HEP Phenomenology·hep-ph
27 papers—18 primary·9 cross-listed·reconstructed*
The purpose of this letter is to point out that some conclusions in the paper (Eur. Phys. J. C {\bf 76}, 324(2016)) are incomplete, and to give complete and improved conclusions. The analytic necessary and sufficient conditions are given for the boundedness-from-below conditions of general scalar potentials of two real scalar fields and and the Higgs bonson .
José F. Nieves🇵🇷 · Sarira Sahu🇲🇽
We consider the propagation of photons in a model of a charged scalar Bose-Einstein (BE) condensate. We determine the dispersion relations of the collective modes, as well as the photon polarization tensor and the dielectric constant in the model. Two modes correspond to the transverse photon polarizations, with dispersion relations of the usual form for transverse photons in a plasma. The other two modes, denoted as the modes, are combinations of the longitudinal photon and the massive scalar field. Their dispersion relations behave very differently as functions of momentum. The mode dispersion relation increases steadily and remains greater than the momentum as the momentum increases. The dispersion relation of the mode decreases in a given momentum range, with the group velocity being negative in that range, while in another range it increases steadily but remains smaller than the momentum, akin to the situation in a medium with an index of refraction greater than 1. We consider the non-relativistic limit of the dispersion relations and discuss some aspects of the results. We also determine the wavefunctions of the modes, which are useful to obtain the corrections to the dispersion relations, e.g., imaginary parts due to the damping effects and/or the effects of scattering, due to the interactions with the excitations of the system. The results can be useful in various physical contexts that have been considered in the literature involving the electrodynamics of a charged scalar BE condensate.
The proton spin puzzle has inspired a vast programme of experiments and theoretical work challenging our understanding of QCD and its role in the structure of hadrons.The proton's internal spin structure is connected to chiral symmetry and, through gluon degrees of freedom in the flavour singlet channel, to the physics of the meson. Why do quarks contribute just about one third of the proton's spin? Why are mesons and their interactions so sensitive to gluonic degrees of freedom? We review the status of these topics and some key observables for forthcoming experiments.
Dana Douqa🇨🇭 · Stefania Bordoni🇨🇭 · Lorenzo Giannessi🇨🇭 · Alexis Nikolakopoulos🇺🇸 · Federico Sánchez🇨🇭 · Caspar Schloesser🇨🇭
We introduce the novel approach of using the superscaling variable as an observable and an analysis tool in the context of charged current neutrino-nucleus interactions. We study the relation between the superscaling variable and the removal energy, in addition to other fundamental parameters of the neutrino-nucleus interaction models. In the second half of the paper, we discuss the experimental viability of this measurement following a study of neutrino energy and missing momentum reconstruction. We show that the superscaling variable is measurable in neutrino interaction experiments provided that the proton is detected in the final state. We discuss the resolution of this measurement, and the limitation imposed by the proton's detection threshold.
R. M. Aguirre🇦🇷 · O. Lourenço🇧🇷
We study pseudoscalar , and meson properties, such as masses and couplings, in dense matter at zero temperature. We use a recently proposed phenomenological quark model, known as the PNJL0, which takes into account the confinement/deconfinement phase transition by means of the traced Polyakov loop () which serves as an order parameter at zero temperature. We consider two different scenarios, namely, symmetric quark matter with equal chemical potentials for all the flavors, and the beta equilibrated matter. In the latter case the hadron-quark phase transition is implemented by a two model approach. For the hadron side we use a relativistic mean-field model with density dependent couplings. We show that induces abrupt changes in the mesons properties with gap sizes regulated by the phenomenological gluonic sector of the model.
Yu-Ji Shi🇨🇳 · Ye Xing🇨🇳 · Zhi-Peng Xing🇨🇳
We studied the decays of Heavy baryon into a pseudoscalar meson and a dark baryon in the recently developed -Mesogenesis scenario, where the two types of effective Lagrangians proposed by the scenario are both considered. The decay amplitudes of are calculated by light-cone sum rules using its light-cone distribution amplitudes. The decay amplitudes of are related with those of through a flavor SU(3) analysis. The uncertainties of threshold parameter and the Borel parameter are both considered in the numerical calculation. The values of effective coupling constants in the -Mesogenesis are taken as their upper limits that obtained from our previous study on the inclusive decay. The upper limits of the decay branching fractions are presented as functions of the dark baryon mass.
