HEP Phenomenology·hep-ph
52 papers—36 primary·16 cross-listed·reconstructed*
Recent progress has demonstrated that the decay carries clean short-distance information, attainable from a measurement of time-dependence sensitive to interference effects. We review the ingredients that go into this proposed extraction, and discuss the sensitivity to the CKM parameter as well as to various NP scenarios.
A general formal derivation of the screened massive expansion is provided by Schwinger-Dyson equations. Some known issues of the expansion are clarified and a more general framework is established for a natural extension of the method to two-loop or to amplitudes which are not directly defined by a generating functional. For instance, a one-loop screened expansion is given for the effective gauge-parameter-independent gluon propagator which arises from the pinch-technique.
Michał Czakon🇩🇪 · Felix Eschment🇩🇪 · Tom Schellenberger🇩🇪
We evaluate the one-loop soft current for the emission of two soft gluons or a soft quark-anti-quark pair in massless Quantum Chromodynamics. The results are exact in dimensional regularisation up to a single Feynman integral. Two terms of the Taylor series of the latter integral as a function of with the dimension of spacetime are available from a recent calculation of one-loop triple-collinear splitting functions. Our formulae are necessary for the construction of a subtraction scheme for the evaluation of next-to-next-to-next-to-leading order cross sections in massless QCD.
Zanbin Xing🇨🇳 · Minghui Ding🇩🇪 · Lei Chang🇨🇳
We provide a novel approach to calculate the gravitational form factor of pion under the ladder approximation of the Bethe-Salpeter equation, with contact interactions. Central to this approach is a symmetry-preserving treatment of the dressed amplitude, which shows explicitly the contributions from intrinsic quarks and bound states, the latter being necessary to produce the -term of pion in the soft-pion limit. The approach we provide in this work can be applied to many processes of physical significance.
G.I. Gakh🇺🇦 · M.I. Konchatnij🇺🇦 · N.P. Merenkov🇺🇦 · E. Tomasi-Gustafsson🇫🇷
The dependence of the nucleon polarization in the reaction over different invariant variables in frame of the non-resonant mechanism, has been derived. The nucleon polarization is expressed in terms of six invariant complex amplitudes, assuming the conservation of the hadron electromagnetic currents and the P-invariance of the hadron electromagnetic interaction. An inclusive experimental setup when the proton (or the antiproton) and the pion are detected in coincidence is considered. Numerical estimations were performed for the so called normal polarization in the energy range from threshold up to GeV, using a specific parametrization of the nucleon electromagnetic form factors and taking into account the unpolarized differential cross section of the non-resonant mechanism, as previously calculated.
Jin Min Yang🇨🇳 · Pengxuan Zhu🇨🇳 · Rui Zhu🇨🇳
This is a brief overview on the low energy supersymmetry in light of current experiments including the LHC searches, the dark matter (DM) detections, the muon g-2 and the CDF II measurement of the W-boson mass. We focus on the minimal framework of supersymmetry, namely the minimal supersymmetric model (MSSM), and obtain the following conclusions: (i) The MSSM can survive all current experiments, albeit suffering from the little hierarchy problem due to the heavy stops pushed up by the LHC searches; (ii) The DM relic density can be readily achieved by the thermal freeze-out of the lightest neutralino and the null results of DM direct detections are typically driving the parameter space to the bino-like lightest neutralino region; (iii) The muon g-2 anomaly reported by FNAL and BNL can be explained at 2-sigma level, which indicates light sleptons and electroweakinos possibly accessible at the HL-LHC; (iv) The CDF II measurement of the W-boson mass can be marginally explained, but requires light stops near TeV which may soon be covered by the LHC searches.
Ritesh Ghosh🇮🇳 · Manu Kurian🇨🇦
Electric charge transport of hadronic matter at finite temperature and magnetic field is studied within the linear sigma model. Anisotropic transport coefficients associated with the charge transport are estimated both in the weak and strong regimes of the magnetic field using the transport theory approach. In a weakly magnetized medium, the magnetic field effects are incorporated through the Lorentz force term in the Boltzmann equation. Strong magnetic field puts further constraints on the motion of charged particles through Landau quantization. Magnetic field-dependent thermal relaxation time is obtained from interaction rates of hadrons with the S-matrix approach by considering the Landau level kinematics of the charged hadrons. Mean-field effects are embedded in the analysis through the temperature-dependent hadron masses. Further, the hadronic medium response to a time-varying external electric field is studied in weak and strong magnetic field regimes. It is seen that electromagnetic responses of the hadronic matter have a strong dependence on the mean-field effects, sigma mass, the strength of the external fields, and its evolution in the medium.
Tong Li🇨🇳 · Rui-Jia Zhang🇨🇳 · Chang-Jie Dai🇨🇳
The Witten effect implies the electromagnetic interactions between axions and magnetic monopoles. Based on the quantum electromagnetodynamics, a generic low-energy axion-photon effective field theory was built by introducing two four-potentials ( and ) to describe a photon. More anomalous axion-photon interactions and couplings (, and ) arise in contrary to the ordinary axion coupling . As a consequence, the conventional axion Maxwell equations are further modified. We properly solve the new axion-modified Maxwell equations and obtain the axion-induced electromagnetic fields given a static electric or magnetic field. It turns out that the dominant couplings and can be probed in the presence of external magnetic field and electric field, respectively. The induced oscillating magnetic fields are always suppressed compared with the electric fields for the axions with large Compton wavelengths. This is contrary to the situation in conventional experiments searching for the oscillating magnetic fields induced by sub-eV axions. Thus, we propose new strategies to measure the new couplings for sub-eV axion in haloscope experiments.
