Fri·Dec 3, 2021Friday·December 3, 2021

1. 01*

   Study of $B_{u,d,s}\to K_0^{\ast }(1430)P$ and $K_0^{\ast }(1430)V$ decays within QCD factorization

   Lili Chen🇨🇳 · Mengfei Zhao🇨🇳 · Yunyun Zhang🇨🇳 · Qin Chang🇨🇳

   We study the nonleptonic charmless $B_{u,d,s}\to K_0^{\ast }(1430)P$ $(P=K,\pi )$ and $K_0^{\ast }(1430)V$ $(V=K^{\ast },\rho ,\omega ,\varphi )$ decays. The amplitudes are calculated within the QCD factorization, and the non-perturbative quantities are evaluated by using a covariant light-front approach. The branching fractions and CP asymmetries of theses decay modes are calculated, some decay modes are first predicted, and some useful relations based on $SU(3)$ flavor symmetry are discussed. Comparing the theoretical results with the current available experimental data, it is found that $K_0^{\ast }(1430)$ can be described as the lowest-lying p-wave $(s,u/d)$ state rather than the first excited one.

   hep-phhep-exPRD(2022)·15 citations
2. 02*

   Explaining excesses in four-leptons at the LHC with a double peak from a CP violating Two Higgs Doublet Model

   Stefan Antusch🇨🇭 · Oliver Fischer🇬🇧 · A. Hammad🇰🇷 · Christiane Scherb🇩🇪

   Extended scalar sectors with additional degrees of freedom appear in many scenarios beyond the Standard Model. Heavy scalar resonances that interact with the neutral current could be discovered via broad resonances in the tails of the four-lepton invariant mass spectrum, where the Standard Model background is small and well understood. In this article we consider a recent ATLAS measurement of four-lepton final states, where the data is in excess over the background for invariant masses above 500 GeV. We discuss the possibility that this excess could be interpreted as a "double peak" from the two extra heavy neutral scalars of a CP violating Two Higgs Doublet Model, both coupling to the $Z$ boson. We apply an iterative fitting procedure to find viable model parameters that can match the excess, resulting in a benchmark point where the observed four-lepton invariant mass spectrum can be explained by two scalar particles $H_2$ and $H_3$, with masses of 540 GeV and 631 GeV, respectively, being admixtures of the CP eigenstates. Our explanation predicts additional production processes for $t\bar{t}$, $W^{+}{W}^{-}$, $4b$ and $\gamma \gamma$, some of which have cross sections close to the current experimental limits. Our results further imply that the electric dipole moment of the electron should be close to the present bounds.

   hep-phJHEP(2022)·8 citations
3. 03*

   Measuring Lepton Flavor Violation at LHC

   K. Asai🇯🇵 · J. Fujimoto🇯🇵 · K. Kaneta🇯🇵 · Y. Kurihara🇯🇵 · S. Tsuno🇯🇵

   A new process with the lepton flavor violation (LFV) is presented in the setup for LHC. The LFV is induced by the one-loop effect through Higgs bosons in the framework of the type-III two Higgs doublet model. It is demonstrated that the vast of parameter space in the Yukawa sector could be accessed by current and future LHC experiments.

   hep-phPRD(2022)·1 citation
4. 04*

   Extraction of freezeout parameters and their dependence on collision energy and collision cross-section

   Muhammad Waqas🇨🇳 · Guang-Xiong Peng🇨🇳 · Muhammad Ajaz🇵🇰 · Abd Al Karim Haj Ismail🇦🇪 · Pei-Pin Yang🇨🇳 · Zafar Wazir🇵🇰

   We used the Blast wave model with Boltzmann Gibbs statistics and analyzed the experimental data of transverse momentum spectra ($p_T$) measured by NA61/SHINE and NA 49 Collaborations in inelastic (INEL) proton-proton, and the most central Beryllium-Beryllium (Be-Be), Argon-Scandium (Ar-Sc) and Lead-Lead (Pb-Pb) collisions. The model results fit the experimental data of NA61/SHINE and NA 49 Collaborations very well. We extracted kinetic freezeout temperature, transverse flow velocity and kinetic freezeout volume directly from the spectra. We also calculated mean transverse momentum and initial temperature from the fit function. It is observed that the kinetic freezeout temperature increases with increasing the collision energy as well as collision cross-section (size of the colliding system). Furthermore, the transverse flow remains unchanged with increasing the collision energy, while it changes randomly with the collision cross-section. Similarly, with the increase in collision energy or the collision cross-section, the freeze-out volume and the average $p_T$ increase. The initial temperature is also observed to be an increasing function of the collision cross-section.

   hep-ph5 citations
5. 05*

   Thermal Leptophilic Light Vector Dark Matter with Spinor Mediator and Muon (g-2) Anomaly

