HEP Phenomenology·hep-ph

Wed·Dec 2, 2020Wednesday·December 2, 2020

20 papers—15 primary·5 cross-listed·reconstructed*

01*
Massive photon propagator in the presence of axionic fluctuations
B. A. S. D. Chrispim🇧🇷 · R. C. L. Bruni🇧🇷 · M. S. Guimaraes🇧🇷
The theory of massive photons in the presence of axions is studied as the effective theory describing the electromagnetic response of semimetals when a particular quartic fermionic pairing perturbation triggers the formation of charged chiral condensates, giving rise to an axionic superconductor. We investigate corrections to the Yukawa-like potential mediated by massive photons due to axion excitations up to one-loop order and compute the modifications of the London penetration length.
hep-phcond-mat.str-elcond-mat.supr-conhep-thPRB(2021)·5 citations
02*
Libra: a package for transformation of differential systems for multiloop integrals
Roman N. Lee🇷🇺
We present a new package for Mathematica system, called Libra. Its purpose is to provide convenient tools for the transformation of the first-order differential systems $\partial_{i} j = M_{i} j$ for one or several variables. In particular, Libra is designed for the reduction to $ϵ$ -form of the differential systems which appear in multiloop calculations. The package also contains some tools for the construction of general solution: both via perturbative expansion of path-ordered exponent and via generalized power series expansion near regular singular points.Libra also has tools to determine the minimal list of coefficients in the asymptotics of the original master integrals, sufficient for fixing the boundary conditions.
hep-phComput.Phys.Commun.(2021)·134 citations
03*
Spectroscopy of heavy-heavy flavour mesons and annihilation widths of quarkonia
Nakul R. Soni🇮🇳 · Rikita M. Parekh🇮🇳 · Janaki J. Patel🇮🇳 · Akshay N. Gadaria🇮🇳 · Jignesh N. Pandya🇮🇳
Within the framework of nonrelativistic quark-antiquark Cornell potential model formalism, we study the annihilation of heavy quarkonia. We determine their annihilation widths resulting into digluon, dilepton, $3 γ$ , $3 g$ and $γ g g$ and compare our findings with the available theoretical results and experimental data. We also provide the charge radii and absolute square of radial Schrödinger wave function at zero quark-antiquark separation for heavy quarkonia and $B_{c}$ mesons.
hep-phFew Body Syst.(2022)·6 citations
04*
Long-lived light neutralinos at Belle II
Sourav Dey🇮🇱 · Claudio O. Dib🇨🇱 · Juan Carlos Helo🇨🇱 · Minakshi Nayak🇮🇱 · Nicolás A. Neill🇨🇱 · Abner Soffer🇮🇱 · Zeren Simon Wang🇹🇼
We consider light neutralinos of mass about 1 GeV, produced from $τ$ lepton rare decays at Belle II, in the context of R-parity-violating (RPV) supersymmetry. With large and clean samples of $τ$ leptons produced at the Belle II experiment, excellent sensitivity to such light neutralinos with the exotic signatures of displaced vertices is expected. We focus on two benchmark scenarios of single RPV operators, $λ_{311}^{'} L_{3} Q_{1} D ˉ_{1}$ and $λ_{312}^{'} L_{3} Q_{1} D ˉ_{2}$ , which induce both the production and decay of the lightest neutralino. For the reconstruction of a displaced vertex, we require at least two charged pions in the final states. We perform Monte-Carlo simulations for both signal and background events, and find that Belle II can explore regions in the parameter space competitive with other probes. In particular, for the $λ_{311}^{'}$ scenario, it can put limits up to two orders of magnitude stronger than the current bounds.
hep-phhep-exJHEP(2021)·27 citations
05*
Dark Matter Macroscopic Pearls, 3.55 keV X-ray line, How big ?
