Tue·Apr 21, 2020Tuesday·April 21, 2020

1. 01*

   The 7% Rule: A Maximum Entropy Prediction on New Decays of the Higgs Boson

   Alexandre Alves🇧🇷 · Alex Gomes Dias🇧🇷 · Roberto da Silva🇧🇷

   The entropy of the Higgs boson decay probabilities distribution in the Standard Model (SM) is maximized for a Higgs mass value that is less than one standard deviation away from the current experimental measurement. This successful estimate of the Higgs mass encourages us to propose tests of the Maximum Entropy Principle (MEP) as a tool for theoretical inferences in other instances of Higgs physics. In this letter, we show that, irrespective of the extension of the SM predicting a new Higgs boson decay channel, its branching ratio can be inferred to be around 7% in such a way that the new entropy of decays still exhibits a maximum at the experimental Higgs mass. This 7% rule can be tested whenever a new Higgs decay channel is found. In order to illustrate the MEP predictions, we apply the MEP inference to Higgs portal models, Higgs-axion interactions, lepton flavour violating decays of the Higgs boson, and a dark gauge boson model.

   hep-phhep-exNPB(2020)·18 citations
2. 02*

   Constraints on $H^{\pm }$ parameter space in 2HDM at $\sqrt{s}=$ 8 TeV and $\sqrt{s}=$ 13 TeV

   Ijaz Ahmed🇵🇰 · Murad Badshah🇵🇰 · Nadia Kausar🇵🇰

   This paper reflects the heavy Higgs scenario where the mass of charged Higgs is equal to or greater than 200 GeV. The CMS observed and expected values of upper limits on the product ${\sigma }_H^{\pm }BR(H^{\pm }\to t{b}^{\mp })$, assuming $H^{\pm }\to t{b}^{\mp }=1$, both at 8 TeV (at integrated luminosity of 19.7 $f{b}^{-1}$ ) and 13 TeV (at integrated luminosity of 35.9 $f{b}^{-1}$ ) c.m energies are used. By comparing these expected and observed upper limits with computational values , we find out the expected and observed exclusion regions of charged Higgs parameter space ($m_H^{\pm }-tan\beta$ space ) in 2HDM both at $\sqrt{s}=$8 and $\sqrt{s}=$ 13 TeV. We compare the expected and observed exclusion regions and observe that exclusion regions made by observed upper limits are always greater than the exclusion made by expected upper limits both at 8 and 13 TeV c.m energies. Only in the mass range from 200 GeV to 220 GeV the expected exclusion region is greater than the observed one only at $\sqrt{s}=$13 TeV. We also equate the exclusion regions at these two different center of mass energies and find that the expected exclusion region and observed exclusion region at $\sqrt{s}=$13 TeV are always greater than the expected exclusion region and observed exclusion region at $\sqrt{S}=$8 TeV respectively.

   hep-phInt.J.Theor.Phys.(2020)·0 citations
3. 03*

   Isospin mass differences of singly heavy baryons

   Ghil-Seok Yang🇰🇷 · Hyun-Chul Kim🇰🇷

   We study the isospin mass differences of singly heavy baryons, based on a pion mean-field approach. We consider both the electromagnetic interactions and the hadronic contributions that arise from the mass difference of the up and down quarks. The relevant parameters have been already fixed by the baryon octet. In addition, we introduce the strong hyperfine interactions between the light quarks inside a chiral soliton and the Coulomb interactions between the chiral soliton and a heavy quark. The numerical results are in good agreement with the experimental data. In particular, the results for the neutral mass relations, which contain only the electromagnetic contributions, are in remarkable agreement with the data, which implies that the pion mean field approach provides a good description of the singly heavy baryons.

   hep-phhep-exhep-latPLB(2020)·15 citations
4. 04*

   Thermoelectric properties of (an-)isotropic QGP in magnetic fields

   He-Xia Zhang🇨🇳 · Jin-Wen Kang🇨🇳 · Ben-Wei Zhang🇨🇳

   The Seebeck effect and the Nernst effect, which reflect the appearance of electric fields along $x$-axis and along $y$-axis ($E_x$ and $E_y$), respectively, induced by the thermal gradient along $x$-axis, are studied in the QGP at an external magnetic field along $z$-axis. We calculate the associated Seebeck coefficient ($S_{xx}$) and Nernst signal ($N$) using the relativistic Boltzmann equation under the relaxation time approximation. In an isotropic QGP, the influences of magnetic field ($B$) and quark chemical potential (${\mu }_q$) on these thermoelectric transport coefficients are investigated. In the presence (absence) of weak magnetic field, we find $S_{xx}$ for a fixed ${\mu }_q$ is negative (positive) in sign, indicating that the dominant carriers for converting heat gradient to electric field are negatively (positively) charged quarks. The absolute value of $S_{xx}$ decreases with increasing temperature. Unlike $S_{xx}$, the sign of $N$ is independent of charge carrier type, and its thermal behavior displays a peak structure. In the presence of strong magnetic field, due to the Landau quantization of transverse motion of (anti-)quarks perpendicular to magnetic field, only the longitudinal Seebeck coefficient ($S_{zz}$) exists. Our results show that the value of $S_{zz}$ at a fixed ${\mu }_q$ in the lowest Landau level (LLL) approximation always remains positive. Within the effect of high Landau levels, $S_{zz}$ exhibits a thermal structure similar to that in the LLL approximation. As the Landau level increases further, $S_{zz}$ decreases and even its sign changes from positive to negative. The computations of these thermoelectric transport coefficients are also extended to a medium with momentum-anisotropy induced by initial spatial expansion as well as strong magnetic field.

   hep-phEPJC(2021)·29 citations
5. 05*

   Producing and detecting long-lived particles at different experiments at the LHC

   Chaochen Yuan🇨🇳 · Huaqiao Zhang🇨🇳 · Yue Zhao🇺🇸 · Guoming Chen🇨🇳

   We propose a new strategy to look for long-lived particles (LLP) at the LHC. The LLPs are produced at one experiment, but its decay products are detected by a detector at another experiment. We use a confining Hidden Valley scenario as a benchmark. Through showering and hadronization, the multiplicity of hidden mesons can be large, and their decay products, dimuon as chosen in this study, are typically too soft to pass triggers in traditional LHC searches. We find the best acceptance is achieved if we produce LLPs at collision points at the LHCb and ALICE experiments, and use the muon chamber of ATLAS for detection. This new search is cost-efficient since it does not require a new detector to be built. Meanwhile, it can provide coverage of interesting parameter space, which is complementary to other proposed LLP searches.

   hep-phhep-exJHEP(2022)·12 citations
6. 06*

   Mass hierarchy from the flavor symmetry in supersymmetric multi-Higgs doublet model

