Tue·Aug 16, 2022Tuesday·August 16, 2022

1. 01*

   Ultra-high energy neutrinos from high-redshift electromagnetic cascades

   AmirFarzan Esmaeili🇧🇷 · Antonio Capanema🇧🇷 · Arman Esmaili🇧🇷 · Pasquale Dario Serpico🇫🇷

   We study the impact of the muon pair production and double pair production processes induced by ultra-high energy photons on the cosmic microwave background. Although the muon pair production cross section is smaller than the electron pair production one, the associated energy loss length is comparable or shorter than the latter (followed by inverse Compton in the deep Klein-Nishina regime) at high-redshift, where the effect of the astrophysical radio background is expected to be negligible. By performing a simulation taking into account the details of $e/\gamma$ interactions at high energies, we show that a significant fraction of the electromagnetic energy injected at $E\gtrsim 10^{19}$eV at redshift $z\gtrsim 5$ is channeled into neutrinos. The double pair production plays a crucial role in enhancing the multiplicity of muon production in these electromagnetic cascades. The ultra-high energy neutrino spectrum, yet to be detected, can in principle harbour information on ultra-high energy sources in the young universe, either conventional or exotic ones, with weaker constraints from the diffuse gamma ray flux compared to their low redshift counterparts.

   hep-phastro-ph.HEPRD(2022)·10 citations
2. 02*

   Why not Neutrinos as the Dark Matter? A Critical Review, KATRIN and New Research Directions

   D.J. Buettner · P.D. Morley

   We challenge the traditional wisdom that cosmological (big bang relic) neutrinos can only be hot Dark Matter. We provide a critical review of the concepts, derivations and arguments in foundational books and recent publications that led respected researchers to proclaim that "[Dark Matter] cannot be neutrinos". We then provide the physics resulting in relic neutrino's significant power loss from the interaction of its anomalous magnetic moment with a high-intensity primordial magnetic fields, resulting in subsequent condensation into Condensed Neutrino Objects (CNOs). Finally, the experimental degenerate mass bounds that would rule out condensed cosmological neutrinos as the Dark Matter (unless there is new physics that would require a modification to the CNO Equation of State) are provided. We conclude with a discussion on new directions for research.

   hep-phastro-ph.HEcond-mat.otherhep-thPhys.Dark Univ.(2023)·2 citations
3. 03*

   The Conformal-Symmetry--Color-Neutrality Connection in Strong Interaction

   M. Kirchbach🇲🇽 · T. Popov🇧🇬 · J.-A. Vallejo🇲🇽

   The color neutrality of hadrons is interpreted as an expression of conformal symmetry of strong interaction, the latter being signaled through the detected "walking" at low transferred momenta, ${\lim }_{Q^2\to 0}{\alpha }_s(Q^2)/\pi \to 1$, of the strong coupling toward a fixed value (${\alpha }_s$ "freezing" ). The fact is that conformal symmetry admits quarks and gluons to reside on the compactified $Ad{S}_5$ boundary, whose topology is $S^1\times S^3$, a closed space that can bear exclusively color-charge neutral configurations, precisely as required by color confinement. The compactification radius, once employed as a second scale alongside with ${\Lambda }_{QCD}$, provides for an ${\alpha }_s(Q^2)$ "freezing" mechanism in the infrared regime of QCD, thus making the conformal-symmetry--color-neutrality connection at low energies evident. In this way, perturbative descriptions of processes in the infrared could acquire meaning. In consequence, it becomes possible to address QCD by quantum mechanics in terms of a conformal wave operator equation, which leads to an efficient description of a wide range of

   hep-phhep-thSpringer Proc.Math.Stat.(2022)·1 citation
4. 04*

   Higgs information in Split-SUSY at the LHC

   Surabhi Gupta🇮🇳 · Sudhir Kumar Gupta🇮🇳

   Information theory turns out to be an interesting tool for studying the consequences of Higgs observations to various new physics candidate theories by means of the information measure as the entropy of Higgs-Boson through its various detection modes at the Large Hadron Collider. The present article investigates the parameter space of a supersymmetric scenario where sfermions and one of the Higgs superfields are decoupled, while the gauginos, Higgsinos, and the remaining Higgs doublet are still allowed to be lighter. Our analysis reveals that this is quite a viable choice in the light of LHC discovery of a Higgs which resembles the SM Higgs-Boson and nothing else so far. While the supersymmetry breaking scale $M_S$ could be as high as $10^{11}$ GeV or so, the most preferred values of the $M_S$ and $\tan \beta$ are found to be around 3.6$\times 10^7$ GeV and $41$ respectively, which is also consistent with the relic abundance of the neutralino dark matter. The corresponding value of neutralino ($m_{{\tilde{\chi }}_1^0}$) LSP is estimated to be around 1.01 TeV. The preferred values of other parameters, namely, the Higgsino mass ($\mu$) and gaugino mass parameters ($M_1$ and $M_2$) are found to be about 1.05 TeV, 1.74 TeV, and 2.57 TeV, respectively.

   hep-phhep-exNPB(2023)·1 citation
5. 05*

   UHE neutrinos encountering decaying and non-decaying magnetic fields of compact stars

   Neetu Raj Singh Chundawat🇮🇳 · Arindam Mandal🇮🇳 · Trisha Sarkar🇮🇳

   The phenomena of neutrino spin flavour precession in the presence of an extraneous magnetic field is a repercussion of neutrino magnetic moment which is consociated with the physics beyond the standard model of electroweak interactions. Ultra high energy neutrinos are spawned from a number of sources in the universe including the highly energetic astrophysical objects such as active galactic nuclei, blazar or supermassive black holes. When such high energy neutrinos pass through any compact stellar objects like neutron stars or white dwarfs, their flux can significantly reduce due to the exorbitant magnetic field provided by these compact objects. For Dirac neutrinos, such phenomena occur due to the conversion of neutrinos to their sterile counterparts. In this work, we consider a neutron star possessing a spatially varying magnetic field which may or may not decay with time. We find that, for the non-decaying magnetic field, the flux of high energy Dirac neutrinos becomes nearly half after passing through the neutron star. The flux is further enfeebled by $\sim 10\%$ in the presence of muons inside the neutron star. For decaying magnetic field, the flux reduction is abated by $\sim 5\%$ as compared to the temporally static magnetic field. In the case of a white dwarf, the depletion of flux is lesser as compared to the neutron stars.

