Tue·Nov 10, 2020Tuesday·November 10, 2020

1. 01*

   Improved sensitivity of interferometric gravitational wave detectors to ultralight vector dark matter from the finite light-traveling time

   Soichiro Morisaki🇺🇸 · Tomohiro Fujita🇯🇵 · Yuta Michimura🇯🇵 · Hiromasa Nakatsuka🇯🇵 · Ippei Obata🇩🇪

   Recently several studies have pointed out that gravitational-wave detectors are sensitive to ultralight vector dark matter and can improve the current best constraints given by the Equivalence Principle tests. While a gravitational-wave detector is a highly precise measuring tool of the length difference of its arms, its sensitivity is limited because the displacements of its test mass mirrors caused by vector dark matter are almost common. In this Letter we point out that the sensitivity is significantly improved if the effect of finite light-traveling time in the detector's arms is taken into account. This effect enables advanced LIGO to improve the constraints on the $U(1{)}_{B-L}$ gauge coupling by an order of magnitude compared with the current best constraints. It also makes the sensitivities of the future gravitational-wave detectors overwhelmingly better than the current ones. The factor by which the constraints are improved due to the new effect depends on the mass of the vector dark matter, and the maximum improvement factors are $470$, $880$, $1600$, $180$ and $1400$ for advanced LIGO, Einstein Telescope, Cosmic Explorer, DECIGO and LISA respectively. Including the new effect, we update the constraints given by the first observing run of advanced LIGO and improve the constraints on the $U(1{)}_B$ gauge coupling by an order of magnitude compared with the current best constraints.

   hep-phastro-ph.COastro-ph.HEgr-qcPRD(2021)·53 citations
2. 02*

   Magnetic field dependence of the neutral pion mass in the linear sigma model with quarks: The strong field case

   Alejandro Ayala🇲🇽 · José Luis Hernández🇲🇽 · L. A. Hernández🇲🇽 · Ricardo L. S. Farias🇧🇷 · R. Zamora🇨🇱

   We use the linear sigma model with quarks to find the magnetic field-induced modifications to the neutral pion mass at one-loop level. The magnetic field effects are introduced by using charged particle propagators in the presence of a magnetic background in the strong field regime. We show that when accounting for the effects of the magnetic field on the model couplings, the vacuum sigma field and the neutral pion self-energy, the neutral pion mass decreases monotonically as a function of the field strength. We find an excellent qualitative and quantitative agreement with recent lattice QCD calculations, reproducing the monotonically decreasing trend with the field strength as well as the decrease when lattice data approaches the physical vacuum pion mass from larger values.

   hep-phnucl-thPRD(2021)·38 citations
3. 03*

   CP Violation in Rare Lepton-Number-Violating $W$ Decays at the LHC

   Fatemeh Najafi🇨🇦 · Jacky Kumar🇨🇦 · David London🇨🇦

   Some models of leptogenesis involve a quasi-degenerate pair of heavy neutrinos $N_{1,2}$ whose masses can be small, $O(\mathrm{GeV})$. Such neutrinos can contribute to the rare lepton-number-violating (LNV) decay $W^{\pm }\to {\ell }_1^{\pm }{\ell }_2^{\pm }(q^{\prime }\bar{q}{)}^{\mp }$. If both $N_1$ and $N_2$ contribute, there can be a CP-violating rate difference between the LNV decay of a $W^{-}$ and its CP-conjugate decay. In this paper, we examine the prospects for measuring such a CP asymmetry $A_{\mathrm{CP}}$ at the LHC. We assume a value for the heavy-light neutrino mixing parameter $|B_{\ell N}{|}^2=10^{-5}$, which is allowed by the present experimental constraints, and consider $5\mathrm{GeV}\le M_N\le 80\mathrm{GeV}$. We consider three versions of the LHC -- HL-LHC, HE-LHC, FCC-hh -- and show that small values of the CP asymmetry can be measured at $3\sigma$, in the range $1\%\lesssim A_{\mathrm{CP}}\lesssim 15\%$.

   hep-phJHEP(2021)·19 citations
4. 04*

   Radiative decays of Upsilon(nS) into S-wave and P-wave charmonium

   Dan-Dan Shen🇨🇳 · Chong-Yang Lu🇨🇳 · Peng Sun🇨🇳 · Ruilin Zhu🇨🇳

   Motivated by very recent measurement of the radiative decays of ${\rm Y}(1S)$ to ${\chi }_{c1}$ at Belle, we use the nonrelativistic QCD factorization theory and calculate the branching fractions of the radiative decays of bottomonium into S-wave and P-wave charmonium, i.e. ${\rm Y}(nS)\to {\eta }_c(nS)+\gamma$ and ${\rm Y}(nS)\to {\chi }_{cJ}+\gamma$. We systematically studied the branching fractions of the radiative decays of bottomonium into charmonium. Compared to the previous calculation, we obtained the analytical expression for the decay widths and considered the color-octet contributions. For ${\rm Y}(nS)\to {\eta }_c(nS)+\gamma$, the relativistic corrections are also obtained. Through the calculation, the theoretical prediction for ${\rm Y}(1S)\to {\chi }_{c1}+\gamma$ is still smaller than the recent Belle measurement. Further theoretical work and experimental analysis are necessary to understand the ${\chi }_{c1}$ production mechanism in upsilon decays.

   hep-phhep-ex2 citations
5. 05*

   Landscape Higgs and sparticle mass predictions from a logarithmic soft term distribution

   Howard Baer🇺🇸 · Vernon Barger🇺🇸 · Shadman Salam🇺🇸 · Dibyashree Sengupta🇹🇼

   Recent work on calculating string theory landscape statistical predictions for the Higgs and sparticle mass spectrum from an assumed power-law soft term distribution yields an expectation for m(h)~ 125 GeV with sparticles (save light higgsinos) somewhat beyond reach of high-luminosity LHC. A recent examination of statistics of SUSY breaking in IIB string models with stabilized moduli suggests a power-law for models based on KKLT stabilization and uplifting while models based on large-volume scenario (LVS) instead yield an expected logarithmic soft term distribution. We evaluate statistical distributions for Higgs and sparticle masses from the landscape with a log soft term distribution and find the Higgs mass still peaks around ~125 GeV with sparticles beyond LHC reach, albeit with somewhat softer distributions than those arising from a power-law.

