Wed·Aug 21, 2019Wednesday·August 21, 2019

1. 01*

   Power-enhanced leading-logarithmic QED corrections to $B_q\to {\mu }^{+}{\mu }^{-}$

   Martin Beneke🇩🇪 · Christoph Bobeth🇩🇪 · Robert Szafron🇩🇪

   We provide a systematic treatment of the previously discovered power-enhanced QED corrections to the leptonic decay $B_q\to {\mu }^{+}{\mu }^{-}$ ($q=d,s$) in the framework of soft-collinear effective theory (SCET). Employing two-step matching on SCET${}_{\text{I}}$ and SCET${}_{\text{II}}$, and the respective renormalization group equations, we sum the leading-logarithmic QED corrections and the mixed QED-QCD corrections to all orders in the couplings for the matrix element of the semileptonic weak effective operator $\sim Q_9$. We propose a treatment of the $B$-meson decay constant and light-cone distribution amplitude in the presence of process-specific QED corrections. Finally we include ultrasoft photon radiation and provide updated values of the non-radiative and radiative branching fractions of $B_q\to {\mu }^{+}{\mu }^{-}$ decay that include the double-logarithmic QED and QCD corrections.

   hep-phJHEP(2019)·244 citations
2. 02*

   Astrophysics-independent determination of dark matter parameters from two direct detection signals

   Juan Herrero-Garcia🇮🇹 · Yannick Müller🇩🇪 · Thomas Schwetz🇩🇪

   Next-generation dark matter direct detection experiments will explore several orders of magnitude in the dark matter--nucleus scattering cross section below current upper limits. In case a signal is discovered the immediate task will be to determine the dark matter mass and to study the underlying interactions. We develop a framework to determine the dark matter mass from signals in two experiments with different targets, independent of astrophysics. Our method relies on a distribution-free, nonparametric two-sample hypothesis test in velocity space, which neither requires binning of the data, nor any fitting of parametrisations of the velocity distribution. We apply our method to realistic configurations of xenon and argon detectors such as XENONnT/DARWIN and DarkSide, and estimate the precision with which the DM mass can be determined. Once the dark matter mass is identified, the ratio of coupling strengths to neutrons and protons can be constrained by using the same data. The test can be applied for event samples of order 20 events, but promising sensitivities require $\gtrsim 100$ events.

   hep-phastro-ph.COhep-exPhys.Dark Univ.(2019)·3 citations
3. 03*

   't Hooft-Polyakov monopole and instanton-like topological solution in gauge-Higgs unification

   K. Hasegawa🇯🇵 · C. S. Lim🇯🇵

   We consider 't Hooft-Polyakov monopole (TPM) as a topological soliton in the 5-dimensional (5D) theory of gauge-Higgs unification. This scenario provides a very natural framework to incorporate the TPM, since the adjoint scalar is builtin as the extra-space component of higher dimensional gauge field. In the process of the analysis, we realize that the condition to be satisfied by the Bogomolny-Prasad-Sommerfield (BPS) state of TPM, the BPS monopole, is equivalent to an (anti-)self-dual condition for the higher dimensional gauge field. This observation, in turn, suggests the presence of instanton-like topological soliton living in the 4D space (including the extra dimension), instead of the 4D space-time in the case of ordinary instanton, say "space-like instanton" with finite energy, instead of finite action. We construct the field configuration for the space-like instanton and calculate its mass, handled by the compactification scale. Next we discuss the BPS monopole, as an anti-self-dual gauge field. We start by constructing a hedgehog-type solution as what is obtained by a local gauge transformation from a trivial vacuum. We also argue in some detail that the relation between these two types of topological solitons becomes manifest through the unified description by use of the ansatz adopted by 't Hooft.

   hep-phhep-thJ.Phys.Soc.Jap.(2020)·4 citations
4. 04*

   Gauged $U(1{)}_{L_{\mu }-L_{\tau }}$ Scotogenic Model in light of $R_{K^{(\ast )}}$ Anomaly and AMS-02 Positron Excess

