HEP Phenomenology·hep-ph

Fri·Jul 17, 2020Friday·July 17, 2020

38 papers—26 primary·12 cross-listed·reconstructed*

01*
Hidden Sector Monopole Dark Matter with Matter Domination
Michael L. Graesser🇺🇸 · Jacek K. Osiński🇺🇸
The thermal freeze-out mechanism for relic dark matter heavier than $O (10 - 100$ TeV $)$ requires cross-sections that violate perturbative unitarity. Yet the existence of dark matter heavier than these scales is certainly plausible from a particle physics perspective, pointing to the need for a non-thermal cosmological history for such theories. Topological dark matter is a well-motivated scenario of this kind. Here the hidden-sector dark matter can be produced in abundance through the Kibble-Zurek mechanism describing the non-equilibrium dynamics of defects produced in a second order phase transition. We revisit the original topological dark matter scenario, focusing on hidden-sector magnetic monopoles, and consider more general cosmological histories. We find that a monopole mass of order ( $1 - 1 0^{5}$ ) PeV is generic for the thermal histories considered here, if monopoles are to entirely reproduce the current abundance of dark matter. In particular, in a scenario involving an early era of matter domination, the monopole number density is always less than or equal to that in a pure radiation dominated equivalent provided a certain condition on critical exponents is satisfied. This results in a larger monopole mass needed to account for a fixed relic abundance in such cosmologies.
hep-phastro-ph.COhep-thJHEP(2020)·12 citations
02*
Right-handed Neutrino Dark Matter, Neutrino Masses, and non-Standard Cosmology in a 2HDM
G. Arcadi🇮🇹 · S. Profumo🇺🇸 · F. S. Queiroz🇧🇷 · C. Siqueira🇧🇷
We explore the dark matter phenomenology of a weak-scale right-handed neutrino in the context of a Two Higgs Doublet Model. The expected signal at direct detection experiments is different from the usual spin-independent and spin-dependent classification since the scattering with quarks depends on the dark matter spin. The dark matter relic density is set by thermal freeze-out and in the presence of non-standard cosmology, where an Abelian gauge symmetry is key for the dark matter production mechanism. We show that such symmetry allows us to simultaneously address neutrino masses and the flavor problem present in general Two Higgs Doublet Model constructions. Lastly, we outline the region of parameter space that obeys collider, perturbative unitarity and direct detection constraints.
hep-phastro-ph.COJCAP(2020)·22 citations
03*
The Monte Carlo Program KKMC for the Lepton or Quark Pair Production at LEP/SLC Energies -- updates of electroweak calculations
A. Arbuzov🇷🇺 · S. Jadach🇵🇱 · Z. Wąs🇵🇱 · B.F.L. Ward🇺🇸 · S.A. Yost🇺🇸
Since the {\tt KKMC} program was published for the first time over 20 years ago, it has gained popularity and was exploited in a broad spectrum of applications. The core part of the program itself did not change much. In contrast, some of the libraries have evolved substantially. The aim of this publication is to archive four versions, alternative to the one published 20 years ago versions of the electroweak libraries (or just parameter initialization versions), which were instrumental for the precision Standard Model calculation from the end of LEP era till now and for the sake of the future applications/comparisons for the future electron-positron colliders, in particular for the FCC-ee related studies. These electroweak libraries are useful for the hadron collider applications as well, for instance for {\tt KKMC-hh} or {\tt TauSpinner} projects.
hep-phComput.Phys.Commun.(2021)·34 citations
04*
Renormalization in gravitational leptogenesis with pseudo-scalar-tensor coupling
Kohei Kamada🇯🇵 · Jun'ya Kume🇯🇵 · Yusuke Yamada🇯🇵
We consider the renormalization in the pseudo-scalar inflation models with the gravitational Chern-Simons term. In this model, lepton asymmetry is generated from the chiral gravitational waves produced due to the Chern-Simons term through the gravitational chiral anomaly. However, it is known that the naive estimate of the expectation value of the gravitational Chern-Pontryagin density as well as the resultant lepton number density depend on the UV-cutoff scale, which raises a question on their validity. In this paper, we propose a way to renormalize the expectation value of the Chern-Pontryagin density to remove the UV-cutoff dependence. We also discuss the renormalized lepton number density when we adopt the minimal subtraction scheme and the viability of the gravitational leptogenesis scenario.
hep-phastro-ph.COgr-qchep-thJCAP(2020)·21 citations
05*
$U S p (32)$ Special Grand Unification
Naoki Yamatsu🇯🇵
We discuss a grand unified theory (GUT) based on a $U S p (32)$ GUT gauge group broken to its subgroups including a special subgroup. A GUT based on an $S O (32)$ GUT gauge group has been discussed on six-dimensional (6D) orbifold space $M^{4} \times T^{2} / Z_{2}$ . It is inspired by the $S O (32)$ string theory behind the $S U (16)$ GUT whose $S U (16)$ is broken to a special subgroup $S O (10)$ . Alternative direction is to embed an $S U (16)$ gauge group into a $U S p (32)$ GUT gauge group, which is inspired by a non-supersymmetric symplectic-type $U S p (32)$ string theory. In a $U S p (32)$ GUT, one generation of the SM fermions is embedded into a 6D bulk Weyl fermion in a $U S p (32)$ defining representation. For a three generation model, all the 6D and 4D gauge anomalies in the bulk and on the fixed points are canceled out without exotic chiral fermions at low energies. The SM Higgs scalar is embedded into a 6D bulk scalar field in a $U S p (32)$ adjoint representation.
