Tue·Nov 21, 2017Tuesday·November 21, 2017

1. 01*

   The two-mass contribution to the three-loop pure singlet operator matrix element

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

   We present the two-mass QCD contributions to the pure singlet operator matrix element at three loop order in x-space. These terms are relevant for calculating the structure function $F_2(x,Q^2)$ at $O({\alpha }_s^3)$ as well as for the matching relations in the variable flavor number scheme and the heavy quark distribution functions at the same order. The result for the operator matrix element is given in terms of generalized iterated integrals that include square root letters in the alphabet, depending also on the mass ratio through the main argument. Numerical results are presented.

   hep-phhep-thNPB(2018)·45 citations
2. 02*

   The Higgs boson in the minimal 3-3-1 model

   G. De Conto🇧🇷 · A. C. B. Machado🇧🇷 · J. P. B. C. de Melo🇧🇷

   In this paper we present the mass matrices and mass eigenstates for the CP-even neutral scalars in the minimal 331 model (m331) and its self-interactions, showing that the m331 automatically reproduces the Higgs potential of the Standard Model. We also present a method to generate numerical solutions for the quarks and leptons masses and their mixings, which we apply to study FCNC processes, being to calculate the contributions of all exotic neutral particles of the m331 to the mass differences in meson oscillations.

   hep-phPLB(2018)·7 citations
3. 03*

   Non-standard heavy vectors at the LHC

   Gennaro Corcella🇮🇹

   Heavy vector-boson hunting is one of the major analyses undertaken by the experiments carried out at the LHC. I will explore two scenarios which have not been investigated yet by the experimental collaborations. The first scenario consists in searching for Z' bosons, predicted by U(1)' GUT-inspired models, by studying its supersymmetric decays, leading to resonant final states with charged leptons and missing energy. Afterwards, I shall discuss the 331 model and the production of doubly-charged vector bileptons, yielding events with two same-sign lepton pairs at the LHC.

   hep-phPoS(2018)·0 citations
4. 04*

   Effect of inverse magnetic catalysis on conserved charge fluctuations in hadron resonance gas model

   Ranjita K. Mohapatra🇮🇳

   The effect of inverse magnetic catalysis (IMC) has been observed on the conserved charge fluctuations and the correlations along the chemical freeze-out curve in a hadron resonance gas model. The fluctuations and the correlations have been compared with and without charge conservations. The charge conservation plays an important role in the calculation of the fluctuations at nonzero magnetic field and for the fluctuations in the strange charge at zero magnetic field. The charge conservation diminishes the correlations ${\chi }_{BS}$ and ${\chi }_{QB}$, but enhances the correlation ${\chi }_{QS}$. The baryonic fluctuations (2nd order) at $B=0.25$ ${GeV}^2$ increases more than two times compared to $B=0$ at higher ${\mu }_B$. The fluctuations have been compared at nonzero magnetic field along the freeze-out curve i.e along fitted parameters of the chemical freeze-out temperature and chemical potentials, with the fluctuations at nonzero magnetic field along the freeze-out curve with the IMC effect, and the results are very different with the IMC effect. This is clearly seen in the products of different moments ${\sigma }^2/M$ and $S\sigma$ of net-kaon distribution.

   hep-phPRC(2019)·10 citations
5. 05*

   Estimating the flux of the 14.4 keV solar axions

   F.T. Avignone III (1)🇺🇸 · R. J. Creswick (1)🇺🇸 · J. D. Vergados (2)🇰🇷 · P. Pirinen (3)🇫🇮 · P. C. Srivastava (4)🇮🇳 · J. Suhonen (5) ((1) University of South Carolina, Columbia, (2) University of Ioannina, Ioannina, (3) University of Jyvaskyla, Department of Physics, (4) Department of Physics, Indian Institute of Technology, (5) University of Jyvaskyla, Department of Physics)🇫🇮

   In this paper we present a calculation of the expected flux of the mono-energetic 14.4 keV solar axions emitted by the M1 type nuclear transition of ${}^{57}$Fe in the Sun. These axions can be detected, e.g., by inverse coherent Bragg-Primakoff conversion in single-crystal TeO${}_2$ bolometers. The ingredients of this calculation are i) the axion nucleon coupling, estimated in several popular axion models and ii)the nuclear spin matrix elements involving realistic shell model calculations with both proton and neutron excitations. For the benefit of the experiments we have also calculated the branching ratio involving axion and photon emission

   hep-phJCAP(2018)·21 citations
6. 06*

   Analytical calculations of ground and excited states of unequal mass heavy pseudoscalar and vector mesons mass spectra using Bethe-Salpeter formalism

   Hluf Negash🇷🇺 · Shashank Bhatnagar🇮🇳

   Considering the fact that, a wide range of variation in masses of various states of heavy pseudoscalar and vector mesons can be seen in different models and the experimental data on masses of many of these states is not yet currently available, in this paper, we study the analytical calculation of heavy pseudoscalar and vector mesons mass spectra ( such as ${\eta }_c$, $B_c$, ${\eta }_b$, $J/\psi$, $B_c^{\ast }$ and ${\rm Y}$) and their corresponding wave functions in the framework of Bethe-Salpeter equation under the covariant instantaneous ansatz. The parameters of the framework were determined by a fit to the heavy pseudoscalar and vector mesons mass spectrum of ground states. These input parameters so fixed were found to give good agreements with data on mass spectra of ground and excited states of these mesons mass spectra.

