Wed·Feb 8, 2023Wednesday·February 8, 2023

1. 01*

   Limiting FCNC induced by a CP symmetry of order 4

   Duanyang Zhao🇨🇳 · Igor P. Ivanov🇨🇳 · Roman Pasechnik🇸🇪 · Pengming Zhang🇨🇳

   CP4 3HDM is a three-Higgs-doublet model based on the $CP$ symmetry of order 4 (CP4). Imposing CP4 leads to remarkable connections between the scalar and Yukawa sectors and unavoidably generates tree-level flavor-changing neutral couplings (FCNC). It remains unclear whether FCNC can be sufficiently suppressed in the CP4 3HDM. In this paper, we systematically explore this issue. We first develop an efficient scanning procedure which takes the quark masses and mixing as input and expresses the FCNC matrices in terms of physical quark observables and quark rotation parameters. This procedure allows us to explore the FCNC effects for all the Yukawa sectors possible within the CP4 3HDM. We find that, out of the eight possible CP4 Yukawa sectors, only two scenarios are compatible with the $K$, $B$, $B_s$ and, in particular, $D$-meson oscillation constraints. The results of this work serve as clear guidelines for future phenomenological scans of the model.

   hep-phJHEP(2023)·5 citations
2. 02*

   Enhancement of dilepton production rate and electric conductivity around QCD critical point

   Toru Nishimura🇯🇵 · Masakiyo Kitazawa🇯🇵 · Teiji Kunihiro🇯🇵

   We investigate whether the soft mode that becomes massless at the QCD critical point (CP) causes an enhancement of the dilepton production rate (DPR) and the electric conductivity around the CP through the modification of the photon self-energy. The modification is described by the so-called Aslamazov-Larkin, Maki-Thompson and density of states terms, which have been taken into account in our previous study on the DPR near the color-superconducting phase transition, with a replacement of the diquark modes with the soft mode of the QCD CP. We show that the coupling of photons with the soft modes brings about an enhancement of the DPR in the low invariant-mass region and the conductivity near the CP, which would be observable in the relativistic heavy-ion collisions.

   hep-phnucl-exnucl-thPTEP(2023)·13 citations
3. 03*

   $A_4$-based model with linear seesaw scheme for lepton mass and mixing

   V. V. Vien🇻🇳 · H. N. Long🇻🇳

   We suggest a low-scale model based on $A_4\times Z_4\times Z_2$ symmetry and a global lepton number $U(1{)}_L$ symmetry capable of generating the current neutrino data. The neutrino mass smallness is reproduced by the linear seesaw mechanism. The model can explain the current observed pattern of lepton mixing in which the reactor and atmospheric angles get the best-fit values, and the solar angle and Dirac phase lie within $3\sigma$ limits. The obtained values of the sum of neutrino mass and the effective neutrino mass are below the present experimental limits.

   hep-phPhys.Scripta(2023)·12 citations
4. 04*

   Delving into the $B_s\to \ell {\ell }^{\prime }$, $B_{(s)}\to (K^{(\ast )},\varphi ,f_2^{\prime },K_2^{\ast })\ell {\ell }^{\prime }$ processes

   Manas K. Mohapatra🇮🇳 · Lopamudra Nayak🇮🇳 · Rashmi Dhamija🇮🇳 · Anjan Giri🇮🇳

   To shed light on the indirect search for new physics beyond the standard model, the long standing discrepancies between the theory and experiment mediated by FCNC $b\to s\ell \ell$ quark level transitions set an ideal testing ground. Though the very recent measurements of $R_K$ and $R_{K^{\ast }}$ are consistent with the standard model, still the excitements remain on the measurements of LHCb experiment with the observables $\mathcal{B}(B_s\to \varphi {\mu }^{+}{\mu }^{-})$ which has deviations at the level of $3.6\sigma$. Additionally, standard deviation of $\sim 3.3\sigma$ and $1.2\sigma$, respectively for $P_5^{\prime }$ in $B\to K^{\ast }{\mu }^{+}{\mu }^{-}$ and the branching ratio in $B_s\to {\mu }^{+}{\mu }^{-}$ processes are observed. Inspired by these discrepancies, we work out the constraints on the new physics coupling parameters in the presence of a non-universal $Z^{\prime }$ model. We then probe the exclusive leptonic decay channels $B_s\to \ell {\ell }^{\prime }$, $B_{(s)}\to (K^{(\ast )},\varphi ,f_2^{\prime },K_2^{\ast })\ell {\ell }^{\prime }$ induced by the neutral current transition $b\to s\ell {\ell }^{\prime }$. We find that the $q^2$ variation of the observables, such as, branching ratio, forward-backward asymmetry, lepton polarization asymmetry, and the very sensible observable, so called non-universality observables for LFV decays display the sensitivity of new physics. In this analysis. we estimate above mentioned observables that could shed light on the window of new physics in the near future.

