Thu·Aug 18, 2022Thursday·August 18, 2022

1. 01*

   Positronium hydride decay into proton, electron, and one or zero photons

   M. Jamil Aslam🇵🇰 · Wen Chen🇨🇦 · Andrzej Czarnecki🇨🇦 · Muhammad Mubasher🇨🇦 · Connor Stephens🇨🇦

   Decay rates of the positronium hydride PsH, a bound state of a proton, a positron, and two electrons, are determined for two rare channels, PsH $\to p^{+}{e}^{-}\gamma$ and PsH $\to p^{+}{e}^{-}$. Previous studies overestimated these rates by factors of about 2 and 700, respectively. We explain the physics underlying these wrong predictions. We confirm a range of static PsH properties, including the non-relativistic ground state energy, expectation values of inter-particle distances and their powers, and the three and four particle coalescence probabilities, using a variational method in the Gaussian basis.

   hep-phphysics.atom-phPRA(2023)·1 citation
2. 02*

   When, Where, and How to Open Data: A Personal Perspective

   Benjamin Nachman🇺🇸

   This is a personal perspective on data sharing in the context of public data releases suitable for generic analysis. These open data can be a powerful tool for expanding the science of high energy physics, but care must be taken in when, where, and how they are utilized. I argue that data preservation even within collaborations needs additional support in order to maximize our science potential. Additionally, it should also be easier for non-collaboration members to engage with collaborations. Finally, I advocate that we recognize a new type of high energy physicist: the 'data physicist', who would be optimally suited to analyze open data as well as develop and deploy new advanced data science tools so that we can use our precious data to their fullest potential. This document has been coordinated with a white paper on open data commissioned by the American Physical Society's (APS) Division of Particles and Field (DPS) Community Planning Exercise ('Snowmass') Theory Frontier [1] and relevant also for the Computational Frontier.

   hep-phhep-exphysics.data-an2 citations
3. 03*

   Bayesian analysis of QGP jet transport using multi-scale modeling applied to inclusive hadron and reconstructed jet data

   R. Ehlers · A. Angerami · R. Arora · S. A. Bass · S. Cao · Y. Chen · L. Du · T. Dai · H. Elfner · W. Fan · R. J. Fries · C. Gale and 46 other authors

   The JETSCAPE Collaboration reports a new determination of jet transport coefficients in the Quark-Gluon Plasma, using both reconstructed jet and hadron data measured at RHIC and the LHC. The JETSCAPE framework incorporates detailed modeling of the dynamical evolution of the QGP; a multi-stage theoretical approach to in-medium jet evolution and medium response; and Bayesian inference for quantitative comparison of model calculations and data. The multi-stage framework incorporates multiple models to cover a broad range in scale of the in-medium parton shower evolution, with dynamical choice of model that depends on the current virtuality or energy of the parton. We will discuss the physics of the multi-stage modeling, and then present a new Bayesian analysis incorporating it. This analysis extends the recently published JETSCAPE determination of the jet transport parameter $\hat{q}$ that was based solely on inclusive hadron suppression data, by incorporating reconstructed jet measurements of quenching. We explore the functional dependence of jet transport coefficients on QGP temperature and jet energy and virtuality, and report the consistency and tensions found for current jet quenching modeling with hadron and reconstructed jet data over a wide range in kinematics and $\sqrt{s_{\text{NN}}}$. This analysis represents the next step in the program of comprehensive analysis of jet quenching phenomenology and its constraint of properties of the QGP.

   hep-phnucl-exnucl-thActa Phys.Polon.Supp.(2023)·12 citations
4. 04*

   Opportunities for theory studies with public collider data: Snowmass 2021

   Matt Bellis🇺🇸 · Brian Shuve🇺🇸 · Anna Barth🇺🇸 · Andres Cook🇺🇸

   Over the last 20+ years, experimentalists have presented tantalizing hints of physics beyond the standard model, but nothing definitive. With the wealth of data from experiments, in particular the collider experiments, it is imperative that the community leave no reasonable model untested and no search unsought. Open datasets from particle physics experiments provide a relatively new and exciting opportunity to extend the reach of these searches by bringing in additional personpower in the form of the theory community. Analysis of these datasets also provides the opportunity for an increased information flow between theorists and experimentalists, an activity which can only benefit the entire field. This paper discusses the potential of this effort, informed by the successes of the last 5 years in the form of results produced by theorists making use of open collider data, primarily the datasets released by the CMS collaboration. Concerns about the potential negative impact on the field are also discussed. For a more detailed accounting of these concerns, see Ref. [1] of the bibliography.