Chao-Jie Fan🇨🇳 · Jun-Kang He🇨🇳
The -wave charmonium electromagnetic Dalitz decays with large recoil momentum are investigated in the framework of perturbative QCD, and the contributions from the small recoil momentum region are described by the overlap of soft wave functions. The transition form factors and the normalized transition form factors in full kinematic region are derived for the first time. It is noticed that there are no IR divergences at one-loop level, and the transition form factors with the relativistic corrections from the internal momentum of are insensitive to both the shapes of distribution amplitudes and the invariant mass of the lepton pair in the large recoil momentum region. Intriguingly, unlike the situation in the -wave charmonium decays , we find the contributions from the small recoil momentum region are comparable with those from the large recoil momentum region in the -wave charmonium decays . By employing the obtained , we give the predictions of the branching ratios , which may come within the range of measurement of present or near-future experiments.
Teng Ji🇩🇪 · Xiang-Kun Dong🇩🇪 · Ulf-G. Meißner🇩🇪
This study focuses on the interaction of the pseudoscalar meson octet and the baryon decuplet. In the continuum, it is observed that several baryon resonances can be produced by the Weinberg-Tomozawa interaction in unitarized chiral perturbation theory, including the , , , and . Among them, the and may exhibit a potential two-pole structures. The unitarized chiral perturbation approach is then applied as the underlying theory to predict the energy levels of these systems in a finite volume. These energy levels are well described by the -matrix parameterization constrained by flavor SU(3) symmetry. With the parameters from the best fits, the poles extracted from the -matrix parameterization closely correspond to those derived from the underlying chiral effective field theory, as long as they are close to physical region and not significantly higher than the lowest relevant threshold.
Chang-Jie Dai🇨🇳 · Tong Li🇨🇳 · Rui-Jia Zhang🇨🇳
The low-mass dark matter (DM) such as axion or wavelike scalar is a plausible DM candidate. Recently, the possible non-standard couplings of low-mass DM has drawn much attention. In this work we investigate the detection of electromagnetic couplings in a few benchmark models of low-mass DM. For illustration, we consider the generic axion electrodynamics including CP violating coupling as well as the newly proposed axion electromagnetodynamics. The superconducting radio frequency (SRF) cavity with two modes has more advantages than the traditional cavity approach with static background field. We utilize the two-mode SRF cavity to probe the generic couplings of low-mass DM with frequency lower than GHz. We show the sensitivity of the SRF cavity to the axion couplings in the above frameworks.
Cheng-Wei Chiang🇹🇼 · Feng-Yang Hsieh🇹🇼 · Shih-Chieh Hsu🇺🇸 · Ian Low🇺🇸
The study of di-Higgs events, both resonant and non-resonant, plays a crucial role in understanding the fundamental interactions of the Higgs boson. In this work we consider di-Higgs events decaying into four -quarks and propose to improve the experimental sensitivity by utilizing a novel machine learning algorithm known as Symmetry Preserving Attention Network (\textsc{Spa-Net}) -- a neural network structure whose architecture is designed to incorporate the inherent symmetries in particle reconstruction tasks. We demonstrate that the \textsc{Spa-Net} can enhance the experimental reach over baseline methods such as the cut-based and the Deep Neural Networks (DNN)-based analyses. At the Large Hadron Collider, with a 14-TeV centre-of-mass energy and an integrated luminosity of 300 fb, the \textsc{Spa-Net} allows us to establish 95\% C.L. upper limits in resonant production cross-sections that are 10\% to 45\% stronger than baseline methods. For non-resonant di-Higgs production, \textsc{Spa-Net} enables us to constrain the self-coupling that is 9\% more stringent than the baseline method.
Liliana Apolinário🇵🇹 · Pablo Guerrero-Rodríguez🇵🇹 · Korinna Zapp🇸🇪
In this manuscript, we illustrate how to use the newly proposed re-clustering algorithm to select jets with different degrees of quenching without biasing their initial transverse momentum spectrum. Our study is based on Z+jet simulated events using the JEWEL Monte Carlo event generator to account for jet quenching effects. We apply the re-clustering algorithm to extract a proxy for a time axis (formation time) within the evolving medium. This information allows us to label jets according to their fragmentation pattern and select populations with enhanced sensitivity to quenching effects. Our results illustrate the potential of jets as precision tools for QGP tomography. Further, we show that the discussed method minimizes the biases stemming from -, - or mass-based jet selection.
