Wed·Oct 19, 2022Wednesday·October 19, 2022

1. 01*

   The ALP explanation to muon $(g-2)$ and its test at future Tera-$Z$ and Higgs factories

   Jia Liu🇨🇳 · Xiaolin Ma🇨🇳 · Lian-Tao Wang🇺🇸 · Xiao-Ping Wang🇨🇳

   Models with an Axion Like Particle (ALP) can provide an explanation for the discrepancy between experimental measurement of the muon anomalous magnetic moment $(g-2{)}_{\mu }$ and the Standard Model prediction. This explanation relies on the couplings of the ALP to the muon and the photon. We also include more general couplings to the electroweak gauge bosons and incorporate them in the calculations up to the 2-loop order. We investigate the existing experimental constraints and find that they do not rule out the ALP model under consideration as a possible explanation for the $(g-2{)}_{\mu }$ anomaly. At the same time, we find the future Tera-$Z$ and Higgs factories, such as the CEPC and FCC-ee, can completely cover the relevant parameter space through searches with final states $(\gamma \gamma )\gamma$, $({\mu }^{+}{\mu }^{-})\gamma$ and $({\mu }^{+}{\mu }^{-}){\mu }^{+}{\mu }^{-}$.

   hep-phhep-exPRD(2023)·22 citations
2. 02*

   Effective model for pure Yang-Mills theory on ${\mathbb{T}}^2\times {\mathbb{R}}^2$ with Polyakov loops

   Daiki Suenaga🇯🇵 · Masakiyo Kitazawa🇯🇵

   We investigate the phase diagram and thermodynamics of $SU(N)$ pure Yang-Mills theory on a manifold ${\mathbb{T}}^2\times {\mathbb{R}}^2$ with an effective model that includes two Polyakov loops along two compactified directions. We find that a rich phase structure can appear owing to the spontaneous breaking of two center symmetries for $N=2$ and $3$. Thermodynamic quantities are obtained in the model and compared with recent lattice results. It is shown that two Polyakov loops play significant roles in thermodynamics on ${\mathbb{T}}^2\times {\mathbb{R}}^2$.

   hep-phhep-lathep-thnucl-thPRD(2023)·5 citations
3. 03*

   Soft gluon-quark-antiquark emission in QCD hard scattering

   Stefano Catani🇮🇹 · Leandro Cieri🇪🇸 · Dimitri Colferai🇮🇹 · Francesco Coradeschi🇮🇹

   We consider the radiation of a soft gluon ($g$) and a soft quark-antiquark ($q\bar{q}$) pair in QCD hard scattering. In the soft limit the scattering amplitude has a singular behaviour that is factorized and controlled by a soft current, which has a process-independent structure in colour space. We evaluate the soft $gq\bar{q}$ current at the tree level for an arbitrary multiparton scattering process. The irreducible correlation component of the current includes strictly non-abelian terms and also terms with an abelian character. Analogous abelian correlations appear for soft photon-lepton-antilepton emission in QED. The squared current for soft $gq\bar{q}$ emission produces colour dipole and colour tripole interactions between the hard-scattering partons. The colour tripole interactions are odd under charge conjugation and lead to charge asymmetry effects. We consider the specific applications to processes with two and three hard partons, and we discuss the structure of the corresponding charge asymmetry contributions. We also generalize our QCD results to the cases of QED and mixed QCD$\times$QED radiative corrections.

   hep-phEPJC(2023)·24 citations
4. 04*

   Single charged Higgs boson production at the LHC

   A. Arhrib🇲🇦 · R. Benbrik🇲🇦 · M. Krab🇲🇦 · B. Manaut🇲🇦 · M. Ouchemhou🇲🇦 · Qi-Shu Yan🇨🇳

   A search for charged Higgs may yield clear and direct signs of new physics outside the realm of the Standard Model (SM). In the Two-Higgs Doublet Model (2HDM), we investigate two of the main single charged Higgs production channels at the Large Hadron Collider (LHC), assuming that either $h$ or $H$ replicates the detected resonance at $\sim 125\mathrm{GeV}$. We consider the possibility of the charged Higgs boson production through the $pp\to H^{\pm }{W}^{\mp }$ and $pp\to H^{\pm }bj$ production processes that may present additional significance at the LHC experiments. Considering the $H^{\pm }\to W^{\pm }{h}_i/A$ decay channels and mainly concentrating on the $b\bar{b}$, $\tau \tau$ and $\gamma \gamma$ decays of $h_i$ and $A$, we examine the possible signatures arising from the aforementioned charged Higgs production and decay in both type-I and type-X realizations of 2HDM. Our study shows that these signatures can have sizable rates at low $\tan \beta$ as long as the condition $M_{H^{\pm }}<m_t-m_b$ is satisfied. As a result, we propose the $bb$, $\tau \tau$ and $\gamma \gamma$ final states associated with $WW$ or $Wbj$ as an encouraging experimental avenue that would complement the LHC search for a charged Higgs boson.

   hep-phPLB(2023)·14 citations
5. 05*

   Analytic Neutrino Oscillation Probabilities

   Chee Sheng Fong🇧🇷

   In the work, we derive exact analytic expressions for $(3+N)$-flavor neutrino oscillation probabilities in an arbitrary matter potential in term of matrix elements and eigenvalues of the Hamiltonian. With the analytic expressions, we demonstrate that nonunitary and nonstandard neutrino interaction scenarios are physically distinct: they satisfy different identities and can in principle be distinguished experimentally. The analytic expressions are implemented in a public code NuProbe, a tool for probing new physics through neutrino oscillations.

