Fri·Jan 17, 2020Friday·January 17, 2020

1. 01*

   Boost-invariant description of polarization within hydrodynamics with spin

   Rajeev Singh🇵🇱

   We briefly review a recently proposed formalism of perfect-fluid hydrodynamics with spin, which is a generalization of the standard hydrodynamic framework and provides a natural tool for describing the evolution of spin-polarized systems of particles with spin 1/2. It is based on the de Groot - van Leeuwen - van Weert forms of energy-momentum and spin tensors and conservation laws. Using Bjorken symmetry we show how this formalism may be used to determine observables describing the polarization of particles measured in the experiment.

   hep-phnucl-thActa Phys.Polon.Supp.(2020)·4 citations
2. 02*

   The Axion Mass from 5D Small Instantons

   Tony Gherghetta🇺🇸 · Valentin V. Khoze🇬🇧 · Alex Pomarol🇪🇸 · Yuri Shirman🇺🇸

   We calculate a new contribution to the axion mass that arises from gluons propagating in a 5th dimension at high energies. By uplifting the 4D instanton solution to five dimensions, the positive frequency modes of the Kaluza-Klein states generate a power-law term in the effective action that inversely grows with the instanton size. This causes 5D small instantons to enhance the axion mass in a way that does not spoil the axion solution to the strong CP problem. Moreover this enhancement can be much larger than the usual QCD contribution from large instantons, although it requires the 5D gauge theory to be near the non-perturbative limit. Thus our result suggests that the mass range of axions (or axion-like particles), which is important for ongoing experimental searches, can depend sensitively on the UV modification of QCD.

   hep-phhep-thJHEP(2020)·89 citations
3. 03*

   Inclusive spectra and Bose-Einstein correlations in small thermal quantum systems

   M.D. Adzhymambetov🇺🇦 · Yu.M. Sinyukov🇺🇦

   The spectra and correlation of identical particles emitted from small local-equilibrium sources are considered. The size of the system is defined by the negative part of the parabolic falling chemical potential. The analytical solution of the problem is found for the case of inclusive measurements. It is shown that in the case where the size of the system is comparable to the thermal wavelength of the particles, the spectra and correlation functions are far from the quasiclassical approximation expected for large systems, and observed femtoscopy scales (interferometry radii) will be essentially smaller than the Gaussian radii of the source. If the maximum value of the chemical potential approaches the critical one, specific for the system, one can consider the possibility of the Bose-Einstein condensation. In such a case the reduction of the intercept of the correlation function for inclusive measurements takes place. The results can be used for the searching of femtoscopy homogeneity lengths in proton-proton collisions at LHC energies.

   hep-phnucl-thPRD(2020)·1 citation
4. 04*

   Grand Pleromal Transmutation : condensates via Konsishi anomaly, dimensional transmutation and ultraminimal GUTs

   Charanjit S. Aulakh🇮🇳

   Using consistency requirements relating chiral condensates imposed by the so called Generalized Konishi Anomaly, we show that dimensional transmutation via gaugino condensation {\emph{in the ultraviolet}} drives gauge symmetry breaking in a large class of {\emph{asymptotically strong}} Super Yang Mills Higgs theories. For Adjoint multiplet type chiral superfields $\Phi$ (transforming as $r\times \bar{r}$ representations of a non Abelian gauge group G), solution of the Generalized Konishi Anomaly(GKA) equations allows calculation of quantum corrected VEVs in terms of the dimensional transmutation scale ${\Lambda }_{UV}\simeq M_X{e}^{\frac{8{\pi }^2}{g^2(M_X)b_0}}$ which determines the gaugino condensate. Thus the gauge coupling at the perturbative unification scale $M_X$ generates GUT symmetry breaking VEVs by non-perturbative dimensional transmutation. This obviates the need for large(or any) input mass scales in the superpotential. Rank reduction can be achieved by including pairs of chiral superfields transforming as either $(\mathbf{Q}(r),\bar{\mathbf{Q}}(\bar{r}))$ or $(\text{Sig}((r\otimes r{)}_{symm})),\text{Sigb}((\bar{r}\otimes \bar{r}{)}_{symm})$, that form trilinear matrix gauge invariants $\bar{Q}\cdot \Phi \cdot Q,\text{Sigb}\cdot \Phi \cdot \text{Sig}$ with $\Phi$. Novel, robust and {\emph{ultraminimal}} Grand unification algorithms emerge from the analysis. We sketch the structure of a realistic Spin(10) model, with the $16$-plet of Spin(10) as the base representation $r$, which mimics the realistic Minimal Supersymmetric GUT but contains even fewer free parameters. We argue that our results point to a large extension of the dominant and normative paradigms of Asymptotic Freedom$/$IR colour confinement and potential driven spontaneous symmetry breaking that have long ruled gauge theories.