   Atsushi Hinata🇯🇵

   We study the supersymmetric standard model with multiple Higgs doublets with gauged $\mathrm{U}(1{)}_X$ flavor symmetry. When the flavor symmetry is broken by the vacuum expectation value of flavon, the ${\mathbb{Z}}_3$ symmetry $M_3$ called matter triality remains and it prohibits the baryon number violation up to dimension-5 operators. We study the contribution of the extra-Higgs fields to the anomaly cancellation of flavor symmetry and analyze the mass spectra including the multiple generations of Higgs fields as well as quarks and leptons. We show a series of $\mathrm{U}(1{)}_X$ charge assignments, which reproduce the observed masses and mixing angles of quark and lepton. We also find that, with such realistic charge assignments, the extra-Higgs fields obtain masses around the intermediate scale and decouple from the electroweak physics because of the holomorphy of superpotential.

   hep-phhep-thJHEP(2020)·6 citations
7. 07*

   Precise predictions for charged Higgs boson pair production in photon-photon collisions

   Mehmet Demirci🇹🇷

   The charged Higgs pair production via photon-photon collisions is investigated in the framework of two Higgs doublet model (2HDM), taking into account a full set of one-loop-level scattering amplitudes, i.e., including electroweak (EW) corrections together with soft and hard QED radiation. The numerical evaluation is carried out for three different scenarios, so-called non-alignment, low-$m_H$ and short-cascade, defined in the presence of the up-to-date experimental constraints and consistent with theoretical constraints as well. The total cross sections of $\gamma \gamma \to H^{-}{H}^{+}$ are scanned over the plane ($m_{{\varphi }^0},\sqrt{s}$), where ${\varphi }^0$ is $h^0$ for low-$m_{H^0}$ scenario and $H^0$ for other two scenarios. The regions of the parameter space in which the production rates are sufficiently large are highlighted for each scenario. The production rates in different polarization collision modes of initial beams are also discussed. It can be enhanced up to two-times by oppositely polarized photons at high energies and right-handed polarized photons at low energies. Furthermore, decay channels of the charged Higgs boson are examined for each scenario. It is observed that the one-loop EW corrections, i.e., the virtual plus real radiation corrections, reduce the tree-level cross sections and the relative correction is typically in the range of $-10\%$ to $-30\%$, depending on model parameters.

   hep-phNPB(2020)·13 citations
8. 08*

   Magnetic field-induced anisotropic interaction in heavy quark bound states

   Salman Ahamad Khan🇮🇳 · Binoy Krishna Patra🇮🇳 · Mujeeb Hasan🇮🇳

   We have investigated how a strong magnetic field (B) could decipher the anisotropic interaction in heavy quark ($Q$) and antiquark ($\bar{Q}$) bound states through the perturbative thermal QCD in real-time formalism. So we thermalize Schwinger propagator for quarks in LLL and the Feynman propagator for gluons to calculate the gluon self-energy. For the quark-loop contribution to the self-energy, the medium does not have any temperature correction and the vacuum term gives rise an anisotropic term whereas the gluon-loop yields temperature correction. This finding in quark-loop contribution corroborates the equivalence of a massless QED in (1+1)-dimension with the massless thermal QCD in strong B, which (quark sector) is reduced to (1+1)-dimension (longitudinal). Thus the permittivity of the medium behaves like as a tensor. Thus the permittivity of medium makes the $Q\bar{Q}$ potential anisotropic, which resembles with a contemporary results found in lattice studies. As a result, potential for $Q\bar{Q}$-pairs aligned transverse to B is more attractive than parallel alignment. However, potential is always more attractive compared to B=0 due to softening of screening mass. However, the imaginary-part of potential becomes smaller compared to B=0. We have next investigated the effects of strong $\mathbf{B}$ on binding energies (B.E.) and thermal widths ($\Gamma$) of ground states of $c\bar{c}$ and $b\bar{b}$ in a time-independent perturbation theory, where binding energies gets increased and widths gets decreased, compared to $B=0$. Finally we have studied the quasi-free dissociation of bound states in a strong B. The dissociation temperatures estimated for $J/\psi$ and ${\rm Y}$ states are obtained as $1.59{\mathrm{T}}_{\mathrm{c}}$ and $2.22{\mathrm{T}}_{\mathrm{c}}$, respectively, which are higher than the estimate in B=0 , thus preventing early dissolution of $Q\bar{Q}$ bound states.

   hep-phcond-mat.softcond-mat.str-elnucl-thPoS(2026)·6 citations
9. 09*

   Theory of Deeply Virtual Compton Scattering off the Unpolarized Proton

   Brandon Kriesten🇺🇸 · Simonetta Liuti🇺🇸

   Using the helicity amplitudes formalism, we study deeply virtual exclusive electron photo-production off an unpolarized nucleon target, $ep\to e^{\prime }{p}^{\prime }\gamma$, through a range of kinematics both in the fixed target setting with initial electron energies of 6 GeV, 11 GeV and 24 GeV, and for an electron ion collider. We reformulate the cross section bringing to the forefront the defining features of the $ep\to e^{\prime }{p}^{\prime }\gamma$ process, where the observables are expressed as bilinear products of the independent helicity amplitudes which completely describe it in terms of the electric, magnetic and axial currents of the nucleon. %This structure is reflected in different ways in the Deeply virtual Compton scattering and Bethe-Heitler parts of the cross section. % These contributions are checked against the Fourier harmonics-based formalism which has provided so far the underlying mathematical framework to study Deeply virtual Compton scattering and related experiments. Using theoretical model calculations of the twist-two generalized parton distributions, $H$, $E$, $\tilde{H}$ and $\tilde{E}$, we uncover large discrepancies between the harmonic series and our proposed framework. Most importantly, these numerical differences appear in the intermediate $Q^2$ range which represents a sweet spot for extracting generalized parton distributions from data. % We provide a framework that is ideal, on one side, to study and compare the different conventions that can be used to describe the leading order contribution to DVCS in QCD, while on the other, it facilitates a quantitative extraction of physically meaningful information from experiment through traceable and controllable approximations in the intermediate $Q^2$ region.

   hep-phPRD(2022)·32 citations
10. 10*

    The Two-mass Contribution to the Three-Loop Polarized Operator Matrix Element $A_{gg,Q}^{(3)}$

    J. Ablinger🇦🇹 · J. Blümlein🇩🇪 · A. De Freitas🇩🇪 · A. Goedicke🇩🇪 · M. Saragnese🇩🇪 · C. Schneider🇦🇹 · K. Schönwald🇩🇪

    We compute the two-mass contributions to the polarized massive operator matrix element $A_{gg,Q}^{(3)}$ at third order in the strong coupling constant ${\alpha }_s$ in Quantum Chromodynamics analytically. These corrections are important ingredients for the matching relations in the variable flavor number scheme and for the calculation of Wilson coefficients in deep--inelastic scattering in the asymptotic regime $Q^2\gg m_c^2,m_b^2$. The analytic result is expressed in terms of nested harmonic, generalized harmonic, cyclotomic and binomial sums in $N$-space and by iterated integrals involving square-root valued arguments in $z$ space, as functions of the mass ratio. Numerical results are presented. New two--scale iterative integrals are calculated.

