Tue·Nov 12, 2019Tuesday·November 12, 2019

1. 01*

   How well do we know neutrino-electron scattering? EFT approach

   Oleksandr Tomalak🇺🇸

   We determine the effective theory of neutrino-electron and neutrino-quark scattering and provide the most precise up-to-date prediction for neutrino-electron scattering cross sections quantifying errors for the first time to be of order $0.2-0.4\%$. Radiative corrections in the theory with electron and neutrinos only involve three effective couplings. One is the Fermi constant which is known with sub-ppm accuracy. Another one has a small error of order $0.02\%$. The uncertainty of the third one is limited by the knowledge of hadronic contributions to charge-isospin vector-vector correlation function.

   hep-phhep-exnucl-exnucl-thPoS(2020)·1 citation
2. 02*

   Decays of charged $B$-mesons into three charged leptons and a neutrino

   A. Danilina🇷🇺 · N. Nikitin🇷🇺 · K. Toms🇺🇸

   In the framework of the Standard Model we present predictions for partial widths, double and single differential distributions, and forward--backward lepton asymmetries for four-leptonic decays $B^{-}\to {\mu }^{+}{\mu }^{-}{\bar{\nu }}_e{e}^{-}$, $B^{-}\to e^{+}{e}^{-}{\bar{\nu }}_{\mu }{\mu }^{-}$, $B^{-}\to {\mu }^{+}{\mu }^{-}{\bar{\nu }}_{\mu }{\mu }^{-}$, and $B^{-}\to e^{+}{e}^{-}{\bar{\nu }}_e{e}^{-}$. We consider the contributions of virtual photon emission from the light and heavy quarks of the $B^{-}$--meson, and we include bremsstrahlung of a virtual photon from the charged lepton in the final state. We use the model of vector meson dominance for calculation of virtual photon emission by the light quark of the $B^{-}$--meson and take into account the isotopic correction.

   hep-phPRD(2020)·19 citations
3. 03*

   Possible Precise Neutrino Unitarity?

   Anatael Cabrera🇫🇷

   The exploration of the Standard Model (SM) leptonic mixing has been led by the study of the neutrino ({\nu}) oscillations phenomenon, whose discovery was acknowledged by the 2015 Nobel prize in physics. Half a century of experimental and theoretical effort has established and demonstrated consistency with the 3{\nu} model and with the so far SM three family evidence. While no direct significant manifestation for physics beyond the Standard Model (BSM) has been found, the SM is known not to suffice to explain all today's observed phenomenology. In the forthcoming decade, most oscillation parameters are expected to yield sub-percent precision. Such a knowledge opens the possibility to experimentally test for BSM manifestation(s) via the direct and competitive exploration of the PMNS matrix unitarity for the first time. Any significant deviation might, in turn, evidence the existence of non-standard states (i.e. new neutrino) and/or interactions, thus allowing for direct discovery potential. Even if no deviations were found, the PMNS matrix structure, very different from its CKM counterpart, is of fundamental importance to our understanding of the leptonic flavour sector. In this document, we shall briefly review today's PMNS unitarity status in the context of existing and future particle physics programme within the next decade. We identify the possible need for a missing experiment(s). One such a case maybe a hypothetical Super Chooz, employing the novel LiquidO technology, to address both directly sensitivity to the unitarity and unique impact to the exploration of the neutrino oscillation phenomena. Such a program is expected to additionally and coherently reinforce the physics of all currently planned experiments via indirect information aiding both the CP violation and mass ordering forthcoming measurements.

   hep-phhep-exPoS(2020)·5 citations
4. 04*

   Limits on non-minimal Lorentz violating parameters through FCNC and LFV processes

   Y. M. P. Gomes🇧🇷 · J. A. Helayel-Neto🇧🇷

   In this work we analyse a non-minimal Lorentz-violating extension of the electroweak theory in the fermionic sector. Firstly we analyse the relation between the CKM rotation in the quark sector and possible contributions of this new coupling to flavour changing neutral currents (FCNC) processes. In sequel we look for non-diagonal terms through possible leptonic flavour violation (LFV) decays. Strong bounds are presented to the Lorentz violating parameters of both the quark and the leptonic sectors.

   hep-phEPJC(2020)·8 citations
5. 05*

   The $X(2239)$ and $\eta (2225)$ as hidden-strange molecular states from $\Lambda \bar{\Lambda }$ interaction