   hep-ph2 citations
5. 05*

   Reinterpretation of searches for long-lived particles from meson decays

   Rebeca Beltrán🇪🇸 · Giovanna Cottin🇨🇱 · Martin Hirsch🇪🇸 · Arsenii Titov🇮🇹 · Zeren Simon Wang🇹🇼

   Many models beyond the Standard Model predict light and feebly interacting particles that are often long-lived. These long-lived particles (LLPs) in many cases can be produced from meson decays. In this work, we propose a simple and quick reinterpretation method for models predicting LLPs produced from meson decays. With the method, we are not required to run Monte-Carlo simulation, implement detector geometries and efficiencies, or apply experimental cuts in an event analysis, as typically done in recasting and reinterpretation works. The main ingredients our method requires are only the theoretical input, allowing for computation of the production and decay rates of the LLPs. There are two conditions for the method to work: firstly, the LLPs in the models considered should be produced from a set of mesons with similar mass and lifetime (or the same meson) and second, the LLPs should, in general, have a lab-frame decay length much larger than the distance between the interaction point and the detector. As an example, we use this method to reinterpret exclusion bounds on heavy neutral leptons (HNLs) in the minimal ``3+1'' scenario, into those for HNLs in the general effective-field-theory framework as well as for axion-like particles. We are able to reproduce existing results, and obtain new bounds via reinterpretation of past experimental results, in particular, from CHARM and Belle.

   hep-phhep-exJHEP(2023)·29 citations
6. 06*

   Measuring inflaton couplings via dark radiation as $\Delta N_{\mathrm{eff}}$ in CMB

   Anish Ghoshal🇵🇱 · Zygmunt Lalak🇵🇱 · Shiladitya Porey🇷🇺

   We study the production of a beyond the Standard Model (BSM) free-streaming relativistic particles which contribute to $N_{eff}$ and investigate how much the predictions for the inflationary analysis change. We consider inflaton decay as the source of this dark radiation (DR) and use the Cosmic Microwave Background (CMB) data from $\text{Planck}$-2018 to constrain the scenarios and identify the parameter space involving couplings and masses of the inflaton that will be within the reach of next-generation CMB experiments like SPT-3G, CMB-S4, \text{CMB-Bh\overline{a}rat}, PICO, CMB-HD, etc. We find that if the BSM particle is produced only from the interaction with inflaton along with Standard Model (SM) relativistic particles, then its contribution to $N_{eff}$ is a monotonically increasing function of the branching fraction, $B_X$ of the inflaton to the BSM particle $X$; $\text{Planck}$ bound on $N_{eff}$ rules out such $B_X\gtrsim 0.09$. Considering two different analyses of $\text{Planck}$+BICEP data together with other cosmological observations, $N_{eff}$ is treated as a free parameter, which relaxes the constraints on scalar spectral index ($n_s$) and tensor-to-scalar ratio ($r$). The first analysis leads to predictions on the inflationary models like Hilltop inflation being consistent with the data. Second analysis rules out the possibility that BSM particle $X$ producing from the inflaton decay in Coleman-Weinberg Inflation or Starobinsky Inflation scenarios. To this end, we assume that SM Higgs is produced along with the BSM particle. We explore the possibilities that $X$ can be either a scalar or a fermion or a gauge boson and consider possible interactions with inflaton and find out the permissible range on the allowed parameter space Planck and those which will be within the reaches of future CMB observations.

   hep-phastro-ph.COPRD(2023)·9 citations
7. 07*

   A combined study of hadronic $D^{+}\to K^{-}{\pi }^{+}{\pi }^{+}$ and $D_s^{+}\to K^{+}{K}^{+}{\pi }^{-}$ decays by means of the analysis of semileptonic $D^{+}\to K^{-}{\pi }^{+}{\ell }^{+}{\nu }_{\ell }$ decays