   hep-phhep-exhep-th2 citations
5. 05*

   Insights into the nature of the $X(3872)$ through B meson decays

   Zhi-Qing Zhang🇨🇳 · Zhi-Lin Guan🇨🇳 · Yan-Chao Zhao🇨🇳 · Zi-Yu Zhang🇨🇳 · Zhi-Jie Sun🇨🇳 · Na Wang🇨🇳 · Xiao-Dong Ren🇨🇳

   We study the decays $B_{c,u,d}\to X(3872)P$ in the perturbative QCD (PQCD) approach, where the puzzling resonance $X(3872)$ is involved and $P$ represents a light pseudoscalar meson $K$ and $\pi$. Assuming the $X(3872)$ as a $1^{++}$ charmonium state, we find the following results: (a) The branching ratios for the decays $B_c^{+}\to X(3872){\pi }^{+}$ and $B_c^{+}\to X(3872)K^{+}$ agree with the results predicted by the covariant light-front approach within errors, but are larger than those given by the generalized factorization approach; (b) The branching ratio for the decay $B^{+}\to X(3872)K^{+}$ is predicted as $(3.8_{-1.0}^{+1.1})\times 10^{-4}$, which is smaller than the previous PQCD calculation result, but still slightly larger than the upper limits set by Belle and BaBar. So we suggest that the decays $B^{0,+}\to X(3872)K^{0,+}$ should be precisely measured by the running LHCb and Belle II experiments, which is very helpful to probe the inner structure of the $X(3872)$; (c) Compared with the decays $B_{u,d}\to X(3872)K$, the decays $B_{u,d}\to X(3872)\pi$ have much smaller branching ratios, which drop to as low as $10^{-6}$; (d) The direct CP violations for these considered decays are very small, only $10^{-3}\sim 10^{-2}$, because the penguin contributions are loop suppressed compared with the tree contributions. Testing the results for the branching ratios and the CP violations including the implicit $SU(3)$ and isospin symmetries in these decays by experiments is helpful to probe the nature of the $X(3872)$.

   hep-phCPC(2023)·3 citations
6. 06*

   Low-Mass dark matter (in)direct detection with inelastic scattering

   Nicole F. Bell🇦🇺 · James B. Dent🇺🇸 · Bhaskar Dutta🇺🇸 · Jason Kumar🇺🇸 · Jayden L. Newstead🇦🇺

   We revisit the detection of luminous dark matter in direct detection experiments. In this scenario, dark matter scatters endothermically to produce an excited state, which decays to produce a photon. We explore ways in which the electron recoil signal from the decay photon can be differentiated from other potential electron recoil signals with a narrow spectral shape. We find that larger volume/exposure xenon detectors will be unable to differentiate the signal origin without significant improvements in detector energy resolution of around an order of magnitude. We also explore what can be learned about a generic luminous dark matter signal with a higher resolution detector. Motivated by the advancements in energy resolution by solid-state detectors, we find that sub-eV resolution enables the discovery of LDM in the presence of background levels that would otherwise make observation impossible. We also find that sub-eV resolution can be used to determine the shape of the luminous dark matter decay spectrum and thus constrain the dark matter mass and velocity distribution.

   hep-phastro-ph.HEPRD(2022)·10 citations
7. 07*

   Monopoles, Strings and Gravitational Waves in Non-minimal Inflation

   Rinku Maji🇮🇳 · Qaisar Shafi🇺🇸

   We discuss how in $SO(10)$ grand unification an observable number density of topologically stable intermediate mass ( $\sim 10^{14}$ GeV) monopoles survive inflation driven by a Coleman-Weinberg potential and non-minimal coupling of the inflaton field to gravity. The scalar spectral index $n_s$ is in excellent agreement with the current observations, and the tensor to scalar ratio $r\gtrsim 0.003$. The model also predicts the presence of intermediate scale topologically stable cosmic strings, and their gravitational wave spectrum reflects the amount of cosmic inflation experienced by the associated symmetry breaking. The discovery of these primordial monopoles and the stochastic gravitational wave background from the strings would provide important new insights regarding the symmetry breaking patterns in the early universe.

   hep-phastro-ph.COhep-thJCAP(2023)·29 citations
8. 08*

   Three-Loop Four-Point Scattering Amplitudes in Massless Gauge Theories

   Amlan Chakraborty🇺🇸 · Giulio Gambuti🇬🇧

   We present novel techniques for the computation of three-loop four-parton scattering amplitudes in full color, non-planar gauge theories. We elaborate on how the analytic results for these amplitudes can be used to confirm the conjectured infrared structure of QCD up to three loops and how all-orders data can be extracted from their high-energy limit.

