Tue·Dec 29, 2020Tuesday·December 29, 2020

1. 01*

   Zeros of Amplitude in the Associated Production of Photon and Leptoquark at $e$-$p$ Collider

   Priyotosh Bandyopadhyay🇮🇳 · Saunak Dutta🇮🇳 · Anirban Karan🇮🇳

   Though various extensions of the Standard Model with higher gauge group predict the existence of leptoquarks, none of them has been observed yet at any of the colliders. In this paper, we study the prospect of several past and future $e$-$p$ colliders like HERA, LHeC and FCC-he to detect them through radiation amplitude zero. We find that the leptoquarks showing zeros in the tree-level single-photon amplitudes at $e$-$p$ collider lie within the complementary set of those exhibiting zeros at $e$-$\gamma$ collider. We present a PYTHIA-based analysis for HERA, LHeC and FCC-he (run II) to detect the leptoquarks with masses 70 GeV, 900 GeV and 1.5 TeV (2.0 TeV) respectively through radiation amplitude zero.

   hep-phEPJC(2021)·13 citations
2. 02*

   Prospects of gravitational waves in the minimal left-right symmetric model

   Mingqiu Li🇨🇳 · Qi-Shu Yan🇨🇳 · Yongchao Zhang🇨🇳 · Zhijie Zhao🇨🇳

   The left-right symmetric model (LRSM) is a well-motivated framework to restore parity and implement seesaw mechanisms for the tiny neutrino masses at or above the TeV-scale, and has a very rich phenomenology at both the high-energy and high-precision frontiers. In this paper we examine the phase transition and resultant gravitational waves (GWs) in the minimal version of LRSM. Taking into account all the theoretical and experimental constraints on LRSM, we identify the parameter regions with strong first-order phase transition and detectable GWs in the future experiments. It turns out in a sizeable region of the parameter space, GWs can be generated in the phase transition with the strength of $10^{-17}$ to $10^{-12}$ at the frequency of 0.1 to 10 Hz, which can be detected by BBO and DECIGO. Furthermore, GWs in the LRSM favor a relatively light $SU(2{)}_R$-breaking scalar $H_3^0$, which is largely complementary to the direct searches of a long-lived neutral scalar at the high-energy colliders. It is found that the other heavy scalars and the right-handed neutrinos in the LRSM also play an important part for GW signal production in the phase transition.

   hep-phJHEP(2021)·29 citations
3. 03*

   Sphaleron Transition Rates and the Chiral Magnetic Effect

   Joseph I. Kapusta🇺🇸 · Ermal Rrapaj🇺🇸 · Serge Rudaz🇺🇸

   The chiral magnetic effect is a novel quantum phenomenon proposed for high-energy nuclear collisions but which has yet to be observed. We quantify the axial charge relaxation time, due to sphalerons, which enters in simulations of this effect. An extrapolation of weak coupling calculations of the sphaleron rate yields rather different relaxation times than strong coupling AdS/CFT calculations. The AdS/CFT relaxation time is the larger one of the two by an order of magnitude, but the weak coupling relaxation time may not be reliable because it is only marginally bigger than the microscopic thermalization time. The role of quark masses has yet to be accurately assessed.

   hep-phnucl-thIJMPE(2022)·2 citations
4. 04*

   Light quarks at finite temperature: chiral restoration and the fate of the $U(1{)}_A$ symmetry

   Angel Gómez Nicola🇪🇸

   We review recent results on the role of light quark states within the QCD phase diagram. In particular, we will discuss how the combined use of theoretical techniques such as Effective Theories, Unitarization and Ward Identities helps to shed light on several important issues regarding chiral symmetry restoration, building bridges with recent lattice analyses. Special attention will be paid to the role of chiral and $U(1{)}_A$ partners in the interplay between those symmetries, which is crucial to properly understand the transition pattern. Light scalar mesons at finite temperature will be shown to be responsible for the description of susceptibilities encoding chiral and $U(1{)}_A$ restoration properties.

   hep-phEur.Phys.J.ST(2021)·9 citations
5. 05*

   Fun with colours: the standard model with two colour QCD has radically different long distance physics

   Saumen Datta🇮🇳 · Sourendu Gupta🇮🇳 · Rishi Sharma🇮🇳

   In our world the standard model of particle physics contains within it the fairly intractable theory called QCD. A toy version with two colours is often studied as a model confining and chiral symmetry breaking field theory. Here we investigate the cascade of changes at various distance scales if we make this change within the standard model. It is possible to limit the changes at the hadronic scale. However, the minor changes that occur actually cascade down to the far infrared, into nuclear and atomic physics, and chemistry. Through this it also possibly affects the evolution of stars and galaxies. We remark on this unexpected sensitivity of the universe to physics at the scale of quarks.

