Wed·Apr 20, 2022Wednesday·April 20, 2022

1. 01*

   Is the resonance $X_0(2900)$ a ground-state or radially excited scalar tetraquark $[ud][\overline{c}\overline{s}]$?

   S. S. Agaev🇦🇿 · K. Azizi🇮🇷 · H. Sundu🇹🇷

   We investigate properties of the ground-state and first radially excited four-quark mesons $X_0$ and $X_0^{\prime }$ with a diquark-antidiquark structure $[ud][\overline{c}\overline{s}]$ and spin-parities $J^{\mathrm{P}}=0^{+}$. Our aim is to reveal whether or not one of these states can be identified with the resonance $X_0(2900)$, recently discovered by the LHCb collaboration. We model $X_0$ and $X_0^{\prime }$ as tetraquarks composed of either axial-vector or scalar diquark and antidiquark pairs. Their spectroscopic parameters are computed by employing the QCD two-point sum rule method and including into analysis vacuum condensates up to dimension $15$. For an axial-axial structure of $X_0^{(\prime )}$, we find partial widths of the decays $X_0^{(\prime )}\to D^{-}{K}^{+}$ and $X_0^{(\prime )}\to D^0{K}^0$, and estimate full widths of the states $X_0^{(\prime )}$. To this end, we calculate the strong couplings at the vertices $X_0^{(\prime )}DK$ in the framework of the light-cone sum rule method. We use also technical approaches of the soft-meson approximation necessary to analyze tetraquark-meson-meson vertices. Obtained results $m=(2545\pm 160)\mathrm{MeV}$ and $m^{\prime }=(3320\pm 120)\mathrm{MeV}$ [$m_{\mathrm{S}}=(2663\pm 110)\mathrm{MeV}$ and $m_{\mathrm{S}}^{\prime }=(3325\pm 85)\mathrm{MeV}$ for a scalar-scalar current] for the masses of the particles $X_0$ and $X_0^{\prime }$, as well as estimates for their full widths ${\Gamma }_0=(140\pm 29)\mathrm{MeV}$ and ${\Gamma }_0^{\prime }=(110\pm 25)\mathrm{MeV}$ allow us to interpret none of them as the resonance $X_0(2900)$ . At the same time, these predictions provide important information about ground-state and radially excited diquark-antidiquark structures $X_0$ and $X_0^{\prime }$, which should be objects of future experimental and theoretical studies.

   hep-phhep-exhep-latPRD(2022)·16 citations
2. 02*

   Changing patterns in electroweak precision with new color-charged states: Oblique corrections and the $W$ boson mass

   Linda M. Carpenter🇺🇸 · Taylor Murphy🇺🇸 · Matthew J. Smylie🇺🇸

   The recent measurement by the CDF Collaboration of the $W$ boson mass is in significant tension with the Standard Model expectation, showing a discrepancy of seven standard deviations. A larger value of $m_W$ affects the global electroweak fit, particularly the best-fit values of the Peskin-Takeuchi parameters $S$, $T$ (and perhaps $U$) that measure oblique corrections from new physics. To meet this challenge, we propose some simple models capable of generating non-negative $S$ and $T$, the latter of which faces the greatest upward pressure from the CDF measurement in scenarios with $U=0$. Our models feature weak multiplets of scalars charged under $\mathrm{SU}(3{)}_{\text{c}}\times \mathrm{U}(1{)}_Y$, which cannot attain nonzero vacuum expectation values but nevertheless produce e.g. $T\ne 0$ given some other mechanism to split the electrically charged and neutral scalars. We compute the oblique corrections in these models and identify ample parameter space supporting the CDF value of $m_W$.

   hep-phPRD(2022)·49 citations
3. 03*

   Bottomonium-like tetraquarks in a chiral quark model

   Gang Yang🇨🇳 · Jialun Ping🇨🇳 · Jorge Segovia🇪🇸

   The low-lying bottomonium-like tetraquarks $b\bar{b}q\bar{q}$ $(q=u,d,s)$ with spin-parity $J^P=0^{+}$, $1^{+}$ and $2^{+}$, and isospin $I=0,1$ or $\frac{1}{2}$, are systematically investigated within the theoretical framework of real- and complex-scaling range of a chiral quark model, which has already been successfully applied in analysis of several multiquark systems. A complete four-body $S$-wave function, which includes meson-meson, diquark-antidiquark and K-type arrangements of quarks, along with all possible color configurations are considered. In the $b\bar{b}q\bar{q}$ $(q=u,d)$ tetraquark system, we found resonance states of $B^{(\ast )}{\bar{B}}^{(\ast )}$, ${\rm Y}\omega$, ${\rm Y}\rho$ and ${\eta }_b\rho$ nature with all possible $I(J^P)$ quantum numbers. Their masses are generally located in the energy range $11.0-11.3$ GeV and their widths are less than $10$ MeV. In addition, extremely narrow resonances, with two-meson strong decay widths less than $1.5$ MeV, are obtained in both $b\bar{b}u\bar{s}$ and $b\bar{b}s\bar{s}$ tetraquark systems. Particularly, four radial excitations of ${\rm Y}{K}^{\ast }$ and ${\eta }_b{K}^{\ast }$ are found at $\sim 11.1$ GeV in $J^P=0^{+}$, $1^{+}$ and $2^{+}$ channels of $b\bar{b}u\bar{s}$ system. One ${\rm Y}(1S)\varphi (2S)$ resonance state is obtained at $11.28$ GeV in the $J^P=1^{+}$ sector.

