Fri·Dec 31, 2021Friday·December 31, 2021

1. 01*

   Backreaction of mesonic fluctuations on the axial anomaly at finite temperature

   G. Fejos🇭🇺 · A. Patkos🇭🇺

   The impact of mesonic fluctuations on the restoration of the $U_A(1)$ anomaly is investigated nonperturbatively for three flavors at finite temperature in an effective model setting. Using the functional renormalization group, the dressed, fully field-dependent Kobayashi-Maskawa--'t Hooft (KMT) anomaly coupling is computed. It is found that mesonic fluctuations strengthen this signature of the $U_A(1)$ breaking as the temperature increases. On the other hand, when instanton effects are included by parametrizing the explicit temperature dependence of the bare anomaly parameter in consistency with the semiclassical result for the tunneling amplitude, a natural tendency appears diminishing the anomaly at high temperatures. As a result of the two competing effects, the dressed KMT coupling shows a well-defined intermediate strengthening behavior around the chiral (pseudo)transition temperature before the axial anomaly gets fully suppressed at high temperature. As a consequence, we conclude that below $T\sim 200\text{MeV}$ the $U_A(1)$ anomaly is unlikely to be effectively restored. Robustness of the conclusions against different assumptions for the temperature dependence of the bare anomaly coefficient is investigated in detail.

   hep-phPRD(2022)·20 citations
2. 02*

   Nonperturbative light-front effective potential for static sources in quenched scalar Yukawa theory

   Sophia S Chabysheva🇺🇸 · John R Hiller🇺🇸

   We compute an effective potential between two fixed sources in light-front quantization of a quenched scalar Yukawa theory that models the interaction of complex scalar fields through the exchange of a neutral scalar. Despite the breaking of explicit rotational symmetry by the use of light-front coordinates, the effective potential is rotationally symmetric and matches the standard Yukawa potential for scalar exchange. The neutral scalar field is represented by a coherent state, which is obtained nonperturbatively as an eigenstate of our model Hamiltonian, with the eigenenergy determining the effective potential. The sources are represented by wave packets that are fixed with respect to ordinary time, but move in light-front coordinates. The theory is quenched, to remove pair-production processes that would otherwise cause the spectrum to be unbounded from below.

   hep-phPRD(2022)·5 citations
3. 03*

   On the mass of the glueballonium

   Enrico Trotti🇵🇱 · Francesco Giacosa🇵🇱

   According to lattice simulations and other theoretical approaches, the scalar glueball is the lightest state in the Yang-Mills sector of QCD. Since within this sector the scalar glueball is stable, the scattering between two glueballs is a well-defined process. Moreover, a glueball-glueball bound state, called glueballonium, might exist if the attraction turns out to be large enough. In this work, we concentrate on the formation of the glueballonium in the context of the dilaton potential. In particular, we investigate the parameter values for which such a glueballonium emerges.

   hep-phRev.Mex.Fis.Suppl.(2022)·4 citations
4. 04*

   Single production of vectorlike $B$ quarks at the CLIC

   Jin-Zhong Han🇨🇳 · Jing Yang🇨🇳 · Shuai Xu🇨🇳 · Han-Kui Wang🇨🇳

   The vector-like quarks are predicted in many new physics scenarios beyond the Standard Model~(SM) and could be seen potential signatures of new physics at the TeV energy scale. In this work, we study single production of exotic singlet and doublet vectorlike bottom quarks (VLQ-$B$) at future Compact Linear Collider~(CLIC) via the process $e^{+}{e}^{-}\to B\bar{b}$ with the decay channel $B\to bZ$ and two types of modes: $Z\to {\ell }^{+}{\ell }^{-}$ and $Z\to \nu \bar{\nu }$. We calculate the cross sections of signal and relevant SM backgrounds. After a fast simulation of the signal and background events, the exclusion limit at 95\% confidence level and $5\sigma$ discovery prospects on the parameters (the coupling strength ${\kappa }_B$ and the VLQ-$B$ mass) have been, respectively, presented at the future CLIC with centre of mass energy $\sqrt{s}=3$ TeV and integrated luminosity of 5~ab${}^{-1}$.

