Fri·Oct 8, 2021Friday·October 8, 2021

1. 01*

   A Reduced basis for CP violation in SMEFT at colliders and its application to Diboson production

   Céline Degrande🇧🇪 · Julien Touchèque🇧🇪

   We show that only 10 (17) CP-odd operators of the SMEFT give the leading, i.e. least suppressed by the new physics scale, CP-violating contributions once we assume that all fermions are massless but the top (and bottom) quark(s). We start with a short review of previous analyses focusing on operators of our reduced basis and list different observables probing their CP violating effects by direct measurements at colliders and by indirect measurements in low-energy observables. Since CP-odd operators typically lead to phase space suppressed interferences, we quantify the efficiency to revive the interference for various observables found in the literature but also for new observables in diboson production. Our new observables are found to be more efficient on the whole experimental fiducial phase space and are complementary to those presented so far as they probe different combinations of operators and get their sensitivities from different regions of the phase space.

   hep-phJHEP(2022)·34 citations
2. 02*

   Explaining the $R_{K^{(\ast )}}$ anomalies in a Fundamental Composite Higgs Model with Gauged $U(1{)}_{S{M}_3-HB}$

   Yi Chung🇺🇸

   A new heavy $Z^{\prime }$ vector boson provides a possible explanation for the neutral current B anomalies. Various $U(1{)}^{\prime }$ gauge groups have been proposed and studied. In this paper, we explore a new type of $U(1{)}^{\prime }$ gauge symmetry inspired by fundamental composite Higgs models with hyperfermions. It is also the first attempt to connect such a $Z^{\prime }$ boson with a solution to the hierarchy problem. The $U(1{)}^{\prime }$ symmetry is identified as the quantum number of the difference between the Standard Model fermion number and hyperbaryon number, written as $SM-HB$. This type of $U(1{)}^{\prime }$ gauge symmetry is naturally broken in some fundamental composite Higgs models, which leads to a TeV-scale $Z^{\prime }$ boson. We present a concrete example based on the minimal fundamental composite Higgs model with $SU(4)/Sp(4)$ coset, where the $Z^{\prime }$ boson is the only state below the compositeness scale beside the composite Higgs. We also show that if the $U(1{)}^{\prime }$ symmetry is third-generation-philic, written as $S{M}_3-HB$, the corresponding $Z^{\prime }$ boson can explain the neutral current B anomalies. The model introduces the composite Higgs and the $Z^{\prime }$ boson from the same symmetry breaking scale, so Higgs physics and flavor physics are now connected. After considering all the experimental constraints and theoretical preferences, we found that there is still a natural parameter space for $SU(4)/Sp(4)$ fundamental composite Higgs model with $N_{HC}=2$, which can be probed in the near future.

   hep-ph6 citations
3. 03*

   SU($N$)-natural inflation

   Tomohiro Fujita🇯🇵 · Kyohei Mukaida🇯🇵 · Kai Murai🇯🇵 · Hiromasa Nakatsuka🇯🇵

   We study SU($N$) gauge fields that couple to the inflaton through the Chern-Simons term. We provide a general procedure to construct homogeneous, isotropic, and attractor solutions of the gauge fields during inflation. The gauge fields develop various VEVs corresponding to different spontaneous symmetry breaking patterns of SU($N$) where embedded SU($2$) subgroups are broken with the spatial rotation SO($3$) symmetry. As specific examples, we construct the stable solutions for $N=3$ and $4$. We also numerically solve the gauge field dynamics and confirm that our analytic solutions are complete and attractor. It is straightforward to apply our procedure to the other simple Lie groups.

   hep-phastro-ph.COhep-thPRD(2022)·17 citations
4. 04*

   Dark gauge boson production from neutron stars via nucleon-nucleon bremsstrahlung