   hep-phhep-exhep-latnucl-ex+1PRD(2022)·8 citations
4. 04*

   The Triplet Dirac Seesaw in the View of the Recent CDF-II W Mass Anomaly

   Oleg Popov🇰🇷 · Rahul Srivastava🇮🇳

   In the present letter, a Dirac neutrino mass model is presented in the view of the new result on W boson mass of $m_W^{CDF-II}=80.4335\pm 0.0094$ GeV, recently reported by the CDF-II experimental collaboration. The newly measured value of the W mass anomaly shows a 7-$\sigma$ deviation from that predicted by the standard model. The model explains the CDF-II W boson mass anomaly by extending the standard model with hypercharge zero vector-like fermion triplet. Symmetry is amended with a global $U(1{)}_{B-L}$ which is broken with an hypercharge zero electroweak triplet. It is demonstrated that the model can successfully explain CDF-II result, Dirac neutrino mass origin, while satisfying standard model precision constraints and collider constraints with scalar and fermion triplet masses in the ranger $1.4$ TeV$-5.2$ TeV and $100$ TeV $-10^{13}$ GeV, respectively.

   hep-phhep-exPLB(2023)·62 citations
5. 05*

   Conditions of general $Z_2$ symmetry and TM${}_{1,2}$ mixing for the minimal type-I seesaw mechanism in an arbitrary basis

   Masaki J. S. Yang🇯🇵

   In this paper, using a formula for the minimal type-I seesaw mechanism by $LD{L}^T$ (or generalized Cholesky) decomposition, conditions of general $Z_2$-invariance for the neutrino mass matrix $m$ is obtained in an arbitrary basis. The conditions are found to be $(M_{22}{a}_i^{+}-M_{12}{b}_i^{+})(M_{22}{a}_j^{-}-M_{12}{b}_j^{-})=-\det M{b}_i^{+}{b}_j^{-}$ for the $Z_2$-symmetric and -antisymmetric part of a Yukawa matrix $Y_{ij}^{\pm }\equiv (Y\pm TY{)}_{ij}/2\equiv (a_j^{\pm },b_j^{\pm })$ and the right-handed neutrino mass matrix $M_{ij}$. In other words, the symmetric and antisymmetric part of $b_i$ must be proportional to those of the quantity ${\tilde{a}}_i\equiv a_i-\frac{M_{12}}{M_{22}}{b}_i$. They are equivalent to the condition that $m$ is block diagonalized by eigenvectors of the generator $T$. These results are applied to three $Z_2$ symmetries, the $\mu -\tau$ symmetry, the TM${}_1$ mixing, and the magic symmetry which predicts the TM${}_2$ mixing. For the case of TM${}_{1,2}$, the symmetry conditions become $M_{22}^2{\tilde{a}}_1^{\mathrm{TBM}}{\tilde{a}}_2^{\mathrm{TBM}}=-\det M{b}_1^{\mathrm{TBM}}{b}_2^{\mathrm{TBM}}$ and $M_{22}^2{\tilde{a}}_{1,2}^{\mathrm{TBM}}{\tilde{a}}_3^{\mathrm{TBM}}=-\det M{b}_{1,2}^{\mathrm{TBM}}{b}_3^{\mathrm{TBM}}$ with components ${\tilde{a}}_i^{\mathrm{TBM}}$ and $b_i^{\mathrm{TBM}}$ in the TBM basis ${\mathbf{v}}_{1,2,3}$. In particular, for the TM${}_2$ mixing, the magic (anti-)symmetric Yukawa matrix with $S_{2}Y=\pm Y$ is phenomenologically excluded because it predicts $m_2=0$ or $m_1,m_3=0$. In the case where Yukawa is not (anti-)symmetric, the mass singular values are displayed without a root sign.

   hep-phNPB(2022)·6 citations
6. 06*

   Neutrino Flavor Model Building and the Origins of Flavor and CP Violation: A Snowmass White Paper

   Yahya Almumin🇺🇸 · Mu-Chun Chen🇺🇸 · Murong Cheng🇺🇸 · Victor Knapp-Perez🇺🇸 · Yulun Li🇺🇸 · Adreja Mondol🇺🇸 · Saul Ramos-Sanchez🇲🇽 · Michael Ratz🇺🇸 · Shreya Shukla🇺🇸

   The neutrino sector offers one of the most sensitive probes of new physics beyond the Standard Model of Particle Physics. The mechanism of neutrino mass generation is still unknown. The observed suppression of neutrino masses hints at a large scale, conceivably of the order of the scale of a Grand Unified Theory (GUT), a unique feature of neutrinos that is not shared by the charged fermions. The origin of neutrino masses and mixing is part of the outstanding puzzle of fermion masses and mixings, which is not explained in the SM. Flavor model building for both quark and lepton sectors is important in order to gain a better understanding of the origin of the structure of mass hierarchy and flavor mixing, which constitute the dominant fraction of the SM parameters. Recent activities in neutrino flavor model building based on non-Abelian discrete flavor symmetries and modular flavor symmetries have been shown to be a promising direction to explore. The emerging models provide a framework that has a significantly reduced number of undetermined parameters in the flavor sector. Model building based on non-Abelian discrete flavor symmetries and their modular variants enables the particle physics community to interpret the current and anticipated upcoming data from neutrino experiments. Pursuit of flavor model building based on such frameworks can also provide connections to possible UV completions, in particular to string theory. We emphasize the importance of constructing models in which the uncertainties of theoretical predictions are smaller than, or at most compatible with, the error bars of measurements in neutrino experiments.