   Seyed Yaser Ayazi🇮🇷 · Ahmad Mohamadnejad🇮🇷

   Inspired by the recently new measurement of $(g-2{)}_{\mu }$ at FermiLab and reported upper bound for electron-dark matter (DM) recoil by the XENON1T collaboration, we revisited phenomenology of a light MeV scale vector dark matter in a leptophilic extension of standard model while a new spinor field plays the role of mediator. A viable parameter space is considered to discuss the possibility of light dark matter relic density as well as anomalous magnetic moment of the muon. We study DM-electron direct detection and cosmological bounds on the parameters space of the model. It is shown that although new bound of $(g-2{)}_{\mu }$ anomaly greatly confines the parametric space of the model, the thermal light dark matter can exist for ${\mathrm{M}}_{\mathrm{DM}}\sim 10^{-1}-10^1\mathrm{GeV}$.

   hep-phInt.J.Theor.Phys.(2023)·4 citations
6. 06*

   Magnetic correction to the Anomalous Magnetic Moment of Electron

   Fan Lin🇨🇳 · Mei Huang🇨🇳

   We investigate the leading order correction of anomalous magnetic moment (AMM) to the electron in weak magnetic field and find that the magnetic correction is negative and magnetic field dependent, indicating a magnetic catalysis effect for the electron gas. In the laboratory to measure the $g-2$, the magnitude of the magnetic field $B$ is several $\mathrm{T}$, correspondingly the magnetic correction to the AMM of electron/muon is around $10^{-34}$/$10^{-42}$, therefore the magnetic correction can be safely neglected in current measurement. However, when the magnitude of the magnetic field strength is comparable with the electron mass, the magnetic correction of electron's AMM will become considerable. This general magnetic correction to charged fermion's AMM can be extended to study QCD matter under strong magnetic field.

   hep-phCommun.Theor.Phys.(2022)·12 citations
7. 07*

   Multistrange Hyperon Production on Nuclear Targets

   G.H. Arakelyan🇦🇲 · C. Merino🇪🇸 · Yu.M. Shabelski🇷🇺

   We consider the experimental data on yields of protons, strange ${\Lambda }^{\prime }$s, and multistrange baryons ($\Xi$, $\Omega$), and antibaryons production on nuclear targets, and the experimental ratios of multistrange to strange antibaryon production, at the energy region from SPS up to LHC, and compare them to the results of the Quark-Gluon String Model calculations. In the case of heavy nucleus collisions, the experimental dependence of the ${\overline{\Xi }}^{+}/\overline{\Lambda }$, and, in particular, of the ${\overline{\Omega }}^{+}/\overline{\Lambda }$ ratios, on the centrality of the collision, shows a manifest violation of quark combinatorial rules.

   hep-phPRD(2022)·4 citations
8. 08*

   $TeV$-Scale Resonant Leptogenesis $A_4$ with a scaling texture

   H.B. Benaoum🇦🇪

   We consider a TeV scale resonant lepogenesis within type-I seesaw mechanism. We show that a concrete model based on $A_4$ flavor symmetry with a scaling ansatz in the neutrino Dirac mass matrix and a retro-circulant heavy Majorana mass matrix can be realized. The full Yukawa coupling matrix $Y_{\nu }$ can be fully reconstructed from the low energy neutrino oscillations data and the quasi-degenerate heavy Majorara neutrino masses. We have carried out a detailed numerical analysis to constrain the Dirac neutrino mass matrix elements. In particular, it was found that its diagonal elements lie near or below the MeV region. Furthermore, we have investigated the allowed regions in the parameter space of the model consistent with both low energy neutrino oscillations data and resonant leptogenesis leading to the observed baryon asymmetry of the universe. Finally, the model has an imperative prediction on the allowed space for the effective Majorana neutrino mass $|m_{ee}|$ in order to account for the observed baryon asymmetry.

   hep-ph0 citations
9. 09*

   Novel and self-consistency analysis of the QCD running coupling ${\alpha }_s(Q)$ in both the perturbative and nonperturbative domains

   Qing Yu🇨🇳 · Hua Zhou🇨🇳 · Xu-Dong Huang🇨🇳 · Jian-Ming Shen🇨🇳 · Xing-Gang Wu🇨🇳

   The QCD coupling ${\alpha }_s$ is the most important parameter for achieving precise QCD predictions. By using the well measured effective coupling ${\alpha }_s^{g_1}(Q)$ defined from the Bjorken sum rules as a basis, we suggest a novel and self-consistency way to fix the ${\alpha }_s$ at all scales: The QCD light-front holographic model is adopted for its infrared behavior, and the fixed-order pQCD prediction under the principle of maximum conformality (PMC) is used for its high-energy behavior. Using the PMC scheme-and-scale independent perturbative series, and by transforming it into the one under the physical $V$-scheme, we observe that a precise ${\alpha }_s$ running behavior in both the perturbative and nonperturbative domains with a smooth transition from small to large scales can be achieved.

   hep-phChin.Phys.Lett.(2022)·20 citations
10. 10*

    LHC Lifetime Frontier and Visible Decay Searches in Composite Asymmetric Dark Matter Models