   Chang Sub Shin🇰🇷 · Seokhoon Yun🇮🇹

   We discuss the dark gauge boson emission from neutron stars via nucleon-nucleon bremsstrahlung. Through the rigorous treatment of the effective field theory prescription and the thermal effect, we derive the relevant couplings of dark gauge bosons to hadrons in medium. As a specific example, the $U(1{)}_{\mathrm{B}-\mathrm{L}}$ gauge boson scenario is chosen to investigate dark gauge boson emissivities during supernovae and cooling of young neutron stars. From the stellar cooling argument, we obtain the constraints on the $\mathrm{B}-\mathrm{L}$ gauge coupling for given gauge boson masses in two observations: the duration of the supernova neutrino signal of SN1987A, and the inferred x-ray luminosity of the compact object in the remnant of SN1987A (NS1987A). In particular, the constraint from SN1987A on the $U(1{)}_{\mathrm{B}-\mathrm{L}}$ gauge boson scenario is revisited. The excluded gauge coupling due to the emission of transverse polarizations is an order of magnitude enhanced compared to the previous derivation. There is also a newly excluded parameter space due to the emission of longitudinal polarizations.

   hep-phastro-ph.HEJHEP(2022)·29 citations
5. 05*

   Probing light dark matter particles with astrophysical experiments

   Tanmay Kumar Poddar🇮🇳

   The evidence of gravitational wave was first indirectly confirmed by the orbital period loss of Hulse-Taylor binary system which agrees well with the Einstein's general relativistic prediction. The perihelion precession of planets, gravitational light bending and Shapiro time delay are other tests of Einstein's general theory of relativity. However there are small uncertainties in the measurements of those observations from the general relativistic prediction. To account those uncertainties, we propose radiation of ultralight axions and vector gauge boson particles in the context of $U(1{)}^{\prime }$ extended beyond standard model scenario. We obtain constraints on ultralight axion parameters (axion mass and decay constant) from the observational uncertainties of orbital period loss of compact binary systems, gravitational light bending, Shapiro time delay and birefringence phenomena. We also obtain the bounds on ultralight $U(1{)}_{L_{\mu }-L_{\tau }}$ gauge bosons from the orbital period loss of compact binary systems. The uncertainties in the perihelion precession of planets also put bounds on the $U(1{)}_{L_e-L_{\mu ,\tau }}$ light gauge bosons. These light particles can be promising candidates of fuzzy dark matter which can be probed from the above precision measurements.

   hep-phastro-ph.COgr-qcPoS(2022)·2 citations
6. 06*

   Particle production as a function of the underlying event in pp collisions simulated with PYTHIA 8

   Gyula Bencédi🇲🇽 · Antonio Ortiz🇲🇽 · Antonio Paz🇲🇽

   In this work we present the production of charged particles associated with high-$p_{\mathrm{T}}$ trigger particles ($8<p_{\mathrm{T}}^{trig.}<15$ GeV /$c$) at mid-pseudorapidity in proton-proton collisions at $\sqrt{s}=5.02$\,TeV simulated with the \textsc{PYTHIA 8} Monte Carlo model. The study is performed as a function of the relative transverse activity classifier, $R_{\mathrm{T}}$, which is the relative charged-particle multiplicity in the transverse region ($\pi /3<|\Delta \varphi |<2\pi /3$) of the di-hadron correlations, and it is sensitive to the Multi-Parton Interactions. The evolution of the yield of associated particles on both the toward and the away regions with $3\le p_{\mathrm{T}}^{assoc.}<8$ GeV/$c$ as a function of $R_{\mathrm{T}}$ is investigated. We propose a strategy which allows for the modelling and subtraction of the Underlying Event (UE) contribution from the toward and the away regions in challenging environments like those characterised by large $R_{\mathrm{T}}$. We found that the signal in the away region becomes broader with increasing $R_{\mathrm{T}}$. Contrarily, the yield increases with $R_{\mathrm{T}}$ in the toward region. This effect is reminiscent of that seen in heavy-ion collisions, where an enhancement of the yield in the toward region for $0-5\%$ central Pb--Pb collisions at ${\sqrt{s}}_{\mathrm{NN}}=2.76$\,TeV was reported. To further understand the role of the UE and additional jet activity, the transverse region is divided into two one-sided sectors, "trans-max" and "trans-min" selected in each event according to which region has larger or smaller charged particle multiplicity. Based on this selection criterion, the observables are studied as a function of $R_{\mathrm{T}}^{\max }$ and $R_{\mathrm{T}}^{\min }$, respectively. The presented results have been published in J. Phys. G 48, no.1, 015007 (2020) and Phys. Rev. D 104, no.1, 016017 (2021).