   hep-ph4 citations
7. 07*

   Subleading hadronic vacuum polarization contributions to muon $g-2$: ${\mu }^{+}{\mu }^{-}\to {\gamma }^{\ast }\to {\pi }^0{\gamma }^{\ast }$

   Deog Ki Hong🇰🇷 · Du Hwan Kim🇰🇷 · Jong-Wan Lee🇰🇷

   We consider the subleading contributions of the hadronic vacuum polarization, involving the ${\pi }^0{\gamma }^{\ast }{\gamma }^{\ast }$ transition form factor, to the muon anomalous magnetic moment $g-2$. Various models for the form factor, based on hadronic ansatzes and holographic principles, are considered: They are the Wess-Zumino-Witten, vector meson dominance, lowest meson dominance (one and two vector resonances) models, and AdS/QCD. The model parameters are determined by fitting the experimental data for the $e^{+}{e}^{-}\to {\pi }^0\gamma$ total cross section. We report numerical results of the corrections to the muon $g-2$ that the resulting values of two vector resonances model are of order-of-magntitude smaller than the one obtained from the dispersion relation.

   hep-phJ.Korean Phys.Soc.(2018)·0 citations
8. 08*

   Non-Abelian quantum field theory of pionic strong interactions

   C. A. Dominguez🇿🇦 · K. Schilcher🇿🇦 · P. Moodley🇿🇦 · G. Tupper🇿🇦

   A renormalizable non-Abelian theory of strong interactions of pions, mediated by rho-mesons, is formulated at tree- and at one-loop level in perturbation theory. Hadron masses are generated through spontaneous symmetry breaking using the Higgs mechanism. Quantization and gauge fixing is achieved using the generalized class of $R_{\xi }$ gauges. As an application of this theory, pion-pion scattering lengths are obtained at tree-level in good agreement with data.

   hep-phhep-th1 citation
9. 09*

   The decay width of the $Z_c(3900)$ as an axialvector tetraquark state in solid quark-hadron duality

   Zhi-Gang Wang🇨🇳 · Jun-Xia Zhang🇨🇳

   In this article, we tentatively assign the $Z_c^{\pm }(3900)$ to be the diquark-antidiquark type axialvector tetraquark state, study the hadronic coupling constants $G_{Z_{c}J/\psi \pi }$, $G_{Z_c{\eta }_c\rho }$, $G_{Z_{c}D{\bar{D}}^{\ast }}$ with the QCD sum rules in details. We take into account both the connected and disconnected Feynman diagrams in carrying out the operator product expansion, as the connected Feynman diagrams alone cannot do the work. Special attentions are paid to matching the hadron side of the correlation functions with the QCD side of the correlation functions to obtain solid duality, the routine can be applied to study other hadronic couplings directly. We study the two-body strong decays $Z_c^{+}(3900)\to J/\psi {\pi }^{+}$, ${\eta }_c{\rho }^{+}$, $D^{+}{\bar{D}}^{\ast 0}$, ${\bar{D}}^0{D}^{\ast +}$ and obtain the total width of the $Z_c^{\pm }(3900)$. The numerical results support assigning the $Z_c^{\pm }(3900)$ to be the diquark-antidiquark type axialvector tetraquark state, and assigning the $Z_c^{\pm }(3885)$ to be the meson-meson type axialvector molecular state.

   hep-phEPJC(2018)·56 citations
10. 10*

    Charged lepton flavor violating Higgs decays at future $e^{+}{e}^{-}$ colliders

    Qin Qin🇩🇪 · Qiang Li🇨🇳 · Cai-Dian Lü🇨🇳 · Fu-Sheng Yu🇨🇳 · Si-Hong Zhou🇨🇳

    After the discovery of the Higgs boson, several future experiments have been proposed to study the Higgs boson properties, including two circular lepton colliders, the CEPC and the FCC-ee, and one linear lepton collider, the ILC. We evaluate the precision reach of these colliders in measuring the branching ratios of the charged lepton flavor violating Higgs decays $H\to e^{\pm }{\mu }^{\mp }$, $e^{\pm }{\tau }^{\mp }$ and ${\mu }^{\pm }{\tau }^{\mp }$. The expected upper bounds on the branching ratios given by the circular (linear) colliders are found to be $\mathcal{B}(H\to e^{\pm }{\mu }^{\mp })<1.2(2.1)\times 10^{-5}$, $\mathcal{B}(H\to e^{\pm }{\tau }^{\mp })<1.6(2.4)\times 10^{-4}$ and $\mathcal{B}(H\to {\mu }^{\pm }{\tau }^{\mp })<1.4(2.3)\times 10^{-4}$ at 95\% CL, which are improved by one to two orders compared to the current experimental bounds. We also discuss the constraints that these upper bounds set on certain theory parameters, including the charged lepton flavor violating Higgs couplings, the corresponding parameters in the type-III 2HDM, and the new physics cut-off scales in the SMEFT, in RS models and in models with heavy neutrinos.

    hep-phhep-exEPJC(2018)·58 citations
11. 11*

    Signals of the double intrinsic heavy quark at the current experiments

    Sergey Koshkarev🇪🇪 · Stefan Groote🇪🇪

    In this paper we review existing data and analyze experimental opportunities for modern experiments to investigate the signals of intrinsic heavy quarks.