   hep-phastro-ph.HEhep-lathep-th+1Indian J.Phys.(2021)·2 citations
6. 06*

   CP-violating Higgs Di-tau Decays: Baryogenesis and Higgs Factories

   Shao-Feng Ge🇨🇳 · Gang Li🇺🇸 · Pedro Pasquini🇨🇳 · Michael J. Ramsey-Musolf🇨🇳

   We demonstrate how probes of CP-violating observables in Higgs di-tau decays at prospective future lepton colliders could provide a test of weak scale baryogenesis with significant discovery potential. Measurements at the Circular Electron Positron Collider, for example, could exclude a CP phase larger than $2.9^{\circ }$ ($5.6^{\circ }$) at 68% (95%) C.L. assuming the Standard Model value for magnitude of the tau lepton Yukawa coupling. Conversely, this sensitivity would allow for a $5\sigma$ discovery for 82% of the CP phase range $[0,2\pi )$. The reaches of the Future Circular Collider - ee and International Linear Collider are comparable. As a consequence, future lepton colliders could establish the presence of CP violation required by lepton flavored electroweak baryogenesis with at least $3\sigma$ sensitivity. Our results illustrate that Higgs factories are not just precision machines but can also make $\mathcal{O}(1)$ measurement of the new physics beyond the Standard Model.

   hep-phhep-exPRD(2021)·20 citations
7. 07*

   Updated constraints on $Z^{\prime }$ and $W^{\prime }$ bosons decaying into bosonic and leptonic final states using the Run 2 ATLAS data

   P. Osland🇳🇴 · A. A. Pankov🇧🇾 · I. A. Serenkova🇧🇾

   The full ATLAS Run 2 data set with time-integrated luminosity of 139 fb${}^{-1}$ in the diboson and dilepton channels is used to probe benchmark models with extended gauge sectors: the $E_6$-motivated Grand Unification models, the left-right symmetric $LR$ and the sequential standard model (EGM). These all predict neutral $Z^{\prime }$ vector bosons, decaying into lepton pairs, $\ell \ell$, or into electroweak gauge boson pairs $WW$, where one $W$ in turn decays semileptonically. 95% C.L. exclusion limits on the $Z^{\prime }$ resonance production cross section times branching ratio to electroweak gauge boson pairs and to lepton pairs in the mass range of $\sim$ 1 - 6 TeV are converted to constraints on the $Z$-$Z^{\prime }$ mixing parameter and the heavy resonance mass. We present exclusion regions on the parameter space of the $Z^{\prime }$ which are significantly extended compared to those obtained from the previous analyses performed with LHC data collected at 7 and 8 TeV in Run 1 as well as at 13 TeV in Run 2 at time-integrated luminosity of 36.1 fb${}^{-1}$ and are the most stringent bounds to date. Also presented, from a similar analysis of electrically charged $W^{\prime }$ bosons arising in the EGM, which can decay through $W^{\prime }\to WZ$ and $W^{\prime }\to \ell \nu$, are limits on the $W$-$W^{\prime }$ mixing parameter and the charged $W^{\prime }$ vector boson mass.

   hep-phhep-exPRD(2021)·20 citations
8. 08*

   Discovery probabilities of Majorana neutrinos based on cosmological data

   M. Agostini🇬🇧 · G. Benato🇮🇹 · S. Dell'Oro🇮🇹 · S. Pirro🇮🇹 · F. Vissani🇮🇹

   We discuss the impact of the cosmological measurements on the predictions of the Majorana mass of the neutrinos, the parameter probed by neutrinoless double-beta decay experiments. Using a minimal set of assumptions, we quantify the probabilities of discovering neutrinoless double-beta decay and introduce a new graphical representation that could be of interest for the community.

   hep-phPRD(2021)·10 citations
9. 09*

   Broadband Dark Matter Axion Detection using a Cylindrical Capacitor

   Wenming Chen🇨🇳 · Yu Gao🇨🇳 · Qiaoli Yang🇨🇳

   Cosmological axions/axion-like particles can compose a significant part of dark matter; however, the uncertainty of their mass is large. Here, we propose to search the axions using a cylindrical capacitor, in which the static electric field converts dark matter axions into an oscillating magnetic field. Due to the odd CPs, the axions couple to the electric field differently compared to the magnetic field. The axion couples to the electric field via a derivative that carries spatial information of incoming dark matter flux, while the coupling to the magnetic field depends on the dark matter density. This difference could be helpful in searching the axions and studies of the integrity of the theory, especially when the axions are very light, in which case the magnetic field-induced signal is DC-like. Orientation dependence could also be used to reduce the kinetic fluctuation-induced noise when multiple detectors operate simultaneously. In addition, a cylindrical setup shields the electric field to the laboratory and encompasses the axion-induced magnetic field within the capacitor. The induced oscillating magnetic field can then be picked up by a sensitive magnetometer. Adding a superconductor ring-coil system into the scheme can further boost the sensitivity and maintain the axion dark matter inherent bandwidth. This proposed setup could be capable of wide mass range searches.