hep-phhep-th3 citations
06*
Hybrid stars from a three-flavor NJL model with two kinds of tensor condensates
M. Morimoto🇯🇵 · Y. Tsue🇯🇵 · J. da Providencia🇵🇹 · C. Providencia🇵🇹 · M. Yamamura🇯🇵
To obtain the equation of state of quark matter and construct hybrid stars, we calculate the thermodynamic potential in the three-flavor Nambu-Jona-Lasinio model including the tensor-type four-point interaction and the Kobayashi-Maskawa-'t Hooft interaction. To construct the hybrid stars, it is necessary to impose the beta-equilibrium and charge neutrality conditions on the system. It is shown that tensor condensed phases appear at large chemical potential. Under the possibility of the existence of the tensor condensates, the relationship between the radius and mass of hybrid stars is estimated.
hep-phnucl-thIJMPE(2020)·2 citations
07*
An explicit construction of the dimension-9 operator basis in the standard model effective field theory
Yi Liao🇨🇳 · Xiao-Dong Ma🇹🇼
We investigate systematically dimension-9 operators in the standard model effective field theory which contains only standard model fields and respects its gauge symmetry. With the help of the Hilbert series approach to classifying operators according to their lepton and baryon numbers and their field contents, we construct the basis of operators explicitly. We remove redundant operators by employing various kinematic and algebraic relations including integration by parts, equations of motion, Schouten identities, Dirac matrix and Fierz identities, and Bianchi identities. We confirm counting of independent operators by analyzing their flavor symmetry relations. All operators violate lepton or baryon number or both, and are thus non-Hermitian. Including Hermitian conjugated operators there are $384 ∣_{Δ B = 0}^{Δ L = \pm 2} + 10 ∣_{Δ B = \pm 2}^{Δ L = 0} + 4 ∣_{Δ B = \pm 1}^{Δ L = \pm 3} + 236 ∣_{Δ B = \pm 1}^{Δ L = \mp 1}$ operators without referring to fermion generations, and $44874 ∣_{Δ B = 0}^{Δ L = \pm 2} + 2862 ∣_{Δ B = \pm 2}^{Δ L = 0} + 486 ∣_{Δ B = \pm 1}^{Δ L = \pm 3} + 42234 ∣_{Δ B = \mp 1}^{Δ L = \pm 1}$ operators when three generations of fermions are referred to, where $Δ L, Δ B$ denote the net lepton and baryon numbers of the operators. Our result provides a starting point for consistent phenomenological studies associated with dimension-9 operators.
hep-phJHEP(2020)·118 citations
08*
Signatures of complex new physics in $b \to c τ ν ˉ$ transitions
Suman Kumbhakar🇮🇳
The anomalies in the measurements of $R_{D}$ and $R_{D^{*}}$ continue to provide motivation for physics beyond the Standard Model. In this work, we assume the new physics Wilson coefficients to be complex and find their values by doing a global fit to the present $b \to c τ ν ˉ$ data. We find that the number of allowed solutions depend on the choice of the upper limit on $B r (B_{c} \to τ ν ˉ)$ . We find that the forward-backward asymmetries in $B \to (D, D^{*}) τ ν ˉ$ decays have the capability to distinguish between different solutions. Further we calculate the maximum values of CP violating triple product asymmetries in $B \to D^{*} τ ν ˉ$ decay allowed the current data. We observe that only one of the three CP asymmetries can be enhanced up to a maximum value of $\sim 2 - 3%$ whereas the other asymmetries remain smaller.
hep-phhep-exNPB(2021)·16 citations
09*
Echoes of 2HDM inflation at the collider experiments
Tanmoy Modak🇹🇼 · Kin-ya Oda🇯🇵
We study the correlation between the constraints on general two Higgs doublet model from Higgs inflation and from collider experiments. The parameter space receives meaningful constraints from direct searches at the Large Hadron Collider and from flavor physics if $m_{H}$ , $m_{A}$ , and $m_{H^{\pm}}$ are in the sub-TeV range, where $H$ , $A$ , and $H^{\pm}$ are the CP even, CP odd, and charged Higgs bosons, respectively. We find that in the parameter region favored by the Higgs inflation, $H$ , $A$ , and $H^{\pm}$ are nearly degenerate in mass.We show that such near degeneracy can be probed directly in the upcoming runs of the Large Hadron Collider, while the future lepton colliders such as the International Linear Collider and the Future Circular Collider would provide complementary probes.
hep-phastro-ph.COhep-exEPJC(2020)·10 citations
10*
Analytic study of dark photon and gravitational wave production from axion
Borna Salehian🇮🇷 · Mohammad Ali Gorji🇯🇵 · Shinji Mukohyama🇯🇵 · Hassan Firouzjahi🇮🇷
Axion-like fields heavier than about $1 0^{- 27}$ eV are expected to oscillate in the radiation dominated epoch when the Hubble parameter drops below their mass. Considering the Chern-Simons coupling with a dark gauge boson, large amount of dark photons are produced during a short time interval through tachyonic resonance instability. The produced dark photons then source gravitational tensor modes leading to chiral gravitational waves. Through this process, one can indirectly probe a large parameter space of coupled axion-dark photon models. In this work we first find an analytic expression for the number density of the dark photons produced during the tachyonic resonance regime. Second, by using the saddle point approximation we find an analytic expression for the gravitational wave spectrum in terms of the mass, coupling and misalignment angle. Our analytic results can be used for the observational analysis of these types of scenarios.