   hep-phPRD(2021)·10 citations
6. 06*

   Implications of Gravitational Waves for Supersymmetric Grand Unification

   So Chigusa🇺🇸 · Yuichiro Nakai🇨🇳 · Jiaming Zheng🇨🇳

   Supersymmetric grand unification based on $SO(10)$ is one of the most attractive paradigms in physics beyond the Standard Model. Inspired by the recent NANOGrav signal, we discuss the implications of detecting a stochastic gravitational wave background emitted by a network of cosmic strings for the $SO(10)$ grand unification. Starting from a minimal model with multiple steps of symmetry breaking, we show that it generally prefers a high intermediate scale above $10^{14}\mathrm{GeV}$ that is favored by observable primordial gravitational waves. The observed spectrum can potentially narrow the possible range of the cosmic string scale and restricts the unified couplings and the unification scale by requiring gauge coupling unification. As an indirect consequence of the high cosmic string scale, the monopole abundance places non-trivial constraints on the theory. These are complementary to the proton decay constraints and probe different facets of supersymmetric $SO(10)$ unification theories.

   hep-phPRD(2021)·22 citations
7. 07*

   Non-global logarithms in hadron collisions at $N_c=3$

   Yoshitaka Hatta🇺🇸 · Takahiro Ueda🇯🇵

   We calculate the rapidity gap survival probability associated with the Higgs decay and Higgs plus dijet production in proton-proton collisions by resumming the leading non-global logarithms without any approximation to the number of colors. For dijet production, depending on partonic subprocesses, the probability involves various `color multipoles', i.e., the product of 4 ($qq\to qq$) or 6 ($qg\to qg$) or 8 ($gg\to gg$) Wilson lines. We calculate all these multipoles for a fixed dijet configuration and discuss the factorization of higher multipoles into lower multipoles as well as the validity of the large-$N_c$ approximation.

   hep-phNPB(2021)·36 citations
8. 08*

   Seesaw Models under the Lens of Angular Distributions at ${\mu }^{+}{\mu }^{-},{\mu }^{+}{\mu }^{+},{\mu }^{+}\gamma$ and ${\mu }^{+}{e}^{-}$ Colliders

   Priyotosh Bandyopadhyay🇮🇳 · Anirban Karan🇮🇳 · Chandrima Sen🇮🇳

   The Seesaw extensions of the Standard Model not only provide a natural explanation for tiny neutrino masses, they also predict additional heavy states such as Majorana neutrinos, charged leptons, and scalar triplets. Distinguishing between these scenarios at future colliders will be essential if such particles are discovered. In this work, we investigate how leptonic colliders offer complementary avenues for this task, focusing on the role of reconstructed angular distributions, which encode information about the underlying matrix elements. One only needs to reconstruct the new particle (or SM charged lepton) in the final state and examine its angular distribution relative to the beam axis, without bothering about the other particles in the final state, and this is sufficient to reveal the underlying simple tree-level Seesaw scenario, as considered in this work. We perform a detailed PYTHIA8-based simulation for different Seesaw realizations: inverse Type-I, Type-II, and inverse Type-III at ${\mu }^{+}{\mu }^{-}$, ${\mu }^{+}{\mu }^{+}$, ${\mu }^{+}\gamma$, and ${\mu }^{+}{e}^{-}$ colliders. Characteristic angular patterns emerge that enable discrimination among the models, with muon colliders providing particularly promising reach. We also comment on the prospects of asymmetric $\mu e$ colliders in probing off-diagonal Yukawa structures.

   hep-phJ.Phys.G(2026)·16 citations
9. 09*

   One-loop Kubo estimations of the shear and bulk viscous coefficients for hot and magnetized Bosonic and Fermionic systems

   Snigdha Ghosh🇮🇳 · Sabyasachi Ghosh🇮🇳

   The expressions of the shear viscosity and the bulk viscosity components in the presence of an arbitrary external magnetic field for a system of hot charged scalar Bosons (spin-0) as well as for a system of hot charged Dirac Fermions (spin-$\frac{1}{2}$) have been derived by employing the one-loop Kubo Formalism. This is done by explicitly evaluating the thermo-magnetic spectral functions of the energy momentum tensors using the real time formalism of finite temperature field theory and the Schwinger proper time formalism. In the present work, a rich quantum field theoretical structure in the expressions of the viscous coefficients in non-zero magnetic field are found, which are different from their respective expressions obtained earlier via kinetic theory based calculations; though, in absence of magnetic field, the one-loop Kubo and the kinetic theory based expressions for the viscosities are known to be identical. We have identified that Kubo and kinetic theory based results of viscosity components follow similar kind of temperature and magnetic field dependency. The relaxation time and the synchrotron frequency in the kinetic theory formalism are realized to be connected respectively with the thermal width of propagator and the transitions among the Landau levels of the charged particles in the Kubo formalism. We believe that, the connection of latter quantities are quite new and probably the present work is the first time addressing this interpretation along with the new expressions of viscosity components, not seen in existing works.

   hep-phnucl-thPRD(2021)·29 citations
10. 10*

    Higgs boson pair production at N${}^3$LO QCD

    Long-Bin Chen🇨🇳 · Hai Tao Li🇺🇸 · Hua-Sheng Shao🇫🇷 · Jian Wang🇨🇳

    Understanding the Higgs potential by measuring its self-interactions is fundamental in answering several big questions, such as electroweak symmetry breaking, electroweak baryogenesis, electroweak phase transition, and electroweak vacuum stability. The most promising way to probe the Higgs potential is to detect Higgs boson pair final state at high-energy colliders. In this talk, we report a recent perturbative calculation for the di-Higgs gluon-fusion process by taking into account N${}^3$LO QCD radiative corrections in the approximation of infinite top quark mass limit. Finite top quark mass effects are also incorporated with several approximate schemes, which are known to be crucial in phenomenological applications. We show a very good asymptotic perturbative convergence at $\mathcal{O}({\alpha }_s^5)$, and demonstrate that the remaining scale uncertainty is only at percent level.