F. Aslan🇺🇸 · M. Boglione🇮🇹 · J. O. Gonzalez-Hernandez🇮🇹 · T. Rainaldi🇺🇸 · T. C. Rogers🇺🇸 · A. Simonelli🇺🇸
We present a first practical implementation of a recently proposed hadron structure oriented (HSO) approach to TMD phenomenology applied to Drell-Yan like processes, including lepton pair production at moderate and boson production. We compare and contrast general features of our methodology with other common practices and emphasize the improvements derived from our approach that we view as essential for applications where extracting details of nonperturbative transverse hadron structure is a major goal. These include the HSO's preservation of a basic TMD parton-model-like framework even while accounting for full TMD factorization and evolution, explicit preservation of the integral relationship between TMD and collinear pdfs, and the ability to meaningfully compare different theoretical models of nonperturbative TMD parton distributions. In our examples, we show that there is significant sensitivity at moderate to both the form of the nonperturbative transverse momentum dependence and the parametrization of collinear parton densities. However, we also find that evolving to , without fitting, results in a satisfactory postdiction of existing data for production, nearly independently of the modeling of nonperturbative transverse momentum behavior. We argue that this demonstrates that moderate measurements should be given greater weight than high measurements in extractions of nonperturbative transverse momentum dependence. We also obtain new extractions of the nonperturbative Collins-Soper kernel within the HSO approach. We discuss its features and compare with some earlier extractions.
Laszlo Gyulai🇭🇺 · Gabor Biro🇭🇺 · Robert Vertesi🇭🇺 · Gergely Gabor Barnafoldi🇭🇺
We use open charm production to estimate how far we can see back in time in high-energy hadron-hadron collisions. We analyze the transverse momentum distributions of the identified D mesons from pp, p--Pb and A--A collisions at the ALICE and STAR experiments covering the energy range from ~GeV up to 7~TeV. Within a non-extensive statistical framework, the common Tsallis parameters for D mesons represent higher temperature and more degrees of freedom than that of light-flavour hadrons. Assuming Bjorken-expansion, the production of D mesons corresponds to a significantly earlier proper time, .
Jorge Baeza-Ballesteros (IFIC, Valencia)🇪🇸 · Johan Bijnens (Lund U.)🇸🇪 · Tomáš Husek (Charles U. and Birmingham U.)🇨🇿 · Fernando Romero-López (MIT)🇺🇸 · Stephen R. Sharpe (Washington U.)🇺🇸 · Mattias Sjö (Lund U. and CPT, Marseille)🇸🇪
The three-particle -matrix, , is a scheme-dependent quantity that parametrizes short-range three-particle interactions in the relativistic-field-theory three-particle finite-volume formalism. In this work, we compute its value for systems of three pions in all isospin channels through next-to-leading order in Chiral Perturbation Theory, generalizing previous work done at maximum isospin. We obtain analytic expressions through quadratic order (or cubic order, in the case of zero isospin) in the expansion about the three-pion threshold.
Hai-Peng Li🇨🇳 · Jing-Yu Yi🇨🇳 · Chu-Wen Xiao🇨🇳 · De-Liang Yao🇨🇳 · Wei-Hong Liang🇨🇳 · Eulogio Oset🇪🇸
We study the correlation functions of the system, which develops a bound state of approximately MeV, using inputs consistent with the state. Then we address the inverse problem starting from these correlation functions to determine the scattering observables related to the system, including the existence of the bound state and its molecular nature. The important output of the approach is the uncertainty with which these observables can be obtained, considering errors in the correlation functions typical of current values in present correlation functions. We find that it is possible to obtain scattering lengths and effective ranges with relative high precision and the existence of a bound state. Although the pole position is obtained with errors of the order of of the binding energy, the molecular probability of the state is obtained with a very small error of the order of . All these findings can serve as motivation to perform such measurements in future runs of high energy hadron collisions.
Juan Manuel Márquez🇲🇽 · Pablo Roig🇲🇽 · Mónica Salinas🇲🇽
We calculate the neutrino-electron elastic scattering cross section, extending the results previously obtained in arXiv:1702.05721v2, in the presence of generic new interactions that take into account all the effects caused by finite neutrino masses. We address the potential significance of a heavy neutrino sector during precision measurements, particularly for tau neutrinos scattering with masses in the MeV range, for which the existing upper bounds on would result in conceivably measurable contributions. Finally, we comment on the possibility to distinguish between Dirac and Majorana neutrinos, including the analysis of the new emerging parameters and its application to illustrative model-dependent scenarios.
Christoph A. Ternes🇮🇹 · Giulia Pagliaroli🇮🇹
We perform an updated analysis of long-baseline accelerator data in the framework of neutrino oscillations in presence of invisible neutrino decay. We analyze data from T2K, NOvA and MINOS/MINOS+ and show that the combined analysis of all experiments improves the previous bound from long-baseline data by approximately one order of magnitude.