   hep-phastro-ph.IMhep-exNPB(2024)·7 citations
10. 10*

    Vacuum Stability Conditions for Higgs Potentials with $SU(2{)}_L$ Triplets

    Gilbert Moultaka🇫🇷 · Michel C. Peyranère🇫🇷

    Tree-level dynamical stability of scalar field potentials in renormalizable theories can in principle be expressed in terms of positivity conditions on quartic polynomial structures. However, these conditions cannot always be cast in a fully analytical resolved form, involving only the couplings and being valid for all field directions. In this paper we consider such forms in three physically motivated models involving $SU(2)$ triplet scalar fields: the Type-II seesaw model, the Georgi-Machacek model, and a generalized two-triplet model. A detailed analysis of the latter model allows to establish the full set of necessary and sufficient boundedness from below conditions. These can serve as a guide, together with unitarity and vacuum structure constraints, for consistent phenomenological (tree-level) studies. They also provide a seed for improved loop-level conditions, and encompass in particular the leading ones for the more specific Georgi-Machacek case. Incidentally, we present complete proofs of various properties and also derive general positivity conditions on quartic polynomials that are equivalent but much simpler than the ones used in the literature.

    hep-phmath-phmath.MPPRD(2021)·28 citations
11. 11*

    Inelastic charged current interaction of supernova neutrinos in two-phase liquid xenon dark matter detectors

    Pijushpani Bhattacharjee🇮🇳 · Abhijit Bandyopadhyay🇮🇳 · Sovan Chakraborty🇮🇳 · Sayan Ghosh🇮🇳 · Kamales Kar🇮🇳 · Satyajit Saha🇮🇳

    It has been known that neutrinos from supernova (SN) bursts can give rise to nuclear recoil (NR) signals arising from coherent elastic neutrino-nucleus scattering (CE$\nu$NS) interaction, a neutral current (NC) process, of the neutrinos with xenon nuclei in future large (multi-ton scale) liquid xenon (LXe) detectors employed for dark matter search, depending on the SN progenitor mass and distance to the SN. In this paper, we show that the same detectors will also be sensitive to inelastic charged current (CC) interactions of the SN electron neutrinos (${\nu }_e$CC) with the xenon nuclei. Such interactions, while creating an electron in the final state, also leave the post-interaction target nucleus in an excited state, the subsequent deexcitation of which produces, among other particles, gamma rays and neutrons. The electron and deexcitation gamma rays will give ``electron recoil" (ER) type signals, while the deexcitation neutrons produce, through their multiple scattering on the xenon nuclei, further xenon nuclear recoils that will also give NR signals (in addition to those produced through the CE$\nu$NS interactions). We discuss the observable scintillation and ionization signals associated with SN neutrino induced CE$\nu$NS and ${\nu }_e$CC events in a generic LXe detector and argue that upcoming sufficiently large LXe detectors should be able to detect both these types of events due to neutrinos from reasonably close by SN bursts. We also note that since the total CC induced ER and NR signals receive contributions predominantly from ${\nu }_e$CC interactions while the CE$\nu$NS contribution comes from NC interactions of {\emph all the six species of neutrinos}, identification of the ${\nu }_e$CC and CE$\nu$NS origin events may offer the possibility of extracting useful information about the distribution of the total SN explosion energy going into different neutrino flavors.

    hep-phastro-ph.HEPRD(2022)·7 citations
12. 12*

    A Note on Gauge Anomaly Cancellation in Effective Field Theories

    Ferruccio Feruglio🇮🇹

    The conditions for the absence of gauge anomalies in effective field theories (EFT) are rivisited. General results from the cohomology of the BRST operator do not prevent potential anomalies arising from the non-renormalizable sector, when the gauge group is not semi-simple, like in the Standard Model EFT (SMEFT). By considering a simple explicit model that mimics the SMEFT properties, we compute the anomaly in the regularized theory, including a complete set of dimension six operators. We show that the dependence of the anomaly on the non-renormalizable part can be removed by adding a local counterterm to the theory. As a result the condition for gauge anomaly cancellation is completely controlled by the charge assignment of the fermion sector, as in the renormalizable theory.

    hep-phhep-thJHEP(2021)·24 citations
13. 13*

    The effects of charmonium on the properties of the $1^{++}$ hidden charm poles in effective field theory

    E. Cincioglu🇹🇷 · A. Ozpineci🇹🇷 · D. Yildirim Yilmaz🇹🇷

    In this study, the properties of the $J^{PC}=1^{++}$ hidden charm poles are analyzed under the variation of the bare 2P charmonium mass within the effective field theory proposed in Ref.[1]. The main focus of the current work is on the pole trajectory of the ${\chi }_{c1}(2P)$ charmonium dressed by the $D{\bar{D}}^{\ast }$ meson loops. It is shown that the trajectories of the pole change radically for values of the bare charmonium mass above a certain value and also depending on how close the pole is to the threshold.

    hep-phNPA(2021)·2 citations
14. 14*

    Residual Mean Field Model of Valence Quarks in the Nucleon

    Christopher Leon🇺🇸 · Misak Sargsian🇺🇸

    We develop a non-perturbative model for valence parton distribution functions (PDFs) based on the mean field interactions of valence quarks in the nucleonic interior. The main motivation for the model is to obtain a mean field description of the valence quarks as a baseline to study the short range quark-quark interactions that generate the high $x$ tail of PDFs. The model is based on the separation of the valence three-quark cluster and residual system in the nucleon. Then the nucleon structure function is calculated within the effective light-front diagrammatic approach introducing nonperturbative light-front valence quark and residual wave functions. Within the model a new relation is obtained between the position, $x_p$, of the peak of $x{q}_V(x)$ distribution of the valence quark and the effective mass of the residual system, $m_R$, in the form: $x_p\approx \frac{1}{4}(1-\frac{m_R}{m_N})$ at starting $Q^2$. This relation explains the difference in the peak positions for d- and u- quarks through the expected difference of residual masses for valence d- and u- quark distributions. The parameters of the model are fixed by fitting the calculated valence quark distributions to the phenomenological PDFs. This allowed us to estimate the overall mean field contribution in baryonic and momentum sum rules for valence d- and u- quarks. Finally, the evaluated parameters of the non-perturbative wave functions of valence 3q-cluster and residual system can be used in calculation of other quantities such as nucleon form factors, generalized partonic and transverse momentum distributions.