    hep-phJ.Phys.Conf.Ser.(2017)·4 citations
12. 12*

    Dispersion theoretic calculation of the $H\to Z+\gamma$ amplitude

    I. Boradjiev🇧🇬 · E. Christova🇧🇬 · H. Eberl🇦🇹

    We have calculated the $W$-loop contribution to the amplitude of the decay $H\to Z+\gamma$ in two different methods: 1) in the $R_{\xi }$-gauge using dimensional regularization (DimReg), and 2) in the unitary gauge through the dispersion method. Using the dispersion method we have followed two approaches: i) without subtraction and ii) with subtraction, the subtraction constant being determined adopting the Goldstone boson equivalence theorem (GBET) at the limit $M_W\to 0$. The results of the calculations in $R_{\xi }$-gauge with DimReg and the dispersion method with the GBET completely coincide, which shows that DimReg is compatible with the dispersion method obeying the GBET.

    hep-phPRD(2018)·12 citations
13. 13*

    The impact of $S$-wave thresholds $D_{s1}{\bar{D}}_s+c.c.$ and $D_{s0}{\bar{D}}_s^{\ast }+c.c.$ on vector charmonium spectrum

    Zheng Cao🇨🇳 · Qiang Zhao🇨🇳

    By investigating the very closely lied $D_{s1}{\bar{D}}_s+c.c.$ and $D_{s0}{\bar{D}}_s^{\ast }+c.c.$ thresholds at about 4.43 GeV we propose that the $\psi (4415)$ and $\psi (4160)$ can be mixing states between the dynamic generated states of the strong $S$-wave $D_{s1}{\bar{D}}_s+c.c.$ and $D_{s0}{\bar{D}}_s^{\ast }+c.c.$ interactions and the quark model states $\psi (4S)$ and $\psi (2D)$. We investigate the $J/\psi K\bar{K}$ final states and invariant mass spectrum of $J/\psi K$ to demonstrate that nontrivial lineshapes can arise from such a mechanism. This process, which goes through triangle loop transitions, is located in the vicinity of the so-called "triangle singularity (TS)" kinematics. As a result, it provides a special mechanism for the production of exotic states $Z_{cs}$, which is the strange partner of $Z_c(3900)$, but with flavor contents of $c\bar{c}q\bar{s}$ (or $c\bar{c}s\bar{q}$) with $q$ denoting $u/d$ quarks. The lineshapes of the $e^{+}{e}^{-}\to J/\psi K\bar{K}$ cross sections and $J/\psi K(J/\psi \bar{K})$ spectrum are sensitive to the dynamically generated state, and we demonstrate that a pole structure can be easily distinguished from open threshold CUSP effects if an exotic state is created. A precise measurement of the cross section lineshapes can test such a mixing mechanism and provide navel information for the exotic partners of the $Z_c(3900)$ in the charmonium spectrum.

    hep-phnucl-exnucl-thPRD(2019)·20 citations
14. 14*

    Oscillations in multiparticle production processes

    Grzegorz Wilk🇵🇱 · Zbigniew Wlodarczyk🇵🇱

    We discuss two examples of oscillations apparently hidden in some experimental results for high energy multiparticle production processes: (i) - the log-periodic oscillatory pattern decorating the power-like Tsallis distributions of transverse momenta, (ii) - the oscillations of the modified combinants obtained from the measured multiplicity distributions. We show that in both cases these phenomena can provide new insight into the dynamics of these processes.

    hep-phcond-mat.stat-mechEntropy(2017)·2 citations
15. 15*

    A simple model for explaining muon-related anomalies and dark matter

    Cheng-Wei Chiang🇹🇼 · Hiroshi Okada🇹🇼

    We propose a model to explain several muon-related experimental anomalies and the abundance of dark matter. We introduce an vector-like exotic lepton that form an iso-doublet and three right-handed Majorana fermions as an iso-singlet. A real/complex scalar field is added as a dark matter candidate. We impose a global $U(1{)}_{\mu }$ symmetry under which fields associated with the SM muon are charged. To stabilize the dark matter, we impose a $Z_2$ (or $Z_3$) symmetry under which the exotic lepton doublet and the real (or complex) scalar field are charged. We find that the model can simultaneously explain the muon anomalous magnetic dipole moment and the dark matter relic density in no conflict with any lepton flavor-violating/conserving observables, with some details depending upon whether the scalar field is real or complex. Besides, we extend the framework to the quark sector in a way similar to the lepton sector, and find that the recent anomalies associated with the $b\to s{\mu }^{+}{\mu }^{-}$ transition can also be accommodated while satisfying constraints such as the $B_{s(d)}\to {\mu }^{+}{\mu }^{-}$ decays and neutral meson mixings.

    hep-phInt.J.Mod.Phys.A(2019)·22 citations
16. 16*

    Production of ${\chi }_c$ pairs in $k_T$-factorization

    Anna Cisek🇵🇱 · Wolfgang Schäfer🇵🇱 · Antoni Szczurek🇵🇱

    We calculate the production of pairs of ${\chi }_c(J)$ mesons with all possible combinations of $J=0,1,2$. The leading order production mechanism is the crossed-channel gluon exchange in the gluon-gluon fusion reaction. The building blocks are the vertices $g^{\ast }{g}^{\ast }\to {\chi }_c(J)$ for off shell gluons. We stick to the color-singlet model and calculate the gluon fusion vertices in the limit of heavy quarks with nonrelativistic motion in the bound state. These vertices are used to construct the $g^{\ast }{g}^{\ast }\to {\chi }_c(J_1){\chi }_c(J_2)$ amplitudes. We then calculate hadron-level cross sections using the $k_T$-factorization approach. In our numerical predictions, we use the KMR-type unintegrated gluon distributions. Several differential distributions at the $pp$ center of mass energy $\sqrt{s}=8\mathrm{TeV}$ are shown. The salient feature of the $t$ and $u$-channel gluon exchange are the broad distributions in rapidity difference $\Delta y$ between ${\chi }_c$ mesons.

