ArcAdiAIl repository digitale DSpace descrive, archivia, indizizza, preserva e distribuisce materiale di ricerca in forma digitale.http://dspace-roma3.caspur.it:802015-05-27T17:40:28Z2015-05-27T17:40:28ZA proposal for B-physics on current latticesBlossier, BenoitDimopoulos, PetrosFrezzotti, RobertoHerdoiza, GregorioJansen, KarlLubicz, VittorioMartinelli, GuidoMichael, ChrisRossi, GiancarloShindler, AndreaSimula, SilvanoTarantino, CeciliaUrbach, Carstenhttp://hdl.handle.net/2307/2262011-12-22T13:34:34Z2010-04-11T22:00:00Z<Titolo>A proposal for B-physics on current lattices</Titolo>
<Autori>Blossier, Benoit; Dimopoulos, Petros; Frezzotti, Roberto; Herdoiza, Gregorio; Jansen, Karl; Lubicz, Vittorio; Martinelli, Guido; Michael, Chris; Rossi, Giancarlo; Shindler, Andrea; Simula, Silvano; Tarantino, Cecilia; Urbach, Carsten</Autori>
<Data di pubblicazione>2010-04-12</Data di pubblicazione>
<Contenuto in>JHEP</Contenuto in>
<Volume>2010</Volume>
<Pagine>1-25</Pagine>
<Abstract>A method to extract B-physics parameters (b-quark mass and fB, fBs decay
constants) from currently available lattice data is presented and tested. The approach is based on the idea of constructing appropriate ratios of heavy-light meson masses and decay
constants, respectively, possessing a precisely known static limit, and evaluating them at
various pairs of heavy quark masses around the charm. Via a smooth interpolation in
the heavy quark mass from the easily accessible charm region to the asymptotic point, B-physics
parameters are computed with a few percent (statistical + systematic) error using
recently produced Nf = 2 maximally twisted Wilson fermions data.</Abstract>2010-04-11T22:00:00ZAn improved Standard Model prediction of BR(B →τν) and its implicationsfor New PhysicsBona, MarcellaCiuchini, MarcoFranco, EnricoLubicz, VittorioMartinelli, GuidoParodi, FabrizioPierini, MaurizioSchiavi, CarloSilvestrini, LucaSordini, ViolaStocchi, AchilleTarantino, CeciliaVagnoni, Vincenzohttp://hdl.handle.net/2307/2272011-12-22T13:34:34Z2010-02-24T23:00:00Z<Titolo>An improved Standard Model prediction of BR(B →τν) and its implicationsfor New Physics</Titolo>
<Autori>Bona, Marcella; Ciuchini, Marco; Franco, Enrico; Lubicz, Vittorio; Martinelli, Guido; Parodi, Fabrizio; Pierini, Maurizio; Schiavi, Carlo; Silvestrini, Luca; Sordini, Viola; Stocchi, Achille; Tarantino, Cecilia; Vagnoni, Vincenzo</Autori>
<Data di pubblicazione>2010-02-25</Data di pubblicazione>
<Contenuto in>Physics Letters B</Contenuto in>
<Volume>687</Volume>
<Pagine>61-69</Pagine>
<Abstract>The recently measured B →τν branching ratio allows to test the Standard Model by probing virtual
effects of new heavy particles, such as a charged Higgs boson. The accuracy of the test is currently
limited by the experimental error on BR(B → τν) and by the uncertainty on the parameters f B and
|Vub|. The redundancy of the Unitarity Triangle fit allows to reduce the error on these parameters and
thus to perform a more precise test of the Standard Model. Using the current experimental inputs, we
obtain BR(B →τν)SM = (0.84±0.11)×10−4, to be compared with BR(B →τν)exp = (1.73±0.34)×10−4.
