Thu·Mar 19, 2020Thursday·March 19, 2020

1. 01*

   Electric transitions of the charmed-strange mesons in a relativistic quark model

   Shao-Feng Chen🇨🇳 · Jing Liu🇨🇳 · Hai-Qing Zhou🇨🇳 · Dian-Yong Chen🇨🇳

   In the present work, we adopt a relativistic constituent quark model to depict the charmed strange meson spectroscopy, in which $D_{s0}(2317)$ and $D_{s1}(2460)$ are considered as the $1^3{P}_0$ and $1P_1^{\prime }$ charmed strange mesons, respectively. By using the wave function obtained from the relativistic quark model, we further investigate the electric transitions between charmed strange mesons. We find the long wave length approximation is reasonable for the charmed strange meson radiative decay by comparing the results with different approximations. The estimated partial widths are all safely under the upper limits of the experimental data. Moreover, we find the branching ratio of $D_{s1}(2536)\to D_s^{\ast }\gamma /D_s\gamma$ are large enough to be detected, which could be searched by further experiments in Belle II and LHCb.

   hep-phhep-exEPJC(2020)·12 citations
2. 02*

   minimal-lagrangians: Generating and studying dark matter model Lagrangians with just the particle content

   Simon May🇩🇪

   minimal-lagrangians is a Python program which allows one to specify the field content of an extension of the Standard Model of particle physics and, using this information, to generate the most general renormalizable Lagrangian that describes such a model. As the program was originally created for the study of minimal dark matter models with radiative neutrino masses, it can handle additional scalar or Weyl fermion fields which are $\mathrm{SU}(3{)}_{\mathrm{C}}$ singlets, $\mathrm{SU}(2{)}_{\mathrm{L}}$ singlets, doublets or triplets, and can have arbitrary $\mathrm{U}(1{)}_{\mathrm{Y}}$ hypercharge. It is also possible to enforce an arbitrary number of global $\mathrm{U}(1)$ symmetries (with ${\mathbb{Z}}_2$ as a special case) so that the new fields can additionally carry such global charges. In addition to human-readable and $\text{LATEX}$ output, the program can generate SARAH model files containing the computed Lagrangian, as well as information about the fields after electroweak symmetry breaking (EWSB), such as vacuum expectation values (VEVs) and mixing matrices. This capability allows further detailed investigation of the model in question, with minimal-lagrangians as the first component in a tool chain for rapid phenomenological studies of "minimal" dark matter models requiring little effort and no unnecessary input from the user.

   hep-phphysics.comp-phComput.Phys.Commun.(2021)·2 citations
3. 03*

   Self-Organized Criticality

   Helmut Satz🇩🇪

   We apply the concept of self-organized criticality in statistical physics to the study of multihadron production in high energy collisions.

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

   Double and Triple Higgs Boson Production at Future Linear Colliders

   Ijaz Ahmed · Fazal Khaliq · Taimoor Khurshid🇵🇰

   In this paper such processes which act as a source of double Higgs production (2H) as well as triple Higgs production (3H) at future linear colliders are analyzed with in 2HDM and its special type-II, MSSM at various center of mass energies. The main aim of this study is to compute and also compare the cross-sections in double and triple Higgs production processes at the future linear colliders. The production of double charged Higgs boson ($H^{+}{H}^{-}$) as well as triple Higgs boson ($H^{+}{H}^{-}{H}^0$),($H^{+}{H}^{-}{h}^0$) are considered for study at two center of mass energies (1.5 TeV and 3 TeV) within two models 2HDM and MSSM at future linear colliders. It is observed that for double charged Higgs production process (H${}^{+}$H${}^{-}$) the resulting cross-section values are almost same in both the models (in 2HDM and MSSM). On the other hand in the case of Triple Higgs production process ($H^{+}{H}^{-}{H}^0$), ($H^{+}{H}^{-}h0$) several orders of enhancement in cross-sections is observed in 2HDM as compared to MSSM. Similarly two types of processes, neutral Higgs pair production ($A^0{H}^0$) as well as ($A^0{h}^0$) and triple neutral Higgs production ($h^0{h}^0{A}^0$) is analyzed in 2HDM type-I at the future linear ${\mu }^{+}$${\mu }^{-}$ collider for various values of center of mass energies from 500 GeV to 3000 GeV (0.5 TeV to 3 TeV). It is observed that the cross-section for neutral Higgs pair production ($A^0{h}^0$) process is comparatively greater than that of neutral Higgs pair production ($A^0{H}^0$) process. Similarly for neutral Higgs Triple production ($h^0{h}^0{A}^0$) an enhancement is seen in cross-sections with increase of tanß.