   hep-phhep-thPoS(2022)·0 citations
9. 09*

   Dark states with electromagnetic form factors at electron colliders

   Yu Zhang🇨🇳 · Mao Song🇨🇳 · Liangwen Chen🇨🇳

   Electromagnetically neutral dark sector particles may feebly interact with photons through higher dimensional effective operators, such as mass-dimension 5 magnetic and electric dipole moment, and a mass-dimension 6 anapole moment and charge radius operators. In this work, we use hypercharge gauge field form factors to treat dark states, which will induce not only electromagnetic form factors but also the corresponding $Z$ boson operators. Taking a Dirac fermion $\chi$ as an example, we investigate the probes of searching for such dark states at current and future $e^{+}{e}^{-}$ collider experiments including BESIII, STCF, Belle II and CEPC via monophoton searches. Comparing to current experiments, we find that electron colliders including BESIII, STCF, Belle II, which operate with the center-of-mass at several GeV, have leading sensitivity on the corresponding electromagnetic form factors for the mass-dimension 5 operators with dark states lighter than several GeV, while they can not provide competitive upper limits for the mass-dimension 6 operators. Future CEPC operated with the center-of-mass on and beyond the mass of $Z$-boson with competitive luminosity can probe the unexplored parameter space for dark states with mass-dimension 5 (6) operators in the mass region of $m\lesssim 100$ GeV (10 MeV $\lesssim m\lesssim 100$ GeV).

   hep-phPRD(2023)·3 citations
10. 10*

    On sum rules for double and triple parton distribution functions and Pythia's model of multiple parton interactions

    Oleh Fedkevych🇮🇹 · Jonathan R. Gaunt🇬🇧

    Multi-parton distributions in a proton, the nonperturbative quantities needed to make predictions for multiple scattering rates, are poorly constrained from theory and data and must be modelled. All Monte Carlo event generators that simulate multiple parton interactions (e.g. Pythia) contain such a model of multi-parton PDFs. One important theoretical constraint for the case of double parton distributions is provided by the so-called number and momentum sum rules. In this paper we investigate to what extent the double parton distribution functions used in the Pythia event generator obey these sum rules. We also derive the number and momentum sum rules for the triple parton distribution functions and discuss how one can use the Pythia code to construct triple parton distribution functions which approximately satisfy these sum rules.

    hep-phJHEP(2023)·4 citations
11. 11*

    Sneutrinos as two inflatons and curvaton and leptogenesis

    Tomo Takahashi🇯🇵 · Toshifumi Yamada🇯🇵 · Shuichiro Yokoyama🇯🇵

    We argue that sneutrinos can be embedded in a multi-field inflation framework where two inflatons and a curvaton simultaneously contribute to primordial fluctuations, which is consistent with current constraints on the spectral index and the tensor-to-scalar ratio from Planck and BICEP/Keck 2018. We also show that the same framework can also explain the baryon asymmetry of the Universe via leptogenesis realized by the decay of the lightest sneutrino. We investigate the parameter range for the scenario to work such as that of sneutrino masses. In particular, we show that the tensor-to-scalar ratio should be larger than $10^{-4}$ for a successful scenario.

    hep-phastro-ph.COgr-qchep-thJCAP(2022)·1 citation
12. 12*

    Unraveling Gluon Jet Quenching through $J/\psi$ Production in Heavy-Ion Collisions

    Shan-Liang Zhang🇨🇳 · Jinfeng Liao🇺🇸 · Guang-You Qin🇨🇳 · Enke Wang🇨🇳 · Hongxi Xing🇨🇳

    Jet quenching has long been regarded as one of the key signatures for the formation of quark-gluon plasma in heavy-ion collisions. Despite significant efforts, the separate identification of quark and gluon jet quenching has remained as a challenge. Here we show that $J/\psi$ in high transverse momentum ($p_{\text{T}}$) region provides a uniquely sensitive probe of in-medium gluon energy loss since its production at high $p_{\text{T}}$ is particularly dominated by gluon fragmentation. Such gluon-dominance is first demonstrated for the baseline of proton-proton collisions within the framework of leading power NRQCD factorization formalism. We then use the linear Boltzmann transport model combined with hydrodynamics for the simulation of jet-medium interaction in nucleus-nucleus collisions. The satisfactory description of experimental data on both nuclear modification factor $R_{\text{AA}}$ and elliptic flow $v_2$ reveals, for the first time, that the gluon jet quenching is the driving force for high $p_{\text{T}}$ $J/\psi$ suppression. This novel finding is further confirmed by the data-driven Bayesian analyses of relevant experimental measurements, from which we also obtain the first quantitative extraction of the gluon energy loss distribution in the quark-gluon plasma.

