HEP Phenomenology·hep-ph
28 papers—21 primary·7 cross-listed·reconstructed*
Dante Bigi🇮🇹 · Sandro Mächler🇮🇹
We compute the effects of a finite boson mass on the inclusive decay rate and the semileptonic moments. To this end we keep terms of when integrating out the boson in the Weak Effective Theory. In the third hadronic invariant mass moment such corrections reach the level but they are smaller than the present-day experimental uncertainties in all observables.
Fabiola Fortuna🇲🇽 · Xabier Marcano🇪🇸 · Marcela Marín🇲🇽 · Pablo Roig🇲🇽
We consider charged lepton flavor violating transitions mediated by the diphoton effective interactions and explore which processes can probe them better. Our analysis includes single and double radiative decays, , as well as conversions in nuclei for all possible flavor combinations, which we compute for the first time for conversions in this framework. We find that currently the best limits are provided by the loop-induced processes, while the best future sensitivities come from conversion in aluminum and from potential searches at Belle II or at the Super Tau Charm Facility. We also motivate the search for at the Mu3e experiment as a complementary probe of these operators.
M. Fabbrichesi🇮🇹 · R. Floreanini🇮🇹 · E. Gabrielli🇮🇹 · L. Marzola🇪🇪
The violation of the Bell inequality is one of the hallmarks of quantum mechanics and can be used to rule out local deterministic alternative descriptions. We utilize the data analysis published by the LHCb collaboration on the helicity amplitudes for the decay to compute the entanglement among the polarizations of the final vector mesons and the violation of the Bell inequality that it entails. We find that quantum entanglement can be detected with a significance well above 5 (nominally 84) and Bell inequality is violated with a significance well above 5 (nominally 36) -- thereby firmly establishing these distinguishing feature of quantum mechanics at high energies in a collider setting and in the presence of strong and weak interactions. Entanglement is also present and the Bell inequality is violated in other decays of the mesons into vector mesons, but with lesser significance.
Uladzimir Khasianevich🇩🇪 · Dominik Stöckinger🇩🇪 · Hyejung Stöckinger-Kim🇩🇪 · Johannes Wünsche🇩🇪
We consider the full flavor structure of the leptoquark model and derive conservative constraints on the elements of the left- and right-handed coupling matrices. We focus on the cases where the muon deviation is explained by muon couplings to the top-quark or to the charm-quark or to all up-type quarks. The most significant constraints arise from charged lepton flavor violating decays of the muon and the lepton and from the conversion process. Kaon decays and perturbativity provide further constraints. We find strong constraints on almost all coupling matrix elements, implying a very hierarchical matrix structure, where individual entries must differ by at least 4 orders of magnitude. The program was used with appropriate model files incorporating the parameterization of the couplings in the up-type mass diagonal basis. The expressions for the leptonic observables were generated and cross-checked with the help of the extension of the program.
Francesco Giovanni Celiberto🇪🇸 · Luigi Delle Rose🇮🇹 · Michael Fucilla🇮🇹 · Gabriele Gatto🇮🇹 · Alessandro Papa🇮🇹
We study the inclusive production, at hadron colliders, of a Higgs boson and a jet widely separated in rapidity. Kinematic sectors explored fall into the so-called semi-hard regime, where both fixed-order and high-energy dynamics come into play. Therefore, we propose a first version of a matching procedure aimed at combining NLO fixed-order computations, as obtained from POWHEG, with the NLL resummation of energy logarithms via JETHAD. According to our knowledge, this represents a novel implementation of a matching in the context of the high-energy resummation at NLL and for rapidity-separated two-particle final states.