Holger Bech Nielsen (Niels Bohr Institutet, giving the talk)🇩🇰 · Colin D. Froggatt (Glasgow University)🇬🇧
We study the 3.55 keV X-ray suspected to arise from dark matter in our model of dark matter consisting of a bubble of a new phase of the vacuum, the surface tension of which keeps ordinary matter under high pressure inside the bubble. We consider two versions of the model: Old large pearls model : We worked for a long time on a pearl picture with pearl / bubbles of cm-size adjusted so that the impacts of them on earth could be identified with events of the mysterious type that happened in Tunguska in 1908. We fit both the very frequency, the 3.55 keV, and the overall intensity of the X-ray line coming from the center of the Milky Way and from galaxy clusters with one parameter in the model in which this radiation comes from collisions of pearls. New small pearl model: Our latest idea is to let the pearls be smaller than atoms but bigger than nuclei so as to manage to fit the 3.5 keV X-rays coming from the Tycho supernova remnant in which Jeltema and Profumo observed this line. Further we also crudely fit the DAMA-LIBRA observation with the small pearls, and even see a possibility for including the electron-recoil-excess seen by the Xenon1T experiment as being due to de-excitation via electron emission of our pearls. The important point of even our small size pearl model is that the cross section of our "macroscopic" pearls is so large that the pearls interact several times in the shielding but, due to their much larger mass than the typical nuclei, are {\bf not stopped by only a few interactions}. Nevertheless only a minute fraction of the relatively strongly interacting pearls reach the 1400 m down to the DAMA experiment, but due to the higher cross section we can fit the data anyway.
hep-ph12 citations
06*
Gluonic Tetracharm Configuration of $X (6900)$
Bing-Dong Wan🇨🇳 · Cong-Feng Qiao🇨🇳
Recently, a new hadronic structure at around $6.9$ GeV was observed in an LHCb experiment. From its limited yet known decay mode, one could still determine that it contains at least four charm quarks and hence belongs to the category of exotic state. This finding indicates for the first time the tetracharm exotic states and is therefore quite importance. In this letter, we propose a nature hybrid interpretation for the structure of $X (6900)$ , i.e. in $[3 ˉ_{c}]_{cc} \otimes [8_{c}]_{G} \otimes [3_{c}]_{c ˉ c ˉ}$ configuration with $J^{P C} = 0^{++}$ , and by using the QCD Sum Rule technique we performed mass spectrum calculation. The results showed that the observed $X (6900)$ could be a gluonic tetracharm state, and some other structures may exist, e.g., one around $7.2$ GeV in the tetracharm hybrid configuration and with $J^{P C} = 0^{-+}$ . We also predict the tetrabottom hybrid states, leaving for future experiment.
hep-phPLB(2021)·106 citations
07*
New developments in model-independent Partial-Wave Analysis
Fabian Michael Krinner🇩🇪 · Stephan Paul🇩🇪
Partial-wave analyses (PWA) are an essential tool for studying resonance structures in decays with hadronic multi-body final states. For several years, more model-independent approaches to such analyses have been used for various decay final states. However, up to now, these methods have mostly been applied to sub-sets of partial waves, also called freed waves. In this article, we explore possibilities and limitations of extended model-independent approaches. We systematically apply various different fit models to the analysis of pseudo data sets, to study both the impact of the mathematical description used for the freed waves and the choice of simultaneously freed waves. We can show that suitable methods exist, which lift restrictions to only sub-sets of freed partial waves and demonstrate hidden caveats present in previous works.
hep-phNucl.Part.Phys.Proc.(2021)·0 citations
08*
Climbing three-Reggeon ladders: four-loop amplitudes in the high-energy limit in full colour
Giulio Falcioni🇬🇧 · Einan Gardi🇬🇧 · Calum Milloy🇮🇹 · Leonardo Vernazza🇮🇹
Using an iterative solution of rapidity evolution equations, we compute partonic $2 \to 2$ gauge theory amplitudes at four loops in full colour up to the Next-to-Next-to-Leading Logarithms (NNLL) in the Regge limit. By contrasting the resulting amplitude with the exponentiation properties of soft singularities we determine the four-loop correction to the soft anomalous dimension at this logarithmic accuracy, which universally holds in any gauge theory. We find that the latter features quartic Casimir contributions beyond those appearing in the cusp anomalous dimension. Finally, in the case of $N = 4$ super Yang-Mills, we also determine the finite hard function at four loops through NNLL in full colour.
