SearcharxivSearch

arXiv subjects

Kenneth Moats

Publications and source records attributed to Kenneth Moats.

7 recordsLinked to original sources

Spectroscopic Assignments of the Excited $B$-Mesons

Excited $B$-mesons have been observed by the D0, CDF, LHCb and CMS experiments. We use the predictions of the relativized quark model to make quark model spectroscopic assignments for these states. We identify the $B_2^*(5747)$ and $B_1(5721)$ as the $B_2^*[1^3P_2]$ and $B_1[1P_1]$ states and the $B_{s2}^*(5840)$ and $B_{s1}(5830)$ as the $B_{s2}^*[1^3P_2]$ and $B_{s1}[1P_1]$ states. More information is needed to identify the $B_J(5970)$ and $B_J(5840)$ states and we suggest a number of measurements to make this identification: the determination of their $J^P$ quantum numbers and either confirming or ruling out their decays to the $B\pi$ final state. With the current information available we believe it most likely that the $B_J(5970)$ is the $B^*[2^3S_1]$ state, with the $B_J(5840)$ needing confirmation.

hep-ph

$B$ and $B_s$ Meson Spectroscopy

Properties of bottom and bottom-strange mesons are computed in two relativized quark models. Model masses and wavefunctions are used to predict radiative transition rates and the $^3P_0$ quark pair creation model is used to compute strong decay widths. A comparison to recently observed bottom and bottom-strange states is made. We find that there are numerous excited $B$ and $B_s$ mesons that have relatively narrow widths and significant branching ratios to simple final states such as $B\pi$, $B^*\pi$, $BK$, and $B^*K$ that could be observed in the near future.

hep-ph

Properties of Excited Charm and Charm-Strange Mesons

We calculate the properties of excited charm and charm-strange mesons. We use the relativized quark model to calculate their masses and wavefunctions that are used to calculate radiative transition partial widths and the $^3P_0$ quark-pair-creation model to calculate their strong decay widths. We use these results to make quark model spectroscopic assignments for recently observed charm and charm-strange mesons. In particular we find that the properties of the $D_J(2550)^0$ and $D_J^*(2600)^0$ are consistent with those of the $2^1S_0(c\bar{u})$ and the $2^3S_1(c\bar{u})$ states respectively, the $D_1^*(2760)^0$, $D_3^*(2760)^-$, and $D_J(2750)^0$ with those of the $1^3D_1(c\bar{u})$, $1^3D_3(d\bar{c})$, and $1D_2(c\bar{u})$ states respectively. We tentatively identify the $D^*_J(3000)^0$ as the $1^3F_4(c\bar{u})$ and favour the $D_J(3000)^0$ to be the $3^1S_0(c\bar{u})$ although we do not rule out the $1F_3$ and $1F_3'$ assignment. For the recently observed charm-strange mesons we identify the $D_{s1}^*(2709)^\pm$, $D_{s1}^*(2860)^-$, and $D_{s3}^*(2860)^-$ as the $2^3S_1(c\bar{s})$, $1^3D_1(s\bar{c})$, and $1^3D_3(s\bar{c})$ states respectively and suggest that the $D_{sJ}(3044)^\pm$ is most likely the $D_{s1}(2P_1')$ or $D_{s1}(2P_1)$ states although it might be the $D_{s2}^*(2^3P_2)$ with the $DK$ final state too small to be observed with current statistics. Based on the predicted properties of excited states, that they not have too large a total width and they have a reasonable branching ratio to simple final states, we suggest states that should be able to be found in the near future. We expect that the tables of properties summarizing our results will be useful for interpreting future observations of charm and charm-strange mesons.

