Mon·Dec 26, 2022Monday·December 26, 2022

1. 01*

   Phenomenology of extended multiHiggs doublet models with $S_4$ family symmetry

   A. E. Cárcamo Hernández🇨🇱 · Catalina Espinoza🇲🇽 · Juan Carlos Gómez-Izquierdo🇲🇽 · Juan Marchant González🇲🇽 · Myriam Mondragón🇲🇽

   We propose extended 3HDM and 4HDM models where the SM gauge symmetry is enlarged by the spontaneously broken $S_4$ group, the preserved $Z_2$ and broken $Z_4$ cyclic symmetries. Each model has three active $SU(2)$ scalar doublets, in addition, the first one has an extra inert scalar singlet, whereas the second model has an inert scalar doublet. Furthermore, each model has several extra gauge singlet scalars, which are triplets under $S_4$. Both models yield the same structure of the mass matrices for the fermion sector, where a radiative seesaw generates the tiny light active neutrinos masses at one-loop level, through the $S_4$ triplets. The presence of flavor changing neutral currents mediated by heavy scalars allowed us to study the $(K^0-{\overline{K}}^0)$ and $(B_{d,s}^0-{\overline{B}}_{d,s}^0)$ meson mixings, in the parameter space that currently satisfies the experimental constraints. On the other hand, due to the preserved $Z_2$ symmetry, our proposed models have stable scalar and fermionic dark matter candidates. Furthermore, these models are consistent with the current pattern of SM fermion masses and mixings, with the measured dark matter relic abundance and successfully accommodate the constraints arising from meson oscillations and oblique parameters. The extra scalars in our models provide radiative corrections to the oblique parameters, where due to the presence of the scalar inert doublet, renders the 4HDM less restrictive than the 3HDM one.

   hep-phEPJC(2024)·23 citations
2. 02*

   Modeling the resonance $T_{cs0}^a(2900{)}^{++}$ as a hadronic molecule $D^{\ast +}{K}^{\ast +}$

   S. S. Agaev🇦🇿 · K. Azizi🇮🇷 · H. Sundu🇹🇷

   The doubly charged scalar resonance $T_{cs0}^a(2900{)}^{++}$ is studied in the context of the hadronic molecule model. We consider $T_{cs0}^a(2900{)}^{++}$ as a molecule $M=D^{\ast +}{K}^{\ast +}$ composed of vector mesons, and calculate its mass, current coupling and full width. The spectroscopic parameters of $M$, i.e., its mass and current coupling, are found by means of the QCD two-point sum rule method by taking into account vacuum expectation values of quark, gluon and mixed operators up to dimension $10$. The width of the molecule $M$ is evaluated through the calculations of the partial widths of the decay channels $M\to D_s^{+}{\pi }^{+}$, $M\to D_s^{\ast +}{\rho }^{+}$, and $M\to D^{\ast +}{K}^{\ast +}$. Partial widths of these processes are determined by strong couplings $g_1$, $g_2$, and $g_3$ of particles at vertices $M{D}_s^{+}{\pi }^{+}$, $M{D}_s^{\ast +}{\rho }^{+}$, and $M{D}^{\ast +}{K}^{\ast +}$ , respectively. We calculate the couplings $g_i$ by employing the QCD light-cone sum rule approach and technical tools of the soft-meson approximation. Predictions obtained for the mass $m=(2924\pm 107)\mathrm{MeV}$ and width $\Gamma =(123\pm 25)\mathrm{MeV}$ of the hadronic molecule $M$ allow us to consider it as a possible candidate of the resonance $T_{cs0}^a(2900{)}^{++}$.

   hep-phhep-exhep-latPRD(2023)·36 citations
3. 03*

   Proton spin, topology and confinement: lessons from QCD${}_2$

   David Frenklakh🇺🇸

   We investigate the relation between the topology of a nucleon and its spin composition. We approach this question in (1+1) dimensional single-flavor QCD with a large number of color. In this limit the theory can be shown to be dual to the exactly solvable sine-Gordon model. The spectrum of baryons and mesons is known analytically, and the baryon is a topological kink of the sine-Gordon model. Using the method of solitonic constituents we construct the state of the baryon and extract its $g_1$ structure function. Due to the topological nature of the baryon state this structure function is enhanced at low Bjorken $x$. We propose this enhancement as an experimental probe of the topological structure of the nucleon state.