    Ayuki Kamada🇰🇷 · Takumi Kuwahara🇰🇷

    The LHC lifetime frontier will probe dark sector in near future, and the visible decay searches at fixed-target experiments have been exploring dark sector. Composite asymmetric dark matter with dark photon portal is a promising framework explaining the coincidence problem between dark matter and visible matter. Dark strong dynamics provides rich structure in the dark sector: the lightest dark nucleon is the dark matter, while strong annihilation into dark pions depletes the symmetric components of the dark matter. Dark photons alleviate cosmological problems. Meanwhile, dark photons make dark hadrons long-lived in terrestrial experiments. Moreover, the dark hadrons are produced through the very same dark photon. In this study, we discuss the visible decay searches for composite asymmetric dark matter models. For a few GeV dark nucleons, the LHC lifetime frontier, MATHUSLA and FASER, has a potential to discover their decay when kinetic mixing angle of dark photon is $ϵ\gtrsim 10^{-4}$. On the other hand, fixed-target experiments, in particular SeaQuest, will have a great sensitivity to dark pions with a mass below GeV and with kinetic mixing $ϵ\gtrsim 10^{-4}$ in addition to the LHC lifetime frontier. These projected sensitivities to dark hadrons in dark photon parameter space are comparable with the future sensitivities of dark photon searches, such as Belle-II and LHCb.

    hep-phJHEP(2022)·9 citations
11. 11*

    Phases of rotating baryonic matter: non-Abelian chiral soliton lattices, antiferro-isospin chains, and ferri/ferromagnetic magnetization

    Minoru Eto🇯🇵 · Kentaro Nishimura🇯🇵 · Muneto Nitta🇯🇵

    A chiral soliton lattice (CSL), proposed as the ground state of rotating baryonic matter at a finite density, is shown to be unstable in a large parameter region for two flavors owing to pion condensations, leading to two types of non-Abelian (NA) CSL phases (dimer and deconfining phases). We determine the phase diagram where the dimer phase meets the other phases and QCD vacuum at three tricritical points. The critical angular velocity for NA-CSLs is lower than the $\eta$-CSL. Each NA soliton carries an isospin, and an antiferro-isospin chain is formed leading to gapless isospinons. The anomalous coupling to the magnetic field provides the NA-CSL ($\eta$-CSL) with a ferrimagnetic (ferromagnetic) magnetization.

    hep-phcond-mat.mes-hallJHEP(2022)·40 citations
12. 12*

    $(g-2{)}_{\mu }$ and SUSY Dark Matter: Direct Detection and Collider Search Complementarity

    Manimala Chakraborti🇵🇱 · Sven Heinemeyer🇪🇸 · Ipsita Saha🇯🇵 · Christian Schappacher🇩🇪

    The electroweak (EW) sector of the Minimal Supersymmetric Standard Model (MSSM) can account for variety of experimental data. The EW particles with masses of a few hundred GeV evade the LHC searches owing to their small production cross sections. Such a light EW sector can in particular explain the reinforced $4.2\sigma$ discrepancy between the experimental result for the anomalous magnetic moment of the muon, \gmin2, and its Standard Model (SM) prediction. The lightest supersymmetric particle (LSP), assumed to be the lightest neutralino, ${\tilde{\chi }}_1^0$, as a Dark Matter (DM) candidate is furthermore in agreement with the observed limits on the DM content of the universe. Here the Next-to LSP (NLSP) serves as a coannihilation partner and is naturally close in mass to the LSP. Such scenarios are also to a large extent in agreement with negative results from Direct Detection (DD) experiments. The DM relic density can fully be explained by a nearly pure bino or a mixed bino/wino LSP. Relatively light wino and higgsino DM, on the other hand, remains easily below the DM relic density upper bound. Using the improved limits on $(g-2{)}_{\mu }$, we explore the mass ranges of the LSP and the NLSP in their correlation with the DM relic density for bino, bino/wino, wino and higgsino DM. In particular analyze the sensitivity of future DM DD experiments to these DM scenarios. We find that higgsino, wino and one type of bino scenario can be covered by future DD experiments. Mixed bino/wino and another type of bino DM can reach DD cross sections below the neutrino floor. In these cases we analyze the complementarity with the (HL-)LHC and future $e^{+}{e}^{-}$ linear colliders. We find that while the prospects for the HL-LHC are interesting, but not conclusive, an $e^{+}{e}^{-}$ collider with $\sqrt{s}\le 1$ TeV can cover effectively all points of the MSSM that may be missed by DD experiments.

    hep-phEPJC(2022)·36 citations
13. 13*

    The force-force-correlator in hot QCD perturbatively and from the lattice

    Jacopo Ghiglieri🇫🇷 · Guy D. Moore🇩🇪 · Philipp Schicho🇫🇮 · Niels Schlusser🇫🇮

    High-energy particles traversing a medium experience modified dispersion. In the Quark-Gluon Plasma, such dispersion affects jet propagation and transport properties and should be determined better. Above $\sim 2T_c$ we expect strongly coupled infrared behavior and perturbative ultraviolet behavior, allowing a perturbative matching to an effective theory called EQCD, which can be studied non-perturbatively. We study the relevant non-local operator in EQCD at next-to-leading order which allows for a complete EQCD-to-lattice match and prepares the groundwork for a matching between EQCD and full QCD. Our results in EQCD show remarkable agreement between perturbation theory and the lattice in the expected regime.

    hep-phhep-latJHEP(2022)·16 citations
14. 14*

    Gluon-mediated inclusive Deep Inelastic Scattering from Regge to Bjorken kinematics