   Jun-Tao Zhu🇨🇳 · Yi Liu🇨🇳 · Dian-Yong Chen🇨🇳 · Longyu Jiang🇨🇳 · Jun He

   In this work, we propose a possible assignment of the newly observed $X(2239)$, as well as the $\eta (2225)$, as a molecular state from the interaction of a baryon $\Lambda$ and an antibaryon $\bar{\Lambda }$. With the help of effective Lagrangians, the $\Lambda \bar{\Lambda }$ interaction is described within the one-boson-exchange model with $\eta$, ${\eta }^{\prime }$, $\omega$, $\varphi$, and $\sigma$ exchanges considered. After inserting the potential kernel into the quasipotential Bethe-Salpeter equation, the bound states from the $\Lambda \bar{\Lambda }$ interaction can be studied by searching for the pole of the scattering amplitude. Two loosely bound states with spin parities $I^G(J^{PC})=0^{+}(0^{-+})$ and $0^{-}(1^{--})$ appear near the threshold almost with the same parameter. The $0^{-}(1^{--})$ state can be assigned to the $X(2239)$ observed at BESIII, which is very close to the $\Lambda \bar{\Lambda }$ threshold. The scalar meson $\eta (2225)$ can be interpreted as a $0^{+}(0^{-+})$ state from the $\Lambda \bar{\Lambda }$ interaction. The annihilation effect is also discussed through a coupled-channel calculation plus a phenomenological optical potential. It provides large widths to two bound states produced from the $\Lambda \bar{\Lambda }$ interaction. The mass of the $1^{-}$ state is a little larger than the mass of the $0^{-}$ state after including the annihilation effect, which is consistent with our assignment of these two states as $X(2239)$ and $\eta (2225)$, respectively. The results suggest that further investigation is expected to understand the structures near the $\Lambda \bar{\Lambda }$ threshold, such as $X(2239)$, $\eta (2225)$, and $X(2175)$.

   hep-phCPC(2020)·16 citations
6. 06*

   Dark-sector physics in the search for the rare decays $K^{+}\to {\pi }^{+}\bar{\nu }\nu$ and $K_L\to {\pi }^0\bar{\nu }\nu$

   Marco Fabbrichesi🇮🇹 · Emidio Gabrielli🇮🇹

   We compute the contribution of the decays $K_L\to {\pi }^{0}Q\bar{Q}$ and $K^{+}\to {\pi }^{+}Q\bar{Q}$, where $Q$ is a dark fermion of the dark sector, to the measured widths for the rare decays $K^{+}\to {\pi }^{+}\nu \bar{\nu }$ and $K_L\to {\pi }^0\nu \bar{\nu }$. The recent experimental limit for $\Gamma (K^{+}\to {\pi }^{+}\nu \bar{\nu })$ from NA62 sets a new and very strict bound on the dark-sector parameters. A branching ratio for $K_L\to {\pi }^{0}Q\bar{Q}$ within the reach of the KOTO sensitivity is possible. The Grossman-Nir bound is weakened by the asymmetric effect of the different kinematic cuts enforced by the NA62 and KOTO experiments. This last feature holds true for all models where the decay into invisible states takes place through a light or massless intermediate state.

   hep-phhep-exEPJC(2020)·30 citations
7. 07*

   Transverse-Momentum-Dependent Parton Distribution Functions from Large-Momentum Effective Theory

   Xiangdong Ji🇺🇸 · Yizhuang Liu🇨🇳 · Yu-Sheng Liu🇨🇳

   We show that transverse-momentum-dependent parton distribution functions (TMDPDFs), important non-perturbative quantities for describing the properties of hadrons in high-energy scattering processes such as Drell-Yan and semi-inclusive deep-inelastic scattering with observed small transverse momentum, can be obtained from Euclidean QCD calculations in the framework of large-momentum effective theory (LaMET). We present a LaMET factorization of the Euclidean quasi-TMDPDFs in terms of the physical TMDPDFs and off-light-cone soft function at leading order in $1/P^z$ expansion, with the perturbative matching coefficient satisfying a renormalization group equation. We also discuss the implementation in lattice QCD with finite-length gauge links as well as the rapidity-regularization-independent factorization for Drell-Yan cross section.

   hep-phhep-exhep-latnucl-ex+1PLB(2020)·104 citations
8. 08*

   Compelling evidence of oscillatory behaviour of hadronic multiplicities in the shifted Gompertz distribution

   R. Aggarwal🇮🇳 · M. Kaur🇮🇳

   Study of charged particle multiplicity distribution in high energy interactions of particles helps in revealing the dynamics of particle production and the underlying statistical patterns, which these distributions follow. Several distributions derived from statistics have been employed to understand its behaviour. In one of our earlier papers, we introduced the shifted Gompertz distribution to investigate this variable and showed that the multiplicity distributions in a variety of processes at different energies can be very well described by this distribution. The fact that the shifted Gompertz distribution, which has been extensively used in diffusion theory, social networks and forecasting has been used for the first time in high energy physics collisions, remains interesting. In this paper we investigate the phenomenon of oscillatory behaviour of the counting statistics observed in the experimental data, resulting from different types of recurrence relations defining the probability distributions. We search for such oscillations in the multiplicity distributions well described by the shifted Gompertz distribution and compare our results with the analysis proposed by G. Wilk et al.

   hep-phAdv.High Energy Phys.(2020)·5 citations
9. 09*

   Charming loops in exclusive rare FCNC $B$-decays

   Dmitri Melikhov🇦🇹

   Rare $B$-decays induced by flavour-changing neutral currents (FCNC) is one of the promising candidates for probing physics beyond the Standard model. However, for identifying potential new physics from the data, reliable control over QCD contributions is necessary. We focus on one of such QCD contributions - the charming loops - that potentially can lead to difficulties in disentangling new physics effects from the observables and discuss the possibility to gain control over theoretical predictions for charming loops.

