Michael Schmidt - Academia.edu (original) (raw)

Uploads

Papers by Michael Schmidt

Research paper thumbnail of Electroweak phase transition and baryogenesis in the nMSSM

Nuclear Physics B, 2006

We analyze the nMSSM with CP violation in the singlet sector. We study the static and dynamical p... more We analyze the nMSSM with CP violation in the singlet sector. We study the static and dynamical properties of the electroweak phase transition. We conclude that electroweak baryogenesis in this model is generic in the sense that if the present limits on the mass spectrum are applied, no severe additional tuning is required to obtain a strong first-order phase transition and to generate a sufficient baryon asymmetry. For this we determine the shape of the nucleating bubbles, including the profiles of CP-violating phases. The baryon asymmetry is calculated using the advanced transport theory to first and second order in gradient expansion presented recently. Still, first and second generation sfermions must be heavy to avoid large electric dipole moments.

Research paper thumbnail of Field trials with channel bit rates of 160 Gbit/s

Optical Fiber Communication, 2006

We present two 8×170 Gbit/s DWDM/OTDM (1.28 Tbit/s) field transmission experiment both over more ... more We present two 8×170 Gbit/s DWDM/OTDM (1.28 Tbit/s) field transmission experiment both over more than 400 km in commercially operated legacy networks of France Telecom (FT) and Deutsche Telekom (DT), respectively. Conventional EDFA based amplification schemes as well as distributed Raman amplified systems are tested. For different levels of polarization mode dispersion due to different quality of the installed fibre

Research paper thumbnail of SO(10)-GUT coherent baryogenesis

Research paper thumbnail of Coherent Baryogenesis and Nonthermal Leptogenesis: A Comparison

Strong and Electroweak Matter 2004 - Proceedings of the SEWM2004 Meeting, 2005

We present a new mechanism for baryogenesis: at preheating after inflation fermions acquire a var... more We present a new mechanism for baryogenesis: at preheating after inflation fermions acquire a varying mass by their coupling to a time dependent field. Their CP-violating mass matrix can generate a charge asymmetry to be transformed into a lepton asymmetry through decay into standard model particles and heavy Majorana neutrinos. In a concrete model of hybrid inflation we compare "coherent baryogenesis" with nonthermal leptogenesis by perturbative decay of the inflation condensates.

Research paper thumbnail of MSSM electroweak baryogenesis and flavour mixing in transport equations

Nuclear Physics B, 2006

We make use of the formalism developed in Ref. [1], and calculate the chargino mediated baryogene... more We make use of the formalism developed in Ref. [1], and calculate the chargino mediated baryogenesis in the Minimal Supersymmetric Standard Model. The formalism makes use of a gradient expansion of the Kadanoff-Baym equations for mixing fermions. For illustrative purposes, we first discuss the semiclassical transport equations for mixing bosons in a space-time dependent Higgs background. To calculate the baryon asymmetry, we solve a standard set of diffusion equations, according to which the chargino asymmetry is transported to the top sector, where it biases sphaleron transitions. At the end we make a qualitative and quantitative comparison of our results with the existing work. We find that the production of the baryon asymmetry of the Universe by CP-violating currents in the chargino sector is strongly constrained by measurements of electric dipole moments.

Research paper thumbnail of Laser deep penetration welding simulation based on a wavelength dependent absorption model

Research paper thumbnail of Numerical Simulations - A Versatile Approach for Better Understanding Dynamics in Laser Material Processing

Research paper thumbnail of Supersymmetric models for gauge inflation

Nuclear Physics B, 2003

We present possible realizations of gauge inflation arising from a 5D N = 1 supersymmetric U (1) ... more We present possible realizations of gauge inflation arising from a 5D N = 1 supersymmetric U (1) model, where the extra dimension is compactified on a circle. A one-loop inflaton effective 4D potential is generated, with the inflaton being a 'Wilson-line field'. It relies on a SUSY breaking. We first consider SUSY breaking to occur spontaneously within a 'no-scale' model by a non zero F-term of the radion superfield which transmits SUSY breaking into the 'visible' sector. As an alternative, we study D-term SUSY breaking originating directly from the 5D gauge supermultiplet. Together with the usual KK resummation method, we present a calculation with the world-line formalism. The latter allows one to get the resulting effective potential directly as a sum over all winding modes. For both presented scenarios, the generated effective potentials have suitable forms for realizing successful inflation, i.e. are flat enough and give the needed number of e-foldings. In addition, there is a natural way to get strongly suppressed values for the potentials, which then could be associated with dark energy/quintessence.