    hep-phPRD(2018)·19 citations
17. 17*

    Recola2: REcursive Computation of One-Loop Amplitudes 2

    Ansgar Denner🇩🇪 · Jean-Nicolas Lang🇩🇪 · Sandro Uccirati🇮🇹

    We present the Fortran95 program Recola2 for the perturbative computation of next-to-leading-order transition amplitudes in the Standard Model of particle physics and extended Higgs sectors. New theories are implemented via model files in the 't Hooft-Feynman gauge in the conventional formulation of quantum field theory and in the Background-Field method. The present version includes model files for the Two-Higgs-Doublet Model and the Higgs-Singlet Extension of the Standard Model. We support standard renormalization schemes for the Standard Model as well as many commonly used renormalization schemes in extended Higgs sectors. Within these models the computation of next-to-leading-order polarized amplitudes and squared amplitudes, optionally summed over spin and colour, is fully automated for any process. Recola2 allows the computation of colour- and spin-correlated leading-order squared amplitudes that are needed in the dipole subtraction formalism. Recola2 is publicly available for download at http://recola.hepforge.org.

    hep-phComput.Phys.Commun.(2018)·139 citations
18. 18*

    Scalar Quintuplet Minimal Dark Matter with Yukawa Interactions: Perturbative up to the Planck Scale

    Chengfeng Cai🇨🇳 · Zhaofeng Kang🇨🇳 · Zhu Luo🇨🇳 · Zhao-Huan Yu🇦🇺 · Hong-Hao Zhang🇨🇳

    We confront the perturbativity problem in the real scalar quintuplet minimal dark matter model. In the original model, the quintuplet quartic self-coupling inevitably hits a Landau pole at a scale $\sim 10^{14}$ GeV, far below the Planck scale. In order to push up this Landau pole scale, we extend the model with a fermionic quintuplet and three fermionic singlets which couple to the scalar quintuplet via Yukawa interactions. Involving such Yukawa interactions at a scale $\sim 10^{10}$ GeV can not only keep all couplings perturbative up to the Planck scale, but can also explain the smallness of neutrino masses via the type-I seesaw mechanism. Furthermore, we identify the parameter regions favored by the condition that perturbativity and vacuum stability are both maintained up to the Planck scale.

    hep-phCPC(2019)·12 citations
19. 19*

    First extraction of the scalar proton dynamical polarizabilities from real Compton scattering data

    B. Pasquini (1, 2)🇮🇹 · P. Pedroni (2)🇮🇹 · S. Sconfietti (1, 2) ((1) U. Pavia, (2) INFN, Pavia)🇮🇹

    We present the first attempt to extract the scalar dipole dynamical polarizabilities from proton real Compton scattering data below pion-production threshold. The theoretical framework combines dispersion relations technique, low-energy expansion and multipole decomposition of the scattering amplitudes. The results are obtained with statistical tools that have never been applied so far to Compton scattering data and are crucial to overcome problems inherent to the analysis of the available data set.

    hep-phhep-exnucl-exnucl-thPRC(2018)·27 citations
20. 20*

    Quasiparticle anisotropic hydrodynamics for ultrarelativistic heavy-ion collisions

    Mubarak Alqahtani🇺🇸 · Mohammad Nopoush🇺🇸 · Radoslaw Ryblewski🇵🇱 · Michael Strickland🇺🇸

    In this proceedings contribution, we will review the basics of quasiparticle anisotropic hydrodynamics. Then, we will present some recent phenomenological results of 3+1d quasiparticle anisotropic hydrodynamics and Pb-Pb $2.76$ TeV collisions from the ALICE collaboration. We show that 3+1d quasiparticle anisotropic hydrodynamics model is able to describe the experimental results for Pb-Pb collisions at $2.76$ TeV quite well for many observables such as the spectra, the elliptic flow, and HBT radii in many centrality classes.

    hep-phnucl-thPoS(2018)·2 citations
21. 21*

    Measuring the Sterile Neutrino CP Phase at DUNE and T2HK

    Sandhya Choubey🇮🇳 · Debajyoti Dutta🇮🇳 · Dipyaman Pramanik🇮🇳

    The CP phases associated with the sterile neutrino cannot be measured in the dedicated short-baseline experiments being built to test the sterile neutrino hypothesis. On the other hand, these phases can be measured in long-baseline experiments, even though the main goal of these experiments is not to test or measure sterile neutrino parameters. In particular, the sterile neutrino phase ${\delta }_{24}$ affects the charged-current electron appearance data in long-baseline experiment. In this paper we show for the first time how well the sterile neutrino phase ${\delta }_{24}$ can be measured by the next-generation long-baseline experiments DUNE, T2HK (and T2HKK). We also show the expected precision with which this sterile phase can be measured by combining the DUNE data with data from T2HK or T2HKK. We also present the sensitivity of these experiments to the sterile mixing angles, both by themselves, as well as when DUNE is combined with T2HK or T2HKK.