   hep-phNPB(2020)·0 citations
5. 05*

   Triangle Singularities and Charmonium-like $XYZ$ States

   Feng-Kun Guo🇨🇳

   The spectrum of hadrons is important for understanding the confinement of quantum chromodynamics. Many new puzzles arose since 2003 due to the abundance of experimental discoveries with the $XYZ$ structures in the heavy quarkonium mass region being the outstanding examples. Hadronic resonances correspond to poles of the $S$-matrix, which has other types of singularities such as the triangle singularity due to the simultaneous on-shellness of three intermediate particles. Here we briefly discuss a few possible manifestations of triangle singularities in the $XYZ$ physics, paying particular attention to the formalism that can be used to analyze the data for charged $Z_c$ structures in the $\psi \pi$ distributions of the reaction $e^{+}{e}^{-}\to \psi {\pi }^{+}{\pi }^{-}$.

   hep-phhep-exnucl-thNucl.Phys.Rev.(2020)·18 citations
6. 06*

   Absolute neutrino mass and the Dirac/Majorana distinction from the weak interaction of aggregate matter

   Alejandro Segarra🇪🇸 · Jose Bernabeu🇪🇸

   The 2$\nu$-mediated force has a range of microns, well beyond the atomic scale. The effective potential is built from the t-channel absorptive part of the scattering amplitude and depends on neutrino properties on-shell. We demonstrate that neutral aggregate matter has a weak charge and calculate the matrix of six coherent charges for its interaction with definite-mass neutrinos. Near the range of the potential the neutrino pair is non-relativistic, leading to observable absolute mass and Dirac/Majorana distinction via different r-dependence and violation of the weak equivalence principle.

   hep-phPRD(2020)·27 citations
7. 07*

   Pseudo-Goldstone Dark Matter in gauged $B-L$ extended Standard Model

   Nobuchika Okada🇺🇸 · Digesh Raut🇺🇸 · Qaisar Shafi🇺🇸

   Gauging the global $B-L$ (Baryon number minus Lepton number) symmetry in the Standard Model (SM) is well-motivated since anomaly cancellations require the introduction of three right-handed neutrinos (RHNs) which play an essential role in naturally generating tiny SM neutrino masses through the seesaw mechanism. In the context of the $B-L$ extended SM, we propose a pseudo-Goldstone boson dark matter (DM) scenario in which the imaginary component of a complex $B-L$ Higgs field serves as the DM in the universe. The DM relic density is determined by the SM Higgs boson mediated process, but its elastic scattering with nucleons through the exchange of Higgs bosons is highly suppressed due to its pseudo-Goldstone boson nature. The model is therefore free from the constraints arising from direct DM detection experiments. We identify regions of the model parameter space for reproducing the observed DM density compatible with the constraints from the Large Hadron Collider and the indirect DM searches by Fermi-LAT and MAGIC.

   hep-phPRD(2021)·45 citations
8. 08*

   Upper limit on first-order electroweak phase transition strength

   Shehu AbdusSalam🇮🇷 · Layla Kalhor🇮🇷 · Mohammad Javad Kazemi🇮🇷

   For a cosmological first-order electroweak phase transition, requiring no sphaleron washout of baryon number violating processes leads to a lower bound on the strength of the transition. The velocity of the boundary between the phases, the so-called bubble wall, can become ultra-relativistic if the friction due to the plasma of particles is not sufficient to retard the wall's acceleration. This bubble ``runaway'' should not occur if a successful baryon asymmetry generation due to the transition is required. Using Boedeker-Moore criterion for bubble wall runaway, within the context of an extension of the standard model of particle physics with a real gauge-single scalar field, we show that a non runaway transition requirement puts an upper bound on the strength of the first-order phase transition.

