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Jonathan L. Rosner

Publications and source records attributed to Jonathan L. Rosner.

At least 19 recordsLinked to original sources
arXiv2025

Flavor Physics at the CEPC: a General Perspective

We discuss the landscape of flavor physics at the Circular Electron-Positron Collider (CEPC), based on the nominal luminosity outlined in its Technical Design Report. The CEPC is designed to operate in multiple modes to address a variety of tasks. At the $Z$ pole, the expected production of 4 Tera $Z$ bosons will provide unique and highly precise measurements of $Z$ boson couplings, while the substantial number of boosted heavy-flavored quarks and leptons produced in clean $Z$ decays will facilitate investigations into their flavor physics with unprecedented precision. We investigate the prospects of measuring various physics benchmarks and discuss their implications for particle theories and phenomenological models. Our studies indicate that, with its highlighted advantages and anticipated excellent detector performance, the CEPC can explore beauty and $τ$ physics in ways that are superior to or complementary with the Belle II and Large-Hadron-Collider-beauty experiments, potentially enabling the detection of new physics at energy scales of 10 TeV and above. This potential also extends to the observation of yet-to-be-discovered rare and exotic processes, as well as testing fundamental principles such as lepton flavor universality, lepton and baryon number conservation, etc., making the CEPC a vibrant platform for flavor physics research. The $WW$ threshold scan, Higgs-factory operation and top-pair productions of the CEPC further enhance its merits in this regard, especially for measuring the Cabibbo-Kobayashi-Maskawa matrix elements, and Flavor-Changing-Neutral-Current physics of Higgs boson and top quarks. We outline the requirements for detector performance and considerations for future development to achieve the anticipated scientific goals.

hep-ex↗
arXiv2024

Possible mixing of a diquark-antidiquark with a $p \bar p$ hadronic molecule

We discuss the possibility that the two nearby resonances observed by BESIII partially below the \,$p\bar p$\, threshold might be due to mixing between two metastable states with the same $J^{PC}=0^{-+}$ quantum numbers, but rather different internal structure. One is a $p \bar p$ hadronic molecule and the other a bound state of a light-quark diquark and an antidiquark, both with spin 1 and isospin 0, a composite color antitriplet and triplet, respectively. The doubling of resonances, one of which may be interpreted as a hadronic molecule, while the other arises from $q \bar q$ annihilation in a state with vacuum quantum numbers may be a more general feature than the specific case considered here.

hep-ph↗
arXiv2023

Single-photon decays in systems with at least one heavy quark

Hadrons containing at least one heavy quark (charm or bottom) frequently have small enough natural widths that decay modes involving a single photon have detectable branching fractions. Photons of typical energy greater than 100 MeV have been directly detected, while those of lower energy have only been inferred. Here we discuss prospects for observing direct sub-100 MeV photons in specific radiative decays of charmed and bottom vector mesons, as well as a spin-excited heavy baryon.

hep-ph↗
arXiv2023

Excited $Ω_c$ baryons as 2S states

The LHCb experiment has recently reported two excited $Ω_c$ resonances decaying to $Ξ_c^+ K^-$, with masses about 3185 and 3327 MeV. We discuss their assignment to $2S_{1/2}$ and $2S_{3/2}$ states, which can be compared with masses based on extrapolation from the observed 1S states. The agreement is not perfect, but weighs against an earlier alternative assignment.

hep-ph↗
arXiv2022

Substructure of Multiquark Hadrons (Snowmass 2021 White Paper)

In recent years there has been a rapidly growing body of experimental evidence for existence of exotic, multiquark hadrons, i.e. mesons which contain additional quarks, beyond the usual quark-antiquark pair and baryons which consist of more than three quarks. In all cases with robust evidence they contain at least one heavy quark Q=c or b, the majority including two heavy quarks. Two key theoretical questions have been triggered by these discoveries: (a) how are quarks organized inside these multiquark states -- as compact objects with all quarks within one confinement volume, interacting via color forces, perhaps with an important role played by diquarks, or as deuteron-like hadronic molecules, bound by light-meson exchange? (b) what other multiquark states should we expect? The two questions are tightly intertwined. Each of the interpretations provides a natural explanation of parts of the data, but neither explains all of the data. It is quite possible that both kinds of structures appear in Nature. It may also be the case that certain states are superpositions of the compact and molecular configurations. This Whitepaper brings together contributions from many leading practitioners in the field, representing a wide spectrum of theoretical interpretations. We discuss the importance of future experimental and phenomenological work, which will lead to better understandingof multiquark phenomena in QCD.

