High Energy Physics - Phenomenology
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Showing new listings for Thursday, 21 November 2024
- [1] arXiv:2411.12798 [pdf, other]
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Title: Efficient on-shell matchingComments: 19 pages + appendices, 3 figures, ancillary filesSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
We propose an efficient method to perform on-shell matching calculations in effective field theories. The standard off-shell approach to matching requires the use of a Green's basis that includes redundant and evanescent operators. The reduction of such a basis to a physical one is often highly non-trivial, difficult to automate and error prone. Our proposal is based on a numerical solution of the corresponding on-shell matching equations, which automatically implements in a trivial way the delicate cancellation between the non-local terms in the full theory and those in the effective one. The use of rational on-shell kinematics ensures an exact analytic solution despite the numerical procedure. In this way we only need a physical basis to perform the matching. Our procedure can be used to reduce any Green's basis to an arbitrary physical one, or to translate between physical bases; to renormalize arbitrary effective Lagrangians, directly in terms of a physical basis; and to perform finite matching, including evanescent contributions, as we discuss with explicit examples.
- [2] arXiv:2411.12866 [pdf, html, other]
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Title: Complete $\mathcal{O}(\alpha_s^2)$ Corrections to the Leptonic Invariant Mass Spectrum in $b\to X_c l\bar{\nu}_l$ DecaySubjects: High Energy Physics - Phenomenology (hep-ph)
In the determination of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$ from inclusive semileptonic $B$-meson decays, moments of the leptonic invariant mass spectrum constitute valuable observables. To evaluate them with sufficient precision, perturbative $\mathcal{O}(\alpha_s^2)$ corrections to the analogous spectrum in the partonic $b\to X_c l\bar{\nu}_l$ decay are necessary. In the present paper, we compute such perturbative corrections in a complete manner, including contributions from the triple-charm channel, namely from the $cc\bar{c}l\bar{\nu}_l$ final states. We present our results in terms of numerical fits in both the single- and triple-charm cases. We confirm the recently found results for the single-charm correction, and analyze the triple-charm channel impact on centralized moments of the spectrum.
- [3] arXiv:2411.12918 [pdf, html, other]
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Title: Equation of state of isospin asymmetric QCD with small baryon chemical potentialsComments: 10 pages, 10 figures, contribution to the 41st International Symposium on Lattice Field Theory (LATTICE2024), Liverpool, UKSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Lattice (hep-lat); Nuclear Theory (nucl-th)
We extend our measurement of the equation of state of isospin asymmetric QCD to small baryon and strangeness chemical potentials, using the leading order Taylor expansion coefficients computed directly at non-zero isospin chemical potentials. Extrapolating the fully connected contributions to vanishing pion sources is particularly challenging, which we overcome by using information from isospin chemical potential derivatives evaluated numerically. Using the Taylor coefficients, we present, amongst others, first results for the equation of state along the electric charge chemical potential axis, which is potentially of relevance for the evolution of the early Universe at large lepton flavour asymmetries.
- [4] arXiv:2411.12979 [pdf, html, other]
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Title: The unification in an $\widehat {\mathfrak{s}\mathfrak{u}}(8)_{ k_U = 1}$ affine Lie algebraComments: 27 pages with references, two appendices, 4 tables, 3 figures. Sequel to: arXiv:2307.07921, arXiv:2402.10471, arXiv:2406.09970, arXiv:2409.03172Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
A flavor-unified theory based on the simple Lie algebra of ${\mathfrak{s}\mathfrak{u}}(8)$ was previously proposed to generate the observed Standard Model quark/lepton mass hierarchies and the Cabibbo-Kobayashi-Maskawa mixing pattern due to their non-universal symmetry properties. A level-$1$ affine Lie algebra of $\widehat{ \mathfrak{s}\mathfrak{u} }(8)_{ k_U =1}$ with the ${\cal N}=1$ supersymmetric extension is found to unify three gauge couplings through the maximally symmetry breaking pattern.
- [5] arXiv:2411.13034 [pdf, html, other]
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Title: Polarization of an electron scattered by static potentialsComments: 14 pages,1 figureSubjects: High Energy Physics - Phenomenology (hep-ph)
We study the polarization of an electron scattered by different static potentials. The initial state of the electron is chosen as a wavepacket to construct the definite orbital angular momentum, and the final polarization of the electron, scattered by different static potentials such as vector, pseudovector, scalar and pseudoscalar potentials, is calculated. Numerical results show that, the sign of the polarization of the electron scattered by the vector potential is opposite to the other three cases, and the magnitude order of the polarization value is consistent with recent experimental result in the collision parameter range $0<b<2\,\mathrm{fm}$.
- [6] arXiv:2411.13091 [pdf, html, other]
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Title: Quark Model Study of Doubly Heavy $\Xi$ and $\Omega$ Baryons via Deep Neural Network and Hybrid OptimizationComments: 12 pages, 3 figuresSubjects: High Energy Physics - Phenomenology (hep-ph)
In the past decades, research on the doubly heavy baryons developed rapidly in both experiments and theories. In this work we study the mass spectra and semileptonic decay widths of the doubly heavy $\Xi$ and $\Omega$ baryons in the framework of the hypercentral constituent quark model. We solve the six-dimensional Schrödinger equation via deep learning and particle swarm optimization techniques to improve the speed and accuracy. Then, we predict the masses of the ground and excited states of single and doubly heavy baryons. Working close to the zero recoil point, we also study the $ b \rightarrow c $ semileptonic decay widths and branching ratios of doubly heavy $\Xi$ and $\Omega$ baryons. Our results are compared to the exist experimental data and other theoretical evaluations. Our predictions of mass spectrum and decay widths provide valuable information for the experiment searching for undiscovered heavy baryon states.
- [7] arXiv:2411.13231 [pdf, html, other]
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Title: Baryogenesis from a Majorana Fermion Coupled to QuarksComments: 20 pages, 6 figuresSubjects: High Energy Physics - Phenomenology (hep-ph)
In the theory with a Majorana fermion ($X$) coupled to quark-like fermions ($Q$) via a dimension-six four-fermion vector-vector interaction, we have computed in an earlier work the baryon asymmetry generated in the decay and scattering processes of the $X$ with $Q$. In this work we consider such processes in the expanding early Universe, set up the Boltzmann equations governing the $X$ and net baryon number densities, and numerically solve them in example benchmark points, taking the thermally averaged decay and scattering rates and their temperature dependence from the earlier study. We find that starting from a baryon symmetric Universe at early time, the presently observed baryon asymmetry of the Universe (BAU) can be explained in this theory over a wide range of mass scales, $M_\chi\in (10^4,10^{16})$~GeV for appropriately chosen couplings. We find that scattering processes play a crucial role in generating the baryon asymmetry in this theory. We present our results in a general manner that should be useful not just in our theory, but also in other related theories that share the essential ingredients. Our results should help guide promising ways to probe such new physics in terrestrial experiments.