    Renaud Boussarie🇫🇷 · Yacine Mehtar-Tani🇺🇸

    We revisit high energy factorization for gluon mediated inclusive Deep Inelastic Scattering (DIS) for which we propose a new semi-classical approach that accounts systematically for the longitudinal extent of the target in contrast with the shockwave limit. In this framework, based on a partial twist expansion, we derive a factorization formula that involves a new gauge invariant unintegrated gluon distribution which depends explicitly on the Feynman $x$ variable. It is shown that both the Regge and Bjorken limits are recovered in this approach. We reproduce in particular the full one loop inclusive DIS cross-section in the leading twist approximation and the all-twist dipole factorization formula in the strict $x=0$ limit. Although quantum evolution is not discussed explicitly in this work, we argue that the proper treatment of the $x$ dependence of the gluon distribution encompasses the kinematic constraint that must be imposed on the phase-space of gluon fluctuations in the target to ensure stability of small-$x$ evolution.

    hep-phnucl-thJHEP(2022)·28 citations
15. 15*

    Meeting the Challenges for Relic Neutrino Detection

    P. S. Bhupal Dev🇺🇸 · Amarjit Soni🇺🇸

    Inspired by Gounaris-Sakurai and Lee-Zumino, we postulate that the weak vector and axial vector currents are dominated by $J^{PC}=1^{--}$ and $1^{++}$ resonances respectively in the appropriate channels of $\nu +\bar{\nu }$ annihilation into quark-antiquark pairs when an ultrahigh-energy incoming $\nu (\bar{\nu })$ strikes a relic $\bar{\nu }(\nu )$. Despite this and some other ideas, it appears the detection of relic neutrinos with just the Standard Model interactions seems extremely difficult at existing or future neutrino telescopes. Thus any positive signal would be due to some non-standard interactions of neutrinos.

    hep-phastro-ph.HEPoS(2022)·7 citations
16. 16*

    The mass exclusion limits for the BSM vector resonances with the direct couplings to the third quark generation

    Mikulas Gintner🇸🇰 · Josef Juran🇨🇿

    The upper bounds that the LHC measurements searching for heavy resonances beyond the Standard model set on the resonance production cross sections are not universal. They depend on various characteristics of the resonance under consideration, and their validity is also limited by the assumptions and approximations applied to their calculations. The bounds are typically used to derive the mass exclusion limits for the new resonances. We address some of the issues that emerge when deriving the mass exclusion limits for the strongly coupled composite $SU(2{)}_{L+R}$ vector resonance triplet which would interact directly to the third quark generation only. We show that the presence of such interactions in the model can lower the mass exclusion limits.

    hep-phPoS(2021)·0 citations
17. 17*

    Perturbative QCD predictions in fixed order for cross section ratios

    L. Sawyer🇺🇸 · C. Waits🇺🇸 · M. Wobisch🇺🇸

    In the standard approach, predictions of perturbative Quantum Chromodynamics for ratios of cross sections are computed as the ratio of fixed-order predictions for the numerator and the denominator. Beyond the lowest order in the perturbative expansion, the result does, however, not correspond to a fixed-order prediction for the ratio. This article describes how exact fixed-order results for ratios of arbitrary cross sections can be obtained. The general method for computations in any order of the perturbative expansion is derived, and results for next-to-leading order and next-to-next-to-leading order calculations are given. The approach is applied to theory predictions for various multi-jet cross section ratios measured at hadron colliders. The two methods are compared with each other and with the experimental data. Recommendations are made how to obtain improved theory predictions with more realistic uncertainty estimates.

    hep-phhep-ex1 citation
18. 18*

    Lepton Flavor in Composite Higgs Models

    Florian Goertz🇩🇪

    In this talk, I will present the status of lepton flavor physics in composite Higgs models with partial compositeness in the light of recent data in the lepton sector. I will consider anarchic flavor setups, scenarios with flavor symmetries, and minimal incarnations of the see-saw mechanism that naturally predict non-negligible lepton compositeness. The focus will be on lepton flavor violating processes, dipole moments, and on probes of lepton flavor universality, all providing stringent tests of partial compositeness. The expected size of effects in the different approaches to lepton flavor and the corresponding constraints will be discussed, including "UV complete", effective, and holographic descriptions.

    hep-phPoS(2022)·5 citations
19. 19*

    obscura: A modular C++ tool and library for the direct detection of (sub-GeV) dark matter via nuclear and electron recoils

    Timon Emken🇸🇪

    For the interpretation of past and future direct searches for dark matter (DM) particles, it is important to be able to provide accurate predictions for event rates and spectra under a variety of possible and viable assumptions in a computationally efficient way. While there exists a few tools to compute DM induced nuclear recoil spectra, 'obscura' is not limited to nuclear targets. Instead its main focus lies on sub-GeV DM searches probing electron recoils which typically requires methods from atomic and condensed matter physics. In the context of sub-GeV DM searches, new ideas such as target materials or detection techniques are being proposed regularly, and the theoretical modelling of these are getting improved continuously. At the same time, currently running experiments continue to publish their results and analyses, setting increasingly strict bounds on the DM parameter space. In such a dynamic field, 'obscura' can be an invaluable tool due to its high level of adaptability and facilitate and accelerate the development of new, reliable research software for the preparation of a DM discovery in the hopefully near future.

