Wed·Mar 25, 2020Wednesday·March 25, 2020

1. 01*

   On the Heisenberg limit for detecting vacuum birefringence

   N. Ahmadiniaz🇩🇪 · T.E. Cowan🇩🇪 · R. Sauerbrey🇩🇪 · U. Schramm🇩🇪 · H.-P. Schlenvoigt🇩🇪 · R. Schützhold🇩🇪

   Quantum electrodynamics predicts the vacuum to behave as a non-linear medium, including effects such as birefringence. However, for experimentally available field strengths, this vacuum polarizability is extremely small and thus very hard to measure. In analogy to the Heisenberg limit in quantum metrology, we study the minimum requirements for such a detection in a given strong field (the pump field). Using a laser pulse as the probe field, we find that its energy must exceed a certain threshold depending on the interaction time. However, a detection at that threshold, i.e., the Heisenberg limit, requires highly non-linear measurement schemes - while for ordinary linear-optics schemes, the required energy (Poisson or shot noise limit) is much larger. Finally, we discuss several currently considered experimental scenarios from this point of view.

   hep-phhep-thquant-phPRD(2020)·21 citations
2. 02*

   Gravitational Waves and Possible Fast Radio Bursts from Axion Clumps

   Sichun Sun🇮🇹 · Yun-Long Zhang🇯🇵

   The axion objects such as axion mini-clusters and axion clouds around spinning black holes induce parametric resonances of electromagnetic waves through the axion-photon interaction. In particular, it has been known that the resonances from the axion with the mass around $10^{-6}$eV may explain the observed fast radio bursts (FRBs). Here we argue that similar bursts of high frequency gravitational waves, which we call the fast gravitational wave bursts (FGBs), are generated from axion clumps with the presence of gravitational Chern-Simons (CS) coupling. The typical frequency is half of the axion mass, which in general can range from kHz to GHz. We also discuss the secondary gravitational wave production associated with FRB, as well as the possible host objects of the axion clouds, such as primordial black holes with typical masses around $10^{-5}{M}_{\odot }$. Future detections of FGBs together with the observed FRBs are expected to provide more evidence for the axion.

   hep-phastro-ph.COgr-qcPRD(2021)·29 citations
3. 03*

   The dual properties of chiral and isospin asymmetric dense quark matter formed of two-color quarks

   T. G. Khunjua🇺🇸 · K. G. Klimenko🇷🇺 · R. N. Zhokhov🇷🇺

   In this paper the phase structure of dense baryon matter composed of $u$ and $d$ quarks with two colors has been investigated in the presence of baryon ${\mu }_B$, isospin ${\mu }_I$ and chiral isospin ${\mu }_{I5}$ chemical potentials in the framework of Nambu--Jona-Lasinio model. In the chiral limit, it has been shown that the duality between phases with spontaneous chiral symmetry breaking and condensation of charged pions, found in the three color case, remains valid in the two color case. In addition, it has been shown that there are two more dualities in the phase diagram in two color case, namely (as in the case with ${\mu }_{I5}=0$), at ${\mu }_{I5}\ne 0$ the general $(\mu ,{\mu }_I,{\mu }_{I5})$-phase portrait of the model has dual symmetry between the phase with condensation of charged pions and the phase with diquark condensation. This duality stays exact even in the physical point, $m_0\ne 0$. And at $m_0=0$ the $(\mu ,{\mu }_I,{\mu }_{I5})$-phase portrait becomes even more symmetrical, since dual symmetry between phases with spontaneous chiral symmetry breaking and diquark condensation appears. It is shown that due to the dualities the phase diagram is extremely symmetric and has interlacing structure. One can show that the phase portrait of two-color NJL model can be obtained just by duality properties from the results of investigations of three-color NJL model (it was noticed only after the numerical calculations have been performed). Three-color case shares only one duality of the two color one, and one can only see a facet of this enormously symmetric picture in the case of three colors. Using dualities only, it is possible to show that there are no mixed phases (phases with two non-zero condensates). This prediction of dualities is of great use, because for sure it can be shown by the direct calculations but it would be enormously more complicated and time-consuming numerically.