hep-ph

Bottomonium Mesons and Strategies for Their Observation

The $B$-factories and Large Hadron Collider experiments have demonstrated the ability to observe and measure the properties of bottomonium mesons. In order to discover missing states it is useful to know their properties to develop a successful search strategy. To this end we calculate the masses and decay properties of excited bottomonium states. We use the relativized quark model to calculate the masses and wavefunctions and the $^3P_0$ quark-pair creation model to calculate decay widths to open bottom. We also summarize results for radiative transitions, annihilation decays, hadronic transitions and production cross sections which are used to develop strategies to find these states. We find that the $b\bar{b}$ system has a rich spectroscopy that we expect to be substantially extended by the LHC and $e^+e^-$ experiments in the near future. Some of the most promising possibilities at the LHC are observing the $\chi_{b(1,2)}(3P)$, $\chi_{b(1,2)}(4P)$ and $\eta_b(3S)$ states in $\gamma \mu^+\mu^-$ final states that proceed via radiative transitions through $\Upsilon(nS)$ intermediate states and $1^3D_J$ and $2^3D_J$ into $\gamma\gamma \mu^+\mu^-$ final states proceeding via $1^3P_J\to 1^3S_1$ and $2^3P_J\to 2^3S_1$ intermediate states respectively. Some of the most interesting possibilities in $e^+e^-$ collisions are studying the $1^3D_J$ states via $4\gamma$ cascades starting with the $\Upsilon (3S)$ and the $3^3P_J$ states in $\gamma\gamma\mu^+ \mu^-$ final states starting with the $\Upsilon (4S)$ and proceeding via $\Upsilon (nS)$ intermediate states. Completing the bottomonium spectrum is an important validation of lattice QCD calculations and a test of our understanding of bottomonium states in the context of the quark model.

hep-ph

The $D_{sJ}^*(2860)$ Mesons as Excited D-wave $c\bar{s}$ States

A new charm-strange meson, the $D_{s1}^*(2863)$, has recently been observed by the LHCb collaboration which also determined the $D_{sJ}^*(2860)$ to have spin 3. One of the speculations about the previously observed $D_{s1}^*(2710)$ is that it is the $1^3D_1(c\bar{s})$ state. In this paper we reexamine the quark model properties and assignments of these three states in light of these new measurements. We conclude that the $D_{s1}^*(2863)$ and $D_{s3}^*(2863)$ are the $1^3D_1 (c\bar{s})$ and $1^3D_3 (c\bar{s})$ states respectively and the $D_{s1}^*(2710)$ is the $2^3S_1(c\bar{s})$ state. In addition to these three states there are another three excited $D_s$ states in this mass region still to be found; the $2^1S_0$ and two $1D_2$ states. We calculate the properties of these states and expect that LHCb has the capability of observing these states in the near future.

hep-ph

Constraining the Little Higgs model of Schmaltz, Stolarski, and Thaler with recent results from the LHC

In this paper, we use the latest Higgs measurements from ATLAS and CMS to constrain the parameter space of the model of Schmaltz, Stolarski and Thaler, a Little Higgs model with two Higgs doublets, which we will refer to as the BLH model. We account for all production and decay modes explored at ATLAS and CMS in two scenarios: a general case, which assumes the $h_0$ state is light ($m_{h_0} \approx 125$ GeV) and the masses of the other neutral scalars ($H_0$ and $A_0$) are allowed to vary, and a case with a near-degeneracy between the masses of the $h_0$ and $A_0$ and, for some choices of parameters, the $H_0$ states. The near-degeneracy scenario can result in an enhanced diphoton rate, as measured by ATLAS, but is largely ruled out by a combination of the $h_0 \rightarrow \tau^+\tau^-$ and the heavy $H_0 \rightarrow W^+W^-$ measurements. In the general case, we find large regions of parameter space that are in better agreement with either the ATLAS or CMS results than is the SM. However, a significantly enhanced diphoton rate is only possible through large contributions to the $h_0 \gamma \gamma$ effective coupling from charged Higgs bosons in a region of parameter space that borders on violation of perturbativity in the scalar sector.

hep-ph

Exploring the heavy quark sector of the Bestest Little Higgs model at the LHC

We present discovery limits for heavy quarks in the Bestest Little Higgs model via pair production at the LHC running at $\sqrt{s} = 7 \mathrm{TeV}$. We study pair produced heavy top-like quarks decaying to $b\bar{b}W^+W^-$ and $t\bar{t}ZZ$ final states and singly produced heavy top-like quarks via t-channel $W$ exchange. These results are compared to currently available limits on heavy top-like quark cross sections from CMS (with 1.14 fb$^{-1}$ integrated luminosity) for two scenarios of Yukawa couplings. We find that the CMS data limits the mass of the lightest top partner to larger than 413 GeV in the first scenario, where the two lightest top-partners have a small mass splitting, and 364 GeV in the second scenario, where the mass splitting between the two lightest top-partners is larger.

hep-ph