Tue·Sep 18, 2018Tuesday·September 18, 2018

1. 01*

   Super-Strong Coupling NJL model in arbitrary space-time dimensions

   Aftab Ahmad🇵🇰 · Angelo Martínez🇲🇽 · Alfredo Raya🇲🇽

   We study chiral symmetry breaking in the Nambu--Jona-Lasinio model regularized in proper-time in arbitrary space-time dimensions through an iterative procedure by writing the gap equation in the form of a discrete dynamical system with the coupling constant as the control parameter. Expectedly, we obtain the critical coupling for chiral symmetry breaking when a nontrivial solution bifurcates away from the trivial one and becomes an attractor. By increasing further the value of the coupling constant, we observe a second bifurcation where the dynamical solution is no longer an attractor, and observation that holds true in all space-time dimensions. In the super-strong coupling regime, the system becomes chaotic.

   hep-phPRD(2018)·6 citations
2. 02*

   The Simplified Likelihood Framework

   Andy Buckley🇬🇧 · Matthew Citron🇺🇸 · Sylvain Fichet🇧🇷 · Sabine Kraml🇫🇷 · Wolfgang Waltenberger🇦🇹 · Nicholas Wardle🇬🇧

   We discuss the simplified likelihood framework as a systematic approximation scheme for experimental likelihoods such as those originating from LHC experiments. We develop the simplified likelihood from the Central Limit Theorem keeping the next-to-leading term in the large $N$ expansion to correctly account for asymmetries. Moreover, we present an efficient method to compute the parameters of the simplified likelihood from Monte Carlo simulations. The approach is validated using a realistic LHC-like analysis, and the limits of the approximation are explored. Finally, we discuss how the simplified likelihood data can be conveniently released in the HepData error source format and automatically built from it, making this framework a convenient tool to transmit realistic experimental likelihoods to the community.

   hep-phhep-exphysics.data-anJHEP(2019)·29 citations
3. 03*

   EMC effect in the next-to-leading order approximation based on the Laplace transformation

   Javad Sheibani🇮🇷 · Abolfazl Mirjalili🇮🇷 · S. Atashbar Tehrani🇮🇷

   In this article, using Laplace transformation , an analytical solution is obtained for the DGLAP evolution equation at the next-to-leading order of perturbative QCD. The technique is also employed to extract, in the Laplace $s$-space, an analytical solution for the nuclear structure function, $F_2^A(x,Q^2)$. Firstly, the results for separate nuclear parton distributions for all parton types are presented which include valence quark densities, the anti-quark and strange sea PDFs and finally the gluon distribution. Based on the Laplace transformation, the obtained parton distribution functions and the nuclear structure function in the $x$-space are compared with the results from the [Phys.\ Rev.\ C series 86, 064301 (2012)] model. Our calculations are in good agreement with the available DIS experimental data as well as theoretical models which contain both small and large values of $x$-Bjorken variable. We compare our nuclear PDFs sets with those from other recent collaborations, in particular with the [ nCTEQ15 ] and [ HKN07] sets. The comparison between our results and those from the literature indicates a good agreement .

   hep-phPRC(2018)·8 citations
4. 04*

   Discretization effects on renormalized gauge-field Green's functions, scale setting and gluon mass

   Ph. Boucaud🇫🇷 · F. De Soto🇪🇸 · K. Raya🇨🇳 · J. Rodríguez-Quintero🇪🇸 · S. Zafeiropoulos🇩🇪

   The $SU(3)$ gauge-field propagators computed from the lattice have been exhaustively used in the investigation of the low-momentum dynamics of QCD, in a judicious interplay with results from other nonperturbative approaches, and for the extraction of fundamental parameters of QCD like ${\Lambda }_{\overline{\mathrm{MS}}}$ as well. The impact of the discretization artifacts and their role in the extrapolation of the results to the continuum limit have not been fully understood so far. We report here about a very careful analysis of the physical scaling violation of the Landau-gauge propagators renormalized in MOM scheme and the Taylor coupling, steering us towards an insightful understanding of the effects from discretization artifacts which makes therefore possible a reliable continuum-limit extrapolation.