Research paper thumbnail of Moduli stabilization in heterotic M-theory

Nuclear Physics B, 2008

We reconsider the ingredients of moduli stabilization in heterotic M-theory. On this line we clos... more We reconsider the ingredients of moduli stabilization in heterotic M-theory. On this line we close a gap in the literature deriving the Kähler potential dependence on vector bundle moduli and charged matter. Crucial in this derivation is our superspace formulation of 5d heterotic M-theory taking into account the Bianchi identities modified by brane terms. Likewise, we obtain the Fayet-Iliopolous terms due to brane localised anomalous U(1)'s. After assembling perturbative and non-perturbative contributions to the superpotential, we study supersymmetric (adS) vacua. It is found that the susy condition decouples the bundle moduli from the geometric moduli. We show that M-theory supersymmetric vacua without five-branes can be found, albeit not at phenomenologically interesting values of the geometric moduli. This result is fairly independent of the choice of vector bundle at the observable brane.

Research paper thumbnail of Microsphere near-field nanostructuring using picosecond pulses

Research paper thumbnail of Intereukin-10 and Kupffer cells protect steatotic mice livers from ischemia-reperfusion injury

European cytokine network, 2014

Steatotic livers are more sensitive to ischemia/reperfusion (I/R) and are thus routinely rejected... more Steatotic livers are more sensitive to ischemia/reperfusion (I/R) and are thus routinely rejected for transplantation because of their increased rate of primary nonfunction (PNF). Lean livers have less I/R-induced damage and inflammation due to Kupffer cells (KC), which are protective after total, warm, hepatic I/R with associated bowel congestion. This protection has been linked to KC-dependent expression of the potent anti-inflammatory cytokine interleukin-10 (IL-10). We hypothesized that pretreatment with exogenous IL-10 would protect the steatotic livers of genetically obese (ob/ob) mice from inflammation and injury induced by I/R. Lean and ob/ob mice were pretreated with either IL-10 or liposomally-encapsulated bisphosphonate clodronate (shown to deplete KC) prior to total, warm, hepatic I/R. IL-10 pretreatment increased survival of ob/ob animals at 24 hrs post-I/R from 30% to 100%, and significantly decreased serum ALT levels. At six hrs post-I/R, IL-10 pretreatment increased ...

Research paper thumbnail of 4D superfield reduction of 5D orbifold SUGRA and heterotic M-theory

Research paper thumbnail of Sizable CP violation in the bosonized Standard Model

Nuclear Physics B, 2009

Using the worldline method, we derive an effective action of the bosonic sector of the Standard M... more Using the worldline method, we derive an effective action of the bosonic sector of the Standard Model by integrating out the fermionic degrees of freedom. The CP violation stemming from the complex phase in the CKM matrix gives rise to CP-violating operators in the one-loop effective action in the next-to-leading order of a gradient expansion. We calculate the prefactor of the appropriate operators and give general estimates of CP violation in the bosonic sector of the Standard Model. In particular, we show that the effective CP violation for weak gauge fields is not suppressed by the Yukawa couplings of the light quarks and is much larger than the bound given by the Jarlskog determinant.

Research paper thumbnail of First transmission of human immunodeficiency virus Type 1 by a cellular blood product after mandatory nucleic acid screening in Germany

Research paper thumbnail of Cold electroweak baryogenesis with Standard Model CP violation

Research paper thumbnail of Influence of Processing Gas on the Ablation Quality at ns-Laser Beam Ablation

Physics Procedia, 2011

In this paper laser beam micro ablation and drilling of metals, especially stainless steel and al... more In this paper laser beam micro ablation and drilling of metals, especially stainless steel and aluminum, with nanosecond (ns) pulses under the influence of gas are studied experimentally. Different gases are compared regarding the ablated volume, the redeposition of ablated material and the resulting accuracy of the drilled hole. With optimizing different process parameters like the scanning velocity and the scanning strategy, different holes with varying inclination angles are produced. As a result suitable process parameters for generating different hole-geometries for stainless steel and aluminum at economic costs are proposed.

