Scientific Commons: W. Buchmuller

The diffractive production of high-p ? jets in deep-inelastic scattering is studied in the semiclassical approach. The p ? -spectra of q¯q and q¯qg diffractive final states are found to be...

Gravitino Dark Matter in R-Parity Breaking Vacua. (2007)

W. Buchmuller, DESY Forschung Hochenergiephysik, L. Covi, K. Hamaguchi, A. Ibarra, T. Yanagida

Journal article

Baryogenesis - 40 Years Later. (2007)

W. Buchmuller, DESY Forschung Hochenergiephysik

Internal report | Preprint

Seesaw Neutrinos From the Heterotic String. (2007)

W. Buchmuller, DESY Forschung Hochenergiephysik, K. Hamaguchi, O. Lebedev, S. Ramos-Sanchez, M. Ratz

Journal article

Local SU(5) Unification from the Heterotic String. (2007)

W. Buchmuller, DESY Forschung Hochenergiephysik, C. Ludeling, J. Schmidt

Journal article

CP Violation and Neutrino Masses and Mixings from Quark Mass Hierarchies. (2007)

W. Buchmuller, DESY Forschung Hochenergiephysik, L. Covi, D. Emmanuel-Costa, S. Wiesenfeldt

Journal article

Eluding the BBN constraints on the stable gravitino (2006)

Buchmuller, W., Hamaguchi, K., Ibe, M., Yanagida, T. T.

We investigate how late-time entropy production weakens the Big-Bang Nucleosynthesis (BBN) constraints on the gravitino as lightest superparticle with a charged slepton as next-to-lightest...

Physics interplay of the LHC and the ILC. (2006)

Weiglein, G., Barklow, T., Boos, E., De Roeck, A., Desch, K., Gianotti, F., ...

Physics at the Large Hadron Collider (LHC) and the International e(+)e(-) Linear Collider (ILC) will be complementary in many respects, as has been demonstrated at previous generations of hadron and...

Physics Interplay of the LHC and the ILC (2005)

Weiglein, G., Barklow, T., Boos, E., De Roeck, A., Desch, K., Gianotti, F., ...

Physics at the Large Hadron Collider (LHC) and the International e+e- Linear Collider (ILC) will be complementary in many respects, as has been demonstrated at previous generations of hadron and...

Leptogenesis as the origin of matter (2005)

Buchmuller, W., Peccei, R. D., Yanagida, T.

We explore in some detail the hypothesis that the generation of a primordial lepton-antilepton asymmetry (Leptogenesis) early on in the history of the Universe is the root cause for the origin of...

Physics Interplay of the LHC and the ILC (2004)

Barklow, T., Boos, E., De Roeck, A., Desch, K., Gianotti, F., ...

Physics at the Large Hadron Collider (LHC) and the International e+e- Linear Collider (ILC) will be complementary in many respects, as has been demonstrated at previous generations of hadron and...

Flavour structure and proton decay in 6D orbifold GUTs (2004)

Buchmuller, W., Covi, L., Emmanuel-Costa, D., Wiesenfeldt, S.

We study proton decay in a supersymmetric {\sf SO(10)} gauge theory in six dimensions compactified on an orbifold. The dimension-5 proton decay operators are forbidden by R-symmetry, whereas the...

Some Aspects of Thermal Leptogenesis (2004)

Buchmuller, W., Di Bari, P., Plumacher, M.

Properties of neutrinos may be the origin of the matter-antimatter asymmetry of the universe. In the seesaw model for neutrino masses this leads to important constraints on the properties of light...

Leptogenesis for Pedestrians (2004)

Buchmuller, W., Di Bari, P., Plumacher, M.

During the process of thermal leptogenesis temperature decreases by about one order of magnitude while the baryon asymmetry is generated. We present an analytical description of this process so that...

Physics Interplay of the LHC and the ILC (2004)

Weiglein, G., Barklow, T., Boos, E., De Roeck, A., Desch, K., Gianotti, F., ...

Physics at the Large Hadron Collider (LHC) and the International e+e- Linear Collider (ILC) will be complementary in many respects, as has been demonstrated at previous generations of hadron and...

Physics Interplay of the LHC and the ILC (2004)

Weiglein, G., Barklow, T., Boos, E., De Roeck, A., Desch, K., Gianotti, F., ...

