Mon·Jan 25, 2021Monday·January 25, 2021

1. 01*

   Hadronic decays of Higgs boson at NNLO matched with parton shower

   YaLu Hu🇨🇳 · ChuanLe Sun🇨🇳 · Xiao-Min Shen🇨🇳 · Jun Gao🇨🇳

   We present predictions for hadronic decays of the Higgs boson at next-to-next-to-leading order (NNLO) in QCD matched with parton shower based on the POWHEG framework. Those include decays into bottom quarks with full bottom-quark mass dependence, light quarks, and gluons in the heavy top quark effective theory. Our calculations describe exclusive decays of the Higgs boson with leading logarithmic accuracy in the Sudakov region and next-to-leading order (NLO) accuracy matched with parton shower in the three-jet region, with normalizations fixed to the partial width at NNLO. We estimated remaining perturbative uncertainties taking typical event shape variables as an example and demonstrated the need of future improvements on both parton shower and matrix element calculations. The calculations can be used immediately in evaluations of the physics performances of detector designs for future Higgs factories.

   hep-phJHEP(2021)·22 citations
2. 02*

   Learning to Simulate High Energy Particle Collisions from Unlabeled Data

   Jessica N. Howard🇺🇸 · Stephan Mandt🇺🇸 · Daniel Whiteson🇺🇸 · Yibo Yang🇺🇸

   In many scientific fields which rely on statistical inference, simulations are often used to map from theoretical models to experimental data, allowing scientists to test model predictions against experimental results. Experimental data is often reconstructed from indirect measurements causing the aggregate transformation from theoretical models to experimental data to be poorly-described analytically. Instead, numerical simulations are used at great computational cost. We introduce Optimal-Transport-based Unfolding and Simulation (OTUS), a fast simulator based on unsupervised machine-learning that is capable of predicting experimental data from theoretical models. Without the aid of current simulation information, OTUS trains a probabilistic autoencoder to transform directly between theoretical models and experimental data. Identifying the probabilistic autoencoder's latent space with the space of theoretical models causes the decoder network to become a fast, predictive simulator with the potential to replace current, computationally-costly simulators. Here, we provide proof-of-principle results on two particle physics examples, $Z$-boson and top-quark decays, but stress that OTUS can be widely applied to other fields.

   hep-phhep-exSci.Rep.(2022)·75 citations
3. 03*

   Photoproduction $\gamma p\to K^{+}\Lambda (1520)$ in an effective Lagrangian approach

   Neng-Chang Wei🇨🇳 · Yu Zhang🇨🇳 · Fei Huang🇨🇳 · De-Min Li🇨🇳

   The data on differential cross sections and photon-beam asymmetries for the $\gamma p\to K^{+}\Lambda (1520)$ reaction have been analyzed within a tree-level effective Lagrangian approach. In addition to the $t$-channel $K$ and $K^{\ast }$ exchanges, the $u$-channel $\Lambda$ exchange, the $s$-channel nucleon exchange, and the interaction current, a minimal number of nucleon resonances in the $s$ channel are introduced in constructing the reaction amplitudes to describe the data. The results show that the experimental data can be well reproduced by including either the $N(2060)5/2^{-}$ or the $N(2120)3/2^{-}$ resonance. In both cases, the contact term and the $K$ exchange are found to make significant contributions, while the contributions from the $K^{\ast }$ and $\Lambda$ exchanges are negligible in the former case and considerable in the latter case. Measurements of the data on target asymmetries are called on to further pin down the resonance contents and to clarify the roles of the $K^{\ast }$ and $\Lambda$ exchanges in this reaction.