Research paper thumbnail of Field transmission of 8x170 Gbit/s over high loss SSMF link using third order distributed Raman amplification

We report transmission of 1x170 Gbit/s over 61 dB and 8x170 Gbit/s over 44 dB attenuating link in... more We report transmission of 1x170 Gbit/s over 61 dB and 8x170 Gbit/s over 44 dB attenuating link in the network of the major European network operator. Third order distributed Raman amplification established long span configuration bridging 210 km, respectively 165 km repeaterless span. @2005 Optical Society of America OCIS codes: (060.2330) Fiber optics communications, (060.2320) Fiber optics amplifiers and oscillators

Research paper thumbnail of The use of malaria antibody tests in the prevention of transfusion-transmitted malaria

Research paper thumbnail of Blood donor screening with cobas s 201/cobas TaqScreen MPX under routine conditions at German Red Cross institutes

Research paper thumbnail of FACS technology used in a new rapid bacterial detection method

Transfusion Medicine, 2006

Culture methods for bacterial detection (BacT/ALERT or Pall eBDS) are currently implemented in bl... more Culture methods for bacterial detection (BacT/ALERT or Pall eBDS) are currently implemented in blood donor screening procedures in many countries. Experience in the first years after implementation of these detection assays showed that although the analytical sensitivity was extremely high (about 1 CFU mL(-1)), the majority of these platelets were still transfused before a positive screening result was attained. Rapid technologies were developed to more effectively prevent transfusion-transmitted bacterial infection. In this study, a new rapid bacterial detection method based on fluorescence-activated cell sorting (FACS) technology was developed. Bacteria were stained with thiazole orange dye for 5 min and measurement was taken immediately after staining. The entire process took only 30 min. Six transfusion-relevant bacteria strains were tested in a spiking study. Without pre-incubation in a special bacteria growth medium, analytical sensitivity ranged between 10(5) CFU mL(-1) (Klebsiella oxytoca and Serratia marcesens) and 10(3) CFU mL(-1) (Escherichia coli). Sensitivity could be improved to 10(1) CFU mL(-1) for all tested bacteria by adding a pre-incubation step (6 h at 37 degrees C). Although preliminary in nature, results of our study suggest that bacterial detection by FACS technology in conjunction with a pre-incubation step offers a sensitive alternative technology to culture methods. Additionally, it provides the benefit of a rapid test time and the opportunity of preventing bacterial transmitted infections more effectively.

Research paper thumbnail of Electroweak phase transition and baryogenesis in the nMSSM

Nuclear Physics B, 2006

We analyze the nMSSM with CP violation in the singlet sector. We study the static and dynamical p... more We analyze the nMSSM with CP violation in the singlet sector. We study the static and dynamical properties of the electroweak phase transition. We conclude that electroweak baryogenesis in this model is generic in the sense that if the present limits on the mass spectrum are applied, no severe additional tuning is required to obtain a strong first-order phase transition and to generate a sufficient baryon asymmetry. For this we determine the shape of the nucleating bubbles, including the profiles of CP-violating phases. The baryon asymmetry is calculated using the advanced transport theory to first and second order in gradient expansion presented recently. Still, first and second generation sfermions must be heavy to avoid large electric dipole moments.

Research paper thumbnail of Field trials with channel bit rates of 160 Gbit/s

Optical Fiber Communication, 2006

We present two 8×170 Gbit/s DWDM/OTDM (1.28 Tbit/s) field transmission experiment both over more ... more We present two 8×170 Gbit/s DWDM/OTDM (1.28 Tbit/s) field transmission experiment both over more than 400 km in commercially operated legacy networks of France Telecom (FT) and Deutsche Telekom (DT), respectively. Conventional EDFA based amplification schemes as well as distributed Raman amplified systems are tested. For different levels of polarization mode dispersion due to different quality of the installed fibre

Research paper thumbnail of SO(10)-GUT coherent baryogenesis

Research paper thumbnail of Coherent Baryogenesis and Nonthermal Leptogenesis: A Comparison

Strong and Electroweak Matter 2004 - Proceedings of the SEWM2004 Meeting, 2005

We present a new mechanism for baryogenesis: at preheating after inflation fermions acquire a var... more We present a new mechanism for baryogenesis: at preheating after inflation fermions acquire a varying mass by their coupling to a time dependent field. Their CP-violating mass matrix can generate a charge asymmetry to be transformed into a lepton asymmetry through decay into standard model particles and heavy Majorana neutrinos. In a concrete model of hybrid inflation we compare "coherent baryogenesis" with nonthermal leptogenesis by perturbative decay of the inflation condensates.

