Wed·Jan 17, 2024Wednesday·January 17, 2024

1. 01*

   Structure of Heavy Mesons in the Light-Front Quark Model

   Ahmad Jafar Arifi🇯🇵 · Lucas Happ🇯🇵 · Shuhei Ohno🇯🇵 · Makoto Oka🇯🇵

   We investigate the structure of ground-state heavy mesons within the light-front quark model, utilizing wave functions derived from the Single Gaussian Ansatz (SGA) and the Gaussian Expansion Method (GEM). By performing a ${\chi }^2$ fit to static properties such as mass spectra and decay constants, we determine the model parameters for each approach. We then compare the impacts of both methods on the light-front wave functions and structural observables. Our analysis reveals significant differences in the distribution amplitudes (DAs) ${\varphi }_{2;M}(x)$ near the endpoints, with GEM showing enhanced amplitudes and correct asymptotic behavior ${\varphi }_{2;M}(x\to 1)\propto (1-x)$, consistent with perturbative QCD. This endpoint behavior is linked to the short-range (high-momentum) wave function governed by color Coulomb interaction and relativistic kinematics. GEM accurately reproduces a power-law damping ${\psi }_0(k\to \infty )\propto 1/k_{\perp }^2$, aligning with perturbative QCD predictions. Furthermore, the electromagnetic form factors of pseudoscalar mesons in the low-$Q^2$ region fall off faster with GEM than with SGA. Overall, while both methods adequately describe static properties, GEM provides a more accurate description of structural properties, being more sensitive to details and asymptotic behaviors.

   hep-phnucl-thPRD(2024)·26 citations
2. 02*

   Renormalons and power corrections in pseudo- and quasi-GPDs

   Vladimir Braun🇩🇪 · Maria Koller🇩🇪 · Jakob Schoenleber🇩🇪

   High-order behavior of the perturbative expansion for short-distance observables in QCD is intimately related to the contributions of small momenta in the corresponding Feynman diagrams and this correspondence provides one with a useful tool to investigate power-suppressed nonperturbative corrections. We use this technique to study the structure of power corrections to parton quasi- and pseudo-GPDs which are used in lattice calculations of generalized parton distributions. As the main result, we predict the functional dependence of the leading power corrections to quasi(pseudo)-GPDs on $x$ variable for nonzero skewedness parameter $\xi$. The kinematic point $x=\pm \xi$ turns out to be special. We find that the nonperturbative corrections to quasi-GPDs at this point are suppressed by the first power of the hard scale only. These contributions come from soft momenta and have nothing to do with the known UV renormalon in the Wilson line. We also show that power corrections can be strongly suppressed by the normalization procedure.

   hep-phPRD(2024)·13 citations
3. 03*

   Direct production of SM-singlet scalars at the muon collider

   Bibhabasu De🇮🇳

   The present work proposes a minimal extension of the Standard Model~(SM) where a gauge-singlet scalar~($\varphi$) can be directly produced at the muon colliders without relying on its mixing with any other doublet state present in the theory. The New Physics~(NP) interactions include a TeV-scale scalar leptoquark of electromagnetic charge 1/3 arising naturally in a grand unifying gauge formulation. Within the proposed framework, the SM-singlet scalar can effectively couple to various SM fields at the one-loop level, out of which the $\bar{\mu }\mu \varphi$ and $\gamma \gamma \varphi$ couplings are crucial to produce it at the future muon colliders. Assuming $\mathcal{O}(1)$ NP couplings, the decay widths and production cross-section of the singlet scalar have been discussed in detail over the considered parameter space. Depending on the resonance scale, di-lepton and/or di-gluon channels can be significant to test/falsify the model.

   hep-phPLB(2024)·7 citations
4. 04*

   Modification of the Sommerfeld effect due to coannihilator decays

   Feng Luo🇨🇳

   In dark matter coannihilation scenarios, the Sommerfeld effect of coannihilators is usually important in calculations of dark matter thermal relic abundance. Due to decays of coannihilators, two annihilating coannihilators can only approach each other from a finite initial separation. While conventional derivations of Sommerfeld factors essentially assume an infinite initial separation, Sommerfeld factors for a pair of annihilating coannihilators may be different. We find that the Sommerfeld factor for a pair of coannihilators is less prominent than the one obtained without considering decays. The modification of the Sommerfeld factor may result in a change of the dark matter thermal relic abundance well beyond the percent level.

