HEP Phenomenology·hep-ph
22 papers—19 primary·3 cross-listed·reconstructed*
Expecting scalar contributions to be less important to a given observable signal than vector ones, in usual scenarios, is a natural intuition. Such assertion should hold for a great part of physically relevant parameter space within most models of interest. In this work, besides stressing that the proposition is not general, we show how the alternative possibility may give light to interesting phenomena.
Shota Kikuchi🇯🇵 · Tatsuo Kobayashi🇯🇵 · Yuya Ogawa🇯🇵 · Hikaru Uchida🇯🇵
We study quark mass matrices derived from magnetized orbifold models. Yukawa matrices at three modular fixed points, and are invariant under , and -transformations. We study these invariances on twisted orbifold. We find that Yukawa matrices have a kind of texture structures although ones at are not realistic. We classify Yukawa textures at and . Moreover we investigate the conditions such that quark mass matrix constructed by Yukawa textures becomes approximately rank one matrix, which is favorable to lead to hierarchical masses between the third generation and the others. It is found that realistic quark mass matrices can be obtained around the -invariant vacuum and -invariant vacuum. As an illustrating example, we show the realization of the quark mass ratios and mixing based on Fritzch and Fritzch-Xing mass matrices.
Woojin Jang🇰🇷 · Jason Sang Hun Lee🇰🇷 · Inkyu Park🇰🇷 · Ian James Watson🇰🇷
The Cabibbo-Kobayashi-Maskawa (CKM) element , representing the coupling between the top and strange quarks, is currently best determined through fits based on the unitarity of the CKM matrix, and measured indirectly through box-diagram oscillations, and loop-mediated rare decays of the or mesons. It has been previously proposed to use the tree level decay of the quark to the quark to determine at the LHC, which has become a top factory. In this paper, we extend the proposal by performing a detailed analysis of measuring in dileptonic events. In particular, we perform detector response simulation, including the reconstruction of , which are used for tagging jets produced by quarks against the dominant decay. We show that it should be possible to exclude at 6.0 with the expected High Luminosity LHC luminosity of 3000 fb.
Sam Van Thurenhout🇩🇪 · Sven-Olaf Moch🇩🇪
We introduce a new method for calculating the mixing matrix for non-singlet quark operators including total derivatives, based solely on their renormalization structure in the chiral limit. As input, the method requires the well-known forward anomalous dimensions, which determine the evolution of parton distribution functions, and a calculation of the matrix elements of operators without total derivatives. Assuming a large number of quark flavors , we are able to calculate the mixing matrix to fifth order in the strong coupling in the -scheme.
Feng Gao🇨🇳 · Hao-Song Li🇨🇳
This paper calculates the magnetic moments of the hidden-charm strange pentaquark states with a quantum number of , , , and in the molecular, diquark-diquark-antiquark, and diquark-triquark models, respectively. Numerical results demonstrate that the magnetic moments change for a different spin-orbit coupling with the same model and when involving different models with the same angular momentum.
Wojciech Florkowski🇵🇱 · Radoslaw Ryblewski🇵🇱 · Rajeev Singh🇵🇱 · Gabriel Sophys🇵🇱
Space-time evolution of spin polarization within the framework of hydrodynamics with spin based on de Groot - van Leeuwen - van Weert forms of energy-momentum and spin tensors is studied. Due to the non-boost invariant flow in the system the spin polarization components couple to each other implying some effects on the spin polarization observables. We study transverse-momentum and rapidity dependence of mean spin polarization vector for hyperons. Our results show qualitative agreement for rapidity dependence of the global spin polarization with the experiments and other models. The quadrupole structure of the longitudinal component at midrapidity is not found, however, as compared to the results for Bjorken expansion, some non-trivial signal at forward rapidities is observed.