   hep-phPoS(2021)·1 citation
7. 07*

   Two Higgs Doublet Model with Scalar Mediation via Yukawa Interactions

   Tajdar Mufti🇵🇰 · Touqeer Zahid🇵🇰

   Scalar sector offers a valuable avenue to explore its implications in the particle physics phenomenology for new physics and several model dependent phenomena. Two Higgs doublet models are among the promising models for such explorations. In the presence of a standard model Higgs, a two Higgs doublet model is studied in which the two Higgs fields are connected with each other via a scalar singlet field. The study is conducted using Dyson Schwinger equations under the Yukawa vertices set at their tree level form up to certain constants. Among the field propagators, the two Higgs propagators are found to be least effected in the parameter space which also reflects in the insignificant beyond the bare mass contributions to the renormalized Higgs masses. Evidence of universality in terms of identical coupling for both Higgs is found in the model. The model is found to be non-trivial in the explored parameter space. There are cutoff effects in the model. Stability in the calculated correlation functions and parameters generally ensues beyond 100 TeV cutoff.

   hep-ph0 citations
8. 08*

   Photoproduction of relativistic QED bound states in hadronic collisions

   R. Francener🇧🇷 · V. P. Goncalves🇧🇷 · B. D. Moreira🇧🇷

   In this paper we investigate the photoproduction of QED bound states in proton -- proton, proton -- nucleus and nucleus -- nucleus collisions at RHIC, LHC and FCC energies considering an accurate treatment of the absorptive corrections and for the nuclear form factor. The total cross sections for the production of singlet and triplet $(l^{+}{l}^{-})$ states, with $l=e,\mu ,\tau$, are estimated and a detailed analysis of the photoproduction of singlet QED bound states is performed considering the rapidity ranges covered by central and forward detectors. The impact of the Coulomb corrections on the parapositronium production in heavy ion collisions is estimated. We predict a large number of events associated to the production of ($e^{+}{e}^{-}$) and (${\mu }^{+}{\mu }^{-}$) states in hadronic collisions.

   hep-phhep-exnucl-exnucl-thEPJA(2022)·16 citations
9. 09*

   Probing Light Mediators in the Radiative Emission of Neutrino Pair

   Shao-Feng Ge🇨🇳 · Pedro Pasquini🇨🇳

   We propose a new possibility of using the coherently enhanced neutrino pair emission to probe light-mediator interactions between electron and neutrinos. With typical momentum transfer at the atomic $\mathcal{O}(1$\,eV) scale, this process is extremely sensitive for the mediator mass range $\mathcal{O}(10^{-3}\sim 10^4$) eV. The sensitivity on the product of couplings with electron ($g^e$ or $y^e$) and neutrinos ($g^{\nu }$ or $y^{\nu }$) can touch down to $|y^e{y}^{\nu }|<10^{-9}\sim 10^{-19}$ for a scalar mediator and $|g^e{g}^{\nu }|<10^{-15}\sim 10^{-26}$ for a vector one, with orders of improvement from the existing constraints.

   hep-phEPJC(2022)·14 citations
10. 10*

    Impact of charged and neutral Drell-Yan Asymmetries on precision measurements

    Francesco Giuli🇮🇹

    We study the impact of future measurements of lepton-charge and forward-backward asymmetries on PDF determination. These results have been obtained employing standard profiling procedures and the open-source platform xFitter. The potential of the combination of charged-current and neutral-current Drell-Yan asymmetries in regions of transverse and invariant masses near the W/Z bosons peaks to improve the PDF uncertainties has also been explored.

