

    Imprints of Dark Photons on Gravitational Wave Polarizations

    Kimihiro Nomura🇯🇵 · Jiro Soda🇯🇵 · Kazushige Ueda🇯🇵 · Ziwei Wang🇨🇳

    We study conversion processes between gravitons and dark photons and reveal the effects of dark photons on the polarization of gravitational waves. Considering cosmological dark magnetic fields, we investigate the evolution of the intensity and polarization of gravitational waves through the conversion. Specifically, we demonstrate that for minimal coupling between gravitons and dark photons, the intensity, circular polarization, and linear polarization evolve separately. We derive explicit formulas for the statistical mean and variance of the intensity and polarization when the gravitational waves pass through magnetic fields with random orientation. The formulas capture how the initial polarization of dark photons will be imprinted on the observed gravitational wave background.

    ↳ gr-qcastro-ph.COhep-phInt.J.Mod.Phys.D(2026)·4 citations
50. 50*

    Beth-Uhlenbeck equation for the thermodynamics of fluctuations in a generalised 2+1D Gross-Neveu model

    Biplab Mahato🇵🇱 · David Blaschke🇩🇪 · Dietmar Ebert🇩🇪

    We study a generalized version of the Gross-Neveu model in 2+1 dimensions. The model is inspired from Graphene, which shows a linear dispersion relation near the Dirac points. The phase structure and the thermodynamic properties in the mean field approximation have been studied before. Here, we go beyond the mean field level by deriving a Beth-Uhlenbeck equation for Gaussian fluctuations formulated in phase shift solutions, which we explore numerically, for the first time including their momentum dependence. We discuss the excitonic mass, fluctuation pressure, and phase shifts. The inclusion of momentum dependence in the phase shift shows a significant difference from the Lorentz-boosted version of the phase shift previously used in the literature. We find resurrection of the pseudoscalar bound states at large momentum above Mott temperature and show that the presence of Landau modes significantly contributes to the fluctuation pressure.

    ↳ cond-mat.mes-hallhep-phnucl-thPRD(2025)·2 citations
51. 51*

    Constraints on axions from patchy screening of the cosmic microwave background

    Samuel Goldstein🇺🇸 · Fiona McCarthy🇬🇧 · Cristina Mondino🇨🇦 · J. Colin Hill🇺🇸 · Junwu Huang🇨🇦 · Matthew C. Johnson🇨🇦

    The resonant conversion of cosmic microwave background (CMB) photons into axions within large-scale structure induces an anisotropic spectral distortion in CMB temperature maps. Applying state-of-the-art foreground cleaning techniques to $\text{Planck}$ CMB observations, we construct maps of axion-induced "patchy screening" of the CMB. We cross-correlate these maps with data from the $\text{unWISE}$ galaxy survey and find no evidence of axions. We constrain the axion-photon coupling, $g_{a\gamma \gamma }\lesssim 2\times 10^{-12}{\mathrm{GeV}}^{-1}$, at the 95% confidence level for axion masses in the range $10^{-13}\mathrm{eV}\lesssim m_a\lesssim 10^{-12}\mathrm{eV}$. These constraints are competitive with the tightest astrophysical axion limits in this mass range and are inferred from robust population-level statistics, which makes them complementary to existing searches that rely on modeling of individual systems.

    ↳ astro-ph.COhep-phPRL(2025)·17 citations
52. 52*

    Non-Gaussianity Beyond the Scalar Sector: A Search for Tensor and Mixed Tensor-Scalar Bispectra with Planck Data

    Oliver H. E. Philcox🇺🇸 · Maresuke Shiraishi🇯🇵

    Primordial gravitational waves could be non-Gaussian, just like primordial scalar perturbations. Although the tensor two-point function has thus-far remained elusive, the three-point function could, in principle, be large enough to be detected in Cosmic Microwave Background temperature and polarization anisotropies. We perform a detailed analysis of tensor and mixed tensor-scalar non-Gaussianity through the Planck PR4 bispectrum, placing constraints on eleven primordial templates, spanning various phenomenological and physical regimes including modifications to gravity, additional fields in inflation, and primordial magnetic fields. All analysis is performed using modern quasi-optimal binned estimators, and yields no evidence for tensor non-Gaussianity, with a maximum detection significance of $2\sigma$. Our constraints are derived primarily from large-scales (except for tensor-scalar-scalar models), and benefit greatly from the inclusion of $B$-modes. Although we find some loss of information from binning, mask effects and residual foreground contamination, our $f_{\mathrm{NL}}$ bounds improve over those of previous analyses by $(20-700)\%$, with six of the eleven models being analyzed for the first time. Unlike for scalar non-Gaussianity, future low-noise experiments such as LiteBIRD, the Simons Observatory and CMB-S4, will yield considerable improvement in tensor non-Gaussianity constraints.