   R. Escribano🇪🇸 · P. Masjuan🇪🇸 · P. Sanchez-Puertas🇪🇸

   We perform a combined study of the two hadronic decays $D^{+}\to K^{-}{\pi }^{+}{\pi }^{+}$ and $D_s^{+}\to K^{+}{K}^{+}{\pi }^{-}$ using a detailed analysis of the semileptonic decays $D^{+}\to K^{-}{\pi }^{+}{\ell }^{+}{\nu }_{\ell }$ ($\ell =e,\mu$) thanks to the high-statistics dataset provided by the BESIII Collaboration. We propose simple and suitable amplitude parametrizations of the studied reactions that shall be of interest to experimentalists for upcoming analyses. These new parametrizations are based on the naïve factorization hypothesis and the description of the resulting matrix elements in terms of well-known hadronic form factors, with special emphasis on the $K\pi$ scalar and vector cases. Such form factors account for two-body final state interactions which fulfill analyticity, unitarity and chiral symmetry constraints. As a result of our study, we find that the $P$-wave contribution fits nicely within the naïve-factorization approach, whereas the $S$-wave contribution requires complex Wilson coefficients that hint for possibly genuine three-body non-factorizable effects. Our hypothesis is further supported by the examination of $D_s^{+}\to K^{+}{K}^{+}{\pi }^{-}$ decays, where we achieve a description in overall good agreement with data.

   hep-phhep-exPRD(2023)·5 citations
8. 08*

   Enhancing the doubly-longitudinal polarization in WZ production at the LHC

   Thi Nhung Dao🇻🇳 · Duc Ninh Le🇻🇳

   We present new results for the theoretical prediction of doubly-polarized cross sections of $WZ$ events at the LHC using leptonic decays. Compared to the previous studies, two new kinematic cuts are considered. These cuts are designed to enhance the doubly-longitudinal (LL) polarization and, at the same time, study the Radiation Amplitude Zero effect. We found a new cut on the rapidity separation between the $Z$ boson and the electron from the $W$ decay which makes the LL fraction largest, namely $|\Delta y_{Z,e}|<0.5$. This result is obtained at the next-to-leading order in the strong and electroweak couplings.

   hep-phhep-exCommun.in Phys.(2023)·22 citations
9. 09*

   Quark mass hierarchies and CP violation in $A_4\times A_4\times A_4$ modular symmetric flavor models

   Shota Kikuchi🇯🇵 · Tatsuo Kobayashi🇯🇵 · Kaito Nasu🇯🇵 · Shohei Takada🇯🇵 · Hikaru Uchida🇯🇵

   We study $A_4\times A_4\times A_4$ modular symmetric flavor models to realize quark mass hierarchies and mixing angles without fine-tuning. Mass matrices are written in terms of modular forms. At modular fixed points $\tau =i\infty$ and $\omega$, $A_4$ is broken to $Z_3$ residual symmetry. When the modulus $\tau$ is deviated from the fixed points, modular forms show hierarchies depending on their residual charges. Thus, we obtain hierarchical structures in mass matrices. Since we begin with $A_4\times A_4\times A_4$, the residual symmetry is $Z_3\times Z_3\times Z_3$ which can generate sufficient hierarchies to realize quark mass ratios and absolute values of the CKM matrix $|V_{\text{CKM}}|$ without fine-tuning. Furthermore, CP violation is studied. We present necessary conditions for CP violation caused by the value of $\tau$. We also show possibilities to realize observed values of the Jarlskog invariant $J_{\text{CP}}$, quark mass ratios and CKM matrix $|V_{\text{CKM}}|$ simultaneously, if $\mathcal{O}(10)$ adjustments in coefficients of Yukawa couplings are allowed.

   hep-phJHEP(2023)·38 citations
10. 10*

    Deep Learning Applications to Particle Physics: from Monte Carlo simulation acceleration to ProtoDUNE reconstruction