    hep-phhep-exhep-thNPB(2020)·29 citations
11. 11*

    Bose-Einstein condensation phenomenology in systems with repulsive interactions

    Oleh Savchuk🇺🇦 · Yehor Bondar🇺🇦 · Oleksandr Stashko🇺🇦 · Roman V. Poberezhnyuk🇺🇦 · Volodymyr Vovchenko🇩🇪 · Mark I. Gorenstein🇺🇦 · Horst Stoecker🇩🇪

    The role of repulsive interactions in statistical systems of Bose particles is investigated. Three different phenomenological frameworks are considered: a mean field model, an excluded volume model, and a model with a medium dependent effective mass. All three models are tuned to yield similar equations of state, with only minor deviations from the ideal Bose gas at small chemical potentials. Our analysis indicates, however, that these models lead to qualitatively different results for the Bose-Einstein condensation phenomenon. We discuss the different aspects of this phenomenon, namely, an onset of the Bose-Einstein condensation, particle number fluctuations, and a behavior of the Bose condensate. The obtained results can be helpful for interpreting the lattice QCD data at small temperature and large isospin chemical potential and the data on multiple pion production in high energy nuclear collisions.

    hep-phnucl-thPRC(2020)·15 citations
12. 12*

    Will the subprocesses $\rho (770,1450{)}^0\to K^{+}{K}^{-}$ contribute large branching fractions for $B^{\pm }\to {\pi }^{\pm }{K}^{+}{K}^{-}$ decays?

    Wen-Fei Wang🇨🇳

    We analyze the quasi-two-body decays $B^{+}\to {\pi }^{+}\rho (770,1450{)}^0\to {\pi }^{+}{K}^{+}{K}^{-}$ in the perturbative QCD approach. The results in this work do not support that large branching fractions contributed by the resonances $\rho (770,1450{)}^0$ in the $B^{\pm }\to {\pi }^{\pm }{K}^{+}{K}^{-}$ decays. The virtual contribution for $K^{+}{K}^{-}$ from the tail of the resonance $\rho (770{)}^0$ which has been ignored in the experimental studies is about $1.5$ times of the $\rho (1450{)}^0\to K^{+}{K}^{-}$ contribution, with the predicted branching fractions ${\mathcal{B}}_v=(1.31\pm 0.27)\times 10^{-7}$ and $\mathcal{B}=(8.96\pm 2.61)\times 10^{-8}$, respectively, for these two subprocesses in the $B^{\pm }\to {\pi }^{\pm }{K}^{+}{K}^{-}$ decays. The absence of $\rho (770{)}^0\to K^{+}{K}^{-}$ for the decay amplitude of a three-body hadronic $B$ decay involving charged kaon pair could probably result in a larger proportion for the contribution from the resonance $\rho (1450{)}^0$ in the experimental analysis.

    hep-phhep-exPRD(2020)·23 citations
13. 13*

    Use of a Generalized Energy Mover's Distance in the Search for Rare Phenomena at Colliders

    M. Crispim Romao🇵🇹 · N. F. Castro🇵🇹 · J. G. Milhano🇵🇹 · R. Pedro🇵🇹 · T. Vale🇵🇹

    In this paper, we expand on the previously proposed concept of Energy Mover's Distance. The resulting observables are shown to provide a way of identifying rare processes in proton-proton collider experiments. It is shown that different processes are grouped together differently and that this can contribute to the improvement of experimental analyses. The $t\bar{t}Z$ production at the Large Hadron Collider is used as a benchmark to illustrate the applicability of the method. Furthermore, we study the use of these observables as new features which can be used in the training of Deep Neural Networks.

    hep-phphysics.comp-phEPJC(2021)·53 citations
14. 14*

    Topological susceptibility, divergent chiral density and phase diagram of chirally imbalanced QCD medium at finite temperature

    Marco Ruggieri🇨🇳 · Maxim N. Chernodub🇷🇺 · Zhen-Yan Lu🇨🇳

    We show that the nonlocal two-flavor Nambu--Jona-Lasinio model predicts the enhancement of both chiral and axial symmetry breaking as the chiral imbalance of hot QCD matter, regulated by a chiral chemical potential ${\mu }_5$, increases. The two crossovers are reasonably close to each other in the range of ${\mu }_5$ examined here and the pseudocritical temperatures rise with ${\mu }_5$. The curvatures of the chiral and axial crossovers for the chiral quark chemical potential approximately coincide and give ${\kappa }_5\simeq -0.011$. We point out that the presence of ${\mu }_5$ in thermodynamic equilibrium is inconsistent with the fact that the chiral charge is not a Noether-conserved quantity for massive fermions. The chiral chemical potential should not, therefore, be considered as a true chemical potential that sets a thermodynamically stable environment in the massive theory, but rather than as a new coupling that may require a renormalization in the ultraviolet domain. The divergence of an unrenormalized chiral density, \corr{coming from zero-point fermionic fluctuations,} is a consequence of this property. We propose a solution to this problem via a renormalization procedure.

    hep-phhep-lathep-thnucl-thPRD(2020)·24 citations
15. 15*

    Unified explanation of flavor anomalies, radiative neutrino mass and ANITA anomalous events in a vector leptoquark model

    P. S. Bhupal Dev🇺🇸 · Rukmani Mohanta🇮🇳 · Sudhanwa Patra🇮🇳 · Suchismita Sahoo🇮🇳

    Driven by the recent experimental hints of lepton-flavor-universality violation in the bottom-quark sector, we consider a simple extension of the Standard Model (SM) with an additional vector leptoquark $V_{\mathrm{LQ}}(3,1,2/3)$ and a scalar diquark $S_{\mathrm{DQ}}(6,1,4/3)$ under the SM gauge group $SU(3{)}_c\times SU(2{)}_L\times U(1{)}_Y$, in order to simultaneously explain the $b\to s{\ell }^{+}{\ell }^{-}$ (with $\ell =e,\mu$) and $b\to c{l}^{-}{\bar{\nu }}_l$ (with $l=e,\mu ,\tau$) flavor anomalies, as well as to generate small neutrino masses through a two-loop radiative mechanism. We perform a global fit to all the relevant and up-to-date $b\to s{\ell }^{+}{\ell }^{-}$ and $b\to c{l}^{-}{\bar{\nu }}_l$ data under the assumption that the leptoquark couples predominantly to second and third-generation SM fermions. We then look over the implications of the allowed parameter space on lepton-flavor-violating $B$ and $\tau$ decay modes, such as $B_s\to l_i^{+}{l}_j^{-},B\to K^{(\ast )}{l}_i^{+}{l}_j^{-},B_s\to \varphi l_i^{+}{l}_j^{-}$, ${\rm Y}(nS)\to \mu \tau$ and $\tau \to \mu \gamma$, $\tau \to \mu \varphi ({\eta }^{(\prime )})$, respectively. Minimally extending this model by adding a fermion singlet $\chi (1,1,0)$ also explains the ANITA anomalous upgoing events. Furthermore, we provide complementary constraints on leptoquark and diquark couplings from high-energy collider and other low-energy experiments to test this model.