hep-phastro-ph.COgr-qchep-thJHEP(2021)·37 citations
11*
Dark matter physics in dark $S U (2)$ gauge symmetry with non-Abelian kinetic mixing
P. Ko🇰🇷 · Takaaki Nomura🇰🇷 · Hiroshi Okada🇰🇷
We investigate a model of dark sector based on non-Abelian $S U (2)_{D}$ gauge symmetry. This dark gauge symmetry is broken into discrete $Z_{2}$ via vacuum expectation values of two real triplet scalars, and an $S U (2)_{D}$ doublet Dirac fermion becomes $Z_{2} -$ odd particles whose lighter component makes stable dark matter candidate. The standard model and dark sector can be connected via the scalar mixing and the gauge kinetic mixing generated by higher dimensional operators. We then discuss relic density of dark matter and implications to collider physics in the model. The most unique signatures of this model at the LHC would be the dark scalar ( $Φ_{1}^{(^{'})}$ ) productions where it subsequently decays into : (1) a fermionic dark matter ( $χ_{l}$ ) and a heavy dark fermion ( $χ_{h}$ ) pair, $Φ_{1}^{(^{'})} \to χ ˉ_{l} χ_{h} (χ ˉ_{h} χ_{l})$ , followed by $χ_{h}$ decays into $χ_{l}$ and non-Abelian dark gauge bosons ( $X_{i}$ 's) which decays into SM fermion pair $f ˉ_{S M} f_{S M}$ resulting in the reaction $pp \to Φ_{1}^{(^{'})} \to χ ˉ_{h} χ_{l} (χ ˉ_{l} χ_{h}) \to f_{S M} f ˉ_{S M} χ_{l} χ ˉ_{l}$ , (2) a pair of $X_{i}$ 's followed by $X_{i}$ decays into a DM pair or the SM fermions resulting in the reaction, $pp \to Φ_{1}^{(^{'})} \to X_{i} X_{i} \to χ ˉ_{l} χ_{l} f_{S M} f ˉ_{S M}$ or even number of $f_{S M} f ˉ_{S M}$ pairs.
hep-phPRD(2021)·17 citations
12*
Two diffraction cones of elastic scattering and structural symmetry conjecture
A.P. Samokhin🇷🇺
The energy dependence of the differential cross-section of elastic proton-proton scattering in the ISR--LHC energy range is discussed for fixed values of momentum transfer in the region of the forward diffraction cone, in the region beyond the second maximum of $d σ / d t$ and in the vicinity of the dip-bump structure. As can be seen from the currently available experimental data, the differential cross-section in the region beyond the second maximum has exactly the same properties as in the forward diffraction cone, including the existence of a stationary point, that is, we observe a second diffraction cone, which has the same origin as the forward peak. The simplest natural explanation for this experimental fact is that the amplitude of high energy elastic scattering is the sum of two similar terms that have the same status and differ only in the values of parameters. The energy dependence of $d σ / d t$ for a fixed $t$ in the region of the dip-bump structure, where these two terms interfere, confirms the above observations. We discuss the possible origin of the two-component structure of the high energy elastic scattering amplitude and explain this by the structural symmetry of the amplitude.
hep-phNPA(2021)·3 citations
13*
Dark Matter, Muon Anomalous Magnetic Moment and the XENON1T Excess
Debajyoti Choudhury🇮🇳 · Suvam Maharana🇮🇳 · Divya Sachdeva🇮🇳 · Vandana Sahdev🇮🇳
A very economic scenario with just three extra scalar fields beyond the Standard Model is invoked to explain the muon anomalous magnetic moment, the requisite relic abundance of dark matter as well as the Xenon-1T excess through the inelastic down-scattering of the dark scalar.
hep-phPRD(2021)·26 citations
14*
New method for non-standard invisible particle searches in tau lepton decays
E. De La Cruz-Burelo🇲🇽 · M. Hernandez-Villanueva🇺🇸 · A. De Yta-Hernandez🇲🇽
Motivated by models proposed to explain the Standard Model anomalies, and the unprecedented $τ^{+} τ^{-}$ data to be collected by the Belle~II experiment during the next years, we study the kinematics of tau pair decays and propose a new method to search for lepton flavor violating processes in tau lepton decays to invisible beyond Standard Model particles, such as $τ \to ℓ α$ , where $ℓ$ is either an electron or a muon, and $α$ is a massive particle that escapes undetected. The new method improves by one order of magnitude the expected upper limit on the $τ \to ℓ α$ production in 3x1 prong tau decays and establishes the possibility of performing this search in 1x1 prong tau decays which has not been previously considered.
hep-phPRD(2020)·20 citations
15*
Production of Light Nuclei in Heavy Ion Collisions via Hagedorn Resonances
Kai Gallmeister🇩🇪 · Carsten Greiner (Goethe University, Frankfurt am Main)🇩🇪
The physical processes behind the production of light nuclei in heavy ion collisions are unclear. The nice theoretical description of experimental yields by thermal models conflicts with the very small binding energies of the observed states, being fragile in such a hot and dense environment. Other available ideas are delayed production via coalescence, or a cooling of the system after the chemical freeze-out according a Saha equation, or a `quench' instead of a thermal freeze-out. A recently derived prescription of an (interacting) Hagedorn gas is applied to consolidate the above pictures. The tabulation of decay rates of Hagedorn states into light nuclei allows to calculate yields usually unaccessable due to very poor Monte Carlo statistics. Decay yields of stable hadrons and light nuclei are calculated. While the scale-free decays of Hagedorn states alone are not compatible with the experimental data, a thermalized hadron and Hagedorn state gas is able to describe the experimental data. Applying a cooling of the system according a Saha-equation with conservation of nucleons and anti-nucleons in number leads to (nearly) temperature independent yields, thus a production of the light nuclei at temperatures much lower than the chemical freeze-out temperature is possible.