- [8] arXiv:2411.13258 [pdf, html, other]
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Title: Path-length dependence of parton and jet energy loss from universal scaling lawsComments: 6 pages, 4 figures. Talk given at the 42nd International Conference on High Energy Physics (ICHEP2024)Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
The universal dependence of hadron suppression, $R_{\rm{AA}}(p_\perp)$, observed at large-$p_\perp$ in heavy ion collisions at RHIC and LHC allows for a systematic determination of the average parton energy loss $\langle \epsilon \rangle$ in quark-gluon plasma (QGP). A simple relation between $\langle \epsilon \rangle$ and the soft particle multiplicity allows for probing the dependence of parton energy loss on the medium path-length. We find that all the available measurements are consistent with $\langle \epsilon \rangle \propto L^\beta$ with $\beta=1.02\pm^{0.09}_{0.06}$, consistent with the pQCD expectation of parton energy loss in a longitudinally expanding QGP. We then show, based on the model predictions, that the data on the azimuthal anisotropy coefficient divided by the collision eccentricity, $v_2/\rm{e}$, follows the same scaling property as $R_{\rm{AA}}$. Finally, a linear relationship between $v_2/\rm{e}$ and the logarithmic derivative of $R_{\rm{AA}}$ at large $p_\perp$ offers a purely data-driven access to the $L$ dependence of parton energy loss. Quite remarkably, both hadron and jet measurements obey this latter relationship, moreover with consistent values of $\beta$. This points to the same parametric path-length dependence of parton and jet energy loss in QGP.
- [9] arXiv:2411.13261 [pdf, html, other]
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Title: A 95 GeV Higgs Boson in the $U(1)_X$ modelComments: 23 pages, 5 figuresSubjects: High Energy Physics - Phenomenology (hep-ph)
The CMS and ATLAS Collaborations have recently reported their findings based on the comprehensive run 2 dataset, detailing their searches for a light Higgs boson with a mass of approximately 95 GeV. We investigate the excesses observed in the $\gamma\gamma$, $\tau{\bar\tau}$ and $b{\bar b}$ data at approximately 95 GeV in the $U(1)_X$ model. Additionally, it also mixes with the SM-like Higgs boson. Research indicates that, in this model, identifying this singlet Higgs state as the lightest Higgs boson holds tremendous potential for explaining the excess observed at approximately 95 GeV. In our calculations, we maintain the masses of the lightest and next-to-lightest Higgs bosons at approximately 95 GeV and 125 GeV, respectively. The study finds that the theoretical predictions for the signal strengths $\mu(h_{95})_{\gamma\gamma}$ $\mu(h_{95})_{\tau{\bar\tau}}$ and $\mu(h_{95})_{b{\bar b}}$ in the $U(1)_X$ model align well with the excesses observed by CMS.
- [10] arXiv:2411.13292 [pdf, html, other]
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Title: Pentaquarks and Maxim V. PolyakovComments: 19 pages, 3 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
This brief review is dedicated to the memory of Maxim V. Polyakov and his pioneering contributions to pentaquark physics. We focus on his seminal 1997 work with Diakonov and Petrov that predicted the $\Theta^+$ pentaquark, a breakthrough that initiated an intense period of research in hadron physics. The field faced a significant setback when the CLAS Collaboration at Jefferson Lab reported null results in 2006, leading to a dramatic decline in light pentaquark research. Nevertheless, Maxim maintained his scientific conviction, supported by continued positive signals from DIANA and LEPS collaborations. Through recent experimental findings on the $\Theta^+$ and the nucleon-like resonance $N^*(1685)$, we examine how Polyakov's theoretical insights, particularly the prediction of a narrow width ($\Gamma \approx 0.5$-$1.0$ MeV), remain relevant to our understanding of the $\Theta^+$ light pentaquark.
- [11] arXiv:2411.13299 [pdf, html, other]
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Title: Gravitational Waves from Metastable Cosmic Strings in Supersymmetric New Inflation ModelComments: 49 pages, 12 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Recent observations by pulsar timing arrays (PTAs) indicate a potential detection of a stochastic gravitational wave (GW) background. Metastable cosmic strings have been recognized as a possible source of the observed signals. In this paper, we propose an $R$-invariant supersymmetric new inflation model. It is characterized by a two-step symmetry breaking $\mathrm{SU}(2) \to \mathrm{U}(1)_G \to \mathrm{nothing}$, incorporating metastable cosmic strings. The field responsible for the initial symmetry breaking acts as the inflaton, while the second symmetry breaking occurs post-inflation, ensuring the formation of the cosmic string network without monopole production. Our model predicts symmetry breaking scales consistent with the string tensions favored by PTA data, $G_\mathrm{N} \mu_\mathrm{str} \sim 10^{-5}$, where $G_\mathrm{N}$ is the Newton constant. Notably, a low reheating temperature is required to suppress non-thermal gravitino production from the decay of inflaton sector fields. This also helps evading LIGO-Virgo-KAGRA constraints, while yielding a distinctive GW signature that future PTA and interferometer experiments can detect. Additionally, we examine the consistency of this scenario with non-thermal leptogenesis and supersymmetric dark matter.
- [12] arXiv:2411.13303 [pdf, html, other]
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Title: Two-pion exchange for coupled-channel heavy-meson heavy-(anti)meson scatteringComments: 41 pages, 18 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Nuclear Theory (nucl-th)
To improve the theoretical understanding of multiquark states like $Z_b(10610)$ and $Z_b(10650)$, we calculate the heavy-meson heavy-(anti)meson scattering potential up to next-to-leading order, $O(Q^2)$, within chiral effective field theory ($\chi$EFT) employing a power counting scheme that explicitly keeps track with the large momentum scale $Q \sim \sqrt{2\mu \delta}$ (where $\delta = m_V - m_P$ is the vector-pseudoscalar mass difference and $\mu$ their reduced mass) introduced by the coupled channel dynamics. We provide expressions for the two-pion exchange (TPE) terms up to $O(Q^2)$ and their partial-wave decomposition. We show that these potentials are well-approximated by contact terms at $O(Q^2)$, with minor residual non-analytic TPE contributions, supporting $\chi$EFT convergence in the theoretical predictions for $Z_b(10610)$ and $Z_b(10650)$, as well as their spin partners. These findings are also relevant for $D^{(*)}D^{(*)}$ scattering, especially for the $T_{cc}$ state, for both physical and lattice QCD data with moderately larger pion masses. We further demonstrate that the differences between isovector and isoscalar potentials for heavy mesons are naturally explained by the TPE contributions.
