HEP Phenomenology·hep-ph
31 papers—21 primary·10 cross-listed·reconstructed*
Antonio Capolupo🇮🇹 · Aniello Quaranta🇮🇹
We discuss the necessity and the emergence of quantum reference frames when attempting to define a rest frame for mixed particles. We analyze the corresponding concept of frame dependent entanglement and how it could affect measurements on mixed mesons and neutrinos.
Kun Cheng🇺🇸 · Yi-Jing Fang🇨🇳 · Tao Han🇺🇸 · Matthew Low🇺🇸
Spin correlation observables of particles produced at colliders generally depend on the coordinate basis. While spin correlations and their associated basis dependence have been studied in top-quark pair production, the basis dependence of spin correlations of a pair has not been studied. In this work, we focus on the azimuthal-angle correlation in the decay of a pair, which encodes spin information in the direction transverse to the rotational axis. We quantitatively describe the basis dependence of the relative azimuthal angle. We further present the optimal coordinate direction to define the azimuthal angle between the decay products of bosons to achieve the maximal spin correlation based on symmetry considerations. The results can be used to optimize the measurement of the CP-even and CP-odd interactions, and have applications to quantum information observables in the vector boson pair system.
Eric Boyers🇺🇸 · Garry Goldstein🇮🇱 · Alexander O. Sushkov🇺🇸
Spin squeezing has been explored in atomic systems as a tool for quantum sensing, improving experimental sensitivity beyond the spin standard quantum limit for certain measurements. To optimize absolute metrological sensitivity, it is beneficial to consider macroscopic spin ensembles, such as nuclear spins in solids and liquids. Coupling a macroscopic spin ensemble to a parametrically-modulated resonant circuit can create collective spin squeezing by generating spin correlations mediated by the circuit. We analyze the squeezing dynamics in the presence of decoherence and finite spin polarization, showing that achieving 7 dB spin squeezing is feasible in several nuclear spin systems. The metrological benefit of squeezing a macroscopic spin ensemble lies in the suppression of technical noise sources in the spin detection system relative to the spin projection noise. This expands the experimental sensitivity bandwidth when searching for signals of unknown frequency and can improve the resonant signal-to-noise ratio. Squeezing macroscopic spin ensembles may prove to be a useful technique for fundamental physics experiments aimed at detecting spin interactions with oscillating background fields, such as ultralight dark matter.
Krish Wu🇺🇸 · Brandon Sun🇺🇸 · Nitish Polishetty🇺🇸 · Justin Kline🇺🇸 · Max Fieg🇺🇸 · Daniel Whiteson🇺🇸
Collisions of particles at the energy frontier can reveal new particles and forces via localized excesses. However, the initial observation may be consistent with a large variety of theoretical models, especially in sectors with new top quark partners, which feature a rich set of possible underlying interactions. We explore the power of the LHC dataset to distinguish between models of the singly produced heavy top-like quark which interacts with the Standard Model through an electromagnetic form factor. We study the heavy top decay to a top quark and a virtual photon which produces a pair of fermions, propose a technique to disentangle the models, and calculate the expected statistical significance to distinguish between various hypotheses.
Ozan Erdoğan🇺🇸 · George Sterman🇺🇸
We review the development of light-cone-ordered perturbation theory in coordinate space (C-LCOPT). Compared to light-cone-ordered perturbation theory in momentum space (LCOPT), the role of intermediate states in LCOPT is played in C-LCOPT by paths, which are ordered sequences of lines and vertices that connect pairs of external points. Each path denominator of C-LCOPT equals the difference between the separation of the minus coordinates of the beginning and ending points of the path and the sum of the light-cone distances of all lines along the path computed from their plus and transverse coordinates. We observe that this method, originally applied to amplitudes, can be extended to cross sections, which are given in terms of closed paths reminiscent of Schwinger-Keldysh formalisms.