    Marco Rossi🇮🇹

    The thesis arises in the context of deep learning applications to particle physics. The dissertation follows two main parallel streams: the development of hardware-accelerated tools for event simulation in high-energy collider physics, and the optimization of deep learning models for reconstruction algorithms at neutrino detectors. Event generation is a central concept in high-energy physics phenomenology studies. The state-of-the-art software dedicated to Monte Carlo simulation is often written for general-purpose computing architectures (CPUs), which allow great flexibility but are not compatible with specialized accelerating devices, GPUs. We present two original tools, PDFFlow and MadFlow, that manage to combine these two aspects in Python. PDFFlow, is a Parton Distribution Functions interpolator, while MadFlow aims at building a complete tool suite to accelerate the whole event generation framework. The reconstruction pipeline at neutrino detectors is comprised of many different algorithms that work in synergy to extract a high-level representation of detector data. All the most important experiments in neutrino physics are developing software to automatically process and extract this information. This work describes the implementation of deep learning techniques to improve neutrino reconstruction efficiency at the ProtoDUNE-SP detector. Two original contributions are presented concerning raw data denoising and a hit-clustering procedure named "slicing". Both denoising and slicing involve the implementation and the training of novel neural network architectures, based on state-of-the-art models in machine learning, such as feed-forward, convolutional and graph neural networks. They represent a proof of concept that these models are indeed capable of providing an important impact on signal reconstruction at neutrino detectors.

    hep-ph2 citations
11. 11*

    Vector Meson Gravitational Form Factors and Generalized Parton Distributions at finite temperature within the soft-wall AdS/QCD Model

    Minaya Allahverdiyeva🇦🇿 · Shahin Mamedov🇦🇿

    We investigate the vector meson's gravitational form factors (GFFs) and generalized parton distributions (GPDs) at finite temperatures within the soft-wall AdS/ QCD model. The plotted soft-wall GFFs graphs at zero temperature are close to the hard-wall results [1]. The dependence on temperature of the GFFs and GPDs is studied using the thermal dilaton approach in the soft-wall model. Plots of thermal GFFs show that they decrease in temperature increase. Also, the gravitational radius of $\rho$ meson decreases in temperature growth and becomes zero around the critical temperature $T_c=0.2\mathrm{GeV}$. GPDs at zero skewness are plotted and analyzed at zero and finite temperature cases.

    hep-phEPJC(2023)·12 citations
12. 12*

    Deconstructing squark contributions to di-Higgs production at the LHC

    Stefano Moretti🇬🇧 · Luca Panizzi🇸🇪 · Jörgen Sjölin🇸🇪 · Harri Waltari🇸🇪

    We present a novel approach to the study of di-Higgs production via gluon-gluon fusion at the LHC. The relevant Feynman diagrams involving two Standard Model-like Higgs bosons $hh$ are computed within a simplified model approach that enables one to interpret possible signals of new physics in a model-independent way as well as to map these onto specific theories. This is possible thanks to a decomposition of such a signal process into all its squared amplitudes and their relative interferences, each of which has a well-defined coupling structure. We illustrate the power of this procedure for the case of both a minimal and next-to-minimal representation of Supersymmetry, for which the new physics effects are due to top squarks entering the loops of $gg\to hh$. The squarks yield both a change of the integrated cross section and peculiar kinematic features in its differential distributions with respect to the Standard Model. These effects can in turn be traced back to the relevant diagrammatic and coupling structures and allow for a detailed analysis of the process. In order to do so, we perform systematic scans of the parameter spaces of such new physics scenarios and identify benchmark points which exhibit potentially observable features during the current and upcoming runs of the LHC.

    hep-phhep-exPRD(2023)·8 citations
13. 13*

    The generalized Crewther relation and V-scheme: analytic $O({\alpha }_s^4)$ results in QCD and QED

    A.L. Kataev🇷🇺 · V.S. Molokoedov🇷🇺

    Using the analytical $\overline{\mathrm{MS}}$-scheme three-loop contribution to the perturbative Coulomb-like part of the static color potential of heavy quark-antiquark system, we obtain the analytical expression for the fourth-order $\beta$-function in the gauge-invariant effective V-scheme in the case of the generic simple gauge group. Also we present the Adler function of electron-positron annihilation into hadrons and the coefficient function of the Bjorken polarized sum rule in the V-scheme up to ${\alpha }_s^4$ terms. We demonstrate that at this level of PT in this effective scheme the $\beta$-function is factorized in the conformal symmetry breaking term of the generalized Crewther relation, which connects the flavor non-singlet contributions to the Adler and Bjorken polarized sum rule functions. We prove why this relation will be true in other gauge-invariant renormalization schemes as well. The obtained results enable to reveal the difference between the V-scheme $\beta$-function in QED and the Gell-Man--Low $\Psi$-function. This distinction arises due to the presence of the light-by-light type scattering corrections first appearing in the static potential at the three-loop level.

