Wed·Feb 9, 2022Wednesday·February 9, 2022

1. 01*

   Slight excess at 130 GeV in search for a charged Higgs boson decaying to a charm quark and a bottom quark at the Large Hadron Collider

   A.G. Akeroyd🇬🇧 · Stefano Moretti🇬🇧 · Muyuan Song🇬🇧

   Searches for a charged Higgs boson ($H^{\pm }$) decaying to a charm quark and a bottom quark ($H^{\pm }\to cb$) have been carried out at the Large Hadron Collider (LHC) in the decay of top quarks ($t\to H^{\pm }b$). In a recent search by the ATLAS collaboration (with all Run II data, 139 fb${}^{-1}$) a local excess of around $3\sigma$ has been observed, which is best fitted by a charged Higgs boson with a mass ($m_{H^{\pm }}$) of around 130 GeV and a product of branching ratios (BRs) given by BR$(t\to H^{\pm }b)\times \mathrm{BR}(H^{\pm }\to cb)=0.16\%\pm 0.06\%$. In the context of Two-Higgs-Doublet Models (2HDM) with independent Yukawa couplings for $H^{\pm }$ we present the parameter space for which this excess (assuming it to be genuine) can be accommodated, taking into account the limits from LHC searches for $H^{\pm }\to cs$ and $H^{\pm }\to \tau \nu$ at $m_{H^{\pm }}$=130 GeV and the constraint from $b\to s\gamma$. It is then shown that such an excess cannot be explained in 2HDMs with natural flavour conservation, but can be accommodated in the flipped Three-Higgs-Doublet Model (3HDM) and in the aligned 2HDM (A2HDM). Upcoming searches with 139 fb${}^{-1}$ in the channels $H^{\pm }\to cb$ (CMS), $H^{\pm }\to cs$ (ATLAS/CMS) and $H^{\pm }\to \tau \nu$ (ATLAS/CMS) will determine if the excess is the first sign of an $H^{\pm }$ with $m_{H^{\pm }}=130$ GeV.

   hep-phJ.Phys.G(2022)·18 citations
2. 02*

   Negative energy states in pionic hydrogen

   Andrzej Czarnecki🇨🇦

   Probabilities of finding an antiparticle in an atom or ion containing a particle of spin 1/2 or spin 0 are determined. The spin 1/2 case was previously solved by Hans Bethe and his work is summarized. The spin 0 case is treated numerically for an arbitrary atomic number and analytically for small atomic numbers. The main tool for the spin 0 case is the Feshbach-Villars representation of the Klein-Gordon equation.

   hep-phphysics.atom-phActa Phys.Polon.Supp.(2022)·2 citations
3. 03*

   A Flexible Divergence Elimination Method for Calculating Lepton Magnetic Moments in Quantum Electrodynamics

   Sergey Volkov🇷🇺

   A precise calculation of the lepton anomalous magnetic moments (AMM) requires an evaluation of the quantum electrodynamics (QED) Feynman diagrams up to five independent loops. The complicated structure of ultraviolet (UV), infrared (IR) and mixed divergences in the corresponding integrals makes it difficult to calculate these high-order contributions in reasonable computer time frame. We demonstrate a method that eliminates all divergences point by point in Feynman parametric space (before integration) and possesses a flexibility that can be used for improving the precision of the numerical integration. This flexibility is especially actual for calculating the contributions of the Feynman diagrams with electron loops to the muon AMM. 3-loop and 4-loop numerical test results are provided. The subtraction procedure is based on a forest formula with linear operators applied to the Feynman amplitudes of UV divergent subdiagrams. It is similar to BPHZ; the difference is in the linear operators used and in the way of combining them. It is equivalent to the on-shell renormalization after summation over diagrams: no residual renormalization is required.

