Fri·Apr 23, 2021Friday·April 23, 2021

1. 01*

   Probing Extended Scalar Sectors with Precision $e^{+}{e}^{-}\to Zh$ and Higgs Diphoton Studies

   Michael J. Ramsey-Musolf🇨🇳 · Jiang-Hao Yu🇨🇳 · Jia Zhou🇺🇸

   We compute the one-loop corrections to $\sigma (e^{+}{e}^{-}\to Zh)$ arising from representative extended Standard Model scalar sector scenarios. According to the new scalar $\mathrm{SU}(2{)}_{\mathrm{L}}$ representations, we consider the inert doublet, real and complex triplet, quintuplet, and septuplet models. With the sub-percent level precision expected for prospective future $e+e-$ collider measurements of $\sigma (e^{+}{e}^{-}\to Zh)$, studies of the Higgsstrahlung process will probe extended scalar sector particle spectrum and interactions in a manner complementary to direct searches at the Large Hadron Collider and possible future $pp$ colliders. We also compare with the sensitivity of future Higgs diphoton decay rate measurements. We find that the $\sigma (e^{+}{e}^{-}\to Zh)$ and $\Gamma (h\to \gamma \gamma )$ complementarity is particularly pronounced for the complex triplet model.

   hep-phJHEP(2021)·12 citations
2. 02*

   Probing the minimal $U(1{)}_X$ model at future electron-positron colliders via the fermion pair-production channel

   Arindam Das🇰🇷 · P. S. Bhupal Dev🇺🇸 · Yutaka Hosotani🇯🇵 · Sanjoy Mandal🇪🇸

   The minimal $U(1{)}_X$ extension of the Standard Model (SM) is a well-motivated new physics scenario, where anomaly cancellation dictates new neutral gauge boson ($Z^{\prime }$) couplings with the SM fermions in terms of the $U(1{)}_X$ charges of the new scalar fields. We investigate the SM charged fermion pair-production process for different values of these $U(1{)}_X$ charges at future $e^{-}{e}^{+}$ colliders: $e^{+}{e}^{-}\to f\bar{f}$. Apart from the standard $\gamma$ and $Z$-mediated processes, this model features additional $s$-channel (or both $s$ and $t$-channel when $f=e^{-}$) $Z^{\prime }$ exchange which interferes with the SM processes. We first estimate the bounds on the $U(1{)}_X$ coupling $(g^{\prime })$ and the $Z^{\prime }$ mass $(M_{Z^{\prime }})$ considering the latest dilepton and dijet constraints from the heavy resonance searches at the LHC. Then using the allowed values of $g^{\prime }$, we study the angular distributions, forward-backward $({\mathcal{A}}_{\mathrm{FB}})$, left-right $({\mathcal{A}}_{\mathrm{LR}})$ and left-right forward-backward $({\mathcal{A}}_{\mathrm{LR},\mathrm{FB}})$ asymmetries of the $f\bar{f}$ final states. We find that these observables can show substantial deviations from the SM results in the $U(1{)}_X$ model, thus providing a powerful probe of the multi-TeV $Z^{\prime }$ bosons at future $e^{+}{e}^{-}$ colliders.

   hep-phhep-exPRD(2022)·65 citations
3. 03*

   Generic One-Loop Matching Conditions for Rare Meson Decays

   Fady Bishara🇩🇪 · Joachim Brod🇺🇸 · Martin Gorbahn🇬🇧 · Ulserik Moldanazarova🇬🇧

   Leptonic and semileptonic meson decays that proceed via flavour-changing neutral currents provide excellent probes of physics of the standard model and beyond. We present explicit results for the Wilson coefficients of the weak effective Lagrangian for these decays in any perturbative model in which these processes proceed via one-loop contributions. We explicitly show that our results are finite and gauge independent, and provide Mathematica code that implements our results in an easily usable form.