Research paper thumbnail of MSSM electroweak baryogenesis and flavour mixing in transport equations

Nuclear Physics B, 2006

We make use of the formalism developed in Ref. [1], and calculate the chargino mediated baryogene... more We make use of the formalism developed in Ref. [1], and calculate the chargino mediated baryogenesis in the Minimal Supersymmetric Standard Model. The formalism makes use of a gradient expansion of the Kadanoff-Baym equations for mixing fermions. For illustrative purposes, we first discuss the semiclassical transport equations for mixing bosons in a space-time dependent Higgs background. To calculate the baryon asymmetry, we solve a standard set of diffusion equations, according to which the chargino asymmetry is transported to the top sector, where it biases sphaleron transitions. At the end we make a qualitative and quantitative comparison of our results with the existing work. We find that the production of the baryon asymmetry of the Universe by CP-violating currents in the chargino sector is strongly constrained by measurements of electric dipole moments.

Research paper thumbnail of Laser deep penetration welding simulation based on a wavelength dependent absorption model

Research paper thumbnail of Numerical Simulations - A Versatile Approach for Better Understanding Dynamics in Laser Material Processing

Research paper thumbnail of Supersymmetric models for gauge inflation

Nuclear Physics B, 2003

We present possible realizations of gauge inflation arising from a 5D N = 1 supersymmetric U (1) ... more We present possible realizations of gauge inflation arising from a 5D N = 1 supersymmetric U (1) model, where the extra dimension is compactified on a circle. A one-loop inflaton effective 4D potential is generated, with the inflaton being a 'Wilson-line field'. It relies on a SUSY breaking. We first consider SUSY breaking to occur spontaneously within a 'no-scale' model by a non zero F-term of the radion superfield which transmits SUSY breaking into the 'visible' sector. As an alternative, we study D-term SUSY breaking originating directly from the 5D gauge supermultiplet. Together with the usual KK resummation method, we present a calculation with the world-line formalism. The latter allows one to get the resulting effective potential directly as a sum over all winding modes. For both presented scenarios, the generated effective potentials have suitable forms for realizing successful inflation, i.e. are flat enough and give the needed number of e-foldings. In addition, there is a natural way to get strongly suppressed values for the potentials, which then could be associated with dark energy/quintessence.

Research paper thumbnail of Moduli stabilization in heterotic M-theory

Nuclear Physics B, 2008

We reconsider the ingredients of moduli stabilization in heterotic M-theory. On this line we clos... more We reconsider the ingredients of moduli stabilization in heterotic M-theory. On this line we close a gap in the literature deriving the Kähler potential dependence on vector bundle moduli and charged matter. Crucial in this derivation is our superspace formulation of 5d heterotic M-theory taking into account the Bianchi identities modified by brane terms. Likewise, we obtain the Fayet-Iliopolous terms due to brane localised anomalous U(1)'s. After assembling perturbative and non-perturbative contributions to the superpotential, we study supersymmetric (adS) vacua. It is found that the susy condition decouples the bundle moduli from the geometric moduli. We show that M-theory supersymmetric vacua without five-branes can be found, albeit not at phenomenologically interesting values of the geometric moduli. This result is fairly independent of the choice of vector bundle at the observable brane.

Research paper thumbnail of Microsphere near-field nanostructuring using picosecond pulses

Research paper thumbnail of Intereukin-10 and Kupffer cells protect steatotic mice livers from ischemia-reperfusion injury

European cytokine network, 2014

Steatotic livers are more sensitive to ischemia/reperfusion (I/R) and are thus routinely rejected... more Steatotic livers are more sensitive to ischemia/reperfusion (I/R) and are thus routinely rejected for transplantation because of their increased rate of primary nonfunction (PNF). Lean livers have less I/R-induced damage and inflammation due to Kupffer cells (KC), which are protective after total, warm, hepatic I/R with associated bowel congestion. This protection has been linked to KC-dependent expression of the potent anti-inflammatory cytokine interleukin-10 (IL-10). We hypothesized that pretreatment with exogenous IL-10 would protect the steatotic livers of genetically obese (ob/ob) mice from inflammation and injury induced by I/R. Lean and ob/ob mice were pretreated with either IL-10 or liposomally-encapsulated bisphosphonate clodronate (shown to deplete KC) prior to total, warm, hepatic I/R. IL-10 pretreatment increased survival of ob/ob animals at 24 hrs post-I/R from 30% to 100%, and significantly decreased serum ALT levels. At six hrs post-I/R, IL-10 pretreatment increased ...