   hep-phhep-thnucl-th0 citations
4. 04*

   Chiral Nonet Mixing in $\pi \eta$ Scattering

   Amir H. Fariborz🇺🇸 · Soodeh Zarepour🇮🇷 · Esmaiel Pourjafarabadi🇮🇷 · S. Mohammad Zebarjad🇮🇷

   The generalized linear sigma model for mixing among two- and four-quark components of scalar (and psedudosclar) mesons below and above 1 GeV is applied to the $\pi \eta$ channel in which the isovector scalars $a_0(980)$ and $a_0(1450)$ are probed. In the leading order, the model parameters have been previously fixed by various low-energy experimental data, and then applied to $\pi \pi$ and $\pi K$ channels in which the properties of the light and broad $\sigma$ and $\kappa$ mesons are extracted in agreement with estimates reported in the literature. With the same parameters fixed in the leading order, in the present work the prediction of the model for the $\pi \eta$ scattering amplitude in the elastic region is given and unitarized with the K-matrix method. The poles of the unitarized scattering amplitude, which determine the mass and decay width of $a_0(980)$ and $a_0(1450)$ are computed. It is found that the model predicts an isovector scalar state below 1 GeV, with mass 984 $\pm$ 6 MeV and decay width 108 $\pm$ 30 MeV which is a clear signal for the $a_0(980)$. The $a_0$ pole extracted in this work, further supports the plausibility of the mixing patterns for scalar mesons predicted by this model according to which there is a significant underlying mixing among scalars below and above 1 GeV, with those below 1 GeV being generally of four-quark nature while those above 1 GeV being overall closer to quark-antiquark states. Predictions for various scattering lengths as well as for properties of $a_0(1450)$ are also presented.

   hep-phhep-exnucl-thEPJC(2022)·4 citations
5. 05*

   The $Zb\bar{b}$ vertex in a left-right model

   Duarte Fontes🇺🇸 · Darius Jurčiukonis🇱🇹 · Luís Lavoura🇵🇹

   We consider the one-loop corrections to the $Zb\bar{b}$ vertex in a $CP$-conserving left--right model (LRM), $viz$. a model with gauge group $SU(2{)}_L\times SU(2{)}_R\times U(1)$. We allow the gauge coupling constants of $SU(2{)}_L$ and $SU(2{)}_R$ to be different. The spontaneous symmetry breaking is accomplished only by doublets and/or singlets of $SU(2{)}_L$ and $SU(2{)}_R$. The lightest massive neutral gauge boson of our LRM is assumed to have the same Yukawa couplings to bottom-quark pairs as the $Z$ of the Standard Model (SM); this assumption has the advantage that, then, the infrared divergences automatically cancel down in the subtraction of the $Zb\bar{b}$ vertex in the SM from the same vertex in the LRM. We effect a proper renormalization of the $Zb\bar{b}$ vertex and check explicitly both its gauge invariance and the cancellation of all the ultraviolet divergences. We find out that a LRM with the above assumptions cannot achieve a better fit to the $Zb\bar{b}$ vertex than a multi-Higgs extension of the SM, $viz$. both models can only achieve a decent fit when one admits scalar particles with very low masses $\lesssim 50$ GeV. This is true even when we allow for markedly different gauge coupling constants of $SU(2{)}_L$ and $SU(2{)}_R$.