    hep-phhep-exnucl-exnucl-thSci.Bull.(2023)·17 citations
13. 13*

    Prospects for $B_{(s)}^0\to {\pi }^0{\pi }^0$ and $B_{(s)}^0\to \eta \eta$ modes and corresponding $CP$ asymmetries at Tera-$Z$

    Yuexin Wang🇨🇳 · Sébastien Descotes-Genon🇫🇷 · Olivier Deschamps🇫🇷 · Lingfeng Li🇺🇸 · Shanzhen Chen🇨🇳 · Yongfeng Zhu🇨🇳 · Manqi Ruan🇨🇳

    The physics potential of measuring $B_{(s)}^0\to {\pi }^0{\pi }^0$ and $B_{(s)}^0\to \eta \eta$ decays via four-photon final states at Tera-$Z$ phase of CEPC or FCC-ee is investigated in this paper. We propose an electromagnetic calorimeter (ECAL) with both high energy resolution and excellent separation power to efficiently reconstruct ${\pi }^0$ and $\eta$ from hadronic final states with high photon multiplicity. The resulting $B$-meson mass resolution is approximately 30 MeV, allowing 3 $\sigma$ separation between $B^0$ and $B_s^0$. With the assistance of the $b$-jet tagging, the relative sensitivities to $B^0\to {\pi }^0{\pi }^0$, $B_s^0\to {\pi }^0{\pi }^0$, $B^0\to \eta \eta$, and $B_s^0\to \eta \eta$ signal strengths at Tera-$Z$ are projected as 0.45%, 4.5%, 18%, and 0.95%, respectively. Their dependence on various detector performances is also discussed. In addition, $B^0\to {\pi }^0{\pi }^0$ and its two isospin-related modes are paid special attention due to their roles in the determination of the CKM angle $\alpha$ (${\varphi }_2$). The anticipated precisions of their branching-ratio and $CP$-asymmetry measurements at Tera-$Z$ are evaluated. We show that the measurement of the time-integrated $B^0\to {\pi }^0{\pi }^0$ $CP$ asymmetry at Tera-$Z$ is complementary to $B$-factory ones. The precision on $\alpha$ combining $Z$- and $B$-factory results reaches $0.4^{\circ }$, lower than the systematic uncertainties attached to isospin breaking.

    hep-phJHEP(2022)·12 citations
14. 14*

    Evidence for intrinsic charm quarks in the proton

    Richard D. Ball🇬🇧 · Alessandro Candido🇮🇹 · Juan Cruz-Martinez🇮🇹 · Stefano Forte🇮🇹 · Tommaso Giani🇳🇱 · Felix Hekhorn🇮🇹 · Kirill Kudashkin🇮🇹 · Giacomo Magni🇳🇱 · Juan Rojo🇳🇱

    The theory of the strong force, quantum chromodynamics, describes the proton in terms of quarks and gluons. The proton is a state of two up quarks and one down quark bound by gluons, but quantum theory predicts that in addition there is an infinite number of quark-antiquark pairs. Both light and heavy quarks, whose mass is respectively smaller or bigger than the mass of the proton, are revealed inside the proton in high-energy collisions. However, it is unclear whether heavy quarks also exist as a part of the proton wavefunction, which is determined by non-perturbative dynamics and accordingly unknown: so-called intrinsic heavy quarks. It has been argued for a long time that the proton could have a sizable intrinsic component of the lightest heavy quark, the charm quark. Innumerable efforts to establish intrinsic charm in the proton have remained inconclusive. Here we provide evidence for intrinsic charm by exploiting a high-precision determination of the quark-gluon content of the nucleon based on machine learning and a large experimental dataset. We disentangle the intrinsic charm component from charm-anticharm pairs arising from high-energy radiation. We establish the existence of intrinsic charm at the 3-standard-deviation level, with a momentum distribution in remarkable agreement with model predictions. We confirm these findings by comparing to very recent data on Z-boson production with charm jets from the LHCb experiment.

    hep-phhep-exhep-latnucl-ex+1Nature(2022)·132 citations
15. 15*

    Pion spectroscopy and dynamics using the holographic light-front Schrödinger equation and the 't Hooft equation