    hep-phhep-exnucl-thEPJC(2022)·5 citations
15. 15*

    Extraction of neutrino Yukawa parameters from displaced vertices of sneutrinos

    Amit Chakraborty🇮🇳 · Stefano Moretti🇬🇧 · Claire H. Shepherd-Themistocleous🇬🇧 · Harri Waltari🇬🇧

    We study displaced signatures of sneutrino pairs potentially emerging at the Large Hadron Collider (LHC) in a Next-to-Minimal Supersymmetric Standard Model supplemented with right-handed neutrinos triggering a Type-I seesaw mechanism. We show how such signatures can be established through a heavy Higgs portal in the presence of both leptonic and hadronic decays of the sneutrinos. We finally illustrate how the Yukawa parameters of the latter can be extracted from fitting kinematical quantities pertaining to the corresponding two displaced vertices, thereby characterising the dynamics of the underlying mechanism of neutrino mass generation. We show our numerical results for the case of both the current and High-Luminosity LHC.

    hep-phJHEP(2021)·5 citations
16. 16*

    Testing clockwork axion with gravitational waves

    Cheng-Wei Chiang🇹🇼 · Bo-Qiang Lu🇹🇼

    We investigate the gravitational waves (GWs) produced from the Peccei-Quinn (PQ) phase transition associated with the clockwork axion. The PQ phase transition can be first-order when the dimension-6 operator is included into the scalar potential. The GWs from the PQ phase transition at scale in the range of $10^3-10^6$ GeV are detectable for the BBO and ALIA interferometers. The LISA and Taiji interferometers can probe the GWs from the PQ scale $f\lesssim 10^4$ GeV, while the GW signals from the scale $f\gtrsim 10^5$ GeV can be detected by the ground-based GW observatories ET and CE. We find that the parameter space ${\kappa }_m\sim 0.06-0.001$, ${\kappa }_l\sim 0.04-0.001$, and $\epsilon \sim 0.1-0.01$ at the scale $f=10^5$ GeV and most of the parameter regions at the scale $f=10^6$ GeV have been excluded by the LIGO O2 run. The LIGO O3 and design phases can further probe the remaining parameter space. We show that the GWs from the annihilation of domain walls with a PQ scale $f\simeq 2\times 10^5$ GeV can induce the stochastic signals indicated by the 12.5-year observation of NANOGrav. The LIGO O3 run has the opportunity of detecting the GW signals from the first-order PQ phase transition around this scale.

    hep-phgr-qcJCAP(2021)·39 citations
17. 17*

    High energy evolution for Gribov-Zwanziger confinement: solution to the equation

    E. Gotsman (Tel Aviv U.)🇮🇱 · Yu. Ivanov (JINR/UTFSM)🇷🇺 · E. Levin (Tel Aviv U./UTFSM)🇮🇱

    In this paper we solved the new evolution equation for high energy scattering amplitudethat stems from the Gribov-Zwanziger approach to the confinement of quarks and gluons. We found that (1) the energy dependence of the scattering amplitude turns out to be the same as for QCD BFKL evolution; (2) the spectrum of the new equation does not depend on the details of the Gribov-Zwanzinger approach and (3) all eigenfunctions coincide with the eigenfunctions of the QCD BFKL equation at large transverse momenta $\kappa \ge 1$. The numerical calculations show that there exist no new eigenvalues with the eigenfunctions which decrease faster than solutions of the QCD BFKL equation at large transverse momenta. The structure of the gluon propagator in Gribov-Zwanziger approach, that stems from the lattice QCD and from the theoretical evaluation, results in the exponential suppression of the eigenfunctions at long distances and in the resolution of the difficulties, which the Colour Glass Condensate (CGC) and some other approaches, based on perturbative QCD, face at large impact parameters. We can conclude that the confinement of quark and gluons, at least in the form of Gribov-Zwanziger approach, does not influence on the scattering amplitude except solving the long standing theoretical problem of its behaviour at large impact parameters.

    hep-phhep-thPRD(2021)·9 citations
18. 18*

    Memory effect in Yang-Mills theory with an axion

    Niko Jokela🇫🇮 · K. Kajantie🇫🇮 · Miika Sarkkinen🇫🇮

    We study the empirical realization of the memory effect in Yang-Mills theory with an axion-like particle, especially in view of the classical vs. quantum nature of the theory. We solve for the coupled equations of motion iteratively in the axionic contributions and explicitly display the gauge invariant effects in terms of field strengths. We apply our results in the context of heavy ion collisions, in the thin nuclear sheet limit, and point out that a probe particle traversing radiation train acquires a longitudinal null memory kick in addition to the usual transverse kick.