   hep-phPRD(2018)·72 citations
5. 05*

   Revisiting lepton-specific 2HDM in light of muon g-2 anomaly

   Lei Wang🇨🇳 · Jin Min Yang🇨🇳 · Mengchao Zhang🇰🇷 · Yang Zhang🇦🇺

   We examine the lepton-specific 2HDM as a solution of muon $g-2$ anomaly under various theoretical and experimental constraints, especially the direct search limits from the LHC and the requirement of a strong first-order phase transition in the early universe. We find that the muon g-2 anomaly can be explained in the region of 32 $<\tan \beta <$ 80, 10 GeV $<m_A<$ 65 GeV, 260 GeV $<m_H<$ 620 GeV and 180 GeV $<m_{H^{\pm }}<$ 620 GeV after imposing the joint constraints from the theory, the precision electroweak data, the 125 GeV Higgs data, the leptonic/semi-hadronic $\tau$ decays, the leptonic $Z$ decays and Br$(B_s\to {\mu }^{+}{\mu }^{-})$. The direct searches from the $h\to AA$ channels can impose stringent upper limits on Br$(h\to AA)$ and the multi-lepton event searches can sizably reduce the allowed region of $m_A$ and $\tan \beta$ (10 GeV $<m_A<$ 44 GeV and 32 $<\tan \beta <$ 60). Finally, we find that the model can produce a strong first-order phase transition in the region of 14 GeV $<m_A<$ 25 GeV, 310 GeV $<m_H<$ 355 GeV and 250 GeV $<m_{H^{\pm }}<$ 295 GeV, allowed by the explanation of the muon $g-2$ anomaly.

   hep-phPLB(2019)·72 citations
6. 06*

   Conformal Ward Identities and the Coupling of QED and QCD to Gravity

   Claudio Coriano🇮🇹 · Matteo Maria Maglio🇮🇹

   We present a general study of 3-point functions of conformal field theory (CFT) in momentum space, following a reconstruction method for tensor correlators, based on the solution of the conformal Ward identities (CWIs), introduced in recent works. We investigate and detail the structure of the CWIs and their non-perturbative solutions, and compare them to perturbation theory, taking QED and QCD as examples. Exact solutions of CFT's in the flat background limit in momentum space are matched by the perturbative realizations in free field theories, showing that the origin the conformal anomaly is related to efffective scalar interactions, generated by the renormalization of the longitudinal components of the corresponding operators.

   hep-phhep-thEPJ Web Conf.(2018)·5 citations
7. 07*

   Dibaryons cannot be the dark matter

   Edward W. Kolb🇺🇸 · Michael S. Turner🇺🇸

   The hypothetical $SU(3)$ flavor-singlet dibaryon state $S$ with strangeness $-2$ has been discussed as a dark-matter candidate capable of explaining the curious 5-to-1 ratio of the mass density of dark matter to that of baryons. We study the early-universe production of dibaryons and find that irrespective of the hadron abundances produced by the QCD quark/hadron transition, rapid particle reactions thermalized the $S$ abundance, and it tracked equilibrium until it "froze out" at a tiny value. For the plausible range of dibaryon masses (1860 - 1890 MeV) and generous assumptions about its interaction cross sections, $S$'s account for at most $10^{-11}$ of the baryon number, and thus cannot be the dark matter. Although it is not the dark matter, if the $S$ exists it might be an interesting relic.

   hep-phastro-ph.COPRD(2019)·25 citations
8. 08*

   Towards an analytic solution of rapid roll inflation with a quartic potential

   Chia-Min Lin🇹🇼

   In this paper, I present an analytic solution to the equation of motion of the inflaton field in a model of rapid roll inflation with a quartic potential by assuming that the Hubble parameter is a constant during inflation. The result is obtained by using Jacobi elliptic functions. The spectral index $n_s$ and the running spectral index $n_s^{\prime }$ is obtained without using rapid roll or extended slow roll approximations. The cosmological consequences of the model is discussed.

   hep-phastro-ph.COhep-thChin.J.Phys.(2019)·0 citations
9. 09*

   Inverse seesaw model with large $SU(2{)}_L$ multiplets and natural mass hierarchy

   Takaaki Nomura🇰🇷 · Hiroshi Okada🇰🇷

   We propose an inverse seesaw model with large $SU(2{)}_L$ multiplet fields which realizes natural mass hierarchies among neutral fermions. Here, lighter neutral fermion mass matrices are induced via two suppression mechanisms; one is small vacuum expectation value of $SU(2{)}_L$ triplet required by rho parameter constraint and the other is generation of Majorana mass term of extra singlet fermions at one-loop level. To realize the loop masses, we impose $Z_2$ symmetry which also guarantees stability of a dark matter candidate. Furthermore, we discuss anomalous magnetic moment and collider physics from interactions of large multiplet fields.