   hep-phJHEP(2021)·11 citations
4. 04*

   Dark matter implications of the KATRIN neutrino mass experiment

   Thede de Boer🇩🇪 · Michael Klasen🇩🇪 · Caroline Rodenbeck🇩🇪 · Sybrand Zeinstra🇩🇪

   We studied the effects of the absolute neutrino mass scale in the scotogenic radiative seesaw model. From a scan over the parameter space of this model, a linear relation between the absolute neutrino mass and the dark sector-Higgs coupling ${\lambda }_5=3.1\times 10^{-9}{m}_{{\nu }_e}/$eV has been established. With the projected sensitivity of the KATRIN experiment nearing cosmologically favored values, a neutrino mass measurement would fix the value of ${\lambda }_5$. Subsequent correlations between the DM mass and the Yukawa coupling between DM and the SM leptons can probe the fermion DM parameter space, when lepton flavor violation constraints are also considered. The results are independent of the neutrino mass hierarchy and the CP phase.

   hep-ph0 citations
5. 05*

   Jet mass distribution in Higgs/vector boson + jet events at hadron colliders with $k_t$ clustering

   Naima Ziani🇩🇿 · Kamel Khelifa-Kerfa🇸🇦 · Yazid Delenda🇩🇿

   We address the issues of clustering and non-global logarithms for jet shapes in the process of production of a Higgs/vector boson associated with a single hard jet at hadron colliders. We perform an analytical fixed-order calculation up to second order in the coupling as well as an all-orders estimation for the specific invariant mass distribution of the highest-$p_t$ jet, for various jet algorithms. Our results are derived in the eikonal (soft) limit and are valid up to next-to-leading logarithmic accuracy. We perform a matching of the resummed distribution to next-to-leading order results from MCFM and compare our findings with the outputs of the Monte Carlo event generators Pythia 8 and Herwig 7. After accounting for non-perturbative effects we compare our results with available experimental data from the CMS collaboration for the Z + jet production. We find good agreement over a wide range of the observable.

   hep-phEPJC(2021)·18 citations
6. 06*

   Tera-Zooming in on light (composite) axion-like particles

   G. Cacciapaglia🇫🇷 · A. Deandrea🇫🇷 · A.M. Iyer🇫🇷 · K. Sridhar🇮🇳

   The Tera-Z phase of future $e^{+}{e}^{-}$ colliders, FCC-ee and CepC, is a goldmine for exploring $Z$ portal physics. We focus on axion-like particles (ALPs) that can be produced via $Z$ decays with a monochromatic photon. As a template model, we consider composite Higgs models with a light pseudo-scalar that couples through the Wess-Zumino-Witten term to the electroweak gauge bosons. For both photophilic and photophobic cases, we show that the Tera-Z can probe composite scales up to $100$s of TeV, well beyond the capability of the LHC and current precision physics. Our results also apply to generic ALPs and, in particular, severely constrain models that explain the muon $g-2$ anomaly.

   hep-phPRD(2022)·20 citations
7. 07*

   Theoretical description of the neutron beta decay in the standard model at the level of 10^{-5}

   A. N. Ivanov🇦🇹 · R. Höllwieser🇩🇪 · N. I. Troitskaya🇦🇹 · M. Wellenzohn🇦🇹 · Ya. A. Berdnkov🇷🇺

   In the framework of the Standard Model (SM) a theoretical description of the neutron beta decay is given at the level of 10^{-5}. The neutron lifetime and correlation coefficients of the neutron beta decay for a polarized neutron, a polarized electron and an unpolarized proton are calculated at the account for i) the radiative corrections of order O(\alpha E_e/m_N) ~ 10^{-5} to Sirlin's outer and inner radiative corrections of order O(\alpha/\pi), ii) the corrections of order O(E^2_e/m^2_N) ~ 10^{-5}, caused by weak magnetism and proton recoil, and iii) Wilkinson's corrections of order 10^{-5} (Wilkinson, Nucl. Phys. A377, 474 (1982)). These corrections define the SM background of the theoretical description of the neutron beta decay at the level of 10^{-5}, which is required by experimental searches of interactions beyond the SM with experimental uncertainties of a few parts of 10^{-5}.

   hep-phnucl-exnucl-thPRD(2021)·9 citations
8. 08*

   Nambu--Jona-Lasinio $SU(3)$ model constrained by lattice QCD: thermomagnetic effects in the magnetization

   William R. Tavares🇧🇷 · Ricardo L. S. Farias🇧🇷 · Sidney S. Avancini🇧🇷 · Varese S. Timóteo🇧🇷 · Marcus B. Pinto🇧🇷 · Gastão Krein🇧🇷