   hep-phastro-ph.HE5 citations
6. 06*

   Ultraviolet completion of pseudo-Nambu-Goldstone dark matter with a hidden U(1) gauge symmetry

   Dan-Yang Liu🇨🇳 · Chengfeng Cai🇨🇳 · Xue-Min Jiang🇨🇳 · Zhao-Huan Yu🇨🇳 · Hong-Hao Zhang🇨🇳

   We propose an ultraviolet completion model for pseudo-Nambu-Goldstone dark matter with a hidden $\mathrm{U}(1)$ gauge symmetry. Compared to previous studies, this setup is simpler, introducing less interactions. Dark matter scattering off nucleons is highly suppressed by the ultraviolet scale and direct detection constraints can be easily evaded. The kinetic mixing between the hidden $\mathrm{U}(1)$ and the $\mathrm{U}(1{)}_{\mathrm{Y}}$ gauge fields would lead to dark matter decays. We find that the current bound on the dark matter lifetime implies that the ultraviolet scale should be higher than $10^{10}\mathrm{GeV}$. The phenomenological constraints from the 125 GeV Higgs measurements, the dark matter relic density, and indirect detection of dark matter annihilation are also investigated.

   hep-phJHEP(2023)·17 citations
7. 07*

   Volume effects on the QCD critical end point from thermal fluctuations within the super statistics framework

   Jorge David Castaño-Yepes🇨🇱 · Fernando Martínez Paniagua🇲🇽 · Victor Muñoz-Vitelly🇲🇽 · Cristian Felipe Ramirez-Gutierrez🇲🇽

   We investigate the impact of the finite volume and the thermal fluctuations on the Critical End Point of the QCD phase diagram. To do so, we implement the super statistics framework with Gamma, $F$, and log-normal distributions and their relation with the Tsallis non-extensive thermodynamics. We compute an effective thermodynamic potential as a function of the inverse temperature fluctuations and explicit dependence on the system volume. To find an analytic expression for the effective potential, we expand the modified Boltzmann factor by using the equilibrium thermodynamic potential computed in the Linear Sigma Model coupled to quarks. We find that the pseudo-critical temperature of transition at vanishing baryon chemical potential is modified by the size of the system being about $7\%$ lower for small volumes. Additionally, the critical endpoint moves to higher densities and lower temperatures (about $12\%$ in both cases). Interestingly, the results are quantitatively the same when the parameter that models the out-of-equilibrium situation is modified, indicating that the chiral symmetry restoration is robust against the thermal fluctuations in this approximation.

   hep-phPRD(2022)·7 citations
8. 08*

   Medium induced jet broadening in a quantum computer

   João Barata🇺🇸 · Xiaojian Du🇩🇪 · Meijian Li🇪🇸 · Wenyang Qian🇪🇸 · Carlos A. Salgado🇪🇸

   QCD jets provide one of the best avenues to extract information about the quark-gluon plasma produced in the aftermath of ultra relativistic heavy ions collisions. The structure of jets is determined by multiparticle quantum interference hard to tackle using perturbative methods. When jets evolve in a QCD medium this interference pattern is modified, adding another layer of complexity. By taking advantage of the recent developments in quantum technologies, such effects might be better understood via direct quantum simulation of jet evolution. In this work, we introduce a precursor to such simulations. Based on the light-front Hamiltonian formalism, we construct a digital quantum circuit that tracks the evolution of a single hard probe in the presence of a stochastic color background. In terms of the jet quenching parameter $\hat{q}$, the results obtained using classical simulators of ideal quantum computers agree with known analytical results. With this study, we hope to provide a baseline for future in-medium jet physics studies using quantum computers.

   hep-phquant-phPRD(2022)·64 citations
9. 09*

   Electroweak precision tests for triplet scalars

   Yu Cheng🇨🇳 · Xiao-Gang He🇹🇼 · Fei Huang🇨🇳 · Jin Sun🇨🇳 · Zhi-Peng Xing🇨🇳

   Electroweak precision observables are fundamentally important for testing the standard model (SM) or its extensions. The influences to observables from new physics within the electroweak sector can be expressed in terms of oblique parameters S, T, U. The recently reported W mass excess anomaly by CDF modifies these parameters in a significant way. By performing the global fit with the CDF new W mass measurement data, we obtain $S=0.03\pm 0.03$, $T=0.06\pm 0.02$ and $U=0.16\pm 0.03$ (or $S=0.14\pm 0.03$, $T=0.24\pm 0.02$ with $U=0$) which is significantly away from zero as SM would predict. The CDF excess strongly indicates the need of new physics beyond SM. We carry out a global fit to study the influence of two different cases of simple extensions by a hyper-charge $Y=1$ triplet scalar $\Delta$ (corresponding to the type-II seesaw model) and a $Y=0$ real triplet scalar $\Sigma$ on electroweak precision tests to determine parameter space in these models to solve the W mass anomaly and discuss the implications. We find that these triplets can affect the oblique parameters significantly at the tree and loop levels.

   hep-phNPB(2023)·41 citations
10. 10*

    Entanglement, CPT and neutral kaons

    Antonio Di Domenico🇮🇹

    Direct tests of T, CP, CPT symmetries in transitions using entangled neutral kaons produced at a $\varphi$-factory are briefly reviewed.

    hep-ph1 citation
11. 11*

    Next-to-leading order QCD predictions for exclusive $J/\psi$ photoproduction in ultraperipheral Pb+Pb collisions at the LHC