   hep-phPLB(2019)·10 citations
10. 10*

    Meson resonances in forward-angle ${\pi }^{+}{\pi }^{-}$ photoproduction

    Ł. Bibrzycki🇵🇱 · P. Bydžovský🇨🇿 · R. Kamiński🇵🇱 · A. P. Szczepaniak🇺🇸

    Assuming that the ${\pi }^{+}{\pi }^{-}$ photoproduction at forward angles and high energies is dominated by one pion exchange we calculate the ${\pi }^{+}{\pi }^{-}$ mass distributions for low partial waves. Predictions of the model agree well Assuming that the ${\pi }^{+}{\pi }^{-}$ photoproduction at forward angles and high energies is dominated by one pion exchange we calculate the ${\pi }^{+}{\pi }^{-}$ mass distributions for low partial waves. Predictions of the model agree well with the experimental data which indicate that the $S$, $P$ and $D$ waves are dominated by the $f_0(980)$, $\rho (770)$ and $f_2(1270)$, resonances respectively.

    hep-phPLB(2019)·7 citations
11. 11*

    Pseudoscalar pole contribution to the hadronic light-by-light piece of $a_{\mu }$

    Adolfo Guevara🇪🇸 · Pablo Roig🇲🇽 · JJ Sanz Cillero🇪🇸

    We have studied the $P\to {\gamma }^{\star }{\gamma }^{\star }$ form factor in Resonance Chiral Theory, with $P={\pi }^0,\eta ,{\eta }^{\prime }$, to compute the contribution of the pseudoscalar pole to the hadronic light-by-light piece of the anomalous magnetic moment of the muon. In this work we allow the leading $U(3)$ chiral symmetry breaking terms, obtaining the most general expression for the form factor of order $\mathcal{O}(m_P^2)$. The parameters of the Effective Field Theory are obtained by means of short distance constraints on the form factor and matching with the expected behavior from QCD. Those parameters that cannot be fixed in this way are fitted to experimental determinations of the form factor within the spacelike momentum region of the virtual photon. Chiral symmetry relations among the transition form factors for ${\pi }^0,\eta$ and ${\eta }^{\prime }$ allow for a simultaneous fit to experimental data for the three mesons. This shows an inconsistency between the BaBar ${\pi }^0$ data and the rest of the experimental inputs. Thus, we find a total pseudoscalar pole contribution of $a_{\mu }^{P,HLbL}=(8.47\pm 0.16)\cdot 10^{-10}$ for our best fit (neglecting the BaBar ${\pi }^0$ data). Also, a preliminary rough estimate of the impact of NLO in $1/N_C$ corrections and higher vector multiplets (asym) enlarges the uncertainty up to $a_{\mu }^{P,HLbL}=(8.47\pm 0.16_{\mathrm{stat}}\pm 0.09_{N_C}{}_{-0.0_{\mathrm{asym}}}^{+0.5})$

    hep-phEPJ Web Conf.(2018)·0 citations
12. 12*

    Hidden-Bottom Pentaquarks

    Gang Yang🇨🇳 · Jialun Ping🇨🇳 · Jorge Segovia🇪🇸

    The LHCb Collaboration has recently reported strong evidences of the existence of pentaquark states in the hidden-charm baryon sector, the so-called $P_c(4380{)}^{+}$ and $P_c(4450{)}^{+}$ signals. Five-quark bound states in the hidden-charm sector were explored by us using, for the quark-quark interaction, a chiral quark model which successfully explains meson and baryon phenomenology, from the light to the heavy quark sector. We extend herein such study but to the hidden-bottom pentaquark sector, analyzing possible bound-states with spin-parity quantum numbers $J^P={\frac{1}{2}}^{\pm }$, ${\frac{3}{2}}^{\pm }$ and ${\frac{5}{2}}^{\pm }$, and in the $\frac{1}{2}$ and $\frac{3}{2}$ isospin sectors. We do not find positive parity hidden-bottom pentaquark states; however, several candidates with negative parity are found with dominant baryon-meson structures ${\Sigma }_b^{(\ast )}{\bar{B}}^{(\ast )}$. The calculated distances among any pair of quarks within the bound-state reflect that molecular-type bound-states are favored when only color-singlet configurations are considered in the coupled-channels calculation whereas compact pentaquarks, which are also deeply bound, can be found when hidden-color configurations are added. Finally, our findings resemble the ones found in the hidden-charm sector but, as expected, we find in the hidden-bottom sector larger binding energies and bigger contributions of the hidden-color configurations.

    hep-phhep-exhep-latnucl-thPRD(2019)·50 citations
13. 13*

    Anisotropic escape mechanism and elliptic flow of bottomonia

    Partha Pratim Bhaduri🇮🇳 · Nicolas Borghini🇩🇪 · Amaresh Jaiswal🇮🇳 · Michael Strickland🇺🇸

