Fri·Mar 6, 2020Friday·March 6, 2020

1. 01*

   Self-contained definition of the Collins-Soper kernel

   Alexey A. Vladimirov🇩🇪

   The rapidity anomalous dimension (RAD), or Collins-Soper kernel, defines the scaling properties of transverse momentum dependent distributions and can be extracted from the experimental data. I derive a self-contained nonperturbative definition that represents RAD without reference to a particular process. This definition makes possible exploration of the properties of RAD by theoretical methods on one side, and the properties of QCD vacuum with collider measurements on another side. To demonstrate these possibilities, I compute the power correction to RAD, its large-b asymptotic, and compare these estimations with recent phenomenological extractions.

   hep-phhep-thPRL(2020)·71 citations
2. 02*

   Vacuum stability and spontaneous violation of the lepton number at low energy scale in a model for light sterile neutrinos

   João Paulo Pinheiro🇧🇷 · C. A. de S. Pires🇧🇷

   It is well known that the Standard Model of the Electroweak interactions rests on a metastable vacuum. This can only be fixed by means of new physics. Presently neutrino physics provides the most intriguing framework to formulate new physics. This is so because, in addition to the problem of the lightness of the active standard neutrinos, currently MiniBooNE experimental result may be indicating that sterile neutrinos exist and are light, too. In this case, it is reasonable to expect that the framework that yields light active and sterile neutrinos could stabilize the vacuum, too. In order to achieve this goal, we consider an extension of the standard model which involves new fermions in the form of right-handed neutrinos (${\nu }_R$) and new scalars in the form of triplet ($\Delta$) and singlet ($\sigma$). Within this framework, tiny masses are obtained when we consider that lepton number is spontaneously broken at low energy scale which means that $\Delta$ and $\sigma$, both, develop very small vacuum expectation values. We investigate if this setting leads to a stable vacuum. For this we obtain the whole set of conditions over the Quartic Terms of the Potential that ensures that the model is Bounded From Below(BFB) and evaluate the RGE-evolution of the self coupling of the Higgs. We show that in such a scenario the Quartic Coupling ${\Phi }^T\Delta \Phi \sigma$, where $\Phi$ is the standard Higgs doublet, is responsible for the stability of the Electroweak Vacuum up to Planck scale. We also extract constraints over the parameters of the Potential by means of Lepton Flavor Violating(LFV) processes and from invisible decay of the standard-like Higgs.

   hep-phPRD(2020)·4 citations
3. 03*

   Scattering Interference effects on $H^{+}\to t\bar{b}$ Signals in MSSM Benchmark Scenarios

   Abdesslam Arhrib🇲🇦 · Duarte Azevedo🇵🇹 · Rachid Benbrik🇲🇦 · Hicham Harouiz🇲🇦 · Stefano Moretti🇬🇧 · Riley Patrick🇦🇺 · Rui Santos🇵🇹

   In this talk an investigation into the interference effects between the process $pp\to \bar{t}b{H}^{+}$ followed by the decay $H^{+}\to t\bar{b}$ and the background process $pp\to t\bar{t}b\bar{b}$ is presented. The level of interference in parts of the parameter space is shown to be high and as such it may spoil the results of typical analyses which treat signal and background as independent. This is shown for two benchmarks of the MSSM.

   hep-phEPJ Web Conf.(2020)·2 citations
4. 04*

   $\gamma$-hadron spectra in p + Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV

   Man Xie🇨🇳 · Xin-Nian Wang · Han-Zhong Zhang🇨🇳

   Under the assumption that a quark-gluon plasma droplet is produced and its evolution can be described by hydrodynamics in p + A collisions, $\gamma$-triggered hadron spectra are studied within a next-to-leading-order perturbative QCD parton model with the medium-modified parton fragmentation functions. The initial conditions and space-time evolution of the small QGP droplet are provided by the superSONIC hydrodynamic model simulations and parton energy loss in such a medium is described by the high-twist (HT) approach. The scaled jet transport coefficient $\hat{q}/T^3$ in this HT approach is extracted from single hadron suppression in central A + A collisions at the same colliding energy. Numerical results for this scenario show that $\gamma$-hadron spectra at $p_{\mathrm{T}}^{\gamma }=12-40$ GeV/$c$ are suppressed by 5\% $\sim$ 10\% in the most central 0 - 10\% p + Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV. The suppression becomes weaker at higher transverse momentum of the $\gamma$ trigger. As a comparison, $\gamma$-hadron suppression in Pb + Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ and 5.02 TeV is also predicted.

