Thu·Jul 23, 2020Thursday·July 23, 2020

1. 01*

   Direct detection signatures of a primordial Solar dark matter halo

   Noah B. Anderson🇺🇸 · Angelina Partenheimer🇺🇸 · Timothy D. Wiser🇺🇸

   A small admixture of dark matter gravitationally bound to the proto-Solar gas cloud could be adiabatically contracted into Earth-crossing orbits with a local density comparable to (or even exceeding) the Galactic halo density. We show that a significant fraction (~25%) of the resulting 'Solar halo' would remain today, surviving perturbations from Jupiter and close encounters with Earth, and would be potentially observable in direct detection experiments. The population would have distinct signatures, including a nonstandard annual modulation and extremely low velocity dispersion compared with the Galactic halo, making it an especially interesting target for coherent or resonant detection of ultralight particles such as axions or dark photons.

   hep-phastro-ph.EPhep-ex14 citations
2. 02*

   New $\tau$-based evaluation of the hadronic contribution to the vacuum polarization piece of the muon anomalous magnetic moment

   J. A. Miranda🇲🇽 · P. Roig🇲🇽

   We revisit the isospin-breaking and electromagnetic corrections to the decay ${\tau }^{-}\to {\pi }^{-}{\pi }^0{\nu }_{\tau }$, which allow its use as input in the two-pion contribution to the (leading order) hadronic vacuum polarization part of the muon anomalous magnetic moment. We extend a previous resonance chiral Lagrangian analysis, which included those operators saturating the next-to-leading order chiral low energy constants, by including the contributions of the next subleading terms. As a result, we improve agreement between the two-pion tau decay and $e^{+}{e}^{-}$ data and reduce the discrepancy between experiment and the SM prediction of $a_{\mu }$ (using $\tau$ input).

   hep-phhep-exPRD(2020)·98 citations
3. 03*

   $\Omega$-dibaryon production with hadron interaction potential from the lattice QCD in relativistic heavy-ion collisions

   S. Zhang🇨🇳 · Y. G. Ma🇨🇳

   Recently the HAL QCD Collaboration reported the $\Omega -\Omega$ and $N-\Omega$ interaction potentials by the lattice QCD simulations. Based on these results, $N\Omega$ (${}^5{S}_2$) and $\Omega \Omega$ (${}^1{S}_0$) bound states were predicted with the binding energy about a few MeV. In addition, $N-\Omega$ HBT correlation function was also measured by the STAR Collaboration as well as the ALICE Collaboration. These results provide dynamical information whether or not $\Omega$-dibaryons exist in the interaction aspects. Another necessary point for the detection of $\Omega$-dibaryons is the experimental environment where the bound state could be produced and survived in the system. In this context, there are at least two necessary conditions to constrain the production probability of $\Omega$-dibaryons, i.e. the one is the necessary short-range attractive interaction to form the bound state and the another is the experimental environment such as heavy-ion collision provides abundant enough strangeness and multiplicity of nucleons. In this Letter the $\Omega -\Omega$ and $\Omega -$nucleon interaction potentials by the lattice QCD simulations were employed to obtain $\Omega \Omega$ (${}^1{S}_0$) and $N\Omega$ (${}^5{S}_2$) wave functions, and then the productions of $\Omega$-dibaryons were estimated by using of a dynamical coalescence mechanism for the relativistic heavy-ion collisions at $\sqrt{s_{NN}}=$ 200 GeV and 2.76 TeV.

   hep-phnucl-exnucl-thPLB(2020)·19 citations
4. 04*

   Next-to-Leading-logarithm threshold resummation for exclusive $B$ meson decays

   Zhi-Qing Zhang🇨🇳 · Hsiang-nan Li

   We extend the threshold resummation of the large logarithms $\ln x$ which appear in factorization formulas for exclusive $B$ meson decays, $x$ being a spectator momentum fraction, to the next-to-leading-logarithm (NLL) accuracy. It is shown that the NLL resummation effect provides suppression in the end-point region with $x\sim 0$ stronger than the leading-logarithm (LL) one, and thus improves perturbative analyses of the above processes. We revisit the $B\to K\pi$ decays under the NLL resummation, and find that it induces 20-25\% variation of the direct CP asymmetries compared to those from the LL resummation. Our way to avoid the Landau singularity in the inverse Mellin transformation causes little theoretical uncertainty.