Albi Kerbizi🇮🇹 · Leif Lönnblad🇸🇪
Quark spin effects in hadronization were recently included in the PYTHIA 8 Monte Carlo event generator for the simulation of the deep inelastic scattering (DIS) process off a polarized proton or neutron target. The spin effects were activated via the external StringSpinner package, which is based on the string+ model of polarized hadronization, and were restricted to the production of pseudoscalar mesons in string fragmentation. The struck quark polarization could either be calculated using parametrizations of the transversity PDFs or be freely specified. In this article we present a major extension of StringSpinner that includes vector meson production in the PYTHIA 8 string fragmentation. The spin-dependent emission and decay processes of the vector mesons are described using the string+ model, which systematically accounts for the quark-spin degree of freedom in the fragmentation chain. The new package works with the version 8.3 of the PYTHIA event generator and it allows for a more complete and quantitative simulation of the final states in polarized semi-inclusive DIS events. Also, it can be used to study the transverse-spin effects for the production of vector mesons. After describing the new version of StringSpinner, examples of its usage in semi-inclusive DIS events are presented.
The Minimal 3-3-1 Model (m331) offers a compelling extension of the Standard Model, with a rich particle content that allows for exciting phenomenological possibilities. The parameter space of the theory, however, remains relatively unconstrained. Regarding its effective range of validity, it is understood in the literature that the coupling diverges at around , which threatens the character of the theory as fundamental. In this work, we rederive the running of the electroweak gauge couplings through a more precise, effective approach, in which the complete parametrization of the full 3-3-1 symmetry is considered at all energies. We show that this more rigorous description guarantees a larger perturbative range for the m331, with a most conservative upper limit going up to around . We also reconsider the usefulness of a relation which eliminates a free parameter of the model in favour of known quantities, regularly invoked within the m331 context.
A. R. Caddell🇦🇺 · V. V. Flambaum🇦🇺 · B. M. Roberts🇦🇺
While most scintillation-based dark matter experiments search for Weakly Interacting Massive Particles (WIMPs), a sub-GeV WIMP-like particle may also be detectable in these experiments. While dark matter of this type and scale would not leave appreciable nuclear recoil signals, it may instead induce ionization of atomic electrons. Accurate modelling of the atomic wavefunctions is key to investigating this possibility, with incorrect treatment leading to a large suppression in the atomic excitation factors. We have calculated these atomic factors for argon, krypton and xenon and present the tabulated results for use with a range of dark matter models. This is made possible by the separability of the atomic and dark matter form factor, allowing the atomic factors to be calculated for general couplings; we include tables for vector, scalar, pseudovector, and pseudoscalar electron couplings. Additionally, we calculate electron impact total ionization cross sections for xenon using the tabulated results as a test of accuracy. Lastly, we provide an example calculation of the event rate for dark matter scattering on electrons in XENON1T and show that these calculations depend heavily on how the low-energy response of the detector is modelled.
Katharena Christy🇺🇸 · Jason Kumar🇺🇸 · Pearl Sandick🇺🇸
We consider constraints on -wave dark matter in a dark matter spike surrounding the supermassive black hole at the center of M87. Owing to the large mass of the black hole, and resulting large velocity dispersion for the dark matter particles in the spike, it is possible for Fermi-LAT and MAGIC data to place tight constraints on -wave annihilation, which would be far more stringent than those placed by observations of dwarf spheroidal galaxies. Indeed, for optimistic choices of the spike parameters, gamma-ray data would exclude thermal -wave dark matter models with a particle mass . But there is significant uncertainty in the properties and parameters of the spike, and for less optimistic scenarios, thermal dark matter candidates would be completely unconstrained. In addition to better understanding the spike parameters, a second key to improving constraints on dark matter annihilation is an accurate astrophysical background model.