    hep-phgr-qchep-thPRD(2021)·4 citations
19. 19*

    Prospects for quarkonium studies at the high-luminosity LHC

    Emilien Chapon🇨🇳 · David d'Enterria🇨🇭 · Bertrand Ducloue🇬🇧 · Miguel G. Echevarria🇪🇸 · Pol-Bernard Gossiaux🇫🇷 · Vato Kartvelishvili🇬🇧 · Tomas Kasemets🇩🇪 · Jean-Philippe Lansberg🇫🇷 · Ronan McNulty🇮🇪 · Darren D. Price🇬🇧 · Hua-Sheng Shao🇫🇷 · Charlotte Van Hulse🇮🇪 and 39 other authors

    Prospects for quarkonium-production studies accessible during the upcoming high-luminosity phases of the CERN Large Hadron Collider operation after 2021 are reviewed. Current experimental and theoretical open issues in the field are assessed together with the potential for future studies in quarkonium-related physics. This will be possible through the exploitation of the huge data samples to be collected in proton-proton, proton-nucleus and nucleus-nucleus collisions, both in the collider and fixed-target modes. Such investigations include, among others, those of: (i) J/psi and Upsilon produced in association with other hard particles; (ii) chi(c,b) and eta(c,b) down to small transverse momenta; (iii) the constraints brought in by quarkonia on gluon PDFs, nuclear PDFs, TMDs, GPDs and GTMDs, as well as on the low-x parton dynamics; (iv) the gluon Sivers effect in polarised-nucleon collisions; (v) the properties of the quark-gluon plasma produced in ultra-relativistic heavy-ion collisions and of collective partonic effects in general; and (vi) double and triple parton scatterings.

    hep-phhep-exnucl-exnucl-thPPNP(2022)·169 citations
20. 20*

    Energy-energy correlation in hadronic Higgs decays: analytic results and phenomenology at NLO

    Jun Gao🇨🇳 · Vladyslav Shtabovenko🇩🇪 · Tong-Zhi Yang🇨🇳

    In this work we complete the investigation of the recently introduced energy-energy correlation (EEC) function in hadronic Higgs decays at next-to-leading order (NLO) in fixed-order perturbation theory in the limit of vanishing light quark masses. The full analytic NLO result for the previously unknown EEC in the $H\to q\bar{q}+X$ channel is given in terms of classical polylogarithms and cross-checked against a numerical calculation. In addition to that, we discuss further corrections to predictions of the Higgs EEC event shape variable, including quark mass corrections, effects of parton shower and hadronization. We also estimate the statistical error on the measurements of the Higgs EEC at future Higgs factories and compare with the current perturbative uncertainty.

    hep-phhep-exJHEP(2021)·46 citations
21. 21*

    Next-to-next-to-leading order event generation for top-quark pair production

    Javier Mazzitelli🇩🇪 · Pier Francesco Monni🇨🇭 · Paolo Nason🇮🇹 · Emanuele Re🇫🇷 · Marius Wiesemann🇩🇪 · Giulia Zanderighi🇩🇪

    The production of top-quark pairs in hadronic collisions is among the most important reactions in modern particle physics phenomenology and constitutes an instrumental avenue to study the properties of the heaviest quark observed in nature. The analysis of this process at the Large Hadron Collider relies heavily on Monte Carlo simulations of the final state events, whose accuracy is challenged by the outstanding precision of experimental measurements. In this letter we present the first matched computation of top-quark pair production at next-to-next-to-leading order in QCD with all-order radiative corrections as implemented via parton-shower simulations. Besides its intrinsic relevance for LHC phenomenology, this work also establishes an important step towards the simulation of other hadronic processes with colour charges in the final state.

    hep-phhep-exPRL(2021)·113 citations
22. 22*

    Avenues to new-physics searches in cosmic ray air showers

    Oliver Fischer🇬🇧 · Maximilian Reininghaus🇩🇪 · Ralf Ulrich🇩🇪

    Cosmic Rays (CR) impinging on the terrestrial atmosphere provide a viable opportunity to study new physics in hadron-nucleus collisions at energies covering many orders of magnitude, including a regime well beyond LHC energies. The permanent flux of primary CR can be used to estimate event rates for a given type of new physics scenario. As a step to estimate the potential for new-physics searches in CR-induced Extensive Air Showers (EAS), we here determine the total luminosity, including the contribution stemming from the cascade of secondaries in hadron-air interactions using Monte Carlo simulations of the hadronic shower component with CORSIKA~8. We show results obtained for single showers and discuss the interplay with the CR spectrum. Furthermore, we discuss the possibility to study BSM phenomenology in EAS, focusing on so-called large-multiplicity Higgs production as an explicit example and its impact on EAS observables.