   hep-phnucl-thPRC(2021)·28 citations
5. 05*

   Asymptotic analysis of Feynman diagrams and their maximal cuts

   B. Ananthanarayan🇮🇳 · Abhijit B. Das🇮🇳 · Ratan Sarkar🇮🇳

   The ASPIRE program, which is based on the Landau singularities and the method of power geometry to unveil the regions required for the evaluation of a given Feynman diagram asymptotically in a given limit, also allows for the evaluation of scaling coming from the top facets. In this work, we relate the scaling having equal components of the top facets of the Newton polytope to the maximal cut of given Feynman integrals. We have therefore connected two independent approaches to the analysis of Feynman diagrams.

   hep-phhep-thEPJC(2020)·20 citations
6. 06*

   Scale-genesis by Dark Matter and Its Gravitational Wave Signal

   Zhaofeng Kang🇨🇳 · Jiang Zhu🇨🇳

   Classical scale invariance (CSI) may shed light on the weak scale origin, but the realistic CSI extension to the standard model requires a bosonic trigger. We propose a scalar Dark Matter(DM) field $X$ as the trigger, establishing a strong connection between the successful radiative breaking of CSI and DM phenomenologies. The latter forces the breaking scale to $\sim \mathcal{O}(\mathrm{TeV})$. It brightens the test prospect of this scenario via gravitational wave, a sharp prediction of CSI phase transition (CSIPT), which is first order and has strong supercooling. Moreover, we carefully deal with some techniques which are commonly used to analyze CSIPT but maybe missed. In particular, we clarify the imprecision of Witten's formula used in the single field case to calculate the bubble nucleation rate and stress that the essence of Witten's approximation is the validity of high temperature expansion.

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

   Fermionic and scalar dark matter with hidden $\mathrm{U}(1)$ gauge interaction and kinetic mixing

   Juebin Lao🇨🇳 · Chengfeng Cai🇨🇳 · Zhao-Huan Yu🇨🇳 · Yu-Pan Zeng🇨🇳 · Hong-Hao Zhang🇨🇳

   We explore the Dirac fermionic and complex scalar dark matter in the framework of a hidden $\mathrm{U}(1{)}_{\mathrm{X}}$ gauge theory with kinetic mixing between the $\mathrm{U}(1{)}_{\mathrm{X}}$ and $\mathrm{U}(1{)}_{\mathrm{Y}}$ gauge fields. The $\mathrm{U}(1{)}_{\mathrm{X}}$ gauge symmetry is spontaneously broken due to a hidden Higgs field. The kinetic mixing provides a portal between dark matter and standard model particles. Besides, an additional Higgs portal can be realized in the complex scalar case. Dark matter interactions with nucleons are typically isospin violating, and direct detection constraints can be relieved. Although the kinetic mixing has been stringently constrained by electroweak oblique parameters, we find that there are several available parameter regions predicting an observed relic abundance through the thermal production mechanism. Moreover, these regions have not been totally explored in current direct and indirect detection experiments. Future direct detection experiments and searches for invisible Higgs decays at a Higgs factory could further investigate these regions.

   hep-phPRD(2020)·19 citations
8. 08*

   Symmetries in $B\to D^{\ast }\ell \nu$ angular observables

   Marcel Algueró🇪🇸 · Sébastien Descotes-Genon🇫🇷 · Joaquim Matias🇪🇸 · Martín Novoa-Brunet🇫🇷

