Renormalization of Non-Commutative Phi^4_4 Field Theory in x Space

In this paper we provide a new proof that the Grosse-Wulkenhaar non-commutative scalar Phi^4_4 theory is renormalizable to all orders in perturbation theory, and extend it to more general models with covariant derivatives. Our proof relies solely on a multiscale analysis in x space. We think this proof is simpler and could be more adapted to the future study of these theories (in particular at the non-perturbative or constructive level).Comment: 32 pages, v2: correction of lemmas 3.1 and 3.2 with no consequence on the main resul

A framework for assessing and implementing the co-benefits of nature-based solutions in urban areas

To address challenges associated with climate resilience, health and well-being in urban areas, current policy platforms are shifting their focus from ecosystem-based to nature-based solutions (NBS), broadly defined as solutions to societal challenges that are inspired and supported by nature. NBS result in the provision of co-benefits, such as the improvement of place attractiveness, of health and quality of life, and creation of green jobs. Few frameworks exist for acknowledging and assessing the value of such co-benefits of NBS and to guide cross-sectoral project and policy design and implementation. In this paper, we firstly developed a holistic framework for assessing co-benefits (and costs) of NBS across elements of socio-cultural and socio-economic systems, biodiversity, ecosystems and climate. The framework was guided by a review of over 1700 documents from science and practice within and across 10 societal challenges relevant to cities globally. We found that NBS can have environmental, social and economic co-benefits and/or costs both within and across these 10 societal challenges. On that base, we develop and propose a seven-stage process for situating co-benefit assessment within policy and project implementation. The seven stages include: 1) identify problem or opportunity; 2) select and assess NBS and related actions; 3) design NBS implementation processes; 4) implement NBS; 5) frequently engage stakeholders and communicate co-benefits; 6) transfer and upscale NBS; and 7) monitor and evaluate co-benefits across all stages. We conclude that the developed framework together with the seven-stage co-benefit assessment process represent a valuable tool for guiding thinking and identifying the multiple values of NBS implementation

Topological Graph Polynomials in Colored Group Field Theory

In this paper we analyze the open Feynman graphs of the Colored Group Field Theory introduced in [arXiv:0907.2582]. We define the boundary graph \cG_{\partial} of an open graph \cG and prove it is a cellular complex. Using this structure we generalize the topological (Bollobas-Riordan) Tutte polynomials associated to (ribbon) graphs to topological polynomials adapted to Colored Group Field Theory graphs in arbitrary dimension

Measurement of CP asymmetries in D(s)+→ηπ+ {D}_{(s)}^{+}\to \eta {\pi}^{+} and D(s)+→η′π+ {D}_{(s)}^{+}\to {\eta}^{\prime }{\pi}^{+} decays

Searches for CP violation in the decays ${D}_{(s)}^{+}\to \eta {\pi}^{+}$ and ${D}_{(s)}^{+}\to {\eta}^{\prime }{\pi}^{+}$ are performed using pp collision data corresponding to 6 fb$^{−1}$ of integrated luminosity collected by the LHCb experiment. The calibration channels ${D}_{(s)}^{+}\to \phi {\pi}^{+}$ are used to remove production and detection asymmetries. The resulting CP-violating asymmetries are${\displaystyle \begin{array}{l}{\mathcal{A}}^{CP}=\left({D}^{+}\to \eta {\pi}^{+}\right)=\left(0.34\pm 0.66\pm 0.16\pm 0.05\right)\%,\\ {}{\mathcal{A}}^{CP}=\left({D}_s^{+}\to \eta {\pi}^{+}\right)=\left(0.32\pm 0.51\pm 0.12\right)\%,\\ {}\begin{array}{l}{\mathcal{A}}^{CP}=\left({D}^{+}\to {\eta}^{\prime }{\pi}^{+}\right)=\left(0.49\pm 0.18\pm 0.06\pm 0.05\right)\%,\\ {}{\mathcal{A}}^{CP}=\left({D}_s^{+}\to {\eta}^{\prime }{\pi}^{+}\right)=\left(0.01\pm 0.12\pm 0.08\right)\%,\end{array}\end{array}}$where the first uncertainty is statistical, the second is systematic and the third, relevant for the D$^{+}$ channels, is due to the uncertainty on ${\mathcal{A}}^{CP}=\left({D}^{+}\to \phi {\pi}^{+}\right)$. These measurements, currently the most precise for three of the four channels considered, are consistent with the absence of CP violation. A combination of these results with previous LHCb measurements is presented.[graphic not available: see fulltext]Searches for $CP$ violation in the decays $D^+_{(s)}\rightarrow \eta \pi^+$ and $D^+_{(s)}\rightarrow \eta^{\prime} \pi^+$ are performed using $pp$ collision data corresponding to 6 fb$^{-1}$ of integrated luminosity collected by the LHCb experiment. The calibration channels $D^+_{(s)}\rightarrow \phi \pi^+$ are used to remove production and detection asymmetries. The resulting $CP$-violating asymmetries are $A^{CP}(D^+ \rightarrow \eta \pi^+) = (0.34 \pm 0.66 \pm 0.16 \pm 0.05)\%$, $A^{CP}(D^+_s \rightarrow \eta \pi^+) = (0.32 \pm 0.51 \pm 0.12)\%$, $A^{CP}(D^+ \rightarrow \eta^{\prime} \pi^+) = (0.49 \pm 0.18 \pm 0.06 \pm 0.05)\%$, $A^{CP}(D^+_s \rightarrow \eta^{\prime} \pi^+) = (0.01 \pm 0.12 \pm 0.08)\%$, where the first uncertainty is statistical, the second is systematic and the third, relevant for the $D^+$ channels, is due to the uncertainty on $A^{CP}(D^+ \to \phi \pi^+)$. These measurements, currently the most precise for three of the four channels considered, are consistent with the absence of $CP$ violation. A combination of these results with previous LHCb measurements is presented