   hep-phPRD(2022)·20 citations
5. 05*

   Perturbative and non-perturbative interactions between heavy quarks and quark-gluon plasma within a unified approach

   Wen-Jing Xing🇨🇳 · Guang-You Qin🇨🇳 · Shanshan Cao🇨🇳

   While perturbative QCD is sufficient for understanding the color, mass and energy dependences of parton energy loss and jet quenching at large transverse momentum in heavy-ion collisions, a simultaneous description of heavy flavor nuclear modification factor $R_{\mathrm{AA}}$ and elliptic flow coefficient $v_2$ at low and intermediate $p_{\mathrm{T}}$ still remains a challenge due to the effects from non-perturbative interactions. In this work, we extend the linear Boltzmann transport model by implementing a generalized Cornell-type potential that incorporates both short-range Yukawa interaction and long-range color confining interaction between heavy quarks and the QGP medium. Combining our new approach for heavy-quark-QGP interaction with a (3+1)-dimensional hydrodynamic model CLVisc for the QGP evolution and a hybrid fragmentation-coalescence model for heavy quark hadronization, we obtain a satisfactory description of heavy meson $R_{\mathrm{AA}}$ and $v_2$ from low to intermediate to high $p_{\mathrm{T}}$ observed at both RHIC and the LHC. By model-data-comparison, we extract for the first time the in-medium heavy quark potential from open heavy flavor measurements; the result is in agreement with the lattice QCD calculation. Our study indicates that while jet quenching at high $p_{\mathrm{T}}$ is dominated by perturbative QCD interactions, non-perturbative interactions are indispensible for understanding heavy flavor quenching and flow at low and intermediate $p_{\mathrm{T}}$.

   hep-phnucl-exnucl-thPLB(2023)·35 citations
6. 06*

   Decoding Dark Matter at future $e^{+}{e}^{-}$ colliders

   Alexander Belyaev🇬🇧 · Arran Freegard🇬🇧 · Ilya F. Ginzburg🇷🇺 · Daniel Locke🇬🇧 · Alexander Pukhov🇷🇺

   We explore the potential of the $e^{+}{e}^{-}$ colliders to discover dark matter and determine its properties such as mass and the spin. For this purpose we study spin zero and spin one-half cases of dark matter, $D$ which belongs to $SU(2)$ weak doublet and therefore has the charged doublet partner, $D^{+}$. For the case of scalar dark matter we chose Inert Doublet Model, while for the case of fermion dark matter we suggest the new minimal fermion dark matter model with only three parameters. We choose two benchmarks for the models under study which provide the correct amount of observed DM relic density and consistent with the current DM searches. We focus on the particular process $e^{+}{e}^{-}\to D^{+}{D}^{-}\to DD{W}^{+}{W}^{-}\to DD(q\bar{q})({\mu }^{\pm }\nu )$ at 500 GeV ILC collider which gives rise to the "di-jet +$\mu$ + missing $E_T$" signature and study it at the level of fast detector simulation, taking into account Bremsstrahlung and ISR effects. We have found that two kinematical observables -- the energy of the muon, $E_{\mu }$, and the angular distribution of $W$-boson, reconstructed from di-jet, $\cos {\theta }_{jj}$ are very powerful in determination of DM mass and spin, respectively. In particular we have demonstrated that in case of fermion DM, the masses can be measured with a few percent accuracy already at 500 fb${}^{-1}$ integrated luminosity. At the same time, the scalar DM model which has about an order of magnitude lower signal, requires about factor of 40 higher luminosity to reach the same accuracy in the mass measurement. We have found that one can distinguish fermion and scalar DM scenarios with about 2 ab${}^{-1}$ total integrated luminosity or less without using the information on the cross sections for benchmarks under study.