   hep-phEPJ Web Conf.(2019)·12 citations
10. 10*

    Relations for Massive Spinors

    Clemens Heuson🇩🇪

    Recently introduced massive spinors are written as 2-vectors consisting of two massless spinors with opposite helicities. With this notation a couple of relations between them can be derived easily, entirely avoiding the spinor indices. The high energy limit of three point amplitudes is discussed shortly. Finally we add some comments on recursion relations with massive particles.

    hep-ph1 citation
11. 11*

    Dark photon manifestation in the triplet-like QED processes $\gamma +{\ell }_i\to {\ell }_j^{+}{\ell }_j^{-}+{\ell }_i$, $i\ne j,$ $i=e,\mu ,$ $j=e,\mu ,\tau$

    G.I. Gakh🇺🇦 · M.I. Konchatnij🇺🇦 · N.P. Merenkov🇺🇦 · E. Tomasi-Gustafsson🇫🇷

    The triplet-like QED processes $\gamma +{\ell }_i\to {\ell }_j^{+}{\ell }_j^{-}+{\ell }_i$ with $i\ne j,$ and $i=e,\mu ,$ $j=e,\mu ,\tau$ has been investigated as the reactions where a dark photon, $A^{\prime }$, is produced as a virtual state with subsequent decay into a ${\ell }_j^{+}{\ell }_j^{-}-$-pair. This effect arises due to the so-called kinetic mixing and is characterized by the small parameter $ϵ$ describing the coupling strength relative to the electric charge $e$. The main advantage of searching $A^{\prime }$ in these processes is that the background to the $A^{\prime }$ signal is pure QED. Concerning $A^{\prime }$, we consider its contribution in the Compton-type diagrams only since, in this case, the virtual dark photon has time-like nature and its propagator has the Breit-Wigner form. So, near the resonance, $A^{\prime }$ can manifest itself. The contribution of $A^{\prime }$ in the Borsellino diagrams is negligible since, in this case, the virtual dark photon is space-like, the $A^{\prime }$ propagator does not peak and the effect is proportional, at least, to ${ϵ}^2$. We calculate the distributions over the invariant mass of the produced ${\ell }_j^{+}{\ell }_j^{-}-$ pair and search for the kinematical region where the Compton-type diagrams contribution is not suppressed with respect to the Borsellino ones. The value of the parameter $ϵ$ is estimated as a function of the dark photon mass for a given number of events.

    hep-phhep-exnucl-thPRD(2020)·1 citation
12. 12*

    Anomalous quartic $WW\gamma \gamma$ couplings in $ep$ collisions at the LHeC and the FCC-he

    V. Ari🇹🇷 · E. Gurkanli🇹🇷 · A. Gutiérrez-Rodríguez🇲🇽 · M. A. Hernández-Ruíz🇲🇽 · M. Köksal🇹🇷

    We conducted a study on measuring $W^{+}{W}^{-}$ production and on the sensitivity limits at $95\%$ Confidence Level on thirteen anomalous couplings obtained by dimension-8 operators which are related to the anomalous quartic $WW\gamma \gamma$ couplings. We consider the main $e^{-}p\to e^{-}{\gamma }^{\ast }{\gamma }^{\ast }p\to e^{-}{W}^{+}{W}^{-}p$ reaction with the sub-process ${\gamma }^{\ast }{\gamma }^{\ast }\to W^{+}{W}^{-}$ at the Large Hadron electron Collider (LHeC) and the Future Circular Collider-hadron electron (FCC-he). For the LHeC, energies of the $e^{-}$ beams are taken to be $E_e=60$ and 140 GeV and the energy of the $p$ beams is taken to be $E_p=7$ TeV. For the FCC-he, energies of the $e^{-}$ beams are taken to be $E_e=60$ and 140 GeV and the energy of the $p$ beams is taken to be $E_p=50$ TeV, respectively. It is interesting to notice that the LHeC and the FCC-he will lead to model-independent limits on the anomalous quartic $WW\gamma \gamma$ couplings which are one order of magnitude stringent than the CMS Collaboration limits, in addition to being competitive with other limits reported in the literature.

    hep-phEur.Phys.J.Plus(2020)·10 citations
13. 13*

    Abelian Fock-Schwinger representation for the quark propagator in external gauge field

    M.A.Zubkov🇮🇱

    We develop the Diakonov-Petrov approach to the representation of the non-Abelian Wilson loop in an Abelian form. First of all, we extend this approach to the Abelian representation of the parallel transporter corresponding to the open curve rather than to the closed contour. Next, we extend this representation to the case of the non-compact groups. The obtained expressions allow to derive the Abelian form of the Schwinger-Fock representation for the quark propagator in an external color gauge field.

    hep-phPLB(2020)·3 citations
14. 14*

    Lorentz and CPT Violation in Partons

    Alan Kostelecky🇺🇸 · Enrico Lunghi🇺🇸 · Nathan Sherrill🇺🇸 · A.R. Vieira🇧🇷

    A framework is presented for the factorization of high-energy hadronic processes in the presence of Lorentz and CPT violation. The comprehensive effective field theory describing Lorentz and CPT violation, the Standard-Model Extension, is used to demonstrate factorization of the hadronic tensor at leading order in electroweak interactions for deep inelastic scattering and for the Drell-Yan process. Effects controlled by both minimal and nonminimal coefficients for Lorentz violation are explored, and the equivalent parton-model description is derived. The methodology is illustrated by determining cross sections and studying estimated attainable sensitivities to Lorentz violation using real data collected at the Hadronen-Elektronen Ring Anlage and the Large Hadron Collider and simulated data for the future US-based electron-ion collider.