   hep-phhep-thUniverse(2023)·35 citations
7. 07*

   Chiral perturbation theory for heavy hadrons and chiral effective field theory for heavy hadronic molecules

   Lu Meng🇩🇪 · Bo Wang🇨🇳 · Guang-Juan Wang🇯🇵 · Shi-Lin Zhu🇨🇳

   Chiral symmetry and its spontaneous breaking play an important role both in the light hadron and heavy hadron systems. The chiral perturbation theory ($\chi$PT) is the low energy effective field theory of the QCD. In this work, we shall review the investigations on the chiral corrections to the properties of the heavy mesons and baryons within the framework of $\chi$PT. We will also review the scatterings of the light pseudoscalar mesons and heavy hadrons, through which many new resonances such as the $D_{s0}^{\ast }(2317)$ could be understood. Moreover, many new hadron states were observed experimentally in the past decades. A large group of these states is near-threshold resonances, such as the charged charmoniumlike $Z_c$ and $Z_{cs}$ states, bottomoniumlike $Z_b$ states, hidden-charm pentaquark $P_c$ and $P_{cs}$ states and the doubly charmed $T_{cc}$ state, etc. They are very good candidates of the loosely bound molecular states composed of a pair of charmed (bottom) hadrons, which are very similar to the loosely bound deuteron. The modern nuclear force was built upon the chiral effective field theory ($\chi$EFT), which is the extension of the $\chi$PT to the systems with two matter fields. The long-range and medium-long-range interactions between two nucleons arise from the single- and double-pion exchange respectively, which are well constrained by the chiral symmetry and its spontaneous breaking. The short-distance interactions can be described by the low energy constants. Such a framework works very well for the nucleon-nucleon scattering and nuclei. In this work, we will perform an extensive review of the progress on the heavy hadronic molecular states within the framework of $\chi$EFT. We shall emphasize that the same chiral dynamics not only govern the nuclei and forms the deuteron, but also dictates the shallow bound states or resonances composed of two heavy hadrons.

   hep-phhep-exhep-latnucl-thPhys.Rept.(2023)·347 citations
8. 08*

   Freeze-in and freeze-out of sterile neutrino dark matter

   Rupert Coy🇧🇪 · Michael A. Schmidt🇦🇺

   A sterile neutrino with a keV-scale mass is a compelling dark matter candidate. We propose a new production mechanism involving the decay and annihilation of a complex scalar singlet with a Higgs portal coupling which develops a vacuum expectation value. The interactions of the resulting pseudo Nambu-Goldstone boson may thermalise the dark sector. We determine the region of parameter space where dark sector thermalisation is reached and discuss the most relevant cosmological observables. The scenario can be considered as the combination of a freeze-in of the dark sector followed by relativistic freeze-out.

   hep-phJCAP(2022)·8 citations
9. 09*

   Coulomb-Nuclear Interference: Theory and Practice for pp-Scattering at 13 TeV

   Vladimir Petrov (1)🇷🇺 · Nikolai Tkachenko (1) ((1) A.A. Logunov Institute for High Energy Physics, NRC "Kurchatov Institute", Protvino, Russia)🇷🇺

   We provide a detailed reconsideration of the theoretical basis for the treatment of Coulomb-nuclear interference (CNI) and a corresponding thorough analysis of the procedure of extraction of the basic parameters ${\rho }^{pp},{\sigma }_{tot}^{pp}$ and $B^{pp}$ from the TOTEM data at $\sqrt{s}=13$ TeV. A more substantiated account of CNI, as well as an in-depth statistical analysis of the TOTEM data at low transferred momenta, give results that differ from those published by the TOTEM collaboration.

   hep-phPRD(2022)·12 citations
10. 10*

    Retrieving Inverse Seesaw parameter space for Dirac Phase Leptogenesis

    Ananya Mukherjee🇮🇳 · Nimmala Narendra🇮🇳

    This work addresses the viability of \textit {Dirac phase leptogenesis}, in a scenario where the light Majorana neutrinos acquire masses by the inverse seesaw (ISS) mechanism. We show that, a successful leptogenesis in the ISS, driven (only) by the Dirac CP phase can be achieved with the involvement of an unorthodox form of the rotational matrix $R=e^{i\mathbf{A}}(e^{\mathbf{A}})$ in the Casas-Ibarra parametrisation. This particular structure of $R$ turns out to be an artefact in explaining the observed baryon asymmetry of the Universe in a pure ISS scenario. We detail here the confined regions of the $R$ matrix parameter space, essential for a successful leptogenesis. The $R$-matrix parameter space assists in rescuing the ISS parameter space needed for successful leptogenesis. This finding is otherwise unprecedented in the ISS set up. Making use of the resulted $R$ matrix parameter space we have calculated the branching ratio for the LFV decay $\mu \to e\gamma$. This accounts for an indirect probe of the $R$-matrix parameter space. The branching ratio obtained from the leptogenesis parameter space surpasses the existing bound on the branching ratio that resulted in a scenario of combined effect of linear and inverse seesaw. We also report here that, for $R=e^{i\mathbf{A}}$ choice leptogenesis demands the Dirac CP phase ($\delta$) to oscillate around $\pi /2$, although for the later choice the constraint on $\delta$ is much relaxed.