   hep-phNPB(2023)·2 citations
6. 06*

   Seesaw Models of Neutrino Masses on the Convex Cone of Positivity Bounds

   Xu Li🇨🇳 · Shun Zhou🇨🇳

   The convex geometric framework of positivity bounds allows us to explore the ultraviolet (UV) states in new physics models from the bottom up. The UV states in three types of seesaw models for tiny Majorana neutrino masses, as irreducible representations of the $\mathrm{SU}(2{)}_{\mathrm{L}}^{}$ gauge group, naturally fit into this framework. Since neutrino masses arising from the dimension-five Weinberg operator imply that the UV states may couple to the left-handed lepton doublet $L$ and the Higgs doublet $H$, we construct a convex cone of positivity bounds to constrain the dimension-eight operators consisting of $L$ or $H$. Such a construction offers a novel way to distinguish between different seesaw models and derive lower bounds on the seesaw scale.

   hep-phPoS·1 citation
7. 07*

   1+ XTZ States within QCD Sum Rules

   R.M. Albuquerque🇧🇷 · S. Narison🇫🇷 · D. Rabetiarivony🇲🇬

   We present improved estimates of the couplings, masses and mass ratios of the $X_Q,Z_Q$ and $T_{QQ\bar{q}{\bar{q}}^{\prime }}$ states using (inverse) QCD Laplace sum rules (LSR), their ratios $\mathcal{R}$ and double ratios (DRSR), within stability criteria. We conclude that the observed $X_c(3872)$ and $Z_c(3900)$ are tetramoles states (superposition of quasi-degenerated molecule and tetraquark states having similar couplings to the currents) with the predicted masses: $M_{{\mathcal{T}}_{X_c}}=3876(44)$ MeV and $M_{{\mathcal{T}}_{Z_c}}=3900(42)$ MeV. We also do an extensive analysis of the four-quark nature of different $T_{QQ\bar{q}{\bar{q}}^{\prime }}$ axial-vector states. Then, combining $\mathcal{R}$ and DRSR, we reanalyze the observed state $X_c(3872)$ and we obtain a precise prediction of $M_{T_{cc}^{1^{+}}}$=3886(6) MeV. Extending to the beauty sector, we find the results: $M_{{\mathcal{T}}_{Z_b}}=10579(99)$ MeV and $M_{X_b}=10545(131)$ MeV. Finally, we confront our combined LSR $\oplus$ DRSR results with the ones from some other approaches (lattices and quark models).

   hep-phNucl.Part.Phys.Proc.(2023)·2 citations
8. 08*

   Investigating ${\rm Y}(ns)\to {\tau }^{+}{\tau }^{-}$ decay in the Leptoquark scenario

   Sambit Kumar Pusty🇮🇳 · Dhiren Panda🇮🇳 · Aishwarya Bhatta🇮🇳

   Several measurements on $R_D,R_{D^{\ast }}$, and $R_{J/\psi }$ by the BaBar, Belle, and LHCb experiments show significant deviations from their Standard Model (SM) predictions, which illustrate the fact that the concept of lepton flavor universality (LFU) is violated in semileptonic $B$ meson as well as leptonic ${\rm Y}(ns)(n=1,2,3)$ decays. Recently BaBar experiment announced that at $1.8\sigma$ level, $R_{{\rm Y}}(3s)=\mathrm{Br}({\rm Y}(3s)\to \tau \bar{\tau })/\mathrm{Br}({\rm Y}(3s)\to \mu \bar{\mu })$ shows an acceptance with the SM. These fascinating findings point towards the possible implication of new physics in the $b\to c\tau \bar{\nu }$ transitions, which in turn, creates a new direction to look for new physics in $b\bar{b}\to \tau \bar{\tau }$ process. Thereby, the new physics contributions to the $b\to c\tau \bar{\nu }$ process would inevitably alter the $b\bar{b}\to \tau \bar{\tau }$ transitions. Here we conduct a ${\chi }^2$ fit to constraining the new parameters by using the measured values of $R_D$, $R{}_D\ast$, $R_{J/\psi }$, $R_{X_C}$, $F_L(D^{\ast })$ and $P_{\tau }(D^{\ast })$. In this context, we investigate the effect of constrained new physics couplings on the branching ratios and LFU parameters $R_{{\rm Y}(ns)}$ through leptoquark models such as $S_3,\widetilde{S_1},\widetilde{R_2},U_1,U_3$ and $V_2$.