- [13] arXiv:2411.13385 [pdf, html, other]
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Title: Radiative Mass Mechanism: Addressing the Flavour Hierarchy and Strong CP PuzzleComments: v0: 19 pages, 1 figure, 1 TableSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
We propose a class of models based on the parity invariant Left-Right Symmetric Model (LRSM), which incorporates the mechanism of radiative generation of fermion masses while simultaneously possessing the solution to the Strong CP problem. A flavour non-universal gauged abelian symmetry is imposed on top of LRSM, which helps in inducing the masses of second and first-generation fermions at one-loop and two-loop, respectively, and thereby reproduces the hierarchical spectrum of the masses. Parity invariance requires the vanishing of the strong CP parameter at the zeroth order, and the non-zero contribution arises at the two-loop level, which is in agreement with the experimental constraints. The minimal model predicts flavour symmetry breaking scale and the $SU(2)_R$ symmetry breaking scale at the same level. flavour non-universality of the new gauge interaction leads to various flavour-changing transitions both in quarks and leptonic sectors and, therefore, has various phenomenologically interesting signatures. The model predicts a new physics scale near $10^8$ GeV or above for phenomenological consistent solutions. This, in turn, restricts strong CP phase $\bar{\theta} \lesssim 10^{-14}$ as the parity breaking scale and flavour scale are related in the minimal framework.
- [14] arXiv:2411.13398 [pdf, html, other]
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Title: Precise Determination of Nucleon Gravitational Form FactorsComments: 8 pages, 6 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex); High Energy Physics - Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
Being closely connected to the origin of the nucleon mass, the gravitational form factors of the nucleon have attracted significant attention in recent years. We present the first model-independent precise determinations of the gravitational form factors of the pion and nucleon at the physical pion mass, using a data-driven dispersive approach. The so-called ``last unknown global property'' of the nucleon, the $D$-term, is determined to be $-\left(3.38^{+0.26}_{-0.32}\right)$. The root mean square radius of the mass distribution inside the nucleon is determined to be $0.97^{+0.02}_{-0.03}~\text{fm}$. Notably, this value is larger than the proton charge radius, suggesting a modern structural view of the nucleon where gluons, responsible for most of the nucleon mass, are distributed over a larger spatial region than quarks, which dominate the charge distribution. We also predict the nucleon angular momentum and mechanical radii, providing further insights into the intricate internal structure of the nucleon.
- [15] arXiv:2411.13431 [pdf, html, other]
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Title: Quasi-Classical Evaluation of Gluon Saturation Induced Helicity EffectsComments: 31 pages, 11 figuresSubjects: High Energy Physics - Phenomenology (hep-ph)
At sub-eikonal order in the high-energy limit, helicity dependences are generally contained in the transverse components of the gluon field. In the gluon saturation regime, novel helicity effects arise from the nonlinear interaction between the eikonal-order longitudinal gluon field and the sub-eikonal-order transverse gluon field. We derive this saturation induced helicity-dependent field both by solving the classical Yang-Mills equations and through direct diagrammatic calculations. Our analysis shows that the saturation induced helicity effect is intrinsically a two-particle (or multi-particle) correlation effect, rather than a single-particle distribution effect. Furthermore, we evaluate this effect in the context of double-spin asymmetry for incoherent diffractive dijet production in longitudinally polarized electron-nucleus collisions, using a simplified helicity-extended McLerran-Venugopalan model. We find that the saturation induced helicity effect further suppresses the back-to-back peak in the dijet azimuthal angle correlation, with a magnitude comparable to that of the direct helicity effect. This gluon saturation induced helicity effect may offer a novel avenue to probe gluon saturation in polarized collisions.
- [16] arXiv:2411.13461 [pdf, html, other]
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Title: Summary of the 16th Applied Antineutrino Physics Workshop 2023Comments: 12 pages, 2 imagesSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
Summary of the 16th Applied Antineutrino Physics Workshop 2023, held in the historic Guildhall in York in the UK from the 18th - 21st September 2023.
- [17] arXiv:2411.13464 [pdf, html, other]
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Title: $H \to ZZ$ as a double-slit experimentComments: LaTeX 6 pagesSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex); Quantum Physics (quant-ph)
The decay $H \to ZZ \to 4\ell$, with $\ell = e,\mu$, can be used to test quantum interference in analogy to the famous double-slit experiment. The observations corresponding to `covering a slit' can be extracted from data in the $ee\mu\mu$ channel, while the observations when both `slits' are open, which include the interference, are measured in the $4e/4\mu$ channels. Furthermore, this process offers a unique opportunity to investigate identical-particle effects at high energies, and provide the first evidence of identical-particle behaviour for muons. Sensitivity at the $4\sigma$ level could be achieved at the high-luminosity upgrade of the Large Hadron Collider.
- [18] arXiv:2411.13466 [pdf, html, other]
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Title: The two-loop fully differential soft function for $Q\bar{Q}V$ production at lepton collidersComments: 15 pages, 1 figure; ancillary files for the analytical resultSubjects: High Energy Physics - Phenomenology (hep-ph)
We consider the production of a pair of heavy quarks $Q\bar{Q}$ in association with a generic colour singlet system $V$ at lepton colliders, and present the first analytic calculation of the two-loop soft function differential in the total momentum of the real radiation. The calculation is performed by reducing the relevant Feynman integrals into a canonical basis of master integrals by means of integration-by-parts identities. The resulting integrals are then evaluated by solving a system of differential equations in the kinematic invariants, whose boundary conditions are determined analytically with some care due to the presence of Coulomb singularities. The fully differential soft function is expressed in terms of Goncharov polylogarithms. This result is an essential ingredient for a range of N$^3$LL resummations for key collider observables at lepton colliders, such as the $Q\bar{Q}V$ production cross section at threshold and observables sensitive to the total transverse momentum of the radiation in heavy-quark final states. Moreover, it constitutes the complete final-final dipole contribution to the fully differential soft function needed for the description of $Q\bar{Q}V$ production at hadron colliders, which plays an important role in the LHC physics programme.