    hep-phhep-exPoS(2021)·2 citations
11. 11*

    Some remarks on $X(6900)$

    Qin-Fang Cao🇨🇳 · Hao Chen🇨🇳 · Hong-Rong Qi🇨🇳 · Han-Qing Zheng🇨🇳

    The analysis of the LHCb data on $X(6900)$ found in the di-$\text{jpsi}$ system is performed using a momentum-dependent Flatté-like parameterization. The use of the pole counting rule and spectral density function sum rule give consistent conclusions that both confining states and molecular states are possible, or it is unable to distinguish the nature of $X(6900)$, if only the di-$\text{jpsi}$ experimental data with current statistics are available. Nevertheless, we found that the lowest state in the di-$J/\psi$ system has very likely the same quantum numbers as $X(6900)$, and $X(6900)$ is probably not interpreted as a $J/\psi -\psi (2S)$ molecular state.

    hep-phCPC(2021)·58 citations
12. 12*

    Neutrino mass and asymmetric dark matter: study with inert Higgs doublet and high scale validity

    Amit Dutta Banik🇨🇳 · Rishav Roshan🇮🇳 · Arunansu Sil🇮🇳

    We consider an inert Higgs doublet (IHD) extension of the Standard Model accompanied with three right handed neutrinos and a dark sector, consisting of a singlet fermion and a scalar, in order to provide a common framework for dark matter, leptognesis and neutrino mass. While the Yukawa coupling of the right handed neutrinos with IHD (having mass in the intermediate regime: 80-500 GeV) is responsible for explaining the observed baryon asymmetry through leptogenesis, its coupling with the dark sector explains the dark matter relic density. The presence of IHD also explains the neutrino mass through radiative correction. We find that study of the high scale validity of the model in this context becomes crucial as it restricts the parameter space significantly. It turns out that there exists a small, but non-zero contribution to the relic density of DM from IHD too. Considering all the constraints from dark matter, leptogenesis, neutrino mass and high scale validity of the model, we perform a study to find out the viable parameter space.

    hep-phJCAP(2021)·21 citations
13. 13*

    Mixing and $CP$ violation in the charm system

    Alexander Lenz🇩🇪 · Guy Wilkinson🇬🇧

    In recent years charm physics has undergone a renaissance, one which has been catalysed by an unexpected and impressive set of experimental results from the $B$-factories, the Tevatron and LHCb. The existence of $D^0\bar{D}{}^0$ oscillations is now well established, and the recent discovery of $CP$ violation in $D^0$ decays has further renewed interest in the charm sector. In this article we review the current status of charm-mixing and $CP$-violation measurements, and assess their agreement with theoretical predictions within the Standard Model and beyond. We look forward to the great improvements in experimental precision that can be expected over the coming two decades, and the prospects for corresponding advances in theoretical understanding.

    hep-phAnn.Rev.Nucl.Part.Sci.(2021)·72 citations
14. 14*

    Novel Rosenbluth Extraction Framework for Compton Form Factors from Deeply Virtual Exclusive Experiments

    Brandon Kriesten · Simonetta Liuti

    We use a generalization of the Rosenbluth separation method for a model independent simultaneous extraction of the Compton Form Factors $\mathcal{H}$ and $\mathcal{E}$, from virtual Compton scattering data on an unpolarized target. A precise evaluation of $\mathcal{H}$ and $\mathcal{E}$, enabled by the proposed method, is the first step towards pinning down the the distribution of angular momentum inside the proton.

    hep-phnucl-exnucl-thPLB(2022)·23 citations
15. 15*

    Two-photon processes in conformal QCD: Resummation of the descendants of leading-twist operators

    V. M. Braun🇩🇪 · Yao Ji🇩🇪 · A. N. Manashov🇩🇪

    Using some techniques of conformal field theories, we find a closed expression for the contribution of leading twist operators and their descendants, obtained by adding total derivatives, to the operator product expansion (OPE) of two electromagnetic currents in QCD. Our expression resums contributions of all twists and to all orders in perturbation theory up to corrections proportional to the QCD $\beta$-function. At tree level and to twist-four accuracy, our result agrees with the expression derived earlier by a different method. The results are directly applicable to deeply-virtual Compton scattering and, e.g., $\gamma {\gamma }^{\ast }$ annihilation in two mesons. As a byproduct, we derive a simple representation for the OPE of two scalar currents that is convenient for applications.

    hep-phhep-thJHEP(2021)·21 citations
16. 16*

    Alternative dark matter phenomenology in a general $U(1{)}_X$ extension of the Standard Model

    Arindam Das🇯🇵 · Kazuki Enomoto🇯🇵 · Shinya Kanemura🇯🇵

    The existence of the neutrino mass and flavor mixing have been experimentally verified. These phenomena strongly motivate to extend the Standard Model (SM). Amongst many possibilities, a simple and interesting extension of the SM can be investigated using a general U$(1{)}_X$ extension of the SM gauge group. Demanding the cancellation of the gauge and mixed gauge gravity anomalies, three right handed neutrinos are introduced in this model where the U$(1{)}_X$ charge assignment becomes a linear combination of U$(1{)}_{\mathrm{B}-\mathrm{L}}$ and U$(1{)}_Y$ hyper-charges. After the U$(1{)}_X$ breaking, an additional neutral gauge boson, $Z^{\prime }$ is evolved and the neutrino mass is generated by the seesaw mechanism. In such a model we investigate the properties of a Dark Matter (DM) candidate which is a massive weakly interacting particle and Dirac type in nature. The stability of the DM is protected by its U$(1{)}_X$ charge. Using the current bounds on the search results of $Z^{\prime }$ at the Large Hadron Collider (LHC) and the dark matter relic abundance we find a phenomenologically viable parameter space of our scenario.

    hep-ph1 citation
17. 17*

    Strong first order electroweak phase transition in 2HDM confronting future Z & Higgs factories

