HEP Phenomenology·hep-ph

Thu·Jan 2, 2020Thursday·January 2, 2020

12 papers—7 primary·5 cross-listed·reconstructed*

01*
Probing Exotic Triple Higgs Couplings at the LHC
Christina Gao🇺🇸 · Nicolás A. Neill🇨🇱
In extended Higgs sectors that exhibit alignment without decoupling, the additional scalars are allowed to have large couplings to the Standard Model Higgs. We show that current nonresonant di-Higgs searches can be straightforwardly adapted to look for additional Higgses in these scenarios, where pair production of non-SM Higgses can be enhanced. For concreteness, we study pair production of exotic Higgses in the context of an almost inert two Higgs doublet model, where alignment is explained through an approximate $Z_{2}$ symmetry under which the additional scalars are odd. In this context, the smallness of the $Z_{2}$ violating parameter suppresses single production of exotic Higgses, but it does not prevent a sizeable trilinear coupling $h H H$ between the SM Higgs ( $h$ ) and the additional states ( $H$ ). We study the process $pp \to h^{*} \to H H$ in the final states $b b ˉ b b ˉ$ , $b b ˉ γ γ$ , and multi-leptons. We find that at the HL-LHC these modes could be sensitive to masses of the additional neutral scalars in the range $130 \mbox G e V ≲ m_{H} ≲ 290 \mbox G e V$ .
hep-phJHEP(2020)·2 citations
02*
Do Proton-Proton collisions at the LHC energies produce Droplets of Quark-Gluon Plasma?
Raghunath Sahoo🇮🇳
The proton-proton ( $pp$ ) collisions at the Large Hadron Collider (LHC), CERN, Switzerland has brought up new challenges and opportunities in understanding the experimental findings in contrast to the conventional lower energy $pp$ collisions. Usually $pp$ collisions are used as the baseline measurement at the GeV and TeV energies in order to understand a possible high density QCD medium formation in heavy-ion collisions. However, the TeV $pp$ collisions have created a new domain of research, where scientists have started observing heavy-ion-like features (signatures) in high-multiplicity $pp$ collisions. This warrants a relook into TeV $pp$ collisions, if at all QGP-droplets are produced in such collisions. In this presentation, I discuss some of the new findings and concepts emerging out in $pp$ collisions at the LHC energies along with some of the new emergent phenomena in particle production.
hep-phhep-exnucl-exnucl-thSpringer Proc.Phys.(2020)·3 citations
03*
$B_{c}$ Meson Spectrum Via Dyson-Schwinger Equation and Bethe-Salpeter Equation Approach
Muyang Chen🇨🇳 · Lei Chang🇨🇳 · Yu-xin Liu🇨🇳
We predict the masses of the lowlying $B_{c}$ mesons with $J^{P} = 0^{-}, 1^{-}, 0^{+}, 1^{+}, 2^{+}$ , using a flavor dependent interaction pattern which gives an unified successful description of the light, heavy-light and heavy mesons and is also appliable to the radial excited heavy mesons. The errors are controlled carefully. With the errors from the RL approximation subduced, our predictions are consistent with the lQCD and quark model results, which supports strongly that the flavor dependent interaction pattern is reasonable. Our predictions provide significant guides to the experiment search of the $B_{c}$ mesons.
hep-phPRD(2020)·33 citations
04*
Are the $Y$ states around 4.6 GeV from $e^{+} e^{-}$ annihilation higher charmonia?