M.A. Arroyo-Ureña🇲🇽 · G. Hernández-Tomé🇲🇽 · G. López-Castro🇲🇽 · P. Roig🇲🇽 · I. Rosell🇪🇸
We calculate the ratios () at one loop following a large- expansion where Chiral Perturbation Theory is enlarged by including the lightest resonances and respecting the short-distance behavior dictated by QCD. We find and , where the uncertainties are induced fundamentally by the counterterms. We test the lepton universality, obtaining and , and analyze the CKM unitarity, getting results at and from unitarity via and , respectively. We also update the search for non-standard interactions in decays. As a by-product, we report the theoretical radiative corrections to the decay rates: and .} \maketitle
S. I. Godunov🇷🇺 · E. K. Karkaryan🇷🇺 · V. A. Novikov🇷🇺 · A. N. Rozanov🇷🇺 · M. I. Vysotsky🇷🇺 · E. V. Zhemchugov🇷🇺
Dilepton production in proton-proton collision through -fusion with one proton scattered elastically while the second produces a hadron jet is considered. Semi-analytical formulas describing the cross section of a muon pair production are presented.
Ze-Fang Jiang🇨🇳 · Shanshan Cao🇨🇳 · Xiang-Yu Wu🇨🇳 · C. B. Yang🇨🇳 · Ben-Wei Zhang🇨🇳
We study the origin of the directed flow of charged particles produced in relativistic heavy-ion collisions. Three different initial conditions, Bozk-Wyskiel, CCNU and Shen-Alzhrani, of energy density distributions are coupled to the (3+1)-dimensional viscous hydrodynamic model CLVisc, and their effects on the development of the anisotropic medium geometry, pressure gradient and radial flow are systematically compared. By comparing to experimental data at both RHIC and LHC, we find that the directed flow provides a unique constraint on the tilt of the initial medium profile in the plane spanned by the impact parameter and space-time rapidity. Within mid-rapidity, the counter-clockwise tilt is shown to be a crucial source of the positive/negative force by the pressure gradient along the impact parameter () direction at backward/forward rapidity, which drives a negative slope of the component of the medium flow velocity with respect to rapidity, and in the end the same feature of the charged particle directed flow.
Fabian Krinner🇩🇪 · Stephan Paul🇩🇪
In the framework of precision experiments, the search for electric dipole moments and the precise determination of magnetic dipole moments (g-2) have since long been of prime interest. Hadronic decays offer the best accuracy, since only the kinematic information carried by a single neutrino per decay is lost. Thus, they reveal more easily precious information on the helicity of the initial tau lepton. However, in contrast to one- or two-body hadronic final states, the description of hadronic multi-body final states depends on the model for the hadronic current. In this work, we determine how the choice of a hadronic model impacts the extraction of tau electric and magnetic dipole moments.
Cesar Ayala🇨🇱 · Gorazd Cvetic🇨🇱 · Diego Teca🇨🇱
We use improved truncated Operator Product Expansion (OPE) for the Adler function, involving two types of terms with dimension , in the double-pinched Borel-Laplace Sum Rules and Finite Energy Sum Rules for the V+A channel strangeless semihadronic decays. The generation of the higher order perturbative QCD terms of the part of the Adler function is carried out using a renormalon-motivated ansatz incorporating the leading UV renormalon and the first two leading IR renormalons. The trunacted part of the Sum Rules is evaluated by two variants of the fixed-order perturbation theory (FO), by Principal Value of the Borel resummation (PV), and by contour-improved perturbation theory (CI). For the experimental V+A channel spectral function we use the ALEPH -decay data. We point out that the truncated FO and PV evaluation methods account correctly for the renormalon structure of the Sum Rules, while this is not the case for the truncated CI evaluation. We extract the value of the coupling [] for the average of the two FO methods and the PV method, which we consider as our main result. If we included in the average also CI extraction, the value would be []. This work is an extension and improvement of our previous work [Eur.Phys.J.C81 (2021) 10, 930] where we used for the truncated OPE a more naive (and widely used) form and where the extracted values for were somewhat lower.