hep-phnucl-thEPJA(2021)·6 citations
16*
Revisiting Helicity Parton Distributions at a Future Electron-Ion Collider
Elke C. Aschenauer🇺🇸 · Ignacio Borsa🇦🇷 · Gonzalo Lucero🇦🇷 · Ana S. Nunes🇺🇸 · Rodolfo Sassot🇦🇷
We studied the impact of future Electron Ion Collider inclusive and semi-inclusive polarized deep inelastic scattering data will have on the determination of the helicity parton distributions. Supplementing the Monte Carlo sampling variant of the DSSV14 analysis with pseudo-data on polarized inclusive and semi-inclusive electron-proton deep inelastic scattering with updated uncertainty estimates and for two different center-of-mass-system energies, $s = 44.7$ GeV and $s = 141.4$ GeV respectively, and on inclusive electron-helium collisions at $s = 115.2$ GeV, we find a remarkable improvement in the determination of the helicity distributions, specially at low parton momentum fraction $x$ . While inclusive electron-proton data at the lowest energy configuration constrain significantly the gluon polarization down to $x \sim 1 0^{- 4}$ , the higher energy configuration strengthens the constraint and extends it one decade further. On the other hand, semi-inclusive data achieves the hitherto elusive flavor separation for sea quarks that can not be obtained from any other inclusive electromagnetic measurement. Collisions with helium complement inclusive proton measurements, pushing the constraints on the combined quark plus anti-quark $u, d$ and $s$ polarizations to an unprecedented level.
hep-phPRD(2020)·54 citations
17*
String Fragmentation in Supercooled Confinement and Implications for Dark Matter
Iason Baldes🇧🇪 · Yann Gouttenoire🇩🇪 · Filippo Sala🇫🇷
A strongly-coupled sector can feature a supercooled confinement transition in the early universe. We point out that, when fundamental quanta of the strong sector are swept into expanding bubbles of the confined phase, the distance between them is large compared to the confinement scale. We suggest a modelling of the subsequent dynamics and find that the flux linking the fundamental quanta deforms and stretches towards the wall, producing an enhanced number of composite states upon string fragmentation. The composite states are highly boosted in the plasma frame, which leads to additional particle production through the subsequent deep inelastic scattering. We study the consequences for the abundance and energetics of particles in the universe and for bubble-wall Lorentz factors. This opens several new avenues of investigation, which we begin to explore here, showing that the composite dark matter relic density is affected by many orders of magnitude.
hep-phastro-ph.COJHEP(2021)·101 citations
18*
Optimized Lepton Universality Tests in $B \to V ℓ ν ˉ$ decays
Gino Isidori🇨🇭 · Olcyr Sumensari🇨🇭
We propose improved Lepton Flavor Universality (LFU) ratios in semileptonic $P \to V ℓ ν ˉ$ decays, when comparing $μ$ and $τ$ modes, that minimize the theoretical form-factor uncertainties. These optimized ratios are obtained with simple cuts or reweighting of the dilepton mass distributions, which imply a minimum loss of signal on the rare tauonic modes while maximizing the cancellation of theoretical uncertainties among the two modes. We illustrate the usefulness of these observables in $B_{c} \to J / ψ$ , $B_{c} \to ψ (2 S)$ , $B \to D^{*}$ and $B_{s} \to D_{s}^{*}$ transitions, showing that in all cases we can reach $O (1%)$ uncertainties on the SM predictions of the improved LFU ratios employing conservatives form-factor uncertainties.
hep-phEPJC(2020)·20 citations
19*
Nonlinear trident in the high-energy limit: Nonlocality, Coulomb field and resummations
Greger Torgrimsson🇩🇪
We study nonlinear trident in laser pulses in the high-energy limit, where the initial electron experiences, in its rest frame, an electromagnetic field strength above Schwinger's critical field. At lower energies the dominant contribution comes from the "two-step" part, but in the high-energy limit the dominant contribution comes instead from the one-step term. We obtain new approximations that explain the relation between the high-energy limit of trident and pair production by a Coulomb field, as well as the role of the Weizsäcker-Williams approximation and why it does not agree with the high- $χ$ limit of the locally-constant-field approximation. We also show that the next-to-leading order in the large- $a_{0}$ expansion is, in the high-energy limit, nonlocal and is numerically very important even for quite large $a_{0}$ . We show that the small- $a_{0}$ perturbation series has a finite radius of convergence, but using Padé-conformal methods we obtain resummations that go beyond the radius of convergence and have a large numerical overlap with the large- $a_{0}$ approximation. We use Borel-Padé-conformal methods to resum the small- $χ$ expansion and obtain a high precision up to very large $χ$ . We also use newer resummation methods based on hypergeometric/Meijer-G and confluent hypergeometric functions.
hep-phhep-thPRD(2020)·24 citations
20*
Constraining Electroweakinos in the Minimal Dirac Gaugino Model
Mark D. Goodsell🇫🇷 · Sabine Kraml🇫🇷 · Humberto Reyes-González🇫🇷 · Sophie L. Williamson🇫🇷
Supersymmetric models with Dirac instead of Majorana gaugino masses have distinct phenomenological consequences. In this paper, we investigate the electroweakino sector of the Minimal Dirac Gaugino Supersymmetric Standard Model (MDGSSM) with regards to dark matter (DM) and collider constraints. We delineate the parameter space where the lightest neutralino of the MDGSSM is a viable DM candidate, that makes for at least part of the observed relic abundance while evading constraints from DM direct detection, LEP and lowenergy data, and LHC Higgs measurements. The collider phenomenology of the thus emerging scenarios is characterised by the richer electroweakino spectrum as compared to the Minimal Supersymmetric Standard Model (MSSM) -- 6 neutralinos and 3 charginos instead of 4 and 2 in the MSSM, naturally small mass splittings, and the frequent presence of long-lived particles, both charginos and/or neutralinos. Reinterpreting ATLAS and CMS analyses with the help of SModelS and MadAnalysis 5, we discuss the sensitivity of existing LHC searches for new physics to these scenarios and show which cases can be constrained and which escape detection. Finally, we propose a set of benchmark points which can be useful for further studies, designing dedicated experimental analyses and/or investigating the potential of future experiments.