    hep-ph3 citations
11. 11*

    Spectroscopy of Light Baryons: $\Delta$ Resonances

    Chandni Menapara🇮🇳 · Ajay Kumar Rai🇮🇳

    The spectroscopy of light, strange baryons have been an important aspect with still unknown resonances and intrinsic baryonic properties. The present document is focused on the $\Delta$ baryons unlike earlier work, here all the four isospin states have been separately obtained treating u and d quarks with different constituent masses. The theoretical framework for calculating the resonance masses is hypercentral Constituent Quark Model (hCQM). The confining potential is taken as of linear form alongwith the addition of spin-dependent as well as first order correction term. The results obtained have been compared with many varied approaches as well as experimental available states. In addition to mass spectra, Regge trajectories for (n,$M^2$) and (J,$M^2$) have been plotted. The magnetic moment as well as transition magnetic moment have been calculated using effective quark mass. The radiative decay width has been studied for ${\Delta }^{+}$ and ${\Delta }^0$ channels.

    hep-phInt.J.Mod.Phys.A(2022)·33 citations
12. 12*

    $J/\psi$ near threshold in holographic QCD: A and D gravitational form factors

    Kiminad A. Mamo🇺🇸 · Ismail Zahed🇺🇸

    The diffractive photoproduction of $J/\Psi$ on a nucleon, is mostly due to gluonic exchanges at all $\sqrt{s}$. In holographic QCD (large number of colors and strong ${}^{\prime }$t Hooft coupling), these exchanges are captured by gravitons near threshold, and their Reggeized Pomeron form asymptotically. We revisit our holographic analysis of the A and D gravitational form factors in light of the new lattice data, and use them to refine our predictions for the photoproduction of $J/\Psi$ near threshold, and the comparison to the GlueX data. We use these results to estimate the scalar and mass radii of the nucleon, and describe the gravitational pressure and shear across a nucleon.

    hep-phhep-exhep-thnucl-ex+1PRD(2022)·94 citations
13. 13*

    Two dark matter candidates in three-Higgs-doublet models with $S_3$ symmetry

    A. Kunčinas🇵🇹 · O. M. Ogreid🇳🇴 · P. Osland🇳🇴 · M. N. Rebelo🇵🇹

    Models with an extended scalar electroweak sector can have vanishing vacuum expectation values in a basis where an underlying symmetry is imposed. Such extensions are very well motivated. If a symmetry prevents couplings between fermions and additional scalars, such scalars could become viable dark matter candidates if some additional criteria are satisfied. We catalogue $S_3$-symmetric three-Higgs-doublet models, also allowing for softly broken $S_3$-symmetric scalar potential terms, based on whether a specific model could possibly accommodate a dark matter candidate. The variety of the $S_3$-symmetric family models arises due to different possibilities to arrange vacuum expectation values. Such models can have vacua with one or two vanishing vacuum expectation values. In our study we assume that the dark matter candidate is stabilised by the ${\mathbb{Z}}_2$ symmetry. The ${\mathbb{Z}}_2$ symmetry is a remnant of $S_3$ symmetry which survived spontaneous symmetry breaking, and not superimposed over $S_3$. We explore two models; with an without CP violation. These models have a single dark and two active scalar sectors. The active sectors behave in many aspects like a Type-I two-Higgs-doublet model. The dark matter candidate masses, in two cases, are different from the known (previously studied) models with three scalar doublets. After investigating the models in detail, identifying parameters compatible with both theoretical and experimental constraints, we found that the dark matter candidate mass could be within the range of $[52.5,89]\text{GeV}$ or $[6.5,44.5]\text{GeV}$ for a model with CP violation.

    hep-phPoS(2022)·2 citations
14. 14*

    Light curves of BSM-induced neutrino echoes in the optically-thin limit

    Ryan Eskenasy🇺🇸 · Ali Kheirandish🇺🇸 · Kohta Murase🇺🇸

    High-energy neutrinos from astrophysical transients serve as a probe of neutrino physics beyond the Standard Model. In particular, nonstandard interaction of neutrinos with the cosmic neutrino background or dark matter (DM) may have imprints on not only their spectra but also the arrival and time-delay distributions. Assuming that the interaction occurs at most once during the neutrino propagation, we provide general analytic formulas for light curves of the neutrino echoes induced by BSM. The formulas can be used for constraining neutrino-neutrino scattering, neutrino-DM scattering, and other scattering processes experienced by relativistic particles.

    hep-phastro-ph.HEPRD(2023)·10 citations
15. 15*

    The cross section of the process $e^{+}{e}^{-}\to \Lambda \bar{\Lambda }$ in the vicinity of charmonium $\psi (3770)$ including three-gluon and $D$-meson loop contributions

    Yu.M. Bystritskiy🇷🇺 · A.I. Ahmadov🇷🇺

    The total cross section of the process $e^{+}{e}^{-}\to \Lambda \bar{\Lambda }$ is calculated within the energy range close to the mass of $\psi (3770)$ charmonium state. Two different contributions were considered: the $D$-meson loop and the three gluon charmonium annihilation one. Both of them contribute noticeably and in sum fairly reproduce the data. Large relative phase for these contributions are generated with respect to the pure electromagnetic mechanism. As a by product the fit for the electromagnetic form factor of $\Lambda$-hyperon is obtained for the large momentum transferred region.