   hep-phnucl-thPRD(2021)·12 citations
4. 04*

   CutLang V2: towards a unified Analysis Description Language

   G. Unel🇺🇸 · S. Sekmen🇰🇷 · A. M. Toon🇱🇧 · B. Gokturk🇹🇷 · B. Orgen🇹🇷 · A. Paul🇮🇹 · N. Ravel🇲🇬 · J. Setpal🇮🇳

   We will present the latest developments in CutLang, the runtime interpreter of a recently-developed analysis description language (ADL) for collider data analysis. ADL is a domain-specific, declarative language that describes the contents of an analysis in a standard and unambiguous way, independent of any computing framework. In ADL, analyses are written in human-readable plain text files, separating object, variable and event selection definitions in blocks, with a syntax that includes mathematical and logical operations, comparison and optimisation operators, reducers, four-vector algebra and commonly used functions. Adopting ADLs would bring numerous benefits to the LHC experimental and phenomenological communities, ranging from analysis preservation beyond the lifetimes of experiments or analysis software to facilitating the abstraction, design, visualization, validation, combination, reproduction, interpretation and overall communication of the analysis contents. Since their initial release, ADL and CutLang have been used for implementing and running numerous LHC analyses. In this process, the original syntax from CutLang v1 has been modified for better ADL compatibility, and the interpreter has been adapted to work with that syntax, resulting in the current release v2. Furthermore, CutLang has been enhanced to handle object combinatorics, to include tables and weights, to save events at any analysis stage, to benefit from multi-core/multi-CPU hardware among other improvements. In this contribution, these and other enhancements are discussed in details. In addition, real life examples from LHC analyses are presented together with a user manual.

   hep-phcs.PLFront.Big Data(2021)·11 citations
5. 05*

   Decay width modeling of Higgs boson within THDM model

   T.V. Obikhod🇺🇦 · I.A. Petrenko🇺🇦

   As part of the search for new physics beyond the Standard Model, we chose the determination of the Higgs boson decay width as one of the least experimentally determined values. The decay widths into the four fermions of the lightest and heaviest CP-even Higgs bosons of the THDM model were calculated, taking into account QCD and electroweak corrections in the NLO approximation. To achieve this goal, the program Monte Carlo Prophecy 4f with special scenarios of parameters, 7B1 and 5B1 were used. It was found that the decay width of the heavier CP-even Higgs boson, H differs from H${}_{SM}$ by 1227.93 times and changes to a negative value when deviating from the standard scenarios. Scale factors k${}_Z^2$ and k${}_W^2$ showed the predominance of the associated with Z boson production cross section of CP-even Higgs boson over the associated with W production cross section.

   hep-phProb.Atomic Sci.Technol.·0 citations
6. 06*

   The two-loop perturbative correction to the (g-2)${}_{\mu }$ HLbL at short distances

   Johan Bijnens🇸🇪 · Nils Hermansson-Truedsson🇨🇭 · Laetitia Laub🇨🇭 · Antonio Rodríguez-Sánchez🇫🇷

   The short-distance behaviour of the hadronic light-by-light (HLbL) contribution to $(g-2{)}_{\mu }$ has recently been studied by means of an operator product expansion in a background electromagnetic field. The leading term in this expansion has been shown to be given by the massless quark loop, and the non-perturbative corrections are numerically very suppressed. Here, we calculate the perturbative QCD correction to the massless quark loop. The correction is found to be fairly small compared to the quark loop as far as we study energy scales where the perturbative running for the QCD coupling is well-defined, i.e.~for scales $\mu \gtrsim 1\mathrm{GeV}$. This should allow to reduce the large systematic uncertainty associated to high-multiplicity hadronic states.

   hep-phJHEP(2021)·112 citations
7. 07*

   Deconfining Phase Boundary of Rapidly Rotating Hot and Dense Matter and Analysis of Moment of Inertia

   Yuki Fujimoto🇯🇵 · Kenji Fukushima🇯🇵 · Yoshimasa Hidaka🇯🇵

   We discuss the effect of rapid rotation on the phase diagram of hadronic matter. The energy dispersion relation is shifted by an effective chemical potential induced by rotation. This suggests that rotation should lower the critical temperature of chiral restoration, but it is still controversial how the deconfinement temperature should change as a function of angular velocity. We adopt the hadron resonance gas model as an approach free from fitting parameters. We identify the deconfinement from the thermodynamic behavior and find that rotation decreases the deconfinement temperature. We also discuss the spatial inhomogeneity of the pressure and give a semi-quantitative estimate of the moment of inertia.