hep-phSciPost Phys.(2020)·24 citations
21*
EFT Interpretation of XENON1T Electron Recoil Excess: Neutrinos and Dark Matter
Giorgio Arcadi🇮🇹 · Andreas Bally🇩🇪 · Florian Goertz🇩🇪 · Karla Tame-Narvaez🇩🇪 · Valentin Tenorth🇩🇪 · Stefan Vogl🇩🇪
We scrutinize the XENON1T electron recoil excess in the scalar-singlet-extended dark matter effective field theory. We confront it with various astrophysical and laboratory constraints both in a general setup and in the more specific, recently proposed, variant with leptophilic $Z_{2}$ -odd mediators. The latter also provide mass to the light leptons via suppressed $Z_{2}$ breaking, a structure that is well fitting with the nature of the observed excess and the discrete symmetry leads to non-standard dark-matter interactions. We find that the excess can be explained by neutrino--electron interactions, linked with the neutrino and electron masses, while dark-matter--electron scattering does not lead to statistically significant improvement. We analyze the parameter space preferred by the anomaly and find severe constraints that can only be avoided in certain corners of parameter space. Potentially problematic bounds on electron couplings from Big-Bang Nucleosynthesis can be circumvented via a late phase transition in the new scalar sector.
hep-phhep-exPRD(2021)·27 citations
22*
Back to (Mass-)Square(d) One: The Neutrino Mass Ordering in Light of Recent Data
Kevin J. Kelly🇺🇸 · Pedro A.N. Machado🇺🇸 · Stephen J. Parke🇺🇸 · Yuber F. Perez-Gonzalez🇺🇸 · Renata Zukanovich Funchal🇧🇷
We inspect recently updated neutrino oscillation data -- specifically coming from the Tokai to Kamioka and NuMI Off-axis $ν_{e}$ Appearance experiments -- and how they are analyzed to determine whether the neutrino mass ordering is normal ( $m_{1} < m_{2} < m_{3}$ ) or inverted ( $m_{3} < m_{1} < m_{2}$ ). We show that, despite previous results giving a strong preference for the normal ordering, with the newest data from T2K and NOvA, this preference has all but vanished. Additionally, we highlight the importance of this result for non-oscillation probes of neutrinos, including neutrinoless double beta decay and cosmology. Future experiments, including JUNO, DUNE, and T2HK will provide valuable information and determine the mass ordering at a high confidence level.
hep-phhep-exPRD(2021)·84 citations
23*
Coherent elastic neutrino-nucleus scattering: EFT analysis and nuclear responses
Martin Hoferichter🇨🇭 · Javier Menéndez🇪🇸 · Achim Schwenk🇩🇪
The cross section for coherent elastic neutrino-nucleus scattering (CE $ν$ NS) depends on the response of the target nucleus to the external current, in the Standard Model (SM) mediated by the exchange of a $Z$ boson. This is typically subsumed into an object called the weak form factor of the nucleus. Here, we provide results for this form factor calculated using the large-scale nuclear shell model for a wide range of nuclei of relevance for current CE $ν$ NS experiments, including cesium, iodine, argon, fluorine, sodium, germanium, and xenon. In addition, we provide the responses needed to capture the axial-vector part of the cross section, which does not scale coherently with the number of neutrons, but may become relevant for the SM prediction of CE $ν$ NS on target nuclei with nonzero spin. We then generalize the formalism allowing for contributions beyond the SM. In particular, we stress that in this case, even for vector and axial-vector operators, the standard weak form factor does not apply anymore, but needs to be replaced by the appropriate combination of the underlying nuclear structure factors. We provide the corresponding expressions for vector, axial-vector, but also (pseudo-)scalar, tensor, and dipole effective operators, including two-body-current effects as predicted from chiral effective field theory. Finally, we update the spin-dependent structure factors for dark matter scattering off nuclei according to our improved treatment of the axial-vector responses.
hep-phhep-exnucl-exnucl-thPRD(2020)·185 citations
24*
Phase Transitions in an Expanding Universe: Stochastic Gravitational Waves in Standard and Non-Standard Histories
Huai-Ke Guo🇺🇸 · Kuver Sinha🇺🇸 · Daniel Vagie🇺🇸 · Graham White🇨🇦
We undertake a careful analysis of stochastic gravitational wave production from cosmological phase transitions in an expanding universe, studying both a standard radiation as well as a matter dominated history. We analyze in detail the dynamics of the phase transition, including the false vacuum fraction, bubble lifetime distribution, bubble number density, mean bubble separation, etc., for an expanding universe. We also study the full set of differential equations governing the evolution of plasma and the scalar field during the phase transition and generalize results obtained in Minkowski spacetime. In particular, we generalize the sound shell model to the expanding universe and determine the velocity field power spectrum. This ultimately provides an accurate calculation of the gravitational wave spectrum seen today for the dominant source of sound waves. For the amplitude of the gravitational wave spectrum visible today, we find a suppression factor arising from the finite lifetime of the sound waves and compare with the commonly used result in the literature, which corresponds to the asymptotic value of our suppression factor. We point out that the asymptotic value is only applicable for a very long lifetime of the sound waves, which is highly unlikely due to the onset of shocks, turbulence and other damping processes. We also point out that features of the gravitational wave spectral form may hold the tantalizing possibility of distinguishing between different expansion histories using phase transitions.