   hep-phastro-ph.COhep-thInt.J.Mod.Phys.A(2021)·7 citations
9. 09*

   Transverse Force Imaging

   Fatma P. Aslan🇺🇸 · Matthias Burkardt🇺🇸 · Marc Schlegel🇺🇸

   While twist-2 GPDs allow for a determination of the distribution of partons on the transverse plane, twist-3 GPDs contain quark-gluon correlations that provide information about the average transverse color Lorentz force acting on quarks. As an example, we use the nonforward generalization of $g_T(x)$, to illustrate how twist-3 GPDs can provide transverse position information about that force.

   hep-ph3 citations
10. 10*

    Prospects for discovering supersymmetric long-lived particles with MoEDAL

    D. Felea🇷🇴 · J. Mamuzic🇪🇸 · R. Masełek🇵🇱 · N. E. Mavromatos🇬🇧 · V. A. Mitsou🇪🇸 · J. L. Pinfold🇨🇦 · R. Ruiz de Austri🇪🇸 · K. Sakurai🇵🇱 · A. Santra🇪🇸 · O. Vives🇪🇸

    We present a study on the possibility of searching for long-lived supersymmetric partners with the MoEDAL experiment at the LHC. MoEDAL is sensitive to highly ionising objects such as magnetic monopoles or massive (meta)stable electrically charged particles. We focus on prospects of directly detecting long-lived sleptons in a phenomenologically realistic model which involves an intermediate neutral long-lived particle in the decay chain. This scenario is not yet excluded by the current data from ATLAS or CMS, and is compatible with astrophysical constraints. Using Monte Carlo simulation, we compare the sensitivities of MoEDAL versus ATLAS in scenarios where MoEDAL could provide discovery reach complementary to ATLAS and CMS, thanks to looser selection criteria combined with the virtual absence of background. It is also interesting to point out that, in such scenarios, in which charged staus are the main long-lived candidates, the relevant mass range for MoEDAL is compatible with a potential role of Supersymmetry in providing an explanation for the anomalous events observed by the ANITA detector.

    hep-phastro-ph.HEhep-exEPJC(2020)·30 citations
11. 11*

    White dwarf cooling via gravity portals

    Grigoris Panotopoulos🇵🇹 · Ilídio Lopes🇵🇹

    We investigate the impact of gravity portal to properties of white dwarfs, such as equation-of-state as well as cooling time. We find that the interaction between dark matter spin-zero bosons and electrons in the mean field approximation softens the equation-of-state, and the object coolers down slower compared to the usual case.

    hep-phastro-ph.SRgr-qcPRD(2020)·5 citations
12. 12*

    Improvement of heavy-heavy and heavy-light currents with the Oktay-Kronfeld action

    Jon A. Bailey🇰🇷 · Yong-Chull Jang🇺🇸 · Sunkyu Lee🇰🇷 · Weonjong Lee · Jaehoon Leem (LANL-SWME Collaboration)🇰🇷

    The CKM matrix elements $V_{cb}$ and $V_{ub}$ can be obtained by combining data from the experiments with lattice QCD results for the semi-leptonic form factors for the $\bar{B}\to D^{\ast }\ell \bar{\nu }$ and $\bar{B}\to \pi \ell \bar{\nu }$ decays. It is highly desirable to use the Oktay-Kronfeld (OK) action for the form factor calculation on the lattice, since the OK action is designed to reduce the heavy quark discretization error down to the $\mathcal{O}({\lambda }^4)$ level in the power counting rules of the heavy quark effective theory (HQET). Here, we present a matching calculation to improve heavy-heavy and heavy-light currents up to the ${\lambda }^3$ order in HQET, the same level of improvement as the OK action. Our final results for the improved currents are being used in a lattice QCD calculation of the semi-leptonic form factors for the $\bar{B}\to D^{\ast }\ell \bar{\nu }$ and $\bar{B}\to D\ell \bar{\nu }$ decays.

    ↳ hep-lathep-phPRD(2022)·12 citations
13. 13*

    Revisiting the detection rate for axion haloscopes

    Dongok Kim🇰🇷 · Junu Jeong🇰🇷 · SungWoo Youn🇰🇷 · Younggeun Kim🇰🇷 · Yannis K. Semertzidis🇰🇷

    The cavity haloscope has been employed to detect microwave photons resonantly converted from invisible cosmic axions under a strong magnetic field. In this scheme, the axion-photon conversion power has been formulated to be valid for certain conditions, either $Q_{cavity}\ll Q_{\mathrm{axion}}$ or $Q_{cavity}\gg Q_{axion}$. This remedy, however, fails when these two quantities are comparable to each other. Furthermore, the noise power flow has been treated independently of the impedance mismatch of the system, which could give rise to misleading estimates of the experimental sensitivity. We revisit the analytical approaches to derive a general description of the signal and noise power. We also optimize the coupling strength of a receiver to yield the maximal sensitivity for axion search experiments.