- [19] arXiv:2411.13494 [pdf, html, other]
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Title: DW-genesis: baryon number from domain wall network collapseComments: 51 pages, 20 figuresSubjects: High Energy Physics - Phenomenology (hep-ph)
Axionic domain walls, as they move through the early universe plasma during their collapse, can generate a net baryon and lepton number through the mechanism of spontaneous baryogenesis, provided that there is a coupling between the axion and the lepton or baryon current. In this paper, we study systematically the baryon asymmetry produced by these domain walls (DWs) at annihilation, within different realisations of the $L$- or $B$-violating sector, and refer to this process as DW-genesis. We find that the baryon number is maximised when the DW network collapses approximately at the moment when the $L$- or $B$-violating interaction decouples. We study a model of minimal leptogenesis, a model of cogenesis, a model of baryogenesis and finally the possibility that the baryon asymmetry is produced by electroweak sphalerons. As phenomenological consequences of DW-genesis, we discuss the expected gravitational wave signal from the DW network annihilation and the prospects for detecting it. However, we finally emphasize that in realisations of the DW-genesis in minimal post-inflationary scenarios, there is a suppression induced by the cancellation between the asymmetry created by "opposite" axionic domain walls attached to the string. We quantify the impact of this cancellation and discuss possible ways to avoid it.
- [20] arXiv:2411.13497 [pdf, html, other]
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Title: Global analysis of $\mu \to e$ interactions in the SMEFTComments: 43 pages, 7 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex); Nuclear Theory (nucl-th)
We study current experimental bounds on charged lepton flavor violating (CLFV) $\mu$-$e$ interactions in the model-independent framework of the Standard Model Effective Field Theory (SMEFT). Assuming a generic flavor structure in the quark sector, we consider the contributions of CLFV operators to low-energy observables, including $\mu\to e\gamma$ and $\mu\to e$ conversion for quark-flavor conserving operators and CLFV meson decays for quark-flavor violating operators. At high energy, we consider limits on CLFV decays of the Higgs and Z bosons and of the top quark, and obtain bounds on operators with light quarks by recasting searches for production of $e\mu$ pairs in $pp$ collisions at the Large Hadron Collider (LHC). We connect observables at low- and high-energy by taking into account renormalization group running and matching between CLFV operators. We also discuss the sensitivity of the future Electron-Ion Collider, where the prospective bounds are derived by imposing simple cuts on final state particles. We find that, in a single operator scenario, bounds on purely leptonic operators are dominated by $\mu \rightarrow e \gamma$ and $\mu \rightarrow e$ conversion. Semileptonic operators with down-type quarks are also dominantly constrained by low-energy observables, while LHC searches lead the bounds on up-type quark-flavor violating operators. Taking simplified multiple-coupling scenarios, we show that it is easy to evade the strongest low-energy bounds from spin-independent $\mu \rightarrow e$ conversion, and that collider searches are competitive and complementary to constraints from spin-dependent $\mu \rightarrow e$ conversion and other low-energy probes.
- [21] arXiv:2411.13514 [pdf, html, other]
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Title: Localized Electromagnetic Perturbations on Vector SolitonsComments: 8 pages, 5 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
Using effective field theory approach one can describe localization of electromagnetic field on a non-topological soliton. Pursuing this aim we consider the U(1) gauge theory with gauge kinetic coupling to a self-interacting complex neutral Proca field. The model possesses single energy scale given by the vector boson mass. Considering spherically symmetric stationary configurations, we study vibrational modes of the Proca field on the background of the soliton and discuss their properties.
- [22] arXiv:2411.13533 [pdf, html, other]
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Title: Finite-size effects on small-$x$ evolution and saturation in proton and nuclear targetsComments: 16 pages, 19 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Nuclear Theory (nucl-th)
Within the Color Glass Condensate effective field theory, we assess the importance of including a finite size for the target on observables sensitive to small-$x$ evolution. To this end, we study the Balitsky-Kovchegov (BK) equation with impact-parameter dependence in the initial condition. We demonstrate that neglecting the dependence on the impact parameter can result in overestimated saturation effects for protons, while it has little effect for heavy nuclei at the energies available at current experiments. When fixing the nonperturbative parameters to the energy dependence of the exclusive $J/\psi$ photoproduction cross section with proton targets, predictions for lead targets are not sensitive to the applied running-coupling prescription, the scheme chosen to resum large transverse logarithms in the BK equation, or the infrared regulator in the evolution.
- [23] arXiv:2411.13541 [pdf, html, other]
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Title: Living dangerously with decoupled first/second generation scalars: SUSY prospects at the LHCComments: 18 pages with 11 .png figuresSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
The string landscape statistical draw to large scalar soft masses leads to a mixed quasi-degeneracy/decoupling solution to the SUSY flavor and CP problems where first/second generation matter scalars lie in the 20-40 TeV range. With increasing first/second generation scalars, SUSY models actually become more natural due to two-loop RG effects which suppress the corresponding third generation soft masses. This can also lead to substantial parameter space regions which are forbidden by the presence of charge and/or color breaking (CCB) minima of the scalar potential. We outline the allowed SUSY parameter space for the gravity-mediated three extra-parameter-non-universal Higgs model NUHM3. The natural regions with m_h~ 125 GeV, \Delta_{EW}<~ 30 and decoupled first/second generation scalar are characterized by rather heavy gluinos and EW gauginos, but with rather small \mu and top-squarks not far beyond LHC Run 2 limits. This scenario also explains why SUSY has so far eluded discovery at LHC in that the parameter space with small scalar and gaugino masses is all excluded by the presence of CCB minima.
New submissions (showing 23 of 23 entries)
- [24] arXiv:2411.11846 (cross-list from hep-th) [pdf, other]
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Title: High-precision black hole scattering with Calabi-Yau manifoldsMathias Driesse, Gustav Uhre Jakobsen, Albrecht Klemm, Gustav Mogull, Christoph Nega, Jan Plefka, Benjamin Sauer, Johann UsovitschComments: 26 pages, 7 figuresSubjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); Algebraic Geometry (math.AG)
Using the worldline quantum field theory formalism, we compute the radiation-reacted impulse, scattering angle, radiated energy and recoil of a classical black hole (or neutron star) scattering event at fifth post-Minkowskian and sub-leading self-force orders (5PM-1SF). This state-of-the-art four-loop computation employs advanced integration-by-parts and differential equation technology, and is considerably more challenging than the conservative 5PM-1SF counterpart. As compared with the conservative 5PM-1SF, in the radiation sector Calabi-Yau three-fold periods appear and contribute to the radiated energy and recoil observables. We give an extensive exposition of the canonicalization of the differential equations and provide details on boundary integrations, Feynman rules, and integration-by-parts strategies. Comparisons to numerical relativity are also performed.