Masoom Singh🇮🇳 · Mauricio Bustamante🇩🇰 · Sanjib Kumar Agarwalla🇮🇳
Discovering new neutrino interactions would represent evidence of physics beyond the Standard Model. We focus on new flavor-dependent long-range neutrino interactions mediated by ultra-light mediators, with masses below eV, introduced by new lepton-number gauge symmetries , , and . Because the interaction range is ultra-long, nearby and distant matter - primarily electrons and neutrons - in the Earth, Moon, Sun, Milky Way, and the local Universe, may source a large matter potential that modifies neutrino oscillation probabilities. The upcoming Deep Underground Neutrino Experiment (DUNE) and the Tokai-to-Hyper-Kamiokande (T2HK) long-baseline neutrino experiments will provide an opportunity to search for these interactions, thanks to their high event rates and well-characterized neutrino beams. We forecast their probing power. Our results reveal novel perspectives. Alone, DUNE and T2HK may strongly constrain long-range interactions, setting new limits on their coupling strength for mediators lighter than eV. However, if the new interactions are subdominant, then both DUNE and T2HK, together, will be needed to discover them, since their combination lifts parameter degeneracies that weaken their individual sensitivity. DUNE and T2HK, especially when combined, provide a valuable opportunity to explore physics beyond the Standard Model.
Jiazhen Shao🇨🇳 · Igor P. Ivanov🇨🇳
Multi-Higgs models equipped with global symmetry groups, either exact or softly broken, offer a rich framework for constructions beyond the Standard Model and lead to remarkable phenomenological consequences. Knowing all the symmetry options within each class of models can guide its phenomenological exploration, as confirmed by the vast literature on the two- and three-Higgs-doublet models. Here, we begin a systematic study of finite non-abelian symmetry groups which can be imposed on the scalar sector of the four-Higgs-doublet model (4HDM) without leading to accidental symmetries. In this work, we derive the full list of such non-abelian groups available in the 4HDM that can be constructed as extensions of cyclic groups by their automorphism groups. This list is remarkably restricted but it contains cases which have not been previously studied. Since the methods we develop may prove useful for other classes of models, we present them in a pedagogical manner.
Alessandro Zenesini🇮🇹 · Anna Berti🇮🇹 · Riccardo Cominotti🇮🇹 · Chiara Rogora🇮🇹 · Ian G. Moss🇬🇧 · Thomas P. Billam🇬🇧 · Iacopo Carusotto🇮🇹 · Giacomo Lamporesi🇮🇹 · Alessio Recati🇮🇹 · Gabriele Ferrari🇮🇹
In quantum field theory, the decay of an extended metastable state into the real ground state is known as ``false vacuum decay'' and it takes place via the nucleation of spatially localized bubbles. Despite the large theoretical effort to estimate the nucleation rate, experimental observations were still missing. Here, we observe bubble nucleation in isolated and highly controllable superfluid atomic systems, and we find good agreement between our results, numerical simulations and instanton theory opening the way to the emulation of out-of-equilibrium quantum field phenomena in atomic systems.
Adil Jueid🇰🇷 · Jinheung Kim🇰🇷 · Soojin Lee🇰🇷 · Jeonghyeon Song🇰🇷 · Daohan Wang🇰🇷
We comprehensively study the potential for discovering lepton flavor violation (LFV) phenomena associated with the and Higgs bosons at the LHeC and FCC-he. Our meticulous investigation reveals the remarkable suitability of electron-proton colliders for probing these rare new physics signals. This is due to the distinct advantages they offer, including negligible pileups, minimal QCD backgrounds, electron-beam polarization , and the capability of distinguishing the charged-current from neutral-current processes. In our pursuit of LFV of the boson, we employ an innovative indirect probe, utilizing the -channel mediation of the boson in the process . For LFV in the Higgs sector, we scrutinize direct observations of the on-shell decays of and through the charged-current production of . Focusing on proves highly efficient due to the absence of positron-related backgrounds in the charged-current modes at electron-proton colliders. Through a dedicated signal-to-background analysis with the boosted decision tree algorithm, we demonstrate that the LHeC with the total integrated luminosity of can put significantly lower bounds than the HL-LHC with . Specifically, we find , , and . Furthermore, our study uncovers the exceptional precision of the FCC-he in measuring the LFV signatures of the and Higgs bosons, which indicates the potential for future discoveries in this captivating field.
The electroexcitation of the Roper resonance, which defines the first radially excited state of the nucleon, is examined within the soft-wall AdS/QCD model. Such excited Fock states are characterized by the leading three-quark component, which determines the main properties of Roper resonance. The differential configurational entropy (DCE) was used in the nuclear interaction with a gauge vector field for transition. Comparing the main results with the recent data of the CLAS Collaboration at JLab shows a good agreement on the accuracy of the computed data.