   hep-phhep-exSciPost Phys.(2023)·10 citations
6. 06*

   Dark Matter from Monogem

   Christopher V. Cappiello🇨🇦 · Neal P. Avis Kozar🇨🇦 · Aaron C. Vincent🇨🇦

   As a supernova shock expands into space, it may collide with dark matter particles, scattering them up to velocities more than an order of magnitude larger than typical dark matter velocities in the Milky Way. If a supernova remnant is close enough to Earth, and the appropriate age, this flux of high-velocity dark matter could be detectable in direct detection experiments, particularly if the dark matter interacts via a velocity-dependent operator. This could make it easier to detect light dark matter that would otherwise have too little energy to be detected. We show that the Monogem Ring supernova remnant is both close enough and the correct age to produce such a flux, and thus we produce novel direct detection constraints and sensitivities for future experiments.

   hep-phastro-ph.COastro-ph.HEPRD(2023)·21 citations
7. 07*

   Symmetry in neutrino oscillation in matter: New picture and the $\nu$SM -- non-unitarity interplay

   Hisakazu Minakata🇺🇸

   We update and summarize the present status of our understanding of the reparametrization symmetry with $i\leftrightarrow j$ state exchange in neutrino oscillation in matter. We introduce a systematic method called ``Symmetry Finder'' (SF) to uncover such symmetries, demonstrate its efficient hunting capability, and examine their characteristic features. Apparently they have a local nature: The 1-2 and 1-3 state exchange symmetries exist at around the solar- and atmospheric-resonances, respectively, with the level-crossing states exchanged. However, this view is not supported, to date, in the globally valid Denton et al. (DMP) perturbation theory, which possesses the 1-2 exchange symmetry but not the 1-3. It is probably due to lack of our understanding, and we find a clue for a larger symmetry structure than that we know. In the latter part of this article, we introduce non-unitarity, or unitarity violation (UV), into the $\nu$SM neutrino paradigm, a low-energy description of beyond $\nu$SM new physics at high (or low) scale. Based on the analyses of UV extended versions of the atmospheric-resonance and the DMP perturbation theories, we argue that the reparametrization symmetry has a diagnostics capability for the theory with the $\nu$SM and UV sectors. A speculation is given on the topological nature of the identity which determines the transformation property of the UV $\alpha$ parameters.

   hep-phSymmetry(2022)·4 citations
8. 08*

   Soft-gluon corrections for $tqZ$ production

   Nikolaos Kidonakis🇺🇸 · Nodoka Yamanaka🇯🇵

   We study soft-gluon corrections for the associated production of a single top quark and a $Z$ boson ($tqZ$ production) at hadron colliders. We find that the radiative corrections are dominated by soft-gluon emission. We calculate the approximate NNLO (aNNLO) cross section at LHC energies, including uncertainties from scale dependence and from parton distributions. We also calculate differential distributions in top-quark rapidity. We show that the aNNLO corrections are significant and they enhance the NLO cross section while decreasing theoretical uncertainties.

   hep-phPLB(2023)·15 citations
9. 09*

   Quark mixing angles vs quark masses: potential approach

   Boris Altshuler🇷🇺

   It is shown that phenomenologically favorable expressions of quark mixing angles through the ratios of current quark masses may be derived as stable points of certain 4-th power in CKM matrix flavor-invariant potentials built with traces of 3x3 quark up and down mass matrices.

   hep-ph0 citations
10. 10*

    Concepts in Lorentz and CPT Violation

    Alan Kostelecky🇺🇸

    This contribution to the CPT'22 meeting provides a brief review of some concepts in Lorentz and CPT violation.

    hep-ph6 citations
11. 11*

    Dispersion relations for $B^{-}\to {\ell }^{-}{\bar{\nu }}_{\ell }{\ell }^{\prime -}{\ell }^{\prime +}$ form factors

    Stephan Kürten🇩🇪 · Marvin Zanke🇩🇪 · Bastian Kubis🇩🇪 · Danny van Dyk🇩🇪

    Using dispersive methods, we study the $B\to {\gamma }^{\ast }$ form factors underlying the decay $B^{-}\to {\ell }^{-}{\bar{\nu }}_{\ell }{\ell }^{\prime -}{\ell }^{\prime +}$. We discuss the ambiguity that arises from a separation of the full $B^{-}\to {\ell }^{-}{\bar{\nu }}_{\ell }{\ell }^{\prime -}{\ell }^{\prime +}$ amplitude into a hadronic tensor and a final-state-radiation piece, including effects from nonvanishing lepton masses. For the eligibility of a dispersive treatment, we propose a decomposition of the hadronic part that leads to four form factors that are free of kinematic singularities. By establishing a set of dispersion relations, we then relate the $B\to {\gamma }^{\ast }$ form factors to the well-known $B\to V$, $V=\omega (782),\rho (770)$, analogues. Using the combination of a series expansion in a conformal variable and a vector-meson-dominance ansatz to parameterize the $B\to {\gamma }^{\ast }$ form factors, we infer the values of the associated unknown parameters from the available input on $B\to V$. The phenomenological application of our formalism includes the determination of the branching ratios and forward-backward asymmetries of the process $B^{-}\to {\ell }^{-}{\bar{\nu }}_{\ell }{\ell }^{\prime -}{\ell }^{\prime +}$ for the two lightest leptons.