Tong Li🇨🇳 · Michael A. Schmidt🇦🇺 · Chang-Yuan Yao🇬🇧
The search for baryon-number-violating (BNV) nucleon decay provides an intriguing probe of new physics beyond the Standard Model (SM). Future neutrino experiments will improve the sensitivity to BNV nucleon decays and can serve to search for dark particles. In this work, we study the sterile neutrino effective field theories (EFTs) with baryon number violation and the impact of light sterile neutrino on BNV nucleon decays. We revisit the dimension-6 and dimension-7 EFT operator bases with or . They are then matched to the baryon chiral perturbation theory. We obtain the effective chiral Lagrangian at low energies and the BNV interactions between the sterile neutrino and baryons and mesons. The rates of nucleon decay to SM neutrinos or a sterile neutrino are calculated. We then show the constraints on the ultraviolet scale from nucleon decay search at Super-K. The correlation of two EFT operators and the dependence on the sterile neutrino mass are also investigated.
Alexander Berezhnoy🇷🇺 · Wolfgang Lucha🇦🇹 · Dmitri Melikhov🇷🇺
We demonstrate that the scalar-mediator dark-matter scenario is consistent with the experimental data on the decay and provides a good description of the shape of the observed excess. Within this scenario, the interaction with dark-matter particles leads to approximately the same excess in and compared to the Standard Model; also the differential distributions of the excess events are similar in shape in the variable measured by experiment.
Subhadeep Roy🇮🇳 · Tanu Gahlaut🇮🇳 · Sadhana Dash🇮🇳
Estimations of event-by-event mean transverse momentum () fluctuations are reported in terms of the integral correlator, , and the skewness of event-wise distribution in protonproton (pp) collisions at TeV with the Monte Carlo event generators PYTHIA8 and HERWIG7. The final-state charged particles with transverse momentum () and pseudorapidity () ranges GeV/ and were considered for the investigation. The correlator, , is observed to follow distinct decreasing trends with average charged particle multiplicity () for the models. Furthermore, both models yield positive finite skewness in low-multiplicity events. Fluctuations are additionally studied using the transverse spherocity estimator () to understand the relative contributions of hard scattering (jets) and other soft processes to the observed fluctuations. Comparing model predictions for fluctuations provides valuable insight into the sensitivity of these fluctuations to hadronization and parton shower models. This is essential for a reliable interpretation of the fluctuation dynamics in pp collisions. Moreover, such comparisons would help to establish a crucial baseline for identifying and studying non-trivial fluctuations in heavy-ion collisions.
Wei-jie Fu🇨🇳 · Chuang Huang🇩🇪 · Jan M. Pawlowski🇩🇪 · Yang-yang Tan🇨🇳 · Li-jun Zhou🇨🇳
We study the full infrared dynamics of 2+1 flavour QCD with the functional renormalisation group approach. We resolve self-consistently the glue dynamics as well as the dynamics of chiral symmetry breaking. The computation hosts no phenomenological parameter or external input. The only ultraviolet input parameters are the physical ones in QCD: the light and strange quark masses. They are adjusted to the physical ratios of the pion and kaon masses, divided by the pion decay constant. The results for other observables of current first-principles computations are in quantitative agreement with the physical ones. This work completes the series of papers, initiated and furthered in [1,2], on dynamical chiral symmetry breaking and the emergence of mesonic bound states within the functional renormalisation group. As a first application we discuss the formation of light mesonic bound states. Amongst other applications such as the phase structure of QCD, the current work paves the way for studying QCD parton distribution functions within the functional renormalisation group approach to first-principles QCD.
Amal Sarkar🇮🇳 · Paramita Deb🇮🇳 · Raghava Varma🇮🇳
The critical end point (CEP) is a key feature of the Quantum Chromodynamics (QCD) phase diagram, where critical phenomena cause higher-order moments of conserved charges net-baryon (), net-charge (), and net-strangeness () to exhibit non-monotonic behavior. These moments and their volume-independent products are sensitive to the correlation length, making them crucial observables in the search for the CEP. In this study, we investigate net-strangeness fluctuations using the finite-volume Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model, incorporating six-quark and eight-quark interactions at energy scales relevant to the RHIC beam energy scan. Our results are compared to STAR net-kaon data and the Hadron Resonance Gas (HRG) model to assess the CEP's existence. Since direct measurement of conserved charges is experimentally challenging, net-proton, net-pion, and net-kaon are used as proxies for , , and . We employ the Subensemble Acceptance Method (SAM) to analyze the acceptance dependence of for net-strangeness fluctuations. Our findings establish a direct mapping between the subvolume (particle fraction) and the total volume (conserved quantities), providing insights into the role of experimental acceptance in fluctuation measurements.