   hep-phCPC(2025)·1 citation
5. 05*

   Analytic auxiliary mass flow to compute master integrals in singular kinematics

   Gaia Fontana🇨🇭 · Thomas Gehrmann🇨🇭 · Kay Schönwald🇨🇭

   The computation of master integrals from their differential equations requires boundary values to be supplied by an independent method. These boundary values are often desired at singular kinematical points. We demonstrate how the auxiliary mass flow technique can be extended to compute the expansion coefficients of master integrals in a singular limit in an analytical manner, thereby providing these boundary conditions. To illustrate the application of the method, we re-compute the phase space integrals relevant to initial-final antenna functions at NNLO, now including higher-order terms in their $ϵ$-expansion in view of their application in third-order QCD corrections.

   hep-phJHEP(2024)·3 citations
6. 06*

   Nonlocal QED and lepton g-2 anomalies

   Hang Li🇨🇳 · P. Wang🇨🇳

   Quantum electrodynamics is generally extended to a nonlocal QED by introducing the correlation functions. The gauge link is introduced to guarantee that the nonlocal QED is locally U(1) gauge invariant. The corresponding Feynman rules as well as the proof of Ward-Takahashi identity are presented. As an example, the anomalous magnetic moments of leptons are studied in nonlocal QED. At one-loop level, besides the ordinary diagrams, there are many additional Feynman diagrams which are generated from the gauge link. It shows the nonlocal QED can provide a reasonable explanation for lepton g-2 anomalies.

   hep-phEPJC(2024)·1 citation
7. 07*

   Unitary model analysis of $f_0(500)$ pole positions by continuously varying $m_{\pi }$: comparison with discrete lattice predictions

   George Rupp🇵🇹

   Resonance, bound-state, and virtual-state pole positions of the $f_0(500)$ scalar meson are computed as a continuous function of pion mass in the framework of a unitarized and analytic coupled-channel model for scalar mesons, described as dynamical quark-antiquark states. The $f_0(500)$ is modeled with both light and strange $q\bar{q}$ seeds, mixing with each other through the common $S$-wave $\pi \pi$, $K\bar{K}$, and $\eta \eta$ meson-meson decay channels. The few model parameters are fitted to experimental $S$-wave $\pi \pi$ phase shifts up to 1 GeV. In the case of the physical ${\pi }^{\pm }$ mass of 139.57 MeV, resonance poles at $(460-i222)$ MeV and $(978-i37.2)$ MeV are found for the $f_0(500)$ and $f_0(980)$, respectively. Resonance, bound-state, and virtual-state pole trajectories are computed and plotted as a function of pion masses up to 500 MeV, both in the complex-energy and complex-momentum planes. The results are discussed and compared to the most advanced lattice QCD computations employing interpolators that correspond to the $q\bar{q}$ and meson-meson channels in the present model, that is, for a few discrete values of the unphysical pion mass in those lattice calculations.

   hep-phhep-latPRD(2024)·2 citations
8. 08*

   Shear and bulk viscosity of quark-gluon plasma with Gribov gluons and quasiparticle quarks

   Sadaf Madni🇮🇳 · Arghya Mukherjee🇮🇳 · Amaresh Jaiswal🇮🇳 · Najmul Haque🇮🇳

   In this study, we analyze the transport properties of the Quark-Gluon Plasma, focusing on bulk ($\zeta$) and shear ($\eta$) viscosities at vanishing chemical potential. To describe the QGP, we employ a quasiparticle model for quarks along with Gribov's prescription for gluons, which effectively captures non-perturbative dynamics. The Gribov parameter ${\gamma }_G$ and the dynamical mass $m_g$ are obtained by solving the one-loop gap equation in the $\overline{\text{MS}}$ renormalization scheme and further using lattice QCD data for the equation of state (EoS) of pure gluonic matter. The interaction between quarks and gluons is reflected in the quark quasi-mass $m_q$, again obtained using lattice EoS data for (2+1)-flavor QCD. Our primary goal is to invertigate the influence of quasi-quarks on the transport coefficients of QGP. Interestingly, we find a substantial decrease in the scaled transport coefficients with rising temperatures within the range ($1\le T/T_c\le 3.5$).