    hep-phhep-thTheor.Math.Phys.(2023)·10 citations
14. 14*

    SMEFT goes dark: Dark Matter models for four-fermion operators

    Ricardo Cepedello🇩🇪 · Fabian Esser🇪🇸 · Martin Hirsch🇪🇸 · Veronica Sanz🇪🇸

    We study ultra-violet completions for d = 6 four-fermion operators in the standard model effective field theory (SMEFT), focusing on models that contain cold dark matter candidates. Via a diagrammatic method, we generate systematically lists of possible UV completions, with the aim of providing sets of models, which are complete under certain, well specified assumptions. Within these lists of models we rediscover many known DM models, as diverse as R-parity conserving supersymmetry or the scotogenic neutrino mass model. Our lists, however, also contain many new constructions, which have not been studied in the literature so far. We also briefly discuss how our DM models could be constrained by reinterpretations of LHC searches and the prospects for HL-LHC and future lepton colliders.

    hep-phJHEP(2023)·19 citations
15. 15*

    Radiative Neutrino Mass with Electroweak Scale Majorana Dark Matter in Scotogenic Model

    Avnish🇮🇳 · Kirtiman Ghosh🇮🇳

    Non-zero neutrino mass and dark matter cast a shadow over the success of the Standard Model (SM) of Particle Physics. The most straightforward extension of the SM to explain these two phenomena is the Scotogenic model, where the SM particle spectrum extends with three isospin singlet right-handed neutrinos and one doublet scalar while all of these being odd under $Z_2$ symmetry. In this work, we have considered the lightest right-handed neutrino as the dark matter candidate and freeze-out mechanism for producing observed dark matter relic density. The observed dark matter relic density, neutrino oscillation data and limits on the charged lepton flavor violation processes impose severe constraints on the model. After satisfying all the constraints, we study the collider signatures of the model at the proposed lepton collider experiments.

    hep-phNPB(2024)·2 citations
16. 16*

    Signals of a New Gauge Boson from IceCube and Muon $g-2$

    Dan Hooper🇺🇸 · Joaquim Iguaz Juan🇫🇷 · Pasquale D. Serpico🇫🇷

    A $Z^{\prime }$ boson associated with a broken $U(1{)}_{L_{\mu }-L_{\tau }}$ gauge symmetry offers an economical solution to the long-standing $g_{\mu }-2$ anomaly, confirmed and strengthened by recent measurements at Fermilab. Here, we revisit the impact of such a $Z^{\prime }$ on the spectrum of high-energy astrophysical neutrinos, as measured by the IceCube experiment. This spectrum has been observed to exhibit a dip-like feature at $E_{\nu }\sim 0.2-1\mathrm{PeV}$, which could plausibly arise from the physics of the sources themselves, but could also be the consequence of high-energy neutrinos resonantly scattering with the cosmic neutrino background, mediated by a $Z^{\prime }$ with a mass on the order of $m_{Z^{\prime }}\sim 10\mathrm{MeV}$. In this study, we calculate the impact of such a $Z^{\prime }$ on the high-energy neutrino spectrum for a variety of model parameters and source distributions. For couplings that can resolve the $g_{\mu }-2$ anomaly, we find that this model could self-consistently produce a spectral feature that is consistent with IceCube's measurement, in particular if the neutrinos observed by IceCube predominantly originate from high-redshift sources.

    ↳ astro-ph.HEhep-phPRD(2023)·12 citations
17. 17*

    Predicting the neutrinoless double-beta decay matrix element of ${}^{136}$Xe using a statistical approach

    Mihai Horoi🇺🇸 · Andrei Neacsu🇷🇴 · Sabin Stoica🇷🇴

    Calculation of the nuclear matrix elements (NMEs) for double-beta decay is of paramount importance for guiding experiments and for analyzing and interpreting the experimental data, especially for the search of the neutrinoless double beta decay mode ($0\nu \beta \beta$). However, there are currently still large differences between the NME values calculated by different methods, hence a quantification of their uncertainties is very much required. In this paper we propose a statistical analysis of $0\nu \beta \beta$ NME for the ${}^{136}Xe$ isotope, based on the interacting shell model, but using three independent effective Hamiltonians, emphasizing the range of the NMEs' most probable values and its correlations with observables that can be obtained from the existing nuclear data. Consequently, we propose a common probability distribution function for the $0\nu \beta \beta$ NME, which has a range of (1.55 - 2.65) at 90\% confidence level, with a mean value of 1.99 and a standard deviation of 0.37.

    ↳ nucl-thhep-phPRC(2023)·24 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.