hep-phastro-ph.COastro-ph.HEhep-thJCAP(2021)·307 citations
25*
Indirect $C P$ probes of the Higgs-top-quark interaction: current LHC constraints and future opportunities
Henning Bahl🇩🇪 · Philip Bechtle🇩🇪 · Sven Heinemeyer🇪🇸 · Judith Katzy🇩🇪 · Tobias Klingl🇩🇪 · Krisztian Peters🇩🇪 · Matthias Saimpert🇨🇭 · Tim Stefaniak🇩🇪 · Georg Weiglein🇩🇪
The $C P$ structure of the Higgs boson in its coupling to the particles of the Standard Model is amongst the most important Higgs boson properties which have not yet been constrained with high precision. In this study, all relevant inclusive and differential Higgs boson measurements from the ATLAS and CMS experiments are used to constrain the $C P$ -nature of the top-Yukawa interaction. The model dependence of the constraints is studied by successively allowing for new physics contributions to the couplings of the Higgs boson to massive vector bosons, to photons, and to gluons. In the most general case, we find that the current data still permits a significant $C P$ -odd component in the top-Yukawa coupling. Furthermore, we explore the prospects to further constrain the $C P$ properties of this coupling with future LHC data by determining $t H$ production rates independently from possible accompanying variations of the $t t ˉ H$ rate. This is achieved via a careful selection of discriminating observables. At the HL-LHC, we find that evidence for $t H$ production at the Standard Model rate can be achieved in the Higgs to diphoton decay channel alone.
hep-phJHEP(2020)·49 citations
26*
Strong decays with the boost-corrected wave functions
Yu.A.Simonov🇷🇺
Strong decay probabilities are calculated using the Lorentz contracted wave functions of decay products, determined in the arbitrary dynamical scheme with the instantaneous interaction. It is shown that the decay width obtains an additional factor defined by the contraction coefficient $C_{m} (s)$ , which for two-body equal mass decays is $C_{m}^{2} (s) = 4 m^{2} / s$ , $s = E^{2}$ . The resulting decay widths are compared to the experimental data, where in particular the $ρ (770), ρ (1450)$ decay data require an additional $1/ s$ dependence of the width to fit the data. Important consequences for the dynamics of hadron decays and scattering are shortly discussed.
hep-phhep-exEPJA(2021)·4 citations
27*
Dispelling a myth on dense neutrino media: fast pairwise conversions depend on energy
Shashank Shalgar🇩🇰 · Irene Tamborra🇩🇰
Pairwise conversions of neutrinos have complicated the challenging goal of quantifying the relevance of neutrino microphysics in compact astrophysical objects, limiting the ability to perform numerical simulations and encouraging the employment of semi-analytical tools, such as the linear stability analysis. Given the high neutrino density, the dependence of pairwise conversions on the neutrino energy has been deemed to play a negligible role. We show that fast pairwise conversions are affected by the neutrino energy, especially in the non-linear regime. An earlier onset of flavor conversions and a higher oscillation frequency are found as the vacuum frequency increases (i.e., the neutrino energy decreases); the oscillation periodicity, otherwise present, is gradually destroyed as the vacuum frequency increases. Such effects are, however, not further exacerbated by the inclusion of spectral energy distributions for neutrinos, contrary to what was found for "slow" neutrino-neutrino conversions. In addition, our findings highlight the dependence of fast pairwise conversions on the neutrino mass ordering for realistic values of the neutrino vacuum frequency. Our findings highlight the limitations intrinsic to widely adopted approximations and extrapolations based on the linear regime of fast conversions. In order to gauge their possible impact on the source physics, a more sophisticated modeling of pairwise conversions is necessary.
↳ astro-ph.HEhep-phJCAP(2021)·40 citations
28*
Charm contribution to ultrahigh-energy neutrinos from newborn magnetars
Jose Alonso Carpio🇺🇸 · Kohta Murase🇺🇸 · Mary Hall Reno🇺🇸 · Ina Sarcevic🇺🇸 · Anna Stasto🇺🇸
Newborn, strongly magnetized neutron stars (so-called magnetars) surrounded by their stellar or merger ejecta are expected to be sources of ultrahigh-energy neutrinos via decay of mesons produced in hadronic interactions of protons which are accelerated to ultrahigh energies by magnetic dissipation of the spindown energy. We show that not only pions and kaons but also charm hadrons, which are typically neglected due to their small production cross sections, can represent dominant contributions to neutrino fluence at ultrahigh energies, because of their short lifetimes, while the ultrahigh-energy neutrino fluence from pion and kaon production is suppressed at early times due to their significant cooling before their decay. We show that the next-generation detectors such as Probe Of Extreme Multi-Messenger Astrophysics (POEMMA), Giant Radio Array for Neurtino Detection (GRAND) and IceCube-Gen2 have a good chance of observing neutrinos, primarily originating from charm hadrons, from nearby magnetars. We also show that neutrinos from nearby magnetar-driven merger novae could be observed in the time interval between $1 0^{2}$ s and $1 0^{3}$ s, where the charm hadron contribution is dominant for neutrino energies above $1 0^{8}$ GeV, of relevance to next generation detectors. We also comment on potential impacts of the charm hadron contribution to the diffuse neutrino flux.
↳ astro-ph.HEhep-phPRD(2020)·19 citations
29*
Towards Testing Sterile Neutrino Dark Matter with Spectrum-Roentgen-Gamma Mission
V.V. Barinov🇷🇺 · R.A. Burenin🇷🇺 · D.S. Gorbunov🇷🇺 · R.A. Krivonos🇷🇺
We investigate the prospects of the SRG mission in searches for the keV-scale mass sterile neutrino dark matter radiatively decaying into active neutrino and photon. The ongoing all-sky X-ray survey of the SRG space observatory with data acquired by the ART-XC and eROSITA telescopes can provide a possibility to fully explore the resonant production mechanism of the dark matter sterile neutrino, which exploits the lepton asymmetry in the primordial plasma consistent with cosmological limits from the Big Bang Nucleosynthesis. In particular, it is shown that at the end of the four year all-sky survey, the sensitivity of the eROSITA telescope near the 3.5 keV line signal reported earlier can be comparable to that of the XMM-Newton with all collected data, which will allow one to carry out another independent study of the possible sterile neutrino decay signal in this area. In the energy range below $\approx 2.4$ keV, the expected constraints on the model parameters can be significantly stronger than those obtained with XMM-Newton. From the ART-XC data, in the energy range approximately from 5 to 20 keV, it can be possible to get more stringent constraints than those obtained with NuSTAR so far. We conclude that the SRG mission has a very high potential in testing the sterile neutrino dark matter hypothesis.