    Mohammad Ahmady🇨🇦 · Satvir Kaur🇨🇳 · Chandan Mondal🇨🇳 · Ruben Sandapen🇨🇦

    We show that the holographic Schrödinger equation of light-front chiral QCD, together with the 't Hooft equation of (1+1)-dimensional QCD in the large $N_c$ limit, can simultaneously describe pion spectroscopy as well as the pion decay constant, charge radius, electromagnetic form factor, photon-to-pion transition form factor, Parton Distribution Function (PDF) and Distribution Amplitude (DA). Furthermore, the chiral-limit constraints, as encoded in the Gell-Mann-Oakes-Renner (GMOR) relation, are satisfied.

    hep-phPLB(2023)·20 citations
16. 16*

    Exploring Higgs-Photon Production at the LHC

    Tisa Biswas🇮🇳 · Anindya Datta🇮🇳

    We have investigated the signal for physics beyond the Standard Model via Higgs plus photon final state, hitherto unobserved at the LHC, in the framework of Standard Model Effective Field Theory. Using the relevant dimension-6 operators, we probe two distinct classes of interactions, based on the Lorentz structure of Higgs couplings to gauge bosons and fermions. To begin with, constraints on the Wilson coefficients of these operators have been derived from existing experimental data. We then focus on the hadronic decay of the Higgs boson to two bottom quarks in the boosted regime, leading to a high $p_T$ fat-jet recoiling against a hard photon. Following a CMS Run II search for a resonance decaying into a Higgs boson and a photon, a detailed signal and background analysis for this channel has been done and limits on the relevant Wilson coefficients have been obtained. By performing a cut-based analysis, we identify some kinematic observables that distinguish between signal and SM background. Minimum values of the Wilson coefficients that will yield $3\sigma$ signal significance at the 14 TeV run of the LHC with $3000\mathrm{f}{\mathrm{b}}^{-1}$ data, have been obtained. A multivariate analysis using a boosted decision tree and exploiting the jet substructure techniques further help to isolate the regions of phase space where the contribution of SMEFT driven signal is significantly enhanced. Finally, we briefly discuss the parameter dependencies and interpretations of the allowed values of the coefficients on a particularly interesting UV complete model namely, Minimal Supersymmetric Standard Model.

    hep-phJHEP(2023)·8 citations
17. 17*

    Azimuthal di-jet correlations with parton branching TMD distributions

    A. Bermudez Martinez🇩🇪 · F. Hautmann🇨🇭

    The parton branching formulation of TMD evolution has recently been used to make predictions for jet observables at the Large Hadron Collider (LHC), including perturbative matching at next-to-leading order (NLO). This contribution presents results for the azimuthal \Delta-\phi correlations in events with di-jets at large transverse momentum. It focuses on the back-to-back region of large \Delta-\phi and discusses prospects for detailed studies of QCD dynamics in this region at the LHC.

    hep-ph10 citations
18. 18*

    Bouncing Dark Matter

    Lucas Puetter🇩🇪 · Joshua T. Ruderman🇺🇸 · Ennio Salvioni🇮🇹 · Bibhushan Shakya🇩🇪

    We present a novel mechanism for thermal dark matter production, characterized by a "bounce": the dark matter equilibrium distribution transitions from the canonical exponentially falling abundance to an exponentially rising one, resulting in an enhancement of the freezeout abundance by many orders of magnitude. We discuss several realizations of bouncing dark matter. The bounce allows the present day dark matter annihilation cross section to be significantly larger than the canonical thermal target, improving the prospects for indirect detection signals.

    hep-phastro-ph.COastro-ph.HEPRD(2024)·15 citations
19. 19*

    To Profile or To Marginalize -- A SMEFT Case Study

    Ilaria Brivio🇩🇪 · Sebastian Bruggisser🇩🇪 · Nina Elmer🇩🇪 · Emma Geoffray🇩🇪 · Michel Luchmann🇩🇪 · Tilman Plehn🇩🇪

    Global SMEFT analyses have become a key interpretation framework for LHC physics, quantifying how well a large set of kinematic measurements agrees with the Standard Model. This agreement is encoded in measured Wilson coefficients and their uncertainties. A technical challenge of global analyses are correlations. We compare, for the first time, results from a profile likelihood and a Bayesian marginalization for a given data set with a comprehensive uncertainty treatment. Using the validated Bayesian framework we analyse a series of new kinematic measurements. For the updated dataset we find and explain differences between the marginalization and profile likelihood treatments.

