Recent studies suggest that global fits of parton distribution functions (PDFs) might inadvertently “fit away” signs of new physics in the high-energy tails of the distributions measured at the high luminosity program of the LHC (HL-LHC). This could lead to spurious effects that might conceal key beyond the Standard Model (BSM) signatures and hinder the success of indirect searches for new physics. In this paper, we demonstrate that future deep-inelastic scattering (DIS) measurements at the Electron-Ion Collider (EIC), and at CERN via <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>FASER</mi><mrow><mi>ν</mi></mrow></mrow></math> and SND@LHC at LHC Run III, and the future neutrino experiments to be hosted at the proposed Forward Physics Facility (FPF) at the HL-LHC, provide complementary constraints on large-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>x</mi></math> sea quarks. These constraints are crucial to mitigate the risk of missing key BSM signals, by enabling precise constraints on large-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>x</mi></math> PDFs through a “BSM-safe” integration of both high- and low-energy data, which is essential for a robust interpretation of the high-energy measurements.

United Kingdom

Unravelling new physics signals at the HL-LHC with EIC and FPF constraints

Heavy axions that couple to both quantum electrodynamics and quantum chromodynamics with masses on the order of MeV–GeV and high-scale decay constants in excess of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo>∼</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>8</mn></mrow></msup><mtext> </mtext><mtext> </mtext><mi>GeV</mi></mrow></math> may arise generically in, e.g., axiverse constructions. In this work we provide the most sensitive search to date for the existence of such heavy axions using Fermi-LAT data toward four recent supernovae (SN): Cassiopea A, SN1987A, SN2023ixf, and SN2024ggi. We account for heavy axion production in the proto-neutron-star cores through nuclear and electromagnetic processes and then the subsequent decay of the axions into photons. While previous works have searched for gamma rays from SN1987A using the Solar Maximum Mission that observed SN1987A during the SN itself, we show that using Fermi Large Area Telescope data provides an approximately 5 orders of magnitude improvement in flux sensitivity for axions with lifetimes larger than around 10 yrs. We find no evidence for heavy axions and exclude large regions of previously unexplored parameter space.

United States

Time-delayed gamma-ray signatures of heavy axions from core-collapse supernovae

We investigate the discovery prospects for a vectorlike top partner (VLT) in the type-II two-Higgs-doublet model (2HDM-II) extended by a vectorlike quark doublet (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>T</mi><mi>B</mi></math>) at the 14 TeV LHC. The study focuses on the pair production process <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi><mo stretchy="false">→</mo><mi>T</mi><mover accent="true"><mi>T</mi><mo stretchy="false">¯</mo></mover><mo stretchy="false">→</mo><mi>b</mi><msup><mi>H</mi><mo>+</mo></msup><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover><msup><mi>H</mi><mo>−</mo></msup><mo stretchy="false">→</mo><mi>b</mi><mo stretchy="false">(</mo><mi>t</mi><mi>b</mi><mo stretchy="false">)</mo><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover><mo stretchy="false">(</mo><mover accent="true"><mi>t</mi><mo stretchy="false">¯</mo></mover><mi>b</mi><mo stretchy="false">)</mo></math>, yielding fully hadronic final states characterized by high <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi></math>-jet multiplicity. Two analysis strategies are employed, requiring at least four or five <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi></math>-tagged jets (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>4</mn><mi>b</mi></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>5</mn><mi>b</mi></mrow></math>), to exploit the signal topology. Assuming a charged Higgs mass of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><msup><mi>H</mi><mo>±</mo></msup></msub><mo>∼</mo><mn>600</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> and a systematic uncertainty of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>δ</mi><mo>=</mo><mn>5</mn><mo>%</mo></math>, the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>4</mn><mi>b</mi></mrow></math> channel enables discovery up to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>T</mi></msub><mo>∼</mo><mn>1200</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">L</mi><mo>=</mo><mn>300</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>, while the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>5</mn><mi>b</mi></mrow></math> analysis extends the reach to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>T</mi></msub><mo>∼</mo><mn>1300</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>. At higher luminosities of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1000</mn><mi>–</mi><mn>3000</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math>, the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>5</mn><mi>b</mi></mrow></math> strategy achieves discovery sensitivity up to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>T</mi></msub><mo>∼</mo><mn>1400</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>. The reach is significantly reduced as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><msup><mi>H</mi><mo>±</mo></msup></msub></math> increases, due to the suppression of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>BR</mi><mo stretchy="false">(</mo><mi>T</mi><mo stretchy="false">→</mo><msup><mi>H</mi><mo>+</mo></msup><mi>b</mi><mo stretchy="false">)</mo></math>: for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><msup><mi>H</mi><mo>±</mo></msup></msub><mo>∼</mo><mn>1000</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>, discovery becomes unattainable across all luminosity and systematic uncertainty configurations. Sensitivity is also strongly impacted by systematic uncertainties: for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>δ</mi><mo>=</mo><mn>10</mn><mo>%</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><msup><mi>H</mi><mo>±</mo></msup></msub><mo>&lt;</mo><mspace linebreak="goodbreak"></mspace><mn>1000</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>, discovery remains viable up to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>T</mi></msub><mo>∼</mo><mn>1200</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>5</mn><mi>b</mi></mrow></math> analysis, while for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>δ</mi><mo>=</mo><mn>20</mn><mo>%</mo></math>, no discovery is achievable for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>T</mi></msub><mo>≥</mo><mn>1000</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>.