↳ astro-ph.COastro-ph.GAhep-phPRD(2021)·15 citations
30*
High-Frequency Gravitational-Wave Detection Using a Chiral Resonant Mechanical Element and a Short Unstable Optical Cavity
Yi Chen🇩🇪 · Muamer Kadic🇩🇪 · David E. Kaplan🇺🇸 · Surjeet Rajendran🇺🇸 · Alexander O. Sushkov🇺🇸 · Martin Wegener🇩🇪
Present gravitational wave detectors are based on the measurement of linear displacement in stable optical cavities. Here, we instead suggest the measurement of the twist of a chiral mechanical element induced by a gravitational wave. The induced twist rotates a flat optical mirror on top of this chiral element, leading to the deflection of an incident laser beam. This angle change is enhanced by multiple bounces of light between the rotating mirror and an originally parallel nearby fixed flat mirror. Based on detailed continuum-mechanics calculations, we present a feasible design for the chiral mechanical element including the rotating mirror. Our approach is most useful for signals in the frequency band 1 -- 100 kHz where we show that fundamental metrological limits would allow for smaller shot noise in this setup in comparison to the detection of linear displacement. We estimate a gravitational wave strain sensitivity between 10^{-21}/\sqrt{Hz} and 10^{-23}/\sqrt{Hz} at around 10 kHz frequency. When appropriately scaling the involved geometrical parameters, the strain sensitivity is proportional to frequency.
↳ gr-qchep-phhep-thquant-ph5 citations
31*
Excluded-volume model for quarkyonic matter II: Three-flavor shell-like distribution of baryons in phase space
Dyana C. Duarte🇺🇸 · Saul Hernandez-Ortiz🇺🇸 · Kie Sang Jeong🇺🇸
We extend the excluded-volume model of isospin symmetric two-flavor dense quarkyonic matter [Phys. Rev. C 101, 035201 (2020)] including strange particles and address its implications for neutron stars. The effective sizes of baryons are defined from the diverging hard-core potentials in the short interdistance regime. Around the hard-core density, the repulsive core between baryons at short distances leads to a saturation in the number density of baryons and generates perturbative quarks from the lower phase space, which leads to the shell-like distribution of baryons by the Pauli exclusion principle. The strange-quark Fermi sea always appears at high densities but the $Λ$ hyperon shell only appears when the effective size of the $Λ$ hyperon is smaller than the effective size of nucleons. We find that the pressure of strange quarkyonic matter can be large enough to support neutron stars with two times solar mass and can have a large sound speed, $c_{s}^{2} ≃ 0.7$ . The fraction of the baryon number carried by perturbative quarks is about 30% at the inner core of most massive neutron stars.
↳ nucl-thhep-phPRC(2020)·35 citations
32*
Analysis of $B_{c} \to τ ν_{τ}$ at CEPC
Taifan Zheng🇨🇳 · Ji Xu🇨🇳 · Lu Cao🇩🇪 · Dan Yu🇨🇳 · Wei Wang🇨🇳 · Soeren Prell🇺🇸 · Yeuk-Kwan E. Cheung🇨🇳 · Manqi Ruan🇨🇳
The precise determination of the $B_{c} \to τ ν_{τ}$ branching ratio provides an advantageous opportunity for understanding the electroweak structure of the Standard Model, measuring the CKM matrix element $∣ V_{c b} ∣$ and probing new physics models. In this paper, we discuss the potential of measuring the processes of $B_{c} \to τ ν_{τ}$ with $τ$ decaying leptonically at the proposed Circular Electron Positron Collider (CEPC). We conclude that during the $Z$ pole operation, the channel signal can achieve five $σ$ significance with $\sim 1 0^{9}$ $Z$ decays, and the signal strength accuracies for $B_{c} \to τ ν_{τ}$ can reach around 1% level at the nominal CEPC $Z$ pole statistics of one trillion $Z$ decays assuming the total $B_{c} \to τ ν_{τ}$ yield is $3.6 \times 1 0^{6}$ . Our theoretical analysis indicates the accuracy could provide a strong constraint on the general effective Hamiltonian for the $b \to c τ ν$ transition. If the total $B_{c}$ yield can be determined to $O (1%)$ level of accuracy in the future, these results also imply $∣ V_{c b} ∣$ could be measured up to $O (1%)$ level of accuracy.
↳ hep-exhep-phCPC(2021)·36 citations
33*
Revised $f_{NL}$ parameter in Curvaton Scenario
Lei-Hua Liu🇨🇳 · Bin Liang🇨🇳 · Ya-Chen Zhou🇨🇳 · Xiao-Dan Liu🇨🇳 · Wu-Long Xu🇨🇳 · Ai-Chen Li🇨🇳
We revise the Non-Gaussianity of canonical curvaton scenario with a generalized $δ N$ formalism, in which it could handle the generic potentials. In various curvaton models, the energy density is dominant in different period including the secondary inflation of curvaton, matter domination and radiation domination. Our method could unify to deal with these periods since the non-linearity parameter $f_{NL}$ associated with Non-Gaussianity is a function of equation of state $w$ . We firstly investigate the most simple curvaton scenario, namely the chaotic curvaton with quadratic potential. Our study shows that most parameter space satisfies with observational constraints. And our formula will nicely recover the well-known value of $f_{NL}$ in the absence of non-linear evolution. From the micro origin of curvaton, we also investigate the Pseudo-Nambu-Goldstone curvaton. Our result clearly indicates that the second short inflationary process for Pseudo-Nambu-Goldstone curvaton is ruled out in light of observations. Finally, our method sheds a new way for investigating the Non-Gaussianity of curvaton mechanism, espeically for exploring the Non-Gaussianity in MSSM curvaton model.