- [25] arXiv:2411.12818 (cross-list from hep-lat) [pdf, html, other]
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Title: Entanglement entropy of a color flux tube in (1+1)D Yang-Mills theoryComments: 14 pages, 9 figuresSubjects: High Energy Physics - Lattice (hep-lat); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th); Nuclear Theory (nucl-th)
In recent work arXiv:2410.00112 , we computed a novel flux tube entanglement entropy (FTE$^2$) of the color flux tube stretched between a heavy quark-antiquark pair on a Euclidean lattice in (2+1)D Yang-Mills theory. Our numerical results suggested that FTE$^2$ can be partitioned into an internal color entanglement entropy and a vibrational entropy corresponding to the transverse excitations of a QCD string, with the latter described by a thin string model. Since the color flux tube does not have transverse excitations in (1+1)D, we analytically compute the contribution of the internal color degrees of freedom to FTE$^2$ in this simpler framework. For the multipartite partitioning of the color flux tube, we find the remarkable result that FTE$^2$ only depends on the number of times the flux tube crosses the border between two spatial regions, and the dimension of the representation of the color group, but not on the string length. The result holds independently of whether the branching points are placed on the vertices of the lattice or in the center of plaquettes.
- [26] arXiv:2411.12909 (cross-list from hep-th) [pdf, html, other]
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Title: On-shell approach to scalar hair in spinning binariesComments: 38 pages, 3 figuresSubjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
We propose an on-shell description of spinning binary systems in gravitational theories where compact objects display scalar hair. The framework involves matter particles of arbitrary spin which, in addition to the minimal coupling to gravitons, are conformally coupled to a massless scalar mediating non-standard interactions. We use the unitary factorization techniques to derive the on-shell amplitudes relevant for emission of scalars and gravitons in matter scattering, paying attention to parametrize the freedom due to contact terms. Using the KMOC formalism, these amplitudes allow one to derive succinct expressions for the radiation waveforms at the leading post-Minkowskian order, together with the associated memory effects. Furthermore, we compute the power emitted via gravitational and scalar radiation in hyperbolic encounters of compact objects. After a continuation to bound orbits, these can be compared with the results obtained in specific scalar-tensor theories where black holes exhibit scalar hair, such as the scalar-Gauss-Bonnet or dynamical Chern-Simons theories. Finally, we identify possible deformations from the conformal coupling that can contribute to radiation observables at the same post-Newtonian order.
- [27] arXiv:2411.12947 (cross-list from astro-ph.HE) [pdf, html, other]
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Title: Kicking the Tires on Picolensing as a Probe of Primordial Black Hole Dark MatterComments: 36 pages, 13 figuresSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
Gravitational-lensing parallax of gamma-ray bursts (GRBs) is an intriguing probe of primordial black hole (PBH) dark matter in the asteroid-mass window, $2\times 10^{-16}M_{\odot} \lesssim M_{\text{PBH}} \lesssim 5 \times 10^{-12}M_{\odot}$. Recent work in the literature has shown exciting potential reach for this "picolensing" signal if a future space mission were to fly two x-/$\gamma$-ray detectors in the Swift/BAT class, with inter-spacecraft separation baselines on the order of the Earth-Moon distance. We revisit these projections with a view to understanding their robustness to various uncertainties related to GRBs. Most importantly, we investigate the impact of uncertainties in observed GRB angular sizes on reach projections for a future mission. Overall, we confirm that picolensing shows great promise to explore the asteroid-mass window; however, we find that previous studies may have been too optimistic with regard to the baselines required. Detector baselines on the order of at least the Earth-L2 distance would make such a mission more robust to GRB size uncertainties; baselines on the order of an astronomical unit (AU) would additionally enable reach that equals or exceeds existing microlensing constraints up to $M_{\text{PBH}}\sim 10^{-5}M_{\odot}$.
- [28] arXiv:2411.13101 (cross-list from hep-lat) [pdf, html, other]
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Title: Updates on the density of states method in finite temperature symplectic gauge theoriesDavid Mason, Ed Bennett, Biagio Lucini, Maurizio Piai, Enrico Rinaldi, Davide Vadacchino, Fabian ZierlerComments: 13 pages, 3 figures. Contribution to Proceedings of the 41st International Symposium on Lattice Field Theory (Lattice 2024), July 28th - August 3rd, 2024, University of Liverpool, UKSubjects: High Energy Physics - Lattice (hep-lat); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
First-order phase transitions in the early universe have rich phenomenological implications, such as the production of a potentially detectable signal of stochastic relic background gravitational waves. The hypothesis that new, strongly coupled dynamics, hiding in a new dark sector, could be detected in this way, via the telltale signs of its confinement/deconfinement phase transition, provides a fascinating opportunity for interdisciplinary synergy between lattice field theory and astro-particle physics. But its viability relies on completing the challenging task of providing accurate theoretical predictions for the parameters characterising the strongly coupled theory. Density of states methods, and in particular the linear logarithmic relaxation (LLR) method, can be used to address the intrinsic numerical difficulties that arise due the meta-stable dynamics in the vicinity of the critical point. For example, it allows one to obtain accurate determinations of thermodynamic observables that are otherwise inaccessible, such as the free energy. In this contribution, we present an update on results of the analysis of the finite temperature deconfinement phase transition in a pure gauge theory with a symplectic gauge group, $Sp(4)$, by using the LLR method. We present a first analysis of the properties of the transition in the thermodynamic limit, and provide a road map for future work, including a brief preliminary discussion that will inform future publications.
- [29] arXiv:2411.13379 (cross-list from astro-ph.CO) [pdf, html, other]
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Title: Exploring the effects of dark matter - dark energy interaction on cosmic evolution in viscous dark energy scenarioComments: 13 pages, 7 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
We explore the influence of interactions between dark matter (DM) and dark energy (DE) on the cosmic evolution of the Universe within a viscous dark energy (VDE) framework. Moving beyond traditional interacting dark energy (IDE) models, we propose a generalized IDE model adaptable to diverse IDE scenarios via IDE coupling parameters. In order to investigate deviations from $\Lambda$CDM across cosmic epochs by highlighting how viscous and the interactions between DM and DE impact cosmic density and expansion rates, we consider a model agnostic form of VDE. Eventually we perform a Bayesian analysis using the Union 2.1 Supernova Ia dataset and Markov Chain Monte Carlo (MCMC) sampling to obtain optimal values of model parameters. This comprehensive analysis provides insights about the interplay between viscous and IDE in shaping the Universe's expansion history.