   We apply the formalism of amplitude symmetries to the angular distribution of the decays $B\to D^{\ast }\ell \nu$ for $\ell =e,\mu ,\tau$. We show that the angular observables used to describe the distribution of this class of decays are not independent in absence of New Physics contributing to tensor operators. We derive sets of relations among the angular coefficients of the decay distribution for the massless and massive lepton cases which can be used to probe in a very general way the consistency among the angular observables and the underlying New Physics at work. We use these relations to access the longitudinal polarisation fraction of the $D^{\ast }$ using different angular coefficients from the ones used by Belle experiment. This in the near future can provide an alternative strategy to measure $F_L^{D^{\ast }}$ in $B\to D^{\ast }\tau \nu$ and to understand the relatively high value measured by the Belle experiment. Using the same symmetries, we identify three observables which may exhibit a tension if the experimental value of $F_L^{D^{\ast }}$ remains high. We discuss how these relations can be exploited for binned measurements. We also propose a new observable that could test for specific scenarios of New Physics generated by light right-handed neutrinos. Finally we study the prospects of testing these relations based on the projected experimental sensitivity of new experiments.

   hep-phJHEP(2020)·31 citations
9. 09*

   Isolated photon production and pion-photon correlations in high-energy $pp$ and $pA$ collisions

   Victor P. Goncalves🇧🇷 · Yuri Lima🇧🇷 · Roman Pasechnik🇸🇪 · Michal Šumbera🇨🇿

   A phenomenological study of the isolated photon production in high energy $pp$ and $pA$ collisions at RHIC and LHC energies is performed. Using the color dipole approach we investigate the production cross section differential in the transverse momentum of the photon considering three different phenomenological models for the universal dipole cross section. We also present the predictions for the rapidity dependence of the ratio of $pA$ to $pp$ cross sections. As a further test of the formalism, for different energies and photon rapidites we analyse the correlation function in azimuthal angle $\Delta \varphi$ between the photon and a forward pion. The characteristic double-peak structure of the correlation function around $\Delta \varphi \simeq \pi$ observed previously for Drell-Yan pair production is found for isolated photon emitted into the forward rapidity region which can be tested by future experiments.

   hep-phhep-exPRD(2020)·23 citations
10. 10*

    Predictions from warped flavordynamics based on the $T^{\prime }$ family group

    Peng Chen🇨🇳 · Gui-Jun Ding🇨🇳 · Jun-Nan Lu🇨🇳 · José W. F. Valle🇪🇸

    We propose a realistic theory of fermion masses and mixings using a five-dimensional warped scenario where all fermions propagate in the bulk and the Higgs field is localized on the IR brane. The assumed $T^{\prime }$ flavor symmetry is broken on the branes by flavon fields, providing a consistent scenario where fermion mass hierarchies arise from adequate choices of the bulk mass parameters, while quark and lepton mixing angles are restricted by the family symmetry. Neutrino mass splittings, mixing parameters and the Dirac CP phase all arise from the type-I seesaw mechanism and are tightly correlated, leading to predictions for the neutrino oscillation parameters, as well as expected \znbb decay rates within reach of upcoming experiments. The scheme also provides a good global description of flavor observables in the quark sector.

    hep-phPRD(2020)·38 citations
11. 11*

    Topologically stable, finite-energy electroweak-scale monopoles

    P. Q. Hung🇺🇸

    The existence of a magnetic monopole, if it exists, remains elusive. Experimental searches have been carried out and are continuing in this quest. Of great uncertainty is the mass of the monopole which is model-dependent and ranging from some Grand Unified scale to the electroweak scale. In this paper, we propose a model where topologically stable, finite-energy monopoles {\em à la} 't Hooft-Polyakov could exist with a mass proportional to the electroweak scale. This comes about in a model of neutrino masses where right-handed neutrinos are {\em non-sterile} whose electroweak-scale Majorana masses are obtained by the coupling to a complex {\em triplet} Higgs field. Custodial symmetry which insures $M_W=M_Z\cos {\theta }_W$ requires the introduction of another triplet Higgs field but {\em real} this time. It is this {\em real Higgs triplet} that is at the core of our proposal.