We review radiative corrections to tau decays into two mesons discussing their impact in new physics searches.
H.-Thomas Janka (1)🇩🇪 · Daniel Kresse (1,2) ((1) MPI Astrophysics, Garching, (2) TUM School of Natural Sciences, Garching)🇩🇪
Neutron stars (NSs) are observed with high space velocities and elliptical orbits in binaries. The magnitude of these effects points to natal kicks that originate from asymmetries during the supernova (SN) explosions. Using a growing set of long-time 3D SN simulations with the Prometheus-Vertex code, we explore the interplay of NS kicks that are induced by asymmetric neutrino emission and by asymmetric mass ejection. Anisotropic neutrino emission can arise from a large-amplitude dipolar convection asymmetry inside the proto-NS (PNS) termed LESA (Lepton-number Emission Self-sustained Asymmetry) and from aspherical accretion downflows around the PNS, which can lead to anisotropic neutrino emission (absorption/scattering) with a neutrino-induced NS kick roughly opposite to (aligned with) the kick by asymmetric mass ejection. In massive progenitors hydrodynamic kicks can reach up to more than 1300 km/s, whereas our calculated neutrino kicks reach (55-140) km/s (estimated upper bounds of (170-265) km/s) and only about (10-50) km/s, if LESA is the main cause of asymmetric neutrino emission. Therefore hydrodynamic NS kicks dominate in explosions of high-mass progenitors, whereas LESA-induced neutrino kicks dominate for NSs born in low-energy SNe of the lowest-mass progenitors, when these explode nearly spherically. Our models suggest that the Crab pulsar with its velocity of about 160 km/s, if born in the low-energy explosion of a low-mass, single-star progenitor, should have received a hydrodynamic kick in a considerably asymmetric explosion. Black holes, if formed by the collapse of short-lived PNSs and solely kicked by anisotropic neutrino emission, obtain velocities of only some km/s.
Atharva Naik🇺🇸 · Andrei Afanasev🇺🇸
The effect of the lepton's mass is significantly enhanced when the beam's energy is on the order of the lepton's mass. In the case of electrons, this corresponds to beam momenta on the order of a few MeV and is negligible in higher energy experiments. In this study, we calculate the differential cross section for the helicity-flip meson exchange interference in elastic muon-proton scattering . In particular, we examine the meson exchange in the -channel for a longitudinally polarized beam and a transversely polarized target. We demonstrate the contribution to be larger for muons due to the lepton mass difference. Then we construct the corresponding beam-target double-spin asymmetries for the target polarized normal and parallel to the momentum transfer in the Breit frame, and then consider the model dependence of the calculation from the estimation of the vertex. The contribution was found to be on the order of for muons in the kinematic region of the MUSE experiment.
Sinya Aoki🇯🇵 · Yasumichi Aoki🇯🇵 · Hidenori Fukaya🇯🇵 · Shoji Hashimoto🇯🇵 · Issaku Kanamori🇯🇵 · Takashi Kaneko🇯🇵 · Yoshifumi Nakamura🇯🇵 · Christian Rohrhofer🇯🇵 · Kei Suzuki🇯🇵 · David Ward (JLQCD Collaboration)🇯🇵
We study the anomaly at high temperatures of lattice QCD with chiral fermions. Gauge ensembles are generated with Möbius domain-wall (MDW) fermions, and the measurements are reweighted to those with overlap fermions. We report on the results for the Dirac spectra, the susceptibility, and the topological susceptibility in the temperature range of , , , and MeV, where the up and down quark masses are set to be near the physical point as well as at lighter or heavier masses.
Without invoking any cumulant determination at the input level, we present here the first calculations of direct estimates of the Lee-Yang zeros of QCD partition function in (2+1)-flavor QCD. These zeros are obtained in complex isospin chemical potential plane using the unbiased exponential resummation formalism on lattices and with physical quark masses. For different temperatures, we illustrate the stability of the zeros closest to the origin from which, we subsequently procure the radius of convergence estimates. From the temperature-dependence study of the real and imaginary parts of these zeros, we try estimating one of the possible critical points forming the second order pion condensate critical line in the isospin phase diagram. Further, we compare these resummed estimates with the corresponding Mercer-Roberts estimates of the subsequent Taylor series expansions of the first three partition function cumulants. We also outline comparisons between resummed and Taylor series results of these cumulants for real and imaginary values of and highlight the behavior of different expansion orders within and beyond the obtained resummed estimates of radius of convergence. We also re-establish that this resummed radius of convergence can efficiently capture the onset of overlap problem for finite real simulations.