hep-ph↗
arXiv2022

The doubly charmed strange tetraquark

The LHCb experiment at CERN has discovered a doubly charmed isoscalar tetraquark $T_{cc}$ with the quantum numbers of $c c \bar u \bar d$ and mass of about 3875 MeV/$c^2$, decaying to $D^0 D^0 π^+$ through the intermediate channel $D^{*+} D^0$. We present a study of its strange companions with the quantum numbers of $c c \bar q \bar s$, where $q = u, d$ and isospin violation is neglected.

hep-ph↗
arXiv2021

Configuration mixing in strange tetraquarks $Z_{cs}$

The BESIII Collaboration has observed a candidate for a $c \bar c s \bar u$ tetraquark $Z_{cs}$ at $(3982.5^{+1.8}_{-2.6} \pm 2.1)$ MeV and width $(12.8^{+5.3}_{-4.4} \pm 3.0)$ MeV, while the LHCb Collaboration has observed a $Z_{cs}$ candidate in the $\jpsi K^-$ channel with mass of $(4003 \pm 6 ^{+4}_{-14})$ MeV and width $(131 \pm 15 \pm 26)$ MeV. In this note we examine the possibility that these two states are distinct eigenstates of a mixing process similar to that which gives rise to two axial-vector mesons labeled by the Particle Data Group $K_1(1270)$ and $K_1(1400)$. The main point is that on top of a $\bar c c$ pair, the $Z_{cs}$ states have the same light quark content as the $K_1$-s. In the compact tetraquark picture this implies several additional states, analogous to members of the $K_1$ nonet. These states have not yet been observed, nor are they required in the molecular approach. Thus experimental discovery or exclusion of these extra states will be a critical test for competing models of exotic mesons with hidden charm.

hep-ph↗
arXiv2020

Interpretation of structure in the di-$J/ψ$ spectrum

Structure in the di-$J/ψ$ mass spectrum observed by the LHCb experiment around 6.9 and 7.2 GeV is interpreted in terms of $J^{PC}=0^{++}$ and $2^{++}$ resonances between a $cc$ diquark and a $\bar c \bar c$ antidiquark, using a recently confirmed string-junction picture to calculate tetraquark masses. The main peak around 6.9 GeV is likely dominated by the $0^{++}(2S)$ state, a radial excitation of the $cc$-$\bar c \bar c$ tetraquark, which we predict at $6.871\pm 0.025$ GeV. The dip around 6.75 GeV is ascribed to the opening of the \Swave\ di-$χ_{c0}$ channel, while the dip around 7.2 GeV could be correlated with the opening of the di-$η_c(2S)$ or $Ξ_{cc} \bar Ξ_{cc}$ channel. The low-mass part of the di-$J/ψ$ structure appears to require a broad resonance consistent with a predicted $2^{++}(1S)$ state with invariant mass around $M_{\rm inv} = 6400$ MeV. Implications for $bb \bar b \bar b$ tetraquarks are discussed.

hep-ph↗
arXiv2020

First exotic hadron with open heavy flavor: $cs\bar u\bar d$ tetraquark

The LHCb Collaboration has reported resonant activity in the channel $D^+ K^-$, identifying two components: $X_0(2900)$ with $J^P = 0^+$ at $2866 {\pm} 7$ MeV, $Γ_0=57{\pm} 13$ MeV and $X_1(2900)$ with $J^P = 1^-$ at $2904 {\pm} 7$ MeV, $Γ_1=110{\pm} 12$ MeV. We interpret the $X_0(2900)$ component as a $cs \bar u\bar d$ isosinglet compact tetraquark, calculating its mass to be $2863 {\pm} 12$ MeV. This is the first exotic hadron with open heavy flavor. The analogous $bs\bar u\bar d$ tetraquark is predicted at $6213 {\pm} 12$ MeV. We discuss possible interpretations of the heavier and wider $X_1(2900)$ state and examine potential implications for other systems with two heavy quarks.

hep-ph↗
arXiv2020

Interpretation of excited $Ω_b$ signals

Recently LHCb reported the discovery of four extremely narrow excited $Ω_b$ baryons decaying into $Ξ_b^0 K^-$. We interpret these baryons as bound states of a $b$-quark and a $P$-wave $ss$-diquark. For such a system there are exactly five possible combinations of spin and orbital angular momentum. We predict two of spin 1/2, two of spin 3/2, and one of spin 5/2, all with negative parity. We favor identifying the observed states as those those with spins 1/2 and 3/2, and give a range of predicted masses for the one with spin 5/2. We update earlier predictions for these states based on the five narrow excited $Ω_c$ states reported by LHCb. An alternative picture of the states in which one of $J=1/2$ is extremely wide and hence not seen by LHCb is discussed.