   hep-phnucl-thPLB(2021)·109 citations
8. 08*

   Lepton polarization asymmetry in $B_{(}s,d{)}^{\ast }$ arrow ${\mu }^{+}{\mu }^{-}$ with new Z' couplings

   P. Maji🇮🇳 · S. Mahata🇮🇳 · S. Biswas🇮🇳 · S. Sahoo🇮🇳

   We study the effect of non-universal $Z^{\prime }$ boson on the rare leptonic decay modes of $B_s^{\ast }$ mesons, mediated by $barrowsll$ quark transition. Rare B decays are sensitive to various new physics operators. As B mesons are composite particles, such decay modes of the excited states are ideal for probing new physics beyond the standard model. We have constrained our model parameters from $B_{(}s,d)-$ {B bar(s,d)}$mixingdatatopredicttheleptonpolarizationasymmetryof$B_(s,d)^*$arrow${\mu}^+ {\mu}^-$channel.ItisfoundthatthisasymmetrydeviatesfromitsSMpredictionalongwiththe$Z'$effect

   hep-phInt.J.Theor.Phys.(2022)·2 citations
9. 09*

   An allowed window for heavy neutral leptons below the kaon mass

   Kyrylo Bondarenko🇨🇭 · Alexey Boyarsky🇳🇱 · Juraj Klaric🇨🇭 · Oleksii Mikulenko🇳🇱 · Oleg Ruchayskiy🇩🇰 · Vsevolod Syvolap🇩🇰 · Inar Timiryasov🇨🇭

   The extension of the Standard Model with two gauge-singlet Majorana fermions can simultaneously explain two beyond-the-Standard-model phenomena: neutrino masses and oscillations, as well as the origin of the matter-antimatter asymmetry in the Universe. The parameters of such a model are constrained by the neutrino oscillation data, direct accelerator searches, big bang nucleosynthesis, and requirement of successful baryogenesis. We show that the combination of all these constraints still leaves an allowed region in the parameter space below the kaon mass. This region can be probed by the further searches of NA62, DUNE, or SHiP experiments.

   hep-phastro-ph.COJHEP(2021)·65 citations
10. 10*

    The Cosmic Axion Background

    Jeff A. Dror🇺🇸 · Hitoshi Murayama🇺🇸 · Nicholas L. Rodd🇺🇸

    Existing searches for cosmic axions relics have relied heavily on the axion being non-relativistic and making up dark matter. However, light axions can be copiously produced in the early Universe and remain relativistic today, thereby constituting a Cosmic $\text{axion}$ Background (C$a$B). As prototypical examples of axion sources, we consider thermal production, dark-matter decay, parametric resonance, and topological defect decay. Each of these has a characteristic frequency spectrum that can be searched for in axion direct detection experiments. We focus on the axion-photon coupling and study the sensitivity of current and future versions of ADMX, HAYSTAC, DMRadio, and ABRACADABRA to a C$a$B, finding that the data collected in search of dark matter can be repurposed to detect axion energy densities well below limits set by measurements of the energy budget of the Universe. In this way, direct detection of relativistic relics offers a powerful new opportunity to learn about the early Universe and, potentially, discover the axion.

    hep-phastro-ph.COhep-exPRD(2021)·123 citations
11. 11*

    Using Pantheon and DES supernova, baryon acoustic oscillation, and Hubble parameter data to constrain the Hubble constant, dark energy dynamics, and spatial curvature

    Shulei Cao🇺🇸 · Joseph Ryan🇺🇸 · Bharat Ratra🇺🇸

    We use Pantheon Type Ia supernova (SN Ia) apparent magnitude, DES-3yr binned SN Ia apparent magnitude, Hubble parameter, and baryon acoustic oscillation measurements to constrain six spatially flat and non-flat cosmological models. These sets of data provide mutually consistent cosmological constraints in the six cosmological models we study. A joint analysis of these data sets provides model-independent estimates of the Hubble constant, $H_0=68.8\pm 1.8\mathrm{km}{\mathrm{s}}^{-1}\mathrm{Mp}{\mathrm{c}}^{-1}$, and the non-relativistic matter density parameter, ${\Omega }_{{\mathrm{m}}_0}=0.294\pm 0.020$. Although the joint constraints prefer mild dark energy dynamics and a little spatial curvature, they do not rule out dark energy being a cosmological constant and flat spatial hypersurfaces. We also add quasar angular size and H II starburst galaxy measurements to the combined data set and find more restrictive constraints.