   hep-phPRD(2024)·13 citations
9. 09*

   Probing the four-fermion operators via the transverse double spin asymmetry at the Electron-Ion Collider

   Hao-Lin Wang🇨🇳 · Xin-Kai Wen🇨🇳 · Hongxi Xing🇨🇳 · Bin Yan🇨🇳

   The chirality-flipping operators of light fermions are currently poorly constrained by experimental analyses due to the lack of interference with Standard Model (SM) amplitudes in traditional observables. In this work, we propose to investigate the semi-leptonic scalar/tensor four-fermion operators of electron and quarks through the transverse double spin asymmetry (DSA) at Electron-Ion Collider, where both the electron and proton beams could be highly transversely polarized. Due to the chirality-flipping nature of these operators, we demonstrate that their interference with the SM results in an unsuppressed contribution to the DSA, and could lead to non-trivial azimuthal $\cos 2\varphi$ and $\sin 2\varphi$ distributions that are linearly dependent on their Wilson coefficients. This new method has the potential to significantly improve the current constraints on these scalar/tensor four-fermion operators without relying on theoretical assumptions about other types of new physics effects, particularly for the tensor type operator of the $u$-quark. Additionally, our findings indicate that both the real and imaginary parts of these operators can be simultaneously constrained and offer a new opportunity for probing potential $CP$-violation effects. However, it is important to note that these results would be sensitive to the quark transversity distributions, which are currently poorly constrained by the experimental data, but could be significantly improved at the upcoming Electron-Ion Collider. Therefore, our work opens up a new avenue to utilize this new spin asymmetry for exploring the new physics effects from the scalar/tensor four-fermion operators.

   hep-phhep-exnucl-exnucl-thPRD(2024)·23 citations
10. 10*

    $t\bar{t}jj$ at the LHC: a study on the additional jets

    Michele Lupattelli🇩🇪

    In this contribution we report on a recent calculation of the $pp\to t\bar{t}jj$ process performed in the dileptonic decay channel using the narrow-width approximation. The next-to-leading order corrections in QCD are included both in the production and decay of the top quarks. For the first time, the additional light jet activity is consistently included at the matrix-element level not only in the production stage of the top-quark pair but also in the decays. The size of the next-to-leading order corrections and the impact of these additional contributions are investigated.

    hep-ph0 citations
11. 11*

    Hot quark matter and merger remnants

    Adamu Issifu🇧🇷 · Tobias Frederico🇧🇷

    This work investigates hot quark matter under the thermodynamic conditions characteristic of a binary neutron star (BNS) merger remnants. We used the density-dependent quark mass model (DDQM) to access the microscopic nuclear equation of state (EoS) in a series of snapshots. The strange quark matter (SQM) is studied at finite temperature and entropy, in the presence of electrons and muons and their corresponding neutrinos to simulate the BNS merger conditions. For the first time, we introduced temperature into the DDQM model using a lattice QCD-motivated approach to construct both isentropic and isothermal EoSs. We observe that as the entropy of the SQM increases, the merger remnant becomes more massive and increases in size, whereas the neutrino abundance also increases. In the fixed-temperature case, on the other hand, we observe that the entropy spreads from the surface towards the center of the remnant. We determine the particle distribution in the core of the remnants, the structure of the remnant, the temperature profile, sound velocity, and the polytropic index, and discuss their effects. The strange-quark star (SQS) remnants satisfy the $2{\mathrm{M}}_{\odot }$ mass constraint associated with neutron stars (NS).

    hep-phnucl-thEPJA(2025)·4 citations
12. 12*

    Split NMSSM from dimensional reduction of a $10D$, $\mathcal{N}=1$, $E_8$ theory over a modified flag manifold

    Gregory Patellis🇵🇹 · Werner Porod🇩🇪 · George Zoupanos🇬🇷

    We review the Standard Model extension that results from the dimensional reduction of a $10D$, $\mathcal{N}=1$, $E_8$ gauge theory over the $M_4\times SU(3)/U(1)\times U(1)\times {\mathbf{Z}}_3$ space, which leads to a $4D$, $\mathcal{N}=1$, $SU(3{)}^3\times U(1{)}^2$ theory. Below the unification scale we obtain a Split NMSSM effective theory. The third generation quark and light Higgs masses are within the experimental limits at 2-loop level and the neutralino LSP mass is predicted $<800$ GeV.