    hep-phSciPost Phys.(2024)·24 citations
20. 20*

    Heavy-Meson Masses in the Framework of Trigonometric Rosen-Morse Potential Using the Generalized Fractional Derivative

    M. Abu-Shady🇪🇬 · Etido P. Inyang🇳🇬

    Trigonometric Rosen-Morse Potential is employed as a mesonic potential interaction. The extended Nikiforov-Uvarov method is used to solve the N-radial Fractional Schrodinger equation analytically. Using the generalized fractional derivative, the energy eigenvalues are obtained in the fractional form. The current findings are used to calculate the masses of mesons such as charmonium, bottomonium, and heavy-light mesons. The current findings are superior to those of other recent studies and show good agreement with experimental data as a result, the fractional parameter is crucial in optimizing meson masses.

    hep-phEast Eur.J.Phys.(2022)·17 citations
21. 21*

    Infinite conformal symmetry and emergent chiral (super)fields of topologically non-trivial configurations: From Yang-Mills-Higgs to the Skyrme model

    Fabrizio Canfora🇨🇱 · Diego Hidalgo🇨🇱 · Marcela Lagos🇨🇱 · Enzo Meneses🇨🇱 · Aldo Vera🇨🇱

    The present manuscript discusses a remarkable phenomenon concerning non-linear and non-integrable field theories in $(3+1)$-dimensions, living at finite density and possessing non-trivial topological charges and non-Abelian internal symmetries (both local and global). With suitable types of ansätze, one can construct infinite-dimensional families of analytic solutions with non-vanishing topological charges (representing the Baryonic number) labelled by both two integers numbers and by free scalar fields in $(1+1)$-dimensions. These exact configurations represent $(3+1)$-dimensional topological solitons hosting $(1+1)$-dimensional chiral modes localized at the energy density peaks. First, we analyze the Yang-Mills-Higgs model, in which the fields depend on all the space-time coordinates (to keep alive the topological Chern-Simons charge), but in such a way to reduce the equations system to the field equations of two-dimensional free massless chiral scalar fields. Then, we move to the non-linear sigma model, showing that a suitable ansatz reduces the field equations to the one of a two-dimensional free massless scalar field. Then, we discuss the Skyrme model concluding that the inclusion of the Skyrme term gives rise to a chiral two-dimensional free massless scalar field (instead of a free massless field in two dimensions as in the non-linear sigma model) describing analytically spatially modulated Hadronic layers and tubes. The comparison of the present approach both with the instantons-dyons liquid approach and with Lattice QCD is shortly outlined.

    ↳ hep-thhep-phnucl-thPRD(2022)·14 citations
22. 22*

    Nuclear-level Effective Theory of $\mu \to e$ Conversion: Formalism and Applications

    W. C. Haxton🇺🇸 · Evan Rule🇺🇸 · Ken McElvain🇺🇸 · Michael J. Ramsey-Musolf🇨🇳

    New mu-to-e conversion searches aim to advance limits on charged lepton flavor violation (CLFV) by four orders of magnitude. By considering P and CP selection rules and the structure of possible charge and current densities, we show that rates are governed by six nuclear responses. To generate a microscopic formulation of these responses, we construct in non-relativistic effective theory (NRET) the CLFV nucleon-level interaction, then embed it in a nucleus. We discuss previous work, noting the lack of a systematic treatment of the various small parameters. Because the momentum transfer is comparable to the inverse nuclear size, a full multipole expansion of the response functions is necessary, a daunting task with Coulomb-distorted electron partial waves. We perform such an expansion to high precision by introducing a simplifying local electron momentum, treating the full set of 16 NRET operators. Previous work has been limited to the simplest charge/spin operators, ignored Coulomb distortion (or alternatively truncated the partial wave expansion) and the nucleon velocity operator, which is responsible for three of the response functions. This generates inconsistencies in the treatment of small parameters. We obtain a "master formula" for mu-to-e conversion that properly treats all such effects and those of the muon velocity. We compute muon-to-electron conversion rates for a series of experimental targets, deriving bounds on the coefficients of the CLFV operators. We discuss the nuclear physics: two types of coherence enhance certain CLFV operators and selection rules blind elastic mu-to-e conversion to others. We discuss the matching of the NRET onto higher level EFTs, and the relation to mu-to-e conversion to other CLFV tests. Finally we describe a publicly available script that can be used to compute mu-to-e conversion rates in nuclear targets.