    hep-phhep-exPRD(2023)·13 citations
12. 12*

    Quarkonium polarization in low-$p_{\mathrm{T}}$ hadro-production: from past data to future opportunities

    Pietro Faccioli🇵🇹 · Ilse Krätschmer🇦🇹 · Carlos Lourenço🇨🇭

    Several fixed-target experiments reported J/$\psi$ and ${\rm Y}$ polarization measurements, as functions of Feynman $x$ ($x_{\mathrm{F}}$) and transverse momentum ($p_{\mathrm{T}}$), in three different polarization frames, using different combinations of beam particles, target nuclei and collision energies. The data form such a diverse and heterogeneous picture that, at first sight, no clear trends can be observed. A more detailed look, however, allows us to discern qualitative physical patterns that inspire and support a simple interpretation: the directly-produced quarkonia result from either gluon-gluon fusion or from quark-antiquark annihilation, with the former mesons being fully longitudinally polarized and the latter being fully transversely polarized. This hypothesis provides a reasonable quantitative description of the J/$\psi$ and ${\rm Y}$(1S) polarizations measured in the $x_{\mathrm{F}}\lesssim 0.5$ kinematical domain. We provide predictions that can be experimentally tested, using proton and/or pion beams, and show that improved J/$\psi$ and $\psi$(2S) polarization measurements in pion-nucleus collisions can provide significant constraints on the poorly known parton distribution functions of the pion.

    hep-ph0 citations
13. 13*

    Radial Oscillations and Dynamical Instability Analysis for Linear-Quadratic GUP-modified White Dwarfs

    John Paul R. Bernaldez🇵🇭 · Adrian G. Abac🇩🇪 · Roland Emerito S. Otadoy🇵🇭

    A modification to the Heisenberg uncertainty principle is called the generalized uncertainty principle (GUP), which emerged due to the introduction of a minimum measurable length, common among phenomenological approaches to quantum gravity. One approach to GUP is called linear-quadratic GUP (LQGUP) which satisfies both the minimum measurable length and the maximum measurable momentum, resulting to an infinitesimal phase space volume proportional to the first-order momentum $(1-\alpha p{)}^{-4}{d}^{3}x{d}^{3}p$, where $\alpha$ is the still-unestablished GUP parameter. In this study, we explore the mass-radius relations of white dwarfs whose equation of state has been modified by LQGUP, and provide them with radial perturbations to investigate the dynamical instability arising from the oscillations. We find from the mass-radius relations that the main effect of LQGUP is to worsen the gravitational collapse by decreasing the mass of the relatively massive white dwarfs (including their limiting mass, while increasing their limiting radius). This effect gets more prominent with larger values of $\alpha$. We then compare the results with available observational data. To further investigate the impact of the GUP parameter, a dynamical instability analysis of the white dwarf was conducted, and we find that instability sets in for all values of $\alpha$. With increasing $\alpha$, we also find that the central density at which instability occurs decreases, resulting to a lower maximum mass. This is in contrast to quadratic GUP, where instability only sets in below a critical value of the quadratic GUP parameter.

    hep-phastro-ph.SRgr-qcAnnals Phys.(2023)·4 citations
14. 14*

    Finite Temperature Considerations in the Structure of Quadratic GUP-modified White Dwarfs

    James David M. Tuñacao🇬🇹 · Adrian G. Abac🇩🇪 · Roland Emerito S. Otadoy🇬🇹

    In quantum gravity phenomenology, the effect of the generalized uncertainty principle (GUP) on white dwarfs has been given much attention in the literature. However, these studies assume a zero temperature equation of state (EoS), consequently excluding young white dwarfs whose initial temperatures are substantially high. To that cause, this paper calculates the Chandrasekhar EoS and resulting mass-radius relations of finite temperature white dwarfs modified by the quadratic GUP, an approach that extends Heisenberg's uncertainty principle by a quadratic term in momenta. The EoS was first approximated by treating the quadratic GUP parameter as perturbative, causing the EoS to exhibit expected thermal deviations at low pressures, and conflicting behaviors at high pressures, depending on the order of approximation. We then proceeded with a full numerical simulation of the modified EoS, and showed that in general, finite temperatures cause the EoS at low pressures to soften, while the quadratic GUP stiffens the EoS at high pressures. This modified EoS was then applied to the Tolman-Oppenheimer-Volkoff equations and its classical approximation to obtain the modified mass-radius relations for general relativistic and Newtonian white dwarfs. The relations for both cases were found to exhibit the expected thermal deviations at small masses, where low-mass white dwarfs are shifted to the high-mass regime at large radii, while high-mass white dwarfs acquire larger masses, beyond the Chandrasekhar limit. Additionally, we find that for sufficiently large values of the GUP parameter and temperature, we obtain mass-radius relations that are completely removed from the ideal case, as high-mass deviations due to GUP and low-mass deviations due to temperature are no longer mutually exclusive.

    hep-phastro-ph.SRgr-qcInt.J.Mod.Phys.D(2023)·2 citations
15. 15*

    Angular distribution of ${\Lambda }_b^0\to p{K}^{-}{\ell }^{+}{\ell }^{-}$ decays comprising $\Lambda$ resonances with spin up to $\le 5/2$

