We report the ground state masses of hadrons containing at least one charm and one bottom quark using lattice quantum chromodynamics. These include mesons with spin (J)-parity (P ) quantum numbers (J P ): 0 − , 1 − , 1 + and 0 + and the spin-1/2 and 3/2 baryons. Among these hadrons only the ground state of 0 − is known experimentally and therefore our predictions provide important information for the experimental discovery of all other hadrons with these quark contents. PACS numbers: 12.38.Gc, 14.20.Lq Recently heavy hadron physics has attracted huge scientific interests mainly due to the prospects of studying new physics beyond the Standard Model at the intensity frontier [1][2][3][4][5], and to study various newly discovered subatomic particles to better understand the confining nature of strong interactions [6][7][8][9][10][11][12]. From the perspective of newly found hadrons itself, a large number of discoveries over the past decade ranging from usual mesons [13][14][15][16][17][18][19][20], baryons [21] along with their excited states [22][23][24][25], to new exotic particles like tetraquarks [26-28] and pentaquarks [29], as well as hadrons whose structures are still elusive [6][7][8][30][31][32][33], have proliferated interests in the study of heavy hadrons. Furthermore, it is envisaged that the large data already collected or to be obtained at different laboratories, particularly at LHCb and Belle II, will further unravel many other hadrons. One variety of such theorized but as yet essentially unobserved (except one) subatomic particles are hadrons made of at least a charm and a bottom quarks, the charmed-bottom (bc) hadrons.Investigations of such hadrons are highly appealing, as they provide a unique laboratory to explore the heavy quark dynamics at multiple scales: 1/m b , 1/m c and 1/Λ QCD . Decay constants and form factors of bc mesons are still unknown but are quite important because of their relevance to investigate physics beyond the standard model, particularly in view of the recent measurement of R(J/ψ) [34]. The information on spin splittings and decay constants can shed light on their structures and help us to understand the nature of strong interactions at multiple scales. Moreover, bc baryon decays can aid in studying b → c transition and |V cb | element of the CKM matrix.However, to date the discovery of these hadrons is limited to only two observations: B c (0 − ) with mass 6275(1) MeV [35] and B c (2S)(0 − ) at 6842(6) MeV [36] while the latter has not yet been confirmed [37]. On the other hand, LHC being an efficient factory for producing bc hadrons [38,39], one would envisage for their discovery and study their decays in near future. Precise theoretical predictions related to the energy spectra and decay of these hadrons are thus utmost essential to guide their discovery.In fact various model calculations exist in literatures on bc mesons [40][41][42][43][44][45][46] and baryons [47][48][49][50][51][52][53]. However, those predictions vary widely, e.g. 1S-hyperfine splitting in B c (bc...

Spin-crossover molecules are very appealing for use in multifunctional spintronic devices because of their ability to switch between high-spin and low-spin states with external stimuli such as voltage and light. In actual devices, the molecules are deposited on a substrate, which can modify their properties. However, surprisingly little is known about such molecule−substrate effects. Here we show for the first time, by grazing incidence X-ray diffraction, that an Fe II spin-crossover molecular layer displays a well-defined epitaxial relationship with a metal substrate. Then we show, by both density functional calculations and a mechanoelastic model, that the resulting epitaxial strain and the related internal pressure can induce a partial spin conversion at low temperatures, which has indeed been observed experimentally. Our results emphasize the importance of substrate-induced spin state transitions and raise the possibility of exploiting them.

Control and manipulation of electric current and, especially, its degree of spin polarization (spin filtering) across single molecules are currently of great interest in the field of molecular spintronics. We explore one possible strategy based on the modification of nanojunction symmetry which can be realized, for example, by a mechanical strain. Such modification can activate new molecular orbitals which were inactive before due to their orbital mismatch with the electrodes conduction states. This can result in several important consequences such as (i) quantum interference effects appearing as Fano-like features in electron transmission and (ii) the change in molecular level hybridization with the electrodes states. We argue that the symmetry change can affect very differently two majority-and minority-spin conductances and thus alter significantly the resulting spin-filtering ratio as the junction symmetry is modified.We illustrate the idea for two basic molecular junctions: Ni/benzene/Ni (perpendicular vs tilted orientations) and Ni/Si chain/Ni (zigzag vs linear chains). In both cases, one highest occupied molecular orbital (HOMO) and one lowest unoccupied molecular orbital (LUMO) (out of HOMO and LUMO doublets) are important. In particular, their destructive interference with other orbitals leads to dramatic suppression of majority-spin conductance in low-symmetry configurations. For a minorityspin channel, on the contrary, the conductance is strongly enhanced when the symmetry is lowered due to an increase in hybridization strength. We believe that our results may offer a potential route for creating molecular devices with a large on-off ratio of spin polarization via quantum interference effects.PACS numbers:

Taylor expansion in powers of baryon chemical potential (µB) is an oft-used method in lattice QCD to compute QCD thermodynamics for µB > 0. Based only upon the few known lowest order Taylor coefficients, it is difficult to discern the range of µB where such an expansion around µB = 0 can be trusted. We introduce a method to compute the lattice QCD equation of state to all orders in µB, which reproduces the truncated Taylor expansion when re-expanded in powers of µB. The method resums contributions of up to n-point correlations (Dn) of the conserved current to all orders in µB, leading to a resummed partition function. We show that the resummed partition function is an approximation to the reweighted partition function at µB = 0. We apply the proposed approach to high-statistics lattice QCD calculations using 2+1 flavors of Highly Improved Staggered Quarks with physical quark masses on 32 3 × 8 lattices and for temperatures T ≈ 145 − 176 MeV. We demonstrate that, as opposed to the Taylor expansion, the resummed version not only leads to markedly improved convergence but also reflects the zeros of the resummed partition function and severity of the sign problem, leading to its eventual breakdown.

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Incorporating functional atomic sites in graphene is essential for realizing advanced two-dimensional materials. Doping graphene with nitrogen offers the opportunity to tune its chemical activity, with significant charge redistribution occurring between molecules and substrate. The necessary atomic scale understanding of how this depends on the spatial distribution of dopants, as well as their positions relative to the molecule, can be provided by scanning tunneling microscopy. Here we show that a non-covalently bonded molecule such as CoPc undergoes a variable charge transfer when placed on N-doped graphene: on a nitrogen pair, it undergoes a redox reaction, with an integral charge transfer, whereas a lower fractional charge transfer occurs over a single nitrogen.Thus the charge state of molecules can be tuned by suitably tailoring the conformation of dopant atoms.

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Abstract. We present preliminary results on the light, charmed and bottom baryon spectra using overlap valence quarks on the background of 2+1+1 flavours HISQ gauge configurations of the MILC collaboration. These calculations are performed on three different gauge ensembles at three lattice spacings (a ∼ 0.12 fm, 0.09 fm and 0.06 fm) and for physical strange, charm and bottom quark masses. The SU(2) heavy baryon chiral perturbation theory is used to extrapolate baryon masses to the physical pion mass and the continuum limit extrapolations are also performed. Our results are consistent with the well measured charmed baryons. We predict the masses of many other states which are yet to be discovered.