hep-phhep-thPRD(2021)·33 citations
09*
$C$ -parameter hadronisation in the symmetric 3-jet limit and impact on $α_{s}$ fits
Gionata Luisoni🇩🇪 · Pier Francesco Monni🇨🇭 · Gavin P. Salam🇬🇧
Hadronisation corrections are crucial in extractions of the strong coupling constant ( $α_{s}$ ) from event-shape distributions at lepton colliders. Although their dynamics cannot be understood rigorously using perturbative methods, their dominant effect on physical observables can be estimated in singular configurations sensitive to the emission of soft radiation. The differential distributions of some event-shape variables, notably the $C$ parameter, feature two such singular points. We analytically compute the leading non-perturbative correction in the symmetric three-jet limit for the $C$ parameter, and find that it differs by more than a factor of two from the known result in the two-jet limit. We estimate the impact of this result on strong coupling extractions, considering a range of functions to interpolate the hadronisation correction in the region between the 2 and 3-jet limits. Fitting data from ALEPH and JADE, we find that most interpolation choices increase the extracted $α_{s}$ , with effects of up to $4%$ relative to standard fits. This brings a new perspective on the long-standing discrepancy between certain event-shape $α_{s}$ fits and the world average.
hep-phEPJC(2021)·52 citations
10*
Counting distributions from the perspective of combinants
Grzegorz Wilk🇵🇱 · Zbigniew Włodarczyk🇵🇱
We present a comprehensive insight into counting distributions from the perspective of the combinants extracted from them. In particular, we focus on cases where these combinants exhibit oscillatory behavior that can provide an invaluable new source of information about the dynamics of the process under study. We show that such behavior can be described only by specific combinations of compound distributions based on the Binomial Distribution and provide their analytical forms which can be used in further investigations and which can be helpful in the analysis of all other types of counting distributions.
hep-phInt.J.Mod.Phys.A(2021)·3 citations
11*
$b \to s τ^{+} τ^{-}$ Physics at Future $Z$ Factories
Lingfeng Li🇨🇳 · Tao Liu🇨🇳
$b \to s τ^{+} τ^{-}$ measurements are highly motivated for addressing lepton-flavor-universality (LFU)-violating puzzles such as $R_{K^{(*)}}$ anomalies. The anomalies of $R_{D^{(*)}}$ and $R_{J / ψ}$ further strengthen their necessity and importance, given that the LFU-violating hints from both involve the third-generation leptons directly. $Z$ factories at the future $e^{-} e^{+}$ colliders stand at a great position to conduct such measurements because of their relatively high production rates and reconstruction efficiencies for $B$ mesons at the $Z$ pole. To fully explore this potential, we pursue a dedicated sensitivity study in four $b \to s τ^{+} τ^{-}$ benchmark channels, namely $B^{0} \to K^{* 0} τ^{+} τ^{-}$ , $B_{s} \to ϕ τ^{+} τ^{-}$ , $B^{+} \to K^{+} τ^{+} τ^{-}$ and $B_{s} \to τ^{+} τ^{-}$ , at the future $Z$ factories. We develop a fully tracker-based scheme for reconstructing the signal $B$ mesons and introduce a semi-quantitative method for estimating their major backgrounds. The simulations indicate that branching ratios of the first three channels can be measured with a precision $\sim O (1 0^{- 7} - 1 0^{- 6})$ and that of $B_{s} \to τ^{+} τ^{-}$ with a precision $\sim O (1 0^{- 5})$ at Tera- $Z$ . The impacts of luminosity and tracker resolution on the expected sensitivities are explored. The interpretations of these results in effective field theory are also presented.
hep-phhep-exJHEP(2021)·29 citations
12*
Curing the unphysical behaviour of NLO quarkonium production at the LHC and its relevance to constrain the gluon PDF at low scales
Jean-Philippe Lansberg🇫🇷 · Melih Arslan Ozcelik🇫🇷
We address the unphysical energy dependence of quarkonium-hadroproduction cross sections at Next-to-Leading Order (NLO) in alpha_S which we attribute to an over-subtraction in the factorisation of the collinear singularities inside the PDFs in the MSbar scheme. Such over- or under-subtractions have a limited phenomenological relevance in most of the scattering processes in particle physics. On the contrary, it is particularly harmful for P_T-integrated charmonium hadroproduction which renders a wide class of NLO results essentially unusable. Indeed, in such processes, alphaS is not so small, the PDFs are not evolved much and can be rather flat for the corresponding momentum fractions and, finally, some process-dependent NLO pieces are either too small or too large. We propose a scale-fixing criterion which avoids such an over-subtraction. We demonstrate its efficiency for eta(c,b) but also for a fictitious light elementary scalar boson. Having provided stable NLO predictions for eta(c,b) P_T-integrated cross sections, sigma^NLO(eta(Q)), and discussed the options to study eta(b) hadroproduction, we argue that their measurement at the LHC can help better determine the gluon PDF at low scales and tell whether the local minimum in conventional NLO gluon PDFs around x=0.001 at scales below 2 GeV is physical or not.