    hep-phhep-exPRD(2020)·60 citations
16. 16*

    Heavy Quark Expansion for Heavy Hadron Lifetimes: Completing the $1/m_b^3$ Corrections

    Thomas Mannel🇩🇪 · Daniel Moreno🇩🇪 · Alexei Pivovarov🇩🇪

    We complete the calculation of the contributions from the dimension six operators in the heavy quark expansion for the total lifetime of heavy hadrons. We give the expressions for the Wilson coefficients of the Darwin term ${\rho }_D$ and the spin-orbit term ${\rho }_{\mathrm{LS}}$ at tree level.

    hep-phJHEP(2020)·44 citations
17. 17*

    Measurement of TeV dark particles due to decay of heavy dark matter in the earth core at IceCube

    Ye Xu🇨🇳

    In the present paper, it is assumed that there exist two species of dark matter: a heavy dark matter particle (HDM) with the mass of O(TeV) which is generated in early universe and a lighter dark matter particle (LDM) which is a relativistic product due to the decay of HDM. HDMs, captured by the earth, decay to high energy LDMs, and these particles can be measured by km${}^3$ neutrino telescopes, like the IceCube detector. A $Z^{\prime }$ portal dark matter model is taken for LDMs to interact with nuclei via a neutral current interaction mediated by a heavy gauge boson $Z^{\prime }$. With the different lifetimes of decay of HDMs and Z${}^{\prime }$ masses, the event rates of LDMs, measured by IceCube, are evaluated in the energy range between 1 TeV and 100 TeV. According to the IceCube data, the upper limit for LDM fluxes is estimated at 90\% C.L. at IceCube. Finally, it is proved that LDMs could be directly detected in the energy range betwen O(1TeV) and O(10TeV) at IceCube with $m_{Z^{\prime }}\lesssim 500GeV$ and ${\tau }_{\varphi }\lesssim 10^{21}$ s.

    hep-phastro-ph.COhep-exPhys.Dark Univ.(2021)·3 citations
18. 18*

    Sterile Neutrino Dark Matter in Left-Right Theories

    Jeff A. Dror🇺🇸 · David Dunsky🇺🇸 · Lawrence J. Hall🇺🇸 · Keisuke Harigaya🇺🇸

    $SU(2{)}_L\times SU(2{)}_R$ gauge symmetry requires three right-handed neutrinos ($N_i$), one of which, $N_1$, can be sufficiently stable to be dark matter. In the early universe, $W_R$ exchange with the Standard Model thermal bath keeps the right-handed neutrinos in thermal equilibrium at high temperatures. $N_1$ can make up all of dark matter if they freeze-out while relativistic and are mildly diluted by subsequent decays of a long-lived and heavier right-handed neutrino, $N_2$. We systematically study this parameter space, constraining the symmetry breaking scale of $SU(2{)}_R$ and the mass of $N_1$ to a triangle in the $(v_R,M_1)$ plane, with $v_R=(10^6-3\times 10^{12})$ GeV and $M_1=(2\mathrm{keV}-1\mathrm{MeV})$. Much of this triangle can be probed by signals of warm dark matter, especially if leptogenesis from $N_2$ decay yields the observed baryon asymmetry. The minimal value of $v_R$ is increased to $10^8\mathrm{GeV}$ for doublet breaking of $SU(2{)}_R$, and further to $10^9\mathrm{GeV}$ if leptogenesis occurs via $N_2$ decay, while the upper bound on $M_1$ is reduced to 100 keV. In addition, there is a component of hot $N_1$ dark matter resulting from the late decay of $N_2\to N_1{\ell }^{+}{\ell }^{-}$ that can be probed by future cosmic microwave background observations. Interestingly, the range of $v_R$ allows both precision gauge coupling unification and the Higgs Parity understanding of the vanishing of the Standard Model Higgs quartic at scale $v_R$. Finally, we study freeze-in production of $N_1$ dark matter via the $W_R$ interaction, which allows a much wider range of $(v_R,M_1)$.

    hep-phastro-ph.COJHEP(2020)·52 citations
19. 19*

    ..., 83106786, 114382724, 1509048322, 2343463290, 27410087742, ... Efficient Hilbert Series for Effective Theories

    Coenraad B. Marinissen🇳🇱 · Rudi Rahn🇳🇱 · Wouter J. Waalewijn🇳🇱

    We present an efficient algorithm for determining the Hilbert series of an effective theory and provide a companion code called ECO (Efficient Counting of Operators) in FORM. For example, the Hilbert series for the dimension 15 operators in the Standard Model Effective Theory (SMEFT) can be obtained in a minute on a single CPU core. While our implementation focusses on SMEFT, we allow for a flexible user input of the light degrees of freedom. Furthermore, gravity, as well as additional U(1) global or gauge symmetries can be included.

    hep-phhep-thPLB(2020)·51 citations
20. 20*

    Contribution of the Darwin operator to non-leptonic decays of heavy quarks

    Alexander Lenz🇬🇧 · Maria Laura Piscopo🇬🇧 · Aleksey V. Rusov🇬🇧

    We compute the Darwin operator contribution ($1/m_b^3$ correction) to the width of the inclusive non-leptonic decay of a $B$ meson ($B^{+}$, $B_d$ or $B_s$), stemming from the quark flavour-changing transition $b\to q_1{\bar{q}}_2{q}_3$, where $q_1,q_2=u,c$ and $q_3=d,s$. The key ideas of the computation are the local expansion of the quark propagator in the external gluon field including terms with covariant derivative of the gluon field strength tensor and the standard technique of the Heavy Quark Expansion (HQE). We confirm the previously known expressions of the $1/m_b^3$ contributions to the semi-leptonic decay $b\to q_1\ell {\bar{\nu }}_{\ell }$, with $\ell =e,\mu ,\tau$ and of the $1/m_b^2$ contributions to the non-leptonic modes. We find that this new term can give a sizeable correction of about $-4\%$ to the non-leptonic decay width of a $B$ meson. For $B_d$ and $B_s$ mesons this turns out to be the dominant correction to the free b-quark decay, while for the $B^{+}$ meson the Darwin term gives the second most important correction - roughly 1/2 to 1/3 of the phase space enhanced Pauli interference contribution. Due to the tiny experimental uncertainties in lifetime measurements the incorporation of the Darwin term contribution is crucial for precision tests of the Standard Model.