    hep-phastro-ph.HEPoS(2021)·2 citations
23. 23*

    Proton Lifetime in Minimal SUSY SU(5) in Light of LHC Results

    K. S. Babu🇺🇸 · Ilia Gogoladze🇺🇸 · Cem Salih Un🇹🇷

    We examine proton decay mediated by color-triplet Higgsinos in minimal supersymmetric $SU(5)$ grand unified theory in light of the discovery of the Higgs boson and the absence of SUSY signals at the LHC. We pay special attention to various threshold effects arising from Planck-suppressed operators that affect the color-triplet Higgsino mass and also correct the wrong mass relations for the light fermions. Our analysis allows for a non-universal SUSY spectrum with the third family scalars having a separate mass compared to the first two families. We identify the allowed parameter space of the model and show that the SUSY scalar masses are constrained by current limits from proton lifetime to be above 5 TeV, while the glunio, Wino and the Higgsinos may be within reach of the LHC. When the SUSY scalar masses are required to be $\le 20$ TeV, so that they are within reach of next generation collider experiments, we find that proton lifetime for the decay $p\to \overline{\nu }{K}^{+}$ is bounded by $\tau (p\to \overline{\nu }{K}^{+})\le 1.1\times 10^{35}$ yrs.

    hep-phJHEP(2022)·16 citations
24. 24*

    Disentangling mass spectra of multiple fields in cosmological collider

    Shuntaro Aoki🇯🇵 · Masahide Yamaguchi🇯🇵

    We study effects of multiple scalar fields (scalar isocurvatons) with the Hubble scale masses on the inflationary bispectrum in the squeezed limit, particular paying attention to the question how to disentangle mass spectra of such fields. We consider two isocurvatons with almost degenerate masses and the coupling of an inflaton to both isocurvatons as an example. We find that the characteristic feature associated with nearly degenerate masses appears in the oscillating part of the bispectrum, which is dominated by a waveform with a specific wavelength roughly given by an inverse of the mass difference. Such a waveform with a relatively longer wavelength can be easily identified and useful for disentangling almost degenerate mass spectra. This situation is in sharp contrast with the case of collider experiments on earth, where the very precise energy resolution corresponding to the mass difference is required to disentangle almost degenerate mass spectra. Therefore, if future observations could detect this kind of a characteristic feature in bispectrum of the primordial curvature perturbations, it can prove the existence of degenerate multiple particles around the Hubble scale and resolve their mass degeneracies.

    ↳ hep-thastro-ph.COhep-phJHEP(2021)·55 citations
25. 25*

    Does CMB Distortion Disfavour Intermediate Mass Dark Matter?

    Claudio Corianò🇮🇹 · Paul H. Frampton🇮🇹

    We investigate the published constraints on MACHOs in the mass region $10^2-10^5{M}_{\odot }$ and their possible contribution to dark matter. We focus on constraints which rely on the accretion of matter which emits X-rays that can lead, after downgrading to microwaves, to distortion of the CMB spectrum and isotropy. The most questionable step in this chain of arguments is the use of overly simplified accretion models. We compare how the same accretion models apply to X-ray observations from supermassive black holes SMBHs, M87 and Sgr A*. The comparison of these two SMBHs with intermediate mass MACHOs suggests that the latter could, after all, provide the constituents of all the dark matter. We discuss the status of other constraints on IM-MACHOs.

    ↳ astro-ph.GAgr-qchep-ph10 citations
26. 26*

    Exploring scalar-photon interactions in energetic astrophysical events

    Ankur Chaubey🇮🇳 · Manoj K. Jaiswal🇮🇳 · Avijit K. Ganguly🇮🇳

    Scalar fields like dilaton appear in quantum field theory (QFT) due to scale symmetry breaking. Their appeal also extends to modified theories of gravity, like $F(R)$ gravity, Horva Lifshitz gravity etc. In unified theories they make their appearance through compactification of the extra dimension. Apart from resolving the issues of compactification scale and size, the particles of their fields can also turn out to be excellent candidate to solve the dark energy (DE) and dark matter (DM) problem of the universe. In this work we study their mixing dynamics with photons in a magnetized media, by incorporating the effect of parity violating part of the photon polarization tensor, evaluated in a finite density magnetized media. This piece, though in general is odd in the external magnetic field strength $eB$; in this work we however have retained terms to $O$($eB$). We are able to demonstrate in this work that, in magnetized medium a dilatonic scalar field $(\varphi )$ can excite the two transverse degrees of freedom (DOF) of the photons. One due to direct coupling and the other indirectly through the parity violating term originating due to magnetized medium effects. This results in the mixing dynamics being governed by, $3\times 3$ mixing matrices. This mixing results in making the underlying media optically active. In this work we focus on the spectro-polarimetric imprints of these particles, on the spectra of the electromagnetic (EM) fields of Gamma Ray Bursters (GRB). Focusing on a range of parameters (i.e., magnetic field strength, plasma frequency $({\omega }_p)$, size of the magnetized volume, coupling strength to photons and their mass) we make an attempt to point out how space-borne detectors should be designed to optimise their detection possibility.