   hep-ph0 citations
9. 09*

   Measurement of flavor asymmetry of light-quark sea in the proton with Drell-Yan dimuon production in $p+p$ and $p+d$ collisions at 120 GeV

   J. Dove🇺🇸 · B. Kerns🇺🇸 · C. Leung🇺🇸 · R. E. McClellan🇺🇸 · S. Miyasaka🇯🇵 · D. H. Morton🇺🇸 · K. Nagai🇯🇵 · S. Prasad🇺🇸 · F. Sanftl🇯🇵 · M. B. C. Scott🇺🇸 · A. S. Tadepalli🇺🇸 · C. A. Aidala🇺🇸 and 57 other authors

   Evidence for a flavor asymmetry between the $\bar{u}$ and $\bar{d}$ quark distributions in the proton has been found in deep-inelastic scattering and Drell-Yan experiments. The pronounced dependence of this flavor asymmetry on $x$ (fraction of nucleon momentum carried by partons) observed in the Fermilab E866 Drell-Yan experiment suggested a drop of the $\bar{d}\left(x\right)/\bar{u}\left(x\right)$ ratio in the $x>0.15$ region. We report results from the SeaQuest Fermilab E906 experiment with improved statistical precision for $\bar{d}\left(x\right)/\bar{u}\left(x\right)$ in the large $x$ region up to $x=0.45$ using the 120 GeV proton beam. Two different methods for extracting the Drell-Yan cross section ratios, ${\sigma }^{pd}/2{\sigma }^{pp}$, from the SeaQuest data give consistent results. The $\bar{d}\left(x\right)/\bar{u}\left(x\right)$ ratios and the $\bar{d}\left(x\right)-\bar{u}\left(x\right)$ differences are deduced from these cross section ratios for $0.13<x<0.45$. The SeaQuest and E866/NuSea $\bar{d}\left(x\right)/\bar{u}\left(x\right)$ ratios are in good agreement for the $x\lesssim 0.25$ region. The new SeaQuest data, however, show that $\bar{d}\left(x\right)$ continues to be greater than $\bar{u}\left(x\right)$ up to the highest $x$ value ($x=0.45$). The new results on $\bar{d}\left(x\right)/\bar{u}\left(x\right)$ and $\bar{d}\left(x\right)-\bar{u}\left(x\right)$ are compared with various parton distribution functions and theoretical calculations.

   hep-phhep-exnucl-exPRC(2023)·22 citations
10. 10*

    Locally finite two-loop QCD amplitudes from IR universality for electroweak production

    Charalampos Anastasiou🇨🇭 · George Sterman🇺🇸

    We describe the implementation of infrared subtractions for two-loop QCD corrections to quark-antiquark annihilation to electroweak final states. The subtractions are given as form-factor integrands whose integrals are known. The resulting subtracted amplitudes are amenable to efficient numerical integration. Our procedure is based on the universality of infrared singularities and requires a relatively limited set of subtractions, whose number grows as the number of two-loop diagrams, rather than with the number of singular regions of integration.

    hep-phhep-thJHEP(2023)·32 citations
11. 11*

    Resonant amplification of a relativistic electron bremsstrahlung on an atom in the undulator field

    P. A. Krachkov🇷🇺 · A. I. Milstein🇷🇺 · N. Yu. Muchnoi🇷🇺

    It is shown that the influence of the undulator field on the motion of a relativistic electron leads to a significant increase of the bremsstrahlung cross section on an atom near the end of the spectrum of undulator radiation. Observation of this effect is quite a realistic task.

    hep-phhep-exphysics.atom-phPLB(2023)·0 citations
12. 12*

    Shaft inflation in Randall-Sundrum model

    Ngo Phuc Duc Loc🇺🇸

    Shaft inflation is a model in which the inflaton potential approaches a plateau far from the origin, while it resembles chaotic inflation near the origin. Meanwhile, the Randall-Sundrum type II model (RSII) is an interesting extra-dimensional model to study cosmological phenomenology. In this paper, we study shaft inflation in the RSII model. We find that the predictions are in excellent agreement with observation. The fundamental five-dimensional Planck scale is found to be $M_5\simeq 10^{16}$ GeV, which is consistent with the lower bound $M_5\gtrsim 10^9$ GeV obtained from experimental Newtonian gravitational bound. This is an important result that can be used to explore further the implications of extra dimension in other contexts.