   We use a three-flavor Nambu--Jona-Lasinio model to study the thermodynamics of strange quark matter under a strong magnetic field. The model Lagrangian features flavor SU(3) four-quark interactions and six-quark interactions that break the UA(1) symmetry. We incorporate thermomagnetic effects in the four-quark coupling. The model predicts magnetic catalysis at low temperatures and inverse magnetic catalysis at temperatures close to the pseudocritical temperature of the QCD transition, in agreement with lattice QCD results. We compute the pressure at the mean field level and obtain the magnetization of quark matter. We adopt the recently proposed vacuum magnetic regularization (VMR) scheme, in that divergent quark mass independent contributions are not subtracted, thereby avoiding unphysical results for the magnetization. We devote special attention to the renormalized magnetization, a projected quantity that allows for direct comparisons with lattice QCD simulations. Our results are in very good agreement with lattice data indicating a paramagnetic behavior for quark matter.

   hep-phhep-latnucl-thEPJA(2021)·23 citations
9. 09*

   Prompt production of the hidden charm pentaquarks in the LHC

   Pan Ling🇨🇳 · Xiao-Hu Dai🇨🇳 · Meng-Lin Du🇪🇸 · Qian Wang🇨🇳

   Motivated by the observation of the first hidden charm pentaquarks by the LHCb collaboration in 2015 and the updated analysis with an order-of-magnitude larger data set in 2019, we estimate their cross sections for the prompt production as well as their heavy quark spin partners, in the ${\Sigma }_c^{(\ast )}{\bar{D}}^{(\ast )}$ hadronic molecular picture, at the center-of-mass energy $7\mathrm{TeV}$ in the $pp$ collision. Their cross sections are several $\mathrm{nb}$ and we would expect several tens hidden charm pentaquark events in the LHC based on its current integrated luminosity. The cross sections show a sizable deviation of the cross sections for hidden charm pentaquarks with the third isospin component $I_z=+\frac{1}{2}$ ($P_c^{+}$) from those with $I_z=-\frac{1}{2}$ ($P_c^0$). The cross sections decrease dramatically with the increasing transverse momentum. Our study can also tell where to search for the missing hidden charm pentaquarks. The confirmation of the complete hidden charm pentaquarks in the heavy quark symmetry would further verify their ${\Sigma }_c^{(\ast )}{\bar{D}}^{(\ast )}$ molecular interpretation. In addition, the relative strength among these cross sections for pentaquarks can help us to identify the quantum numbers of the $P_c(4440)$ and $P_c(4457)$.

   hep-phhep-exEPJC(2021)·16 citations
10. 10*

    WHIZARD 3.0: Status and News

    Pascal Stienemeier🇩🇪 · Simon Braß🇩🇪 · Pia Bredt🇩🇪 · Wolfgang Kilian🇩🇪 · Nils Kreher🇩🇪 · Thorsten Ohl🇩🇪 · Jürgen Reuter🇩🇪 · Vincent Rothe🇩🇪 · Tobias Striegl🇩🇪

    This article summarizes the talk given at the LCWS 2021 conference on the status and news of the WHIZARD Monte Carlo event generator. We presented its features relevant for the physics program of future lepton and especially linear colliders as well as recent developments towards including NLO perturbative corrections and a UFO interface to study models beyond the Standard Model. It takes as reference the version 3.0.0$\beta$ released in August 2020 and additionally discusses the developments that will be included in the next major version 3.0.0 to be released in April 2021.

    hep-ph14 citations
11. 11*

    Polarization and Correlation Effects in Lepton Flavor Violated Decays Induced by Axion-Like Particle

    Kai Ma🇨🇳

    Lepton flavor violated processes are strongly suppressed in the Standard Model, but can be sizable in some extended models. The current experimental bounds on decay modes ${\ell }^{\prime \pm }\to a{\ell }^{\pm }$ are much weaker than the other processes because of the huge irreducible backgrounds ${\ell }^{\prime \pm }\to {\ell }^{\pm }{\bar{\nu }}_{\ell }{\nu }_{{\ell }^{\prime }}$. In this paper, we study polarization effects of both the signals and backgrounds. We find that signals and backgrounds have distinctive polarization effects, and for the irreducible backgrounds both longitudinal and transverse polarization effects survive when the relative momentum of the two neutrinos are integrated out. At low energy $e^{+}{e}^{-}$ collider, for instance the Belle II experiment, leptons are generated in pair but with no net polarization. However, we show that polarization correlation of the lepton pair is a useful observable for probing the signal. More interestingly, the polarization correlation depends on product of scalar and pseudo-scalar couplings, and hence are sensitive to their relative sign. Because kinematical reconstruction or tagging is not necessary, number of the available signal events increases significantly.