    hep-phPRD(2022)·7 citations
16. 16*

    $W$-Boson Mass Anomaly from Scale Invariant 2HDM

    Karim Ghorbani🇮🇷 · Parsa Ghorbani🇮🇷

    The recently reported measurement of the $W$-boson mass by CDF-II collaboration is significantly heavier than that of the Standard Model prediction. We study this anomaly in the scale invariant Two-Higgs-Doublet-Model (SI-2HDM) with a ${\mathbb{Z}}_2$ symmetry to avoid the flavor-changing-neutral-current (FCNC). In this scenario the Higgs particle is the classically massless scalon in the SI-2HDM gaining its mass by radiative corrections, hence being naturally light. Moreover, because of the scale symmetry the model is more predictive respect to the generic 2HDM. We show that the oblique parameters depending on the masses of the charged and CP-even (CP-odd) neutral scalar components of the SI-2HDM denoted respectively by $M_{H^{\pm }}$ and $M_h$ ($M_A$), are large enough to accommodate the $W$-boson mass anomaly in the model. There are as well viable regions in the mass spectrum of the SI-2HDM that evade the experimental bounds from colliders on the charged Higgs and neutral scalars.

    hep-phNPB(2022)·74 citations
17. 17*

    Discovery prospects of a vectorlike top partner decaying to a singlet boson

    Akanksha Bhardwaj🇬🇧 · Kartik Bhide🇮🇳 · Tanumoy Mandal🇮🇳 · Subhadip Mitra🇮🇳 · Cyrin Neeraj🇮🇳

    The possibility of a vectorlike top partner decaying to a new colourless weak-singlet scalar or pseudoscalar has attracted some attention in the literature. We investigate the production of a weak-singlet charge-$2/3$ $T$ quark that can decay to a spinless boson ($\Phi$) and a top quark at the LHC. Earlier, in 2203.13753, we have shown that in a large part of the parameter space, the $T\to t\Phi$ and the loop-induced $\Phi \to gg$ decays become the dominant decay modes for these particles. Here, we investigate the discovery prospects of the $T$ quark in this region through the above decays. In particular, we focus on the $pp\to TT\to (t\Phi )(t\Phi )\to (t(gg))(t(gg))$ channel. Separating this signal from the huge Standard Model background is a challenging task, forcing us to employ a multivariate machine-learning technique. We find that the above channel can be a discovery channel of the top partner in the large part of the parameter space where the above decay chain dominates. Our analysis is largely model-independent, and hence our results would be useful in a broad class of new physics models.

    hep-phhep-exPRD(2022)·27 citations
18. 18*

    Dynamically vanishing Dirac neutrino mass from quantum scale symmetry

    Astrid Eichhorn🇩🇰 · Aaron Held🇩🇪

    We present a mechanism which drives Dirac neutrino masses to tiny values along the Renormalization Group flow, starting from an asymptotically safe ultraviolet completion of the third generation of the Standard Model including quantum gravity. At the same time, the mechanism produces a mass-splitting between the neutrino and the quark sector and also generates the mass splitting between top and bottom quark. The mechanism hinges on the hypercharges of the fermions and produces a tiny neutrino Yukawa coupling, because the right-handed neutrino is sterile and does not carry hypercharge.

    hep-phgr-qchep-thPLB(2023)·26 citations
19. 19*

    Going beyond Soft plus Virtual

    A. H. Ajjath · Pooja Mukherjee🇩🇪 · V. Ravindran🇮🇳

    We present a formalism that sums up the soft-virtual (SV) and next-to-SV (NSV) diagonal contributions to inclusive colorless productions in hadron colliders to all orders in perturbative QCD. Using factorisation theorem, renormalisation group invariance and employing the transcendental structure of perturbative results, we show the exponential behavior of soft-collinear function. This allows us to predict certain SV and NSV terms to all orders from lower order information. We also present an integral representation for the coefficient functions which is suitable for Mellin $N$-space resummation.

    hep-phPRD(2022)·18 citations
20. 20*

    CDF W mass anomaly from a dark sector with a Stueckelberg-Higgs portal

    Mingxuan Du🇨🇳 · Zuowei Liu🇨🇳 · Pran Nath🇺🇸

    We propose an explanation to the new W mass measurement recently reported by the CDF collaboration, which is larger than the standard model expectation by about 7 standard deviations. To alleviate the tensions that are imposed on the electroweak sector by the new W mass measurement, we carry out an analysis in the Stueckelberg extended standard model where a new neutral gauge boson appears which mixes with the two neutral gauge bosons in the electroweak sector both via the Stueckelberg mass terms and via the gauge invariant Stueckelberg-Higgs portal interaction and spoils the custodial symmetry at the tree level so that the simple relation between the W boson mass and the Z boson mass does not hold. We find that such an extension increases the W boson mass if the new gauge boson mass is larger than the Z boson mass. We further show that there exists a significant part of the parameter space in the extended model which includes the CDF mass anomaly and is consistent with the various observables at the Z pole and consistent with the ATLAS dilepton limits. The Stueckelberg $Z_{\mathrm{St}}^{\prime }$ boson, which resolves the CDF W mass anomaly, should be searchable in future LHC experiments.