Prabal Adhikari🇺🇸 · Inga Strümke🇳🇴
We study three-flavor QCD in a uniform magnetic field using chiral perturbation theory (PT). We construct the vacuum free energy density, quark condensate shifts induced by the magnetic field and the renormalized magnetization to in the chiral expansion. We find that the calculation of the free energy is greatly simplified by cancellations among two-loop diagrams involving charged mesons. In comparing our results with recent -flavor lattice QCD data, we find that the light quark condensate shift at is in better agreement than the shift at . We also find that the renormalized magnetization, due to its smallness, possesses large uncertainties at due to the uncertainties in the low-energy constants.
Huner Fanchiotti🇦🇷 · Carlos A. García Canal🇦🇷 · Vicente Vento🇪🇸
We study the energy loss of excited monopolium in an atomic medium. We perform a classical calculation in line with a similar calculation performed for charged particles which leads in the non relativistic limit to the Bethe-Bloch formula except for the density dependence of the medium, which we do not consider in this paper. Our result shows that for maximally deformed Rydberg states the ionization of monopolium in a light atomic medium is similar to that of light ions.
Gholamhossein Haghighat🇮🇷 · Reza Jafari🇮🇷 · Hamzeh Khanpour🇮🇷 · Mojtaba Mohammadi Najafabadi🇮🇷
In this paper, we use the charged-current Higgs boson production process at future electron-proton colliders, , with the subsequent decay of the Higgs boson into a pair, to probe the Standard Model effective field theory with dimension-six operators involving the Higgs boson and the bottom quark. The study is performed for two proposed future high-energy electron-proton colliders, the Large Hadron Electron Collider (LHeC) and the Future Circular Collider (FCC-he) at the center-of-mass energies of 1.3 TeV and 3.46 TeV, respectively. Constraints on the CP-even and CP-odd couplings are derived by analyzing the simulated signal and background samples. A realistic detector simulation is performed and a multivariate technique using the gradient Boosted Decision Trees algorithm is employed to discriminate the signal from background. Expected limits are obtained at Confidence Level for the LHeC and FCC-he assuming the integrated luminosities of 1, 2 and 10 ab. We find that using 1 ab of data, the CP-even and CP-odd couplings can be constrained with accuracies of the order of and , respectively, and a significant region of the unprobed parameter space becomes accessible.
Asher Berlin🇺🇸 · Tanner Trickle🇺🇸
Detection of axion dark matter heavier than a meV is hindered by its small wavelength, which limits the useful volume of traditional experiments. This problem can be avoided by directly detecting in-medium excitations, whose energies are decoupled from the detector size. We show that for any target inside a magnetic field, the absorption rate of electromagnetically-coupled axions into in-medium excitations is determined by the dielectric function. As a result, the plethora of candidate targets previously identified for sub-GeV dark matter searches can be repurposed as broadband axion detectors. We find that a exposure with noise levels comparable to recent measurements is sufficient to probe parameter space currently unexplored by laboratory tests. Noise reduction by only a few orders of magnitude can enable sensitivity to the QCD axion in the mass range.
Oleg Lebedev🇫🇮 · Yann Mambrini🇫🇷 · Jong-Hyun Yoon🇫🇷
We study inflationary models based on a non-minimal coupling of a singlet scalar to gravity, focussing on the preheating dynamics and the unitarity issues in this regime. If the scalar does not have significant couplings to other fields, particle production after inflation is far less efficient than that in Higgs inflation. As a result, unitarity violation at large non-minimal couplings requires a different treatment. We find that collective effects in inflaton scattering processes during preheating make an important impact on the unitarity constraint. Within effective field theory, the consequent upper bound on the non-minimal coupling is of order a few hundreds.