    hep-phhep-exJHEP(2020)·47 citations
21. 21*

    Dark Kinetic Heating of Neutron Stars from Contact Interactions with Relativistic Targets

    Aniket Joglekar🇺🇸 · Nirmal Raj🇨🇦 · Philip Tanedo🇺🇸 · Hai-Bo Yu🇺🇸

    Dark matter can capture in neutron stars from scattering off ultra-relativistic electrons. We present a method to calculate the capture rate on degenerate targets with ultra-relativistic momenta in a compact astronomical object. Our treatment accounts for the target momentum and the Fermi degeneracy of the system. We derive scaling relations for scattering with relativistic targets and confirm consistency with the non-relativistic limit and Lorentz invariance. The potential observation of kinetic heating of neutron stars has a larger discovery reach for dark matter-lepton interactions than conventional terrestrial direct detection experiments. We map this reach onto a set of bosonic and fermionic effective contact interactions between dark matter and leptons as well as nucleons. We show the results for the contact operators up to dimension 6 for spin-0 and spin-1/2 dark matter interactions with relativistic as well as non-relativistic Standard Model fermions. Highlights of this program in the case of vector mediated interactions are presented in a companion letter [1]. Our method is generalizable to dark matter scattering in any degenerate medium where the Pauli exclusion principle leads to relativistic targets with a constrained phase space for scattering.

    hep-phastro-ph.HEPRD(2020)·99 citations
22. 22*

    Properties of magnetized neutral pions at zero and finite temperature in nonlocal chiral quark models

    D. Gómez Dumm🇦🇷 · M.F. Izzo Villafañe🇦🇷 · N.N. Scoccola🇦🇷

    The behavior of ${\pi }^0$ meson properties in the presence of a uniform external magnetic field is studied in the context of a nonlocal extension of the Polyakov-Nambu-Jona-Lasinio model. The analysis includes the ${\pi }^0$ mass, the effective ${\pi }^0$-quark coupling and the pion-to-vacuum hadronic form factors, both at zero and finite temperature. Numerical results are compared with previous calculations carried out within the local NJL model, when available. The validity of chiral relations and the features of deconfinement and chiral symmetry restoration transitions are discussed.

    hep-phPRD(2020)·14 citations
23. 23*

    A Foreground Model Independent Estimation of Joint Posterior of CMB E mode Polarization over Large Angular Scales

    Ujjal Purkayastha🇮🇳 · Vipin Sudevan🇮🇳 · Rajib Saha🇮🇳

    Ever since Cosmic Microwave Background (CMB) signal is being measured by various satellites based observations with increasing experimental accuracies there has been a parallel increase in the demand for a CMB reconstruction technique which can provide accurate estimates of CMB signal and the theoretical angular power spectrum along with reliable statistical error estimates associated with them. In this work, we estimate the joint posterior of CMB E mode signal (S) and corresponding theoretical angular power spectrum (C^E_l) over large angular scales given the simulated polarization observations of future generation COrE satellite mission. To generate samples from the joint distribution we employ the ILC technique with prior information of CMB E mode covariance matrix augmented by a Gibbs sampling technique. We estimate the marginalized densities of S and C^E_l using the samples from full-posterior. The best fit cleaned E mode map and the corresponding angular power spectrum agree well with the input E mode map and the sky power spectrum implying accurate reconstruction using COrE like observations. Using the samples C^E_l of all Gibbs chains we estimate the likelihood function P(C^E_l|D) of any arbitrary C^E_l given simulated observed maps (D) of COrE mission following Blackwell-Rao estimator. The likelihood function can be seamlessly integrated to the cosmological parameter estimation method. Apart from producing an accurate estimate of E mode signal over large angular scales our method also builds a connection between the component reconstruction and reliable cosmological parameter estimation using CMB E mode observations over large angular scales. The entire method does not assume any explicit models for E mode foreground components in order to remove them, which is an attractive property since foreground modelling uncertainty does not pose as a challenge in this case.

    ↳ astro-ph.COhep-phhep-thMod.Phys.Lett.A(2022)·4 citations
24. 24*

    Locating the freeze-out curve in heavy-ion collisions

    Marcus Bluhm (SUBATECH, Nantes and Darmstadt, EMMI)🇫🇷 · Marlene Nahrgang (SUBATECH, Nantes and Darmstadt, EMMI)🇫🇷 · Jan M. Pawlowski (Heidelberg U. and Darmstadt, EMMI)🇩🇪

    Based on transport equations we argue that the chiral dynamics in heavy-ion collisions at high collision energies effectively decouples from the thermal physics of the fireball. With full decoupling at LHC energies the chiral condensate relaxes to its vacuum expectation value on a much shorter time scale than the typical evolution time of the fluid dynamical fields and their fluctuations. In particular, the net-baryon density remains coupled to the bulk evolution at all collision energies. As the mass scales of the hadrons are controlled by the chiral condensate, it is reasonable to employ vacuum masses in the statistical description of the hadron production at the chemical freeze-out for high collision energies. We predict that at lower collision energies the coupling of the chiral condensate to the thermal medium gradually increases with consequences for the related hadronic masses. A new estimate for the location of the freeze-out curve takes these effects into account.

    ↳ nucl-thhep-phnucl-ex8 citations
25. 25*

    Axion Gamma-Ray Signatures from Quark Matter in Neutron Stars and Gravitational Wave Comparisons

    Bijan Berenji🇺🇸

    We present a theoretical model for detecting axions from neutron stars in a QCD phase of quark matter. The axions would be produced from a quark-antiquark pair $u\bar{u}$ or $d\bar{d}$, in loop(s) involving gluons. The chiral anomaly of QCD and the spontaneously broken symmetry are invoked to explain the non-conservation of the axion current. From the coupling form factors, the axion emissivities ${ϵ}_a$ can be derived, from which fluxes can be determined. We predict a photon flux, which may be detectable by Fermi LAT, and limits on the QCD mass $m_a$. In this model, axions decay to gamma rays in a 2-photon vertex. We may determine the expected fluxes from the theoretical emissivity. The sensitivity curve from the Fermi Large Area Telescope (Fermi LAT) would allow axion mass constraints for neutron stars as low as $m_a\le 10^{-14}$ eV 95$\%C.L.$. Axions could thus be detectable in gamma rays for neutron stars as distant as 100 kpc. A signal from LIGO GWS 170817 could be placed from the NS-NS merger, which gives an upper limit of $m_a\le 10^{-10}$ eV.