The Standard Model prediction can be modified by New Physics effects in the decay amplitude as well
as in the Unitarity Triangle fit. We discuss how to disentangle the two possible contributions in the case
of minimal flavour violation at large tan β and generic loop-mediated New Physics. We also consider two
specific models with minimal flavour violation: the Type-II Two Higgs Doublet Model and the Minimal
Supersymmetric Standard Model.</Abstract>2010-02-24T23:00:00ZFCNC processes in the Littlest Higgs model with T-parity: an updateBlanke, MonikaBuras, Andrzej J.Duling, BjoernRecksiegel, StefanTarantino, Ceciliahttp://hdl.handle.net/2307/2332011-12-22T13:35:27Z2010-02-28T23:00:00Z<Titolo>FCNC processes in the Littlest Higgs model with T-parity: an update</Titolo>
<Autori>Blanke, Monika; Buras, Andrzej J.; Duling, Bjoern; Recksiegel, Stefan; Tarantino, Cecilia</Autori>
<Data di pubblicazione>2010-03</Data di pubblicazione>
<Contenuto in>Acta Physica Polonica B</Contenuto in>
<Volume>41</Volume>
<Pagine>657-683</Pagine>
<Abstract>We update our 2006–2007 results for FCNC processes in the Littlest
Higgs model with T-parity (LHT). The removal of the logarithmic UV
cutoff dependence in our previous results through a new contribution to
the Z0-penguin diagrams identified by Goto et al. and del Aguila et al.,
while making the deviations from the SM expectations in the quark sector
less spectacular, still allows for sizable new physics effects in K !
and KL ! 0`+` decays and in the CP-asymmetry S with the latter
unaffected by the new contribution. We extend our analysis by a study
of the fine-tuning required to fit the data on "K and by the inclusion of
the decay KL ! + . A number of correlations can distinguish this
model from the custodially protected Randall–Sundrum model analysed
recently. We also reconsider lepton flavour violating decays, including now
a discussion of fine-tuning. While the `i ! `j
decays are unaffected
by the removal of the logarithmic cutoff dependence, the branching ratios
for decays with three leptons in the final state, like ! 3e are lowered
by almost an order of magnitude. In spite of this, the pattern of lepton
flavour violation in the LHT model can still be distinguished from the one
in supersymmetric models.</Abstract>2010-02-28T23:00:00ZfB and fBs with maximally twisted Wilson fermionsBlossier, BenoitDimopoulos, PetrosFrezzotti, RobertoHerdoiza, GregorioJansen, KarlLubicz, VittorioMartinelli, GuidoMichael, ChrisRossi, GiancarloSanfilippo, FrancescoShindler, AndreaSimula, SilvanoTarantino, CeciliaUrbach, CarstenWagner, Marchttp://hdl.handle.net/2307/2282011-12-22T13:39:36Z2009-12-31T23:00:00Z<Titolo>fB and fBs with maximally twisted Wilson fermions</Titolo>
<Autori>Blossier, Benoit; Dimopoulos, Petros; Frezzotti, Roberto; Herdoiza, Gregorio; Jansen, Karl; Lubicz, Vittorio; Martinelli, Guido; Michael, Chris; Rossi, Giancarlo; Sanfilippo, Francesco; Shindler, Andrea; Simula, Silvano; Tarantino, Cecilia; Urbach, Carsten; Wagner, Marc</Autori>
<Data di pubblicazione>2010</Data di pubblicazione>
<Pagine>151-158</Pagine>
<Abstract>We present a lattice QCD calculation of the heavy-light decay constants fB and fBs performed
with Nf = 2 maximally twisted Wilson fermions, at four values of the lattice spacing. The decay
constants have been also computed in the static limit and the results are used to interpolate the
observables between the charmand the infinite-mass sectors, thus obtaining the value of the decay