    ↳ astro-ph.COastro-ph.GAgr-qchep-ph+1PRD(2025)·10 citations
53. 53*

    Full-shape analysis with simulation-based priors: cosmological parameters and the structure growth anomaly

    Mikhail M. Ivanov🇺🇸 · Andrej Obuljen🇨🇭 · Carolina Cuesta-Lazaro🇺🇸 · Michael W. Toomey🇺🇸

    We explore full-shape analysis with simulation-based priors, which is the simplest approach to galaxy clustering data analysis that combines effective field theory (EFT) on large scales and numerical simulations on small scales. The core ingredient of our approach is the prior density of EFT parameters which we extract from a suite of 10500 galaxy simulations based on the halo occupation distribution (HOD) model. We measure the EFT parameters with the field-level forward model, which enables us to cancel cosmic variance. On the theory side, we develop a new efficient approach to calculate field-level transfer functions using time-sliced perturbation theory and the logarithmic fast Fourier transform. We find that the cosmology dependence of EFT parameters of galaxies is approximately degenerate with the HOD parameters, and hence it can be ignored for the purpose of prior generation. We use neural density estimation to model the measured distribution of EFT parameters. Our distribution model is then used as a prior in a reanalysis of the BOSS full-shape galaxy power spectrum data. Assuming the $\Lambda$CDM model, we find significant ($\approx 30\%$ and $\approx 60\%$) improvements for the matter density fraction and the mass fluctuation amplitude, which are constrained to ${\Omega }_m=0.315\pm 0.010$ and ${\sigma }_8=0.671\pm 0.027$. The value of the Hubble constant does not change, $H_0=68.7\pm 1.1$~km/s/Mpc. This reaffirms earlier reports of the structure growth tension from the BOSS data. Finally, we use the measured EFT parameters to constrain the galaxy-dark matter connection.

    ↳ astro-ph.COastro-ph.IMhep-phhep-thPRD(2025)·71 citations
54. 54*

    Hunting Primordial Black Hole Dark Matter in Lyman-$\alpha$ Forest

    Akash Kumar Saha🇮🇳 · Abhijeet Singh🇮🇳 · Priyank Parashari🇮🇳 · Ranjan Laha🇮🇳

    A very pressing question in contemporary physics is the identity of Dark Matter (DM). Primordial Black Holes (PBHs) are one of the most well-motivated DM candidates. Light PBHs have been constrained by either the non-detection of their Hawking radiation itself, or by the non-observation of any measurable effects of this radiation on astrophysical and cosmological observables. We constrain the PBH contribution to the DM density by non-detection of their Hawking radiation's effect on the intergalactic medium (IGM) temperature evolution. We use the latest deductions of IGM temperature from Lyman-$\alpha$ forest observations. We put constraints on the fraction of DM as PBHs with masses $5\times 10^{15}$ g - $10^{17}$ g, separately for spinning and non-spinning BHs. We derive constraints by dealing with the heating effects of the astrophysical reionization sources on the IGM in two ways. In one way, we completely neglect this heating due to astrophysical sources, thus giving us weaker constraints, but completely robust to the reionization history of the universe. In the second way, we utilise some modelling of the ionization and temperature history, and use it to derive more stringent constraints. We find that for non-spinning PBHs of mass $10^{16}$ g, the current measurements can constrain the PBH-density to be $\lesssim$ 0.1\% of the total DM. We find that these constraints are competitive, and hence provide a new observable to probe the nature of PBH DM. The systematics affecting Lyman-$\alpha$ forest measurements are different from other constraining observations, and thus this is a complementary probe.

    ↳ astro-ph.COastro-ph.HEgr-qchep-ph+1EPJC(2025)·27 citations
55. 55*

    Negative non-Gaussianity as a salvager for PBHs with PTAs in bounce

    Sayantan Choudhury🇮🇳 · Kritartha Dey🇮🇳 · Siddhant Ganguly🇮🇳 · Ahaskar Karde🇮🇳 · Swapnil Kumar Singh🇮🇳 · Pranjal Tiwari🇮🇳

    Non-Gaussianity in the primordial curvature perturbation is a crucial element of the early universe due to its significant impact on the primordial black hole (PBH) production. In this work, we focus on the effects of negative non-Gaussianity on PBH abundance through the lens of the compaction function criterion for PBH formation. Our setup utilizes an effective field theory of non-singular bounce, including the standard slow-roll inflation with an ultra-slow roll phase for amplifying the curvature perturbations to form PBHs. We investigate with two separate values of the non-Gaussianity parameter, $f_{\mathrm{NL}}=(-39.95,-35/8)$, found within the ekpyrotic contraction and the matter bounce scenarios, respectively, and show that a negatively large amount of $f_{\mathrm{NL}}$ can provide sizeable abundance, $10^{-3}\le f_{\mathrm{PBH}}\le 1$, and completely mitigates the PBH overproduction issue. We also highlight that the case with the effective sound speed $c_s=1$, coupled with $f_{\mathrm{NL}}=-39.95$, provides an agreement under $1\sigma$ for the scalar-induced gravitational wave explanation of the latest PTA (NANOGrav15 and EPTA) signal. Lastly, we extract an upper bound on the most negative value of, $f_{\mathrm{NL}}\sim -60$, below which we show breaching of the underlying perturbativity constraints on the power spectrum amplitude.

    ↳ astro-ph.COgr-qchep-phhep-thEPJC(2025)·23 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.