   hep-phhep-thnucl-thJHEP(2020)·28 citations
4. 04*

   The study of the incoming parton energy loss effect on the NLO nuclear Drell-Yan ratios

   Li-Hua Song🇨🇳 · Shang-Fei Xin🇨🇳 · Yin-Jie Zhang🇨🇳

   At a next-to-leading order calculation, the initial-state energy loss of the quark is investigated by means of the Drell-Yan experimental data including the new E906 measurements. Furthermore, the incoming gluon energy loss effect embedded in the Compton scattering subprocess of the nuclear Drell-Yan process is also examined. The next-to-leading order computations for Drell-Yan ratios are carried out with the SW quenching weights (provided by Salgado and Wiedemann to evaluate the probability distribution that quark (gluon) loses the energy), as well as the nuclear parton distributions (obtained by only fitting the existing experimental data on nuclear structure functions). It is found that the obtained calculations that consider the incoming quark energy loss agree well with the experimental data particularly for E906 data. In addition, the incoming gluon energy loss embodied in the primary next-to-leading order Compton scattering subprocess is not obvious, which may be due to the form of the Drell-Yan differential cross section ratio as a function of the quark momentum fraction ($R_{A_1/A_2}(x_1,x_2,x_F)$) minimizes the influence of the QCD next-to-leading order correction.

   hep-phJ.Phys.G(2020)·1 citation
5. 05*

   Analysis of the tetraquark and hexaquark molecular states with the QCD sum rules

   Zhi-Gang Wang🇨🇳

   In this article, we construct the color-singlet-color-singlet type currents and the color-singlet-color-singlet-color-singlet type currents to study the scalar $D^{\ast }{\bar{D}}^{\ast }$, $D^{\ast }{D}^{\ast }$ tetraquark molecular states and the vector $D^{\ast }{D}^{\ast }{\bar{D}}^{\ast }$, $D^{\ast }{D}^{\ast }{D}^{\ast }$ hexaquark molecular states with the QCD sum rules in details. In calculations, we choose the pertinent energy scales of the QCD spectral densities with the energy scale formula $\mu =\sqrt{M_T^2-(2{\mathbb{M}}_c{)}^2}$ and $\sqrt{M_H^2-(3{\mathbb{M}}_c{)}^2}$ for the tetraquark and hexaquark molecular states respectively in a consistent way. We obtain stable QCD sum rules for the scalar $D^{\ast }{\bar{D}}^{\ast }$, $D^{\ast }{D}^{\ast }$ tetraquark molecular states and the vector $D^{\ast }{D}^{\ast }{\bar{D}}^{\ast }$ hexaquark molecular state, but cannot obtain stable QCD sum rules for the vector $D^{\ast }{D}^{\ast }{D}^{\ast }$ hexaquark molecular state. The connected (nonfactorizable) Feynman diagrams at the tree level (or the lowest order) and their induced diagrams via substituting the quark lines make positive contributions for the scalar $D^{\ast }{D}^{\ast }$ tetraquark molecular state, but make negative or destructive contributions for the vector $D^{\ast }{D}^{\ast }{D}^{\ast }$ hexaquark molecular state. It is of no use or meaningless to distinguish the factorizable and nonfactorizable properties of the Feynman diagrams in the color space in the operator product expansion so as to interpret them in terms of the hadronic observables, we can only obtain information about the short-distance and long-distance contributions.