    ↳ hep-exhep-phphysics.ins-detJCAP(2020)·65 citations
14. 14*

    Constraints on the velocity dispersion of Dark Matter from Cosmology and new bounds on scattering from the Cosmic Dawn

    Iván Rodríguez-Montoya🇲🇽 · Vladimir Ávila-Reese🇲🇽 · Abdel Pérez-Lorenzana🇲🇽 · Jorge Venzor🇲🇽

    The observational value of the velocity dispersion, $\Delta \upsilon$, is missing in the Dark Matter (DM) puzzle. Non-zero or non-thermal DM velocities can drastically influence Large Scale Structure and the 21-cm temperature at the epoch of the Cosmic Dawn, as well as the estimation of DM physical parameters, such as the mass and the interaction couplings. To study the phenomenology of $\Delta \upsilon$ we model the evolution of DM in terms of a simplistic and generic Boltzmann-like momentum distribution. Using cosmological data from the Cosmic Microwave Background, Baryonic Acoustic Oscillations, and Red Luminous Galaxies, we constrain the DM velocity dispersion for a broad range of masses $10^{-3}eV<m_{\chi }<10^{9}eV$, finding $\Delta {\upsilon }_0\lesssim$ 0.33 km/s (99% CL). Including the EDGES $T_{21}$-measurements, we extend our study to constrain the baryon-DM interaction in the range of DM velocities allowed by our analysis. As a consequence, we present new bounds on two electromagnetic models of DM, namely minicharged particles (MCPs) and electric dipole moment (EDM). For MCPs, the parameter region that is consistent with EDGES and independent bounds on cosmological and stellar physics is very small, pointing to the sub-eV mass regime of DM. A window in the MeV-GeV may still be compatible with these bounds for MCP models without a hidden photon. But the EDM parameter region consistent with EDGES is excluded by Big-Bang Nucleosynthesis and Collider Physics.

    ↳ astro-ph.COhep-phphysics.acc-phApJ(2020)·0 citations
15. 15*

    Detectable Optical Signatures of QED Vacuum Nonlinearities using High-Intensity Laser Fields

    Leonhard Klar🇩🇪

    Up to date, quantum electrodynamics (QED) is the most precisely tested quantum field theory. Nevertheless, particularly in the high-intensity regime it predicts various phenomena that so far have not directly been accessible in all-optical experiments, such as photon-photon scattering phenomena induced by quantum vacuum fluctuations. Here, we focus on all-optical signatures of quantum vacuum effects accessible in the high-intensity regime of electromagnetic fields. We present an experimental setup giving rise to signal photons distinguishable from the background. This configuration is based on two optical pulsed petawatt lasers: one generates a narrow but high-intensity scattering center to be probed by the other one. We calculate the differential number of signal photons attainable with this field configuration analytically and compare it with the background of the driving laser beams.

    ↳ physics.opticshep-phParticles(2020)·12 citations
16. 16*

    The Early Stages of Heavy Ion Collisions

    Francois Gelis🇫🇷

    Heavy ion collisions pose interesting challenges to quantum chromodynamics, because they probe the parton structure of the incoming nuclei at very small longitudinal momentum fractions. Combined with the large size of nuclei, this may lead to the phenomenon of gluon saturation. The Color Glass Condensate is an effective QCD description that aims to cope with such a situation. In this talk, I show how one may study heavy ion collisions in this framework.

    ↳ nucl-thhep-phPoS(2020)·0 citations
17. 17*

    Search for invisible decay of a Higgs boson produced at the CEPC

    Yuhang Tan · Xin Shi · Ryuta Kiuchi · Manqi Ruan · Maoqiang Jing · Xin Mo · Xinchou Lou · Gang Li · Kaili Zhang · Susmita Jyotishmati

    The existence of dark matter has been established in astrophysics. However, there is no candidate for DM in the Stand Model (SM). In SM, the Higgs boson can only decay invisibly via $H\to Z{Z}^{\ast }\to \nu \bar{\nu }\nu \bar{\nu }$ or DM, so any evidence of invisible Higgs decay that exceeds BR (H$\to$inv.) will immediately point to a phenomenon that is beyond the standard model (BSM). In this paper, we report on the upper limit of BR (H$\to$invisible) estimated for three channels, including two leptonic channels and one hadronic channel, under the assumption predicted by SM. With the SM ZH production rate, the upper limit of BR (H$\to$inv.) could reach 0.24\% at the 95\% confidence level.