    ↳ astro-ph.HEhep-phJ.Mod.Phys.(2025)·1 citation
26. 26*

    Magnetic susceptibility of QCD matter and its decomposition from the lattice

    Gunnar S. Bali (1 and 2)🇩🇪 · Gergely Endrődi (3 and 4)🇩🇪 · Stefano Piemonte (1) ((1) Regensburg U., (2) Tata Inst., (3) Bielefeld U., (4) Frankfurt U.)🇩🇪

    We determine the magnetic susceptibility of thermal QCD matter by means of first principles lattice simulations using staggered quarks with physical masses. A novel method is employed that only requires simulations at zero background field, thereby circumventing problems related to magnetic flux quantization. After a careful continuum limit extrapolation, diamagnetic behavior (negative susceptibility) is found at low temperatures and strong paramagnetism (positive susceptibility) at high temperatures. We revisit the decomposition of the magnetic susceptibility into spin- and orbital angular momentum-related contributions. The spin term -- related to the normalization of the photon lightcone distribution amplitude at zero temperature -- is calculated non-perturbatively and extrapolated to the continuum limit. Having access to both the full magnetic susceptibility and the spin term, we calculate the orbital angular momentum contribution for the first time. The results reveal the opposite of what might be expected based on a free fermion picture. We provide a simple parametrization of the temperature- and magnetic field-dependence of the QCD equation of state that can be used in phenomenological studies.

    ↳ hep-lathep-phnucl-thJHEP(2020)·64 citations
27. 27*

    Constraints on Axions from a Theoretical Model of Spatially-Extended Gamma-Ray Emission from Neutron Stars

    Bijan Berenji🇺🇸

    Axions are hypothetical particles proposed to solve the strong CP problem in QCD and may constitute a significant fraction of the dark matter in the Universe. Axions are expected to be produced in neutron stars and subsequently decay, producing gamma-rays detectable by the Fermi Large Area Telescope (Fermi-LAT). Considering that light QCD axions, as opposed to axions $>1$eV, may travel a long range before they decay into gamma rays, neutron stars may appear as a spatially-extended source of gamma rays. We extend our previous search for gamma rays from axions, based on a point source model, to consider the neutron star as an extended source of gamma rays. The extended consideration of neutron stars' leads to higher sensitivity to searches for axions, as it will be shown. We investigate the spatial emission of gamma rays using phenomenological models of neutron star axion emission. We present models including the fundamental astrophysics and relativistic, extended gamma-ray emission from axions around neutron stars. A Monte Carlo simulation of the LAT gives us an expectation for the extended angular profile and spectrum. For a source of $\simeq$ 100 pc, we predict a mean angular spread of $\simeq 2^{\circ }$ with gamma-ray energies in the range 10-200 MeV. We demonstrate the feasibility of setting more stringent limits for axions in this mass range, excluding a range not probed by observations before. We consider projected sensitivities for mass limits on axions from J0108-1431. Based on the extended angular profile of the source, the expected sensitivity of the 95\% CL upper limit on the axion mass from J0108-1431 is $\lesssim$10 meV. The limit based on 7.9 years of Fermi-LAT data is 0.76 meV for an inner temperature of the neutron star of 20 MeV.

    ↳ astro-ph.HEhep-phJournal of Modern Physics, 2024·2 citations
28. 28*

    Editorial to the special issue "probing new physics with black holes"

    Aurélien Barrau🇫🇷

    Black holes are fantastic laboratories to probe new physics. Both theoretically and experimentally, many new ideas are emerging to use them as tools for understanding better quantum gravity or classical gravity beyond general relativity. I briefly review some new results.

    ↳ gr-qchep-phUniverse(2020)·1 citation
29. 29*

    Anomalous Lorentz transformation and side jump of a massive fermion

    Feng Li🇨🇳 · Shuai Y.F. Liu🇨🇳

    The side jump in the anomalous Lorentz transformation, arising from the spin-orbit interactions, plays important roles in various intriguing physics, such as chiral vortical effects and spin polarization. In this work, the side jump of the spin-half massive particles, which has rarely been discussed, is visualized and evaluated for the first time. A compact analytical expression describing such side jumps is derived, and found approaching the one describing the chiral fermions in the massless limit. It is further demonstrated that the covariance of the total angular momentum, which would be broken by a normal Lorentz transformation, is restored after the obtained side jumps are taken into account.

    ↳ nucl-thhep-phhep-th7 citations
30. 30*

    Can axion clumps be formed in a pre-inflationary scenario?

    Hayato Fukunaga🇯🇵 · Naoya Kitajima🇯🇵 · Yuko Urakawa🇯🇵

    The QCD axion and an axion-like particle (ALP) are compelling candidates of dark matter. For the QCD axion, it is known that when the Peccei-Quinn (PQ) symmetry is spontaneously broken after inflation, the large initial fluctuation can lead to axion clump formation. On the other hand, when the symmetry is already broken during inflation, it has been believed that the axion clump formation does not occur due to the small amplitude of the initial axion fluctuation. We revisit this prevailing understanding, considering both the QCD axion and an ALP. We find that for the QCD axion, the clump formation does not occur even if we consider an extremely fine-tuned initial condition. Meanwhile, it turns out that for an ALP which allows a more general potential form, the clump formation can take place through the tachyonic instability or/and the resonance instability, considering a multiple cosine potential.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2021)·18 citations
31. 31*

    Charmed baryon spectrum from lattice QCD near the physical point

    Huseyin Bahtiyar🇹🇷 · Kadir Utku Can🇦🇺 · Guray Erkol🇹🇷 · Philipp Gubler🇯🇵 · Makoto Oka🇯🇵 · Toru T. Takahashi🇯🇵

    We calculate the low-lying spectrum of charmed baryons in lattice QCD on the $32^3\times 64$, $N_f=2+1$ PACS-CS gauge configurations at the almost physical pion mass of $\sim 156$ MeV/c${}^2$. By employing a set of interpolating operators with different Dirac structures and quark-field smearings for the variational analysis, we extract the ground and first few excited states of the spin-$1/2$ and spin-$3/2$, singly-, doubly-, and triply-charmed baryons. Additionally, we study the ${\Xi }_c$-${\Xi }_c^{\prime }$ mixing and the operator dependence of the excited states in a variational approach. We identify several states that lie close to the experimentally observed excited states of the ${\Sigma }_c$, ${\Xi }_c$ and ${\Omega }_c$ baryons, including some of the ${\Xi }_c$ states recently reported by LHCb. Our results for the doubly- and triply-charmed baryons are suggestive for future experiments.