Research paper thumbnail of 4D superfield reduction of 5D orbifold SUGRA and heterotic M-theory

Research paper thumbnail of Sizable CP violation in the bosonized Standard Model

Nuclear Physics B, 2009

Using the worldline method, we derive an effective action of the bosonic sector of the Standard M... more Using the worldline method, we derive an effective action of the bosonic sector of the Standard Model by integrating out the fermionic degrees of freedom. The CP violation stemming from the complex phase in the CKM matrix gives rise to CP-violating operators in the one-loop effective action in the next-to-leading order of a gradient expansion. We calculate the prefactor of the appropriate operators and give general estimates of CP violation in the bosonic sector of the Standard Model. In particular, we show that the effective CP violation for weak gauge fields is not suppressed by the Yukawa couplings of the light quarks and is much larger than the bound given by the Jarlskog determinant.

Research paper thumbnail of First transmission of human immunodeficiency virus Type 1 by a cellular blood product after mandatory nucleic acid screening in Germany

Research paper thumbnail of Cold electroweak baryogenesis with Standard Model CP violation

Research paper thumbnail of Influence of Processing Gas on the Ablation Quality at ns-Laser Beam Ablation

Physics Procedia, 2011

In this paper laser beam micro ablation and drilling of metals, especially stainless steel and al... more In this paper laser beam micro ablation and drilling of metals, especially stainless steel and aluminum, with nanosecond (ns) pulses under the influence of gas are studied experimentally. Different gases are compared regarding the ablated volume, the redeposition of ablated material and the resulting accuracy of the drilled hole. With optimizing different process parameters like the scanning velocity and the scanning strategy, different holes with varying inclination angles are produced. As a result suitable process parameters for generating different hole-geometries for stainless steel and aluminum at economic costs are proposed.

Research paper thumbnail of Field transmission of 8x170 Gbit/s over high loss SSMF link using third order distributed Raman amplification

We report transmission of 1x170 Gbit/s over 61 dB and 8x170 Gbit/s over 44 dB attenuating link in... more We report transmission of 1x170 Gbit/s over 61 dB and 8x170 Gbit/s over 44 dB attenuating link in the network of the major European network operator. Third order distributed Raman amplification established long span configuration bridging 210 km, respectively 165 km repeaterless span. @2005 Optical Society of America OCIS codes: (060.2330) Fiber optics communications, (060.2320) Fiber optics amplifiers and oscillators

Research paper thumbnail of The use of malaria antibody tests in the prevention of transfusion-transmitted malaria

Research paper thumbnail of Blood donor screening with cobas s 201/cobas TaqScreen MPX under routine conditions at German Red Cross institutes

Research paper thumbnail of FACS technology used in a new rapid bacterial detection method

Transfusion Medicine, 2006

Culture methods for bacterial detection (BacT/ALERT or Pall eBDS) are currently implemented in bl... more Culture methods for bacterial detection (BacT/ALERT or Pall eBDS) are currently implemented in blood donor screening procedures in many countries. Experience in the first years after implementation of these detection assays showed that although the analytical sensitivity was extremely high (about 1 CFU mL(-1)), the majority of these platelets were still transfused before a positive screening result was attained. Rapid technologies were developed to more effectively prevent transfusion-transmitted bacterial infection. In this study, a new rapid bacterial detection method based on fluorescence-activated cell sorting (FACS) technology was developed. Bacteria were stained with thiazole orange dye for 5 min and measurement was taken immediately after staining. The entire process took only 30 min. Six transfusion-relevant bacteria strains were tested in a spiking study. Without pre-incubation in a special bacteria growth medium, analytical sensitivity ranged between 10(5) CFU mL(-1) (Klebsiella oxytoca and Serratia marcesens) and 10(3) CFU mL(-1) (Escherichia coli). Sensitivity could be improved to 10(1) CFU mL(-1) for all tested bacteria by adding a pre-incubation step (6 h at 37 degrees C). Although preliminary in nature, results of our study suggest that bacterial detection by FACS technology in conjunction with a pre-incubation step offers a sensitive alternative technology to culture methods. Additionally, it provides the benefit of a rapid test time and the opportunity of preventing bacterial transmitted infections more effectively.