Tatsuya Banno🇯🇵 · Junji Hisano🇯🇵 · Teppei Kitahara🇯🇵 · Kiyoto Ogawa🇯🇵 · Naohiro Osamura🇯🇵
We study the renormalization of the QCD angle at the two-loop level focusing on divergent and finite -violating contributions from evanescent operators, using dimensional regularization with the BMHV scheme. When one considers the Lagrangian in -dimensional space-time instead of four dimensions in dimensional regularization, evanescent operators that break the chiral symmetry are induced. Consequently, -odd and -odd fermion loops in the BMHV scheme generate evanescent contributions to the QCD angle. We carefully classify the evanescent contributions into two types: one originating from the evanescent operators at the one-loop level and the other directly produced by two-loop calculations. We show that renormalization of the parameters in the BMHV scheme keeps removing those unphysical contributions to the QCD angle at any scale at the two-loop level. We also discuss how the rephasing invariance of the radiative correction to the QCD angle is realized in the BMHV scheme.
Seyed Yaser Ayazi🇮🇷 · Mojtaba Hosseini🇮🇷
We revisit the possibility of producing Weakly Interacting Massive Particle (WIMP) dark matter via a freeze-in mechanism triggered by a supercooled first-order phase transition (FOPT) in the early universe. Unlike traditional freeze-out and FIMP scenarios, this mechanism relies on a rapid entropy injection that dilutes the preexisting dark matter abundance and prevents re-equilibration due to a sudden mass increase. In this study, we systematically examine a variety of single-component dark matter models-including vector, fermionic, and scalar-mediated candidates-to assess whether they can satisfy the key cosmological condition T2 >> T1, required for successful WIMP freeze-in after FOPT. Contrary to earlier results, our revised analysis finds that none of the models fulfill this condition across viable parameter spaces. We confirm, however, that the scalar dark matter model analyzed in Ref. [1] is the only known viable single-component model that fulfills T2 >> T1 and enables WIMP freeze-in via this mechanism. These findings place important constraints on model-building efforts and suggest that successful freeze-in after FOPT may require multi-component or more complex dark sectors beyond the scope of minimal models.
Iñigo Asiáin🇪🇸 · Domènec Espriu🇪🇸 · Federico Mescia🇮🇹
Loss of unitarity in an effective field theory is often cured by the appearance of dynamical resonances, revealing the presence of new degrees of freedom. These resonances may manifest themselves when suitable unitarization techniques are implemented in the effective theory, which in the scalar-isoscalar channel require using the coupled-channel formalism. Experimental detection of a resonance would provide precious information on the couplings and constants of the relevant effective theory. Conversely, the absence of a resonance where the unitarized effective theory predicts it should be allows us to rule out a certaing range of couplings that would otherwise be allowed. Likewise, the appearence of unphysical (e.g. acausal) resonances is telling us that no UV completion could give rise to the corresponding couplings in the effective theory. In this talk we summarize the systematical procedure we have implemented in order to confront the effective theory with the absence or presence of resonances in the vector boson fusion channel at the LHC.
Haijing Zhou🇨🇳 · Guangning Ban🇫🇷
In the presence of a light singlet-like scalar, the bino-dominated dark matter (DM) candidate in the -symmetric next-to-minimal supersymmetric standard model (-NMSSM) exhibits notable deviations from its counterpart in the minimal supersymmetric standard model (MSSM), both in terms of its inherent properties and the mechanisms determining its relic abundance and detection prospects. Motivated by recent progress in experimental particle physics, this study systematically investigates the implications for the \( \mathbb{Z}_3 \)-NMSSM framework featuring a light bino-dominated DM particle and a light singlet-like scalar, ensuring theoretical consistency with empirical observations. Of particular significance are the latest results from the LUX-ZEPLIN (LZ) direct detection experiment, supersymmetry (SUSY) searches at the Large Hadron Collider (LHC), and precision measurements of the Muon g-2 anomaly at Fermilab, which collectively impose complementary constraints on the model's viable parameter space. A comprehensive parameter scan was conducted using the MultiNest algorithm, incorporating constraints from LZ-2022 data, LHC Higgs analyses, Muon g-2 measurements, and B-physics observables. The analysis reveals that current experimental limits -- particularly those on spin-independent (SI) and spin-dependent (SD) DM-nucleon scattering cross-sections and LHC constraints on electroweakinos -- severely restrict the model. Nevertheless, the framework remains capable of naturally accommodating the observed Z boson and standard model-like Higgs boson masses, accounting for the Muon g-2 anomaly, and inducing sizable corrections to the W boson mass. These results are distinctive to the NMSSM and emerge from the interplay of bino-dominated DM and singlino components, with essential contributions from higgsino.