constants at the physical b quark mass. Our preliminary results are fB = 191(14)MeV, fBs =
243(14)MeV, fBs/ fB = 1.27(5). They are in good agreement with those obtained with a novel
approach, recently proposed by our Collaboration (ETMC), based on the use of suitable ratios
having an exactly known static limit.</Abstract>2009-12-31T23:00:00ZStatus of the Unitarity Triangle AnalysisBona, MarcellaCiuchini, MarcoFranco, EnricoLubicz, VittorioMartinelli, GuidoParodi, FabrizioPierini, MaurizioSchiavi, CarloSilvestrini, LucaSordini, ViolaStocchi, AchilleTarantino, CeciliaVagnoni, Vincenzohttp://hdl.handle.net/2307/2392011-12-22T13:39:36Z2008-12-31T23:00:00Z<Titolo>Status of the Unitarity Triangle Analysis</Titolo>
<Autori>Bona, Marcella; Ciuchini, Marco; Franco, Enrico; Lubicz, Vittorio; Martinelli, Guido; Parodi, Fabrizio; Pierini, Maurizio; Schiavi, Carlo; Silvestrini, Luca; Sordini, Viola; Stocchi, Achille; Tarantino, Cecilia; Vagnoni, Vincenzo</Autori>
<Data di pubblicazione>2009</Data di pubblicazione>
<Pagine>160-163</Pagine>
<Abstract>We present an update of the Unitarity Triangle (UT) analysis, within the Standard Model (SM)
and beyond. Within the SM the main novelties are the inclusion in eK of the contributions of
x and fe 6= p /4 pointed out by A. J. Buras and D. Guadagnoli, and an accurate prediction of
BR(B→tn), by using the indirect determination of |Vub| from the UT fit, which can be compared
to the present experimental result. In the generalization of the UT analysis to investigate New
Physics (NP) effects, the estimate of x is more delicate and only the effect of fe 6= p /4 has
been included. We confirm an hint of NP in the Bs-¯Bs mixing at the 2.9s level, which makes a
comparison with new experimental data certainly desired.</Abstract>2008-12-31T23:00:00ZUpdate of the Unitarity Triangle AnalysisTarantino, Ceciliahttp://hdl.handle.net/2307/2212011-12-22T13:35:27Z2009-08-14T22:00:00Z<Titolo>Update of the Unitarity Triangle Analysis</Titolo>
<Autori>Tarantino, Cecilia</Autori>
<Data di pubblicazione>2009-08-15</Data di pubblicazione>
<Contenuto in>NUCLEAR PHYSICS A</Contenuto in>
<Volume>827</Volume>
<Pagine>439C-444C</Pagine>
<Abstract>We present the update of the Unitarity Triangle (UT) analysis withinthe Standard Model (SM) and beyond. Within the SM, combining the directmeasurements on sides and angles, the UT turns out to beoverconstrained in a consistent way, showing that the CKM matrix is thedominant source of flavour mixing and CP-violation and that New Physics(NP) effects can appear at most as small corrections to the CKMpicture. Generalizing the UT analysis to investigate NP effects,constraints on b -> s transitions are also included and both CKM and NPparameters are fitted simultaneously. While no evidence of NP effectsis found in K-(K) over bar and B-d-(B) over bar (d) mixing, in theB-s-(B) over bar (s) mixing an hint of NP is found at the 2.9 sigma,level. The UT analysis beyond the SM also allows us to derive bounds onthe coefficients of the most general Delta F = 2 effective Hamiltonian,that can be translated into bounds on the NP scale.</Abstract>2009-08-14T22:00:00ZFCNC Processes in the LHT Model: a 2009 LookTarantino, Ceciliahttp://hdl.handle.net/2307/3012011-12-22T13:39:36Z2008-12-31T23:00:00Z<Titolo>FCNC Processes in the LHT Model: a 2009 Look</Titolo>
<Autori>Tarantino, Cecilia</Autori>
<Data di pubblicazione>2009</Data di pubblicazione>