Observation of the Bs0 ⁣→D∗+D∗−B^0_s\!\to D^{*+}D^{*-} decay

International audienceThe first observation of the ${B}_s^0$→ D$^{∗+}$D$^{∗−}$ decay and the measurement of its branching ratio relative to the B$^{0}$→ D$^{∗+}$D$^{∗−}$ decay are presented. The data sample used corresponds to an integrated luminosity of 9 fb$^{−1}$ of proton-proton collisions recorded by the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV between 2011 and 2018. The decay is observed with more than 10 standard deviations and the time-integrated ratio of branching fractions is determined to be$\frac{\mathcal{B}\left({B}_s^0\to {D}^{\ast +}{D}^{\ast -}\right)}{\mathcal{B}\left({B}^0\to {D}^{\ast +}{D}^{\ast -}\right)}=0.269\pm 0.032\pm 0.011\pm 0.008,$where the first uncertainty is statistical, the second systematic and the third due to the uncertainty of the fragmentation fraction ratio f$_{s}$/f$_{d}$. The ${B}_s^0$→ D$^{*+}$D$^{*−}$ branching fraction is calculated to be$\mathcal{B}\left({B}_s^0\to {D}^{\ast +}{D}^{\ast -}\right)=\left(2.15\pm 0.26\pm 0.09\pm 0.06\pm 0.16\right)\times {10}^{-4},$where the fourth uncertainty is due to the B$^{0}$→ D$^{*+}$D$^{*−}$ branching fraction. These results are calculated using the average ${B}_s^0$ meson lifetime in simulation. Correction factors are reported for scenarios where either a purely heavy or a purely light ${B}_s^0$ eigenstate is considered.[graphic not available: see fulltext

Measurement of the Z boson production cross-section in proton-lead collisions at sNN \sqrt{s_{\textrm{NN}}} = 8.16 TeV

This article presents the first measurement of the differential $Z$-boson production cross-section in the forward region using proton-lead collisions with the LHCb detector. The dataset was collected at a nucleon-nucleon centre-of-mass energy of $\sqrt{s_\mathrm{NN}}=8.16\,\mathrm{TeV}$ in 2016, corresponding to an integrated luminosity of $30.8\,\mathrm{nb}^{-1}$. The forward-backward ratio and the nuclear modification factors are measured together with the differential cross-section as functions of the $Z$ boson rapidity in the centre-of-mass frame, the transverse momentum of the $Z$ boson and a geometric variable $\phi^{*}$. The results are in good agreement with the predictions from nuclear parton distribution functions, providing strong constraining power at small Bjorken-$x$.This article presents the first measurement of the differential Z-boson production cross-section in the forward region using proton-lead collisions with the LHCb detector. The dataset was collected at a nucleon-nucleon centre-of-mass energy of $\sqrt{s_{\textrm{NN}}}$ = 8.16 TeV in 2016, corresponding to an integrated luminosity of 30.8 nb$^{−1}$. The forward-backward ratio and the nuclear modification factors are measured together with the differential cross-section as functions of the Z boson rapidity in the centre-of-mass frame, the transverse momentum of the Z boson and a geometric variable ϕ$^{*}$. The results are in good agreement with the predictions from nuclear parton distribution functions, providing strong constraining power at small Bjorken-x.[graphic not available: see fulltext]This article presents the first measurement of the differential $Z$-boson production cross-section in the forward region using proton-lead collisions with the LHCb detector. The dataset was collected at a nucleon-nucleon centre-of-mass energy of $\sqrt{s_\mathrm{NN}}=8.16\,\mathrm{TeV}$ in 2016, corresponding to an integrated luminosity of $30.8\,\mathrm{nb}^{-1}$. The forward-backward ratio and the nuclear modification factors are measured together with the differential cross-section as functions of the $Z$ boson rapidity in the centre-of-mass frame, the transverse momentum of the $Z$ boson and a geometric variable $\phi^{*}$. The results are in good agreement with the predictions from nuclear parton distribution functions, providing strong constraining power at small Bjorken-$x$