    hep-phhep-ex10 citations
12. 12*

    Leptoquarks and Matter Unification: Flavor Anomalies and the Muon $g-2$

    Pavel Fileviez Perez🇺🇸 · Clara Murgui🇺🇸 · Alexis D. Plascencia🇺🇸

    We discuss the minimal theory for quark-lepton unification at the low scale. In this context, the quarks and leptons are unified in the same representations and neutrino masses are generated through the inverse seesaw mechanism. The properties of the leptoquarks predicted in this theory are discussed in detail and we investigate the predictions for the leptonic and semi-leptonic decays of mesons. We study the possibility to explain the current value of ${\mathcal{R}}_K$ reported by the LHCb collaboration and the value of the muon anomalous magnetic moment reported by the Muon $g-2$ experiment at Fermilab.

    hep-phhep-exPRD(2021)·62 citations
13. 13*

    Sterile neutrino dark matter in a U(1) extension of the standard model

    Sho Iwamoto🇭🇺 · Károly Seller🇭🇺 · Zoltán Trócsányi🇭🇺

    We explore the parameter space of a U(1) extension of the standard model -- also called the super-weak model -- from the point of view of explaining the observed dark matter energy density in the Universe. The new particle spectrum contains a complex scalar singlet and three right-handed neutrinos, among which the lightest one is the dark matter candidate. We explore both freeze-in and freeze-out mechanisms of dark matter production. In both cases, we find regions in the plane of the super-weak coupling vs. the mass of the new gauge boson that are not excluded by current experimental constraints. These regions are distinct and the one for freeze-out will be explored in searches for neutral gauge boson in the near future.

    hep-phastro-ph.COJCAP(2022)·30 citations
14. 14*

    Pair production seeded by electrons in noble gases as a method for the laser intensity diagnostics

    I. A. Aleksandrov🇷🇺 · A. A. Andreev🇷🇺

    In this study we explore the possibility of using the process of electron-positron pair creation in strong laser fields as a tool for measuring the intensity of the corresponding laser radiation. In the initial state we consider either free electron gas or gas of neutral xenon, the electrons of which get ionized. Once these seed electrons gain sufficient energy in the external laser field, they can emit high-energy photons which subsequently decay producing electron-positron pairs via the Breit-Wheeler mechanism. By detecting the resulting positrons, one can recover the value of the laser intensity by means of the one-to-one correspondences deduced in the present investigation. We analyze two different configurations of the external field: the setup involving an individual focused laser pulse and the combination of two counterpropagating laser pulses. Performing numerical calculations and analyzing their accuracy, we demonstrate that based on our estimates, the laser intensity can be determined within the range $10^{23}$-$10^{26}\text{W}/{\text{cm}}^2$ with a relative uncertainty of $10$-$50\%$.

    ↳ physics.plasm-phhep-phPRA(2021)·3 citations
15. 15*

    Symmetry from Entanglement Suppression

    Ian Low🇺🇸 · Thomas Mehen🇺🇸

    Symmetry is among the most fundamental and powerful concepts in nature, whose existence is usually taken as given, without explanation. We explore whether symmetry can be derived from more fundamental principles from the perspective of quantum information. Starting with a two-qubit system, we show there are only two minimally entangling logic gates: the Identity and the SWAP, where SWAP interchanges the two states of the qubits. We further demonstrate that, when viewed as an entanglement operator in the spin-space, the $S$-matrix in the two-body scattering of fermions in the $s$-wave channel is uniquely determined by unitarity and rotational invariance to be a linear combination of the Identity and the SWAP. Realizing a minimally entangling $S$-matrix would give rise to global symmetries, as exemplified in Wigner's spin-flavor symmetry and Schrödinger's conformal invariance in low energy Quantum Chromodynamics. For $N_q$ species of qubit, the Identity gate is associated with an $[SU(2){]}^{N_q}$ symmetry, which is enlarged to $SU(2N_q)$ when there is a species-universal coupling constant.