James P. Edwards🇬🇧 · Naser Ahmadiniaz🇩🇪 · Sebastian M. Schmidt🇩🇪 · Christian Kohlfürst🇩🇪
Quantum kinetic theory is an important tool for studying non-equilibrium, non-perturbative and non-linear interactions within an open quantum system, and as such is able to provide an unprecedented view on particle production in the relativistic, ultra-high intensity regime of quantum electrodynamics. By re-organising the relativistic quantum transport equations for Abelian plasmas and integrating them with a perturbative expansion, we significantly expand the scope for kinetic theories to further elucidate the peculiarities of particle production at a spectral level. Keywords: Assisted Schwinger effect, Strong-field quantum electrodynamics, relativistic quantum transport, quantum kinetic theory, non-equilibrium quantum many-body physics.
We review the method of the differential equations for the evaluation of multi-loop Feynman integrals. In particular, we focus on the series expansion approach for solving the system of differential equation and we discuss how to perform the analytical continuation of the result to entire (complex) phase-space. This approach allow us to consider arbitrary internal complex masses. This review is based on a lecture given by the author at the "Advanced School and Workshop on Multiloop Scattering Amplitudes" held in NISER, Bhubaneswar (India) in January 2024.
Preserving the unique role of the one Higgs doublet of the standard model, it is proposed that quark and lepton mass patterns, often ascribed to the Froggatt-Nielsen mechanism using nonrenormalizable higher-dimensional terms, may be enforced in a renormalizable theory of just one Higgs doublet by the scotogenic mechanism with soft symmetry breaking in the dark sector. A revised version of the original model of charged leptons and neutrinos is discussed.
In the polarized background field, the coupling constant will be influenced. We quantify this effect and propose that it can be measured at the EIC and EicC through the Bethe-Heitler process.
Matteo Becchetti🇮🇹 · Maximilian Delto🇩🇪 · Sara Ditsch🇩🇪 · Philipp Alexander Kreer🇩🇪 · Mattia Pozzoli🇮🇹 · Lorenzo Tancredi🇩🇪
We present a computation of the one-loop QCD corrections to top-quark pair production in association with a boson, including terms up to order in dimensional regularization. Providing a first glimpse into the complexity of the corresponding two-loop amplitude, this result is a first step towards a description of this process at next-to-next-to-leading order (NNLO) in QCD. We perform a tensor decomposition and express the corresponding form factors in terms of a basis of independent special functions with compact rational coefficients, providing a structured framework for future developments. In addition, we derive an explicit analytic representation of the form factors, valid up to order , expressed in terms of logarithms and dilogarithms. For the complete set of special functions required, we obtain a semi-numerical solution based on generalized power series expansion.
Valerie Domcke🇨🇭 · Miguel Escudero🇨🇭 · Mario Fernandez Navarro🇬🇧 · Stefan Sandner🇺🇸
Large primordial lepton flavor asymmetries with almost vanishing total baryon-minus-lepton number can evade the usual BBN and CMB constraints if neutrino oscillations lead to perfect flavor equilibration. Solving the momentum averaged quantum kinetic equations (QKEs) describing neutrino oscillations and interactions, we perform the first systematic investigation of this scenario, uncovering a rich flavor structure in stark contradiction to the assumption of simple flavor equilibration. We find (i) a particular direction in flavor space, for normal (inverted) neutrino mass hierarchy, in which the flavor equilibration is efficient and primordial asymmetries are essentially unconstrained, (ii) a minimal washout factor, yielding a conservative estimate for the allowed primordial asymmetries in a generic flavor direction, and (iii) particularly strong or weak washout if one of the initial flavor asymmetries vanishes due to non-adiabatic muon- or electron-driven MSW transitions. These results open up the possibility of a first-order QCD phase transition facilitated by large lepton asymmetries as well as baryogenesis from large and compensated asymmetries. Our first-principles approach of deriving momentum averaged QKEs includes collision terms beyond the damping approximation, energy transfer between the neutrino and electron-photon plasma, and provides a fast and reliable way to investigate the impact of primordial lepton asymmetries at the time of BBN. We publicly release the Mathematica code COFLASY-M on GitHub which solves the QKEs numerically.