Measurement of the CKM angle γγ with B±→D[K∓π±π±π∓]h± B^\pm \to D[K^\mp π^\pm π^\pm π^\mp] h^\pm decays using a binned phase-space approach

The CKM angle $\gamma$ is determined from $C\!P$-violating observables measured in ${B^\pm \to D[ K^\mp \pi^\pm\pi^\pm\pi^\mp] h^\pm}$, $(h = K,\pi)$ decays, where the measurements are performed in bins of the decay phase-space of the $D$ meson. Using proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of $7, 8$ and $13\,\text{TeV}$, corresponding to a total integrated luminosity of $9\,\text{fb}^{-1}$, $\gamma$ is determined to be \begin{equation*} \gamma = \left( 54.8 \: ^{+\:6.0 }_{-\:5.8} \: ^{+\:0.6}_{-\:0.6} \: ^{+\:6.7}_{-\:4.3} \right)^\circ, \end{equation*} where the first uncertainty is statistical, the second systematic and the third from the external inputs on the coherence factors and strong phases of the $D$-meson decays.The CKM angle γ is determined from CP-violating observables measured in B$^{±}$ → D[K$^{∓}$π$^{±}$π$^{±}$π$^{∓}$]h$^{±}$, (h = K, π) decays, where the measurements are performed in bins of the decay phase-space of the D meson. Using proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to a total integrated luminosity of 9 fb$^{−1}$, γ is determined to be$\gamma ={\left(54.8\begin{array}{c}+6.0\\ {}-5.8\end{array}\begin{array}{c}+0.6\\ {}-0.6\end{array}\begin{array}{c}+6.7\\ {}-4.3\end{array}\right)}^{\circ },$where the first uncertainty is statistical, the second systematic and the third from the external inputs on the coherence factors and strong phases of the D-meson decays.[graphic not available: see fulltext]The CKM angle $\gamma$ is determined from $C\!P$-violating observables measured in ${B^\pm \to D[ K^\mp \pi^\pm\pi^\pm\pi^\mp] h^\pm}$, $(h = K,\pi)$ decays, where the measurements are performed in bins of the decay phase-space of the $D$ meson. Using proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of $7, 8$ and $13\,\text{TeV}$, corresponding to a total integrated luminosity of $9\,\text{fb}^{-1}$, $\gamma$ is determined to be \begin{equation*} \gamma = \left( 54.8 \: ^{+\:6.0 }_{-\:5.8} \: ^{+\:0.6}_{-\:0.6} \: ^{+\:6.7}_{-\:4.3} \right)^\circ, \end{equation*} where the first uncertainty is statistical, the second systematic and the third from the external inputs on the coherence factors and strong phases of the $D$-meson decays

First observation and branching fraction measurement of the Λb0→Ds−p {\Lambda}_b^0\to {D}_s^{-}p decay

International audienceThe first observation of the ${\Lambda}_b^0\to {D}_s^{-}p$ decay is presented using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of $\sqrt{s}$ = 13 TeV, corresponding to a total integrated luminosity of 6 fb$^{−1}$. Using the ${\Lambda}_b^0\to {\Lambda}_c^{+}{\pi}^{-}$ decay as the normalisation mode, the branching fraction of the ${\Lambda}_b^0\to {D}_s^{-}p$ decay is measured to be $\mathcal{B}\left({\Lambda}_b^0\to {D}_s^{-}p\right)=\left(12.6\pm 0.5\pm 0.3\pm 1.2\right)\times {10}^{-6}$, where the first uncertainty is statistical, the second systematic and the third due to uncertainties in the branching fractions of the ${\Lambda}_b^0\to {\Lambda}_c^{+}{\pi}^{-}$, ${D}_s^{-}\to {K}^{-}{K}^{+}{\pi}^{-}$ and ${\Lambda}_c^{+}\to p{K}^{-}{\pi}^{+}$ decays.[graphic not available: see fulltext