    ↳ astro-ph.COgr-qchep-phhep-thMNRAS(2021)·110 citations
12. 12*

    Transport properties of superfluid phonons in neutron stars

    Cristina Manuel🇪🇸 · Laura Tolos🇪🇸

    We review the effective field theory associated with the superfluid phonons that we use for the study of transport properties in the core of superfluid neutrons stars in their low temperature regime. We then discuss the shear and bulk viscosities together with the thermal conductivity coming from the collisions of superfluid phonons in neutron stars. With regard to shear, bulk, and thermal transport coefficients, the phonon collisional processes are obtained in terms of the equation of state and the superfluid gap. We compare the shear coefficient due to the interaction among superfluid phonons with other dominant processes in neutron stars, such as electron collisions. We also analyze the possible consequences for the r-mode instability in neutron stars. As for the bulk viscosities, we determine that phonon collisions contribute decisively to the bulk viscosities inside neutron stars. For the thermal conductivity resulting from phonon collisions, we find that it is temperature independent well below the transition temperature. We also obtain that the thermal conductivity due to superfluid phonons dominates over the one resulting from electron-muon interactions once phonons are in the hydrodynamic regime. As the phonons couple to the $Z$ electroweak gauge boson, we estimate the associated neutrino emissivity. We also briefly comment on how the superfluid phonon interactions are modified in the presence of a gravitational field or in a moving background.

    ↳ nucl-thastro-ph.HEhep-phUniverse(2021)·3 citations
13. 13*

    QCD Critical Point and High Baryon Density Matter

    Bedangadas Mohanty🇮🇳 · Nu Xu🇨🇳

    We report the latest results on the search for the QCD critical point in the QCD phase diagram through high energy heavy-ion collisions. The measurements discussed are based on the higher moments of the net-proton multiplicity distributions in heavy-ion collisions. A non-monotonic variation in the product of kurtosis times the variance of the net-proton distribution is observed as a function of the collision energy with 3$\sigma$ significance. We also discuss the results of the thermal model in explaining the measured particle yield ratios in heavy-ion collisions and comparison of the different variants of hardon resonance gas model calculation to the data on higher moments of net-proton distributions. We end with a note that the upcoming programs in high baryon density regime at various experimental facilities will complete the search for the QCD critical point through heavy-ion collisions.

    ↳ nucl-exhep-exhep-phnucl-thActa Phys.Polon.Supp.(2021)·4 citations
14. 14*

    Muon identification in a compact single-layered water Cherenkov detector and gamma/hadron discrimination using Machine Learning techniques

    R. Conceição🇵🇹 · B. S. González🇵🇹 · A. Guillén🇪🇸 · M. Pimenta🇵🇹 · B. Tomé🇵🇹

    The muon tagging is an essential tool to distinguish between gamma and hadron-induced showers in wide field-of-view gamma-ray observatories. In this work, it is shown that an efficient muon tagging (and counting) can be achieved using a water Cherenkov detector with a reduced water volume and 4 PMTs, provided that the PMT signal spatial and time patterns are interpreted by an analysis based on Machine Learning (ML). The developed analysis has been tested for different shower and array configurations. The output of the ML analysis, the probability of having a muon in the WCD station, has been used to notably discriminate between gamma and hadron induced showers with $S/\sqrt{B}\sim 4$ for shower with energies $E_0\sim 1$TeV. Finally, for proton-induced showers, an estimator of the number of muons was built by means of the sum of the probabilities of having a muon in the stations. Resolutions about $20\%$ and a negligible bias are obtained for vertical showers with $N_{\mu }>10$.

    ↳ physics.ins-dethep-exhep-phEPJC(2021)·24 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.