    Anja Beck🇬🇧 · Thomas Blake🇬🇧 · Michal Kreps🇬🇧

    This paper describes the angular distribution of ${\Lambda }_b^0\to \Lambda (\to p{K}^{-}){\ell }^{+}{\ell }^{-}$ decays. A full expression is given for the case of multiple interfering spin-states with spin $\le \frac{5}{2}$. This distribution is relevant for future measurements of ${\Lambda }_b^0\to p{K}^{-}{\ell }^{+}{\ell }^{-}$ decays, where different states cannot easily be separated based on their mass alone. New observables arise when considering spin-$\frac{5}{2}$ states as well as interference between states. An exploration of their behaviour for a variety of beyond the Standard Model scenarios shows that some of these observables exhibit interesting sensitivity to the Wilson coefficients involved in $b\to s{\ell }^{+}{\ell }^{-}$ transitions. Others are insensitive to the Wilson coefficients and can be used to verify the description of ${\Lambda }_b^0\to \Lambda$ form-factors. A basis of weighting functions that can be used to determine all of the angular observables described in this paper in a moment analysis of the experimental data is also provided.

    hep-phJHEP(2023)·8 citations
16. 16*

    W-exchange contribution in hadronic decays of bottom baryon

    Fayyazuddin🇵🇰

    The nonleptonic decays of \Lambda_{b} that are dominated by W exchange are studied. In particular, the decay modes \varLambda_{b}\to\varDelta^{0}D^{0},\varDelta^{-}D^{+},\Sigma^{*-}D_{s}^{+}, \Lambda_{b}\to\Sigma_{c}^{*+}\pi^{-},\Sigma_{c}^{*0}\pi^{0},\Xi_{c}^{*0}K^{0} and \varLambda_{b}\to\Sigma_{c}^{+}\pi^{-} are analyzed. In an another aspect, the decay \Lambda_{b}\to\Lambda_{c}^{+}\pi^{-} in the factorization anstaz is studied. It is shown that factorization contributes to parity-violating (s-wave) amplitude A only. Hence factorization gives asymmetry parameter \alpha=0. However, the dominant contribution to parity conserving (p-wave) amplitude B comes from W exchange, i.e., from the baryon pole, giving asymmetry parameter \alpha=-0.77.

    hep-ph1 citation
17. 17*

    Axion dark matter from first-order phase transition, and very high energy photons from GRB 221009A

    Shota Nakagawa🇯🇵 · Fuminobu Takahashi🇯🇵 · Masaki Yamada🇯🇵 · Wen Yin🇯🇵

    We study an axion-like particle (ALP) that experiences the first-order phase transition with respect to its mass or potential minimum. This can be realized if the ALP obtains a potential from non-perturbative effects of SU($N$) gauge theory that is confined via the first-order phase transition, or if the ALP is trapped in a false vacuum at high temperatures until it starts to oscillate about the true minimum. The resulting ALP abundance is significantly enhanced compared to the standard misalignment mechanism, explaining dark matter in a broader parameter space that is accessible to experiments e.g. IAXO, ALPS-II, and DM-radio. Furthermore, the viable parameter space includes a region of the mass $m_a\simeq 10^{-7}-10^{-8}$ eV and the ALP-photon coupling $g_{a\gamma \gamma }\simeq 10^{-11}{\mathrm{GeV}}^{-1}$ that can explain the recent observation of very high energy photons from GRB221009A via axion-photon oscillations. The parameter region suggests that the FOPT can generate the gravitational wave that explains the NANOGrav hint. If the ALP in this region explains dark matter, then the ALP has likely experienced a first-order phase transition.

    hep-phastro-ph.COastro-ph.HEPLB(2023)·69 citations
18. 18*

    Self-consistent extraction of spectroscopic bounds on light new physics

    Cédric Delaunay🇫🇷 · Jean-Philippe Karr🇫🇷 · Teppei Kitahara🇯🇵 · Jeroen C. J. Koelemeij🇳🇱 · Yotam Soreq🇮🇱 · Jure Zupan🇺🇸

    Fundamental physical constants are determined from a collection of precision measurements of elementary particles, atoms and molecules. This is usually done under the assumption of the Standard Model~(SM) of particle physics. Allowing for light new physics~(NP) beyond the SM modifies the extraction of fundamental physical constants. Consequently, setting NP bounds using these data, and at the same time assuming the CODATA recommended values for the fundamental physical constants, is not reliable. As we show in this Letter, both SM and NP parameters can be simultaneously determined in a consistent way from a global fit. For light vectors with QED-like couplings, such as the dark photon, we provide a prescription that recovers the degeneracy with the photon in the massless limit, and requires calculations only at leading order in the small new physics couplings. At present, the data show tensions partially related to the proton charge radius determination. We show that these can be alleviated by including contributions from a light scalar with flavor non-universal couplings.

    hep-phhep-exphysics.atom-phPRL(2023)·24 citations
19. 19*

    Multi-Collinear Splitting Kernels for Track Function Evolution

    Hao Chen🇨🇳 · Max Jaarsma🇳🇱 · Yibei Li🇨🇳 · Ian Moult🇺🇸 · Wouter J. Waalewijn🇳🇱 · Hua Xing Zhu🇨🇳