    hep-phNPB(2021)·39 citations
12. 12*

    The Spectrum of $P$-Wave Hidden-Charm Exotic Mesons in the Diquark Model

    Jesse F. Giron🇺🇸 · Richard F. Lebed🇺🇸

    We study the fine structure in the spectrum of known and predicted negative-parity hidden-charm exotic meson states, which comprise the lowest $P$-wave multiplet in the dynamical diquark model. Starting with a form previously shown to successfully describe the $S$-wave states, we develop a 5-parameter Hamiltonian that includes spin-orbit and tensor terms. After discussing the experimental status of the observed $J^{PC}=1^{--}$ states $Y$ with respect to masses and decay modes (classified by eigenvalues of heavy-quark spin), we note a number of inconsistencies between measurements from different experiments that complicate a unique determination of the spectrum. Outlining a variety of scenarios for interpreting the $Y$ data, we perform fits to each one, obtaining results that demonstrate differing possibilities for the $P$-wave spectra. Choosing one of these fits for illustration, we predict masses for all 28 isomultiplets in this $1P$ multiplet, compare the results to tantalizing hints in the data, and discuss the rich discovery potential for new states.

    hep-phPRD(2020)·33 citations
13. 13*

    A Model of Metastable EeV Dark Matter

    Emilian Dudas🇫🇷 · Lucien Heurtier🇺🇸 · Yann Mambrini🇫🇷 · Keith A. Olive🇺🇸 · Mathias Pierre🇪🇸

    We propose a model where a long-lived pseudoscalar EeV particle can be produced with sufficient abundance so as to account for the cold dark matter density, despite having a Planck mass suppressed coupling to the thermal bath. Connecting this state to a hidden sterile neutrino sector through derivative couplings, induced by higher dimensional operators, allows one to account for light neutrino masses while having a lifetime that can be much larger than the age of the Universe. Moreover, the same derivative coupling accounts for the production of dark matter in the very first instant of the reheating. Given the sensitivity of the IceCube and ANITA collaborations, we study the possible signatures of such a model in the form of Ultra-High-Energy Cosmic Rays in the neutrino sector, and show that such signals could be detected in the near future.

    hep-phastro-ph.COastro-ph.HEhep-thPRD(2020)·30 citations
14. 14*

    Constraining the gravitational coupling of axion dark matter at LIGO

    Sunghoon Jung🇰🇷 · TaeHun Kim🇰🇷 · Jiro Soda🇯🇵 · Yuko Urakawa🇯🇵

    The axion-gravity Chern-Simons coupling is well motivated but is relatively weakly constrained, partly due to difficult measurements of gravity. We study the sensitivity of LIGO measurements of chirping gravitational waves (GWs) on such coupling. When the frequency of the propagating GW matches with that of the coherent oscillation of axion dark matter field, the decay of axions into gravitons can be stimulated, resonantly enhancing the GW. Such a resonance peak can be detected at LIGO as a deviation from the chirping waveform. Since all observed GWs will undergo similar resonant enhancement from the Milky-Way (MW) axion halo, LIGO O1+O2 observations can potentially provide the strongest constraint on the coupling, at least for the axion mass $m_a=5\times 10^{-13}-5\times 10^{-12}$ eV. Along the course, we also emphasize the relevance of the finite coherence of axion fields and the ansatz separating forward and backward propagations of GWs. As a result, the parity violation of the Chern-Simons coupling is not observable from chirping GWs.

    hep-phgr-qcPRD(2020)·27 citations
15. 15*

    PhaseTracer: tracing cosmological phases and calculating transition properties

    Peter Athron🇦🇺 · Csaba Balazs🇦🇺 · Andrew Fowlie🇨🇳 · Yang Zhang🇦🇺

    We present a C++ software package called PhaseTracer for mapping out cosmological phases, and potential transitions between them, for Standard Model extensions with any number of scalar fields. PhaseTracer traces the minima of effective potential as the temperature changes, and then calculates the critical temperatures, at which the minima are degenerate. PhaseTracer is constructed with modularity, flexibility and practicality in mind. It is fast and stable, and can receive potentials provided by other packages such as FlexibleSUSY. PhaseTracer can be useful analysing cosmological phase transitions which played an important role in the very early evolution of the Universe. If they were first order they could generate detectable gravitational waves and/or trigger electroweak baryogenesis to generate the observed matter anti-matter asymmetry of the Universe. The code can be obtained from https://github.com/PhaseTracer/PhaseTracer.

    hep-phEPJC(2020)·60 citations
16. 16*

    Bounds on light sterile neutrino mass and mixing from cosmology and laboratory searches