   Zhi-Long Han🇨🇳 · Ran Ding🇨🇳 · Su-Jie Lin🇨🇳 · Bin Zhu🇨🇳

   We study the gauged $U(1{)}_{L_{\mu }-L_{\tau }}$ scotogenic model with emphasis on latest measurement of LHCb $R_{K^{(\ast )}}$ anomaly and AMS-02 positron excess. In this model, neutrino masses are induced at one-loop level with $Z_2$-odd particles, i.e., right-handed neutrinos $N_{\ell }(\ell =e,\mu ,\tau )$ and inert scalar doublet $\eta$ inside the loop. Meanwhile, the gauged $U(1{)}_{L_{\mu }-L_{\tau }}$ symmetry is broken spontaneously by the scalar singlet $S$, resulting to the massive gauge boson $Z^{\prime }$. Provided certain couplings to quarks induced by heavy vector-like quarks, the gauge boson $Z^{\prime }$ would contribute to the transition $b\to s{\mu }^{+}{\mu }^{-}$, hence explain the $R_{K^{(\ast )}}$ anomaly. As for the Majorana fermion DM $N$, the gauge boson $Z^{\prime }$ and the singlet Higgs $H_0$ will generate various annihilation channels, among which the $NN\to Z^{\prime }{Z}^{\prime }$ and $NN\to Z^{\prime }{H}_0(\to Z^{\prime }{Z}^{\prime })$ channel could be used to interpret the AMS-02 positron excess. We give a comprehensive analysis on model parameter space with consider various current constraints. The combined analysis shows that the $R_{K^{(\ast )}}$ anomaly and AMS-02 positron excess can be explained simultaneously.

   hep-phEPJC(2019)·39 citations
5. 05*

   The 96 GeV Diphoton Excess in the Seesaw Extensions of the Natural NMSSM

   Junjie Cao🇨🇳 · Xinglong Jia🇨🇳 · Yuanfang Yue🇨🇳 · Haijing Zhou🇨🇳 · Pengxuan Zhu🇨🇳

   The Next-to Minimal Supersymmetric Standard Model (NMSSM) with a Type-I seesaw mechanism extends the NMSSM by three generations of right-handed neutrino fields to generate neutrino mass. As a byproduct it renders the lightest sneutrino as a viable DM candidate. Due to the gauge singlet nature of the DM, its scattering with nucleon is suppressed in most cases to coincide spontaneously with the latest XENON-1T results. Consequently, broad parameter spaces in the Higgs sector, especially a light Higgsino mass, are resurrected as experimentally allowed, which makes the theory well suited to explain the long standing $b\bar{b}$ excess at LEP-II and the continuously observed $\gamma \gamma$ excess by CMS collaboration. We show by both analytic formulas and numerical results that the theory can naturally predict the central values of the excesses in its broad parameter space, and the explanations are consistent with the Higgs data of the discovered Higgs boson, $B-$physics and DM physics measurements, the electroweak precision data as well as the LHC search for sparticles. Part of the explanations may be tested by future DM experiments and the SUSY search at the LHC.

   hep-phPRD(2020)·87 citations
6. 06*

   On the Properties of the Effective Jarlskog Invariant for Three-flavor Neutrino Oscillations in Matter