    We study the role of anisotropic escape in generating the elliptic flow of bottomonia produced in ultrarelativistic heavy-ion collisions. We implement temperature-dependent decay widths for the various bottomonium states, to calculate their survival probability when traversing through the anisotropic hot medium formed in non-central collisions. We employ the recently developed 3+1d quasiparticle anisotropic hydrodynamic simulation to model the space-time evolution of the quark-gluon plasma. We provide a quantitative prediction for transverse momentum dependence of bottomonium elliptic flow and nuclear modification factor for Pb$+$Pb collisions in $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV at the Large Hadron Collider.

    hep-phnucl-thPRC(2019)·41 citations
14. 14*

    Analytic result for the nonplanar hexa-box integrals

    D. Chicherin🇩🇪 · T. Gehrmann🇨🇭 · J. M. Henn🇩🇪 · N. A. Lo Presti🇬🇧 · V. Mitev🇩🇪 · P. Wasser🇩🇪

    In this paper, we analytically compute all master integrals for one of the two non-planar integral families for five-particle massless scattering at two loops. We first derive an integral basis of 73 integrals with constant leading singularities. We then construct the system of differential equations satisfied by them, and find that it is in canonical form. The solution space is in agreement with a recent conjecture for the non-planar pentagon alphabet. We fix the boundary constants of the differential equations by exploiting constraints from the absence of unphysical singularities. The solution of the differential equations in the Euclidean region is expressed in terms of iterated integrals. We cross-check the latter against previously known results in the literature, as well as with independent Mellin-Barnes calculations.

    hep-phhep-thJHEP(2019)·86 citations
15. 15*

    Why the angular distribution of the top decay lepton is unchanged by anomalous $tbW$ coupling

    Rohini M. Godbole🇮🇳 · Michael E. Peskin🇺🇸 · Saurabh D. Rindani🇮🇳 · Ritesh K. Singh🇮🇳

    We give a simple physical argument to understand the observation that the angular distribution of the top decay lepton depends only on the polarisation of the top and is independent of any anomalous $tbW$ coupling to linear order.

    hep-phhep-exPLB(2019)·11 citations
16. 16*

    Investigating jet-medium interaction using charge dependent three-particle correlation in high multiplicity p+Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV

    Debojit Sarkar🇮🇳

    Although many observations in high multiplicity p+Pb collisions at the LHC indicate striking similarity to heavy ion collisions, no evidence of jet-medium interactions has been observed till date. We study the effect of jet-medium interaction on the charge dependent three-particle correlation in high multiplicity p+Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV using EPOS 3 event generator. The short range component of the three-particle correlation is dominated by the jet fragmentation and has a unique charge dependence as observed in the minimum bias p+Au collisions at the RHIC energy. In EPOS 3, similar pattern has been observed in the lower multiplicity classes of p+Pb collisions where jet fragmentation plays the dominant role. Interestingly, the charge dependence of three-particle correlation gets diminished in the higher multiplicity classes of p+Pb collisions where the jet-medium interactions as implemented in EPOS 3 plays an important role. The current study can, therefore, provide possible ways to investigate the jet-medium interaction in high multiplicity classes of small collision systems at the LHC energies.

    hep-phhep-ex1 citation
17. 17*

    Double-real contribution to the quark beam function at N${}^3$LO QCD

    Kirill Melnikov🇩🇪 · Robbert Rietkerk🇩🇪 · Lorenzo Tancredi🇨🇭 · Christopher Wever🇩🇪

    We compute the master integrals required for the calculation of the double-real emission contributions to the matching coefficients of 0-jettiness beam functions at next-to-next-to-next-to-leading order in perturbative QCD. As an application, we combine these integrals and derive the double-real gluon emission contribution to the matching coefficient $I_{qq}(t,z)$ of the quark beam function.

    hep-phJHEP(2019)·26 citations
18. 18*

    Constraints on a 2HDM with a singlet scalar and implications in the search for heavy bosons at the LHC

    Stefan von Buddenbrock🇿🇦 · Alan S. Cornell🇿🇦 · Elie D. R. Iarilala🇿🇦 · Mukesh Kumar🇿🇦 · Bruce Mellado🇿🇦 · Xifeng Ruan🇿🇦 · Esra Mohammed Shrif🇿🇦