   hep-ph1 citation
5. 05*

   Large long-distance contributions to the electric dipole moments of charged leptons in the standard model

   Yasuhiro Yamaguchi🇯🇵 · Nodoka Yamanaka🇯🇵

   We reevaluate the electric dipole moment (EDM) of charged leptons in the standard model using hadron effective models. We find unexpectedly large EDM generated by the hadron level long-distance effect, $d_e=5.8\times 10^{-40}$, $d_{\mu }=1.4\times 10^{-38}$, and $d_{\tau }=-7.3\times 10^{-38}$ ecm, with an error bar of 70\%, exceeding the conventionally known four-loop level elementary contribution by several orders of magnitude.

   hep-phhep-exnucl-thPRL(2020)·129 citations
6. 06*

   Thermal Evolution of Neutron Stars as a Probe of Physics beyond the Standard Model

   Keisuke Yanagi🇯🇵

   Thermal evolution of neutron stars (NSs) is studied as a probe of physics beyond the standard model. We first review the standard cooling theory of NSs in detail, with an emphasis on the roles of nucleon superfluidity. Then we discuss non-standard evolution with axion and dark matter (DM); axion production enhances the cooling while DM accretion leads to heating of NSs. To evaluate the effect of DM heating, we need to compare it to the rotochemical heating, which is caused by the out-of-equilibrium beta processes in a NS. In the dissertation, we also investigate the rotochemical heating in the presence of both neutron and proton superfluidity.

   hep-phastro-ph.HEastro-ph.SR7 citations
7. 07*

   Production of $f_0(980)$ meson at the LHC: Color evaporation versus color-singlet gluon-gluon fusion

   Piotr Lebiedowicz🇵🇱 · Rafał Maciuła🇵🇱 · Antoni Szczurek🇵🇱

   The production of the $f_0(980)$ meson at high energies is not well understood. We investigate two different potential mechanisms for inclusive scalar meson production in the $k_t$-factorization approach: color-singlet gluon-gluon fusion and color evaporation model. The ${\gamma }^{\ast }{\gamma }^{\ast }\to f_0(980)$ form factor(s) can be constraint from the $f_0(980)$ radiative decay width. The $g^{\ast }{g}^{\ast }\to f_0(980)$ form factors are obtained by a replacement of ${\alpha }_{\mathrm{em}}$ electromagnetic coupling constant by ${\alpha }_{\mathrm{s}}$ strong coupling constant and appropriate color factors. The form factors for the two couplings are parametrized with a function motivated by recent results for scalar quarkonia. The differential cross sections are calculated in the $k_t$-factorization approach with modern unintegrated gluon distributions. Unlike for quarkonia it seems rather difficult to describe a preliminary ALICE data for inclusive production of $f_0(980)$ exclusively by the color singlet gluon-gluon fusion mechanism. Two different scenarios for flavor structure of $f_0(980)$ are considered in this context. We consider also mechanism of fusion of quark-antiquark associated with soft gluon emission in a phenomenological color evaporation model (CEM) used sometimes for quarkonium production. Here we use $k_t$-factorization version of CEM to include higher-order contributions. In addition, for comparison we consider also NLO collinear approach with $q\bar{q}q$ and $q\bar{q}g$ color octet partonic final states. Both approaches lead to a similar result. However, very large probabilities are required to describe the preliminary ALICE data. The pomeron-pomeron fusion mechanism is also discussed and results are quantified.

   hep-phhep-exPLB(2020)·8 citations
8. 08*

   Three-body decay of ${\Lambda }_c^{\ast }(2765)$ and determination of its spin-parity