    hep-phEPJC(2018)·38 citations
22. 22*

    Consistent Searches for SMEFT Effects in Non-Resonant Dijet Events

    Stefan Alte🇩🇪 · Matthias König🇨🇭 · William Shepherd🇩🇪

    We investigate the bounds which can be placed on generic new-physics contributions to dijet production at the LHC using the framework of the Standard Model Effective Field Theory, deriving the first consistently-treated EFT bounds from non-resonant high-energy data. We recast an analysis searching for quark compositeness, equivalent to treating the SM with one higher-dimensional operator as a complete UV model. In order to reach consistent, model-independent EFT conclusions, it is necessary to truncate the EFT effects consistently at order $1/{\Lambda }^2$ and to include the possibility of multiple operators simultaneously contributing to the observables, neither of which has been done in previous searches of this nature. Furthermore, it is important to give consistent error estimates for the theoretical predictions of the signal model, particularly in the region of phase space where the probed energy is approaching the cutoff scale of the EFT. There are two linear combinations of operators which contribute to dijet production in the SMEFT with distinct angular behavior; we identify those linear combinations and determine the ability of LHC searches to constrain them simultaneously. Consistently treating the EFT generically leads to weakened bounds on new-physics parameters. These constraints will be a useful input to future global analyses in the SMEFT framework, and the techniques used here to consistently search for EFT effects are directly applicable to other off-resonance signals.

    hep-phhep-exJHEP(2018)·43 citations
23. 23*

    Neutrino Oscillation Measurements Computed in Quantum Field Theory

    Andrew Kobach🇺🇸 · Aneesh V. Manohar🇺🇸 · John McGreevy🇺🇸

    We perform a calculation in quantum field theory of neutrino oscillation probabilities, where we include simultaneously the source, detector, and neutrino fields in the Hamiltonian. Within the appropriate limits associated with current neutrino oscillation experiments, we recover the standard oscillation formula. On the other hand, we find that the dominant contributions to the amplitude are associated with different neutrino mass eigenstates being emitted at different times, such that they arrive at the detector at the same time. This is contrary to the neutrino wave packet picture, where they are emitted simultaneously and separate as they travel to the detector. This has direct consequences regarding the mechanisms that lead to a damping of neutrino oscillations for very long baselines. Our analysis also provides a pedagogical example of a measurement process in quantum mechanics.

    hep-phhep-thPLB(2018)·24 citations
24. 24*

    Light Resonances and the Low-$q^2$ Bin of $R_{K^{\ast }}$

    Wolfgang Altmannshofer🇺🇸 · Michael J. Baker🇨🇭 · Stefania Gori🇺🇸 · Roni Harnik🇺🇸 · Maxim Pospelov🇨🇦 · Emmanuel Stamou🇺🇸 · Andrea Thamm🇨🇭

    LHCb has reported hints of lepton-flavor universality violation in the rare decays $B\to K^{(\ast )}{\ell }^{+}{\ell }^{-}$, both in high- and low-$q^2$ bins. Although the high-$q^2$ hint may be explained by new short-ranged interactions, the low-$q^2$ one cannot. We thus explore the possibility that the latter is explained by a new light resonance. We find that LHCb's central value of $R_{K^{\ast }}$ in the low-$q^2$ bin is achievable in a restricted parameter space of new-physics scenarios in which the new, light resonance decays preferentially to electrons and has a mass within approximately $10$ MeV of the di-muon threshold. Interestingly, such an explanation can have a kinematic origin and does not require a source of lepton-flavor universality violation. A model-independent prediction is a narrow peak in the differential $B\to K^{\ast }{e}^{+}{e}^{-}$ rate close to the di-muon threshold. If such a peak is observed, other observables, such as the differential $B\to K{e}^{+}{e}^{-}$ rate and $R_K$, may be employed to distinguish between models. However, if a low-mass resonance is not observed and the low-$q^2$ anomaly increases in significance, then the case for an experimental origin of the lepton-flavor universality violating anomalies would be strengthened. To further explore this, we also point out that, in analogy to $J/\psi$ decays, $e^{+}{e}^{-}$ and ${\mu }^{+}{\mu }^{-}$ decays of $\varphi$ mesons can be used as a cross check of lepton-flavor universality by LHCb with $5$ fb${}^{-1}$ of integrated luminosity.

    hep-phhep-exJHEP(2018)·53 citations
25. 25*

    Secondary dips and the asymptotics

    S.M. Troshin🇷🇺 · N.E. Tyurin🇷🇺

    We point out how to detect experimentally the energy region where asymptotics starts to manifest itself in hadron scattering relating appearance of the secondary dips in the differential cross-section of elastic scattering $d\sigma /dt$ with beginning of the asymptotic energy region. The consideration relies on the differential characteristics. The framework of the impact parameter picture of proton--proton interactions is being used.

    hep-phhep-exMod.Phys.Lett.A(2018)·2 citations
26. 26*

    A Hint of a Blue Axion Isocurvature Spectrum?