    We study a two-Higgs doublet model extended with an additional singlet scalar (2HDM+S), and provide a brief introduction to the model and its parameters. Constraints are applied to the parameter space of this model in order to accommodate a number of features in the data that have been interpreted in von Buddenbrock et al (2018 J. Phys. G 45 115003) as the result of the $H\to Sh$ decay produced via gluon-gluon fusion and in association with top quarks. Implications on the phenomenology of the heavy pseudo-scalar ($A$) and charged scalar ($H^{+}$) are discussed. In particular, the decays $A\to ZH$ and $H^{+}\to W^{+}H$ become prominent. This leads to final states with multiple leptons and $b$-quarks. The decay $A\to ZH\to ZSh$ results in the production of a high transverse momentum $Z$ produced in association with a lepton and two $b$-quarks with little additional jet activity. These predictions are compared to the data with model's benchmark points. With the parameters obtained here the model is able to accommodate the features at the LHC reported in von Buddenbrock et al (2018 J. Phys. G 45 115003). Without varying these parameters additional excesses in the $Zb\overline{b}$ and $t\overline{t}$ invariant mass spectra, and the production of $3$ leptons plus two $b$-tagged jets can be explained assuming $m_A\approx 600$\,GeV.

    hep-phJ.Phys.G(2019)·40 citations
19. 19*

    4-Gluon Vertex Splitting Function and Jet Observables

    Fayez M. Abu-Ajamieh🇺🇸

    I generalize the Altarelli-Parisi approach to finding the QCD splitting functions to the case of 4-vertex interactions. I apply the results to the 4-gluon interaction and use them to define several jet observables. I estimate the correction associated with the 4-gluon interaction compared with QCD 3-vertex interactions, and find that such a correction can be significant, especially at low energies. For instance, it is estimated that at energy scales between 100 GeV and 1 TeV, the corrections associated with the 4-g vertex could range between ~ 6% - 10%, however, the correction becomes smaller at the TeV scale and 3-vertex interactions become significantly more dominant.

    hep-ph0 citations
20. 20*

    Proton charge radius extraction from electron scattering data using dispersively improved chiral effective field theory

    J. M. Alarcón🇪🇸 · D. W. Higinbotham🇺🇸 · C. Weiss🇺🇸 · Z. Ye🇺🇸

    We extract the proton charge radius from the elastic form factor (FF) data using a novel theoretical framework combining chiral effective field theory and dispersion analysis. Complex analyticity in the momentum transfer correlates the behavior of the spacelike FF at finite $Q^2$ with the derivative at $Q^2=0$. The FF calculated in the predictive theory contains the radius as a free parameter. We determine its value by comparing the predictions with a descriptive global fit of the spacelike FF data, taking into account the theoretical and experimental uncertainties. Our method allows us to use the finite-$Q^2$ FF data for constraining the radius (up to $Q^2\sim$ 0.5 GeV${}^2$ and larger) and avoids the difficulties arising in methods relying on the $Q^2\to 0$ extrapolation. We obtain a radius of 0.844(7) fm, consistent with the high-precision muonic hydrogen results.

    hep-phhep-latnucl-exnucl-th+1PRC(2019)·72 citations
21. 21*

    Cosmological window onto the string axiverse and the supersymmetry breaking scale

    Luca Visinelli🇸🇪 · Sunny Vagnozzi🇸🇪

    In the simplest picture, the masses of string axions populating the axiverse depend on two parameters: the supersymmetry breaking scale $M_{\mathrm{susy}}$ and the action $S$ of the string instantons responsible for breaking the axion shift symmetry. In this work, we explore whether cosmological data can be used to probe these two parameters. Adopting string-inspired flat priors on ${\log }_{10}{M}_{\mathrm{susy}}$ and $S$, and imposing that $M_{\mathrm{susy}}$ be sub-Planckian, we find $S=198\pm 28$. These bounds suggest that cosmological data complemented with string-inspired priors select a quite narrow axion mass range within the axiverse, ${\log }_{10}(m_a/\mathrm{eV})=-21.5_{-2.3}^{+1.3}$. We find that $M_{\mathrm{susy}}$ remains unconstrained due to a fundamental parameter degeneracy with $S$. We explore the significant impact of other choices of priors on the results, and we comment on similar findings in recent previous literature.

    hep-phastro-ph.COgr-qchep-thPRD(2019)·153 citations
22. 22*

    How high is the neutrino floor?

    C. Boehm🇦🇺 · D.G. Cerdeno🇬🇧 · P.A.N. Machado🇺🇸 · A. Olivares-Del Campo🇬🇧 · E. Perdomo🇬🇧 · E. Reid🇬🇧

    In this paper, we compute the contribution to the coherent elastic neutrino-nucleus scattering cross section from new physics models in the neutrino sector. We use this information to calculate the maximum value of the so-called neutrino floor for direct dark matter detection experiments, which determines when these detectors are sensitive to the neutrino background. After including all relevant experimental constraints in different simplified neutrino models, we have found that the neutrino floor can increase by various orders of magnitude in the region of dark matter masses below 10 GeV in the case of scalar mediators, however, this spectacular enhancement is subject to the re-examination of supernovae bounds. The increase is approximately a factor of two for vector mediators. In the light of these results, future claims by direct detection experiments exploring the low-mass window must be carefully examined if a signal is found well above the expected Standard Model neutrino floor.