Asher Berlin🇺🇸 · Raffaele Tito D'Agnolo🇫🇷 · Sebastian A. R. Ellis🇨🇭 · Jury I. Radkovski🇨🇦
We discuss a novel detection technique for millicharged dark matter that makes use of existing light-shining-through-wall (LSW) experiments searching for massive dark photons. Since millicharged particles interact with both the visible and dark sectors, a small background of such particles enables the search for visible signals even in the limit of a massless dark photon. Furthermore, for sufficiently large couplings, a small dark matter subcomponent consisting of millicharged particles can have a terrestrial abundance that is significantly enhanced with respect to its galactic abundance. We leverage this fact to show that in certain parts of parameter space, future runs of the LSW Dark SRF experiment can be used to set the strongest limits on millicharged relics.
Kazuki Ikeda🇺🇸 · Dmitri E. Kharzeev🇺🇸 · Shuzhe Shi🇺🇸
The chiral magnetic wave (CMW) is a macroscopic quantum phenomenon that arises due to the mixing of the electric and chiral charge oscillations induced by the chiral anomaly. In this study we report the first quantum simulation (on classical hardware) of the real-time dynamics of CMWs in Schwinger model. Our quench protocol is the following: at we suddenly place an electric dipole at the middle of our lattice. Due to chiral anomaly, this dipole excites the CMW that propagates towards the edges of the lattice. In Schwinger model tuned to the conformal critical point (at , ), we find a gapless linear CMW that propagates with the speed of light. For massless Schwinger model (), we find a gapped linear CMW, in accord with previous analytical analyses. For massive Schwinger model (that is dual to strongly interacting bosonic theory), we enter the new regime of nonlinear CMWs, where we find a surprise. Specifically, for , the frequency of electric charge oscillations becomes much smaller than the frequency of the oscillations of the chiral charge. For , we find a solution corresponding to a nearly static electric dipole with fast oscillations of the chiral charge confined within. We call this solution a "thumper" and study its properties in detail.
D. Avila Rojas🇲🇽 · S. Hernández-Cadena🇲🇽 · M. M. González🇲🇽 · A. Pratts🇲🇽 · R. Alfaro🇲🇽 · J. Serna-Franco🇲🇽
GRB 221009A has posed a significant challenge to our current understanding of the mechanisms that produce TeV photons in gamma-ray bursts (GRB). On one hand, the Klein-Nishina (KN) effect of the inverse Compton scattering leads to less efficient energy losses of high-energy electrons. In the other hand, at a redshift of 0.151, the TeV spectrum of GRB 221009A undergoes significant absorption by the Extragalactic Background Light (EBL). Therefore, the observation of a 13-TeV photon in this event implies the presence of enormous photon fluxes at the source, which the Synchrotron Self-Compton mechanism in external shocks cannot easily generate. As an alternative, some authors have suggested the possibility of converting the TeV-photons into Axion-like particles (ALPs) at the host galaxy, in order to avoid the effects of EBL absorption, and then reconverting them into photons within the Milky Way. While this solution relaxes the requirement of very high photon fluxes, the KN effect still poses a challenge. Previously, we have shown that the injections of ALPs could explain the observation of 13-TeV photons. Here, we include the energy dependence of the survival probability and the amount of energy carried to determine the ALP candidates which could potentially explain the TeV photons observed by LHAASO and their hard spectrum. We found that the allowed candidates are generally cluster around masses of eV. We also considered different EBL models, for the one predicting larger attenuation tends to reject ALP candidates with the lowest coupling factor. For some hypothesis of EBL model, these candidates are found below a region of the parameter space in which, if detected, ALPs could account for all of the cold dark matter in the Universe.
Rui Zhang🇺🇸 · Jack Holligan🇺🇸 · Xiangdong Ji🇺🇸 · Yushan Su🇺🇸
In lattice-QCD calculations of parton distribution functions (PDFs) via large-momentum effective theory, the leading power (twist-three) correction appears as due to the linear-divergent self-energy of Wilson line in quasi-PDF operators. For lattice data with hadron momentum of a few GeV, this correction is dominant in matching, as large as 30\% or more. We show how to eliminate this uncertainty through choosing the mass renormalization parameter consistently with the resummation scheme of the infrared-renormalon series in perturbative matching coefficients. An example on the lattice pion PDF data at GeV shows an improvement of matching accuracy by a factor of more than in the expansion region .