    Kari J. Eskola🇫🇮 · Chris A. Flett🇫🇮 · Vadim Guzey🇫🇮 · Topi Löytäinen🇫🇮 · Hannu Paukkunen🇫🇮

    We present the first study of rapidity-differential cross sections of coherent exclusive $J/\psi$ photoproduction in heavy-ion ultraperipheral collisions (UPCs) at the LHC, $\text{d}\sigma (\text{Pb}+\text{Pb}\to \text{Pb}+J/\psi +\text{Pb})/\text{d}y$, to NLO in collinear factorisation. Taking the generalised parton distributions as their forward limit counterparts, the NLO contributions in the cross sections are quantified and we show that the real part of the amplitude and quark-PDF contributions must not be neglected. We further evaluate the uncertainties arising from the scale-choice at both LO and NLO, and compare our results with exclusive $J/\psi$ photoproduction data in Pb+Pb UPCs from LHC. The scale dependence in $\text{d}\sigma (\text{Pb}+\text{Pb}\to \text{Pb}+J/\psi +\text{Pb})/\text{d}y$ is sizable, but we can find a scale-choice at NLO that reproduces the Pb+Pb UPC data at both Run 1 and Run 2 collision energies. This process has traditionally been suggested to be a direct probe of nuclear gluon distributions. We show that the situation changes rather dramatically from LO to NLO, where the interplay of both gluon and quark contributions, and in particular their relative signs, play a significant role. We end with some concluding remarks about the outlook of this observable within a tamed collinear factorisation.

    hep-ph1 citation
12. 12*

    Inclusive weak-annihilation decays and lifetimes of beauty-charmed baryons

    Guo-He Yang🇨🇳 · En-Pei Liang🇨🇳 · Qin Qin🇨🇳 · Kang-Kang Shao🇨🇳

    Imbalanced beauty-charmed baryons ${\Xi }_{bc}^{+,0}$ are of great significance to the development of heavy flavor physics. In this work, we study the inclusive weak-annihilation decays of ${\Xi }_{bc}^{+,0}$ and their contributions to the ${\Xi }_{bc}^{+,0}$ lifetimes. For the calculation of the inclusive ${\Xi }_{bc}^{+,0}\to X_{cs}$ decay width where $X_{cs}$ stands for the sum of the final states with charm number +1 and strange number -1, we work in the heavy diquark effective theory which provides us with a convenient technical tool to construct the operator product expansion. The ${\Xi }_{bc}^{+,0}$ is considered to be a superposition of two states with one containing a spin-0 $bc$ diquark and the other one containing a spin-1 $bc$ diquark. It is found that both the ${\Xi }_{bc}^{+,0}$ lifetimes and the ${\Xi }_{bc}^{+,0}\to X_{cs}$ branching ratios are very sensitive to the $bc$ spin in ${\Xi }_{bc}^{+,0}$. The ${\Xi }_{bc}^{+,0}\to X_{cd}$ results are also presented. As ${\Xi }_{bc}^{+}$ has a longer lifetime than ${\Xi }_{bc}^0$ and bigger branching ratios of similar decay channels, the exclusive decays ${\Xi }_{bc}^{+}\to D^{(\ast )+}\Lambda$, ${\Xi }_{bc}^{+}\to {\Lambda }_c^{+}{\bar{K}}^{(\ast )0}$, ${\Xi }_{bc}^{+}\to D^{(\ast )+}{K}^{-}p$, and ${\Xi }_{bc}^{+}\to D^0{\bar{K}}^{(\ast )0}p$ are more promising for experimental searches of ${\Xi }_{bc}^{+,0}$ at the LHC comparing with exclusive decay ${\Xi }_{bc}^0\to D^{0}p{K}^{-}$.

    hep-phPRD(2022)·8 citations
13. 13*

    Consistency of the string inspired electroweak axion with cosmic birefringence

    Weikang Lin🇨🇳 · Tsutomu T. Yanagida🇨🇳

    We revisit the constraint from the recently reported cosmic birefringence on axion-like particles with a general decay constant. A particular attention is paid to the naturalness of the model parameter space, which has been overlooked in the literature. We show that the observed cosmic birefringence is naturally explained by the electroweak axion with a string-theory inspired decay constant $F_A\simeq 10^{16}$ GeV.

    hep-phastro-ph.COPRD(2023)·24 citations
14. 14*

    Search for single production of vectorlike $B$-quarks at the LHC

    Jin-Zhong Han🇨🇳 · Yao-Bei Liu🇨🇳 · Lu Xing🇨🇳 · Shuai Xu🇨🇳

    New vectorlike quarks have been proposed in many scenarios of new physics beyond the Standard Model, which address the hierarchy problem and may be potentially discovered at the Large Hadron Collider~(LHC). Based on a model-independent framework, we propose to search for the vectorlike $B$-quark~(VLQ-$B$) and focus on resonant production via $b$-gluon fusion through chromomagnetic interactions. We then explore the possible signals of the VLQ-$B$ through the $B\to tW$ decay mode at the 14 TeV LHC. After a rapid simulation of signal and background events, the $2\sigma$ excluded regions and the $5\sigma$ discovery reach in the parameter plane of ${\kappa }_B-M_B$ are obtained at the LHC with an integrated luminosity of 300~(3000) fb${}^{-1}$ in the dilepton final states.

    hep-phCPC(2022)·17 citations
15. 15*

    Repulsive vector interaction as a trigger for the non-conformal peak in $V_s^2$

    Marcus Benghi Pinto🇧🇷

    Considering the NJL model with a repulsive vector channel, parametrized by $G_V$, I show that one may generate a non-monotonic behavior for the speed of sound which peaks at $V_s^2>1/3$. This can be achieved by assuming $G_V$ to be density dependent so that the resulting EoS is stiff/repulsive at low densities and soft/non-repulsive at high densities. The interpolation between the two regimes happens through a cross-over which takes place after the first order chiral transition sets in. The model explicitly shows that a non-conformal peak in $V_s^2$ is not in tension with the QCD trace anomaly being positive at all densities, supporting recent claims in this direction. A brief discussion on how the running coupling may affect the mass-radius relation is carried out in the context of simple non-strange quark stars.