<Pagine>185-188</Pagine>
<Abstract>We present a summary of our recent analysis update of flavour changing neutral current (FCNC)
processes in the Littlest Higgs model with T-parity (LHT). The essential novelties of our update
are: the removal of the logarithmicUV cutoff dependence by the inclusion of the new contribution
to the Z0-penguin diagrams identified by Goto et al. and by del Aguila et al., the study of the decay
KL →m+m−, a discussion of fine-tuning in eK and Br(m →eg ).</Abstract>2008-12-31T23:00:00ZVector and scalar form factors for K- and D-mesonsemileptonic decays from twisted mass fermionswith Nf = 2Di Vita, StefanoHaas, BenjaminLubicz, VittorioMescia, FedericoSimula, SilvanoTarantino, Ceciliahttp://hdl.handle.net/2307/2712011-12-22T13:39:36Z2008-12-31T23:00:00Z<Titolo>Vector and scalar form factors for K- and D-mesonsemileptonic decays from twisted mass fermionswith Nf = 2</Titolo>
<Autori>Di Vita, Stefano; Haas, Benjamin; Lubicz, Vittorio; Mescia, Federico; Simula, Silvano; Tarantino, Cecilia</Autori>
<Data di pubblicazione>2009</Data di pubblicazione>
<Pagine>257-264</Pagine>
<Abstract>We present lattice results for the formfactors relevant in the K→p ℓnℓ and D→p ℓnℓ semileptonic
decays, obtained from simulations with two flavors of dynamical twisted-mass fermions and pion
masses as light as 260 MeV. For K →p ℓn decays we discuss the estimates of the main sources
of systematic uncertainties, including the quenching of the strange quark, leading to our final result
f+(0) = 0.9560(57)stat.(62)syst.. Combined with the latest experimental data, our value of
f+(0) implies for the CKMmatrix element |Vus| the value 0.2267(5)exp.(20) f+(0) consistent with
the first-row CKM unitarity. For D →p ℓnℓ decays the application of Heavy Meson Chiral Perturbation
Theory allows to extrapolate our results for both the scalar and the vector form factors
at the physical point with quite good accuracy, obtaining a nice agreement with the experimental
data. In particular at zero-momentumtransfer we obtain f+(0) = 0.64(5). A preliminary analysis
of the discretization effects is presented and discussed.</Abstract>2008-12-31T23:00:00ZK ->pi l nu semileptonic form factors from two-flavor lattice QCDLubicz, VittorioMescia, FedericoSimula, SilvanoTarantino, Ceciliahttp://hdl.handle.net/2307/3152011-12-22T13:35:27Z2009-11-30T23:00:00Z<Titolo>K ->pi l nu semileptonic form factors from two-flavor lattice QCD</Titolo>
<Autori>Lubicz, Vittorio; Mescia, Federico; Simula, Silvano; Tarantino, Cecilia</Autori>
<Data di pubblicazione>2009-12</Data di pubblicazione>
<Contenuto in>Physical review D</Contenuto in>
<Volume>80</Volume>
<Pagine>111502</Pagine>
<Abstract>We present new lattice results of the K ->pi l nu semileptonic formfactors obtained from simulations with two flavors of dynamicaltwisted-mass fermions, using pion masses as light as 260 MeV. Our mainresult is f(+)(0)=0.9560(84), which, combined with the latestexperimental data for K-l3 decays, leads to|V-us|=0.2267(5)(exp)(20)(f+)(0). Using the PDG(2008) determinations of|V-ud| and |V-ub| our result implies for the unitarity relation|V-ud|(2)+|V-us|(2)+|V-ub|(2)=1.0004(15). For the O(p(6)) term of thechiral expansion of f(+)(0) we get Delta f equivalent tof(+)(0)-1-f(2)=-0.0214(84).</Abstract>2009-11-30T23:00:00ZK ->pi l nu semileptonic form factors from two-flavor lattice QCDLubicz, VittorioMescia, FedericoSimula, SilvanoTarantino, Ceciliahttp://hdl.handle.net/2307/3612011-12-22T13:35:27Z2009-12-29T23:00:00Z<Titolo>K ->pi l nu semileptonic form factors from two-flavor lattice QCD</Titolo>