   hep-phPRD(2022)·9 citations
7. 07*

   Jet Physics from the Ground Up

   Andrew J. Larkoski🇺🇸

   These are lecture notes presented at the online 2021 QUC Winter School on Energy Frontier hosted by the Korea Institute for Advanced Study. They extend lectures presented at the 2017 and 2018 CTEQ summer schools and the 2020 Hadron Collider Physics Summer School hosted by Fermilab. Jets in quantum chromodynamics (QCD) are motivated from familiar results in classical electricity and magnetism, through identification of structures that exhibit approximate scale invariance. From this point, an effective description of QCD jets is developed from simple assumptions that necessitate all-orders resummation for obtaining finite results. With machine learning becoming an increasingly important tool of particle physics, I discuss its utility exclusively from the biased view for increasing human knowledge. A simple argument that the likelihood for quark versus gluon discrimination is infrared and collinear safe is presented as an example of this approach. End-of-lecture exercises are also provided.

   hep-phhep-ex3 citations
8. 08*

   Present status of radiative and rare kaon decays

   Oscar Cata🇩🇪

   I review recent developments in rare and radiative kaon decays from the theory side, with emphasis on those modes that are actively analyzed by the experimental collaborations.

   hep-phEPJ Web Conf.(2022)·0 citations
9. 09*

   A model of quark and lepton compositeness

   Bogdan A. Dobrescu🇺🇸

   In the chiral $SU(15)$ gauge theory presented here, the quarks and leptons are bound states ("prebaryons") of massless preons. The Standard Model charges of the preons imply 3 generations of quarks and leptons, plus some vectorlike fermions lighter than the confining scale ${\Lambda }_{\mathrm{pre}}$. Under certain assumptions about the chiral dynamics, bound states of two prebaryons behave as Higgs fields. The QCD and electroweak groups may unify above ${\Lambda }_{\mathrm{pre}}$, while $SU(15)$ prevents rapid proton decay.

   hep-phhep-thPRL(2022)·12 citations
10. 10*

    On Extraction of Twist-Two Compton Form Factors from DVCS Observables Through Harmonic Analysis

    Kyle Shiells🇺🇸 · Yuxun Guo🇺🇸 · Xiangdong Ji🇺🇸

    We investigate the exercise of locally extracting the real and imaginary parts of the four twist-2 Compton form factors (CFFs) $\{\mathcal{H},\mathcal{E},\tilde{\mathcal{H}},\tilde{\mathcal{E}}\}$ which arise in the deeply virtual Compton scattering (DVCS) process $e+p\to e+p+\gamma$. Neglecting dynamical higher-twist contributions, we find that there are a sufficient number of DVCS observables and degrees of freedom to extract all 8 leading quantities model-independently, exploiting the azimuthal dependence of the absolute cross sections across all possible beam and target polarizations at a common kinematical point in $\{Q,t,x_B,y\}$. As an example, for typical JLab lab-frame kinematics, we simplify the reduced DVCS observables to their dominant terms, providing a sufficient number of equations for local determination of the twist-2 CFFs. We demonstrate the feasibility using harmonic fitting to both cross sections and beam spin asymmetries with both real and pseudo-data.

    hep-phhep-thJHEP(2022)·17 citations
11. 11*

    Accidental symmetries in the scalar potential of the Standard Model extended with two Higgs triplets

    Xin Wang🇨🇳 · Yilin Wang🇨🇳 · Shun Zhou🇨🇳

    The extension of the Standard Model (SM) with two Higgs triplets offers an appealing way to account for both tiny Majorana neutrino masses via the type-II seesaw mechanism and the cosmological matter-antimatter asymmetry via the triplet leptogenesis. In this paper, we classify all possible accidental symmetries in the scalar potential of the two-Higgs-triplet model (2HTM). Based on the bilinear-field formalism, we show that the maximal symmetry group of the 2HTM potential is $\mathrm{SO}(4)$ and eight types of accidental symmetries in total can be identified. Furthermore, we examine the impact of the couplings between the SM Higgs doublet and the Higgs triplets on the accidental symmetries. The bounded-from-below conditions on the scalar potential with specific accidental symmetries are also derived. Taking the $\mathrm{SO}(4)$-invariant scalar potential as an example, we investigate the vacuum structures and the scalar mass spectra of the 2HTM.