   Xin Wang🇨🇳 · Shun Zhou🇨🇳

   In this paper, we show that the ratio of the effective Jarlskog invariant $\tilde{\mathcal{J}}$ for leptonic CP violation in three-flavor neutrino oscillations in matter to its counterpart $\mathcal{J}$ in vacuum $\tilde{\mathcal{J}}/\mathcal{J}\approx 1/({\hat{C}}_{12}^{}{\hat{C}}_{13}^{})$ holds as an excellent approximation, where ${\hat{C}}_{12}^{}\equiv \sqrt{1-2{\hat{A}}_{\ast }^{}\cos 2{\theta }_{12}^{}+{\hat{A}}_{\ast }^2}$ with ${\hat{A}}_{\ast }^{}\equiv a{\cos }^2{\theta }_{13}^{}/{\Delta }_{21}^{}$ and ${\hat{C}}_{13}^{}\equiv \sqrt{1-2A_{\mathrm{c}}^{}\cos 2{\theta }_{13}^{}+A_{\mathrm{c}}^2}$ with $A_{\mathrm{c}}^{}\equiv a/{\Delta }_{\mathrm{c}}^{}$. Here ${\Delta }_{ij}^{}\equiv m_i^2-m_j^2$ (for $ij=21,31,32$) stand for the neutrino mass-squared differences in vacuum and ${\theta }_{ij}^{}$ (for $ij=12,13,23$) are the neutrino mixing angles in vacuum, while ${\Delta }_{\mathrm{c}}^{}\equiv {\Delta }_{31}^{}{\cos }^2{\theta }_{12}^{}+{\Delta }_{32}^{}{\sin }^2{\theta }_{12}^{}$ and the matter parameter $a\equiv 2\sqrt{2}{G}_{\mathrm{F}}^{}{N}_e^{}E$ are defined. This result has been explicitly derived by improving the previous analytical solutions to the renormalization-group equations of effective neutrino masses and mixing parameters in matter. Furthermore, as a practical application, such a simple analytical formula has been implemented to understand the existence and location of the extrema of $\tilde{\mathcal{J}}$.

   hep-phNPB(2020)·13 citations
7. 07*

   The gluon Sivers function and its process dependence from RHIC data

   Cristian Pisano🇮🇹 · Umberto D'Alesio🇮🇹 · Carlo Flore🇮🇹 · Francesco Murgia🇮🇹 · Pieter Taels🇮🇹

   We present a phenomenological analysis of available data on single spin asymmetries for pion and $D$ meson production in proton-proton collisions at RHIC within the color gauge invariant generalized parton model (CGI-GPM), which includes initial (ISIs) and final (FSIs) state interactions in a transverse momentum dependent formalism. This study allows us, for the first time, to put preliminary constraints on the two independent gluon Sivers functions entering the model. We also present a comparison with the simpler generalized parton model (without ISIs and FSIs).

   hep-phPoS(2019)·0 citations
8. 08*

   Global fits of the SM parameters

   Jens Erler🇩🇪

   I present a global survey of weak mixing angle measurements and other precision experiments and discuss the issue of correlations of the theoretical uncertainties in precision observables. Hadronic vacuum polarization effects complicate global fits in various ways and are also covered alongside some representative fit results.

   hep-phhep-exnucl-exPoS(2019)·1 citation
9. 09*

   Electroweak Precision Tests of the SM

   Jens Erler🇩🇪

   A global survey of weak mixing angle measurements at low and high energies is presented. Then I will discuss theoretical uncertainties in precision observables with special emphasis on their correlations. The important role of vacuum polarization in global fits will also be addressed before fit results are presented.

   hep-phnucl-exFrascati Phys.Ser.(2019)·4 citations
10. 10*

    Production of $J/\psi$ quarkonia in color evaporation model based on $k_T$-factorization

    Rafal Maciula🇵🇱 · Antoni Szczurek🇵🇱

    We use a new approach to color evaporation model (CEM) for quarkonium production. The production of $c\bar{c}$ pairs is performed within $k_T$-factorization approach using different unintegrated gluon distribution functions (UGDF) from the literature. We include all recent improvements to color evaporation model. We get poor description of the large transverse momentum distributions of $J/\psi$ with the JH-2013 CCFM-based UGDF. Here explicit inclusion of $2\to 3$ processes considerably improves the situation. Similar effects are discussed in the context of the KMR UGDF.