Morocco

Taiwan

Poland

Search for charged Higgs bosons through vectorlike top quark pair production at the LHC

We analyze <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>B</mi></mrow><mrow><mn>0</mn></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>K</mi></mrow><mrow><mn>0</mn></mrow></msup><mover accent="true"><mrow><mo>ℓ</mo></mrow><mrow><mo stretchy="true">¯</mo></mrow></mover><mo>ℓ</mo></mrow></math> long-distance contributions induced by the rescattering of a pair of charmed and charmed-strange mesons. We present an explicit estimate of these contributions using an effective description in terms of hadronic degrees of freedom, supplemented by data on the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mn>0</mn></msup><mo stretchy="false">→</mo><msup><mi>D</mi><mo>*</mo></msup><msub><mi>D</mi><mi>s</mi></msub><mo stretchy="false">(</mo><msubsup><mi>D</mi><mi>s</mi><mo>*</mo></msubsup><mi>D</mi><mo stretchy="false">)</mo></math> transition in order to reproduce the corresponding discontinuity in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mn>0</mn></msup><mo stretchy="false">→</mo><msup><mi>K</mi><mn>0</mn></msup><mover accent="true"><mo>ℓ</mo><mo stretchy="true">¯</mo></mover><mo>ℓ</mo></math> amplitude. The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mo>*</mo></msup><msub><mi>D</mi><mi>s</mi></msub><mo stretchy="false">(</mo><msubsup><mi>D</mi><mi>s</mi><mo>*</mo></msubsup><mi>D</mi><mo stretchy="false">)</mo><mi>K</mi></math> vertex is estimated using heavy-hadron chiral perturbation theory, obtaining an accurate description of the whole rescattering process in the low-recoil (or high-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>q</mi><mn>2</mn></msup></math>) limit. We also present an extrapolation to the whole kinematical region introducing hadronic form factors. The explicit estimate of the leading <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mo>*</mo></msup><msub><mi>D</mi><mi>s</mi></msub><mo stretchy="false">(</mo><msubsup><mi>D</mi><mi>s</mi><mo>*</mo></msubsup><mi>D</mi><mo stretchy="false">)</mo></math> intermediate state leads to a long-distance amplitude which does not exceed a few percent relative to the short-distance one. The consequences of this result for the extraction of the short-distance coefficient <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>C</mi><mn>9</mn></msub></math> are discussed.

Switzerland

Explicit estimate of charm rescattering in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>B</mi></mrow><mrow><mn>0</mn></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>K</mi></mrow><mrow><mn>0</mn></mrow></msup><mover accent="true"><mrow><mo>ℓ</mo></mrow><mrow><mo stretchy="true">¯</mo></mrow></mover><mo>ℓ</mo></mrow></math>

We extract the complex frequency of the lowest quasinormal mode (QNM) from the holographically computed entropy density near thermodynamic equilibrium. The system under study is a purely thermal supersymmetric Yang-Mills <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>4</mn></math> plasma undergoing homogeneous isotropization dynamics. Starting from a far-from-equilibrium initial state, the system evolves toward equilibrium entropy, forming a stairway pattern. Our analysis reveals that the rate of increase of the stairway is twice the decay rate (imaginary part) of the lowest QNM. Based on this observation, we propose a model that explains how this information is encoded in the entropy. The model is further extended to include finite temperature, R-charge density, and scalar condensate, revealing an additional feature: the system’s dominant dissipation channel may shift to one driven by the scalar condensate, depending on the chemical potential.