Physics at the Large Hadron Collider (LHC) and the International e+e- Linear Collider (ILC) will be complementary in many respects, as has been demonstrated at previous generations of hadron and...

Quarks and Leptons between Branes and Bulk (2003)

Asaka, T., Buchmuller, W., Covi, L.

We study a supersymmetric SO(10) gauge theory in six dimensions compactified on an orbifold. Three sequential quark-lepton families are localized at the three fixpoints where SO(10) is broken to its...

The Neutrino Mass Window for Baryogenesis (2003)

Buchmuller, W., Di Bari, P., Plumacher, M.

Interactions of heavy Majorana neutrinos in the thermal phase of the early universe may be the origin of the cosmological matter-antimatter asymmetry. This mechanism of baryogenesis implies stringent...

Cosmic Microwave Background, Matter-Antimatter Asymmetry and Neutrino Masses (2002)

Buchmuller, W., Di Bari, P., Plumacher, M.

We study the implications of thermal leptogenesis for neutrino parameters. Assuming that decays of N_1, the lightest of the heavy Majorana neutrinos, initiate baryogenesis, we show that the final...

CP Violation, Neutrino Mixing and the Baryon Asymmetry (2001)

Buchmuller, W., Wyler, D.

We study neutrino masses and mixings based on the simplest SO(10) mass relations and the seesaw mechanism. We find that the requirement of large neutrino mixings determines the relative magnitude of...

False Vacuum Decay after Inflation (2001)

Asaka, T., Buchmuller, W., Covi, L.

Inflation is terminated by a non-equilibrium process which finally leads to a thermal state. We study the onset of this transition in a class of hybrid inflation models. The exponential growth of...

Thermal Production of Gravitinos (2000)

Bolz, M., Brandenburg, A., Buchmuller, W.

We evaluate the gravitino production rate in supersymmetric QCD at high temperature to leading order in the gauge coupling. The result, which is obtained by using the resummed gluon propagator,...

Combined analysis of diffractive and inclusive structure functions in the semiclassical framework (1999)

Buchmuller, W., Gehrmann, T., Hebecker, A.

Small-x DIS is described as the scattering of a partonic fluctuation of the photon off a superposition of target color fields. Diffraction occurs if the emerging partonic state is in a color singlet....

Matter Antimatter Asymmetry and Neutrino Properties (1999)

Buchmuller, W., Plumacher, M.

The cosmological baryon asymmetry can be explained as remnant of heavy Majorana neutrino decays in the early universe. We study this mechanism for two models of neutrino masses with a large...

Neutrino Mixing and the Pattern of Supersymmetry Breaking (1999)

Buchmuller, W., Delepine, D., Vissani, F.

We study the implications of a large $\nu_\mu - \nu_\tau$ mixing angle on lepton flavour violating radiative transitions in supersymmetric extensions of the standard model. The transition rates are...

Inclusive and Diffractive Structure Functions at Small x (1998)

Buchmuller, W., Gehrmann, T., Hebecker, A.

In the semiclassical approach, inclusive and diffractive quark and gluon distributions are expressed in terms of correlation functions of Wilson loops. Each Wilson loop integrates the colour field...

Classical Limit for Scalar Fields at High Temperature (1997)

Buchmuller, W., Jakovac, A.

We study real-time correlation functions in scalar quantum field theories at temperature $T=1/\beta$. We show that the behaviour of soft, long wavelength modes is determined by classical statistical...

Baryon Asymmetry of the Universe and Lepton Mixing (1997)

Buchmuller, W., Plumacher, M.

Baryogenesis appears to require lepton number violation. This is naturally realized in extensions of the standard model containing right-handed neutrinos. We discuss the generation of a baryon...

CP Asymmetry in Majorana Neutrino Decays (1997)

Buchmuller, W., Plumacher, M.

We study CP asymmetries in lepton-number violating two-body scattering processes and show how they are related to CP asymmetries in the decays of intermediate massive Majorana neutrinos. Self-energy...

Soft Colour Interactions and Diffractive DIS (1997)

Buchmuller, W.

The basic ideas and some results of the semiclassical approach to diffractive DIS are briefly described. In the production of high-$p_{\perp}$ jets boson-gluon fusion is predicted to be the dominant...

Classical Statistical Mechanics and Landau Damping (1997)

Buchmuller, W., Jakovac, A.

We study the retarded response function in scalar $\phi^4$-theory at finite temperature. We find that in the high-temperature limit the imaginary part of the self-energy is given by the classical...