Jun-Zhang Wang🇨🇳 · Ri-Qing Qian🇨🇳 · Xiang Liu🇨🇳 · Takayuki Matsuki🇯🇵
In this work, we present the mass spectrum of higher charomona around and above 4.6 GeV by adopting the unquenched potential model. We perform a combined fit to the updated experimental data of $e^{+} e^{-} \to ψ (2 S) π^{+} π^{-}$ and $e^{+} e^{-} \to Λ_{c} Λ ˉ_{c}$ . To understand the "platform" structure observed in the range of $4.57 \sim 4.60$ GeV existing in the $Λ_{c} Λ ˉ_{c}$ invariant mass spectrum of $e^{+} e^{-} \to Λ_{c} Λ ˉ_{c}$ of BESIII, we introduce two resonances in this combined fit to the $e^{+} e^{-} \to ψ (2 S) π^{+} π^{-}$ and $e^{+} e^{-} \to Λ_{c} Λ ˉ_{c}$ , which have resonance parameters, $m_{Y_{1}} = 4585 \pm 2$ MeV, $Γ_{Y_{1}} = 29.8 \pm 8.0$ MeV, $m_{Y_{2}} = 4676 \pm 7$ MeV, and $Γ_{Y_{2}} = 85.7 \pm 15.0$ MeV. Furthermore, combining with our theoretical results, we indicate that the two charmonium-like $Y$ states can be due to two higher charmonia, which are mixtures of $6 S$ and $5 D$ $c c ˉ$ states. Their two-body open-charm decay behaviors are given. Under the same framework, our analysis of the data of $e^{+} e^{-} \to D_{s}^{+} D_{s 1} (2536)^{-}$ recently released by Belle supports to introduce these two higher charmonia around 4.6 GeV. Additionally, we predict the masses and two-body open-charm decays of six higher charmonia $ψ (n S)$ and $ψ (m D)$ with $n = 7, 8, 9$ and $m = 6, 7, 8$ above 4.6 GeV. Search for these higher charmonia will be an interesting issue for the running BESIII and BelleII, and even the possible Super Tau-Charm Factory discussed in China.
hep-phhep-exPRD(2020)·39 citations
05*
Ernest Henley and the shape of baryons
Alfons J. Buchmann🇩🇪
Calculations of pion-baryon couplings, baryon quadrupole and octupole moments, baryon spin and orbital angular momentum done in collaboration with Ernest Henley are reviewed. A common theme of this work is the shape of baryons. Also, a personal account of my work with Ernest Henley during the period 1999-2013 is given.
hep-phnucl-thIJMPE(2019)·2 citations
06*
Production of $P -$ wave charmed and charmed-strange mesons in pion and kaon induced reactions
Jing Liu🇨🇳 · Qi Wu🇨🇳 · Jun He🇨🇳 · Dian-Yong Chen🇨🇳 · Takayuki Matsuki🇯🇵
In the present work, we investigate the production of $P -$ wave charmed or charmed-strange mesons in the pion or kaon induced reactions on a proton target. The total cross sections as well as the differential cross sections depending on the scattering angle are evaluated in an effective Lagrangian approach. Our estimations indicate that magnitude of the cross sections strongly depends on the model parameter but such dependence can be almost completely canceled for the cross section ratios. These model independent ratios can be taken as a good criterion of the validity of heavy quark limit in the charmed region, which is helpful to understand $P$ -wave charmed and charmed-strange mesons.
hep-phhep-exPRD(2020)·11 citations
07*
Generation of quasiparticles by particle-antiparticle mixing and limitations of quantum mechanics
Chang-Hun Lee🇹🇼
The mixing of a neutral unstable particle and its antiparticle has been usually discussed in the framework of quantum mechanics in the literature. In this paper, the particle-antiparticle mixing is discussed fully in the quantum field theory, and it is shown that quantum mechanics is not the proper non-relativistic limit of the quantum field theory in the presence of such mixing. Moreover, it is also shown that a discrepancy indeed exists between the results from quantum mechanics and the quantum field theory, which can sometimes make big differences in theoretical predictions of observables such as decay widths. This result has an implication for the mixing of neutral mesons and the CP violation in their decays.
hep-ph2 citations
08*
Relaxing the TCC Bound on Inflationary Cosmology?