    Daniel J. H. Chung🇺🇸 · Amol Upadhye🇺🇸

    It is known that if the Peccei-Quinn symmetry breaking field is displaced from its minimum during inflation, the axion isocurvature spectrum is generically strongly blue tilted with a break transition to a flat spectrum. We fit this spectrum (incorporated into the "vanilla" $\Lambda$-CDM cosmological model) to the Planck and BOSS DR11 data and find a mild hint for the presence of axionic blue-tilted isocurvature perturbations. We find the best fit parameter region is consistent with all of the dark matter being composed of QCD axions in the context of inflationary cosmology with an expansion rate of order $10^8$ GeV, the axion decay constant of order $10^{13}$ GeV, and the initial misalignment angle of order unity. Intriguingly, isocurvature with a spectral break may at least partially explain the low-$\ell$ vs. high-$\ell$ anomalies seen in the CMB data.

    ↳ astro-ph.COhep-phPRD(2018)·24 citations
27. 27*

    Dark matter component decaying after recombination: Sensitivity to BAO and RSD probes

    A. Chudaykin🇷🇺 · D. Gorbunov🇷🇺 · I. Tkachev🇷🇺

    It has been recently suggested~\cite{Berezhiani:2015yta} that a subdominant fraction of dark matter decaying after recombination may alleviate tension between high-redshift (CMB anisotropy) and low-redshift (Hubble constant, cluster counts) measurements. In this report, we continue our previous study~\cite{Chudaykin:2016yfk} of the decaying dark matter (DDM) model adding all available recent baryon acoustic oscillation (BAO) and redshift space distortions (RSD) measurements. We find, that the BAO/RSD measurements generically prefer the standard $\Lambda$CDM and combined with other cosmological measurements impose an upper limit on the DDM fraction at the level of $\sim$\,5\,\%, strengthening by a factor of 1.5 limits obtained in \cite{Chudaykin:2016yfk} mostly from CMB data. However, the numbers vary from one analysis to other based on the same Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12 (DR12) galaxy sample. Overall, the model with a few percent DDM fraction provides a better fit to the combined cosmological data as compared to the $\Lambda$CDM: the cluster counting and direct measurements of the Hubble parameter are responsible for that. The improvement can be as large as 1.5\,$\sigma$ and grows to 3.3\,$\sigma$ when the CMB lensing power amplitude ${\mathrm{A}}_{\mathrm{L}}$ is introduced as a free fitting parameter.

    ↳ astro-ph.COhep-phPRD(2018)·49 citations
28. 28*

    Methodology study of machine learning for the neutron star equation of state

    Yuki Fujimoto🇯🇵 · Kenji Fukushima🇯🇵 · Koichi Murase🇯🇵

    We discuss a methodology of machine learning to deduce the neutron star equation of state from a set of mass-radius observational data. We propose an efficient procedure to deal with a mapping from finite data points with observational errors onto an equation of state. We generate training data and optimize the neural network. Using independent validation data (mock observational data) we confirm that the equation of state is correctly reconstructed with precision surpassing observational errors. We finally discuss the relation between our method and Bayesian analysis with an emphasis put on generality of our method for underdetermined problems.

    ↳ nucl-thastro-ph.HEhep-phPRD(2018)·82 citations
29. 29*

    Measurement of $\mathrm{H}\to {\mu }^{+}{\mu }^{-}$ production in association with a Z boson at the CEPC

    Zhenwei Cui🇨🇳 · Qiang Li🇨🇳 · Gang Li🇨🇳 · Manqi Ruan🇨🇳 · Lei Wang🇨🇳 · Daneng Yang🇨🇳

    The Circular Electron-Positron Collider (CEPC) is a future Higgs factory proposed by the Chinese high energy physics community. It will operate at a center-of-mass energy of 240-250 GeV and is expected to accumulate an integrated luminosity of 5 ab${}^{-1}$ with ten years of operation. At CEPC, Higgs bosons are dominantly produced from $ZH$ associated process. Vast amount of Higgs events collected will enable precise studies of its properties including Yukawa couplings to massive particles. With {\sc GEANT4}-based simulation of detector effects, we study CEPC feasibility on measuring Higgs boson decaying into a pair of muons. The results with or without information from Z boson decay products are provided, which show a signal significance of over 10 standard deviations can be achieved and the H-$\mu$-$\mu$ coupling can be measured within $10\%$ accuracy.

    ↳ hep-exhep-phCPC(2018)·2 citations
30. 30*

    Measurement of ${}^{144}\mathrm{Pr}$ beta-spectrum with Si(Li) detectors for the purpose of determining the spectrum of electron antineutrinos

    A.V. Derbin🇷🇺 · S.V. Bakhlanov🇷🇺 · I.S. Drachnev🇷🇺 · I.P. Filipov🇷🇺 · L.A. Lukyanchenko🇷🇺 · I.N. Machulin🇷🇺 · V.N. Muratova🇷🇺 · N.V. Pilipenko🇷🇺 · D.A. Semenov🇷🇺 · E.V. Unzhakov🇷🇺

    Here we present the specifications of the newly developed beta-spectrometer based on thick full absorption Si(Li) detector. The spectrometer can be used for precision measurements of various beta-spectra, namely for the beta-spectrum shape study of ${}^{144}$Pr, which is considered to be the most promising anti-neutrino source for sterile neutrino searches.