Diego Gonzalez🇯🇵 · Naoya Kitajima🇯🇵 · Fuminobu Takahashi🇯🇵 · Wen Yin🇯🇵
We study the formation and evolution of domain walls with initial inflationary fluctuations by numerical lattice calculations that, for the first time, correctly take into account correlations on superhorizon scales. We find that, contrary to the widely-held claim {over the past few tens of years}, the domain wall network exhibits remarkable stability even when the initial distribution is largely biased toward one of the minima. This is due to the fact that the domain wall network retains information about initial conditions on superhorizon scales, and that the scaling solution is not a local attractor in this sense. Our finding immediately implies that such domain walls will have a significant impact on cosmology, including the production of gravitational waves, baryogenesis, and dark matter from domain walls. Applying this result to the axion-like particle domain wall, we show that it not only explains the isotropic cosmic birefringence suggested by the recent analysis, but also predicts anisotropic cosmic birefringence that is nearly scale-invariant on large scales and can be probed by future CMB observations.
There is increasing evidence suggesting a discrepancy between the cosmic dipole observed in the number count of distant galaxies and the one derived from the cosmic microwave background (CMB). In this study, we investigate the possibility that the cosmic dipole problem can be addressed by considering the QCD axion, a hypothetical particle that arises from the spontaneous breaking of the Peccei-Quinn symmetry and is postulated to constitute the dark matter in our universe.
Matthew Gignac🇺🇸 · Can Kilic🇺🇸 · Rakhi Mahbubani🇭🇷 · Taewook Youn🇺🇸
Pixel tracklets, disappearing tracks reconstructed with only pixel hits, have proven to be a promising technique in LHC analyses to search for dark matter candidates at the LHC that belong to a nearly-degenerate electroweak multiplet. However, a Pseudo-Dirac electroweak doublet fermion, arguably the most interesting such possibility, has a shorter lifetime and therefore existing tracklet searches are less sensitive in this case. We assess the performance of a tracklet search optimized for shorter lifetimes by requiring only three pixel hits for the tracklet reconstruction, and by demanding an accompanying soft track for suppressing backgrounds. We estimate how far the sensitivity of existing searches can be extended into the region of parameter space with this optimized search.
M.N. Anaam🇨🇳 · Liang Zheng🇨🇳 · H.M. Alfanda🇨🇳 · Zhongbao Yin🇨🇳
Strange hadron production in pp collisions at TeV is studied with PYTHIA 8 and EPOS event generators via the two-particle correlation method. After pairing charged particles as trigger particles with associated strange hadrons and , the strange baryon to meson per trigger yield ratios / dependent on transverse momentum ( are investigated within the near- and away-side jet region as well as the underlying event (UE) region. The modified string fragmentation effects of color reconnection and string shoving mechanisms implemented in PYTHIA 8 and the final state evolution effects built in EPOS are compared in this study. It is found that dependence of the per trigger yield ratio in UE is similar to that in the inclusive measurements while the in-jet result is smaller. We also show that the ratio at both near- and away-side jet region in the intermediate region decreases significantly with trigger , which suggests the hard process effects might contribute to the strange baryon to meson enhancement at intermediate . The much higher ratio in UE and the striking difference between the near and away side of the in-jet results with low trigger predicted by the EPOS model indicate that the soft process effects induced by the final state evolution further increase the strange baryon production and can be still effective in a higher region compared to the string fragmentation type models.
Surasree Mazumder🇮🇳 · Vinod Chandra🇮🇳 · Santosh K Das🇮🇳
Heavy Quarks (HQs) serve as excellent probes to understand various characteristics of deconfined hot QCD medium, comprising light quarks and gluons, created in the Heavy Ion Collisions (HICs). Strong magnetic fields in non-central HICs may significantly affect HQ dynamics in this medium. Exploring the impact of the magnetic field on the perturbative and non-perturbative transport coefficients of HQ is an intriguing endeavor. This necessitates the development of a comprehensive theoretical framework accommodating the non-perturbative Quantum Chromo Dynamics(npQCD) description alongside perturbative QCD(pQCD). The present work provides such a formulation in which Quarkonium potential in the hot and magnetic QCD medium is implemented as the effective gluon propagator to calculate the rate of elastic scattering between HQ and the light partons inside a medium of hot Quark Gluon Plasma(QGP) in the presence of a strong but uniform magnetic field. Diffusion coefficients of a charm quark have been computed for a short-range Yukawa potential ( pQCD) as well as a long-range confining/non-perturbative potential (npQCD) for two cases in which the velocity of the charm quark is parallel and perpendicular to the magnetic field respectively. Non-perturbative contribution is seen to dominate over the perturbative one in the regime of low temperatures and low to intermediate momenta of charm quark. As the momentum of charm quark as well as the temperature of the medium increase pQCD starts to gain on the npQCD contribution, ultimately prevailing at higher temperatures and charm momenta.
Bhubanjyoti Bhattacharya🇺🇸 · Suman Kumbhakar🇨🇦 · David London🇨🇦 · Nicolas Payot🇨🇦
We impose U spin symmetry () on the Hamiltonian for decays. As expected, we find the equality of amplitudes related by the exchange . We also find that the amplitudes for the processes , and form a U-spin triangle relation. The amplitudes for , and form a similar triangle relation. And these two triangles are related to one another by . We perform fits to the observables for these six decays. If perfect U spin is assumed, the fit is very poor. If U-spin-breaking contributions are added, we find many scenarios that can explain the data. However, in all cases, 100\% U-spin breaking is required, considerably larger than the naive expectation of . This is the U-spin puzzle; it may be strongly hinting at the presence of new physics.
We discuss recent progress in Standard Model predictions related to Higgs boson physics at the LHC and comment on the combination of higher order corrections with potential effects of heavy New Physics parametrised by Effective Field Theories.