   hep-phJ.Phys.Conf.Ser.(2023)·3 citations
4. 04*

   Particle Transformer for Jet Tagging

   Huilin Qu🇨🇭 · Congqiao Li🇨🇳 · Sitian Qian🇨🇳

   Jet tagging is a critical yet challenging classification task in particle physics. While deep learning has transformed jet tagging and significantly improved performance, the lack of a large-scale public dataset impedes further enhancement. In this work, we present JetClass, a new comprehensive dataset for jet tagging. The JetClass dataset consists of 100 M jets, about two orders of magnitude larger than existing public datasets. A total of 10 types of jets are simulated, including several types unexplored for tagging so far. Based on the large dataset, we propose a new Transformer-based architecture for jet tagging, called Particle Transformer (ParT). By incorporating pairwise particle interactions in the attention mechanism, ParT achieves higher tagging performance than a plain Transformer and surpasses the previous state-of-the-art, ParticleNet, by a large margin. The pre-trained ParT models, once fine-tuned, also substantially enhance the performance on two widely adopted jet tagging benchmarks. The dataset, code and models are publicly available at https://github.com/jet-universe/particle_transformer.

   hep-phcs.LGhep-exphysics.data-anProceedings of the 39th International Con…·300 citations
5. 05*

   Analysis of the bottom-charm baryon states with QCD sum rules

   Zhi-Gang Wang🇨🇳 · Qi Xin🇨🇳

   In this work, we explore the ground state mass spectrum of the bottom-charm baryon states in the framework of the QCD sum rules in a comprehensive way. In calculations, we distinguish the contributions of the positive-parity and negative-parity baryon states unambiguously, and investigate the energy scale dependence of the QCD sum rules in details and observe that the acceptable energy scales are $\mu =2.0\sim 2.8\mathrm{GeV}$, while the best energy scale is $\mu =2.0\mathrm{GeV}$. The predictions can be confronted to the experimental data in the future and shed light on the QCD low energy dynamics.

   hep-phInt.J.Mod.Phys.A(2022)·6 citations
6. 06*

   Dark matter, supernova neutrinos and other backgrounds in direct dark matter searches. The ANDES laboratory prospects

   K.J. Fushimi🇦🇷 · M.M. Saez🇦🇷 · M.E. Mosquera🇦🇷 · O. Civitarese🇦🇷

   Dark Matter particles can be detected directly via their elastic scattering with nuclei. Next generation experiments can eventually find physical evidences about dark matter candidates. With this motivation in mind, we have calculated the expected signals of dark matter particles in xenon detectors. The calculations were performed by considering different masses and parameters within the minimal supersymmetric standard model. Since the detectors can also detect neutrinos, we have analyzed the supernova neutrino signal including a sterile neutrino in the formalism. Using this 3+1 scheme, we make predictions for both the normal and inverse mass hierarchy. In order to perform a study of the response of planned direct-detection experiments, to be located in ANDES (Agua Negra Deep Experimental Site), we have calculated the neutrino contributions to the background by taken into account reactor's neutrinos and geoneutrinos at the site of the lab. As a test detector, we take a Xenon1T-like array.

   hep-phastro-ph.HEIJMPE(2021)·2 citations
7. 07*

   Triangle Singularity in the Production of $T_{cc}^{+}$(3875) and a Soft Pion

   Eric Braaten🇺🇸 · Li-Ping He🇩🇪 · Kevin Ingles🇺🇸 · Jun Jiang🇨🇳

   The double-charm tetraquark meson $T_{cc}^{+}(3875)$ can be produced in high-energy proton-proton collisions by the creation of the charm mesons $D^{\ast +}{D}^0$ at short distances followed by their binding into $T_{cc}^{+}$. The $T_{cc}^{+}$ can also be produced by the creation of $D^{\ast +}{D}^{\ast +}$ at short distances followed by their rescattering into $T_{cc}^{+}{\pi }^{+}$. A charm-meson triangle singularity produces a narrow peak in the $T_{cc}^{+}{\pi }^{+}$ invariant mass distribution 6.1 MeV above the threshold with a width of about 1 MeV. Well beyond the peak, the differential cross section decreases with the invariant kinetic energy $E$ of $T_{cc}^{+}{\pi }^{+}$ as $E^{-1/2}$. The fraction of $T_{cc}^{+}$ that are accompanied by ${\pi }^{+}$ with $E<m_{\pi }$ is estimated to be roughly 3%. The fraction of $T_{cc}^{+}$ events with $T_{cc}^{+}{\pi }^{+}$ in the narrow peak from the triangle singularity could be comparable.