    hep-phhep-ex0 citations
11. 11*

    Jet Drift and Collective Flow in Heavy-Ion Collisions

    Logan Antiporda🇺🇸 · Joseph Bahder🇺🇸 · Hasan Rahman🇺🇸 · Matthew D. Sievert🇺🇸

    We study the tomographic applications of a new phenomenon we dub "jet drift" -- the deflection of high-energy particles and jets toward the direction of a flowing medium -- to the quark-gluon plasma produced in heavy-ion collisions. While the physics of jet drift is quite general, for specificity we consider the case of photon-jet production at mid-rapidity. Beginning with the simplest possible model, a large slab of uniformly flowing plasma, we systematically introduce the geometrical elements of a heavy-ion collision in a simple optical Glauber model. We find that the moving medium causes the jet to drift in the direction of the flow, bending its trajectory and leaving detailed signatures of the flow pattern in the distribution of $\gamma +\mathrm{jet}$ acoplanarities. In the elliptical geometries produced in non-central collisions, this drift effect leads to a strong geometry coupling which persists despite the addition of event-by-event fluctuations in the jet production point, impact parameter, and acoplanarity. We propose a new observable to measure the jet drift effect through the correlation of $\gamma +\mathrm{jet}$ acoplanarities with the elliptic flow of soft particles. Preliminary estimates suggest this correlation may be studied at sPHENIX and the LHC.

    hep-phnucl-thPRD(2022)·38 citations
12. 12*

    Shining ALP Dark Radiation

    Joerg Jaeckel🇩🇪 · Wen Yin🇯🇵

    String scenarios typically not only predict axion-like particles (ALPs) but also significant amounts of ALP dark radiation originating from the decay of the inflaton or a more general modulus. In this paper, we study the decay of such non-thermally produced relativistic (but massive) ALPs to photons. If the ALPs are sufficiently highly energetic, contribute to $\Delta N_{\mathrm{eff}}\gtrsim \mathcal{O}(0.001)$ and have a mass $m_a\gtrsim$ MeV we find that, using observations of X-, and $\gamma$-rays, the CMB and BBN, very small values of the ALP-photon coupling can be probed, corresponding to an origin of this coupling at the string (or even Planck) scale.

    hep-phastro-ph.COhep-exPRD(2022)·18 citations
13. 13*

    Higgs decays to two leptons and a photon beyond leading order in the SMEFT

    T. Corbett🇩🇰 · T. Rasmussen🇩🇰

    We present the three-body decay of the Higgs boson into two leptons and a photon to dimension-eight in the Standard Model Effective Field Theory (SMEFT). In order to obtain this result we interfere the full one-loop Standard Model result with the tree-level result in the SMEFT. This is the first calculation of the partial width of the Higgs boson into two leptons and a photon in the SMEFT to incorporate the full one-loop dependence for the Standard Model as well as the full tree level dimension-eight dependence in the SMEFT. We find that this channel can aid in distinguishing strongly interacting and weakly interacting UV completions of the SMEFT under standard assumptions. We also find that this channel presents the opportunity to distinguish different operator Classes within the SMEFT, potentially including contact $H\bar{\ell }\ell \gamma$ operators which are first generated only at dimension-eight in the SMEFT.

    hep-phSciPost Phys.(2022)·18 citations
14. 14*

    Real corrections to Higgs boson pair production at NNLO in the large top quark mass limit

    Joshua Davies🇬🇧 · Florian Herren🇺🇸 · Go Mishima🇯🇵 · Matthias Steinhauser🇩🇪

    In this paper we consider the next-to-next-to-leading order total cross section of Higgs boson pair production in the large top quark mass limit and compute four expansion terms in $1/m_t^2$. Good convergence is observed below the top quark threshold, which makes our results a valuable input for approximation methods which aim for next-to-next-to-leading order corrections over the whole kinematic range. We present details on various steps of our calculation; in particular, we provide results for three- and four-particle phase-space master integrals and describe in detail the evaluation of the collinear counterterms.