    Wei Su🇦🇺 · Anthony G. Williams🇦🇺 · Mengchao Zhang🇨🇳

    The electroweak phase transition can be made first order by extending the Standard Model (SM) Higgs sector with extra scalars. The same new physics can explain the matter-antimatter asymmetry of the universe by supplying an extra source of CP violation and sphaleron processes. In this paper we study the existence of a strong first order electroweak phase transition (SFOEWPT) in the type-I and type-II two Higgs doublet models (2HDM). We focus on how the SFOEWPT requirement constraints the spectrum of non-SM Higgs. Through a parameter space scan, we find that SFOEWPT suggests upper limits on the masses of heavy Higgs $m_{A/H/H^{\pm }}$, which is less than 1 TeV. High temperature expansion and Higgs vacuum uplifting is used for an analytical understanding of our results. We also study the probe ability on SFOEWPT from Higgs and $Z$-pole precision measurements at the one-loop level at future Higgs & $Z$ factories. And together with theoretical constraints, sizeable loop corrections require $m_A\approx m_{H^{\pm }}>m_H$ to meet SFOEWPT condition in Type-II 2HDM.

    hep-phJHEP(2021)·55 citations
18. 18*

    Fully-heavy pentaquark states

    Jian-Rong Zhang🇨🇳

    Developing the calculation techniques to fivefold heavy hadrons, we perform the study of novel fully-heavy $QQQQ\bar{Q}$ pentaquark states by the QCD sum rule approach that is firmly based on the QCD basic theory. Numerically, masses of fully-heavy pentaquark states are calculated to be $7.41_{-0.31}^{+0.27}\text{mbox}GeV$ for $cccc\bar{c}$ and $21.60_{-0.22}^{+0.73}\text{mbox}GeV$ for $bbbb\bar{b}$, respectively. In experiment, these predicted all-heavy pentaquark states could be searched for in the ${\Omega }_{QQQ}{\eta }_Q$ invariant mass spectrum.

    hep-phhep-exPRD(2021)·28 citations
19. 19*

    Polarized ${\Lambda }_b$ baryon decay to $p\pi$ and a dilepton pair

    Diganta Das🇮🇳 · Ria Sain🇮🇳

    The recent anomalies in $b\to s{\ell }^{+}{\ell }^{-}$ transitions could originate from some New Physics beyond the Standard Model. Either to confirm or to rule out this assumption, more tests of $b\to s{\ell }^{+}{\ell }^{-}$ transition are needed. Polarized ${\Lambda }_b$ decay to a $\Lambda$ and a dilepton pair offers a plethora of observables that are suitable to discriminate New Physics from the Standard Model. In this paper, we present a full angular analysis of a polarized ${\Lambda }_b$ decay to a $\Lambda (\to p\pi ){\ell }^{+}{\ell }^{-}$ final state. The study is performed in a set of the operator where the Standard Model operator basis is supplemented with its chirality flipped counterparts, and new scalar and pseudo-scalar operators. The full angular distribution is calculated by retaining the mass of the final state leptons. At the low hadronic recoil, we use the Heavy Quark Effective Theory framework to relate the hadronic form factors which lead to simplified expression of the angular observables where short- and long-distance physics factorize. Using the factorized expressions of the observables, we construct a number of tests of short- and long-distance physics including null tests of the Standard Model and its chirality flipped counterparts that can be carried out using experimental data.

    hep-phPRD(2021)·5 citations
20. 20*

    Parameter Inference from Event Ensembles and the Top-Quark Mass

    Forrest Flesher🇺🇸 · Katherine Fraser🇺🇸 · Charles Hutchison🇺🇸 · Bryan Ostdiek🇺🇸 · Matthew D. Schwartz🇺🇸

    One of the key tasks of any particle collider is measurement. In practice, this is often done by fitting data to a simulation, which depends on many parameters. Sometimes, when the effects of varying different parameters are highly correlated, a large ensemble of data may be needed to resolve parameter-space degeneracies. An important example is measuring the top-quark mass, where other physical and unphysical parameters in the simulation must be marginalized over when fitting the top-quark mass parameter. We compare three different methodologies for top-quark mass measurement: a classical histogram fitting procedure, similar to one commonly used in experiment optionally augmented with soft-drop jet grooming; a machine-learning method called DCTR; and a linear regression approach, either using a least-squares fit or with a dense linearly-activated neural network. Despite the fact that individual events are totally uncorrelated, we find that the linear regression methods work most effectively when we input an ensemble of events sorted by mass, rather than training them on individual events. Although all methods provide robust extraction of the top-quark mass parameter, the linear network does marginally best and is remarkably simple. For the top study, we conclude that the Monte-Carlo-based uncertainty on current extractions of the top-quark mass from LHC data can be reduced significantly (by perhaps a factor of 2) using networks trained on sorted event ensembles. More generally, machine learning from ensembles for parameter estimation has broad potential for collider physics measurements.

    hep-phJHEP(2021)·11 citations
21. 21*

    The Semi-Classical Regime for Dark Matter Self-Interactions

    Brian Colquhoun🇨🇦 · Saniya Heeba🇩🇪 · Felix Kahlhoefer🇩🇪 · Laura Sagunski🇩🇪 · Sean Tulin🇨🇦

    Many particle physics models for dark matter self-interactions - motivated to address long-standing challenges to the collisionless cold dark matter paradigm - fall within the semi-classical regime, with interaction potentials that are long-range compared to the de Broglie wavelength for dark matter particles. In this work, we present a quantum mechanical derivation and new analytic formulas for the semi-classical momentum transfer and viscosity cross sections for self-interactions mediated by a Yukawa potential. Our results include the leading quantum corrections beyond the classical limit and allow for both distinguishable and identical dark matter particles. Our formulas supersede the well-known formulas for the momentum transfer cross section obtained from the classical scattering problem, which are often used in phenomenological studies of self-interacting dark matter. Together with previous approximation formulas for the cross section in the quantum regime, our new results allow for nearly complete analytic coverage of the parameter space for self-interactions with a Yukawa potential. We also discuss the phenomenological implications of our results and provide a new velocity-averaging procedure for constraining velocity-dependent self-interactions. Our results have been implemented in the newly released code CLASSICS.

    hep-phastro-ph.COastro-ph.GAPRD(2021)·63 citations
22. 22*

    Gluon fragmentation into ${}^3{P}_J^{[1,8]}$ quark pair and test of NRQCD factorization at two-loop level