    hep-phhep-exPLB(2022)·57 citations
21. 21*

    Simulating neutrino echoes induced by secret neutrino interactions

    Jose Alonso Carpio🇺🇸 · Kohta Murase🇺🇸

    New neutrino interactions beyond the Standard Model (BSM) have been of much interest in not only particle physics but also cosmology and astroparticle physics. We numerically investigate the time delay distribution of astrophysical neutrinos that interact with the cosmic neutrino background. Using the Monte Carlo method, we develop a framework that enables us to simulate the time-dependent energy spectra of high-energy neutrinos that experience even multiple scatterings en route and to handle the sharp increase in the cross section at the resonance energy. As an example, we focus on the case of secret neutrino interactions with a scalar mediator. While we find the excellent agreement between analytical and simulation results for small optical depths, our simulations enable us to study even optically-thick cases that are not described by the simplest analytic estimates. Our simulations are used to understand effects of cosmological redshifts, neutrino spectra and flavors. The developments will be useful for probing BSM neutrino interactions with not only current neutrino detectors such as IceCube and Super-Kamiokande but also future neutrino detectors such as IceCube-Gen2 and Hyper-Kamiokande.

    hep-phastro-ph.HEJCAP(2023)·10 citations
22. 22*

    Combined explanation of $W$-mass, muon $g-2$, $R_{K^{(\ast )}}$ and $R_{D^{(\ast )}}$ anomalies in a singlet-triplet scalar leptoquark model

    Arvind Bhaskar🇮🇳 · Anirudhan A. Madathil🇮🇳 · Tanumoy Mandal🇮🇳 · Subhadip Mitra🇮🇳

    In addition to the long-standing anomalies seen in the muon $g-2$, $R_{K^{(\ast )}}$, and $R_{D^{(\ast )}}$ observables by various independent experiments, the CDF Collaboration has found another significant one in the $W$-boson mass. These anomalies might be intertwined at a fundamental level and have a single new-physics explanation. In this paper, we present a simultaneous solution to these anomalies with two scalar leptoquarks of roughly equal mass -- one weak-singlet $S_1$ and the other a weak-triplet $S_3$ -- which mix through a Higgs portal. The solution has only a few new couplings and TeV-scale leptoquarks, making the solution testable at the LHC. We put a lower and upper bound on the leptoquark masses in this setup from the current LHC data and the assumption that all new couplings are within the perturbative limit.

    hep-phPRD(2022)·88 citations
23. 23*

    New reactor data improves robustness of neutrino mass ordering determination

    Peter B. Denton🇺🇸 · Julia Gehrlein🇺🇸

    In neutrino oscillation physics numerous exact degeneracies exist under the name LMA-Dark. These degeneracies make it impossible to determine the sign of $\Delta m_{31}^2$ known as the atmospheric mass ordering with oscillation experiments alone in the presence of new neutrino interactions. The combination of different measurements including multiple oscillation channels and neutrino scattering experiments lifts some aspects of these degeneracies. In fact, previous measurements of coherent elastic neutrino nucleus scattering (CEvNS) by COHERENT already ruled out the LMA-Dark solution for new physics with mediators heavier than $M_{Z^{\prime }}\sim 50$ MeV while cosmological considerations disfavor these scenarios for mediators lighter than $M_{Z^{\prime }}\sim 3$ MeV. Here we leverage new data from the Dresden-II experiment which provides the strongest bounds on CEvNS with reactor neutrinos to date. We show that this data completely removes the degeneracies in the ${\nu }_e$ sector for mediators down to the MeV scale at which point constraints from the early universe take over. While the LMA-Dark degeneracy is lifted in the ${\nu }_e$ sector, it can still be restored in the ${\nu }_{\mu }$ and ${\nu }_{\tau }$ sector or with very specific couplings to up and down quarks, and we speculate on a path forward.

    hep-phhep-exPRD(2022)·34 citations
24. 24*

    $Z$ boson mixing and the mass of the $W$ boson

    Yu-Pan Zeng🇨🇳 · Chengfeng Cai🇨🇳 · Yu-Hang Su🇨🇳 · Hong-Hao Zhang🇨🇳

    We explore the possibility of explaining the $W$ boson mass with an extra gauge boson mixing with the $Z$ boson at tree level. Extra boson mixing with the $Z$ boson will change the expression of the $Z$ boson mass, thus altering the $W$ boson mass. We explore two models in this work. We find that in the Derivative Portal Dark Matter model, there are parameters space which can give the observed $W$ boson mass, as well as the observed Dark Matter relic density. These parameters space can also fulfill the constraints from the electroweak oblique parameters and Dark Matter indirect detection. In the U(1) extension model, the kinetic mixing between extra boson and $B$ boson can also give the observed $W$ boson mass. However, to fulfill electroweak oblique parameters fit the kinetic mixing in the U(1) model can only contribute about $27\mathrm{MeV}$ extra mass to the Standard Model $W$ boson mass. Both models indicate the extra vector boson with the best fit mass around $120\mathrm{GeV}$.

    hep-phPRD(2023)·39 citations
25. 25*

    Detecting High-Energy Neutrino Minibursts from Local Supernovae with Multiple Neutrino Observatories

    Ali Kheirandish🇺🇸 · Kohta Murase🇺🇸

    Growing evidence from multi-wavelength observations of extragalactic supernovae (SNe) has established the presence of dense circumstellar material in Type II SNe. Interaction between the SN ejecta and the circumstellar material should lead to diffusive shock acceleration of cosmic rays and associated high-energy emission. Observation of high-energy neutrinos along with the MeV neutrinos from SNe will provide unprecedented opportunities to understand unanswered questions in cosmic-ray and neutrino physics. We show that current and future neutrino detectors can identify high-energy neutrinos from an extragalactic SN in the neighborhood of the Milky Way. We present the prospects for detecting high-energy neutrino minibursts from SNe in known local galaxies, and demonstrate how the network of multiple high-energy neutrino detectors will extend the horizon for the identification of high-energy SN neutrinos. We also discuss high-energy neutrino emission from SN 2023ixf.