   A. J. Arifi🇯🇵 · H. Nagahiro🇯🇵 · A. Hosaka🇯🇵 · K. Tanida🇯🇵

   We study three-body decays of ${\Lambda }_c^{\ast }(2765)\to {\Lambda }_c^{+}{\pi }^{+}{\pi }^{-}$ by using effective Lagrangians in a non-relativistic framework. We consider the sequential decays through ${\Sigma }_c(2455)\pi$ and ${\Sigma }_c^{\ast }(2520)\pi$ in intermediate states which are dominant contributions. The coupling constants in the effective Lagrangians are computed in the quark model. We demonstrate that the ratio $R=\Gamma ({\Lambda }_c^{\ast }\to {\Sigma }_c^{\ast }(2520)\pi )/\Gamma ({\Lambda }_c^{\ast }\to {\Sigma }_c(2455)\pi )$ and angular correlations are sensitive to the spin and parity of ${\Lambda }_c^{\ast }(2765)$. Thus, the measurement of these observables in experimental facilities such as Belle and LHCb can provide useful constraints to determine the spin and parity of ${\Lambda }_c^{\ast }(2765)$.

   hep-phnucl-thPRD(2020)·14 citations
9. 09*

   Renormalization of a model for spin-1 matter fields

   Ailier Rivero-Acosta🇲🇽 · Carlos A. Vaquera-Araujo🇲🇽

   In this work, the one-loop renormalization of a theory for fields transforming in the $(1,0)\oplus (0,1)$ representation of the Homogeneous Lorentz Group is studied. The model includes an arbitrary gyromagnetic factor and self-interactions of the spin 1 field, which has mass dimension one. The model is shown to be renormalizable for any value of the gyromagnetic factor.

   hep-phEPJC(2020)·2 citations
10. 10*

    Bottom quark mass effects in associated $WH$ production with $H\to b\bar{b}$ decay through NNLO QCD

    Arnd Behring🇩🇪 · Wojciech Bizon🇩🇪 · Fabrizio Caola🇬🇧 · Kirill Melnikov🇩🇪 · Raoul Röntsch🇨🇭

    We present a computation of NNLO QCD corrections to the production of a Higgs boson in association with a $W$ boson at the LHC followed by the decay of the Higgs boson to a $b\bar{b}$ pair. At variance with previous NNLO QCD studies of the same process, we treat $b$ quarks as massive. An important advantage of working with massive $b$ quarks is that it makes the use of flavor jet algorithms unnecessary and allows us to employ conventional jet algorithms to define $b$ jets. We compare NNLO QCD descriptions of the associated $WH(b\bar{b})$ production with massive and massless $b$ quarks and also contrast them with the results provided by parton showers. We find $\mathcal{O}(5\%)$ differences in fiducial cross sections computed with massless and massive $b$ quarks. We also observe that much larger differences between massless and massive results, as well as between fixed-order and parton-shower results, can arise in selected kinematic distributions.

    hep-phPRD(2020)·32 citations
11. 11*

    The ${\Lambda }_b\to {\Lambda }^{\ast }(1520)(\to N\bar{K}){\ell }^{+}{\ell }^{-}$ decay at low-recoil in HQET

    Diganta Das🇮🇳 · Jaydeb Das🇮🇳

    In this paper we discuss the Standard Model and new physics sensitivity of the ${\Lambda }_b\to {\Lambda }^{\ast }(1520)(\to N\bar{K}){\ell }^{+}{\ell }^{-}$ decay at low-recoil, where ${\ell }^{\pm }$ are massive leptons and $N\bar{K}=\{p{K}^{-},n{\bar{K}}^0\}$. We provide a full angular distribution with a set of operators that includes the Standard Model operators and their chirality flipped counterparts, and new scalar and pseudo-scalar operators. The resulting angular distribution allows us to construct observables that we study in the Standard Model and in model-independent new physics scenarios. To reduce the hadronic effects emanating from the ${\Lambda }_b\to {\Lambda }^{\ast }(1520)$ transition form factors, we exploit the Heavy Quark Effective theory framework valid at low ${\Lambda }^{\ast }(1520)$ recoil, \emph{i.e.,} large dilepton invariant mass squared $q^2\sim \mathcal{O}(m_b^2)$. Working to the leading order in $1/m_b$ and including $\mathcal{O}({\alpha }_s)$ corrections, we compute the `improved Isgur-Wise relations' between the form factors. The relations correlate the form factors and thereby allow the description of this decay at the low-recoil region with a smaller number of independent form factors.