   hep-phEPJC(2021)·2 citations
5. 05*

   Study of strange non-strange hadron ratios in pp and p-Pb collisions at LHC energies

   Sarita Sahoo (1 and 2)🇮🇳 · Rama Chandra Baral · Pradip Kumar Sahu (1 and 2)🇮🇳 · Mina Ketan Parida (2) ((1) Institute of Physics, HBNI, Bhubaneswar, India, (2) CETMS, Siksha 'O' Anusandhan Deemed to be University, Bhubaneswar, India)🇮🇳

   It has been observed that the yields of strange and multi-strange hadrons relative to pion increase significantly with the event charged-particle multiplicity. We notice from experimental data that yield ratios between non-strange hadrons, like p/$\pi$ or hadrons of same strange content, like $\Lambda$/K${}_s^0$, show similar enhancement. We have studied this behavior within the ambit of a parton model (EPOS3) and A Multi-Phase Transport (AMPT) model in pp and p-Pb collisions at LHC energies. We investigate model predictions of yields and yield ratios of different identified hadron productions as a function of charged-particle multiplicity and compare them with published ALICE results. The string melting versions of AMPT and EPOS are found to establish enhancements in the particle yield ratios.

   hep-phnucl-th0 citations
6. 06*

   A Phenomenological Approach to Multi-Higgs Production at High Energy

   Fayez M. Abu-Ajamieh🇫🇷

   We tackle the issue of the factorial growth in the amplitudes of multi-Higgs production at high energy by developing a phenomenological approach based on the Higgs splitting functions and Sudakov factors. We utilize the method of generating functionals to define several jet observables for the Higgs sector. Our results suggest that pure Higgs splittings should retain a good UV behavior in contrast to the common picture represented by the breakdown of perturbation theory and violation of unitarity due to the high multiplicity of particles produced at or near threshold, which is found in scalar theories. We thus argue that the issue of the factorial growth in the amplitude of multi-Higgs production is probably associated with applying perturbation theory in a regime where it is no longer valid, as opposed to being a sign of new physics.

   hep-phAsian Journal of Research and Reviews in Physics(2022)·3 citations
7. 07*

   Production of vector mesons in pentaquark states resonance channel in $p$-$A$ ultraperipheral collisions

   Ya-Ping Xie🇨🇳 · Xiao-Yun Wang🇨🇳 · Xurong Chen🇨🇳

   Ultraperipheral collisions (UPCs) of protons and nuclei are important for the study of the photoproduction of vector mesons and exotic states. The photoproduction of vector mesons in the pentaquark resonance channel in $p\text{mbox}-Au$ UPCs at the Relative Heavy Ion Collider (RHIC) and $p$-$Pb$ UPCs at the Large Hadron Collider (LHC) is investigated by employing STARlight package. The cross sections of vector mesons via pentaquark state resonances channel are obtained using effective Lagrangian method. The pseudo-rapidity and rapidity distributions of $J/\psi$ and ${\rm Y}(1S)$ are given for $p\text{mbox}-Au$ UPCs at the RHIC and $p$-$Pb$ at the LHC. It is found that the RHIC is a better platform for discovering the pentaquark states than the LHC. Moreover, $P_b(11080)$ is easier to identify than $P_c(4312)$ because the background of ${\rm Y}(1S)$ is weaker than $J/\psi$ in the $t$-channel at the RHIC.