    ↳ hep-thhep-lathep-phnucl-th+1PRD(2021)·98 citations
16. 16*

    Revisiting the compatibility problem between the gauge principle and the observability of the canonical orbital angular momentum in the Landau problem

    Masashi Wakamatsu🇯🇵 · Yoshio Kitadono🇨🇳 · Liping Zou🇨🇳 · Pengming Zhang🇨🇳

    As is widely-known, the eigen-functions of the Landau problem in the symmetric gauge are specified by two quantum numbers. The first is the familiar Landau quantum number $n$, whereas the second is the magnetic quantum number $m$, which is the eigen-value of the canonical orbital angular momentum (OAM) operator of the electron. The eigen-energies of the system depend only on the first quantum number $n$, and the second quantum number $m$ does not correspond to any direct observables. This seems natural since the canonical OAM is generally believed to be a {\it gauge-variant} quantity, and observation of a gauge-variant quantity would contradict a fundamental principle of physics called the {\it gauge principle}. In recent researches, however, Bliohk et al. analyzed the motion of helical electron beam along the direction of a uniform magnetic field, which was mostly neglected in past analyses of the Landau states. Their analyses revealed highly non-trivial $m$-dependent rotational dynamics of the Landau electron, but the problem is that their papers give an impression that the quantum number $m$ in the Landau eigen-states corresponds to a genuine observable. This compatibility problem between the gauge principle and the observability of the quantum number $m$ in the Landau eigen-states was attacked in our previous letter paper. In the present paper, we try to give more convincing answer to this delicate problem of physics, especially by paying attention not only to the {\it particle-like} aspect but also to the {\it wave-like} aspect of the Landau electron.

    ↳ quant-phhep-phnucl-thphysics.opticsAnnals Phys.(2021)·8 citations
17. 17*

    Prerequisites for heavy quark coalescence in heavy-ion collisions

    Taesoo Song🇩🇪 · Gabriele Coci🇩🇪

    The coalescence model assumes instant formation of a bound state from unbound particles based on the overlapping of two states in spatial and momentum spaces and quantum numbers. Therefore, applied to the hadronization of partons, it provides a snapshot of a Quark-Gluon Plasma (QGP) just before hadronization. We use the coalescence model for the formation of the ground state of open heavy flavor and the statistical model for heavier states. Assuming that all heavy flavors in thermal equilibrium hadronize through the coalescence, we find that the QGP just before hadronization is not composed of completely randomized partons but must have strong correlations in color charges as well as in momentum and/or coordinate spaces between heavy quark and light (anti-)quark.

    ↳ nucl-thhep-lathep-phNPA(2022)·11 citations
18. 18*

    Sub-TeV hadronic interaction model differences and their impact on air showers

    Álvaro Pastor-Gutiérrez🇩🇪 · Harm Schoorlemmer🇩🇪 · Robert Daniel Parsons🇩🇪 · Michael Schmelling🇩🇪

    In the sub-TeV regime, the most widely used hadronic interaction models disagree significant lying their predictions for post-first interaction and ground-level particle spectra from cosmic ray induced air showers. These differences generate an important source of systematic uncertainty in their experimental use. We investigate the nature and impact of model uncertainties through a simultaneous analysis of ground level particles and first interaction scenarios. We focus on air shower primaries with energies close to the transition between high and low energy hadronic interaction models, where the dissimilarities have been shown to be the largest and well within the range of accelerator measurements. Interaction models are shown to diverge as several shower scenarios are compared, reflecting intrinsic differences in the model theoretical frameworks. Finally, we discuss the importance of interactions in the energy regime where the switching between models occurs (<1 TeV) and the effect of the choice of model on the number of hadronic interactions within cosmic ray induced air showers of higher energies.