<Autori>Lubicz, Vittorio; Mescia, Federico; Simula, Silvano; Tarantino, Cecilia</Autori>
<Data di pubblicazione>2009-12-30</Data di pubblicazione>
<Contenuto in>Physical Review D</Contenuto in>
<Volume>80</Volume>
<Pagine>111502</Pagine>
<Abstract>We present new lattice results of the K ->pi l nu semileptonic form factors obtained from simulations with two flavors of dynamicaltwisted-mass fermions, using pion masses as light as 260 MeV. Our main result is f(+)(0)=0.9560(84), which, combined with the latest experimental data for Kl3 decays, leads to |Vus|=0.2267(5)(exp)(20)(f+(0)). Using the PDG(2008) determinations of|Vud| and |Vub| our result implies for the unitarity relation |Vud|^2+|Vus|^2+|Vub|^2=1.0004(15). For the O(p^6) term of the chiral expansion of f+(0) we get Delta f = f+(0)-1-f2=-0.0214(84).</Abstract>2009-12-29T23:00:00ZPseudoscalar decay constants of kaon and D-mesons from Nf=2 twisted mass Lattice QCDETM, CollaborationBlossier, BenoitDimopoulos, PetrosFrezzotti, RobertoHaas, BenjaminHerdoiza, GregorioJansen, KarlLubicz, VittorioMescia, FedericoPalao, DavidShindler, AndreaSimula, SilvanoTarantino, CeciliaUrbach, Carstenhttp://hdl.handle.net/2307/3982011-12-22T13:35:27Z2009-06-30T22:00:00Z<Titolo>Pseudoscalar decay constants of kaon and D-mesons from Nf=2 twisted mass Lattice QCD</Titolo>
<Autori>ETM, Collaboration; Blossier, Benoit; Dimopoulos, Petros; Frezzotti, Roberto; Haas, Benjamin; Herdoiza, Gregorio; Jansen, Karl; Lubicz, Vittorio; Mescia, Federico; Palao, David; Shindler, Andrea; Simula, Silvano; Tarantino, Cecilia; Urbach, Carsten</Autori>
<Data di pubblicazione>2009-07</Data di pubblicazione>
<Contenuto in>Journal of High Energy Physics</Contenuto in>
<Volume>07</Volume>
<Pagine>043</Pagine>
<Abstract>We present the results of a lattice QCD calculation of the pseudoscalar meson decay constants fπ, fK, fD and fDs, performed with Nf=2 dynamical fermions. The simulation is carried out with the tree-level improved Symanzik gauge action and with the twisted mass fermionic action at maximal twist. We have considered for the final analysis three values of the lattice spacing, a = 0.10 fm, 0.09 fm and 0.07 fm, with pion masses down to mπ = 270 MeV. Our results for the light meson decay constants are fK = 158.1(2.4) MeV and fK/fπ = 1.210(18). From the latter ratio, by using the experimental determination of Γ(K → μbar nuμ(γ))/Γ(π → μbar nuμ(γ)) and the average value of |Vud| from nuclear beta decays, we obtain |Vus| = 0.2222(34), in good agreement with the determination from semileptonic Kl3 decays and the unitarity constraint. For the D and Ds meson decay constants we obtain fD = 197(9) MeV, fDs = 244(8) MeV and fDs/fD = 1.24(3). Our result for fD is in good agreement with the CLEO experimental measurement. For fDs our determination is smaller than the PDG 2008 experimental average but in agreement with a recent improved measurement by CLEO at the 1.4 σ level.</Abstract>2009-06-30T22:00:00Zf_B and f_Bs with maximally twisted Wilson fermionsETM CollaborationBlossier, BenoitDimopoulos, PetrosFrezzotti, RobertoHerdoiza, GregorioJansen, KarlLubicz, VittorioMartinelli, GuidoMichael, ChrisRossi, GiancarloSanfilippo, FrancescoShindler, AndreaSimula, SilvanoTarantino, CeciliaUrbach, CarstenWagner, Marchttp://hdl.handle.net/2307/4032011-12-22T13:39:36Z2008-12-31T23:00:00Z<Titolo>f_B and f_Bs with maximally twisted Wilson fermions</Titolo>