    Peng Zhang🇨🇳 · Ce Meng🇨🇳 · Yan-Qing Ma🇨🇳 · Kuang-Ta Chao🇨🇳

    The next-to-leading order (NLO) ($\mathcal{O}({\alpha }_s^3)$) corrections for gluon fragmentation functions to a heavy quark-antiquark pair in ${}^3{P}_J^{[1,8]}$ states are calculated within the NRQCD factorization. We use integration-by-parts reduction and differential equations to semi-analytically calculate fragmentation functions in full-QCD, and find that infrared divergences can be absorbed by the NRQCD long distance matrix elements. Thus, the NRQCD factorization conjecture is verified at two-loop level via a physical process, which is free of artificial ultraviolet divergences. Through matching procedure, infrared-safe short distance coefficients and $\mathcal{O}({\alpha }_s^2)$ perturbative NRQCD matrix elements $⟨{\mathcal{O}}^{{}^3{P}_J^{[1,8]}}({}^3{S}_1^{[8]}){⟩}_{\mathrm{NLO}}$ are obtained simultaneously. The NLO short distance coefficients are found to have significant corrections comparing with the LO ones.

    hep-phJHEP(2021)·21 citations
23. 23*

    Detection of astrophysical tau neutrino candidates in IceCube

    R. Abbasi🇺🇸 · M. Ackermann🇩🇪 · J. Adams🇳🇿 · J. A. Aguilar🇧🇪 · M. Ahlers🇩🇰 · M. Ahrens🇸🇪 · C. Alispach🇨🇭 · A. A. Alves Jr.🇩🇪 · N. M. Amin🇺🇸 · K. Andeen🇺🇸 · T. Anderson🇺🇸 · I. Ansseau🇧🇪 and 353 other authors

    High-energy tau neutrinos are rarely produced in atmospheric cosmic-ray showers or at cosmic particle accelerators, but are expected to emerge during neutrino propagation over cosmic distances due to flavor mixing. When high energy tau neutrinos interact inside the IceCube detector, two spatially separated energy depositions may be resolved, the first from the charged current interaction and the second from the tau lepton decay. We report a novel analysis of 7.5 years of IceCube data that identifies two candidate tau neutrinos among the 60 ``High-Energy Starting Events'' (HESE) collected during that period. The HESE sample offers high purity, all-sky sensitivity, and distinct observational signatures for each neutrino flavor, enabling a new measurement of the flavor composition. The measured astrophysical neutrino flavor composition is consistent with expectations, and an astrophysical tau neutrino flux is indicated at 2.8$\sigma$ significance.

    ↳ hep-exastro-ph.HEhep-phEPJC(2022)·140 citations
24. 24*

    Pulsating hydrogen-deficient white dwarfs and pre-white dwarfs observed with TESS: I. Asteroseismology of the GW Vir stars RX J2117+3412, HS 2324+3944, NGC 6905, NGC 1501, NGC 2371, and K 1-16

    Alejandro H. Córsico🇦🇷 · Murat Uzundag🇨🇱 · S. O. Kepler🇧🇷 · Leandro G. Althaus🇦🇷 · Roberto Silvotti🇮🇹 · Andrzej S. Baran🇵🇱 · Maja Vučković🇨🇱 · Klaus Werner🇩🇪 · Keaton J. Bell🇺🇸 · Michael Higgins🇺🇸

    In this paper, we present a detailed asteroseismological analysis of six GW Vir stars including the observations collected by the TESS mission. We processed and analyzed TESS observations of RX J2117+3412, HS 2324+3944, NGC 6905, NGC 1501, NGC 2371, and K 1-16. We carried out a detailed asteroseismological analysis of these stars on the basis of PG 1159 evolutionary models that take into account the complete evolution of the progenitor stars. In total, we extracted 58 periodicities from the TESS light curves using a standard pre-whitening procedure to derive the potential pulsation frequencies. All the oscillation frequencies that we found are associated with g-mode pulsations with periods spanning from $\sim 817$ s to $\sim 2682$ s. We find constant period spacings for all but one star, which allowed us to infer their stellar masses and constrain the harmonic degree $\ell$ of the modes. We performed period-to-period fit analyses on five of the six analyzed stars. For four stars, we were able to find an asteroseismological model with masses in agreement with the stellar-mass values inferred from the period spacings, and generally compatible with the spectroscopic masses. We estimated the seismological distance and compared it with the precise astrometric distance measured with GAIA. Finally, we find that the period spectrum of K 1-16 exhibits dramatic changes in frequency and amplitude. The high-quality data collected by the TESS space mission, considered simultaneously with ground-based observations, are able to provide a very valuable input to the asteroseismology of GW Vir stars, similar to the case of other classes of pulsating white-dwarf stars. The TESS mission, in conjunction with future space missions and upcoming surveys, will make impressive progress in white-dwarf asteroseismology.

    ↳ astro-ph.SRhep-phAstron.Astrophys.(2021)·3 citations
25. 25*

    Topology change and emergent scale symmetry in compact star matter via gravitational wave detection

    Wen-Cong Yang🇨🇳 · Yong-Liang Ma🇨🇳 · Yue-Liang Wu🇨🇳

    Topological structure has been extensively studied and confirmed in highly correlated condensed matter physics. We explore the gravitational waves emitted from binary neutron star mergers using the pseudoconformal model for dense nuclear matter for compact stars. This model considers the topology change and the possible emergent scale symmetry and satisfies all the constraints from astrophysics. We find that the location of the topology change affects gravitational waves dramatically owing to its effect on the equation of state. In addition, the effect of this location on the waveforms of the gravitational waves is within the ability of the on-going and up-coming facilities for detecting gravitational waves, thus suggesting a possible way to measure the topology structure in nuclear physics.

    ↳ nucl-thastro-ph.HEhep-phSCPMA(2021)·8 citations
26. 26*

    Hydrodynamic effective field theory and the analyticity of hydrostatic correlators

    Akash Jain🇨🇦 · Pavel Kovtun🇨🇦 · Adam Ritz🇨🇦 · Ashish Shukla🇨🇦

    We study one-loop corrections to retarded and symmetric hydrostatic correlation functions within the Schwinger-Keldysh effective field theory framework for relativistic hydrodynamics, focusing on charge diffusion. We first consider the simplified setup with only diffusive charge density fluctuations, and then augment it with momentum fluctuations in a model where the sound modes can be ignored. We show that the loop corrections, which generically induce non-analyticities and long-range effects at finite frequency, non-trivially preserve analyticity of retarded correlation functions in spatial momentum due to the KMS constraint, as a manifestation of thermal screening. For the purposes of this analysis, we develop an interacting field theory for diffusive hydrodynamics, seen as a limit of relativistic hydrodynamics in the absence of temperature and longitudinal velocity fluctuations.