Cheng Zhang🇨🇳 · Qian-Shun Dai🇨🇳 · Ding Yu Shao🇨🇳
We study the azimuthal angular decorrelation of the dijet production via photon fusion in ultra-peripheral heavy ion collisions. The impact parameter dependent cross section of quark-antiquark pairs production is derived using the equivalent photon approximation, and the contribution from final-state QCD radiations to the azimuthal angular distribution are calculated within Soft-Collinear Effective Theory. We carry out the QCD resummation of large logarithms of the azimuthal angle as well as the jet radius at next-to-leading logarithmic accuracy. In the end we present the normalized differential cross section for azimuthal decorrelation of the dijet pair and find that our results are consistent with the measurements reported by the ATLAS collaboration.
Xue-Chao Feng · Ke-Wei Wei · Jie-Wu
Based on the mass relations from the Regge phenomenology, we revisit the mass spectrum of meson nonet. The masses of kaon and member of () meson nonet are obtained and the results are compared with the values from different theoretical models. Moreover, the strong decay properties of the kaon and are presented in the model. On the basis of results, we suggest the assignment of meson nonet need further tested in the new experiment in the future. Our results also provide mass constraints for the study of these states.
Yu Shi🇨🇳 · Shu-Yi Wei🇨🇳 · Jian Zhou🇨🇳
We develop a novel Monte Carlo parton branching algorithm based on the Gribov-Levin-Ryskin (GLR) equation. The formulations of both forward evolution and backward evolution for the GLR equation are presented. The results from the Monte Carlo implementation of the GLR equation are in full agreement with its numerical solutions. Our work thus paves the way for developing an event generator that embodies the saturation effect.
The discovery of hadronic states beyond the conventional two-quark meson and three-quark baryon picture in the last two decades is one of the most amazing accomplishments in fundamental physics research. Many experiments contributed to this field despite of the original goals of the design. We review the experimental progress on the study of the quarkoniumlike states -- states with at least one heavy quark-antiquark pair and possible light quarks, also known as XYZ states. We give a general review and then focus on the new experimental results on the X(3872) and its bottom-quark partner X_b, the X(3960), the Y(4260), Y(4500), Y(4660), and Y(10750), and the charged charmoniumlike Z_c and Z_{cs} states. The observations suggest that we did observe hadronic molecules and we also observed hadronic states with some other quark configurations. Possible further studies at the existing and future facilities are briefly discussed.
Guido Martinelli🇮🇹 · Silvano Simula🇮🇹 · Ludovico Vittorio🇫🇷
In this contribution we analyse the heavy-to-light decays through the Dispersive Matrix method, which can be applied to any semileptonic decays of hadrons once lattice QCD computations of the hadronic Form Factors and of the relevant susceptibilities are available. We will explicitly discuss the application of the Dispersive Matrix approach to both and decays. As usual in our analysis strategy, only LQCD computations of the FFs at high values of the momentum transfer will be used to determine the shape of the FFs in the whole kinematical range without making any assumption on their momentum dependence. Then, the experimental data will be used only to obtain our final exclusive determinations of . In this way, our calculation of the FFs allows to obtain pure theoretical estimates of several quantities of phenomenological interest, for instance the ratio of the differential decay rates , which is an important tool for testing Lepton Flavour Universality. We will also present a summary of all the results obtained so far for semileptonic decays within the Dispersive Matrix approach.
K. Hidaka (1)🇯🇵 · H. Eberl (2)🇦🇹 · E. Ginina (2) ((1) Tokyo Gakugei U., (2) HEPHY, Vienna)🇦🇹
We study the CP-even neutral Higgs boson decays in the Minimal Supersymmetric Standard Model (MSSM) with general quark flavor violation (QFV), identifying the h as the Higgs boson with a mass of 125 GeV. We compute the widths of the h decays to at full one-loop level. For the loop-induced h decays to photon photon and gluon gluon we compute the widths at NLO QCD level. {\it For the first time}, we perform a systematic MSSM parameter scan including Supersymmetric (SUSY) QFV parameters respecting all the relevant constraints, i.e. theoretical constraints from vacuum stability conditions and experimental constraints, such as those from K- and B-meson data, electroweak precision data, and the 125 GeV Higgs boson data from recent LHC experiments, as well as the limits on SUSY particle masses from the LHC experiment. We also take into account the expected SUSY particle mass limits from the future HL-LHC experiment in our analysis. {\it In strong contrast to} the usual studies in the MSSM with quark flavor conservation, we find that the deviations of these MSSM decay widths from the Standard Model (SM) values can be quite sizable and that there are significant correlations among these deviations. Future lepton colliders such as ILC, CLIC, CEPC, FCC-ee and MuC can observe such sizable deviations from the SM at high signal significance {\it even after} the failure of SUSY particle discovery at the HL-LHC. In case the deviation pattern shown here is really observed at the lepton colliders, then it would strongly suggest the discovery of QFV SUSY (the MSSM with general QFV).
Rachid Benbrik (1)🇲🇦 · Mohammed Boukidi (1)🇲🇦 · Stefano Moretti (2) (3) ((1) Polydisciplinary Faculty, Laboratory of Fundamental and Applied Physics, Cadi Ayyad University, Sidi Bouzid, Safi, Morocco, (2) School of Physics and Astronomy, University of Southampton, United Kingdom, (3) Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden)🇬🇧
We study the phenomenology of charged Higgs bosons () and Vector-Like Quarks (VLQs), denoted as , the latter possessing a charge identical to the top quark one, within the framework of the Two Higgs Doublet Model Type-II (2HDM-II). Upon examining two scenarios, one featuring a singlet (2HDM-II+) and another a doublet (2HDM-II+), we discover that the presence of VLQs has a significant effect on the (pseudo)scalar sector of the 2HDM-II. In particular, this leads to a reduction in the strict constraint on the mass of the charged Higgs boson, which is imposed by -physics observables, specifically . {The observed reduction stems from modifications in the charged Higgs couplings to the Standard Model (SM) top and bottom quarks}. Notably, the degree of this reduction varies distinctly between the singlet 2HDM+ and doublet 2HDM+ scenarios. Additionally, our investigation extends to constraints imposed by the oblique parameters and on the VLQ mixing angles. Furthermore, to facilitate efficient exploration of the '2HDM-II+VLQ' parameter space, we present results on pair production of VLQs (), followed by and decays, yielding a distinctive final state. This investigation thus provides valuable insights guiding the search for extended Higgs and quark sectors at the Large Hadron Collider (LHC) at CERN.