   hep-phPRD(2022)·35 citations
8. 08*

   Spin waves in spin hydrodynamics

   Victor E. Ambrus🇷🇴 · Radoslaw Ryblewski🇵🇱 · Rajeev Singh🇵🇱

   The propagation properties of spin degrees of freedom are analyzed in the framework of relativistic hydrodynamics with spin based on the de Groot--van Leeuwen--van Weert definitions of the energy-momentum and spin tensors. We derive the analytical expression for the spin wave velocity for arbitrary statistics and show that it goes to half the speed of light in the ultra-relativistic limit. We find that only the transverse degrees of freedom propagate, analogously to electromagnetic waves. Finally, we consider the effect of dissipative corrections and calculate the damping coefficients for the case of Maxwell-Jüttner statistics.

   hep-phnucl-thPRD(2022)·28 citations
9. 09*

   One-loop Corrections to the Higgs Boson Invisible Decay in a Complex Singlet Extension of the SM

   Felix Egle🇩🇪 · Margarete Mühlleitner🇩🇪 · Rui Santos🇵🇹 · João Viana🇵🇹

   The search for dark matter (DM) at colliders is founded on the idea of looking for something invisible. There are searches based on production and decay processes where DM may reveal itself as missing energy. If nothing is found, our best tool to constrain the parameter space of many extensions of the Standard Model (SM) with a DM candidate is the Higgs boson. As the measurements of the Higgs couplings become increasingly precise, higher-order corrections will start to play a major role. The tree-level contribution to the invisible decay width provides information about the portal coupling. Higher-order corrections also gives us access to other parameters from the dark sector of the Higgs potential that are not present in the tree-level amplitude. In this work we will focus on the complex singlet extension of the SM in the phase with a DM candidate. We calculate the one-loop electroweak corrections to the decay of the Higgs boson into two DM particles. We find that the corrections are stable and of the order of a few percent. The present measurement of the Higgs invisible branching ratio, BR$(H\to$ invisible $)<0.11$, already constrains the parameter space of the model at leading order. We expect that by the end of the LHC the experimental measurement will require the inclusion of the electroweak corrections to the decay in order to match the experimental accuracy. Furthermore, the only competing process, which is direct detection, is shown to have a cross section below the neutrino floor.

   hep-phPRD(2022)·18 citations
10. 10*

    Celestial Blocks and Transverse Spin in the Three-Point Energy Correlator

    Hao Chen🇨🇳 · Ian Moult🇺🇸 · Joshua Sandor🇺🇸 · Hua Xing Zhu🇨🇳

    Quantitative theoretical techniques for understanding the substructure of jets at the LHC enable new insights into the dynamics of QCD, and novel approaches to search for new physics. Recently, there has been a program to reformulate jet substructure in terms of correlation functions, $⟨\mathcal{E}({\vec{n}}_1)\mathcal{E}({\vec{n}}_2)\cdots \mathcal{E}({\vec{n}}_k)⟩$, of light-ray operators, $\mathcal{E}(\vec{n})$, allowing the application of techniques developed in the study of Conformal Field Theories (CFTs). In this paper we further develop these techniques in the particular context of the three-point correlator $⟨\mathcal{E}({\vec{n}}_1)\mathcal{E}({\vec{n}}_2)\mathcal{E}({\vec{n}}_3)⟩$, using recently computed perturbative data in both QCD and $\mathcal{N}=4$ sYM. We derive the celestial blocks appearing in the light-ray operator product expansion (OPE) of the three-point correlator, and use the Lorentzian inversion formula to extract the spectrum of light-ray operators appearing in the expansion, showing, in particular, that the OPE data is analytic in transverse spin. Throughout our presentation, we highlight the relation between the OPE approach, and more standard splitting function based approaches of perturbative QCD, emphasizing the utility of the OPE approach for incorporating symmetries in jet substructure calculations. We hope that our presentation introduces a number of new techniques to the jet substructure community, and also illustrates the phenomenological relevance of the study of light-ray operators in the OPE limit to the CFT community.

    hep-phhep-thJHEP(2022)·70 citations
11. 11*

    Canonical and Non-canonical Inflation in the light of the recent BICEP/Keck results