    ↳ hep-exhep-phCPC(2020)·26 citations
18. 18*

    Precision Measurements in the Higgs Sector at ATLAS and CMS

    Andre Sopczak (Institute of Experimental and Applied Physics, Czech Technical University in Prague)🇨🇿

    A concise review of precision measurements in the Higgs sector of the Standard Model (SM) of particle physics is given using ATLAS and CMS data. The results are based on LHC Run-2 data, taken between 2015 and 2018. Impressive progress has been made since the discovery of the Higgs boson in 2012 for measuring all major production and decay modes. Good agreement with the SM predictions was observed in all measurements.

    ↳ hep-exhep-phPoS(2020)·19 citations
19. 19*

    Dynamical RG and Critical Phenomena in de Sitter Space

    Daniel Green🇺🇸 · Akhil Premkumar🇺🇸

    Perturbative quantum field theory in de Sitter space is known to give rise to a variety of contributions that diverge with time (secular terms). Despite significant progress, a complete understanding of the physical origin of these divergences remains an outstanding problem. In this paper, we will study the origin of secular divergences in de Sitter space for interacting theories that are near attractive conformal fixed points. We show that the secular divergences are determined by the anomalous dimensions of the same theory in flat space and can be re-summed using the dynamical renormalization group. This behavior is mandatory at the conformal fixed point but we show that it holds away from the fixed point as well. We analyze this problem in general using conformal perturbation theory and study conformally coupled scalar fields in four and $4-ϵ$ dimensions as examples.

    ↳ hep-thhep-phJHEP(2020)·49 citations
20. 20*

    Complex poles and spectral functions of Landau gauge QCD and QCD-like theories

    Yui Hayashi🇯🇵 · Kei-Ichi Kondo🇯🇵

    In view of the expectation that the existence of complex poles is a signal of confinement, we investigate the analytic structure of the gluon, quark, and ghost propagators in the Landau gauge QCD and QCD-like theories by employing an effective model with a gluon mass term of the Yang-Mills theory, which we call the massive Yang-Mills model. In this model, we particularly investigate the number of complex poles in the parameter space of the model consisting of gauge coupling constant, gluon mass, and quark mass for the gauge group $SU(3)$ and various numbers of quark flavors $N_F$ within the asymptotic free region. Both the gluon and quark propagators at the best-fit parameters for $N_F=2$ QCD have one pair of complex conjugate poles, while the number of complex poles in the gluon propagator varies between zero and four depending on the number of quark flavors and quark mass. Moreover, as a general feature, we argue that the gluon spectral function of this model with nonzero quark mass is negative in the infrared limit. In sharp contrast to gluons, the quark and ghost propagators are insensitive to the number of quark flavors within the current approximations adopted in this paper. These results suggest that details of the confinement mechanism may depend on the number of quark flavors and quark mass.

    ↳ hep-thhep-phPRD(2020)·26 citations
21. 21*

    Comparing parametric and non-parametric velocity-dependent one-scale models for domain wall evolution

    P. P. Avelino🇵🇹

    We perform a detailed comparison between a recently proposed parameter-free velocity-dependent one-scale model and the standard parametric model for the cosmological evolution of domain wall networks. We find that the latter overestimates the damping of the wall motion due to the Hubble expansion and neglects the direct impact of wall decay on the evolution of the root-mean-square velocity of the network. We show that these effects are significant but may be absorbed into a redefinition of the momentum parameter. We also discuss the implications of these findings for cosmic strings. We compute the energy loss and momentum parameters of the standard parametric model for cosmological domain wall evolution using our non-parametric velocity-dependent one-scale model in the context of cosmological models having a power law evolution of the scale factor $a$ with the cosmic time $t$ ($a\propto t^{\lambda }$, $0<\lambda <1$), and compare with the results obtained from numerical field theory simulations. We further provide simple linear functions which roughly approximate the dependence of the energy loss and momentum parameters on $\lambda$.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2020)·11 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.