    hep-phhep-th0 citations
13. 13*

    Nambu and Compositeness

    Christopher T. Hill🇺🇸

    The Nambu--Jona-Lasinio model is the simplest field theory of a composite scalar boson, consisting of a pair of chiral fermions. A bound state emerges from an assumed point-like 4-fermion interaction and is described by local effective field, $\Phi (x)$. We review this in the context of the renormalization group and show some its phenomenological successes, such as the QCD chiral dynamics and the prediction of stable heavy-light resonances that reveal the single light quark chiral dynamics. We also review some NJL--inspired composite Higgs models. We then describe a novel UV completion of the NJL model, to an extended interaction, where the solution is described by a bilocal effective, Yukawa field, $\Phi (x,y)$. I conclude with a personal recollection of Yoichiro Nambu.

    hep-phhep-exhep-th3 citations
14. 14*

    Wave packet treatment of neutrino flavour and spin oscillations in galactic and extragalactic magnetic fields

    Artem Popov🇷🇺 · Alexander Studenikin🇷🇺

    We consider neutrino flavour and spin oscillations in a magnetic field using formalism of wave packets. Decoherence effects due to neutrino wave packets separation are studied. The considered effects are especially important for describing astrophysical neutrino oscillations, since they propagate on kiloparsec scale and bigger. The obtained results are of interest for neutrino telescopes IceCube, Baikal-GVD and KM3NeT, and also can be applied for description of supernovae neutrino oscillations effects would be detected by JUNO and Hyper-Kamiokande.

    hep-phSpringer Proc.Phys.(2025)·0 citations
15. 15*

    A Note on the Quality of Dilatonic Ultralight Dark Matter

    Jay Hubisz🇺🇸 · Shaked Ironi🇮🇱 · Gilad Perez🇮🇱 · Rogerio Rosenfeld🇧🇷

    Dilatons are pseudo-Nambu-Goldstone bosons arising from the breaking of conformal invariance. In this letter we point out that in general a dilaton mass has a power-law dependence on a small parameter related to the explicit breaking of conformal invariance whereas the ratio between the ultraviolet and infrared scales in the theory are exponentially related to the same parameter. We show that this scaling results in a separation between the dilaton mass and the infrared scale that can not be arbitrary large. Therefore a small dilaton mass necessarily is associated to a secluded conformal sector. We argue that the fact that the dilaton field must have a small displacement from the minimum of its effective potential generated near the infrared scale precludes a cosmologically interesting amount of dilatonic dark matter to be produced by a misalignment mechanism in the early Universe.

    hep-phPLB(2024)·18 citations
16. 16*

    Wake forces in a background of quadratically coupled mediators

    Ken Van Tilburg🇺🇸

    Two particles can exert forces on each other when embedded in a sea of weakly-coupled particles. These "wake forces'' occur whenever the source and target particles have quadratic interactions with the mediating particles; they are proportional to the ambient energy density, and typically have a range of order the characteristic de Broglie wavelength of the background. The effect can be understood as source particles causing a disturbance in the background waves -- a wake -- which subsequently interacts with the target particles. Wake forces can be mediated by bosons or fermions, can have spin dependence, may be attractive or repulsive, and have a generally anisotropic spatial profile and range that depends on the phase-space distribution of the ambient particles. In this work, I investigate the application of wake forces to dark matter searches, recast existing limits on short-range forces into leading constraints on dark matter with quadratic couplings, and sketch out potential experimental modifications to optimize sensitivity. Wake forces occur in the Standard Model: the presence of the cosmic neutrino background induces a millimeter-range force about 22 orders of magnitude weaker than gravity. Wake forces may also be relevant in condensed-matter and atomic physics.