D. Pitonyak🇺🇸 · C. Cocuzza🇺🇸 · A. Metz🇺🇸 · A. Prokudin🇺🇸 · N. Sato🇺🇸
We make several comments on the recent work in Ref.~\cite{Rogers:2024nhb} while also reaffirming and adding to the work in Ref.~\cite{Pitonyak:2023gjx}. We show that the factorization formula for in Ref.~\cite{Rogers:2024nhb} is equivalent to a version one can derive using the definition of a -hadron fragmentation function (FF) introduced in Ref.~\cite{Pitonyak:2023gjx}. In addition, we scrutinize how to generalize the number density definition of a single-hadron FF to a -hadron FF, arguing that the definition given in Ref.~\cite{Pitonyak:2023gjx} should be considered the standard one. We also emphasize that the evolution equations for dihadron FFs~(DiFFs) in Ref.~\cite{Pitonyak:2023gjx} have the same splitting functions as those for single-hadron FFs. Therefore, the DiFF (and -hadron FF) definitions in Ref.~\cite{Pitonyak:2023gjx} have a natural number density interpretation and are consistent with collinear factorization using the standard hard factors and evolution kernels. Moreover, we make clear that the operator definition for the DiFF written down in Ref.~\cite{Rogers:2024nhb} agrees exactly with the one in Ref.~\cite{Pitonyak:2023gjx}. Contrary to what is implied in Ref.~\cite{Rogers:2024nhb}, this definition did not appear in the literature prior to the work in Ref.~\cite{Pitonyak:2023gjx}. There also seem to be inconsistencies in how appears in previous unpolarized cross section formulas in the literature.
Irene Lopez Imaz🇪🇸 · German Sborlini🇪🇸
Unveiling hidden symmetries within Feynman diagrams is crucial for achieving more efficient computations in high-energy physics. In this paper, we study the symmetries underlying the causal Loop-Tree Duality (LTD) representations through a {graph-theoretic} analysis. Focusing on the integrand-level representations of -point functions at one loop, we examine their degeneration and discover that different causal representations are interconnected through specific transformations arising from the symmetries of cut diagrams. Furthermore, the degeneration is linked to algebraic constraints among the different causal thresholds. Our findings shed new light on the deeper structures of Feynman integrals and pave the way for significantly accelerating their calculation by interrelating different approaches.
Alejandro Ayala🇲🇽 · José Jorge Medina-Serna🇲🇽 · Isabel Domínguez🇲🇽 · Ivonne Maldonado🇷🇺 · María Elena Tejeda-Yeomans🇲🇽
In the context of the description of how the vortical motion, produced in peripheral heavy-ion collisions, is transferred to the spin of hadrons, we compute the -meson propagator at finite temperature and baryon density. This propagator encodes the properties of a medium consisting mainly of nucleons{, and can be used to model the main interactions between hadrons} in the corona region of the reaction. We compute the one-loop self-energy in an approximation that accounts for the large nucleon mass. From the real part of the self-energy, we find the dispersion relation and show that the -mass receives a non-negligible thermal and baryon chemical dependent {contribution}. From the imaginary part, we also compute the spectral density, which we show to contain a piece coming from the branch cut associated with Landau damping. We also present approximations for the dispersion relation and the residue at the pole in the small- and large-momentum regimes and complement the calculation, providing the sum rules satisfied by the propagator. This study aims to determine one of the elements needed to compute how the vortical motion in the corona region of the reaction is transferred to the spin of hyperons that can interact with nucleons by -meson exchange.