    hep-phJ.Open Source Softw.(2021)·5 citations
20. 20*

    Impact of bound states on non-thermal dark matter production

    Julian Bollig🇩🇪 · Stefan Vogl🇩🇪

    We explore the impact of non-perturbative effects, namely Sommerfeld enhancement and bound state formation, on the cosmological production of non-thermal dark matter. For this purpose, we focus on a class of simplified models with t-channel mediators. These naturally combine the requirements for large corrections in the early Universe, i.e. beyond the Standard Model states with long range interactions, with a sizable new physics production cross section at the LHC. We find that the dark matter yield of the superWIMP mechanism is suppressed considerably due to the non-perturbative effects under consideration. This leads to a significant shift in the cosmologically preferred parameter space of non-thermal dark matter in these models. We also revisit the implications of LHC bounds on long-lived particles associated with non-thermal dark matter and find that testing this scenario at the LHC is a bigger challenge than previously anticipated.

    hep-phastro-ph.COJCAP(2022)·13 citations
21. 21*

    Bound-state effects on dark matter coannihilation: Pushing the boundaries of conversion-driven freeze-out

    Mathias Garny🇩🇪 · Jan Heisig🇧🇪

    Bound-state formation can have a large impact on the dynamics of dark matter freeze-out in the early Universe, in particular for colored coannihilators. We present a general formalism to include an arbitrary number of excited bound states in terms of an effective annihilation cross section, taking bound-state formation, decay and transitions into account, and derive analytic approximations in the limiting cases of no or efficient transitions. Furthermore, we provide explicit expressions for radiative bound-state formation rates for states with arbitrary principal and angular quantum numbers $n,\ell$ for a mediator in the fundamental representation of $SU(3{)}_c$, as well as electromagnetic transition rates among them in the Coulomb approximation. We then assess the impact of bound states within a model with Majorana dark matter and a colored scalar $t$-channel mediator. We consider the regime of coannihilation as well as conversion-driven freeze-out (or coscattering), where the relic abundance is set by the freeze-out of conversion processes. We find that the region in parameter space where the latter occurs is considerably enhanced into the multi-TeV regime. For conversion-driven freeze-out, dark matter is very weakly coupled, evading direct and indirect detection constraints but leading to prominent signatures of long-lived particles that provide great prospects to be probed by dedicated searches at the upcoming LHC runs.

    hep-phastro-ph.COPRD(2022)·46 citations
22. 22*

    $B\to P,V$ form factors with the $B$-meson light-cone sum rules

    Yue-Long Shen🇨🇳 · Yan-Bing Wei🇩🇪

    In this review, we discuss the calculation of the $B\to P,V$ form factors within the framework of the light-cone sum rules with the light-cone distribution amplitudes of the $B$ meson. A detailed introduction to the definition, scale evolution, and phenomenological models of the $B$-meson distribution amplitudes is presented. We show two equivalent approaches of calculating the next-to-leading order QCD corrections to the sum rules for the form factors, i.e., the method of regions and the step-by-step matching in the soft-collinear effective theory. The power suppressed corrections to the $B\to P,V$ form factors especially the contributions from the higher-twist $B$-meson distribution amplitudes are displayed. We also present numerical results of the form factors including both the QCD and the power corrections, and phenomenological applications of the predicted form factors such as the determination of the CKM matrix element $|V_{ub}|$.

    hep-phAdv.High Energy Phys.(2022)·14 citations
23. 23*

    Notes on basis-independent computations with the Dirac algebra

    Walter Grimus🇦🇹

    In these notes we first review Pauli's proof of his `fundamental theorem' that states the equivalence of any two sets of Dirac matrices $\{{\gamma }^{\mu }\}$. Due to this theorem not only all physical results in the context of the Dirac equation have to be independent of the basis chosen for the Dirac matrices, but it should also be possible to obtain the results without resorting to a specific basis in the course of the computation. Indeed, we demonstrate this in the case of the behaviour of Dirac spinors under Lorentz transformations, the quantization of the Dirac field, the expectation value of the spin operator and several other topics. In particular, we emphasize the totally different physics and mathematics background of the matrix $\beta$, used in the definition of the conjugate Dirac spinor, and ${\gamma }^0$. Finally, we compare the basis-independent manipulations with those performed in the Weyl basis of Dirac matrices. The present notes provide a self-contained introduction to the Dirac theory by solely exploiting the simplicity of the Dirac algebra and the power of Pauli's Theorem.

    hep-ph0 citations
24. 24*

    Chromo-electric screening length in 2+1 flavor QCD

    Peter Petreczky🇺🇸 · Sebastian Steinbeißer🇩🇪 · Johannes Heinrich Weber🇩🇪

    We study Polyakov loop as well as correlators of real and imaginary parts of the Polyakov loop in 2+1 flavor QCD at finite temperature. We use hypercubic (HYP) smearing to improve the signal in the lattice calculations and to obtain reliable results for the correlators at large distances. From the large distance behavior of the correlators we estimate the chromo-electric screening length to be (0.38-44)/T. Furthermore, we show that the short distance distortions due to HYP smearing do not affect the physics of interest

    ↳ hep-lathep-phPoS(2022)·6 citations
25. 25*

    Color-kinematics duality, double copy and the unitarity method for higher-derivative QCD and quadratic gravity

    Gabriel Menezes🇧🇷

    Here we discuss color-kinematics duality for higher-derivative QCD-like amplitudes. We explicitly show that the duality still holds in this case and it can be instrumental in constructing the associated quadratic-gravity amplitudes by using the double-copy prescription. This allows one to drastically simplify calculations. We also evaluate some tree-level Compton scattering amplitudes in higher-derivative Yang-Mills and quadratic gravity coupled with matter. Furthermore, we illustrate the application of generalized unitarity method for both cases by studying a specific one-loop amplitude.