    hep-phPoS(2019)·1 citation
11. 11*

    Enhanced production of ${\Lambda }_c$ in proton-proton collisions at the LHC

    Rafal Maciula🇵🇱 · Antoni Szczurek🇵🇱

    We calculate cross section for production of $D$ mesons and ${\Lambda }_c$ baryons in proton-proton collisions at the LHC. The cross section for production of $c\bar{c}$ pairs is calculated within $k_T$-factorization approach with the Kimber-Martin-Ryskin unintegrated gluon distributions. We show that our approach well describes the $D^0$, $D^{+}$ and $D_s$ experimental data. We try to understand recent ALICE and LHCb data for ${\Lambda }_c$ production with the $c\to {\Lambda }_c$ independent parton fragmentation approach. The Peterson fragmentation functions are used. The $f_{c\to {\Lambda }_c}$ fragmentation fraction and ${\epsilon }_c^{\Lambda }$ parameter for $c\to {\Lambda }_c$ are varied. Although one can agree with the ALICE data using standard estimation of model uncertainties one cannot describe simultaneously the ALICE and the LHCb data with the same set of parameters. The fraction $f_{c\to {\Lambda }_c}$ neccessary to describe the ALICE data is much larger than the average value obtained from $e^{+}{e}^{-}$ or $ep$ experiments. It seems very difficult, if not impossible, to understand the ALICE data within the considered independent parton fragmentation scheme.

    hep-phPoS(2019)·0 citations
12. 12*

    Long distance effects in inclusive rare $B$ decays and phenomenology of $\bar{B}\to X_d{\ell }^{+}{\ell }^{-}$

    Tobias Huber🇩🇪 · Tobias Hurth🇩🇪 · Jack Jenkins🇺🇸 · Enrico Lunghi🇺🇸 · Qin Qin🇩🇪 · K. Keri Vos🇩🇪

    Rare inclusive $B$ decays such as $\bar{B}\to X_{s(d)}{\ell }^{+}{\ell }^{-}$ are interesting probes for physics beyond the Standard Model. Due to the complementarity to their exclusive counterparts, they might shed light on the anomalies currently seen in exclusive $b\to s$ transitions. Distinguishing new-physics effects from the Standard Model requires precise predictions and necessitates the control of long distance effects. In the present work we revisit and improve the description of various long distance effects in inclusive decays such as charmonium and light-quark resonances, nonfactorisable power corrections, and cascade decays. We then apply these results to a state-of-the-art phenomenological study of $\bar{B}\to X_d{\ell }^{+}{\ell }^{-}$, including also logarithmically enhanced QED corrections and the recently calculated five-body contributions. To fully exploit the new-physics potential of inclusive flavour-changing neutral current decays, the $\bar{B}\to X_d{\ell }^{+}{\ell }^{-}$ observables should be measured in a dedicated Belle II analysis.

    hep-phhep-exJHEP(2019)·27 citations
13. 13*

    Exotic decays of top partners: mind the search gap

    Giacomo Cacciapaglia🇫🇷 · Thomas Flacke🇰🇷 · Myeonghun Park🇰🇷 · Mengchao Zhang🇨🇳

    Many standard model extensions, including composite Goldstone Higgs models, predict vector-like fermionic top-partners at the TeV scale. The intensive search programmes by ATLAS and CMS focus on decays into a 3${}^{\mathrm{rd}}$ generation quark and an electroweak boson ($W,Z,h$). However, underlying models of partial compositeness contain additional states that give rise to exotic top partner decays. We consider a well-motivated scenario in which a charge-$2/3$ top-partner decays into a pseudo-scalar, $T\to ta$, with $a\to gg\text{mbox}orb\bar{b}$ dominating below the $t\bar{t}$ threshold. We show that the constraints on the top partner mass from QCD pair production are substantially weakened, still allowing a top partner mass as light as $400$ GeV.

    hep-phhep-exPLB(2019)·72 citations
14. 14*

    The High-Energy Frontier of the Intensity Frontier: Closing the Dark Photon, Inelastic Dark Matter, and Muon g-2 Windows