    Steffen Hagstotz🇸🇪 · Pablo F. de Salas🇸🇪 · Stefano Gariazzo🇪🇸 · Martina Gerbino🇮🇹 · Massimiliano Lattanzi🇮🇹 · Sunny Vagnozzi🇬🇧 · Katherine Freese🇸🇪 · Sergio Pastor🇪🇸

    We provide a consistent framework to set limits on properties of light sterile neutrinos coupled to all three active neutrinos using a combination of the latest cosmological data and terrestrial measurements from oscillations, $\beta$-decay and neutrinoless double-$\beta$ decay ($0\nu \beta \beta$) experiments. We directly constrain the full $3+1$ active-sterile mixing matrix elements $|U_{\alpha 4}{|}^2$, with $\alpha \in (e,\mu ,\tau )$, and the mass-squared splitting $\Delta m_{41}^2\equiv m_4^2-m_1^2$. We find that results for a $3+1$ case differ from previously studied $1+1$ scenarios where the sterile is only coupled to one of the neutrinos, which is largely explained by parameter space volume effects. Limits on the mass splitting and the mixing matrix elements are currently dominated by the cosmological data sets. The exact results are slightly prior dependent, but we reliably find all matrix elements to be constrained below $|U_{\alpha 4}{|}^2\lesssim 10^{-3}$. Short-baseline neutrino oscillation hints in favor of eV-scale sterile neutrinos are in serious tension with these bounds, irrespective of prior assumptions. We also translate the bounds from the cosmological analysis into constraints on the parameters probed by laboratory searches, such as $m_{\beta }$ or $m_{\beta \beta }$, the effective mass parameters probed by $\beta$-decay and $0\nu \beta \beta$ searches, respectively. When allowing for mixing with a light sterile neutrino, cosmology leads to upper bounds of $m_{\beta }<0.09$ eV and $m_{\beta \beta }<0.07$ eV at 95\% C.L, more stringent than the limits from current laboratory experiments.

    ↳ astro-ph.COhep-exhep-phPRD(2021)·109 citations
17. 17*

    Excluded-volume model for quarkyonic Matter: Three-flavor baryon-quark Mixture

    Dyana C. Duarte🇺🇸 · Saul Hernandez-Ortiz🇺🇸 · Kie Sang Jeong🇺🇸

    The single-flavor excluded-volume model based on the effective size of baryons reproduces the hard-soft density evolution of the equation of state (EoS) required by the recent studies of GW170817. This phenomenological model basically realizes the concept of quarkyonic matter which is introduced from large-$N_c$ gauge theory for dense matter. Enhanced nucleon interactions and dynamically generated quark degrees of freedom can reproduce the hard-soft evolution of the EoS. In this paper, we extend the excluded-volume model to a three-flavor system by considering electromagnetic charge and possible weak equilibrium in order to obtain a proper description for the hard-soft behavior of the EoS inferred from the gravitational waves observations.

    ↳ nucl-thhep-phPRC(2020)·56 citations
18. 18*

    Dark matter Annihilation in the Most Luminous and the Most Massive Ultracompact Dwarf Galaxies (UCD)

    Elaine C. F. S. Fortes🇧🇷 · Oswaldo D. Miranda🇧🇷 · Floyd W. Stecker🇺🇸 · Carlos A. Wuensche🇧🇷

    In this paper, we explore the potential astrophysical signatures of dark matter (DM) annihilations in ultra-compact dwarf galaxies (UCDs) considering two of the richest known galaxy clusters within 100 million light-years, nominally, Virgo and Fornax. Fornax UCD3 is the most luminous known UCD and M59 UCD3 is the most massive known UCD. With the detection of a 3.5 million solar mass black hole (BH) in Fornax UCD3, we carefully model several dark matter (DM) enhanced profile scenarios, considering the presence of both a supermassive black hole (SMBH) and DM. For Fornax UCD3, the comparison of the stellar and dynamical masses suggests that there is little content of DM in UCDs. M59 UCD3 did not receive the same attention in simulations as Fornax UCD3, however deep radio imaging and X-ray observations were performed for M59 UCD3 and can be used to place limits in DM content of these UCDs. We take an average estimate of dark matter content and used the Salpeter and Kroupa mass functions. We model Fornax UCD3 and M59 UCD3 to have a DM content that is the average of these mass functions. We then analyze the constraints for Fornax and M59 UCD3 coming from $\gamma$-ray and radio sources, considering a dark matter particle with a mass between 10 and 34 GeV in our simulations. In the absence of a strong $\gamma$-ray signature, we show that the synchrotron emission from electrons and positrons produced by DM annihilations can be very sensitive to indirect DM search. We find that DM parameters can be significantly constrained at radio frequencies and that the spike profiles play an interesting role in the deep study of the enhancements of DM & BH interactions in ultra-compact galaxies.