Vahid Kamali🇨🇦 · Robert Brandenberger🇨🇦
We demonstrate that the strict upper bounds on the energy scale of inflation and on the tensor-to-scalar ratio can be somewhat relaxed if we assume that - after an initial period of slow rolling when scales probed today in CMB experiments exit the Hubble radius - the equation of state of the background changes to correspond to an almost marginally accelerating universe. Constructing an actual model in which this happens appears, however, to be unnatural.
↳ hep-thastro-ph.COgr-qchep-phEPJC(2020)·27 citations
09*
Strengthening the TCC Bound on Inflationary Cosmology
Robert Brandenberger🇨🇦 · Edward Wilson-Ewing🇨🇦
We show that the constraints which follow from the {\it Trans-Planckian Censorship Conjecture} for inflationary cosmology can be strengthened if the pre-inflationary universe was dominated by radiation. The resulting upper bound on the energy scale of inflation is $η \sim 1 0^{4} GeV$ , close to the scale accessible to accelerator experiments.
↳ hep-thastro-ph.COgr-qchep-phJCAP(2020)·31 citations
10*
Musings on the Current Status of HEP
M. Shifman🇺🇸
I briefly summarize my personal opinions on the current status of HEP theory and comment on the so-called "non-empiric confirmation."
↳ physics.hist-phhep-phhep-thMod.Phys.Lett.A(2020)·9 citations
11*
Causality and Renormalization in Finite-Time-Path Out-of-Equilibrium $ϕ^{3}$ QFT
Ivan Dadić🇭🇷 · Dubravko Klabučar🇭🇷
Our aim is to contribute to quantum field theory (QFT) formalisms useful for descriptions of short time phenomena, dominant especially in heavy ion collisions. We formulate out-of-equilibrium QFT within the finite-time-path formalism (FTP) and renormalization theory (RT). The potential conflict of FTP and RT is investigated in $g ϕ^{3}$ QFT, by using the retarded/advanced ( $R / A$ ) basis of Green functions and dimensional renormalization (DR). For example, vertices immediately after (in time) divergent self-energy loops do not conserve energy, as integrals diverge. We "repair" them, while keeping $d < 4$ , to obtain energy conservation at those vertices. Already in the S-matrix theory, the renormalized, finite part of Feynman self-energy $Σ_{F} (p_{0})$ does not vanish when $∣ p_{0} ∣ \to \infty$ and cannot be split to retarded and advanced parts. In the Glaser--Epstein approach, the causality is repaired in the composite object $G_{F} (p_{0}) Σ_{F} (p_{0})$ . In the FTP approach, after repairing the vertices, the corresponding composite objects are $G_{R} (p_{0}) Σ_{R} (p_{0})$ and $Σ_{A} (p_{0}) G_{A} (p_{0})$ . In the limit $d \to 4$ , one obtains causal QFT. The tadpole contribution splits into diverging and finite parts. The diverging, constant component is eliminated by the renormalization condition $⟨ 0∣ ϕ ∣0 ⟩ = 0$ of the S-matrix theory. The finite, oscillating energy-nonconserving tadpole contributions vanish in the limit $t \to \infty$ .
↳ hep-thhep-phParticles(2019)·4 citations
12*
Beyond Symmetries : Anomalies in Transverse Ward--Takahashi Identities
Yi-Da Li🇨🇳 · Qing Wang🇨🇳
Anomalies in transverse Ward--Takahashi identities are studied, allowing discussion of the feasibility of anomalies arising in general non-symmetry Ward--Takahashi identities. We adopt the popular Fujikawa's method and rigorous dimensional renormalization to verify the existence of transverse anomalies to one-loop order and any loop order, respectively. The arbitrariness of coefficients of transverse anomalies is revealed, and a way out is also proposed after relating transverse anomalies to Schwinger terms and comparing symmetry and non-symmetry anomalies. Papers that claim the non-existence of transverse anomalies are reviewed to find anomalies hidden in their approaches. The role played by transverse anomalies is discussed.
↳ hep-thhep-phPRD(2020)·1 citation

* 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.