    Jets and their substructure play a central role in many analyses at the Large Hadron Collider (LHC). To improve the precision of measurements, as well as to enable measurement of jet substructure at increasingly small angular scales, tracking information is often used due to its superior angular resolution and robustness to pile-up. Calculations of track-based observables involve non-perturbative track functions, that absorb infrared divergences in perturbative calculations and describe the transition to charged hadrons. The infrared divergences are directly related to the renormalization group evolution (RGE), and can be systematically computed in perturbation theory. Unlike the standard DGLAP evolution, the RGE of the track functions is non-linear, encoding correlations in the fragmentation process. We compute the next-to-leading order (NLO) evolution of the track functions, which involves in its kernel the full $1\to 3$ splitting function. We discuss in detail how how we implement the evolution equation numerically, and illustrate the size of the NLO corrections. We also show that our equation can be viewed as a master equation for collinear evolution at NLO, by illustrating that by integrating out specific terms, one can derive the evolution for any $N$-hadron fragmentation function. Our results provide a crucial ingredient for obtaining track-based predictions for generic measurements at the LHC, and for improving the description of the collinear dynamics of jets.

    hep-phhep-exnucl-thJHEP(2023)·46 citations
20. 20*

    Collinear Parton Dynamics Beyond DGLAP

    Hao Chen🇨🇳 · Max Jaarsma🇳🇱 · Yibei Li🇨🇳 · Ian Moult🇺🇸 · Wouter J. Waalewijn🇳🇱 · Hua Xing Zhu🇨🇳

    Renormalization group evolution equations describing the scale dependence of quantities in quantum chromodynamics (QCD) play a central role in the interpretation of experimental data. Arguably the most important evolution equations for collider physics applications are the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) equations, which describe the evolution of a quark or gluon fragmenting into hadrons, with only a single hadron identified at a time. In recent years, the study of the correlations of energy flow within jets has come to play a central role at collider experiments, necessitating an understanding of correlations, going beyond the standard DGLAP paradigm. In this Letter we derive a general renormalization group equation describing the collinear dynamics that account for correlations in the fragmentation. We compute the kernel of this evolution equation at next-to-leading order (NLO), where it involves the $1\to 3$ splitting functions, and develop techniques to solve it numerically. We show that our equation encompasses all previously-known collinear evolution equations, namely DGLAP and the evolution of multi-hadron fragmentation functions. As an application of our results, we consider the phenomenologically-relevant example of energy flow on charged particles, computing the energy fraction in charged particles in $e^{+}{e}^{-}\to$ hadrons at NNLO. Our results are an important step towards improving the understanding of the collinear dynamics of jets, with broad applications in jet substructure, ranging from the study of multi-hadron correlations, to the description of inclusive (sub)jet production, and the advancement of modern parton showers.

    hep-phhep-exnucl-thPRD(2025)·49 citations
21. 21*

    Soft-Collinear Gravity and Soft Theorems

    Martin Beneke🇩🇪 · Patrick Hager🇩🇪 · Robert Szafron🇺🇸

    This chapter reviews the construction of ``soft-collinear gravity'', the effective field theory which describes the interaction of collinear and soft gravitons with matter (and themselves), to all orders in the soft-collinear power expansion, focusing on the essential concepts. Among them are an emergent soft background gauge symmetry, which lives on the light-like trajectories of energetic particles and allows for a manifestly gauge-invariant representation of the interactions in terms of a soft covariant derivative and the soft Riemann tensor, and a systematic treatment of collinear interactions, which are absent at leading power in gravity. The gravitational soft theorems are derived from soft-collinear gravity at the Lagrangian level. The symmetries of the effective theory provide a transparent explanation of why soft graviton emission is universal to sub-sub-leading power, but gauge boson emission is not and suggest a physical interpretation of the form of the universal soft factors in terms of the charges corresponding to the soft symmetries. The power counting of soft-collinear gravity further provides an understanding of the structure of loop corrections to the soft theorems.

    ↳ hep-thhep-ph21 citations
22. 22*

    Through Iron & Ice: Searching for Sterile Neutrinos at the IceCube Neutrino Observatory

    Alejandro Diaz🇺🇸

    Despite the rapid progression in our understanding of neutrinos over the last half century, much is left unknown about their properties. This leaves neutrinos as the most promising portal for Beyond Standard Model (BSM) physics, and neutrinos have already provided fruitful surprises. A number of neutrino experiments in the last three decades have observed anomalous oscillation signals consistent with a mass-squared splitting of $\Delta m^2\sim 1{\text{eV}}^2$, motivating the existence and search for sterile neutrinos. On the other hand, other experiments have failed to see such a signal. In this thesis, we present two analyses. The first is an update to the sterile neutrino global fits with the inclusion of recent experimental data. We find that the 3+1 model provides a better fit to the global data set compared to the null, with an improvement of $\Delta {\chi }^2=51$ with the addition of only 3 degrees of freedom, corresponding to $6.6\sigma$. While a substantial improvement, we also find a irreconcilable tension between the data sets of $5.1\sigma$, calculated using the parameter goodness-of-fit test. This motivates the exploration of expanded models: a 3+2 model, and a 3+1+Decay model. In the 3+2 model, we find negligible improvement to the fit, and an even worse tension of $5.5\sigma$. In the more exotic 3+1+Decay model, we find the tension reduced to $3.6\sigma$. While a substantial improvement compared to the 3+1 model with the introduction of only one additional parameter, the tension is still too large to assuage concerns. The second analysis is the results of an expanded IceCube sterile neutrino search. A previous sterile neutrino search found no evidence for sterile neutrinos, finding a p-value of 8%. Of the three sterile mixing angles, ${\theta }_{14},{\theta }_{24}$, and ${\theta }_{34}$, only ${\theta }_{24}$ was fitted for, as ${\theta }_{14}$ was negligible and ${\theta }_{34}=0$ was considered a conservative assumption. We present results of an analysis where we include ${\theta }_{34}$ to the fitted model. Both a frequentist and Bayesian analysis were conducted, with fits done in terms of the mass-squared splitting $\Delta m_{41}^2$ and the mixing matrix parameters $|U_{\mu 4}{|}^2$ and $|U_{\tau 4}{|}^2$. The frequentist analysis finds a best fit at $\Delta m_{41}^2=5.0{\text{eV}}^2$, $|U_{\mu 4}{|}^2=0.04$, and $|U_{\tau 4}{|}^2=0.006$, with a p-value of 5.2% assuming Wilks' Theorem with 3 degrees of freedom. Pseudoexperiments are indicating a smaller p-value 2.7%. The Bayesian analysis finds a similar best fit point at $\Delta m_{41}^2=5.0{\text{eV}}^2$, $|U_{\mu 4}{|}^2=0.02$, and $|U_{\tau 4}{|}^2=0.006$, with a Bayes factor indicating a ``Very Strong'' preference for this sterile hypothesis over the null hypothesis.