    ↳ astro-ph.GAhep-phJCAP(2021)·1 citation
19. 19*

    An extended $R_{{\Psi }_m}^{(2)}(\Delta S_2)$ correlator for detecting and characterizing the Chiral Magnetic Wave

    Niseem Magdy (1)🇺🇸 · Mao-Wu Nie (2,3)🇨🇳 · Ling Huang (4,5,6)🇨🇳 · Guo-Liang Ma (4,6)🇨🇳 · Roy. A. Lacey (7) ((1) Department of Physics, University of Illinois at Chicago, IL, USA, (2) Institute of Frontier and Interdisciplinary Science, Shandong University, China, (3) Key Laboratory of Particle Physics and Particle Irradiation, Ministry of Education, Shandong University, China, (4) Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China, (5) University of Chinese Academy of Sciences, Beijing, China, (6) Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Institute of Modern Physics, Fudan University, Shanghai, China, (7) Depts. of Chemistry & Physics, Stony Brook University, Stony Brook, NY)🇺🇸

    The extended $R_{{\Psi }_m}^{(2)}(\Delta S_2)$ correlator is presented and examined for its efficacy to detect and characterize the quadrupole charge separation ($\Delta S_2$) associated with the purported Chiral Magnetic Wave (CMW) produced in heavy-ion collisions. Sensitivity tests involving varying degrees of proxy CMW signals injected into events simulated with the Multi-Phase Transport Model (AMPT), show that the $R_{{\Psi }_m}^{(2)}(\Delta S_2)$ correlator provides discernible responses for the background- and CMW-driven charge separation. This distinction could aid identification of the CMW via measurements of the $R_{{\Psi }_2}^{(2)}(\Delta S_2)$ and $R_{{\Psi }_3}^{(2)}(\Delta S_2)$ correlators, relative to the second- (${\Psi }_2$) and third-order (${\Psi }_3$) event planes. The tests also indicate a level of sensitivity that would allow for robust experimental characterization of the CMW signal.

    ↳ nucl-exhep-exhep-phnucl-thPLB(2020)·6 citations
20. 20*

    Neutron-neutron scattering length from ${\pi }^{+}$ photoproduction on the deuteron

    Satoshi X. Nakamura (Univ. Science and Technology of China)🇨🇳 · Takatsugu Ishikawa (ELPH, Tohoku Univ.)🇯🇵 · Toru Sato (RCNP, Osaka Univ.)🇯🇵

    We discuss the possibility of extracting the neutron-neutron scattering length $a_{nn}$ and effective range $r_{nn}$ from cross section data ($d^2\sigma /d{M}_{nn}/d{\Omega }_{\pi }$), as a function of the $nn$ invariant mass $M_{nn}$, for ${\pi }^{+}$ photoproduction on the deuteron ($\gamma d\to {\pi }^{+}nn$). The analysis is based on a $\gamma d\to {\pi }^{+}nn$ reaction model in which realistic elementary amplitudes for $\gamma p\to {\pi }^{+}n$, $NN\to NN$, and $\pi N\to \pi N$ are built in. We show that $M_{nn}$ dependence (lineshape) of a ratio $R_{\mathrm{th}}$, $d^2\sigma /d{M}_{nn}/d{\Omega }_{\pi }$ normalized by $d\sigma /d{\Omega }_{\pi }$ for $\gamma p\to {\pi }^{+}n$ and the nucleon momentum distribution inside the deuteron, at the kinematics with ${\theta }_{\pi }=0^{\circ }$ and $E_{\gamma }\sim 250$ MeV is particularly useful for extracting $a_{nn}$ and $r_{nn}$ from the corresponding data $R_{\exp }$. It is found that $R_{\exp }$ with 2% error, resolved into the $M_{nn}$ bin width of 0.04 MeV (corresponding to the $p_{\pi }$ bin width of 0.05 MeV$/c$), can determine $a_{nn}$ and $r_{nn}$ with uncertainties of $\pm 0.21$ fm and $\pm 0.06$ fm, respectively, for the case of $a_{nn}=-18.9$ fm and $r_{nn}=2.75$ fm. The requirement of such narrow bin widths indicates that the momenta of the incident photon and the emitted ${\pi }^{+}$ have to be measured with high resolutions. This can be achieved by utilizing virtual photons of very small $Q^2$ from electron scattering at Mainz MAMI facility. The proposed method for determining $a_{nn}$ and $r_{nn}$ from $\gamma d\to {\pi }^{+}nn$ has a great experimental advantage over the previous one utilizing ${\pi }^{-}d\to \gamma nn$ for being free from the formidable task of controlling the neutron detection efficiency and its uncertainty.