    hep-phastro-ph.COJCAP(2019)·104 citations
23. 23*

    Crossed Topology in Two-Loop Dispersive Approach

    A. Aleksejevs🇨🇦

    We extend existing dispersive approach in subloop insertion to the case of crossed two-loop box type topologies. Based on the ideas of the Feynman trick, mass shift approach and dispersive representation of two-point Passarino-Veltman function we expressed two-loop scalar diagrams in the compact analytical form suitable for the automatization of the calculations. The results are expressed in a way that the numerical integration over Feynman and dispersive parameters and differentiation with respect to mass shift parameters are required in the final stage only.

    ↳ hep-thhep-ph4 citations
24. 24*

    Thermodynamic Geometry of Strongly Interacting Matter

    P. Castorina🇮🇹 · M. Imbrosciano🇮🇹 · D. Lanteri🇮🇹

    The thermodynamic geometry formalism is applied to strongly interacting matter to estimate the deconfinement temperature. The curved thermodynamic metric for Quantum Chromodynamics (QCD) is evaluated on the basis of lattice data, whereas the hadron resonance gas model is used for the hadronic sector. Since the deconfinement transition is a crossover, the geometric criterion used to define the \mbox{(pseudo-)critical} temperature, as a function of the baryonchemical potential ${\mu }_B$, is $R(T,{\mu }_B)=0$, where $R$ is the scalar curvature. The (pseudo-)critical temperature, $T_c$, resulting from QCD thermodynamic geometry is in good agreement with lattice and phenomenological freeze-out temperature estimates. The crossing temperature, $T_h$, evaluated by the hadron resonance gas, which suffers of some model dependence, is larger than $T_c$ (about $20\%$) signaling remnants of confinement above the transition.

    ↳ nucl-thhep-phPRD(2018)·10 citations
25. 25*

    Soft rescattering in the timelike proton form factor within a spacetime scheme

    Andrea Bianconi🇮🇹 · Egle Tomasi-Gustafsson🇫🇷

    The annihilation of a lepton pair into a proton-antiproton pair, and the reverse process, allow for a measurement of the timelike proton form factors. This work aims at studying the corrections due to direct soft interactions between the proton and the antiproton before their annihilation or after their creation. The analysis is carried on in the spacetime formalism used by us in a series of recent works on timelike FFs. In particular the effect of $\bar{p}p$ annihilation into many-meson states is considered. We expect it to determine similar real and imaginary parts for the form factor near the $\bar{p}p$ channel threshold. We also discuss the possibility that the timelike FF differ by a phase in the hadron pair production and annihilation.

    ↳ nucl-thhep-phPRC(2018)·3 citations
26. 26*

    Dark matter deficient galaxies in the Illustris flat-$\Lambda$CDM model structure formation simulation

    Hai Yu🇨🇳 · Bharat Ratra🇺🇸 · Fa-Yin Wang🇨🇳

    Surveying dark matter deficient galaxies (those with dark matter mass to stellar mass ratio $M_{\mathrm{dm}}/M_{\mathrm{star}}<1$) in the Illustris simulation of structure formation in the flat-$\Lambda$CDM cosmogony, we find $M_{\mathrm{star}}\approx 2\times 10^8{M}_{\text{sun}}$ galaxies that have properties similar to those ascribed by \citet{vanDokkumetal2018a} to the ultra-diffuse galaxy NGC1052-DF2. The Illustris simulation also contains more luminous dark matter deficient galaxies. Illustris galaxy subhalo 476171 is a particularly interesting outlier, a massive and very compact galaxy with $M_{\mathrm{star}}\approx 9\times 10^{10}{M}_{\text{sun}}$ and $M_{\mathrm{dm}}/M_{\mathrm{star}}\approx 0.1$ and a half-stellar-mass radius of $\approx 2$ kpc. If the Illustris simulation and the $\Lambda$CDM model are accurate, there are a significant number of dark matter deficient galaxies, including massive luminous compact ones. It will be interesting to observationally discover these galaxies, and to also more clearly understand how they formed, as they are likely to provide new insight into and constraints on models of structure formation and the nature of dark matter.

    ↳ astro-ph.GAgr-qchep-phhep-th8 citations
27. 27*

    News from the Lattice: example of the pion distribution amplitude

    Piotr Korcyl🇵🇱

    In this contribution I present a brief summary of recent progress in selected Lattice QCD techniques and subsequently illustrate them using the example of the current calculations of moments of meson distribution amplitude as well as of a direct evaluation of meson distribution amplitude.