    hep-phgr-qchep-thJCAP(2023)·2 citations
13. 13*

    Comprehensive Study of Multi-scale Jet-medium Interaction

    Y. Tachibana🇯🇵 · A. Angerami🇺🇸 · R. Arora🇺🇸 · S. A. Bass🇺🇸 · S. Cao🇨🇳 · Y. Chen🇺🇸 · T. Dai🇺🇸 · L. Du🇨🇦 · R. Ehlers🇺🇸 · H. Elfner🇩🇪 · W. Fan🇺🇸 · R. J. Fries🇺🇸 and 46 other authors

    We explore jet-medium interactions at various scales in high-energy heavy-ion collisions using the JETSCAPE framework. The physics of the multi-stage modeling and the coherence effect at high virtuality is discussed through the results of multiple jet and high-$p_{\mathrm{T}}$ particle observables, compared with experimental data. Furthermore, we investigate the jet-medium interaction involved in the hadronization process.

    hep-phnucl-thActa Phys.Polon.Supp.(2023)·1 citation
14. 14*

    The gravitational form factors of the electron in quantum electrodynamics

    Adam Freese🇺🇸 · Andreas Metz🇺🇸 · Barbara Pasquini🇮🇹 · Simone Rodini🇫🇷

    We calculate the gravitational form factors of the electron at one loop in quantum electrodynamics, decomposing these into contributions from the electron and photon parts of the energy-momentum tensor. Ultraviolet divergences are removed through renormalization in the $\overline{\text{MS}}$ scheme. Infrared divergences are isolated and results are given in both dimensional regularization and photon-mass regularization. The form factors contain information about the electron's energy and angular momentum structure in QED, as well as its mass radius. Whenever possible, we compare our results with the existing literature.

    hep-phhep-thPLB(2023)·21 citations
15. 15*

    A new look at the $P_{cs}$ states from a molecular perspective

    Albert Feijoo🇪🇸 · Wen-Fei Wang🇨🇳 · Chu-Wen Xiao🇨🇳 · Jia-Jun Wu🇨🇳 · Eulogio Oset🇪🇸 · Juan Nieves🇪🇸 · Bing-Song Zou🇨🇳

    We have a look at the $P_{cs}$ states generated from the interaction of ${\bar{D}}^{(\ast )}{\Xi }_c^{(\prime \ast )}$ coupled channels. We consider the blocks of pseudoscalar-baryon $({\frac{1}{2}}^{+},{\frac{3}{2}}^{+})$ and vector-baryon $({\frac{1}{2}}^{+},{\frac{3}{2}}^{+})$, and find $10$ resonant states coupling mostly to $\bar{D}{\Xi }_c,{\bar{D}}^{\ast }{\Xi }_c,\bar{D}{\Xi }_c^{\prime },{\bar{D}}^{\ast }{\Xi }_c^{\prime },\bar{D}{\Xi }_c^{\ast }$ and ${\bar{D}}^{\ast }{\Xi }_c^{\ast }$. A novel aspect of the work is the realization that the $\bar{D}{\Xi }_c,{\bar{D}}_s{\Lambda }_c$ or ${\bar{D}}^{\ast }{\Xi }_c,{\bar{D}}_s^{\ast }{\Lambda }_c$ channels, with a strong transition potential, collaborate to produce a larger attraction than the corresponding states $\bar{D}{\Sigma }_c,\bar{D}{\Lambda }_c$ or ${\bar{D}}^{\ast }{\Sigma }_c,{\bar{D}}^{\ast }{\Lambda }_c$ appearing in the generation of the strangenessless $P_c$ states, since in the latter case the transition potential between those channels is zero. The extra attraction obtained in the $\bar{D}{\Xi }_c,{\bar{D}}^{\ast }{\Xi }_c$ pairs preclude the association of these channels to the $P_{cs}(4338)$ and $P_{cs}(4459)$ states respectively. Then we find a natural association of the $P_{cs}(4338)$ state coupling mostly to ${\bar{D}}^{\ast }{\Xi }_c$ while the $P_{cs}(4459)$ is associated to the state found that couples mostly to $\bar{D}{\Xi }_c^{\prime }$. Four more states appear, like in other molecular pictures, and some of the states are degenerate in spin. Counting different spin states we find $10$ states, which we hope can be observed in the near future.