    ↳ hep-thcond-mat.stat-mechhep-phnucl-th+1JHEP(2021)·27 citations
27. 27*

    A hydrodynamic study of hyperon spin polarization in relativistic heavy ion collisions

    Baochi Fu🇨🇳 · Kai Xu🇨🇳 · Xu-Guang Huang🇨🇳 · Huichao Song🇨🇳

    We perform a systematic study of the spin polarization of hyperons in heavy-ion collisions using the MUSIC hydrodynamic model with A Multi-Phase Transport (AMPT) pre-equilibrium dynamics. Our model calculations nicely describe the measured collision-energy, centrality, rapidity, and $p_T$ dependence of $\Lambda$ polarization. We also study and predict the global spin polarization of ${\Xi }^{-}$ and ${\Omega }^{-}$ as a function of collision energy, which provides a baseline for the studies of the magnetic moment, spin, and mass dependence of the spin polarization. For the local spin polarization, we calculate the radial and azimuthal components of the transverse $\Lambda$ polarization and find specific modulating behavior which could reflect the circular vortical structure. However, our model fails to describe the azimuthal-angle dependence of the longitudinal and transverse $\Lambda$ polarization, which indicates that the hydrodynamic framework with the spin Cooper-Frye formula under the assumption of thermal equilibrium of spin degree of freedom needs to be improved.

    ↳ nucl-thhep-phnucl-exPRC(2021)·115 citations
28. 28*

    The simplest description of charge propagation in a strong background

    Martin Lavelle🇬🇧 · David McMullan🇬🇧

    Exploiting the gauge freedom associated with the Volkov description of a charge propagating in a plane wave background, we identify a new type of gauge choice which significantly simplifies the theory. This allows us to develop a compact description of the propagator for both scalar and fermionic matter, in a circularly polarised background. It is shown that many of the usually observed structures are gauge artefacts. We then analyse the full ultraviolet behaviour of the one-loop corrections for such charges. This enables us to identify and contrast the different renormalisation prescriptions needed for both types of matter.

    ↳ hep-thhep-phPRD(2021)·2 citations
29. 29*

    Vacuum decay constraints on the Higgs curvature coupling from inflation

    Andreas Mantziris🇬🇧 · Tommi Markkanen🇪🇪 · Arttu Rajantie🇬🇧

    We derive lower bounds for the Higgs-curvature coupling from vacuum stability during inflation in three inflationary models: quadratic and quartic chaotic inflation, and Starobinsky-like power-law inflation. In contrast to most previous studies we take the time-dependence of the Hubble rate into account both in the geometry of our past light-cone and in the Higgs effective potential, which is approximated with three-loop renormalisation group improvement supplemented with one-loop curvature corrections. We find that in all three models, the lower bound is $\xi \gtrsim 0.051\dots 0.066$ depending on the top quark mass. We also demonstrate that vacuum decay is most likely to happen a few $e$-foldings before the end of inflation.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2021)·26 citations
30. 30*

    Nuclear Potential of Final State Nucleons and Nucleons Plus Pions in Lepton Nucleus Scattering

    Arie Bodek🇺🇸 · Tejin Cai🇺🇸

    Within the impulse approximation, the modeling of the energy of final state leptons in electron and neutrino quasielastic and pion production processes on nuclear targets in the region of the $\Delta$ resonance depends on several parameters. These parameters include the removal energy of the initial state nucleon from the nucleus ${ϵ}^{P,N}$, the potentials of electrons, nucleons and pions in the Coulomb field of the nucleus $|V_{eff}|$, and the kinetic energy dependent nuclear potential for final state nucleons ($U_{opt}^{QE}$) and "nucleon plus pion" final states in the region of the $\Delta$ resonance which we refer to as $U_{opt}^{\Delta }$. We extract these parameters from electron scattering data. Previous studies have shown that real part of the optical potential for a nucleon bound in ${}_6^{12}C$ at zero kinetic energy $U_{opt}^{P,N}(T=0)\approx$ 44 MeV is larger than that for the $\Delta$(1232) resonance $U_{opt}^{\Delta }(T=0)\approx$ 30 MeV. We find the reverse at higher kinetic energies. For example at T=100 MeV we find a nucleon potential $U_{opt}^{P,N}(T=100MeV)$=20$\pm$5 MeV and $U_{opt}^{\Delta }(T=100MeV)$= 30$\pm$5 MeV. The two results are consistent for two reasons. First, theoretically the kinetic energy dependence of the $\Delta$ potential is flatter than that of the nucleon. Secondly, in our analysis the extracted $U_{opt}^{\Delta }$ values are the nuclear potential for {\it"nucleon plus pion"} final states in the region of the $\Delta$ resonances and therefore includes contributions from both resonance and non resonance pion production processes. For Monte Carlo generators that only include the effects of Fermi motion and nuclear potentials, the relevant parameter is the effective nuclear potential for the "nucleon plus pion" final state.

    ↳ nucl-thhep-exhep-phnucl-exPoS(2021)·0 citations
31. 31*

    Quantum black hole spectroscopy: probing the quantum nature of the black hole area using LIGO-Virgo ringdown detections

    Danny Laghi🇮🇹 · Gregorio Carullo🇮🇹 · John Veitch🇬🇧 · Walter Del Pozzo🇮🇹

    We present a thorough observational investigation of the heuristic quantised ringdown model presented in Foit & Kleban (2019). This model is based on the Bekenstein-Mukhanov conjecture, stating that the area of a black hole horizon is an integer multiple of the Planck area $l_P^2$ multiplied by a phenomenological constant, $\alpha$, which can be viewed as an additional black hole intrinsic parameter. Our approach is based on a time-domain analysis of the gravitational wave signals produced by the ringdown phase of binary black hole mergers detected by the LIGO and Virgo collaboration. Employing a full Bayesian formalism and taking into account the complete correlation structure among the black hole parameters, we show that the value of $\alpha$ cannot be constrained using only GW150914, in contrast to what was suggested in Foit & Kleban (2019). We proceed to repeat the same analysis on the new gravitational wave events detected by the LIGO and Virgo Collaboration up to 1 October 2019, obtaining a combined-event measure equal to $\alpha =15.6_{-13.3}^{+20.5}$ and a combined log odds ratio of $0.1\pm 0.6$, implying that current data are not informative enough to favour or discard this model against general relativity. We then show that using a population of $\mathcal{O}(20)$ GW150914-like simulated events - detected by the current infrastructure of ground-based detectors at their design sensitivity - it is possible to confidently falsify the quantised model or prove its validity, in which case probing $\alpha$ at the few % level. Finally we classify the stealth biases that may show up in a population study.