   hep-phCommun.Theor.Phys.(2021)·13 citations
6. 06*

   Classifying Pole of Amplitude Using Deep Neural Network

   Denny Lane B. Sombillo🇵🇭 · Yoichi Ikeda🇯🇵 · Toru Sato🇯🇵 · Atsushi Hosaka🇯🇵

   Most of exotic resonances observed in the past decade appear as peak structure near some threshold. These near-threshold phenomena can be interpreted as genuine resonant states or enhanced threshold cusps. Apparently, there is no straightforward way of distinguishing the two structures. In this work, we employ the strength of deep feed-forward neural network in classifying objects with almost similar features. We construct a neural network model with scattering amplitude as input and nature of pole causing the enhancement as output. The training data is generated by an S-matrix satisfying the unitarity and analyticity requirements. Using the separable potential model, we generate a validation data set to measure the network's predictive power. We find that our trained neural network model gives high accuracy when the cut-off parameter of the validation data is within $400$-$800\text{mbox}MeV$. As a final test, we use the Nijmegen partial wave and potential models for nucleon-nucleon scattering and show that the network gives the correct nature of pole.

   hep-phhep-exnucl-exnucl-thPRD(2020)·29 citations
7. 07*

   Electroweakino searches at the HL-LHC in the baryon number violating MSSM

   Rahool Kumar Barman🇮🇳 · Biplob Bhattacherjee🇮🇳 · Indrani Chakraborty🇮🇳 · Arghya Choudhury🇮🇳 · Najimuddin Khan🇮🇳

   The projected reach of direct electroweakino searches at the HL-LHC ($\sqrt{s}=14\mathrm{TeV},3000\mathrm{f}{\mathrm{b}}^{-1}$ LHC) in the framework of simplified models with R-parity violating (RPV) operators: ${\lambda }_{112}^{\prime \prime }{u}^c{d}^c{s}^c$ and ${\lambda }_{113}^{\prime \prime }{u}^c{d}^c{b}^c$, is studied. Four different analysis channels are chosen: $Wh$ mediated $1l+2b+jets+\mathrm{E}{/}_{\mathrm{T}}$, $Wh$ mediated $1l+2\gamma +jets+\mathrm{E}{/}_{\mathrm{T}}$, $WZ$ mediated $3l+jets+\mathrm{E}{/}_{\mathrm{T}}$ and $WZ$ mediated $3l+2b+jets+\mathrm{E}{/}_{\mathrm{T}}$ and the projected exclusion/discovery reach of direct wino searches in these channels is analyzed by performing a detailed cut based collider analysis. The projected exclusion contour reaches up to $600-700\mathrm{GeV}$ for a massless bino-like ${\chi }_1^0$ from searches in the $Wh$ mediated $1l+2b+jets+\mathrm{E}{/}_{\mathrm{T}}$, $Wh$ mediated $1l+2\gamma +jets+\mathrm{E}{/}_{\mathrm{T}}$ and $WZ$ mediated $3l+jets+\mathrm{E}{/}_{\mathrm{T}}$ channels, while the $WZ$ mediated $3l+2b+jets+\mathrm{E}{/}_{\mathrm{T}}$ search channel is found to have a projected exclusion reach up to $600\mathrm{GeV}$ for $150\mathrm{GeV}<M_{{\chi }_1^0}<250\mathrm{GeV}$. The baryon number violating simplified scenario considered in this work is found to furnish a weaker projected reach (typically by a factor of $\sim 1/2$) than the R-parity conserving (RPC) case. The projected reach at the HL-LHC in these four channels is also recast for realistic benchmark scenarios.

   hep-phPRD(2021)·16 citations
8. 08*

   QCD Challenges from pp to A-A Collisions

   J. Adolfsson🇸🇪 · A. Andronic🇩🇪 · C. Bierlich🇸🇪 · P. Bozek🇵🇱 · S. Chakraborty🇸🇪 · P. Christiansen🇸🇪 · D. D. Chinellato🇧🇷 · R. J. Fries🇺🇸 · G. Gustafson🇸🇪 · H. van Hees🇩🇪 · P. M. Jacobs🇺🇸 · D. J. Kim🇫🇮 and 28 other authors