    Yu-Dai Tsai🇺🇸 · Patrick deNiverville🇺🇸 · Ming Xiong Liu🇺🇸

    We study hidden sector and long-lived particles at past (CHARM and NuCal), present (NA62 and SeaQuest/DarkQuest), and future (LongQuest) experiments that are at the high-energy frontier of the intensity frontier. We focus on exploring the minimal vector portal and variere-lifetime particles (VLP). VLP models have mostly been devised to explain experimental anomalies while avoiding existing constraints, and we demonstrate that proton fixed-target experiments provide one of the most powerful probes for the sub-GeV to few GeV mass range of the VLP models, using inelastic dark matter (iDM) as an example. We consider an iDM model with small mass splitting that yields the observed dark matter (DM) relic abundance, and a scenario with a sizable mass splitting that can also explain the muon $g-2$ anomaly. We set strong limits based on the CHARM and NuCal experiments, which come close to excluding iDM as full-abundance thermal DM candidates in the MeV to GeV mass range, for the mass arrangements and small mass splittings we consider. We also study the future projections based on NA62 and SeaQuest/DarkQuest, and update the constraints of the minimal dark photon parameter space. We found that NuCal sets the only existing constraint in $ϵ\sim 10^{-8}-10^{-4}$ regime reaching $\sim$ 800 MeV in dark photon mass due to the resonant enhancement of the proton bremsstrahlung production. Finally, we propose LongQuest, a three-stage thorough retool of the SeaQuest experiment with short ($\lesssim$ 5 m), medium ($\sim$ 5 m), and long baseline ($\gtrsim$ 35 m) tracking stations/detectors, as a multi-purpose machine to explore dark sector particles with a wide range of couplings to the standard model sector.

    hep-phastro-ph.COhep-exhep-thPRL(2021)·154 citations
15. 15*

    How much joint resummation do we need?

    Gillian Lustermans🇳🇱 · Andreas Papaefstathiou🇳🇱 · Wouter J. Waalewijn🇳🇱

    Large logarithms that arise in cross sections due to the collinear and soft singularities of QCD are traditionally treated using parton showers or analytic resummation. Parton showers provide a fully-differential description of an event but are challenging to extend beyond leading logarithmic accuracy. On the other hand, resummation calculations can achieve higher logarithmic accuracy but often for only a single observable. Recently, there have been many resummation calculations that jointly resum multiple logarithms. Here we investigate the benefits and limitations of joint resummation in a case study, focussing on the family of $e^{+}{e}^{-}$ event shapes called angularities. We calculate the cross section differential in n angularities at next-to-leading logarithmic accuracy. We investigate whether reweighing a flat phase-space generator to this resummed prediction, or the corresponding distributions from Herwig and Pythia, leads to improved predictions for other angularities. We find an order of magnitude improvement for n = 2 over n = 1, highlighting the benefit of joint resummation, but diminishing returns for larger values of n.

    hep-phJHEP(2019)·3 citations
16. 16*

    Non-relativistic susceptibility and a dark matter application

    S. Biondini🇳🇱 · Seyong Kim🇰🇷 · M. Laine🇨🇭

    When thermal rate equations are derived for the evolution of slow variables, it is often practical to parametrize the right-hand side with chemical potentials. To close the system, the chemical potentials are subsequently re-expressed in terms of the slow variables, which involves the consideration of a "susceptibility". Here we study a non-relativistic situation in which chemical potentials are large compared with the temperature, as is relevant for late-time pair annihilations in dark matter freeze-out. An order-of-magnitude estimate and a lattice simulation are presented for a susceptibility dominated by bound states of stop-like mediators. After this "calibration", the formalism is applied to a model with Majorana singlet dark matter, confirming that masses up to the multi-TeV domain are viable in the presence of sufficient (though not beyond a limit) mass degeneracy in the dark sector.

    hep-phhep-latJCAP(2019)·11 citations
17. 17*

    Analysis of the hidden-charm tetraquark mass spectrum with the QCD sum rules

    Zhi-Gang Wang🇨🇳

    In this article, we take the pseudoscalar, scalar, axialvector, vector, tensor (anti)diquark operators as the basic constituents, and construct the scalar, axialvector and tensor tetraquark currents to study the mass spectrum of the ground state hidden-charm tetraquark states with the QCD sum rules in a comprehensive way. We revisit the assignments of the $X$, $Y$, $Z$ states, such as the $X(3860)$, $X(3872)$, $X(3915)$, $X(3940)$, $X(4160)$, $Z_c(3900)$, $Z_c(4020)$, $Z_c(4050)$, $Z_c(4055)$, $Z_c(4100)$, $Z_c(4200)$, $Z_c(4250)$, $Z_c(4430)$, $Z_c(4600)$, etc in the scenario of tetraquark states in a consistent way based on the QCD sum rules. Furthermore, we discuss the feasibility of applying the QCD sum rules to study the tetraquark states and tetraquark molecular states (more precisely, the color-singlet-color-singlet type tetraquark states), which begin to receive contributions at the order $\mathcal{O}({\alpha }_s^0)$, not at the order $\mathcal{O}({\alpha }_s^2)$.