    hep-phJHEP(2020)·30 citations
12. 12*

    ${\pi }^0$-$\eta$-${\eta }^{\prime }$ mixing from $V\to P\gamma$ and $P\to V\gamma$ decays

    Rafel Escribano🇪🇸 · Emilio Royo🇪🇸

    An enhanced phenomenological model that includes isospin-symmetry breaking is presented in this letter. The model is then used in a number of statistical fits to the most recent experimental data for the radiative transitions $VP\gamma$ ($V=\rho$, $K^{\ast }$, $\omega$, $\varphi$ and $P=\pi$, $K$, $\eta$, ${\eta }^{\prime }$) and estimations for the mixing angles amongst the three pseudoscalar states with vanishing third-component of isospin are obtained. The quality of the performed fits is good, e.g. ${\chi }_{\text{min}}^2/\text{d.o.f}=1.9$. The current experimental uncertainties allow for isospin symmetry violations with a confidence level of approximately $2.5\sigma$.

    hep-phhep-exPLB(2020)·31 citations
13. 13*

    Minimal flavor violation in the see-saw portal

    Daniele Barducci🇮🇹 · Enrico Bertuzzo🇧🇷 · Andrea Caputo🇪🇸 · Pilar Hernandez🇪🇸

    We consider an extension of the Standard Model with two singlet leptons, with masses in the electroweak range, that induce neutrino masses via the see-saw mechanism, plus a generic new physics sector at a higher scale, $\Lambda$. We apply the minimal flavor violation (MFV) principle to the corresponding Effective Field Theory ($\nu$SMEFT) valid at energy scales $E\ll \Lambda$. We identify the irreducible sources of lepton flavor and lepton number violation at the renormalizable level, and apply the MFV ansätz to derive the scaling of the Wilson coefficients of the $\nu$SMEFT operators up to dimension six. We highlight the most important phenomenological consequences of this hypothesis in the rates for exotic Higgs decays, the decay length of the heavy neutrinos, and their production modes at present and future colliders. We also comment on possible astrophysical implications.

    hep-phJHEP(2020)·22 citations
14. 14*

    Quark masses and mixings in minimally parameterized UV completions of the Standard Model

    Reinhard Alkofer🇦🇹 · Astrid Eichhorn🇩🇰 · Aaron Held🇬🇧 · Carlos M. Nieto🇮🇹 · Roberto Percacci🇮🇹 · Markus Schröfl🇦🇹

    We explore a simple parameterization of new physics that results in an ultraviolet complete gauge-quark sector of the Standard Model. Specifically, we add an antiscreening contribution to the beta functions of the gauge couplings and a flavor-independent, antiscreening contribution to the beta functions of the Yukawa couplings. These two free parameters give rise to an intricate web of Renormalization Group fixed points. Their predictive power extends to the flavor structure and mixing patterns, which we investigate to demonstrate that some of the free parameters of the Standard Model could be determined by the Renormalization Group flow.

    hep-phhep-thAnnals Phys.(2020)·65 citations
15. 15*

    QCD phase transition in the chiral limit

    Olaf Kaczmarek🇩🇪 · Frithjof Karsch🇩🇪 · Anirban Lahiri🇩🇪 · Lukas Mazur🇩🇪 · Christian Schmidt🇩🇪

    We present a lattice QCD based determination of the chiral phase transition temperature in QCD with two massless (up and down) and one strange quark having its physical mass. We propose and calculate two novel estimators for the chiral transition temperature for several values of the light quark masses, corresponding to Goldstone pion masses in the range of $58\mathrm{MeV}\lesssim m_{\pi }\lesssim 163\mathrm{MeV}$. The chiral phase transition temperature is determined by extrapolating to vanishing pion mass using universal scaling analysis. After thermodynamic, continuum and chiral extrapolations we find the chiral phase transition temperature $T_c^0=132_{-6}^{+3}$ MeV. We also present some preliminary calculations on interplay of effective $U_A(1)$ restoration and chiral phase transition towards chiral limit.