    ↳ nucl-thhep-exhep-phnucl-exPRC(2023)·37 citations
23. 23*

    Scaling of kinematical, global observables, energy and entropy densities in p+p, p+Pb and Pb+Pb collisions from 0.01 to 13 TeV

    Eleazar Cuautle🇲🇽 · Edgar Domínguez Rosas🇲🇽 · Mario Rodríguez-Cahuantzi🇲🇽

    The multiplicity and average transverse momentum of the charged and identified particles produced in different kinds of colliding systems are an example of global observables used to characterize events over a wide range of energy. Studying these observables provides insights into the collective phenomena and the geometric scaling properties of the systems created in ultra-relativistic p-Pb, Pb-Pb, and even in p-p collisions. The first part of this work presents a study of these variables using different Monte Carlo event generators. It analyzes their sensitivity to find collective phenomena at 0.01, 0.9, 2.76, 7, and 13 TeV, finding a less satisfactory description as the energy decreases. The second part analyzes the average transverse momentum of charged hadrons as a function of the multiplicity for p-p, p-Pb, and Pb-Pb data from the CMS and ALICE experiments. Comparing with Monte Carlo event generators, we look for a possible scaling law of average transverse momentum scaled to the overlap transverse collision area. Additionally, the experimental data are used to compute thermodynamical quantities such as the energy and entropy densities in the Bjorken approach. The results are compared with predictions from EPOS and PYTHIA Monte Carlo event generators. We observe an excellent agreement for <pT> from p-p but not for thermodynamical observables, where a sudden rise in a small <pT> range resembles the lattice QCD results for the $ϵ/T^4$ as a function of the temperature; however, only the experimental data from p-p show a kind of saturation.

    ↳ nucl-exhep-phJ.Phys.G(2022)·1 citation
24. 24*

    Can primordial parity violation explain the observed cosmic birefringence?

    Tomohiro Fujita🇯🇵 · Yuto Minami🇯🇵 · Maresuke Shiraishi · Shuichiro Yokoyama🇯🇵

    Recently, the cross-correlation between $E$- and $B$-mode polarization of the cosmic microwave background (CMB), which is well explained by cosmic birefringence with rotation angle $\beta \approx 0.3$ deg, has been found in CMB polarization data. We carefully investigate the possibility of explaining the observed $EB$ correlation by the primordial chiral gravitational waves (CGWs), which can be generated in the parity-violating theories in the primordial Universe. We found that the CGWs scenario does not work due to the overproduction of the $BB$ auto-correlation which far exceeds the observed one by SPTPol and POLARBEAR.

    ↳ astro-ph.COgr-qchep-phPRD(2022)·27 citations
25. 25*

    Symmetry restoration in the vicinity of neutron stars with a nonminimal coupling

    Masato Minamitsuji🇵🇹 · Shinji Tsujikawa🇯🇵

    We propose a new model of scalarized neutron stars (NSs) realized by a self-interacting scalar field $\varphi$ nonminimally coupled to the Ricci scalar $R$ of the form $F(\varphi )R$. The scalar field has a self-interacting potential and sits at its vacuum expectation value ${\varphi }_v$ far away from the source. Inside the NS, the dominance of a positive nonminimal coupling over a negative mass squared of the potential leads to a symmetry restoration with the central field value ${\varphi }_c$ close to $0$. This allows the existence of scalarized NS solutions connecting ${\varphi }_v$ with ${\varphi }_c$ whose difference is significant, whereas the field is located in the vicinity of $\varphi ={\varphi }_v$ for weak gravitational stars. The Arnowitt-Deser-Misner mass and radius of NSs as well as the gravitational force around the NS surface can receive sizable corrections from the scalar hair, while satisfying local gravity constraints in the Solar system. Unlike the original scenario of spontaneous scalarization induced by a negative nonminimal coupling, the catastrophic instability of cosmological solutions can be avoided. We also study the cosmological dynamics from the inflationary epoch to today and show that the scalar field $\varphi$ finally approaches the asymptotic value ${\varphi }_v$ without spoiling a successful cosmological evolution. After $\varphi$ starts to oscillate about the potential minimum, the same field can also be the source for cold dark matter.

    ↳ gr-qcastro-ph.COhep-phhep-thPLB(2023)·4 citations
26. 26*

    Semirelativistic Potential Modelling of Bound States: Advocating Due Rigour

    Wolfgang Lucha🇦🇹

    The Poincaré-covariant quantum-field-theoretic description of bound states by the homogeneous Bethe-Salpeter equation usually exhibits an intrinsic complexity that can be attenuated by allowing this formalism to undergo various simplifications. The resulting approximate outcome's reliability can be assessed by applying several rigorous constraints on the nature of the bound-state spectra; most prominent here are existence, number and location of discrete eigenvalues.