    ↳ hep-lathep-phPRD(2020)·65 citations
32. 32*

    Fractionalized Quasiparticles in Dense Baryonic Matter

    Mannque Rho🇫🇷

    I discuss a novel scenario on how baryonic matter could turn into a Fermi liquid of fractionalized baryons driven by high density inside compact stars. It involves the "hidden" local vector bosons $\rho$ and $\omega$ together with the "hidden" scale symmetry dilaton $\chi$, both taken to be "dual" to the quarks and gluons of QCD in the sense of quark $\leftrightarrow$ hadron duality and offers a possibility, exploiting the "Cheshire Cat Principle", to unify the "dichotomy" of baryons described in terms of skyrmions and fractional quantum Hall (FQH) droplets {\it and} to explore how the baryonic matter could behave as density goes way beyond the normal nuclear matter density to the density regime where "deconfined" quarks are presumed to figure. The question is raised as to whether the fractionalized characteristics of the "stuff" -- whatever they are -- can be "probed" in the dense star core of compact stars.

    ↳ nucl-thhep-ph12 citations
33. 33*

    Effects of anomalous magnetic moment of quarks on the dilepton production from hot and dense magnetized quark matter using the NJL model

    Snigdha Ghosh🇮🇳 · Nilanjan Chaudhuri🇮🇳 · Sourav Sarkar🇮🇳 · Pradip Roy🇮🇳

    Dilepton production rate (DPR) from hot and dense quark matter is studied in the presence of an arbitrary external magnetic field using the 2-flavour Nambu--Jona-Lasinio (NJL) model. The anomalous magnetic moment (AMM) of the quarks is taken into consideration while calculating the constituent quark mass as well as the DPR from the thermo-magnetic medium. An infinite number of quark Landau levels is incorporated so that no approximations are made on the strength of the background magnetic field. The analytic structure of the two point vector current correlation function in the complex energy plane reveals that, in addition to the usual Unitary cut, a non-trival Landau cut appears in the physical kinematic domains solely due to the external magnetic field. Moreover, these kinematic domains of the Unitary and Landau cuts are found to be significantly modified due to the AMM of the quarks. With finite AMM of the quarks, for certain values of the external magnetic field, the kinematically forbidden gap between the Unitary and Landau cuts are shown to vanish leading to the generation of a continuous spectrum of dilepton emission over the whole invariant mass region not observed earlier.

    ↳ nucl-thhep-phPRD(2020)·39 citations
34. 34*

    Suppressed cosmic growth in coupled vector-tensor theories

    Antonio De Felice🇯🇵 · Shintaro Nakamura🇯🇵 · Shinji Tsujikawa🇯🇵

    We study a coupled dark energy scenario in which a massive vector field $A_{\mu }$ with broken $U(1)$ gauge symmetry interacts with the four-velocity $u_c^{\mu }$ of cold dark matter (CDM) through the scalar product $Z=-u_c^{\mu }{A}_{\mu }$. This new coupling corresponds to the momentum transfer, so that the background vector and CDM continuity equations do not have explicit interacting terms analogous to the energy exchange. Hence the observational preference of uncoupled generalized Proca theories over the $\Lambda$CDM model can be still maintained at the background level. Meanwhile, the same coupling strongly affects the evolution of cosmological perturbations. While the effective sound speed of CDM vanishes, the propagation speed and no-ghost condition of a longitudinal scalar of $A_{\mu }$ and the CDM no-ghost condition are subject to nontrivial modifications by the $Z$ dependence in the Lagrangian. We propose a concrete dark energy model and show that the gravitational interaction on scales relevant to the linear growth of large-scale structures can be smaller than the Newton constant at low redshifts. This leads to the suppression of growth rates of both CDM and total matter density perturbations, so our model allows an interesting possibility for reducing the tension of matter density contrast ${\sigma }_8$ between high- and low-redshift measurements.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2020)·23 citations
35. 35*

    Heavy ${\Omega }_c$ and ${\Omega }_b$ baryons in the quark model

    E. Ortiz-Pacheco🇲🇽 · R. Bijker🇲🇽 · A. Giachino🇮🇹 · E. Santopinto🇮🇹

    In this contribution, we present a study of ground- and excited-state ${\Omega }_c$ and ${\Omega }_b$ baryons consisting of two strange quarks and a heavy charm or bottom quark. An analysis in the quark model shows that the recently observed excited ${\Omega }_c$ and ${\Omega }_b$ states can be interpreted in terms of $\lambda$-mode excitations.

    ↳ nucl-thhep-exhep-phnucl-exJ.Phys.Conf.Ser.(2020)·16 citations
36. 36*

    Analysis of the data on spin density matrix elements for $\gamma p\to K^{\ast +}\Lambda$

    Neng-Chang Wei🇨🇳 · Ai-Chao Wang🇨🇳 · Fei Huang🇨🇳 · De-Min Li🇨🇳

    In our previous work [Phys. Rev. C {\bf 96}, 035206 (2017)], the high-precision differential cross-section data for $\gamma p\to K^{\ast +}\Lambda$ reported by the CLAS Collaboration has been analyzed within an effective Lagrangian approach. It was found that apart from the $t$-channel $K$, $K^{\ast }$, and $\kappa$ exchanges, the $u$-channel $\Lambda$, $\Sigma$, and ${\Sigma }^{\ast }$ exchanges, the $s$-channel $N$ exchange, and the interaction current, one needs to introduce at least two nucleon resonances in the $s$ channel in constructing the reaction amplitudes to describe the cross-section data. One of the needed resonances is $N(2060)5/2^{-}$, and the other one could be one of the $N(2000)5/2^{+}$, $N(2040)3/2^{+}$, $N(2100)1/2^{+}$, $N(2120)3/2^{-}$, and $N(2190)7/2^{-}$ resonances. In this paper, we further include in our analysis the data on spin density matrix elements for $K^{\ast }$ meson reported recently by the CLAS Collaboration, with the purpose being to impose further constraints on extracting the resonance contents and to gain a better understanding of the reaction mechanism. It turns out that with the new data on spin density matrix elements taken into account, only the set with the $N(2060)5/2^{-}$ and $N(2000)5/2^{+}$ resonances among those five possible solutions extracted from the analysis of the differential cross-section data can satisfactorily describe the data on both the differential cross sections and the spin density matrix elements. Further analysis shows that this reaction is dominated by the $t$-channel $K$ exchange and $s$-channel $N(2060)5/2^{-}$ and $N(2000)5/2^{+}$ exchanges.