    ↳ gr-qcastro-ph.HEhep-phClass.Quant.Grav.(2021)·32 citations
32. 32*

    Influence of modified light-flavor hadron spectra on particle yields in the statistical hadronization model

    A. Andronic🇩🇪 · P. Braun-Munzinger🇩🇪 · D. Gündüz🇩🇪 · Y. Kirchhoff🇩🇪 · M. K. Köhler🇩🇪 · J. Stachel🇩🇪 · M. Winn🇫🇷

    Hadron production in relativistic nuclear collisions is well described in the framework of the Statistical Hadronization Model (SHM). We investigate the influence on SHM predictions of hadron mass spectra for light-flavor baryons and mesons modified by the addition of about 500 new states as predicted by lattice QCD and a relativistic quark model. The deterioration of the resulting thermodynamic fit quality obtained for PbPb collision data at sqrt(s_nn) = 2.76 TeV suggests that the additional states are not suited to be naively used since also interactions among the states as well as non-resonant contributions need to be considered in the SHM approach. Incorporating these effects via the pion nucleon interaction determined from measured phase shifts leads again to excellent reproduction of the experimental data. This is a strong indication that at least the additional nucleon excited states cannot be understood and used as independent resonances.

    ↳ nucl-thhep-lathep-phnucl-exNPA(2021)·20 citations
33. 33*

    Classification of Non-Supersymmetric Pati-Salam Heterotic String Models

    Alon E. Faraggi🇬🇧 · Viktor G. Matyas🇬🇧 · Benjamin Percival🇬🇧

    We extend the classification of fermionic ${\mathbb{Z}}_2\times {\mathbb{Z}}_2$ heterotic string orbifolds to non--supersymmetric Pati--Salam (PS) models in two classes of vacua, that we dub $\tilde{S}$--models and $S$--models. The first correspond to compactifications of a tachyonic ten--dimensional vacuum, whereas the second correspond to compactifications of the ten--dimensional tachyon--free $SO(16)\times SO(16)$ heterotic string. In both cases we develop a systematic method to extract tachyon--free four--dimensional models. We show that tachyon--free configurations arise with probability $\sim 0.002$ and $\sim 0.01$ in the first and second case, respectively. We adapt the `fertility methodology' that facilitates the extraction of phenomenological models. We show that Pati--Salam $\tilde{S}$--models do not contain heavy Higgs scalar representations that are required to break the PS symmetry to the Standard Model and are therefore not phenomenologically viable. Hence, we argue that in $\tilde{S}$--models the $SO(10)$ GUT symmetry must be broken at the string scale to the Standard--like Model subgroup. We extract tachyon--free three generation models in both cases that contain an equal number of massless bosonic and fermionic degrees of freedom, $i.e.$ with $a_{00}=N_b^0-N_f^0=0$, and analyse their one--loop partition function.

    ↳ hep-thhep-phPRD(2021)·42 citations
34. 34*

    The full Boltzmann hierarchy for dark matter-massive neutrino interactions

    Markus R. Mosbech🇦🇺 · Celine Boehm🇦🇺 · Steen Hannestad🇩🇰 · Olga Mena🇪🇸 · Julia Stadler🇩🇪 · Yvonne Y. Y. Wong🇦🇺

    The impact of dark matter-neutrino interactions on the measurement of the cosmological parameters has been investigated in the past in the context of massless neutrinos exclusively. Here we revisit the role of a neutrino-dark matter coupling in light of ongoing cosmological tensions by implementing the full Boltzmann hierarchy for three massive neutrinos. Our tightest 95% CL upper limit on the strength of the interactions, parameterized via $u_{\chi }=\frac{{\sigma }_0}{{\sigma }_{Th}}{\left(\frac{m_{\chi }}{100\text{GeV}}\right)}^{-1}$, is $u_{\chi }\le 3.34\cdot 10^{-4}$, arising from a combination of Planck TTTEEE data, Planck lensing data and SDSS BAO data. This upper bound is, as expected, slightly higher than previous results for interacting massless neutrinos, due to the correction factor associated with neutrino masses. We find that these interactions significantly relax the lower bounds on the value of ${\sigma }_8$ that is inferred in the context of $\Lambda$CDM from the Planck data, leading to agreement within 1-2$\sigma$ with weak lensing estimates of ${\sigma }_8$, as those from KiDS-1000. However, the presence of these interactions barely affects the value of the Hubble constant $H_0$.

    ↳ astro-ph.COhep-phJCAP(2021)·60 citations
35. 35*

    Spin observables of proton-deuteron elastic scattering at SPD NICA energies within the Glauber model and pN amplitudes

    Yu.N.Uzikov (1,2 3)🇷🇺 · J.Haidenbauer (4)🇩🇪 · A. Bazarova (5)🇰🇿 · A.A.Temerbayev (5,6) ((1) Joint Institute for Nuclear Researches, Dubna, Russia, (2) Dubna State University, Dubna, Russia, (3) Department of Physics, M.V. Lomonosov State University, Moscow, Russia, (4) Institute for Advanced Simulation and Institut für Kernphysik, Forschungszentrum Jülich GmbH, Jülich, Germany, (5) L.N. Gumilyov Eurasian National University, Nur-Sultan, Kazakhstan, (6) Institute of Nuclear Physics, Astana branch, Nur-Sultan, Kazakhstan)🇰🇿

    A systematic analysis of nucleon-nucleon scattering amplitudes is available up to a laboratory energy of $3$~GeV in case of the $pp$ system and up to $1.2$ GeV for $pn$. At higher energies there is only incomplete experimental information on $pp$ elastic scattering, whereas data for the $pn$ system are very scarce. We apply the spin-dependent Glauber theory to calculate spin observables of $pd$ elastic scattering at $3$-$50$ GeV/c using $pp$ amplitudes available in the literature and parametrized within the Regge formalism. The calculated vector $A_y^p$, $A_y^d$ and tensor $A_{xx}$, $A_{yy}$ analyzing powers and the spin-correlation coefficients $C_{y,y}$, $C_{x,x}$, $C_{yy,y}$, $C_{xx,y}$ can be measured at SPD NICA and, thus, will provide a test of the used $pN$ amplitudes.