Search for the lepton-flavour violating decays B0→K∗0μ±e∓B^0 \to K^{*0} \mu^\pm e^\mp and Bs0→ϕμ±e∓B_s^0 \to \phi \mu^\pm e^\mp

A search for the lepton-flavour violating decays $B^0 \to K^{*0} \mu^\pm e^\mp$ and $B_s^0 \to \phi \mu^\pm e^\mp$ is presented, using proton-proton collision data collected by the LHCb detector at the LHC, corresponding to an integrated luminosity of $9\,\text{fb}^{-1}$. No significant signals are observed and upper limits of \begin{align} {\cal B}( B^0 \to K^{*0} \mu^+ e^- ) &< \phantom{1}5.7\times 10^{-9}~(6.9\times 10^{-9}),\newline {\cal B}( B^0 \to K^{*0} \mu^- e^+ ) &< \phantom{1}6.8\times 10^{-9}~(7.9\times 10^{-9}),\newline {\cal B}( B^0 \to K^{*0} \mu^\pm e^\mp ) &< 10.1\times 10^{-9}~(11.7\times 10^{-9}),\newline {\cal B}( B_s^0 \to \phi \mu^\pm e^\mp ) &< 16.0\times 10^{-9}~(19.8\times 10^{-9}) \end{align} are set at $90\%~(95\%)$ confidence level. These results constitute the world's most stringent limits to date, with the limit on the decay $B_s^0 \to \phi \mu^\pm e^\mp$ the first being set. In addition, limits are reported for scalar and left-handed lepton-flavour violating New Physics scenarios.A search for the lepton-flavour violating decays B$^{0}$ → K$^{*0}$μ$^{±}$e$^{∓}$ and ${B}_s^0$→ ϕμ$^{±}$e$^{∓}$ is presented, using proton-proton collision data collected by the LHCb detector at the LHC, corresponding to an integrated luminosity of 9 fb$^{−1}$. No significant signals are observed and upper limits of${\displaystyle \begin{array}{c}\mathcal{B}\left({B}^0\to {K}^{\ast 0}{\mu}^{+}{e}^{-}\right)<5.7\times {10}^{-9}\left(6.9\times {10}^{-9}\right),\\ {}\mathcal{B}\left({B}^0\to {K}^{\ast 0}{\mu}^{-}{e}^{+}\right)<6.8\times {10}^{-9}\left(7.9\times {10}^{-9}\right),\\ {}\mathcal{B}\left({B}^0\to {K}^{\ast 0}{\mu}^{\pm }{e}^{\mp}\right)<10.1\times {10}^{-9}\left(11.7\times {10}^{-9}\right),\\ {}\mathcal{B}\left({B}_s^0\to \phi {\mu}^{\pm }{e}^{\mp}\right)<16.0\times {10}^{-9}\left(19.8\times {10}^{-9}\right)\end{array}}$are set at 90% (95%) confidence level. These results constitute the world’s most stringent limits to date, with the limit on the decay ${B}_s^0$→ ϕμ$^{±}$e$^{∓}$ the first being set. In addition, limits are reported for scalar and left-handed lepton-flavour violating New Physics scenarios.[graphic not available: see fulltext]A search for the lepton-flavour violating decays $B^0 \to K^{*0} \mu^\pm e^\mp$ and $B_s^0 \to \phi \mu^\pm e^\mp$ is presented, using proton-proton collision data collected by the LHCb detector at the LHC, corresponding to an integrated luminosity of $9\,\text{fb}^{-1}$. No significant signals are observed and upper limits of \begin{align} {\cal B}( B^0 \to K^{*0} \mu^+ e^- ) &< \phantom{1}5.7\times 10^{-9}~(6.9\times 10^{-9}),\newline {\cal B}( B^0 \to K^{*0} \mu^- e^+ ) &< \phantom{1}6.8\times 10^{-9}~(7.9\times 10^{-9}),\newline {\cal B}( B^0 \to K^{*0} \mu^\pm e^\mp ) &< 10.1\times 10^{-9}~(11.7\times 10^{-9}),\newline {\cal B}( B_s^0 \to \phi \mu^\pm e^\mp ) &< 16.0\times 10^{-9}~(19.8\times 10^{-9}) \end{align} are set at $90\%~(95\%)$ confidence level. These results constitute the world's most stringent limits to date, with the limit on the decay $B_s^0 \to \phi \mu^\pm e^\mp$ the first being set. In addition, limits are reported for scalar and left-handed lepton-flavour violating New Physics scenarios