    hep-phhep-exhep-latnucl-thPLB(2023)·56 citations
16. 16*

    Positivity bounds at one-loop level: the Higgs sector

    Xu Li🇨🇳

    In this paper, we promote the convex cone method of positive bounds from tree level to loop level. This method is general and can be applied to obtain leading $s^2$ positivity bounds on the forward scattering process in the standard model effective field theory. To obtain the loop level bounds, the original tree level bounds are modified by loop corrections, which involve low dimensional coefficients. New positivity bounds being valid at one loop level on the four-Higgs scattering have been provided. We study some specific ultraviolet models to check the validity of the new bounds. In addition, the renormalisation group effect on positivity is explored. We point out that as long as the new bounds are satisfied at the cutoff scale $\Lambda$, they will also be satisfied at all scales.

    hep-phhep-exhep-thJHEP(2023)·26 citations
17. 17*

    Medium modifications of Heavy Quarkonia masses in a generalized Linear Sigma Model

    Arpita Mondal🇮🇳 · Pallabi Parui🇮🇳 · Amruta Mishra🇮🇳

    We study the mass shifts of the charmonium ($\bar{c}c$) states ($J/\psi$, $\psi (2S)$, $\psi (1D)$, ${\chi }_{c0}$, ${\chi }_{c1}$ and ${\chi }_{c2}$) as well as the bottomonium ($\bar{b}b$) states (${\rm Y}(1S)$, ${\rm Y}(2S)$, ${{\rm Y}}_2(1D)$, ${\chi }_{b0}$, ${\chi }_{b1}$ and ${\chi }_{b2}$) in isospin asymmetric nuclear matter. These are investigated using a generalized linear sigma model. The broken scale invariance of QCD is incorporated in the chiral $SU(2)\times SU(2)$ Lagrangian through an effective potential involving logarithmic terms of a scalar (glueball) dilaton field $\chi$. The mass shifts of the quarkonium states are obtained through the medium modifications of the dilaton field which simulates the scalar gluon condensate of QCD. We observe an appreciable mass drop in the states of heavy quarkonia under this study. The in-medium masses at finite densities thus obtained should modify the in-medium partial decay widths of heavy quarkonia to open heavy flavor mesons. These density effects can be probed in in the high energy nuclear collisions at the future facility at GSI (at Germany) and JINR (at Russia) in the experiments producing highly dense baryonic matter.

    hep-phnucl-th1 citation
18. 18*

    Decomposition of multi-particle azimuthal correlations in Q-cumulant analysis

    L. Nadderd🇷🇸 · J. Milosevic🇷🇸 · D. Devetak🇷🇸 · F. Wang🇺🇸

    The method of Q-cumulants is a powerful tool to study the fine details of azimuthal anisotropies in high energy nuclear collisions. This paper presents a new method, based on mathematical induction, to evaluate the analytical form of the high-order Q-cumulants. The ability of this method is demonstrated via a toy model that uses the elliptic power distribution to simulate anisotropic emission of particles, quantified in terms of Fourier flow harmonics v_{n}. The method can help in studying the large amount of event statistics that can be collected in the future, and to allow measurements of very high central moments of the v_{2} distribution. This can in turn facilitate progress in understanding the initial geometry, input to hydrodynamic calculations of medium expansion in high energy nuclear collisions, as well as constraints on it.