    ↳ hep-exhep-ph1 citation
23. 23*

    Towards the finite-volume spectrum of the Roper resonance

    Daniel Severt🇩🇪

    The finite-volume energy levels corresponding to the Roper resonance based on a two-flavor chiral effective Lagrangian at leading one-loop order are investigated. It is shown that the Roper mass can be extracted from these levels for not too large lattice volumes. Further, to include three-body $N\pi \pi$ dynamics, a non-relativistic effective field theory for the Roper resonance within a covariant particle-dimer picture is introduced. This particle-dimer approach is a suitable framework to investigate three-particle scattering relevant for the Roper channel. The appearing dimer fields are analyzed, the energy levels of the Roper resonance in a finite volume are calculated and compared to the results from the chiral effective Lagrangian.

    ↳ hep-lathep-phnucl-thPoS(2023)·4 citations
24. 24*

    Flavour-changing neutral scalar interactions of the top quark

    Nuno Castro🇵🇹 · Kirill Skovpen🇧🇪

    A study of the top quark interactions via flavour-changing neutral current (FCNC) processes provides an intriguing connection between the heaviest elementary particle of the standard model (SM) of particle physics and the new scalar bosons that are predicted in several notable SM extensions. The production cross sections of the processes with top-scalar FCNC interactions can be significantly enhanced to the observable level at the CERN Large Hadron Collider. The present review summarizes the latest experimental results on the study of the top quark interactions with the Higgs boson via FCNC and describes several promising directions to look for new scalar particles.

    ↳ hep-exhep-phUniverse(2022)·11 citations
25. 25*

    Constraints on Late Time Violations of the Equivalence Principle in the Dark Sector

    Cameron C. Thomas🇬🇧 · Carsten van de Bruck🇬🇧

    If dark energy is dynamical due to the evolution of a scalar field, then in general it is expected that the scalar is coupled to matter. While couplings to the standard model particles are highly constrained by local experiments, bounds on couplings to dark matter (DM) are only obtained from cosmological observations and they are consequently weaker. It has recently been pointed out that the coupling itself can become non-zero only at the time of dark energy domination, due to the evolution of dark energy itself, leading to a violation of the equivalence principle (EP) in the dark sector at late times. In this paper we study a specific model and show that such late-time violations of the EP in the DM sector are not strongly constrained by the evolution of the cosmological background and by observables in the linear regime (e.g. from the cosmic microwave background radiation). A study of perturbations in non-linear regime is necessary to constrain late--time violations of the equivalence principle much more strongly.

    ↳ hep-thastro-ph.COgr-qchep-phJCAP(2023)·4 citations
26. 26*

    Generative models uncertainty estimation

    Lucio Anderlini🇮🇹 · Constantine Chimpoesh🇷🇺 · Nikita Kazeev🇷🇺 · Agata Shishigina🇷🇺

    In recent years fully-parametric fast simulation methods based on generative models have been proposed for a variety of high-energy physics detectors. By their nature, the quality of data-driven models degrades in the regions of the phase space where the data are sparse. Since machine-learning models are hard to analyse from the physical principles, the commonly used testing procedures are performed in a data-driven way and can't be reliably used in such regions. In our work we propose three methods to estimate the uncertainty of generative models inside and outside of the training phase space region, along with data-driven calibration techniques. A test of the proposed methods on the LHCb RICH fast simulation is also presented.

    ↳ cs.LGhep-exhep-phJ.Phys.Conf.Ser.(2023)·5 citations
27. 27*

    First-order QCD transition in a primordial magnetic field

    Gaoqing Cao🇨🇳

    Recalling the expectation of an extremely strong primordial magnetic field $H$, we recheck transitions among the phases of chiral symmetry restoration ($\chi SR$), chiral symmetry breaking ($\chi SB$), and pion superfluidity ($\pi SF$)in the QCD epoch of the early Universe. For homogeneous phases in a finite $H$, a sensible scheme is adopted to determine the phase boundaries of $\pi SF$, which is also superconductivity phase itself. In the first part, the QCD phase diagrams are studied in detail within the chiral effective Polyakov-Nambu--Jona-Lasinio model and the transitions involving $\pi SF$ are found to be of first order at relatively small $H$. As expected from the Meissner effect, the regime of $\pi SF$ shrinks with increasing $H$ and completely vanishes beyond a threshold value. In the second part, the bubble dynamics is illuminated for the stronger first-order transition, $\chi SR\to \pi SF$, in the more convenient Polyakov-quark-meson model. The coupled equations of motion of pion condensate and magnetic field are solved consistently to give the bubble structure. Then, based on bubble collisions, we explore gravitational wave (GW) emission by developing a simple toy model in advance; and the characteristic frequency of the relic GW is estimated to be of the order $0.1-1\mathrm{K}$ or $10^9-10^{10}\mathrm{Hz}$ in our galaxy.