- [30] arXiv:2411.13520 (cross-list from quant-ph) [pdf, html, other]
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Title: Quantum Attention for Vision Transformers in High Energy PhysicsAlessandro Tesi, Gopal Ramesh Dahale, Sergei Gleyzer, Kyoungchul Kong, Tom Magorsch, Konstantin T. Matchev, Katia MatchevaComments: 9 pages, 7 figuresSubjects: Quantum Physics (quant-ph); Machine Learning (cs.LG); High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph)
We present a novel hybrid quantum-classical vision transformer architecture incorporating quantum orthogonal neural networks (QONNs) to enhance performance and computational efficiency in high-energy physics applications. Building on advancements in quantum vision transformers, our approach addresses limitations of prior models by leveraging the inherent advantages of QONNs, including stability and efficient parameterization in high-dimensional spaces. We evaluate the proposed architecture using multi-detector jet images from CMS Open Data, focusing on the task of distinguishing quark-initiated from gluon-initiated jets. The results indicate that embedding quantum orthogonal transformations within the attention mechanism can provide robust performance while offering promising scalability for machine learning challenges associated with the upcoming High Luminosity Large Hadron Collider. This work highlights the potential of quantum-enhanced models to address the computational demands of next-generation particle physics experiments.
- [31] arXiv:2411.13523 (cross-list from quant-ph) [pdf, html, other]
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Title: Quantum gravitational decoherence of a mechanical oscillator from spacetime fluctuationsComments: Comments are welcomeSubjects: Quantum Physics (quant-ph); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
We consider the scenario of a fluctuating spacetime due to a deformed commutation relation with a fluctuating deformation parameter, or to a fluctuating metric tensor. By computing the resulting dynamics and averaging over these fluctuations, we find that a system experiences a decoherence in the momentum basis. We studied the predictions of the model for a free particle and an harmonic oscillator. Using experimental data taken from a mechanical oscillator prepared in quantum states of motion, we put a bound on the free parameters of the considered model. In addition, we comment on how these measurements can also provide bounds to other phenomenological quantum gravity models, such as the length scale for nonlocal dynamics.
Cross submissions (showing 8 of 8 entries)
- [32] arXiv:2405.17564 (replaced) [pdf, html, other]
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Title: New realisation of light thermal dark matter with enhanced detection prospectsAmit Adhikary, Debasish Borah, Satyabrata Mahapatra, Indrajit Saha, Narendra Sahu, Vicky Singh ThounaojamComments: 23 pages, 9 captioned figures, matches version accepted for publication in JCAPSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Light dark matter (DM) with mass around the GeV scale faces weaker bounds from direct detection experiments. If DM couples strongly to a light mediator, it is possible to have observable direct detection rate. However, this also leads to a thermally under-abundant DM relic due to efficient annihilation into light mediators. We propose a novel scenario where a first-order phase transition (FOPT) occurring at MeV scale can restore GeV scale DM relic by changing the mediator mass sharply at the nucleation temperature. The MeV scale FOPT predicts stochastic gravitational waves with nano-Hz frequencies within reach of pulsar timing array (PTA) based experiments like NANOGrav. In addition to enhancing direct detection rate, the light mediator can also give rise to the required DM self-interactions necessary to solve the small scale structure issues of cold dark matter. The existence of light scalar mediator and its mixing with the Higgs keep the scenario verifiable at different particle physics experiments.
- [33] arXiv:2406.13234 (replaced) [pdf, html, other]
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Title: Probing ALP Lepton Flavour Violation at $\mu$TRISTANComments: 31 pages, 10 figures, 8 tables; v2: discussion added, muonium oscillation limits corrected, results unchanged, version to be published in PRDSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
Axion-like particles (ALPs) with lepton flavour violating (LFV) interactions are predicted within a wide range of flavoured ALP models. The proposed $\mu$TRISTAN high-energy $e^-\mu^+$ and $\mu^+\mu^+$ collider will provide a good opportunity to explore flavour physics in the charged lepton sector. In this work, based on a model-independent effective Lagrangian describing the ALP leptonic interactions, we investigate the potential of $\mu$TRISTAN to probe ALP LFV couplings. We analyse the testability of selected ALP production channels with potential sensitivity at $\mu$TRISTAN, considering different beams and collision energies, including $e^- \mu^+ \to a \gamma$, $e^- \mu^+ \to e^- \tau^+ a$, $\mu^+ \mu^+ \to \mu^+ \tau^+ a$, and $e^- \mu^+ \to \tau^- \mu^+ a$. The produced ALP $a$ is either long-lived or can promptly decay to flavour violating or conserving charged lepton final states. In particular, combining the above LFV ALP production modes with a suitable LFV decay mode, one can identify signatures that are virtually free of Standard Model background. We show the resulting sensitivity of $\mu$TRISTAN to LFV ALP couplings and compare it with multiple low-energy leptonic constraints and the future improvements thereof. We find that $\mu$TRISTAN can be generally complementary to searches for low-energy LFV processes and measurements of the leptonic magnetic dipole moments and has the capability to explore unconstrained parameter space for ALP masses in the $\mathcal{O}(1)$ to $\mathcal{O}(100)$~GeV range. In the light ALP regime, however, the parameter space that $\mu$TRISTAN is sensitive to, has been already excluded by low-energy searches for LFV decays.
- [34] arXiv:2407.08436 (replaced) [pdf, html, other]
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Title: Detection of dilute axion stars with stimulated decayComments: 7 pages, 3 figures; accepted for publication in Physical Review DSubjects: High Energy Physics - Phenomenology (hep-ph)
The anomalous orbits of trans-Neptunian objects can be accounted for by the planet 9 hypothesis. One intriguing possibility is that planet 9 could be a dilute axion star captured by the solar system, with the ratio of the axion star to dark matter being approximately 1/10. Although dilute axion stars can emit monochromatic signals through two-photon decay, the spontaneous decay signal is too weak to be detected by radio telescopes. However, we find that stimulated decay of the dilute axion star, which explains planet 9, can occur by directing a radio beam with a power of 50MW into the star. The resulting echo can be detected by terrestrial telescopes such as SKA, FAST, ngLOBO, and LOFAR. Therefore, the dilute axion star can be distinguished from other planet 9 candidates, such as a primordial black hole or a free-floating planet captured by the solar system.
- [35] arXiv:2407.13828 (replaced) [pdf, html, other]
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Title: Anisotropic charge transport in strongly magnetized relativistic matterComments: 19 pages, 7 figures; v2: the final version published in Eur. Phys. J. CJournal-ref: Eur. Phys. J. C 84, 1179 (2024)Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th); Nuclear Theory (nucl-th)
We investigate electrical charge transport in hot magnetized plasma using first-principles quantum field theoretical methods. By employing Kubo's linear response theory, we express the electrical conductivity tensor in terms of the fermion damping rate in the Landau-level representation. Utilizing leading-order results for the damping rates from a recent study within a gauge theory, we derive the transverse and longitudinal conductivities for a strongly magnetized plasma. The analytical expressions reveal drastically different mechanisms that explain the high anisotropy of charge transport in a magnetized plasma. Specifically, the transverse conductivity is suppressed, while the longitudinal conductivity is enhanced by a strong magnetic field. As in the case of zero magnetic field, longitudinal conduction is determined by the probability of charge carriers to remain in their quantum states without damping. In contrast, transverse conduction critically relies on quantum transitions between Landau levels, effectively lifting charge trapping in localized Landau orbits. We examine the temperature and magnetic field dependence of the transverse and longitudinal electrical conductivities over a wide range of parameters and investigate the effects of a nonzero chemical potential. Additionally, we extend our analysis to strongly coupled quark-gluon plasma and study the impact of the coupling constant on the anisotropy of electrical charge transport.