    ↳ hep-lathep-phnucl-thNIC Series volume 50, page 193 (2020); IS…·25 citations
16. 16*

    Spontaneous Symmetry Breakdown of Scale Symmetries

    Ichiro Oda🇯🇵

    We discuss spontaneous symmetry breakdown (SSB) of both global and local scale symmetries in scalar-tensor gravity with two scalar fields, one of which couples nonminimally to scalar curvature while the other is a normal scalar field. In case of a global scale symmetry, by moving from the Jordan frame to the Einstein frame, a normal scalar field becomes massive while the dilaton remains massless after the SSB. In case of a local scale symmetry, we take a gauge fixing condition for the local scale invariance, $aR+b{\varphi }^2=k$, which was found in our previous study of a Weyl's quadratic gravity. Together with locally scale invariant potential terms in a classical action, this gauge condition generates a Higgs potential whose vacuum expectation value (VEV) produces the Einstein-Hilbert action with an $R^2$ term in the lowest level of approximation. One interesting aspect in this model is that a massless Nambu-Goldstone boson associated with a scale invariance is absorbed into the metric tensor field and consequently an $R^2$ term is induced in the action.

    ↳ hep-thgr-qchep-ph3 citations
17. 17*

    Limits on $w$CDM from the EFTofLSS with the PyBird code

    Guido D'Amico🇮🇹 · Leonardo Senatore🇺🇸 · Pierre Zhang🇨🇳

    We apply the Effective Field Theory of Large-Scale Structure to analyze the $w$CDM cosmological model. By using the full shape of the power spectrum and the BAO post-reconstruction measurements from BOSS, the Supernovae from Pantheon, and a prior from BBN, we set the competitive CMB-independent limit $w=-1.046_{-0.052}^{+0.055}$ at $68\%$ C.L.. After adding the Planck CMB data, we find $w=-1.023_{-0.030}^{+0.033}$ at $68\%$ C.L.. Our results are obtained using PyBird, a new, fast Python-based code which we make publicly available.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2021)·200 citations
18. 18*

    Measurement of the Photon Beam Asymmetry in $\vec{\gamma }p\to K^{+}{\Sigma }^0$ at $E_{\gamma }=8.5$ GeV

    The GlueX Collaboration: S. Adhikari🇺🇸 · A. Ali🇩🇪 · M. Amaryan🇺🇸 · A. Austregesilo🇺🇸 · F. Barbosa🇺🇸 · J. Barlow🇺🇸 · E. Barriga🇺🇸 · R. Barsotti🇺🇸 · T. D. Beattie🇨🇦 · V. V. Berdnikov🇷🇺 · T. Black🇺🇸 · W. Boeglin🇺🇸 and 114 other authors

    We report measurements of the photon beam asymmetry $\Sigma$ for the reaction $\vec{\gamma }p\to K^{+}{\Sigma }^0$(1193) using the GlueX spectrometer in Hall D at Jefferson Lab. Data were collected using a linearly polarized photon beam in the energy range of 8.2-8.8 GeV incident on a liquid hydrogen target. The beam asymmetry $\Sigma$ was measured as a function of the Mandelstam variable $t$, and a single value of $\Sigma$ was extracted for events produced in the $u$-channel. These are the first exclusive measurements of the photon beam asymmetry $\Sigma$ for the reaction in this energy range. For the $t$-channel, the measured beam asymmetry is close to unity over the $t$-range studied, $-t=(0.1-1.4)$(GeV/$c$)${}^2$, with an average value of $\Sigma =1.00\pm 0.05$. This agrees with theoretical models that describe the reaction via the natural-parity exchange of the $K^{\ast }$(892) Regge trajectory. A value of $\Sigma =0.41\pm 0.09$ is obtained for the $u$-channel integrated up to $-u=2.0$~(GeV/$c$)${}^2$.