    ↳ nucl-thhep-phPRC(2020)·10 citations
37. 37*

    Direct CP violation and the $\Delta I=1/2$ rule in $K\to \pi \pi$ decay from the Standard Model

    Ryan Abbott🇺🇸 · Thomas Blum🇺🇸 · Peter A. Boyle🇬🇧 · Mattia Bruno🇨🇭 · Norman H. Christ🇺🇸 · Daniel Hoying🇺🇸 · Chulwoo Jung🇺🇸 · Christopher Kelly🇺🇸 · Christoph Lehner🇩🇪 · Robert D. Mawhinney🇺🇸 · David J. Murphy🇺🇸 · Christopher T. Sachrajda🇬🇧 and 3 other authors

    We present a lattice QCD calculation of the $\Delta I=1/2$, $K\to \pi \pi$ decay amplitude $A_0$ and ${\epsilon }^{\prime }$, the measure of direct CP-violation in $K\to \pi \pi$ decay, improving our 2015 calculation of these quantities. Both calculations were performed with physical kinematics on a $32^3\times 64$ lattice with an inverse lattice spacing of $a^{-1}=1.3784(68)$ GeV. However, the current calculation includes nearly four times the statistics and numerous technical improvements allowing us to more reliably isolate the $\pi \pi$ ground-state and more accurately relate the lattice operators to those defined in the Standard Model. We find $\mathrm{Re}(A_0)=2.99(0.32)(0.59)\times 10^{-7}$ GeV and $\mathrm{Im}(A_0)=-6.98(0.62)(1.44)\times 10^{-11}$ GeV, where the errors are statistical and systematic, respectively. The former agrees well with the experimental result $\mathrm{Re}(A_0)=3.3201(18)\times 10^{-7}$ GeV. These results for $A_0$ can be combined with our earlier lattice calculation of $A_2$ to obtain $\mathrm{Re}({\epsilon }^{\prime }/\epsilon )=21.7(2.6)(6.2)(5.0)\times 10^{-4}$, where the third error represents omitted isospin breaking effects, and Re$(A_0)$/Re$(A_2)=19.9(2.3)(4.4)$. The first agrees well with the experimental result of $\mathrm{Re}({\epsilon }^{\prime }/\epsilon )=16.6(2.3)\times 10^{-4}$. A comparison of the second with the observed ratio Re$(A_0)/$Re$(A_2)=22.45(6)$, demonstrates the Standard Model origin of this "$\Delta I=1/2$ rule" enhancement.

    ↳ hep-lathep-exhep-phPRD(2020)·148 citations
38. 38*

    Relieving the Hubble tension with primordial magnetic fields

    Karsten Jedamzik🇫🇷 · Levon Pogosian🇨🇦

    The standard cosmological model determined from the accurate cosmic microwave background measurements made by the Planck satellite implies a value of the Hubble constant $H_0$ that is $4.2$ standard deviations lower than the one determined from Type Ia supernovae. The Planck best fit model also predicts higher values of the matter density fraction ${\Omega }_m$ and clustering amplitude $S_8$ compared to those obtained from the Dark Energy Survey Year 1 data. Here we show that accounting for the enhanced recombination rate due to additional small-scale inhomogeneities in the baryon density may solve both the $H_0$ and the $S_8-{\Omega }_m$ tensions. The additional baryon inhomogeneities can be induced by primordial magnetic fields present in the plasma prior to recombination. The required field strength to solve the Hubble tension is just what is needed to explain the existence of galactic, cluster, and extragalactic magnetic fields without relying on dynamo amplification. Our results show clear evidence for this effect and motivate further detailed studies of primordial magnetic fields, setting several well-defined targets for future observations.

    ↳ astro-ph.COhep-phPRL(2020)·251 citations
39. 39*

    The Effective Halo Model: Creating a Physical and Accurate Model of the Matter Power Spectrum and Cluster Counts

    Oliver H. E. Philcox🇺🇸 · David N. Spergel🇺🇸 · Francisco Villaescusa-Navarro🇺🇸

    We introduce a physically-motivated model of the matter power spectrum, based on the halo model and perturbation theory. This model achieves 1\% accuracy on all $k-$scales between $k=0.02h{\mathrm{Mpc}}^{-1}$ to $k=1h{\mathrm{Mpc}}^{-1}$. Our key ansatz is that the number density of halos depends on the non-linear density contrast filtered on some unknown scale $R$. Using the Effective Field Theory of Large Scale Structure to evaluate the two-halo term, we obtain a model for the power spectrum with only two fitting parameters: $R$ and the effective `sound speed', which encapsulates small-scale physics. This is tested with two suites of cosmological simulations across a broad range of cosmologies and found to be highly accurate. Due to its physical motivation, the statistics can be easily extended beyond the power spectrum; we additionally derive the one-loop covariance matrices of cluster counts and their combination with the matter power spectrum. This yields a significantly better fit to simulations than previous models, and includes a new model for super-sample effects, which is rigorously tested with separate universe simulations. At low redshift, we find a significant ($\sim 10\%$) exclusion covariance from accounting for the finite size of halos which has not previously been modeled. Such power spectrum and covariance models will enable joint analysis of upcoming large-scale structure surveys, gravitational lensing surveys and cosmic microwave background maps on scales down to the non-linear scale. We provide a publicly released Python code.

    ↳ astro-ph.COastro-ph.GAastro-ph.IMhep-ph+1PRD(2020)·43 citations
40. 40*

    Using quasar X-ray and UV flux measurements to constrain cosmological model parameters

    Narayan Khadka🇺🇸 · Bharat Ratra🇺🇸

    Risaliti and Lusso have compiled X-ray and UV flux measurements of 1598 quasars (QSOs) in the redshift range $0.036\le z\le 5.1003$, part of which, $z\sim 2.4-5.1$, is largely cosmologically unprobed. In this paper we use these QSO measurements, alone and in conjunction with baryon acoustic oscillation (BAO) and Hubble parameter [$H(z)$] measurements, to constrain cosmological parameters in six different cosmological models, each with two different Hubble constant priors. In most of these models, given the larger uncertainties, the QSO cosmological parameter constraints are mostly consistent with those from the $H(z)$ + BAO data. A somewhat significant exception is the non-relativistic matter density parameter ${\Omega }_{m0}$ where the QSO data favors ${\Omega }_{m0}\sim 0.5-0.6$ in most models. Consequently in joint analyses of QSO data with $H(z)$ + BAO data the one-dimensional ${\Omega }_{m0}$ distributions shift slightly toward larger values. A joint analysis of the QSO + $H(z)$ + BAO data is consistent with the current standard model, spatially-flat $\Lambda$CDM, but mildly favors closed spatial hypersurfaces and dynamical dark energy. Since the higher ${\Omega }_{m0}$ values favored by the QSO data appear to be associated with the $z\sim 2-5$ part of these data, and conflict somewhat with strong indications for ${\Omega }_{m0}\sim 0.3$ from most $z<2.5$ data as well as from the cosmic microwave background anisotropy data at $z\sim 1100$, in most models, the larger QSO data ${\Omega }_{m0}$ is possibly more indicative of an issue with the $z\sim 2-5$ QSO data than of an inadequacy of the standard flat $\Lambda$CDM model.

    ↳ astro-ph.COgr-qchep-phhep-thMNRAS(2020)·105 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.