    hep-phJHEP(2020)·17 citations
15. 15*

    Radiative corrections in proton--antiproton annihilation to electron-positron and their application to the PANDA experiment

    Yu.M. Bystritskiy🇷🇺 · V.A. Zykunov🇷🇺 · A. Dbeyssi🇩🇪 · M. Zambrana🇩🇪 · F. Maas🇩🇪 · E. Tomasi-Gustafsson🇫🇷

    Radiative corrections to the annihilation of proton--antiproton into electron--positron are revisited, including virtual and real (soft and hard) photon emission. This issue is relevant for the time-like form factors measurements planned at the PANDA experiment at the FAIR facility, in next future. The relevant formulas are given. A stand-alone Monte-Carlo integrator is developed on the basis of the calculated radiative cross section and its application to the PANDA experiment is illustrated.

    hep-phhep-exnucl-thEPJA(2020)·2 citations
16. 16*

    The Rayleigh Bubble in Quark Matter under a Strong Magnetic Field

    B.O. Kerbikov · M.S. Lukashov

    The transition of QGP from fluid-dynamical regime to freeze-out is accompanied by the onset of instabilities. In the present paper we investigate the impact of the magnetic field on the Rayleigh instability. We show that extremely strong field generated in peripheral heavy ion collisions has an insignificant influence on the Rayleigh bubble dynamics. Magnetic "friction" turns out to be much weaker than the viscous one.

    hep-phnucl-thPRD(2020)·1 citation
17. 17*

    The Equal-Time Quark Propagator in Coulomb Gauge

    Davide Campagnari🇩🇪 · Hugo Reinhardt🇩🇪

    We investigate the equal-time (static) quark propagator in Coulomb gauge within the Hamiltonian approach to QCD. We use a non-Gaussian vacuum wave functional which includes the coupling of the quarks to the spatial gluons. The expectation value of the QCD Hamiltonian is expressed by the variational kernels of the vacuum wave functional by using the canonical recursive Dyson--Schwinger equations (CRDSEs) derived previously. Assuming the Gribov formula for the gluon energy we solve the CRDSE for the quark propagator in the bare-vertex approximation together with the variational equations of the quark sector. Within our approximation the quark propagator is fairly insensitive to the coupling to the spatial gluons and its infrared behaviour is exclusively determined by the strongly infrared diverging instantaneous colour Coulomb potential.

    hep-phhep-thPRD(2019)·3 citations
18. 18*

    Dirac neutrino from the breaking of Peccei-Quinn symmetry

    Seungwon Baek🇰🇷

    We propose a model where Dirac neutrino mass is obtained from small vacuum expectation value (VEV) of neutrino-specific Higgs doublet without fine-tuning problem. The small VEV results from a seesaw-like formula with the high energy scale identified as the Peccei-Quinn (PQ) symmetry breaking scale. Axion can be introduced {\it à la} KSVZ or DFSZ. The model suggests neutrino mass, solution to the strong CP problem, and dark matter may be mutually interconnected.

    hep-phPLB(2020)·28 citations
19. 19*

    Mesons at finite chemical potential and the Silver-Blaze property of QCD

    Pascal J. Gunkel🇩🇪 · Christian S. Fischer🇩🇪 · Philipp Isserstedt🇩🇪

    We summarize our results for light (pseudo-)scalar mesons at finite chemical potential and vanishing temperature. We extract the meson bound state wave functions, masses, and decay constants up to the first-order phase transition from the homogeneous Bethe-Salpeter equation and confirm the validity of the Silver-Blaze property. For this purpose, we solve a coupled set of truncated Dyson-Schwinger equations for the quark and gluon propagators of QCD in Landau gauge.

    hep-phJ.Phys.Conf.Ser.(2020)·6 citations
20. 20*

    Sensitivity of Future Hadron Colliders to Leptoquark Pair Production in the Di-Muon Di-Jets Channel

    B. C. Allanach (University of Cambridge)🇬🇧 · Tyler Corbett (University of Copenhagen)🇩🇰 · Maeve Madigan (University of Cambridge)🇬🇧

    We estimate the future sensitivity of the high luminosity (HL-) and high energy (HE-) modes of the Large Hadron Collider (LHC) and of a 100 TeV future circular collider (FCC-hh) to leptoquark (LQ) pair production in the muon-plus-jet decay mode of each LQ. Such LQs are motivated by the fact they provide an explanation for the neutral current $B-$anomalies. For each future collider, Standard Model (SM) backgrounds and detector effects are simulated. From these, sensitivities of each collider are found. Our measures of sensitivity are based upon a Run II ATLAS search, which we also use for validation. We illustrate with a narrow scalar ('$S_3$') LQ and find that, in our channel, the HL-LHC has exclusion sensitivity to LQ masses up to 1.8 TeV, the HE-LHC up to 4.8 TeV and the FCC-hh up to 13.5 TeV.