↳ astro-ph.COgr-qchep-phhep-thPRD(2021)·13 citations
34*
Field of a moving locked charge in classical electrodynamics
Alexander J. Silenko🇷🇺
The paradox of a field of a moving locked charge (confined in a closed space) is considered and solved with the use of the integral Maxwell equations. While known formulas obtained for instantaneous fields of charges moving along straight and curved lines are fully correct, measurable quantities are average electric and magnetic fields of locked charges. It is shown that the average electric field of locked charges does not depend on their motion. The average electric field of protons moving in nuclei coincides with that of protons being at rest and having the same spatial distribution of the charge density. The electric field of a twisted electron is equivalent to the field of a centroid with immobile charges which spatial distribution is defined by the wave function of the twisted electron.
↳ physics.class-phhep-phnucl-thMod.Phys.Lett.A(2020)·1 citation
35*
The Double Box and Hexagon Conformal Feynman Integrals
B. Ananthanarayan🇮🇳 · Sumit Banik🇮🇳 · Samuel Friot🇫🇷 · Shayan Ghosh🇩🇪
The off-shell massless six-point double box and hexagon conformal Feynman integrals with generic propagator powers are expressed in terms of linear combinations of multiple hypergeometric series of the generalized Horn type. These results are derived from 9-fold Mellin-Barnes representations obtained from their dual conformal Feynman parameter representations. The individual terms in the presented expressions satisfy the differential equation that relates the double box in $D$ dimensions to the hexagon in $D + 2$ dimensions.
↳ hep-thhep-phmath-phmath.MPPRD(2020)·30 citations
36*
Investigating the detection of dark matter subhalos as extended sources with Fermi-LAT
Mattia Di Mauro🇺🇸 · Martin Stref🇫🇷 · Francesca Calore🇫🇷
Cold dark matter (DM) models for structure formation predict that DM subhalos are present in the Galaxy. In the standard paradigm of DM as weakly interacting massive particle, subhalos are expected to shine in gamma rays and to provide a signal detectable with current instruments, notably with the Large Area Telescope (LAT) aboard the Fermi~satellite. This is the main motivation behind searches for DM signals towards dwarf spheroidal galaxies and unidentified Fermi-LAT sources. A significant angular extension detected from unassociated sources located at relatively high latitudes is considered a "smoking gun" signature for identifying DM subhalos. In the present work, we systematically explore, by means of state-of-the-art models of cold DM halos in the Galaxy, the detectability of extended subhalos with Fermi-LAT. We simulate a DM signal exploring different assumptions of subhalos distribution in the Galaxy and DM profile, and reconstruct its flux through a realistic Fermi-LAT analysis pipeline. In the most optimistic case, we show that a detection of extended DM subhalos can be made for annihilation cross sections higher than $3 \times 1 0^{- 26}$ cm $^{3}$ /s (for a 100 GeV DM mass), still compatible with existing gamma-ray constraints, and that, in this case, the preference for extension of the source (vs point-like hypothesis) is significant. For fainter signals, instead, halos not only do not show significant extension, but they are not even detectable significantly as point-like sources.
↳ astro-ph.HEastro-ph.GAhep-phPRD(2020)·21 citations
37*
Higgs-confinement phase transitions with fundamental representation matter
Aleksey Cherman🇺🇸 · Theodore Jacobson🇺🇸 · Srimoyee Sen🇺🇸 · Laurence G. Yaffe🇺🇸
We discuss the conditions under which Higgs and confining regimes in gauge theories with fundamental representation matter fields can be sharply distinguished. It is widely believed that these regimes are smoothly connected unless they are distinguished by the realization of global symmetries. However, we show that when a $U (1)$ global symmetry is spontaneously broken in \emph{both} the confining and Higgs regimes, the two phases can be separated by a phase boundary. The phase transition between the two regimes may be detected by a novel topological vortex order parameter. We first illustrate these ideas by explicit calculations in gauge theories in three spacetime dimensions. Then we show how our analysis generalizes to four dimensions, where it implies that nuclear matter and quark matter are sharply distinct phases of QCD with an approximate $S U (3)$ flavor symmetry.
↳ hep-thhep-phnucl-thPRD(2020)·38 citations
38*
Near-threshold $K^{*} (892)^{+}$ meson production in the interaction of $π^{-}$ mesons with nuclei
E. Ya. Paryev🇷🇺
We study the inclusive strange vector meson $K^{*} (892)^{+}$ production in $π^{-} A$ reactions at near-threshold laboratory incident pion momenta of 1.4--2.0 GeV/c within a nuclear spectral function approach. The approach accounts for incoherent primary $π^{-}$ meson--proton $π^{-} p \to K^{*} (892)^{+} Σ^{-}$ production processes as well as the influence of the scalar $K^{*} (892)^{+}$ --nucleus potential (or the $K^{*} (892)^{+}$ in-medium mass shift) on these processes. We calculate the absolute differential and total cross sections for the production of $K^{*} (892)^{+}$ mesons off carbon and tungsten nuclei at laboratory angles of 0 $^{\circ}$ --45 $^{\circ}$ and at these momenta within five scenarios for the above shift. We show that the $K^{*} (892)^{+}$ momentum distributions and their excitation functions (absolute and relative) possess a high sensitivity to changes in the in-medium $K^{*} (892)^{+}$ mass shift in the low-momentum region of 0.1--0.6 GeV/c. Therefore, the measurement of such observables in a dedicated experiment at the GSI pion beam facility in the near-threshold momentum domain will allow to get valuable information on the $K^{*} (892)^{+}$ in-medium properties.
↳ nucl-thhep-phnucl-exCPC(2020)·6 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.