Zhigang Bu🇨🇳 · Lingang Zhang · Shiyu Liu🇨🇳 · Baifei Shen🇨🇳 · Ruxin Li🇨🇳 · Igor P. Ivanov🇨🇳 · Liangliang Ji🇨🇳
Collision of ultra-intense optical laser and X-ray free electron laser (XFEL) pulses is a promising approach to detecting nonlinear vacuum polarization (VP), a long-standing prediction of quantum electrodynamics remaining to be tested. Identifying the signals induced by polarized vacuum relies on purifying the X-ray polarization and poses significant challenges due to strongly reduced signal and low signal-to-noise ratio (SNR). Here we propose an approach that allows one to directly detect VP signals without the need for an X-ray polarizer. We identify a new VP effect in collision of an X-ray probe with an intense laser in a vortex mode, which we call the super light-by-light scattering (super-LBL), through which signal photons are kicked out of the X-ray background with large tangential momentum. Super-LBL originates from the gradient force of the vortical vacuum current in azimuthal direction and induces momentum exchange beyond the transverse momentum of laser-photon. This effect efficiently sets the scattered signal photons apart from the X-ray background, producing observable signals with both the strength and SNR more than two orders of magnitude higher than those from the known VP effects. This finding paves the way for single-shot detection of nonlinear VP phenomena with current ultra-intense laser and XFEL technologies.
Sebastian M. Dawid🇺🇸 · Zachary T. Draper🇺🇸 · Andrew D. Hanlon🇺🇸 · Ben Hörz🇩🇪 · Colin Morningstar🇺🇸 · Fernando Romero-López🇨🇭 · Stephen R. Sharpe🇺🇸 · Sarah Skinner🇺🇸
We use lattice QCD calculations of the finite-volume spectra of systems of two and three mesons to determine, for the first time, three-particle scattering amplitudes with physical quark masses. Our results are for combinations of and , at a lattice spacing fm, and in the isospin-symmetric limit. We also obtain accurate results for maximal-isospin two-meson amplitudes, with those for and being the first determinations at the physical point. Dense lattice spectra are obtained using the stochastic Laplacian-Heaviside method, and the analysis leading to scattering amplitudes is done using the relativistic finite-volume formalism. Results are compared to chiral perturbation theory and to phenomenological fits to experimental data, finding good agreement.
Andrei E. Egorov🇷🇺 · Aleksey A. Alekseev🇵🇱
A. Parkhomov reported in the past the detection of strong, short, sporadic, nearly everyday decay rate increases in -isotopes placed at the focus of a concave mirror directed at a clear sky. He interpreted this effect as neutrino-induced decay. These neutrinos were assumed to be slow and arrive from space in the form of gravitationally collimated beams. We precisely replicated this experiment for the purpose of independent verification. We recorded about 50 days of data employing Geiger-counter-based signal and control detectors, K and Sr/Y isotopes as -sources. We did not detect any significant difference between the data from signal and control detectors, both datasets obeyed the standard Poissonian process. Thus, we robustly excluded the hypothesized new effect. We suspect that A. Parkhomov was just misled by a trivial electromagnetic instability of his setup.
B. Hacisahinoglu🇹🇷 · S. Ozkorucuklu🇹🇷 · M. Ovchynnikov🇨🇭 · M.G. Albrow🇺🇸 · A. Penzo🇺🇸 · O. Aydilek🇹🇷
The Standard Model (SM) fails to explain many problems (neutrino masses, dark matter, and matter-antimatter asymmetry, among others) that may be resolved with new particles beyond the Standard model (BSM). The fact that such new particles are not yet observed may be explained either by their too high mass or by very small coupling to SM particles. The latter case implies long lifetimes. Such long-lived particles (LLPs) would have signatures different from those of SM particles. Searches in the "central region" are covered by the LHC general purpose experiments. The forward small angle region far from the interaction point (IP) is unexplored. Such particles would have large energy = (1~TeV) and Lorentz time dilation factor , hence long decay distances. A new class of specialized LHC detectors dedicated to LLP searches has been proposed for the forward regions. Among these experiments, FASER is already operational, and FACET is under consideration at a location 100 meters from IP5 (the CMS intersection). However, some features of FACET require a specially enlarged beam pipe, which cannot be implemented for Run 4. In this study, we explore a simplified version of the proposed detector, PREFACE, compatible with the standard LHC beam pipe in the HL-LHC in Run 4. Realistic Geant4 simulations are performed and the background is evaluated. A preliminary analysis of the physics potential with the PREFACE geometry indicates that several significant channels could be accessible with sensitivities comparable to FACET and other LLP searches.