    hep-phPRD(2020)·58 citations
18. 18*

    Deeply inelastic scattering structure functions on a hybrid quantum computer

    Niklas Mueller🇺🇸 · Andrey Tarasov🇺🇸 · Raju Venugopalan🇺🇸

    We outline a strategy to compute deeply inelastic scattering structure functions using a hybrid quantum computer. Our approach takes advantage of the representation of the fermion determinant in the QCD path integral as a quantum mechanical path integral over 0+1-dimensional fermionic and bosonic worldlines. The proper time evolution of these worldlines can be determined on a quantum computer. While extremely challenging in general, the problem simplifies in the Regge limit of QCD, where the interaction of the worldlines with gauge fields is strongly localized in proper time and the corresponding quantum circuits can be written down. As a first application, we employ the Color Glass Condensate effective theory to construct the quantum algorithm for a simple dipole model of the $F_2$ structure function. We outline further how this computation scales up in complexity and extends in scope to other real-time correlation functions.

    ↳ hep-thhep-phnucl-thquant-phPRD(2020)·89 citations
19. 19*

    Inflation in supergravity from field redefinitions

    Michal Artymowski🇮🇱 · Ido Ben-Dayan🇮🇱

    Supergravity (SUGRA) theories are specified by a few functions, most notably the real Kähler function denoted by $G(T_i,{\bar{T}}_i)=K+\log |W{|}^2$, where K is a real Kähler potential, and W is a holomorphic superpotential. A field redefinition $T_i\to f_1(T_i)$ does not change neither the theory, nor the Kähler geometry. Similarly, the Kähler transformation, $K\to K+f_2+{\bar{f}}_2,W\to e^{-f_2}W$ where $f_2$ is holomorphic also leaves G and hence the theory and the geometry invariant. However, if we perform a field redefinition only in $K(T_i,{\bar{T}}_i)\to K(f(T_i),f({\bar{T}}_i))$, while keeping the same superpotential $W(T_i)$, we get a different theory, as G is not invariant under such a transformation while maintaining the same Kähler geometry. This freedom of choosing $f(T_i)$ allows constructing an infinite number of new theories given a fixed Kähler geometry and a predetermined superpotential W. Our construction generalizes previous ones that were limited by the holomorphic property of $W$. In particular it allows for novel inflationary SUGRA models and particle phenomenology model building, where the different models correspond to different choices of field redefinitions. We demonstrate this possibility by constructing several prototypes of inflationary models (hilltop, Starobinsky-like, plateau, log-squared and bell-curve) all in flat Kähler geometry and an originally renormalizable superpotential $W$. The models are in accord with current observations and predict $r\in [10^{-6},0.06]$ spanning several decades that can be easily obtained. In the bell-curve model, there also exists a built-in gravitational reheating mechanism with $T_R\sim \mathcal{O}(10^{7}GeV)$.

    ↳ hep-thgr-qchep-phSymmetry(2020)·7 citations
20. 20*

    Neutrino Detectors as Tools for Nuclear Security

    Adam Bernstein🇺🇸 · Nathaniel Bowden🇺🇸 · Bethany L. Goldblum🇺🇸 · Patrick Huber🇺🇸 · Igor Jovanovic🇺🇸 · John Mattingly🇺🇸

    For over 40 years, physicists have considered possible uses for neutrino detectors in nuclear nonproliferation, arms control, and fissile materials security. Neutrinos are an attractive fission signature because they readily pass through matter. The same property makes neutrinos challenging to detect in systems that would be practical for nuclear security applications. This colloquium presents a broad overview of several potential neutrino applications, including the near-field monitoring of known reactors, far-field monitoring of known or discovery of undeclared reactors, detection of reactor waste streams, and detection of nuclear explosions. We conclude that recent detector advances have made near-field monitoring feasible. Farther-field reactor detection and waste stream detection monitoring are possible in some cases with further research and development. Very long-range reactor monitoring and nuclear explosion detection do not appear feasible for the foreseeable future due to considerable physical and/or practical constraints.