Electroweak Phase Transition and Neutrino Masses (1996)

Buchmuller, W.

The presently observed cosmological baryon asymmetry has been finally determined at the time of the electroweak phase transition, when baryon and lepton number violating interactions fell out of...

Baryon Asymmetry and Neutrino Mixing (1996)

Buchmuller, W., Plumacher, M.

In theories where $B-L$ is a spontaneously broken local symmetry, the cosmological baryon asymmetry can be generated by the out-of-equilibrium decay of heavy Majorana neutrinos. We study this...

Gluon Radiation in Diffractive Electroproduction (1996)

Buchmuller, W., Hebecker, A., McDermott, M. F.

Order $\alpha_s$-corrections to the diffractive structure functions $F_L^D$ and $F_2^D$ at large $Q^2$ and small $x$ are evaluated in the semiclassical approach, where the initial proton is treated...

Double-logarithmic Scaling of the Structure Function F_2 at small x (1996)

Buchmuller, W., Haidt, D.

Recent data on the structure function F_2(x,Q^2) at small values of x are analysed and compared with theoretical expectations. It is shown that the observed rise at small x is consistent with a...

Semiclassical Approach to Structure Functions at Small x (1995)

Buchmuller, W., Hebecker, A.

Inclusive and diffractive structure functions for electron-proton scattering are calculated in a semiclassical approach at large momentum transfer $Q^2$ and small values of the scaling variable $x$....

Calculating the diffractive from the inclusive structure function (1995)

Buchmuller, W., Hebecker, A.

It is demonstrated that the global properties of the rapidity gap events at HERA can be understood based on electron-gluon scattering and a non-perturbative mechanism of colour neutralization. Using...

A PARTON MODEL FOR DIFFRACTIVE PROCESSES IN DEEP INELASTIC SCATTERING (1995)

Buchmuller, W., Hebecker, A.

We demonstrate that the global properties of the ``rapidity gap'' events, observed at HERA, can be understood based on electron-gluon scattering as the underlying partonic process. Using the measured...

Abelian versus Non-Abelian Higgs Model in Three Dimensions (1995)

Buchmuller, W., Philipsen, O.

We study the phase structure of the abelian Higgs model in three dimensions based on perturbation theory and a set of gauge independent gap equations for Higgs boson and vector boson masses. Contrary...

THERMODYNAMICS OF THE ELECTROWEAK PHASE TRANSITION (1995)

Buchmuller, W., Fodor, Z., Hebecker, A.

We discuss several general aspects of the free energy of the standard model at high temperatures. In particular the Clausius-Clapeyron equation is shown to yield a relation between the latent heat...

Phase Structure and Phase Transition of the SU(2) Higgs Model in Three Dimensions (1994)

Buchmuller, W., Philipsen, O.

We derive a set of gauge independent gap equations for Higgs boson and vector boson masses for the SU(2) Higgs model in three dimensions. The solutions can be associated with the Higgs phase and the...

Gauge Invariant Treatment of the Electroweak Phase Transition (1994)

Buchmuller, W., Fodor, Z., Hebecker, A.

We evaluate the gauge invariant effective potential for the composite field $\sigma=2\Phi^{\dagger}\Phi$ in the SU(2)-Higgs model at finite temperature. Symmetric and broken phases correspond to the...

Confinement in Three Dimensions and the Electroweak Phase Transition (1994)

Buchmuller, W., Fodor, Z.

The infrared behaviour of the standard model at finite temperature is determined by the confining phase of the SU(2)-Higgs model in three dimensions. Due to the Landau singularity of the...

Gravitino Dark Matter at LHC and GLAST. 2007-07-11 - 2007-07-25

W. Buchmuller, DESY Forschung Hochenergiephysik

Conference presentation

Leptogenesis as the Origin of Matter. 2007-10-22 - 2007-10-22

W. Buchmuller, DESY Forschung Hochenergiephysik, Colloquium Zurich Switzerland

Conference presentation

Supergravity at Colliders and in Gamma-Ray Astronomy. 2007-11-07 - 2007-11-07

W. Buchmuller, DESY Forschung Hochenergiephysik, Colloquium Utrecht Netherlands

Conference presentation

Dark Matter in the Universe. 2007-11-27 - 2007-11-27

W. Buchmuller, DESY Forschung Hochenergiephysik, Colloquium Mainz Germany

Conference presentation