hep-ph↗
arXiv2020

Mass inequalities for baryons with heavy quarks

Baryons with one or more heavy quarks have been shown, in the context of a nonrelativistic description, to exhibit mass inequalities under permutations of their quarks, when spin averages are taken. These inequalities sometimes are invalidated when spin-dependent forces are taken into account. A notable instance is the inequality $2E(Mmm) > E(MMm) + E(mmm)$, where $m = m_u = m_d$, satisfied for $M = m_b$ or $M = m_c$ but not for $M = m_s$, unless care is taken to remove effects of spin-spin interactions. Thus in the quark-level analog of nuclear fusion, the reactions $Λ_b Λ_b \to Ξ_{bb}N$ and $Λ_c Λ_c \to Ξ_{cc}^{++}n$ are exothermic, releasing respectively 138 and 12 MeV, while $ΛΛ\to ΞN$ is endothermic, requiring an input of between 23 and 29 MeV. Here we explore such mass inequalities in the context of an approach, previously shown to predict masses successfully, in which contributions consist of additive constituent-quark masses, spin-spin interactions, and additional binding terms for pairs each member of which is at least as heavy as a strange quark.

hep-ph↗
arXiv2020

Duality Between Hydrogen Atom and Oscillator Systems via Hidden SO(d,2) Symmetry and 2T-physics

The relation between motion in $-1/r$ and $r^{2}$ potentials, known since Newton, can be demonstrated by the substitution $r\rightarrow r^{2}$ in the classical/quantum radial equations of the Kepler/Hydrogen problems versus the harmonic oscillator. This suggests a duality-type relationship between these systems. However, when both radial and angular components of these systems are included the possibility of a true duality seems to be remote. Indeed, investigations that explored and generalized Newton's radial relation, including algebraic approaches based on noncompact groups such as SO(4,2), have never exhibited a full duality consistent with Newton's. On the other hand, 2T-physics predicts a host of dualities between pairs of a huge set of systems that includes Newton's two systems. These dualities take the form of rather complicated canonical transformations that relate the full phase spaces of these respective systems in all directions. In this paper we focus on Newton's case by imposing his radial relation to find an appropriate basis for 2T-physics dualities, and then construct the full duality. Using the techniques of 2T-physics, we discuss the hidden symmetry of the actions (beyond the symmetry of Hamiltonians) for the Hydrogen atom in $D$-dimensions and the harmonic oscillator in $\bar{D}$ dimensions. The symmetries lead us to find the one-to-one relation between the quantum states, including angular degrees of freedom, for specific values of $\left( D,\bar{D}\right) $, and construct the explicit quantum canonical transformation in those special cases. We find that the canonical transformation has itself a hidden gauge symmetry that is crucial for the respective phase spaces to be dual even when $D\neq\bar{D}$. In this way we display the surprising beautiful symmetry of the full duality that generalizes Newton's radial duality.

hep-th↗
arXiv2019

Heavy-quark exotics

The heavy quarks $c$ and $b$ stabilize exotic meson $(qq\bar q \bar q)$ and baryon $(qqqq \bar q)$ states. We discuss work with M. Karliner on molecules containing $c \bar c$ and $b \bar b$; the first doubly charmed baryon; isospin splittings; $Ξ_{cc}^+ = ccd$ and $Ω_{cc} = ccs$ masses; lifetimes; tetraquarks stable under strong and electromagnetic decay; excited $Ω_{c}$ states; and P-wave excitation energies.

hep-ph↗
arXiv2019

Status of isospin splittings in mesons and baryons

Current measurements of isospin splittings in mesons and baryons are sufficiently precise that they allow estimates of the mass difference between constituent up and down quarks. Some previous results are updated in the light of these new measurements, and the importance of better measurements of some observables such as $M(K^{*\pm})$, $M(B^{*0})-M(B^0)$, and isospin splittings in bottom baryons is noted.

hep-ph↗
arXiv2018

Scaling of P-wave excitation energies in heavy-quark systems

A simple regularity in anticipating P-wave excitation energies of states with heavy quarks is noted. It can apply to systems such as the negative-parity $Σ_c$, $Σ_b$, and $Ω_c$, $\bar Q Q$ quarkonia, and the bottom-charmed meson $B_c$. When one subtracts a term accounting for phenomenological energies of heavy quarks binding with one another in S-waves, the residual excitation energies display an approximately linear behavior in the reduced mass of constituents, all the way from the $Λ$ to the $Υ$.

hep-ph↗
arXiv2018

Addendum to "Overview of $Λ_c$ decays''

An earlier analysis of observed and anticipated $Λ_c$ decays [M. Gronau and J. L. Rosner, Phys.\ Rev.\ D {\bf 97}, 116015 (2018)] is provided with a table of inputs and a figure denoting branching fractions. This addendum is based on the 2018 Particle Data Group compilation and employs a statistical isospin model to estimate branching fractions for as-yet-unseen decay modes.

hep-ph↗