    ↳ astro-ph.HEcond-mat.otherhep-exhep-ph+1PRD(2020)·5 citations
27. 27*

    A $w-M$ phantom transition at $z_t<0.1$ as a resolution of the Hubble tension

    George Alestas🇬🇷 · Lavrentios Kazantzidis🇬🇷 · Leandros Perivolaropoulos🇬🇷

    A rapid phantom transition of the dark energy equation of state parameter $w$ at a transition redshift $z_t<0.1$ of the form $w(z)=-1+\Delta w\Theta (z_t-z)$ with $\Delta w<0$ can lead to a higher value of the Hubble constant while closely mimicking a Planck18/$\Lambda$CDM form of the comoving distance $r(z)={\int }_0^z\frac{d{z}^{\prime }}{H(z^{\prime })}$ for $z>z_t$. Such a transition however would imply a significantly lower value of the SnIa absolute magnitude $M$ than the value $M_C$ imposed by local Cepheid calibrators at $z<0.01$. Thus, in order to resolve the $H_0$ tension it would need to be accompanied by a similar transition in the value of the SnIa absolute magnitude $M$ as $M(z)=M_C+\Delta M\Theta (z-z_t)$ with $\Delta M<0$. This is a Late $w-M$ phantom transition ($LwMPT$). It may be achieved by a sudden reduction of the value of the normalized effective Newton constant $\mu =G_{\mathrm{eff}}/G_{\mathrm{N}}$ by about $6\%$ assuming that the absolute luminosity of SnIa is proportional to the Chandrasekhar mass which varies as ${\mu }^{-3/2}$. We demonstrate that such an ultra low $z$ abrupt feature of $w-M$ provides a better fit to cosmological data compared to smooth late time deformations of $H(z)$ that also address the Hubble tension. For $z_t=0.02$ we find $\Delta w\simeq -4$, $\Delta M\simeq -0.1$. This model also addresses the growth tension due to the predicted lower value of $\mu$ at $z>z_t$. A prior of $\Delta w=0$ (no $w$ transition) can still resolve the $H_0$ tension with a larger amplitude $M$ transition with $\Delta M\simeq -0.2$ at $z_t\simeq 0.01$. This implies a larger reduction of $\mu$ for $z>0.01$ (about $12\%$). The $LwMPT$ can be generically induced by a scalar field non-minimally coupled to gravity with no need of a screening mechanism since in this model $\mu =1$ at $z<0.01$.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2021)·113 citations
28. 28*

    Radial profile of bottom quarks in jets in high-energy nuclear collisions

    Sa Wang🇨🇳 · Wei Dai🇨🇳 · Ben-Wei Zhang🇨🇳 · Enke Wang🇨🇳

    Angular correlations between heavy quark (HQ) and its tagged jet are potentially new tools to gain insight into the in-medium partonic interactions in relativistic heavy-ion collisions. In this work, we present the first theoretical study on the radial profiles of B mesons in jets in Pb+Pb collisions at the LHC. The initial production of bottom quark tagged jet in p+p is computed by SHERPA which matches the next-to-leading order matrix elements with contributions of parton shower, whereas the massive quark traversing the QGP described by a Monte Carlo model SHELL which can simultaneously simulate light and heavy flavor in-medium energy loss within the framework of Langevin evolution. In p+p collisions, we find that at lower $p_T^Q$ the radial profiles of heavy flavors in jets are sensitive to the heavy quark mass. In $0-10\%$ Pb+Pb collisions at $\sqrt{{\mathrm{s}}_{\mathrm{NN}}}=5.02$ TeV, we observe an inverse modification pattern of the B mesons radial profiles in jets at $4<{\mathrm{p}}_{\mathrm{T}}^{\mathrm{Q}}<20$ GeV compared to that of D mesons: the jet quenching effects narrow the jet radial profile of B mesons in jets while broaden that of D mesons in jets. We find that in A+A collisions, the contribution dissipated from the higher ${\mathrm{p}}_{\mathrm{T}}^{\mathrm{Q}}>20$ GeV region naturally has a narrower initial distribution and consequently leads to a narrower modification pattern of radial profile; however the diffusion nature of the heavy flavor in-medium interactions will give rise to a broader modification pattern of radial profile. These two effects consequently compete and offset with each other, and the b quarks in jets benefit more from the former and suffers less diffusion effect compared to that of c quarks in jets. These findings can be tested in the future experimental measurements at the LHC to gain better understanding of the mass effect of jet quenching.

    ↳ nucl-thhep-phCPC(2021)·22 citations
29. 29*

    On the three-particle analog of the Lellouch-Lüscher formula

    Fabian Müller🇩🇪 · Akaki Rusetsky🇩🇪

    Using non-relativistic effective field theory, we derive a three-particle analog of the Lellouch-Lüscher formula at the leading order. This formula relates the three-particle decay amplitudes in a finite volume with their infinite-volume counterparts and, hence, can be used to study the three-particle decays on the lattice. The generalization of the approach to higher orders is briefly discussed.