    ↳ astro-ph.HEhep-exhep-phApJ(2023)·37 citations
26. 26*

    Superconducting phase transition in planar fermionic models with Dirac cone tilting

    Y. M. P. Gomes🇧🇷 · Rudnei O. Ramos🇧🇷

    The chiral and superconducting gaps are studied in the context of a planar fermion model with four-fermion interactions. The effect of the tilt of the Dirac cone on both gaps is shown and discussed. Our results point to two different behaviors exhibited by planar fermionic systems. We show that there is a threshold value ${\tilde{t}}^{\ast }$ for the effective tilt parameter such that when $|\tilde{\mathbf{t}}|<{\tilde{t}}^{\ast }$, the superconducting phase persists for negative values of the superconducting coupling constant. For positive values of the superconducting coupling constant, the induction of a superconducting gap by a chemical potential exists and which is similar to the one seen in graphene-like systems. For $|\tilde{\mathbf{t}}|>{\tilde{t}}^{\ast }$ and a negative superconducting coupling constant, the superconducting phase can be present, but it is restricted to a smaller area in the phase portrait. Our analysis also shows that when $|\tilde{\mathbf{t}}|>{\tilde{t}}^{\ast }$ and for positive values for the superconducting coupling constant, the induction of a superconducting gap in the presence of a chemical potential is ruled out. In this case, the increase of the chemical potential works in favor of the manifestation of a metallic phase.

    ↳ cond-mat.str-elhep-phhep-thPRB(2023)·9 citations
27. 27*

    Gamma-ray burst data strongly favor the three-parameter fundamental plane (Dainotti) correlation relation over the two-parameter one

    Shulei Cao🇺🇸 · Maria Dainotti🇯🇵 · Bharat Ratra🇺🇸

    Gamma-ray bursts (GRBs), observed to redshift $z=9.4$, are potential probes of the largely unexplored $z\sim 2.7-9.4$ part of the early Universe. Thus, finding relevant relations among GRB physical properties is crucial. We find that the Platinum GRB data compilation, with 50 long GRBs (with relatively flat plateaus and no flares) in the redshift range $0.553\le z\le 5.0$, and the LGRB95 data compilation, with 95 long GRBs in $0.297\le z\le 9.4$, as well as the 145 GRB combination of the two, strongly favor the three-dimensional (3D) fundamental plane (Dainotti) correlation relation (between the peak prompt lumininosity, the luminosity at the end of the plateau emission, and its rest frame duration) over the two-dimensional one (between the luminosity at the end of the plateau emission and its duration). The 3D Dainotti correlations in the three data sets are standardizable. We find that while LGRB95 data have $\sim 50$% larger intrinsic scatter parameter values than the better-quality Platinum data, they provide somewhat tighter constraints on cosmological-model and GRB-correlation parameters, perhaps solely due to the larger number of data points, 95 versus 50. This suggests that when compiling GRB data for the purpose of constraining cosmological parameters, given the quality of current GRB data, intrinsic scatter parameter reduction must be balanced against reduced sample size.

    ↳ astro-ph.COgr-qchep-phhep-thMNRAS(2022)·53 citations
28. 28*

    Velocity-like maximum polarization: irreversibility and quantum measurements

    Oleg Teryaev🇷🇺

    The polarization emerging in the subsequent scattering processes can never exceed $1$ which corresponds to the fully polarized pure state. This property is shown to be provided by the addition rule similar to that for relativistic velocities never exceeding the speed of light. The cases of spin $1/2$ and $1$ are considered. The photon linear polarization in Thomson scattering is monotonically increasing. This directness is shown to be a consequence of spin measurement procedure and may be the particular example of ithe anticipated relation between quantum measurement and time irreversibility. The emergent polarization may be considered as a case of opposing time's arrows corresponding to microscopic (spin) and macroscopic (momentum) degrees of freedom, respectively.

    ↳ quant-phgr-qchep-phnucl-thPRC(2022)·3 citations
29. 29*

    A new method for directly computing reduced density matrices

    Christian Käding🇦🇹 · Mario Pitschmann🇦🇹

    We demonstrate the power of a first principle-based and practicable method that allows for the perturbative computation of reduced density matrix elements of an open quantum system without making use of any master equations. The approach is based on techniques from non-equilibrium quantum field theory like thermo field dynamics, the Schwinger-Keldsyh formalism, and the Feynman-Vernon influence functional. It does not require the Markov approximation and is essentially a Lehmann-Szymanzik-Zimmermann-like reduction. In order to illustrate this method, we consider a real scalar field as an open quantum system interacting with an environment comprising another real scalar field. We give a general formula that allows for the perturbative computation of density matrix elements for any number of particles in a momentum basis. Finally, we consider a simple toy model and use this formula to obtain expressions for some of the system's reduced density matrix elements.