   hep-phCPC(2021)·8 citations
8. 08*

   Integral X-ray constraints on sub-GeV Dark Matter

   Marco Cirelli🇫🇷 · Nicolao Fornengo🇮🇹 · Bradley J. Kavanagh🇪🇸 · Elena Pinetti🇫🇷

   Light Dark Matter (DM), defined here as having a mass between 1 MeV and about 1 GeV, is an interesting possibility both theoretically and phenomenologically, at one of the frontiers of current progress in the field of DM searches. Its indirect detection via gamma-rays is challenged by the scarcity of experiments in the MeV-GeV region. We look therefore at lower-energy X-ray data from the Integral telescope, and compare them with the predicted DM flux. We derive bounds which are competitive with existing ones from other techniques. Crucially, we include the contribution from inverse Compton scattering on galactic radiation fields and the CMB, which leads to much stronger constraints than in previous studies for DM masses above 20 MeV.

   hep-phastro-ph.COPRD(2021)·102 citations
9. 09*

   Landau gauge Yang-Mills propagators in the complex momentum plane

   Christian S. Fischer🇩🇪 · Markus Q. Huber🇩🇪

   We calculate the dressed gluon and ghost propagators of Landau gauge Yang-Mills theory in the complex momentum plane from their Dyson-Schwinger equations. To this end, we develop techniques for a direct calculation such that no mathematically ill-posed inverse problem needs to be solved. We provide a detailed account of the employed ray technique and discuss a range of tools to monitor the stability of the numerical calculation. Within a truncation employing model ansaetze for the three-point vertices and neglecting effects due to four-point functions, we find a singularity in the gluon propagator in the second quadrant of the complex $p^2$-plane. Although the location of this singularity turns out to be strongly dependent on the model for the three-gluon vertex, it occurs always at complex momenta for the range of models considered.

   hep-phhep-thPRD(2020)·61 citations
10. 10*

    A Neural Resampler for Monte Carlo Reweighting with Preserved Uncertainties

    Benjamin Nachman🇺🇸 · Jesse Thaler🇺🇸

    Monte Carlo event generators are an essential tool for data analysis in collider physics. To include subleading quantum corrections, these generators often need to produce negative weight events, which leads to statistical dilution of the datasets and downstream computational costs for detector simulation. Building on the recent proposal of a positive resampler method to rebalance weights within histogram bins, we introduce neural resampling: an unbinned approach to Monte Carlo reweighting based on neural networks that scales well to high-dimensional and variable-dimensional phase space. We pay particular attention to preserving the statistical properties of the event sample, such that neural resampling not only maintains the mean value of any observable but also its Monte Carlo uncertainty. This uncertainty preservation scheme is general and can also be applied to binned (non-neural network) resampling. To illustrate our neural resampling approach, we present a case study from the Large Hadron Collider of top quark pair production at next-to-leading order matched to a parton shower.

    hep-phhep-exphysics.data-anPRD(2020)·61 citations
11. 11*

    Exploring Jet Substructure in Semi-visible jets

    Deepak Kar🇿🇦 · Sukanya Sinha🇿🇦

    Semi-visible jets arise in strongly interacting dark sectors, where parton evolution includes dark sector emissions, resulting in jets overlapping with missing transverse momentum. The implementation of semi-visible jets is done using the Pythia Hidden valley module to duplicate the QCD sector showering. In this work, several jet substructure observables have been examined to compare semi-visible jets and light quark/gluon jets. These comparisons were performed using different dark hadron fraction in the semi-visible jets (signal). The extreme scenarios where signal consists either of entirely dark hadrons or visible hadrons offers a chance to understand the effect of the specific dark shower model employed in these comparisons. We attempt to decouple the behaviour of jet-substructure observables due to inherent semi-visible jet properties, from model dependence owing to the existence of only one dark shower model as mentioned above.