Venezuela

Brazil

Extracting more information from entropy

We study the patterns of multipartite entanglement in Chern-Simons theory with compact simple gauge group <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>G</mi></mrow></math> and level <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>k</mi></math> for states defined by the path integral on “link complements,” i.e., compact manifolds whose boundaries consist of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>n</mi></math> topologically linked tori. We focus on link complements which can be described topologically as fibrations over a Seifert surface. We show that the entanglement structure of such fibered link complement states is controlled by a topological invariant, the monodromy of the fibration. Thus, the entanglement structure of a Chern-Simons link state is not simply a function of the link, but also of the background manifold in which the link is embedded. In particular, we show that any link possesses an embedding into some background that leads to Greenberger–Horne–Zeilinger state (GHZ)-like entanglement. Furthermore, we demonstrate that all fibered links with periodic monodromy have GHZ-like entanglement, i.e., a partial trace on any link component produces a separable state. These results generalize to any three dimensional topological field theory with a dual chiral rational conformal field theory.

Multipartite entanglement structure of fibered link states

Anti–de Sitter/QCD models are being extensively studied because they seem to offer an entirely tractable and radically different approach to the phases of QCD whose region of validity is precisely the region of strong interactions. In this context, a missing ingredient has been the absence of a bulk description dual to a confined hadronic phase at finite baryon density. In this work, we discuss a class of backgrounds that fill this lacuna. Applying physically motivated boundary conditions, we obtain phase diagrams which compare reasonably with approaches based on the Polyakov-Nambu-Jona-Lasino model. We also show that such backgrounds can play a similar role in geometries with a dilaton field.

India

Confined phases at finite density in the hardwall model

Based on an analysis that considers the isotropic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi><mi>T</mi></mrow></math>-odd standard model extension (SME) coefficients, we find new constraints for them coming from a combined DUNE and ESSnuSB fit. Furthermore, we investigate the correlations of the standard oscillation parameters, the leptonic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math>-violating phase, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>δ</mi></mrow><mrow><mi>C</mi><mi>P</mi></mrow></msub></mrow></math>, and the atmospheric mixing angle, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>sin</mi><mn>2</mn></msup><msub><mi>θ</mi><mn>23</mn></msub></math>, with respect to the SME coefficients <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><msub><mi>a</mi><mi>L</mi></msub><msup><mo stretchy="false">)</mo><mi>T</mi></msup></math>. The combination of DUNE and ESSnuSB may establish the strongest limit on the diagonal coefficient <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><msub><mi>a</mi><mi>L</mi></msub><msubsup><mo stretchy="false">)</mo><mrow><mi>μ</mi><mi>μ</mi></mrow><mi>T</mi></msubsup></math> compared to the existing limits in the literature. We also consider the possible effect of the SME coefficient <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><msub><mi>a</mi><mi>L</mi></msub><msup><mo stretchy="false">)</mo><mi>Z</mi></msup></math> on neutrino propagation and discuss how this can affect DUNE limits on the coefficient <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><msub><mi>a</mi><mi>L</mi></msub><msup><mo stretchy="false">)</mo><mi>T</mi></msup></math> found elsewhere.

China

Mexico

Constraining the isotropic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi><mi>T</mi></mrow></math>-odd coefficients of the standard model extension by a combined DUNE and ESSnuSB analysis

We introduce the alaric parton shower for simulating quantum chromodynamics (QCD) radiation at hadron colliders and present numerical results from an implementation in the event generator sherpa. alaric provides a consistent framework to quantify certain systematic uncertainties which cannot be eliminated by comparing the parton shower with analytic resummation. In particular, it allows us to study recoil effects away from the soft and collinear limits without the need to change the evolution variable or the splitting functions. We assess the performance of alaric in Drell-Yan lepton pair and QCD jet production, and present the first multijet merging for the new algorithm.

alaric parton shower for hadron colliders

The study of chaos and complexity in non-Hermitian quantum systems poses significant challenges due to the emergence of complex eigenvalues in their spectra. Recently, the singular value decomposition (SVD) method was proposed to address these challenges. In this work, we identify two critical shortcomings of the SVD approach when analyzing Krylov complexity and spectral statistics in non-Hermitian settings. First, we show that SVD fails to reproduce conventional eigenvalue statistics in the Hermitian limit for systems with nonpositive definite spectra, as exemplified by a variant of the Sachdev-Ye-Kitaev (SYK) model. Second, and more fundamentally, Krylov complexity and spectral statistics derived via SVD cannot distinguish chaotic from integrable non-Hermitian dynamics, leading to results that conflict with complex spacing ratio analysis. Our findings reveal that SVD is inadequate for probing quantum chaos in non-Hermitian systems, and we advocate employing more robust methods, such as the bi-Lanczos algorithm, for future research in this direction.