hep-phhep-exnucl-exnucl-thEPJC(2021)·34 citations
13*
A Proposed Network to Detect Axion Quark Nugget Dark Matter
Xunyu Liang🇨🇦 · Egor Peshkov🇨🇦 · Ludovic Van Waerbeke🇨🇦 · Ariel Zhitnitsky🇨🇦
A network of synchronized detectors can increase the likelihood of discovering the QCD axion, within the Axion Quark Nugget (AQN) dark matter model. A similar network can also discriminate the X-rays emitted by the AQNs from the background signal. These networks can provide information on the directionality of the dark matter flux (if any), as well as its velocity distribution, and can therefore test the Standard Halo Model. We show that the optimal configuration to detect AQN-induced axions is a triangular network of stations 100 km apart. For X-rays, the optimal network is an array of tetrahedral units.
hep-phastro-ph.COPRD(2021)·14 citations
14*
Higgs alignment and novel $C P$ -Violating observables in two-Higgs-doublet models
Ian Low🇺🇸 · Nausheen R. Shah🇺🇸 · Xiao-Ping Wang🇨🇳
Null results from searches for new physics at the Large Hadron Collider (LHC) tend to enforce the belief that new particles must be much heavier than the weak scale. We undertake a systematic study of the interplay between Higgs alignment and $C P$ -violation in complex two-Higgs-doublet models, which enables us to construct a $C P$ -violating scenario where new Higgs bosons are close to the weak scale after including stringent constraints from the electric dipole moment and measurements at the LHC. In addition, we propose a novel potential signal of $C P$ -violation in the Higgs-to-Higgs decays, $h_{3} \to h_{2} h_{1}$ , where $h_{3}, h_{2}$ , and $h_{1}$ are the heaviest, second heaviest and the Standard Model-like neutral Higgs bosons, respectively. The decay could manifest itself in triple boson final states in $h_{1} h_{1} h_{1}$ and $h_{1} h_{1} Z$ , which are quite distinct and provide unique venues for new measurements at the LHC.
hep-phhep-exPRD(2022)·29 citations
15*
Electroweak Restoration at the LHC and Beyond: The $V h$ Channel
Li Huang🇺🇸 · Samuel D. Lane🇺🇸 · Ian M. Lewis🇺🇸 · Zhen Liu🇺🇸
The LHC is exploring electroweak (EW) physics at the scale EW symmetry is broken. As the LHC and new high energy colliders push our understanding of the Standard Model to ever-higher energies, it will be possible to probe not only the breaking of but also the restoration of EW symmetry. We propose to observe EW restoration in double EW boson production via the convergence of the Goldstone boson equivalence theorem. This convergence is most easily measured in the vector boson plus Higgs production, $V h$ , which is dominated by the longitudinal polarizations. We define EW restoration by carefully taking the limit of zero Higgs vacuum expectation value (vev). EW restoration is then measured through the ratio of the $p_{T}^{h}$ distributions between $V h$ production in the Standard Model and Goldstone boson plus Higgs production in the zero vev theory, where $p_{T}^{h}$ is the Higgs transverse momentum. As EW symmetry is restored, this ratio converges to one at high energy. We present a method to extract this ratio from collider data. With a full signal and background analysis, we demonstrate that the 14 TeV HL-LHC can confirm that this ratio converges to one to 40% precision while at the 27 TeV HE-LHC the precision will be 6%. We also investigate statistical tests to quantify the convergence at high energies. Our analysis provides a roadmap for how to stress test the Goldstone boson equivalence theorem and our understanding of spontaneously broken symmetries, in addition to confirming the restoration of EW symmetry.
hep-phPRD(2021)·14 citations
16*
Graph Generative Adversarial Networks for Sparse Data Generation in High Energy Physics
Raghav Kansal🇺🇸 · Javier Duarte🇺🇸 · Breno Orzari🇧🇷 · Thiago Tomei🇧🇷 · Maurizio Pierini🇨🇭 · Mary Touranakou🇨🇭 · Jean-Roch Vlimant🇺🇸 · Dimitrios Gunopulos🇬🇷
We develop a graph generative adversarial network to generate sparse data sets like those produced at the CERN Large Hadron Collider (LHC). We demonstrate this approach by training on and generating sparse representations of MNIST handwritten digit images and jets of particles in proton-proton collisions like those at the LHC. We find the model successfully generates sparse MNIST digits and particle jet data. We quantify agreement between real and generated data with a graph-based Fréchet Inception distance, and the particle and jet feature-level 1-Wasserstein distance for the MNIST and jet datasets respectively.