    hep-phnucl-th5 citations
16. 16*

    Spin-Flavor Precession Phase Effects in Supernova

    T. Bulmus🇹🇷 · Y. Pehlivan🇹🇷

    We study the phase effects driven by neutrino magnetic moment for Majorana neutrinos in a core collapse supernova. A neutrino with a large magnetic moment is emitted in a superposition of energy eigenstates from the neutrinosphere. These energy eigenstates can interfere to create a phase effect at a partially adiabatic spin flavor precession (SFP) resonance. We examine the dependence of the SFP phase effect on the size of the neutrino magnetic moment as well as its variation with the post bounce time. In particular, at late post-bounce times the SFP resonance becomes wider and eventually overlaps with the Mikheev-Smirnov-Wolfenstein (MSW) resonance. At this point, Landau-Zener criteria for adiabaticity can no longer be applied to individual resonances, but we show that SFP phase effect is still present after the overlap. We also discuss the observability of the SFP phase effect at late post bounce times where it is more likely to make an impact. Our analysis for the Deep Underground Neutrino Experiment (DUNE) reveals that at low energies event rates do not fluctuate despite the presence of a sizable SFP phase effect. We find larger event rate fluctuations at high energies, but these fluctuations are also erased in the energy spectra of the observed charged leptons. A more refined treatment of electron fraction and the inclusion of neutrino-neutrino interactions may change our conclusions for observability in future studies.

    hep-phastro-ph.HEastro-ph.SRChin.J.Phys.(2024)·7 citations
17. 17*

    $X(3872)$ and $T_{cc}$: structures and productions in heavy ion collisions

    Hyeongock Yun🇰🇷 · Daeho Park🇰🇷 · Sungsik Noh🇰🇷 · Aaron Park🇰🇷 · Woosung Park🇰🇷 · Sungtae Cho🇰🇷 · Juhee Hong🇰🇷 · Yongsun Kim🇰🇷 · Sanghoon Lim🇰🇷 · Su Houng Lee🇰🇷

    We argue why the recently observed $T_{cc}$ could either be a compact multiquark configuration or a loosely bound molecular configuration composed of charmed mesons, whereas the $X(3872)$ is most likely a molecular configuration. The argument is based on different short range interactions for these tetraquark states coming from the color-color and color-spin interaction in a quark model, and the presence of a common strong D-wave mixing at larger distance similar to the deuteron case, which for the molecular configurations lead to large sizes. Such an analogy at large distance allows us to calculate the transverse momentum dependence of the loosely bound molecular configuration of tetraquarks produced in heavy ion collisions using the coalescence model that successfully reproduces the deutron data using the proton spectra. The ratio of the integrated $X(3872)$ yield obtained from our method to the $\psi (2S)$ yield obtained from statistical hadronization model method is calculated to be $0.806\pm 0.234$, which is a factor of 2.47 larger than that obtained by using statistical model predictions for both particles and in line with the data from the CMS experiment. As the previously calculated transverse momentum distribution of the $T_{cc}$ assuming the structure to be a compact multiquark configuration is markedly different, experimental measurements of the transverse distribution of the tetraquark states will discriminate between their two possible structures.

    hep-phnucl-thPRC(2023)·33 citations
18. 18*

    Uncertainties in neutrino oscillation parameter sensitivity due to resonance processes at NO$\nu$A

    Paramita Deka🇮🇳 · Nilavjyoti Hazarika🇮🇳 · Kalpana Bora🇮🇳

    The long baseline (LBL) neutrino experiments use heavy nuclear targets for neutrino scattering in which nuclear effects give rise to complications in measuring the neutrino oscillation parameters up to high precision. These nuclear effects are not yet fully understood and therefore need to be quantified as they contribute to the systematic uncertainties. Precision reconstruction of neutrino energy is one of the main components in measuring the oscillation parameters, and it is required that the neutrino energy is reconstructed with very high precision. In this work, we investigate the effects of the resonance (RES) interaction process using two models for carbon target for ${\nu }_{\mu }\to {\nu }_{\mu }$ disappearance channel of the NO$\nu$A experiment, on neutrino-nucleus scattering cross section, events, and neutrino oscillation parameter sensitivity. We also incorporate the realistic detector specifications of NO$\nu$A. To quantify the systematic uncertainties due to RES interactions, we compare the cross-sections, events, and sensitivity analysis for two models of RES processes - Rein-Sehgal and Berger-Sehgal, and comment on which model produces more precision. We observe that RES processes contribute significantly, and should be included carefully in models while extracting neutrino oscillation parameters.

    hep-phInt.J.Mod.Phys.A(2022)·2 citations
19. 19*

    Contributions to the Muon $g-2$ from a Three-Form Field

    Da Huang🇨🇳 · Yong Tang🇨🇳 · Yue-Liang Wu🇨🇳

    We examine contributions to the muon dipole moment $g-2$ from a 3-form field $\Omega$, which naturally arises from many fundamental theories, such as the string theory and the hyperunified field theory. In particular, by calculating the one-loop Feynman diagram, we have obtained the leading-order $\Omega$-induced contribution to the muon $g-2$, which is found to be finite. Then we investigate the theoretical constraints from perturbativity and unitarity. Especially, the unitarity bounds are yielded by computing the tree-level ${\mu }^{+}{\mu }^{-}$ scattering amplitudes of various initial and final helicity configurations. As a result, despite the strong unitarity bounds imposed on this model of $\Omega$, we have still found a substantial parameter space which can accommodates the muon $g-2$ data.