    hep-phhep-exEPJC(2020)·37 citations
21. 21*

    Anomalous anomalies from virtual black holes

    Joseph Bramante🇨🇦 · Elizabeth Gould🇨🇦

    We investigate gravitational UV/IR mixing models that predict a breakdown of low energy effective field theory, from loop-level, non-local gravitational corrections to particle processes. We determine how the choice of IR cutoff in these theories alters predictions for lepton magnetic moments. Using Brookhaven E821 muon magnetic moment data, we exclude models of UV/IR mixing with an IR cutoff set by a spherical volume enclosing the experiment. On the other hand, an IR cutoff defined by the simply-connected spatial volume containing the trajectories of the muons, implies a correction to the muon magnetic moment which may have already been observed.

    hep-phgr-qchep-thPRD(2020)·6 citations
22. 22*

    Cutting Multiparticle Correlators Down to Size

    Patrick T. Komiske🇺🇸 · Eric M. Metodiev🇺🇸 · Jesse Thaler🇺🇸

    Multiparticle correlators are mathematical objects frequently encountered in quantum field theory and collider physics. By translating multiparticle correlators into the language of graph theory, we can gain new insights into their structure as well as identify efficient ways to manipulate them. In this paper, we highlight the power of this graph-theoretic approach by "cutting open" the vertices and edges of the graphs, allowing us to systematically classify linear relations among multiparticle correlators and develop faster methods for their computation. The naive computational complexity of an $N$-point correlator among $M$ particles is $\mathcal{O}(M^N)$, but when the pairwise distances between particles can be cast as an inner product, we show that all such correlators can be computed in linear $\mathcal{O}(M)$ runtime. With the help of new tensorial objects called Energy Flow Moments, we achieve a fast implementation of jet substructure observables like $C_2$ and $D_2$, which are widely used at the Large Hadron Collider to identify boosted hadronic resonances. As another application, we compute the number of leafless multigraphs with $d$ edges up to $d=16$ (15,641,159), conjecturing that this is the same as the number of independent kinematic polynomials of degree $d$, previously known only to $d=8$ (279).

    hep-phhep-thmath.COPRD(2020)·22 citations
23. 23*

    Three-loop soft function for heavy-to-light quark decays

    Robin Brüser🇩🇪 · Ze Long Liu🇺🇸 · Maximilian Stahlhofen🇩🇪

    We compute the 1-jettiness soft function for the decay of a heavy quark into a light quark jet plus colorless particles at three-loop order in soft-collinear effective theory. The 1-jettiness measurement fixes the total small light-cone momentum component of the soft radiation with respect to the jet direction. This soft function is a universal ingredient to the factorization of heavy-to-light quark decays in the limit of small 1-jettiness. Our three-loop result is required for resummation at the N${}^3$LL${}^{\prime }$ level, e.g. near the endpoint in the photon energy spectrum of the $B\to X_s\gamma$ decay. It is also a necessary ingredient for future calculations of fully-differential heavy-to-light quark decay rates at N${}^3$LO using the $N$-jettiness subtraction method, e.g. for semileptonic top decays. Using our result for the soft anomalous dimension we confirm predictions on the universal infrared structure of QCD scattering amplitudes with a massive external quark at three loops.

    hep-phJHEP(2020)·31 citations
24. 24*

    Scalar gauge dynamics and Dark Matter

    Dario Buttazzo🇮🇹 · Luca Di Luzio🇩🇪 · Parsa Ghorbani🇮🇹 · Christian Gross🇮🇹 · Giacomo Landini🇮🇹 · Alessandro Strumia🇮🇹 · Daniele Teresi🇮🇹 · Jin-Wei Wang🇮🇹

    We consider theories with one gauge group (SU, SO or Sp) and one scalar in a two-index representation. The renormalizable action often has accidental symmetries (such as global U(1) or unusual group parities) that lead to one or more stable states, providing Dark Matter candidates. We discuss the confined phase(s) of each theory and compute the two Higgs phases, finding no generic dualities among them. Discrete gauge symmetries can arise and accidental symmetries can be broken, possibly giving pseudo-Goldstone Dark Matter. Dark Matter candidates can have a complicated sub-structure characteristic of each group and can be accompanied by extra dark radiation.

    hep-phastro-ph.COhep-thJHEP(2020)·29 citations
25. 25*

    Towards a precision calculation of the effective number of neutrinos $N_{\mathrm{eff}}$ in the Standard Model I: The QED equation of state