    hep-phPRD(2024)·38 citations
17. 17*

    Photons in the proton: implications for the LHC

    The NNPDF Collaboration: Richard D. Ball🇬🇧 · Andrea Barontini🇮🇹 · Alessandro Candido🇮🇹 · Stefano Carrazza🇮🇹 · Juan Cruz-Martinez🇨🇭 · Luigi Del Debbio🇬🇧 · Stefano Forte🇮🇹 · Tommaso Giani🇳🇱 · Felix Hekhorn🇮🇹 · Zahari Kassabov🇬🇧 · Niccolò Laurenti🇮🇹 · Giacomo Magni🇳🇱 and 6 other authors

    We construct a set of parton distribution functions (PDFs), based on the recent NNPDF4.0 PDF set, that also include a photon PDF. The photon PDF is constructed using the LuxQED formalism, while QED evolution accounting for O(alpha), O(alpha alphas) and O(alpha^2) corrections is implemented and benchmarked by means of the EKO code. We investigate the impact of QED effects on NNPDF4.0, and compare our results both to our previous NNPDF3.1QED PDF set and to other recent PDF sets that include the photon. We assess the impact of photon-initiated processes and electroweak corrections on a variety of representative LHC processes, and find that they can reach the 5% level in vector boson pair production at large invariant mass.

    hep-phEPJC(2024)·54 citations
18. 18*

    Quantum detection of new physics in top-quark pair production at the LHC

    Fabio Maltoni🇧🇪 · Claudio Severi🇬🇧 · Simone Tentori🇧🇪 · Eleni Vryonidou🇬🇧

    The recent observation of entanglement between top and anti-top quarks at the LHC opens the way to interpreting collider data with quantum information tools. In this work we investigate the relevance of quantum observables in searches of new physics. To this aim, we study spin correlations of top/anti-top pairs originating from various intermediate resonances, and compare the discovery reach of quantum observables compared to classical ones. We find that they provide complementary information and, in several notable cases, also the additional leverage necessary to detect new effects.

    hep-phJHEP(2024)·96 citations
19. 19*

    Higgs Width and Couplings at High Energy Muon Colliders with Forward Muon Detection

    Peiran Li🇺🇸 · Zhen Liu🇺🇸 · Kun-Feng Lyu🇺🇸

    We propose a novel method using the $ZZ$-fusion channel and forward muon detection at high-energy muon colliders to address the challenge of the Higgs coupling-width degeneracy. Our approach enables inclusive Higgs rate measurement to 0.75% at 10~TeV muon collider, breaking the coupling-width degeneracy. Results indicate the potential to refine Higgs coupling to sub-percent levels and estimate its total width within (-0.41%, +2.1%). Key insights include the effectiveness of forward muon tagging in signal-background separation despite broad recoil mass distribution due to muon energy reconstruction and beam energy spread. The study emphasizes the significance of muon rapidity coverage up to $|\eta (\mu )|<6$, enhancing measurement precision. Our findings highlight the unique capabilities of high-energy lepton colliders for model-independent Higgs coupling determination and lay the groundwork for future advancements in muon collider technology and Higgs physics research.

    hep-phPRD(2024)·34 citations
20. 20*

    Double-graviton production from Standard Model plasma

    J. Ghiglieri🇫🇷 · M. Laine🇨🇭 · J. Schütte-Engel🇺🇸 · E. Speranza🇨🇭

    The thermal plasma filling the early universe generated a stochastic gravitational wave background that peaks in the microwave frequency range today. If the graviton production rate is expressed as a series in a fine-structure constant, $\alpha$, and the temperature over the Planck mass, $T_{}^2/m_{\mathrm{pl}}^2$, then the lowest-order contributions come from single ($\sim \alpha T_{}^2/m_{\mathrm{pl}}^2$) and double ($\sim T_{}^4/m_{\mathrm{pl}}^4$) graviton production via $2\to 2$ scatterings. We show that in the Standard Model, single-graviton production dominates if the maximal temperature is smaller than $4\times 10_{}^{18}$ GeV. This justifies previous calculations which relied solely on single-graviton production. We mention Beyond the Standard Model scenarios in which the single and double-graviton contributions could be of comparable magnitudes. Finally, we elaborate on what these results imply for the range of applicability of General Relativity as an effective theory.