Maxime De Sousa🇫🇷 · Aurélien Barrau🇫🇷 · Killian Martineau🇫🇷
Group field theory has shown to be a promising framework to derive cosmological predictions from full quantum gravity. In this brief note, we revisit the background dynamics when interaction terms are taken into account and conclude that, although the bounce is clearly robust, providing a geometrical explanation for inflation seems to be very difficult. We consider possible improvements and modifications of the original scenario and derive several limits on the parameters of the model.
Federico Gasparotto🇩🇪 · Stefan Weinzierl🇩🇪 · Xiaofeng Xu🇩🇪
We report on an exact calculation of lattice correlation functions on a finite four-dimensional lattice with either Euclidean or Minkowskian signature. The lattice correlation functions are calculated by the method of differential equations. This method can be used for Euclidean and Minkowskian signature alike. The lattice correlation functions have a power series expansion in , where is the coupling. We show that this series is convergent for all non-zero values of . At small coupling we quantify the accuracy of perturbative approximations. At the technical level we systematically investigate the interplay between twisted cohomology and the symmetries of the twist function.
We reveal the quark exchange effects related to both the kinetic energy and various interactions in the single flavored dibaryon bound states with in the quark models. The hadron covalent bond can be established by the shared identical quarks due to the quark exchange effect between two colorless baryons. Such hadron covalent bond plays a decisive role in the deuteronlike di- and di- covalent molecule states. The -meson exchange is indispensable in the deuteronlike di- and compact di- states. The hadron covalent bond clearly appears in the di- state but is hidden in the di- state. The chromomagnetic interaction is always repulsive in the di-, di-, di-, and di- states. The color-electric interaction is strongly attractive in the di- state but weakly attractive or repulsive in the di-, di-, and di- states.
Swarnim Shirke🇮🇳 · Suprovo Ghosh🇮🇳 · Debarati Chatterjee🇮🇳 · Laura Sagunski🇩🇪 · Jürgen Schaffner-Bielich🇩🇪
In this work, we perform the first systematic investigation of effects of the presence of dark matter on -mode oscillations in neutron stars (NSs). Using a self-interacting dark matter (DM) model based on the neutron decay anomaly and a hadronic model obtained from the posterior distribution of a recent Bayesian analysis, we impose constraints on the DM self-interaction strength using recent multimessenger astrophysical observations. We also put new constraints on the DM fraction for this model of DM. The constrained DM interaction strength is then used to estimate DM self-interaction cross section and shear viscosity resulting from DM, which is found to be several orders of magnitude smaller than shear viscosity due to hadronic matter. Assuming chemical equilibrium among DM fermions and neutrons, we estimate the bulk viscosity resulting from the dark decay of neutrons considering different scenarios for the temperature dependence of the reaction rate and investigate the effect on the -mode instability window. We conclude that DM shear and bulk viscosity may significantly modify the -mode instability window compared with the minimal hadronic viscosities, depending on the temperature dependence of the process. We also found that for the window to be compatible with the X-ray and pulsar observational data, the rate for the dark decay process must be fast.
Traditionally, scalar theory in four dimensions is thought to be quantum trivial in the continuum. This tradition is apparently well grounded both in physics arguments and mathematical proofs. Digging into the proofs one finds that they do not actually cover all physically meaningful situations, in particular the case of multi-component fields and non-polynomial action. In this work, I study multi-component scalar field theories in four dimensions in the continuum and show that they do evade the apparently foregone conclusion of triviality. Instead, one finds a non-trivial interacting theory that has two phases, bound states and non-trivial scattering amplitudes in the limit of many components. This has potentially broad implications, both for the foundations of quantum field theory as well as for the experimentally accessible Higgs sector of the Standard Model.
* 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.