    Swagat S. Mishra🇬🇧 · Varun Sahni🇮🇳

    We discuss implications of the latest BICEP/Keck data release for inflationary models, with particular emphasis on scalar fields with non-canonical Lagrangians of the type $\mathcal{L}=X^{\alpha }-V(\varphi )$. The observational upper bound on the tensor-to-scalar ratio, $r\le 0.036$, implies that the whole family of monomial power law potentials $V(\varphi )\sim {\varphi }^p$ are now ruled out in the canonical framework at $95\%$ confidence, which includes the simplest classic inflationary potentials such as $\frac{1}{2}{m}^2{\varphi }^2$ and $\lambda {\varphi }^4$. Instead, current observations strongly favour asymptotically flat plateau potentials. However, working in the non-canonical framework, we demonstrate that monomial potentials, as well as the Higgs potential with its Standard Model self-coupling, can easily be accommodated by current CMB data. We find striking similarities between the $\{n_{{}_S},r\}$ flow lines of monomial potentials in the non-canonical framework and the T-model $\alpha$-attractors in the canonical framework. Significantly, $V(\varphi )$ can originate from Planck scale initial values $V(\varphi )\simeq m_p^4$ in non-canonical models while in plateau-like canonical inflation the initial value of the potential is strongly suppressed $V_{\mathrm{plat}}(\varphi )\le 10^{-10}{m}_p^4$. This has bearing on the issue of initial conditions for inflation and allows for the equipartition of the kinetic and potential terms in non-canonical models.

    ↳ astro-ph.COgr-qchep-phhep-th19 citations
12. 12*

    Finite-Volume Pionless Effective Field Theory for Few-Nucleon Systems with Differentiable Programming

    Xiangkai Sun🇺🇸 · William Detmold🇺🇸 · Di Luo🇺🇸 · Phiala E. Shanahan🇺🇸

    Finite-volume pionless effective field theory provides an efficient framework for the extrapolation of nuclear spectra and matrix elements calculated at finite volume in lattice QCD to infinite volume, and to nuclei with larger atomic number. In this work, it is demonstrated how this framework may be implemented via a set of correlated Gaussian wavefunctions optimised using differentiable programming and via solution of a generalised eigenvalue problem. This approach is shown to be significantly more efficient than a stochastic implementation of the variational method based on the same form of correlated Gaussian wavefunctions, yielding comparably accurate representations of the ground-state wavefunctions with an order of magnitude fewer terms. The efficiency of representation allows such calculations to be extended to larger systems than in previous work. The method is demonstrated through calculations of the binding energies of nuclei with atomic number $A\in \{2,3,4\}$ in finite volume, matched to lattice QCD calculations at quark masses corresponding to $m_{\pi }=806$ MeV, and infinite-volume effective field theory calculations of $A\in \{2,3,4,5,6\}$ systems based on this matching.

    ↳ nucl-thhep-lathep-phPRD(2022)·12 citations
13. 13*

    FLUKA cross sections for cosmic-ray interactions with the DRAGON2 code

    Pedro de la Torre Luque🇸🇪 · Mario Nicola Mazziotta🇮🇹 · Alfredo Ferrari🇩🇪 · Francesco Loparco🇮🇹 · Paola Sala🇮🇹 · Davide Serini🇮🇹

    Secondary particles produced in spallation reactions of cosmic rays with the interstellar gas provide valuable information that allow us to investigate the injection and transport of charged particles in the Galaxy. A good understanding of the cross sections of production of these particles is crucial to correctly interpret our models, although the existing experimental data is very scarce and uncertain. We have developed a new set of cross sections, both inelastic and inclusive, computed with the {\tt FLUKA} Monte Carlo nuclear code and tested its compatibility with CR data. Inelastic and inclusive cross sections have been compared to the most up-to-date data and parameterisations finding a general good agreement. Then, these cross sections have been implemented in the {\tt DRAGON2} code to characterize the spectra of CR nuclei up to $Z=26$ and the secondary-to-primary ratios of B, Be and Li. Interestingly, we find that the FLUKA cross sections allow us to predict an energy-dependence of the B, Be and Li flux ratios which is compatible with AMS-02 data and to reproduce simultaneously these flux ratios with a scaling lower than $20\%$. Finally, we implement the cross sections of production of gamma rays, calculated with {\tt FLUKA}, in the {\tt Gammasky} code and compute diffuse gamma-ray sky maps and the local HI emissivity spectrum, finding a very good agreement with Fermi Large Area Telescope data.