    hep-phhep-exSciPost Phys.(2021)·29 citations
12. 12*

    Revisiting Magnetogenesis during Inflation

    Alireza Talebian🇮🇷 · Amin Nassiri-Rad🇮🇷 · Hassan Firouzjahi🇮🇷

    We revisit the mechanism of primordial magnetogenesis during inflation by taking into account the dynamics of the stochastic noises of the electromagnetic perturbations. We obtain the associated Langevin and Fokker-Planck equations for the electromagnetic fields and solve them analytically. It is shown that while the backreactions of the electric field energy density may spoil inflation too early, but there are regions of parameter space where the usual decaying behavior of the magnetic fields are replaced by a mean-reverting process of stochastic dynamics. As a result, the magnetic fields settle down into an equilibrium state with the amplitude significantly larger than what is obtained in the absence of the stochastic noises. We show that magnetic fields with present time amplitude $\sim 10^{-13}$ Gauss and coherent length $\mathrm{Mpc}$ can be generated while the backreactions of the electric field perturbations are under control.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2020)·27 citations
13. 13*

    Probing neutron-hidden neutron transitions with the MURMUR experiment

    C. Stasser🇧🇪 · G. Terwagne🇧🇪 · J. Lamblin🇫🇷 · O. Méplan🇫🇷 · G. Pignol🇫🇷 · B. Coupé🇧🇪 · S. Kalcheva🇧🇪 · S. Van Dyck🇧🇪 · M. Sarrazin🇫🇷

    MURMUR is a new passing-through-walls neutron experiment designed to constrain neutron/hidden neutron transitions allowed in the context of braneworld scenarios or mirror matter models. A nuclear reactor can act as a hidden neutron source, such that neutrons travel through a hidden world or sector. Hidden neutrons can propagate out of the nuclear core and far beyond the biological shielding. However, hidden neutrons can weakly interact with usual matter, making possible for their detection in the context of low-noise measurements. In the present work, the novelty rests on a better background discrimination and the use of a mass of a material - here lead - able to enhance regeneration of hidden neutrons into visible ones to improve detection. The input of this new setup is studied using both modelizations and experiments, thanks to tests currently performed with the experiment at the BR2 research nuclear reactor (SCK$\cdot$CEN, Mol, Belgium). A new limit on the neutron swapping probability p has been derived thanks to the measurements taken during the BR2 Cycle 02/2019A: $p<4.0\times 10^{-10}$ at 95% CL. This constraint is better than the bound from the previous passing-through-wall neutron experiment made at ILL in 2015, despite BR2 is less efficient to generate hidden neutrons by a factor 7.4, thus raising the interest of such experiment using regenerating materials.

    ↳ nucl-exhep-exhep-phphysics.ins-detEPJC(2021)·19 citations
14. 14*

    Crystals of superconducting Baryonic tubes in the low energy limit of QCD at finite density

    Fabrizio Canfora🇨🇱 · Marcela Lagos🇨🇱 · Aldo Vera🇨🇱

    The low energy limit of QCD admits (crystals of) superconducting Baryonic tubes at finite density. We begin with the Maxwell-gauged Skyrme model in (3+1)-dimensions (which is the low energy limit of QCD in the leading order of the large N expansion). We construct an ansatz able to reduce the seven coupled field equations in a sector of high Baryonic charge to just one linear Schrodinger-like equation with an effective potential (which can be computed explicitly) periodic in the two spatial directions orthogonal to the axis of the tubes. The solutions represent ordered arrays of Baryonic superconducting tubes as (most of) the Baryonic charge and total energy is concentrated in the tube-shaped regions. They carry a persistent current (which vanishes outside the tubes) even in the limit of vanishing U(1) gauge field: such a current cannot be deformed continuously to zero as it is tied to the topological charge. Then, we discuss the subleading corrections in the 't Hooft expansion to the Skyrme model (called usually \mathcal{L}_{6}$,$\mathcal{L}_{8}$ and so on). Remarkably, the very same ansatz allows to construct analytically these crystals of superconducting Baryonic tubes at any order in the 't Hooft expansion. Thus, no matter how many subleading terms are included, these ordered arrays of gauged solitons are described by the same ansatz and keep their main properties manifesting a universal character. On the other hand, the subleading terms can affect the stability properties of the configurations setting lower bounds on the allowed Baryon density.

    ↳ hep-thastro-ph.HEgr-qchep-ph+1EPJC(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.