    ↳ physics.ins-dethep-exhep-phnucl-ex0 citations
31. 31*

    New quasibound states of the compound nucleus in $\alpha$-particle capture by the nucleus

    Sergei P. Maydanyuk (1 and2)🇨🇳 · Peng-Ming Zhang (1)🇨🇳 · Li-Ping Zou (1) ((1) Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China, (2) Institute for Nuclear Research, National Academy of Sciences of Ukraine, Kiev, 03680, Ukraine)🇨🇳

    We generalize the theory of nuclear decay and capture of Gamow that is based on tunneling through the barrier and internal oscillations inside the nucleus. In our formalism an additional factor is obtained, which describes distribution of the wave function of the $\alpha$ particle inside the nuclear region. We discover new most stable states (called quasibound states) of the compound nucleus (CN) formed during the capture of $\alpha$ particle by the nucleus. With a simple example, we explain why these states cannot appear in traditional calculations of the $\alpha$ capture cross sections based on monotonic penetrabilities of a barrier, but they appear in a complete description of the evolution of the CN. Our result is obtained by a complete description of the CN evolution, which has the advantages of (1) a clear picture of the formation of the CN and its disintegration, (2) a detailed quantum description of the CN, (3) tests of the calculated amplitudes based on quantum mechanics (not realized in other approaches), and (4) high accuracy of calculations (not achieved in other approaches). These peculiarities are shown with the capture reaction of $\alpha {+}^{44}\mathrm{Ca}$. We predict quasibound energy levels and determine fusion probabilities for this reaction. The difference between our approach and theory of quasistationary states with complex energies applied for the $\alpha$ capture is also discussed. We show (1) that theory does not provide calculations for the cross section of $\alpha$ capture (according to modern models of the $\alpha$ capture), in contrast with our formalism, and (2) these two approaches describe different states of the $\alpha$ capture (for the same $\alpha$-nucleus potential).

    ↳ nucl-thhep-phnucl-exPRC(2017)·13 citations
32. 32*

    Eigenvector continuation with subspace learning

    Dillon Frame🇺🇸 · Rongzheng He🇺🇸 · Ilse Ipsen🇺🇸 · Daniel Lee🇺🇸 · Dean Lee🇺🇸 · Ermal Rrapaj🇺🇸

    A common challenge faced in quantum physics is finding the extremal eigenvalues and eigenvectors of a Hamiltonian matrix in a vector space so large that linear algebra operations on general vectors are not possible. There are numerous efficient methods developed for this task, but they generally fail when some control parameter in the Hamiltonian matrix exceeds some threshold value. In this work we present a new technique called eigenvector continuation that can extend the reach of these methods. The key insight is that while an eigenvector resides in a linear space with enormous dimensions, the eigenvector trajectory generated by smooth changes of the Hamiltonian matrix is well approximated by a very low-dimensional manifold. We prove this statement using analytic function theory and propose an algorithm to solve for the extremal eigenvectors. We benchmark the method using several examples from quantum many-body theory.

    ↳ nucl-thcond-mat.str-elcs.NAhep-lat+2PRL(2018)·181 citations
33. 33*

    Wess-Zumino and Super Yang-Mills Theories in D=4 Integral Superspace

    L. Castellani🇮🇹 · R. Catenacci🇮🇹 · P. A. Grassi🇮🇹

    We reconstruct the action of $N=1,D=4$ Wess-Zumino and $N=1,2,D=4$ super-Yang-Mills theories, using integral top forms on the supermanifold ${\mathcal{M}}^{(4|4)}$. Choosing different Picture Changing Operators, we show the equivalence of their rheonomic and superspace actions. The corresponding supergeometry and integration theory are discussed in detail. This formalism is an efficient tool for building supersymmetric models in a geometrical framework.

    ↳ hep-thhep-phmath-phmath.MPJHEP(2018)·8 citations
34. 34*

    Critical point of nuclear matter and beam energy dependence of net proton number fluctuations

    Volodymyr Vovchenko🇩🇪 · Lijia Jiang🇩🇪 · Mark I. Gorenstein🇺🇦 · Horst Stoecker🇩🇪

    The beam energy dependence of net baryon number susceptibilities is studied in the framework of the hadron resonance gas model with the attractive and repulsive van der Waals interactions between baryons. The collision energy dependences for the skewness $S\sigma$ and kurtosis $\kappa {\sigma }^2$ deviate significantly from the Poisson baseline and demonstrate the existence of rich structures at moderate collision energies. This behavior may result from the critical end point of the nuclear liquid-gas first order phase transition. In particular, $\kappa {\sigma }^2$ shows a non-monotonic energy dependence, and, in contrast to the standard scenario for the QCD critical point, it does not decrease at low collision energies. It is also found that the measurable net proton fluctuations differ significantly from the net baryon fluctuations when interactions between baryons cannot be neglected. The results are compared with the experimental net proton number fluctuations measured by the STAR collaboration.

    ↳ nucl-thhep-phnucl-exPRC(2018)·37 citations
35. 35*

    Interacting dark energy in the dark $SU(2{)}_R$ model

    Ricardo G. Landim🇧🇷 · Rafael J. F. Marcondes🇧🇷 · Fabrízio F. Bernardi🇧🇷 · Elcio Abdalla🇧🇷

    We explore the cosmological implications of the interactions among the dark particles in the dark $SU(2{)}_R$ model. It turns out that the relevant interaction is between dark energy and dark matter, through a decay process. With respect to the standard $\Lambda$CDM model, it changes only the background equations. We note that the observational aspects of the model are dominated by degeneracies between the parameters that describe the process. Thus, only the usual $\Lambda$CDM parameters, such as the Hubble expansion rate and the dark energy density parameter (interpreted as the combination of the densities of the dark energy doublet) could be constrained by observations at this moment.