    Jack J. Bennett🇦🇺 · Gilles Buldgen🇧🇪 · Marco Drewes🇧🇪 · Yvonne Y. Y. Wong🇦🇺

    We revisit several aspects of Standard Model physics at finite temperature that drive the theoretical value of the cosmological parameter $N_{\mathrm{eff}}$, the effective number of neutrinos in the early universe, away from 3. Our chief focus is finite-temperature corrections to the equation of state of the QED plasma in the vicinity of neutrino decoupling at $T\sim 1$ MeV, where $T$ is the photon temperature. Working in the instantaneous decoupling approximation, we recover at $\mathcal{O}(e^2)$, where $e$ is the elementary electric charge, the well-established correction of $\delta N_{\mathrm{eff}}^{(2)}\simeq 0.010$ across a range of plausible neutrino decoupling temperatures, in contrast to an erroneous claim in the recent literature which found twice as large an effect. At $\mathcal{O}(e^3)$ we find a new and significant correction of $\delta N_{\mathrm{eff}}^{(3)}\simeq -0.001$ that has so far not been accounted for in any precision calculation of $N_{\mathrm{eff}}$, significant because this correction is potentially larger than the change in $N_{\mathrm{eff}}$ induced between including and excluding neutrino oscillations in the transport modelling. In addition to the QED equation of state, we make a first pass at quantifying finite-temperature QED corrections to the weak interaction rates that directly affect the neutrino decoupling process, and find that the $\mathcal{O}(e^2)$ thermal electron mass correction induces a change of $\delta N_{\mathrm{eff}}^{m_{\mathrm{th}}}\lesssim 10^{-4}$. A complete assessment of the various effects considered in this work on the final value of $N_{\mathrm{eff}}$ will necessitate an account of neutrino energy transport beyond the instantaneous decoupling approximation. However, relative to $N_{\mathrm{eff}}=3.044$ obtained in the most recent such calculation, we expect the new effects found in this work to lower the number to $N_{\mathrm{eff}}=3.043$.

    hep-phastro-ph.COJCAP(2020)·129 citations
26. 26*

    Unraveling the nature of universal dynamics in $O(N)$ theories

    K. Boguslavski🇦🇹 · A. Piñeiro Orioli🇺🇸

    Many-body quantum systems far from equilibrium can exhibit universal scaling dynamics which defy standard classification schemes. Here, we disentangle the dominant excitations in the universal dynamics of highly-occupied $N$-component scalar systems using unequal-time correlators. While previous equal-time studies have conjectured the infrared properties to be universal for all $N$, we clearly identify for the first time two fundamentally different phenomena relevant at different $N$. We find all $N\ge 3$ to be indeed dominated by the same Lorentzian ``large-$N$'' peak, whereas $N=1$ is characterized instead by a non-Lorentzian peak with different properties, and for $N=2$ we see a mixture of two contributions.

    hep-phcond-mat.quant-gascond-mat.stat-mechPRD(2020)·30 citations
27. 27*

    Dark Matter, Dark Photon and Superfluid He-4 from Effective Field Theory

    A. Caputo🇪🇸 · A.Esposito🇨🇭 · E. Geoffray🇨🇭 · A. D. Polosa🇮🇹 · S. Sun🇮🇹

    We consider a model of sub-GeV dark matter whose interaction with the Standard Model is mediated by a new vector boson (the dark photon) which couples kinetically to the photon. We describe the possibility of constraining such a model using a superfluid He-4 detector, by means of an effective theory for the description of the superfluid phonon. We find that such a detector could provide bounds that are competitive with other direct detection experiments only for ultralight vector mediator, in agreement with previous studies. As a byproduct we also present, for the first time, the low-energy effective field theory for the interaction between photons and phonons.

    hep-phhep-thPLB(2020)·35 citations
28. 28*

    A new anomaly free flipped 341 model

    Meriem Djouala🇩🇿 · Noureddine Mebarki🇩🇿 · Habib Aissaoui🇩🇿

    A new flipped $SU(3{)}_C\otimes SU(4{)}_L\otimes U(1{)}_X$ model without exotic electric charges is proposed. All the quarks families are arranged in the same representation while leptons generations are in different representations leading to a tree level FCNC. Moreover, It is shown that the cancellation of the triangle chiral anomalies requires new additional leptons 10-plet and quadruplet. All fermions masses have been also discussed. Furthermore, using the most recent experimental data of the branching ratios of $\mu \to ee\bar{e}$ and $\mu \to e\gamma$ rare decay modes, stringent bounds on the heavy neutral bosons masses and the muon-electron mixing matrix element are obtained.

    hep-phInt.J.Mod.Phys.A(2021)·3 citations
29. 29*

    Gauge mediation without gravitino problem by virtue of the QCD anomaly

    Nobuki Yoshimatsu🇯🇵

    We consider the possibility that the Peccei-Quinn charged dynamical supersymmetry breaking (DSB) of m_{3/2}=O(eV) for the Intriligator-Seiberg-Shih model, an axion, converted from a Nambu-Goldstone boson, could become a dark matter candidate, while the QCD anomaly and a sizable \mu value are naturally generated. We also stress that rather minimal DSB content is sufficient to yield the observed mass of the lightest Higgs boson, other than the acceptable soft mass of sparticles in the observable sector.

    hep-phPRD(2019)·1 citation
30. 30*

    Universal scale factors relating mesonic fields and quark operators

    Amir H. Fariborz🇺🇸 · J. Ho🇨🇦 · T.G. Steele🇨🇦

    Scale factor matrices relating mesonic fields in chiral Lagrangians and quark-level operators of QCD sum-rules are shown to be constrained by chiral symmetry, resulting in universal scale factors for each chiral nonet. Built upon this interplay between chiral Lagrangians and QCD sum-rules, the scale factors relating the $a_0$ isotriplet scalar mesons to their underlying quark composite field were recently determined. It is shown that the same technique when applied to $K_0^{\ast }$ isodoublet scalars reproduces the same scale factors, confirming the universality property and further validating this connection between chiral Lagrangians and QCD sum-rules which can have nontrivial impacts on our understanding of the low-energy QCD, in general, and the physics of scalar mesons in particular.