- [36] arXiv:2407.14150 (replaced) [pdf, html, other]
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Title: QCD corrections of $e^+e^- \to J/\psi+c+\bar{c}$ using the principle of maximum conformalityComments: 13 pages, 11 figures, matches published version, to be published in Phys. Rev. DSubjects: High Energy Physics - Phenomenology (hep-ph)
In this paper, we compute the total and differential cross sections for $e^+e^- \to J/\psi+c+\bar{c}$ at the $B$ factories up to next-to-leading order (NLO) corrections within the framework of nonrelativistic QCD factorization theory. We then obtain improved pQCD series of those cross sections by using the Principle of Maximum Conformality (PMC). We show that the PMC can be applied for any pQCD calculable observable at the total and differential levels via a self-consistent way in perturbation theory. We observe that a more precise prompt total cross section at the NLO level can be achieved after applying the PMC, e.g. $\sigma|_{\rm prompt}^{\rm PMC}= 0.565^{+0.144}_{-0.125}~\text{pb}$. Here the uncertainty is the squared average of those from the $\alpha_s$ fixed-point uncertainty $\Delta\alpha_s(M_Z)$, the uncertainty of charm quark mass $\Delta m_c$, and an estimated contribution of the uncalculated NNLO-terms as predicted by the Padé approximation approach. The differential cross sections $d\sigma/dP_{J/\psi}$, $d\sigma/d|\cos \theta|$, and $d\sigma/dz$ for $e^+e^- \to J/\psi+c+\bar{c}$ are further examined. Those results show that by further considering the feed-down contributions, the PMC predictions show better agreement with the Belle measurements.
- [37] arXiv:2407.19383 (replaced) [pdf, html, other]
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Title: Hunting for the prospective $T_{cc}$ family based on the diquark-antidiquark configurationComments: 24 pagesSubjects: High Energy Physics - Phenomenology (hep-ph)
Inspired by the first $T_{cc}$ observation at the LHCb Collaboration, the spectroscopic properties of the entire isoscalar and isovector $T_{cc}$ family are systematically unveiled by means of multiple sorts of relativized and nonrelativistic diquark formalisms, encompassing the Godfrey-Isgur relativized diquark model, the modified Godfrey-Isgur relativized diquark model incorporating the color screening effects, the nonrelativistic diquark model with the Gaussian type hyperfine potential, and the nonrelativistic diquark model with the Yukawa type hyperfine potential. The theoretical outcomes of various diquark-antidiquark scenarios are inclined to categorize the $T_{cc}(3875)^+$ structure as the exemplary candidate of the $1S$-wave isoscalar axial-vector double-charm tetraquark state. In light of the diquark-antidiquark configuration, this work investigates the mixing angles of the orbitally excited isovector $T_{cc}$ states and the magic mixing angles of the ideal heavy-light tetraquarks for the first time. As the advancement of the experimental detection capability, these phenomenological predictions will effectively boost the hunting for the prospective low-lying $T_{cc}$ states in the future.
- [38] arXiv:2408.08605 (replaced) [pdf, html, other]
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Title: Parametrically amplified super-radiance towards hot big bang universeComments: 7 pages, 2 figures, accepted form for journal publication; explanations are substantially improved from the first versionSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
We propose a mechanism of preheating stage after inflation, using a new idea of parametrically amplified super-radiance. Highly coherent state, characterized by macro-coherence of scalar field coupled to produced massless particle in pairs, is created by parametric resonance effects associated with field oscillation around its potential minimum, within a Hubble volume. The state is described effectively by the simple Dicke-type of super-radiance model, and super-radiant pulse is emitted within a Hubble time, justifying neglect of cosmic expansion. Produced particles are shown to interact to change their energy and momentum distribution to realize thermal hot big bang universe. A long standing problem of heating after inflation may thus be solved. A new dark matter candidate produced at the emergence of thermalized universe is suggested as well.
- [39] arXiv:2409.05337 (replaced) [pdf, html, other]
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Title: Masses and radiative decay widths of the $D_{s0}^*(2317)$ and $D_{s1}^{\prime}(2460)$ and their bottom analogsComments: 18 pages, 3 tables, 7 figuresJournal-ref: Phys. Rev. D 110, 094037 (2024)Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
We study the mass spectra and radiative decays of $D_{s0}^*(2317)$ and $D_{s1}^{\prime}(2460)$ in an unquenched framework. In addition to coupled channel effects between the $c\bar{s}$ cores and $D^{(*)}K$ channels, $D^{(*)}K$-$D^{(*)}K$ self interactions are also considered in this work and we succeed to reproduce their mass spectra. Furthermore, we study the radiative decays of the $D_{s0}^*(2317)$ and $D_{s1}^{\prime}(2460)$ by simultaneously including the compound structures of conventional $c\bar{s}$ cores and $D^{(*)}K$ components. We also calculate their bottom analogs with heavy quark symmetry. Our study offers useful insights into the important unquenched effects in the formation of $D_{s0}^*(2317)$, $D_{s1}^{\prime}(2460)$ and the bottom counterparts.
- [40] arXiv:2111.14376 (replaced) [pdf, html, other]
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Title: The gradient flow at higher orders in perturbation theoryComments: 9 pages, presentation at the 38th International Symposium on Lattice Field Theory, 26th-30th July 2021, Massachusetts Institute of Technology, USA; v2: typos fixedSubjects: High Energy Physics - Lattice (hep-lat); High Energy Physics - Phenomenology (hep-ph)
Various results for higher-order perturbative calculations in the gradient-flow formalism are reviewed, including the gradient-flow beta function and the small-flow-time expansion of the hadronic vacuum polarization and the energy-momentum tensor. In addition, the strategy of regions is outlined in order to obtain systematic expansions of gradient-flow integrals, for example at large and small flow times.