    ↳ hep-lathep-phEPJ Web Conf.(2019)·0 citations
28. 28*

    DeepEfficiency - optimal efficiency inversion in higher dimensions at the LHC

    Mikael Mieskolainen🇫🇮

    We introduce a new high dimensional algorithm for efficiency corrected, maximally Monte Carlo event generator independent fiducial measurements at the LHC and beyond. The approach is driven probabilistically using a Deep Neural Network on an event-by-event basis, trained using detector simulation and even only pure phase space distributed events. This approach gives also a glimpse into the future of high energy physics, where experiments publish new type of measurements in a radically multidimensional way.

    ↳ physics.data-anhep-exhep-phstat.ML3 citations
29. 29*

    Reconstruction of the mass of Higgs boson pairs in events with Higgs boson pairs decaying into four $\tau$ leptons

    Karl Ehatäht🇪🇪 · Luca Marzola🇪🇪 · Christian Veelken🇪🇪

    Various theories beyond the Standard Model predict the existence of heavy resonances decaying to Higgs (H) boson pairs. In order to maximize the sensitivity of searches for such resonances, it is important that experimental analyses cover a variety of decay modes. The decay of H boson pairs to four $\tau$ leptons (HH$\to \tau \tau \tau \tau$) has not been discussed in the literature so far. This decay mode provides a small branching fraction, but also comparatively low backgrounds. We present an algorithm for the reconstruction of the mass of the H boson pair in events in which the H boson pair decays via HH$\to \tau \tau \tau \tau$ and the $\tau$ leptons subsequently decay into electrons, muons, or hadrons. The algorithm achieves a resolution of $7$-$22\%$ relative to the mass of the H boson pair, depending on the mass of the resonance.

    ↳ hep-exhep-ph3 citations
30. 30*

    Computer algebra tools for Feynman integrals and related multi-sums

    Johannes Blümlein🇩🇪 · Carsten Schneider🇦🇹

    In perturbative calculations, e.g., in the setting of Quantum Chromodynamics (QCD) one aims at the evaluation of Feynman integrals. Here one is often faced with the problem to simplify multiple nested integrals or sums to expressions in terms of indefinite nested integrals or sums. Furthermore, one seeks for solutions of coupled systems of linear differential equations, that can be represented in terms of indefinite nested sums (or integrals). In this article we elaborate the main tools and the corresponding packages, that we have developed and intensively used within the last 10 years in the course of our QCD-calculations.

    ↳ cs.SChep-phhep-thmath-ph+1PoS(2018)·0 citations
31. 31*

    Aspects of approximation in modelling of the symmetry energy

    Ilona Bednarek🇵🇱 · Monika Pienkos🇵🇱 · Jan Sladkowski🇵🇱 · Jacek Syska🇵🇱

    Quality of approximations is an important issue in modelling nuclear matter. It is shown that the Padé approximation provides a useful tool for describing the symmetry energy in highly asymmetric systems. The focus is on the symmetry energy constraints. Some implications of the obtained results for astrophysics are also discussed.

    ↳ nucl-thastro-ph.SRhep-phJ. Phys. Soc. Jpn. - Vol. 88, no. 12 (201…·4 citations
32. 32*

    Gauging Fine-Tuning

    Feraz Azhar🇺🇸 · Abraham Loeb🇺🇸

    We introduce a mathematical framework for quantifying fine-tuning in general physical settings. In particular, we identify two distinct perspectives on fine-tuning, namely, a local and a global perspective --- and develop corresponding measures. These measures apply broadly to settings characterized by an arbitrary number of observables whose values are dependent on an arbitrary number of parameters. We illustrate our formalism by quantifying fine-tuning as it arises in two pertinent astrophysical settings: (i) in models where a significant fraction of the dark matter in the universe is in the form of primordial black holes, and (ii) in scenarios that derive the fraction of protons in habitable dark-matter halos from underlying models of cosmic inflation.

    ↳ astro-ph.COhep-phphysics.hist-phPRD(2018)·14 citations
33. 33*

    Review of Lepton Universality tests in B decays

    Simone Bifani🇬🇧 · Sebastien Descotes-Genon🇫🇷 · Antonio Romero Vidal🇪🇸 · Marie-Helene Schune🇫🇷

    Several measurements of tree- and loop-level b-hadron decays performed in the recent years hint at a possible violation of Lepton Universality. This article presents an experimental and theoretical overview of the current status of the field.

    ↳ hep-exhep-phJ.Phys.G(2019)·242 citations
34. 34*

    Can we detect quantum gravity with compact binary inspirals?