    ↳ hep-thgr-qchep-phJHEP(2022)·23 citations
26. 26*

    Lattice determination of the pion mass difference $M_{{\pi }^{+}}-M_{{\pi }^0}$ at order $\mathcal{O}({\alpha }_{em})$ and $\mathcal{O}((m_d-m_u{)}^2)$ including disconnected diagrams

    R. Frezzotti🇮🇹 · G. Gagliardi🇮🇹 · V. Lubicz🇮🇹 · G. Martinelli🇮🇹 · F. Sanfilippo🇮🇹 · S. Simula🇮🇹

    We present our preliminary results concerning the charged/neutral pion mass difference $M_{{\pi }^{+}}-M_{{\pi }^0}$ at order $\mathcal{O}({\alpha }_{em})$ in the QED interactions, and for $M_{{\pi }^{+}}-M_{{\pi }^0}$ at order $\mathcal{O}\left((m_d-m_u{)}^2\right)$ in the strong isospin-breaking term. The latter contribution provides a determination of the $\mathrm{SU}(2)$ chiral perturbation theory low-energy constant ${\ell }_7$, whose present estimate is affected by a rather large uncertainty. The disconnected contributions appearing in the diagrammatic expansion of $M_{{\pi }^{+}}-M_{{\pi }^0}$, being very noisy, are notoriously difficult to evaluate and have been neglected in our previous calculations. By making use of twisted mass Lattice QCD simulations and adopting the RM123 method, we will show that taking profit from our recently proposed rotated twisted-mass (RTM) scheme, tailored to improve the signal on these kinds of observables, it is possible to evaluate the disconnected diagrams with good precision. For the QED induced pion mass difference, we obtain, after performing the extrapolation towards the continuum and thermodynamic limit and at the physical point, the preliminary value $M_{{\pi }^{+}}-M_{{\pi }^0}=4.622(95)\mathrm{MeV}$, that is in good agreement with the experimental result. For the determination of the low-energy constant ${\ell }_7$, our result ${\ell }_7=2.5(1.4)\times 10^{-3}$, which is limited so far to a single lattice spacing, is in agreement and improves phenomenological estimates.

    ↳ hep-lathep-phPoS(2022)·4 citations
27. 27*

    Impact of jet-production data on the next-to-next-to-leading-order determination of HERAPDF2.0 parton distributions

    H1 · ZEUS Collaborations: I. Abt · R. Aggarwal · V. Andreev · M. Arratia · V. Aushev · A. Baghdasaryan · A. Baty · K. Begzsuren · O. Behnke · A. Belousov · A. Bertolin and 223 other authors

    The HERAPDF2.0 ensemble of parton distribution functions (PDFs) was introduced in 2015. The final stage is presented, a next-to-next-to-leading-order (NNLO) analysis of the HERA data on inclusive deep inelastic $ep$ scattering together with jet data as published by the H1 and ZEUS collaborations. A perturbative QCD fit, simultaneously of ${\alpha }_s(M_Z^2)$ and and the PDFs, was performed with the result ${\alpha }_s(M_Z^2)=0.1156\pm 0.0011(\exp ){}_{-0.0002}^{+0.0001}(\mathrm{model}$ $+\mathrm{parameterisation})\pm 0.0029(\mathrm{scale})$. The PDF sets of HERAPDF2.0Jets NNLO were determined with separate fits using two fixed values of ${\alpha }_s(M_Z^2)$, ${\alpha }_s(M_Z^2)=0.1155$ and $0.118$, since the latter value was already chosen for the published HERAPDF2.0 NNLO analysis based on HERA inclusive DIS data only. The different sets of PDFs are presented, evaluated and compared. The consistency of the PDFs determined with and without the jet data demonstrates the consistency of HERA inclusive and jet-production cross-section data. The inclusion of the jet data reduced the uncertainty on the gluon PDF. Predictions based on the PDFs of HERAPDF2.0Jets NNLO give an excellent description of the jet-production data used as input.