↳ physics.data-ancs.LGhep-exhep-ph+122 citations
17*
Radiative $α^{7} m$ QED contribution to the helium Lamb shift
Vojtěch Patkóš🇨🇿 · Vladimir A. Yerokhin🇷🇺 · Krzysztof Pachucki🇵🇱
We present a derivation of the last unknown part of the $α^{7} m$ contribution to the Lamb shift of a two-electron atom, induced by the radiative QED effects beyond the Bethe logarithm. This derivation is performed in the framework of nonrelativistic quantum electrodynamics and is valid for the triplet (spin $S = 1$ ) atomic states. The obtained formulas are free from any divergences and are suitable for a numerical evaluation. This opens a way for a complete numerical calculation of the $α^{7} m$ QED effects in helium, which will allow an accurate determination of the nuclear charge radius from measurements of helium transition frequencies.
↳ physics.atom-phhep-phPRA(2021)·12 citations
18*
Excited $J^{--}$ meson resonances at the SU(3) flavor point from lattice QCD
Christopher T. Johnson🇺🇸 · Jozef J. Dudek🇺🇸
We present the first calculation within lattice QCD of excited light meson resonances with $J^{P C} = 1^{--}$ , $2^{--}$ and $3^{--}$ . Working with an exact SU(3) flavor symmetry, for the singlet representation of pseudoscalar-vector scattering, we find two $1^{--}$ resonances, a lighter broad state and a heavier narrow state, a broad $2^{--}$ resonance decaying in both $P$ - and $F$ -waves, and a narrow $3^{--}$ state. We present connections to experimental $ω_{J}^{⋆}, ϕ_{J}^{⋆}$ resonances decaying into $π ρ$ , $K K ˉ^{*}$ , $η ω$ and other final states.
↳ hep-lathep-phPRD(2021)·29 citations
19*
Classification of three generation models by orbifolding magnetized $T^{2} \times T^{2}$
Kouki Hoshiya🇯🇵 · Shota Kikuchi🇯🇵 · Tatsuo Kobayashi🇯🇵 · Yuya Ogawa🇯🇵 · Hikaru Uchida🇯🇵
We study orbifolding by the $Z_{2}^{(per)}$ permutaion of $T_{1}^{2} \times T_{2}^{2}$ with magnetic fluxes and its twisted orbifolds. We classify the possible three generation models which lead to non-vanishing Yukawa couplings on the magnetized $T_{1}^{2} \times T_{2}^{2}$ and orbifolds including the $Z_{2}^{(per)}$ permutation and $Z_{2}^{(t)}$ twist. We also study the modular symmetry on such orbifold models. As an illustrating model, we examine the realization of quark masses and mixing angles.
↳ hep-thhep-phPTEP(2021)·30 citations
20*
Strategies to Detect Dark-Matter Decays with Line-Intensity Mapping
José Luis Bernal🇺🇸 · Andrea Caputo🇮🇱 · Marc Kamionkowski🇺🇸
The nature of dark matter is a longstanding mystery in cosmology, which can be studied with laboratory or collider experiments, as well as astrophysical and cosmological observations. In this work, we propose realistic and efficient strategies to detect radiative products from dark-matter decays with line-intensity mapping (LIM) experiments. This radiation will behave as a line interloper for the atomic and molecular spectral lines targeted by LIM surveys. The most distinctive signatures of the contribution from dark-matter radiative decays are an extra anisotropy on the LIM power spectrum due to projection effects, as well as a narrowing and a shift towards higher intensities of the voxel intensity distribution. We forecast the minimum rate of decays into two photons that LIM surveys will be sensitive to as function of the dark-matter mass in the range $\sim 1 0^{- 6} - 10$ eV, and discuss how to reinterpret such results for dark matter that decays into a photon and another particle. We find that both the power spectrum and the voxel intensity distribution are expected to be very sensitive to the dark-matter contribution, with the voxel intensity distribution being more promising for most experiments considered. Interpreting our results in terms of the axion, we show that LIM surveys will be extremely competitive to detect its decay products, improving several orders of magnitudes (depending on the mass) the sensitivity of laboratory and astrophysical searches, especially in the mass range $\sim 1 - 10$ eV.
↳ astro-ph.COhep-phPRD(2021)·48 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.