Jian-Peng Wang🇨🇳 · Qin Qin🇨🇳 · Fu-Sheng Yu🇨🇳
In this letter, we propose a novel approach to concurrently measure the complementary violation observables induced by -odd correlations and their corresponding -even counterparts, where represents time reversal. Our analysis demonstrates that -odd and -even correlations, when satisfying specific conditions, result in cosine and sine strong phase dependencies of the corresponding violation, respectively. Additionally, we identify pairs of these violation observables in hadron decays depend on precisely the same strong phases within the helicity amplitude scheme. This complementarity effectively reduces the strong phase reliance in the study of violation, while also mitigating the risk of suppressed violation due to exceptionally small strong phases. Furthermore, our proposal holds potential for uncovering violation in baryon decays that have not yet been observed in experiments.
J.P. Carlomagno🇦🇷 · S.A. Ferraris🇦🇷 · D. Gómez Dumm🇦🇷 · A.G. Grunfeld🇦🇷
We study the phase diagram in the plane for quark matter under the influence of a strong uniform magnetic field , in the framework of a non-local extension of the two-flavor Polyakov Nambu-Jona-Lasinio model. We analyze the deconfinement and chiral symmetry restoration transitions in the mean field approximation. For the considered parameterization, it is found that there is always a critical end point (CEP) in the plane that separates a first-order transition line from a smooth crossover. The location of the CEP is studied as a function of the magnetic field.
Yi-Song Lu🇨🇳 · You-Kai Wang🇨🇳 · Xiang-Yuan You🇨🇳
Being one of the golden channels for precise measurement of Higgs properties, the process provides an opportunity to detect the anomalous couplings in searching of new physics beyond the Standard Model. In this paper, we adopt the method of spinor helicity amplitudes to calculate the amplitudes of process at the LHC in the frame of the effective dimension-6 operators. Signal processes of CP-even and CP-odd anomalous couplings in Higgs on/off-shell region and their interference are simulated by using the package MCFM. The most sensitive angle to extract the CP violated coupling coefficients, which is defined as the angle between two decay planes in Higgs rest frame, is found for experimental measurements.
One of the simplest extensions of the Standard Model (SM) consists in adding a scalar singlet. This second Higgs boson is able to solve several fundamental problems of SM. Additional scalar particles arise naturally in composite Higgs scenarios in which some confining "strong sector" beyond the SM drives the electroweak symmetry breaking. The underlying strongly coupled gauge theory may be similar to QCD and could be modeled holographically. We construct a bottom-up holographic model for description of the spectrum of composite Higgs particles. The model is based on the holographic Soft Wall model and the Wilson confinement criterion. The constructed model predicts the existence of a second Higgs boson with a mass of about 515 GeV.
Matthias Diez🇦🇹 · Reinhard Alkofer🇦🇹 · Christian Kohlfürst🇩🇪
Particle production through ultra-strong electric fields is a well-studied research field. Nevertheless, despite repeated attempts to relate the production rate within the field to the formation time of a particle, the latter is still shrouded in mystery. We provide an interpretation of a particle distribution at finite times enabling us to isolate and, therefore, identify the relevant time scales regarding particle formation in quantum physics within and beyond perturbation theory.
Clay Cordova🇺🇸 · Sungwoo Hong🇺🇸 · Seth Koren🇺🇸 · Kantaro Ohmori🇯🇵
We explore generalized global symmetries in theories of physics beyond the Standard Model. Theories of bosons generically contain 'non-invertible' chiral symmetries, whose presence indicates a natural paradigm to break this symmetry by an exponentially small amount in an ultraviolet completion. For example, in models of gauged lepton family difference such as the phenomenologically well-motivated , there is a non-invertible lepton number symmetry which protects neutrino masses. We embed these theories in gauged non-Abelian horizontal lepton symmetries, e.g. , where the generalized symmetries are broken nonperturbatively by the existence of lepton family magnetic monopoles. In such theories, either Majorana or Dirac neutrino masses may be generated through quantum gauge theory effects from the charged lepton Yukawas e.g. . These theories require no bevy of new fields nor ad hoc additional global symmetries, but are instead simple, natural, and predictive: the discovery of a lepton family at low energies will reveal the scale at which emerges from a larger gauge symmetry.
The positive hyperon production asymmetries that have been measured at LHC are real demonstrations of string junction role in the baryon charge transfer at baryon production in HE proton-proton interactions. In order to invent the neutral heavy particle with zero baryon charge as a candidate for Dark Matter, it is necessary to turn back to the times of dual topological unitarization of hadroproduction physics, where the pomeron exchanges play leading role with the growing energies. The topological presentation of pomeron exchange at the HE proton-proton collision is a cylinder that is covered with a quark-gluon net. Taking into account that the junction of three gluons (SJ) has the positive baryon number, as well as the antijunction (antiSJ) is of negative baryon charge, the neutral self-connected baryonium configuration with zero baryon charge is a torus that is covered by a discrete number of hexagons with 3 string junction and 3 antijunction vertices each. The possibilities to observ such baryonium tori are discussed in this paper for three cases: collisions at p-p collider, the cosmic particle collisions with the atmosphere, and in the relativistic jets at the Active Galaxy Nuclei as well.