    hep-phMod.Phys.Lett.A(2020)·5 citations
31. 31*

    Inert Doublet Model signatures at future $e^{+}{e}^{-}$ colliders

    Dorota Sokolowska🇧🇷 · Jan Kalinowski🇵🇱 · Jan Klamka🇵🇱 · Wojciech Kotlarski🇩🇪 · Pawel Sopicki🇵🇱 · Tania Robens🇭🇷 · Aleksander Filip Zarnecki🇵🇱

    The Inert Doublet Model (IDM) is one of the simplest extensions of the Standard Model (SM), providing a dark matter candidate. It is a two Higgs doublet model with a discrete $Z_2$ symmetry, that prevents the scalars of the second doublet (inert scalars) from coupling to the SM fermions and makes the lightest of them stable. We study a large group of IDM scenarios, which are consistent with current constraints on direct detection, including the most recent bounds from the XENON1T experiment and relic density of dark matter, as well as with all collider and low-energy limits. We propose a set of benchmark points with different kinematic features, that promise detectable signals at future $e^{+}{e}^{-}$ colliders. Two inert scalar pair-production processes are considered, $e^{+}{e}^{-}\to H^{+}{H}^{-}$ and $e^{+}{e}^{-}\to AH$, followed by decays of $H^{\pm }$ and $A$ into final states which include the lightest and stable neutral scalar dark matter candidate $H$. Significance of the expected observations is studied for different benchmark models and different running scenarios, for centre-of-mass energies up to 3 TeV. Numerical results are presented for the signal signatures with two muons or an electron and a muon in the final state. For high mass scenarios, when the significance is too low for the leptonic signatures, the semi-leptonic signature can be used as the discovery channel.

    hep-phPoS(2020)·14 citations
32. 32*

    Long-range electroweak amplitudes of single hadrons from Euclidean finite-volume correlation functions

    Raúl A. Briceño🇺🇸 · Zohreh Davoudi🇺🇸 · Maxwell T. Hansen🇨🇭 · Matthias R. Schindler🇺🇸 · Alessandro Baroni🇺🇸

    A relation is presented between single-hadron long-range matrix elements defined in a finite Euclidean spacetime, and the corresponding infinite-volume Minkowski amplitudes. This relation is valid in the kinematic region where any number of two-hadron states can simultaneously go on shell, so that the effects of strongly-coupled intermediate channels are included. These channels can consist of non-identical particles with arbitrary intrinsic spins. The result accommodates general Lorentz structures as well as non-zero momentum transfer for the two external currents inserted between the single-hadron states. The formalism, therefore, generalizes the work by Christ et al.~[Phys.Rev. D91 114510 (2015)], and extends the reach of lattice quantum chromodynamics (QCD) to a wide class of new observables beyond meson mixing and rare decays. Applications include Compton scattering of the pion ($\pi {\gamma }^{\star }\to [\pi \pi ,K\overline{K}]\to \pi {\gamma }^{\star }$), kaon ($K{\gamma }^{\star }\to [\pi K,\eta K]\to K{\gamma }^{\star }$) and nucleon ($N{\gamma }^{\star }\to N\pi \to N{\gamma }^{\star }$), as well as double-$\beta$ decays, and radiative corrections to the single-$\beta$ decay, of QCD-stable hadrons. The framework presented will further facilitate generalization of the result to studies of nuclear amplitudes involving two currents from lattice QCD.

    ↳ hep-lathep-phnucl-thPRD(2020)·51 citations
33. 33*

    Lattice QCD calculation of the pion charge radius using a model-independent method

    Xu Feng🇨🇳 · Yang Fu🇨🇳 · Lu-Chang Jin🇺🇸

    We use a method to calculate the hadron's charge radius without model-dependent momentum extrapolations. The method does not require the additional quark propagator inversions on the twisted boundary conditions or the computation of the momentum derivatives of quark propagators and thus is easy to implement. We apply this method to the calculation of pion charge radius $⟨r_{\pi }^2⟩$. For comparison, we also determine $⟨r_{\pi }^2⟩$ with the traditional approach of computing the slope of the form factors. The new method produces results consistent with those from the traditional method and with statistical errors 1.5-1.9 times smaller. For the four gauge ensembles at the physical pion masses, the statistical errors of $⟨r_{\pi }^2⟩$ range from 2.1% to 4.6% by using $\lesssim 50$ configurations. For the ensemble at $m_{\pi }\approx 340$ MeV, the statistical uncertainty is even reduced to a sub-percent level.

    ↳ hep-lathep-exhep-phPRD(2020)·50 citations
34. 34*

    Jet-fluid interaction in the EPOS3-Jet framework

    Iurii Karpenko🇫🇷 · Joerg Aichelin🇫🇷 · Pol Bernard Gossiaux🇫🇷 · Martin Rohrmoser🇵🇱 · Klaus Werner🇫🇷

    EPOS3-Jet is an integrated framework for jet modelling in heavy ion collisions, where the initial hard (jet) partons are produced along with soft (medium) partons in the initial state EPOS approach. The jet partons then propagate in the hydrodynamically expanding medium. The energy and momentum lost by the jet partons is added to the hydrodynamic medium via the source terms. The full evolution proceeds in a concurrent mode, without separating hydrodynamic and jet parts. In this report, we examine the medium recoil effects in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV LHC energy in the EPOS3-Jet framework.