    hep-phJHEP(2022)·29 citations
15. 15*

    A semi-numerical method for one-scale problems applied to the $\overline{\mathrm{MS}}$-on-shell relation

    Matteo Fael🇩🇪 · Fabian Lange🇩🇪 · Kay Schönwald🇩🇪 · Matthias Steinhauser🇩🇪

    We discuss a practical approach to compute master integrals entering physical quantities which depend on one parameter. As an example we consider four-loop QCD corrections to the relation between a heavy quark mass defined in the $\overline{\mathrm{MS}}$ and on-shell scheme in the presence of a second heavy quark.

    hep-phSciPost Phys.Proc.(2022)·7 citations
16. 16*

    Reflecting on chirality: CP-violating extensions of the single scalar-leptoquark solutions for the $(g-2{)}_{e,\mu }$ puzzles and their implications for lepton EDMs

    Innes Bigaran🇦🇺 · Raymond R. Volkas🇦🇺

    We study the two scalar leptoquarks capable of generating chirally-enhanced, sign-dependent contributions to lepton magnetic dipole moments (MDMs) and electric dipole moments (EDMs), $R_2\sim (3,2,7/6)$ and $S_1\sim (3,1,-1/3)$. We consider the case in which the electron and muon sectors are decoupled, and leptoquark couplings are assigned complex values. Adopting the coupling ansatz that the electron dipole operator is generated by charm-containing loops, and muon dipole operator by top-containing loops, we find that both minimal leptoquark models remain viable solutions for reconciling anomalies in the muon and electron MDMs, accounting for either of the two current (disparate) electron MDM results from Cs and Rb interferometry experiments. We also examine the correlated corrections to the muon and electron masses generated by these models, and argue that to minimise fine-tuning this introduces an upper bound on viable leptoquark ($\varphi$) masses, $m_{\varphi }<\mathcal{O}(4)$ TeV. Similar arguments allow us to make a prediction for the upper bound of the muon EDM generated by these models, $|d_{\mu }|<\mathcal{O}(10^{-22})e$ cm, which could be within reach of upcoming experimental programs, including Muon g$-$2 at Fermilab (FNAL), and muEDM at Paul Scherrer Institute (PSI).

    hep-phPRD(2022)·32 citations
17. 17*

    Constraining cosmological phase transitions with the Parkes Pulsar Timing Array

    Xiao Xue🇩🇪 · Ligong Bian🇨🇳 · Jing Shu🇨🇳 · Qiang Yuan🇨🇳 · Xingjiang Zhu🇨🇳 · N. D. Ramesh Bhat🇦🇺 · Shi Dai🇦🇺 · Yi Feng🇦🇺 · Boris Goncharov🇦🇺 · George Hobbs🇦🇺 · Eric Howard🇦🇺 · Richard N. Manchester🇦🇺 and 6 other authors

    A cosmological first-order phase transition is expected to produce a stochastic gravitational wave background. If the phase transition temperature is on the MeV scale, the power spectrum of the induced stochastic gravitational waves peaks around nanohertz frequencies, and can thus be probed with high-precision pulsar timing observations. We search for such a stochastic gravitational wave background with the latest data set of the Parkes Pulsar Timing Array. We find no evidence for a Hellings-Downs spatial correlation as expected for a stochastic gravitational wave background. Therefore, we present constraints on first-order phase transition model parameters. Our analysis shows that pulsar timing is particularly sensitive to the low-temperature ($T\sim 1-100$ MeV) phase transition with a duration $(\beta /H_{\ast }{)}^{-1}\sim 10^{-2}-10^{-1}$ and therefore can be used to constrain the dark and QCD phase transitions.