    ↳ astro-ph.HEhep-phJCAP(2022)·35 citations
14. 14*

    Physical symmetries and gauge choices in the Landau problem

    Masashi Wakamatsu🇯🇵 · Akihisa Hayashi🇯🇵

    Due to a special nature of the Landau problem, in which the magnetic field is uniformly spreading over the whole two-dimensional plane, there necessarily exist three conserved quantities, i.e. two conserved momenta and one conserved orbital angular momentum for the electron, independently of the choice of the gauge potential. Accordingly, the quantum eigen-functions of the Landau problem can be obtained by diagonalizing the Landau Hamiltonian together with one of the above three conserved operators with the result that the quantum mechanical eigen-functions of the Landau problem can be written down for arbitrary gauge potential. The purpose of the present paper is to clarify the meaning of gauge choice in the Landau problem based on this gauge-potential-independent formulation, with a particular intention of unraveling the physical significance of the concept of gauge-invariant-extension of the canonical orbital angular momentum advocated in recent literature on the nucleon spin decomposition problem. At the end, our analysis is shown to disclose a physically vacuous side face of the gauge symmetry.

    ↳ quant-phhep-phmath-phmath.MP+1EPJA(2022)·14 citations
15. 15*

    Generalised Parton Distributions from Lattice Feynman-Hellmann Techniques

    Alec Hannaford-Gunn🇦🇺 · Kadir Utku Can🇦🇺 · Roger Horsley🇬🇧 · Holder Perlt🇩🇪 · Paul Rakow🇬🇧 · Gerrit Schierholz🇩🇪 · Hinnerk Stüben🇩🇪 · Ross Young🇦🇺 · James Zanotti🇦🇺

    We report on the use of Feynman-Hellmann techniques to calculate the off-forward Compton amplitude (OFCA) in lattice QCD. At leading-twist, the Euclidean OFCA is parameterised by the Mellin moments of generalised parton distributions (GPDs). Hence we extract GPD moments for two values of the soft momentum transfer, $t=-1.10,-2.20{\text{GeV}}^2$ and zero-skewness kinematics at an unphysical pion mass of $m_{\pi }\approx 470\text{MeV}$. This includes the first determination of the $n=4$ moments.

    ↳ hep-lathep-phnucl-thPoS(2022)·4 citations
16. 16*

    Odderon observation: explanations and answers to questions/objections regarding the PRL publication

    Kenneth Österberg (on behalf of the D0 and TOTEM collaborations)🇫🇮

    The odderon observation recently published by the D0 and TOTEM collaborations has been widely accepted by a majority of the particle physics community and its importance recognized through dedicated physics seminars in the world major labs and physics institute. Naturally also some questions and objections have been raised, either privately or publicly, in discussion sessions and articles. In this proceedings article, a comprehensive list of these questions and objections are answered and supplementary material is provided. The methods and assumptions used in the extrapolation of the $pp$ elastic differential cross section to $\sqrt{s}$ = 1.96 TeV and its comparison to the D0 measurement in $p\bar{p}$ are shown to be valid and reasonable. Likewise, the methods and choices used for the $\rho$ measurement at LHC. Furthermore, objections against the odderon interpretation are demonstrated not to be valid. Finally, the combination of the different odderon significances, leading to the first experimental observation of odderon exchange, is shown to be well founded.

    ↳ hep-exhep-ph4 citations
17. 17*

    Virtual Photon Emission in Leptonic Decays of Charged Pseudoscalar Mesons

    G. Gagliardi🇮🇹 · V. Lubicz🇮🇹 · G. Martinelli🇮🇹 · F. Mazzetti🇮🇹 · C. T. Sachrajda🇬🇧 · F. Sanfilippo🇮🇹 · S. Simula🇮🇹 · N. Tantalo🇮🇹