    hep-phastro-ph.COgr-qcJCAP(2024)·27 citations
21. 21*

    Quark flavor physics with lattice QCD

    Stefan Meinel🇺🇸

    This is an overview of quark flavor physics as presented in a plenary talk at Lattice 2023. In the first part, I discuss the main processes and lattice-QCD inputs used to determine the Wolfenstein parameters of the Cabibbo-Kobayashi-Maskawa matrix. In the second part, I review selected further processes that are being used to search for physics beyond the Standard Model. New results presented at Lattice 2023 are referenced throughout, but detailed discussions are limited to selected work published prior to the conference. QED corrections, inclusive decays on the lattice, and processes involving hadronic resonances are not discussed in detail here, as they were covered in other plenary talks at Lattice 2023 and Lattice 2022.

    ↳ hep-lathep-exhep-phPoS(2024)·7 citations
22. 22*

    Transport and Connection to Heavy-ion Collisions via Heavy Flavor Probes

    Hai-Tao Shu🇺🇸

    The heavy ion experiments in Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) are going through upgrade in the next five years, shifting their focus more on the hard processes in the new runs. One of the main goals is to draw a finer image for the quark gluon plasma (QGP). The heavy flavor probes , which witness the whole history of heavy ion collision are particularly sensitive to test the properties of QGP formed in such collisions. The lattice results for heavy flavor probes provide transport and phenomenological models crucial inputs to describe the experimental observations like the strong suppression of the nuclear modification factor $R_{AA}$ and the non-zero azimuthal anisotropy at low $p_T$. In the last two years we have seen significant advances in the lattice QCD studies of heavy flavor probes, including the in-medium quarkonium properties, the complex static quark-antiquark potential and the heavy quark diffusion from lattice simulations at nonzero temperature. These achievements substantially deepen our understanding of the fate of quarkonium, the screening/unscreening of the complex potential and the temperature and quark mass dependence of the heavy quark diffusion in thermal medium. In these proceedings, we review recent results and briefly discuss possible directions in these studies.

    ↳ hep-lathep-phnucl-thPoS(2024)·2 citations
23. 23*

    Quantum Simulations of Hadron Dynamics in the Schwinger Model using 112 Qubits

    Roland C. Farrell🇺🇸 · Marc Illa🇺🇸 · Anthony N. Ciavarella🇺🇸 · Martin J. Savage🇺🇸

    Hadron wavepackets are prepared and time evolved in the Schwinger model using 112 qubits of IBM's 133-qubit Heron quantum computer ibm_torino. The initialization of the hadron wavepacket is performed in two steps. First, the vacuum is prepared across the whole lattice using the recently developed SC-ADAPT-VQE algorithm and workflow. SC-ADAPT-VQE is then extended to the preparation of localized states, and used to establish a hadron wavepacket on top of the vacuum. This is done by adaptively constructing low-depth circuits that maximize the overlap with an adiabatically prepared hadron wavepacket. Due to the localized nature of the wavepacket, these circuits can be determined on a sequence of small lattices using classical computers, and then robustly scaled to prepare wavepackets on large lattices for simulations using quantum computers. Time evolution is implemented with a second-order Trotterization. To reduce both the required qubit connectivity and circuit depth, an approximate quasi-local interaction is introduced. This approximation is made possible by the emergence of confinement at long distances, and converges exponentially with increasing distance of the interactions. Using multiple error-mitigation strategies, up to 14 Trotter steps of time evolution are performed, employing 13,858 two-qubit gates (with a CNOT depth of 370). The propagation of hadrons is clearly identified, with results that compare favorably with Matrix Product State simulations. Prospects for a near-term quantum advantage in simulations of hadron scattering are discussed.

    ↳ quant-phhep-lathep-phnucl-thPRD(2024)·234 citations
24. 24*

    Testing gravity with Extreme-Mass-Ratio Inspirals

    Alejandro Cárdenas-Avendaño🇺🇸 · Carlos F. Sopuerta🇺🇸

    Extreme-mass-ratio inspirals consist of binary systems of compact objects, with orders of magnitude differences in their masses, in the regime where the dynamics are driven by gravitational wave emission. The unique nature of extreme-mass-ratio inspirals facilitates the exploration of diverse and stimulating tests related to various aspects of black holes and General Relativity. These tests encompass investigations into the spacetime geometry, the dissipation of the binary system energy and angular momentum, and the impact of the intrinsic non-linear effects of the gravitational interaction. This review accounts for the manifold opportunities for testing General Relativity, ranging from examinations of black hole properties to cosmological and multimessenger tests.