    ↳ physics.soc-phhep-exhep-phnucl-ex+1RMP(2020)·83 citations
21. 21*

    Search for dark matter annihilation in the center of the Earth with 8 years of IceCube data

    Giovanni Renzi (for the IceCube Collaboration)

    Dark matter particles in the galactic halo can scatter off particles in celestial bodies such as stars or planets, lose energy and become gravitationally trapped. In this process, an accumulation of dark matter in the center of celestial bodies is expected, for example, at the center of the Earth. If dark matter self-annihilates into Standard Model particles, the end products of these annihilations include neutrinos. The IceCube Neutrino Observatory at the geographic South Pole can detect the resulting flux of neutrinos originating from dark matter annihilation in the center of the Earth. A search for this signal is on-going using 8 years of IceCube data and probing different annihilation channels. Here the sensitivities are presented for this new analysis, showing significant improvements with respect to the previous analyses from IceCube and other experiments.

    ↳ astro-ph.HEhep-phPoS(2020)·15 citations
22. 22*

    Deconvolution of 3-D Gaussian kernels

    Z.K. Silagadze🇷🇺

    Ulmer and Kaissl formulas for the deconvolution of one-dimensional Gaussian kernels are generalized to the three-dimensional case. The generalization is based on the use of the scalar version of the Grad's multivariate Hermite polynomials which can be expressed through ordinary Hermite polynomials.

    ↳ physics.data-anhep-phPLA(2019)·0 citations
23. 23*

    Cosmology With Low-Redshift Observations: No Signal For New Physics

    Koushik Dutta🇮🇳 · Anirban Roy🇮🇹 · Ruchika🇮🇳 · Anjan A Sen🇮🇳 · M. M. Sheikh-Jabbari🇮🇷

    We analyse various low-redshift cosmological data from Type-Ia Supernova, Baryon Acoustic Oscillations, Time-Delay measurements using Strong-Lensing, $H(z)$ measurements using Cosmic Chronometers and growth measurements from large scale structure observations for $\Lambda$CDM and some different dark energy models. By calculating the Bayesian Evidence for different dark energy models, we find out that the $\Lambda$CDM still gives the best fit to the data with $H_0=70.3_{-1.35}^{+1.36}$ Km/s/Mpc (at $1\sigma$). This value is in $2\sigma$ or less tension with various low and high redshift measurements for $H_0$ including SH0ES, Planck-2018 and the recent results from H0LiCOW-XIII. The derived constraint on $S_8={\sigma }_8\sqrt{{\Omega }_{m0}/0.3}$ from our analysis is $S_8=0.76_{-0.03}^{+0.03}$, fully consistent with direct measurement of $S_8$ by KiDS+VIKING-450+DES1 survey. We hence conclude that the $\Lambda$CDM model with parameter constraints obtained in this work is consistent with different early and late Universe observations within $2\sigma$. We therefore, do not find any compelling reason to go beyond concordance $\Lambda$CDM model.

    ↳ astro-ph.COhep-phhep-thPRD(2019)·40 citations
24. 24*

    Time-Reversed Gamma-Ray Burst Light Curve Characteristics as Transitions between Subluminal and Superluminal Motion

    Jon Hakkila (College of Charleston) · Robert Nemiroff (Michigan Technological University)

    We introduce a simple model to explain the time-reversed and stretched residuals in gamma-ray burst (GRB) pulse light curves. In this model an impactor wave in an expanding GRB jet accelerates from subluminal to superluminal velocities, or decelerates from superluminal to subluminal velocities. The impactor wave interacts with the surrounding medium to produce Cherenkov and/or other collisional radiation when traveling faster than the speed of light in this medium, and other mechanisms (such as thermalized Compton or synchrotron shock radiation) when traveling slower than the speed of light. These transitions create both a time-forward and a time-reversed set of light curve features through the process of Relativistic Image Doubling (RID). The model can account for a variety of unexplained yet observed GRB pulse behaviors including the amount of stretching observed in time-reversed GRB pulse residuals and the relationship between stretching factor and pulse asymmetry. The model is applicable to all GRB classes since similar pulse behaviors are observed in long/intermediate GRBs, short GRBs, and x-ray flares. The free model parameters are the impactor's Lorentz factor when moving subluminally, its Lorentz factor when moving superluminally, and the speed of light in the impacted medium.