    ↳ nucl-thhep-phPhys.Part.Nucl.(2022)·9 citations
36. 36*

    Generating ultra-dense pair beams using 400 GeV/c protons

    C. D. Arrowsmith · N. Shukla · N. Charitonidis · R. Boni · H. Chen · T. Davenne · D. H. Froula · B. T. Huffman · Y. Kadi · B. Reville · S. Richardson · S. Sarkar and 5 other authors

    A previously unexplored experimental scheme is presented for generating low-divergence, ultra-dense, relativistic, electron-positron beams using 400 GeV/c protons available at facilities such as HiRadMat and AWAKE at CERN. Preliminary Monte-Carlo and Particle-in-cell simulations demonstrate the possibility of generating beams containing $10^{13}-10^{14}$ electron-positron pairs at sufficiently high densities to drive collisionless beam-plasma instabilities, which are expected to play an important role in magnetic field generation and the related radiation signatures of relativistic astrophysical phenomena. The pair beams are quasi-neutral, with size exceeding several skin-depths in all dimensions, allowing for the first time the examination of the effect of competition between transverse and longitudinal instability modes on the growth of magnetic fields. Furthermore, the presented scheme allows for the possibility of controlling the relative density of hadrons to electron-positron pairs in the beam, making it possible to explore the parameter spaces for different astrophysical environments.

    ↳ physics.plasm-phastro-ph.HEhep-phPRResearch(2021)·14 citations
37. 37*

    Constraints on dark matter to dark radiation conversion in the late universe with DES-Y1 and external data

    Angela Chen🇺🇸 · Dragan Huterer🇺🇸 · Sujeong Lee🇺🇸 · Agnès Ferté🇺🇸 · Noah Weaverdyck🇺🇸 · Otavio Alonso Alves🇧🇷 · C. Danielle Leonard🇬🇧 · Niall MacCrann🇺🇸 · Marco Raveri🇺🇸 · Anna Porredon🇺🇸 · Eleonora Di Valentino🇬🇧 · Jessica Muir🇺🇸 and 72 other authors

    We study a phenomenological class of models where dark matter converts to dark radiation in the low redshift epoch. This class of models, dubbed DMDR, characterizes the evolution of comoving dark matter density with two extra parameters, and may be able to help alleviate the observed discrepancies between early- and late-time probes of the universe. We investigate how the conversion affects key cosmological observables such as the CMB temperature and matter power spectra. Combining 3x2pt data from Year 1 of the Dark Energy Survey, {\it Planck}-2018 CMB temperature and polarization data, supernovae (SN) Type Ia data from Pantheon, and baryon acoustic oscillation (BAO) data from BOSS DR12, MGS and 6dFGS, we place new constraints on the amount of dark matter that has converted to dark radiation and the rate of this conversion. The fraction of the dark matter that has converted since the beginning of the universe in units of the current amount of dark matter, $\zeta$, is constrained at 68\% confidence level to be $<0.32$ for DES-Y1 3x2pt data, $<0.030$ for CMB+SN+BAO data, and $<0.037$ for the combined dataset. The probability that the DES and CMB+SN+BAO datasets are concordant increases from 4\% for the $\Lambda$CDM model to 8\% (less tension) for DMDR. The tension in $S_8={\sigma }_8\sqrt{{\Omega }_{\mathrm{m}}/0.3}$ between DES-Y1 3x2pt and CMB+SN+BAO is slightly reduced from $2.3\sigma$ to $1.9\sigma$. We find no reduction in the Hubble tension when the combined data is compared to distance-ladder measurements in the DMDR model. The maximum-posterior goodness-of-fit statistics of DMDR and $\Lambda$CDM model are comparable, indicating no preference for the DMDR cosmology over $\Lambda$CDM.

    ↳ astro-ph.COhep-phPRD(2021)·53 citations
38. 38*

    (Phenomenology/Lattice-Compatible) $SU(3)$ M$\chi$PT HD up to $\mathcal{O}(p^4)$ and the $\mathcal{O}\left(R^4\right)$-Large-$N$ Connection

    Vikas Yadav🇮🇳 · Gopal Yadav🇮🇳 · Aalok Misra🇮🇳

    Obtaining the values of the coupling constants of the low energy effective theory corresponding to QCD, compatible with experimental data, even in the (vector) mesonic sector from (the $\mathcal{M}$-theory uplift of) a UV-complete string theory dual, has thus far been missing in the literature. We take the first step in this direction by obtaining the values of the coupling constants of the $\mathcal{O}(p^4)$ $\chi$PT Lagrangian in the chiral limit involving the NGBs and $\rho$ meson (and its flavor partners) from the $\mathcal{M}$-theory /type IIA dual of large-$N$ thermal QCD, inclusive of the $\mathcal{O}(R^4)$ corrections. We observe that ensuring compatibility with phenomenological/lattice results (the values ) as given in arXiv:1510.01634[hep-ph], requires a relationship relating the $\mathcal{O}(R^4)$ corrections and large-$N$ suppression. In other words, QCD demands that the higher derivative corrections and the large-$N$ suppressed corrections in its M/string theory dual are related. As a bonus, we explicitly show that the $\mathcal{O}(R^4)$ corrections in the UV to the $\mathcal{M}$-theory uplift of the type IIB dual of large-$N$ thermal QCD, can be consistently set to be vanishingly small.

    ↳ hep-thhep-phnucl-thJHEP(2021)·17 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.