Search results for "D meson"

Exploring the D* rho system within QCD sum rules

2013

We present a study of the D* rho system made by using the method of QCD sum rules to determine the mass of possible resonances generated in the same system. Using isospin and spin projectors, we investigate the different configurations and obtain evidences for three D* mesons with isospin I = 1/2, spin S = 0, 1, 2 and with masses 2500 +/- 67, 2523 +/- 60, and 2439 +/- 119 MeV, respectively. The last state can be associated with D-2*(2460) ( spin 2) listed by the Particle Data Group, while one of the first two might be related to D* (2640), with unknown spin parity. In the case of I = 3/2 we also find evidences of three states with spin 0, 1, and 2, respectively, with masses 2467 +/- 82, 242…

Measurement of ratios of branching fractions andCP-violating asymmetries ofB±→D*K±decays

2008

We report a study of B^± → D^*K^± decays with D^* decaying to Dπ^0 or Dγ, using 383×10^6 B[overline B] pairs collected at the Y(4S) resonance with the BABAR detector at the SLAC PEP-II B Factory. The D meson decays under study include a non-CP mode (K^±π^-/_+), CP-even modes (K^±K^-/_+,π^±π^-/_+), and CP-odd modes (K_S^0π^0,K_S^0φ,K_S^0ω). We measure ratios (R^*_(CP±) of branching fractions of decays to CP eigenmode states and to flavor-specific states as well as CP asymmetries (A^*_(CP±). These measurements are sensitive to the unitarity triangle angle γ. We obtain A_(CP+)^*=-0.11±0.09±0.01, R_(CP+)^*=1.31±0.13±0.04, and A_(CP-)^*=0.06±0.10±0.02, R_(CP-)^*=1.10±0.12±0.04, where the first e…

Study ofCPviolation inB∓→Dh∓(h=K,π) with the modesD→K∓π±π0,D→π+π−π0andD→K+K−π0

2015

An analysis of the decays of B--/+ -> DK -/+ and B--/+ -> D pi(-/+) is presented in which the D meson is reconstructed in the three-body final states K--/+pi(+/-)pi(0), pi(+)pi(-)pi(0) and K+K-pi(0). Using data from LHCb corresponding to an integrated luminosity of 3.0 fb(-1) of pp collisions, measurements of several CP observables are performed. First observations are obtained of the suppressed Atwood-Dunietz-Soni decay B--/+ -> [pi K-+(+/-)pi(0)](D)pi(-/+) and the quasi-Gronau-London-Wyler decay B--/+ -> [K+K-pi(0)](D)pi(-/+). The results are interpreted in the context of the unitarity triangle angle gamma and related parameters.

Measurement ofCPobservables inB±→DCPK±decays and constraints on the CKM angleγ

2010

Using the entire sample of 467×10^6 Υ(4S)→BB[overbar] decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at the SLAC National Accelerator Laboratory, we perform an analysis of B^± → DK^± decays, using decay modes in which the neutral D meson decays to either CP-eigenstates or non-CP-eigenstates. We measure the partial decay rate charge asymmetries for CP-even and CP-odd D final states to be A_(CP+) = 0.25±0.06±0.02 and A_(CP-) = -0.09±0.07±0.02, respectively, where the first error is the statistical and the second is the systematic uncertainty. The parameter A_(CP+) is different from zero with a significance of 3.6 standard deviations, constituting evidence f…

Inclusive D∗-meson production in ep scattering at low Q2 in the GM-VFN scheme at NLO

2009

Abstract We have calculated the next-to-leading order cross sections for the inclusive production of D ∗ -mesons in ep collisions at HERA for finite, although very small Q 2 . In this Q 2 -range, the same approximations as for photoproduction can be used. Our calculation is performed in the general-mass variable-flavour-number scheme. In this approach, large logarithms of the charm transverse momentum are resummed and finite terms depending on m 2 / p T 2 are kept in the hard scattering cross sections. The theoretical results are compared with recent data from the ZEUS Collaboration at HERA. On average, we find good agreement.

A narrow quasi-bound state of the DNN system

2013

Abstract We have investigated a charmed system of DNN (composed of two nucleons and a D meson) by a complementary study with a variational calculation and a Faddeev calculation with fixed-center approximation (Faddeev-FCA). In the present study, we employ a DN potential based on a vector–meson exchange picture in which a resonant Λ c ( 2595 ) is dynamically generated as a DN quasi-bound state, similarly to the Λ ( 1405 ) as a K ¯ N one in the strange sector. As a result of the study of variational calculation with an effective DN potential and three kinds of NN potentials, the D N N ( J π = 0 − , I = 1 / 2 ) is found to be a narrow quasi-bound state below Λ c ( 2595 ) N threshold: total bin…

Charm quark mass and D-meson decay constants from two-flavour lattice QCD

2013

We present a computation of the charm quark's mass and the leptonic D-meson decay constants f_D and f_{D_s} in two-flavour lattice QCD with non-perturbatively O(a) improved Wilson quarks. Our analysis is based on the CLS configurations at two lattice spacings (a=0.065 and 0.048 fm, where the lattice scale is set by f_K) and pion masses ranging down to ~ 190 MeV at L*m_pi > 4, in order to perform controlled continuum and chiral extrapolations with small systematic uncertainties.

Measurement ofCPViolation Parameters with a Dalitz Plot Analysis ofB±→Dπ+π−π0K±

2007

We report the results of a CP violation analysis of the decay B-+/- -> D pi+pi(-)pi K-0(+/-), where D-pi(+)pi(-)pi(0) indicates a neutral D meson detected in the final state pi(+)pi(-)pi(0), excluding K-S(0)pi(0). The analysis makes use of 324x10(6) e(+)e -> B (B) over bar events recorded by the BABAR experiment at the PEP-II e(+)e(-) storage ring. Analyzing the pi(+)pi(-)pi(0) Dalitz plot distribution and the B-+/- -> D-pi(+)pi(-)pi K-0(+/-) branching fraction and decay rate asymmetry, we find the following one-standard-deviation constraints on the amplitude ratio and on the weak and strong phases: 0.06 pi(+)pi(-)pi(0) decay amplitude.

Inclusive D* -Meson Photoproduction in the GM-VFNS

2009

Constraints for nuclear PDFs from the LHCb D-meson data

2019

We quantify the impact of LHCb D-meson measurements at $\sqrt{s}=5 \, {\rm TeV}$ on the EPPS16 and nCTEQ15 nuclear PDFs. In our study, the theoretical description of D-meson production is based on the recently developed SACOT-$m_{\rm T}$ variant of the general-mass variable-flavour-number formalism, and the impact on PDFs is estimated via reweighting methods. We pay special attention on the theoretical uncertainties known to us, and are led to exclude the $p_{\rm T}<3 \, {\rm GeV}$ region from our main analysis. The LHCb data can be accommodated well within EPPS16 and nCTEQ15, and the data provide stringent constraints on the gluons in the shadowing/antishadowing regions. No evidence of …