    hep-phJHEP(2023)·3 citations
20. 20*

    Electromagnetic transition form factors of nucleons from the hard-wall AdS/QCD model

    Shahin Mamedov🇦🇿 · Shahnaz Taghiyeva🇦🇿

    The electromagnetic transition form factors for the transition between the ground and excited states of nucleons are studied in the framework of the hard-wall model of AdS/QCD. The profile functions of the spinor and vector fields in the bulk of AdS space are presented. Using AdS/CFT correspondence between the generating functions in the bulk and boundary theories an expression for the transition form factors are obtained from the bulk action for the interaction between the photon and nucleon fields. We consider the R(1710, 1535, 1440)\rightarrow N transitions and plot the Dirac and Pauli form factor dependencies on transferred momentum square. Also, the spiral amplitudes for these transitions are presented.

    hep-phJ.Korean Phys.Soc.(2024)·3 citations
21. 21*

    Domain wall networks from first-order phase transitions and gravitational waves

    Dongdong Wei🇨🇳 · Yun Jiang🇨🇳

    In the first-order phase transitions (PTs) colliding bubble is an important gravitational wave (GW) source. Following bubble collision, domain walls can be formed when degenerate vacua occur as a result of the breaking of a discrete symmetry relevant to new physics at electroweak or higher scales. Using lattice simulations, we study the dynamical evolution of domain walls and find that the networks of the domain wall are formed around the completion of PTs and the lifetime of the wall networks largely depends on whether or not the degeneracy of true vacua is broken. Our numerical results indicate that domain wall networks continue to produce GWs in the aftermath of PTs, leading to dramatically changing the spectral shape and enhancing the magnitude by about one order. The resulting GW power spectra are peaked at $k{R}_{\ast }\simeq \pi$, above the peak wavenumber it has a decaying power law close to $k^{-1.2}$ followed by a slowly decreasing plateau with the UV cutoff at $k{R}_{\ast }\sim \mathcal{O}(10^2)$

    hep-phastro-ph.COgr-qcPRD(2024)·14 citations
22. 22*

    Inclusive $J/\psi$ and ${\rm Y}$ emissions from single-parton fragmentation in hybrid high-energy and collinear factorization

    Francesco Giovanni Celiberto🇮🇹 · Michael Fucilla🇮🇹

    We present a novel study on the inclusive production of a heavy quarkonium ($J/\psi$ or ${\rm Y}$), in association with a light-flavored jet, as a test field of the high-energy QCD dynamics. The large transverse momenta at which the two final-state objects are detected permits us to perform an analysis in the spirit of the variable-flavor number scheme (VFNS), in which the cross section for the hadroproduction of a light parton is convoluted with a perturbative fragmentation function that describes the transition from a light quark to a heavy hadron. The quarkonium collinear fragmentation function is built as a product between a short-distance coefficient function, which encodes the resummation of DGLAP type logarithms, and a non-perturbative long-distance matrix element (LDME), calculated in the non-relativistic QCD (NRQCD) framework. Our theoretical setup is the hybrid high-energy and collinear factorization, where the standard collinear approach is supplemented by the resummation of leading and next-to-leading energy-type logarithms \emphà la} BFKL. We propose this reaction as a suitable channel to probe the production mechanisms of quarkonia at high energies and large transverse momenta and to possibly unveil the transition region from the heavy-quark pair production mechanism to the single-parton fragmentation one.

    hep-ph21 citations
23. 23*

    Vector-like Quarks

    Gustavo Castelo Branco🇵🇹 · M. N. Rebelo🇵🇹

    In this talk we emphasise the importance of vector-like quarks (VLQs) and their potential to solve some of the open questions of the Standard Model. These are, in some sense minimal extensions of the Standard Model, that can be probed in the next round of experiments. We also make an analogy between vector-like quarks(VLQs) and right-handed neutrinos, emphasising that in both cases some of the flavour dogmas of the SM are violated in a controlled way.

    hep-phPoS(2022)·11 citations
24. 24*

    $S$-wave fully charmed tetraquark resonant states

    Guang-Juan Wang🇯🇵 · Qi Meng🇨🇳 · Makoto Oka🇯🇵

    We calculate the mass spectrum of the $S$-wave fully-charmed tetraquark resonant states $cc\bar{c}\bar{c}$ in the nonrelativistic quark model, which successfully describes the charmonium spectrum. The four-body system is solved with the Gaussian expansion method. The complex scaling technique is used to identify the genuine resonances. With the nonrelativistic quark model, our results show the existence of two $cc\bar{c}\bar{c}$ resonances in each of the $J^{PC}=$ $0^{++}$, $1^{+-}$ and $2^{++}$ sectors, respectively. In the $S$-wave sector, no resonance is found at the energy region of the $X(6200)$ and $X(6600)$ states. The lower $0^{++}$ and $2^{++}$ resonances are located around $100$ MeV higher than the $X(6900)$ state observed in experiments but have the decay widths consistent with the experiment. The higher $0^{++}$ and $2^{++}$ resonances are found at around $7.2$ GeV with the widths of $60.6$ MeV and $91.2$ MeV, respectively, and they may be good candidates for the $X(7200)$ state.

    hep-phhep-exPRD(2022)·47 citations
25. 25*

    Azimuthally-correlated contributions to QCD transverse-momentum resummation at $\mathcal{O}({\alpha }_{\mathrm{S}}^2)$

    Prasanna K. Dhani🇮🇹

    Singular factors originating from the QCD factorisation of scattering amplitudes in soft and collinear limits play a prominent role in both organising and computing high-order perturbative contributions to hard-scattering cross sections. In this talk, we start from the factorisation structure of scattering amplitudes in the collinear limit, and we introduce collinear functions that have a process-independent structure. These collinear functions, which are defined at the fully-differential level, can then be integrated over the appropriate observable-dependent phase space to compute logarithmically-enhanced contributions to the corresponding observable. For transverse-momentum dependent observables, we show how the collinear functions can be defined without introducing what is known as rapidity divergences in the literature. We present the results of explicit computations of the collinear functions up to next-to-next-to-leading order in the QCD perturbation theory.