    ↳ gr-qcastro-ph.HEhep-phhep-thIn Recent Progress on Gravity Tests. Spri…·41 citations
25. 25*

    Searches for FCNC and lepton flavour violating interactions of the top quark with the ATLAS detector

    Pavol Bartos (on behalf of the ATLAS Collaboration)🇸🇰

    The LHC is a top quark factory and provides a unique opportunity to look for flavour changing neutral current or charged-lepton flavour violating interactions of the top quark. These processes are highly suppressed in the Standard Model and are beyond the experimental sensitivity, but can receive enhanced contributions in many extensions of the Standard Model. Results of searches for flavour changing neutral current $tqH$ vertex and charged-lepton flavour violating $\mu \tau tq$ vertex are presented. The searches find good agreement with the Standard Model expectation and derived exclusion bounds are improved very significantly.

    ↳ hep-exhep-ph0 citations
26. 26*

    Quenched Static force from generalized Wilson loops with gradient flow

    Julian Mayer-Steudte🇩🇪

    We compute the static force on the lattice in the quenched case directly through generalized Wilson loops. We modify the Wilson loop by inserting an $E$-field component on one of the temporal Wilson lines. However, chromo-field components prevent us from performing the continuum limit properly, hence, we use gradient flow to renormalize the field insertion. As a result, we obtain continuum results and compare them to perturbative expression to extract ${\Lambda }_0$, and we predict the value $\sqrt{8t_0}{\Lambda }_{\overline{\text{MS}}}^{n_f=0}=0.629_{-26}^{+22}$. This work serves as preparation for similar operators with field insertions required in nonrelativistic effective field theories.

    ↳ hep-lathep-phhep-thnucl-thPoS(2024)·0 citations
27. 27*

    Scaling results for charged sectors of near conformal QCD

    Jahmall Bersini🇯🇵 · Alessandra D'Alise🇮🇹 · Clelia Gambardella🇮🇹 · Francesco Sannino🇮🇹

    We provide the leading near conformal corrections on a cylinder to the scaling dimension ${\Delta }_Q^{\ast }$ of fixed isospin charge $Q$ operators defined at the lower boundary of the Quantum Chromodynamics conformal window: \begin{equation} \Delta_Q = \Delta_Q^\ast +\left(\frac{m_{\sigma}}{4 \pi \nu}\right)^2 \, Q^{\frac{\Delta}{3}} B_1 + \left(\frac{m_\pi(\theta)}{4\pi \nu} \right)^4\ Q^{\frac{2}{3}(1-\gamma)} B_2 + \mathcal{O}\left ( m_\sigma^4 , m_\pi^8, m_\sigma^2 m_\pi^4\right) \ . \nonumber \end{equation} The results are expressed in powers of the dilaton and pion masses in units of the chiral symmetry breaking scale $4\pi \nu$ with the theta-angle dependence encoded directly in the pion mass. The characteristic $Q$-scaling is dictated by the quark mass operator anomalous dimension $\gamma$ and the one characterising the dilaton potential $\Delta$. The coefficients $B_i$ with $i=1,2$ depend on the geometry of the cylinder and properties of the nearby conformal field theory.

    ↳ hep-thhep-lathep-phPRD(2024)·4 citations
28. 28*

    Probing parton distributions in ep/eA and ultra-peripheral collisions

    Spencer R. Klein🇺🇸

    Real or virtual photons are excellent probes of nuclear structure, with a strong sensitivity to gluon distributions. Photonic reactions can be studied using ultra-peripheral collisions or at an electron-ion collider. Final states like dijets or open charm production are directly sensitive to the gluon distributions in nuclei. Exclusive reactions, like exclusive vector meson production or deeply virtual Compton scattering (DVCS) go further, requiring at least two gluons. In the Good-Walker paradigm, coherent exclusive photoproduction is sensitive to the average nuclear configuration (including gluonic hot spots), and the Fourier transform of the differential cross-section $d\sigma /dt$ gives the transverse distribution of partonic targets in a nucleus. The incoherent photoproduction cross-section is sensitive to partonic fluctuations, including gluonic hot spots. Some reactions, such as dijet production, involve multiple momentum scales, and thus may be able to probe the Wigner distribution of nuclear targets. Finally, incoherent photoproduction is sensitive to partonic fluctuations; an analysis of $J/\psi$ photoproduction on proton targets found that the data clearly preferred a fluctuating lumpy proton.