    hep-phCPC(2023)·1 citation
19. 19*

    The theoretical study of $D_s^{+}\to {\pi }^{+}{\pi }^0{\pi }^0$

    Xuan Luo🇨🇳 · Aojia Xu🇨🇳 · Ruitian Li🇨🇳 · Hao Sun🇨🇳

    Inspired by recent BESIII's amplitude analysis on $D_s^{+}\to {\pi }^{+}{\pi }^0{\pi }^0$, we develop a model based on the chiral unitary approach to discribe the $D_s^{+}\to {\pi }^{+}{\pi }^0{\pi }^0$ decay, where $D_s^{+}$ decays into a ${\pi }^{+}$ and a quark-antiquark pair through weak decay of charm quark. The interaction of pseudoscalar mesons produced by the hadronization of quark-antiquark pair will lead to dynamically generated $f_0(980)$. The dominant amplitudes from resonances $f_0(1370)$ and $f_2(1270)$ in BESIII fit are also included in our model. In addition to above contributions, to obtain a good fit we also add a amplitude from resonance $f_2(1430)$ to our model. Our model fits well $M_{{\pi }^0{\pi }^0}$ and $M_{{\pi }^{+}{\pi }^0}$ invariant mass distributions simultaneously.

    hep-phPRD(2023)·2 citations
20. 20*

    Dark matter from WIMP to FIMP over three regimes: Cosmology versus Colliders

    Laura Lopez-Honorez🇧🇪 · Quentin Decant🇧🇪 · Sam Junius🇧🇪 · Michel H.G. Tytgat🇧🇪

    Dark matter models can give rise to specific signatures at particle physics experiments or in cosmology. The details of the cosmological history can also influence the new physics signals to be expected at e.g. collider experiments. In these proceedings, we briefly summarize the case of dark matter weakly to feebly coupled to Standard Model fermions through t-channel portal dividing the discussion into three main regimes. We also underline the interplay between cosmology and particle physics.

    hep-phFrascati Phys.Ser.(2022)·1 citation
21. 21*

    Bounds on Long-lived Dark Matter Mediators from Neutron Stars

    Thong T. Q. Nguyen🇹🇼 · Tim M. P. Tait🇺🇸

    Neutron stars close to the Galactic center are expected to swim in a dense background of dark matter. For models in which the dark matter has efficient interactions with neutrons, they are expected to accumulate their own local cloud of dark matter, making them appealing targets for observations seeking signs of dark matter annihilation. For theories with very light mediators, the dark matter may annihilate into pairs of mediators which are sufficiently long-lived to escape the star and decay outside it into neutrinos. We examine the bounds on the parameter space of heavy ($\sim$TeV to $\sim$PeV) dark matter theories with long-lived mediators decaying into neutrinos based on observations of high energy neutrino observatories, and make projections for the future. We find that these observations provide information that is complementary to terrestrial searches, and probe otherwise inaccessible regimes of dark matter parameter space.

    hep-phastro-ph.COastro-ph.HEPRD(2023)·69 citations
22. 22*

    Study of Hadron Masses with Faddeev-Popov Eigenmode Projection in the Coulomb Gauge

    Hiroki Ohata🇯🇵 · Hideo Suganuma🇯🇵

    Using SU(3) lattice QCD, we investigate role of spatial gluons for hadron masses in the Coulomb gauge, considering the relation between QCD and the quark model. From the Coulomb-gauge configurations at the quenched level on a $16^3\times 32$ lattice at $\beta$ = 6.0, we consider the $\vec{A}=0$ projection, where all the spatial gluon fields are set to zero. In this projection, the inter-quark potential is unchanged. We investigate light hadron masses and find that nucleon and delta baryon masses are almost degenerate. This result suggests that the N-$\Delta$ mass difference arises from the color-magnetic interactions, which is consistent with the quark model picture. Next, as a generalization of this projection, we expand spatial gluon fields in terms of Faddeev-Popov eigenmodes and leave only some partial components. We find that the $\mathrm{N}-\Delta$ and $0^{++}-2^{++}$ glueball mass splittings are almost reproduced only with 1 \% low-lying components. This suggests that low-lying color-magnetic interaction leads to the hadron mass splitting.