    We study the radiative leptonic decays $P\to \ell {\nu }_{\ell }{\ell }^{\prime +}{\ell }^{\prime -}$, where $P$ is a pseudoscalar meson and $\ell$ and ${\ell }^{\prime }$ are charged leptons. In such decays the emitted photon is off-shell and, in addition to the "point-like" contribution in which the virtual photon is emitted either from the lepton or the meson treated as a point-like particle, four structure-dependent (SD) form factors contribute to the amplitude. We present a strategy for the extraction of the SD form factors and implement it in an exploratory lattice computation of the decay rates for the four channels of kaon decays ($\ell ,{\ell }^{\prime }=e,\mu$). It is the SD form factors which describe the interaction between the virtual photon and the internal hadronic structure of the decaying meson, and in our procedure we separate the SD and point-like contributions to the amplitudes. We demonstrate that the form factors can be extracted with good precision and, in spite of the unphysical quark masses used in our simulation ($m_{\pi }\simeq 320$MeV and $m_K\simeq 530$MeV), the results for the decay rates are in reasonable semiquantitative agreement with experimental data (for the channels where these exist). Following this preparatory work, the emphasis of our future work will be on obtaining results at physical quark masses and on the control of the systematic uncertainties associated with discretisation and finite-volume errors.

    ↳ hep-lathep-phPRD(2022)·20 citations
18. 18*

    Discrete Anomaly Matching for the Pouliot Type Dualities

    Teruhiko Kawano🇯🇵

    We compute the 't Hooft anomalies of discrete symmetries in the Pouliot type dual theories and check their anomaly matching conditions. The Pouliot type dual theories we will consider in this paper are two dual pairs; the dual pair of $\mathcal{N}=1$ supersymmetric theories of a $Spin(7)$ gauge theory with spinors and a $SU(N_f-4)$ gauge theory with a symmetric tensor, fundamentals and singlets, and the other dual pair of $\mathcal{N}=1$ supersymmetric theories of a $Spin(10)$ gauge theory with a spinor and vectors and a $SU(N_f-5)$ gauge theory with a symmetric tensor, fundamentals and singlets. We will show that the both pairs satisfy the discrete anomaly matching conditions.

    ↳ hep-thhep-phNPB(2022)·0 citations
19. 19*

    Is Local $H_0$ At Odds With Dark Energy EFT?

    Bum-Hoon Lee🇰🇷 · Wonwoo Lee🇰🇷 · Eoin Ó Colgáin🇰🇷 · M. M. Sheikh-Jabbari🇮🇷 · Somyadip Thakur🇰🇷

    Local $H_0$ determinations currently fall in a window between $H_0\sim 70$ km/s/Mpc (TRGB) and $H_0\sim 76$ km/s/Mpc (Tully-Fisher). In contrast, BAO data calibrated in an early $\Lambda$CDM universe are largely consistent with Planck-$\Lambda$CDM, $H_0\sim 67.5$ km/s/Mpc. Employing a generic two parameter family of evolving equations of state (EoS) for dark energy (DE) $w_{\text{DE}}(z)$ and mock BAO data, we demonstrate that if i) $w_{\text{DE}}(z=0)<-1$ and ii) integrated DE density less than $\Lambda$CDM, then $H_0$ increases. EoS that violate these conditions at best lead to modest $H_0$ increases within $1\sigma$. Tellingly, Quintessence and K-essence satisfy neither condition, whereas coupled Quintessence can only satisfy ii). Beyond these seminal DE Effective Field Theories (EFTs), we turn to explicit examples. Working model agnostically in an expansion in powers of redshift $z$, we show that Brans-Dicke/$f(R)$ and Kinetic Gravity Braiding models within the Horndeski class can lead to marginal and modest increases in $H_0$, respectively. We confirm that as far as increasing $H_0$ is concerned, no DE EFT model can outperform the phenomenological two parameter family of the DE models. Evidently, the late universe may no longer be large enough to accommodate $H_0$, BAO and DE described by EFT.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2022)·154 citations
20. 20*

    Prospects for studies of $D^{\ast 0}\to {\mu }^{+}{\mu }^{-}$ and $B_{(s)}^{\ast 0}\to {\mu }^{+}{\mu }^{-}$ decays