    ↳ astro-ph.COhep-phPRL(2021)·105 citations
18. 18*

    Future Constraints on Primordial Black Holes from XGIS-THESEUS

    Diptimoy Ghosh🇮🇳 · Divya Sachdeva🇮🇳 · Praniti Singh🇮🇳

    Current observations allow Primordial Black Holes (PBHs) in asteroid mass range $10^{17}-10^{22}$ g to constitute the entire dark matter (DM) energy density (barring a small mass range constrained by 21 cm observations). In this work, we explore the possibility of probing PBH with masses $10^{17}-10^{19}\mathrm{g}$ via upcoming X and Gamma Imaging Spectrometer (XGIS) telescope array on-board the Transient High-Energy Sky and Early Universe Surveyor (THESEUS) mission. While our projected limits are comparable with those proposed in the literature for $10^{16}\mathrm{g}<M_{\mathrm{PBH}}<10^{17}\mathrm{g}$, we show that the XGIS-THESEUS mission can potentially provide the strongest bound for $10^{17}\mathrm{g}<M_{\mathrm{PBH}}\lesssim 3\times 10^{18}\mathrm{g}$ for non-rotating PBHs. The bounds become more stringent by nearly an order of magnitude for maximally rotating PBHs in the mass range $5\times 10^{15}\mathrm{g}<M_{\mathrm{PBH}}\lesssim 10^{19}\mathrm{g}$.

    ↳ astro-ph.COhep-phPRD(2022)·23 citations
19. 19*

    Update on (2+1+1)-flavor QCD equation of state

    Johannes Heinrich Weber🇩🇪 · Alexei Bazavov🇺🇸 · Peter Petreczky🇺🇸

    We report on preliminary results from the calculations of the QCD equation of state for 2+1+1 flavors using HISQ action. The calculations are performed on lattices with temporal extents $N_{\tau }=6,8,10$, and $12$ and aspect ratio $N_{\sigma }/N_{\tau }=4$. We find that there is a significant contribution to the pressure from charm quarks at temperatures $T>300$ MeV.

    ↳ hep-lathep-phnucl-thPoS(2022)·5 citations
20. 20*

    3D template-based $Fermi$-LAT constraints on the diffuse supernova axion-like particle background

    Francesca Calore🇫🇷 · Pierluca Carenza🇸🇪 · Christopher Eckner🇫🇷 · Tobias Fischer🇵🇱 · Maurizio Giannotti🇺🇸 · Joerg Jaeckel🇩🇪 · Kei Kotake🇯🇵 · Takami Kuroda🇩🇪 · Alessandro Mirizzi🇮🇹 · Francesco Sivo🇮🇹

    Axion-like particles (ALPs) may be abundantly produced in core-collapse (CC) supernovae (SNe), hence the cumulative signal from all past SN events can create a diffuse flux peaked at energies of about 25~MeV. We improve upon the modeling of the ALPs flux by including a set of CC SN models with different progenitor masses, as well as the effects of failed CC SNe -- which yield the formation of black holes instead of explosions. Relying on the coupling strength of ALPs to photons and the related Primakoff process, the diffuse SN ALP flux is converted into gamma rays while traversing the magnetic field of the Milky Way. The spatial morphology of this signal is expected to follow the shape of the Galactic magnetic field lines. We make use of this via a template-based analysis that utilizes 12 years of $Fermi$-LAT data in the energy range from 50 MeV to 500 GeV. In our benchmark case of the realization of astrophysical and cosmological parameters, we find an upper limit of $g_{a\gamma }\lesssim 3.76\times 10^{-11}{\mathrm{GeV}}^{-1}$ at 95$\%$ confidence level for $m_a\ll 10^{-11}$ eV, while we find that systematic deviations from this benchmark scenario induce an uncertainty as large as about a factor of two. Our result slightly improves the CAST bound, while still being a factor of six (baseline scenario) weaker than the SN1987A gamma-ray burst limit.

    ↳ astro-ph.HEhep-phPRD(2022)·67 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.