    ↳ nucl-thhep-phnucl-exSpringer Proc.Phys.(2020)·1 citation
35. 35*

    Corrections to the gravitational wave phasing

    Shaoqi Hou🇨🇳 · Xi-Long Fan🇨🇳 · Zong-Hong Zhu🇨🇳

    The gravitational wave, traveling a long cosmological distance to reach interferometers, interacts with the (homogeneous and isotropic) cosmological background, so generally speaking, its amplitude and phase are modified in some nontrivial way. As the sensitivity of interferometers is improved, one may detect corrections to the short-wavelength approximation, which naturally includes the information of cosmological evolution. In this work, the Newman-Penrose variable ${\Psi }_4$ has been calculated to show that there are two new corrections to the short-wavelength approximation. One formally occurs at the first post-Newtonian order but is highly suppressed by the Hubble parameters; the other occurs at the fifth post-Newtonian order, which is due to the variation of the amplitude. The first correction contains the evolution of the Universe, but it may not be easily detected. The second one indicates that the short-wavelength approximation has to be corrected, when the more accurate waveforms with the higher-order post-Newtonian terms are calculated.

    ↳ gr-qcastro-ph.COhep-phPRD(2020)·6 citations
36. 36*

    On the inflationary massive field with a curved field manifold

    Dong-Gang Wang🇳🇱

    Massive fields during inflation provide an interesting opportunity to test new physics at very high energy scales. Meanwhile in fundamental realizations, the inflationary field space typically has a curved geometry, which may leave detectable imprints in primordial observables. In this paper we study an extension of quasi-single field inflation where the inflaton and the massive field belong to a curved field manifold. Because of the nontrivial field space curvature, the massive field here can get significant mass corrections of order the Hubble scale, thus the quasi-single field predictions on primordial non-Gaussianity are affected. We derive the same result in an equivalent approach by using the background effective field theory of inflation, where a dimension-6 operator is identified to play an important role and its cutoff scale is associated with the curvature scale of the field space. In addition, due to the slow-roll evolution of the inflaton, this type of mass correction has intrinsic time-dependence. Consequently, the running mass modifies the scaling behaviour in the squeezed limit of the scalar bispectrum, while the resulting running index measures the curvature of the internal field space. Therefore the minimal setup of a massive field within curved field space during inflation may naturally lead to new observational signatures of the field space geometry.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2020)·53 citations
37. 37*

    The Schrödinger-Poisson method for Large-Scale Structure

    Mathias Garny🇩🇪 · Thomas Konstandin🇩🇪 · Henrique Rubira🇩🇪

    We study the Schrödinger-Poisson (SP) method in the context of cosmological large-scale structure formation in an expanding background. In the limit $\hslash \to 0$, the SP technique can be viewed as an effective method to sample the phase space distribution of cold dark matter that remains valid on non-linear scales. We present results for the 2D and 3D matter correlation function and power spectrum at length scales corresponding to the baryon acoustic oscillation (BAO) peak. We discuss systematic effects of the SP method applied to cold dark matter and explore how they depend on the simulation parameters. In particular, we identify a combination of simulation parameters that controls the scale-independent loss of power observed at low redshifts, and discuss the scale relevant to this effect.

    ↳ astro-ph.COhep-phJCAP(2020)·22 citations
38. 38*

    Status of the MUonE experimental proposal

    Graziano Venanzoni🇮🇹

    We present the status of the MUonE experimental proposal which aims at determining the leading order hadronic contribution to the muon g-2 by measuring the hadronic part of the photon vacuum polarization in the space-like region.

    ↳ hep-exhep-phPoS(2020)·0 citations
39. 39*

    DANCE: Dark matter Axion search with riNg Cavity Experiment

    Yuta Michimura🇯🇵 · Yuka Oshima🇯🇵 · Taihei Watanabe🇯🇵 · Takuya Kawasaki🇯🇵 · Hiroki Takeda🇯🇵 · Masaki Ando🇯🇵 · Koji Nagano🇯🇵 · Ippei Obata🇯🇵 · Tomohiro Fujita🇯🇵

    We have proposed a new approach to search for axion dark matter with an optical ring cavity [Phys. Rev. Lett. 121, 161301 (2018)]. The coupling of photons to axions or axion-like particles makes a modulated difference in the phase velocity between left- and right-handed photons. Our method is to measure this phase velocity difference with a ring cavity, by measuring the resonant frequency difference between two circular polarizations. Our estimation shows that the sensitivity to axion-photon coupling constant $g_{a\gamma }$ for axion mass $m\lesssim 10^{-10}$ eV can be improved by several orders of magnitude compared with the current best limits. In this paper, we present the principles of the Dark matter Axion search with riNg Cavity Experiment (DANCE) and the status of the prototype experiment, DANCE Act-1.

    ↳ physics.ins-detastro-ph.IMhep-phJ.Phys.Conf.Ser.(2020)·36 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.