    ↳ quant-phhep-phnucl-thEPJ Web Conf.(2022)·0 citations
27. 27*

    QCD at the Future Circular ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$ Collider

    Eduardo Ploerer (for the FCC collaboration)🇧🇪

    The Future Circular Collider in the ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$ configuration offers the opportunity to significantly improve SM measurements with dedicated runs at the Z-pole, WW threshold, ZH (240 GeV), and $\mathrm{t}\bar{\mathrm{t}}$ threshold. With a factor of approximately $10^5$ more statistics at the Z-pole and $10^4$ at the WW threshold than at LEP, the FCC-ee will enable the extraction of the strong coupling ${\alpha }_s$ at the per-mille level. Parton showering studies exploiting the pure gluon sample from $\mathrm{ZH}(\to \mathrm{gg})$ will greatly improve our understanding of gluon radiation and fragmentation, directly impacting quark vs gluon discrimination studies. Further possibilities include precision hadronization studies and colour reconnection studies at the WW threshold. Some elements of the rich precision QCD program of the FCC-ee are outlined below.

    ↳ hep-exhep-ph2 citations
28. 28*

    Vorticity of Twisted Spinor Fields

    Andrei Afanasev🇺🇸 · Carl E. Carlson🇺🇸 · Asmita Mukherjee🇮🇳

    Spinor fields with a vortex structure in free space that allow them to have arbitrary integer orbital angular momentum along the direction of motion have been studied for some time. Relatively new is the observation in a certain context that the vortex center of this field structure is, unlike a classical whirlpool, not singular. We point out that there are several ways to calculate the local velocity of the spinor field and that all but one show a singular vorticity at the vortex line. That one, using the Dirac bilinear current with no derivatives, is the only one so far (to our knowledge) studied in the literature in this context and we further show how to understand an apparent conflict in the existing results.

    ↳ quant-phhep-ph0 citations
29. 29*

    Searching for axion-like particles through CMB birefringence from string-wall networks

    Mudit Jain🇺🇸 · Ray Hagimoto🇺🇸 · Andrew J. Long🇺🇸 · Mustafa A. Amin🇺🇸

    Axion-like particles (ALPs) can form a network of cosmic strings and domain walls that survives after recombination and leads to anisotropic birefringence of the cosmic microwave background (CMB). In addition to studying cosmic strings, we clarify and emphasize how the formation of ALP-field domain walls impacts the cosmic birefringence signal; these observations provide a unique way of probing ALPs with masses in the range $3H_0\lesssim m_a\lesssim 3H_{\mathrm{cmb}}$. Using measurements of CMB birefringence from several telescopes, we find no evidence for axion-defect-induced anisotropic birefringence of the CMB. We extract constraints on the model parameters that include the ALP mass $m_a$, ALP-photon coupling $\mathcal{A}\propto g_{a\gamma \gamma }{f}_a$, the domain wall number $N_{\mathrm{dw}}$, and parameters characterizing the abundance and size of defects in the string-wall network. Considering also recent evidence for isotropic CMB birefringence, we find it difficult to accommodate this with the non-detection of anisotropic birefringence under the assumption that the signal is generated by an ALP defect network.

    ↳ astro-ph.COhep-phJCAP(2022)·48 citations
30. 30*

    Experimental Search For Interference Effects In qq At LHC

    Arman Boroumand Naeini (Department of Physics, University of Warwick, United Kingdom)🇬🇧

    At present, the simulations for hadronic Z decay used at the Large Hadron Collider (LHC) neglect the effects of interference between the electroweak production of the hadronic Z boson and the Quantum Chromodynamics (QCD) production of $q\bar{q}$. Indeed, the diboson Monte Carlo samples are generated independently from QCD processes. The purpose of this project is to assess the validity of this simulation approach by studying these interference effects, comparing Monte Carlo samples to experimental data. In particular, regions of low transverse momenta are explored for the first time, revealing new challenges unique to these regions. Three sigma evidence for ZZ $\to$ $b\bar{b}\mu \bar{\mu }$ is found at low transverse momenta for the very first time. However, the error on the mass peak is too large to provide any sufficient evidence for interference. As such, there is no evidence to suggest that the simulation strategies adopted at the LHC are inadequate.

    ↳ hep-exhep-ph0 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.