   This paper is a write-up of the ideas that were presented, developed and discussed at the third International Workshop on QCD Challenges from pp to A-A, which took place in August 2019 in Lund, Sweden. The goal of the workshop was to focus on some of the open questions in the field and try to come up with concrete suggestions for how to make progress on both the experimental and theoretical sides. The paper gives a brief introduction to each topic and then summarizes the primary results.

   hep-phhep-exnucl-exnucl-thEPJA(2020)·38 citations
9. 09*

   Probing angle of birefringence due to long range axion hair from pulsars

   Tanmay Kumar Poddar🇮🇳 · Subhendra Mohanty🇮🇳

   Rotating neutron star or pulsar can be a possible source of pseudo Nambu Goldstone bosons or axions which can mediate long range axionic hair outside of the pulsar. When the electromagnetic radiation is emitted from pulsar and passes through the long range axion hair, the axion rotates the polarization of the electromagnetic radiation and produces birefringence. We obtain the angle of birefringence due to this long range axionic hair as $0.42^{\circ }$. This result is independent of the rotational frequency, radius of the pulsar, mass of the axion, and axion photon coupling constant. This value is within the accuracy of measuring the linear polarization angle of pulsar light which is $\le 1.0^{\circ }$. Our result continues to hold as long as the range of the axion hair (inverse of axion mass) is greater than the radius of the pulsar, i.e; $m_a<10^{-11}$eV and the axion decay constant $f_a\lesssim \mathcal{O}(10^{17}\mathrm{GeV})$.

   hep-phastro-ph.COPRD(2020)·30 citations
10. 10*

    The Neutrino Casimir Force

    Alexandria Costantino🇺🇸 · Sylvain Fichet🇧🇷

    In the low energy effective theory of the weak interaction, a macroscopic force arises when pairs of neutrinos are exchanged. We calculate the neutrino Casimir force between plates, allowing for two different mass eigenstates within the loop. We also provide the general potential between point sources. We discuss the possibility of distinguishing whether neutrinos are Majorana or Dirac fermions using these quantum forces.

    hep-phquant-phJHEP(2020)·26 citations
11. 11*

    Global asymptotic dynamics of Cosmological Einsteinian Cubic Gravity

    Israel Quiros🇲🇽 · Ricardo García-Salcedo🇲🇽 · Tame Gonzalez🇲🇽 · Jorge Luis Morales Martínez🇲🇽 · Ulises Nucamendi🇲🇽

    In this paper we investigate the cosmological dynamics of an up to cubic curvature correction to General Relativity (GR) known as Cosmological Einsteinian Cubic Gravity (CECG), whose vacuum spectrum consists of the graviton exclusively and its cosmology is well-posed as an initial value problem. We are able to uncover the global asymptotic structure of the phase space of this theory. It is revealed that an inflationary matter-dominated bigbang is the global past attractor which means that inflation is the starting point of any physically meaningful cosmic history. Given that higher order curvature corrections to GR are assumed to influence the cosmological dynamics at early times -- high energies/large curvature limit -- the late-time inflation can not be a consequence of the up to cubic order curvature modifications. We confirm this assumption by showing that late-time acceleration of the expansion in the CECG model is possible only if add a cosmological constant term.

    ↳ gr-qcastro-ph.COhep-phPRD(2020)·29 citations
12. 12*

    Axion oscillations in binary systems: angle-action surgery

    Vincent Desjacques🇮🇱 · Evgeni Grishin🇮🇱 · Yonadav Barry Ginat🇮🇱

    Scalar, tensor waves induce oscillatory perturbations in Keplerian systems that can be probed with measurements of pulsar timing residuals. In this paper, we consider the imprint of coherent oscillations produced by ultralight axion dark matter on the Roemer time delay. We use the angle-action formalism to calculate the time evolution of the observed signal and its dependence on the orbital parameters and the axion phase. We derive exact analytical expressions for arbitrary binary pulsar mass ratio and eccentricity, alleviating the need for long numerical integrations. We emphasize the similarity of the expected signal-to-noise ratio with the response of a harmonic oscillator to an external oscillatory driving. We validate our theoretical predictions with numerical simulations. Our results furnish a useful benchmark for numerical codes and analysis procedures and, hopefully, will motivate the search for such imprints in real data.