Mathieu Giroux🇨🇦 · Andrzej Pokraka🇺🇸 · Franziska Porkert🇩🇪 · Yoann Sohnle🇸🇪
We consider the 5-mass kite family of self-energy Feynman integrals and present a systematic approach for constructing an epsilon-form basis, along with its differential equation pulled back onto the moduli space of two tori. Each torus is associated with one of the two distinct elliptic curves this family depends on. We demonstrate how the locations of relevant punctures, which are required to parametrize the full image of the kinematic space onto this moduli space, can be extracted from integrals over maximal cuts. A boundary value is provided such that the differential equation is systematically solved in terms of iterated integrals over g-kernels and modular forms. Then, the numerical evaluation of the master integrals is discussed, and important challenges in that regard are emphasized. In an appendix, we introduce new relations between g-kernels.
Ricardo Z. Ferreira🇵🇹 · Alessio Notari🇪🇸 · Oriol Pujolàs🇪🇸 · Fabrizio Rompineve🇨🇭
Unstable domain wall (DW) networks in the early universe are cosmologically viable and can emit a large amount of gravitational waves (GW) before annihilating. As such, they provide an interpretation for the recent signal reported by Pulsar Timing Array (PTA) collaborations. A related important question is whether such a scenario also leads to significant production of Primordial Black Holes (PBH). We investigate both GW and PBH production using 3D numerical simulations in an expanding background, with box sizes up to , including the annihilation phase. We find that: i) the network decays exponentially, i.e. the false vacuum volume drops as , with the conformal time; ii) the GW spectrum is larger than traditional estimates by more than one order of magnitude, due to a delay between DW annihilation and the sourcing of GWs. We then present a novel semi-analytical method to estimate the PBH abundances: rare false vacuum pockets of super-Hubble size collapse to PBHs if their energy density becomes comparable to the background when they cross the Hubble scale. Smaller (but more abundant) pockets will instead collapse only if they are close to spherical. This introduces very large uncertainties in the final PBH abundance. The first phenomenological implication is that the DW interpretation of the PTA signal is compatible with observational constraints on PBHs, within the uncertainties. Second, in a different parameter region, the dark matter can be entirely in the form of asteroid-mass PBHs from the DW collapse. Remarkably, this would also lead to a GW background in the observable range of LIGO-Virgo-KAGRA and future interferometers, such as LISA and Einstein Telescope.
Gonzalo Alonso-Álvarez🇨🇦 · James M. Cline🇨🇦 · Caitlyn Dewar🇨🇦
Evidence for a stochastic gravitational wave (GW) background, plausibly originating from the merger of supermassive black holes (SMBHs), is accumulating with observations from pulsar timing arrays. An outstanding question is how inspiraling SMBHs get past the "final parsec" of separation, where they have a tendency to stall before GW emission alone can make the binary coalesce. We argue that dynamical friction from the dark matter (DM) spike surrounding the black holes is sufficient to resolve this puzzle, if the DM has a self-interaction cross section of order cm/g. The same effect leads to a softening of the GW spectrum at low frequencies as suggested by the current data. For collisionless cold DM, the friction deposits so much energy that the spike is disrupted and cannot bridge the final parsec, while for self-interacting DM, the isothermal core of the halo can act as a reservoir for the energy liberated from the SMBH orbits. A realistic velocity dependence, such as generated by the exchange of a massive mediator like a dark photon, is favored to give a good fit to the GW spectrum while providing a large enough core. A similar velocity dependence has been advocated for solving the small-scale structure problems of cold DM.
Tucker Manton🇺🇸 · Stephon Alexander🇺🇸
Gravitational wave physics can probe theories that extend beyond General Relativity. Motivated by the attention on the Kalb-Ramond field as a dark matter candidate, in this work, we study a parity violating dimension four operator which couples the dual Riemann curvature to the 2-form field. After mapping the equations of motion for the right- and left-handed gravitational wave amplitudes to the novel parameterization presented in \cite{Jenks:2023pmk}, we discuss constraints on the model parameters in light of the coincident electromagnetic/gravitational wave signal of GW170817.
The primary challenge in detecting ultrahigh energy (UHE) neutrinos with energies exceeding eV is to instrument a large enough volume to detect the extremely low flux, which falls as . We explore in this article the feasibility of using the forest as a detector. Trees have been shown to be efficient broadband antennas, and may, without damage to the tree, be instrumented with a minimum of apparatus. A large scale array of such trees may be the key to achieving the requisite target volumes for UHE neutrino astronomy.
* 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.