Itamar J. Allali🇺🇸 · Mark P. Hertzberg🇺🇸 · Yi Lyu🇺🇸
In recent work we showed that the relic dark matter abundance of QCD axions can be altered when the Peccei-Quinn (PQ) field is coupled to very light scalar/s, rendering the effective axion mass dynamical in the early universe. In this work we develop this framework further, by introducing a new extended symmetry group to protect the new particles' mass. We find that with a new global symmetry, with large , we can not only account for the lightness of the new scalars, but we can reduce the axion relic abundance in a technically natural way. This opens up the possibility of large PQ scales, including approaching the GUT scale, and still naturally producing the correct relic abundance of axions. Also, in these models the effective PQ scale is relatively small in the very early universe, and so this can help towards alleviating the isocurvature problem from inflation. Furthermore, instead of possible over-closure from cosmic strings, the extended symmetry implies the formation of non-topological textures which provide a relatively small abundance.
We discuss the production of dark matter with mass of order - TeV and couplings to the standard model, a scenario we refer to as the `mesotuned WIMP'. Given the lack of new physics observed at the LHC, indicating we live in a world with some degree of fine-tuning, this scale is a natural scale to expect new particles to appear. However, dark matter with mass in this range and large couplings is difficult to produce with the observed relic abundance via the usual mechanisms. Here we discuss the nonthermal production of dark matter and show that this mechanism can produce the observed dark matter in this mass range, but requires a specific relationship between the dark matter mass and the reheat temperature. It is shown that the avoided deconfinement model removes the dependence on the reheat temperature and predicts a dark matter candidate that can be tested at the Cherenkov Telescope Array and direct detection experiments, offering a natural setting for mesotuned WIMP dark matter.
Bahman Dehnadi🇩🇪 · Ivan Novikov🇩🇪 · Frank J. Tackmann🇩🇪
We present predictions for the photon energy spectrum in inclusive decays mediated by the electromagnetic penguin operator to NLL. We use soft-collinear effective theory (SCET) to resum the singular contributions in the peak region at large photon energy. In the tail region the resummed predictions are matched to fixed order at NLO, where we include the known fixed-order contributions for up to . We develop a method to suitably parametrize the still unknown nonsingular corrections in terms of theory nuisance parameters, whose variations provide an estimate of the associated theory uncertainty. In this context, we also study different ways to treat higher-order cross terms in the matching. Another important aspect of our analysis is the short-distance scheme used for the -quark mass . We find that in the present context, the 1 mass scheme, which was previously used up to 2-loop order, fails to work at 3-loop order, because the mass scheme enters at a soft scale much smaller than here, for which the 1 scheme was not devised. Using instead the MSR mass scheme with , we obtain stable results with good perturbative convergence up to NLL.
Johannes Haller🇩🇪 · Andreas Hoecker🇨🇭 · Roman Kogler🇩🇪 · Klaus Mönig🇩🇪 · Jörg Stelzer🇨🇭
We present results from the global electroweak fit to precision measurements in the Standard Model (SM). The fit uses the latest theoretical calculations for observables on the pole and the boson mass, yielding precise SM predictions for the effective weak mixing angle and the masses of the and Higgs bosons, as well as the top quark. We study the impact of the latest measurements on the fit and provide comparisons of the resulting predictions for individual observables with recent measurements.
Digvijay Wadekar🇺🇸 · Zihui Wang🇺🇸
Cold interstellar gas systems have been used to constrain dark matter (DM) models by the condition that the heating rate from DM must be lower than the astrophysical cooling rate of the gas. Following the methodology of Wadekar and Farrar (2021), we use the interstellar medium of a gas-rich dwarf galaxy, Leo T, and a Milky Way-environment gas cloud, G33.4-8.0 to constrain DM. Leo T is a particularly strong system as its gas can have the lowest cooling rate among all the objects in the late Universe (owing to the low volume density and metallicity of the gas). Milky Way clouds, in some cases, provide complementary limits as the DM-gas relative velocity in them is much larger than that in Leo T. We derive constraints on the following scenarios in which DM can heat the gas: interaction of axions with hydrogen atoms or free electrons in the gas, deceleration of relic magnetically charged DM in gas plasma, dynamical friction from compact DM, hard sphere scattering of composite DM with gas. Our limits are complementary to DM direct detection searches. Detection of more gas-rich low-mass dwarfs like Leo T from upcoming 21cm and optical surveys can improve our bounds.
Amit Adhikary🇵🇱 · Shankha Banerjee🇨🇭 · Rahool Kumar Barman🇺🇸 · Brian Batell🇺🇸 · Biplob Bhattacherjee🇮🇳 · Camellia Bose🇮🇳 · Zhuoni Qian🇨🇳 · Michael Spannowsky🇬🇧
We study the prospects for observing exotic decays of the Standard Model Higgs boson into light beyond the Standard Model scalars with mass in the single Higgs and Higgs pair production channels at the high luminosity run of the Large Hadron Collider (HL-LHC). Discovery prospects for single Higgs production in the gluon-gluon fusion and vector boson fusion modes with the Higgs boson decaying via the exotic mode are analyzed at the HL-LHC. The projected sensitivity for exotic Higgs decays in the non-resonant Higgs pair production channel at the HL-LHC and a future TeV hadron collider (FCC-hh) are also estimated. Furthermore, we study HL-LHC's potential reach for the Higgs-strahlung process in the channel, taking into account the contamination from non-resonant Higgs pair production. Finally, the potential reach for resonant Higgs pair production in the channel % at the HL-LHC is also explored for several choices of . Our studies suggest that significant improvements over existing bounds are achievable in several production channels, motivating new dedicated searches for at the HL-LHC and future colliders.