    hep-phhep-thPoS(2022)·1 citation
26. 26*

    Exploring the Neutrino Sector of the Minimal Left-Right Symmetric Model

    Gustavo F. S. Alves🇧🇷 · Chee Sheng Fong🇧🇷 · Luighi P. S. Leal🇧🇷 · Renata Zukanovich Funchal🇧🇷

    We explore the neutrino sector of the minimal left-right symmetric model, with the additional charge conjugation discrete symmetry, in the tuned regime where type-I and type-II seesaw mechanisms are equally responsible for the light neutrino masses. We show that unless the charged lepton mixing matrix is the identity and the right handed neutrino mass matrix has no phases, we expect sizable lepton flavor violation and electron dipole moment in this region. We use results from recent neutrino oscillation fits, bounds on neutrinoless double beta decay, $\mu \to e\gamma$, $\mu \to 3e$, $\mu \to e$ conversion in nuclei, the muon anomalous magnetic moment, the electron electric dipole moment and cosmology to determine the viability of this region. We derive stringent limits on the heavy neutrino masses and mixing angles as well as on the vacuum expectation value $v_L$, which drives the type-II seesaw contribution, using the current data. We discuss the perspectives of probing the remaining parameter space by future experiments.

    hep-ph8 citations
27. 27*

    FCNC in Concurrent Dark Photon and Dark $Z$ Models

    Lopamudra Mukherjee🇺🇸

    In this work we fit the available binned data of the differential decay distribution of the exclusive $B\to K^{(\ast )}{\ell }^{+}{\ell }^{-}$ and $B_s\to \varphi {\mu }^{+}{\mu }^{-}$ decays to the mass and mixing parameters of a light dark vector boson model. Due to an incorrect assessment of the dominant contribution of the dark $Z$ model to the FCNC B-meson decays, a previous work in literature reported that $\mathcal{O}(1)$ mixings were allowed by the data. In this talk we report the correct calculations and constraints on the mixing parameters as well as the mass of the dark vector boson using the marginalization technique. We also study other relevant bounds on the parameter space from low energy experiments such as the atomic parity violation, $K^{+}\to {\mu }^{+}+invisible$ decay, $B_s-{\overline{B}}_s$ mixing etc and find that inspite of obtaining a good fit to the experimental $b\to s{\ell }^{+}{\ell }^{-}$ data, the entire parameter space gets ruled out from some of the above bounds. In case of a model with tiny mixing and additional interaction of the dark $Z$ to the muon, some bounds are relaxed while some others are violated.

    hep-ph0 citations
28. 28*

    Imprints of LGI violation in Mesons

    Kiran Sharma (IIT Bhilai)🇮🇳 · Aryabrat Mahapatra (IIT Bhubaneswar)🇮🇳 · Prasanta K. Panigrahi (IISER Kolkata)🇮🇳 · Sudhanwa Patra (IIT Bhilai)🇮🇳

    Quantum mechanics has always proven emphatically as one of the main cornerstones in all of science since its inception. Initially, it has also faced many skeptics from many scientific proponents of its complete description of reality. However, John Bell once devised a theorem on quantitative grounds to show how local realism is expressed in quantum mechanics. As Bell's inequality claims the non-existence of local hidden variable theories, on the same footing, we have Leggett-Garg's Inequality (LGI), which sets a quantum-classical limit for temporally correlated quantum systems. In the context of particle physics, specially in the field of neutrino and meson oscillations, one can conveniently implement LGI to test the quantum foundations at the probability level. Here, we discuss the significant LGI violation characteristics in B- and K- meson oscillations, taking into account their decoherence, CP violation, and decay parameters. We have emphasized the fact that \textit{Tsirelson} bounds can be achieved under certain conditions. Our focal point is to show the signature of these bounds that appears only to specific alterations of decay and decoherence effects. Also, we discuss and comment on the behavior or effect of decoherence and decay widths playing out from the perspective of LGI by taking their available values from various experiments. This may help us to understand the underlying principles and techniques of neutral meson open quantum systems.

    hep-phEur.Phys.J.Plus(2024)·0 citations
29. 29*

    MSW effect with quark matter: Neutron Star as a case study

    Hiranmaya Mishra (NISER, Bhubaneswar)🇮🇳 · Prasanta K. Panigrahi (IISER Kolkata)🇮🇳 · Sudhanwa Patra (IIT Bhilai)🇮🇳 · Utpal Sarkar (IISER Kolkata)🇮🇳

    With the recent findings from various astrophysical results hinting towards possible existence of strange quark matters with the baryonic resonances such as ${\Lambda }^0,{\Sigma }^0,\Xi ,\Omega$ in the core of neutron stars, we investigate the MSW effect, in general, in quark matter. We find that the resonance condition for the complete conversion of down-quark to strange quark requires estremely large matter density (${\rho }_u\simeq 10^5\text{mbox}{fm}^{-3}$). Nonetheless the neutron stars provide a best condition for the conversion to be statistically significant which is of the same order as is expected from imposing charge neutrality condition. This has a possibility of resolving the hyperon puzzle as well as the equation of state for dense baryonic matter.

    hep-phastro-ph.HEnucl-th0 citations
30. 30*

    A Model for Dark Energy Based on Baryonic Charges with General Yang-Mills Symmetry