    ↳ hep-lathep-phJHEP(2021)·51 citations
30. 30*

    Vector Bosons and Jets in Proton Collisions

    Alessandro Tricoli🇺🇸 · Marek Schönherr🇬🇧 · Paolo Azzurri🇮🇹

    Events with vector bosons produced in association with jets have been extensively studied at hadron colliders and provide high-accuracy tests of the Standard Model. A good understanding of these processes is of paramount importance for precision Higgs physics, as well as for searches for new physics. In particular, associated production of $\gamma$, $W$ or $Z$ bosons with light-flavor and heavy-flavor jets is a powerful tool for testing perturbative QCD calculations, Monte Carlo event generators, and can also constrain the parametrizations used to describe the parton content of the proton. Furthermore, events with a $W$ or $Z$ boson produced with two well-separated jets can be used to distinguish between electroweak and strong production mechanisms, and to set limits on contributions of physics beyond the Standard Model. This review summarises the historical theoretical developments and the state-of-the-art in the modeling of vector-boson-plus-jet physics, while focusing on experimental results by LHC collaborations in Run-1 and Run-2, and including comparisons with recent measurements at the Tevatron.

    ↳ hep-exhep-phRMP(2021)·17 citations
31. 31*

    Brilliant attosecond {\gamma}-ray emission and high-yield positron production from intense laser-irradiated Nano-Micro array

    Liang-qi Zhang🇨🇳 · Shao-dong Wu🇨🇳 · Hai-rong Huang🇨🇳 · Hao-yang Lan🇨🇳 · Wei-yuan Liu🇨🇳 · Yu-chi Wu🇨🇳 · Yue Yang🇨🇳 · Zong-qing Zhao🇨🇳 · Zhi-chao Zhu🇨🇳 · Wen Luo🇨🇳

    We investigate a novel scheme for brilliant attosecond {\gamma}-ray emission and high-yield positron production, which is accomplished with an ultra-intense laser pulse incident upon a Nano-Micro array (NMA) with substrate incorporated. This scheme is able to realize effectively electron acceleration and colliding geometry. Both the {\gamma}-ray flash and positron bunch are then generated with high conversion efficiency. At laser intensity of I_0 = 8 times 10^{23} W/cm^2, ~27% of the laser energy is transferred successfully into the {\gamma}-rays, and ~0.7% of the laser energy into the positrons. As a consequence, ultra-short (~440 as) and ultra-brilliant (~10^{24} photons s^{-1} mm^{-2} mrad^{-2} per 0.1%BW @ 15 MeV) {\gamma}-ray burst, and high-yield (1.48 times 10^{11}) and overdense (~10^{22} cm^{-3}) positron bunch are generated. We found a sub-linear scaling of laser-to-photon conversion efficiency (proportional to I_0^{0.75}) and a super-linear scaling of laser-to-positron conversion efficiency (proportional to I_0^{2.5}) with the laser intensity. Multi-dimensional particle-in-cell simulations show that particle ({\gamma} photon and positron) generation can be manipulated by laser-focusing position, and NMA's length and spacing. Optimal conditions for particle generation in NMAs are obtained, indicating that microwire array has the advantage over nanowire array in particle generation in the extreme laser fields. Furthermore, positron annihilation effect in high-energy-density (HED) environment is discussed. The scheme using NMAs would provide effective avenues toward investigating attosecond nuclear science and HED physics with the coming 10 PW laser facilities.

    ↳ physics.plasm-phhep-phPhys.Plasmas(2021)·14 citations
32. 32*

    Baryon isocurvature constraints on the primordial hypermagnetic fields

    Kohei Kamada🇯🇵 · Fumio Uchida🇯🇵 · Jun'ichi Yokoyama🇯🇵

    It has been pointed out that hypermagnetic helicity decay at the electroweak symmetry breaking may have produced the observed baryon asymmetry of the Universe through the chiral anomaly in the standard model of particle physics. Although fully helical magnetic field that can adequately produce the observed baryon asymmetry is not strong enough to explain the origin of the intergalactic magnetic field inferred by the Fermi satellite, the mixture of helical and nonhelical primordial magnetic fields may explain both baryogenesis and the intergalactic magnetic fields simultaneously. We first show that such a scenario is ruled out by the constraint on the amplitude of baryon isocurvature perturbations produced by the primordial magnetic fields to avoid overproduction of deuterium at the big bang nucleosynthesis. Then we show that any attempt to explain the origin of intergalactic magnetic field by primordial magnetogenesis before the electroweak symmetry breaking does not work due to the above constraint irrespective of the helicity and baryogenesis mechanism.

    ↳ astro-ph.COhep-phhep-thJCAP(2021)·39 citations
33. 33*

    Simultaneous Block Diagonalization of Matrices of Finite Order

    Ingolf Bischer🇩🇪 · Christian Döring🇩🇪 · Andreas Trautner🇩🇪

    It is well known that a set of non-defect matrices can be simultaneously diagonalized if and only if the matrices commute. In the case of non-commuting matrices, the best that can be achieved is simultaneous block diagonalization. Here we give an efficient algorithm to explicitly compute a transfer matrix which realizes the simultaneous block diagonalization of unitary matrices whose decomposition in irreducible blocks (common invariant subspaces) is known from elsewhere. Our main motivation lies in particle physics, where the resulting transfer matrix must be known explicitly in order to unequivocally determine the action of outer automorphisms such as parity, charge conjugation, or time reversal on the particle spectrum.

    ↳ math-phhep-phhep-thmath.MP+1J.Phys.A(2021)·3 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.