Pooja Siwach🇺🇸 · Anna M. Suliga🇺🇸 · A. Baha Balantekin🇺🇸
Extreme conditions present in the interiors of the core-collapse supernovae make neutrino-neutrino interactions not only feasible but dominant in specific regions, leading to the non-linear evolution of the neutrino flavor. Results obtained when such collective neutrino oscillations are treated in the mean-field approximation deviate from the results using the many-body picture because of the ignored quantum correlations. We present the first three flavor many-body calculations of the collective neutrino oscillations. The entanglement is quantified in terms of the entanglement entropy and the components of the polarization vector. We propose a qualitative measure of entanglement in terms of flavor-lepton number conserved quantities. We find that in the cases considered in the present work, the entanglement can be underestimated in two flavor approximation. The dependence of the entanglement on mass ordering is also investigated. We also explore the mixing of mass eigenstates in different mass orderings.
Luis Alvarez-Gaume🇺🇸 · Miguel A. Vazquez-Mozo🇪🇸
Anomalies are a very powerful tool in constraining theories beyond the standard model. We give a pedagogical overview of some topics illustrating the important role played by spacetime anomalies in string theory. After discussing the general problem of anomaly cancellation in quantum field theory, the focus is set on the cancellation of anomalies in type-I string theory through the Green-Schwarz mechanism. The notion of anomaly inflow is also reviewed, as well as its application to the evaluation of D-brane anomalous couplings. Finally, we briefly comment on recent developments concerning the reformulation of anomalies in the language of category theory.
Reza Javadinezhad🇺🇸 · Massimo Porrati🇺🇸
The angular momentum radiated in gravitational scattering can be changed by performing a supertranslation of the asymptotic metric, i.e. by adding radiation with infinite wavelenght to the metric. This puzzling property can be avoided by adopting a supertranslation-invariant definition of the angular momentum flux in general relativity. Definitions currently available in the literature cannot reproduce the flux necessary to obtain the correct radiation reaction effects in gravitational scattering. They also disagree with computations of the flux performed using scattering amplitudes and soft graviton theorems. In this paper we provide a new supertranslation-invariant definition of the angular momentum flux in gravitational scattering that uses only asymptotic metric data and reproduces the flux necessary to obtain the correct radiation reaction effects.
Sanatan Digal🇮🇳 · Vinod Mamale🇮🇳 · Sabiar Shaikh🇮🇳
We study lattice cutoff effects on the confinement-deconfinement transition and the symmetry in -Higgs theory in dimensions. The Higgs in this study is a complex triplet with vanishing bare mass and quartic coupling. The lattice cutoff is regulated by varying the number of temporal lattice sites, . Our results show that the nature of the confinement-deconfinement transition depends on . For the transition is found to be the end point of a first-order transition and is first order for . The distributions of the Polyakov loop and other observables, sensitive to the symmetry, show that the strength of explicit breaking decreases with . Up to , the free energy difference between states decreases with , suggesting the realization of symmetry in the continuum limit.
Razieh Emami · Paul Tiede · Sheperd S. Doeleman · Freek Roelofs · Maciek Wielgus · Lindy Blackburn · Matthew Liska · Koushik Chatterjee · Bart Ripperda · Antonio Fuentes · Avery Broderick · Lars Hernquist and 10 other authors
We propose to trace the dynamical motion of a shearing hot spot near the SgrA* source through a dynamical image reconstruction algorithm, StarWarps. Such a hot spot may form as the exhaust of magnetic reconnection in a current sheet near the black hole horizon. A hot spot that is ejected from the current sheet into an orbit in the accretion disk may shear and diffuse due to instabilities at its boundary during its orbit, resulting in a distinct signature. We subdivide the motion to two distinct phases; the first phase refers to the appearance of the hot spot modelled as a bright blob, followed by a subsequent shearing phase simulated as a stretched ellipse. We employ different observational arrays, including EHT(2017,2022) and the next generation event horizon telescope (ngEHTp1, ngEHT) arrays, in which few new additional sites are added to the observational array. We make dynamical image reconstructions for each of these arrays. Subsequently, we infer the hot spot phase in the first phase followed by the axes ratio and the ellipse area in the second phase. We focus on the direct observability of the orbiting hot spot in the sub-mm wavelength. Our analysis demonstrates that newly added dishes may easily trace the first phase as well as part of the second phase, before the flux is reduced substantially. The algorithm used in this work can be extended to any other types of the dynamical motion. Consequently, we conclude that the ngEHT is a key to directly observe the dynamical motions near variable sources, such as SgrA*.
Tingqi Cai🇨🇳 · Qianhang Ding🇨🇳 · Yi Wang🇨🇳
Recent observations indicate a tension between the CMB and quasar dipoles. This tension challenges the cosmological principle. We propose that if we live in a gigaparsec scale void, the CMB and quasar dipolar tension can be reconciled. This is because we are unlikely to live at the center of the void. And a within 10\% offset from the center will impact the quasars and CMB differently in their dipolar anisotropies. As we consider a large and thick void, our setup can also ease the Hubble tension.
Giorgio Galanti🇮🇹 · Marco Roncadelli🇮🇹 · Fabrizio Tavecchio🇮🇹
About one month after the revolutionary discovery of the Gamma Ray Burst (GRB) GRB 221009A and intense theoretical efforts to explain its detection, time seems to us ripe to make an assessment of the axion-like particle (ALP) based scenarios, since it is a common belief that conventional physics would have prevented such a detection. We overcome the almost complete lack of information -- so far only astronomical telegrams have been released -- by relying as much as possible upon the analogy with the emission from the GRB 190114C detected by the MAGIC collaboration in 2019, since it was the highest energy GRB detected before and for a time lapse similar to that over which GRB 221009A has been observed.