    hep-phJHEP(2022)·1 citation
12. 12*

    Thermal Relaxation and Cooling of Quark Stars with a Strangelet Crust

    Joas Zapata🇧🇷 · Rodrigo Negreiros🇧🇷 · Thiago Sales🇧🇷 · Prashanth Jaikumar🇺🇸

    In this article, we explore the cooling of isolated quark stars. These objects are structured of a homogeneous quark matter core and crusted by matter. To do this, we adopt two kinds of crust: (i) a crust made of purely nuclear matter following the Baym-Pethick-Sutherland (BPS) equation of state (EoS) and (ii) a crust made of nuggets of strange quark matter (strangelets). Both models have the same quark matter core described by the MIT bag model EoS. Our main purpose is to quantify the effects of a strangelet crust on the cooling and relaxation times of these strange stars. We also perform a thorough study of the thermal relaxation of quark stars, in which we have found that objects with a strangelet crust have a significantly different thermal relaxation time. Our study also includes the possible effects of color superconductivity in the quark core.

    hep-phastro-ph.HEnucl-thAstron.Astrophys.(2022)·11 citations
13. 13*

    Lattice QCD calculation of the two-photon exchange contribution to the muonic-hydrogen Lamb shift

    Yang Fu🇨🇳

    We develop a method for lattice QCD calculation of the two-photon exchange (TPE) contribution to the muonic-hydrogen Lamb shift. To demonstrate the feasibility of this method, we also present an exploratory study with a gauge ensemble at $m_{\pi }=142$ MeV. By adopting the infinite-volume reconstruction (IVR) method along with an optimized subtraction scheme, we obtain a preliminary result of the TPE contribution which agrees well with previous calculation using other methods and one magnitude smaller compare to the large $\sim 300\mu$eV discrepancy for the proton radius puzzle.

    ↳ hep-lathep-phnucl-thPoS(2022)·2 citations
14. 14*

    Probing isocurvature perturbations with 21-cm global signal in the light of HERA result

    Teppei Minoda🇯🇵 · Shintaro Yoshiura🇦🇺 · Tomo Takahashi🇯🇵

    We argue that the 21-cm global signal can be a powerful probe of isocurvature perturbations, particularly for the ones with blue-tilted spectra. Although the 21-cm global signal is much affected by astrophysical processes, which give some uncertainties when cosmological models are investigated, recent results from HERA have constrained several astrophysical parameters, whose information can reduce the ambiguities originating from astrophysics. We show that the size and spectral tilt of isocurvature perturbations can be well inferred from the 21-cm global signal once the information on astrophysics from the HERA results is taken into account.

    ↳ astro-ph.COastro-ph.GAgr-qchep-phPRD(2022)·10 citations
15. 15*

    Hyper-Fast Positive Energy Warp Drives

    Erik W. Lentz🇺🇸

    Solitons in space-time capable of transporting time-like observers at superluminal speeds have long been tied to violations of the weak, strong, and dominant energy conditions of general relativity. This trend was recently broken by a new approach that identified soliton solutions capable of superluminal travel while being sourced by purely positive energy densities. This is the first example of hyper-fast solitons satisfying the weak energy condition, reopening the discussion of superluminal mechanisms rooted in conventional physics. This article summarizes the recent finding and its context in the literature. Remaining challenges to autonomous superluminal travel, such as the dominant energy condition, horizons, and the identification of a creation mechanism are also discussed.

    ↳ gr-qcastro-ph.HEhep-ph10 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.