    ↳ astro-ph.HEhep-phEPJC(2021)·8 citations
19. 19*

    Color Transparency and the Proton Form Factor- Feynman Wins

    Olivia Caplow-Munro🇺🇸 · Gerald A. Miller🇺🇸

    A recent experiment [{\bf Phys. Rev. Lett. 126,082301 (2021)}] used the $(e,e^{\prime }p)$ reaction on ${}^{12}$C to search for the effects of color transparency (the absence of final state interactions). Color transparency was said to be ruled out. The ability to observe the effects of color transparency depends on the ability of a putative point-like-configuration (PLC), formed in a high-momentum transfer coherent reaction, to escape the nucleus without expanding its size. We study the expansion aspect of color transparency using superconformal baryon-meson symmetry and light-front holographic QCD. A new formalism is obtained and used to analyze the recent experiment. The resulting conclusion is that effects of expansion would not be sufficiently significant in causing final state interactions to occur. Therefore we conclude that a PLC was not formed. This means that the Feynman mechanism involving virtual photon absorption on a single high momentum quark is responsible for high momentum electromagnetic form factor of the proton.

    ↳ nucl-thhep-phnucl-exPRC(2021)·17 citations
20. 20*

    Asymptotic nonlocality

    Jens Boos🇺🇸 · Christopher D. Carone🇺🇸

    We construct a theory of real scalar fields that interpolates between two different theories: a Lee-Wick theory with $N$ propagator poles, including $N-1$ Lee-Wick partners, and a nonlocal infinite-derivative theory with kinetic terms modified by an entire function of derivatives with only one propagator pole. Since the latter description arises when taking the $N\to \infty$ limit, we refer to the theory as "asymptotically nonlocal." Introducing an auxiliary-field formulation of the theory allows one to recover either the higher-derivative form (for any $N$) or the Lee-Wick form of the Lagrangian, depending on which auxiliary fields are integrated out. The effective scale that regulates quadratic divergences in the large-$N$ theory is the would-be nonlocal scale, which can be hierarchically lower than the mass of the lightest Lee-Wick resonance. We comment on the possible utility of this construction in addressing the hierarchy problem.

    ↳ hep-thhep-phPRD(2021)·13 citations
21. 21*

    Limits on Sub-GeV Dark Matter from the PROSPECT Reactor Antineutrino Experiment

    M. Andriamirado🇺🇸 · A. B. Balantekin🇺🇸 · H. R. Band🇺🇸 · C. D. Bass🇺🇸 · D. E. Bergeron🇺🇸 · N. S. Bowden🇺🇸 · C. D. Bryan🇺🇸 · T. Classen🇺🇸 · A. J. Conant🇺🇸 · G. Deichert🇺🇸 · M. V. Diwan🇺🇸 · M. J. Dolinski🇺🇸 and 46 other authors

    If dark matter has mass lower than around 1 GeV, it will not impart enough energy to cause detectable nuclear recoils in many direct-detection experiments. However, if dark matter is upscattered to high energy by collisions with cosmic rays, it may be detectable in both direct-detection experiments and neutrino experiments. We report the results of a dedicated search for boosted dark matter upscattered by cosmic rays using the PROSPECT reactor antineutrino experiment. We show that such a flux of upscattered dark matter would display characteristic diurnal sidereal modulation, and use this to set new experimental constraints on sub-GeV dark matter exhibiting large interaction cross-sections.

    ↳ hep-exhep-phPRD(2021)·58 citations
22. 22*

    Swampland Conditions for Higher Derivative Couplings from CFT

    Sandipan Kundu🇺🇸

    There are effective field theories that cannot be embedded in any UV complete theory. We consider scalar effective field theories, with and without dynamical gravity, in $D$-dimensional anti-de Sitter (AdS) spacetime with large radius and derive precise bounds (analytically) on the coupling constants of higher derivative interactions ${\varphi }^2{\square }^k{\varphi }^2$ by only requiring that the dual CFT obeys the standard conformal bootstrap axioms. In particular, we show that all such coupling constants, for even $k\ge 2$, must satisfy positivity, monotonicity, and log-convexity conditions in the absence of dynamical gravity. Inclusion of gravity only affects constraints involving the ${\varphi }^2{\square }^2{\varphi }^2$ interaction which now can have a negative coupling constant. Our CFT setup is a Lorentzian four-point correlator in the Regge limit. We also utilize this setup to derive constraints on effective field theories of multiple scalars. We argue that similar analysis should impose nontrivial constraints on the graviton four-point scattering amplitude in AdS.

    ↳ hep-thgr-qchep-phJHEP(2022)·29 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.