<Autori>ETM Collaboration; Blossier, Benoit; Dimopoulos, Petros; Frezzotti, Roberto; Herdoiza, Gregorio; Jansen, Karl; Lubicz, Vittorio; Martinelli, Guido; Michael, Chris; Rossi, Giancarlo; Sanfilippo, Francesco; Shindler, Andrea; Simula, Silvano; Tarantino, Cecilia; Urbach, Carsten; Wagner, Marc</Autori>
<Data di pubblicazione>2009</Data di pubblicazione>
<Pagine>151</Pagine>
<Abstract>We present a lattice QCD calculation of the heavy-light decay constants f_B and f_Bs performed with Nf=2 maximally twisted Wilson fermions, at four values of the lattice spacing. The decay constants have been also computed in the static limit and the results are used to interpolate the observables between the charm and the infinite-mass sectors, thus obtaining the value of the decay constants at the physical b quark mass. Our preliminary results are f_B=191(14) MeV, f_Bs=243(14) MeV, f_Bs/f_B=1.27(5). They are in good agreement with those obtained with a novel approach, recently proposed by our Collaboration (ETMC), based on the use of suitable ratios having an exactly known static limit.</Abstract>2008-12-31T23:00:00ZPseudoscalar decay constants of kaon and D-mesons from N-f=2 twisted mass Lattice QCDBlossier, BenoîtDimopoulos, PedroFrezzotti, RobertoHaas, BenjaminHerdoiza, GregorioJansen, KarlLubicz, VittorioMescia, FedericoPalao, DavidShindler, AndreaSimula, SilvanoTarantino, CeciliaUrbach, CarstenWenger, Urshttp://hdl.handle.net/2307/5262013-09-25T15:14:26Z2009-06-30T22:00:00Z<Titolo>Pseudoscalar decay constants of kaon and D-mesons from N-f=2 twisted mass Lattice QCD</Titolo>
<Autori>Blossier, Benoît; Dimopoulos, Pedro; Frezzotti, Roberto; Haas, Benjamin; Herdoiza, Gregorio; Jansen, Karl; Lubicz, Vittorio; Mescia, Federico; Palao, David; Shindler, Andrea; Simula, Silvano; Tarantino, Cecilia; Urbach, Carsten; Wenger, Urs</Autori>
<Data di pubblicazione>2009-07</Data di pubblicazione>
<Contenuto in>Journal of high energy physics</Contenuto in>
<Volume>2009</Volume>
<Pagine>043</Pagine>
<Abstract>We present the results of a lattice QCD calculation of the pseudoscalar meson decay constants f(pi), f(K), f(D) and f(Ds), performed with N-f =2 dynamical fermions. The simulation is carried out with the tree-level improved Symanzik gauge action and with the twisted mass fermionic action at maximal twist. We have considered for the final analysis three values of the lattice spacing, a similar or equal to 0.10 fm, 0.09 fm and 0.07 fm, with pion masses down to m(pi) similar or equal to 270 MeV. Our results for the light meson decay constants are f(K) =158.1(2.4) MeV and f(K)/f(pi) = 1.210(18). From the latter ratio, by using the experimental determination of Gamma(K -> munu(mu)(gamma))/Gamma(pi -> mu nu(mu)(gamma)) and the average value of vertical bar V-ud vertical bar from nuclear beta decays, we obtain vertical bar V-us vertical bar = 0.2222(34), in good agreement with the determination from semileptonic K-13 decays and the unitarity constraint. For the D and D-s meson decay constants we obtain f(D) =197(9) MeV, f(Ds) = 244(8) MeV and f(Ds)/f(D) = 1.24(3). Our result for f(D) is in good agreement with the CLEO experimental measurement. For f(Ds) our determination is smaller than the PDG 2008 experimental average but in agreement with a recent improved measurement by CLEO at the 1.4 sigma level.</Abstract>2009-06-30T22:00:00Z