    ↳ nucl-thgr-qchep-phPRD(2023)·7 citations
28. 28*

    Scaling solutions of wiggly cosmic strings: II. Time-varying coarse-graining scale solutions

    A. Almeida🇵🇹 · C. J. A. P. Martins🇵🇹

    We continue our exploration of the wiggly generalisation of the Velocity-Dependent One Scale Model for cosmic strings, through the study of its allowed asymptotic scaling solutions. We extend the work of a previous paper [Almeida $\&$ Martins, Phys. Rev. D 104 (2021) 043524] by considering the more comprehensive case of a time-varying coarse-graining scale for the string wiggles. The modeling of the evolution of the network therefore relies on three main mechanisms: Hubble expansion, energy transfer mechanisms (e.g., the production of loops and wiggles) and the choice of the scale at which wiggles are coarse-grained. We analyse the role of each of them on the overall behaviour of the network, and thus in the allowed scaling solutions. In Minkowski space, we find that linear scaling, previously observed in numerical simulations without expansion, is not possible with a changing averaging scale. For expanding universes, we find that the three broad classes of scaling solutions -- with the wiggliness disappearing, reaching scaling, or growing -- still exist but are differently impacted by the time evolution of the coarse-graining scale. Nambu-Goto type solutions (without wiggles) are unaffected, growing wiggliness solutions are trivially generalized, while for solutions where wiggliness reaches scaling the expansion rate for which the solution exists is decreased with respect to the one for a fixed coarse-graining scale. Finally, we also show that the inclusion of a time-varying coarse-graining scale allows, in principle, for additional scaling solutions which, although mathematically valid, are not physical. Overall, our mapping of the landscape of the allowed scaling solutions of the wiggly Velocity-Dependent One Scale Model paves the way for the detailed testing of the model, to be done by forthcoming high-resolution field theory and Nambu-Goto simulations.

    ↳ astro-ph.COgr-qchep-phPRD(2022)·5 citations
29. 29*

    Study of SU(2) gauge theories with multiple Higgs fields in different representations

    Guilherme Catumba🇪🇸 · Atsuki Hiraguchi🇹🇼 · George W.-S. Hou🇹🇼 · Karl Jansen🇩🇪 · Ying-Jer Kao🇹🇼 · C.-J. David Lin🇹🇼 · Alberto Ramos · Mugdha Sarkar🇹🇼

    We study two different SU(2) gauge-scalar theories in 3 and 4 spacetime dimensions. Firstly, we focus on the 3 dimensional SU(2) theory with multiple Higgs fields in the adjoint representation, that can be mapped to cuprate systems in condensed matter physics which host a rich phase diagram including high-Tc superconductivity. It has been proposed that the theory with 4 adjoint Higgs fields can be used to explain the physics of hole-doped cuprates for a wide range of parameters. We show exploratory results on the phase diagram of the theory. On the other hand, we are interested in the 4 dimensional theory with 2 sets of fundamental scalar (Higgs) fields, which is relevant to the 2 Higgs Doublet Model (2HDM), a proposed extension to the Standard Model of particle physics. The goal is to understand the particle spectrum of the theory at zero temperature and the electroweak phase transition at finite temperature. We present exploratory results on scale setting and the multi-parameter phase diagram of this theory.

    ↳ hep-latcond-mat.supr-conhep-phPoS(2023)·5 citations
30. 30*

    Landau and leading singularities in arbitrary space-time dimensions

    Wojciech Flieger🇩🇪 · William J. Torres Bobadilla🇩🇪

    Using the decomposition of the $D$-dimensional space-time into parallel and perpendicular subspaces, we study and prove a connection between Landau and leading singularities for $N$-point one-loop Feynman integrals by applying multi-dimensional theory of residues. We show that if $D=N$ and $D=N+1$, the leading singularity corresponds to the inverse of the square root of the leading Landau singularity of the first and second type, respectively. We make use of this outcome to systematically provide differential equations of Feynman integrals in canonical forms and the extension of the connection of these singularities at multi-loop level by exploiting the loop-by-loop approach. Illustrative examples with the calculation of Landau and leading singularities are provided to supplement our results.

    ↳ hep-thhep-phEur.Phys.J.Plus(2024)·28 citations
31. 31*

    On the Hagedorn Temperature in Holographic Confining Gauge Theories

    Francesco Bigazzi🇮🇹 · Tommaso Canneti🇮🇹 · Aldo L. Cotrone🇮🇹

    The divergence of the string partition function due to the exponential growth of states is a well-understood issue in flat spacetime. It can be interpreted as the appearance of tachyon modes above a certain temperature, known as the Hagedorn temperature $T_H$. In the literature, one can find some intuitions about its generalization to curved spacetimes, where computations are extremely hard and explicit results cannot be provided in general. In this paper, we present a genus-zero estimate of $T_H$, at leading order in ${\alpha }^{\prime }$, for string theories on curved backgrounds holographically dual to confining gauge theories. This is a particularly interesting case, since the holographic correspondence equates $T_H$ with the Hagedorn temperature of the dual gauge theories. For concreteness we focus on Type IIA string theory on a well known background dual to an $SU(N)$ Yang-Mills theory. The resulting Hagedorn temperature turns out to be proportional to the square root of the Yang-Mills confining string tension. The related coefficient, which at leading order is analytically determined, is the same as the one for Type II theories in flat space. While the calculation is performed in a specific model, the result applies in full generality to confining gauge theories with a top-down holographic dual.