    F. Abudinén🇬🇧 · T. Blake🇬🇧 · U. Egede🇦🇺 · T. Gershon🇬🇧

    Weak decays of the vector $D^{\ast 0}$ and $B_{(s)}^{\ast 0}$ mesons to the $\text{mumu}$ final state provide novel potential to test the Standard Model of particle physics. Such processes have extremely small branching fractions as the vector mesons are able to decay through electromagnetic and (for the $D^{\ast 0}$ meson) strong interactions. Nonetheless, the production of copious quantities of these particles in LHC collisions, and the ability to exploit experimental techniques that can suppress background to low levels, provides good potential to reach interesting sensitivity. The possibility to reconstruct these processes as part of the decay chain of $B^{-}$ or $B_c^{+}$ mesons appears particularly attractive due to the clean experimental signature of the displaced vertex. Indeed, published LHCb data on $\text{Bm}\to \text{pim}\text{mumu}$ decays already implies a stringent limit on the branching fraction of $D^{\ast 0}\to {\mu }^{+}{\mu }^{-}$. Estimates are made on the achievable sensitivity to $D^{\ast 0}\to {\mu }^{+}{\mu }^{-}$ and $B_{(s)}^{\ast 0}\to {\mu }^{+}{\mu }^{-}$ decays with the LHCb experiment.

    ↳ hep-exhep-phEPJC(2022)·8 citations
21. 21*

    Relations among topological solitons

    Muneto Nitta🇯🇵

    We clarify relations among topological solitons in various dimensions: a domain wall, non-Abelian vortex, magnetic monopole and Yang-Mills instanton, together with a (non-Abelian) sine-Gordon soliton, baby Skyrmion (lump) and Skyrmion. We construct a composite configuration consisting of a domain wall, vortex, magnetic monopole and Yang-Mills instanton (wall-vortex-monopole-instanton) using the effective theory technique or moduli approximation. Removing some solitons from such a composite, we obtain all possible composite solitons in the form of solitons within a soliton, including all the previously known configurations, yielding relations among topological solitons.

    ↳ hep-thhep-phPRD(2022)·31 citations
22. 22*

    Three-point energy correlators and the celestial block expansion

    Cyuan-Han Chang🇺🇸 · David Simmons-Duffin🇺🇸

    We study the three-point energy correlator (EEEC), defined as a matrix element of a product of three energy detectors at different locations on the celestial sphere. Lorentz symmetry implies that the EEEC can be decomposed into special functions called celestial blocks. We compute three-point celestial blocks in an expansion around the collinear limit, where the three detectors approach each other on the celestial sphere. The leading term is a traditional $d-2$-dimensional four-point conformal block, and thus the collinear EEEC behaves like a conformally-invariant four-point function in $d-2$ dimensions. We obtain the coefficients of the conformal block decomposition for the collinear EEEC at leading nontrivial order in weakly-coupled $\mathcal{N}=4$ SYM and QCD. These data allow us to make certain all-orders predictions for the collinear EEEC in various kinematic limits, including the OPE limit and the double lightcone limit. We also study Ward identities satisfied by the EEEC and compute contact terms in the EEEC in weakly-coupled $\mathcal{N}=4$ SYM. Finally, we study the celestial block expansion of the EEEC in planar $\mathcal{N}=4$ SYM at strong coupling, determining celestial block coefficients to leading and first subleading order at large $\lambda$.

    ↳ hep-thhep-phJHEP(2023)·55 citations
23. 23*

    Quantum spin-flavour memory of ultrahigh-energy neutrino

    P. Kurashvili🇵🇱 · L. Chotorlishvili🇵🇱 · K. A. Kouzakov🇷🇺 · A. I. Studenikin🇷🇺

    There are two types of uncertainties related to the measurements done on a quantum system: statistical and those related to non-commuting observables and incompatible measurements. The latter indicates the quantum system's inherent nature and is in the scope of the present study. We explore uncertainties related to the interstellar ultrahigh-energy neutrino and introduce a novel concept: quantum spin-flavour memory. Advanced uncertainty measures are entropic measures, and the effect of the quantum memory reduces the uncertainty. The problem in question corresponds to a real physical event: high-energy Dirac neutrinos emitted by some distant source and propagating towards the earth. The neutrino has a finite magnetic moment and interacts with both deterministic and stochastic interstellar magnetic fields. To describe the effect of a noisy environment, we exploit the Lindblad master equation for the neutrino density matrix. Quantum spin-flavour memory we quantify in terms of the generalized Kraus's trade-off relation. This trade-off relation converts to the equality when quantum memory is absent. We discovered that while most measures of quantum correlations show their irrelevance, the quantum spin-flavour discord is the quantifier of the quantum spin-flavour memory.

    ↳ quant-phhep-phhep-thEur.Phys.J.Plus(2022)·5 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.