    Jong-Ping Hsu🇺🇸 · Leonardo Hsu🇺🇸

    General Yang-Mills symmetry and Yang-Mills gravity in inertial frames presents a possible avenue for understanding dark energy phenomenon in terms of the extremely small baryon charges of protons and neutrons. General gauge transformations involve vector gauge functions and Hamilton's characteristic phase functions rather than scalar gauge functions and usual phase functions. One has fourth-order gauge field equations, which lead to a static linear potential between two point baryonic charges. Together with gravitational force, the model predicts that in the early universe, when the gravitational force was dominant, not only was the expansion occurring at a decreasing rate, the rate of change of the deceleration was decreasing due to a $1/r^2$ dependence. In the present universe, when the baryonic force is dominant, the cosmic acceleration should be approximately constant and has a maximum value $a_{max}\approx 10^{-13}m/s^2$, as measured in an inertial frame. We hope that these properties of the late-time cosmic acceleration can be tested in the future.

    hep-phhep-th0 citations
31. 31*

    One-Electron Quantum Cyclotron as a Milli-eV Dark-Photon Detector

    Xing Fan🇺🇸 · Gerald Gabrielse🇺🇸 · Peter W. Graham🇺🇸 · Roni Harnik🇺🇸 · Thomas G. Myers🇺🇸 · Harikrishnan Ramani🇺🇸 · Benedict A. D. Sukra🇺🇸 · Samuel S. Y. Wong🇺🇸 · Yawen Xiao🇺🇸

    We propose using trapped electrons as high-$Q$ resonators for detecting meV dark photon dark matter. When the rest energy of the dark photon matches the energy splitting of the two lowest cyclotron levels, the first excited state of the electron cyclotron will be resonantly excited. A proof-of-principle measurement, carried out with one electron, demonstrates that the method is background-free over a 7.4 day search. It sets a limit on dark photon dark matter at 148 GHz (0.6 meV) that is around 75 times better than previous constraints. Dark photon dark matter in the 0.1-1 meV mass range (20-200 GHz) could likely be detected at a similar sensitivity in an apparatus designed for dark photon detection.

    ↳ hep-exastro-ph.COhep-phphysics.atom-ph+1PRL(2022)·36 citations
32. 32*

    Summing Feynman diagrams in the worldline formalism

    Naser Ahmadiniaz🇩🇪 · James P. Edwards🇬🇧 · Cristhiam Lopez-Arcos🇨🇴 · Misha A. Lopez-Lopez🇺🇸 · C. Moctezuma Mata🇲🇽 · José Nicasio🇲🇽 · Christian Schubert🇲🇽

    The worldline formalism shares with string theory the property that it allows one to write down master integrals that effectively combine the contributions of many Feynman diagrams. While at the one-loop level these diagrams differ only by the position of the external legs along a fixed line or loop, at multiloop they generally involve different topologies. Here we summarize various efforts that have been made over the years to exploit this property in a computationally meaningful way. As a first example, we show how to generalize the Landau-Khalatnikov-Fradkin formula for the non-perturbative gauge transformation of the fermion propagator in QED to the general $2n$ - point case by pure manipulations at the path-integral level. At the parameter-integral level, we show how to integrate out individual photons in the low-energy expansion, and then sketch a recently introduced general framework for the analytical evaluation of such worldline integrals involving a reduction to quantum mechanics on the circle and the relation between inverse derivatives and Bernoulli polynomials.

    ↳ hep-thhep-phPoS(2022)·9 citations
33. 33*

    There and Sharp Again: The Circle Journey of Nucleons and Energy Deposition

    Giuliano Giacalone🇩🇪

    A central question in high-energy nuclear phenomenology is how the geometry of the quark-gluon plasma (QGP) formed in relativistic nuclear collisions is precisely shaped. In our understanding of such processes, two features are especially crucial for the determination of the QGP geometry, respectively, the nucleon size and the energy deposition scheme. This contribution reports on the (circular) evolution of such features in state-of-the-art model incarnations of heavy-ion collisions over the past seven years. Ideas for future directions of investigation are pointed out.

    ↳ nucl-thhep-exhep-phnucl-ex14 citations
34. 34*

    Testing the collectivity in large and small colliding systems with test particles

    Han-Sheng Wang🇨🇳 · Guo-Liang Ma🇨🇳

    We propose a test-particle method to probe the transport dynamics of the establishment and development of collective flow in large and small systems of heavy-ion collisions. We place test particles as passengers into the partonic medium created by Au$+$Au midcentral collisions at $\sqrt{s_{NN}}$ = 200 GeV and $p$ $+$ Pb central collisions at $\sqrt{s_{NN}}$ = 5.02 TeV, using a multiphase transport model. With the help of test particles in two extreme test cases, we demonstrate that parton collisions play an important role in establishing and developing collectivity in large and small colliding systems. The collectivity established by final state parton collisions is much stronger in large colliding systems compared to small colliding systems. The collectivity from the initial state can persist or survive more easily in small colliding systems than in large colliding systems due to fewer parton collisions. Our study provides a new method to understand the origin of collectivity in large and small colliding systems at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider.

    ↳ nucl-thhep-phnucl-exPRC(2022)·4 citations
35. 35*

    Relativistic correction to the dissociation temperature of B_c mesons in the hot medium

    Guangyu Li🇨🇳 · Baoyi Chen🇨🇳 · Yunpeng Liu🇨🇳

    By solving two body Dirac equations with potentials at finite temperature, we calculated the dissociation temperature T_d of B_c mesons in the quark-gluon plasma. It is found that the T_d becomes higher with the relativistic correction than the T_d from the Schroedinger equation. Both the short range interaction and the constant term of the potential at the long-range scale have a contribution to the shift of T_d, while the spin interaction is negligible.