    ↳ gr-qcastro-ph.COastro-ph.GAastro-ph.HE+1ApJ(2020)·9 citations
13. 13*

    Not quite black holes as dark matter

    Ufuk Aydemir🇨🇳 · Bob Holdom🇨🇦 · Jing Ren🇨🇳

    Primordial black holes that survive until the present have been considered as a dark matter candidate. In this paper we argue that primordial 2-2-hole remnants provide a more promising and testable option. 2-2-holes arise in quadratic gravity as a new family of classical solutions for ultracompact matter distributions and they possess the black hole exterior without an event horizon. They may serve as the endpoint of gravitational collapse, providing a resolution for the information loss problem. Intriguing thermodynamic behavior is found for these objects when sourced by a thermal gas. A large 2-2-hole radiates with a Hawking-like temperature and exhibits an entropy-area law. At a late stage, the evaporation slows down and essentially stops as the mass asymptotically approaches a minimal value. This remnant mass is determined by a fundamental scale in quadratic gravity. We study the cosmological and astrophysical implications of having these remnants as dark matter and derive the corresponding constraints. A distinctive phenomenon associated with remnant mergers occurs, predicting fluxes of high-energy astrophysical particles due to the spectacular evaporation of the merger product. Measurements of high-energy photon and neutrino fluxes could possibly bound the remnant mass to be not far above the Planck mass. Early-universe physics, on the other hand, requires that 2-2-holes quickly evolve into the remnant state after formation, putting an upper bound on the formation mass.

    ↳ gr-qcastro-ph.COastro-ph.HEhep-ph+1PRD(2020)·19 citations
14. 14*

    Propagation of non-linear waves in hot, ideal, and non-extensive quark-gluon plasma

    Trambak Bhattacharyya🇷🇺 · Abhik Mukherjee🇷🇺

    We study the propagation of energy density perturbation in a hot, ideal quark-gluon medium in which quarks and gluons follow the Tsallis-like momentum distributions. We have observed that a non-extensive MIT bag equation of state obtained with the help of the quantum Tsallis-like distributions gives rise to a breaking wave solution of the equation dictating the evolution of energy density perturbation. However, the breaking of waves is delayed when the value of the Tsallis q parameter and the Tsallis temperature T are higher.

    ↳ nucl-thhep-exhep-phEPJC(2020)·11 citations
15. 15*

    Lattice QCD and baryon-baryon interactions: HAL QCD method

    Sinya Aoki🇯🇵 · Takumi Doi🇯🇵

    In this article, we review the HAL QCD method to investigate baryon-baryon interactions such as nuclear forces in lattice QCD. We first explain our strategy in detail to investigate baryon-baryon interactions by defining potentials in field theories such as QCD. We introduce the Nambu-Bethe-Salpeter (NBS) wave functions in QCD for two baryons below the inelastic threshold. We then define the potential from NBS wave functions in terms of the derivative expansion, which is shown to reproduce the scattering phase shifts correctly below the inelastic threshold. Using this definition, we formulate a method to extract the potential in lattice QCD. Secondly, we discuss pros and cons of the HAL QCD method, by comparing it with the conventional method, where one directly extracts the scattering phase shifts from the finite volume energies through the Lüscher's formula. We give several theoretical and numerical evidences that the conventional method combined with the naive plateau fitting for the finite volume energies in the literature so far fails to work on baryon-baryon interactions due to contaminations of elastic excited states. On the other hand, we show that such a serious problem can be avoided in the HAL QCD method by defining the potential in an energy-independent way. We also discuss systematics of the HAL QCD method, in particular errors associated with a truncation of the derivative expansion. Thirdly, we present several results obtained from the HAL QCD method, which include (central) nuclear force, tensor force, spin-orbital force, and three nucleon force. We finally show the latest results calculated at the nearly physical pion mass, $m_{\pi }\simeq 146$ MeV, including hyperon forces which lead to form $\Omega \Omega$ and $N\Omega$ dibaryons.