    ↳ hep-thhep-lathep-phJHEP(2023)·11 citations
32. 32*

    Loop-by-loop Differential Equations for Dual (Elliptic) Feynman Integrals

    Mathieu Giroux🇨🇦 · Andrzej Pokraka🇨🇦

    We present a loop-by-loop method for computing the differential equations of Feynman integrals using the recently developed dual form formalism. We give explicit prescriptions for the loop-by-loop fibration of multi-loop dual forms. Then, we test our formalism on a simple, but non-trivial, example: the two-loop three-mass elliptic sunrise family of integrals. We obtain an epsilon-form differential equation within the correct function space in a sequence of relatively simple algebraic steps. In particular, none of these steps relies on the analysis of $q$-series. Then, we discuss interesting properties satisfied by our dual basis as well as its simple relation to the known epsilon-form basis of Feynman integrands. The underlying K3-geometry of the three-loop four-mass sunrise integral is also discussed. Finally, we speculate on how to construct a "good" loop-by-loop basis at three-loop.

    ↳ hep-thhep-phmath-phmath.MPJHEP(2023)·63 citations
33. 33*

    Extended superscaling with two-particle emission in electron and neutrino scattering

    V.L. Martinez-Consentino🇪🇸 · J.E. Amaro🇪🇸 · P.R. Casale🇪🇸 · I. Ruiz Simo🇪🇸

    An extended superscaling analysis of quasielastic electron scattering data is proposed by parametrizing the scaling function as the sum of a symmetric function corresponding to the emission of a single particle plus a contribution from the phase space of two-particle emission. The phase space of two-particle emission (2p2h) is multiplied by a q-dependent parameter that has been fitted to describe the tail behavior of the scaling function. This approach allows for an alternative description of the quasielastic electron scattering data, incorporating the contributions from both single-particle and two-particle emission processes induced by the one-body current and explaining the asymmetry of the scaling function. In a factorized schematic model based on the independent-pair approximation, the 2p2h parameter is related to the high-momentum distribution of the pair averaged over 2p-2h excitations. However, in the phenomenological fitting approach undertaken here, this coefficient includes other contributions such as interference with two-body currents and effects of the final-state interactions. We present predictions for the inclusive two-nucleon emission cross section induced by electrons and neutrinos.

    ↳ nucl-thhep-phPRD(2023)·14 citations
34. 34*

    Gluon Parton Distribution of the Nucleon from 2+1+1-Flavor Lattice QCD in the Physical-Continuum Limit

    Zhouyou Fan🇺🇸 · William Good🇺🇸 · Huey-Wen Lin🇺🇸

    We present the first physical-continuum limit $x$-dependent nucleon gluon distribution from lattice QCD using the pseudo-PDF approach, on lattice ensembles with $2+1+1$ flavors of highly improved staggered quarks (HISQ), generated by MILC Collaboration. We use clover fermions for the valence action on three lattice spacings $a\approx 0.9$, 0.12 and 0.15~fm and three pion masses $M_{\pi }\approx 220$, 310 and 690~MeV, with nucleon two-point measurements numbering up to $O(10^6)$ and nucleon boost momenta up to 3~GeV. We study the lattice-spacing and pion-mass dependence of the reduced pseudo-ITD matrix elements obtained from the lattice calculation, then extrapolate them to the continuum-physical limit before extracting $xg(x)/⟨x{⟩}_g$. We use the gluon momentum fraction $⟨x{⟩}_g$ calculated from the same ensembles to determine the nucleon gluon unpolarized PDF $xg(x)$ for the first time entirely through lattice-QCD simulation. We compare our results with previous single-ensemble lattice calculations, as well as selected global fits.

    ↳ hep-lathep-phnucl-thPRD(2023)·35 citations
35. 35*

    The Tameness of Quantum Field Theory, Part I -- Amplitudes

    Michael R. Douglas🇺🇸 · Thomas W. Grimm🇳🇱 · Lorenz Schlechter🇳🇱

    We propose a generalized finiteness principle for physical theories, in terms of the concept of tameness in mathematical logic. A tame function or space can only have a finite amount of structure, in a precise sense which we explain. Tameness generalizes the notion of an analytic function to include certain non-analytic limits, and we show that this includes many limits which are known to arise in physics. For renormalizable quantum field theories, we give a general proof that amplitudes at each order in the loop expansion are tame functions of the external momenta and the couplings. We then consider a variety of exact non-perturbative results and show that they are tame but only given constraints on the UV definition of the theory. This provides further evidence for the recent conjecture of the second author that all effective theories that can be coupled to quantum gravity are tame. We also discuss whether renormalization group flow is tame, and comment on the applicability of our results to effective theories.

    ↳ hep-thhep-phmath.LOAdv.Theor.Math.Phys.(2024)·19 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.