- [41] arXiv:2210.10623 (replaced) [pdf, html, other]
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Title: Names from Greek Myth in Fundamental PhysicsComments: 12 pages + bibliography + 2 indices; suggestions for more entries welcome; v3 update: ~10 new names added, future updates in this https URLSubjects: Popular Physics (physics.pop-ph); High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph); Physics Education (physics.ed-ph)
Greek mythology supplies fundamental physics with the names of numerous (100+) experiments, machines, codes, and phenomena. I present the central narrative of Greek mythos via these names. Hyperlinks are provided for their physics counterparts, and the names are collected in myth- and physics-themed indices.
- [42] arXiv:2403.12286 (replaced) [pdf, html, other]
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Title: Bounds on the photon mass via the Shapiro effect in the solar systemComments: 12 pages, 3 figures. Added appendix D. Matches published versionJournal-ref: Phys. Rev. D 110, 095017 (2024)Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
We study the effects of a finite mass for the photon on its propagation in a weak gravitational field. In particular, we analyse the gravitational time delay, also known as the Shapiro effect. We work in isotropic coordinates in the weak-field limit and find that the mass-dependent corrections enhance the gravitational time delay. Doppler-tracking data from the Cassini mission allow us to set an upper bound on the photon mass, namely $m_\gamma < 4.9 \times 10^{-7} \, {\rm eV/c^2}$ at $95\%$ CL. We also discuss next-generation solar-system tests of general relativity that could improve this upper limit, potentially by a factor of ten. Though not competitive with the currently best limits, our bound is at the ballpark of earlier ones based on the gravitational bending of light by the Sun.
- [43] arXiv:2405.03983 (replaced) [pdf, html, other]
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Title: Key drivers of the preference for dynamic dark energyZhiqi Huang, Jianqi Liu, Jianfeng Mo, Yan Su, Junchao Wang, Yanhong Yao, Guangyao Yu, Zhengxin Zhu, Zhuoyang Li, Zhenjie Liu, Haitao Miao, Hui TongComments: MEET-U project I; accepted for publication in PRDSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
Joint analysis of the baryon acoustic oscillations (BAO) measurement by the Dark Energy Spectroscopic Instrument (DESI) first data release, Type Ia supernovae (SNe) of the Dark Energy Survey Year 5 (DES5YR) release and cosmic microwave background (CMB) data favors a quintom-like dynamic dark energy model over the standard Lambda cold dark matter ($\Lambda$CDM) model at $3.9\sigma$ level (Adame et al. 2024). We confirm the previous finding in the literature that the preference for dynamic dark energy does not rely on the detailed modeling of CMB physics and remains at a similar significance level ($3.2\sigma$) when the full CMB likelihood is replaced by a CMB acoustic-oscillation angle ($\theta_\star$) prior and a baryon abundance ($\Omega_bh^2$) prior. The computationally efficient $\theta_\star$ and $\Omega_bh^2$ priors allow us to take a frequentist approach by comparing DES5YR SNe and DESI BAO with a large number ($\gtrsim 10^4$) of Planck-constrained $\Lambda$CDM simulations. We find that $\geq 3.2\sigma$ preference for dynamic dark energy is very rare (occurrence rate = $0.28\%$) in simulations. When we combine DESI BAO with SN simulations or combine DES5YR SNe with BAO simulations, the occurrence rate of $\geq 3.2\sigma$ preference for dynamic dark energy increases to $1.2\%$ and $4.8\%$, respectively. These results indicate an internal inconsistency, i.e., a significant tension between DESI BAO + DES5YR SNe and Planck-constrained $\Lambda$CDM models in both Bayesian and frequentist points of view. Although both DESI BAO and DES5YR SNe contribute to the preference for dynamic dark energy, the contribution from DES5YR SNe is more significant. In the frequentist point of view, even DES5YR SNe alone is in tension with Planck-constrained $\Lambda$CDM models, though in Bayesian point of view this tension is prior dependent and inclusive.
- [44] arXiv:2406.02359 (replaced) [pdf, html, other]
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Title: Primordial gravitational wave backgrounds from phase transitions with next generation ground based detectorsComments: Invited review for a CQG Focus Issue on the science case for next generation ground based GW detectors; 53 pages, 9 figures; corrected version after referee reports, results unchanged, references addedSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
Third generation ground-based gravitational wave (GW) detectors, such as Einstein Telescope and Cosmic Explorer, will operate in the $(\text{few}-10^4)$ Hz frequency band, with a boost in sensitivity providing an unprecedented reach into primordial cosmology. Working concurrently with pulsar timing arrays in the nHz band, and LISA in the mHz band, these 3G detectors will be powerful probes of beyond the standard model particle physics on scales $T\gtrsim 10^{7}$GeV. Here we focus on their ability to probe phase transitions (PTs) in the early universe. We first overview the landscape of detectors across frequencies, discuss the relevance of astrophysical foregrounds, and provide convenient and up-to-date power-law integrated sensitivity curves for these detectors. We then present the constraints expected from GW observations on first order PTs and on topological defects (strings and domain walls), which may be formed when a symmetry is broken irrespective of the order of the phase transition. These constraints can then be applied to specific models leading to first order PTs and/or topological defects. In particular we discuss the implications for axion models, which solve the strong CP problem by introducing a spontaneously broken Peccei-Quinn (PQ) symmetry. For post-inflationary breaking, the PQ scale must lie in the $10^{8}-10^{11}$ GeV range, and so the signal from a first order PQ PT falls within reach of ground based 3G detectors. A scan in parameter space of signal-to-noise ratio in a representative model reveals their large potential to probe the nature of the PQ transition. Additionally, in heavy axion type models domain walls form, which can lead to a detectable GW background. We discuss their spectrum and summarise the expected constraints on these models from 3G detectors, together with SKA and LISA.
- [45] arXiv:2409.04453 (replaced) [pdf, html, other]
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Title: Prospects for searching for sterile neutrinos with gravitational wave and $\gamma$-ray burst joint observationsComments: 14 pages, 4 figuresSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
Sterile neutrinos can influence the evolution of the universe, and thus cosmological observations can be used to detect them. Future gravitational wave (GW) observations can precisely measure absolute cosmological distances, helping to break parameter degeneracies generated by traditional cosmological observations. This advancement can lead to much tighter constraints on sterile neutrino parameters. This work provides a preliminary forecast for detecting sterile neutrinos using third-generation GW detectors in combination with future short $\gamma$-ray burst observations from a THESEUS-like telescope, an approach not previously explored in the literature. Both massless and massive sterile neutrinos are considered within the $\Lambda$CDM cosmology. We find that using GW data can greatly enhance the detection capability for massless sterile neutrinos, reaching 3$\sigma$ level. For massive sterile neutrinos, GW data can also greatly assist in improving the parameter constraints, but it seems that effective detection is still not feasible.