    ↳ hep-exhep-phEPJC(2022)·44 citations
28. 28*

    Particle physics and cosmology of the string derived no-scale flipped $SU(5)$

    Ignatios Antoniadis🇫🇷 · Dimitri V. Nanopoulos🇺🇸 · John Rizos🇬🇷

    In a recent paper, we identified a cosmological sector of a flipped $SU(5)$ model derived in the free fermionic formulation of the heterotic superstring, containing the inflaton and the goldstino superfields with a superpotential leading to Starobinsky type inflation, while $SU(5)\times U(1)$ is still unbroken. Here, we study the properties and phenomenology of the vacuum after the end of inflation, where the gauge group is broken to the Standard Model. We identify a set of vacuum expectation values, triggered by the breaking of an anomalous $U(1{)}_A$ gauge symmetry at roughly an order of magnitude below the string scale, that solve the F and D-flatness supersymmetric conditions up to 6th order in the superpotential which is explicitly computed, leading to a successful particle phenomenology. In particular, all extra colour triplets become superheavy guaranteeing observable proton stability, while the Higgs doublet mass matrix has a massless pair eigenstate with realistic hierarchical Yukawa couplings to quarks and leptons. The supersymmetry breaking scale is constrained to be high, consistent with the non observation of supersymmetric signals at the LHC.

    ↳ hep-thhep-phEPJC(2022)·15 citations
29. 29*

    Soft Scattering Evaporation of Dark Matter Subhalos by Inner Galactic Gases

    Xiao-jun Bi🇨🇳 · Yu Gao🇨🇳 · Mingjie Jin🇨🇳 · Yugen Lin🇨🇳 · Qian-Fei Xiang🇨🇳

    The large gap between a galactic dark matter subhalo's velocity and its own gravitational binding velocity creates the situation that small subhalos can be evaporated before dark matter thermalize with baryons due to the low binding velocity. In case dark matter acquires an electromagnetic dipole moment, the survival of low-mass subhalos requires stringent limits on the photon-mediated soft scattering. The current stringent direct detection limits indicate for a small dipole moment, which lets DM decouple early and allows small subhalos to form. We calculate the DM kinetic decoupling temperature in the Early Universe and evaluate the smallest protohalo mass. In the late Universe, low-mass subhalos can be evaporated via soft collision by ionized gas and accelerated cosmic rays. We calculate the subhalos evaporation rate and show that subhalos lighter than $10^{-5}{M}_{\odot }$ in the gaseous inner galactic region are subject to evaporation via dark matter's effective electric and magnetic dipole moments below current direct detection limits, which potentially affects the low-mass subhalos distribution in the galactic center.

    ↳ astro-ph.COhep-phEPJC(2023)·3 citations
30. 30*

    Testing the EFT paradigm with top quark final states in proton-proton collisions at LHC with ATLAS and CMS

    Dennis Schwarz🇦🇹

    With the absence of the direct detection of new physics and the large data set collected at the LHC, the search for indirect effects in precision measurements became popular. Effective field theories enable to interpret these effects that originate from physics manifested at currently unreachable energy scales in a model independent framework. In this report, an overview of new analyses performed by the ATLAS and CMS Collaborations in the field of top quark physics is given.

    ↳ hep-exhep-ph0 citations
31. 31*

    Entanglement and scattering in quantum electrodynamics: S-matrix information from an entangled spectator particle

    Juan D. Fonseca🇧🇷 · B. Hiller🇵🇹 · J. B. Araujo🇵🇹 · I. G. da Paz🇧🇷 · Marcos Sampaio🇧🇷

    We consider a general quantum field relativistic scattering involving two half spin fermions, $A$ and $B$, which are initially entangled with another fermion $C$ that does not participate in the scattering dynamics. We construct general expressions for the reduced spin matrices for the out-state considering a general tripartite spin-entangled state. In particular we study an inelastic QED process at tree-level, namely $e^{-}{e}^{+}\to {\mu }^{-}{\mu }^{+}$ and a half spin fermion $C$ as an spectator particle which can be entangled to the $AB$ system in the following ways: W state, GHZ state, $|{\text{A}}^{\alpha }⟩\otimes |{\Psi }^{\pm }{⟩}_{\text{BC}}$ and $|{\text{A}}^{\alpha }⟩\otimes |{\Phi }^{\pm }{⟩}_{\text{BC}}$, where $\{|{\Psi }^{\pm }⟩,|{\Phi }^{\pm }⟩\}$ are the Bell basis states and $|{\text{A}}^{\alpha }⟩$ is a spin superposition state of system $A$. We calculate the von-Neumann entropy variation before and after the scattering for the particle $C$ and show that spin measurements in $C$ contain numerical information about the total cross section of the process. We compare the initial states W and GHZ as well as study the role played by the parameter $\alpha$ in the evaluation of the entropy variations and the cross section encoded in the spectator particle.

    ↳ quant-phhep-phhep-thPRD(2022)·24 citations
32. 32*

    Anisotropy of phase transition gravitational wave and its implication for primordial seeds of the Universe

    Yongping Li · Fa Peng Huang🇨🇳 · Xiao Wang🇨🇳 · Xinmin Zhang🇨🇳

    We quantitatively study how the primordial density fluctuations are imprinted on the anisotropy of the phase transition gravitational wave (PTGW). Generated long before recombination and free from Silk damping, the anisotropic PTGW might reveal the density perturbation seeded from inflation or alternatives. We find new behaviors of the PTGW anisotropy power spectrum. The PTGW anisotropy is stronger than the anisotropy of the cosmic microwave background temperature at all scales, and the high-$\ell$ multiples are enhanced about 1 order due to the early integrated Sachs-Wolfe effect. Furthermore, differences in primordial power spectra at small scales manifest themselves more significantly on the angular power spectrum of PTGW anisotropy compared to that of the cosmic microwave background. These properties might provide a novel clue to understanding the primordial density perturbation of our early Universe and thereby complete our understanding of inflation theory. Taking nanohertz PTGW from dark matter models as a typical example, we obtain amplitudes of PTGW anisotropy which are about 4 or 3 orders weaker than the isotropic PTGW energy spectra.