    ↳ hep-thhep-phquant-phPRD(2023)·33 citations
30. 30*

    The charm-quark contribution to light-by-light scattering in the muon $(g-2)$ from lattice QCD

    En-Hung Chao🇩🇪 · Renwick J. Hudspith🇩🇪 · Antoine Gérardin🇫🇷 · Jeremy R. Green🇮🇪 · Harvey B. Meyer🇩🇪

    We compute the hadronic light-by-light scattering contribution to the muon $g-2$ from the charm quark using lattice QCD. The calculation is performed on ensembles generated with dynamical $(u,d,s)$ quarks at the SU(3)${}_{\mathrm{f}}$ symmetric point with degenerate pion and kaon masses of around 415 MeV. It includes the connected charm contribution, as well as the leading disconnected Wick contraction, involving the correlation between a charm and a light-quark loop. Cutoff effects turn out to be sizeable, which leads us to use lighter-than-physical charm masses, to employ a broad range of lattice spacings reaching down to 0.039 fm and to perform a combined charm-mass and continuum extrapolation. We use the ${\eta }_c$ meson to define the physical charm-mass point and obtain a final value of $a_{\mu }^{\mathrm{HLbL},\mathrm{c}}=(2.8\pm 0.5)\times 10^{-11}$, whose uncertainty is dominated by the systematics of the extrapolation. Our result is consistent with the estimate based on a simple charm-quark loop, whilst being free of any perturbative scheme dependence on the charm mass. The mixed charm-light disconnected contraction contributes a small negative amount to the final value.

    ↳ hep-lathep-phEPJC(2022)·92 citations
31. 31*

    Revisiting the evidences for spectral anomalies in distant blazars: new data on the photon-ALP mixing

    Francesco Cenedese🇮🇹 · Alberto Franceschini🇮🇹 · Giorgio Galanti🇮🇹

    We re-examine possible dependencies on redshift of the spectral parameters of blazars observed at very-high energies (VHEs) with Imaging Atmospheric Cherenkov telescopes (IACTs). This is relevant to assess potential effects with the source distance of the photon to axion-like particle (ALP) mixing, that would deeply affect the propagation of VHE photons across the Universe. We focus our spectral analysis on 38 BL Lac objects (32 high-peaked and 6 intermediate-peaked) up to redshift $z\simeq 0.5$, and a small sample of 5 Flat Spectrum Radio Quasars up to $z=1$ treated independently to increase the redshift baseline. The 78 independent spectra of these sources are first of all carefully corrected for the gamma-gamma interaction with photons of the Extragalactic Background Light, that are responsible for the major redshift-dependent opacity effect. Then, the corrected spectra are fitted with simple power-laws to infer the intrinsic spectral indices ${\Gamma }_{\mathrm{em}}$ at VHE, to test the assumption that such spectral properties are set by the local rather than the global cosmological environment. We find some systematic anti-correlations with redshift of ${\Gamma }_{\mathrm{em}}$ that might indicate, although with low-significance, a spectral anomaly potentially requiring a revision of the photon propagation process. More conclusive tests with higher statistical significance will require the observational improvements offered by the forthcoming new generation of Cherenkov arrays (CTA, ASTRI, LHAASO).

    ↳ astro-ph.HEhep-phMNRAS(2022)·1 citation
32. 32*

    Gauge Field Theory Vacuum and Cosmological Inflation

    George Savvidy🇬🇷

    The deep interrelation between elementary particle physics and cosmology manifests itself when one considers the contribution of quantum fluctuations of vacuum fields to the dark energy and the effective cosmological constant. The contribution of zero-point energy exceeds by many orders of magnitude the observational cosmological upper bound on the energy density of the universe. Therefore it seems natural to expect that vacuum fluctuations of the fundamental fields would influence the cosmological evolution in any way. Our aim in this review article is to describe a recent investigation of the influence of the Yang-Mills vacuum polarisation and of the chromomagnetic condensation on the evolution of Friedmann cosmology, on inflation and on primordial gravitational waves. We derive the quantum energy-momentum tensor and the corresponding quantum equation of state for gauge field theory using the effective Lagrangian approach. The energy-momentum tensor has a term proportional to the space-time metric and provides a finite non-diverging contribution to the effective cosmological constant. This allows to investigate the influence of the gauge field theory vacuum polarisation on the evolution of Friedmann cosmology, inflation and primordial gravitational waves. The Type I-IV solutions of the Friedmann equations induced by the gauge field theory vacuum polarisation provide an alternative inflationary mechanism and a possibility for late-time acceleration. The Type II solution of the Friedmann equations generates the initial exponential expansion of the universe of finite duration and the Type IV solution demonstrates late-time acceleration. The solutions fulfil the necessary conditions for the amplification of primordial gravitational waves.

    ↳ hep-thastro-ph.COgr-qchep-ph0 citations
33. 33*

    Physics in the tau-charm Region at BESIII

    H. B. Li🇨🇳 · W. Gradl🇩🇪 · X. R. Lyu🇺🇸 · C. Z. Yuan🇨🇳 · M. Y. Dong🇨🇳 · Y. N. Gao🇨🇳 · X. C. Lo🇨🇳 · M. Maggiora🇮🇹 · Y. J. Mao🇨🇳 · R. E. Mitchell🇺🇸 · H. P. Peng🇨🇳 · X. Y. Shen🇨🇳 and 22 other authors

    The Beijing Spectrometer (BESIII) collaboration uses $e^{+}{e}^{-}$ collisions in the tau-charm energy region to study a broad spectrum of topics. These include studies of light mesons and light baryons, studies of charmonium, including exotic mesons and baryons containing charmonium, studies of charmed mesons and baryons, studies of QCD and tau physics, as well as searches for new physics. The following is a Snowmass white paper that outlines the BESIII accomplishments and potential in each of these areas.

    ↳ hep-exhep-ph30 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.