    ↳ nucl-thhep-phCPC(2023)·1 citation
36. 36*

    Unified description of high-energy nuclear collisions based on dynamical core--corona picture

    Yuuka Kanakubo🇯🇵

    I establish the dynamical core--corona initialization framework (DCCI2) as a state-of-the-art dynamical framework that is capable of describing small and large colliding systems at the LHC energies. Under the core--corona picture, contributions from both equilibrated (core) and non-equilibrated (corona) components are implemented. I describe the dynamical separation of the system into the core and corona at the initial stage by incorporating the core--corona picture into the novel dynamical initialization framework. With DCCI2, I simulate $p$+$p$ collisions at $\sqrt{s}=7,13$ TeV and $Pb$+$Pb$ collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV. Especially, I extract the fractions of core and corona components in final hadron yields in $p$+$p$ and $Pb$+$Pb$ collisions as functions of multiplicity, and reveal that the core components become dominant at $⟨d{N}_{\mathrm{ch}}/d\eta {⟩}_{|\eta |<0.5}\approx 20$. I also find that the corona contribution at very low $p_T$ (below $p_T\approx 1$ GeV) is non-negligible even in $Pb$+$Pb$ collisions and show that such contributions significantly affect $p_T$-integrated flow coefficients. These results strongly suggest the importance of considering non-equilibrated components to extract transport coefficients of quark-gluon plasma from model-to-data comparisons quantitatively.

    ↳ nucl-thhep-phnucl-ex2 citations
37. 37*

    Impact of the ligand deformation on the $\mathcal{P}$,$\mathcal{T}$-violation effects in the YbOH molecule

    Anna Zakharova🇷🇺 · Alexander Petrov🇷🇺

    The ytterbium monohydroxide is a promising molecule for a new physics searches. It is well known that levels of the opposite parity, separated by the energy split, so-called $l$-doublets, define the experimental electric field strength required for the molecule polarization. In addition, in our previous paper [Phys.Rev. A 105, L050801 (2022)] we have shown that the value of $l$-doubling directly influences the sensitivity of linear triatomic molecules to the $\mathcal{P}$,$\mathcal{T}$-odd effects. In our work [The JCP 155, 164301 (2021)] we have calculated the value of $l$-doubling for the YbOH molecule with approximation of fixed O-H bond length. Accounting the importance of this property, in the present study we consider the additional degree of freedom corresponding to the ligand (OH) deformation.

    ↳ physics.atom-phhep-phphysics.chem-phquant-phJ.Chem.Phys.(2022)·6 citations
38. 38*

    Models of modified-inertia formulation of MOND

    Mordehai Milgrom🇮🇱

    Models of "modified-inertia" formulation of MOND are described and applied to nonrelativistic many-body systems. They involve time-nonlocal equations of motion. Momentum, angular momentum, and energy are (nonlocally) defined, whose total values are conserved for isolated systems. The models make all the salient MOND predictions. Yet, they differ from existing "modified-gravity" formulations in some second-tier predictions. The models describe correctly the motion of a composite body in a low-acceleration field even when the internal accelerations of its constituents are high. They exhibit a MOND external field effect (EFE) that shows some important differences from what we have come to expect from modified-gravity versions: In one, simple example of the models, what determines the EFE, in the case of a dominant external field, is $\mu (\theta ⟨a_{ex}⟩/a_0)$, where $\mu (x)$ is the MOND `interpolating function' that describes rotation curves, compared with $\mu (a_{ex}/a_0)$ for presently-known modified-gravity formulations. The two main differences are that while $a_{ex}$ is the momentary value of the external acceleration, $⟨a_{ex}⟩$ is a certain time average of it, and that $\theta >1$ is an extra factor that depends on the frequency ratio of the external- and internal-field variations. Only ratios of frequencies enter, and $a_0$ remains the only new dimensioned constant. For a system on a circular orbit in a galaxy (such as the vertical dynamics in a disc galaxy), the first difference disappears, since $⟨a_{ex}⟩=a_{ex}$. But the $\theta$ factor can appreciably enhance the EFE in quenching MOND effects, over what is deduced in modified gravity. Some exact solutions are also described, such as for rotation curves, for an harmonic force, and the general, two-body problem, which in the deep-MOND regime reduces to a single-body problem.

    ↳ astro-ph.GAgr-qchep-phPRD(2022)·31 citations
39. 39*

    Testing the Hubble law with Pantheon+

    Deng Wang🇨🇳

    The Hubble law (HL) governs the low-redshift (low-z) evolution of the distance of an object. However, there is a lack of an investigation of its validity and effective radius for a long time, since the low-z background data with a high precision is scarce. The latest Type Ia supernovae sample Pantheon+ having a significant increase of low-z data provides an excellent opportunity to test the HL. We propose a generalized HL and implement the first modern test of the HL with Pantheon+. We obtain the constraint on the deviation parameter $\alpha =1.00118\pm 0.00044$, confirm the validity of linear HL with a $0.04\%$ precision and give the transition redshift $z_t=0.03$ and luminosity distance $D_{L,t}=123.13\pm 1.75$ Mpc, which means that HL holds when $z<0.03$ and breaks down at a distance of $D_L>123.13$ Mpc. Comparing the ability of Type Ia supernovae and HII galaxies in testing the HL, we stress the uniqueness and strong power of Type Ia supernovae in probing the low-z physics.

    ↳ astro-ph.COastro-ph.GAgr-qchep-ph1 citation
40. 40*

    Fluctuations of conserved charges in strong magnetic fields from lattice QCD

    Heng-Tong Ding🇨🇳 · Sheng-Tai Li🇨🇳 · Jun-Hong Liu🇨🇳 · Xiao-Dan Wang🇨🇳

    We present the first lattice QCD results of the second order fluctuations of and correlations among net baryon number, electric charge and strangeness in (2+1)-flavor lattice QCD in the presence of a background magnetic field with physical pion mass $m_{\pi }=135$ MeV. To mimic the magnetic field strength produced in the early stage of heavy-ion collision experiments we use 6 different values of the magnetic field strength up to $\sim$10$m_{\pi }^2$. We find that the correlations between baryon number and electric charge along the transition line are substantially affected by magnetic fields in the current $eB$ window, which could be useful for probing the existence of a magnetic field in heavy-ion collision experiments.

    ↳ hep-lathep-phnucl-exnucl-thActa Phys.Polon.Supp.(2023)·16 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.