Ken'ichi Sugiura🇯🇵 · Shun Furusawa🇯🇵 · Kohsuke Sumiyoshi🇯🇵 · Shoichi Yamada🇯🇵
It is known that muons are scarce just after the birth of a proto-neutron star via a supernova explosion but get more abundant as the proto-neutron star cools via neutrino emissions on the Kelvin-Helmholtz timescale. In this paper we evaluate all the relevant rates of the neutrino interactions with muons at different times in the proto-neutron star cooling. We are particularly interested in the late phase (), which will be accessible in the next Galactic supernova but has not been studied well so far. We calculate both leptonic and semi-leptonic processes, for the latter of which we pay attention also to the form factors with their dependence on the transferred momentum as well as to the modification of the dispersion relations for nucleons on the mean field level. We find that the flavor-exchange reactions and can be dominant, particularly at low energies, over the capture of on neutron and the scatterings of on nucleons as the opacity sources for these species and that the inverse muon decay can overwhelm the scatterings of and on nucleons again at low energies. At high energies, on the other hand, the corrections in the semi-leptonic processes mentioned above are more important. We also show the non-trivial energy- and angular dependences of the flavor-exchange reactions and the inverse muon decay. In the study of the diffusion coefficients from these reactions, we find that is most affected. These pieces of information are indispensable for numerical computations and the interpretation of results thereof for the proto-neutron star cooling particularly at the very late phase.
Gianluca Calcagni🇪🇸 · Marco Frasca🇮🇹 · Anish Ghoshal🇵🇱
We consider a formalism to describe the false-vacuum decay of a scalar field in gauge theories in non-perturbative regimes. We find that the larger the gauge coupling with respect to the self-coupling of the scalar, the shallower the local minimum of the unstable vacuum, to the point where it disappears. This offers the possibility to obtain a consistent picture of early universe cosmology: at high temperatures, a false-vacuum decay is strongly favoured and the universe naturally evolves towards a stable state.
Antonio Boveia🇺🇸 · Mohamed Berkat🇸🇪 · Thomas Y. Chen🇺🇸 · Aman Desai · Caterina Doglioni🇸🇪 · Alex Drlica-Wagner🇺🇸 · Susan Gardner🇺🇸 · Stefania Gori🇺🇸 · Joshua Greaves🇸🇪 · Patrick Harding🇺🇸 · Philip C. Harris🇺🇸 · W. Hugh Lippincott🇺🇸 and 15 other authors
The fundamental nature of Dark Matter is a central theme of the Snowmass 2021 process, extending across all Frontiers. In the last decade, advances in detector technology, analysis techniques and theoretical modeling have enabled a new generation of experiments and searches while broadening the types of candidates we can pursue. Over the next decade, there is great potential for discoveries that would transform our understanding of dark matter. In the following, we outline a road map for discovery developed in collaboration among the Frontiers. A strong portfolio of experiments that delves deep, searches wide, and harnesses the complementarity between techniques is key to tackling this complicated problem, requiring expertise, results, and planning from all Frontiers of the Snowmass 2021 process.
Igor R. Klebanov🇺🇸 · Vladimir Narovlansky🇺🇸 · Zimo Sun🇺🇸 · Grigory Tarnopolsky🇺🇸
A pair of the 2D non-unitary minimal models is known to be equivalent to a variant of the minimal model. We discuss the RG flow from this model to another non-unitary minimal model, . This provides new evidence for its previously proposed Ginzburg-Landau description, which is a symmetric theory of two scalar fields with cubic interactions. We also point out that is equivalent to the superconformal minimal model with the diagonal modular invariant. Using the 5-loop results for theories of scalar fields with cubic interactions, we exhibit the expansions of the dimensions of various operators. Their extrapolations are in quite good agreement with the exact results in 2D. We also use them to approximate the scaling dimensions in for the theories in the universality class.
Razieh Emami🇺🇸 · Richard Anantua🇺🇸 · Angelo Ricarte · Sheperd S. Doeleman🇺🇸 · Avery Broderick🇨🇦 · George Wong🇺🇸 · Lindy Blackburn🇬🇧 · Maciek Wielgus🇩🇪 · Ramesh Narayan · Grant Tremblay · Charles Alcock🇺🇸 · Lars Hernquist🇺🇸 and 6 other authors
We explore the plasma matter content in the innermost accretion disk/jet in M87* as relevant for an enthusiastic search for the signatures of anti-matter in the next generation of the Event Horizon Telescope (ngEHT). We model the impact of non-zero positron-to-electron ratio using different emission models including a constant electron to magnetic pressure (constant model) with a population of non-thermal electrons as well as a R-beta model populated with thermal electrons. In the former case, we pick a semi-analytic fit to the force-free region of a general relativistic magnetohydrodynamic (GRMHD) simulation, while in the latter case, we analyze the GRMHD simulations directly. In both cases, positrons are being added at the post-processing level. We generate polarized images and spectra for some of these models and find out that at the radio frequencies, both of the linear and the circular polarizations get enhanced per adding pairs. On the contrary, we show that at higher frequencies a substantial positron fraction washes out the circular polarization. We report strong degeneracies between different emission models and the positron fraction, though our non-thermal models show more sensitivities to the pair fraction than the thermal models. We conclude that a large theoretical image library is indeed required to fully understand the trends probed in this study, and to place them in the context of large set of parameters which also affect polarimetric images, such as magnetic field strength, black hole spin, and detailed aspects of the electron temperature and the distribution function.
Susana J. Landau🇦🇷 · Micol Benetti🇮🇹 · Alejandro Perez🇫🇷 · Daniel Sudarsky🇲🇽
A discrete space-time structure lying at about the Planck scale may become manifest in the form of very small violations of the conservation of the matter energy-momentum tensor. In order to include such kind of violations, forbidden within the General Relativity framework, the theory of unimodular gravity seems as the simplest option to describe the gravitational interaction. In the cosmological context, a direct consequence of such violation of energy conservation might be heuristically viewed a "diffusion process of matter (both dark and ordinary)" into an effective dark energy term in Einstein's equations, which leads under natural assumptions to an adequate estimate for the value of the cosmological constant. Previous works have also indicated that these kind of models might offer a natural scenario to alleviate the Hubble tension. In this work, we consider a simple model for thecosmological history including a late time occurrence of such energy violation and study the modifications of the predictions for the anisotropy and polarization of the Cosmic Microwave Background (CMB). We compare the model's predictions with recent data from the CMB, Supernovae Type Ia, cosmic chronometers and Baryon Acoustic Oscillations. The results show the potential of this type of model to alleviate the Hubble tension.