    ↳ astro-ph.COhep-phBraz.J.Phys.(2018)·11 citations
36. 36*

    Derived Born cross sections of $e^{+}{e}^{-}$ annihilation into open charm mesons from CLEO-c measurements

    Xiang-Kun Dong🇨🇳 · Liang-Liang Wang🇨🇳 · Chang-Zheng Yuan🇨🇳

    The exclusive Born cross sections of the production of $D^0$, $D^{+}$ and $D_s^{+}$ mesons in $e^{+}{e}^{-}$ annihilation at 13 energy points between 3.970 and 4.260 GeV are obtained by applying corrections for initial state radiation and vacuum polarization to the observed cross sections measured by CLEO-c experiment. Both the statistical and the systematic uncertainties for the obtained Born cross sections are properly estimated.

    ↳ hep-exhep-phCPC(2018)·16 citations
37. 37*

    A novel way to determine the scale of inflation

    Kari Enqvist🇫🇮 · Robert J. Hardwick🇬🇧 · Tommi Tenkanen🇬🇧 · Vincent Vennin🇬🇧 · David Wands🇬🇧

    We show that in the Feebly Interacting Massive Particle (FIMP) model of Dark Matter (DM), one may express the inflationary energy scale $H_{\ast }$ as a function of three otherwise unrelated quantities, the DM isocurvature perturbation amplitude, its mass and its self-coupling constant, independently of the tensor-to-scalar ratio. The FIMP model assumes that there exists a real scalar particle that alone constitutes the DM content of the Universe and couples to the Standard Model via a Higgs portal. We consider carefully the various astrophysical, cosmological and model constraints, accounting also for variations in inflationary dynamics and the reheating history, to derive a robust estimate for $H_{\ast }$ that is confined to a relatively narrow range. We point out that, within the context of the FIMP DM model, one may thus determine $H_{\ast }$ reliably even in the absence of observable tensor perturbations.

    ↳ astro-ph.COhep-phJCAP(2018)·35 citations
38. 38*

    Finite temperature spectral functions in the O(N)-model

    Jan M. Pawlowski🇩🇪 · Nils Strodthoff🇺🇸 · Nicolas Wink🇩🇪

    We directly calculate spectral functions in the O(N)-model at finite temperature within the framework of the Functional Renormalization group. Special emphasis is put on a fully numerical framework involving four-dimensional regulators preserving Euclidean O(4) and Minkowski Lorentz invariance, an important prerequisite for future applications. Pion and sigma meson spectral functions are calculated for a wide range of temperatures across the phase transition illustrating the applicability of the general framework for finite temperature applications. In addition, various aspects concerning the interplay between the Euclidean and real time two-point function are discussed.

    ↳ hep-thhep-phPRD(2018)·68 citations
39. 39*

    Measuring the Local Diffusion Coefficient with H.E.S.S. Observations of Very High-Energy Electrons

    Dan Hooper🇺🇸 · Tim Linden🇺🇸

    The HAWC Collaboration has recently reported the detection of bright and spatially extended multi-TeV gamma-ray emission from Geminga, Monogem, and a handful of other nearby, middle-aged pulsars. The angular profile of the emission observed from these pulsars is surprising, in that it implies that cosmic-ray diffusion is significantly inhibited within ~25 pc of these objects, compared to the expectations of standard Galactic diffusion models. This raises the important question of whether the diffusion coefficient in the local interstellar medium is also low, or whether it is instead better fit by the mean Galactic value. Here, we utilize recent observations of the cosmic-ray electron spectrum (extending up to ~20 TeV) by the H.E.S.S. Collaboration to show that the local diffusion coefficient cannot be as low as it is in the regions surrounding Geminga and Monogem. Instead, we conclude that cosmic rays efficiently diffuse through the bulk of the local interstellar medium. Among other implications, this further supports the conclusion that pulsars significantly contribute to the observed positron excess.

    ↳ astro-ph.HEastro-ph.GAhep-phPRD(2018)·57 citations
40. 40*

    Thermalized axion inflation: natural and monomial inflation with small $r$

    Ricardo Z. Ferreira🇪🇸 · Alessio Notari🇪🇸

    A safe way to reheat the universe, in models of natural and quadratic inflation, is through shift symmetric couplings between the inflaton $\varphi$ and the Standard Model (SM), since they do not generate loop corrections to the potential $V(\varphi )$. We consider such a coupling to SM gauge fields, of the form $\varphi F\tilde{F}/f$, with sub-Planckian $f$. In this case gauge fields can be exponentially produced already {\it during inflation} and thermalize via interactions with charged particles, as pointed out in previous work. This can lead to a plasma of temperature $T$ during inflation and the thermal masses $gT$ of the gauge bosons can equilibrate the system. In addition, inflaton perturbations $\delta \varphi$ can also have a thermal spectrum if they have sufficiently large cross sections with the plasma. In this case inflationary predictions are strongly modified: (1) scalar perturbations are thermal, and so enhanced over the vacuum, leading to a generic way to {\it suppress} the tensor-to-scalar ratio $r$; (2) the spectral index is $n_s-1=\eta -4ϵ$. After presenting the relevant conditions for thermalization, we show that thermalized natural and monomial models of inflation agree with present observations and have $r\approx 10^{-3}-10^{-2}$, which is within reach of next generation CMB experiments.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2018)·30 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.