Ian Balitsky🇺🇸 · Wayne Morris🇺🇸 · Anatoly Radyushkin🇺🇸
We formulate the basic points of the pseudo-PDF approach to the lattice calculation of polarized gluon PDFs. We present the results of our calculations of the one-loop corrections for the bilocal correlator of gluonic fields. Expressions are given for a general situation when all four indices are arbitrary, and also for specific combinations of indices corresponding to three matrix elements that contain the twist-2 invariant amplitude related to the polarized PDF. We study the evolution properties of these matrix elements, and derive matching relations between Euclidean and light-cone Ioffe-time distributions. These relations are necessary for extraction of the polarized gluon distributions from the lattice data.
Guy D. Moore🇩🇪 · Soeren Schlichting🇩🇪 · Niels Schlusser🇩🇪 · Ismail Soudi🇺🇸
The interaction of a jet with the medium created in heavy-ion collisions is not yet fully understood from a QCD perspective. This is mainly due to the non-perturbative nature of this interaction which affects both transverse jet momentum broadening and jet quenching. We discuss how lattice simulations of Electrostatic QCD, can be matched to full, four dimensional QCD, to determine non-perturbative contributions to the momentum broadening kernel. We determine the momentum broadening kernel in impact parameter and momentum space and finally show how these results can be used in phenomenological calculations of in-medium splitting rates.
Rabindra N. Mohapatra🇺🇸 · Nobuchika Okada🇺🇸
We present a unified theory of inflation, neutrino mass, baryogenesis and dark matter where global lepton number symmetry and its breaking play a crucial role. The basic idea is to use a lepton number carrying complex scalar field as the inflaton as well as the field that implements Affleck-Dine (AD) leptogenesis. Dark matter is the massive majoron which is a pseudo-Goldstone boson, resulting from the spontaneous breaking of lepton number symmetry supplemented by explicit lepton number violation needed to implement AD leptogenesis. The magnitude of the resulting in the model is related to the mass of the pseudo-Goldstone dark matter, connecting two apparently disconnected cosmological observations. Inverse seesaw mechanism with lepton number breaking at low scale is crucial to prevent washout of the lepton asymmetry during the universe's evolution. The model seems to provide an economical solution to several puzzles of the standard model of particle physics and cosmology in one stroke.
Vincenzo Cirigliano🇺🇸 · David Díaz-Calderón🇪🇸 · Adam Falkowski🇫🇷 · Martín González-Alonso🇪🇸 · Antonio Rodríguez-Sánchez🇫🇷
Hadronic decays are studied as probe of new physics. We determine the dependence of several inclusive and exclusive observables on the Wilson coefficients of the low-energy effective theory describing charged-current interactions between light quarks and leptons. The analysis includes both strange and non-strange decay channels. The main result is the likelihood function for the Wilson coefficients in the tau sector, based on the up-to-date experimental measurements and state-of-the-art theoretical techniques. The likelihood can be readily combined with inputs from other low-energy precision observables. We discuss a combination with nuclear beta, baryon, pion, and kaon decay data. In particular, we provide a comprehensive and model-independent description of the new physics hints in the combined dataset, which are known under the name of the Cabibbo anomaly.
Pavel Fileviez Perez🇺🇸 · Alexis D. Plascencia🇮🇹
We discuss a simple theory predicting the existence of a Dirac dark matter candidate from gauge anomaly cancellation. In this theory, the spontaneous breaking of local baryon number at the low scale can be understood. We show that the constraint from the dark matter relic abundance implies an upper bound on the theory of a few tens of TeV. We study the correlation between the dark matter constraints and the prediction for the electric dipole moment (EDM) of the electron. We point out the implications for the diphoton decay width of the Standard Model Higgs. Furthermore, we study the decays of the new Higgs present in the theory, we show that the branching ratio into two photons can be large and discuss the strong correlation between the dark matter constraints and the properties of the new Higgs decays. This theory could be tested at current or future experiments by combining the results from dark matter, collider and EDM experiments.