    ↳ hep-exhep-phnucl-exPoS(2024)·1 citation
29. 29*

    The Regge bootstrap, from linear to non-linear trajectories

    Christopher Eckner🇫🇷 · Felipe Figueroa🇫🇷 · Piotr Tourkine🇫🇷

    We present a numerical linear programming bootstrap to construct dual model scattering amplitudes. Dual models describe tree-level exchanges of higher spin resonances in theories like string theory and large $N$ gauge theories. Despite being very simple objects, their numerical bootstrap has proven challenging due to slow convergence of the infinite sums over resonances. Our bootstrap succeeds thanks to an efficient parametrization of the amplitude in terms of Mandelstam-Regge poles and the use of combined regions that make crossing symmetry constraining. Along the way, we discover and conjecture a property of "super-unitarity" of the Veneziano amplitude, which we use to keep a linear problem. As results, we present first the study of a class of string-like amplitudes with linear trajectories, for which we observe that the Veneziano amplitude lies at a preferred location, at the bottom of a pit, which minimizes crossing. Then, we introduce a toy-model deformation to non-linear trajectories, mimicking some features of QCD, for which our algorithm also detects a clear pit. This gives compelling evidence that our bootstrap is able to produce amplitudes that can exhibit non-trivial phenomenological features.

    ↳ hep-thhep-phPRD(2025)·38 citations
30. 30*

    Gravitational Raman Scattering in Effective Field Theory: a Scalar Tidal Matching at $\mathcal{O}(G^3)$

    Mikhail M. Ivanov🇺🇸 · Yue-Zhou Li🇺🇸 · Julio Parra-Martinez🇨🇦 · Zihan Zhou🇺🇸

    We present a framework to compute amplitudes for the gravitational analog of the Raman process, a quasi-elastic scattering of waves off compact objects, in worldline effective field theory (EFT). As an example, we calculate third post-Minkowskian (PM) order ($\mathcal{O}(G^3)$), or two-loop, phase shifts for the scattering of a massless scalar field including all tidal effects and dissipation. Our calculation unveils two sources of the classical renormalization-group flow of dynamical Love numbers: a universal running independent of the nature of the compact object, and a running self-induced by tides. Restricting to the black hole case, we find that our EFT phase shifts agree exactly with those from general relativity, provided that the relevant static Love numbers are set to zero. In addition, we carry out a complete matching of the leading scalar dynamical Love number required to renormalize a universal short scale divergence in the S-wave. Our results pave the way for systematic calculations of gravitational Raman scattering at higher PM orders.

    ↳ hep-thastro-ph.COastro-ph.HEgr-qc+1PRL(2024)·80 citations
31. 31*

    Robust Anomaly Detection for Particle Physics Using Multi-Background Representation Learning

    Abhijith Gandrakota🇺🇸 · Lily Zhang🇺🇸 · Aahlad Puli🇺🇸 · Kyle Cranmer🇺🇸 · Jennifer Ngadiuba🇺🇸 · Rajesh Ranganath🇺🇸 · Nhan Tran🇺🇸

    Anomaly, or out-of-distribution, detection is a promising tool for aiding discoveries of new particles or processes in particle physics. In this work, we identify and address two overlooked opportunities to improve anomaly detection for high-energy physics. First, rather than train a generative model on the single most dominant background process, we build detection algorithms using representation learning from multiple background types, thus taking advantage of more information to improve estimation of what is relevant for detection. Second, we generalize decorrelation to the multi-background setting, thus directly enforcing a more complete definition of robustness for anomaly detection. We demonstrate the benefit of the proposed robust multi-background anomaly detection algorithms on a high-dimensional dataset of particle decays at the Large Hadron Collider.

    ↳ hep-excs.LGhep-phphysics.data-anMach.Learn.Sci.Tech.(2024)·4 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.