    ↳ hep-lathep-phEPJ Web Conf.(2022)·0 citations
23. 23*

    Gravitational Effect on Fundamental Physical Observables

    Yoshimasa Kurihara🇯🇵

    This report studies possible gravitational effects on measurements of fundamental physical observables such as the fine structure constant and the lepton magnetic moment. Although a static gravitational potential does not contribute to physical observables owing to Einstein's equivalent principle, a dynamic degree with finite momentum transfer can contribute to them. In other words, a laboratory frame fixed on the Earth is not an inertial system; thus, Earth's gravity can contribute to local observables. We investigate experimental results measuring the fine structure constant and electron and muon magnetic moments using the quantum field theoretic method under the Schwarzschild background field. We prepare classical vierbein and spin-connection fields owing to the Schwarzschild metric in the momentum space of the local Lorentz space and estimate possible gravitational effects at the surface of the Earth as $\mathcal{O}(10^{-9})$, which is consistent with the current discrepancy between measured and calculated values of the muon anomalous magnetic moment. On the other hand, the gravitational effect does not contribute to the fine structure constant measurements. We propose a possible test of gravitational effects in particle physics using precise measurement of muon properties in the J-PARK.

    ↳ gr-qchep-ph0 citations
24. 24*

    $\Xi$-nuclear constraints from ${\Xi }^{-}$ emulsion capture events

    Eliahu Friedman🇮🇱 · Avraham Gal🇮🇱

    All five KEK and J-PARC two-body ${\Xi }^{-}$+${}^A$Z $\to$ ${}_{\Lambda }^{A^{\prime }}$Z'+${}_{\Lambda }^{A^{\prime \prime }}$Z'' capture events in light emulsion nuclei, including KISO and IBUKI in ${}^{14}$N, are consistent with Coulomb-assisted $1p_{{\Xi }^{-}}$ nuclear states. The underlying $\Xi$-nuclear potential is strongly attractive, with nuclear-matter depth $V_{\Xi }$ larger than 20 MeV. The recent ${}^{14}$N capture events KINKA and IRRAWADDY assigned by J-PARC E07 to $1s_{{\Xi }^{-}}$ nuclear states, and implying considerably shallower $V_{\Xi }$, have also another interpretation as $1p_{{\Xi }^0}$ nuclear states.

    ↳ nucl-thhep-phnucl-exEPJ Web Conf.(2022)·5 citations
25. 25*

    Lattice calculation of the R-ratio smeared with Gaussian kernel

    Constantia Alexandrou🇨🇾 · Simone Bacchio🇨🇾 · Alessandro De Santis🇮🇹 · Petros Dimopoulos🇫🇷 · Jacob Finkenrath🇨🇾 · Roberto Frezzotti🇮🇹 · Giuseppe Gagliardi🇮🇹 · Marco Garofalo🇩🇪 · Kyriakos Hadjiyiannakou🇨🇾 · Bartosz Kostrzewa🇩🇪 · Karl Jansen🇩🇪 · Vittorio Lubicz🇮🇹 and 6 other authors

    The ratio $R(E)$ of the cross-sections for $e^{+}{e}^{-}\to$ hadrons and $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}$ is a valuable energy-dependent probe of the hadronic sector of the Standard Model. Moreover, the experimental measurements of $R(E)$ are the inputs of the dispersive calculations of the leading hadronic vacuum polarization contribution to the muon $g-2$ and these are in significant tension with direct lattice calculations and with the muon $g-2$ experiment. In this talk we discuss the results of our first-principles lattice study of $R(E)$. By using a recently proposed method for extracting smeared spectral densities from Euclidean lattice correlators, we have calculated $R(E)$ convoluted with Gaussian kernels of different widths $\sigma$ and central energies up to $2.5$ GeV. Our theoretical results have been compared with the KNT19 [1] compilation of experimental results smeared with the same Gaussian kernels and a tension (about three standard deviations) has been observed for $\sigma \sim 600$ MeV and central energies around the $\rho$-resonance peak.

    ↳ hep-lathep-phPoS(2023)·5 citations

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