Philip Schuster🇺🇸 · Natalia Toro🇺🇸 · Kevin Zhou🇺🇸
Electron beam fixed target experiments such as NA64 and LDMX use missing energy-momentum to detect the production of dark matter and other long-lived states. The most studied production mechanism is dark Bremsstrahlung through a vector mediator. In this work, we explore a complementary source of missing energy-momentum signals: Bremsstrahlung photons can convert to hard vector mesons in exclusive photoproduction processes, which then decay to dark matter or other invisible particles, such as neutrinos. We find that existing NA64 data can improve the leading constraints on invisible light vector meson decays, while a future run of LDMX could improve them by up to orders of magnitude. For the examples of a dark photon and a gauge boson mediator, accounting for meson decays substantially enhances these experiments' sensitivity, especially to thermal relic dark matter of mass .
Gia Dvali🇩🇪 · Lena Funcke🇺🇸 · Tanmay Vachaspati🇺🇸
We study the formation and evolution of topological defects that arise in the post-recombination phase transition predicted by the gravitational neutrino mass model in [Dvali, Funcke, Phys. Rev. D 93, 113002 (2016)]. In the transition, global skyrmions, monopoles, strings, and domain walls form due to the spontaneous breaking of the neutrino flavor symmetry. These defects are unique in their softness and origin; as they appear at a very low energy scale, they only require Standard Model particle content, and they differ fundamentally depending on the Majorana or Dirac nature of the neutrinos. One of the observational signatures is the time dependence and space dependence of the neutrino mass matrix, which could be observable in future neutrino experiments. Already existing data rule out parts of the parameter space in the Majorana case. The detection of this effect could shed light onto the open question of the Dirac versus Majorana neutrino nature.
Thomas Becher🇨🇭 · Thomas Rauh🇨🇭 · Xiaofeng Xu🇨🇭
The soft radiation emitted in jet cross sections can resolve the directions and colors of individual hard partons, leading to a complicated pattern of logarithmically enhanced terms in the perturbative series. Starting from a factorization theorem and solving the renormalization group equations for its ingredients, these large logarithms can be resummed. In this paper, we extract the two-loop anomalous dimension governing the resummation of subleading logarithms in jet cross sections and other non-global observables. This anomalous dimension can be obtained by considering soft limits of hard amplitudes, but the presence of collinear singularities in intermediate expressions makes its extraction delicate. As a consistency check, we use our results to predict the known subleading non-global logarithms in the two-jet cross section.
Yan Lyu🇨🇳 · Hui Tong🇨🇳 · Takuya Sugiura🇯🇵 · Sinya Aoki🇯🇵 · Takumi Doi🇯🇵 · Tetsuo Hatsuda🇯🇵 · Jie Meng🇨🇳 · Takaya Miyamoto🇯🇵
We present a first study on a pair of triply charmed baryons, in the channel, on the basis of the HAL QCD method. The measurements are perfomed on the -flavor lattice QCD configurations with nearly physical light-quark masses and physical charm-quark mass. We show that the system with the Coulomb repulsion taking into account the charge form factor of leads to the scattering length fm and the effective range fm, which indicates is located in the unitary regime.
Marko Jercic🇭🇷 · Ivan Jercic🇭🇷 · Nikola Poljak🇭🇷
The properties of decays that take place during jet formation cannot be easily deduced from the final distribution of particles in a detector. In this work, we first simulate a system of particles with well defined masses, decay channels, and decay probabilities. This presents the "true system" for which we want to reproduce the decay probability distributions. Assuming we only have the data that this system produces in the detector, we decided to employ an iterative method which uses a neural network as a classifier between events produced in the detector by the "true system" and some arbitrary "test system". In the end, we compare the distributions obtained with the iterative method to the "true" distributions.
John F. Donoghue🇺🇸 · Gabriel Menezes🇧🇷
We provide a brief overview of what is known about Quadratic Gravity, which includes terms quadratic in the curvatures in the fundamental action. This is proposed as a renormalizeable UV completion for quantum gravity which continues to use the metric as the fundamental dynamical variable. However, there are unusual field-theoretic consequences because the propagators contain quartic momentum dependence. At the present stage of our understanding, Quadratic Gravity continues to be a viable candidate for a theory of quantum gravity.
* 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.