    ↳ nucl-exhep-exhep-phPRC(2020)·15 citations
19. 19*

    Ricci linear Weyl/Maxwell mutual sourcing

    Aharon Davidson🇮🇱 · Tomer Ygael🇮🇱

    We elevate the field theoretical similarities between Maxwell and Weyl vector fields into a full local scale/gauge invariant Weyl/Maxwell mutual sourcing theory. In its preliminary form, and exclusively in four dimensions, the associated Lagrangian is dynamical scalar field free, hosts no fermion matter fields, and Holdom kinetic mixing is switched off. The mutual sourcing term is then necessarily spacetime curvature (not just metric) dependent, and inevitably Ricci linear, suggesting that a non-vanishing spacetime curvature can in principle induce an electromagnetic current. In its mature form, however, the Weyl/Maxwell mutual sourcing idea serendipitously constitutes a novel variant of the gravitational Weyl-Dirac (incorporating Brans-Dicke) theory. Counter intuitively, and again exclusively in four dimensions, the optional quartic scalar potential gets consistently replaced by a Higgs-like potential, such that the co-divergence of the Maxwell vector field resembles a conformal vacuum expectation value.

    ↳ gr-qchep-phhep-thUniverse(2020)·0 citations
20. 20*

    Classical Gravitational Scattering at $\mathcal{O}(G^3)$ from Feynman Diagrams

    Clifford Cheung🇺🇸 · Mikhail P. Solon🇺🇸

    We perform a Feynman diagram calculation of the two-loop scattering amplitude for gravitationally interacting massive particles in the classical limit. Conveniently, we are able to sidestep the most taxing diagrams by exploiting the test-particle limit in which the system is fully characterized by a particle propagating in a Schwarzschild spacetime. We assume a general choice of graviton field basis and gauge fixing that contains as a subset the well-known deDonder gauge and its various cousins. As a highly nontrivial consistency check, all gauge parameters evaporate from the final answer. Moreover, our result exactly matches that of Bern et al., here verified up to sixth post-Newtonian order while also reproducing the same unique velocity resummation at third post-Minkowksian order.

    ↳ hep-thgr-qchep-phJHEP(2020)·177 citations
21. 21*

    Charging the Conformal Window

    Domenico Orlando🇮🇹 · Susanne Reffert🇨🇭 · Francesco Sannino🇩🇰

    We investigate the properties of near-conformal dynamics in a sector of large charge when approaching the lower boundary of the conformal window from the chirally broken phase. To elucidate our approach we use the time-honored example of the phenomenologically relevant SU(2) color theory featuring $N_f$ Dirac fermions transforming in the fundamental representation of the gauge group. In the chirally broken phase we employ the effective pion Lagrangian featuring also a pseudo-dilaton to capture a possible smooth conformal-to-non-conformal phase transition. We charge the baryon symmetry of the Lagrangian and study its impact on the ground state and spectrum of the theory as well as the would-be conformal dimensions of the lowest large-charge operator. We moreover study the effects of and dependence on the fermion mass term.

    ↳ hep-thhep-lathep-phPRD(2021)·32 citations
22. 22*

    Towards the QED beta function and renormalons at $1/N_f^2$ and $1/N_f^3$

    Nicola Andrea Dondi🇩🇰 · Gerald V. Dunne🇺🇸 · Manuel Reichert🇩🇰 · Francesco Sannino🇩🇰

    We determine the $1/N_f^2$ and $1/N_f^3$ contributions to the QED beta function stemming from the closed set of nested diagrams. At order $1/N_f^2$ we discover a new logarithmic branch-cut closer to the origin when compared to the $1/N_f$ results. The same singularity location appears at $1/N_f^3$, and these correspond to a UV renormalon singularity in the finite part of the photon two-point function.

    ↳ hep-thhep-lathep-phPRD(2020)·26 citations
23. 23*

    Exploring Hamiltonian Truncation in $\mathbf{d}=2+1$

    Joan Elias Miro🇮🇹 · Edward Hardy🇬🇧

    We initiate the application of Hamiltonian Truncation methods to solve strongly coupled QFTs in $d=2+1$. By analysing perturbation theory with a Hamiltonian Truncation regulator, we pinpoint the challenges of such an approach and propose a way that these can be addressed. This enables us to formulate Hamiltonian Truncation theory for ${\varphi }^4$ in $d=2+1$, and to study its spectrum at weak and strong coupling. The results obtained agree well with the predictions of a weak/strong self-duality possessed by the theory. The ${\varphi }^4$ interaction is a strongly relevant UV divergent perturbation, and represents a case study of a more general scenario. Thus, the approach developed should be applicable to many other QFTs of interest.

    ↳ hep-thcond-mat.stat-mechcond-mat.str-elhep-lat+1PRD(2020)·41 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.