    ↳ astro-ph.COhep-phPRD(2022)·21 citations
33. 33*

    Testing f(R) gravity models with quasar X-ray and UV fluxes

    Matías Leizerovich🇦🇷 · Lucila Kraiselburd🇦🇷 · Susana J. Landau🇦🇷 · Claudia G. Scóccola🇦🇷

    Recently, Active Galactic Nuclei (AGNs) have been proposed as standardizable candles, thanks to an observed non-linear relation between their X-ray and optical-ultraviolet (UV) luminosities, which provides an independent measurement of their distances. In this paper, we use these observables for the first time to estimate the parameters of f(R) gravity models (specifically the Hu-Sawicki and the exponential models) together with the cosmological parameters. The importance of this type of modified gravity theories lies in the fact that they can explain the late time accelerated expansion of the universe without the inclusion of a dark energy component. We have also included other observable data to the analyses such as estimates of the Hubble parameter H(z) from Cosmic Chronometers, the Pantheon Type Ia supernovae compilation, and Baryon Acoustic Oscillations measurements. Our results show that the allowed space parameter is restricted when both AGN and BAO data are added to CC and SnIa data, being the BAO data set the most restrictive one. We can also conclude that even though our results are consistent with the ones from the LCDM model, small deviations from General Relativity, than can be successfully described by the f(R) models studied in this paper, are also allowed by the considered data sets.

    ↳ astro-ph.COgr-qchep-phPRD(2022)·27 citations
34. 34*

    Primordial black holes from spectator field bubbles

    David Navidad Maeso🇪🇪 · Luca Marzola🇪🇪 · Martti Raidal🇪🇪 · Ville Vaskonen🇪🇸 · Hardi Veermäe🇪🇪

    We study the evolution of light spectator fields in an asymmetric polynomial potential. During inflation, stochastic fluctuations displace the spectator field from the global minimum of its potential, populating the false vacuum state and thereby allowing for the formation of false vacuum bubbles. By using a lattice simulation, we show that these bubbles begin to contract once they re-enter the horizon and, if sufficiently large, collapse into black holes. This process generally results in the formation of primordial black holes, which, due to the specific shape of their mass function, are constrained to yield at most 1% of the total dark matter abundance. However, the resulting population can source gravitational wave signals observable at the LIGO-Virgo experiments, provide seeds for supermassive black holes or cause a transient matter-dominated phase in the early Universe.

    ↳ astro-ph.COhep-phhep-thJCAP(2022)·40 citations
35. 35*

    Rotating and vibrating symmetric top molecule RaOCH${}_3$ in the fundamental $\mathcal{P}$, $\mathcal{T}$-violation searches

    Anna Zakharova🇷🇺

    We study the influence of the rotations and vibrations of the symmetric top RaOCH${}_3$ molecule on its effectiveness as a probe for the $\mathcal{P}$ and $\mathcal{T}$-violating effects, such as the electron electric dipole moment (eEDM) and the scalar-pseudoscalar electron-nucleon interaction (Ne-SPS). The corresponding enhancement parameters $E_{\mathrm{eff}}$ and $E_{\mathrm{s}}$ are computed for the ground and first excited rovibrational states with different values of the angular momentum component $K$. For the lowest $K$-doublet with $v_{\perp }=0$ and $K=1$ the values are $E_{\mathrm{eff}}=47.647GV/cm$ and $E_{\mathrm{s}}=62.109\mathrm{kHz}$. The results show larger deviation from the equilibrium values than in triatomic molecules.

    ↳ physics.atom-phhep-phphysics.chem-phquant-phPRA(2022)·12 citations
36. 36*

    The Linear Template Fit

    Daniel Britzger🇩🇪

    The estimation of parameters from data is a common problem in many areas of the physical sciences, and frequently used algorithms rely on sets of simulated data which are fit to data. In this article, an analytic solution for simulation-based parameter estimation problems is presented. The matrix formalism, termed the Linear Template Fit, calculates the best estimators for the parameters of interest. It combines a linear regression with the method of least squares. The algorithm uses only predictions calculated for a few values of the parameters of interest, which have been made available prior to its execution. The Linear Template Fit is particularly suited for performance critical applications and parameter estimation problems with computationally intense simulations, which are otherwise often limited in their usability for statistical inference. Equations for error propagation are discussed in detail and are given in closed analytic form. For the solution of problems with a nonlinear dependence on the parameters of interest, the Quadratic Template Fit is introduced. As an example application, a determination of the strong coupling constant from inclusive jet cross section data at the CERN Large Hadron Collider is studied and compared with previously published results.

    ↳ physics.data-anhep-exhep-phstat.AP+1EPJC(2022)·12 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.