    Alexander C. Jenkins🇬🇧 · Andreas G. A. Pithis🇬🇧 · Mairi Sakellariadou🇬🇧

    Treating general relativity as an effective field theory, we compute the leading-order quantum corrections to the orbits and gravitational-wave emission of astrophysical compact binaries. These corrections are independent of the (unknown) nature of quantum gravity at high energies, and generate a phase shift and amplitude increase in the observed gravitational-wave signal. Unfortunately (but unsurprisingly), these corrections are undetectably small, even in the most optimistic observational scenarios.

    ↳ gr-qcastro-ph.HEhep-phPRD(2018)·9 citations
35. 35*

    Physics Beyond the Multiverse - Naturalness and the Quest for a Fundamental Theory

    Heinrich Päs🇩🇪

    Finetuning and Naturalness are extra-empirical theory assessments that reflect our expectation how scientific theories should provide an intuitive understanding about the foundations underlying the observed phenomena. Recently, the absence of new physics at the LHC and the theoretical evidence for a multiverse of alternative physical realities, predicted by our best fundamental theories, have casted doubts about the validity of these concepts. In this essay we argue that the discussion about Finetuning should not predominantly concentrate on the desired features a fundamental theory is expected to have, but rather on the question what a theory needs to qualify as fundamental in the first place. By arguing that a fundamental description of the Universe should possess zero entropy, we develop a 'holistic' concept for the most fundamental layer of reality: The fundamental description of the Universe is the Universe itself, understood as an entangled quantum state. Adopting a universal applicability of quantum mechanics, in this framework the behavior of subsystems can be understood as the perspectival experience of an entangled quantum Universe perceived through the "lens of decoherence". In this picture the fundamental reality is non-local, and finetuned coincidences in effective theories may be understood in a way similar to EPR-correlations. This notion provides a fresh view on the topic of Naturalness and Finetuning since it suggests that Finetuning problems and hints for anthropic explanations are an artefact of theories building up on subsystems rather than on the fundamental description. Recent work in quantum gravity aiming at an understanding of spacetime geometry from entanglement entropy could be interpreted as a first sign of such a paradigm shift.

    ↳ physics.hist-phhep-phhep-thFound.Phys.(2019)·2 citations
36. 36*

    Searches for Dark Matter Particles at the LHC

    Marta Felcini🇮🇪

    The searches for new particles that could be constituents of the dark matter in the universe are an essential part of the physics program of the experiments at the Large Hadron Collider. An overview of recent dark matter candidate searches is presented with a focus on new results obtained by the ATLAS and CMS experiments from the analysis of the proton-proton collision data at 13 TeV center-of-mass energy collected in the first part of Run 2.

    ↳ hep-exhep-ph27 citations
37. 37*

    Particle acceleration and the origin of the very high energy emission around black holes and relativistic jets

    Elisabete de Gouveia Dal Pino🇧🇷 · Grzegorz Kowal🇧🇷 · Luis Kadowaki🇧🇷 · Tania E. Medina Torrejón🇧🇷 · Yosuke Mizuno🇮🇱 · Chandra Singh🇩🇪

    Particle acceleration induced by fast magnetic reconnection may help to solve current puzzles related to the interpretation of the very high energy (VHE) and neutrino missions from AGNs and compact sources in general. Our general relativistic-MHD simulations of accretion disk-corona systems reveal the growth of turbulence driven by MHD instabilities that lead to the development of fast magnetic reconnection in the corona. In addition, our simulations of relativistic MHD jets reveal the formation of several sites of fast reconnection induced by current-driven kink turbulence. The injection of thousands of test particles in these regions cause acceleration up to energies of several PeVs, thus demonstrating the ability of this process to accelerate particles and produce VHE and neutrino emission, specially in blazars. Finally, we discuss how reconnection can also explain the observed VHE luminosity-black hole mass correlation, involving hundreds of non-blazar sources like Perseus A, and black hole binaries.

    ↳ astro-ph.HEhep-phIAU Symp.(2020)·4 citations
38. 38*

    ReSyst: a novel technique to Reduce the Systematic uncertainty for precision measurements

    Petra Van Mulders🇧🇪

    We are in an era of precision measurements at the Large Hadron Collider. The precision that can be achieved on some of those is limited however due to large systematic uncertainties. This paper introduces a new technique to reduce the total systematic uncertainty by quantifying the systematic impact of single events and correlating it with event observables to identify classes of events that are more sensitive to systematic effects. A proof of concept is presented by means of a simplified top quark mass estimator applied on simulated events. Even without a thorough optimization, it is shown that the total systematic uncertainty can be reduced by at least 30%.

    ↳ physics.data-anhep-exhep-phJHEP(2019)·2 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.