    ↳ hep-lathep-phnucl-thFront.in Phys.(2020)·81 citations
16. 16*

    Actinide and lanthanide molecules to search for strong CP-violation

    Leonid V. Skripnikov🇷🇺 · Nikolai S. Mosyagin🇷🇺 · Anatoly V. Titov🇷🇺 · Victor V. Flambaum🇦🇺

    The existence of the fundamental CP-violating interactions inside the nucleus leads to the existence of the nuclear Schiff moment. The Schiff moment potential corresponds to the electric field localized inside the nucleus and directed along its spin. This field can interact with electrons of an atom and induce the permanent electric dipole moment (EDM) of the whole system. The Schiff moment and corresponding electric field are enhanced in the nuclei with the octupole deformation leading to the enhanced atomic EDM. There is also a few-order enhancement of the T,P-violating effects in molecules due to the existence of energetically close levels of opposite parity. We study the Schiff moment enhancement in the class of diatomic molecules with octupole-deformed lanthanide and actinide nuclei: ${}^{227}$AcF, ${}^{227}$AcN, ${}^{227}$AcO${}^{+}$, ${}^{229}$ThO, ${}^{153}$EuO${}^{+}$ and ${}^{153}$EuN. Projecting the existing experimental achievements to measure EDM in diamagnetic molecules with spherical nucleus (${}^{205}$TlF) to the considered systems one can expect a very high sensitivity to the quantum chromodynamics parameter $\bar{\theta }$ and other hadronic CP-violation parameters surpassing the current best limits by several orders of magnitude. It can have a dramatic impact on the modern understanding of the nature of CP-violating fundamental interactions.

    ↳ physics.atom-phhep-phnucl-thphysics.chem-phPhys.Chem.Chem.Phys.(2020)·32 citations
17. 17*

    Generalizing the relativistic quantization condition to include all three-pion isospin channels

    Maxwell T. Hansen🇨🇭 · Fernando Romero-López🇪🇸 · Stephen R. Sharpe🇺🇸

    We present a generalization of the relativistic, finite-volume, three-particle quantization condition for non-identical pions in isosymmetric QCD. The resulting formalism allows one to use discrete finite-volume energies, determined using lattice QCD, to constrain scattering amplitudes for all possible values of two- and three-pion isospin. As for the case of identical pions considered previously, the result splits into two steps: The first defines a non-perturbative function with roots equal to the allowed energies, $E_n(L)$, in a given cubic volume with side-length $L$. This function depends on an intermediate three-body quantity, denoted ${\mathcal{K}}_{\mathrm{df},3}$, which can thus be constrained from lattice QCD input. The second step is a set of integral equations relating ${\mathcal{K}}_{\mathrm{df},3}$ to the physical scattering amplitude, ${\mathcal{M}}_3$. Both of the key relations, $E_n(L)\leftrightarrow {\mathcal{K}}_{\mathrm{df},3}$ and ${\mathcal{K}}_{\mathrm{df},3}\leftrightarrow {\mathcal{M}}_3$, are shown to be block-diagonal in the basis of definite three-pion isospin, $I_{\pi \pi \pi }$, so that one in fact recovers four independent relations, corresponding to $I_{\pi \pi \pi }=0,1,2,3$. We also provide the generalized threshold expansion of ${\mathcal{K}}_{\mathrm{df},3}$ for all channels, as well as parameterizations for all three-pion resonances present for $I_{\pi \pi \pi }=0$ and $I_{\pi \pi \pi }=1$. As an example of the utility of the generalized formalism, we present a toy implementation of the quantization condition for $I_{\pi \pi \pi }=0$, focusing on the quantum numbers of the $\omega$ and $h_1$ resonances.

    ↳ hep-lathep-phnucl-thJHEP(2020)·99 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.