    ↳ astro-ph.HEhep-ph10 citations
25. 25*

    Summary of Working Group 5: Physics with Heavy Flavours

    V. Bhardwaj🇮🇳 · J. Libby🇮🇳 · J. Virto🇩🇪

    We present a summary of heavy-flavour physics at the the time of the DIS2019 conference. This summary is based upon the relevant plenary and parallel talks presented at the workshop. The summary is divided into four broad areas: (1) spectroscopy, (2) the production of b and c quarks in collisions, (3) top quark production and properties, and (4) b and c quark decay.

    ↳ hep-exhep-phPoS(2019)·0 citations
26. 26*

    On polarized scattering equations for superamplitudes of 11D supergravity and ambitwistor superstring

    Igor Bandos🇪🇸

    We revisited the formalism of 11D polarized scattering equation by Geyer and Mason from the perspective of spinor frame approach and spinor moving frame formulation of the 11D ambitwistor superstring action. In particular, we rigorously obtain the equation for the spinor function on Riemann sphere from the supertwistor form of the ambitwistor superstring action, write its general solution and use it to derive the polarized scattering equation. We show that the expression used by Geyer and Mason to motivate their ansatz for the solution of polarized scattering equation can be obtained from our solution after a suitable gauge fixing. To this end we use the hidden gauge symmetries of the 11D ambitwistor superstring, including $SO(16)$, and the description of ambitwistor superstring as a dynamical system in an 11D superspace enlarged by bosonic directions parametrized by 517 tensorial central charge coordinates $Z^{\underline{\mu }\underline{\nu }}$ and $Z^{\underline{\mu }\underline{\nu }\underline{\rho }\underline{\sigma }\underline{\kappa }}$. We have also found the fermionic superpartner of the polarized scattering equation. This happens to be a differential equation in fermionic variables imposed on the superamplitude, rather then just a condition on the scattering data as the bosonic polarized scattering equation is. D=10 case is also discussed stressing the similarities and differences with 11D systems. The useful formulation of 10D ambitwistor superstring considers it as a dynamical system in superspace enlarged with 126 tensorial central charge coordinates $Z^{\mu \nu \rho \sigma \kappa }$.

    ↳ hep-thgr-qchep-phJHEP(2019)·11 citations
27. 27*

    A new probe of Axion-Like Particles: CMB polarization distortions due to cluster magnetic fields

    Suvodip Mukherjee🇫🇷 · David N. Spergel🇺🇸 · Rishi Khatri🇮🇳 · Benjamin D. Wandelt🇫🇷

    We propose using the upcoming Cosmic Microwave Background (CMB) ground based experiments to detect the signal of ALPs (Axion like particles) interacting with magnetic fields in galaxy clusters. The conversion between CMB photons and ALPs in the presence of the cluster magnetic field can cause a polarized spectral distortion in the CMB around a galaxy cluster. The strength of the signal depends upon the redshift of the galaxy cluster and will exhibit a distinctive spatial profile around it depending upon the structure of electron density and magnetic field. This distortion produces a different shape from the other known spectral distortions like $y$-type and $\mu$-type and hence are separable from the multi-frequency CMB observation. The spectrum is close to kinematic Sunyaev-Zeldovich (kSZ) signal but can be separated from it using the polarization information. For the future ground-based CMB experiments such as Simons Observatory and CMB-S4, we estimate the measurability of this signal in the presence of foreground contamination, instrument noise and CMB anisotropies. This new avenue can probe the photon-ALP coupling over the ALP mass range from $10^{-13}$ eV to $10^{-12}$ eV with two orders of magnitude better accuracy from CMB-S4 than the current existing bounds.

    ↳ astro-ph.COhep-phhep-thJCAP(2020)·33 citations

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