Ifan Williams🇬🇧 · Mathieu Pellen🇩🇪
We present universal building blocks for the quantum integration of generic cross sections in high-energy physics. We make use of Fourier quantum Monte Carlo integration (MCI) as implemented in Quantinuum's quantum MCI engine to provide an extendable methodology for generating efficient circuits that can implement generic cross-section calculations, providing a quadratic speed-up in root mean-squared error convergence with respect to classical MCI. We focus on a concrete example of a decay process to illustrate our work.
Özgür Akarsu🇹🇷 · Leandros Perivolaropoulos🇬🇷 · Anna Tsikoundoura🇬🇷 · A. Emrah Yükselci🇹🇷 · Alexander Zhuk🇩🇪
We investigate the dynamics and cosmological implications of dark energy (DE), modeled as a scalar field with a hyperbolic tangent potential that induces a smooth shift in the effective cosmological constant (CC), encompassing transitions such as AdS-dS, 0-dS, and dS-dS, with the mirror AdS-dS as a particular case aligned with the CDM scenario. In our construction, a phantom scalar field with a negative kinetic term drives a bottom-up transition from an AdS-like vacuum at high redshifts to a dS-like vacuum at low redshifts, thereby providing a physical underpinning for the CDM scenario. Despite the negative kinetic term, the step-like form of the potential prevents pathologies such as unbounded energy growth, Big Rip, and violations of the WEC. Our numerical integration of the equations of motion shows that the model is consistent with both CMB data and the SH0ES determination of , thereby addressing the tension, with all key kinematical parameters-, , and -evolving smoothly. The total energy density of the phantom and matter system remains positive at all times, and the effective EoS stays above -1, ensuring that the WEC is satisfied. While the phantom field's energy density and pressure remain finite throughout, its EoS exhibits a safe singularity as its energy density smoothly crosses zero. We perform analysis of the transition period, demonstrating that the evolution of the DE density from a negative CC-like regime to a positive one does not exactly mirror the behavior of the potential-e.g., it lasts longer-as it also involves the kinetic term. We also show that analogous quintessence models featuring dS-dS transitions predict an value lower than CDM, thereby failing to address the tension. Our results establish a robust theoretical foundation for the CDM scenario.
H.-Thomas Janka (MPI Astrophysics, Garching)🇩🇪
Self-consistent, multidimensional core-collapse supernova (SN) simulations, especially in 3D, have achieved tremendous progress over the past 10 years. They are now able to follow the entire evolution from core collapse through bounce, neutrino-triggered shock revival, shock breakout at the stellar surface to the electromagnetic SN outburst and the subsequent SN remnant phase. Thus they provide general support for the neutrino-driven explosion mechanism by reproducing observed SN energies, neutron-star (NS) kicks, and diagnostically relevant radioactive isotope yields; they allow to predict neutrino and gravitational-wave signals for many seconds of proto-NS cooling; they confirm correlations between explosion and progenitor or remnant properties already expected from previous spherically symmetric (1D) and 2D models; and they carve out various scenarios for stellar-mass black-hole (BH) formation. Despite these successes it is currently unclear which stars explode or form BHs, because different modeling approaches disagree and suggest the possible importance of the 3D nature of the progenitors and of magnetic fields. The role of neutrino flavor conversion in SN cores still needs to be better understood, the nuclear equation of state including potential phase transitions implies major uncertainties, the SN 1987A neutrino measurements raise new puzzles, and tracing a possible correlation of NS spins and kicks requires still more refined SN simulations.
P. A. L. Mourão🇧🇷 · G. L. L. W. Levy🇧🇷 · J. A. Helayël-Neto🇧🇷
Our present contribution sets out to investigate how combined effects of Lorentz invariance violation (LIV) and loop quantum gravity (LQG)-modified photon dispersion relations affect the threshold anomaly of cosmic photons. The point of departure is the post-Maxwellian version of electromagnetism induced by LQG effects. We then consider the problem of gamma-ray attenuation by the extragalactic background light (EBL) and the cosmic microwave background radiation (CMB) dominated by the Breit-Wheeler Effect. By following this path, we aim at the establishment of a new bridge between LIV and astrophysical phenomena in the framework of LQG, providing a robust explanation for recent ultra high energy (UHE) astrophysical observations.
* 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.