    ↳ nucl-thhep-phnucl-ex5 citations
21. 21*

    The Evolution of Primordial Black Holes and their Final Observable Spins

    V. De Luca🇨🇭 · G. Franciolini🇨🇭 · P. Pani🇮🇹 · A. Riotto🇨🇭

    Primordial black holes in the mass range of ground-based gravitational-wave detectors can comprise a significant fraction of the dark matter. Mass and spin measurements from coalescences can be used to distinguish between an astrophysical or a primordial origin of the binary black holes. In standard scenarios the spin of primordial black holes is very small at formation. However, the mass and spin can evolve through the cosmic history due to accretion. We show that the mass and spin of primordial black holes are correlated in a redshift-dependent fashion, in particular primordial black holes with masses below $\mathcal{O}(30)M_{\odot }$ are likely non-spinning at any redshift, whereas heavier black holes can be nearly extremal up to redshift $z\sim 10$. The dependence of the mass and spin distributions on the redshift can be probed with future detectors such as the Einstein Telescope. The mass and spin evolution affect the gravitational waveform parameters, in particular the distribution of the final mass and spin of the merger remnant, and that of the effective spin of the binary. We argue that, compared to the astrophysical-formation scenario, a primordial origin of black hole binaries might better explain the spin distribution of merger events detected by LIGO-Virgo, in which the effective spin parameter of the binary is compatible to zero except possibly for few high-mass events. Upcoming results from LIGO-Virgo third observation run might reinforce or weaken these predictions.

    ↳ astro-ph.COgr-qchep-phJCAP(2020)·189 citations
22. 22*

    Relativistic Dynamics of Fluctuations and QCD Critical Point

    Xin An🇺🇸

    We review the recent development on a systematic deterministic formalism describing dynamics of both bulk and fluctuations in an arbitrary relativistic hydrodynamic flow carrying conserved charges. In particular, we discuss the implementation of such general formalism near the QCD critical point.

    ↳ hep-thcond-mat.stat-mechhep-phnucl-thNPA(2021)·8 citations
23. 23*

    Arbitrary $\ell$-state solutions of the Klein-Gordon equation with the Manning-Rosen plus a Class of Yukawa potentials

    A. I. Ahmadov🇦🇿 · M. Demirci🇹🇷 · S. M. Aslanova🇦🇿 · M. F. Mustamin🇹🇷

    Focusing on an improved approximation scheme, we present how to treat the centrifugal and the Coulombic behavior terms and then to obtain the bound state solutions of the Klein-Gordon (KG) equation with the Manning-Rosen plus a Class of Yukawa potentials. By means of the Nikiforov-Uvarov (NU) and supersymmetric quantum mechanics (SUSYQM) methods, we present the energy spectrum for any $\ell$-state and the corresponding radial wave functions in terms of the hypergeometric functions. From both methods we obtain the same results. Several special cases for the potentials which are useful for other physical systems are also discussed. These are consistent with those results in previous works. We obtain that the energy level $E$ is sensitive to the potential parameter $\delta$ at fixed values of other parameters and increases when $\delta$ runs from $0.05$ to $0.3$. Furthermore, $E$ is sensitive to the quantum numbers $\ell$ and $n_r$ for a given $\delta$, as expected.

    ↳ quant-phhep-phmath-phmath.MPPLA(2020)·45 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.