Barry T. Chiang🇺🇸 · Jeremiah P. Ostriker🇺🇸 · Hsi-Yu Schive🇹🇼
Ultralight axion-like particles eV, or Fuzzy Dark Matter (FDM), behave comparably to cold dark matter (CDM) on cosmological scales and exhibit a kpc-size de Broglie wavelength capable of alleviating established (sub-)galactic-scale problems of CDM. Substructures inside an FDM halo incur gravitational potential perturbations, resulting in stellar heating sufficient to account for the Galactic disc thickening over a Hubble time, as first demonstrated by Church et al. We present a more sophisticated treatment that incorporates the full baryon and dark matter distributions of the Milky Way and adopts stellar disc kinematics inferred from recent Gaia, APOGEE, and LAMOST surveys. Ubiquitous density granulation and subhalo passages respectively drive inner disc thickening and flaring of the outer disc, resulting in an observationally consistent `U-shaped' disc vertical velocity dispersion profile with the global minimum located near the solar radius. The observed age-velocity dispersion relation in the solar vicinity can be explained by the FDM-substructure-induced heating and places an exclusion bound eV. We assess non-trivial uncertainties in the empirical core-halo relation, FDM subhalo mass function and tidal stripping, and stellar heating estimate. The mass range eV favoured by the observed thick disc kinematics is in tension with several exclusion bounds inferred from dwarf density profiles, stellar streams, and Milky Way satellite populations, which could be significantly relaxed due to the aforesaid uncertainties. Additionally, strongly anisotropic heating could help explain the formation of ultra-thin disc galaxies.
Z. H. Zhang🇨🇳 · L. T. Yang🇨🇳 · Q. Yue🇨🇳 · K. J. Kang🇨🇳 · Y. J. Li🇨🇳 · H. P. An🇨🇳 · Greeshma C.🇹🇼 · J. P. Chang🇨🇳 · Y. H. Chen🇨🇳 · J. P. Cheng🇨🇳 · W. H. Dai🇨🇳 · Z. Deng🇨🇳 and 72 other authors
We present novel constraints on boosted light dark matter particles (denoted as ``'') from evaporating primordial black holes (PBHs) using 205.4 kgday data from the China Jinping Underground Laboratory's CDEX-10 p-type point contact germanium detector with a 160 eVee analysis threshold. from PBHs with masses ranging from 110 g to 710 g are searched in this work. In the presence of PBH abundance compatible with present bounds, our result excludes the -nucleon elastic-scattering cross section region from 3.410 cm to 2.310 cm for of 1 keV to 24 MeV from PBHs with masses of 510 g, as well as from 1.110 cm to 7.610 cm for of 1 keV to 0.6 MeV from PBHs with masses of 710 g. If the -nucleon elastic-scattering cross section can be determined in the future, the abundance of PBHs may be severely constrained by evaporation. With the lower threshold (160 eVee) of the CDEX-10 experiment compared to the previously used experiments, this work allows for a better reach at soft spectra produced by heavier PBHs, which demonstrates the vast potential of such a technical route to pursue from larger PBHs with a low threshold.
Burak Dagli🇹🇷 · Bora Ketenoglu🇹🇷 · Saleh Sultansoy🇹🇷
Luminosities of muon-proton and muon-nucleus collisions at a recently proposed muon-ion collider (MuIC) at Brookhaven National Laboratory (BNL) in the USA have been estimated using A Luminosity Optimizer for High Energy Physics (AloHEP) software keeping in mind beam-beam tune-shift values. It is shown that L = 3.6x10 cms and L = 2.84x10 cms values can be achieved at MuIC. The physics search potential of the collider is superior to HERA. However, LHeC will provide 2 orders of higher luminosities at approximately same center-of-mass (CoM) energies.
Aoumeur Daddi Hammou🇫🇷 · Nicola Bartolo🇮🇹
We study the effect of quantum decoherence on the inflationary cosmological perturbations. This process might imprint specific observational signatures revealing the quantum nature of the inflationary mechanism being related to the longstanding issue of the quantum-to-classical transition of inflationary fluctuations. Several works have investigated the effect of quantum decoherence on the statistical properties of primordial fluctuations. In particular, it has been shown that cosmic decoherence leads to corrections to the curvature power spectrum predicted by standard slow-roll inflation. Equally interesting, a non zero curvature trispectrum has been shown to be purely induced by cosmic decoherence, but surprisingly, decoherence seems not to generate any bispectrum. We further develop such an analysis by adopting a generalized form of the pointer observable, showing that decoherence does induce a non vanishing curvature bispectrum and providing a specific underlying concrete physical process. Present constraints on primordial bispectra allow to put an upper bound on the strength of the environment-system interaction. In full generality, the decoherence-induced bispectrum can be scale dependent provided one imposes the corresponding correction to the power spectrum to be scale independent. Such scale dependence on the largest cosmological scales might represent a distinctive imprint of the quantum decoherence process taking place during inflation. We also provide a criterion that allows to understand when cosmic decoherence induces scale independent corrections, independently of the type of environment considered. As a final result, we study the effect of cosmic decoherence on tensor perturbations and we derive the decoherence corrected tensor-to-scalar perturbation ratio. In specific cases, decoherence induces a blue tilted correction to the standard tensor power spectrum.
* 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.